Abstract: ObjectiveTo investigate the expression of human ribonucleotide reductase large subunit M1 (RRM1) in the patients with gastric adenocarcinoma and its clinical significance. MethodsThe expressions of RRM1 were detected in 88 cases of gastric adenocarcinoma and 20 cases of normal gastric tissues by immunohistochemical method. The correlations between the expression of RRM1 and clinicopathological characteristics were analyzed. ResultsThe positive expression rate of RRM1 in gastric adenocarcinoma was 83.0% (73/88). And RRM1 was negative in the entire normal gastric tissues. The positive expression of RRM1 was not associated with patient′s age (χ2=0.352, P=0.553), gender (χ2=0.493, P=0.482), depth of tumor infiltration depth (χ2=0.007, P=0.933), lymph nodes metastasis (χ2=0.121, P=0.728) and distant metastasis (P=0.415). But it was related to the degree of tumor differentiation (χ2=7.740, P=0.021) and clinical stage (χ2=5.733, P=0.017).  ConclusionThe expression of RRM1 is positive expression in most gastric adenocarcinoma, and is associated with the degree of tumor differentiation and clinical stage. It is of great significance to detect the expression of RRM1 in gastric adenocarcinoma for confirming the diagnosis and judging malignant degree of the tumor. It also may have potential value in choosing the best therapeutic scheme and estimating prognosis.

Key words: Stomach neoplasms, Immunohistochemistry, Ribonucleotide reductase large subunit M1