TIM-3 expression and its association with overall survival in primary osteosarcoma

T-cell immunoglobulin and mucin domain-containing-3 (TIM-3) performs a critical function in immune tolerance by suppressing the activation and proliferation of T cells. TIM-3 serves an important role in tumor progression in a number of carcinomas, including non-small cell lung cancer, hepatitis B virus-associated hepatocellular carcinoma, Langerhans cell sarcoma, head and neck cancer and follicular B cell non-Hodgkin lymphoma. The aim of the present study was to evaluate the possible association of TIM-3 with the prognosis of osteosarcoma. TIM-3 expression was assessed by immunohistochemical analysis in osteosarcoma tissues. The association between TIM-3 expression and prognosis was examined. To assess the association between TIM-3 expression levels and clinicopathological features, a Fisher's exact test was used. TIM-3 overexpression was indicated to be associated with surgical treatment and survival. Kaplan-Meier analysis indicated that TIM-3 is an independent predictor of overall survival, and its overexpression was indicated to be associated with poor prognosis in patients with osteosarcoma. Additionally, reverse transcription-quantitative polymerase chain reaction and western blot analysis were carried out to evaluate TIM-3 expression levels in fresh tumor tissue samples, adjacent-tissue samples, osteosarcoma cell lines, and in an osteoblastic cell line. TIM-3 was indicated to be overexpressed in fresh osteosarcoma tissue samples and in osteosarcoma cell lines. In conclusion, TIM-3 overexpression is associated with poor survival among patients with osteosarcoma and may be a possible therapeutic target in these types of tumors.