The apoptotic effects of progesterone on breast cancer (MCF-7) and human osteosarcoma (MG-636) cells

Antitumor progestins activity: Cytostatic effect and immune response

Progestins are used to treat some hormone-sensitive tumors. This review discusses the mechanisms of progestins' effects on tumor cells, the differences in the effects of progesterone and its analogs on different tumor types, and the influence of progestins on the antitumor immune response. Progestins cause a cytostatic effect, but at the same time they can suppress the antitumor immune response, and this can promote the proliferation and metastasis of tumor cells. Such progestins as dienogest, megestrol acetate and levonorgestrel increase the activity of NK-cells, which play a major role in the body's fight against tumor cells. The use of existing progestins and the development of new drugs with gestagenic activity may hold promise in oncotherapy.

Anti-cancer activity, and molecular docking of novel hybrid heterocyclic steroids revealed promising anti-hepatocellular carcinoma agent: Implication of cyclin dependent kinase-2 pathway

To identify new steroidal agents with potential biological activities, we synthesized hybrid steroids containing thiazole, pyrazole, isoxazole, thiophene or phthalazine moiety. Epi-androsterone 1 reacted with phenylthiosemicarbazide to afford the corresponding androstane-4-phenyl-3-thiosemicarbazone derivative 2. The latter product was used in the synthesis of a series of annulated steroid derivatives. Also, Epi-androsterone 1 reacted with the thienopyridazine derivative 16 to afford the thieno[3,4-d]pyridazino-N-ylidenoandrostane derivative 17. Compound 17 reacted readily with electron-poor olefins to yield the corresponding phthalazine steroid derivatives. Detailed experimental and spectroscopic evidences for the structures of the newly synthesized compounds are explained. Compounds 3, 7, 8a, 12a, 14, 17 and 21a, were investigated individually as anticancer agents on different panel of human malignant cell lines. Moreover, a computer modelling investigation was performed to speculate the macromolecular targets for the most promising candidate. The results revealed a concentration-dependent reduction in the number of viable cells in all cancer cell lines. Most notably, compound 7 was the most effective compound against all tested cancer cell lines, especially against HepG2 cell line; therefore, the mode of action of this compound against HCC was investigated. Compound 7 was able to induce cell cycle arrest, and DNA fragmentation in HepG2 cells. Moreover, compound 7 induced apoptosis via upregulating the expression of caspase-3, -8, -9, P53, Bax and inhibiting the expression of BCL2, and CDK2 genes. Our results highlighted compound 7 as a promising anti-hepatocellular carcinoma agent, with theoretical, and practical potential binding affinity with CDK2; therefore, more investigations are required to elucidate its chemotherapeutic value as anti-HCC agent.

Preclinical Evidence of Progesterone as a New Pharmacological Strategy in Human Adrenocortical Carcinoma Cell Lines

BACKGROUND

Adrenocortical cancer (ACC) is a rare malignancy with a dismal prognosis. The treatment includes mitotane and EDP chemotherapy (etoposide, doxorubicin, and cisplatin). However, new therapeutic approaches for advanced ACC are needed, particularly targeting the metastatic process. Here, we deepen the role of progesterone as a new potential drug for ACC, in line with its antitumoral effect in other cancers.

METHODS

NCI-H295R, MUC-1, and TVBF-7 cell lines were used and xenografted in zebrafish embryos. Migration and invasion were studied using transwell assays, and MMP2 activity was studied using zymography. Apoptosis and cell cycle were analyzed by flow cytometry.

RESULTS

Progesterone significantly reduced xenograft tumor area and metastases formation in embryos injected with metastatic lines, MUC-1 and TVBF-7. These results were confirmed in vitro, where the reduction of invasion was mediated, at least in part, by the decrease in MMP2 levels. Progesterone exerted a long-lasting effect in metastatic cells. Progesterone caused apoptosis in NCI-H295R and MUC-1, inducing changes in the cell-cycle distribution, while autophagy was predominantly activated in TVBF-7 cells.

CONCLUSION

Our results give support to the role of progesterone in ACC. The involvement of its analog (megestrol acetate) in reducing ACC progression in ACC patients undergoing EDP-M therapy is now under investigation in the PESETA phase II clinical study.

A New Role of Acute Phase Proteins: Local Production Is an Ancient, General Stress-Response System of Mammalian Cells

The prevailing general view of acute-phase proteins (APPs) is that they are produced by the liver in response to the stress of the body as part of a systemic acute-phase response. We demonstrated a coordinated, local production of these proteins upon cell stress by the stressed cells. The local, stress-induced APP production has been demonstrated in different tissues (kidney, breast cancer) and with different stressors (hypoxia, fibrosis and electromagnetic heat). Thus, this local acute-phase response (APR) seems to be a universal mechanism. APP production is an ancient defense mechanism observed in nematodes and fruit flies as well. Local APP production at the tissue level is also supported by sporadic literature data for single proteins; however, the complex, coordinated, local appearance of this stress response has been first demonstrated only recently. Although a number of literature data are available for the local production of single acute-phase proteins, their interpretation as a local, coordinated stress response is new. A better understanding of the role of APPs in cellular stress response may also be of diagnostic/prognostic and therapeutic significance.

Cytotoxic Effect of Progesterone, Tamoxifen and Their Combination in Experimental Cell Models of Human Adrenocortical Cancer

Progesterone (Pg) and estrogen (E) receptors (PgRs and ERs) are expressed in normal and neoplastic adrenal cortex, but their role is not fully understood. In literature, Pg demonstrated cytotoxic activity on AdrenoCortical Carcinoma (ACC) cells, while tamoxifen is cytotoxic in NCI-H295R cells. Here, we demonstrated that in ACC cell models, ERs were expressed in NCI-H295R cells with a prevalence of ER-β over the ER-α.Metastasis-derived MUC-1 and ACC115m cells displayed a very weak ER-α/β signal, while PgR cells were expressed, although at low level. Accordingly, these latter were resistant to the SERM tamoxifen and scarcely sensitive to Pg, as we observed a lower potency compared to NCI-H295R cells in cytotoxicity (IC50: MUC-1 cells: 67.58 µM (95%CI: 63.22-73.04), ACC115m cells: 51.76 µM (95%CI: 46.45-57.67) and cell proliferation rate. Exposure of NCI-H295R cells to tamoxifen induced cytotoxicity (IC50: 5.43 µM (95%CI: 5.18-5.69 µM) mainly involving ER-β, as their nuclear localization increased after tamoxifen: Δ A.U. treated vs untreated: 12 h: +27.04% (p < 0.01); 24 h: +36.46% (p < 0.0001). This effect involved the SF-1 protein reduction: Pg: -36.34 ± 9.26%; tamoxifen: -46.25 ± 15.68% (p < 0.01). Finally, in a cohort of 36 ACC samples, immunohistochemistry showed undetectable/low level of ERs, while PgR demonstrated a higher expression. In conclusion, ACC experimental cell models expressed PgR and low levels of ER in line with data obtained in patient tissues, thus limiting the possibility of a clinical approach targeting ER. Interestingly, Pg exerted cytotoxicity also in metastatic ACC cells, although with low potency.