Next-generation sequencing in early-stage multiple primary lung cancer: The prognostic significance of genomic accumulation status and BCL2L11.

OBJECTIVE

This study aimed to define the genomic features of tumors and to delineate the potential mutational pattern underlying the prognosis of patients using large-panel next-generation sequencing (NGS) assays. Additionally, the study sought to explore the biological functions and prognostic significance of PRMT8 in BCL2L11 lung cancer.

METHODS

A total of 53 patients were enrolled, with a total of 130 malignant tumors. Clinical variables were collected, and the NGS sequencing of a large panel of 116 tumor-associated genes was performed. According to the gene mutation series and the number of mutation sites, the patients were divided into a series of groups. We then utilized the TCGA-LUAD database to conduct differential gene expression analysis, KEGG enrichment analysis, GSEA, and prognostic evaluation. Cell experiments (transwell migration assays, wound healing assay, CCK8 assay, and apoptosis assay) were utilized to verify the roles of PRMT8 on A549 cell. Western blotting was used to investigate the effect of PRMT8 on the mTORC1 signaling pathway.

RESULTS

The patients exceeding the IA stage were associated with a significantly shorter DFS than those in the IA stage (mean time: 27.5 vs. 50.6 months, p = 0.044), and BCL2L11 subsets were associated with a significantly worse DFS (31.9 vs. 50.2 months, p = 0.047). In the subgroups, the patients with a single gene mutation series with multiple gene mutation sites had a shorter DFS than those with a single mutation site (37.6 vs. 53.9 months, p = 0.047); and those with four gene series with over four mutation sites displayed a longer DFS than those with four sites (25.7 vs. 58 months, p = 0.034). In a Cox Multivariate analysis, exceeding the IA stage and a BCL2L11 mutation were considered unfavorable independent prognostic factors (HR = 5.102, 95 %CI: 1.526 to 17.054; p = 0.008, and HR = 6.010, 95 %CI: 1.636 to 22.079; p = 0.007, respectively). A lower gene mutation series (≤2) was an independent factor for a longer DFS (HR = 0.276, 95 %CI: 0.086 to 0.882; p = 0.03). Our study found that PRMT8 was upregulated in the BCL2L11 group and associated with increased patient survival. Biological experiments showed that PRMT8 overexpression reduced cell viability, promoted apoptosis, inhibited migration and invasion, and suppressed mTORC1 pathway phosphorylation.

CONCLUSIONS

The prognosis of patients with early-stage MPLC may potentially be related to the accumulation status of gene mutation series and sites; their driving powers may offset each other. Taken together, the application of genomic profiling may prove to be useful for subdividing and precisely managing patients with MPLC. In addition, high expression of PRMT8 presented as an independent prognostic biomarker in lung cancer patients harboring the BCL2L11 mutation.