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.

Long non-coding RNA CCAT1 is overexpressed in endometrial cancer and regulates growth and transcriptome of endometrial adenocarcinoma cells.

BACKGROUND: Long non-coding RNAs (lncRNAs) play important roles in regulation of gene expression and are involved in pathogenesis of different diseases including cancer. Recent studies suggested the lncRNA Colon cancer associated transcript-1 (CCAT1) to act as putative oncogene. In this study, to elucidate the role of this lncRNA in endometrial cancer, we examined its expression in normal endometrium and type 1 endometrial cancer and knocked down its expression in endometrial cancer cell lines followed by transcriptome and pathway analyses. METHODS: CCAT1 expression was examined in 100 tissue samples of normal endometrium and type 1 endometrial cancer tissues by means of RT-qPCR. Knockdown of CCAT1 expression in HEC-1B and RL95/2 endometrial cancer cells was performed by siRNA transfection. Affymetrix GeneChip arrays were used to elucidate the effect of both lncRNAs on the transcriptome of these cell lines. RESULTS: Median CCAT1 expression was found to be 9.3-fold higher in endometrial cancer when compared to normal endometrium (p < 0.05). In contrast to premenopausal endometrium and G1, G2 and G3 graded endometrial cancer, CCAT1 expression was nearly absent in postmenopausal tissue. Knockdown of CCAT1 by transient siRNA transfection significantly reduced proliferation of HEC-1B cancer cells in vitro by 35.5 % 6 days after transfection and notably reduced their colony formation ability. Affymetrix microarray and Ingenuity pathway analyses revealed a set of up- or down-regulated genes in transfected ERα-negative HEC-1B cells forming a network controlled by the key regulators TNF and TP53, including genes known to be involved in growth control, providing putative molecular mechanisms underlying the observed growth inhibition of HEC-1B cells. In contrast, CCAT1 knockdown in ERα-positive RL95/2 cells did not significantly affect proliferation, but resulted in down-regulation of a network of ERα target genes. CONCLUSIONS: Given that the lncRNA CCAT1 was found to be overexpressed in endometrial cancer, affected the growth of HEC-1B cells and the expression of growth regulatory genes, our data suggest CCAT1 to exert oncogenic functions in endometrial cancer and encourage further studies to examine to what extent this lncRNA might be a potential therapy target in this cancer entity.

MicroRNA heterogeneity in endometrial cancer cell lines revealed by deep sequencing.

The aim of the present study was to obtain comprehensive microRNA (miRNA) profiles of type I [Ishikawa (ISK)] and type II (HEC-1B) human endometrial adenocarcinoma cell lines, utilizing the latest high-throughput sequencing techniques. RNA was extracted from ISK and HEC-1B cell lines. Sequencing results were obtained from a next-generation sequencing platform. Using the miRBase database and a series of software pipelines, miRNA expression was analyzed in the ISK and HEC-1B cell lines. It was revealed that the type and quantity of miRNAs in the two cell types varied significantly; 34 miRNAs were upregulated and 105 miRNAs were downregulated in HEC-1B cells compared with those of ISK cells. Furthermore, it was observed that the expression pattern of the miRNA (miR)-17-92 cluster differed between the two cell types, and the expression levels of the miR-200 family in ISK cells were markedly increased compared with those of HEC-1B cells. The present study therefore identified potential novel biomarkers, which may be useful in the differentiation between type I and type II endometrial cancer, and also revealed miRNA alterations that may be associated with endometrial cancer and its underlying pathogenic mechanisms.

MicroRNA miR-302 inhibits the tumorigenicity of endometrial cancer cells by suppression of Cyclin D1 and CDK1.

MicroRNA miR-302 has been found to induce some tumor cell lines to "transdifferentiate" into miRNA-induced pluripotent stem cells (mirPS), thereby inhibiting tumor cell proliferation and reducing tumorigenicity. This study firstly found that miR-302 inhibited the proliferation and migration of endometrial cell line, Ishikawa and HEC-1-B, and arrested cell cycle at the G2/M phase. In addition, miR-302 inhibited tumorigenicity in immunodeficient mice transplanted with Ishikawa cells. Microarray and Western blotting results showed that miR-302 significantly inhibited CDK1 and Cyclin D1 gene expression in Ishikawa cells. MiR-302 directly targeted Cyclin D1, but indirectly regulated CDK1 gene expression.

Effects of indomethacin on expression of PTEN tumour suppressor in human cancers.

BACKGROUND: Previous studies reported that Non-steroidal Anti-inflammatory Drugs (NSAIDs), chemicals, and food supplements can be used to up-regulate the PTEN mRNA and protein expression, suggesting that these substances may be used in prevention and/or treatment of various human cancers like spinal, brain, colon, breast, prostate, bladder and endometrial cancers. AIM: This was to study expression and sub-cellular localisation of PTEN protein, and review the effect(s) of indomethacin on PTEN's expression in cultured Human Endometrial Cancer (HEC 1B) cell line, which is known to express significant amounts of the wild-type PTEN. MATERIALS AND METHODS: This involves culture and incubation of artificial HEC 1B cells. All procedures were undertaken in the cell culture hood under the recommended sterile conditions. The cells were then incubated with different concentrations of indomethacin solution, for variable durations and finally fixed (with paraformaldehyde) and stained with fluorescein-labelled diluted secondary antibody (FITC). Immunocytochemistry (IHC) and fluorescent microscopy were then employed for the detection and localisation of the specific antigen (PTEN), using antibodies. RESULTS: The HEC 1B cells, which were cultured and incubated with different concentrations of indomethacin solution, expressed the PTEN protein, most of which was localised to the nucleus with minimal cytoplasmic expression. Increased PTEN expression was observed following treatment of the cells with various concentrations of the solution for variable durations, although there was cell death at higher concentrations and longer duration. This procedure was repeated several times, in order to have consistency and to validate the results. CONCLUSION: This study agrees with previous studies in similar human cell lines and supports the idea that NSAIDs and other drugs may be used in the future for prevention of human cancers. However, more studies need to be carried out to substantiate these observations.