, a New Biomarker of Lung Adenocarcinoma.

OBJECTIVES

The roles played by β-III-spectrin, also known as spectrin beta, non-erythrocytic 2 (), in the occurrence and development of lung adenocarcinoma (LUAD) have not been previously examined. Our study aimed to reveal the relationship between the expression and LUAD.

MATERIALS AND METHODS

Twenty pairs of LUAD tissues and adjacent tissues were collected from patients diagnosed and treated at the Thoracic Surgery Department of The First Affiliated Hospital of Zhengzhou University from July 2019 to September 2020. RNA sequencing (RNA-seq) analysis determined that the expression of was higher in LUAD samples than in adjacent normal tissues. The expression levels of were examined in various databases, including the Cancer Cell Line Encyclopedia (CCLE), Gene Expression Omnibus (GEO), and Human Protein Atlas (HPA). The Search Tool for the Retrieval of Interacting Genes (STRING) online website was used to examine protein-protein interactions involving , and the results were visualized by Cytoscape software. The Molecular Complex Detection (MCODE) plug-in for Cytoscape software was used to identify functional modules of the obtained protein-protein interaction (PPI) network. Gene enrichment analysis was performed, and survival analysis was conducted using the Kaplan-Meier plotter. The online prediction website TargetScan was used to predict SPTBN2-targeted miRNA sequences by searching for sequences. Finally, we verified the expression of in the obtained tissue samples using real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The human lung cancer cell lines A549 and H1299 were selected for the transfection of small interfering RNA (siRNA) targeting (si-SPTBN2), and the knockdown efficiency was evaluated by RT-qPCR. The cellular proliferation, migration, and invasion capacities of A549 and H1299 cells were determined using the cell counting kit-8 (CCK-8) proliferation assay; the wound-healing assay and the Transwell migration assay; and the Matrigel invasion assay, respectively.

RESULTS

The expression of in non-small cell lung cancer (NSCLC) ranked 13th among cancer cell lines based on the CCLE database. At the mRNA and protein levels, the expression levels of were higher in LUAD tissues than in normal lung tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that proteins related to were enriched in apoptotic and phagosomal pathways. Kaplan-Meier survival analysis revealed that expression was significantly related to the prognosis of patients with LUAD. The TargetScan database verified that miR-16 was a negative regulator of mRNA expression. The results of the CCK-8 cell proliferation assay revealed that knockdown significantly inhibited the cell proliferation abilities of A549 and H1299 cells. The wound-healing assay indicated that knockdown resulted in reduced migration after 48 h compared with the control group. The Transwell migration and invasion test revealed that the migration and invasion abilities were greatly decreased by knockdown compared with control conditions.

CONCLUSION

We uncovered a novel gene, , that was significantly upregulated in LUAD tissues relative to normal tissue expression. is highly expressed in LUAD, positively correlated with poor prognosis, and can promote the proliferation, migration, and invasion of LUAD cells.