Anti-tumor Effect And Mechanism Of Icaritin On Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma(OSCC)is one of the most common cancers in the world.With the increasing incidence of disease,it has caused serious harm to human health and quality of life.Nowadays,the molecular mechanisms of the occurrence and development of OSCC are still unclear.Therefore,the main stream therapeutic regimen for OSCC includes radiotherapy and surgery.Due to the high occurrence of metastasis and local recurrence and the chemotherapy drug resistance,the five year survival rate of OSCC patients wasn’t significantly improved.Therefore,it is imperative to develop new drugs for the treatment of OSCC.Icaritin is a hydrolytic product of icarin from Epimedium Genus,a traditional Chinese herbal medicine.Previous studies showed that icaritin had various pharmacological and biological effects,including cardiovascular function improvement,hormone regulation and modulation of immunological function.Icaritin was recently demonstrated to induce apoptosis and growth inhibition,down-regulate tumor angiogenesis,as well as inhibit invasion and epithelial-to-mesenchymal transition in human cancer cells.Thus,in order to find new and effective therapeutic agents for prevention and treatment,the current study aimed to investigate the effect of icaritin on OSCC and explore the potential mechanism.This study was divided into three parts as follows:Part I The biological properties and mechanism of icartin on OSCC cellsObjective:Icaritin,a traditional Chinese medicine,possesses antitumor activity.The current study aimed to investigate the effect of icaritin OSCC and explore the potential mechanism.Method:OSCC cell lines were incubated with various concentrations of icaritin for indicated hours,and then the cell proliferation was analyzed by CCK-8 and the apoptosis was assessed with PI and Annexin V-FITC staining,in addition,autophagy was determined by monodansylcadaverine staining.Invasion and migration were observed by Transwell assay.The expressions of correlated proteins of proliferation,apoptosis and autophagy,as well as signal transducer and activator of transcription 3(STAT3)signal network were also evaluated by western blot.Results:Icaritin significantly inhibited the cell proliferation of OSCC in vitro and reduced the expression of pro-proliferative proteins,cyclin A2 and cyclin D1.Besides,icaritin induced apoptosis and increased cleaved caspase 3 and cleaved poly-(ADP-ribose)polymerase(PARP)expression.Moreover,autophagy was activated by icaritin in OSCC cell lines.Icaritin significantly inhibited the expression of phospho-STAT3(p=STAT3)in a dose-and time-dependent manner.Conclusion:The results demonstrated that icaritin suppressed proliferation and promoted apoptosis and autophagy,as well as inhibited STAT3 signaling of OSCC in vitro.PartⅡ The chemoprevention effect of icaritin in an oral specific carcinogenesis mouse model.Objective:In the present study,an oral specific carcinogenesis mouse model was used to establish precancerous lesions,and the preventive effect of icaritin on OSCC was studied.Method:Mice were given 4-Nitroquinoline-l-oxide(4NQO)in the drinking water.After 14 weeks,sixteen mice with at least one premalignant lesion in the tongue were reverted to regular water,and randomly distributed into treatment and control groups.All animals were euthanized on week 22,and tissues were fixed and processed for further studies.Results:The number of malignant tumors in treated group was significantly less than the control group(P<0.05)(Figure 7C),The expression of p-JAK2 and p-STAT3 in the treatment group was significantly less than that in the control group(P<0.05).Conclusion:Icaritin could significantly reduce the transformation of oral precancerous lesions and the development of oral squamous cell carcinoma.PartⅢ Preparation,characterization and antitumor activity of icaritin nanoparticlesObjective:The current study aimed to modify the structure of icaritin by using water-soluble nanoparticle carrier in order to steadily release in tumor environment.Methods:PEG(2000)-PCL(5000),PEG(2000)-PCL(2000)and PEG(2000)-PLGA(5000)were used to coat icaritin molecules.The particle size,potential,entrapment efficiency and drug loading of the nanoparticles were measured.Then the nano drugs were used in vitro drug uptake test,cytotoxicity test compared with common icaritin.Results:The PEG(2000)-PCL(5000)group had the best effect of drug loding.Compared with the common icaritin,the nanoparticles could be dissolved in water,and enter the cell faster and could inhibit cell proliferation more efficient(P<0.05).Conclusion:With the preparation of nano particles,the performance of icaritin could be effectively improved.The inhibition effect of icaritin on OSCC was more effective.