Perspectives for next generation sequencing in patients with follicular lymphoma

Abstract

Aim. To study the prognostic significance of gene mutations and intracellular signaling pathways involved in lymphomagenesis in patients with follicular lymphoma using next generation sequencing (NGS).Materials and methods. The prospective study included 26 patients with a median age of 51.5 years. Mutational screening was performed for cohort using custom NGS Panel of 118 genes. Gene set enrichment analysis (GSEA) was performed using Metascape. The data was analyzed in SPSS Statistics 26 and R 4.2.2.Results. The highest mutation frequency was noted in the genes: KMT2C – 50 %, KMT2D – 50 %, CREBBP – 31 %, NOTCH2 – 31 %, GNAS – 23 %. Missense mutations occurred with a frequency of 84.3 %. ARID1A gene mutation is an unfavorable prognostic factor according to progressive-free (p = 0.014) and event-free (p = 0.029) survival analysis. Tumor mutation burden (TMB) was defined as the number of mutations per megabase (Mb) of the coding sequence, the median TMB was 5.0 (3.3–8.3) mutations/Mb. The TMB threshold of 6 mutations/Mb divided patients into groups with high (44 %) and low (56 %) TMB. In the high TMB group, 2-year event-free survival was 27.3 % (95 % confidence interval 6.0–61.0), which was significantly lower than in low TMB group – 72.7 % (95 % confidence interval 41.9–91.6; p = 0.037). The most enriched cellular pathways according to GSEA results were regulation of cell activation (–log10(q-value) = 6.357), chromatin remodeling (–log10(q-value) = 5.707), histone modification (–log10(q-value) = 4.569). We have also demonstrated other possibilities of GSEA using follicular lymphoma as an example.Conclusion. TMB is a significant prognostic factor in patients with follicular lymphoma. We have shown that mutations in the MYC, CREBBP, EZH2, KMT2D genes lead to dysregulation in several intracellular processes, mediating complex molecular changes. The most enriched intracellular pathways in follicular lymphoma are those of chromatin remodeling, regulation of cell activation and histone modification.

Keywords

• follicular lymphoma
• next generation sequencing
• tumor mutation burden
• gene set enrichment analysis
• mutation
• epigenetics
• signaling pathway
• prognosis