Background: Contribution of immunosuppressive cytokines to tumor progression in many types of cancers has been suggested. To characterize the in vivo expression of immunosuppressive cytokines in gastric cancer, we analyzed the messenger RNA (mRNA) expression of transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) in human gastric carcinoma tissues.
Methods: Both tumor tissues and nontumor tissues from each resected specimen of 29 primary gastric carcinomas were tested for IL-10 and TGF-beta mRNA expression by the reverse transcriptase-polymerase chain reaction (RT-PCR), and the mRNA expression was correlated with various pathological parameters of the tumors.
Results: Among the 29 tumors, mRNAs of TGF-beta and IL-10 were detected in 79% and 62% of tumor samples, respectively. These cytokines were detected only in 31% for TGF-beta and 17% for IL-10 in nontumor samples. Both mRNAs were frequently expressed in the poorly differentiated adenocarcinomas and the tumor tissues with high degree of stage or lymph node metastasis.
Conclusions: Local expression of immunosuppressive cytokines may contribute to the progression of primary gastric carcinomas possibly through immunosuppression.