Correlation between oncogene integrator complex subunit 7 and a poor prognosis in lung adenocarcinoma.

Abstract

Lung adenocarcinoma (LUAD) is one of the most common types of cancer worldwide with high incidence and mortality rates. The integrator complex subunit 7 (INTS7) encodes a subunit of the integrator complex that mediates small-nuclear ribonucleic acid (RNA) processing and has been shown to be associated with RNA polymerase II. However, the clinical significance of INTS7 in LUAD is still not clear and needs to be investigated. The single-cell sequencing of a publicly available data set was conducted to compare the expression levels and percentages of INTS7 in lung malignant cells at different classifications and stages. Further, 33 cancer types from The Cancer Genome Atlas (TCGA) database were analyzed, protein-protein interaction (PPI) networks were constructed, and functional annotations were undertaken for the INTS7 gene. INTS7 small-interfering RNAs were transfected into LUAD cell lines, and cell biological behaviors, such as migration, invasion, apoptosis and proliferation capacity, were then examined. We found that the expression of INTS7 was significantly more upregulated in the LUAD tissues than the adjacent normal tissues. Increased INTS7 messenger RNA expression was correlated with TNM (tumor node metastasis classification) stage and gender in LUAD patients. Further, the Kaplan-Meier survival analysis indicated that LUAD patients with high INTS7 expression levels had a worse prognosis than those with low INTS7 expression levels. Finally, we found that silencing INTS7 inhibited LUAD cell viability and invasion in vitro. These results suggest that INTS7 can be used as a potential therapy target and prognostic marker for LUAD. Further, INTS7 may aggravate migration and invasion, induce the proliferation, and attenuate the apoptosis capacity of cells in LUAD.