| Colorectal cancer(CRC)is a common malignant tumor in gastrointestinal tract that threaten human life and health,as the third leading cause of cancer mortality globally.Especially in China,with the development of economy,changes in the modern lifestyle and diet,and the increasing age of populations,the incidence of CRC is becoming high and increases among young adults.In the meantime,the pathogenesis of CRC is complex and chemotherapy is considered as the most effective treatment.But the one of obstacles in CRC chemotherapy is that the commonly used reagents such as 5-fluorouracil and cisplatin have highly side effects and strong resistance,which leads to the failure of therapy.Therefore,the investigation of effective and low toxicity anti-colon cancer reagents has become an urgent task.Recently,in the development of drugs,polysaccharides from fungi have gained increasing attention for their antitumor activity with low toxicity.Among these fungi,Gloeostereum incarnatum has been used as an important source of nutritional diet and medicine for diseases such as enteritis,dysenteries.Additionally,recent studies revealed that the fruitbody and fermentation broth from G.incarnatum have the activities of antimicrobial,anti-inflammatory and immunomodulatory.However,the therapeutic efficacy of G.incarnatum polysaccharides(GIPS)on CRC is not reported yet.Therefore,in this study,we aim to investigate the effects and mechanisms of GIPS on CRC.The main contents and results are as follows:1.Extraction optimization of polysaccharides from G.incarnatum.In this paper GIPS is obtained with the sequential steps of water extraction,deproteinization with trichloroacetic acid,alcohol precipitation and further purification by dialysis and chromatography on a DEAE-52 cellulose anion exchange column.A single-factor analysis is conducted to determine the optimal condition for deproteinization.The production rate and purity of GIPS are 12.36% and 86.41% with the extraction technology,which laid a foundation for us to study the activity of GIPS.2.The effects and mechanisms of GIPS on colon cancer mice.In APC-deleted colon cancer mice model,physiological and biochemical tests are determined after 8 weeks of GIPS treatment,the levels of related cytokines are detected by antibody array,enzyme linked immunosorbent assay and western blot.The results show that GIPS treatment effectively reverses the weight loss and liver damage in colon cancer mice,and substantially decreases the number and size of tumor.The antibody array reveals that GIPS is involved in the regulation of inflammation related pathway,interleukin signaling pathway,Wnt signaling pathway,apoptosis and angiogenesis pathway,with 89 cytokines among 308 ones being of significant differential expression.Further detection of cytokine markers by ELISA and western blot confirms that GIPS can inhibit the expression of IL-1?,IL-4,IL-6,IL-17,IL-22,TNF-?,MMP-2,MMP-9,Wnt1,?-catenin,Frizzled-7,LRP5/6 and GSK-3?,while promote the expression of IL-15,IL-18,DKK1 and Kremen-2,which indicates that GIPS inhibits cell proliferation,angiogenesis in tumor,and blocks both tumor invasion and metastasis.Especially in Wnt/?-catenin signaling pathway,the inhibitory effects of GIPS are significant that the expression level of Wnt signal and its receptors in the tumor cell membrane is inhibited,while the degradation of ?-catenin in cytoplasm is promoted,which plays a crucial role for anti-colon cancer activity of GIPS.In summary,the colon cancer mice model experiments demonstrated the antitumor activity of GIPS on colon cancer,and preliminarily determined its mechanism.This study provides pharmacodynamic evidence that GIPS may prevent or serve as a drug candidate for treating CRC. |
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