Investigation of the possible effects of long non-coding RNA (lncrna) cytor on the molecular mechanisms of metastasis and hippo signal pathways in breast cancer cell lines

Breast cancer is one of the cancers with the highest incidence among women worldwide. Metastasis formation is one of the most important causes of mortality in breast cancer patients. In this study, the effects of CYTOR expression, which is the most common malignancy among women and shows molecular subtype heterogeneity, on cell viability, apoptosis and molecular mechanisms in metastasis processes after suppression of siRNA expression in breast breast cancer cell lines were investigated. The suppressive effects of different doses of CYTOR on MDA-MB-231 and HCC1428 (cisplatin-resistant human mammary gland epithelium stage IV adenocarcinoma) cells on cell proliferation after 24 and 48 hours were determined by 3-(4.5-Dimethyltriazol-2-yl)-2.5 diphenyltetrazolium bromide (MTT) method. In addition, its effect on apoptotic (Bax, Bcl-2) and metastatic process genes (YAP1, MST1, LATS1, CTGF, ECAD, NCAD) was determined using the RT-PCR method. As a result of the study, the expression levels of the CYTOR gene were determined in MDA-MB-231 and HCC1428 cell lines. Then, when compared with the negative control siRNA containing group, gene expression was suppressed by 60% with 5 nM siCYTOR-323 and 80% with siCYTOR-779 for MDA-MB-231 cells. CYTOR expression was suppressed by 88% with 5 nM siCYTOR-572 and 76% with siCYTOR-779 in HCC1428 cells. The suppressive effect of CYTOR on cell viability was observed in both cell lines at 48 hours. It was observed that siRNA-mediated CYTOR silencing weakened the migration and invasion ability of the cells. In addition, it was found with qRT-PCR experiment that suppression of CYTOR caused a decrease in the expression of the YAP1 gene, one of the main effectors of the HIPPO pathway, and the CTGF gene, one of its target genes.