Purpose: Synaptotagmin7 (SYT7) belongs to the synaptotagmin gene family and plays an important role in synaptic transmission. However, the function of this gene in most human cancer especially in colorectal cancer (CRC) remains unknown. In this research, we examined SYT7's role in CRC and tried to reveal its underlying mechanism. Methods: We examined SYT7's expression levels in normal colorectal tissue and CRC tissues from 83 patients and analyzed the possible correlation between the expression level of SYT7 and pathological characteristics. The influences of SYT7 knockdown on cell growth were detected by Celigo image cytometer, colony formation assay, cell cycle analysis and apoptosis assay in vitro. The possible molecular mechanism was assessed using a microarray and Ingenuity Pathway Analysis. Results: Our results show that the expression of SYT7 is upregulated in colorectal cancer tissues in comparison with normal tissues and positively correlated with the pathological stage of colorectal cancer. (P=0.015). We examined SYT7's role in human colorectal cancer cell line RKO by using SYT7-shRNA and revealed that SYT7 knockdown inhibit cell proliferation (P=8.6E-5), clonogenic ability (P=4.5E-6) and promoted G2/M Phase arrest and apoptosis (P=4.6E-7). Multiple cancer-associated pathways regulated by SYT7 were unraveled by microarray and Ingenuity Pathway Analysis. Conclusions: Our study suggests that SYT7 plays an important role in the development of CRC and SYT7 may become a new therapeutic target in CRC.
Keywords: Synaptotagmin7; TCGA; apoptosis; colorectal cancer; proliferation.