The Mechanism Of Lenvatinib In Hepatocellular Carcinoma And The Synergistic Effect By Elemene

Background:Liver cancer is one of the most common malignant tumors in the world with high incidence,high mortality and poor prognosis.A large number of patients have been in the middle and late stage at the beginning of diagnosis,and complicated with liver cirrhosis.They cannot undergo radical treatment such as surgery,and can only rely mainly on drugs for systematic treatment.At present,Sorafenib and Lenvatinib are the only first-line target drugs for the treatment of hepatocellular carcinoma（HCC）.Sorafenib was approved by the Food and Drug Administration（FDA）in 2007,but the objective response rate（ORR）was less than 10%.In 2018,Lenvatinib was approved for the first-line treatment in HCC.Compared with Sorafenib,Lenvatinib can significantly improve the PFS and ORR,but cannot significantly prolong overall survival（OS）,and the ORR was only 24%.Lenvatinib inhibits VEGFR,FGFR,PDGFR,RET and KIT,but the molecular mechanism based on HCC cells has not been clarified.Elemene,as a national second-class anti-tumor drug,can directly kill tumor cells and is also commonly used in combination therapy with other drugs to increase efficacy and reduce toxicity.Elemene injection combined with Sorafenib can significantly improve the therapeutic effect of patients with HCC,reduce adverse reactions,and have a positive effect on improving the prognosis.Both Lenvatinib and Sorafenib can inhibit HCC by targeting common targets such as VEGFR,suggesting that Lenvatinib may also improve the therapeutic effect by combining with Elemene.Purpose:This study aims to detect the anti-HCC mechanism of Lenvatinib,and find strategy to enhance the sensitivity of Lenvatinib.Methods:Firstly,the inhibitory effect of Lenvatinib on a variety of HCC cells was determined through cytological experiments.Then,the anti-tumor mechanism of Lenvatinib was further revealed and verified by transcriptome sequencing and cytological experiments.Finally,the synergistic effect by Elemene,an active ingredient of traditional Chinese medicine,on Lenvatinib was explored by a variety of cytological experiments.Results:By detecting the IC₅₀ of Lenvatinib in various HCC cell lines,it was clear that Huh1,Hep3B,SNU739 and SNU449 cell lines were more sensitive to Lenvatinib,While Hep G2,SMMC7721 and HCCLM3 cell lines were less sensitive.Using cytological experiments further confirmed that Lenvatinib could selectively inhibit the proliferation and migration of HCC cells,and significantly induce apoptosis of sensitive cells,resulting in cell cycle arrest at G1 phase.Through transcriptome sequencing and cytological experiments,it was further revealed that in sensitive cell lines,Lenvatinib inhibited HCC by inhibiting Wnt signaling pathway and inducing the expression of GADD45B.In the tolerant cell lines,Lenvatinib could not induce GADD45B expression significantly,resulting in poor efficacy.Further studies have found that Elemene could significantly improve the sensitivity of tolerance cell lines to Lenvatinib,promoted the inhibition of proliferation and migration,significantly induce apoptosis.Conclusion:In this study,we found that Lenvatinib could promote the expression of GADD45B by inhibiting Wnt signaling in sensitive cells,and play an anti-cancer role.However,the response of GADD45B in tolerant cells was not high,which not only enriched the molecular mechanism of Lenvatinib in inhibiting liver cancer,but also suggested that GADD45B,the new target negatively regulated by Wnt signaling,might become a potential marker for clinical response of Lenvatinib.In addition,this study found that elemene,the active ingredient of traditional Chinese medicine,had a certain sensitization effect on Lenvatinib-tolerance HCC cells,which opened up novel ideas and methods for the clinical combination of Lenvatinib.