title: VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death.
abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.
authors.affiliation: Department of Ultrasonograph, Changshu No. 2 People's Hospital, Changshu, China.
authors.forename: Qinyi
authors.initials: Q
authors.lastname: Qian
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of General Surgery, Changshu No. 2 People's Hospital, Changshu, China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Songbing
authors.initials: S
authors.lastname: He
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. Electronic address: 372710369@qq.com.
authors.forename: Daiwei
authors.initials: D
authors.lastname: Wan
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China. Electronic address: 505339704@qq.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Gu
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects / Q000235:genetics; D000071186:Beclin-1; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D016895:Culture Media, Serum-Free; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D019311:Staurosporine / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D016895:Culture Media, Serum-Free; D008565:Membrane Proteins; C526584:VMP1 protein, human; D019311:Staurosporine
keywords: Apoptosis; Autophagy; Colorectal cancer; VMP1