Exploration of the Role of the lncRNA MALAT1 in Hepatic Alveolar Echinococcosis by Regulating the miR-378c/IGF1R Axis Via High-throughput Sequencing

Abstract

Background: Hepatic alveolar echinococcosis (HAE) is a severe parasitic disease with invasive growth characteristics similar to those of malignant tumors, and most patients cannot be cured by surgery. The drug treatment options are limited. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play key regulatory roles in the progression of various diseases, including liver cancer. The functions of molecules such as lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-378c in cancer have been widely reported, but their roles in HAE remain unclear. Objectives: This study aims to identify aberrant lncRNAs as diagnostic biomarkers for the progression of hepatic alveolar echinococcosis through RNA sequencing (RNA-seq), and to investigate the potential mechanisms underlying lncRNA dysregulation in the advancement of this disease. Methods: This paired-tissue study used RNA-seq (discovery set) on hepatic alveolar echinococcosis lesion tissues and matched adjacent liver tissues from three patients, followed by independent cohort validation by quantitative real-time polymerase chain reaction (qRT-PCR) (n = 20 for MALAT1 and insulin-like growth factor 1 receptor (IGF1R); n=13 for miR-378c). Lesion tissues from hepatic alveolar echinococcosis patients served as the experimental group, with adjacent tissues as controls. Metastasis-associated lung adenocarcinoma transcript 1 and IGF1R expression were further verified by qRT-PCR in lesion tissues and in liver tissues less than 1 cm and greater than 1 cm from the lesion. Meanwhile, miR-378c expression was assessed in a subset of patients. Potential binding sites among MALAT1, miR-378c, and IGF1R were predicted using StarBase and validated by dual-luciferase reporter assays. Results: A total of 914 significantly differentially expressed lncRNAs were screened by RNA-seq in three samples of hepatic alveolar echinococcosis lesion tissues and adjacent tissues. Quantitative real-time polymerase chain reaction verification revealed that MALAT1 and IGF1R were highly expressed and that the level of miR-378c was low in hepatic alveolar echinococcosis lesions. A dual-luciferase assay revealed that MALAT1 targeted miR-378c and miR-378c targeted IGF1R in the three cases of hepatic alveolar echinococcosis. Differential expression was analyzed using DESeq2 with Benjamini–Hochberg false discovery rate (FDR) correction (FDR < 0.05, |fold change (FC)| > 2). In the validation cohort, qRT-PCR confirmed that MALAT1 and IGF1R were significantly upregulated whereas miR-378c was significantly downregulated in lesion tissues (P < 0.05). Correlation analysis showed that MALAT1 was negatively associated with miR-378c and positively associated with IGF1R, and miR-378c was negatively associated with IGF1R. Conclusions: LncRNA MALAT1 may be involved in the progression of hepatic alveolar echinococcosis by acting as a molecular sponge for miR-378c and regulating the expression of the downstream target gene IGF1R.