Expression of tumor necrosis factor-alpha and interleukin-6 in oral squamous cell carcinoma

To explore the role of cytokines in tumor development and clinical manifest ations, we examined the expressions of tumor necrosis Factor-alpha (TNF-alp ha) and interleukin-6 (IL-6) in tumor tissues obtained from 57 patients wit h oral squamous cell carcinoma (OSCC) and their relationships to pathologic al grade and staging. Enzyme-linked immunosorbent assay on the tumor tissue s demonstrated elevated concentrations of TMF-alpha and IL-6 proteins and u pregulated mRNA levels were detected by the reverse transcription-polymeras e chain reaction method when compared to those in normal control tissues, T hese cytokines and their transcripts were localized in stromal macrophages and in the tumor cells in particular of the front area of tumor tissues, po ssibly indicating active synthesis of these cytokines by tumor cells. Large r-sized tumors (T3, 4) contained significantly greater levels of IL-6 prote ins than small-sized tumors (T1, 2) (P<0.05). The levels of these cytokines were significantly reduced in cases with effective pre-treatment with radi ation or anti-cancer agents compared to those in the less effective group ( P<0.05, grade IIa vs. grade IV for both TNF-alpha and IL-6). The present st udy thus demonstrated enhanced expression of cytokines in OSCC tissues.