AUTHOR=Liu Dongyu , Li Jiaxin , Hao Wanjun , Lin Xu , Xia Jiqiao , Zhu Jiyuan , Yang Shuo , Yang Xiuqin 

TITLE=Chimeric RNA TNNI2-ACTA1-V1 Regulates Cell Proliferation by Regulating the Expression of NCOA3

JOURNAL=Frontiers in Veterinary Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.895190

DOI=10.3389/fvets.2022.895190

ISSN=2297-1769

ABSTRACT=<p>Chimeric RNA is a crucial target for tumor diagnosis and drug therapy, also having its unique biological role in normal tissues. <italic>TNNI2-ACTA1-V1</italic> (<italic>TA-V1</italic>), a chimeric RNA discovered by our laboratory in porcine muscle tissue, can inhibit the proliferation of Porcine Skeletal Muscle Satellite Cells (PSCs). The regulatory mechanism of <italic>TA-V1</italic> in PSCs remains unclear, but we speculate that <italic>NCOA3, DDR2</italic> and <italic>RDX</italic> may be the target genes of <italic>TA-V1</italic>. In this study, we explored the effects of <italic>NCOA3, DDR2</italic> and <italic>RDX</italic> on cell viability and cell proliferation by CCK-8 assay, EdU staining and flow cytometry. Furthermore, the regulatory pathway of proliferation in PSCs mediated by <italic>TA-V1</italic> through <italic>NCOA3</italic> or <italic>CyclinD1</italic> was elucidated by co-transfection and co-immunoprecipitation (Co-IP). The results revealed that overexpression of <italic>NCOA3</italic> significantly increased cell viability and the expression level of <italic>CyclinD1</italic>, and also promotes cell proliferation by changing cells from the G1 phase to the S phase. In addition, inhibiting the expression of <italic>NCOA3</italic> substantially reduced cell viability and inhibited cell proliferation. Overexpression of <italic>DDR2</italic> and <italic>RDX</italic> had no significant effect on cell viability and proliferation. Co-transfection experiments showed that <italic>NCOA3</italic> could rescue the proliferation inhibition of PSCs caused by <italic>TA-V1</italic>. Co-IP assay indicated that <italic>TA-V1</italic> directly interacts with <italic>NCOA3</italic>. Our study explores the hypothesis that <italic>TA-V1</italic> directly regulates <italic>NCOA3</italic>, indirectly regulating <italic>CyclinD1</italic>, thereby regulating PSCs proliferation. We provide new putative mechanisms of porcine skeletal muscle growth and lay the foundation for the study of chimeric RNA in normal tissues.</p>