AAMDC Promotes The Metastasis Of Hepatocellular Carcinoma Via Activating The MTOR Pathway

Background:Hepatocellular carcinoma(HCC)is the most common pathological type of primary liver cancer and the fourth leading cause of cancer-related death worldwide.Although the current therapeutic methods for HCC mainly include surgery,ablation therapy,immunotherapy,and other means,there are still some limitations.It is of great significance to the clinical management of HCC patients to elucidate the biological functions and mechanisms of molecular markers that play an essential role in the occurrence and development of HCC thoroughly.AAMDC is a gene on chromosome 11,and its role in tumor progression is unclear.Previous studies have confirmed that AAMDC is involved in the differentiation of preadipocytes into adipocytes in cattle and mice,and induce fat synthesis.In recent years,a small number of scientific studies have found that AAMDC is involved in a variety of metabolic regulations and is regarded as a noncharacteristic oncogene in aggressive estrogen receptor-positive breast cancer.Overexpression of AAMDC can reverse the inhibitory effect of solanine on gastric cancer.There have been no studies of AAMDC in HCC.In this study,we aimed to explore the expression,clinical significance,biological function,and potential mechanism of AAMDC in HCC.Objectives:This study aimed to clarify the relationship between AAMDC and clinical indicators in patients with HCC,to reveal the localization and expression level of AAMDC in HCC cells,and to explore the effect of AAMDC on the migration and invasion ability of HCC cells and its related mechanism.Methods:(1)Analyzing the correlation between the expression of AAMDC in HCC and the involvement of clinicopathology and patient prognosis through tumor-related databases at home and abroad;(2)Detecting the expression of AAMDC in HCC tissues and paracancerous tissues by immunohistochemistry,and analyzing its clinical value;(3)q RT-PCR and Western blot were used to detect m RNA and protein expression of AAMDC in normal liver cell line L-02 and five HCC cell lines SNU387,Huh7,LM3,Hep G2,and PLC-8024;(4)SNU387 and Huh7 cells were transfected with si RNAs of AAMDC,Hep G2 and PLC-8024 cells were transfected with overexpression plasmids of AAMDC,and the effect of AAMDC on the biological characteristics of HCC cells was detected by Transwell and other experiments after Western blot detection;(5)Determining the localization of AAMDC in HCC cells by immunofluorescence;(6)Determining the interacting protein network of AAMDC by Co-IP and mass spectrometry;(7)Using transcriptome sequencing to determine the regulation of the m TOR pathway by AAMDC and verify the role and mechanism of AAMDC in promoting the progression of HCC in vitro.Results:(1)AAMDC is highly expressed in HCC tissues and is associated with poor disease-free survival.(2)Compared with L-02,the expression levels of m RNA and protein of AAMDC in SNU387,Huh7,LM3,Hep G2,and PLC-8024 have increased.(3)Overexpression of AAMDC enhanced the migration and invasion ability of HCC cells;Knocking down AAMDC weakened the migration and invasion ability of HCC cells.(4)AAMDCs are mainly distributed in the cytoplasm of HCC.(5)Mass spectrometry and co-immunoprecipitation results showed that AAMDC interacts with FASN(fatty acid synthase).(6)High-throughput transcriptome sequencing and vitro experiments showed that overexpression of AAMDC activates the m TOR pathway.Conclusions:AAMDC is up-regulated in hepatocellular carcinoma.By interacting with FASN,AAMDC activates the m TOR signaling pathway,thereby promoting the invasion and metastasis of HCC and exerting an oncogene function.