Prognostic and Therapeutic Applications of RKIP in Cancer, 2020
Abstract The RAF kinase inhibitory protein (RKIP) is a member of the phosphatidyl ethanolamine-bi... more Abstract The RAF kinase inhibitory protein (RKIP) is a member of the phosphatidyl ethanolamine-binding protein family that has a central role in several protein kinase signaling cascades. RKIP is expressed in a variety of different mammalian species and its expression is associated with an increasing number of diseases that appear to have inflammation as an underlying tone. This brief perspective evaluates the role of RKIP in cancer; highlighting some it’s relevant molecular targets and its pharmacological targeting. The role of RKIP in other conditions such as heart failure, diabetes, asthma, and Alzheimer’s disease are also briefly highlighted.
International Journal of Endocrinology and Metabolism, 2020
Publishing in peer-reviewed high-quality journals is a gold standard method for disseminating sci... more Publishing in peer-reviewed high-quality journals is a gold standard method for disseminating scientific work. Choosing the right journal is one of the most important and difficult aspects of publishing research results. Submitting to an inappropriate journal is one of the most common reasons for fast rejection of manuscripts, resulting in time wasted by the authors and journals' editors. Here, we discuss important factors that should be considered for choosing the right journal to get your work published successfully and effectively. The most important factors for journal targeting are: (1) The journal's characteristics, including its scientific prestige, performance, publishing model, acceptance possibility, and specialty; (2) the manuscript's characteristics, including its relevance to the journal's aim and scope, its intrinsic value, meaning the novelty of the research, soundness of the methodology, potential impact in the field, and its implication; and (3) authors' priorities and limitations.
Hydrogen sulfide (H 2 S) was once considered to have only toxic properties, until it was discover... more Hydrogen sulfide (H 2 S) was once considered to have only toxic properties, until it was discovered to be an endogenous signaling molecule. The effects of H 2 S are dose dependent, with lower concentrations being beneficial and higher concentrations, cytotoxic. This scenario is especially true for the effects of H 2 S on mitochondrial function, where higher concentrations of the gasotransmitter inhibit the electron transport chain, and lower concentrations stimulate bioenergetics in multiple ways. Here we review the role of H 2 S in mitochondrial function and its effects on cellular physiology.
Nitric oxide (NO) and its pro and anti-tumor activities are dual roles that continue to be debate... more Nitric oxide (NO) and its pro and anti-tumor activities are dual roles that continue to be debated in cancer biology. The cell situations in the tumor and within the tumor microenvironment also have roles involving NO. In early tumorigenic events, macrophages in the tumor microenvironment promote tumor cell death, and later are reprogramed to support the growth of tumor, through regulatory events involving NO and several stimulatory signals. These two opposing and active phenotypes of tumor associated macrophages known as the M1 or anti-tumorigenic state and M2 or pro-tumorigenic state show differences in metabolic pathways such as glycolysis and arginine utilization, signaling pathways and cytokine induction including iNOS expression, therefore contributing to their function. Polarization of M2 to M1 macrophages, inhibition of M2 state, or reprogramming via NO in combination with other signals may determine or alter tumor kinetics. These strategies and an overview are presented.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Forum on Immunopathological Diseases and Therapeutics, 2012
Nitric oxide (NO)-releasing agents such as JS-K and NO-releasing hybrids such as NO-and NONO-nons... more Nitric oxide (NO)-releasing agents such as JS-K and NO-releasing hybrids such as NO-and NONO-nonsteroidal anti-inflammatory drugs are novel agents with great potential for controlling cancer. Although studied extensively, a key question pertaining to their molecular targets and mechanism of action remains unclear: the role of NO in the overall biological effect of these agents. It has been shown that NO can directly modify sulfhydryl residues of proteins through Snitrosylation and induce apoptosis. We showed that 3 structurally diverse NO-nonsteroidal antiinflammatory drugs S-nitrosylated nuclear factor-κB p65 in vitro and in vivo and also showed that these agents S-nitrosylated caspase-3 in vivo. JS-K reduced nuclear β-catenin and cyclin D1 protein levels without affecting cytosolic β-catenin expression. On the basis of a time course study, S-nitrsolyation of nuclear β-catenin was determined to precede its degradation. These data provide a mechanistic role for NO and a rationale for the chemopreventive effects of these novel agents.
CPT (carnitine palmitoyltransferase) 1 and CPT2 regulate fatty acid oxidation. Recombinant rat CP... more CPT (carnitine palmitoyltransferase) 1 and CPT2 regulate fatty acid oxidation. Recombinant rat CPT2 was isolated from the soluble fractions of bacterial extracts and expressed in Escherichia coli. The acyl-CoA chain-length-specificity of the recombinant CPT2 was identical with that of the purified enzyme from rat liver mitochondrial inner membranes. The Km for carnitine for both the mitochondrial preparation and the recombinant enzyme was identical. In isolated mitochondrial outer membranes, cardiolipin (diphosphatidylglycerol) increased CPT1 activity 4-fold and the Km for carnitine 6-fold. It decreased the Ki for malonyl-CoA inhibition 60-fold, but had no effect on the apparent Km for myristoyl-CoA. Cardiolipin also activated recombinant CPT2 almost 4-fold, whereas phosphatidylglycerol, phosphatidylserine and phosphatidylcholine activated the enzyme 3-, 2- and 2-fold respectively. Most of the recombinant CPT2 was found to have substantial interaction with cardiolipin. A model is pr...
A seminal advance in the prevention of colon cancer has been the observation that nonsteroidal an... more A seminal advance in the prevention of colon cancer has been the observation that nonsteroidal antiinflammatory drugs (NSAIDs) reduce the incidence of and mortality from colon cancer by about half. Among current efforts to overcome the side effects of NSAIDs, an important limitation for their application as chemopreventive agents, is the synthesis of nitric oxide-releasing NSAIDs. These novel compounds may display greater safety and greater efficacy compared to their parent traditional NSAIDs and thus hold significant promise as chemopreventive agents against human colon cancer. In this review we discuss salient features of their pharmacology, in vitro and animal data pertaining to colon cancer, their mechanisms of action, and assess their potential in the chemoprevention of colon cancer.
Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It... more Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It inhibited the growth of Jurkat T-leukemia cells with an IC 50 of 1.9 ± 0.2 µM whereas that of ASA was >5000 µM. It dose-dependently inhibited proliferation and induced apoptosis in these cells, causing a G 0 /G 1 cell cycle arrest. HS-ASA down-regulated-catenin protein levels and reduced mRNA and protein expression of-catenin/TCF downstream target genes cyclinD1 and cmyc. Aspirin up to 5 mM had no effect on-catenin expression. HS-ASA also increased caspase-3 protein levels and dose-dependently increased its activity. These effects were substantially blocked by z-VAD-fmk, a pan-caspase inhibitor.
Journal of Pharmacology and Experimental Therapeutics, 2005
The seminal epidemiological observation that nonsteroidal antiinflammatory drugs (NSAIDs) prevent... more The seminal epidemiological observation that nonsteroidal antiinflammatory drugs (NSAIDs) prevent colon and possibly other cancers has spurred novel approaches to cancer prevention. The known inhibitory effect of NSAIDs on the eicosanoid pathway prompted studies focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E 2 levels and the overexpression of COX-2 in colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. Their efficacy in the prevention of sporadic colon and other cancers remains unknown; one COX-2 inhibitor has been withdrawn because of side effects, and there are concerns about whether these effects are class-specific. There is evidence to suggest that COX-2 may not be the only or ideal eicosanoid
ABSTRACTThe acute‐phase response is associated with profound effects on oxidative drug metabolism... more ABSTRACTThe acute‐phase response is associated with profound effects on oxidative drug metabolism. However, the effects on glucuronidation are poorly characterized. The aim of the present study was to determine the role of mediators of the acute‐phase response in the regulation of hepatic uridine diphosphate glucuronosyltransferase (UGT) expression. Family 1 and family 2 UGT isoforms were studied in turpentine‐injected rats and in primary hepatocyte cultures exposed to cytokines and/or dexamethasone. In the in vivo model, glucuronidation of p‐nitrophenol was unaffected, while testosterone glucuronidation was reduced to 65% of control (P < 0.01). In contrast, the mRNA level of UGT1*1 (which metabolizes bilirubin, not phenols) was depressed to 16% of control (P < 0.002), while the mRNA level of UGT2B3 (which metabolizes testosterone) was reduced to 53% (P < 0.05). In primary hepatocyte culture, dexamethasone treatment resulted in a 3.4‐fold induction of UGT1*1 mRNA levels (P ...
to acid and LPS. 3. These findings demonstrate a potential role for human esophageal MFlike strom... more to acid and LPS. 3. These findings demonstrate a potential role for human esophageal MFlike stromal cells in the pathogenesis of esophageal mucosal disorders.
Modulation of drug metabolizing enzymes, leading to facilitated elimination of carcinogens repres... more Modulation of drug metabolizing enzymes, leading to facilitated elimination of carcinogens represents a successful strategy for cancer chemoprevention. Nitric oxidedonating aspirin (NO-ASA) is a promising agent for the prevention of colon and other cancers. We studied the effect of NO-ASA on drug metabolizing enzymes in HT-29 human colon adenocarcinoma and Hepa 1c1c7 mouse liver adenocarcinoma cells and in Min mice treated with NO-ASA for 3 weeks. In these cell lines, NO-ASA induced the activity and expression of NAD(P)H:quinone oxireductase (NQO) and glutathione S-transferase (GST). Compared with untreated Min mice, NO-ASA increased in the liver the activity (nmol/min/mg; mean AE SEM for all) of NQO (85 AE 6 versus 128 AE 11, P50.05) and GST (2560 AE 233 versus 4254 AE 608, P 50.005) and also in the intestine but not in the kidney; the expression of NQO1 and GST P1-1 was also increased. NO-ASA had only a marginal effect on P450 1A1 and P450 2E1, two phase I enzymes. The release of NO from NO-ASA, determined with a selective microelectrode was paralleled by the induction of NQO1 and abrogated by NO scavengers; an exogenous NO donor also induced the expression of NQO1. NO-ASA induced concentration-dependently the translocation of Nrf2 into the nucleus as documented by immunofluorescence and immunoblotting; this paralleled the induction of NQO1 and GST P1-1. Thus NO-ASA induces phase II enzymes, at least in part, through the action of NO that it releases and by modulating the Keap1-Nrf2 pathway; this effect may be part of its mechanism of action against colon and other cancers.
Introduction: Nitric oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) consisting ... more Introduction: Nitric oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) consisting of a conventional NSAID to which an NO releasing moiety -ONO2 is covalently attached through a spacer have emerged as a new class of pharmaceutical agents. The released NO has proapoptotic effects which may cause DNA damage, leading to p53 activation, proteasome inhibition, and/or cytochrome c release from mitochondria, resulting from activation of the mitochondrial permeability transition pore or damage to mitochondrial membrane phospholipids. NO can directly modify sulfhydryl residues of proteins through S-nitrosylation, which has emerged as an important posttranslational protein modification based on prototypic redox mechanisms in signal transduction. The transcription factor, NF-κB is constitutively expressed in many tumors and characterizes all inflammatory responses. As apoptosis is a dominant anti-tumor pathway for chemotherapy-induced cell death, NF-κB may also be involved in resistance to cancer chemotherapy. Caspase-3 activation is intimately involved in apoptosis. In this study we evaluated the actions of meta-NO-aspirin (m-NO-ASA) and NO-naproxen which inhibit cell growth and induce apoptosis on NF-κB expression and caspase-3 activity and determined whether these agents S-nitrosylate these proteins. Methods: m-NO-ASA and NO-naproxen synthesized by us. Cell line: HT-29 human colon cancer cells. Growth inhibition: MTT. Animal studies: Rats (5 per group) were gavaged with ASA (180 mg/kg) or naproxen (40 mg/kg) or equimolar amounts of NO-ASA or NO-naproxen and killed 6h later after which their stomachs were rapidly removed, gently washed, and frozen in liquid nitrogen. Caspase-3 activity: commercial kit. Protein S-nitrosylation: Biotin switch assay (Jaffrey et al, Nature Cell Biology, 2001, 3:193-197); NF-κB, caspase-3, TNF-α, and biotinylated protein levels: immunoblotting. We also used the NO-donor SNAP as a positive control. Results: In vitro: m-NO-ASA and NO-naproxen inhibited the growth of HT29 colon cancer cells with IC50s of 187 ± 10 µM and 97 ± 5 µM at 24 hr respectively. NF-κB expression was reduced, however, caspase-3 enzyme activity and protein levels were increased by these agents in a dose- and time-dependent manner. NO-NSAID treatment for 24 hr at 0.5 x IC50, IC50 and 2 x IC50 caused an increase in both the total S-nitrosylated proteins and S-nitrosylated NF-κB (p-65 protein) and caspase-3 expression. These effects were reversed by carboxy-PTIO (an NO scavenger). In vivo: NO-NSAIDs caused an increase in total S-nitrosylated proteins and an increase in S-nitrosylated NF-κB, and TNF-α protein levels. Conclusions: These data strongly suggest S-nitrosylation as a potential molecular mechanism for the observed effects of NO-NSAIDs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1487.
Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Introduction: Chronic in... more Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Introduction: Chronic inflammation is widely recognized as an underlying etiological factor in carcinogenesis; there is enough evidence to support the use of non-steroidal anti-inflammatory drugs (NSAIDs) as chemopreventive agents. However, their wide use is precluded due to significant toxicity. Recently, a new class of hydrogen sulfide-releasing NSAIDs have been described in which the parent NSAID is covalently linked to a dithiolethione moiety (5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione) which release hydrogen sulfide. HS-NSAIDs have enhanced safety and efficacy compared to their traditional counterparts. Since NSAIDs are regarded as prototypical chempreventive agents, here we compared naproxen and its hydrogen sulfide-releasing (HS-naproxen) analog using a human colon cancer cell line and also evaluated its effect on NF-κB whose induction is strongly implicated in some cancers. Methods: HS-naproxen was synthesized and purified at our lab with 1H-NMR verification. Cell line: HT-29 human adenocarcimoma; Cell growth: MTT; Cell cycle phase distribution: Flow cytometry; Apoptosis: subdiploid (sub-G/G1) peak in DNA content histograms; Proliferation: PCNA; NF-κB: enzyme-linked immunosorbent assay (ELISA). GSH levels: colorimetric method. Results: HS-naproxen inhibited the growth of HT-29 cells with an IC50 of 72 ± 5 µM whereas for naproxen the IC50 was 2800 ± 190 µM at 24h. HS-naproxen treatment of HT-29 cells at 0.5xIC50, 1xIC50, and 2xIC50 for 24 hrs induced apoptosis (12 ± 1%, 54 ± 3%, 71 ± 3%), inhibited proliferation (PCNA, 71 ± 3%, 49 ± 5%, 26 ± 4%), and caused a G/G1 cell cycle block. Activation of NF-κB was inhibited as demonstrated by ELISA, at 0.5xIC50, 1xIC50, and 2xIC50 the reduction was 22 ± 3%, 47 ± 2%, and 62 ± 4% respectively. Cellular GSH levels were also reduced dose-dependently by HS-naproxen, suggesting a condition of oxidative stress. Conclusions: HS-naproxen inhibits HT-29 cell growth and inhibits NF-κB activation. These data suggest that HS-naproxen may be useful as chemopreventive agent against colon cancer and merits further evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1353. doi:10.1158/1538-7445.AM2011-1353
Introduction: The clinical usefulness of non-steroidal anti-inflammatory drugs (NSAIDs) combined ... more Introduction: The clinical usefulness of non-steroidal anti-inflammatory drugs (NSAIDs) combined with their potentially life-threatening toxicity has prompted intensive efforts to identify safer alternatives, which will at least maintain their pharmacological properties. The search for a “better NSAID” has resulted in at least two modified hybrids, one that releases nitric oxide (NO-NSAIDs), and another that releases hydrogen sulfide (HS-NSAIDs). These agents although much safer and more potent than their traditional counterparts, have IC50s for cell growth inhibition that are in the micro-molar range. Therefore, we postulated that a new hybrid that incorporated the active parts of each compound may be more potent and effective than either one. Our hypothesis has proved to be correct. We have synthesized a number of NSAID based NOSH (nitric oxide-, hydrogen sulfide-releasing) compounds that release both H2S and NO, and have IC50s for cell growth inhibition in the low nano-molar range. Methods: Compounds: Aspirin based NOSH-1, NOSH-2, NOSH-3, and NOSH-4 were synthesized and purified by us with 1H-NMR verification. Human cancer cell lines: colon (HT-29, HCT 15, SW480), breast (MCF-7, MDA-MB-231, SKBR3), pancreas (BxPC-3, MIA PaCa-2), lung (A549), prostate (LNCap), leukemia (Jurkat). Cell growth: MTT. Anti-inflammatory: paw edema induced by intraplantar injection of 100 µL of 1% carrageenan, paw volumes measured up to the tibiotarsal joint immediately prior to carrageenan injection and thereafter at 1hr intervals up to 6hrs. Drugs were administered orally 1 hr before carrageenan; COX enzyme: immunoblotting, PGE2: ELISA Results: All NOSH compounds were more effective than aspirin in inhibiting the growth of colon, breast, pancreas, prostate, lung, and leukemia cancer cell lines. The IC50s at 24h were in the range 48 nM to 6.5 µM depending on the cell line and the compound. The corresponding IC50 for aspirin was >5000 µM in all cell lines. Our lead compound NOSH-1, had a enhanced potency of >100,000-fold. NOSH-1 dose-dependently decreased the carrageenan-induced edema 1h after administration and maintained this anti-inflammatory effect throughout the experiment (up to 6h). PGE2 levels within the inflamed rat paw were also reduced by NOSH-1. Carrageenan induced both COX-1 and COX-2 expression which were dose-dependently inhibited by NOSH-1. Conclusions: NOSH compounds are a new class of anti-inflammatory agents. NOSH-1, our lead compound is very potent in inhibiting a number of different cancer cell lines of different tissue origin suggesting a tissue independent effect. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3899. doi:1538-7445.AM2012-3899
Introduction: In our search for a better non-steroidal anti-inflammatory drug (NSAID) we have syn... more Introduction: In our search for a better non-steroidal anti-inflammatory drug (NSAID) we have synthesized a series of nitric oxide-, and hydrogen sulfide-releasing hybrid compounds that have IC50s for cell growth inhibition in the low nano-molar range. We have termed these NOSH compounds. Our lead agent, NOSH-aspirin is in the order of 100,000 to 250,000-fold more potent than aspirin in inhibiting colon cancer cell growth over a 24-72h time period. NOSH-aspirin although highly potent, has very limited cyto-toxicity, lactate dehydrogenase (LDH) release at 4 times its IC50 for cell growth inhibition was less than 10% at 24h. Here we report our results on the effects of NOSH-aspirin treatment on established tumors in a xenograft model of human colon cancer cells. Methods: Compound: NOSH-aspirin was synthesized and purified by us with 1H-NMR verification. Cell line: HT-29 human adenocarcimoma; Xenografts: Male athymic SKID mice were implanted s.c. in the right flank with HT-29 (2 x 106) cells suspended in 50% Matrigel, after 10 days the animals were randomly divided into 4 groups (N = 7/group) and gavaged daily with NOSH-aspirin (25 or 50 or 100 mg/kg body weight) or vehicle. Tumor volume and animal weight were recorded every 3 days. After 3 weeks of treatment, mice were sacrificed, tumors excised, weighed, and fixed in 10% buffered formalin for immunohistochemical studies. Results: NOSH-aspirin had no effect on the weight of the mice even at the highest concentration used. There were no overt signs of toxicity. It dose-dependently reduced tumor mass by 50 ± 7%, 75 ± 5%, 90 ± 3 % at 25, 50, and 100 mg/kg, respectively. Tumor volume was also dose-dependently reduced as a function of time. NOSH-aspirin inhibited growth of HT-29 colon cancer cells xenografts as a result of reduced proliferation (decreased PCNA expression), and induction apoptosis (increased number of TUNEL positive cells). NF-κB, activated in control xenografts was significantly inhibited by NOSH-aspirin. Conclusions: NOSH-aspirin has potent anti-cancer affects and merits further evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3898. doi:1538-7445.AM2012-3898
Introduction: Regular uses of non-steroidal anti-inflammatory drugs (NSAIDs) in general and aspir... more Introduction: Regular uses of non-steroidal anti-inflammatory drugs (NSAIDs) in general and aspirin in particular have been associated with reductions in a number of cancers including, colon, breast, pancreas and others. However, NSAIDs have significant side effects, which precludes their wide spread use. In our search for a “better NSAID”, we have synthesized a series of nitric oxide-, and hydrogen sulfide-releasing hybrid compounds that have IC50s for cell growth inhibition in the low nano-molar range. We have termed these NOSH compounds. Our lead agent, NOSH-aspirin is in the order of 100,000 to 250,000-fold more potent than aspirin in inhibiting colon cancer cell growth over a 24-72h-time period. NOSH-aspirin although highly potent, is essentially devoid of any cyto-toxicity as judged by lactate dehydrogenase (LDH) release. Here we report our results on the effects of NOSH-aspirin treatment on established tumors in a xenograft model of human colon, breast (both ER- and ER+), and...
Fenretinide [N-(4-Hydroxyphenyl)retinamide, 4-HPR] (10(-10)-10(-6) M) treatment of HT-29 human co... more Fenretinide [N-(4-Hydroxyphenyl)retinamide, 4-HPR] (10(-10)-10(-6) M) treatment of HT-29 human colon cancer cells for 24-72 h significantly inhibited their growth. Using HCT-15 cells, 4-HPR had limited inhibitory effects on cell proliferation over the same concentration range and time period. The inhibitory effects of 4-HPR on cell growth in HT-29 cells were markedly reduced in the presence of exogenously added prostaglandins (PGs), suggesting a possible role for inhibition of PG synthesis as a mechanism for 4-HPR&#39;s antiproliferative effects. Inhibition of PGE(2) production was caused by 4-HPR in a concentration-dependent manner and decreased COX-2 but not COX-1 mRNA levels; this is the first indication that 4-HPR selectively inhibits COX-2 gene expression. Our findings suggest a possible mechanism for the chemopreventive and anti-proliferative effects of 4-HPR.
Prognostic and Therapeutic Applications of RKIP in Cancer, 2020
Abstract The RAF kinase inhibitory protein (RKIP) is a member of the phosphatidyl ethanolamine-bi... more Abstract The RAF kinase inhibitory protein (RKIP) is a member of the phosphatidyl ethanolamine-binding protein family that has a central role in several protein kinase signaling cascades. RKIP is expressed in a variety of different mammalian species and its expression is associated with an increasing number of diseases that appear to have inflammation as an underlying tone. This brief perspective evaluates the role of RKIP in cancer; highlighting some it’s relevant molecular targets and its pharmacological targeting. The role of RKIP in other conditions such as heart failure, diabetes, asthma, and Alzheimer’s disease are also briefly highlighted.
International Journal of Endocrinology and Metabolism, 2020
Publishing in peer-reviewed high-quality journals is a gold standard method for disseminating sci... more Publishing in peer-reviewed high-quality journals is a gold standard method for disseminating scientific work. Choosing the right journal is one of the most important and difficult aspects of publishing research results. Submitting to an inappropriate journal is one of the most common reasons for fast rejection of manuscripts, resulting in time wasted by the authors and journals' editors. Here, we discuss important factors that should be considered for choosing the right journal to get your work published successfully and effectively. The most important factors for journal targeting are: (1) The journal's characteristics, including its scientific prestige, performance, publishing model, acceptance possibility, and specialty; (2) the manuscript's characteristics, including its relevance to the journal's aim and scope, its intrinsic value, meaning the novelty of the research, soundness of the methodology, potential impact in the field, and its implication; and (3) authors' priorities and limitations.
Hydrogen sulfide (H 2 S) was once considered to have only toxic properties, until it was discover... more Hydrogen sulfide (H 2 S) was once considered to have only toxic properties, until it was discovered to be an endogenous signaling molecule. The effects of H 2 S are dose dependent, with lower concentrations being beneficial and higher concentrations, cytotoxic. This scenario is especially true for the effects of H 2 S on mitochondrial function, where higher concentrations of the gasotransmitter inhibit the electron transport chain, and lower concentrations stimulate bioenergetics in multiple ways. Here we review the role of H 2 S in mitochondrial function and its effects on cellular physiology.
Nitric oxide (NO) and its pro and anti-tumor activities are dual roles that continue to be debate... more Nitric oxide (NO) and its pro and anti-tumor activities are dual roles that continue to be debated in cancer biology. The cell situations in the tumor and within the tumor microenvironment also have roles involving NO. In early tumorigenic events, macrophages in the tumor microenvironment promote tumor cell death, and later are reprogramed to support the growth of tumor, through regulatory events involving NO and several stimulatory signals. These two opposing and active phenotypes of tumor associated macrophages known as the M1 or anti-tumorigenic state and M2 or pro-tumorigenic state show differences in metabolic pathways such as glycolysis and arginine utilization, signaling pathways and cytokine induction including iNOS expression, therefore contributing to their function. Polarization of M2 to M1 macrophages, inhibition of M2 state, or reprogramming via NO in combination with other signals may determine or alter tumor kinetics. These strategies and an overview are presented.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Forum on Immunopathological Diseases and Therapeutics, 2012
Nitric oxide (NO)-releasing agents such as JS-K and NO-releasing hybrids such as NO-and NONO-nons... more Nitric oxide (NO)-releasing agents such as JS-K and NO-releasing hybrids such as NO-and NONO-nonsteroidal anti-inflammatory drugs are novel agents with great potential for controlling cancer. Although studied extensively, a key question pertaining to their molecular targets and mechanism of action remains unclear: the role of NO in the overall biological effect of these agents. It has been shown that NO can directly modify sulfhydryl residues of proteins through Snitrosylation and induce apoptosis. We showed that 3 structurally diverse NO-nonsteroidal antiinflammatory drugs S-nitrosylated nuclear factor-κB p65 in vitro and in vivo and also showed that these agents S-nitrosylated caspase-3 in vivo. JS-K reduced nuclear β-catenin and cyclin D1 protein levels without affecting cytosolic β-catenin expression. On the basis of a time course study, S-nitrsolyation of nuclear β-catenin was determined to precede its degradation. These data provide a mechanistic role for NO and a rationale for the chemopreventive effects of these novel agents.
CPT (carnitine palmitoyltransferase) 1 and CPT2 regulate fatty acid oxidation. Recombinant rat CP... more CPT (carnitine palmitoyltransferase) 1 and CPT2 regulate fatty acid oxidation. Recombinant rat CPT2 was isolated from the soluble fractions of bacterial extracts and expressed in Escherichia coli. The acyl-CoA chain-length-specificity of the recombinant CPT2 was identical with that of the purified enzyme from rat liver mitochondrial inner membranes. The Km for carnitine for both the mitochondrial preparation and the recombinant enzyme was identical. In isolated mitochondrial outer membranes, cardiolipin (diphosphatidylglycerol) increased CPT1 activity 4-fold and the Km for carnitine 6-fold. It decreased the Ki for malonyl-CoA inhibition 60-fold, but had no effect on the apparent Km for myristoyl-CoA. Cardiolipin also activated recombinant CPT2 almost 4-fold, whereas phosphatidylglycerol, phosphatidylserine and phosphatidylcholine activated the enzyme 3-, 2- and 2-fold respectively. Most of the recombinant CPT2 was found to have substantial interaction with cardiolipin. A model is pr...
A seminal advance in the prevention of colon cancer has been the observation that nonsteroidal an... more A seminal advance in the prevention of colon cancer has been the observation that nonsteroidal antiinflammatory drugs (NSAIDs) reduce the incidence of and mortality from colon cancer by about half. Among current efforts to overcome the side effects of NSAIDs, an important limitation for their application as chemopreventive agents, is the synthesis of nitric oxide-releasing NSAIDs. These novel compounds may display greater safety and greater efficacy compared to their parent traditional NSAIDs and thus hold significant promise as chemopreventive agents against human colon cancer. In this review we discuss salient features of their pharmacology, in vitro and animal data pertaining to colon cancer, their mechanisms of action, and assess their potential in the chemoprevention of colon cancer.
Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It... more Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It inhibited the growth of Jurkat T-leukemia cells with an IC 50 of 1.9 ± 0.2 µM whereas that of ASA was >5000 µM. It dose-dependently inhibited proliferation and induced apoptosis in these cells, causing a G 0 /G 1 cell cycle arrest. HS-ASA down-regulated-catenin protein levels and reduced mRNA and protein expression of-catenin/TCF downstream target genes cyclinD1 and cmyc. Aspirin up to 5 mM had no effect on-catenin expression. HS-ASA also increased caspase-3 protein levels and dose-dependently increased its activity. These effects were substantially blocked by z-VAD-fmk, a pan-caspase inhibitor.
Journal of Pharmacology and Experimental Therapeutics, 2005
The seminal epidemiological observation that nonsteroidal antiinflammatory drugs (NSAIDs) prevent... more The seminal epidemiological observation that nonsteroidal antiinflammatory drugs (NSAIDs) prevent colon and possibly other cancers has spurred novel approaches to cancer prevention. The known inhibitory effect of NSAIDs on the eicosanoid pathway prompted studies focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E 2 levels and the overexpression of COX-2 in colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. Their efficacy in the prevention of sporadic colon and other cancers remains unknown; one COX-2 inhibitor has been withdrawn because of side effects, and there are concerns about whether these effects are class-specific. There is evidence to suggest that COX-2 may not be the only or ideal eicosanoid
ABSTRACTThe acute‐phase response is associated with profound effects on oxidative drug metabolism... more ABSTRACTThe acute‐phase response is associated with profound effects on oxidative drug metabolism. However, the effects on glucuronidation are poorly characterized. The aim of the present study was to determine the role of mediators of the acute‐phase response in the regulation of hepatic uridine diphosphate glucuronosyltransferase (UGT) expression. Family 1 and family 2 UGT isoforms were studied in turpentine‐injected rats and in primary hepatocyte cultures exposed to cytokines and/or dexamethasone. In the in vivo model, glucuronidation of p‐nitrophenol was unaffected, while testosterone glucuronidation was reduced to 65% of control (P < 0.01). In contrast, the mRNA level of UGT1*1 (which metabolizes bilirubin, not phenols) was depressed to 16% of control (P < 0.002), while the mRNA level of UGT2B3 (which metabolizes testosterone) was reduced to 53% (P < 0.05). In primary hepatocyte culture, dexamethasone treatment resulted in a 3.4‐fold induction of UGT1*1 mRNA levels (P ...
to acid and LPS. 3. These findings demonstrate a potential role for human esophageal MFlike strom... more to acid and LPS. 3. These findings demonstrate a potential role for human esophageal MFlike stromal cells in the pathogenesis of esophageal mucosal disorders.
Modulation of drug metabolizing enzymes, leading to facilitated elimination of carcinogens repres... more Modulation of drug metabolizing enzymes, leading to facilitated elimination of carcinogens represents a successful strategy for cancer chemoprevention. Nitric oxidedonating aspirin (NO-ASA) is a promising agent for the prevention of colon and other cancers. We studied the effect of NO-ASA on drug metabolizing enzymes in HT-29 human colon adenocarcinoma and Hepa 1c1c7 mouse liver adenocarcinoma cells and in Min mice treated with NO-ASA for 3 weeks. In these cell lines, NO-ASA induced the activity and expression of NAD(P)H:quinone oxireductase (NQO) and glutathione S-transferase (GST). Compared with untreated Min mice, NO-ASA increased in the liver the activity (nmol/min/mg; mean AE SEM for all) of NQO (85 AE 6 versus 128 AE 11, P50.05) and GST (2560 AE 233 versus 4254 AE 608, P 50.005) and also in the intestine but not in the kidney; the expression of NQO1 and GST P1-1 was also increased. NO-ASA had only a marginal effect on P450 1A1 and P450 2E1, two phase I enzymes. The release of NO from NO-ASA, determined with a selective microelectrode was paralleled by the induction of NQO1 and abrogated by NO scavengers; an exogenous NO donor also induced the expression of NQO1. NO-ASA induced concentration-dependently the translocation of Nrf2 into the nucleus as documented by immunofluorescence and immunoblotting; this paralleled the induction of NQO1 and GST P1-1. Thus NO-ASA induces phase II enzymes, at least in part, through the action of NO that it releases and by modulating the Keap1-Nrf2 pathway; this effect may be part of its mechanism of action against colon and other cancers.
Introduction: Nitric oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) consisting ... more Introduction: Nitric oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) consisting of a conventional NSAID to which an NO releasing moiety -ONO2 is covalently attached through a spacer have emerged as a new class of pharmaceutical agents. The released NO has proapoptotic effects which may cause DNA damage, leading to p53 activation, proteasome inhibition, and/or cytochrome c release from mitochondria, resulting from activation of the mitochondrial permeability transition pore or damage to mitochondrial membrane phospholipids. NO can directly modify sulfhydryl residues of proteins through S-nitrosylation, which has emerged as an important posttranslational protein modification based on prototypic redox mechanisms in signal transduction. The transcription factor, NF-κB is constitutively expressed in many tumors and characterizes all inflammatory responses. As apoptosis is a dominant anti-tumor pathway for chemotherapy-induced cell death, NF-κB may also be involved in resistance to cancer chemotherapy. Caspase-3 activation is intimately involved in apoptosis. In this study we evaluated the actions of meta-NO-aspirin (m-NO-ASA) and NO-naproxen which inhibit cell growth and induce apoptosis on NF-κB expression and caspase-3 activity and determined whether these agents S-nitrosylate these proteins. Methods: m-NO-ASA and NO-naproxen synthesized by us. Cell line: HT-29 human colon cancer cells. Growth inhibition: MTT. Animal studies: Rats (5 per group) were gavaged with ASA (180 mg/kg) or naproxen (40 mg/kg) or equimolar amounts of NO-ASA or NO-naproxen and killed 6h later after which their stomachs were rapidly removed, gently washed, and frozen in liquid nitrogen. Caspase-3 activity: commercial kit. Protein S-nitrosylation: Biotin switch assay (Jaffrey et al, Nature Cell Biology, 2001, 3:193-197); NF-κB, caspase-3, TNF-α, and biotinylated protein levels: immunoblotting. We also used the NO-donor SNAP as a positive control. Results: In vitro: m-NO-ASA and NO-naproxen inhibited the growth of HT29 colon cancer cells with IC50s of 187 ± 10 µM and 97 ± 5 µM at 24 hr respectively. NF-κB expression was reduced, however, caspase-3 enzyme activity and protein levels were increased by these agents in a dose- and time-dependent manner. NO-NSAID treatment for 24 hr at 0.5 x IC50, IC50 and 2 x IC50 caused an increase in both the total S-nitrosylated proteins and S-nitrosylated NF-κB (p-65 protein) and caspase-3 expression. These effects were reversed by carboxy-PTIO (an NO scavenger). In vivo: NO-NSAIDs caused an increase in total S-nitrosylated proteins and an increase in S-nitrosylated NF-κB, and TNF-α protein levels. Conclusions: These data strongly suggest S-nitrosylation as a potential molecular mechanism for the observed effects of NO-NSAIDs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1487.
Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Introduction: Chronic in... more Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Introduction: Chronic inflammation is widely recognized as an underlying etiological factor in carcinogenesis; there is enough evidence to support the use of non-steroidal anti-inflammatory drugs (NSAIDs) as chemopreventive agents. However, their wide use is precluded due to significant toxicity. Recently, a new class of hydrogen sulfide-releasing NSAIDs have been described in which the parent NSAID is covalently linked to a dithiolethione moiety (5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione) which release hydrogen sulfide. HS-NSAIDs have enhanced safety and efficacy compared to their traditional counterparts. Since NSAIDs are regarded as prototypical chempreventive agents, here we compared naproxen and its hydrogen sulfide-releasing (HS-naproxen) analog using a human colon cancer cell line and also evaluated its effect on NF-κB whose induction is strongly implicated in some cancers. Methods: HS-naproxen was synthesized and purified at our lab with 1H-NMR verification. Cell line: HT-29 human adenocarcimoma; Cell growth: MTT; Cell cycle phase distribution: Flow cytometry; Apoptosis: subdiploid (sub-G/G1) peak in DNA content histograms; Proliferation: PCNA; NF-κB: enzyme-linked immunosorbent assay (ELISA). GSH levels: colorimetric method. Results: HS-naproxen inhibited the growth of HT-29 cells with an IC50 of 72 ± 5 µM whereas for naproxen the IC50 was 2800 ± 190 µM at 24h. HS-naproxen treatment of HT-29 cells at 0.5xIC50, 1xIC50, and 2xIC50 for 24 hrs induced apoptosis (12 ± 1%, 54 ± 3%, 71 ± 3%), inhibited proliferation (PCNA, 71 ± 3%, 49 ± 5%, 26 ± 4%), and caused a G/G1 cell cycle block. Activation of NF-κB was inhibited as demonstrated by ELISA, at 0.5xIC50, 1xIC50, and 2xIC50 the reduction was 22 ± 3%, 47 ± 2%, and 62 ± 4% respectively. Cellular GSH levels were also reduced dose-dependently by HS-naproxen, suggesting a condition of oxidative stress. Conclusions: HS-naproxen inhibits HT-29 cell growth and inhibits NF-κB activation. These data suggest that HS-naproxen may be useful as chemopreventive agent against colon cancer and merits further evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1353. doi:10.1158/1538-7445.AM2011-1353
Introduction: The clinical usefulness of non-steroidal anti-inflammatory drugs (NSAIDs) combined ... more Introduction: The clinical usefulness of non-steroidal anti-inflammatory drugs (NSAIDs) combined with their potentially life-threatening toxicity has prompted intensive efforts to identify safer alternatives, which will at least maintain their pharmacological properties. The search for a “better NSAID” has resulted in at least two modified hybrids, one that releases nitric oxide (NO-NSAIDs), and another that releases hydrogen sulfide (HS-NSAIDs). These agents although much safer and more potent than their traditional counterparts, have IC50s for cell growth inhibition that are in the micro-molar range. Therefore, we postulated that a new hybrid that incorporated the active parts of each compound may be more potent and effective than either one. Our hypothesis has proved to be correct. We have synthesized a number of NSAID based NOSH (nitric oxide-, hydrogen sulfide-releasing) compounds that release both H2S and NO, and have IC50s for cell growth inhibition in the low nano-molar range. Methods: Compounds: Aspirin based NOSH-1, NOSH-2, NOSH-3, and NOSH-4 were synthesized and purified by us with 1H-NMR verification. Human cancer cell lines: colon (HT-29, HCT 15, SW480), breast (MCF-7, MDA-MB-231, SKBR3), pancreas (BxPC-3, MIA PaCa-2), lung (A549), prostate (LNCap), leukemia (Jurkat). Cell growth: MTT. Anti-inflammatory: paw edema induced by intraplantar injection of 100 µL of 1% carrageenan, paw volumes measured up to the tibiotarsal joint immediately prior to carrageenan injection and thereafter at 1hr intervals up to 6hrs. Drugs were administered orally 1 hr before carrageenan; COX enzyme: immunoblotting, PGE2: ELISA Results: All NOSH compounds were more effective than aspirin in inhibiting the growth of colon, breast, pancreas, prostate, lung, and leukemia cancer cell lines. The IC50s at 24h were in the range 48 nM to 6.5 µM depending on the cell line and the compound. The corresponding IC50 for aspirin was >5000 µM in all cell lines. Our lead compound NOSH-1, had a enhanced potency of >100,000-fold. NOSH-1 dose-dependently decreased the carrageenan-induced edema 1h after administration and maintained this anti-inflammatory effect throughout the experiment (up to 6h). PGE2 levels within the inflamed rat paw were also reduced by NOSH-1. Carrageenan induced both COX-1 and COX-2 expression which were dose-dependently inhibited by NOSH-1. Conclusions: NOSH compounds are a new class of anti-inflammatory agents. NOSH-1, our lead compound is very potent in inhibiting a number of different cancer cell lines of different tissue origin suggesting a tissue independent effect. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3899. doi:1538-7445.AM2012-3899
Introduction: In our search for a better non-steroidal anti-inflammatory drug (NSAID) we have syn... more Introduction: In our search for a better non-steroidal anti-inflammatory drug (NSAID) we have synthesized a series of nitric oxide-, and hydrogen sulfide-releasing hybrid compounds that have IC50s for cell growth inhibition in the low nano-molar range. We have termed these NOSH compounds. Our lead agent, NOSH-aspirin is in the order of 100,000 to 250,000-fold more potent than aspirin in inhibiting colon cancer cell growth over a 24-72h time period. NOSH-aspirin although highly potent, has very limited cyto-toxicity, lactate dehydrogenase (LDH) release at 4 times its IC50 for cell growth inhibition was less than 10% at 24h. Here we report our results on the effects of NOSH-aspirin treatment on established tumors in a xenograft model of human colon cancer cells. Methods: Compound: NOSH-aspirin was synthesized and purified by us with 1H-NMR verification. Cell line: HT-29 human adenocarcimoma; Xenografts: Male athymic SKID mice were implanted s.c. in the right flank with HT-29 (2 x 106) cells suspended in 50% Matrigel, after 10 days the animals were randomly divided into 4 groups (N = 7/group) and gavaged daily with NOSH-aspirin (25 or 50 or 100 mg/kg body weight) or vehicle. Tumor volume and animal weight were recorded every 3 days. After 3 weeks of treatment, mice were sacrificed, tumors excised, weighed, and fixed in 10% buffered formalin for immunohistochemical studies. Results: NOSH-aspirin had no effect on the weight of the mice even at the highest concentration used. There were no overt signs of toxicity. It dose-dependently reduced tumor mass by 50 ± 7%, 75 ± 5%, 90 ± 3 % at 25, 50, and 100 mg/kg, respectively. Tumor volume was also dose-dependently reduced as a function of time. NOSH-aspirin inhibited growth of HT-29 colon cancer cells xenografts as a result of reduced proliferation (decreased PCNA expression), and induction apoptosis (increased number of TUNEL positive cells). NF-κB, activated in control xenografts was significantly inhibited by NOSH-aspirin. Conclusions: NOSH-aspirin has potent anti-cancer affects and merits further evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3898. doi:1538-7445.AM2012-3898
Introduction: Regular uses of non-steroidal anti-inflammatory drugs (NSAIDs) in general and aspir... more Introduction: Regular uses of non-steroidal anti-inflammatory drugs (NSAIDs) in general and aspirin in particular have been associated with reductions in a number of cancers including, colon, breast, pancreas and others. However, NSAIDs have significant side effects, which precludes their wide spread use. In our search for a “better NSAID”, we have synthesized a series of nitric oxide-, and hydrogen sulfide-releasing hybrid compounds that have IC50s for cell growth inhibition in the low nano-molar range. We have termed these NOSH compounds. Our lead agent, NOSH-aspirin is in the order of 100,000 to 250,000-fold more potent than aspirin in inhibiting colon cancer cell growth over a 24-72h-time period. NOSH-aspirin although highly potent, is essentially devoid of any cyto-toxicity as judged by lactate dehydrogenase (LDH) release. Here we report our results on the effects of NOSH-aspirin treatment on established tumors in a xenograft model of human colon, breast (both ER- and ER+), and...
Fenretinide [N-(4-Hydroxyphenyl)retinamide, 4-HPR] (10(-10)-10(-6) M) treatment of HT-29 human co... more Fenretinide [N-(4-Hydroxyphenyl)retinamide, 4-HPR] (10(-10)-10(-6) M) treatment of HT-29 human colon cancer cells for 24-72 h significantly inhibited their growth. Using HCT-15 cells, 4-HPR had limited inhibitory effects on cell proliferation over the same concentration range and time period. The inhibitory effects of 4-HPR on cell growth in HT-29 cells were markedly reduced in the presence of exogenously added prostaglandins (PGs), suggesting a possible role for inhibition of PG synthesis as a mechanism for 4-HPR&#39;s antiproliferative effects. Inhibition of PGE(2) production was caused by 4-HPR in a concentration-dependent manner and decreased COX-2 but not COX-1 mRNA levels; this is the first indication that 4-HPR selectively inhibits COX-2 gene expression. Our findings suggest a possible mechanism for the chemopreventive and anti-proliferative effects of 4-HPR.
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Papers by Khosrow Kashfi