Summary Long-read nanopore sequencing enables simultaneous detection of germline variation and native DNA base modifications on individual DNA molecules, providing a unique opportunity to investigate allele-specific epigenetic regulation. Here, we performed whole-genome nanopore sequencing on normal and tumor prostate tissues to characterize differential methylation, methylation entropy, and allele-specific methylation (ASM) associated with noncoding genetic variants. Genome-wide analysis identified extensive cancer-associated differentially methylated regions (DMRs), with hypermethylated DMRs significantly enriched near transcription start sites and transcriptional regulatory regions. Integration with transcriptomic datasets revealed strong inverse relationships between promoter methylation and gene expression, while 5-hydroxymethylcytosine (5hmC) levels positively correlated with transcriptional activity across gene bodies. Using fragment-level methylation patterns enabled by long-read sequencing, we further quantified methylation entropy incorporating both 5mCG and 5hmCG states. Cancer-hypermethylated DMRs exhibited markedly reduced entropy, consistent with clonal fixation of methylation states during tumor progression. Entropy profiling across chromatin annotations demonstrated maximal epigenetic heterogeneity at partially modified enhancer-associated regions. To investigate cis-regulatory genetic effects, we developed a simple ASM framework (nanoASM) that can partition sequencing reads by allelic state and identifies allele-specific DMRs directly from long-read data. Compared with conventional population-level mQTL analysis, ASM demonstrated substantially improved statistical efficiency by leveraging within-individual contrasts and reducing sample-level heterogeneity. Although germline single nucleotide polymorphisms (SNPs) were largely shared between normal and tumor tissues, ASM patterns differed substantially, with tumor-associated ASM regions displaying significantly larger genomic span and stronger allelic methylation differences. Comparative analysis with TCGA prostate mQTL and GTEx prostate eQTL datasets demonstrated substantial concordance between ASM directionality and downstream transcriptional effects, particularly for variants located within DMRs and near transcription start sites. At the IRX4 prostate cancer risk locus, ASM identified an androgen-responsive regulatory domain overlapping AR ChIP-seq and H3K27ac peaks, nominating rs6885084 as a candidate functional variant. At the PSCA locus, ASM anchored by rs4736369 was associated with allele-specific methylation, chromatin activation, transcript abundance, and isoform usage. Together, these findings establish nanopore-based ASM analysis as a powerful approach for resolving functional noncoding variants and their regulatory domains they control in prostate cancer.
Antegrade administration of mitomycin gel for upper tract urothelial carcinoma
via
percutaneous nephrostomy tube: a
multi‐institutional
retrospective cohort s
Objectives To assess the safety profile of antegrade mitomycin gel instillation through a percutaneous nephrostomy tube (PCNT) for upper tract urothelial carcinoma (UTUC) with the aim of decreasing morbidity associated with therapy. Patients and Methods Patients undergoing antegrade administration of mitomycin gel via PCNT were retrospectively included for analysis from four tertiary referral centres between 2020 and 2022. The primary outcome was safety profile, as graded by Common Terminology Criteria for Adverse Events (v5.0). Post‐therapy disease burden was assessed by primary disease evaluation (PDE) via ureteroscopy. Results Thirty‐two patients received at least one dose of mitomycin gel via PCNT for UTUC, 29 of whom completed induction and underwent PDE. Thirteen patients (41%) had residual tumour present prior to induction therapy. At a median of 15.0 months following first dose of induction therapy, ureteric stenosis occurred in three patients (9%), all of whom were treated without later recurrence or chronic stenosis. Other adverse events included fatigue (27%), flank pain (19%), urinary tract infection (12%), sepsis (8%) and haematuria (8%). No patients had impaired renal function during follow‐up and there were no treatment‐related deaths. Seventeen patients (59%) had no evidence of disease at PDE and have not experienced recurrence at a median follow‐up of 13.0 months post induction. Conclusions Administration of mitomycin gel via a PCNT offers a low rate of ureteric stenosis, demonstrates a favourable safety profile, and is administered without general anaesthesia.
Genomic landscape and evolution of metastatic chromophobe renal cell carcinoma
Chromophobe renal cell carcinoma (chRCC) typically shows ~7 chromosome losses (1, 2, 6, 10, 13, 17, and 21) and ~31 exonic somatic mutations, yet carries ~5%–10% metastatic incidence. Since extensive chromosomal losses can generate proteotoxic stress and compromise cellular proliferation, it is intriguing how chRCC, a tumor with extensive chromosome losses and a low number of somatic mutations, can develop lethal metastases. Genomic features distinguishing metastatic from nonmetastatic chRCC are unknown. An integrated approach, including whole-genome sequencing (WGS), targeted ultradeep cancer gene sequencing, and chromosome analyses (FACETS, OncoScan, and FISH), was performed on 79 chRCC patients including 38 metastatic (M-chRCC) cases. We demonstrate that TP53 mutations (58%), PTEN mutations (24%), and imbalanced chromosome duplication (ICD, duplication of ≥ 3 chromosomes) (25%) were enriched in M-chRCC. Reconstruction of the subclonal composition of paired primary-metastatic chRCC tumors supports the role of TP53 , PTEN , and ICD in metastatic evolution. Finally, the presence of these 3 genomic features in primary tumors of both The Cancer Genome Atlas kidney chromophobe (KICH) ( n = 64) and M-chRCC ( n = 35) cohorts was associated with worse survival. In summary, our study provides genomic insights into the metastatic progression of chRCC and identifies TP53 mutations, PTEN mutations, and ICD as high-risk features.