[Up-regulation of TIM-3 on CD4+ tumor infiltrating lymphocytes predicts poor prognosis in human non-small-cell lung cancer].

OBJECTIVE

To characterize the expression of negative costimulatory molecule, T cell immunoglobulin and mucin-domain-containing molecules 3 (TIM-3), on tumor infiltrating lymphocytes (TILs) in human non-small-cell lung cancer (NSCLC) and explore the clinical significance of the expression.

METHODS

A total of 56 human lung cancer tissue specimens were obtained from pathologically confirmed and newly diagnosed NSCLC patients. Infiltrating lymphocytes from both tumor tissues and adjacent normal lung tissues were analyzed for TIM-3 expression by immunofluorescence staining and flow cytometry. Correlation analysis was performed between TIM-3 expression on TILs and the prognosis of the patients.

RESULTS

The expression of TIM-3 on CD4+ TILs in tumor tissues [(28.64±10.46)%] was significantly higher than that on CD4+ T cells in adjacent normal tissues [(13.32±6.95)%]. Similarly, the expression of TIM-3 on CD8+ TILs in tumor tissues [(30.77±15.58)%] was up-regulated as compared with that on CD8+ T cells in adjacent normal tissues [(12.98±8.19)%]. Moreover, majority of the TIM-3 positive TILs from both adjacent normal tissues and tumor lung tissues were positive for another negative costimulatory molecule, programmed death 1 (PD-1). Importantly, TIM-3 expression on CD4+ TILs was correlated with poor prognosis of the patients.

CONCLUSION

TIM-3, as a key negative regulator in the anti-tumor immunity, contributes to the tumor immune evasion. It has an adverse influence on the prognosis of NSCLC patients.