The Expression Of Notch1 Protein In Esophageal Squamous Carcinoma

ObjectiveEsophageal carcinoma (EC) is one of the most common malignant tumors World wide. It is the forth most prevalent malignancy in China. China is a high-incidence country of esophageal carcinoma, more than 70% of all esophageal cancer patients in the world are Chinese. Esophageal carcinoma exists in 2 main histopathological types-esophageal squamous cell caicinoma(ESCC) and esophageal adenocarcinoma (EADC). In China, about 90% of esophageal cancers are ESCC. Most of the patients with esophageal cancer were found in late stage, because their early symptom didn't manifest and poor treatment.The five-year survival rate was only about 25% after ablation. But, if resection in early stage, the five-year survival rate elevates to 90%, and the ten-year survival rate is around 73%. Approaching the pathogenesis of esophageal cancer and searching the biomarker for early detection and early diagnosis become one of the main directions of the scientific research at present. Recently, many scientists had made painstaking effort to look for the mechanism of esophageal cancer, thereby, we can realize the diagnosis and treatment in early stage. But the etiology and pathogenesis is still in nubilous up to now. So it would be a gigantic mission to continue the research on esophageal carcinoma. As a signal transduction pathway, the Notch gene turned out to be not only plays a critical role in normal tissue and cells differentiation and growth but also correlate to the occurrence and growth of tumorous.some scholar found that Notch1 expressed abnormally in tumorous for instance,in the uterine cervix cancer, endometrial cancer, renal carcinoma, lung cancer, breast cancer and neuroblastoma. therefore Notch1 was reconstred more and more as a new method to preven and treat the tumorous. the expression and changing mechanism of Notch1 protein in ESCC has not been detected still.Here, we would detect the expression of Notch1 protein in esophageal squamous carcinoma. We expected to explain the role of Notch1 signaling pathway in ESCC. So we would offer a new accordance for the diagnosis and therapy of esophageal cancer in future.Material and MethodsTumor sample: fresh specimens from 35 cases of esophageal squamous cell carcinoma (tumor and the matched adjacent normal tissue) and 16 case of cancer in situ were received as discarded material from the Anyang Cancer Hospital, Henan province, China. Clinicalpathology reports and histopathological diagnosis of each specimen were reviewed to determine the nature of the disease.Immunohistochemistry: Protein levels of Notch1 expression were detected by immunohistochemistry in 35 esophageal squamous cell carcinoma,16 precancerous lesions and 35 normal mucous epithelium tissues . Representative formalin fixed and paraffin embedded tissue sections (4μm thickness) were used for immunohistochemistry with specific antibodies to human Notch1 (Santa Cruz Biotechnology, Santa Cmz, CA). All primary antibodies have been previously tested for immunohistostaining. Immunohistochemistry was carried out as previously reported. The assessment of the results included the number of positive cells and the staining degree and comprehensive evaluation.Western-blot:Utilize Western blot to check the diferent expression of Notch1 protein in another 5 esophageal squamous cell carcinoma and normal mucous epithelium tissues.RT-PCR:The expression of Notch1 mRNA was examined in 5 cases of esophageal squamous cell carcinoma and normal mucous epithelium tissues by reverse transcription polymerase chain reaction (RT-PCR). Total RNAs were extracted using Trizol reagent from Invitrogen according to the manufacturer's instructions. The Notchl gene were amplified with the primers designed Primer 5.0software.Result①The positive rates of the expression of notchl protein in normal mucous epithelium tissues and precancerous lesions were 82.9%,68.7%,which did not differ statistically(P>0.05),however both of them were significantly higher than 37.1% in esophageal squamous cell carcinoma(P<0.05).②The low expression of Notchl protein in esophageal squamous cell carcinoma did not correlate with diameter of tumors,tumor stage and the site of tumors(P>0.05),but correlate significantly with lymph node metastasis (P<0.05).③The results of the Western blot show that the expression of the Notchl protein in tumor tissues is obviously lower than normal tissues in the same patient.④The results of RT-PCR show that the expression of Notchl mRNA is differentamong tumor tissues and normal tissues in the same patient.Conclusion①The Notchl protein shows a low expression in the esophageal squamous us cell carcinoma.②The low expression of Notchl protein may contribute to invasion and transference of esophageal squamous cell carcinoma.