LBX2-AS1 is a
long non-coding RNA that facilitates the development of
gastrointestinal cancers and
lung cancer, but its participation in
ovarian cancer development remained uninvestigated. Clinical data retrieved from TCGA
ovarian cancer database and the clinography of 60
ovarian cancer patients who received anti-
cancer treatment in our facility were analysed. The overall cell growth, colony formation, migration, invasion, apoptosis and tumour formation on nude mice of
ovarian cancer cells were evaluated before and after lentiviral-based LBX2-AS1 knockdown. ENCORI platform was used to explore LBX2-AS1-interacting
microRNAs and target genes of the candidate
microRNAs.
Luciferase reporter gene assay and
RNA pulldown assay were used to verify the putative
miRNA-
RNA interactions.
Ovarian cancer tissue specimens showed significant higher LBX2-AS1 expression levels that non-cancerous counterparts. High expression level of LBX2-AS1 was significantly associated with reduced overall survival of patients. LBX2-AS1 knockdown significantly down-regulated the cell growth, colony formation, migration, invasion and tumour formation capacity of
ovarian cancer cells and increased their apoptosis in vitro. LBX2-AS1 interacts with and thus inhibits the function of miR-455-5p and miR-491-5p, both of which restrained the expression of E2F2 gene in
ovarian cancer cells via
mRNA targeting. Transfection of
miRNA inhibitors of these two
miRNAs or forced expression of E2F2 counteracted the effect of LBX2-AS1 knockdown on
ovarian cancer cells. LBX2-AS1 was a novel
cancer-promoting
lncRNA in
ovarian cancer. This
lncRNA increased the cell growth, survival, migration, invasion and tumour formation of
ovarian cancer cells by inhibiting miR-455-5p and miR-491-5p, thus liberating the expression of E2F2
cancer-promoting gene.