Interleukin-12-related cytokine gene expression in carcinomas of the breast, lung, and larynx: A study at tissue level

Tumor-infiltrating lymphocytes (TIL) consist of T helper 1 (Th1) and T help er 2 (Th2) cells producing interferon-gamma (IFN-gamma) and interleukin-4 ( IL-4), respectively Interleukin-12 (IL-12) induces Th1 and Th2 differentiat ion. Therefore, IL-12, IFN-gamma, and IL-4 gene expression were evaluated b y reverse transcriptase-polymerase chain reaction in carcinomas of the brea st (n = 10), lung (n = 17), and larynx (n = 13) to investigate whether TIL activation is IL-12-related. IL-12 and IFN-gamma were codistributed in brea st carcinomas, and IL-4 was demonstrated in three instances. IL-12 and IFN- gamma were detected in 15 and 13 lung carcinomas, respectively, and were co distributed in 11 cases; IL-4 was observed in 9 cases and was codistributed with IL-12 and IFN-gamma in 7 instances. IL-12 and IFN-gamma expression wa s observed in five and nine larynx carcinomas, respectively, and were codis tributed in four cases; IL-4 was detected in five instances. These data ind icate that breast, lung, and larynx carcinomas are characterized by differe nt patterns of IL-12, IFN-II, and IL-4 gene expression and suggest that Th1 activation may be induced, at least in part, by the neoplastic microenviro nment.