Study Of Inhibition Effect Of Docosahexaenoic Acid Plus5-fluorouracil On The Proliferation Of HepG2and Its Mechanism

Primary liver cancer (PLC, hereinafter referred to as HCC) is one of the most common malignant tumors. High degree of malignant primary hepatocellular carcinoma, the natural survival is short, because of their disease hidden by the time of diagnosis to surgery compared with10%-20%. Patients with hepatocellular carcinoma recurrence rate after5years up to70%, while surgical treatment alone may not fundamentally solve the problem of hepatocellular carcinoma recurrence. For the late clinical hepatocellular carcinoma mainly in surgery, interventional therapy and high-dose chemotherapy-based, but the long-term use of traditional chemotherapy drugs to cancer drug resistance is increasingly common, which greatly affected the clinical application of chemotherapy drugs. Thus, the solution for advanced hepatocellular carcinoma chemotherapy drug resistance in optimal chemotherapy regimen is especially necessary.Docosahexaenoic acid (DHA) commonly known as "Brain Gold", is composed of a linolenic acid by desaturation and elongation reaction formation, otherwise the product of eicosapentaenoic acid (Eicosapentaenoic Acid, EPA). Numerous studies show that DHA can selectively kill tumor cells, but less effect on normal cells, the mechanism involved in tumor cell proliferation, apoptosis and differentiation induced inhibition of cyclooxygenase and lipid peroxidation, immunological function of cancer, suppression of cachexia factor and so on.The research is to examine the activity of DHA increasing the growth suppression ability of the antimetabolite5-FU on hepatocellular carcinoma HepG2cells and identify the alteration of several mRNA expressions after cells being incubated with the combination.Methods1. CCK8assay was used to investigate the effect of DHA or5-FU on HepG2cells in vitro.2.Annexin-V-PE/PI was used to detect the early apoptotic rate of HepG2cells.3. Hoechest33258staining was used to observate the changes of nulei morphology.4.Mitochondrial membrane potential was demonstrated by JC-1fluorescence.5. Western Blot was used to analyze the protein levels of Bcl-2, Bax, MAPK or Caspase-8. ResultsThe inhibitory action on proliferation of DHA combined5-FU group was more significantly than5-FU group conformed by CCK8.The apoptotic rate and mitochondrial membrane potential of DHA combined5-FU group was significantly difference than5-FU group; The level of Bcl-2or p-ERK were more significantly decreased in the DHA combined5-FU group than5-FU group. The level of p-JNK or Cleaved Caspase8activity could be significantly activated by DHA combined5-FU group than5-FU group. Whereas the level of Bax or p-P38remained unchanged.ConclusionCCK-8assay, Annexin-V-PE/PI, Hoechst33258staining and JC-1fluorescence were proved that DHA could significantly enhance the sensitivity of hepatocellular carcinoma cells to5-FU.DHA could significantly enhance the apoptosis of hepatocellular carcinoma cells induced by5-FU through downregulating the expression of Bcl-2, activating p-JNK, Cleaved Caspase-8and depressing p-ERK.