The Case-control Study Of Esophageal Squamous Cell Carcinoma And MiR-21 In Serum/plasma

Background & Objective: Esophageal cancer is the 8th most common malignancy inthe world.Both the morbidity and the mortality of esophageal squamous cellcarcinoma (ESCC) in China ranks first around the world. In the vast majority ofcases, patients with ESCC are always diagnosed in the middle and late stages ofthe disease,besides the overall five-year survival rate is very low. However,the 10-year survival rate of patients would amount to 95.00% if patients receivethe surgery in the early stage. Therefore, it is necessary to improve the earlydiagnosis rate of esophageal cancer. At present,we have commonly used theesophageal function tests, imaging diagnostics, cytological examination ofesophagus and esophageal endoscopy to diagnose, but they can give patients damagesand pains,and have poor sensitivity for diagnosis. In the past studies, miRNA mightprovide new complementary tumour markers. Compared with traditional diagnosticmethods, evaluating expression of microRNA in serum/plasma would provide a newchoice for esophageal cancer diagnosis. As an important miRNA, miR-21 has abnormalexpression in multiple tumor cells, getting involved in cell differentiation,proliferation and apoptosis.It is closely related to tumor and is conducive todiagnosis, treatment and prognosis of tumor. However, the current research on therelevance between miR-21 in serum/plasma and ESCC is scarce. This study revealedthe expression of miR-21 in the serum/plasma of patients with ESCC and evaluatedthe miRNAs level in serum/plasma as a new potential biomarker for ESCC.Methods: Blood samples were collected from the Department of Clinical Laboratory,the First Affiliated Hospital to Shantou University Medical College, transportedwith ice box and stored in the ultra-low temperature refrigerator. Total RNAs wereextracted by the Trizol using the serum/plasma of 22 patients with esophagealsquamous cell carcinoma and healthy subjects. In addition, Total RNAs wereextracted by the Trizol using the serum/plasma from patients before and afteroperation. The total RNAs were analyzed for purity and integrity by applying UV spectrophotometry and gel imaging system. The stem-loop RT primers PCR amplimersof miR-21 and internal reference U6 were designed and the expression levels ofmiR-21 and internal reference U6 were detected with SYBR Green real-timequantitative PCR. All the data were analyzed by spss17.0.Results: The melting curves of U6 and miR-21 detected with SYBR Green real-timequantitative PCR were correct, with specific PCR products. Most of expressionlevels of miR-21 in serum/plasma of patients with ESCC(68.2%) were lower than thecounterpart in the healthy control group, but the result was not statisticallysignificant (P＞0.05). Yet, the expression levels of miR-21 in serum/plasma ofpatients after operation were as 4.56 times as the counterpart before operation(P<0.05). The expression levels of miR-21 in serum/plasma of patients with ESCCwere not associated with gender, age, cancer site, differentiation, stage,metastasis type or chemotherapy or not (P> 0.05), but related to operation or notand metastasis or not (P<0.05).Conclusions: The expression levels of miR-21 in serum/plasma of patients withESCC were lower than the counterpart in the healthy control group, but the resultwas not statistically significant. The expression level of miR-21 in serum/plasmaof patients with had association with operation or not and metastasis or not. AsmiRNA in serum/plasma is stable, blood after testing can be used to detect themiRNAs expression levels. The expression level of miR-21 in serum/plasma ispossible to provide the diagnosis of esophageal cancer with a new molecularbiomarker, but it need further research by increasing the sample size.