Studies On The Induction Of Apoptosis And Autophagy In Colon Cancer HCT116 By Extract Of Meat-like Ganoderma Lucidum

Meat-like Ganoderma lucidum,also known as Tai Sui,has a long medicinal tradition in China.It was recorded as early as in Li Shizhen’s Compendium of Materia Medica,that "eating for a long time,being light and not old,prolonging immortality".However,the nature and properties of Meat-like Ganoderma lucidum have not yet been confirmed,since the academia has different opinions about it.Most scholars believe that Meat-like Ganoderma lucidum is a large Myxomycete complex between protozoa and fungi.Meat-like Ganoderma lucidum’s values in many aspects,for example,a good ability to clarify oxygen free radicals,anti aging and enhance immunity,have been identified in different studies.In addition,its effect of anti-tumor has also been recorded in many publications.Our experiments investigate the nature of Meat-like Ganoderma lucidum.For years,cancer has become one of the most fatal diseases confusing scientific community.Due to its increasing morbidity and mortality,colorectal cancer causes numerous deaths every year.As a primary malignant tumor,at present,there is no effective treatment for colorectal cancer,whereupon surgery is still the fist choice.Even though,a series of unneglectable problems of postoperation also lead an increasing risk index.According to the latest data from the National Cancer Center,Colorectal cancer is ranked the fifth death rate of malignant tumors in China in 2015.Therefore,new therapies and drugs must be taken into consideration under such condition.In this study,human colon cancer HCT116 cells were treated with extract from Meat-like Ganoderma lucidum to study the effect of Ganoderma lucidum on anti-tumor effect of colon cancer.During the experiment,the cell viability was detect by CCK-8 for the first time,and preliminarily determined the concentration of the low dose,the medium dose,the high dose(2 ug/mL,4 ug/mL,6 ug/mL)and time for treatment(24 h).Apoptotic rate were measured using flow cytometry assay and others.Through those studies,we found that the extract of A can active caspase-3,caspase-8 and caspase-9,which suggests the extract inducing HCT116 cell apoptosis through caspase family.To reveal the mechanism of Meat-like Ganoderma lucidum’s influence on HCT116 cells,related factors were tested by Western Blot.Through the expression of JNK,p38,ERK and other related proteins was measured,we found A can induce JNK phosphorylation and ROS production.Further more,we hypothesize that the apoptosis induced by Meat-like Ganoderma lucidum’s extract was also accompanied by cell autophagy,as the cells’ death rate reduced while not completely reversed with the treatment of caspase inhibitor z-VAD-fmk.Based on this phenomenon,the expression of LC3B-II protein was detected as a autophagy marker.The result indicated that Meat-like Ganoderma lucidum’s extract could induce autophagy in HCT116 cells as well.In addition,we found ROS inhibitors can reverse apoptosis and autophagy in HCT116 cells induced by Ganoderma lucidum’s extract.According to the results above,we xenografted HCT116 cells on nude mice to identify the suppression of Meat-like Ganoderma lucidum’s extract on tumor.Meat-like Ganoderma lucidum’s extract was administered by intragastric administration(2 mg/mL,5 mg/mL,and 10 mg/mL).By measuring the tumor volume and tumor weight,these results showed that the tumor volume in the low,medium and high dose groups decreased by 11.65%,43.34% and 64.96%.In addition,immunohistochemistry was used to detect expression of Ki67 and cleave Casepase-3,which was decreased.And protein expression of p-JNK was increased.The results showed that Meat-like Ganoderma lucidum’s extract can inhibit the growth of colon cancer HCT116 cells in nude mice,which is consistent with the cell results.And apoptosis and autophagy were induced in colon cancer cells via ROS/JNK signaling pathway.In conclusion,our results show that Meat-like Ganoderma lucidum’s extract induces apoptosis and autophagy through ROS/JNK signaling pathway in colon cancer HCT116 cells.In vivo study indicated that Meat-like Ganoderma lucidum’s extract could suppress tumor growth,which is to induce cell death through apoptosis and autophagy.Therefor,we can draw the conclusion that Meat-like Ganoderma lucidum is a promising candidate for the development of anti-tumor drugs against colon cancer.