title: SIPL1 enhances the proliferation, attachment, and migration of CHO cells by inhibiting PTEN function.
abstract: The PTEN tumour suppressor plays critical roles in inhibiting cell proliferation, adhesion and migration through downregulation of the PI3K-AKT pathway. SIPL1 is a novel PTEN‑negative regulator (PTEN-NR) that contributes to PTEN inactivation during tumorigenesis. However, whether SIPL1 plays a role in inhibiting PTEN function in the process of cell adhesion and migration remains unclear. The aim of this study was to investigate this possibility using CHO-K1 cells, and western blotting, qPCR analyses and microscopy. Results showed that the overexpression of SIPL1 in CHO-K1 cells decreased the amount of PTEN protein. The downregulation was not caused by an obvious reduction in PTEN mRNA levels or ubiquitin-dependent protein degradation. Nonetheless, the reduction was functional, as SIPL1 overexpression increased the activation of AKT under serum‑starved conditions, promoting CHO-K1 cell proliferation in an AKT‑dependent manner. Furthermore, SIPL1 increased the migration and attachment of CHO-K1 cells. Taken together, the evidence suggested that SIPL1 promotes AKT activation by decreasing the amount of PTEN protein in CHO-K1 cells, thereby promoting cell proliferation and migration.
authors.affiliation: Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON L8N 4A6, Canada.
authors.forename: Jason
authors.initials: J
authors.lastname: De Melo
authors.affiliation: Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON L8N 4A6, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Wu
authors.affiliation: Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON L8N 4A6, Canada.
authors.forename: Lizhi
authors.initials: L
authors.lastname: He
authors.affiliation: Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON L8N 4A6, Canada.
authors.forename: Judy
authors.initials: J
authors.lastname: Yan
authors.affiliation: Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON L8N 4A6, Canada.
authors.forename: Damu
authors.initials: D
authors.lastname: Tang
mesh_terms: D000818:Animals; D016466:CHO Cells; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D006224:Cricetinae; D003412:Cricetulus; D004789:Enzyme Activation; D057809:HEK293 Cells; D006801:Humans; D051059:PTEN Phosphohydrolase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism*
chemical_list: C575183:SHARPIN protein, human; D014452:Ubiquitins; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase