Expression pattern of circadian rhythm-related genes and its potential relationship with miRNAs activity in endometrial cancer.

OBJECTIVES: The circadian clock is an autonomous oscillator that controls key aspects of cell physiology, including metabolism, transcriptional state, and cell signaling. Disturbances of circadian rhythms lead to disruption of cell and tissue homeostasis, which promotes carcinogenesis. The aim of the study was to determine the expression of circadian rhythm-related genes in endometrial cancer and to select miRNAs involved in the regulation of their expression. MATERIAL AND METHODS: 50 endometrial tissue samples were collected from patients who underwent hysterectomy: 40 diagnosed with endometrial cancer and 10 without cancer. Expression profile of circadian rhythm-related genes was evaluated using microarrays and validated with RT-qPCR. MicroRNA expression was assessed using microarrays. Then mirTAR tool was used to identify miRNAs involved in the expression regulation of circadian rhythm-related genes. RESULTS: CLOCK expression is disrupted in endometrial cancer, which may be due to miR-15b, miR-331-3p and miR-200a overexpression. Elevated NPAS2 and CSNK1D levels may be associated with miR-432 silencing. In addition, high miR-874 and miR-200a expression may be potentially responsible for the reduction of PER3 level. CONCLUSIONS: Change of CLOCK, CSNK1D, NPAS2 and PER3 expression may suggest that circadian rhythms are disrupted in endometrial cancer. A possible mechanism of the observed changes may be related to miRNAs activity.

Interplay between miRNAs and Genes Associated with Cell Proliferation in Endometrial Cancer.

Endometrial cancer develops as a result of abnormal cell growth associated with uncontrolled cell proliferation, excessive activation of signaling pathways and miRNA activity. The aim of this study was to determine the expression profile of genes associated with cell proliferation and to assess which miRNAs can participate in the regulation of their expression. The study enrolled 40 patients with endometrial cancer and 10 patients without neoplastic changes. The expression profile of genes associated with cell proliferation and the expression profile of miRNAs were assessed using microarrays. RT-qPCR was performed to validate mRNA microarray results. The mirTAR tool was used to identify miRNAs that regulate the activity of genes associated with cell proliferation. Decreased expression of IGF1 and MYLK, as well as SOD2 overexpression, were observed in endometrial cancer using both mRNA microarrays and RT-qPCR. Microarray analysis showed low levels of NES and PRKCA, but this was only partially validated using RT-qPCR. Reduced activity of MYLK may be caused by increased miR-200c, miR-155 and miR-200b expression. Cell proliferation is disturbed in endometrial cancer, which may be associated with an overexpression of miR-200a, miR-200c, and miR-155, making it a potential diagnostic marker.

Identification of a gene expression profile associated with the regulation of angiogenesis in endometrial cancer.

The publication of the human genome sequence provided direction in the search for novel diagnostic and therapeutic methods for the treatment of human diseases. The aim of the present study was to investigate the hypothesis that the expression profile of genes involved in the regulation of angiogenesis may be a marker in endometrial cancer that facilitates the diagnosis and prognosis of patients, as well as the identification of novel therapeutic targets. The current study included 36 patients with grade (G) 1 to 3 endometrial cancer, and a control group of patients consisting of females that qualified for the removal of the uterus. Out of these, 28 samples (control, 3; G1, 7; G2, 12; and G3, 6) were selected for microarray analysis. Molecular analysis of the endometrial samples involved the extraction of total RNA, purification of the obtained extracts and subsequent analysis of the gene expression profiles using an oligonucleotide microarray technique (GeneChip® Human Genome U133A plates). The results indicated that the mRNA expression profile of genes involved in the regulation of angiogenesis varies depending on the degree of histological differentiation of endometrial adenocarcinoma. Similar results were obtained from descriptive statistics characterizing the expression profile of 691 mRNAs associated with the regulation of angiogenesis in the groups of patients with endometrial adenocarcinoma. In addition, the results of the present study indicated that neuropilin2 (NRP2) may serve an important role in the activity of endothelial cells, and may affect vascular endothelial growth factor, and potentially plexins and integrins via regulation of their functions. An understanding of how these proteins interact remains to be determined; however, elucidating these interactions may provide an explanation for the mechanisms underlying angiogenesis. In conclusion, the results of the present study suggest that NRP2 may be a valuable target for investigation in future pharmacological studies involving angiogenesis in endometrial cancer.