Knockdown of L-type amino acid transporter 1 inhibits the proliferation and migration of colorectal cancer cell line HT29

Objective To investigate the effect of L-type amino acid transporter 1 (LAT1) on colorectal cancer cell proliferation and migration. Methods LAT1-specific small interfering RNA (siLAT1) and control small interfering RNA (siCON) were synthesized. Then, HT29 cell line was selected to generate the colorectal cancer cell model with LAT1 deficiency using small interfering RNA (siRNA) transfection. real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and Western blotting were used to confirm the efficiency of the transfection after treatment with siRNA for 48 h. After that, cell counting kit-8 (CCK-8) assay and Transwell migration assay were used to examine whether silencing LAT1 with siRNA could affect cell proliferation and migration in HT29 cells, respectively. Results Silencing LAT1 with siRNA could drastically reduce the expression of LAT1 mRNA and the Knockdown efficiency was (73.2±5.2)% (t=11.410, P<0.01). Meanwhile, Western blotting also comfirmed that siLAT1 could reduce protein expression of LAT1 (0.68±0.06 versus 0.21±0.04, t=4.492, P<0.05). Furthermore, CCK-8 assay suggested that knockdown of LAT1 significantly inhibited the viability of HT29 cells treated with siLAT1 versus those treated with siCON (P<0.05). The results of the Transwell migration assay indicated that migration of HT29 cells treated with siLAT1 was drastically reduced compared with those treated with siCON (66±11 versus 156±29, t=5.083, P<0.05). Conclusion Downregulated LAT1 suppressed the ability of colorectal cell proliferation and migration in vitro. Key words: L-type amino acid transporter 1; Colorectal cancer; Small interfering RNA; Proliferation; Migration