State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, People's Republic of China.
Mol Biol Rep. 2010 Jun;37(5):2189-98. doi: 10.1007/s11033-009-9701-5. Epub 2009 Aug 13.
Phosphatidylinositol-4-phosphate 5-kinase-like 1 (PIP5KL1), the forth member of phosphatidylinositol-4-phosphate 5-kinases (PIPKs) type I, acts as a scaffold for localization and activation of PIPKs, which mediates numerous cellular processes. However, the role of PIP5KL1 in the development of human cancer is still lacking. We therefore examined the expression of PIP5KL1 in human normal and cancer tissues by tissue microarrays (TMAs). Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence imaging analysis were used to testify the mRNA and protein levels of PIP5KL1 in human gastric cancer cell line (BGC823). The cell proliferation was investigated with 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay. Both wound healing and transwell migration assay were performed to study the cell migration. The phosphorylation of v-akt murine thymoma viral oncogene homolog 1 (AKT1) was determined by western immunoblot analysis. Immunostaining of gastric cancer tissue microarrays revealed a negative correlation between PIP5KL1 overexpression and gastric cancer in situ. Transient transfection PIP5KL1 induced a significant increase expression at both transcriptional and translational levels and consequent robust inhibition of proliferation (P < 0.05) and migration (P < 0.05) of BGC823 cells. Overexpression of PIP5KL1 markedly inhibited (P < 0.05) serum-induced phosphorylation of AKT1. Taken together, these studies indicate a functional negative correlation between elevated levels of PIP5KL1 and the development of human gastric cancer, suggesting that PIP5KL1 overexpression may suppress gastric cancer formation.
磷脂酰肌醇-4-磷酸 5-激酶样 1（PIP5KL1）是磷脂酰肌醇-4-磷酸 5-激酶（PIPKs）I 型的第四个成员，作为 PIPKs 的定位和激活支架，介导许多细胞过程。然而，PIP5KL1 在人类癌症发展中的作用仍不清楚。因此，我们通过组织微阵列（TMA）检查了人正常和癌组织中 PIP5KL1 的表达。逆转录-聚合酶链反应（RT-PCR）和免疫荧光成像分析用于验证人胃癌细胞系（BGC823）中 PIP5KL1 的 mRNA 和蛋白水平。使用 3-(4,5)-二甲基噻唑 (-z-y1)-3,5-二苯基四唑溴盐（MTT）测定法研究细胞增殖。进行划痕愈合和 Transwell 迁移实验以研究细胞迁移。通过 Western 免疫印迹分析测定 v-akt 鼠胸腺瘤病毒癌基因同源物 1（AKT1）的磷酸化。胃癌组织微阵列的免疫染色显示 PIP5KL1 过表达与胃癌原位之间存在负相关。瞬时转染 PIP5KL1 诱导转录和翻译水平的显著增加，并导致 BGC823 细胞增殖（P < 0.05）和迁移（P < 0.05）的显著抑制。PIP5KL1 的过表达显著抑制（P < 0.05）血清诱导的 AKT1 磷酸化。总之，这些研究表明 PIP5KL1 水平升高与人类胃癌的发展之间存在功能负相关，表明 PIP5KL1 过表达可能抑制胃癌的形成。
