Human recombinant FSH induces chemoresistance in human breast cancer cells via HIF-1α activation†.

Breast cancer patients under 40 years of age who are candidate to chemotherapy with alkylating drugs may undergo controlled ovarian stimulation (COS) with recombinant human follicle-stimulating hormone (rhFSH) in order to get fertility preservation by mature oocyte cryostorage. The direct effect(s) of exogenous rhFSH on the chemosensitivity of breast cancer is currently unknown. To clarify this issue, we incubated four different breast cancer cell lines with rhFSH (10 IU/L, 24 h) and then we exposed them to doxorubicin (DOX) or cyclophosphamide (CPA). The effect(s) of rhFSH on human breast cancer cells treated with DOX or CPA was measured in terms of (1) cell viability, (2) cytotoxicity, (3) multidrug resistance (MDR) genes and proteins expression and activities, and (4) hypoxia-inducible factor 1-alpha (HIF-1α) activation. Pretreatment with rhFSH significantly increased the viability of breast cancer cells after treatment with DOX or CPA, and reduced the lactate dehydrogenase leakage and reactive oxygen species production. Moreover, after preincubation with rhFSH, the MDR proteins (Pgp, MPR1, and BCRP) expression and activity resulted upregulated and the HIF-1α pathway activated. In addition, the use of a widely used HIF-1α inhibitor, the 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), prevented the rhFSH effect on the onset of MDR. Taken together, these observations suggest that a short exposure to rhFSH induces chemoresistance to DOX and CPA in human breast cancer cells via HIF-1α activation.

Angiogenic properties of endometrial mesenchymal stromal cells in endothelial co-culture: an in vitro model of endometriosis.

Study Question: Can endometrial mesenchymal stromal cells (E-MSCs) differentiate into endothelial cells in an in vitro co-culture system with human umbilical vein endothelial cells (HUVECs)? Summary Answer: E-MSCs can acquire endothelial markers and function in a direct co-culture system with HUVECs. What is Known Already: E-MSCs have been identified in the human endometrium as well as in endometriotic lesions. E-MSCs appear to be involved in formation of the endometrial stromal vascular tissue and the support of tissue growth and vascularization. The use of anti-angiogenic drugs appears as a possible therapeutic strategy against endometriosis. Study Design, Size, Duration: This is an in vitro study comprising patients receiving surgical treatment of ovarian endometriosis (n = 9). Participants/Materials, Setting, Methods: E-MSCs were isolated from eutopic and ectopic endometrial tissue and were characterized for the expression of mesenchymal and endothelial markers by FACS analysis and Real-Time PCR. CD31 acquisition was evaluated by FACS analysis and immunofluorescence after a 48 h-direct co-culture with green fluorescent protein +-HUVECs. A tube-forming assay was set up in order to analyze the functional potential of their interaction. Finally, co-cultures were treated with the anti-angiogenic agent Cabergoline. Main Results and the Role of Chance: A subpopulation of E-MSCs acquired CD31 expression and integrated into tube-like structures when directly in contact with HUVECs, as observed by both FACS analysis and immunofluorescence. The isolation of CD31+ E-MSCs revealed significant increases in CD31, vascular endothelial growth factor receptor 2, TEK receptor tyrosine kinase and vascular endothelial-Cadherin mRNA expression levels with respect to basal and to CD31neg cells (P < 0.05). On the other hand, the expression of mesenchymal genes such as c-Myc, Vimentin, neuronal-Cadherin and sushi domain containing 2 remained unchanged. Cabergoline treatment induced a significant reduction of the E-MSC angiogenic potential (P < 0.05 versus control). Large Scale Data: Not applicable. Limitations, Reasons for Caution: Further studies are necessary to investigate the cellular and molecular mechanisms underlying the endothelial cell differentiation. Wider Implications of the Findings: E-MSCs may undergo endothelial differentiation, and be potentially involved in the development of endometriotic implants. Cell culture systems that more closely mimic the cellular complexity typical of endometriotic tissues in vivo are required to develop novel strategies for treatment. Study Funding/Competing Interest(s): This study was supported by the 'Research Fund ex-60%', University of Turin, Turin, Italy. All authors declare that their participation in the study did not involve actual or potential conflicts of interests.

Endometrial adult/progenitor stem cells: pathogenetic theory and new antiangiogenic approach for endometriosis therapy.

The cyclical arrival of endometrial cells into the abdominal cavity through retrograde flux at menstruation represents the etiopathogenetic basis of endometriosis. The endometrium has peculiar regenerative properties linked to the presence of adult stem cells similar to mesenchymal stem cells (MSCs). Once in the abdominal cavity, these MSCs could proliferate, invade, and differentiate into endometrial cells, finally generating ectopic implants. As only differentiated endometrial cells, and not endometrial MSCs, possess steroid hormone receptors, MSCs could be responsible for the high rate of persistence/recurrence of the disease after hypoestrogenism-inducing therapies. Even angiogenesis promoted by MSCs could play an important role, as survival and proliferation of endometriotic tissue depend on the formation of new blood vessels. Inhibition of angiogenesis represents, in fact, a new, promising therapeutic approach for the disease. Further, medications directly targeting endometriosis MSCs could be effective, alone or in association with hormonal treatments, in increasing the success of medical treatment.