JAK-STAT signalling controls cancer stem cell properties including chemotherapy resistance in myxoid liposarcoma.

Myxoid liposarcoma (MLS) shows extensive intratumoural heterogeneity with distinct subpopulations of tumour cells. Despite improved survival of MLS patients, existing therapies have shortcomings as they fail to target all tumour cells. The nature of chemotherapy-resistant cells in MLS remains unknown. Here, we show that MLS cell lines contained subpopulations of cells that can form spheres, efflux Hoechst dye and resist doxorubicin, all properties attributed to cancer stem cells (CSCs). By single-cell gene expression, western blot, phospho-kinase array, immunoprecipitation, immunohistochemistry, flow cytometry and microarray analysis we showed that a subset of MLS cells expressed JAK-STAT genes with active signalling. JAK1/2 inhibition via ruxolitinib decreased, while stimulation with LIF increased, phosphorylation of STAT3 and the number of cells with CSC properties indicating that JAK-STAT signalling controlled the number of cells with CSC features. We also show that phosphorylated STAT3 interacted with the SWI/SNF complex. We conclude that MLS contains JAK-STAT-regulated subpopulations of cells with CSC features. Combined doxorubicin and ruxolitinib treatment targeted both proliferating cells as well as cells with CSC features, providing new means to circumvent chemotherapy resistance in treatment of MLS patients.

Long-Term Oocyte-Like Cell Development in Cultures Derived from Neonatal Marmoset Monkey Ovary.

We use the common marmoset monkey (Callithrix jacchus) as a preclinical nonhuman primate model to study reproductive and stem cell biology. The neonatal marmoset monkey ovary contains numerous primitive premeiotic germ cells (oogonia) expressing pluripotent stem cell markers including OCT4A (POU5F1). This is a peculiarity compared to neonatal human and rodent ovaries. Here, we aimed at culturing marmoset oogonia from neonatal ovaries. We established a culture system being stable for more than 20 passages and 5 months. Importantly, comparative transcriptome analysis of the cultured cells with neonatal ovary, embryonic stem cells, and fibroblasts revealed a lack of germ cell and pluripotency genes indicating the complete loss of oogonia upon initiation of the culture. From passage 4 onwards, however, the cultured cells produced large spherical, free-floating cells resembling oocyte-like cells (OLCs). OLCs strongly expressed several germ cell genes and may derive from the ovarian surface epithelium. In summary, our novel primate ovarian cell culture initially lacked detectable germ cells but then produced OLCs over a long period of time. This culture system may allow a deeper analysis of early phases of female primate germ cell development and-after significant refinement-possibly also the production of monkey oocytes.

Mesenchymal stem cells repair germinal cells of seminiferous tubules of sterile rats.

BACKGROUND: Mesenchymal stem cells (MSCs) are undifferentiated cells that can differentiate and divide to other cell types. Transplantation of these cells to the different organs is used for curing various diseases. OBJECTIVE: The aim of this research was whether MSCs transplantation could treat the sterile testes. MATERIALS AND METHODS: In this experimental study, Donor MSCs were isolated from bone marrow of Wistar rats. The recipients were received 40 mg/kg of busulfan to stop endogenous spermatogenesis. The MSCs were injected into the left testes. Cell tracing was done by labeling the MSCs by 5-Bromo-2- Deoxy Uridine (BrdU). The immunohistochemical and morphometrical studies were performed to analysis the curing criteria. RESULTS: The number of spermatogonia (25.38±1.57), primary spermatocytes (55.41±1.62) and spermatozoids (4.95±1.30)×10(6) in busulfan treated animals were decreased significantly as compared to the control group (33.35±1.78, 64.44±2.00) and (10.50±1.82)×10(6) respectively but stem cells therapy help the spermatogenesis begin more effective in these animals (32.78±1.99, 63.59±2.01) and (9.81±1.33)×10(6) respectively than the control group. The injected BrdU labeled mesenchymal stem cells differentiated to spermatogonia and spermatozoa in the seminiferous tubules of the infertile testis and also to the interstitial cells between tubules. CONCLUSION: We concluded that testis of host infertile rats accepted transplanted MSCs. The transplanted MSCs could differentiate into germinal cells in testicular seminiferous tubules. This article extracted from M.Sc. Thesis. (Bentolhoda Fereydouni).