Gene regulation profiles by progesterone and dexamethasone in human endometrial cancer Ishikawa H cells

Global expression analysis of endometrial cancer cells in response to progesterone identifies new therapeutic targets

Progesterone prevents development of endometrial cancers through its receptor (PR) although the molecular mechanisms have yet to be fully characterized. In this study, we performed a global analysis of gene regulation by progesterone using human endometrial cancer cells that expressed PR endogenously or exogenously. We found progesterone strongly inhibits multiple components of the platelet derived growth factor receptor (PDGFR), Janus kinase (JAK), signal transducer and activator of transcription (STAT) pathway through PR. The PDGFR/JAK/STAT pathway signals to control numerous downstream targets including AP-1 transcription factors Fos and Jun. Treatment with inhibitors of the PDGFR/JAK/STAT pathway significantly blocked proliferation in multiple novel patient-derived organoid models of endometrial cancer, and activation of this pathway was found to be a poor prognostic signal for the survival of patients with endometrial cancer from The Cancer Genome Atlas. Our study identifies this pathway as central to the growth-limiting effects of progesterone in endometrial cancer and suggests that inhibitors of PDGFR/JAK/STAT should be considered for future therapeutic interventions.

Stochastic model of ERK-mediated progesterone receptor translocation, clustering and transcriptional activity

Progesterone receptor (PR) transcriptional activity is a key factor in the differentiation of the uterine endometrium. By consequence, progestin has been identified as an important treatment modality for endometrial cancer. PR transcriptional activity is controlled by extracellular-signal-regulated kinase (ERK) mediated phosphorylation, downstream of growth factor receptors such as EGFR. However, phosphorylation of PR also targets it for ubiquitination and destruction in the proteasome. Quantitative studies of these opposing roles are much needed toward validation of potential new progestin-based therapeutics. In this work, we propose a spatial stochastic model to study the effects of the opposing roles for PR phosphorylation on the levels of active transcription factor. Our numerical simulations confirm earlier in vitro experiments in endometrial cancer cell lines, identifying clustering as a mechanism that amplifies the ability of progesterone receptors to influence gene transcription. We additionally show the usefulness of a statistical method we developed to quantify and control variations in stochastic simulations in general biochemical systems, assisting modelers in defining minimal but meaningful numbers of simulations while guaranteeing outputs remain within a pre-defined confidence level.

PSRR: A Web Server for Predicting the Regulation of miRNAs Expression by Small Molecules

Background: MicroRNAs (miRNAs) play key roles in a variety of pathological processes by interacting with their specific target mRNAs for translation repression and may function as oncogenes (oncomiRs) or tumor suppressors (TSmiRs). Therefore, a web server that could predict the regulation relations between miRNAs and small molecules is expected to achieve implications for identifying potential therapeutic targets for anti-tumor drug development.

Methods: Upon obtaining positive/known small molecule-miRNA regulation pairs from SM2miR, we generated a multitude of high-quality negative/unknown pairs by leveraging similarities between the small molecule structures. Using the pool of the positive and negative pairs, we created the Dataset1 and Dataset2 datasets specific to up-regulation and down-regulation pairs, respectively. Manifold machine learning algorithms were then employed to construct models of predicting up-regulation and down-regulation pairs on the training portion of pairs in Dataset1 and Dataset2, respectively. Prediction abilities of the resulting models were further examined by discovering potential small molecules to regulate oncogenic miRNAs identified from miRNA sequencing data of endometrial carcinoma samples.

Results: The random forest algorithm outperformed four machine-learning algorithms by achieving the highest AUC values of 0.911 for the up-regulation model and 0.896 for the down-regulation model on the testing datasets. Moreover, the down-regulation and up-regulation models yielded the accuracy values of 0.91 and 0.90 on independent validation pairs, respectively. In a case study, our model showed highly-reliable results by confirming all top 10 predicted regulation pairs as experimentally validated pairs. Finally, our predicted binding affinities of oncogenic miRNAs and small molecules bore a close resemblance to the lowest binding energy profiles using molecular docking. Predictions of the final model are freely accessible through the PSRR web server at https://rnadrug.shinyapps.io/PSRR/.

Conclusion: Our study provides a novel web server that could effectively predict the regulation of miRNAs expression by small molecules.

Dexamethasone differentially depletes tumour and peripheral blood lymphocytes and can impact the efficacy of chemotherapy/checkpoint blockade combination treatment

Dexamethasone is a synthetic glucocorticoid commonly used for the prevention and management of side effects in cancer patients undergoing chemotherapy. While it is effective as an anti-emetic and in preventing hypersensitivity reactions, dexamethasone depletes peripheral blood lymphocytes and impacts immune responses. The effect of dexamethasone on the number and quality of tumour-infiltrating leukocytes has not been reported. To address this, we calibrated the dose in two different strains of mice to achieve the same extent of peripheral blood lymphocyte depletion observed in patients with cancer. Doses that caused analogous depletion of T and B lymphocytes and NK cells from the peripheral blood, elicited no change in these populations within the tumour. The expression of immune checkpoint molecules PD-1, OX40, GITR and TIM3 on tumour-infiltrating lymphocytes was not altered. We found that dexamethasone had a small but significant deleterious impact on weakly efficacious chemoimmunotherapy but had no effect when the protocol was highly efficacious. Based on these results, we predict that dexamethasone will have a modest negative influence on the overall effectiveness of chemoimmunotherapy treatment.

Proteasome inhibitors modulate anticancer and anti-proliferative properties via NF-kB signaling, and ubiquitin-proteasome pathways in cancer cell lines of different organs

BACKGROUND

Cancer is second most common cause of death in the United State. There are over 100 different types of cancer associated with different human organs, predominantly breast, liver, pancreas, prostate, colon, rectum, lung, and stomach. We have recently reported properties of pro-inflammatory (for treatment of various types of cancers), and anti-inflammatory (for cardiovascular disease and diabetes) compounds. The major problem associated with development of anticancer drugs is their lack of solubility in aqueous solutions and severe side effects in cancer patients. Therefore, the present study was carried out to check anticancer properties of selected compounds, mostly aqueous soluble, in cancer cell lines from different organs.

METHODS

The anticancer properties, anti-proliferative, and pro-apoptotic activity of novel naturally occurring or FDA approved, nontoxic, proteasome inhibitors/activators were compared. In addition to that, effect of δ-tocotrienol on expression of proteasome subunits (X, Y, Z, LMP7, LMP2, LMP10), ICAM-1, VCAM-1, and TNF-α using total RNAs derived from plasmas of hepatitis C patients was investigated.

RESULTS

Our data demonstrated that following compounds are very effective in inducing apoptosis of cancer cells: Thiostrepton, dexamethasone, 2-methoxyestradiol, δ-tocotrienol, quercetin, amiloride, and quinine sulfate have significant anti-proliferation properties in Hela cells (44% - 87%) with doses of 2.5-20 μM, compared to respective controls. Anti-proliferation properties of thiostrepton, 2-methoxyestradiol, δ-tocotrienol, and quercetin were 70% - 92%. However, thiostrepton, dexamethasone, 2-methoxyestradiol, δ-tocotrienol, quercetin, and quinine sulphate were effective in pancreatic, prostate, breast, lungs, melanoma, Β-lymphocytes, and T-cells (Jurkat: 40% to 95%) compared to respective controls. In lung cancer cells, these compounds were effective between 5 and 40 μM. The IC₅₀ values of anti-proliferation properties of thiostrepton in most of these cell lines were between doses of 2.5-5 μM, dexamethasone 2.5-20 μM, 2-methoxyestradiol 2.5-10 μM, δ-tocotrienol 2.5-20 μM, quercetin 10-40 μM, and (-) Corey lactone 40-80 μM. In hepatitis C patients, δ-tocotrienol treatment resulted in significant decrease in the expression of pro-inflammatory cytokines.

CONCLUSIONS

These data demonstrate effectiveness of several natural-occurring compounds with anti-proliferative properties against cancer cells of several organs of humans. Thiostrepton, dexamethasone, 2-methoxyestradiol, δ-tocotrienol and quercetin are very effective for apoptosis of cancer cells in liver, pancreas, prostate, breast, lung, melanoma, Β-lymphocytes and T-cells. The results have provided an opportunity to test these compounds either individually or in combination as dietary supplements in humans for treatment of various types of cancers.

Dopamine D2 receptor antagonist sulpiride enhances dexamethasone responses in the treatment of drug-resistant and metastatic breast cancer

Recent evidence shows that dopamine D2-like receptor (D2DR) antagonists, such as trifluoperazine and thioridazine, are effective for cancer therapy and inhibition of cancer stem-like cells (CSCs). In this study, we investigated the anti-cancer effects of combination therapy of dexamethasone (DEX) and sulpiride (SUL), an atypical antipsychotic, against drug-resistant and metastatic breast cancers and further explored the underlying mechanisms. Oral administration of SUL (25, 100 mg·kg^-1·d^-1) alone did not inhibit the tumor growth in human breast cancer MCF-7/Adr xenograft model, but dose-dependently decreased the proportion of CSCs in vitro and in vivo. In contrast, combination therapy of SUL (50 mg·kg^-1·d^-1) and DEX (8 mg·kg^-1·d^-1) markedly suppressed the tumor growth in MCF-7/Adr xenograft model with little systemic toxicity and lung metastasis in murine metastatic breast cancer 4T1 xenograft model. Among the metastasis-associated biomarkers analyzed, the combination therapy significantly decreased the levels of MMP-2, but increased E-cadherin levels in 4T1 xenograft tumors. Moreover, the combination therapy significantly inhibited the cell colony formation, migration and invasion of 4T1 and human breast cancer MDA-MB-231 cells in vitro. Addition of a specific D2DR agonist 7-OH-DPAT to the combination therapy reversed the enhanced anti-cancer effects in vivo and CSC population loss in tumor tissues. Our data demonstrate that SUL remarkably enhances the efficacy of DEX in the treatment of drug-resistant and metastatic breast cancer via the antagonism of D2DR, which might result from the eradication of CSCs.

Effects of a hyperandrogenaemic state on the proliferation and decidualization potential in human endometrial stromal cells

OBJECTIVE

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women, involving hyperandrogenaemia and insulin resistance. Treatment options include dexamethasone, as well as the off-label use of metformin. To evaluate the impact of those drugs on cyclic changes in endometrial development, we tested possible effects of metformin and dexamethasone on endometrial stromal cells decidualisation, proliferation, and gene regulation in a hyperandrogenaemic microenvironment in vitro.

METHODS/DESIGN

Ten endometrial biopsies (of which five were decidualized in vitro) were used from regularly cycling women. Cells were treated with testosterone, dexamethasone, and metformin in different concentrations. Thereafter, cells were assessed for proliferation and decidualization capacity, as well as mTor and MMP-2 gene regulation.

RESULTS

Metformin showed a dose-dependent negative effect on prolactin secretion, a known decidualization marker. This effect was stronger in a hyperandrogenaemic condition and could not be compensated by dexamethasone. Testosterone had a dose dependent negative effect on proliferation in decidualized endometrial stromal cells. Dexamethasone slightly compensated the negative proliferative effect only in low-dose testosterone. High-dose metformin also showed a dose-dependent reduction in endometrial stromal cell proliferation without a major impact by testosterone or dexamethasone in decidualized and non-decidualized cells. High-dose metformin significantly reduced the expression of matrix metalloproteinase-2 (MMP-2) and mechanistic Target of Rapamycin (mTor), regardless of the concentration of dexamethasone and testosterone. The strongest effect could be observed for the combination with high-dose dexamethasone.

CONCLUSION

When therapies, such as metformin and dexamethasone, are used to normalize peripheral androgen levels in patients with PCOS, their effect on the endometrial microenvironment should be taken into consideration as well, especially metformin has to be used with caution because of its dose dependent, possibly inhibiting effect at the endometrial proliferation.

The estrogen receptor joins other cancer biomarkers as a predictor of outcome

Endometrial cancer, the most common gynecologic malignancy in the United States, is on the rise, and survival is worse today than 40 years ago. In order to improve the outcomes, better biomarkers that direct the choice of therapy are urgently needed. In this review, we explore the estrogen receptor as the most studied biomarker and the best predictor for response for endometrial cancer reported to date.

Molecular target therapies in endometrial cancer: from the basic research to the clinic

Molecular targeted therapies represent an interesting field of pharmacological research in endometrial cancer. The loss of PTEN (phosphatase and tensin homolog deleted on chromosome 10) function, with consequent activation of the PI3K (phosphatidylinositol-3-kinase)-AKT (serine/threonine-specific protein kinase)-mTOR (mammalian target of rapamycin) signaling pathway, occurs in 32-83% of endometrioid-type endometrial carcinomas, thus suggesting a role for mTOR inhibition in this malignancy. Some analogues of rapamycin (CCI-799, RAD-001, AP-23573) have been developed and tested in different tumors including endometrioid-type endometrial carcinoma. For example, AP-23573 achieved a clinical benefit response in 33% of 27 heavily pretreated patients, and CCI-799 obtained a 26% partial response rate and a 63% stable disease rate in 19 patients. Overexpression of ErbB-2 (epidermal growth factor type II receptor) has been detected in 18-80% of uterine papillary serous carcinomas (UPSCs), thus providing a biological rationale for the use of trastuzumab in these aggressive tumors. UPSC often overexpresses claudin-3 and claudin-4, which represent the epithelial receptors for Clostridium perfringens enterotoxin (CPE). CPE-mediated therapy might be a novel treatment modality for UPSC resistant to chemotherapy. A better understanding of the signaling transduction pathways that are dysregulated in endometrioid-type endometrial carcinoma and UPSC will allow the development of novel molecular targeted therapies.

Progesterone-mediated regulation of catechol-O-methyl transferase expression in endometrial cancer cells

The effects of estrogen and progesterone on the expression of estrogen-metabolizing enzymes such as catechol-O-methyl transferase (COMT) are not known. COMT converts genotoxic catecholestrogens to anticarcinogenic methoxyestrogens in the endometrium. The aim of this study is to investigate the effect of progesterone on COMT expression in well-differentiated endometrial cancer cells. The wild-type Ishikawa cell line as well as progesterone receptor A- or progesterone receptor B-transfected Ishikawa cells were used for in vitro studies. The regulation of COMT expression by progesterone was studied using Western blots, Hoechst dye DNA proliferation studies, and wild-type and/or site-directed mutagenesis of COMT promoter 1-luciferase reporter gene. Progesterone upregulated COMT protein expression in Ishikawa cells through progesterone receptor A isoform. COMT promoter activity was differentially regulated by the 3 half-site progesterone response elements in the COMT promoter. High doses of 2-ME2 inhibited Ishikawa cell proliferation. These data suggest that COMT expression is hormonally regulated in well-differentiated human endometrial cancer cells. COMT regulation and 2-ME2 production in the endometrium may affect endometrial carcinogenesis.

Consequences of the loss of p53, RB1, and PTEN: Relationship to gefitinib resistance in endometrial cancer

OBJECTIVE

These studies demonstrate how loss of function mutations or downregulation of key tumor suppressors missing from type I and type II endometrial cancer cells contributes to carcinogenesis and to resistance to the EGFR inhibitor gefitinib (ZD1839).

METHODS

Cell models devoid of tumor suppressors PTEN and RB1 or PTEN were studied. PTEN, RB1 and p53 expression was reinstated, and the effects on cell cycle, apoptosis, and cell cycle regulators were evaluated.

RESULTS

In Ishikawa H cells that model type I endometrial cancer in the loss of PTEN and RB1, re-expressing PTEN and RB1 increased the apoptotic and G1 phases and decreased the S and G2-M phases, which further sensitize the cells to gefitinib. Expressing p53 in Hec50co that model type II tumors by loss of this tumor suppressor arrested cells at the G1-S checkpoint, and apoptosis was also induced. Yet this did not improve sensitivity to gefitinib. Modulation of the cell cycle regulators responsible for these changes is explored, and a potential new therapeutic target, MDM2, is identified.

CONCLUSION

The downregulation of p53 expression in type II Hec50co cells is linked to gefitinib resistance. In addition, the overexpression of MDM2, the principal factor that inhibits p53 function also occurs in these resistant cells. MDM2 phosphorylation is only partially blocked by gefitinib, and high MDM2 expression may relate to drug resistance.