Downregulated Expression of Tropomyosin 1 in Intrahepatic Cholangiocarcinoma: A Predictor of Recurrence and Prognosis.

ABSTRACT

BACKGROUND The downregulation of tropomyosin 1 (TPM1) has been observed in various tumors, but few studies have focused on the clinical significance of TPM1 in intrahepatic cholangiocarcinoma (ICC). In the present study, we investigated the prognostic significance of TPM1 in ICC. MATERIAL AND METHODS A total of 124 patients with ICC were enrolled in this study. Quantitative real-time polymerase chain reaction (qRT-RCR) was performed to examine the mRNA levels of TPM1 in ICC tissue samples and adjacent noncancerous tissue specimens, while the protein level of TPM1 in tissue specimens were investigated using immunohistochemistry assay. The correlation of TPM1 with clinicopathological features of ICC was analyzed by chi-square test. Survival analysis was performed with Kaplan-Meier method. The Cox proportional hazards model was used to evaluate the prognostic value of TPM1 in patients with ICC. RESULTS TPM1 expression was significantly downregulated in ICC tissues at mRNA and protein levels (P<0.001 for both). Downregulated TPM1 mRNA was negatively associated with tumor size (P=0.001) and TNM stage (P=0.007). Moreover, survival analysis demonstrated that patients with low TPM1 expression had a shorter overall survival (OS) (P<0.001) and recurrence-free survival (RFS) (P<0.001) than those with high TPM1 expression. Additionally, multivariate analysis showed that TPM1 could be a potential biomarker for predicting the recurrence (HR=4.632, 95% CI 3.832-10.368, P<0.001) and survival outcome (HR=5.320, 95% CI 2.627-11.776, P<0.001) of ICC. CONCLUSIONS TPM1 may serve as a useful biomarker for predicting tumor recurrence and prognosis in patients with ICC.