The opposite role of alternatively spliced isoforms of LINC00477 in gastric cancer

Background: Aberrant transcript alternative splicing is an important regulatory process closely connected with oncogenesis. Purpose: The objective of this study was to determine the phenotype and function of a novel long noncoding RNA (lncRNA) LINC00477 in gastric cancer. Patients and methods: The gastric cancer samples of 140 from Oncomine database and 17 from our own hospital, as well as three gastric cancer cell lines MKN-45, AGS and KATO III were used in this study. The expression of the spliced isoforms of LINC00477 were tested. The tumor effects of LINC00477 on gastric cancer were investigated in vitro and in vivo. The mechanism of LINC00477 interacted with aconitase 1 (ACO1) was further examined by RIP and pull down assay. Results: The overall expression of LINC00477 was reduced in gastric cancers compared to normal gastric tissues. The isoform 1 of LINC00477 was down-regulated while the isoform 2 was up-regulated in gastric cancer cells. The opposite role of isoforms 1 and 2 in the proliferation and migration of cancer cells in vitro and in vivo was observed. Furthermore, isoform 1 of LINC00477 was determined to interact with ACO1 and suppress the conversion ability from citrate to isocitrate by ACO1. Conclusion: we presented the important roles of the spliced isoforms of long noncoding RNA, LINC00477 in gastric carcinogenesis.