[Mycoplasma infection in human gastriointestinal carcinoma tissues].

Abstract

OBJECTIVE: To explore the association between the carcinoma and mycoplasma infection by immunohistochemistry. METHODS: Antigen of anti-tumor monoclonal antibody PD4 was identified as mycoplasma hyorhinis. Using immunohistochemistry to study archived paraffin-embedded gastriointestinal tract carcinomas tissue. The PCR was applied to amplify the mycoplasma DNA for confirming immunohistochemistry results. RESULTS: It was showed that mycoplasma was present in 56% (50/90 cases) of gastric carcinoma. The cancer tissues with high differentiation had a higher mycoplasma infection ratio than that of low differentiation cancer tissues. (P < 0.05). In control cases, mycoplasma infection was 28% (18/49) in chronic superficial gastritis, 30% (14/46) in gastric ulcer and 37% (18/49) in intestinal metaplasia of the stomach. Mycoplasma infection was 55.1% (32/58) in colon carcinoma and 20.9% (10/49) in adenomarous polyp (P < 0.005). It seems that colon carcinoma tissues with slight pathological grade had a higher percent of mycoplasma infection than that of cancer tissues with moderate and heavy pathological grade (P < 0.05). CONCLUSION: The high infection of mycoplasmas in carcinoma tissues suggest an association between mycoplasma and cancer. The mechanism involved in oncogenesis by mycoplasmas remains to be elucidated.