SNHG۶ ۲۰۳ RNA May be Involved in the Cell Cycle Progression in HER۲-Negative Breast Cancer Cells

Background & Objective: Long noncoding RNAs (lncRNAs) as challenging molecules are more known compared to those in the  last decade. These transcripts have been validated for carcinogenesis in many types of tissue. Functions of lncRNAs in cancer induction include cell cycle, epithelial to mesenchymal transition progression, apoptosis inhibition, cell migration, and invasion stimulation . LncRNA small nucleolar host (SNHG۶) have been proven as an oncogenic transcript in many types of cancer.Methods: RNA extraction was performed for ۴۷ breast specimens in patients with cancer  and cDNAs were synthesized. Relative expression of target variants was determined by qPCR and calculated based on the ΔΔCt method. SNHG۶ ۲۰۳ was cloned into pcDNA ۳.۱+ vector for overexpression in MCF۷ (HER۲-) and SK-BR۳ (HER۲+) cells. The cell cycle progression of transfected cells was assessed by flow cytometry. Cell migration ability of transfected cells was evaluated by the scratch method and Image J software. Finally, cell viability was assessed by the MTT method.Results: Among four splice variants of SNHG۶ (۲۰۲, ۲۰۳, ۲۰۴, and ۲۰۷), SNHG۶ ۲۰۳ was proved as an overexpressed splice variant in breast cancer tumors. This transcript was expressed in HER۲-negative breast tumors more frequently than in the positive ones. Overexpression of this variant in target cells resulted in cell cycle progression of MCF۷ as HER۲-negative cells. Moreover, the overexpression of SNHG۶ ۲۰۳ led to a lower migration ability of MCF۷ cells and a non-significant reduction of their viability as HER۲-negative breast cancer cells.

Keywords:

Breast Neoplasm , Cell cycle , lncRNA