Expression Of HLA-A, B MRNA On Peripheral Blood Mononuclear Cell Of Espphageal Cancer Patients

BackgroundsThe esophageal carcinoma is one of common malignant tumors of digestive system.The incidence rate in malignant tumors is situated in sixth in the world.70 percent of esophageal carcinomas were happened in China and the incidence rate is situated in fourth.The features is difficult with early diagnosis and bad prognosis,the male incidence of women are 2 times.Esophageal hair all over the world each year about 300,000 cancer cases.The esophageal cancer incidence rate is ten thousand 13/10 in our country.It can not be diagnosed in early stage,When the symptoms appear,most of the cancer cells have been diffused and metastasesed.The survival rate in five years of esophageal carcinoma hovered at 10 percent all the time.The outcome of esophageal carcinoma is far from satisfaction to the advanced stage with metastasesed and recurred patients by the traditional treatment such as surgery,radiotherapy and chemotherapy.If diagnosed and treated in the early stage,however,the survival rate will be greatly improved.Therefore,the best approach to make the patients with esophageal carcinoma live longer is to diagnose and treat in the early stage.The human major histocompatibility complex(MHC),also called the human leukocyte antigen(HLA),is the most polymorphic region in the whole human genome and plays a key role in the human immune system.Tumor escape from host immunosurveillance is frequently attributed to the alteration of human leukocyte antigen(HLA)-presenting molecules on neoplastic cells.In fact,the major function of HLA class I molecules is to present viral and tumoral antigens to cytotoxic T lymphocyte(CTL),giving rise to the first steps of antiviral or antitumoral immune response.The complete loss of human HLA classI molecules results in a resistance to CTL-mediated lysis,but in turn it renders tumor ceils susceptible to natural killer(NK) cell-mediated killing.HLA class I molecules expression have been reported in different human tumors at variable Frequency,so,the researches on the polymorphism of HLA are very useful for both anthropological studies and clinical medicine.AimsTo investigate the expression level of HLA-A,B mRNA on Peripheral Blood Mononuclear Cell(PBMC) of esophageal cancer patients and its clinical significance.MethodsAccording to HLA-A,HLA-B gene sequence announced in GenBank,select the conservative region of gene to design specific primers. Peripheral blood mononuclear cells HLA-A,B mRNA were detected by real-time reverse quantitative PCR method in 62 patients with Esophageal Cancer and 45 healthy individuals.ResultsThe relative expression ratio of PBMC HLA-A,B mRNA was 0.41±0.26,0.37±0.28 in carcinoma group,1.12±0.54,1.19±0.60 in healthy group,respectively.The expression level of HLA-A,B mRNA on PBMC of esophageal cancer group was significantly lower than healthy control group.ConclusionThe expression of HLA-B mRNA and HLA-B antigen from PBLs in patients with esophageal cancer,especially metastasis of differentiation cancer were lower or lost wholly,leading to default of antigen presentation,the decline of HLA-B mRNA is possible an important mechanism for leading evasion of esophageal cancer from Immunosurveillance.Results from these data confirm that HLA-A,B play a critical role in the tumor immunity response.HLA-A,B mRNA expression level on PBMC was reduced significantly when tumor occurs.On this ground,it may become an available tumor marker.The data may provide a new method and direction to tumor early diagnosis and treatment.