Long Non-coding RNA HCG18 Promotes The Progression Of Hepatocellular Carcinoma

BackgroundLiver cancer includes primary liver cancer and secondary metastatic liver cancer,of which primary liver cancer ranks fourth in the incidence of malignant tumors in the world.Primary liver cancer includes primary hepatocellular carcinoma(HCC),primary cholangiocarcinoma(ICC),primary hepatocyte-cholangiocarcinoma(HCC-ICC)three pathological types,in which hepatocellular carcinoma accounts for more than two-thirds.Primary hepatocellular carcinoma with high morbidity and mortality,ranks sixth in the incidence of malignant tumors worldwide.The main causes of the disease are hepatitis B and C virus infections,long-term alcohol abuse,aflatoxin poisoning,nonalcoholic fatty liver and so on.The incidence factors in different regions are also significantly different.For Western developed countries,the causes are mainly long-term alcoholism and non-alcoholic fatty liver.For China,the main causes are hepatitis B and C viral infection and aflatoxin poisoned.However,there are also very few people whose causes are unclear.With the continuous improvement of medical level,the diagnosis of liver cancer is also constantly improved.Among them,liver color Doppler ultrasonography has been widely used as a routine screening method for hepatocellular carcinoma.The application of computed tomography(CT)and imaging(Magnetic Resonance Imaging MRI)has greatly improved the early diagnosis rate and accuracy of hepatocellular carcinoma.Therapeutic methods are also constantly improved,including surgical resection,liver transplantation,and percutaneous hepatocellular carcinoma radiofrequency ablation as the main treatment for early liver cancer.However,due to the concealed hepatocellular carcinoma,the clinical manifestations are not obvious.Most patients are diagnosed with advanced hepatocellular carcinoma and lose the best treatment.Although percutaneous transhepatic arterial chemoembolization,the use of targeted drugs such as sorafenib toluene can delay the survival time of patients,but overall the treatment effect is not good,the 5-year survival rate is still less than 20%.Hepatocellular carcinoma has a high degree of malignancy and poor therapeutic effect.The main reason is that the pathogenesis of liver cancer is still unclear.Therefore,exploring the pathogenesis of liver cancer will provide new ideas for the treatment of hepatocellular carcinoma.Long noncoding RNA(LncRNA)is an RNA sequence that has no fixed open reading frame and is more than 200 nucleotides in length.Long non-coding RNA plays an important role in many life processes such as act as signaling molecules,guiding molecules,decoy molecules or scaffold molecules in chromosomal gene expression,and its abnormal expression is closely related to various diseases.Abnormalities in long non-coding RNA in nucleotide sequence,spatial structure,expression level,and regulatory protein binding capacity can cause multiple tumors such as breast cancer,lung cancer,prostate cancer,colon cancer,bladder cancer,gallbladder cancer,and liver cancer.With the application and research of second-generation sequencing,more and more long-chain non-coding RNAs and their functions have been discovered.For example,LncRNA MT1 JP inhibits gallbladder carcinogenesis by regulating miR-214-3p expression;LncRNA SNHG16 promotes the occurrence of liver cancer by regulating miR-302a-3p/ FGF19 axis,and the imprinted gene H19 acts as a tumor suppressor in colon cancer but has a cancer-promoting effect in breast cancer and bladder cancer.Therefore,it is necessary to analyze the mechanism of different long-chain non-coding RNAs in different tumors.By exploring the relationship and mechanism between long-chain non-coding RNA and tumors,that can serves the molecular diagnosis and targeted therapy of tumors.Our study found human leucocyte antigen complex group 18(HCG18)abnormally express in hepatoma tissures by the Cancer Genome Atlas Project(TCGA)database,and through cell proliferation experiments,cell cycle and apoptosis experiments,cell migration and invasion experiments explored the effects of HCG18 in hepatocellular carcinoma on multiple levels and multiple directions,and explored its underlying mechanisms by using online analysis tool.ObjectiveBased on bioinformatics technology and public network data platform,we intend to analyze the expression of long non-coding RNA HCG18 in pan-tumor or HCC,its relationship with the survival and prognosis of patients with HCC.And by cell experiments to investigate the biological activity effects of long non-coding RNA HCG18 to the development of HCC.Methods1.Basing TCGA dataset,analysing the expression of long non-coding RNA HCG18 in HCC tissues,and analyze its relationship with clinicopathological features and survival prognosis of the patients with HCC.2.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the expression levels of HCG18 in hepatocarcinoma tissues and matched paracancerous tissues,HCC cells and normal liver cells.3.Reduce the expression of HCG18 in hepatoma cell lines MHCC97 H and Hep3 B by small interfering RNA(si-RNA)and negative control RNA(NC-RNA)by transfection technique.4.The biological functions of HCG18 were detected by CCK-8 assay,colony formation assay,EdU assay,transwell migration and invasion assays,cell cycle and apoptosis.Western blot was used to detect the expression of cell cycle related proteins and apoptosis-related proteins.5.By gene expression profiling(GEPIA)to explore the potential molecular mechanism of HCG18 affecting the biological activity of hepatocellular carcinoma.Results1.The expression level of long non-coding RNA HCG18 in TCGA database is up-regulated in hepatocellular carcinoma tissues compared with that in normal liver tissues;The patients with high HCG18 expression had a poor differentiation,late TNM stage,high AFP level and poor prognosis.2.qRT-PCR assay verified that long non-coding RNA HCG18 was highly expressed in hepatocarcinoma tissures and hepatoma cell lines MHCC97 H and Hep3B;silencing of long non-coding RNA HCG18 expression significantly inhibited the proliferation of hepatoma cells in vitro.3.Knock down long non-coding RNA HCG18 expression,induce hepatoma cell cycle arrest in G0/G1 phase,and promote hepatoma cell apoptosis.4.The silenced long non-coding RNA HCG18 significantly inhibited the migration ability of hepatoma cells;compared with the negative control group,the invasion ability of hepatoma cells with low long non-coding RNA HCG18 expression group was significantly reduced.5.Long non-coding RNA HCG18 expression correlates with ERK1/2 expression levels.Conclusion1.Long non-coding RNA HCG18 is highly expressed in hepatocellular carcinoma tissues and HCC cells,and high-expression long non-coding RNA HCG18 promotes the development of primary hepatocellular carcinoma.2.The proliferation ability of hepatocellular carcinoma cells with low expression of HCG18 was decreased,the cell cycle was arrested in G0/G1 phase,the apoptosis rate increased,cell migration and invasion abilities decreased.3.Long non-coding RNA HCG18 may promote the development of primary hepatocellular carcinoma by regulating ERK1/2 signaling pathway.