The Roles And Mechanisms Of OLA1 In The Progress And Prognosis Of Colorectal Cancer

BackgroundColorecatal cancer has been one of the leading cancers worldwide.The key to improve the clinical cure rate of colorectal cancer is to discover new molecular indicators,accurately predict the prognosis of patients and provide further treatment.We have previously reported that Obg-like ATPase 1(OLA1)deletion induced embryonic development delay and organ size reduction.Increasing evidence showed embryonic development and tumorigenesis had similar mechanisms.OLA1 plays an important role in the development and treatment of lung cancer and breast cancer,while its effect on the progress and survival of colorectal cancer is still unclear.The present research aims to clarify the influence and possible mechanism of OLAI on colorectal cancer through clinical data analysis,in vivo and in vitro experiments,and molecular biology experiments.MethodsTo clarify the effect of OLA1 in the development and progress on colorectal cancer patients,we analyzed OLAI expression and clinical pathological characteristics from public database,cancer tissue chip and the biobank of our hospital.Two colorectal cancer cell lines(Hct116 and SW480)with OLA1 knock-down were constructed via shRNA,and the effects of OLA1 on cancer cell proliferation and migration were both observed in vitro and in vivo.Based on R2 platform,we collected the first 1,000 genes positively correlated with OLA1 from 4 colorectal cancer microarrays.The common genes were extracted by Venn diagram and the target gene was later verified in TCGA database to find out the possible downstream pathways of OLA1.Western blot,fluorescence co-localization and nuclear-cytoplasmic protein extraction were applied to investigate the possible influence of OLA1 on YAP.Finally,based on the simulation of the combination conformation between OLA1 and listed drugs in DrugBank database,the free energy of OLA1 and drugs was calculated by iGEMDOCK software the top 20 were extracted as possible inhibitors of OLA1.ResultsBoth mRNA and protein expression was siginificanlty higher in the primary colorectal cancer than that in the normal mucosa.Multivariate COX regression analysis showed that OLA1 was one of the independent risk factors for colorectal cancer prognosis,and a higher expression suggested poorer prognosis(HR:2.47,1.255-4.844,p=0.005).In vitro,OLA1 knockdown colorectal cancer cell lines,Hct116 and SW480,were significantly decreased in cell proliferation,clone formation and migration.In vivo,Hct116-shOLA1 was significantly decreased in subcutaneous tumorigenesis and lung metastasis in nude mice.By means of joint screening in gene microarrays and Spearmen test based on TCGA database,it was found that the expression of OLA1 was significantly correlated with YAP,the key molecule of Hippo-YAP pathway(r2=0.14,p<0.001).Western Blot showed that the knockdown of OLA1 resulted in down-regulation of phosphorylation at YAP-397,and RT-PCR further verified that OLA1 knockdown inhibited the transcription of YAP target genes.Finally,through the simulation and calculation of the combined conformation of OLA1 and drugs in DrugBank,the first 20 drugs(such as acarbotan,telmisartan,etc.)were preliminarily extracted as the possible inhibitors of OLA1.Conclusion1.OLA1 promotes the progression and metastasis of colorectal cancer and is an independent risk factor for poor prognosis.2.OLA1 was proved to promote the malignant phenotype of colorectal cancer in vitro and in vivo.3.OLA1 inhibits the phosphorylation of YAP-397,which facilates YAP nuclar translocation and promote the activation of downstream witch induces the progress of colorectal cancer.4.Through computer simulation,the top 20 drugs of free binding energy(such as acarbose,telmisartan,etc.)were screened out as possible inhibitors of OLA1.