The recent letter by Ivanovic commenting on work published by our group on very small embryonic-l... more The recent letter by Ivanovic commenting on work published by our group on very small embryonic-like stem cells (VSELs) in cord blood and bone marrow raises important questions on the properties and regenerative potential of VSELs. Similar to embryonic stem cells, being pluripotent by nature, VSELs are expected to have maximum regenerative potential compared with adult stem cells with limited ''plasticity.'' We propose that both hematopoietic (HSCs) and mesenchymal (MSCs) stem cells with cytoplasmic OCT-4 are possibly descendants ''progenitors'' derived from VSELs with nuclear OCT-4. Being pluripotent and quiescent by nature, VSELs may serve as a good autologous source of pluripotent stem cells (with minimal risk of teratoma formation) for regenerative medicine.
Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare popula... more Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare population of quiescent, bone marrow (BM)-residing very small embryonic-like stem cells (VSELs) can be specified like PGCs into hematopoietic stem/progenitor cells (HSPCs). These two properties of VSELs support the possibility of a developmental origin of HSPCs from migrating PGCs. Methods: To address a potential link between VSELs and germ line cells we analyzed by RT-PCR and FACS expression of erythropoietin receptor (EpoR) on murine bone marrow-and human umbilical cord blood-derived VSELs, murine and human teratocarcinoma cell lines and human ovarian cancer cells. A proper gating strategy and immunostaining excluded from FACS analysis potential contamination by erythroblasts. Furthermore, the transwell chemotaxis assays as well as adhesion and signaling studies were performed to demonstrate functionality of erythropoietin-EpoR axes on these cells. Results: We report here that murine and human VSELs as well as murine and human teratocarcinoma cell lines and ovarian cancer cell lines share a functional EpoR. Conclusions: Our data provide more evidence of a potential developmental link between germline cells, VSELs, and HSCs and sheds more light on the developmental hierarchy of the stem cell compartment in adult tissues.
Background: Follicle stimulating hormone (FSH) exerts action on both germline and somatic compart... more Background: Follicle stimulating hormone (FSH) exerts action on both germline and somatic compartment in both ovary and testis although FSH receptors (FSHR) are localized only on the somatic cells namely granulosa cells of growing follicles and Sertoli cells in the seminiferous tubules. High levels of FSH in females are associated with poor ovarian reserve, ovarian hyper stimulation syndrome etc. and at the same time FSH acts as a survival factor during in vitro organotypic culture of ovarian cortical strips. Thus a further understanding of FSH action on the ovary is essential. We have earlier reported presence of pluripotent very small embryonic-like stem cells (VSELs express Oct-4A in addition to other pluripotent markers) and their immediate descendants 'progenitors' ovarian germ stem cells (OGSCs express Oct-4B in addition to other germ cell markers) in ovarian surface epithelium (OSE) in various mammalian species including mice, rabbit, monkey, sheep and human. Present study was undertaken to investigate the effect of pregnant mare serum gonadotropin (PMSG) on adult mice ovaries with a focus on VSELs, OGSCs, postnatal oogenesis and primordial follicle assembly. Methods: Ovaries were collected from adult mice during different stages of estrus cycle and after 2 and 7 days of PMSG (5 IU) treatment to study histo-architecture and expression for FSHR, pluripotent stem cells , meiosis and germ cell specific markers. Results: PMSG treatment resulted in increased FSHR and proliferation as indicated by increased FSHR and PCNA immunostaining in OSE and oocytes of primordial follicles (PF) besides the granulosa cells of large antral follicles. Small 1-2 regions of multilayered OSE invariably associated with a cohort of PF during estrus stage in control ovary were increased to 5-8 regions after PMSG treatment. This was associated with an increase in pluripotent transcripts (Oct-4A, Nanog), meiosis (Scp-3) and germ cells (Oct-4B, Mvh) specific markers. MVH showed positive immuno staining on germ cell nest-like clusters and at places primordial follicles appeared connected through oocytes. Conclusions: The results of the present study show that gonadotropin (PMSG) treatment to adult mouse leads to increased pluripotent stem cell activity in the ovaries, associated with increased meiosis, appearance of several cohorts of PF and their assembly in close proximity of OSE. This was found associated with the presence of germ cell nests and cytoplasmic continuity of oocytes in PF. We have earlier reported that pluripotent ovarian stem cells in the adult mammalian ovary are the VSELs which give rise to slightly differentiated OGSCs. Thus we propose that gonadotropin through its action on pluripotent VSELs augments neo-oogenesis and PF assembly in adult mouse ovaries.
Gonadotropin treatment augments postnatal cell nests and cytoplasmic continuity of oocytes in PF.... more Gonadotropin treatment augments postnatal cell nests and cytoplasmic continuity of oocytes in PF. We have earlier reported that pluripotent ovarian stem cells in the adult mammalian ovary are the VSELs which give rise to slightly differentiated OGSCs. Thus we propose that
Journal of Cancer Stem Cell Research, Feb 27, 2015
It has been proposed that established cell lines contain populations of cancer stem cells (CSCs),... more It has been proposed that established cell lines contain populations of cancer stem cells (CSCs), which are responsible for expansion of these cell lines and their metastatic potential. To address this issue better, we employed a human ovarian cancer cell line, A2780, and sorted cells according to the postulated highly mestatatic cancer stem cell phenotype, CD24+CD44-, and the less-metastatic CD24-CD44+ and CD24-CD44- phenotypes. These cells were employed in chemotaxis assays in vitro to migrate in response to conditioned media harvested from bone marrow or liver cells damaged by irradiation and in in vivo assays to grow tumors after injection into immunodeficient mice. We also sorted single cells expressing all three phenotypes by FACS and expanded them to grow clones. We found that the CD24+CD44- cells are a highly migratory population compared with CD24-CD44+ and CD24-CD44- cells and were seeded in higher numbers in murine bone marrow and liver after intravenous injection. Most i...
Background. There are well-known side effects of chemotherapy and radiotherapy that are mainly re... more Background. There are well-known side effects of chemotherapy and radiotherapy that are mainly related to the toxicity and impaired function of vital organs; however, the induction by these therapies of expression of several pro-metastatic factors in various tissues and organs that in toto create a pro-metastatic microenvironment is still, surprisingly, not widely acknowledged. On the other hand, it is very well known that, after infusion into a host after myeloablative treatment by radio-chemotherapy, HSPCs home efficiently to BM in response to several chemotactic factors upregulated in the BM microenvironment. Hypothesis . To explain this phenomenon, we hypothesized that toxic damage in BM and other organs due to radio and/or chemotherapy administered for treatment of malignancies leads to upregulation in “bystander” tissues of several factors, such as chemokines, growth factors, bioactive phosphosphingolipids, and small- molecule alarmines, that attract normal circulating stem ce...
Background: Mesenchymal stromal cells (MSCs) play an important role in bone marrow (BM) by provid... more Background: Mesenchymal stromal cells (MSCs) play an important role in bone marrow (BM) by providing a supportive microenvironment for hematopoietic stem/progenitor cells (HSPCs). MSCs are also employed in organ regeneration as a rich source of several paracrine signals that inhibit apoptosis and promote angiogenesis in damaged tissues. As reported in the literature, several mediators, including a growth factor (HGF), a chemokine (SDF-1), bioactive lipids (S1P, C1P), and extracellular nucleotides (ATP, UTP), affect MSC biology and migration. In parallel, evidence has accumulated that the most primitive mesodermal precursors of MSCs (small BM-residing and peripheral blood (PB)-circulating Sca-1+Lin–CD45– cells in mice and CD133+Lin–CD45– cells in humans) express certain embryonic stem cell markers, such as the transcription factor Oct-4 and the SSEA-1/4 antigens (Stem Cells Dev. 2014;23:689-701), and also express several genes characteristic of migrating primordial germ cells (Leukem...
Ovarian cancer is a highly aggressive and deadly disease. Currently, the treatment for ovarian ca... more Ovarian cancer is a highly aggressive and deadly disease. Currently, the treatment for ovarian cancer entails cytoreductive surgery followed by chemotherapy, mainly cisplatin or carboplatin combined with paclitaxel. Although this regimen is initially effective in a high percentage of cases, unfortunately, after few months of initial treatment, tumor relapse occurs due to platinum-resistance. DOXIL (liposomal preparation of doxorubicin) is a choice of drug for recurrent ovarian cancer. However, its response rate is very low and is accompanied by myocardial toxicity. Resistance to chemotherapy and recurrence of cancer is primarily attributed to the presence of cancer stem cells (CSCs), a small population of cells present in cancer. Effect of DOXIL and withaferin A (WFA), both alone and in combination, was investigated on cell proliferation of ovarian cancer cell line A2780 and tumor growth in SCID mice bearing i.p. ovarian tumors. ALDH1 cells were isolated from A2780 using cell sorter...
Background: The existence in adult tissues of developmentally early stem cells with broader speci... more Background: The existence in adult tissues of developmentally early stem cells with broader specification potential may suggest the presence of embryonic primordial germ cell (PGC) remnants in post-natal organs. To support this small, quiescent stem cells (VSELs) that express several markers of PGCs reside in adult murine bone marrow (BM) (Leukemia 2010;24:1450), and like PGCs, are kept quiescent by erasure of imprinting on paternally imprinted genes (Leukemia 2009;23:2042). As reported hematopoietic stem/progenitor cells (HSPCs) can become specified from a population of migrating PGCs isolated from embryos (Blood 1995;86:463) as well as from adult bone marrow VSELs (Leukemia 2011;25,1278). In support of this intriguing possibility, HSPCs and PGCs are both highly migratory populations of stem cells, and specification of the first primitive HSPCs in yolk sac blood islands as well as the origin of definitive HSPCs in the aorta-gonado-mesonephros region are chronologically and anatomically correlated with the developmental migration of PGCs in extra- and intra-embryonic tissues on their way to the genital ridges. Hypothesis: Based on these observations, we have hypothesized that PGC-derived cells as well as HSPCs share some common receptors, and we tested the expression of gonadotropic hormone receptors (GHR) and erythropoietin receptor (EpoR) on HSPCs and PGC-derived cells, respectively. Materials and Methods. We employed RT-PCR studies to evaluate the expression of GHR on normal and malignant HSPCs, whereas we evaluated the expression of EpoR on teratocarcinoma and ovarian cancer cell lines. The functionality of these receptors was tested by chemotaxis, adhesion, and proliferation assays, and we performed signal transduction studies employing specific ligands for gonadal receptors to stimulate HSPCs and erythropoietin (EPO) to stimulate germline-derived cells. Results. We observed the expression of functional FSH, LH, PRL, estrogen, and androgen receptors on normal murine and human HSPCs and in leukemia cell lines. At the same time, we observed the presence of functional EpoRs on murine and human teratocarcinoma cells and ovarian cancer cell lines. Conclusions. Our data provide further evidence for the existence of a developmental link between germline and hematopoiesis and shed new light on the developmental hierarchy of the stem cell compartment in adult tissues and possibility that some malignancies may develop from embryonic remnants. These observations also have important practical implications: i) pituitary gonadal hormones could be employed in selected cases of BM failure to stimulate hematopoiesis and ii) EPO treatment (e.g., because of anemia after chemotherapy) should be avoided in patients with germline malignancies. Citation Format: Malwina Suszynska, Katarzyna Mierzejewska, Agata Poniewierska-Baran, Ahmed Abdelbasit Ismail, Gabriela Schneider, Pranesh Gunjal, Janina Ratajczak, Sham S. Kakar, Magda Kucia, Mariusz Z. Ratajczak. Embryonic rest hypothesis of cancer development revisited: functional gonadotropic hormone receptors are expressed by normal and malignant hematopoietic cells and functional erythropoietin receptor is expressed by germline-derived tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4072. doi:10.1158/1538-7445.AM2015-4072
Background: One of side effects of chemotherapy and radiotherapy is the induction of several fact... more Background: One of side effects of chemotherapy and radiotherapy is the induction of several factors in various tissues and organs that create a pro-metastatic microenvironment for cancer cells that survive initial treatment. Methods: In the present study, we employed human ovarian cancer cell line A2780 and immunodeficient mice xenogrfat model to test effect of both ibuprofen and dexamethasone to ameliorate the therapy-induced pro-metastatic microenvironment in bone marrow, liver, and lung. Results: In our studies, we found that total body irradiation or administration of cisplatin increases the metastatic spread of human ovarian cancer cells transplanted into immunodeficient mice compared with animals unexposed to irradiation or cisplatin. Moreover, conditioned media harvested from irradiated murine bone marrow, lung, and liver chemoattracted human ovarian cancer cells, and this chemotactic activity was inactivated by heat, suggesting a major involvement of peptide or peptide-bound chemoattractants. We also observed that human ovarian cancer cells proliferate better if exposed to cell debris harvested from irradiated murine bone marrow. Finally, the pro-metastatic microenvironment in mice induced by radio-or chemotherapy was significantly ameliorated if animals were treated at the time of radiotherapy administration with non-steroid (ibuprofen) or steroid (prednisone) anti-inflammatory drugs. Conclusions: In summary, we propose that a radiochemotherapy-induced, pro-metastatic microenvironment plays an important role in the metastasis of cancer cells that are resistant to treatment. Such cells have characteristics of cancer stem cells and are highly migratory, and simple, intensive, anti-inflammatory treatment by non-steroid agents to suppress induction of pro-metastatic factors after radiochemotherapy would be an interesting anti-metastatic treatment alternative.
Background We have earlier reported that follicle stimulating hormone (FSH) modulates ovarian ste... more Background We have earlier reported that follicle stimulating hormone (FSH) modulates ovarian stem cells which include pluripotent, very small embryonic-like stem cells (VSELs) and their immediate descendants ‘progenitors’ termed ovarian germ stem cells (OGSCs), lodged in adult mammalian ovarian surface epithelium (OSE). FSH may exert pleiotropic actions through its alternatively spliced receptor isoforms. Four isoforms of FSH receptors (FSHR) are reported in literature of which FSH-R1 and FSH-R3 have biological activity. Present study was undertaken to identify FSHR isoforms mediating FSH action on ovarian stem cells, using sheep OSE cells culture as the study model. Methods Cultures of sheep OSE cells (a mix of epithelial cells, VSELs, OGSCs and few contaminating red blood cells) were established with and without FSH 5IU/ml treatment. Effect of FSH treatment on self-renewal of VSELs and their differentiation into OGSCs was studied after 15 hrs by qRT-PCR using markers specific for...
It has been proposed that established cell lines contain populations of cancer stem cells (CSCs),... more It has been proposed that established cell lines contain populations of cancer stem cells (CSCs), which are responsible for expansion of these cell lines and their metastatic potential. To address this issue better, we employed a human ovarian cancer cell line, A2780, and sorted cells according to the postulated highly mestatatic cancer stem cell phenotype, CD24 C CD44 À , and the less-metastatic CD24 À CD44 C and CD24 À CD44 À phenotypes. These cells were employed in chemotaxis assays in vitro to migrate in response to conditioned media harvested from bone marrow or liver cells damaged by irradiation and in in vivo assays to grow tumors after injection into immunodeficient mice. We also sorted single cells expressing all three phenotypes by FACS and expanded them to grow clones. We found that the CD24 C CD44 À cells are a highly migratory population compared with CD24 À CD44 C and CD24 À CD44 À cells and were seeded in higher numbers in murine bone marrow and liver after intravenous injection. Most importantly, we observed that singly sorted cells efficiently expanded ex vivo into cell populations that represented all phenotypes of the parental cell line. Thus, our data indicate that cells expressing a certain set of markers, e.g., CD24, have at any given moment a higher potential to migrate and metastasize. However, cells that are CD24-negative, if expanded from a singly sorted cell, may give rise to cells containing all of the markers, including CD24. Based on this finding, we propose that the CSC phenotype in cell lines fluctuates with cell expansion.
Endometrium undergoes dramatic growth, breakdown and regeneration throughout reproductive period ... more Endometrium undergoes dramatic growth, breakdown and regeneration throughout reproductive period in mammals. Stem cells have been implicated in the process however their origin, nature, anatomical localization and characterization still remain obscure. Classical concept of presence of stem cells in the basal layer of endometrium was recently challenged when side population and label retaining cells were found to be distributed throughout endometrium. We have earlier reported very small embryonic-like stem cells (VSELs) in adult mammalian ovary and testis as a small population of cells with nuclear OCT-4 along with progenitors (spermatogonial stem cells and ovarian germ stem cells) with cytoplasmic OCT-4. Present study was undertaken to gauge presence of VSELs in bilaterally ovariectomized mouse uterus and their modulation by hormones. Bilaterally ovariectomized mice were subjected to sequential estradiol and progesterone treatment in order to induce proliferation, differentiation an...
Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare popula... more Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare population of quiescent, bone marrow (BM)-residing very small embryonic-like stem cells (VSELs) can be specified like PGCs into hematopoietic stem/progenitor cells (HSPCs). These two properties of VSELs support the possibility of a developmental origin of HSPCs from migrating PGCs. Methods: To address a potential link between VSELs and germ line cells we analyzed by RT-PCR and FACS expression of erythropoietin receptor (EpoR) on murine bone marrow-and human umbilical cord blood-derived VSELs, murine and human teratocarcinoma cell lines and human ovarian cancer cells. A proper gating strategy and immunostaining excluded from FACS analysis potential contamination by erythroblasts. Furthermore, the transwell chemotaxis assays as well as adhesion and signaling studies were performed to demonstrate functionality of erythropoietin -EpoR axes on these cells. Results: We report here that murine and human VSELs as well as murine and human teratocarcinoma cell lines and ovarian cancer cell lines share a functional EpoR.
The recent letter by Ivanovic commenting on work published by our group on very small embryonic-l... more The recent letter by Ivanovic commenting on work published by our group on very small embryonic-like stem cells (VSELs) in cord blood and bone marrow raises important questions on the properties and regenerative potential of VSELs. Similar to embryonic stem cells, being pluripotent by nature, VSELs are expected to have maximum regenerative potential compared with adult stem cells with limited ''plasticity.'' We propose that both hematopoietic (HSCs) and mesenchymal (MSCs) stem cells with cytoplasmic OCT-4 are possibly descendants ''progenitors'' derived from VSELs with nuclear OCT-4. Being pluripotent and quiescent by nature, VSELs may serve as a good autologous source of pluripotent stem cells (with minimal risk of teratoma formation) for regenerative medicine.
Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare popula... more Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare population of quiescent, bone marrow (BM)-residing very small embryonic-like stem cells (VSELs) can be specified like PGCs into hematopoietic stem/progenitor cells (HSPCs). These two properties of VSELs support the possibility of a developmental origin of HSPCs from migrating PGCs. Methods: To address a potential link between VSELs and germ line cells we analyzed by RT-PCR and FACS expression of erythropoietin receptor (EpoR) on murine bone marrow-and human umbilical cord blood-derived VSELs, murine and human teratocarcinoma cell lines and human ovarian cancer cells. A proper gating strategy and immunostaining excluded from FACS analysis potential contamination by erythroblasts. Furthermore, the transwell chemotaxis assays as well as adhesion and signaling studies were performed to demonstrate functionality of erythropoietin-EpoR axes on these cells. Results: We report here that murine and human VSELs as well as murine and human teratocarcinoma cell lines and ovarian cancer cell lines share a functional EpoR. Conclusions: Our data provide more evidence of a potential developmental link between germline cells, VSELs, and HSCs and sheds more light on the developmental hierarchy of the stem cell compartment in adult tissues.
Background: Follicle stimulating hormone (FSH) exerts action on both germline and somatic compart... more Background: Follicle stimulating hormone (FSH) exerts action on both germline and somatic compartment in both ovary and testis although FSH receptors (FSHR) are localized only on the somatic cells namely granulosa cells of growing follicles and Sertoli cells in the seminiferous tubules. High levels of FSH in females are associated with poor ovarian reserve, ovarian hyper stimulation syndrome etc. and at the same time FSH acts as a survival factor during in vitro organotypic culture of ovarian cortical strips. Thus a further understanding of FSH action on the ovary is essential. We have earlier reported presence of pluripotent very small embryonic-like stem cells (VSELs express Oct-4A in addition to other pluripotent markers) and their immediate descendants 'progenitors' ovarian germ stem cells (OGSCs express Oct-4B in addition to other germ cell markers) in ovarian surface epithelium (OSE) in various mammalian species including mice, rabbit, monkey, sheep and human. Present study was undertaken to investigate the effect of pregnant mare serum gonadotropin (PMSG) on adult mice ovaries with a focus on VSELs, OGSCs, postnatal oogenesis and primordial follicle assembly. Methods: Ovaries were collected from adult mice during different stages of estrus cycle and after 2 and 7 days of PMSG (5 IU) treatment to study histo-architecture and expression for FSHR, pluripotent stem cells , meiosis and germ cell specific markers. Results: PMSG treatment resulted in increased FSHR and proliferation as indicated by increased FSHR and PCNA immunostaining in OSE and oocytes of primordial follicles (PF) besides the granulosa cells of large antral follicles. Small 1-2 regions of multilayered OSE invariably associated with a cohort of PF during estrus stage in control ovary were increased to 5-8 regions after PMSG treatment. This was associated with an increase in pluripotent transcripts (Oct-4A, Nanog), meiosis (Scp-3) and germ cells (Oct-4B, Mvh) specific markers. MVH showed positive immuno staining on germ cell nest-like clusters and at places primordial follicles appeared connected through oocytes. Conclusions: The results of the present study show that gonadotropin (PMSG) treatment to adult mouse leads to increased pluripotent stem cell activity in the ovaries, associated with increased meiosis, appearance of several cohorts of PF and their assembly in close proximity of OSE. This was found associated with the presence of germ cell nests and cytoplasmic continuity of oocytes in PF. We have earlier reported that pluripotent ovarian stem cells in the adult mammalian ovary are the VSELs which give rise to slightly differentiated OGSCs. Thus we propose that gonadotropin through its action on pluripotent VSELs augments neo-oogenesis and PF assembly in adult mouse ovaries.
Gonadotropin treatment augments postnatal cell nests and cytoplasmic continuity of oocytes in PF.... more Gonadotropin treatment augments postnatal cell nests and cytoplasmic continuity of oocytes in PF. We have earlier reported that pluripotent ovarian stem cells in the adult mammalian ovary are the VSELs which give rise to slightly differentiated OGSCs. Thus we propose that
Journal of Cancer Stem Cell Research, Feb 27, 2015
It has been proposed that established cell lines contain populations of cancer stem cells (CSCs),... more It has been proposed that established cell lines contain populations of cancer stem cells (CSCs), which are responsible for expansion of these cell lines and their metastatic potential. To address this issue better, we employed a human ovarian cancer cell line, A2780, and sorted cells according to the postulated highly mestatatic cancer stem cell phenotype, CD24+CD44-, and the less-metastatic CD24-CD44+ and CD24-CD44- phenotypes. These cells were employed in chemotaxis assays in vitro to migrate in response to conditioned media harvested from bone marrow or liver cells damaged by irradiation and in in vivo assays to grow tumors after injection into immunodeficient mice. We also sorted single cells expressing all three phenotypes by FACS and expanded them to grow clones. We found that the CD24+CD44- cells are a highly migratory population compared with CD24-CD44+ and CD24-CD44- cells and were seeded in higher numbers in murine bone marrow and liver after intravenous injection. Most i...
Background. There are well-known side effects of chemotherapy and radiotherapy that are mainly re... more Background. There are well-known side effects of chemotherapy and radiotherapy that are mainly related to the toxicity and impaired function of vital organs; however, the induction by these therapies of expression of several pro-metastatic factors in various tissues and organs that in toto create a pro-metastatic microenvironment is still, surprisingly, not widely acknowledged. On the other hand, it is very well known that, after infusion into a host after myeloablative treatment by radio-chemotherapy, HSPCs home efficiently to BM in response to several chemotactic factors upregulated in the BM microenvironment. Hypothesis . To explain this phenomenon, we hypothesized that toxic damage in BM and other organs due to radio and/or chemotherapy administered for treatment of malignancies leads to upregulation in “bystander” tissues of several factors, such as chemokines, growth factors, bioactive phosphosphingolipids, and small- molecule alarmines, that attract normal circulating stem ce...
Background: Mesenchymal stromal cells (MSCs) play an important role in bone marrow (BM) by provid... more Background: Mesenchymal stromal cells (MSCs) play an important role in bone marrow (BM) by providing a supportive microenvironment for hematopoietic stem/progenitor cells (HSPCs). MSCs are also employed in organ regeneration as a rich source of several paracrine signals that inhibit apoptosis and promote angiogenesis in damaged tissues. As reported in the literature, several mediators, including a growth factor (HGF), a chemokine (SDF-1), bioactive lipids (S1P, C1P), and extracellular nucleotides (ATP, UTP), affect MSC biology and migration. In parallel, evidence has accumulated that the most primitive mesodermal precursors of MSCs (small BM-residing and peripheral blood (PB)-circulating Sca-1+Lin–CD45– cells in mice and CD133+Lin–CD45– cells in humans) express certain embryonic stem cell markers, such as the transcription factor Oct-4 and the SSEA-1/4 antigens (Stem Cells Dev. 2014;23:689-701), and also express several genes characteristic of migrating primordial germ cells (Leukem...
Ovarian cancer is a highly aggressive and deadly disease. Currently, the treatment for ovarian ca... more Ovarian cancer is a highly aggressive and deadly disease. Currently, the treatment for ovarian cancer entails cytoreductive surgery followed by chemotherapy, mainly cisplatin or carboplatin combined with paclitaxel. Although this regimen is initially effective in a high percentage of cases, unfortunately, after few months of initial treatment, tumor relapse occurs due to platinum-resistance. DOXIL (liposomal preparation of doxorubicin) is a choice of drug for recurrent ovarian cancer. However, its response rate is very low and is accompanied by myocardial toxicity. Resistance to chemotherapy and recurrence of cancer is primarily attributed to the presence of cancer stem cells (CSCs), a small population of cells present in cancer. Effect of DOXIL and withaferin A (WFA), both alone and in combination, was investigated on cell proliferation of ovarian cancer cell line A2780 and tumor growth in SCID mice bearing i.p. ovarian tumors. ALDH1 cells were isolated from A2780 using cell sorter...
Background: The existence in adult tissues of developmentally early stem cells with broader speci... more Background: The existence in adult tissues of developmentally early stem cells with broader specification potential may suggest the presence of embryonic primordial germ cell (PGC) remnants in post-natal organs. To support this small, quiescent stem cells (VSELs) that express several markers of PGCs reside in adult murine bone marrow (BM) (Leukemia 2010;24:1450), and like PGCs, are kept quiescent by erasure of imprinting on paternally imprinted genes (Leukemia 2009;23:2042). As reported hematopoietic stem/progenitor cells (HSPCs) can become specified from a population of migrating PGCs isolated from embryos (Blood 1995;86:463) as well as from adult bone marrow VSELs (Leukemia 2011;25,1278). In support of this intriguing possibility, HSPCs and PGCs are both highly migratory populations of stem cells, and specification of the first primitive HSPCs in yolk sac blood islands as well as the origin of definitive HSPCs in the aorta-gonado-mesonephros region are chronologically and anatomically correlated with the developmental migration of PGCs in extra- and intra-embryonic tissues on their way to the genital ridges. Hypothesis: Based on these observations, we have hypothesized that PGC-derived cells as well as HSPCs share some common receptors, and we tested the expression of gonadotropic hormone receptors (GHR) and erythropoietin receptor (EpoR) on HSPCs and PGC-derived cells, respectively. Materials and Methods. We employed RT-PCR studies to evaluate the expression of GHR on normal and malignant HSPCs, whereas we evaluated the expression of EpoR on teratocarcinoma and ovarian cancer cell lines. The functionality of these receptors was tested by chemotaxis, adhesion, and proliferation assays, and we performed signal transduction studies employing specific ligands for gonadal receptors to stimulate HSPCs and erythropoietin (EPO) to stimulate germline-derived cells. Results. We observed the expression of functional FSH, LH, PRL, estrogen, and androgen receptors on normal murine and human HSPCs and in leukemia cell lines. At the same time, we observed the presence of functional EpoRs on murine and human teratocarcinoma cells and ovarian cancer cell lines. Conclusions. Our data provide further evidence for the existence of a developmental link between germline and hematopoiesis and shed new light on the developmental hierarchy of the stem cell compartment in adult tissues and possibility that some malignancies may develop from embryonic remnants. These observations also have important practical implications: i) pituitary gonadal hormones could be employed in selected cases of BM failure to stimulate hematopoiesis and ii) EPO treatment (e.g., because of anemia after chemotherapy) should be avoided in patients with germline malignancies. Citation Format: Malwina Suszynska, Katarzyna Mierzejewska, Agata Poniewierska-Baran, Ahmed Abdelbasit Ismail, Gabriela Schneider, Pranesh Gunjal, Janina Ratajczak, Sham S. Kakar, Magda Kucia, Mariusz Z. Ratajczak. Embryonic rest hypothesis of cancer development revisited: functional gonadotropic hormone receptors are expressed by normal and malignant hematopoietic cells and functional erythropoietin receptor is expressed by germline-derived tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4072. doi:10.1158/1538-7445.AM2015-4072
Background: One of side effects of chemotherapy and radiotherapy is the induction of several fact... more Background: One of side effects of chemotherapy and radiotherapy is the induction of several factors in various tissues and organs that create a pro-metastatic microenvironment for cancer cells that survive initial treatment. Methods: In the present study, we employed human ovarian cancer cell line A2780 and immunodeficient mice xenogrfat model to test effect of both ibuprofen and dexamethasone to ameliorate the therapy-induced pro-metastatic microenvironment in bone marrow, liver, and lung. Results: In our studies, we found that total body irradiation or administration of cisplatin increases the metastatic spread of human ovarian cancer cells transplanted into immunodeficient mice compared with animals unexposed to irradiation or cisplatin. Moreover, conditioned media harvested from irradiated murine bone marrow, lung, and liver chemoattracted human ovarian cancer cells, and this chemotactic activity was inactivated by heat, suggesting a major involvement of peptide or peptide-bound chemoattractants. We also observed that human ovarian cancer cells proliferate better if exposed to cell debris harvested from irradiated murine bone marrow. Finally, the pro-metastatic microenvironment in mice induced by radio-or chemotherapy was significantly ameliorated if animals were treated at the time of radiotherapy administration with non-steroid (ibuprofen) or steroid (prednisone) anti-inflammatory drugs. Conclusions: In summary, we propose that a radiochemotherapy-induced, pro-metastatic microenvironment plays an important role in the metastasis of cancer cells that are resistant to treatment. Such cells have characteristics of cancer stem cells and are highly migratory, and simple, intensive, anti-inflammatory treatment by non-steroid agents to suppress induction of pro-metastatic factors after radiochemotherapy would be an interesting anti-metastatic treatment alternative.
Background We have earlier reported that follicle stimulating hormone (FSH) modulates ovarian ste... more Background We have earlier reported that follicle stimulating hormone (FSH) modulates ovarian stem cells which include pluripotent, very small embryonic-like stem cells (VSELs) and their immediate descendants ‘progenitors’ termed ovarian germ stem cells (OGSCs), lodged in adult mammalian ovarian surface epithelium (OSE). FSH may exert pleiotropic actions through its alternatively spliced receptor isoforms. Four isoforms of FSH receptors (FSHR) are reported in literature of which FSH-R1 and FSH-R3 have biological activity. Present study was undertaken to identify FSHR isoforms mediating FSH action on ovarian stem cells, using sheep OSE cells culture as the study model. Methods Cultures of sheep OSE cells (a mix of epithelial cells, VSELs, OGSCs and few contaminating red blood cells) were established with and without FSH 5IU/ml treatment. Effect of FSH treatment on self-renewal of VSELs and their differentiation into OGSCs was studied after 15 hrs by qRT-PCR using markers specific for...
It has been proposed that established cell lines contain populations of cancer stem cells (CSCs),... more It has been proposed that established cell lines contain populations of cancer stem cells (CSCs), which are responsible for expansion of these cell lines and their metastatic potential. To address this issue better, we employed a human ovarian cancer cell line, A2780, and sorted cells according to the postulated highly mestatatic cancer stem cell phenotype, CD24 C CD44 À , and the less-metastatic CD24 À CD44 C and CD24 À CD44 À phenotypes. These cells were employed in chemotaxis assays in vitro to migrate in response to conditioned media harvested from bone marrow or liver cells damaged by irradiation and in in vivo assays to grow tumors after injection into immunodeficient mice. We also sorted single cells expressing all three phenotypes by FACS and expanded them to grow clones. We found that the CD24 C CD44 À cells are a highly migratory population compared with CD24 À CD44 C and CD24 À CD44 À cells and were seeded in higher numbers in murine bone marrow and liver after intravenous injection. Most importantly, we observed that singly sorted cells efficiently expanded ex vivo into cell populations that represented all phenotypes of the parental cell line. Thus, our data indicate that cells expressing a certain set of markers, e.g., CD24, have at any given moment a higher potential to migrate and metastasize. However, cells that are CD24-negative, if expanded from a singly sorted cell, may give rise to cells containing all of the markers, including CD24. Based on this finding, we propose that the CSC phenotype in cell lines fluctuates with cell expansion.
Endometrium undergoes dramatic growth, breakdown and regeneration throughout reproductive period ... more Endometrium undergoes dramatic growth, breakdown and regeneration throughout reproductive period in mammals. Stem cells have been implicated in the process however their origin, nature, anatomical localization and characterization still remain obscure. Classical concept of presence of stem cells in the basal layer of endometrium was recently challenged when side population and label retaining cells were found to be distributed throughout endometrium. We have earlier reported very small embryonic-like stem cells (VSELs) in adult mammalian ovary and testis as a small population of cells with nuclear OCT-4 along with progenitors (spermatogonial stem cells and ovarian germ stem cells) with cytoplasmic OCT-4. Present study was undertaken to gauge presence of VSELs in bilaterally ovariectomized mouse uterus and their modulation by hormones. Bilaterally ovariectomized mice were subjected to sequential estradiol and progesterone treatment in order to induce proliferation, differentiation an...
Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare popula... more Background: Expressing several markers of migrating primordial germ cells (PGCs), the rare population of quiescent, bone marrow (BM)-residing very small embryonic-like stem cells (VSELs) can be specified like PGCs into hematopoietic stem/progenitor cells (HSPCs). These two properties of VSELs support the possibility of a developmental origin of HSPCs from migrating PGCs. Methods: To address a potential link between VSELs and germ line cells we analyzed by RT-PCR and FACS expression of erythropoietin receptor (EpoR) on murine bone marrow-and human umbilical cord blood-derived VSELs, murine and human teratocarcinoma cell lines and human ovarian cancer cells. A proper gating strategy and immunostaining excluded from FACS analysis potential contamination by erythroblasts. Furthermore, the transwell chemotaxis assays as well as adhesion and signaling studies were performed to demonstrate functionality of erythropoietin -EpoR axes on these cells. Results: We report here that murine and human VSELs as well as murine and human teratocarcinoma cell lines and ovarian cancer cell lines share a functional EpoR.
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Papers by Pranesh Gunjal