The Research Of Phosphatidylinositol Pathway Related Molecules Ric-tor And FoxO1 Relationship With Gastric Cardiac Carcinoma

Objective:To determine the feasibility of Rictor and Fox O1 as early diagnosis of gastric cardia adenocarcinoma(GCA), we investigated the expression difference between Rictor and Fox O1 in GCA and the adjacent non-cancerous tissues and then analyzed their correlation with the clinicopathological feature of GCA.Methods:We recruited the 30 patients diagnosed with histologically confirmed GCA in the first affiliated hospital of He’nan university of science and technology from February 2012 to October 2013 and collected the GCA tissues and adjacent non-cancerous tissues. All the subjects in our study haven’t had radiotherapy and chemotherapy before operation in our study.(1) Determination of Rictor/Fox O1 m RNA in GCA: Gene primers of Rictor/Fox O1 were designed and RT-PCR was used to determine the level of Rictor/Fox O1 m RNA expressed in GCA and the adjacent non-cancerous tissues.(2) Determination of Rictor/Fox O1 protein in GCA: Immunohistochemistry and western blot were used to determine the level of Rictor/Fox O1 in GCA and the adjacent noncancerous tissues. All statistical analyses were accomplished using the SPSS version 17.0.Results:(1) RT-PCR results indicated Rictor m RNA expressed in both GCA and the adjacent non-cancerous tissues. The expression level in GCA was lower than that in the adjacent non-cancerous tissues in twenty-six cases(86.7%) and higher in four cases(13.3%), and difference was significant(P<0.05). Fox O1 m RNA also expressed in both GCA and the adjacent non-cancerous tissues. Twenty-five cases(83.3%) was lower in GCA and five(16.7%) was higher, which also showed a significant difference(P<0.05).(2) Immunohistochemistry showed that the positive rate of Rictor protein in GCA was 46.7%(14/30) and 76.7%(23/30) in the adjacent non-cancerous tissues, which was significantly different(P<0.05). And the decrease of Rictor expression in GCA showed a significant correlation to tumor differentiation degree(P<0.05), but no correlation was found to age, gender, TNM-staging and lymph node metastasis(P>0.05). The positive rate of Fox O1 protein in GCA was 53.3%(16/30) and 86.7%(26/30) in the adjacent non-cancerous tissues, which also showed a significant difference(P<0.05). And the decrease of Fox O1 expression in GCA showed a significant correlation to tumor differentiation degree(P<0.05), but no correlation was found to age, gender, TNM-staging and lymph node metastasis(P>0.05).(3) Western blot indicated Rictor protein expressed in both GCA and the adjacent non-cancerous tissues. The expression level in GCA was lower than that in the adjacent non-cancerous tissues in twenty-four cases(80.0%) and higher in six cases(20.0%), and difference was significant(P<0.05). Fox O1 protein also expressed in both GCA and the adjacent non-cancerous tissues. Twenty-four cases(80.0%) was lower in GCA and six(20.0%) was higher, which also showed a significant difference(P<0.05).(4) The consistency analysis was conducted between Weatern blot and RT-PCR for both Rictor and Fox O1, and the coefficients were r=0.609 and r=0.429 which indicated a positive correlation between protein expression and RNA expression for Rictor and Fox O1.(5) The consistency analysis was also conducted between Rictor and Fox O1 by comparison of their Western blot and RT-PCR. The coefficients were r=0.429 and r=0.87 and a positive correlation between Rictor and Fox01 was also indicated.Conclusion:(1) The expression of Rictor in gastric cardia carcinoma is lower than that in the corresponding adjacent tissues, suggesting that Rictor may be involved in the process of gastric carcinogenesis, development and invasion and metastasis.(2) The expression of Fox O1 in gastric cardia carcinoma is lower than that in the corresponding adjacent tissues of gastric cardia cancer, suggesting that Fox O1 may be related to cancer development and metastasis, indicating that a high expression of Fox O1 in gastric cardia carcinoma adjacent tissues may be an important process of carcinogenesis of gastric cardia mucosa.(3) The expression of Rictor and Fox O1 were positively correlated, probably for the reason that upstream gene of Rictor activated the expression of the downstream gene Fox O1 in the signal transduction pathway of PI3K/AKT/m TOR, indicating that Rictor and Fox O1 gene may have a synergistic effect in GCA.