DLGAP1-AS2–Mediated Phosphatidic Acid Synthesis Activates YAP Signaling and Confers Chemoresistance in Squamous Cell Carcinoma
Yabing Nan, Qingyu Luo, Xiaowei Wu, Shi Liu, Pengfei Zhao, Wan Chang, Aiping Zhou, Zhihua Liu
Abstract
Squamous cell carcinomas (SCC) constitute a group of human malignancies that originate from the squamous epithelium. Most patients with SCC experience treatment failure and relapse and have a poor prognosis due to de novo and acquired resistance to first-line chemotherapeutic agents. To identify chemoresistance mechanisms and to explore novel targets for chemosensitization, we performed whole-transcriptome sequencing of paired resistant and parental SCC cells. We identified DLGAP1 antisense RNA 2 (D-AS2) as a crucial noncoding RNA that contributes to chemoresistance in SCC. Mechanistically, D-AS2 affected chromatin accessibility around the histone mark H3K27ac of FAM3 metabolism regulating signaling molecule D (FAM3D), reducing FAM3D mRNA transcription and extracellular protein secretion. FAM3D interacted with the Gαi-coupled G protein-coupled receptors formyl peptide receptor 1 (FPR1) and FPR2 to suppress phospholipase D (PLD) activity, and reduced FAM3D increased PLD signaling. Moreover, activated PLD promoted phosphatidic acid (PA) production and subsequent nuclear translocation of yes-associated protein (YAP). Accordingly, in vivo administration of a D-AS2-targeting antisense oligonucleotide sensitized SCC to cisplatin treatment. In summary, this study shows that D-AS2/FAM3D-mediated PLD/PA lipid signaling is essential for SCC chemoresistance, suggesting D-AS2 can be targeted to sensitize SCC to cytotoxic chemotherapeutic agents. SIGNIFICANCE: This study identifies D-AS2 as a targetable lipid-related long noncoding RNA that increases phospholipase D activity to promote YAP signaling, triggering chemoresistance in SCC.