Abstract: Abstract: Objective To compare the expression of CD49f splicing isoforms in different human stem cells and colon cancer cell lines, and construct lentiviral vectors overexpressing specific isoform. Methods The expressions of CD49f isoforms in different cells was detected by RT-PCR and real-time PCR. The lentiviral vectors overexpressing CD49f isoforms were constructed by molecular cloning method. The overexpression of CD49f in colon cancer cell line HT29 was confirmed by FCM, Western Blot and real-time PCR, the invasive ability was detected by transwell assay. Results CD49f splicing isoform B was highly expressed in H9 human embryonic stem cell line, while isoform A expressed in epithelial cells. Both isoform A and B were expressed in mesenchymal cells. CD49f isoforms A and B were also expressed in colorectal cancer cell lines, while HT29 and HCT116 showed higher expression of isoform A than isoform B, HCT8 and LoVo showed higher expression of isoform B than isoform A. Overexpression of CD49f isoform B greatly increased the invasive ability of HT29 cells, while isoform A showed no effect. Conclusions The expressions of CD49f splicing isoforms A and B in different types of cells are significantly different, which suggests CD49f isoforms play different biological functions in cells.

Key words: CD49f, alternative splicing, stem cells, colorectal cancer cells, vector construction