Expression of Scavenger receptor class A, member 5 protein in hepatocellular carcinoma and the relationship with promoter methylation

Abstract

Objective To investigate the expression and clinical significance of Scavenger receptor class A, member 5 (SCARA5) in patients with hepatocellular carcinoma (HCC), and to explore the relationship between methylation status of SCARA5 gene promoter and its protein expression. Methods SCARA5 expression in tumor and matched adjacent non-cancerous liver tissues from 112 patients with HCC was deteced by immunohistochemistry using tissue microarray technology. The relationship between the protein expression of SCARA5 and the clinical, pathological features in patients with HCC was also analyzed. The promoter methylation patterns of SCARA5 gene in tumor and matched adjacent non-cancerous liver tissues were also measured by methylation-specific PCR technique. Results Negative and weak staining of SCARA5 was observed in 77.7% (87/112) of the HCC tissue samples, contrast to 25.0% (28/112) in the adjacent non-cancerous liver tissue samples. SCARA5 was significantly decreased in HCC tissues (P 0.05). However, the expression of SCARA5 was significantly correlated with tumor size, vascular invasion, Edmondson-Steiner grade and TNM stage (P<0.05). Methylation of SCARA5 gene promoter was found in 60.7% of the all tumor tissue samples. However, methylation was only found in 11.6% of the adjacent non-tumor samples, which was significantly lower than that in tumor tissue samples (P<0.05). Meanwhile, the expression of SCARA5 in tumor tissue samples was negatively correlated with promoter methylation status (P<0.05). Conclusion It suggests that the decreased expression of SCARA5 may have an important role in the development of HCC, and the promoter methylation of SCARA5 gene may be one of the reasons for the decreased expression of SCARA5. Key words: Carcinoma, hepatocellular; Scavenger receptor class A, member 5; Tumor suppressor gene; Methylation