Biology subjects

Attiyeh, M. A.

Publications and source records attributed to Attiyeh, M. A..

3 recordsLinked to original sources

bioRxiv2026

NEIL2 regulates RNA polymerase II dynamics to suppress transcription replication conflicts in pancreatic cancer

Transcription replication conflicts (TRCs) arise from spatiotemporal interference between replication and transcription machinery and contribute to genome instability in cancer cells. In pancreatic ductal adenocarcinoma (PDAC) cells, oncogenic KRAS drives TRC formation, and base excision repair (BER) contributes to TRC resolution as an adaptive response. Here, we show that TRCs are enriched in pancreatic tumor sections from patients and are associated with malignant progression. We identify NEIL2, a bifunctional DNA glycosylase in the BER pathway, as a critical regulator of TRCs in PDAC cells. Mechanistically, NEIL2 loss causes aberrant RNA polymerase II (RNAPII) occupancy at transcription start sites and downstream of transcription end sites. Dysregulated RNAPII dynamics promote R-loop-dependent and -independent TRCs contributing to replication stress, DNA damage, and impaired cancer cell proliferation. Notably, the DNA-binding motif of NEIL2 necessary for canonical BER function is dispensable for TRC regulation. Together, these findings reveal an unrecognized role for NEIL2 in regulating RNAPII dynamics and mitigating TRCs in pancreatic cancer cells.

molecular biology↗

bioRxiv2020

Evolutionary Dynamics of Non-Coding Regions in Pancreatic Ductal Adenocarcinoma

While the non-coding genome appears to play a role, the dynamic nature of noncoding alterations with respect to clonal progression of solid tumors remains unexplored. To address this gap in knowledge we performed multiregional whole genome sequencing and clonal analysis to elucidate the evolutionary dynamics of non-coding regions in pancreatic cancer relative to those of the coding genome. We find that the mutational burden of noncoding DNA is higher than coding DNA. However, when noncoding DNA was segregated into enhancer and non-enhancer regions, enhancers were more similar to coding DNA. Mutational signatures of noncoding and coding DNA further revealed the similar mutational spectra of enhancers to coding DNA whereas the mutational spectra of non-enhancer, noncoding DNA had an entirely different pattern. These findings shed light on the role of noncoding DNA in pancreatic cancer.

cancer biology↗

bioRxiv2019

The Genetic Basis of Transcriptional and Spatial Heterogeneity of Squamous Features in Pancreatic Ductal Adenocarcinoma

Recent studies indicate that pancreatic cancer expression profiles are variable and largely reflect a classical or basal-type phenotype. We performed genetic sequencing, RNA-seq, and histologic review of multiregion sampled pancreatic cancers and found that squamous and squamoid features, indicators of poor prognosis, correlate with a "basal-like" expressional type. Cancers with squamous features were more likely to have truncal mutations in chromatin modifier genes and intercellular heterogeneity for MYC amplification that was associated with entosis. In most patients the basal phenotype coexisted with a glandular component, and phylogenetic studies indicated that it arose from a subclonal population in the tumor. These data provide a unifying paradigm for understanding the interrelationship of basal-type features, squamous histology, and somatic mutations in chromatin modifier genes in the context of the clonal evolution of pancreatic cancer.

cancer biology↗