Primary and acquired resistance to anticancer antibody immunotherapies presents significant clini... more Primary and acquired resistance to anticancer antibody immunotherapies presents significant clinical challenges. Here, we demonstrate that proteolytic inactivation of cancer-targeting antibodies is an unappreciated contributor to cancer immune evasion, and the finding presents novel opportunities for ther-apeutic intervention. A single peptide bond cleavage in the IgG1 hinge impairs cancer cell killing due to structural derange-ment of the Fc region. Hinge-cleaved trastuzumab gradually accumulated on the surfaces of HER2-expressing cancer cell lines in vitro, and was greatly accelerated when the cells were engineered to express the potent bacterial IgG-degrading pro-teinase (IdeS). Similar to cancer-related matrix metalloprotei-nases (MMP), IdeS exposes a hinge neoepitope that we have developed an antibody, mAb2095-2, to specifically target the epitope. In in vitro studies, mAb2095-2 restored the lost anti-body-dependent cell-mediated cytotoxicity functionality of cell-bound single-...
Osteosarcoma (OS) pulmonary metastasis translates into poor patient survival. The implication of ... more Osteosarcoma (OS) pulmonary metastasis translates into poor patient survival. The implication of PD-1-PD-L1 pathway in the context of NK cells and/or macrophages in OS is unknown. We investigated the effect of anti-PD-1 in OS lung metastasis and the role of NK cells and/or macrophages in anti-PD-1 responses. A human LM7 OS mouse model was used. Immunohistochemistry for tissues (PD-L1, caspase-3, Ki-67, NK cells, macrophages), and Western blotting for OS lung tumors (p-Stat3, p-Erk1/2) was performed. NK and macrophages were assessed using flow cytometry. NK cell and macrophage depletion were conducted using anti-asialo GM1 and clodrosome, respectively. PD-L1 expression was observed in human OS cells and OS patient lung metastases. Anti-PD1 antibody led to a significant decrease in the number of OS lung metastases, enhanced tumor apoptosis, decreased tumor cell proliferation, and p-STAT-3/p-Erk1/2 signaling blockade in OS lung tumors. NK cells and macrophages in OS lung tumors expressed PD-1 and anti-PD1 increased NK cell and macrophage tumor infiltration. Increased numbers of antitumor M1 macrophages and decreased pro-inflammatory M2 macrophages were seen. NK depletion did not affect therapeutic effect of anti-PD-1, suggesting that NK cells were not directly involved. However, macrophage depletion significantly compromised anti-PD1 efficacy, confirming their role in efficacy of anti-PD-1 against OS lung metastasis. Our findings suggest that OS lung metastases regression by anti-PD1 can be attributed to activated tumor M1 macrophages and reduced M2 macrophages. Owing to the co-relation of M1 macrophages with OS patient outcome, we provide a novel mechanism of PD-1 blockade and a basis for future clinical trials for anti-PD-1 antibodies in OS.
Primary and acquired resistance to anticancer antibody immunotherapies presents significant clini... more Primary and acquired resistance to anticancer antibody immunotherapies presents significant clinical challenges. Here, we demonstrate that proteolytic inactivation of cancer-targeting antibodies is an unappreciated contributor to cancer immune evasion, and the finding presents novel opportunities for therapeutic intervention. A single peptide bond cleavage in the IgG1 hinge impairs cancer cell killing due to structural derangement of the Fc region. Hinge-cleaved trastuzumab gradually accumulated on the surfaces of HER2-expressing cancer cell lines in vitro, and was greatly accelerated when the cells were engineered to express the potent bacterial IgG-degrading proteinase (IdeS). Similar to cancer-related matrix metalloproteinases (MMP), IdeS exposes a hinge neoepitope that we have developed an antibody, mAb2095-2, to specifically target the epitope. In in vitro studies, mAb2095-2 restored the lost antibody-dependent cell-mediated cytotoxicity functionality of cell-bound single-cleaved trastuzumab (scIgG-T). In vivo, mAb2095-2 rescued the impaired Fc-dependent tumor-suppressive activity of scIgG-T in a xenograft tumor model and restored the recruitment of immune effector cells into the tumor microenvironment. More importantly, an Fc-engineered proteinase-resistant version of mAb2095-2 rescued trastuzumab antitumor efficacy in a mouse tumor model with human cancer cells secreting IdeS, whereas trastuzumab alone showed significantly reduced antitumor activity in the same model. Consistently, an Fc-engineered proteinase-resistant version of trastuzumab also greatly improved antitumor efficacy in the xenograft tumor model. Taken together, these findings point to a novel cancer therapeutic strategy to rescue proteolytic damage of antibody effector function by an Fc-engineered mAb against the hinge neoepitope and to overcome cancer evasion of antibody immunity. Mol Cancer Ther; 14(3); 681-91. Ó2014 AACR.
Coronavirus disease 2019 (COVID-19) is a fast-developing viral pandemic spreading across the glob... more Coronavirus disease 2019 (COVID-19) is a fast-developing viral pandemic spreading across the globe. Due to lack of availability of proven medicines against COVID-19, physicians have resorted to tre...
HER3 (ErbB3), which is a member of the human epidermal growth factor receptor (EGFR) family has e... more HER3 (ErbB3), which is a member of the human epidermal growth factor receptor (EGFR) family has emerged as a key oncogene in cancer progression. HER3 overexpression has been observed in lung, prostate, melanomas and colon cancers and is associated with poor patient prognosis. HER3 has been known to play a role in resistance mechanisms towards EGFR tyrosine kinase inhibitors like Gefitinib and anti-HER2 antibodies like Trastuzumab in lung and breast cancers respectively. Upon ligand (neuregulin) binding, HER3 heterodimerizes with its partner receptors, inducing phosphorylation of its tyrosine residues in the c-terminal tail, which mediate HER3-dependent signaling. By binding to the HER3 c-terminal tail, Src homology 2 domain (SH2) or phosphotyrosine-binding (PTB) proteins may regulate the neuregulin-induced signaling. Here, we used a SH2 profiling approach to discover novel SH2 adaptor proteins interacting with HER3 and found that the SH2 adaptor protein Crk II (C10 regulator of kina...
Osteosarcoma (OS) is the most common primary malignant bone tumor in children. Pulmonary metastas... more Osteosarcoma (OS) is the most common primary malignant bone tumor in children. Pulmonary metastasis is the major cause of mortality in OS patients with a 25-30 % 5-year survival rate. Therefore, development of novel targeted approaches like immunotherapy has been the interest of investigators. Previously, we have demonstrated that Liposomal muramyl tripeptipe phosphatidyl ethanolamine (L-MTP-PE) reduced the metastatic burden in animal models and caused an 8% improvement in the overall survival of patients with OS metastatic disease through macrophage activation. The adoptive transfer of mature natural killer (NK) cells activated ex vivo has exhibited anti-tumor efficacy in breast cancer and lymphoma models. It has been shown that NK cells exert cytotoxicity against OS cells in vitro. Aerosolized interleukin 2 (IL-2) administered to dogs with OS lung disease has demonstrated therapeutic benefit. Additionally, Guma S. R. et al. showed that aerosol IL-2 enhanced the efficacy of infused...
CHAPTER 5. Therapeutic efficacy against OS lung metastases in vivo through inhibition of tumor ce... more CHAPTER 5. Therapeutic efficacy against OS lung metastases in vivo through inhibition of tumor cell proliferation and increased tumor cell apoptosis .
Aim: To test whether combining interleukin (IL)-11Rα chimeric antigen receptor (CAR) T-cells with... more Aim: To test whether combining interleukin (IL)-11Rα chimeric antigen receptor (CAR) T-cells with an anti-programmed death (PD-1) antibody (an immune checkpoint inhibitor) is an effective therapeutic approach in osteosarcoma (OS), allowing improved tumor eradication. Methods: IL-11Rα-CAR T-cells were cocultured in vitro with human LM7 OS tumor cells (with and without anti-PD-1 antibody). Coculture of LM7 cells with purified T-cells served as the control. Cytotoxicity and surface PD-1 expression were analyzed in all groups. Results: PD-1 expression increased during expansion of CAR T-cells. Exposure of immune cells to tumor cells in vitro subsequently decreased surface PD-1 expression on the CAR T-cells. Addition of an anti-PD-1 antibody (Clone J110) to further decrease surface PD-1 expression on CAR T-cells before coculture did not enhance cytotoxic effects of the CAR T-cells against LM7 cells. Conclusion: This combination of IL-11Rα-CAR T-cells and an anti-PD-1 antibody did not pro...
Advanced breast cancer is notorious for its aggressive nature and poor prognosis. An ablated regu... more Advanced breast cancer is notorious for its aggressive nature and poor prognosis. An ablated regulation in the EGFR family receptor signaling has been linked to the development of numerous tumor types, including breast cancer. HER3 is a unique member of the EGFR family that lacks intrinsic tyrosine kinase activity. However, HER3 can initiate signaling when dimerized with other family members such as HER2. HER3 overexpression is correlated with poor survival in breast cancer patients. HER3 also plays an important role in drug resistance mechanism such as in trastuzumab resistant breast cancer cell lines where it dimerize with EGFR to initiate signaling via the PI3K/Akt pathway. The identification of interaction partners of HER39s C-tail is critical to understand the signaling mechanism underpinning HER39s role in drug resistance and in progression of breast cancer. Our laboratory has identified a panel of novel HER3-interacting proteins by a combined immunoprecipitation and mass-spectrometry approach. One of the novel HER3 interacting proteins is DJ-1 which is a chaperone protein that plays an important role in the development of many cancers, including breast cancer. DJ-1 knockdown in high HER3 expressing breast cancer cell lines such as MCF-7 and MDA- MB-453 resulted in the reduction in HER3 levels as well as proteins downstream of the HER3 signaling pathway such as MAPK. We have also demonstrated that DJ-1 knockdown led to decrease in cancer cell proliferation. Studies are now in progress to determine the mechanism of regulation of HER3 by DJ-1 and the impact of DJ-1 KD in in vivo breast cancer xenograft models. These studies will help us to decipher key molecules which regulate HER3 mediated signaling and their role in breast cancer development and progression. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-11-03.
Interleukin-2 (IL-2) is a very well-known cytokine that has been studied for the past 35 years. I... more Interleukin-2 (IL-2) is a very well-known cytokine that has been studied for the past 35 years. It plays a major role in the growth and proliferation of many immune cells such NK and T cells. It is an important immunotherapy cytokine for the treatment of various diseases including cancer. Systemic delivery of IL-2 has shown clinical benefit in renal cell carcinoma and melanoma patients. However, its use has been limited by the numerous toxicities encountered with the systemic delivery. Intravenous IL-2 causes the well-known "capillary leak syndrome," or the leakage of fluid from the circulatory system to the interstitial space resulting in hypotension (low blood pressure), edema, and dyspnea that can lead to circulatory shock and eventually cardiopulmonary collapse and multiple organ failure. Due to the toxicities associated with systemic IL-2, an aerosolized delivery approach has been developed, which enables localized delivery and a higher local immune cell activation. Since proteins are absorbed via pulmonary lymphatics, after aerosol deposition in the lung, aerosol delivery provides a means to more specifically target IL-2 to the local immune system in the lungs with less systemic effects. Its benefits have extended to diseases other than cancer. Delivery of IL-2 via aerosol or as nebulized IL-2 liposomes has been previously shown to have less toxicity and higher efficacy against sarcoma lung metastases. Dogs with cancer provided a highly relevant means to determine biodistribution of aerosolized IL-2 and IL-2 liposomes. However, efficacy of single-agent IL-2 is limited. As in general, for most immune-therapies, its effect is more beneficial in the face of minimal residual disease. To overcome this limitation, combination therapies using aerosol IL-2 with adoptive transfer of T cells or NK cells have emerged.Using a human osteosarcoma (OS) mouse model, we have demonstrated the efficacy of single-agent aerosol IL-2 and combination therapy aerosol IL-2 and NK cells or aerosol IL-2 and interleukin 11 receptor alpha-directed chimeric antigen receptor-T cells (IL-11 receptor α CAR-T cells) against OS pulmonary metastases. Combination therapy resulted in a better therapeutic effect. A Phase-I trial of aerosol IL-2 was done in Europe and proved to be safe. Others and our preclinical studies provided the basis for the development of a Phase-I aerosol IL-2 trial in our institution to include younger patients with lung metastases. OS, our disease of interest, has a peak incidence in the adolescent and young adult years. Our goal is to complete this trial in the next 2 years.In this chapter, we summarize the different effects of IL-2 and cover the advantages of the aerosol delivery route for diseases of the lung with an emphasis on some of our most recent work using combination therapy aerosol IL-2 and NK cells for the treatment of OS lung metastases.
Background There has been a dramatic increase in T cell receptor (TCR) sequencing spurred, in par... more Background There has been a dramatic increase in T cell receptor (TCR) sequencing spurred, in part, by the widespread adoption of this technology across academic medical centers and by the rapid commercialization of TCR sequencing. While the raw TCR sequencing data has increased, there has been little in the way of approaches to parse the data in a biologically meaningful fashion. The ability to parse this new type of 'big data' quickly and efficiently to understand the T cell repertoire in a structurally relevant manner has the potential to open the way to new discoveries about how the immune system is able to respond to insults such as cancer and infectious diseases.
Epidermal growth factor receptor (EGFR) is a novel molecular target for anticancer therapy. This ... more Epidermal growth factor receptor (EGFR) is a novel molecular target for anticancer therapy. This study examined the effects of anti-EGFR antibody cetuximab on two human androgen-independent prostate carcinoma cell lines, Du145 and PC-3. Cell proliferation was monitored with a trypan blue viability assay. Cell apoptosis and cell cycle profile was evaluated by flow cytometry. The expression of various signaling molecules was examined by Western immunoblotting. Cetuximab (100 microg/ml) caused a significant growth inhibition by inducing cell apoptosis in Du145 cells, but not in PC-3 cells. It caused EGFR down-regulation and inhibited EGFR Tyr-845 autophosphorylation in both Du145 and PC-3 cells. However, EGFR phosphorylation at Tyr-1173 and MAPK 44/42 phosphorylation were inhibited in Du145 cells, but not in PC-3 cells. Cetuximab was not able to inhibit Akt phosphorylation in either prostate cancer cell line. Du145 cells only showed a very moderate response to cetuximab whereas PC-3 ce...
Crk (C10 regulator of kinase) adaptor proteins are highly expressed in many types of human cancer... more Crk (C10 regulator of kinase) adaptor proteins are highly expressed in many types of human cancers and often contribute to aggressive cancer phenotypes. Crk II, a member of CRK family, has been reported to regulate cell migration and metastasis in breast cancer cells. However, its role in other cancer types has not been reported. In this study, we investigated the molecular function of Crk II in prostate cancer (PCa) cells (CWR-22rv1) in vitro and using a mouse tumor model. Results showed that Crk II knockdown by shRNA-mediated silencing (Crk II-shRNA) in the PCa cells significantly inhibited both cancer cell migration and invasion in cell culture study. Crk II-shRNA cancer cells also significantly decreased colony formation in vitro, but had no significant reduction of tumor volume after 4 weeks of cancer cell xenografting in vivo when compared to the scramble control. Interestingly, Crk II-shRNA cancer cells showed a greatly reduced level of insulin-like growth factor 1 receptor (...
Primary and acquired resistance to anticancer antibody immunotherapies presents significant clini... more Primary and acquired resistance to anticancer antibody immunotherapies presents significant clinical challenges. Here, we demonstrate that proteolytic inactivation of cancer-targeting antibodies is an unappreciated contributor to cancer immune evasion, and the finding presents novel opportunities for ther-apeutic intervention. A single peptide bond cleavage in the IgG1 hinge impairs cancer cell killing due to structural derange-ment of the Fc region. Hinge-cleaved trastuzumab gradually accumulated on the surfaces of HER2-expressing cancer cell lines in vitro, and was greatly accelerated when the cells were engineered to express the potent bacterial IgG-degrading pro-teinase (IdeS). Similar to cancer-related matrix metalloprotei-nases (MMP), IdeS exposes a hinge neoepitope that we have developed an antibody, mAb2095-2, to specifically target the epitope. In in vitro studies, mAb2095-2 restored the lost anti-body-dependent cell-mediated cytotoxicity functionality of cell-bound single-...
Osteosarcoma (OS) pulmonary metastasis translates into poor patient survival. The implication of ... more Osteosarcoma (OS) pulmonary metastasis translates into poor patient survival. The implication of PD-1-PD-L1 pathway in the context of NK cells and/or macrophages in OS is unknown. We investigated the effect of anti-PD-1 in OS lung metastasis and the role of NK cells and/or macrophages in anti-PD-1 responses. A human LM7 OS mouse model was used. Immunohistochemistry for tissues (PD-L1, caspase-3, Ki-67, NK cells, macrophages), and Western blotting for OS lung tumors (p-Stat3, p-Erk1/2) was performed. NK and macrophages were assessed using flow cytometry. NK cell and macrophage depletion were conducted using anti-asialo GM1 and clodrosome, respectively. PD-L1 expression was observed in human OS cells and OS patient lung metastases. Anti-PD1 antibody led to a significant decrease in the number of OS lung metastases, enhanced tumor apoptosis, decreased tumor cell proliferation, and p-STAT-3/p-Erk1/2 signaling blockade in OS lung tumors. NK cells and macrophages in OS lung tumors expressed PD-1 and anti-PD1 increased NK cell and macrophage tumor infiltration. Increased numbers of antitumor M1 macrophages and decreased pro-inflammatory M2 macrophages were seen. NK depletion did not affect therapeutic effect of anti-PD-1, suggesting that NK cells were not directly involved. However, macrophage depletion significantly compromised anti-PD1 efficacy, confirming their role in efficacy of anti-PD-1 against OS lung metastasis. Our findings suggest that OS lung metastases regression by anti-PD1 can be attributed to activated tumor M1 macrophages and reduced M2 macrophages. Owing to the co-relation of M1 macrophages with OS patient outcome, we provide a novel mechanism of PD-1 blockade and a basis for future clinical trials for anti-PD-1 antibodies in OS.
Primary and acquired resistance to anticancer antibody immunotherapies presents significant clini... more Primary and acquired resistance to anticancer antibody immunotherapies presents significant clinical challenges. Here, we demonstrate that proteolytic inactivation of cancer-targeting antibodies is an unappreciated contributor to cancer immune evasion, and the finding presents novel opportunities for therapeutic intervention. A single peptide bond cleavage in the IgG1 hinge impairs cancer cell killing due to structural derangement of the Fc region. Hinge-cleaved trastuzumab gradually accumulated on the surfaces of HER2-expressing cancer cell lines in vitro, and was greatly accelerated when the cells were engineered to express the potent bacterial IgG-degrading proteinase (IdeS). Similar to cancer-related matrix metalloproteinases (MMP), IdeS exposes a hinge neoepitope that we have developed an antibody, mAb2095-2, to specifically target the epitope. In in vitro studies, mAb2095-2 restored the lost antibody-dependent cell-mediated cytotoxicity functionality of cell-bound single-cleaved trastuzumab (scIgG-T). In vivo, mAb2095-2 rescued the impaired Fc-dependent tumor-suppressive activity of scIgG-T in a xenograft tumor model and restored the recruitment of immune effector cells into the tumor microenvironment. More importantly, an Fc-engineered proteinase-resistant version of mAb2095-2 rescued trastuzumab antitumor efficacy in a mouse tumor model with human cancer cells secreting IdeS, whereas trastuzumab alone showed significantly reduced antitumor activity in the same model. Consistently, an Fc-engineered proteinase-resistant version of trastuzumab also greatly improved antitumor efficacy in the xenograft tumor model. Taken together, these findings point to a novel cancer therapeutic strategy to rescue proteolytic damage of antibody effector function by an Fc-engineered mAb against the hinge neoepitope and to overcome cancer evasion of antibody immunity. Mol Cancer Ther; 14(3); 681-91. Ó2014 AACR.
Coronavirus disease 2019 (COVID-19) is a fast-developing viral pandemic spreading across the glob... more Coronavirus disease 2019 (COVID-19) is a fast-developing viral pandemic spreading across the globe. Due to lack of availability of proven medicines against COVID-19, physicians have resorted to tre...
HER3 (ErbB3), which is a member of the human epidermal growth factor receptor (EGFR) family has e... more HER3 (ErbB3), which is a member of the human epidermal growth factor receptor (EGFR) family has emerged as a key oncogene in cancer progression. HER3 overexpression has been observed in lung, prostate, melanomas and colon cancers and is associated with poor patient prognosis. HER3 has been known to play a role in resistance mechanisms towards EGFR tyrosine kinase inhibitors like Gefitinib and anti-HER2 antibodies like Trastuzumab in lung and breast cancers respectively. Upon ligand (neuregulin) binding, HER3 heterodimerizes with its partner receptors, inducing phosphorylation of its tyrosine residues in the c-terminal tail, which mediate HER3-dependent signaling. By binding to the HER3 c-terminal tail, Src homology 2 domain (SH2) or phosphotyrosine-binding (PTB) proteins may regulate the neuregulin-induced signaling. Here, we used a SH2 profiling approach to discover novel SH2 adaptor proteins interacting with HER3 and found that the SH2 adaptor protein Crk II (C10 regulator of kina...
Osteosarcoma (OS) is the most common primary malignant bone tumor in children. Pulmonary metastas... more Osteosarcoma (OS) is the most common primary malignant bone tumor in children. Pulmonary metastasis is the major cause of mortality in OS patients with a 25-30 % 5-year survival rate. Therefore, development of novel targeted approaches like immunotherapy has been the interest of investigators. Previously, we have demonstrated that Liposomal muramyl tripeptipe phosphatidyl ethanolamine (L-MTP-PE) reduced the metastatic burden in animal models and caused an 8% improvement in the overall survival of patients with OS metastatic disease through macrophage activation. The adoptive transfer of mature natural killer (NK) cells activated ex vivo has exhibited anti-tumor efficacy in breast cancer and lymphoma models. It has been shown that NK cells exert cytotoxicity against OS cells in vitro. Aerosolized interleukin 2 (IL-2) administered to dogs with OS lung disease has demonstrated therapeutic benefit. Additionally, Guma S. R. et al. showed that aerosol IL-2 enhanced the efficacy of infused...
CHAPTER 5. Therapeutic efficacy against OS lung metastases in vivo through inhibition of tumor ce... more CHAPTER 5. Therapeutic efficacy against OS lung metastases in vivo through inhibition of tumor cell proliferation and increased tumor cell apoptosis .
Aim: To test whether combining interleukin (IL)-11Rα chimeric antigen receptor (CAR) T-cells with... more Aim: To test whether combining interleukin (IL)-11Rα chimeric antigen receptor (CAR) T-cells with an anti-programmed death (PD-1) antibody (an immune checkpoint inhibitor) is an effective therapeutic approach in osteosarcoma (OS), allowing improved tumor eradication. Methods: IL-11Rα-CAR T-cells were cocultured in vitro with human LM7 OS tumor cells (with and without anti-PD-1 antibody). Coculture of LM7 cells with purified T-cells served as the control. Cytotoxicity and surface PD-1 expression were analyzed in all groups. Results: PD-1 expression increased during expansion of CAR T-cells. Exposure of immune cells to tumor cells in vitro subsequently decreased surface PD-1 expression on the CAR T-cells. Addition of an anti-PD-1 antibody (Clone J110) to further decrease surface PD-1 expression on CAR T-cells before coculture did not enhance cytotoxic effects of the CAR T-cells against LM7 cells. Conclusion: This combination of IL-11Rα-CAR T-cells and an anti-PD-1 antibody did not pro...
Advanced breast cancer is notorious for its aggressive nature and poor prognosis. An ablated regu... more Advanced breast cancer is notorious for its aggressive nature and poor prognosis. An ablated regulation in the EGFR family receptor signaling has been linked to the development of numerous tumor types, including breast cancer. HER3 is a unique member of the EGFR family that lacks intrinsic tyrosine kinase activity. However, HER3 can initiate signaling when dimerized with other family members such as HER2. HER3 overexpression is correlated with poor survival in breast cancer patients. HER3 also plays an important role in drug resistance mechanism such as in trastuzumab resistant breast cancer cell lines where it dimerize with EGFR to initiate signaling via the PI3K/Akt pathway. The identification of interaction partners of HER39s C-tail is critical to understand the signaling mechanism underpinning HER39s role in drug resistance and in progression of breast cancer. Our laboratory has identified a panel of novel HER3-interacting proteins by a combined immunoprecipitation and mass-spectrometry approach. One of the novel HER3 interacting proteins is DJ-1 which is a chaperone protein that plays an important role in the development of many cancers, including breast cancer. DJ-1 knockdown in high HER3 expressing breast cancer cell lines such as MCF-7 and MDA- MB-453 resulted in the reduction in HER3 levels as well as proteins downstream of the HER3 signaling pathway such as MAPK. We have also demonstrated that DJ-1 knockdown led to decrease in cancer cell proliferation. Studies are now in progress to determine the mechanism of regulation of HER3 by DJ-1 and the impact of DJ-1 KD in in vivo breast cancer xenograft models. These studies will help us to decipher key molecules which regulate HER3 mediated signaling and their role in breast cancer development and progression. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-11-03.
Interleukin-2 (IL-2) is a very well-known cytokine that has been studied for the past 35 years. I... more Interleukin-2 (IL-2) is a very well-known cytokine that has been studied for the past 35 years. It plays a major role in the growth and proliferation of many immune cells such NK and T cells. It is an important immunotherapy cytokine for the treatment of various diseases including cancer. Systemic delivery of IL-2 has shown clinical benefit in renal cell carcinoma and melanoma patients. However, its use has been limited by the numerous toxicities encountered with the systemic delivery. Intravenous IL-2 causes the well-known "capillary leak syndrome," or the leakage of fluid from the circulatory system to the interstitial space resulting in hypotension (low blood pressure), edema, and dyspnea that can lead to circulatory shock and eventually cardiopulmonary collapse and multiple organ failure. Due to the toxicities associated with systemic IL-2, an aerosolized delivery approach has been developed, which enables localized delivery and a higher local immune cell activation. Since proteins are absorbed via pulmonary lymphatics, after aerosol deposition in the lung, aerosol delivery provides a means to more specifically target IL-2 to the local immune system in the lungs with less systemic effects. Its benefits have extended to diseases other than cancer. Delivery of IL-2 via aerosol or as nebulized IL-2 liposomes has been previously shown to have less toxicity and higher efficacy against sarcoma lung metastases. Dogs with cancer provided a highly relevant means to determine biodistribution of aerosolized IL-2 and IL-2 liposomes. However, efficacy of single-agent IL-2 is limited. As in general, for most immune-therapies, its effect is more beneficial in the face of minimal residual disease. To overcome this limitation, combination therapies using aerosol IL-2 with adoptive transfer of T cells or NK cells have emerged.Using a human osteosarcoma (OS) mouse model, we have demonstrated the efficacy of single-agent aerosol IL-2 and combination therapy aerosol IL-2 and NK cells or aerosol IL-2 and interleukin 11 receptor alpha-directed chimeric antigen receptor-T cells (IL-11 receptor α CAR-T cells) against OS pulmonary metastases. Combination therapy resulted in a better therapeutic effect. A Phase-I trial of aerosol IL-2 was done in Europe and proved to be safe. Others and our preclinical studies provided the basis for the development of a Phase-I aerosol IL-2 trial in our institution to include younger patients with lung metastases. OS, our disease of interest, has a peak incidence in the adolescent and young adult years. Our goal is to complete this trial in the next 2 years.In this chapter, we summarize the different effects of IL-2 and cover the advantages of the aerosol delivery route for diseases of the lung with an emphasis on some of our most recent work using combination therapy aerosol IL-2 and NK cells for the treatment of OS lung metastases.
Background There has been a dramatic increase in T cell receptor (TCR) sequencing spurred, in par... more Background There has been a dramatic increase in T cell receptor (TCR) sequencing spurred, in part, by the widespread adoption of this technology across academic medical centers and by the rapid commercialization of TCR sequencing. While the raw TCR sequencing data has increased, there has been little in the way of approaches to parse the data in a biologically meaningful fashion. The ability to parse this new type of 'big data' quickly and efficiently to understand the T cell repertoire in a structurally relevant manner has the potential to open the way to new discoveries about how the immune system is able to respond to insults such as cancer and infectious diseases.
Epidermal growth factor receptor (EGFR) is a novel molecular target for anticancer therapy. This ... more Epidermal growth factor receptor (EGFR) is a novel molecular target for anticancer therapy. This study examined the effects of anti-EGFR antibody cetuximab on two human androgen-independent prostate carcinoma cell lines, Du145 and PC-3. Cell proliferation was monitored with a trypan blue viability assay. Cell apoptosis and cell cycle profile was evaluated by flow cytometry. The expression of various signaling molecules was examined by Western immunoblotting. Cetuximab (100 microg/ml) caused a significant growth inhibition by inducing cell apoptosis in Du145 cells, but not in PC-3 cells. It caused EGFR down-regulation and inhibited EGFR Tyr-845 autophosphorylation in both Du145 and PC-3 cells. However, EGFR phosphorylation at Tyr-1173 and MAPK 44/42 phosphorylation were inhibited in Du145 cells, but not in PC-3 cells. Cetuximab was not able to inhibit Akt phosphorylation in either prostate cancer cell line. Du145 cells only showed a very moderate response to cetuximab whereas PC-3 ce...
Crk (C10 regulator of kinase) adaptor proteins are highly expressed in many types of human cancer... more Crk (C10 regulator of kinase) adaptor proteins are highly expressed in many types of human cancers and often contribute to aggressive cancer phenotypes. Crk II, a member of CRK family, has been reported to regulate cell migration and metastasis in breast cancer cells. However, its role in other cancer types has not been reported. In this study, we investigated the molecular function of Crk II in prostate cancer (PCa) cells (CWR-22rv1) in vitro and using a mouse tumor model. Results showed that Crk II knockdown by shRNA-mediated silencing (Crk II-shRNA) in the PCa cells significantly inhibited both cancer cell migration and invasion in cell culture study. Crk II-shRNA cancer cells also significantly decreased colony formation in vitro, but had no significant reduction of tumor volume after 4 weeks of cancer cell xenografting in vivo when compared to the scramble control. Interestingly, Crk II-shRNA cancer cells showed a greatly reduced level of insulin-like growth factor 1 receptor (...
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