Objective The aim of this study was to investigate the molecular regulatory mechanism of cancer susceptibility candidate 15(CASC15),a long-stranded non-coding RNA(lncRNA),in hepatocellular carcinoma(HCC).Methods Bioinformat-ics methods were used to predict the expression of target genes and analyze the relationship between the expression of target genes and the survival time of patients;Hepatocellular carcinoma tissues and adjacent tissues from patients with HCC were collected;CCK-8,Tr-answell,and flow cytometry experiments were used to detect proliferation,invasion,migration and apoptosis of SMMC7721 cells and Huh-7 cells;The dual-luciferase assay was used to detect the targeting relationship between miR-144-3p and CASC15,as well as leucine rich repeat containing protein 1(LRRC1);RT-qPCR and Western blot were used to detect mRNA and protein expression of target genes;Immunofluorescence was used for protein localization of target genes;Replicate experiment was performed to verify the effect of CASC15/miR-144-3p/LRRC1 on the progression of HCC.In vivo experiment was performed to verify the effect of CASC15 on HCC progression.Results TCGA database and RT-qPCR assay showed high expression of CASC15,low expression of miR-144-3p,and high expression of LRRC1 in HCC tissues and cells(P<0.05).The results of cell function experiments on proliferation,inva-sion and migration showed that CASC15 and LRRC1 played a promoting role in tumor development,while miR-144-3p had an inhibi-tory effect,consistent with the results of apoptosis experiments(P<0.05).Cell function experiments showed that CASC15 inhibited miR-144-3p function,miR-144-3p inhibited LRRC1,and CASC15 bound to miR-144-3p,leading to the upregulation of LRRC1.The replicate experimental results indicated that CASC15 promoted LRRC1 expression through inhibiting miR-144-3p,thereby pro-moting HCC cell proliferation,invasion and migration,and inhibiting apoptosis.Conclusion CASC15 may promote HCC progression by regulating the miR-144-3p/LRRC1 axis.