Membrane-receptor initiated proliferative effects of dienogest in human breast cancer 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.

Microfluidics-derived hierarchical microparticles for the delivery of dienogest for localized endometriosis therapy

Drug therapy is one of the most important strategies for treating gynecological diseases. Local drug delivery is promising for achieving optimal regional drug exposure, considering the complex anatomy and dynamic environment of the upper genital tract. Here, we present microparticle-based microcarriers with a hierarchical structure for localized dienogest (DNG) delivery and endometriosis treatment. The microparticles were fabricated by microfluidics and consisted of photo-crosslinked bovine serum albumin hydrogel particles (D@P-B MPs) encapsulating DNG-loaded PLGA (poly lactic-co-glycolic acid) microspheres. Such design enables the microparticles to have sustained release capacity and cell adhesion ability. Based on this, the microparticles were applied for the treatment of peritoneal endometriosis through intraperitoneal injection. The performance of the microparticles in inhibiting the growth of ectopic lesions as well as their anti-inflammatory, anti-angiogenesis, and pelvic pain-relieving effects are well demonstrated in vivo. These findings indicate that the present hierarchical microparticles are good candidates for localized treatment of endometriosis and are promising for the management of gynecological diseases. STATEMENT OF SIGNIFICANCE: We prepared photo-crosslinked bovine serum albumin hydrogel particles (D@P-B MPs) encapsulating DNG-loaded PLGA microspheres using microfluidic electrospray. Such hierarchical structure provided multiple functions of the particles as drug carriers. The hierarchical microparticles not only supported the sustained release of drugs but also provided adhesion to human ectopic endometrial stromal cells. The hierarchical microparticles represented a localized treatment method for endometriosis and is promising for the management of gynecological diseases.

Effects of Dienogest on breasts of women of reproductive age and women in menopausal transition: A cohort study

Dienogest appears not to have any adverse breast effects on women of reproductive age.

Progesterone Receptor Membrane Component (PGRMC)1 and PGRMC2 and Their Roles in Ovarian and Endometrial Cancer

Cancers of the female reproductive tract are both lethal and highly prevalent. For example, the five-year survival rate of women diagnosed with ovarian cancer is still less than 50%, and endometrial cancer is the fourth most common cancer in women with > 65,000 new cases in the United States in 2020. Among the many genes already established as key participants in ovarian and endometrial oncogenesis, progesterone receptor membrane component (PGRMC)1 and PGRMC2 have gained recent attention given that there is now solid correlative information supporting a role for at least PGRMC1 in enhancing tumor growth and chemoresistance. The expression of PGRMC1 is significantly increased in both ovarian and endometrial cancers, similar to that reported in other cancer types. Xenograft studies using human ovarian and endometrial cancer cell lines in immunocompromised mice demonstrate that reduced expression of PGRMC1 results in tumors that grow substantially slower. While the molecular underpinnings of PGRMCs' mechanisms of action are not clearly established, it is known that PGRMCs regulate survival pathways that attenuate stress-induced cell death. The objective of this review is to provide an overview of what is known about the roles that PGRMC1 and PGRMC2 play in ovarian and endometrial cancers, particularly as related to the mechanisms through which they regulate mitosis, apoptosis, chemoresistance, and cell migration.

Solving the Puzzle: What Is the Role of Progestogens in Neovascularization?

Ovarian sex steroids can modulate new vessel formation and development, and the clarification of the underlying mechanism will provide insight into neovascularization-related physiological changes and pathological conditions. Unlike estrogen, which mainly promotes neovascularization through activating classic post-receptor signaling pathways, progesterone (P4) regulates a variety of downstream factors with angiogenic or antiangiogenic effects, exerting various influences on neovascularization. Furthermore, diverse progestins, the synthetic progesterone receptor (PR) agonists structurally related to P4, have been used in numerous studies, which could contribute to unequal actions. As a result, there have been many conflicting observations in the past, making it difficult for researchers to define the exact role of progestogens (PR agonists including naturally occurring P4 and synthetic progestins). This review summarizes available evidence for progestogen-mediated neovascularization under physiological and pathological circumstances, and attempts to elaborate their functional characteristics and regulatory patterns from a comprehensive perspective.

Crosstalk between progesterone receptor membrane component 1 and estrogen receptor α promotes breast cancer cell proliferation

Progesterone (P4) and estradiol (E2) have been shown to stimulate and regulate breast cancer proliferation via classical nuclear receptor signaling through progesterone receptor (PR) and estrogen receptor α (ERα), respectively. However, the basis of communication between PR/ERα and membrane receptors remains largely unknown. Here, we aim to identify classical and nonclassical endocrine signaling mechanisms that can alter cell proliferation through a possible crosstalk between PR, ERα, and progesterone receptor membrane component 1 (PGRMC1), a membrane receptor frequently observed in breast cancer cells. While P4 and E2 treatment increased cell proliferation of ER+/PR+/PGRMC1 overexpressing breast cancer cells, silencing ERα and PR or treatment with selective estrogen receptor modulator (SERM) tamoxifen, or (PR-antagonist) RU-486 decreased cell proliferation. All four treatments rapidly altered PGRMC1 mRNA levels and protein expression. Furthermore, P4 and E2 treatments rapidly activated EGFR a known interacting partner of PGRMC1 and its downstream signaling. Interestingly, downregulation of ERα by tamoxifen and ERα silencing decreased the expression levels of PGRMC1 with no repercussions to PR expression. Strikingly PGRMC1 silencing decreased ERα expression irrespective of PR. METABRIC and TCGA datasets further demonstrated that PGRMC1 expression was comparable to that of ERα in Luminal A and B breast cancers. Targeting of PR, ERα, and PGRMC1 confirmed that a crosstalk between classical and nonclassical signaling mechanisms exists in ER+ breast cancer cells that could enhance the growth of ER+/PR+/PGRMC1 overexpressing tumors.

Association of circulating Progesterone Receptor Membrane Component-1 (PGRMC1) with breast tumor characteristics and comparison with known tumor markers

OBJECTIVES

Progesterone receptor membrane component-1 (PGRMC1) expressed in breast cancer tissue has been suggested to predict a worse prognosis. The aim of this study was to assess for the first time if blood concentrations of PGRMC1 are also associated with receptor status, tumor diameter, grading, and lymphatic status. The second aim was comparison with known tumor markers.

METHODS

A total of 372 women, including 278 patients with invasive breast cancer, 65 with benign breast disease, and 29 healthy women (control), were recruited. PGRMC1 blood concentrations were measured by a recently developed enzyme-linked immunosorbant assay, and were correlated to predictive tumor characteristics and compared with serum carcinoembryonic antigen (CEA), CA125, and CA153.

RESULTS

PGRMC1 levels in the cancer group were significantly higher than in the control and benign group and increased with higher cancer stages (P < 0.05). PGRMC1 concentrations in the estrogen receptor (ER)+/progesterone receptor (PR)+ group were higher than in the ER-/PR- group, related to larger tumor diameter and the presence of lymph node metastasis (P < 0.05). Multivariable linear regression analysis was used to control the confounding factors. Tumor diameter, lymphatic metastasis, and ER (but not PR) were positively associated with PGRMC1 (P < 0.05). The receiver-operating characteristic curve (ROC) analysis was used to assess area under the curve (AUC). AUC was 87.9% for stages III+IV and 80.8% for stages I+II (P < 0.01). ROC did not find significant effects on AUC for CA125, only significant for CEA and CA153 for stages III+IV.

CONCLUSION

As PGRMC1 levels are positively associated with breast tumor characteristics known to predict a worse diagnosis, PGRMC1 may be valuable as a new tumor marker, and superior to CEA, C125, and CA153. Because of the positive association with ER-expression, PGRMC1 may interact with this receptor.

PGRMC1 in animal breast cancer tissue and blood is associated with increased tumor growth with norethisterone in contrast to progesterone and dydrogesterone: four-arm randomized placebo-controlled xenograft study

Progesterone receptor membrane component 1 (PGRMC1) is mediating strong breast cancer cell proliferation induced by certain synthetic progestogens which we have shown within already published in vitro studies. Aim was now to use an animal model, to compare tumor growth using progesterone and its isomer dydrogesterone with norethisterone, which elicited in our in vitro studies the strongest proliferating effect. For the first time, we wanted to investigate if growth can be correlated both with blood concentrations and tissue expression of PGRMC1 to identify if PGRMC1 could be a new tumor marker. Prospective, randomized, blinded, placebo-controlled four-arm study (45-50 days); PGRMC1-transfected or empty-vector T47D- and MCF7-xenotransplants were each treated with estradiol (E2) +placebo; E2 + progesterone; E2 + norethisterone; E2 + dydrogesterone; blood PGRMC1 assessed by a novel ELISA, tissue expression by immunohistochemistry. PGRMC1-transfected tumors further increased with E2 + norethisterone but not with E2-dydrogesterone or E2-progesterone. In both PGRMC1-xenograft groups (T47D, MCF7) with E2/norethisterone, the blood concentrations and tissue expression of PGRMC1 were higher than in all other 14 groups (p < .05), with positive significant correlation between blood PGRMCI concentrations and tissue PGRMC1 expression. In the presence of PGRMC1, certain progestogens could increase the growth of breast tumor, which now also should be tested in clinical studies.

Progesterone receptor membrane component 1 regulates lipid homeostasis and drives oncogenic signaling resulting in breast cancer progression

Background

PGRMC1 (progesterone receptor membrane component 1) is a highly conserved heme binding protein, which is overexpressed especially in hormone receptor-positive breast cancer and plays an important role in breast carcinogenesis. Nevertheless, little is known about the mechanisms by which PGRMC1 drives tumor progression. The aim of our study was to investigate the involvement of PGRMC1 in cholesterol metabolism to detect new mechanisms by which PGRMC1 can increase lipid metabolism and alter cancer-related signaling pathways leading to breast cancer progression.

Methods

The effect of PGRMC1 overexpression and silencing on cellular proliferation was examined in vitro and in a xenograft mouse model.

Next, we investigated the interaction of PGRMC1 with enzymes involved in the cholesterol synthesis pathway such as CYP51, FDFT1, and SCD1. Further, the impact of PGRMC1 expression on lipid levels and expression of enzymes involved in lipid homeostasis was examined. Additionally, we assessed the role of PGRMC1 in key cancer-related signaling pathways including EGFR/HER2 and ERα signaling.

Results

Overexpression of PGRMC1 resulted in significantly enhanced proliferation. PGRMC1 interacted with key enzymes of the cholesterol synthesis pathway, alters the expression of proteins, and results in increased lipid levels. PGRMC1 also influenced lipid raft formation leading to altered expression of growth receptors in membranes of breast cancer cells. Analysis of activation of proteins revealed facilitated ERα and EGFR activation and downstream signaling dependent on PGRMC1 overexpression in hormone receptor-positive breast cancer cells. Depletion of cholesterol and fatty acids induced by statins reversed this growth benefit.

Conclusion

PGRMC1 may mediate proliferation and progression of breast cancer cells potentially by altering lipid metabolism and by activating key oncogenic signaling pathways, such as ERα expression and activation, as well as EGFR signaling. Our present study underlines the potential of PGRMC1 as a target for anti-cancer therapy.

PGRMC1 can trigger estrogen-dependent proliferation of breast cancer cells: estradiol vs. equilin vs. ethinylestradiol

Objective: Previous studies have shown that progesterone receptor membrane component 1 (PGRMC1) expressed in breast cancer tissue can predict a worse prognosis for breast cancer patients. Moreover, we demonstrated that PGRMC1 can increase the proliferation of progestogens. However, the role of PGRMC1 in terms of estrogen-induced proliferation and comparing different estrogens is still unclear. Methods: Non-transfected and PGRMC1-transfected T-47D cells were stimulated with estradiol (E2), with equilin (EQ), or with ethinylestradiol (EE) at 1, 10, and 100 nmol/l. Increase of proliferation was compared with a control (without estrogens) and with the estrogen-induced stimulation in empty vector cells vs. PGRMC1-transfected cells. Results: The empty vector cells showed significant proliferation (12-15%) with all three estrogens only at the highest concentration, with no relevant differences between the estrogens. PGRMC1-transfected cells showed about three-fold higher proliferation (29-66%), whereby E2 elicited the strongest and EE the lowest proliferating effects, significantly lower compared to E2 and also compared to EQ. No significant differences were seen between E2 and EQ. Conclusions: PGRMC1 increases strongly the estrogen-dependent breast cell proliferation. The proliferating effects of EE may be lower compared to E2 and EQ. This could have importance in comparing hormone therapy and contraception. Thus, PGRMC1 not only could predict the risk using progestogens but also of different estrogens.

The choice of progestogen for HRT in menopausal women: breast cancer risk is a major issue

Doctors and patients fear the risk of breast cancer when using hormone replacement therapy (HRT). This review focuses on the choice of progestogen for HRT in menopausal. The Women's Health Initiative (WHI) has been the only large double-blind placebo-controlled study testing the risk of breast cancer (BC) using HRT. No increased risk using estrogen (E)-only was seen, there was a significant decrease in mortality due to BC after the use of HRT which persisted during the recent 18-year follow-up of the WHI. In contrast in the combined arm the risk increased. In about 20 observational studies using mostly medroxyprogesterone acetate (MPA) or estradiol-norethisterone acetate (NETA) an increased BC-risk was observed comparable with the WHI. Only for natural progestogen, progesterone and for dydrogesterone (retro-isomer of progesterone) was no increased risk seen for up to 5-8 years, when compared directly with other progestogens, but for longer treatment an increased risk cannot be excluded. In contrast, the mortality due to BC after use of E-only and combined HRT decreased in about a dozen observational studies, and was very recently confirmed in a Finnish study evaluating 490,000 women using estradiol (E2) plus different progestogens. There have been already more than 70 studies evaluating the risk of BC during HRT, and still there are many open questions. Therefore, this review covers our own and other experimental research which could answer important questions. Experimental research has demonstrated that certain synthetic progestogens, but not progesterone and to some extent also not dydrogesterone, can accelerate the proliferation of breast cancer cells in vitro and in animal studies via special cell membrane components which we recently also detected in patients with BC, and we found differences comparing all available synthetic progestogens. Derived from these mechanisms future research may provide screening for patients at risk and predict the prognosis of possible BC.

Membrane-initiated effects of Serelys® on proliferation and apoptosis of human breast cancer cells

Herbal extracts used for the alleviation of postmenopausal symptoms might have a lower risk of breast cancer development than hormone therapy. Serelys^® is a product composed of purified pollen cytoplasm extracts. Recent experimental data revealed that estrogens might trigger a further proliferative effect on breast cancer cells via the progesterone receptor membrane component-1 (PGRMC1) in addition to the proliferative effect via intracellularly located receptors. MCF-7 and T47D cells were stably transfected with PGRMC1. Different concentrations of the extract alone and in combination with fixed concentrations of estradiol or a growth factor mixture were tested. Proliferation of treated cells was determined by the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl-tetrazolium bromide (MTT)-test and apoptosis was determined using a Cell Death Detection ELISA kit (CDD). Serelys^® was neutral in the cell lines transfected or not transfected with PGRMC1. It was also neutral in combination with estradiol or growth factors in terms of cell proliferation and cell apoptosis. Thus in contrast to hormone therapy Serelys^® appears to trigger no further breast cancer risk when applied in the post menopause to women, who do or do not overexpress PGRMC1. Overall Serelys^® may be an effective alternative for alleviating postmenopausal symptoms without increasing breast cancer risk.

Progesterone receptor membrane component 1 as a potential prognostic biomarker for hepatocellular carcinoma

AIM

To investigate the clinicopathological significance of progesterone receptor membrane component 1 (PGRMC1) and PGRMC2 in hepatocellular carcinoma (HCC).

METHODS

We performed immunohistochemical staining to evaluate the estrogen receptor (ER), progesterone receptor (PR), PGRMC1, and PGRMC2 in a clinical cohort consisting of 89 paired HCC and non-tumor liver samples. We also analyzed HCC data (n = 373) from The Cancer Genome Atlas (TCGA). We correlated the expression status of PGRMC1 and PGRMC2 with clinicopathological indicators and the clinical outcomes of the HCC patients. We knocked down or overexpressed PGRMC1 in HCC cell lines to evaluate its biological significance in HCC cell proliferation, differentiation, migration, and invasion.

RESULTS

We found that few HCC cases expressed ER (5.6%) and PR (4.5%). In contrast, most HCC cases expressed PGRMC1 (89.9%) and PGRMC2 (100%). PGRMC1 and PGRMC2 exhibited significantly lower expression in tumor tissue than in non-tumor tissue (P < 0.001). Lower PGRMC1 expression in HCC was significantly associated with higher serum alpha-fetoprotein expression (P = 0.004), poorer tumor differentiation (P = 0.045) and liver capsule penetration (P = 0.038). Low PGRMC1 expression was an independent predictor for worse disease-free survival (P = 0.002, HR = 2.384, CI: 1.377-4.128) in our cases, as well as in the TCGA cohort (P < 0.001, HR = 2.857, CI: 1.781-4.584). The expression of PGRMC2 did not relate to patient outcome. PGRMC1 knockdown promoted a poorly differentiated phenotype and proliferation of HCC cells in vitro, while PGRMC1 overexpression caused the opposite effects.

CONCLUSION

PGRMC1 is a non-classical hormonal receptor that negatively regulates hepatocarcinogenesis. PGRMC1 down-regulation is associated with progression of HCC and is a poor prognostic indicator.

Progesterone receptor membrane component 1 is phosphorylated upon progestin treatment in breast cancer cells

Menopausal hormone therapy, using estrogen and synthetic progestins, is associated with an increased risk of developing breast cancer. The effect of progestins on breast cells is complex and not yet fully understood. In previous in vitro and in vivo studies, we found different progestins to increase the proliferation of Progesterone Receptor Membrane Component-1 (PGRMC1)-overexpressing MCF7 cells (MCF7/PGRMC1), suggesting a possible role of PGRMC1 in transducing membrane-initiated progestin signals.

Understanding the activation mechanism of PGRMC1 by progestins will provide deeper insights into the mode of action of progestins on breast cells and the often-reported phenomenon of elevated breast cancer rates upon progestin-based hormone therapy. In the present study, we aimed to further investigate the effect of progestins on receptor activation in MCF7 and T47D breast cancer cell lines. We report that treatment of both breast cancer cell lines with the progestin norethisterone (NET) induces phosphorylation of PGRMC1 at the Casein Kinase 2 (CK2) phosphorylation site Ser181, which can be decreased by treatment with CK2 inhibitor quinalizarin. Point mutation of the Ser181 phosphorylation site in MCF7/PGRMC1 cells impaired proliferation upon NET treatment. This study gives further insights into the mechanism of differential phosphorylation of the receptor and confirms our earlier hypothesis that phosphorylation of the CK2-binding site is essential for activation of PGRMC1. It further suggests an important role of PGRMC1 in the tumorigenesis and progression of breast cancer in progestin-based hormone replacement therapy.

The emerging role of progesterone receptor membrane component 1 (PGRMC1) in cancer biology

Progesterone receptor membrane component 1 (PGRMC1) is a multi-functional protein with a heme-binding moiety related to that of cytochrome b₅, which is a putative progesterone receptor. The recently solved PGRMC1 structure revealed that heme-binding involves coordination by a tyrosinate ion at Y113, and induces dimerization which is stabilized by hydrophobic stacking of heme on adjacent monomers. Dimerization is required for association with cytochrome P450 (cyP450) enzymes, which mediates chemoresistance to doxorubicin and may be responsible for PGRMC1's anti-apoptotic activity. Here we review the multiple attested involvement of PGRMC1 in diverse functions, including regulation of cytochrome P450, steroidogenesis, vesicle trafficking, progesterone signaling and mitotic spindle and cell cycle regulation. Its wide range of biological functions is attested to particularly by its emerging association with cancer and progesterone-responsive female reproductive tissues. PGRMC1 exhibits all the hallmarks of a higher order nexus signal integration hub protein. It appears capable of acting as a detector that integrates information from kinase/phosphatase pathways with heme and CO levels and probably redox status.