ABSTRACT
@#[Abstract] Objective: To investigate the expression of human endogenous retrovirus subfamily H long terminal repeat associating protein 2 (HHLA2) in hepatocellular carcinoma (HCC) tissues and its correlation with the clinicopathological characteristics and prognosis of patients with HCC. Methods: Based on TCGA database, the correlation between HHLA2 mRNA expression and B7 family genes in human HCC tissues was analyzed. HHLA2 expression in 90 pairs of HCC tissues and their adjacent tissues was detected by tissue microarry and immunohistochemical staining. Wilcoxon rank sum test was used to compare the difference of HHLA2 expression between HCC tissues and its adjacent tissues. The chi-square test was used to analyze the relationship between HHLA2 expression in human HCC tissues and clinicopathological features of the patients. Kaplan-Meier survival analysis was performed to analyze the correlation between HHLA2 expression and patients’ overall survival (OS), and the Cox model was used to evaluate the prognostic value of different indices. Results: The expression level of HHLA2 mRNA in HCC tissues was correlated with B7 family CD274, C10orf54, PDCD1LG2, ICOSLG and CD276. The expression level of HHLA2 in HCC tissues was significantly correlated with tumor size (χ2=4.531, P<0.05). The OS of HCC patients with high HHLA2 expression was significantly shorter than that of the patients with lower HHLA2 expression (HR=1.878, 95%CI: 1.066-3.309, P<0.05). The COX model showed that tumor size (HR=2.493, 95%CI: 1.310-4.742, P<0.01) could be used as an independent risk factor for the prognostic prediction of the patients. Conclusion: HHLA2 is significantly correlated with the prognosis of HCC patients, and can be used as a potential target for HCC immunotherapy.
ABSTRACT
Objective To investigate the effect of retinoblastoma binding protein 4 (RBBP4)in Sp1 -mediated HIV long terminal repeat(LTR)transcription.Methods RBBP4 expression vector and Sp1 expression vector were respectively co-transfected into 293 T cells with HIV promoter pHIV-LTR-Luc or Sp1 site mutated pHIV-LTR-sp1 -mut by liposome transfection,and the transfected cells were examined by dual luciferase reporter assay system.The effect of RBBP4 on the binding of Sp1 to LTR was further studied by chromatin immunoprecipitation (ChIP)and electrophoretic mobility shift assay (EMSA).Results The relative firefly luciferase activity activated by Sp1 was decreased from 62.5 to 16 at the dose of 500 ng of RBBP4 expression vector (t =14.52,P <0.01 ).When the Sp1 binding sites were mutated,the effects of 100,300 or 500 ng of RBBP4 expression vector on the firefly luciferase activity of HIV LTR were not statistically significance (t =1 .897,2.357 and 3.162,all P <0.05).ChIP results showed that when the binding of RBBP4 on HIV LTR increased,the binding of Sp1 on HIV LTR increased significantly (t =11 .93,P <0.01 ),while the reduced binding of RBBP4 on HIV LTR significantly attenuated the binding of Sp1 onto LTR(t =11 .38,P <0.01 ).The effect of RBBP4 on the binding of Sp1 to DNA in ChIP assays was further verified by EMSA assays.Conclusion RBBP4 can inhibit the Sp1 -mediated HIV LTR transcription in 293 T cells.