The Relationship Between Periostin Expression And The Progression And Prognosis Of Gastric Cancer

Gastric cancer,being the fourth most common cancer in the world,its high morbidity,malignant degree and lack of progress in treatment strategy makes it to be the second most common reason of malignant tumor death.Resection is still the main therapeutic mean for treating gastric cancer.However,as the hidden characteristic of the beginning of gastric cancer,namely lacking of specific symptoms,most of the gastric cancer are under progressing when conducting definite diagnosis.Currently,90% hospitalized patients are under progressing period and only about 10% early gastric cancer patients.According to previous report,the survival rate of mucosal carcinoma in five years is close to 100% and the survival rate of I stage of gastric cancer in five years which is under regular treatment is 82%-95%,the II stage 55%,and the III stage 15%-30%,IV stage only 2%.In recent years,chemistry greatly facilitates the treatment of gastric cancer,but the side effects of chemotherapy are also very big.Moreover,the drug resistance produced by the tumor cells reduces the chemotherapy effect.Thus,the survival rate of gastric cancer under progressing in five years is still less than 30%.Clinical prognosis of cancer mainly depends on the patient clinical pathological stage in operation.Currently,the early diagnosis of cancer mainly depends on gastroscope and tumor marker screening.However,the gastroscope would cause much pain and the patient has little tolerance,thus it is rejected by by most of the patients who should have done gastroscope to exclude malignant tumor.As a result,most gastric cancer patients are delayed for treatment.Nowadays,the commonly used gastric cancer marker has little uniqueness and sensitivity which would not be increased until in progressive stage.As a result,it can not meet the requirement of early discovery,early diagnosis and early treatment.According to the follow up documents of the patient after operation,many gastric patients who are in the same clinical pathological stage have big difference of surviving time after operation.Some patients who are in early stage come across recurrence and metastasis early.On the contrary,some patients who are in the late stage are relatively late to come across recurrence and metastasis In recent years,there are increasing studies which found out many biological behaviors of genetic marker affecting gastric cancer.The unique abnormal genetic expression has a close relation with the tumor development including tumor development,invasion,and metastasis as well as inactivation of tumor suppressor gene,especially P53 and APC gene.The previously discovered genetic markers of gastric cancer are high neither in sensitivity nor in specificity.As a result,looking for a new genetic marker is beneficial for identifying biological behavior and can provide evidence for early diagnosis and further formulating treatment scheme.Periostin,the so-called osteoblast specific factor 2,is a kind of secretory cell adhesion protein.The recent studies show the increased expression of Periostin on various tumors.The activated Akt/PKB and FAK signal pathway plays an important role in facilitating tumorigenesis,tumor vessel generation,invision,metastasis,and the occurrence as well as development of various tumors such as colon cancer,gastric cancer,pancreatic cancer,oophoroma,mammary cancer,thyroid carcinoma and neuroblastoma.The study aims to further identify the relation between the abnormal expressions of periostin and clinical pathology of gastric cancer and prognosis as well as clarify its affect on gastric cancer biological behavior so as to look for new breakthrough for gastric cancer diagnosis and treatment.Part ?The relation between the high expression of periostin and the genesis,progression,prognosis of gastric cancer.Purpose:Further clarify the relation of expression level of osteoblast specific factor2 and the formation,invasion,metastasis and prognosis of gastric cancer.Methods:Select the cancer tissue microarray of 316 cases of postoperative patients with gastric cancer and complete clinical and pathological data admitted in our hospital from January 2008 to December 2010 to conduct immunohistochemical analysis for periostin cellular localization and expression level.Combining the clinical and pathological data of patients,Apply ?2test to compare the internal connection between the expression of periostin and patient's gender,age,Borrmann type,tumor site,tumor size,T stage,N stage,TNM stage,differentiation degree of gastric cancer,preoperative chemotherapy,preoperative serum CEA and preoperative serum CA19-9.Apply Kaplan Meier method to calculate and analyze the relation between periostin expression level,disease free survival and overall survival.The univariate and multivariate survival analysis was performed by using Cox proportional hazards model.Results:Periostin protein was mainly localized in cytoplasm and its positive rate of expression in gastric carcinoma is significantly higher than that of the normal gastric mucosa.Periostin expression level is relevant to the number of lymph node metastasis,depth of invasion and TNM staging.The deeper the tumor invading the gastric wall,the more number of lymph node metastasis,the later of the TNM stage,the higher of the periostin expression.However,it is not obviously relevant to patient's gender,age,Borrmann type,tumor site,tumor size,differentiation,serum CEA and serum CA19-9.COX single factor and multi factor analysis show that the Borrmann typing,tumor location,tumor size,T stage,N stage,TNM stage,serum CEA and periostin expression level are the influence factors of disease-free survival of patients with gastric cancer;Borrmann typing,tumor location,tumor size,T stage,N stage,TNM stage,serum CEA,differentiation,periostin expression level are the influence factors of overall survival of patients with gastric cancer;T staging,N staging,TNM staging,postoperative chemotherapy,periostin expression level are the independent influencing factors of disease-free survival and overall survival in patients with gastric cancer.Conclusion:The expression of periostin is closely related to the development of gastric cancer and it is the independent influencing factor of poor post operative prognosis in patients with gastric cancer.Part ?Periostin promote the proliferation of gastric cancer cellPurpose Identify the influence of periostin on gastric cancer cell proliferation.Method Transfection of Periostin high expression gastric cancer cells with siRNA;Apply western blot?RT-PCR method to detect transfection efficiency;Apply CCK8 to study the change of proliferation of gastric cancer cells after perostin being knocked out.Result: Apply western blot?RT-PCR to detect and find that the periostin is obviously knocked out;Apply CCK8 to detect and find that gastric cancer cell proliferation ability of the periostin knock down group reduce obviously comparing with the control group.Conclusion: periostin promote gastric cancer cell proliferation.