Altered expression of mitochondrial cytochrome c oxidase I and NADH dehydrogenase 4 transcripts associated with gastric tumorigenesis and tumor dedifferentiation.

This study aimed to detect the expression of mitochondrial mRNA in normal and cancerous gastric tissues and discuss their association with clinicopathological characteristics. Semi-quantitative reverse-transcription PCR was used to analyze mitochondrial transcripts in 42 cases of matched cancerous and normal gastric tissues. Expression of these genes was then statistically analyzed to determine the correlation with the clinicopathological characteristics from the patients. Transcripts of cytochrome c oxidase I (CO I) and NADH dehydrogenase 4 (ND4) were highly expressed in gastric cancer tissues compared to normal gastric tissues (P=0.005 and P=0.001, respectively). The expression levels of CO I and ND4 were higher in the diffused type of gastric cancer than in the intestinal type (P=0.024 and P=0.0002, respectively). Elevated expression of CO I and ND4 were associated with gastric tumorigenesis and tumor dedifferentiation ex vivo.