It was speculated
that different subcelluar distribution of phospho-p70S6K might have distinct biological function in the malignant transformation of gastric epithelial cells. The 70-kDa S6 kinase (p70S6K) is a cytoplasmic Ser/Thr kinase that is mainly known to regulate protein translation through phosphorylation of the 40S ribosomal protein S6. Activation of p70S6K is achieved through phosphorylation on multiple Ser/Thr residues by stimulation with growth factors such as epidermal growth factor (EGF), thrombin, and lysophosphatidic acid (LPA)[23, 24]. To the role of phopsho-p0S6K protein in the progression of gastric carcinoma, its expression was compared with the aggressive behaviors of carcinoma and for the first time found that nuclear phosphor-P70S6K expression was inversely linked to tumor size, depth of invasion, lymph node find more metastasis and UICC staging. It was suggested that down-regulated Selleck Elafibranor expression of nuclear phospho-P70S6K was involved in the growth, invasion and metastasis of gastric carcinoma and might be employed to indicate the biological behaviors of gastric carcinoma in clinicopathological Liproxstatin-1 solubility dmso practice. Although gastric cancer is malignant tumor originating from the same gastric epithelium, its morphological features vary substantially with the individual patients [13]. According to Lauren’s classification,
intestinal-type carcinomas are characterized by cohesive carcinoma cells forming gland-like tubular structures with expanding or infiltrative growth pattern. The cell cohesion is less apparent or absent in diffuse-type carcinoma and cancer cells diffusely spread in the gastric wall lesions. Tumors that contain approximately equal quantities of intestinal and diffuse components are called mixed carcinoma [13, 14]. These three markers were preferably expressed in the older patients with gastric cancer and intestinal-type carcinoma. Here, it was noted that mTOR, cytoplasmic and nuclear P70SK6 expression was higher in intestinal-than diffuse-type carcinomas, indicating that these three markers might play an important role in intestinal-type carcinogenesis, Phosphoglycerate kinase but less in de novo carcinogenic pathway and underlie the molecular basis for differentiation
of both carcinomas. To clarify the prognostic significance of mTOR, cytoplasmic or nuclear P70S6K expression, we here analyzed their relation with the survival of 412 patients with gastric carcinoma and found a close relationship link between the positivity of mTOR and nuclear phospho-P70S6K expression and favorable survival. Multivariate analysis demonstrated six independent prognostic factors such as age, depth of invasion, lymphatic invasion, lymph node metastasis, Lauren’s classification and mTOR expression were independent prognostic factors for overall gastric carcinomas. However, several evidences indicated that phosphor-mTOR expression was closely linked to the poor prognosis of the patients with cervical adenocarcioma or hepatocellular carcinoma [18, 25].