The objective of this study was to determine the expression of the important vesicle trafficking- regulating factor Rab25 in human gastric cancer tissues, to analyze the correlation between Rab25 protein expression wi...The objective of this study was to determine the expression of the important vesicle trafficking- regulating factor Rab25 in human gastric cancer tissues, to analyze the correlation between Rab25 protein expression with gastric cancer occurrence and development, and to discuss the correlation of Rab25 protein expression with gastric cancer cell metastasis. The overall aim was to provide experimental evidence that can be used to design future biological treatments of human gastric cancer. Human gastric cancer tissue and the adjacent normal gastric tissue were surgically removed, and immunohistochemistry and Western blotting were used to detect Rab25 protein expression. The correlation between Rab25 protein expression with the development and pathological characteristics of gastric cancer was analyzed. Using RNAi, Rab25 expression was reduced in the gastric cancer cell line MGC80-3, and the changes in MGC80-3 cell invasiveness were then monitored. Immunohistochemistry showed that the Rab25 protein expression rates were 78.21% and 23.08% in gastric carcinoma and the adjacent normal gastric tissue, respectively. Immunohistochemistry and Western blot results showed that Rab25 protein expression in gastric cancer was significantly higher than in adjacent normal gastric tissues （t）〈0.01）. Less differentiated gastric cancer cells had higher expression of Rab25 protein （P〈0.01）. Gastric carcinomas from patients with a late pathological stage （Ⅲ-Ⅳ） had significantly higher Rab25 protein expression than early stage （Ⅰ-Ⅱ） patients （P〈0.01）. Gastric carcinomas from patients with lymph node metastasis had significantly higher Rab25 protein expression than lymph node metastasis- free patients （P〈0.01）. Gastric carcinomas from patients with distant metastases had significantly higher Rab25 protein expression than the distant metastasis-negative patients （P〈0.01）. Rab25 protein expression in gastric cancer was not affected by the patients＇ sex, age, or tumor size （P〉0.05）. MGCS0-3 cells transfected with Rab25 siRNA had significantly lower Rab25 protein expression （P〈0.01） and a significantly lower number of cells that passed through a Transwell chamber compared with non-transfected controls and the transfected control group （P〈0.01）. Rab25 protein expression is associated with the development of gastric cancer, siRNA knockdown of Rab25 protein expression in MGC80-3 gastric cancer cells reduced MGC80-3 cell invasiveness and provided experimental evidence for potential future biological treatment strategies of human gastric cancer.展开更多
Parkinson＇s disease（PD） associated leucine-rich repeat kinase 2（LRRK2） mutants have shown pathogenic effects on a variety of subcellular processes. Two small GTPases Rac1 and Rab29 have been indicated as possible...Parkinson＇s disease（PD） associated leucine-rich repeat kinase 2（LRRK2） mutants have shown pathogenic effects on a variety of subcellular processes. Two small GTPases Rac1 and Rab29 have been indicated as possible downstream effectors participating in LRRK2 signaling but their detail mechanisms remain unclear. In this study, we have used biochemical and cell biology approaches to address whether two GTPases interact with LRRK2 and hence function differently in LRRK2 mediated pathogenesis. Here we show that Rac1 and Rab29 specifically interact with LRRK2 with higher affinity for Rab29 and with different preference in functional domain binding. Mutant Rab29 but not Racl alters the endosome-to-TGN retrograde trafficking of a cargo protein cation-independent mannose-6-phosphate receptor（CI-M6 PR） and its stability. On the other hand, overexpressed wild type Rab29 but not Racl rescued the altered retrograde membrane trafficking induced by the pathogenic mutant LRRK2^（G2019 S）. Furthermore,both Rac1 and Rab29 rescued neurite shortening in differentiated SH-SY5 Y cells induced by LRRK2^（G2019 S）. Our study strongly suggests that Rac1 and Rab29 are involved in distinct functions as downstream effectors in LRRK2 signaling pathways.展开更多
文摘The objective of this study was to determine the expression of the important vesicle trafficking- regulating factor Rab25 in human gastric cancer tissues, to analyze the correlation between Rab25 protein expression with gastric cancer occurrence and development, and to discuss the correlation of Rab25 protein expression with gastric cancer cell metastasis. The overall aim was to provide experimental evidence that can be used to design future biological treatments of human gastric cancer. Human gastric cancer tissue and the adjacent normal gastric tissue were surgically removed, and immunohistochemistry and Western blotting were used to detect Rab25 protein expression. The correlation between Rab25 protein expression with the development and pathological characteristics of gastric cancer was analyzed. Using RNAi, Rab25 expression was reduced in the gastric cancer cell line MGC80-3, and the changes in MGC80-3 cell invasiveness were then monitored. Immunohistochemistry showed that the Rab25 protein expression rates were 78.21% and 23.08% in gastric carcinoma and the adjacent normal gastric tissue, respectively. Immunohistochemistry and Western blot results showed that Rab25 protein expression in gastric cancer was significantly higher than in adjacent normal gastric tissues （t）〈0.01）. Less differentiated gastric cancer cells had higher expression of Rab25 protein （P〈0.01）. Gastric carcinomas from patients with a late pathological stage （Ⅲ-Ⅳ） had significantly higher Rab25 protein expression than early stage （Ⅰ-Ⅱ） patients （P〈0.01）. Gastric carcinomas from patients with lymph node metastasis had significantly higher Rab25 protein expression than lymph node metastasis- free patients （P〈0.01）. Gastric carcinomas from patients with distant metastases had significantly higher Rab25 protein expression than the distant metastasis-negative patients （P〈0.01）. Rab25 protein expression in gastric cancer was not affected by the patients＇ sex, age, or tumor size （P〉0.05）. MGCS0-3 cells transfected with Rab25 siRNA had significantly lower Rab25 protein expression （P〈0.01） and a significantly lower number of cells that passed through a Transwell chamber compared with non-transfected controls and the transfected control group （P〈0.01）. Rab25 protein expression is associated with the development of gastric cancer, siRNA knockdown of Rab25 protein expression in MGC80-3 gastric cancer cells reduced MGC80-3 cell invasiveness and provided experimental evidence for potential future biological treatment strategies of human gastric cancer.
基金supported by the National Nature Science Foundation of China (Grant No. 31371436 andNo. 8157051134)the laboratory start-up grant from Nanjing Medical University to Y.Liu
文摘Parkinson＇s disease（PD） associated leucine-rich repeat kinase 2（LRRK2） mutants have shown pathogenic effects on a variety of subcellular processes. Two small GTPases Rac1 and Rab29 have been indicated as possible downstream effectors participating in LRRK2 signaling but their detail mechanisms remain unclear. In this study, we have used biochemical and cell biology approaches to address whether two GTPases interact with LRRK2 and hence function differently in LRRK2 mediated pathogenesis. Here we show that Rac1 and Rab29 specifically interact with LRRK2 with higher affinity for Rab29 and with different preference in functional domain binding. Mutant Rab29 but not Racl alters the endosome-to-TGN retrograde trafficking of a cargo protein cation-independent mannose-6-phosphate receptor（CI-M6 PR） and its stability. On the other hand, overexpressed wild type Rab29 but not Racl rescued the altered retrograde membrane trafficking induced by the pathogenic mutant LRRK2^（G2019 S）. Furthermore,both Rac1 and Rab29 rescued neurite shortening in differentiated SH-SY5 Y cells induced by LRRK2^（G2019 S）. Our study strongly suggests that Rac1 and Rab29 are involved in distinct functions as downstream effectors in LRRK2 signaling pathways.
