Endometrial cancer is the most common gynaecological cancer and advanced disease has a very poor prognosis. There are also no biomarkers for endometrial cancer. Micro RNA (miRs) are known to be dysregulated in endometrial cancer. The expression of miR-29 family members (-a and –b) are downregulated in endometrial cancer. However, a role for miR-29c and its targets in endometrial cancer growth remain to be elucidated. The aim of this study was to investigate the functional effects of re-introducing miR-29c expression in endometrial cancer cell lines and identify which miR-29c targets may contribute to cancer progression.
Real-time PCR for miR-29c expression was performed on human endometrial tumour grades 1-3 and benign tissue as well as endometrial cancer cell lines Ishikawa, HEC1A and AN3CA. Cell lines were transfected with miR-29c mimic and negative control. xCELLigence real-time cell monitoring was performed to analyse proliferation and migration and Flow cytometry for apoptosis and cell cycle population percentages. miR-29c target genes in the 3 cell lines were analysed using real-time PCR.
miR-29c was down regulated in grade 1-3 endometrial cancer samples compared to benign endometrium (p<0.0001 respectively). miR-29c expression was reduced in Ishikawa (p<0.0001) and AN3CA (p<0.01) but not HEC1A cell lines compared to non-cancerous primary human endometrial epithelial cells. Overexpression of miR-29c reduced proliferation (p<0.05 HEC1A and p<0.001 AN3CA at 72hr), increased apoptosis (p<0.001 Ishikawa and p<0.05 AN3CA) and reduced miR-29c target genes (CAV1, CDC42, SIRT1, FBN1, HBP1, ITGB1, NUMB, MCL1, MCL1, SGK1, VEGFA and MDM2) across the three cell lines. Inhibition of miR-29c in HEC1A cells increased proliferation (p<0.05 at 72hr) and COL4A1 expression (p<0.01).
The re-introduction of miR-29c to endometrial cancer cell lines reduced proliferation, increased apoptosis and reduced miR-29c target genes in vitro. This suggests miR-29c may be a therapeutic target for endometrial cancer.