Whole-genome sequencing (WGS) was performed for 13 pairs of tumor-normal samples from patients diagnosed with NKTL. Genomic DNA from tumor tissue was extracted with QIAamp DNA Mini Kit. The DNA for the matching normal was obtained from blood or buccal swabs and purified by Blood and Cell Culture DNA Mini kit or E.Z.N.A. Tissue DNA Kit (Omega Bio-tek) according to manufacturer’s instructions. The quantity and quality were assessed by Quant-iT PicoGreen dsDNA Assay Kit (Invitrogen) and agarose gel electrophoresis. All sequencing libraries were prepared using TruSeq Nano DNA Library Prep Kit (Illumina). Paired-end sequencing was performed on Illumina HiSeq 2000 or HiSeq X Ten as 2x101 bp or 2x151 bp, respectively. 8 NKTL FFPE specimens were screened for somatic mutations using deep targeted capture sequencing (TCS). FFPE rolls or slides were extracted using QIAamp DNA FFPE Tissue kit (QIAGEN). The FFPE genomic DNA was treated with NEBNext FFPE DNA Repair Mix and assessed by Quant-it PicoGreen dsDNA Assay Kit (Invitrogen). The library was generated from 10-200 ng DNA with SureSelectXT Low Input Target Enrichment System for Illumina Paired-End Sequencing Library (Agilent Technologies) according to manufacturer’s instructions. RNA based probe was designed with SureDesign (Agilent Technologies) to target-capture 140 genes. Next, the captured libraries were pooled in equimolar concentration and sequenced on Illumina Novaseq 6000 platform with SP or S1 chip. Reads aligning to 40 selected genes were isolated post-alignment for this submission. Prefix used in filenames: T - Tumor samples N - Matched-Normal samples
Activating mutations in PIK3CA generate large clones in the aging human esophagus. Here we investigate the underlying cellular mechanisms regulating their expansion by lineage tracing. Expression of an activating heterozygous Pik3caH1047R mutation in single progenitor cells of the mouse esophagus tilts cell fate towards proliferation, generating mutant clones that outcompete their wild type neighbours. The mutation leads to increased aerobic glycolysis through the activation of Hif1α transcriptional targets. In vitro and in vivo interventions that level out differences in activation of the PI3K/HIF1α/aerobic glycolysis axis between wild type and Pik3caH1047R cells attenuate the competitive advantage of the mutants. In contrast, metabolic conditions that alter Insulin/PI3K signalling, such as type-1 diabetes or diet-induced insulin resistance, further increase Pik3caH1047R mutant competitiveness in mice. Consistently, the density of activating PIK3CA mutations in human esophagus is increased in overweight individuals. We conclude that the metabolic environment influences the mutational landscape of normal epithelia. Clinically feasible interventions that even out signalling imbalances between wild type and mutant cells may therefore limit the expansion of oncogenic mutants in normal tissues.
Autologous T-cell therapies show limited efficacy in chronic lymphocytic leukemia (CLL), where acquired immune dysfunction prevails. In CLL, disturbed mitochondrial metabolism has been linked to defective T-cell activation and proliferation. Recent research suggests that lipid metabolism regulates mitochondrial function and differentiation in T cells, yet its role in CLL remains unexplored. This comprehensive study compares T-cell lipid metabolism in CLL patients and healthy donors, revealing critical dependence on exogenous cholesterol for human T-cell expansion following TCR-mediated activation. Using multi-omics and functional assays, we found that T cells present in viably frozen samples of patients with CLL (CLL T cells) showed impaired adaptation to cholesterol deprivation and inadequate upregulation of key lipid metabolism transcription factors. CLL T cells exhibited altered lipid storage, with increased triacylglycerols and decreased cholesterol, and inefficient fatty acid oxidation (FAO). Functional consequences of reduced FAO in T cells were studied using samples from patients with inherent FAO disorders. Reduced FAO was associated with lower T-cell activation but did not affect proliferation. This implicates low cholesterol levels as a primary factor limiting T-cell proliferation in CLL. Consequently, CLL T cells displayed fewer and less clustered lipid rafts, potentially explaining the impaired immune synapse formation observed in these patients. Our findings highlight significant disruptions in lipid metabolism as drivers of functional deficiencies in CLL T cells, underscoring the pivotal role of cholesterol in T-cell proliferation. This study suggests that modulating cholesterol metabolism could enhance T-cell function in CLL, presenting novel immunotherapeutic approaches to improve outcome in this challenging disease.
