Endometrial Cancer Cells Research Articles

Phytochemical Profiling and Biological Effects of Glycyrrhiza glabra L.

Glycyrrhiza glabra L. commonly known as licorice belonging to the family Leguminosae is an ayurvedic medicinal plant having substantial pharmacological properties such as anti-inflammatory and anticancer effects. Analysed ethnopharmacological studies show phytochemical and biological activities of the plant extract and serve as a resource for studying anti- endometriosis. According to WHO, 176 million women in the world are affected with endometriosis condition and up to 30-50% of women may experience infertility. Our study aims to evaluate in vitro activity of ethanolic extract of Glycyrrhiza glabra in different cell lines, DPPH assay and HPLC studies in order to propose it to be an effective remedy in endometriosis treatment. In vitro cytotoxic assessment of the extract was determined in estrogenic (MCF 7), non-estrogenic (MDAMB 231) and endometrial cancer cell lines (Ishikawa) along with its safety assessment in normal cell lines (L929). The extract of G. glabra exhibited DPPH radical scavenging activity with 77.09% inhibition in 100 μg concentration. Cytotoxic activity of extract in MCF 7, MDAMB 231, endometrial cancer cells- Ishikawa and significant cell viability in normal L929 cell line shows promising effect of the extract and suggests it as a possible therapeutic adjuvant for treating endometriosis.

Cinobufacini suppresses malignant behaviors of endometrial cancer by regulating NF-κB pathway

ABSTRACT Cinobufagin has inhibitory effects on various tumors, but there are few studies on gynecological tumors. This study explored the function and molecular mechanism of cinobufagin in endometrial cancer (EC). Different concentrations of cinobufagin treated EC cells (Ishikawa and HEC-1). Clone formation, methyl thiazolyl tetrazolium (MTT), flow cytometry, and transwell assays were used to detect malignant behaviors. A Western blot assay was performed to detect protein expression. Cinobufacini was sensitive to the inhibition of EC cell proliferation in a time- and concentration-dependent manner. Meanwhile, EC cell apoptosis was induced by cinobufacini. In addition, cinobufacini impaired the invasive and migratory abilities of EC cells. More importantly, cinobufacini blocked the nuclear factor kappa beta (NF-κB) pathway in EC by inhibiting p-IkBα and p-p65 expression. Cinobufacini suppresses malignant behaviors of EC by blocking the NF-κB pathway.

YBX2 modulates mRNA stability via interaction with YTHDF2 in endometrial cancer cells

RNA-binding proteins (RBPs) fine-tune gene expression by modulating RNA stability, translation, and degradation. RBPs are involved in the development of endometrial cancer. In particular, Y-box-binding protein 2 (YBX2), a germ cell-specific member of the YBX family, has been reported to maintain cancer stem cell-like phenotypes in endometrial cancer. However, the mechanism by which YBX2 modulates mRNA stability in endometrial cancer cells remains unknown. In this study, we examined the effects of the ectopic expression of YBX2 in endometrial adenocarcinoma-derived Ishikawa cells. We found that elevated levels of YBX2 delayed cell proliferation, without increasing cell apoptosis. Transcriptomic analysis revealed disturbances in gene expression caused by YBX2. Interestingly, heat shock protein family A (Hsp70) member 6 (HSPA6) levels were downregulated due to the reduced mRNA stability after YBX2 binding. YBX2 facilitated the formation of relatively stable cytoplasmic granules in tumor cells via its mRNA binding domain. Moreover, N6-methyladenosine (m6A) reader proteins are recruited by YBX2 granules via the cold-shock domain. Notably, knockdown of YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2), an m6A reader, ameliorated the reduction in HSPA6 mRNA levels induced by YBX2, indicating the synergistic effects of YBX2 and YTHDF2 on mRNA stability. Therefore, YBX2 regulates RNA stability by interacting with the m6A reader proteins.

Abstract 440: The role of PELP1 inhibitor SMIP34 in the treatment of endometrial cancer

Abstract Background: Endometrial cancer (ECa) is the fourth most prevalent type of cancer in women. Although ECa mostly affects older women, both the mortality and incidence rates are rapidly rising in women under the age of 40. Response rates and progression free survival are still low for recurrent ECa treatments such as hormone therapy, chemotherapy, and targeted therapies like Bevacizumab and Everolimus. There is an unmet need for the development of novel targeted therapeutics to support current ECa-directed treatments. The progression of many cancers, including ECa, is linked to proto-oncogenic PELP1 (proline-, glutamic acid-, and leucine-rich protein 1). In this investigation, we evaluated the efficacy of the PELP1 inhibitor, SMIP34, both alone and in combination with mTOR inhibitors in ECa. Methods: Using 13 distinct ECa cells, the effect of SMIP34 alone and in conjunction with mTOR inhibitors was assessed using the cell viability and colony formation assays. Using flow cytometry and Annexin-V/PI labeling, the ability of SMIP34 to promote apoptosis was evaluated. The effect of SMIP34 on cell cycle progression was evaluated using FACS analyses. RT-qPCR, Western blotting, and global RNA-seq were used for mechanistic studies. ECa patient-derived organoids (PDO), explants (PDEX) and xenograft model were used to assess the impact of SMIP34. TNM and Dependency Map (DepMap) databases were used to profile the status of PELP1 in ECa. The status of PELP1 in ECa tissues was analyzed using IHC analyses of ECa tumor tissue Microarrays. Results: Analysis of TNM plots showed that PELP1 expression was higher in ECa than in normal endometrium. Data from DepMap confirmed that PELP1 is required for the survival and expansion of ECa cells. SMIP34 treatment of established and primary patient-derived ECa cells significantly reduced cell viability and colony formation with an IC50 of 2-10µM. PELP1 knockdown significantly reduced the effect of SMIP34. Further, SMIP34 treatment induced apoptosis and promoted S-phase arrest in ECa cells. RNA-seq analyses showed that SMIP34 regulated genes positively correlated with p53 and apoptosis pathways, while negatively correlated with ribosome and eukaryotic translation elongation pathways. Western blot analyses confirmed that SMIP34 treatment reduced the levels of PELP1 and its complex of proteins including TEX10, LAS1L, SENP3. Mechanistic studies demonstrated that SMIP34 treatment attenuated the activation of mTOR signaling in ECa cells. Accordingly, SMIP34 enhanced the effect of mTOR inhibitors on ECa cells. SMIP34 is effective in reducing cell viability in PDO and limited the cells proliferation of PDEX. Importantly, SMIP34 treatment significantly reduced of the growth of ECa cell line-derived xenografts. Conclusions: Collectively, our results suggest that SMIP34 inhibits ECa growth in vitro, in vivo, and ex vivo and combination of SMIP34 with mTOR inhibitor represents a novel therapeutic strategy for ECa. Citation Format: Xue Yang, Zexuan Liu, Weiwei Tang, Uday P. Pratap, Alexia B. Collier, Kristin A. Alwegg, Nicole Spencer, Xiaonan Li, Philip T. Valente, Edward R. Kost, Suryavathi Viswanadhapalli, Ratna K. Vadlamudi. The role of PELP1 inhibitor SMIP34 in the treatment of endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 440.

Abstract 4928: Gedatolisib, a well-tolerated pan-PI3K/mTOR inhibitor, exhibits potent therapeutic effects on endometrial cancer models regardless of their PI3K pathway mutational status

Abstract Background: The PI3K, AKT, and mTOR (PAM) pathway is one of the most commonly activated oncogenic pathways in gynecological cancers. Loss of PTEN function and PIK3CA activating mutations are especially frequent in endometrial cancer (EC). Targeting the PAM pathway, in combination with other cooperative oncogenic pathways (e.g., the estrogen pathway), is a promising EC treatment strategy. Currently, everolimus, an mTORC1 inhibitor, in combination with letrozole, an aromatase inhibitor, is one of the available hormonal therapy options for patients with advanced endometrioid EC. Most PAM inhibitors (PAM-i) selectively spare (or weakly inhibit) one or more key PAM pathway components, which can lead to drug resistance. To minimize drug resistance, a more comprehensive inhibition of the PI3K isoforms and downstream mTOR complexes may be required. We hypothesized that gedatolisib, which potently inhibits all Class I PI3K isoforms, mTORC1, and mTORC2, can potentially be an effective and well tolerated therapy for patients with EC. Methods: A panel of endometrial, ovarian and cervical cancer cell lines with different PI3K pathway mutational status were assayed for their sensitivity to gedatolisib and other PAM inhibitors (PI3K-α: alpelisib, pan-PI3K: copanlisib; AKT: capivasertib; mTORC1: everolimus; pan-PI3K/mTOR: gedatolisib). Cell viability, cell proliferation, and flow cytometry analytical assays were conducted. Xenograft studies evaluating gedatolisib in EC cell lines were also performed. Results: Gedatolisib strongly inhibited PAM pathway activation, and reduced cell cycle progression and cell viability in the endometrial, ovarian, and cervical cancer cell lines. Compared to the other PAM-i, Gedatolisib exhibited superior anti-proliferative potency and efficacy in almost all the cell lines tested, regardless of the PI3K pathway mutational status or cancer type. In EC xenografts, gedatolisib substantively inhibited tumor growth irrespective of the cell line models’ PI3K pathway mutational status. Conclusions: We demonstrated that, gedatolisib induces superior anti-proliferative activity compared to the other PAM pathway inhibitors, regardless of the PI3K pathway mutational status of the cancer cell lines evaluated. Gedatolisib as a single agent and in combination with other therapies has previously reported promising preliminary clinical efficacy and safety in various solid tumor types, including EC. In summary, nonclinical and preliminary clinical data supports the development of gedatolisib in combination with hormonal therapy for treatment of patients with EC. Citation Format: Stefano Rossetti, Aaron Broege, Ian MacNeil, Ben Rich, Jhomary Molden, Brian Sullivan, Lance Laing. Gedatolisib, a well-tolerated pan-PI3K/mTOR inhibitor, exhibits potent therapeutic effects on endometrial cancer models regardless of their PI3K pathway mutational status. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4928.

Abstract 675: Understanding SETDB1-mediated tumor immune evasion mechanism in endometrial cancer

Abstract SETDB1 is characterized as an important epigenetic regulator in many different cancers and involved in transcriptional silencing of many different processes and pathways. It is often overexpressed in many different cancers including colon, melanoma, breast and pancreatic cancers and its high expression is correlated with worse patient outcome. Often associated with repressing complexes such as HUSH and KAP1/KRAB, it has been shown to repress many different genes such as p53 and p21 through histone H3K9 methylation. In addition, it has been implicated in regulating transposable elements (TEs), primarily of the LTR types as well as SINEs and LINEs. Activation of TEs is key to induction of anti-viral response genes such as the type I interferon pathway and immune-stimulated genes (ISGs) which in turn promote innate immune response against the tumor. Here, we show that SETDB1 promotes tumor growth in endometrial cancer possibly through establishing an immune evasion from the innate immune system. Mice subcutaneously injected with SETDB1 depleted endometrial cancer cells show prolonged survival time and reduced tumorigenesis. In NSG mice, we demonstrate that subcutaneously injected endometrial cancer cell, ISHIKAWA, shows both increased penetration and recruitment of macrophages in the tumor when SETDB1 is knocked out. Our macrophage-cancer cells co-culture in-vitro assay suggests that macrophages induce greater killing in SETDB1-/- cells when stimulated into M1 phenotype more so than in WT cancer cells. Further, tumor IHC analysis shows greater proliferation capacity for control tumor relative to SETDB1-/- as evident by greater mitotic figures per unit area and Ki67 staining score. We further show that cytokines such as CCL5 and CXCL9 (previously reported for their positive correlation with T-cell infiltration in tumor) are significantly upregulated in SETDB1 knockout tumors relative to non-targeting control tumors (NT) as well as in cell lines. Endometrial cancer TCGA data show significant negative correlation between SETDB1 and markers of T-cell infiltration such as CD8A and IFNG as well as cytokines CCL5 and CXCL9. Overall, these findings show important implication of SETDB1 in macrophage recruitment and macrophage-mediated killing of cancer cells in addition to its role in promoting tumor cells proliferation. Citation Format: Kiarash Salari, Matthew Wells, Eleanor R. Johnson, Tianyue Li, Jiaqing Hao, Bing Li, Shujie Yang. Understanding SETDB1-mediated tumor immune evasion mechanism in endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 675.

Abstract 1175: Systematic profiling of conditional pathway activation as a new class of cancer dependency

Abstract The paradigm of cancer dependencies and targeted therapies has been nearly exclusively focused on inhibiting critical pathways or nodes in cancer. However, conditional activation of signaling pathways as a new source of selective cancer vulnerabilities has not been systematically characterized. In this study, we sought to systematically identify context-specific gene activation lethalities in cancer. We performed lineage-specific mutual-exclusivity (ME) analysis using 69,393 cancer patient genomes in cohorts of AACR-GENIE, TCGA, and Foundation One, across 12 cancer lineages, and identified ME mutation pairs within MAPK, PI3K and WNT pathways indicative of evolutionarily negative selection. To functionally test whether mutual exclusive genetic alterations likely create negative selection pressures in cancer, we developed a lentiviral method to achieve simultaneous ectopic ORF expression ~500 barcoded cancer cell lines for large-scale gain-of-function genetic perturbation. Using this technology, we systematically profiled the pan-cancer vulnerability landscape upon activating 10 key pathway nodes, revealing selective activation dependencies associated with specific biomarkers. We validated the anti-tumor effect of PI3K hyperactivation in PIK3CA/PTEN double-mutant endometrial cancer cell lines. Notably, we find that subsets of APC-mutant colorectal cancers retain active destruction complexes. Upon further depletion of APC or direct expression of β-catenin, the resulting WNT pathway hyperactivation impairs the viability of APC-mutant colorectal cancers in in vitro cell lines and organoids and in in vivo tumor models. Together, our study reveals a new class of conditional gene activation dependencies in cancer. Citation Format: Liang Chang, Nancy Y. Jung, Adel Atari, Devishi Kesar, Diego J. Rodriguez, Matthew A. Rees, Melissa Ronan, William R. Sellers. Systematic profiling of conditional pathway activation as a new class of cancer dependency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1175.

Abstract 4877: Mutant or overexpressed SF3B1 facilitates endometrial cancer tumorigenesis

Abstract Aberrant expression or mutations in core splicing factors including U2AF1, SRSF2, ZRSR2, and SF3B1 found to drive tumorigenesis of various malignant tumors e.g., myelodysplastic syndromes, chronic lymphocytic leukemia, uveal melanoma, and breast cancer. Importantly, the amplifications and mutations in SF3B1, the pioneer splicing factor, are reportedly far more common than those in other splicing factors. However, the functional relevance and underlying mechanisms of dysregulated SF3B1 in endometrial cancer are not investigated. Endometrial cancer is the fourth most common cancer in women in the United States and there will be about 65,950 new endometrial cancer cases in the current year alone with 12,550 estimated cancer deaths in the United States. In this study, we thus investigated the role of SF3B1 in endometrial adenocarcinoma. We found SF3B1 is one of the most frequently amplified or mutated splicing factors in endometrial cancer. Specifically, analysis of The Cancer Genome Atlas (TCGA) uterine pan-cancer dataset revealed that up to 9% of endometrial cancers have SF3B1 mutations or amplification. Additionally, we showed that the SF3B1 protein is overexpressed in human as well as mouse endometrial tumor samples. Further analysis found elevated SF3B1 protein in multiple endometrial cancer cell lines even in the absence of SF3B1 mutations. However, we did not observe any altered expression at the transcript level. Further, we identified a correlation between the over-expressed SF3B1 levels and the tumorigenicity/invasive potential of cancer cell lines. For instance, endometrial cancer cell lines (Ishikawa, AN3CA, KLE) with over-expressed SF3B1 levels were much more tumorigenic and invasive than those with low endogenous SF3B1 levels (normal human endometrial epithelial cells, RL-95-2 cells). Moreover, cell viability assays revealed that Ishikawa, AN3CA, and KLE cells were more susceptible to the loss of SF3B1 or treatment with the SF3B1 inhibitor Pladienolide-B (PLAD-B) than RL-95-2 cells. To further ensure that overexpressed or mutated SF3B1 drives endometrial tumorigenesis, we transiently transfected an empty vector or a vector expressing FLAG-tagged wild-type SF3B1 or vector with mutated SF3B1 construct R957Q into RL-95-2 cells which have minimal endogenous SF3B1. Analysis of proliferation assays revealed that cells overexpressing SF3B1 proliferated significantly more than cells expressing empty vector. Intriguingly, we observed that RL-95-2 cells over-expressing R957Q mutants were even more proliferative than the cells expressing wild-type SF3B1. Together, this data suggest that SF3B1 over-expression and mutation play a crucial oncogenic role in endometrial cancer, and these findings may support the development of SF3B1 inhibitors to treat this disease. Citation Format: Pooja Popli, Xinchao Deng, Premal Thaker, Ramakrishna Kommagani. Mutant or overexpressed SF3B1 facilitates endometrial cancer tumorigenesis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4877.

Abstract 4885: APR-246 cytotoxic effects are TP53 independent in endometrial cancer cell lines

Abstract Background: The majority (80%) of endometrial cancer (EC) related mortality is due to high-grade tumor histology, which harbor high rates of TP53 mutations. APR-246 is a small-molecule drug designed to restore WT p53 signaling in TP53-mutant cancers and has yet to be explored in EC. We aimed to test the cytotoxic potential for APR-246 in EC and its downstream impact. Methods: Using 3 parental EC cell lines with differing TP53 statuses, JHUEM2 (WT), Hec108 (hetero P151H), and Hec1B (R248Q), we generated dose-response curves for APR-246. Cells were treated for 24 hours and viability assessed with CellTiter-Glo after 9 days. To assess for mutation specific effect, we generated dose-response curves using a WT non-targeting control (NTC), CRISPR/Cas9 KO of TP53, and five KO cell lines complemented with 5 common TP53 mutations (R248Q, R248W, R273C, R273H, Y220C). Western blot analysis was performed to assess for p53, p21, PUMA, GADD45, and NOXA using whole-cell lysates, after treatment with 20μM of APR-246 for 24 hours. To further evaluate for a time-dependent effect, 2 representative variants (R248Q and R273C) after 6 and 24 hours of incubation with 50μM APR-246 and 10μM of Nutlin-3. Results: APR-246 demonstrated a negative, dose-dependent effect on cell viability in all EC cell lines. IC50s for JHUEM2, Hec108, and Hec1B were 2.5μM, 4.3μM, and 4.5μM respectively. For NTC, the IC50 was (1.7μM), while TP53-KO (7.5μM) demonstrated similar IC50 values to the variants (6.5-11.9μM). Two variants (Y220C and R248W), had significantly (<0.001 and <0.01 respectively) higher IC50 values (11.9 and 9.1 μM respectively). In Western blot analysis, no p53 downstream signaling via p21, GADD45, PUMA, and NOXA was observed for any variants. Conclusions: Our results demonstrate that APR-246's cytotoxic effects in EC seem to be p53-independent. Potential mechanisms for the anti-neoplastic effects of APR-246 include activity targeting antioxidant pathways demonstrated in other solid tumors and provides an area for further investigation in TP53mut EC. Citation Format: Camilla Yu, Aaron Petty, Roberto Vargas. APR-246 cytotoxic effects are TP53 independent in endometrial cancer cell lines. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4885.

Abstract 1090: Dominant-negative TP53 variants confer radiation resistance in endometrial cancer

Abstract Introduction: High-grade endometrial cancers (EC) belonging to the “serous-like” cluster are known to portend a worse clinical outcome. The direct contribution of commonly identified TP53 variants on radiotherapy (RT) response has not been demonstrated in EC. Methods: To assess the impact of TP53 variants, allelic frequency, and p53/p21 signaling on radio-resistance in vitro, we utilized a high-throughput radiation assay and intron targeting CRISPR-Cas9 knockout approach in two low copy-number/TP53 wild-type EC cell lines (JHUEM1/JHUEM2). This approach facilitated TP53 cDNA complementation in a TP53-null background without significant impact from copy-number burden. The effect on radiation response was determined using high-throughput methodology and area under the curve (AUC) calculation along 5 dose-points. All experiments were carried out using 2 monoclonal isolates for each guide RNA (4 total replicates) and 2 non-targeting controls. Results: Knockout (KO) of wild-type TP53 resulted in loss of downstream p21 signaling and increased radio-resistance, demonstrating the role of p53 signaling on RT response. Complementation with five common TP53 missense variants (Y220C, R273C, R273H, R248Q, R248W) into the KO cell lines led to increased p53 accumulation without an effect on p21 signaling or RT response. Complementation into the WT cell lines, mimicking tumors with low allelic frequency/heterozygous mutations, led to abrogation of p21 signaling and increased radio-resistance, establishing their gain-of-function/dominant-negative impact. Conclusions: Our findings directly implicate TP53 status on radiotherapy response in EC, providing biologic rationale for the clinical observation that these patients may benefit from chemotherapy. Additionally, our findings demonstrate that dominant-negative variant alleles similarly impact RT response by abrogating p21 signaling. Citation Format: Aaron Petty, Arda Durmaz, Brian Yard, Jacob Scott, Roberto Vargas. Dominant-negative TP53 variants confer radiation resistance in endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1090.

Loss of NLRP3 reduces oxidative stress and polarizes intratumor macrophages to attenuate immune attack on endometrial cancer.

The interaction between endometrial cancer (EMC) cells and intratumoral macrophages plays a significant role in the development of the disease. PYD domains-containing protein 3 (NLRP3) inflammasome formation triggers caspase-1/IL-1β signaling pathways and produces reactive oxygen species (ROS) in macrophages. However, the role of NLRP3-regulated ROS production in macrophage polarization and the subsequent growth and metastasis of EMC remains unknown. We conducted bioinformatic analysis to compare NLRP3 levels in intratumoral macrophages from EMC and normal endometrium. In vitro experiments involved knocking out NLRP3 in macrophages to shift the polarization from an anti-inflammatory M1-like phenotype to a proinflammatory M2-like phenotype and reduce ROS production. The impact of NLRP3 depletion on the growth, invasion, and metastasis of co-cultured EMC cells was assessed. We also evaluated the effect of NLRP3 depletion in macrophages on the growth and metastasis of implanted EMC cells in mice. Our bioinformatic analysis showed significantly lower NLRP3 levels in intratumoral macrophages from EMC than those from normal endometrium. Knocking out NLRP3 in macrophages shifted their polarization to a proinflammatory M2-like phenotype and significantly reduced ROS production. NLRP3 depletion in M2-polarized macrophages increased the growth, invasion, and metastasis of co-cultured EMC cells. NLRP3 depletion in M1-polarized macrophages reduced phagocytic potential, which resulted in weakened immune defense against EMC. Additionally, NLRP3 depletion in macrophages significantly increased the growth and metastasis of implanted EMC cells in mice, likely due to compromised phagocytosis by macrophages and a reduction in cytotoxic CD8+ T cells. Our results suggest that NLRP3 plays a significant role in regulating macrophage polarization, oxidative stress, and immune response against EMC. NLRP3 depletion alters the polarization of intratumoral macrophages, leading to weakened immune defense against EMC cells. The reduction in ROS production by the loss of NLRP3 may have implications for the development of novel treatment strategies for EMC.

Vitexin suppresses the proliferation, angiogenesis and stemness of endometrial cancer through the PI3K/AKT pathway

Context Endometrial cancer is a common gynecologic malignancy. Vitexin is an active flavonoid compound with an antitumor function. Objective This study elucidated the role of vitexin in endometrial cancer development and clarified the potential mechanism. Materials and methods The toxicity of vitexin (0–80 μM) treatment for 24 h on HEC-1B and Ishikawa cells was tested utilizing the CCK-8 assay. Endometrial cancer cells were divided into vitexin 0, 5, 10, and 20 μM groups. Cell proliferation, angiogenesis and stemness in vitro after treatment with vitexin (0, 5, 10, 20 μM) for 24 h were evaluated using the EdU staining assay, tube formation assay and sphere formation assay, respectively. Twelve BALB/c mice were grouped into control and vitexin (80 mg/kg) groups to monitor tumour growth for 30 days. Results Vitexin suppressed cell viability of HEC-1B (IC50 = 9.89 μM) and Ishikawa (IC50 = 12.35 μM) cells. The proliferation (55.3% and 80% for HEC-1B; 44.7% and 75% for Ishikawa), angiogenesis (54.3% and 78.4% for HEC-1B; 47.1% and 68.2% for Ishikawa) and stemness capacity (57.2% and 87.3% for HEC-1B; 53.4% and 78.4% for Ishikawa) of endometrial cancer cells were inhibited by 10 and 20 μM vitexin. Furthermore, the inhibitory effects of vitexin on endometrial cancer were reversed by PI3K/AKT agonist 740Y-P (20 μM). Moreover, the xenograft tumour experiment lasting for 30 days proved that vitexin (80 mg/kg) blocked tumour growth of endometrial cancer in vivo. Discussion and conclusions Vitexin has therapeutic potential on endometrial cancer, which supports further clinical trials.

Conventional and new proposals of GnRH therapy for ovarian, breast, and prostatic cancers.

For many years, luteinizing hormone-releasing hormone or gonadotropin-releasing hormone (GnRH) analogs have been used to treat androgen or estrogen-dependent tumors. However, emerging evidence shows that the GnRH receptor (GnRH-R) is overexpressed in several cancer cells, including ovarian, endometrial, and prostate cancer cells, suggesting that GnRH analogs could exert direct antitumoral actions in tumoral tissues that express GnRH-R. Another recent approach based on this knowledge was the use of GnRH peptides for developing specific targeted therapies, improving the delivery and accumulation of drugs in tumoral cells, and decreasing most side effects of current treatments. In this review, we discuss the conventional uses of GnRH analogs, together with the recent advances in GnRH-based drug delivery for ovarian, breast, and prostatic cancer cells.

UBE2C-mediated Autophagy Inhibition via Ubiquitination of SIRT1 Contributes to Endometrial Cancer Progression.

Our study highlights the tumorigenic role and regulatory mechanism of UBE2C in endometrial cancer; UBE2C inhibits endometrial cancer cell apoptosis through autophagy-related mechanisms and our findings provide new insights into the treatment of endometrial cancer.

A ciprofloxacin derivative with four mechanisms of action overcomes paclitaxel resistance in p53-mutant and MDR1 gene-expressing type II human endometrial cancer

Dysfunction of the p53 gene and the presence of the MDR1 gene are associated with many malignant tumors including endometrial cancer and are responsible for cancer therapeutic resistance and poor survival. Thus, there is a critical need to devise novel combinatorial therapies with multiple mechanisms of action to overcome drug resistance. Here, we report a new ciprofloxacin derivative (CIP2b) tested either alone or in combination with taxanes against four human endometrial cancer cell lines. In vitro studies revealed that a combination of paclitaxel + CIP2b had synergistic cytotoxic effects against MDR1-expressing type-II human endometrial cancer cells with loss-of-function p53 (Hec50co LOFp53). Enhanced antitumor effects were confirmed by substantial increases in caspase-3 expression, cell population shifts toward the G2/M phase, and reduction of cdc2 phosphorylation. It was found that CIP2b targets multiple pathways including the inhibition of MDR1, topoisomerase I, and topoisomerase II, as well as enhancing the effects of paclitaxel (PTX) on microtubule assembly. In vivo treatment with the combination of PTX + CIP2b also led to significantly increased accumulation of PTX in tumors (compared to CIP2b alone) and reduction in tumor growth. Enhanced in vivo cytotoxic effects were confirmed by histological and immunohistochemical examination of the tumor tissues. Complete blood count and blood biochemistry data confirmed the absence of any apparent off-target toxicity. Thus, combination therapy involving PTX and CIP2b targeted multiple pathways and represents an approach that could result in improved tolerance and efficacy in patients with type-II endometrial cancer harboring the MDR1 gene and p53 mutations.

LIM1 contributes to the malignant potential of endometrial cancer.

The incidence of endometrial cancer (EC) has been increasing worldwide. However, because there are limited chemotherapeutic options for the treatment of EC, the prognosis of advanced-stage EC is poor. Gene expression profile datasets for EC cases registered in The Cancer Genome Atlas (TCGA) was reanalyzed. Highly expressed genes in advanced-stage EC (110 cases) compared with early-stage EC (255 cases) were extracted and Gene Ontology (GO) enrichment analysis was performed. Among the enriched genes, Kaplan-Meier (KM) plotter analysis was performed. Candidate genes expression was analyzed in HEC50B cells and Ishikawa cells by RT-qPCR. In HEC50B cells, LIM homeobox1 (LIM1) was knocked down (KD) and cell proliferation, migration, and invasion ability of the cells were evaluated. Xenografts were generated using LIM1-KD cells and tumor growth was evaluated. Ingenuity Pathway Analysis (IPA) of RNA-seq data using LIM-KD cells was performed. Expression of phospho-CREB and CREB-related proteins were evaluated in LIM1-KD cells by western blotting and in xenograft tissue by immunofluorescent staining. Two different CREB inhibitors were treated in HEC50B and cell proliferation was evaluated by MTT assay. Reanalysis of TCGA followed by GO enrichment analysis revealed that homeobox genes were highly expressed in advanced-stage EC. Among the identified genes, KM plotter analysis showed that high LIM1 expression was associated with a significantly poorer prognosis in EC. Additionally, LIM1 expression was significantly higher in high-grade EC cell lines, HEC50B cells than Ishikawa cells. Knockdown of LIM1 showed reduced cell proliferation, migration and invasion in HEC50B cells. Xenograft experiments revealed that tumor growth was significantly suppressed in LIM1-KD cells. IPA of RNA-seq data using LIM-KD cells predicted that the mRNA expression of CREB signaling-related genes was suppressed. Indeed, phosphorylation of CREB was decreased in LIM1-KD cells and LIM1-KD cells derived tumors. HEC50B cells treated by CREB inhibitors showed suppression of cell proliferation. Collectively, these results suggested that high LIM1 expression contributed to tumor growth via CREB signaling in EC. Inhibition of LIM1 or its downstream molecules would be new therapeutic strategies for EC.

PVT1/miR-136/Sox2/UPF1 axis regulates the malignant phenotypes of endometrial cancer stem cells

Tumor stem cells (TSCs) are thought to contribute to the progression and maintenance of cancer. Previous studies have suggested that plasmacytoma variant translocation 1 (PVT1) has a tumor-promoting effect on endometrial cancer; however, its mechanism of action in endometrial cancer stem cells (ECSCs) is unknown. Here, we found that PVT1 was highly expressed in endometrial cancers and ECSCs, correlated with poor patient prognosis, promoted the malignant behavior and the stemness of endometrial cancer cells (ECCs) and ECSCs. In contrast, miR-136, which was lowly expressed in endometrial cancer and ECSCs, had the opposite effect, and knockdown miR-136 inhibited the anticancer effects of down-regulated PVT1. PVT1 affected miR-136 specifically binding the 3’ UTR region of Sox2 by competitively “sponging” miR-136, thus positively saving Sox2. Sox2 promoted the malignant behavior and the stemness of ECCs and ECSCs, and overexpression Sox2 inhibited the anticancer effects of up-regulated miR-136. Sox2 can act as a transcription factor to positively regulate Up-frameshift protein 1 (UPF1) expression, thereby exerting a tumor-promoting effect on endometrial cancer. In nude mice, simultaneously downregulating PVT1 and upregulating miR-136 exerted the strongest antitumor effect. We demonstrate that the PVT1/miR-136/Sox2/UPF1 axis plays an important role in the progression and maintenance of endometrial cancer. The results suggest a novel target for endometrial cancer therapies.

IGFBP‑rP1 affects the proliferation, apoptosis and macrophage polarization of endometrial cancer cells by regulating the PI3K/AKT pathway.

Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) is a potential tumor suppressor gene in a variety of cancers including colorectal cancer and breast cancer. However, its role and the potential mechanism in endometrial carcinoma (EC) are still unclear. The purpose of this study was to explore the effect of IGFBP-rP1 on EC cell proliferation and apoptosis and its underlying mechanism. Western blot analysis and reverse transcription-quantitative PCR were used to assess protein and gene expression levels of IGFBP-rP1 in EC cells. Overexpression of IGFBP-rP1 and/or AKT serine/threonine kinase was used to analyze their effects on cell proliferation and apoptosis of the EC cells. Co-immunoprecipitation and glutathione S transferase pull-down assays were used to analyze the interaction between IGFBP-rP1 and AKT. The expression of IGFBP-rP1 in EC cells was downregulated. Overexpression of IGFBP-rP1 inhibited the proliferation and induced apoptosis of EC cells, which were abolished by the overexpression of AKT. In addition, IGFBP-rP1 directly interacted with AKT to inhibit PI3K/AKT signaling. Additionally, M0 macrophages were induced by EC cells to differentiate into M2 macrophages, which was reversed by IGFBP-rP1. Overexpression of AKT in EC cells abolished the inhibitory effect of IGFBP-rP1 on M2 polarization. IGFBP-rP1 as an oncogenic factor inhibits M2 polarization of TAMs through PI3K/AKT signaling pathway and may be a potentially valuable target for EC therapy.

A novel necroptosis-associated miRNA signature predicting prognosis of endometrial cancer and correlated with immune infiltration.

Necroptosis is a form of programmed cell death identified irrelevant to caspases, which plays an important role in the tumorigenesis and development of cancer. MicroRNAs (miRNAs) are important regulators of both necroptosis and cancer. Expression of sixteen necroptosis-associated miRNAs were analyzed in 546 endometrial cancer (EC) tissues and 33 paracancerous samples from the Cancer Genome Atlas (TCGA). Cox regression analysis was used to evaluate the correlations between miRNAs and overall survival. MiRNAs risk score (Mrs) and nomogram were established to assess the potential value of necroptosis-related miRNAs on prognosis. Expression of miRNA-148a-3p in endometrial cancer cells and endometrial epithelial cells was detected by quantitative real-time PCR (qRT-PCR). The targets genes of miR-148a-3p were predicted using miRDB, miRTarBase and TargetScan and the prognostic-related genes were screened. Immune infiltration analysis was conducted to explore the potential mechanism of these target genes. We identified fourteen differentially expressed miRNAs and selected seven miRNAs (miR-15a-5p, miR148a-3p, miR-7-5p, miR-141-3p, miR-200a-5p, miR-223-3p, miR-16-5p) for prognostic-model construction. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for 1-, 2- and 5-year survival were 0.678, 0.652 and 0.656 respectively. Multivariate analysis revealed that the Mrs was an independent prognostic factor considering other risk factors (HR=1.928, 95% CI=1.072-3.467, P=0.028). Among these miRNAs, miRNA-148a-3p was up-regulated in cancer tissues and cells, and Kaplan-Meier analysis showed its significance in overall survival (OS). The target genes, DNAJB4 and PRNP, were associated with poor prognosis and correlated with tumor immune infiltration. Our study constructed a novel necroptosis-associated miRNAs model for prognosis prediction, and DNAJB4 and PRNP may be therapeutic targets for EC.

Integrated multi-omics analyses and functional validation reveal TTK as a novel EMT activator for endometrial cancer

BackgroundCancer-testis antigens (CTAs) are often expressed in tumor and testicular tissues but not in other normal tissues. To date, there has been no comprehensive study of the expression and clinical significance of CTA genes associated with endometrial cancer (EC) development. Additionally, the clinical relevance, biological role, and molecular mechanisms of the CTA gene TTK protein kinase (TTK) in EC are yet to be fully understood.MethodsUsing bioinformatics methods, we comprehensively investigated the genomic, transcriptomic, and epigenetic changes associated with aberrant TTK overexpression in EC samples from the TCGA database. We further investigated the mechanisms of the lower survival associated with TTK dysregulation using single-cell data of EC samples from the GEO database. Cell functional assays were used to confirm the biological roles of TTK in EC cells.ResultsWe identified 80 CTA genes that were more abundant in EC than in normal tissues, and high expression of TTK was significantly linked with lower survival in EC patients. Furthermore, ROC analysis revealed that TTK could accurately distinguish stage I EC tissues from benign endometrial samples, suggesting that TTK has the potential to be a biomarker for early EC detection. We found TTK overexpression was more prevalent in EC patients with high-grade, advanced tumors, serous carcinoma, and TP53 alterations. Furthermore, in EC tissue, TTK expression showed a strong positive correlation with EMT-related genes. With single-cell transcriptome data, we identified a proliferative cell subpopulation with high expression of TTK and known epithelial–mesenchymal transition (EMT)-related genes and transcription factors. When proliferative cells were grouped according to TTK expression levels, the overexpressed genes in the TTKhigh group were shown to be functionally involved in the control of chemoresistance. Utilizing shRNA to repress TTK expression in EC cells resulted in substantial decreases in cell proliferation, invasion, EMT, and chemoresistance. Further research identified microRNA-21 (miR-21) as a key downstream regulator of TTK-induced EMT and chemoresistance. Finally, the TTK inhibitor AZ3146 was effective in reducing EC cell growth and invasion and enhancing the apoptosis of EC cells generated by paclitaxel.ConclusionOur findings establish the clinical significance of TTK as a new biomarker for EC and an as-yet-unknown carcinogenic function. This present study proposes that the therapeutic targeting of TTK might provide a viable approach for the treatment of EC.