Expression and Significances of MTSS1 in Pancreatic Cancer

Thus far, expression of metastasis suppressor 1 (MTSS1), its clinicopathologic and prognostic significances in pancreatic cancer (PC) remain unknown. Expression of MTSS1 was detected by Western blotting in PC cell lines, and by tissue microarray-based immunohistochemical staining in paired tumor and non-tumor samples from 242 patients with PC. Furthermore, the correlations between MTSS1 expression and clinicopathologic variables as well as overall survival were evaluated. In PC cell lines, MTSS1 was differentially expressed. In addition, MTSS1 expression was significantly lower in tumor than in non-tumor tissues (P < 0.001 in both McNemar and Mann-Whitney U tests). High tumoral expression of MTSS1 was closely associated with absence of lymph node metastasis (P = 0.023). Univariate analysis found that high MTSS1 expression in tumor tissues was a strong predictor of favorable overall survival in the whole cohort (P < 0.001). Besides, its impacts on prognosis were also observed in nine out of fourteen subgroups. Finally, MTSS1 expression was identified as an independent prognostic marker in the whole cohort (P = 0.031) as well as in six subgroups (P < 0.05), as shown by multivariate Cox regression test. Down-regulation of MTSS1 expression is evident in PC, and is associated with lymph node metastasis and poor prognosis.