The Inhibitory Effect Of BBI608 And Its Derivative On The Hepatocellular Carcinoma Cells And The Possible Mechanism

Objective: Hepatocellular carcinoma(HCC)is mainly primary hepatocellular carcinoma,which threatens the lives of patients.Every year,the number of new cases and deaths is about 900,000,and the trend is rising continuously.It has become a major cause of cancer-related deaths in China.At present,most effective therapies are hepatectomy,liver transplantation and ablation(only about 30% of eligible early patients),with high recurrence rate and low survival rate.As a global health problem,there is still no appropriate way to solve it.STAT3 plays an important role in maintaining normal development,dealing with acute phase response,chronic inflammation and autoimmune metabolism.STAT3 is mainly activated by a series of pathways such as cytokines,growth factors and non-receptor tyrosine kinase activation.The normal physiological activation mode is transient,but it is activated for a long time in tumor cells,accelerating the proliferation of tumor cells,new capillary formation,invasion of host adjacent tissues,and metastasis of other organs or sites,immune escape and blocking apoptosis.STAT3 is a key regulator of many carcinogenic pathways,so it is considered as a promising anti-cancer target.BBI608(Napabucasin),a small molecule STAT3 inhibitor for cancer stem cells,can be absorbed orally.BBI608 can target STAT3,inhibit the sustained activation of STAT3 and the proliferation of cancer stem cells,gene transcription,block gene expression of cancer stem cells isolated from various cancers,and block spherogenesis formation or kill stem cells.BBI608 can also reduce cancer recurrence and metastasis.More importantly,studies have shown that BBI608 seems to have no adverse effects on hematopoietic cells or other normal adult stem cells.Only a few patients have mild gastrointestinal discomfort.In June 2016,BBI608 was approved by the FDA for the treatment of gastroesophageal junction(GEJ)cancer,and in November 2016,the FDA approved it for the treatment of pancreatic cancer.BBI608 clinical trials currently under way include clinical effects of glioma,leukemia,lymphoma,colon cancer,liver cancer,gastric cancer,pancreatic cancer,lung cancer and mesothelioma.It is considered to be one of the most promising anticancer drugs.Methods: Hep G2,Bel-7402 and L02 cells were cultured normally.First,CCK8 assay was used to detect the inhibitory effects of BBI608 and its derivatives LD-17 on the proliferation of hepatocellular carcinoma cells Hep G2,Bel-7402 and normal hepatocytes L02.The apoptotic effects of BBI608 and its derivatives LD-17 on human hepatocellular carcinoma cells Hep G2 and Bel-7402 were detected by flow cytometry.The effects of BBI608 and its derivatives LD-17 on the expression of target genes(STAT3)and Bcl-2 and Bax in human hepatocellular carcinoma cells Hep G2,Bel-7402 were detected by Western blot.Results:1.CCK8 results showed that BBI608 and its derivatives LD-17 at different concentrations significantly inhibited the proliferation of hepatocellular carcinoma cells Hep G2 and Bel-7402 in a time-concentration-dependent manner.2.Flow cytometry assay showed that the apoptotic rate of Hep G2 and Bel-7402 cells increased significantly with the increase of BBI608 and LD-17 concentration.3.Western blot assay showed that BBI608 and its derivatives LD-17 decreased the STAT3 phosphorylation of and Bcl-2 protein in Hep G2 and Bel-7402 hepatocellular carcinoma cells,increased the expression of Bax protein in a dose-dependent manner.Conclusion: 1.BBI608 and its derivatives LD-17 can inhibit the proliferation of hepatocellular carcinoma cells Hep G2 and Bel-7402 in a dose-and time-dependent manner.2.BBI608 and its derivatives LD-17 have anti-HCC effects mainly by promoting the apoptosis of Hep G2 and Bel-7402 cells.