HEDGEHOG/GLI Modulates The PRR11-SKA2 Bidirectional Transcription Unit in Lung Squamous Cell Carcinomas

We previously demonstrated that proline-rich protein 11 (PRR11) and spindle and kinetochore associated 2 (SKA2) constituted a head-to-head gene pair driven by a prototypical bidirectional promoter, and this gene pair synergistically promoted the development of non-small-cell lung cancer. However, the signaling pathways leading to the ectopic expression of this gene pair remain obscure. In the present study, we first analyzed the lung squamous cell carcinoma (LSCC) relevant RNA sequencing data from the TCGA database by the correlation analysis of gene expression and gene set enrichment analysis (GSEA), revealing that the PRR11-SKA2 correlated gene list highly resembled the Hedgehog (Hh) pathway activation-related gene set. Subsequently, GLI1/2 inhibitor GANT-61 or GLI1/2-siRNA inhibited Hh pathway of LSCC cells, concomitantly decreasing the expression levels of PRR11 and SKA2. Furthermore, the mRNA expression profile of LSCC cells treated with GANT-61 was detected by RNA sequencing, displaying 397 differentially expressed genes (203 upregulated genes and 194 downregulated genes). Out of them, one gene set, including BIRC5, NCAPG, CCNB2 and BUB1, involved in cell division and interacted with both PRR11 and SKA2. These genes were verified as the downregulated genes via RT-PCR and their high expression significantly correlated with shorter overall survival of LSCC patients. Taken together, our results indicated that GLI1/2 mediated the expression of the PRR11-SKA2-centric gene set which served as unfavorable prognostic indicators for LSCC patients, potentializing new combinatorial diagnostic and therapeutic strategies in LSCC. We first analyzed the lung squamous cell carcinoma (LSCC) relevant RNA sequencing data from the TCGA database by the correlation analysis of gene expression and gene set enrichment analysis (GSEA), revealing that the PRR11-SKA2 correlated gene list highly resembled the Hedgehog (Hh) pathway activation-related gene set. Subsequently, GLI1/2 inhibitor GANT-61 or GLI1/2-siRNA inhibited Hh pathway of LSCC cells, concomitantly decreasing the expression levels of PRR11 and SKA2. Furthermore, the mRNA expression profile of LSCC cells treated with GANT-61 was detected by RNA sequencing, displaying 397 differentially expressed genes (203 upregulated genes and 194 downregulated genes). Out of them, one gene set, including BIRC5, NCAPG, CCNB2 and BUB1, involved in cell division and interacted with both PRR11 and SKA2. These genes were verified as the downregulated genes via RT-PCR and their high expression significantly correlated with shorter overall survival of LSCC patients.