Role Of Decorin Deficient Microenvironment In Colorectal Cancer Progression And Metastasis

Colorectal Cancer(CRC)is one of the most common malignant tumors.By 2015,the number of new cases of colorectal cancer in China was 376,300,and the number of deaths was 191,000.More and more evidence indicates that the occurrence and development of colorectal cancer are due to the genetic and epigenetic changes caused by the complex interaction between cells in the microenvironment.The pathogenesis of colorectal cancer is a gradual accumulation process involving multiple factors,multiple genes and multi-molecular signals.Decorin(DCN)is one of the important components of the extracellular matrix and has many biological activities.Numerous studies have confirmed that DCN plays an important role in tumor development.A growing research shows that DCN,as an important component of the tumor microenvironment,interacts with multiple factors or cell membrane receptors,plays a major role in tumor occurrence,development and metastasis.It is likely to be a tumor suppressor,which suggests that it may become a new anti-tumor drug.Tumor microenvironment refers to the internal environment of the tumor during its occurrence.In the malignant process of tumor,EMT is an important mechanism to obtain malignant phenotype in various epithelial neoplastic cells.In the process of EMT,cells decrease their adhesion ability,lose epithelial traits and obtain mesenchymal traits,promote the malignant tumor invasion and metastasis by active interaction between cancer cells and stromal cells in tumor microenvironment.As the results:(1)Knockout of DCN promotes EMT in tumor microenvironmentFirstly,the model of colorectal cancer in the wild-type and DCN gene knockout mice induced by AOM was established to explore the development and metastasis of colorectal cancer in different microenvironments.Western blot found,compared with wild-type mice,the expression of MMP2,EMT related protein markers such as N-cadherin,Vimentin,?-SMA,Snail and Twist1 was increased,and the expression of epithelial marker E-cadherin was decresed in DCN gene knockout mice intestinal epithelial cells.With the elongation of the molding cycle,the tumor formation rate increased gradually while the expression of EMT related molecules gradually increased.In addition,the expression of COX-2 and ICAM-1 was increased after DCN was missing,and it increased with the development of colorectal tumor invasion and metastasis.These results suggested that the tumor microenvironment without DCN could promote the EMT process of epithelial mesenchymal transformation to promote the proliferation,invasion and metastasis of colorectal tumors.(2)The mechanism of DCN alone or with celecoxib to inhibit the development of colorectal cancer.In vivo,AOM induced wild-type and DCN gene knockout colon cancer mice were selected,according to the genotype was divided into four groups: blank solvent control group,the separate treatment group of DCN,Celecoxib single agent treatment group,DCN combined with Celecoxib group.The IHC assay showed that the expression of MMP2 was reduced after DCN combined with Celecoxib.Western blot and RT-qPCR found that the expression of EMT-related genes was decreased and the expression of E-cadherin was increased,and also the mRNA expression levels of COX-2,PGE2 were significantly decreased after DCN combined with Celecoxib.Celecoxib,a selective COX-2 inhibitor,it`s drug sensitivity was increased and drug resistance was decreased after combined with DCN.Therefore,it can be seen that DCN combined with Celecoxib can negatively regulate the EMT process and provide an important basis for early diagnosis and metastasis of colorectal cancer.(3)DCN combined with Celecoxib enhances the inhibition of invasion and metastasis of colorectal cancerIn order to explore the DCN alone or with celecoxib for biological activity and possible mechanism of colorectal cancer cells,we choose the colorectal cancer cells SW480 in logarithmic phase,the experiment is divided into four groups: blank control group,DCN recombinant protein(1 ?g/mL)single dose groups,celecoxib(40 ?M)single dose group,as well as the DCN recombinant protein combined celecoxib dosage groups.MTT assay combined with cell scratch wound and plate clone formation assay results found that different concentrations of DCN recombinant protein and Celecoxib showed dose-dependent inhibition of SW480 cells proliferation.Both of them combined treatment can significantly reduced the proliferation ability of SW480 cells,inhibited the healing of scratching and the ability of single cell colony formation;Western blot assay results show that the inhibitory mechanism of DCN recombinant protein alone or with Celecoxib on the EMT process of SW480 cells,Both of them combined treatment can be negative regulation of EMT process,which inhibit colorectal cancer cell proliferation,migration and metastasis ability.In summary,this study investigated the absence of DCN and the regulatory role of EMT-related signal molecules by DCN in the invasion and metastasis of colorectal cancer.We first discovered the biological activity and possible mechanism of DCN alone or with clinical antitumor drug Celecoxib,and DCN can inhibit the proliferation,invasion and metastasis of colorectal cancer.Therefore,DCN is related to down-regulation of EMT-related signaling pathways and inhibiting tumor occurrence and metastasis of colorectal cancer.In-depth exploration of the biological function and mechanism of DCN will provide a solid theoretical basis for DCN treatment and prevention of colorectal cancer and other diseases.