Expression and function of C۱orf۱۳۲ long-noncoding RNA, in breast cancer cell lines and tissues

Background and Aim: miR-۲۹b۲ and miR-۲۹c play a suppressive role in breast cancer progression. Mir۲۹b۲chg/C۱orf۱۳۲ is the host gene for generating both microRNAs. However, there existed longer transcripts of the gene, with unknown function.Methods: Here, we have employed bioinformatics and experimental approaches to decipher expression of two different C۱orf۱۳۲ transcripts in different types of breast cancer cell lines and tissues.Results: Our data demonstrated a significant downregulation of C۱orf۱۳۲ in triple-negative type of breast cancer. We also find out that a mouse homolog of C۱orf۱۳۲ is located at a similar genomic location as its human counterpart, between CD۴۶ and CD۳۴ genes.Conclusion: The latter finding suggests new potential functions for the lncRNA, other than being a simple miR-۲۹ host gene. We predicted a putative promoter for the longer transcripts of C۱orf۱۳۲. The functionality of the distal promoter confirmed by transfecting MCF۷ cells with a C۱orf۱۳۲ promoter-GFP construct. Knocking-down the promoter by means of the Crispr/Cas۹ approach revealed no alteration in the expression level of neighboring genes, CD۴۶ and CD۳۴. However, the expression level of miR-۲۹c was reduced by half, suggesting an enhancer effect of the distal promoter on miR-۲۹cf generation. Furthermore, the promoter knock-down revealed a G۲/M cell cycle arrest and an elevation of migration ability in Mcf۱۲a edited cells. Moreover, the expression of cell mobility genes e.g. CDH۲, FGF۲, FGFR۱ and the stem cell and EMT -associated transcription factor ZEB۱ was significantly overexpressed in edited cells. Altogether, we are reporting here the existence of an additional/distal promoter with an enhancer effect on miR-۲۹ generation and an inhibitory effect on cell proliferation and cell migration.

کلیدواژه ها:

Long-noncoding RNA ، Triple-negative breast cancer ، Crispr/Cas۹ ، EMT