Prognosis, Significance and Positive Correlation of Rab1A and p-S6K/Gli1 Expression in Gastric Cancer

Background: Gastric Cancer (GC) is a frequently common malignancy. Recent studies have reported Rab1A as an activator of mTORC1, and the mTOR1 pathway is involved in regulating Gli1 expression in several cancers. Only a few studies have been performed to explore the relationship between Rab1A and p-S6K/Gli1in GC. Methods: Immunohistochemistry (IHC) was performed to explore the association of Rab1A/p-S6K/Gli1 expression and prognosis in 117 GC tissue samples and adjacent normal tissues. Results: Our results indicated that Rab1A/p-S6K/Gli1 was significantly overexpressed in GC tissues. High expression of Rab1A was closely related to the tumor size and the depth of tumor invasion. In addition, Rab1A expression was closely related with p-S6K/Gli1 expression in GC, and high level of Rab1A/p-S6K/Gli1 caused worse prognosis of GC patients. The univariate and multivariate analysis indicated that the expression of Rab1A was an independent prognostic factor. Moreover, both high Rab1A and p-S6K expression led to a worse prognosis when compared to a single positive expression as well as both high Rab1A/Gli1 expression also led to a worse prognosis than the single positive expression of Rab1A/Gli1. Strikingly, the overexpression of p-S6K also led to a worse prognosis in Rab1A positive patients, as did Gli1. Conclusion: Our results indicate that Rab1A/mTOR/S6K/Gli1 axis played a crucial role in GC, which may provide a novel field on targeted therapy of GC, especially for mTORC1-targeted therapy-resistant cancers.