Inhibiting the PI3K/Akt pathway reversed progestin resistance in endometrial cancer

Liposome-encapsulated progesterone efficiently suppresses B-lineage cell proliferation

Progesterone suppresses several ancient pathways in a concentration-dependent manner. Based on these characteristics, progesterone is considered a candidate anticancer drug. However, the concentration of progesterone used for therapy should be higher than the physiological concentration, which makes it difficult to develop progesterone-based anticancer drugs. We previously developed liposome-encapsulated progesterone (Lipo-P4) with enhanced anticancer effects, which strongly suppressed triple-negative breast cancer cell proliferation in humanized mice. In this study, we aimed to clarify whether Lipo-P4 effectively suppresses the proliferation of B-lineage cancer cells. We selected six B-cell lymphoma and two myeloma cell lines, and analyzed their surface markers using flow cytometry. Next, we prepared liposome-encapsulated progesterone and examined its effect on cell proliferation in these B-lineage cancer cells, three ovarian clear cell carcinoma cell lines, two prostate carcinoma cell lines, and one triple-negative breast cancer adenocarcinoma cell line. Lipo-P4 suppressed the proliferation of all cancer cell lines. All B-lineage cell lines, except for the HT line, were more susceptible than the other cell types, regardless of the expression of differentiation markers. Empty liposomes did not suppress cell proliferation. These results suggest that progesterone encapsulated in liposomes efficiently inhibits the proliferation of B-lineage cells and may become an anticancer drug candidate for B-lineage cancers.

Comparative effects of progestin-based combination therapy for endometrial cancer or atypical endometrial hyperplasia: a systematic review and network meta-analysis

Objectives

The objective of this network meta-analysis is to systematically compare the efficacy of diverse progestin-based combination regimens in treating patients diagnosed with endometrial cancer or atypical endometrial hyperplasia. The primary goal is to discern the optimal combination treatment regimen through a comprehensive examination of their respective effectiveness.

Methods

We systematically searched four prominent databases: PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials, for randomized controlled trials addressing the efficacy of progestins or progestin combinations in the treatment of patients with endometrial cancer or atypical endometrial hyperplasia. The search spanned from the inception of these databases to December 2023. Key outcome indicators encompassed survival indices, criteria for assessing efficacy, as well as pregnancy and relapse rate. This study was registered in PROSPERO (CRD42024496311).

Results

From the 1,558 articles initially retrieved, we included 27 studies involving a total of 5,323 subjects in our analysis. The results of the network meta-analysis revealed that the mTOR inhibitor+megestrol acetate (MA)+tamoxifen regimen secured the top rank in maintaining stable disease (SD) (SUCRA=73.4%) and extending progression-free survival (PFS) (SUCRA=72.4%). Additionally, the progestin combined with tamoxifen regimen claimed the leading position in enhancing the partial response (PR) (SUCRA=75.2%) and prolonging overall survival (OS) (SUCRA=80%). The LNG-IUS-based dual progestin regimen emerged as the frontrunner in improving the complete response (CR) (SUCRA=98.7%), objective response rate (ORR) (SUCRA=99.1%), pregnancy rate (SUCRA=83.7%), and mitigating progression (SUCRA=8.0%) and relapse rate (SUCRA=47.4%). In terms of safety, The LNG-IUS-based dual progestin regimen had the lowest likelihood of adverse events (SUCRA=4.2%), while the mTOR inhibitor regimen (SUCRA=89.2%) and mTOR inbitor+MA+tamoxifen regimen (SUCRA=88.4%) had the highest likelihood of adverse events.

Conclusions

Patients diagnosed with endometrial cancer or atypical endometrial hyperplasia exhibited the most favorable prognosis when undergoing progestin combination therapy that included tamoxifen, mTOR inhibitor, or LNG-IUS. Notably, among these options, the LNG-IUS-based dual progestin regimen emerged as particularly promising for potential application.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024496311.

Low-density lipoprotein receptor-related protein 5/6 promotes endometrial cancer progression and cancer cell immune escape

The study investigated the potential association of the low-density lipoprotein (LDL) genome with endometrial cancer progression based on the Gene Expression Omnibus data set and The Cancer Genome Atlas data set. Differential and weighted gene coexpression network analysis was performed on endometrial cancer transcriptome datasets GSE9750 and GSE106191. The protein-protein interaction network was built using LDL-receptor proteins and the top 50 tumor-associated genes. Low-density lipoprotein-related receptors 5/6 (LRP5/6) in endometrial cancer tissues were correlated with oncogenes, cell cycle-related genes, and immunological checkpoints using Spearman correlation. MethPrimer predicted the LRP5/6 promoter CpG island. LRP2, LRP6, LRP8, LRP12, low-density lipoprotein receptor-related protein-associated protein, and LRP5 were major LDL-receptor-related genes associated with endometrial cancer. LRP5/6 was enriched in various cancer-related pathways and may be a key LDL-receptor-related gene in cancer progression. LRP5/6 may be involved in the proliferation process of endometrial cancer cells by promoting the expression of cell cycle-related genes. LRP5/6 may be involved in the proliferation of endometrial cancer cells by promoting the expression of cell cycle-related genes. LRP5/6 may promote the immune escape of cancer cells by promoting the expression of immune checkpoints, promoting endometrial cancer progression. The MethPrimer database predicted that the LRP5/6 promoter region contained many CpG islands, suggesting that DNA methylation can occur in the LRP5/6 promoter region. LRP5/6 may aggravate endometrial cancer by activating the phosphoinositide 3-kinase/protein kinase B pathway.

Metformin inhibits cell proliferation and ACTH secretion in AtT20 cells via regulating the MAPK pathway

We investigated the impact of metformin on ACTH secretion and tumorigenesis in pituitary corticotroph tumors. The mouse pituitary tumor AtT20 cell line was treated with varying concentrations of metformin. Cell viability was assessed using the CCK-8 assay, ACTH secretion was measured using an ELISA kit, changes in the cell cycle were analyzed using flow cytometry, and the expression of related proteins was evaluated using western blotting. RNA sequencing was performed on metformin-treated cells. Additionally, an in vivo BALB/c nude xenograft tumor model was established in nude mice, and immunohistochemical staining was conducted for further verification. Following metformin treatment, cell proliferation was inhibited, ACTH secretion decreased, and G1/S phase arrest occurred. Analysis of differentially expressed genes revealed cancer-related pathways, including the MAPK pathway. Western blotting confirmed a decrease in phosphorylated ERK1/2 and phosphorylated JNK. Combining metformin with the ERK1/2 inhibitor Ulixertinib resulted in a stronger inhibitory effect on cell proliferation and POMC (Precursors of ACTH) expression. In vivo studies confirmed that metformin inhibited tumor growth and reduced ACTH secretion. In conclusion, metformin inhibits tumor progression and ACTH secretion, potentially through suppression of the MAPK pathway in AtT20 cell lines. These findings suggest metformin as a potential drug for the treatment of Cushing's disease.

TSLP enhances progestin response in endometrial cancer via androgen receptor signal pathway

BACKGROUND

The enriched proteins within in vitro fertilisation (IVF)-generated human embryonic microenvironment could reverse progestin resistance in endometrial cancer (EC).

METHODS

The expression of thymic stromal lymphopoietin (TSLP) in EC was evaluated by immunoblot and IHC analysis. Transcriptome sequencing screened out the downstream pathway regulated by TSLP. The role of TSLP, androgen receptor (AR) and KANK1 in regulating the sensitivity of EC to progestin was verified through a series of in vitro and in vivo experiments.

RESULTS

TSLP facilitates the formation of a BMP4/BMP7 heterodimer, resulting in activation of Smad5, augmenting AR signalling. AR in turn sensitises EC cells to progestin via KANK1. Downregulation of TSLP, loss of AR and KANK1 in EC patients are associated with tumour malignant progress. Moreover, exogenous TSLP could rescue the anti-tumour effect of progestin on mouse in vivo xenograft tumour.

CONCLUSIONS

Our findings suggest that TSLP enhances the sensitivity of EC to progestin through the BMP4/Smad5/AR/KANK1 axis, and provide a link between embryo development and cancer progress, paving the way for the establishment of novel strategy overcoming progestin resistance using embryo original factors.

Impacts of ovarian reserve on conservative treatment for endometrial cancer and atypical hyperplasia

Objectives

Real-world data indicated that some endometrial atypical hyperplasia (EAH) and early endometrial carcinoma (EEC) patients of fertility preservation had a normal ovarian reserve, while some had a decreased ovarian reserve (DOR). This study was designed to investigate the effect of baseline ovarian reserve on the treatment of EAH and EEC patients who ask for preservation of fertility.

Methods

This was a prospective cohort study conducted at a single university-affiliated fertility center. A total of 102 EAH and EEC patients who received fertility-preserving treatment between March 2019 and August 2020 were included and divided into a DOR group (n=22) and a non-DOR group (n=80).

Results

The 32-week CR rate of the non-DOR group was significantly higher than that of the DOR group (60.3% vs. 33.3%, P =0.028). The DOR group had a longer treatment duration to achieve CR than the non-DOR group (40.07 vs. 29.71 weeks, P=0.008, HR: 0.54, 95% CI: 0.36-0.86). Multivariate logistic regression analyses demonstrated that DOR (OR: 0.35, 95% CI: 0.13-0.99, P=0.049) and BMI ≥25 kg/m2 (OR: 0.40, 95% CI: 0.17-0.92, P=0.031) were negatively associated with 32-week CR.

Conclusions

Decreased baseline ovarian reserve is negatively correlated with the efficacy of fertility-preserving treatment in EAH and EEC patients, as this group has a lower CR rate and a longer treatment duration to achieve CR than those without DOR.

Progesterone-Cationic Lipid Conjugate-Based Self-Aggregates for Cancer Cell-Selective Uptake through Macropinocytosis and the Antitumour Effect

Progesterone (PR) is an endogenous steroid hormone that activates the progesterone receptor (PgR) and is known to play a critical role in cancer progression. Herein, we report the development of cationic lipid-conjugated PR derivatives by covalently conjugating progesterone with cationic lipids of varying hydrocarbon chain lengths (n = 6-18) through a succinate linker. Cytotoxicity studies performed on eight different cancer cell lines reveal that PR10, one of the lead derivatives, exerts notable toxicity (IC₅₀ = 4-12 μM) in cancer cells irrespective of their PgR expression status and remains largely nontoxic to noncancerous cells. Mechanistic studies show that PR10 induces G2/M-phase cell cycle arrest in cancer cells, leading to apoptosis and cell death by inhibiting the PI3K/AKT cell survival pathway and p53 upregulation. Further, in vivo study shows that PR10 treatment significantly reduces melanoma tumor growth and prolongs the overall survival of melanoma tumor-bearing C57BL/6J mice. Interestingly, PR10 readily forms stable self-aggregates of ∼190 nm size in an aqueous environment and exhibits selective uptake into cancerous cell lines. In vitro uptake mechanism studies in various cell lines (cancerous cell lines B16F10, MCF7, PC3, and noncancerous cell line HEK293) using endocytosis inhibition proves that PR10 nanoaggregates enter selectively into the cancer cells predominantly using macropinocytosis and/or caveolae-mediated endocytosis. Overall, this study highlights the development of a self-aggregating cationic derivative of progesterone with anticancer activity, and its cancer cell-selective accumulation in nanoaggregate form holds great potential in the field of targeted drug delivery.

Progesterone Resistance in Endometriosis: Current Evidence and Putative Mechanisms

Endometriosis is an estrogen-dependent disease characterized by the growth of endometrial-like tissue outside the uterus. Progestins are currently the most commonly used treatment for endometriosis because of their excellent therapeutic effects and limited side effects. However, progestins have been unsuccessful in some symptomatic patients. The inability of the endometrium to respond properly to progesterone is known as progesterone resistance. An increasing body of evidence suggests the loss of progesterone signaling and the existence of progesterone resistance in endometriosis. The mechanisms of progesterone resistance have received considerable scholarly attention in recent years. Abnormal PGR signaling, chronic inflammation, aberrant gene expression, epigenetic alterations, and environmental toxins are considered potential molecular causes of progesterone resistance in endometriosis. The general objective of this review was to summarize the evidence and mechanisms of progesterone resistance. A deeper understanding of how these mechanisms contribute to progesterone resistance may help develop a novel therapeutic regimen for women with endometriosis by reversing progesterone resistance.

RNA-seq and ATAC-seq analysis of CD163+ macrophage-induced progestin-insensitive endometrial cancer cells

BACKGROUND

Progestins are used as fertility-sparing regimens for young patients with stage 1A endometrioid endometrial cancer (EEC) and atypical endometrial hyperplasia (AEH). CD163⁺ macrophages promote estrogen-dependent EEC development, but whether they induce progestin insensitivity remains unclear. This study aimed to investigate the possible effects of CD163⁺ macrophages on progestin response in AEH/EEC patients.

METHODS

The number of infiltrating CD163⁺ macrophages in progestin-insensitive and -sensitive endometrial lesions was compared. The effects of CD163⁺ macrophages on progestin responses and progesterone receptor (PR) expression in EC cells were evaluated in vitro. ATAC-seq and RNA-seq were combined to identify molecular/biological changes induced by CD163⁺ macrophages in progestin-insensitive EC cells.

RESULTS

Increased CD163⁺ macrophage infiltration was significantly associated with progestin insensitivity and longer treatment durations in AEH/EEC patients. Additionally, the number of CD163⁺ macrophages was negatively correlated with PR expression in AEH/EEC tissues. Furthermore, the CD163⁺ macrophage-mediated microenvironment and secreted cytokines downregulated PR expression and impaired the response of EC cells to medroxyprogesterone acetate (MPA). RNA-seq analysis demonstrated that CD163⁺ macrophages antagonized PR signaling by blocking or even reversing MPA-regulated differential gene expression. Based on RNA-seq and ATAC-seq analyses, extracellular matrix (ECM) signaling and ECM-related transcription factors, FOXF2, POU1F1, and RUNX1were identified to potentially be involved in CD163⁺ macrophage-induced progestin insensitivity in endometrial cancer patients.

CONCLUSIONS

We identified CD163⁺ macrophages as an important mediator of progestin desensitization and an unfavorable factor for the efficacy of fertility-preserving treatment in AEH/EEC patients.

Verteporfin reverses progestin resistance through YAP/TAZ-PI3K-Akt pathway in endometrial carcinoma

Progestin resistance is a problem for patients with endometrial carcinoma (EC) who require conservative treatment with progestin, and its underlying mechanisms remain unclear. YAP and TAZ (YAP/TAZ), downstream transcription coactivators of Hippo pathway, promote viability, metastasis and also drug resistance of malignant tumors. According to our microarray analysis, YAP/TAZ were upregulated in progestin resistant IshikawaPR cell versus progestin sensitive Ishikawa cell, which implied that YAP/TAZ may be a vital promotor of resistance to progestin. We found YAP/TAZ had higher expression levels among the resistant tissues than sensitive tissues. In addition, knocking down YAP/TAZ decreased cell viability, inhibited cell migration and invasion and increased the sensitivity of IshikawaPR cell to progestin. On the contrary, overexpression of YAP/TAZ increased cell proliferation, metastasis and promoted progestin resistance. We also confirmed YAP/TAZ were involved in progestin resistant process by regulating PI3K-Akt pathway. Furthermore, Verteporfin as an inhibitor of YAP/TAZ could increase sensitivity of IshikawaPR cells to progestin in vivo and in vitro. Our study for the first time indicated that YAP/TAZ play an important role in progestin resistance by regulating PI3K-Akt pathway in EC, which may provide ideas for clinical targeted therapy of progestin resistance.

ABX-1431 inhibits the development of endometrial adenocarcinoma and reverses progesterone resistance by targeting MGLL

Endometrial cancer is a common gynecological malignancy. With the onset of EC patients younger, conservative treatment with progesterone has become an important option for patients trying to preserve reproductive function. However, progesterone resistance is a key factor affecting the efficacy of therapy and it is urgent to clarify the mechanism so as to propose a potential target and inhibit the development of endometrial adenocarcinoma and progesterone resistance. MGLL, an important factor involved in lipid mobilization, is overexpressed in many tumors, however the biological function of MGLL in the development of endometrial adenocarcinoma and the process of progesterone resistance still remains unclear. In this study, we first found MGLL was highly expressed in progesterone resistant samples of endometrial adenocarcinoma, and then we verified its expression was increased in endometrial adenocarcinoma. Through in vitro and in vivo experiments, we demonstrated that overexpression of MGLL promoted tumor proliferation, metastasis and the occurrence of progestogen resistance, knockdown MGLL inhibited tumor proliferation, metastasis and reversed progestogen resistance. In addition, knockdown of MGLL can sensitize endometrial adenocarcinoma cells to progesterone, possibly by affecting ROS generation and reducing the expression of AKR1C1. Finally, it was verified that ABX-1431, MGLL inhibitor, reversed progesterone resistance and enhanced the sensitivity of endometrial adenocarcinoma to progesterone both in vitro and in vivo. In conclusion, the high expression of MGLL is involved in the occurrence and development of endometrial adenocarcinoma and progesterone resistance. Targeted inhibition of MGLL by inhibitors may be an effective method for the treatment of progesterone resistance in endometrial adenocarcinoma.

Progestin Resistance and Corresponding Management of Abnormal Endometrial Hyperplasia and Endometrial Carcinoma

With a younger tendency in morbidity age, endometrial cancer (EC) incidence has grown year after year. Worse, even more commonly occurring is endometrial hyperplasia (EH), which is a precancerous endometrial proliferation. For young women with early EC and EH who want to preserve fertility, progestin therapy has been utilized as a routine fertility-preserving treatment approach. Nevertheless, progestin medication failure in some patients is mostly due to progestin resistance and side effects. In order to further analyze the potential mechanisms of progestin resistance in EH and EC, to provide theoretical support for effective therapeutic strategies, and to lay the groundwork for searching novel treatment approaches, this article reviews the current therapeutic effects of progestin in EH and EC, as well as the mechanisms and molecular biomarkers of progestin resistance, and systematically expounds on the potential therapeutic methods to overcome progestin resistance.

Brusatol sensitizes endometrial hyperplasia and cancer to progestin by suppressing NRF2-TET1-AKR1C1-mediated progestin metabolism

Progestin resistance is the main obstacle for the conservative therapy to maintain fertility in women with endometrial cancer. Brusatol was identified as an inhibitor of the NRF2 pathway; however, its impact on progestin resistance and the underlying mechanism remains unclear. Here, we found that brusatol sensitized endometrial cancer to progestin by suppressing NRF2-TET1-AKR1C1-mediated progestin metabolism. Brusatol transcriptionally suppressed AKR1C1 via modifying the hydroxymethylation status in its promoter region through TET1 inhibition. Suppression of AKR1C1 by brusatol resulted in decreased progesterone catabolism and maintained potent progesterone to inhibit endometrial cancer growth. This inhibition pattern has also been found in the established xenograft mouse and organoid models. Aberrant overexpression of AKR1C1 was found in paired endometrial hyperplasia and cancer samples from the same individuals with progestin resistance, whereas attenuated or loss of AKR1C1 was observed in post-treatment samples with well progestin response as compared with paired pre-treatment tissues. Our findings suggest that AKR1C1 expression pattern may serve as an important biomarker of progestin resistance in endometrial cancer.

MIG-6 Is Critical for Progesterone Responsiveness in Human Complex Atypical Hyperplasia and Early-Stage Endometrial Cancer

Women with complex atypical hyperplasia (CAH) or early-stage endometrioid endometrial cancer (EEC) are candidates for fertility preservation. The most common approach is progesterone (P4) therapy and deferral of hysterectomy until after completion of childbearing. However, P4 therapy response rates vary, and molecular mechanisms behind P4 resistance are poorly understood. One potential molecular cause of P4 resistance is a loss or attenuation of PGR expression. Mitogen-inducible gene 6 (MIG-6) is critical for P4 responsiveness. MIG-6 protein expression in the endometrial epithelial and stromal cells from women with CAH and EEC was significantly lower compared to women without CAH or EEC. The P4-responsive women (10/15) exhibited an increase of MIG-6 expression in epithelial and stromal cells compared to P4-resistant women (5/15). In addition, immunohistochemical analysis for PGR results showed that stromal PGR levels are significantly higher in P4-responsive women compared to P4-resistant women, whereas epithelial PGR expression was not different. A reverse correlation of MIG-6 and pAKT levels was observed in early-stage EEC patients. Studies strongly suggest that loss of MIG-6 and PGR and activation of pAKT lead to P4 resistance in CAH and EEC. These results will help to elucidate the molecular mechanism leading to P4 resistance in CAH and EEC.

Efficacy of metformin therapy in patients with cancer: a meta-analysis of 22 randomised controlled trials

BACKGROUND

To investigate whether metformin monotherapy or adjunctive therapy improves the prognosis in patients with any type of cancer compared to non-metformin users (age ≥18).

METHODS

Databases (Medline, Embase, and the Cochrane Central Register of Controlled Trials) and clinical trial registries ( ClinicalTrials.gov ; the World Health Organization International Clinical Trials Registry Platform) were screened for randomized, controlled trials (RCT) reporting at least progression-free survival (PFS) and/or overall survival (OS). Main outcome measures included hazard ratios (HR), and combined HRs and 95% confidence intervals (CI) were calculated using random-effects models.

RESULTS

Of the 8419 records screened, 22 RCTs comprising 5943 participants were included. Pooled HRs were not statistically significant in both PFS (HR 0.97, 95% CI 0.82-1.15, I² = 50%) and OS (HR 0.98, 95% CI 0.86-1.13, I² = 33%) for patients with cancer between the metformin and control groups. Subgroup analyses demonstrated that metformin treatment was associated with a marginally significant improvement in PFS in reproductive system cancers (HR 0.86, 95% CI 0.74-1.00) and a significantly worse PFS in digestive system cancers (HR 1.45, 95% CI 1.03-2.04). The PFS or OS was observed consistently across maintenance dose, diabetes exclusion, median follow-up, risk of bias, and combined antitumoral therapies.

CONCLUSION

Metformin treatment was not associated with cancer-related mortality in adults compared with placebo or no treatment. However, metformin implied beneficial effects in the PFS of the patients with reproductive system cancers but was related to a worse PFS in digestive system cancers.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42022324672.

Glucose transporters: Important regulators of endometrial cancer therapy sensitivity

Glucose is of great importance in cancer cellular metabolism. Working together with several glucose transporters (GLUTs), it provides enough energy for biological growth. The main glucose transporters in endometrial cancer (EC) are Class 1 (GLUTs 1–4) and Class 3 (GLUTs 6 and 8), and the overexpression of these GLUTs has been observed. Apart from providing abundant glucose uptake, these highly expressed GLUTs also participate in the activation of many crucial signaling pathways concerning the proliferation, angiogenesis, and metastasis of EC. In addition, overexpressed GLUTs may also cause endometrial cancer cells (ECCs) to be insensitive to hormone therapy or even resistant to radiotherapy and chemoradiotherapy. Therefore, GLUT inhibitors may hopefully become a sensitizer for EC precision-targeted therapies. This review aims to summarize the expression regulation, function, and therapy sensitivity of GLUTs in ECCs, aiming to provide a new clue for better diagnosis and treatment of EC.

Genistein induces long-term expression of progesterone receptor regardless of estrogen receptor status and improves the prognosis of endometrial cancer patients

Progesterone is used to treat uterine endometrial cancer in young patients wishing to preserve their fertility as well as in advanced or recurrent patients, but its response rate is limited. The antitumor effect of progesterone is mediated by progesterone receptor (PR) binding. Hence, loss of progesterone’s therapeutic effect, i.e., development of progesterone resistance, is mainly due to decreased PR expression. However, little is known about underlying mechanisms that regulate PR expression. Immunohistochemistry analysis of specimens from 31 young, endometrial cancer patients showed that elevated PR expression significantly increased (P < 0.05) rates of progression-free and overall survival. We investigated mechanisms of regulating PR expression and suppressing cell proliferation using genistein, a chemotherapeutic agent against different cancers. Genistein inhibits cell growth by inducing cell cycle arrest in G2 and apoptosis; moreover, it upregulates prolonged expression of PR-B and forkhead box protein O1, regardless of estrogen receptor alpha expression in endometrial cancer cells. Genistein-induced PR expression decreases CCAAT/enhancer binding protein beta expression and activates c-Jun N-terminal kinase pathway, rather than causing epigenetic alterations of the PR promoter. Therefore, increased PR expression is an important antitumor effect of genistein. This may help to improve the response rates of fertility-sparing treatments for young patients.

Progestins as Anticancer Drugs and Chemosensitizers, New Targets and Applications

Progesterone and its synthetic analogues, progestins, participate in the regulation of cell differentiation, proliferation and cell cycle progression. Progestins are usually applied for contraception, maintenance of pregnancy, and hormone replacement therapy. Recently, their effectiveness in the treatment of hormone-sensitive tumors was revealed. According to current data, the anticancer activity of progestins is mainly mediated by their cytotoxic and chemosensitizing influence on different cancer cells. In connection with the detection of previously unknown targets of the progestin action, which include the membrane-associated progesterone receptor (PR), non-specific transporters related to the multidrug resistance (MDR) and mitochondrial permeability transition pore (MPTP), and checkpoints of different signaling pathways, new aspects of their application have emerged. It is likely that the favorable influence of progestins is predominantly associated with the modulation of expression and activity of MDR-related proteins, the inhibition of survival signaling pathways, especially TGF-β and Wnt/β-catenin pathways, which activate the proliferation and promote MDR in cancer cells, and the facilitation of mitochondrial-dependent apoptosis. Biological effects of progestins are mediated by the inhibition of these signaling pathways, as well as the direct interaction with the nucleotide-binding domain of ABC-transporters and mitochondrial adenylate translocase as an MPTP component. In these ways, progestins can restore the proliferative balance, the ability for apoptosis, and chemosensitivity to drugs, which is especially important for hormone-dependent tumors associated with estrogen stress, epithelial-to-mesenchymal transition, and drug resistance.

Efficacy of the LNG-IUS for treatment of endometrial hyperplasia and early stage endometrial cancer: Can biomarkers predict response?

Endometrial Cancer (EC) is the most common gynaecologic malignancy in the developed world, and is increasing in premenopausal women. The surgical standard of care for early-stage EC is not possible in women with concurrent comorbidities or women who desire a fertility sparing approach. The Levonorgestrel Intrauterine System (LNG-IUS) is gaining traction as an alternative treatment for endometrial hyperplasia and early stage EC in inoperable women. Whilst early evidence appears promising, predictive biomarkers need to be established to determine non-responders, which make up one in three women. This timely review discusses the current literature around the identification of clinical, molecular and novel biomarkers that show potential to predict response to progesterone treatment, including the LNG-IUS.

Chlorpromazine Sensitizes Progestin-Resistant Endometrial Cancer Cells to MPA by Upregulating PRB

Medroxyprogesterone acetate (MPA) is the main conservative treatment for endometrial cancer (EC) patients desirable to preserve fertility and those who cannot suffer from surgery. Considering the high incidence of progestin resistance and recurrence of MPA treatment, we reproposed antipsychotics chlorpromazine (CPZ) as a new strategy for both progestin-sensitive and -resistant endometrial cancer. Cytobiology experiments indicated that CPZ could significantly suppress proliferation, migration/invasion and induce apoptosis in Ishikawa (ISK) and KLE EC cell lines. And xenograft mouse models were constructed to validate the antitumor effect and toxicity of CPZ in-vivo. CPZ inhibited the growth at a low dose of 3mg/kg and the mice exhibited no signs of toxicity. Next, concomitant treatment and sequential treatment with CPZ and MPA were proceeded to analysis the synergistic effect in EC cells. Concomitant treatment only performed a limited synergistic effect on apoptosis in ISK and KLE cells. Nevertheless, sequential treatment showed favorable synergistic effects in progestin-resistant KLE cells. Finally, a stable MPA-resistant cell line shRNA was established to explore the mechanism of CPZ reversing progestin resistance. Immunoblot data showed that CPZ inhibited the activation of PI3K/AKT signal in ISK and KLE cells and upregulated PRB expression in progestin-resistant cells, by which CPZ overcame progestin resistance to MPA. Thus, CPZ might act as a candidate drug for conservative treatment and sequential treatment with CPZ and MPA could be a suitable therapeutic option for progestin resistant patients.

Ganoderma tsugae suppresses the proliferation of endometrial carcinoma cells via Akt signaling pathway

Ganoderma is one of the common medicinal mushrooms in traditional Chinese medicine. Previous researches have unveiled the multifaceted biological activity of Ganoderma extract. Ganoderma tsugae has been investigated the potential on curing prostate, colon, lung, epidermoid, breast and ovarian cancers, but not including endometrial cancer. Endometrial cancer is a gynecological malignant tumor with serious drug resistance problem in clinical cancer treatment. This study aimed to demonstrate the first study of Ganoderma on treating endometrial cancer. The Ganoderma tsugae ethanol extract (GTEE) could suppress the proliferation of endometrial cancer cells HEC-1-A, KLE, and AN3 CA. GTEE also induced G1/S phase arrest and mitochondria-mediated apoptosis in endometrial cancer cells. Furthermore, the Akt signaling pathway could be suppressed by GTEE. Therefore, our results suggest for the first time that GTEE has the potential to be an adjuvant therapeutic agent in the treatment of endometrial cancer.

The role of mitogen-activated protein kinase signaling pathway in endometriosis

AIM

Endometriosis is an estrogen-dependent chronic inflammatory condition which causes pain, infertility, and predisposition for ovarian cancer. Endometriosis generates a unique microenvironment for survivability of endometriotic lesions which includes cell proliferation, differentiation, migration, and apoptosis. For these cellular activities, cascading activations of intracellular kinases are needed. Many kinase signaling pathways, IKKβ/NK-κB pathway, PI3K/AKT/mTOR, and the mitogen-activated protein kinase (MAPK) pathways (ERK1/2, p38, and JNK), are activated in endometriosis. In this review, we focus on the role of MAPK pathways in endometriosis.

METHODS

To identify the role of MAP Kinase signaling pathway in endometriosis we searched the Pubmed database using the search terms in various combinations "endometriosis," "endometrium," "ovary," "MAPK pathway," "ERK pathway," "p38 pathway," "JNK pathway," "estrogen," and "progesterone."

RESULTS

According to the current literature, MAPK signaling pathway has various roles in generating microenvironment and survival of endometriosis. Abnormal MAPK activation in migration, implantation, growth, invasion into the pelvic structures, proliferation, and apoptosis leads to the form of endometriosis and to worsen the condition in patients with endometriosis.

CONCLUSION

To further investigations on the effective and long-term endometriosis treatment, MAPK signaling pathways may be targeted. Molecular mechanism of MAPK signaling pathway in endometriosis should be more deeply understood and clinical trials should be more commonly performed for possible new endometriosis treatments to improve fertility and rescue endometriosis irreversibly.

Prospective phase II trial of levonorgestrel intrauterine device: nonsurgical approach for complex atypical hyperplasia and early-stage endometrial cancer

BACKGROUND

The incidence of complex atypical hyperplasia and early-stage endometrioid endometrial cancer is increasing, in part owing to the epidemic of obesity, which is a risk factor tightly linked to the development of endometrial hyperplasia and cancer. The standard upfront treatment for complex atypical hyperplasia and early-stage endometrial cancer is hysterectomy. However, nonsurgical treatment of early-stage endometrial neoplasia may be necessary owing to medical comorbidities precluding surgery or desired future fertility.

OBJECTIVE

This study aimed to evaluate the efficacy of the levonorgestrel intrauterine device to treat complex atypical hyperplasia and grade 1 endometrioid endometrial carcinoma.

STUDY DESIGN

A single-institution, single-arm, phase II study of the levonorgestrel intrauterine device (52 mg levonorgestrel, Mirena) was conducted in patients with complex atypical hyperplasia or grade 1 endometrioid endometrial cancer. The primary endpoint was pathologic response rate at 12 months, including complete or partial response. Quality of life and toxicity were assessed. Molecular analyses for proliferation markers, hormone-regulated genes, and wingless-related integration site pathway activation were performed at baseline and 3 months.

RESULTS

A total of 57 patients were treated (21 endometrial cancer, 36 complex atypical hyperplasia). The median age was 48.0 years, and the median body mass index was 45.5 kg/m². Of the 47 evaluable patients, 12-month response rate was 83% (90% credible interval, 72.7-90.3)-37 were complete responders (8 endometrial cancer; 29 complex atypical hyperplasia), 2 were partial responders (2 endometrial cancer), 3 had stable disease (2 endometrial cancer; 1 complex atypical hyperplasia), and 5 had progressive disease (3 endometrial cancer; 2 complex atypical hyperplasia). After stratification for histology, the response rate was 90.6% for complex atypical hyperplasia and 66.7% for grade 1 endometrioid endometrial cancer. Notably, 4 patients (9.5%) experienced relapse after the initial response. Adverse events were mild, primarily irregular bleeding and cramping. Quality of life was not negatively affected. At 3 months, exogenous progesterone effect was present in 96.9% of responders (31 of 32) vs 25% of nonresponders (2 of 8) (P=.001). Nonresponders had higher baseline proliferation (Ki67) and lower dickkopf homolog 3 gene expression than responders (P=.023 and P=.030). Nonresponders had significantly different changes in secreted frizzled-related protein 1, frizzled class receptor 8, and retinaldehyde dehydrogenase 2 compared with responders.

CONCLUSION

The levonorgestrel intrauterine device has a substantial activity in complex atypical hyperplasia and grade 1 endometrioid endometrial cancer, with a modest proportion demonstrating upfront progesterone resistance. Potential biomarkers were identified that may correlate with resistance to therapy; further exploration is warranted.

Identification and Validation of MSX1 as a Key Candidate for Progestin Resistance in Endometrial Cancer

Purpose

Progestin resistance is a critical obstacle for endometrial conservative therapy. Therefore, studies to acquire a more comprehensive understanding of the mechanisms are urgent. However, the pivotal molecules are still unexplored.

Materials and Methods

We downloaded GSE121367 from the GEO database. The “limma” R language package was applied to identify differentially expressed genes (DEGs). We conducted Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA). Protein–protein interaction was constructed by STRING and visualized in Cytoscape. The tumor immune microenvironment was explored by the TISIDB database. Methylation validation and overall survival analysis were conducted by the TCGA database. In addition, the upstream modulators of hub genes were predicted by miRTarBase and Network Analyst databases. The expression levels of candidate genes were validated by quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemical assay (IHC). Cell growth, clone formation, migration, invasion, and wound healing assays were studied to explore the role of MSX1 in progestin resistance in vitro.

Results

A total of 3,282 DEGs were identified and they were mostly enriched in the cell adhesion pathway. We screened out ten hub genes whose genomic alteration rates were low based on the current endometrial carcinoma sample sets. Has-miR-335-5p, has-miR-124-3p, MAZ, and TFDP1 were the most prominent upstream regulators. The methylation status of CDH1, JAG1, EPCAM, and MSX1 was decreased, corresponding to their high protein expression, which also predicted better overall survival. The homeobox protein of MSX1 showed significant tissue specificity and better prognostic value and its knockdown inhibited epithelial–mesenchymal transitions (EMT) and enhanced progesterone efficacy.

Conclusion

Our study identified that the gene of MSX1 promised to be the specific indicator and therapeutic target for progestin resistance. This would shed new light on the underlying biological mechanism to overcome progestin resistance of endometrial cancer.

Therapeutic Targets and Opportunities in Endometrial Cancer: Update on Endocrine Therapy and Nonimmunotherapy Targeted Options

Worldwide, the incidence of endometrial cancer is increasing. Although the prognosis remains good for patients diagnosed with early-stage disease, for those diagnosed with recurrent or metastatic disease, options have been limited, and prognosis is short. Optimizing and identifying new well-tolerated treatments for women living with endometrial cancer is a top priority. A new era is dawning where we are starting to see the integration of clinically relevant genomic and pathologic data to inform and refine treatment strategies for women with endometrial cancer. Here, we focus on reviewing nonimmunotherapy-based targeted treatment options and emerging directions for women with endometrial cancer.

Everolimus, Letrozole, and Metformin in Women with Advanced or Recurrent Endometrioid Endometrial Cancer: A Multi-Center, Single Arm, Phase II Study

PURPOSE

Treatment for patients with recurrent endometrioid endometrial cancer (EEC) are limited as paclitaxel is the only second-line chemotherapy with a response rate >13%. Targeting PIK3/mTOR in combination with hormonal therapy has shown promise. The addition of metformin may enhance this response. We conducted a phase II study evaluating everolimus, letrozole, and metformin in advanced/recurrent EEC.

PATIENTS AND METHODS

A Simon two-stage design was employed. Women with ≤2 prior chemotherapy regimens for recurrence were eligible. Pretreatment biopsy was required, followed by everolimus 10 mg orally, letrozole 2.5 mg orally, and metformin 500 mg orally twice a day on a 4-week cycle. The primary endpoint was clinical benefit (CB), defined as complete response (CR), partial response (PR), or stable disease (SD) confirmed at 16 weeks. Patients were treated until progression or toxicity.

RESULTS

Sixty-two patients were enrolled. Median age was 62 years (40-77) with 401 cycles completed, median of 6 cycles (1-31). Fifty-four patients were evaluable for response with a CB rate of 50% (27/54). Best overall response (OR) was PR 28% (15/54) and SD 22% (12/54). Thirteen patients received >12 cycles. Median follow-up was 17.9 months (2-47). Median progression-free survival was 5.7 [95% confidence interval (CI), 3.0-8.1] and OS was 19.6 months (95% CI, 14.2-26.3). Positive progesterone receptor expression was associated with CB (89.5% vs. 27.3%, P = 0.001).

CONCLUSIONS

Everolimus, letrozole, and metformin resulted in 50% CB and 28% OR in women with recurrent EEC. Progesterone receptor-positive tumors may have better response; validation studies are needed.See related commentary by Madariaga et al., p. 523.

Medroxyprogesterone acetate causes the alterations of endoplasmic reticulum related mRNAs and lncRNAs in endometrial cancer cells

BACKGROUND

Progestin is effective to promote endometrial cancer (EC) cells apoptosis, however, continuous progestin administration causes low level of progestin receptor B (PRB), further resulting in progestin resistance. Here, we performed microarray analysis on Ishikawa cells (PRB+) treated with medroxyprogesterone acetate (MPA) to explore the molecular mechanism underlying the inhibitory influence of MPA on PRB+ EC cells.

METHODS

Microarray analysis was performed by using Ishikawa cells (PRB+) treated with MPA. Differentially expressed mRNA and long noncoding RNAs (lncRNAs) were identified. Furthermore, the functions of these mRNAs and lncRNAs were predicted by functional enrichment analysis. QRT-PCR was further performed to verify the microarray data.

RESULTS

A total of 358 differentially expressed genes and 292 lncRNAs were identified in Ishikawa cells (PRB+) treated with MPA. QRT-PCR verified these data. Functional enrichment analysis identified endoplasmic reticulum (ER) stress as the key pathway involved in the inhibitory effect of MPA on EC cells. And the ER stress apoptotic molecule CHOP and ER stress related molecule HERPUD1 were both highly expressed in Ishikawa cells (PRB+) treated with MPA. Co-expression analysis showed lnc-CETP-3 was highly correlated with CHOP and HERPUD1, suggesting it might participate in ER stress pathway-related EC cell apoptosis caused by MPA. In addition, compared with untreated cells, lnc-CETP-3, CHOP and HERPUD1 were significantly up-regulated in Ishikawa cells (PRB+) treated with MPA, whereas they have no statistical significance in KLE cells (PRB-).

CONCLUSIONS

MPA may activate ER stress by progesterone-PRB pathway to up-regulate CHOP expression, which may be one of the molecular mechanisms underlying the inhibitory effect of MPA on EC cells with PRB+. Lnc-CETP-3 might be involved in this process. These findings may provide therapeutic targets for EC patients with PRB-, and resistance-related targets to increase the sensitivity of MPA on EC cells.

Clinical and Expression Significance of AKT1 by Co-expression Network Analysis in Endometrial Cancer

Introduction: Endometrial cancer is one of the most common uterine cancers worldwide. AKT is reported to regulate progesterone receptor B dependent transcription and angiogenesis in endometrial cancer. However, the potential mechanisms of AKT in the tumor progression of endometrial cancer remain unclear.

Methods: We used GSE72708 with gene expression profiles of AKT regulation from the GEO database. We performed GSEA analysis to explore pathway enrichments. We found that most upregulated enriched pathways in siAKT group were associated with acid metabolism and immune network. Endometrial cancer and various signaling pathways were downregulated enriched. Moreover, different molecular mechanism of regulation between progestin (R5020) and AKT was identified, which were related to VEGF signaling pathway. The hub genes were evaluated by immunohistochemical staining of endometrial cancer tissues.

Results: We screened out a total of 623 differentially expressed genes among different groups. According to weighted gene co-expression network analysis (WGCNA) method, four distinct modules were identified. We found brown module showed a very high positive correlation with siAKT group and a very high negative correlation with R5020 group. A total of six hub genes including PBK, BIRC5, AURKA, GTSE1, KNSTRN, and PSMB10 were finally identified associated with AKT1. In addition, the data also shows that the higher expression of AKT1, GTSE1, BIRC5, AURKA, and KNSTRN is significantly associate with poor prognosis of endometrial cancer.

Conclusion: Our study identified six hub genes related to the prognosis of endometrial cancer, which may provide new insights into the underlying biological mechanisms driving the tumorigenesis of endometrial cancer, especially in AKT1 regulation.

Prognostic Potential of Alternative Splicing Markers in Endometrial Cancer

Alternative splicing (AS), an important post-transcriptional regulatory mechanism that regulates the translation of mRNA isoforms and generates protein diversity, has been widely demonstrated to be associated with oncogenic processes. In this study, we systematically analyzed genome-wide AS patterns to explore the prognostic implications of AS in endometrial cancer (EC). A total of 2,324 AS events were identified as being associated with the overall survival of EC patients, and eleven of these events were further selected using a random forest algorithm. With the implementation of a generalized, boosted regression model, a prognostic AS model that aggregated these eleven markers was ultimately established with high performance for risk stratification in EC patients. Functional analysis of these eleven AS markers revealed various potential signaling pathways implicated in the progression of EC. Splicing network analysis demonstrated the notable correlation between the expression of splicing factors and AS markers in EC and further determined eight candidate splicing factors that could be therapeutic targets for EC. Taken together, the results of this study present the utility of AS profiling in identifying biomarkers for the prognosis of EC and provide comprehensive insight into the molecular mechanisms involved in EC processes.

Metformin Enhances Nomegestrol Acetate Suppressing Growth of Endometrial Cancer Cells and May Correlate to Downregulating mTOR Activity In Vitro and In Vivo

This study investigated the effect of a novel progestin and its combination with metformin on the growth of endometrial cancer (EC) cells. Inhibitory effects of four progestins, including nomegestrol acetate (NOMAC), medroxyprogesterone acetate, levonorgestrel, and cyproterone acetate, were evaluated in RL95-2, HEC-1A, and KLE cells using cell counting kit-8 assay. Flow cytometry was performed to detect cell cycle and apoptosis. The activity of Akt (protein kinase B), mTOR (mammalian target of rapamycin) and its downstream substrates 4EBP1 (4E-binding protein 1) and eIF4G (Eukaryotic translation initiation factor 4G) were assayed by Western blotting. Nude mice were used to assess antitumor effects in vivo. NOMAC inhibited the growth of RL95-2 and HEC-1A cells, accompanied by arresting the cell cycle at G0/G1 phase, inducing apoptosis, and markedly down-regulating the level of phosphorylated mTOR/4EBP1/eIF4G in both cell lines (p < 0.05). Metformin significantly increased the inhibitory effect of and apoptosis induced by NOMAC and strengthened the depressive effect of NOMAC on activity of mTOR and its downstream substrates, compared to their treatment alone (p < 0.05). In xenograft tumor tissues, metformin (100 mg/kg) enhanced the suppressive effect of NOMAC (100 mg/kg) on mTOR signaling and increased the average concentration of NOMAC by nearly 1.6 times compared to NOMAC treatment alone. Taken together, NOMAC suppressing the growth of EC cells likely correlates to down-regulating the activity of the mTOR pathway and metformin could strengthen this effect. Our findings open a new window for the selection of progestins in hormone therapy of EC.

CRISPR/Cas9-Mediated Gene Knockout of ARID1A Promotes Primary Progesterone Resistance by Downregulating Progesterone Receptor B in Endometrial Cancer Cells

Medroxyprogesterone (MPA) is used for the conservative treatment of endometrial cancer. Unfortunately, progesterone resistance seriously affects its therapeutic effect. The purpose of the current study was to investigate the influence of deletion of AT-rich interactive domain 1A (ARID1A) in progesterone resistance in Ishikawa cells. Ablation of ARID1A was conducted through the CRISPR/Cas9 technology. Acquired progesterone-resistant Ishikawa (Ishikawa-PR) cells were generated by chronic exposure of Ishikawa cells to MPA. The sensitivity of the parental Ishikawa, Ishikawa-PR, and ARID1A-deficient cells to MPA and/or LY294002 was determined using the Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis. In addition, Western blot analysis and reverse transcription-polymerase chain reaction was performed to evaluate the mRNA and protein expression levels of ARID1A, progesterone receptor B (PRB), and P-AKT. Both Ishikawa-PR and ARID1A knockout cells showed insensitivity to MPA, downregulation of PRB, and hyperphosphorylation of AKT compared to the parental Ishikawa cells. Pretreatment with LY294002 significantly enhanced the ability of MPA to suppress proliferation and to induce apoptosis in the parental and Ishikawa-PR cells via the inhibition of AKT activation and upregulation of PRB transcriptional activity. However, the PRB transcriptional activity and insensitivity to MPA were irreversible by LY294002 in ARID1A-deficient cells. Ablation of ARID1A is associated with low PRB expression, which serves an important role in primary progesterone resistance. Akt inhibition cannot rescue PRB or sensitize to MPA in ARID1A knockout cells. These findings suggest that ARID1A may act as a reliable biomarker to predict the response for the combination of AKT inhibitor and MPA treatment.

Comprehensive bioinformatics analysis of acquired progesterone resistance in endometrial cancer cell line

BACKGROUND

Progesterone resistance is a problem in endometrial carcinoma, and its underlying molecular mechanisms remain poorly understood. The aim of this study was to elucidate the molecular mechanisms of progesterone resistance and to identify the key genes and pathways mediating progesterone resistance in endometrial cancer using bioinformatics analysis.

METHODS

We developed a stable MPA (medroxyprogesterone acetate)-resistant endometrial cancer cell subline named IshikawaPR. Microarray analysis was used to identify differentially expressed genes (DEGs) from triplicate samples of Ishikawa and IshikawaPR cells. PANTHER, DAVID and Metascape were used to perform gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and cBioPortal for progesterone receptor (PGR) coexpression analysis. GEO microarray (GSE17025) was utilized for validation. The protein-protein interaction network (PPI) and modular analyses were performed using Metascape and Cytoscape. Further validation were performed by real-time polymerase chain reaction (RT-PCR).

RESULTS

In total, 821 DEGs were found and further analyzed by GO, KEGG pathway enrichment and PPI analyses. We found that lipid metabolism, immune system and inflammation, extracellular environment-related processes and pathways accounted for a significant portion of the enriched terms. PGR coexpression analysis revealed 7 PGR coexpressed genes (ANO1, SOX17, CGNL1, DACH1, RUNDC3B, SH3YL1 and CRISPLD1) that were also dramatically changed in IshikawaPR cells. Kaplan-Meier survival statistics revealed clinical significance for 4 out of 7 target genes. Furthermore, 8 hub genes and 4 molecular complex detections (MCODEs) were identified.

CONCLUSIONS

Using microarray and bioinformatics analyses, we identified DEGs and determined a comprehensive gene network of progesterone resistance. We offered several possible mechanisms of progesterone resistance and identified therapeutic and prognostic targets of progesterone resistance in endometrial cancer.

Fertility-preserving treatment in women with early endometrial cancer: the Chinese experience

Endometrial cancer (EC) is the most common malignant tumor of the female reproductive tract in developed countries and the second most common gynecologic malignancy in China. Although EC is most often diagnosed in postmenopausal women, the increase in obesity rates and other lifestyle changes has been accompanied by an increase in the prevalence of EC among younger women. Approximately 4% of patients are diagnosed before the age of 40 years and before having given birth. Such patients may have a strong desire to preserve their fertility despite oncologic risks and thus may be reluctant to undergo standard treatment for EC, which includes hysterectomy, bilateral salpingo-oophorectomy, and surgical staging. Therefore, more conservative treatment approaches may need to be discussed, along with their associated oncologic and reproductive outcomes. In fact, various studies have confirmed the effectiveness and safety of conservative treatment in EC. This review aimed to provide a concise yet informative overview of the current status of fertility-preserving treatment for EC in China, as well as to summarize the latest and ongoing research efforts in this area.

Bu Shen Yang Xue Prescription Has Treating Effect on Endometrial Cancer through FSH/PI3K/AKT/Gankyrin/HIF-α/cyclinD 1 Pathway in Ishikawa Cells

Background. The formulation of Bu Shen Yang Xue (BSYX) has been clinically used in treating gynecologic disease in China, especially for the development of the endometrium. Endometrial carcinoma is the most common malignant tumor of the female genital tract in developed countries. And few studies have been reported on the antitumor activity of BSYX. Therefore, this study aimed to investigate the effect of BSYX on endometrial cancer and make an initial discussion of the underlining mechanisms in Ishikawa cells. Methods and Results. Firstly, 60 SPF female nude mice were randomly divided into control group, model group, BSYX group, and positive group. The models of subcutaneous tumor xenograft of nude mice were established by injection of human endometrial carcinoma cell line Ishikawa tumor cell suspension. Compared with model group, BSYX reduced effectively tumor volume and changed pathological feature in mice tumor issue. Meanwhile, proteins from tumor issues were detected by western blot analysis. The protein levels of follicle-stimulating hormone receptor (FSHR), p-Akt/Akt, Gankyrin, and cyclinD1 in the model group were higher than those in control group but the expression in BSYX group was lower than that in the model group. The hypoxia inducible factor alpha (HIF-α) protein level in the model group was lower than those in control group and upregulated in BSYX group. In addition, Ishikawa cells were cultured and then exposed to follicle-stimulating hormone (FSH), LY294002, a highly selective PI3K inhibitor and serum containing BSYX, respectively. LY294002 and BSYX markedly decreased the cancer cell viability and migration ability and increased the apoptosis rate. FSH promoted the cancer cell ability and migration ability. LY294002 and BSYX evidently downregulated the proteins levels of FSHR, p-Akt/Akt, Gankyrin, and cyclinD1 and upregulated the expression of HIF-α protein, and FSH was on the opposite. Conclusions. Taken together, our results showed that the formulation of BSYX had antitumor effect on endometrial cancer in vivo and in vitro and was related with FSH/PI3K/AKT/Gankyrin/HIF-α/cyclinD1 transduction pathway.

Progesterone Resistance in Endometriosis: an Acquired Property?

Endometriosis is the growth of endometrial tissue outside the uterus and is characterized by progesterone resistance and changes in global and progesterone target gene expression. However, the mechanism behind this and whether it is innate, acquired, or present in both the eutopic and ectopic tissue in not always clear. We find large-scale gene expression studies in eutopic tissue, indicative of progesterone resistance, are often contradictory, potentially due to the dynamic nature of this tissue, whereas suppressed progesterone receptor expression is supported in ectopic but not eutopic tissue. This suggests more studies are required in eutopic tissue particularly, and that potentially the suppressed progesterone receptor (PR) expression is a consequence of the pathogenic process and exposure to the peritoneal environment.

miR-182 aids in receptive endometrium development in dairy goats by down-regulating PTN expression

Increasing evidence has shown that miRNAs play important roles in endometrium development during the menstrual cycle in humans and many other animals. Our previous data indicated that miR-182 levels increase 15.55-fold and pleiotrophin (PTN) levels decrease 20.97-fold in the receptive endometrium (RE, D15) compared with the pre-receptive endometrium (PE, D5) in dairy goats. The present study shows that miR-182 is widely expressed in different tissues of dairy goats and that its expression levels are regulated by E2 and P4 in endometrial epithelium cells (EECs). We confirmed that PTN is a target of miR-182 and that miR-182 regulates the protein levels of AKT, Bcl-2, FAS, MAPK, Caspase-3 and SP1 in EECs. Furthermore, miR-182 up-regulates or maintains the expression levels of osteopontin (OPN), cyclooxygenase-2 (COX-2) and prolactin receptor (PRLR) in EECs, suggesting that miR-182 is an important regulatory factor in the construction of endometrial receptivity in dairy goats. In conclusion, miR-182 participates in the development of endometrial receptivity by down-regulating PTN and affecting the expression of select apoptosis-related genes and increasing or maintaining the expression levels of OPN, COX-2 and PRLR in the EECs of dairy goats.

Mechanism of progestin resistance in endometrial precancer/cancer through Nrf2-AKR1C1 pathway

Progestin resistance is a main obstacle for endometrial precancer/cancer conservative therapy. Therefore, biomarkers to predict progestin resistance and studies to gain a more detailed understanding of the mechanism are needed. The antioxidant Nrf2-AKR1C1 signal pathway exerts chemopreventive activity. However whether it plays a role in progestin resistance has not been explored. In this study, elevated levels of AKR1C1 and Nrf2 were found in progestin-resistant endometrial epithelia, but not in responsive endometrial glands. Exogenous overexpression of Nrf2/AKR1C1 resulted in progestin resistance. Inversely, silencing of Nrf2 or AKR1C1 rendered endometrial cancer cells more susceptible to progestin treatment. Moreover, medroxyprogesterone acetate withdrawal resulted in suppression of Nrf2/AKR1C1 expression accompanied by a reduction of cellular proliferative activity. In addition, brusatol and metformin overcame progestin resistance by down-regulating Nrf2/AKR1C1 expression. Our findings suggest that overexpression of Nrf2 and AKR1C1 in endometrial precancer/cancer may be part of the molecular mechanisms underlying progestin resistance. If validated in a larger cohort, overexpression of Nrf2 and AKR1C1 may prove to be useful biomarkers to predict progestin resistance. Targeting the Nrf2/AKR1C1 pathway may represent a new therapeutic strategy for treatment of endometrial hyperplasia/cancer.

New Targeted Agents in Endometrial Cancer: Are We Really Making Progress?

Endometrial cancer is the most common gynecological malignancy in Europe and North America. Metastatic and recurrent disease is generally incurable with poor prognosis. Recent advances in molecular profiling of endometrial cancer have elucidated four distinct molecular subtypes with different biology and prognosis which should facilitate the development of treatments tailored to disease-specific subgroups. To date, some molecular-targeted agents have shown interesting clinical activity in the recurrent setting, but no targeted therapies are approved for endometrial cancer. Novel pan-PI3K, AKT, and dual PI3K-mTOR inhibitors are being investigated with early signs of activity, but there are concerns about tolerability and toxicity in this often elderly patient population with comorbidities. The development of anti-angiogenic therapies, PARP inhibitors, and immunotherapies, alone or in combinations, appear to be promising strategies. This paper will describe the current evidence supporting the efficacy of molecular-targeted agents already tested in the treatment of metastatic and recurrent EC, and provide some insights on emerging data related to novel-targeted therapies.

Targeting mTOR pathway in gynecological malignancies: Biological rationale and systematic review of published data

BACKGROUND

mTOR inhibitors are widely used in different malignancies with several trials testing their efficacy and safety in gynecological malignancies. We aimed to review the current evidence that support the expansion of using such drugs in the treatment of advanced gynecological cancers.

METHODS

A comprehensive systematic review of literature has been conducted to include prospective trials that used everolimus, temsirolimus or ridaforolimus in the management of gynecological cancers and have available efficacy and toxicity results.

RESULTS

A total of 23 studies including 980 patients were considered eligible for our review. Our review included 16 phase II and 7 phase I studies with the majority of patients having uterine cancers. Regarding Endometrial cancer, the CBR ranged from 21% to 60% and median PFS from 2.8 months to 7.3 months. In Ovarian cancers, CBR ranged from 24% to 50% and median PFS from 3.2 months to 5.9 months. In the single phase II study in cervical cancer the CBR was 61% and median PFS was 3.5 months. The toxicity profile was consistent with what was observed previously in other malignancies with fatigue, mucositis, and hematological toxicities being the most common adverse events observed.

CONCLUSION

mTOR inhibitors seem to be a promising option in the second line management of advanced gynecological cancers with best safety and efficacy outcomes when given as a single agent or in combination with hormonal treatment. More research is needed for better patient selection.

Chemotherapy for Endometrial Cancer in Adjuvant and Advanced Disease Settings

: Level I evidence exists for use of adjuvant chemotherapy in stage IIIC endometrial cancer (positive lymph nodes), although results of randomized trials have varied. Chemotherapy is also often recommended for high-risk subsets of stage I disease, such as serous carcinomas, although prospective trial data to validate this practice are lacking. Carboplatin plus paclitaxel is the current standard regimen, based on extrapolation of data from the metastatic setting. Several clinical trials have compared adjuvant pelvic radiotherapy alone to a combination of radiotherapy and chemotherapy with mixed results. One of the largest of these trials, Postoperative Radiation Therapy in Endometrial Carcinoma 3 (PORTEC-3), has completed accrual and is awaiting data maturation. Metastatic disease is not curable. For tumors of low-grade endometrioid histology with a prolonged time to recurrence, endocrine therapy with a progestin-based regimen is appropriate. Chemotherapy will be used in most other cases, and the standard first-line regimen is carboplatin and paclitaxel. Few chemotherapy agents have been shown to produce meaningful response rates in the second-line setting. Molecularly targeted therapies such as mTOR inhibitors and antiangiogenic agents including bevacizumab have been studied but their role in the armamentarium remains uncertain.

IMPLICATIONS FOR PRACTICE

Following surgical resection and staging for endometrial cancer, adjuvant chemotherapy with carboplatin and paclitaxel can be administered to patients with a high risk for recurrence. This includes patients with stage IIIC disease with positive lymph nodes, and high-risk subsets of stage I disease such as serous carcinomas. In the metastatic setting, endocrine therapy can be considered, particularly for patients with lower-grade disease and a prolonged time to recurrence. Combined therapy with carboplatin and paclitaxel is the standard of care used for front-line chemotherapy. Antiangiogenic agents are clearly active, but how they should be integrated into treatment is not yet determined. Immunotherapy is a promising direction for patients with mismatch repair-deficient or polymerase ε-mutated tumors.

HE4 is a novel tissue marker for therapy response and progestin resistance in medium- and low-risk endometrial hyperplasia

Background:

The aim of the present study was to investigate whether changes in the tissue expression of human epididymis-specific protein 4 (HE4) could predict therapy resistance and relapse after progestin hormone therapy for medium- and low-risk endometrial hyperplasia.

Methods:

Endometrial biopsies were obtained from women participating in a multicentre RCT performed according to the CONSORT guidelines; the women were randomly assigned to either LNG-IUS; 10 mg of oral medroxyprogesterone acetate (MPA) administered for 10 days per cycle; or 10 mg of oral MPA administered daily for 6 months. Of the 153 women who completed therapy, 141 had adequate material for immunohistochemistry in pre- and post-treatment biopsies. An antibody to HE4 (clone 12A2 monoclonal IgG1 antibody, Fujirebio Diagnostics, Inc.) was used for the immunohistochemical staining of the pre- and post-treatment biopsies from each participant. The expression of HE4 staining was evaluated by the histological score (H-score) using light microscopy.

Results:

Changes in the expression of HE4 (H-score) during therapy were related to the therapy group (P<0.001) and therapy response (P<0.001) of the individuals but could not predict relapse (P>0.05). Changes in the intracellular bodies were shown to predict both the therapy response (P=0.038) and relapse (P=0.014).

Conclusions:

Changes in the expression of HE4 during progestin therapy regimens can predict therapy response or indicate progestin resistance for medium- and low-risk endometrial hyperplasia.

Akt regulates progesterone receptor B-dependent transcription and angiogenesis in endometrial cancer cells

Progestins have long been used clinically for the treatment of endometrial cancers, however, the response rates to progestin therapy vary and the molecular mechanisms behind progestin insensitivity are poorly understood. We hypothesized that in PTEN mutated endometrial cancers, hyperactive Akt signaling downregulates Progesterone Receptor B (PRB) transcriptional activity, leading to overall impaired progestin responses. We report that inhibition of Akt with the Akt inhibitor, MK-2206 (MK), in conjunction with progestin (R5020) treatment, is sufficient to upregulate a subset of PRB target genes in Ishikawa cells stably expressing PRB (PRB-Ishikawa). Through gene ontology analysis of Akt-regulated PRB target genes, angiogenesis was found to be the principle process regulated by Akt-PRB. To further interrogate the mechanism by which Akt modulates PRB transcriptional activity, ChIP-Mass Spectrometry was performed to identify potential cofactors that differentially interact with PRB in the presence of the R5020 and MK+R5020. 14-3-3σ was identified as a protein enriched in the MK+R5020 dataset, and it was demonstrated that 14-3-3σ is required for the upregulation in PRB target gene expression following inhibition of Akt. In order to determine the ramifications of MK+R5020 treatment on angiogenesis, in vitro assays were performed and combinatorial MK+R5020 treatment significantly decreased endothelial cell invasion and tube formation more than MK or R5020 treatment alone. Furthermore, we found that combinatorial MK-2206+Progesterone treatments decreased angiogenesis and proliferation in the Pten^d/d conditional mouse model of endometrial cancer. Taken together, these findings suggest that a combinatorial therapeutic approach utilizing Akt inhibitors with progestins may improve the efficacy of progestin therapy for the treatment of endometrial cancer.

Emerging strategies for targeting PI3K in gynecologic cancer

Ovarian, endometrial and cervical cancers are the most prevalent gynecologic cancers in the United States and account for significant mortality. Translational research into these cancers has highlighted the distinctive molecular and genomic profiles of these cancers finding that, even within a disease site, the landscapes and drivers of neoplasia are distinctive. Despite this molecular diversity, activation of the phosphatidylinositol-3-kinase (PI3K) pathway appears to be conserved in subsets of these tumors, suggesting that strategies that antagonize mediators in this signaling cascade could offer anti-tumor efficacy. Extensive pre-clinical and clinical data have demonstrated that single agent targeted therapies lead to modest single agent activity of generally limited duration, even in the setting of innate PI3K pathway activation via mutation or amplification. These findings in the laboratory and clinic have prompted investigations into resistance pathways following PI3K pathway inhibition in order to understand escape pathways and restore tumor cell sensitivity. A next generation of clinical trial investigations will focus on novel combinations in order to define how these important therapeutics can be used in the clinic. This review will present preclinical data that supports the role of the PI3K pathway in ovarian, endometrial and cervical cancers, in addition to discussing the reported clinical trial experience with PI3K pathway inhibition. A specific focus will be on the rationale behind ongoing clinical trials utilizing novel agents in concert with PI3K pathway inhibitors to reverse resistance in populations with and without gain of function alterations in this oncogenic signaling cascade.

Genetic and molecular analyses reveal G6PC as a key element connecting glucose metabolism and cell cycle control in ovarian cancer

We aimed to evaluate the role of glucose-6-phosphatase, catalytic subunit (G6PC) in ovarian cancer and to exploit its therapeutic potential. With reproduction of The Cancer Genome Atlas (TCGA) database, we studied expressions of genes in the glucose metabolism pathways in silico. The cBioPortal For Cancer Genomics was used to study the clinical, pathological and molecular profiles of G6PC. In vitro studies were performed to validate the function of G6PC and the effect of genetic and pharmaceutical G6PC inhibition. In 158 ovarian cancer (OvCa) patients with complete RNA-seq data, G6PC expression was increased in 27 patients (17 %). Both overall survival (OS) and disease-free period were significantly shorter in cases with increased G6PC level. Significantly decreased total and phosphorylated CDKN1B level was noted in OvCa with increased G6PC expression. Silenced G6PC in OvCa cells induced decreased cell proliferation, viability, invasiveness and anchorage-independent cell growth. G6PC silencing also induced enhanced cell cycle control proteins and restoration of CDKN1B level. Pharmaceutical inhibition of G6PC with specific compound showed similar effects to genetic silencing. G6PC played dual roles both in glucose metabolism and cell cycle control in OvCa, which potentiated it a promising therapeutic target.