Clinical And Basic Research On Prognosis And Prediction Of Therapy In Colorectal Cancer

Part I: Development and Validation of Nomograms for Predicting Survival in Patients with Non-metastatic Colorectal CancerObjective: To construct high-accuracy prognostic evaluation system is an important step to improve the clinical outcome of colorectal cancer(CRC)treatment.However,the prognostic value of traditional TNM staging system is limited in patients with localized CRC.This study aimed to identify readily available clinical factors most helpful in predicting survival of patients with non-metastatic CRC,and to develop prognostic nomograms that can serve as a useful guide in patient management.Methods: Eighteen baseline clinical and laboratory factors were included in the analysis of this study.On the basis of data from 822 patients with resected non-metastatic CRC,nomograms for predicting overall survival(OS)and cancer-specific survival(CSS)were established using Cox regression model.The predictive performance of the nomograms was assessed by concordance index(C-index)and calibration plot.An independent external cohort of 171 patients was used to validate the nomograms.Results: On multivariate analyses of the derivation set,the nomograms for OS and CSS shared common significant prognostic factors: age,first-degree relative cancer history,differentiation grade,vessels/nerves invasion,TNM stage,carcinoembryonic antigen(CEA),carbohydrate antigen(CA)9-9 and prognostic nutritional index(PNI).The nomograms displayed good accuracy in predicting OS and CSS,with C-indexes of 0.75 and 0.76,respectively.The calibration plots also showed an excellent agreement between the predicted and observed survival probabilities.Furthermore,the predictive accuracy of the nomograms was confirmed in the validation set,with C-indexes of 0.79 and 0.83 for OS and CSS,respectively.Conclusions: We developed and externally validated two prognostic nomograms for patients with non-metastatic CRC,which could provide individual prediction of OS and CSS with high accuracy.The nomograms can assist clinical decision making for treatment and follow-up,and may aid in clinical trial design.Part II: Study on the Function and Mechanism of MAP4K1 in Oxaliplatin Resistance of Colorectal Cancer CellsObjective: Our previous study showed that MAP4K1 was associated with clinical outcomes of colorectal cancer(CRC)patients treated with oxaliplatin-based chemotherapy.This study aimed to investigate the function and mechanism of MAP4K1 in Oxaliplatin resistance of CRC cells.Methods: 1.Real time PCR was used to quantify m RNA levels of MAP4K1 in RKO,LS174 T,SW620,HCT-116,SW480,CW-2,Caco2 and DLD-1 CRC cells.CCK-8 was used to analyze the impact of different concentrations of oxaliplatin on the proliferation of each cell line.The relationship between MAP4K1 expression and 72 h half-inhibitory concentration(IC50)values of oxaliplatin in the eight CRC cell lines was analyzed using SPSS software.2.By using RNA interference,we suppressed the expression of MAP4K1 in DLD-1 cell line.Flow cytometry and Western blot were respectively used to detect the effect of MAP4K1 down-regulation on cell apoptotic rate and the expression of apoptosis-related protein and MAPK pathway-related protein in DLD-1 cell line after treated with oxaliplatin for 48 h.Results: 1.The results of CCK-8 showed that the cell growth inhibition effect of oxaliplatin increased in a dose-dependent manner with rising concentration in CRC cells.Furthermore,a positive linear relationship between MAP4K1 expression and 72 h IC50 values of oxaliplatin was observed in the eight CRC cell lines(Pearson correlation coefficient = 0.796,P = 0.018).2.Flow cytometry showed that,compared with the negative and blank control groups,the total cell apoptosis rates of MAP4K1 knockdown group were significantly higher(P <0.05).In addition,Western blot showed that in the MAP4K1 knockdown group,the expression of p21 was strongly upregulated but the phosphorylation levels of Akt at Ser473,p38 MAPK at Thr180/Tyr182,JNK at Thr183/Tyr185 and Bad at Ser136 were downregulated significantly.Conclusions: MAP4K1 can affect the apoptosis induced by oxaliplatin in CRC cells,which is probably mediated by phosphorylation of Bad via mitochondrial apoptosis pathway.