Abstract: SLC2A6 is a member of the facilitative glucose transporter family, it codes GLUT6 protein. SLC2A6 is up-regulated in several numerous cancers, but is not widely expressed in normal tissues. In order to elucidate the functions and underlying mechanisms for SLC2A6 controlling cancer cell proliferation and apoptosis, we screened two SLC2A6 knockdown lung adenocarcinoma A549 cell lines by CRISPR/Cas9 to illustrate the effects of SLC2A6 on biological process. SLC2A6 expression in mRNA and protein levels has been reduced in SLC2A6-knockdown A549 cells. Western Blot analysis confirmed that SLC2A6 protein expression decreased by 74% in KD1 and 83% in KD2 cells, respectively, compared with the control vehicle. In SLC2A6 mRNA expression level, there are 70.6%±2.0% and 76.9%±4.1% reduction in KD1 and KD2 cells, respectively, compared with wild-type A549 cells. The results of MTT assay indicated that the proliferation rate of KD cells was slower. The fold change of cell number on the fifth day of growth decreased from 22.1±1.0 in WT cells to 13.5±0.9 or 12.2±1.0 than in KD1 and KD2 cells (P＜0.001). The cell cycle analysis via flow cytometry demonstrateed that SLC2A6 KD cells arrested at G2/M phase, as the percentage of cells in the G2 phase increased from 16.0%±1.0% of wild type (WT) cells to 23.0%±1.1% of KD1 cells or 27.4%±0.4% of KD2 cells (P＜0.05). Moreover, the results of cell cycle regulators RNA expression showed that G2/M arrest was associated with the regulation of expression APC, Rad9a, CDK1, cdc25 and p21Waf1/Cip1. In conclusion, our findings revealed a novel role for SLC2A6 in regulating cancer cell growth, which suggested that SLC2A6 may represent a viable anti-cancer drug target.

Key words: SLC2A6, A549 cells, CRISPR/Cas9, cell proliferation, cell cycle