Circ-PDZD8 promotes cell growth and glutamine metabolism in non-small cell lung cancer by enriching LARP1 via sequestering miR-330-5p.

Abstract

The deregulation of circular RNA (circRNA) is widely reported in carcinogenesis. The purpose of this study was to investigate the role of circRNA-PDZ domain containing 8 (circ-PDZD8) in non-small cell lung cancer (NSCLC) progression. The histological structure of tissues was identified by hematoxylin-eosin (HE) staining analysis. The expression levels of circ-PDZD8, miR-330-5p and la ribonucleoprotein 1 (LARP1) mRNA were ascertained by qPCR. Cell counting kit-8, colony formation, flow cytometry, and transwell assays were employed for functional analysis. Glutamine metabolism was monitored by glutamine consumption, alpha ketoglutarate (α-KG) level and adenosine triphosphate (ATP) level. A xenograft model was established to ascertain the role of circ-PDZD8 in vivo. The putative binding relationships were verified by dual-luciferase and RIP studies. Circ-PDZD8 expression was highly increased in NSCLC. Circ-PDZD8 knockdown inhibited cell growth, migratory capacity, invasiveness and glutamine metabolism but enhanced cell apoptosis in NSCLC cells. Circ-PDZD8 blocked miR-330-5p expression, and miR-330-5p inhibition overturned the effects of circ-PDZD8 absence. LARP1 targeted by miR-330-5p, and miR-330-5p upregulation-impaired cell growth, motility and glutamine metabolism were recovered by LARP1 overexpression. Circ-PDZD8 knockdown was also shown to impede solid tumor growth. Circ-PDZD8 promotes NSCLC cell growth and glutamine metabolism by increasing LARP1 via competitively targeting miR-330-5p.