Prognostic significance of low expression of B-cell translocation gene 1 (BTG 1) in skin squamous cell carcinoma

Although the B-cell translocation gene 1 (BTG1) plays an important role in apoptosis and negatively regulates cell proliferation, BTG1 expression in skin squamous cell carcinoma (SCC) has not been reported. In this study, we wanted to investigate the significance of BTG1 expression in SCC and adjacent tissues. The expression of BTG1 protein and mRNA in SCC tissues and adjacent tissues were detected by immunohistochemistry technique (IHC), Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). IHC staining showed that the positive expression rate of BTG1 protein in SCC tissues was 54.00%; and the positive rate was 90.50% in the adjacent tissues. Western blot showed that the expression of BTG1 protein in SCC tissues was significantly lower than that in the adjacent tissues (P<0.05). RT-PCR showed that the positive rate of BTG1 mRNA in SCC was 50.50%, which was significantly lower than that in adjacent tissues 89.00% (P<0.05). Both BTG1 mRNA and protein expression are related to tumor diameter, stage, tumor metastasis and the degree of tumor differentiation in SCC. Patients exhibiting lower BTG1 protein expression in the SCC tissues had a significantly shorter disease-specific survival rate. BTG1 protein expression, tumor diameter, tumors site and stage were independent factors affecting the overall survival of postoperative patients. Further, BTG1 overexpression inhibited A431 cell proliferation ability, while BTG silencing enhanced A431 cell proliferation ability. The lower expression of BTG1 in SCC may be associated with the occurrence, development and prognosis of SCC.