Role Of Hedgehog Signaling Pathway And TAK1in Tumorigenesis And Prognosis For Pancreatic Cancer

Pancreatic cancer(PC) is one of the common tumor of digestive system and one of themost lethal human cancers. Pancreatic cancer lacks specific clinical symptoms in the earlystage, but has high tendency to invase locally and metastasize because of high malignantdegree.It appear that the majority of the patients confirmed have no chance of surgicalresection, attributing to the existence of local or wide metastasis.The5years survival rateis not more than6%. So increase the rate of early diagnosis is the key to receive earlytreatment, improve patients’ survival and and decrease the mortality. There are no effectivenon-invasive examination, so it is urgent to study and unveil the molecular mechanism ofpancreatic cancer, to provide new molecular targets for its early diagnosis and optimaltreatment.Abnormal activation of Hedgehog (Hh) signaling pathway is widespread in pancreaticcancer, related to its genesis and development.As reported, the expression of Shh and Gli1,members of Hh pathway, in pancreatic cancer tissues is low to moderate;the expression ofShh and Gli1protein is related to clinical pathological features significantly. Sufu,thenegative regulatory factor of Hh signaling pathways expresses in pancreatic cancer tissuepositively, but not in normal pancreatic tissue and pancreatic tissue adjacent to carcinoma.One of the members of the MAPKKK family,TGF-β activated kinase1(TAK1) is akey regulatory factor of many signal transduction chain reaction in the process ofinflammation, immune, stress response and cancer. Some researchs report that TAK1caninduce activation of NF-ΚB in various forms. And Shh,the ligand of Hh pathway,is a directtranscriptional target of NF-ΚB. The activation of NF-ΚB is associated with Hhpathway in pancreatic cancer. Thus, we assume that, TAK1also plays a role in the progressof pancreatic cancer, and maybe coordinate with Hh pathway.Based on these researches, this experiment is designed to detect the expression levelof the important members of Hh signaling pathway (Shh, Gli1, Sufu),TAK1and itsactivatory form, PTAK1in pancreatic cancer.we also analysis the correlation between thetwo pathways and clinical pathological parameters, to study their role in the prognosis ofpancreatic cancer. This study consists of two parts, as described below.1.A study of the relationship between expression of Shh,Gli1,Sufu,TAK1andPTAK1in pancreatic cancer tissues and the clinical pathological parameters of thepatientsOBJECTIVE:To test the expression of Shh,Gli1,Sufu,TAK1and PTAK1in pancreatic cancer tissues and determine whether their expression is correlated with theclinical pathological parameters of patients with PDAC.METHODS: From May31,2005to September11,2009, patients underwentmacroscopically curative resection in Changhai Hospital were recruited in this study.Surgical specimens obtained from169patients with PDAC. We reviewed all valuablemedical information during their hospitalization and follow the patients by phone.The maincontent included demology characteristics, medical history, surgical records, pathologicalreport and so on.All members are with a confirmed histologic diagnosis of primary PDAC.patients of pancreatic ductal adenocarcinoma were diagnosed with pathology．We detectedthe expression of the five proteins by Envision immunohistochemistry in the pancreaticcancer tissues and adjacent tissues．The correlations of the five proteins expression withtumor stage, lymph node metastasis and distant metastasis were examined by chi-squaretest and multivariate logistic regression.RESULTS: The percents of cases with high Shh、Gli1、Sufu、TAK1and PTAK1expression are105（70%）、136（84.5%）、46（30.1%）、126（80.3%）and130（81.3%）respectively.(1) Correlations between Shh,Gli1,Sufu,TAK1and PTAK1Expression andClinicopathological FeaturesExpression of Shh is positively correlated with Sufu (P<0.05).Expression of Gli1is positively correlated with Sufu and TAK1(P<0.05).Expression of Sufu is positively correlated with Shh,Gli1and TAK1(P<0.05).Expression of TAK1is positively correlated with Gli1and Sufu(P<0.05).Shh expression was significa ntly correlated with tumor stage, lymph nodemetastasis and distant metastasis (P<0.05).Gli1expression was significantly correlatedwith local invasion and differentiated degree (P<0.05).Sufu expression was significantlycorrelated with lymph node Metastasis (P<0.05). TAK1expression was significantlycorrelated with tumor site(P<0.05).(2) Relationship between Shh、Gli1、Sufu、TAK1and PTAK1Expression and TumorStageIn univariate analysis,five variables,including Shh expression, Gli1expression, Sufuexpression, tumor site and differentiated degree were associated with tumor stage (P<0.25).Excluding patients in stage Ⅲ and Ⅳ,we found：In univariate analysis, Shh expression, Gli1expression, Sufu expression, TAK1 expression and PTAK1expression,tumor site and age were associated with tumor stage(P<0.25).In the multivariate logistic regression model,high Shh expression and tumor site wereshown to be significantly and independently associated with advanced tumorstage(P<0.05).(3)Relationship between Shh、Gli1、Sufu、TAK1and PTAK1Expression and LymphNode MetastasisUnivariate analysis showed that lymph node metastasis was associated with age,tumorsite,local invasion,distant metastasis,Shh expression,Sufu expression and PTAK1expression(P<0.25).In the multivariate logistic regression model,high Shh expression and distantmetastasis were shown to be significantly and independently associated withlymph node metastasis(P<0.05).CONCLUSION: Expression of TAK1is positively correlated with Gli1and Sufu，indicates the two pathways may be associated with the other.Shh expression wassignificantly correlated with tumor stage, lymph node Metastasis and distantmetastasis.Gli1expression was significantly correlated with local invasion anddifferentiated degree.Sufu expression was significantly correlated with lymph nodeMetastasis.Low Gli1expression was shown to be significantly and independentlyassociated with advanced tumor stage(Excluding patients in stage Ⅲ and Ⅳ, high Shhexpression was shown to be significantly and independently associated with advancedtumor stage). High Shh expression was significantly and independently associated withlymph node metastasis. Hh signal pathway was related to the clinical pathological featuresof the patients with pancreatic cancer.2.A study of the relationship between levels of Shh、Gli1、Sufu、TAK1and PTAK1in cancer tissue and prognosis for patients with pancreatic cancerOBJECTIVE:To evaluate whether the expression of Shh、Gli1、Sufu、TAK1andPTAK1is associated with poor prognosis after curative resection for pancreatic ductaladenocarcinoma(PDAC)respectively.METHODS: From May31,2005to September11,2009,169patients underwentmacroscopically curative resection in Changhai Hospital were recruited in this study. Allmembers had no history of adjuvant therapy before operation.We reviewed all valuablemedical information,which consisted of demology characteristics,private habits,medical history,laboratory results,surgical records, pathological reports and overallsurvival(OS).we followed the patients by phone,which was closed on February6,2013.Prognostic significance of Shh、Gli1、Sufu、TAK1and PTAK1expression were evaluatedby Kaplan–Meier method and Cox regression.RESULT:169eligible patients completed their follow-up reports at the endpoint.Theirmedian age(minimum,maximum)was60.7years(from26years to81years),and60.9%were men.The median follow-up time was50.4months (range,4.87-92.2months),and3patients (1.8%)were censored because they died within30days after surgery.The medianOS of eligible patients were10.73months(95%confidence interval[CI],10.98-13.56months). The percents of cases with high Shh、Gli1、Sufu、TAK1and PTAK1expressionare105（70%）、136（84.5%）、46（30.1%）、126（80.3%）and130（81.3%）respectively.In univariate survival analyses,OS was associated with sex, distant metastasis,tumorstage, CA199, tumor differentiation, lymph node metastasis, the expression ofGli1,Sufu,TAK1and PTAK1(P<0.25). Low expression of Gli1,Sufu,TAK1andPTAK1,distant metastasis,advanced tumor stage,high CA199were significantly correlatedwith shorter OS(P<0.05).In multivariate survival analyses,OS was significantly and independently correlatedwith PTAK1expression, CA199and tumor differentiation(P<0.05).When survival analysis was carried out on the protein composition, we found Sufuand TAK1may enhance the protective effect of Gli1; Protection effect of Gli1and PTAK1may be synergic. So are TAK1and Sufu.CONCLUSION:Low Gli1、Sufu、TAK1、PTAK1expression is associated with poorprognosis for surgically resected PDAC. PTAK1expression was significantly andindependently correlated with OS.It suggests that those two pathways may act in theprocess of pancreatic ductal adenocarcinoma. Sufu and TAK1may enhance the protectiveeffect of Gli1; Protection effect of Gli1and PTAK1may be synergic. So is TAK1andSufu.The two ways TAK1(PTAK1) and Hh signaling pathway may influence each other inthe occurrence and development of pancreatic cancer.