ObjectiveTo study the clinical significance of the 3-hydroxyisobutyrate dehydrogenase (HIBADH) expressions in gastric adenocarcinoma tissues and its biological function in gastric cancer cells.MethodsSeventy-six patients with gastric adenocarcinoma who were hospitalized in Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University, School of Medicine between January 2006 and December 2007 were recruited in our research. Immunohistochemical (IHC) staining was used to detect the HIBADH protein in primary gastric adenocarcinoma tissues, adjacent tissues, and metastatic lymph node tissues of gastric cancer. Then, the relationships among the expression of HIBADH protein, the clinical features, and the prognosis were analyzed. The MKN45 gastric cancer cell line of HIBADH overexpression was picked up and constructed as stable HIBADH knockdown cell lines. The biological function of HIBADH protein in gastric cancer cells was confirmed through in vitro experiments such as cell proliferation assay, migration and invasion assay, and scratch-wound assay.ResultsThe positive expression rate of HIBADH protein in the 76 gastric adenocarcinoma tissues was significantly higher than that of the adjacent tissues (χ2=54.738, P<0.001). Moreover, the higher expression level of HIBADH protein was related to the larger tumor diameter, the higher tumor lymphatic invasion rate, the later pT stage, the higher the lymph node metastasis rate, and the later pTNM stage (P<0.05). HIBADH protein was also highly expressed in lymph nodes with metastatic carcinoma, and positiverate was 100% (48/48). The 10-year survival rate of patients in the HIBADH protein positive group and HIBADH protein negative group were 16.4% and 69.4%, respectively, which showed the latter group had a longer survival time (χ2=19.612, P<0.001). The migration capacity, invasion capacity, and scratch-wound capacity of the MKN45 cells were significantly decreased after HIBADH protein knockdown (P<0.05), but the proliferation capacity of the cells was not significantly changed (P>0.05).ConclusionsThe overexpression of HIBADH protein in gastric cancer suggests later tumor stage and poor prognosis. Inhibition expression of HIBADH protein can reduce the motility capacity of gastric cancer cells.