10146

G3BP1

GTPase activating protein (SH3 domain) binding protein 1;G3BP1;GTPase activating protein (SH3 domain) binding protein 1

ATP-dependent DNA helicase VIII|G3BP-1|GAP SH3 domain-binding protein 1|GAP binding protein|Ras-GTPase-activating protein SH3-domain-binding protein|RasGAP-associated endoribonuclease G3BP|ras GTPase-activating protein-binding protein 1

5q33.1

protein-coding

OBJECTIVE: To investigate the expressions and significances of Ras-GTPase-activating protein SH 3 domain binding protein(G3BP) and osteopontin (OPN) proteins in esophageal squamous carcinoma (ESC). METHODS: The expressions of G3BP and OPN proteins in 80 cases of ESC were detected by immunohistochemistry. The relationships between the 2 protein expression and tumor size, differentiation degree, TNM stage, lymph node metastasis and prognosis of ESC were also explored. RESULTS: (1) The positive expression rate of G3BP in ESC was 71.3%, and the rate in lymphoid metastatic group was significantly higher than that in non lymphoid metastatic group (Z=-2.283, P=0.022), but no relations were found between G3BP expression and diameter of tumor, differentiation and TNM grade (P>0.05). The G3BP positive expression group had shorter survival time than G3BP negative expression group (P=0.000). (2) The positive expression rate of OPN in ESC was 100%, and the degree of OPN expression was correlated with the differentiation (chi(2)=10.766, P=0.005) and lymphoid metastasis (Z=-2.289, P=0.022), but no relationship was found between the diameter of tumor and TNM grade (P>0.05). The expression of OPN were significantly related to survivals in a negative time-dependent manner in ESC patients (P=0.000). (3) The expression of G3BP protein correlated positively with the degree of OPN expression in ESC tissue (r(s)=0.376, P=0.001). CONCLUSIONS: The expressions of G3BP and OPN proteins have a close relationship with lymphoid metastasis and survival in ESC patients. G3BP and OPN proteins can be considered as predictors of prognosis in ESC patients.

AIM: To investigate the expression and significance of G3BP and RhoC proteins in esophageal squamous carcinoma (ESC). METHODS: The expression of G3BP and Rhoc proteins in 80 cases of ESC was detected by immunohistochemistry. The relationship was studied between the expression of the two proteins and tumor size, differentiation degree, TNM stage, lymph node metastasis and prognosis of ESC. RESULTS: The positive expression rate of G3BP in ESC was 71.25%; and the rate in the lymph node metastasis group was significantly higher than that in the non-lymph node metastasis group (Z = -2.283, P = 0.022), but no relations were found between G3BP expression and tumor size, differentiation degree and TNM stage (P > 0.05). The group with G3BP positive expression had shorter survival time than the group with G3BP negative expression (P = 0.000). The positive expression rate of RhoC in ESC was 66.25%; and the rate in the lymph node metastasis group was significantly higher than that in the non-lymph node metastasis group (Z = -2.115, P < 0.05), but no relations were found between RhoC expression and tumor size, differentiation degree and TNM stage (P > 0.05). The RhoC positive expression group had a shorter survival time than the RhoC negative expression group (P < 0.001. The expression of G3BP protein correlated positively with the expression of RhoC in ESC tissues (rs = 0.656, P < 0.001). CONCLUSION: The expression of G3BP and RhoC protein is closely related to the lymph node metastasis and survival in ESC patients. G3BP and RhoC proteins can be considered as predictors of prognosis in ESC patients.

We report a novel function for the CD24 molecule in pancreatic cancer cells. Intracellular CD24 is associated with stress granules that contain specific mRNAs and RNA-binding proteins that regulate mRNA stability and translation. Intracellular CD24 in stress granules is associated with G3BP, a phosphorylation-dependent endoribonuclease. The vesicles in which the CD24/G3BP complex localizes are transported toward cell protrusions in migrating cells. We show that G3BP binds to and degrades Binder of Arl Two (BART) mRNA. BART was originally identified as a binding partner of ARL2, a small G-protein implicated as a regulator of microtubule dynamics and folding. Intracellular CD24 inhibits the specific endoribonuclease activity of G3BP toward BART mRNA in stress granules. We show that knockdown of CD24 increases retroperitoneal invasion and liver metastasis of pancreatic cancer cells in an orthotopic xenograft model, and that BART also prevents retroperitoneal invasion and liver metastasis of pancreatic cancer cells. Our results imply that surface CD24 may play a role in the inhibition of cell invasion and metastasis, and that intracellular CD24 inhibits invasiveness and metastasis through its influence on the posttranscriptional regulation of BART mRNA levels via G3BP RNase activity.