Biology subjects

Dinh, K.

Publications and source records attributed to Dinh, K..

3 recordsLinked to original sources

bioRxiv2026

COATS Identifies Copy-Number-Dependent Drivers and Enablers of Aneuploidy in Cancer

Aneuploidy is a hallmark of most cancers but at the same time has been shown to decrease cellular fitness. Thus, to solve this conundrum, a current hypothesis in the field is that specific SCNAs may promote tolerance to the aneuploid state and/or promote additional chromosomal instability (CIN) and more aneuploidy. In other words, gains or losses of oncogenes (OGs) and tumor suppressor genes (TSGs) can, in turn, drive further CIN, promoting additional somatic alterations, or enhance aneuploid cell survival. Despite their importance, CN-dependent OGs and TSGs associated with aneuploidy remain largely unidentified. Here, we present a new method, Copy-number-dependent Oncogenes And Tumor Suppressors (COATS), to identify pan-cancer and cancer-specific CN-dependent OGs and TSGs associated with aneuploidy (Aneu-OGs and Aneu-TSGs). COATS integrates information theory and statistical tests to analyze gene expression, copy number, and aneuploidy, and incorporates timing analysis to distinguish early drivers of CIN from late tolerance enablers. Interestingly, using the CINner simulation framework, we show that aneuploidy drivers tend to occur earlier than aneuploidy enablers. Applying COATS to 33 TCGA cancer types, we identified 479 pan-cancer amplification-dependent Aneu-OGs and 141 deletion-dependent Aneu-TSGs. For validation, we used shRNA to knock down CCT5, a COATS-identified pan-cancer Aneu-OG predicted to promote aneuploidy tolerance, in isogenic aneuploid and near-diploid cells. Strikingly, CCT5 depletion was selectively toxic in aneuploid cells, supporting its classification as an aneuploidy tolerance enabler gene. Overall, our study defines a set of CN-dependent genes associated with aneuploidy and points to candidate therapeutic targets for chromosomally unstable cancers.

Cancer Biology↗

bioRxiv2025

Gastric epithelium from BRCA1 and BRCA2 carriers harbors increased double-stranded DNA damage and augmented growth.

An accumulating body of evidence suggests carriers of a pathogenic germline variant (PGV) in BRCA1 or BRCA2 have increased gastric cancer (GC) risk. BRCA1 and BRCA2 are tumor suppressor genes involved in promoting homologous recombination to repair double-stranded DNA breaks. The aim of this investigation was to identify differences within the gastric epithelium and in patient-derived gastric organoids (PDGOs) between BRCA1 and BRCA2 carriers and non-carriers to determine if evidence of early gastric carcinogenesis exists amongst these carriers. First, using gastric epithelial biopsies, BRCA2 carriers were found to harbor higher expression of the proliferative marker Ki-67 within the antral gastric epithelium and strikingly, biopsies from both BRCA1 and BRCA2 carriers displayed a marked increase in double-stranded DNA damage. These results were further explored using PDGOs, where a growth advantage was observed for both BRCA1 and BRCA2 PDGOs compared to non-carrier PDGOs. Furthermore, both BRCA1 and BRCA2 PDGOs displayed a more pronounced enhancement of Ki-67 expression as well as increased double stranded DNA damage compared to non-carrier PDGOs. Importantly, none of the PDGOs showed signs of BRCA1 or BRCA2 loss of heterozygosity, potentially indicating a haploinsufficient phenotype. Taken together, these novel findings suggest that haploinsufficiency in BRCA1 and BRCA2 carriers may lead to DNA damage in the gastric epithelium, which may serve as an early event contributing to GC development.

cancer biology↗

bioRxiv2023

Prefrontal dynamics and encoding of flexible rule switching

Behavioral flexibility, the ability to adjust behavioral strategies in response to changing environmental contingencies and internal demands, is fundamental to cognitive functions. Despite a large body of pharmacology and lesion studies, the precise neurophysiological mechanisms that underlie behavioral flexibility are still under active investigations. This work is aimed to determine the role of a brainstem-to-prefrontal cortex circuit in flexible rule switching. We trained mice to perform a set-shifting task, in which they learned to switch attention to distinguish complex sensory cues. Using chemogenetic inhibition, we selectively targeted genetically-defined locus coeruleus (LC) neurons or their input to the medial prefrontal cortex (mPFC). We revealed that suppressing either the LC or its mPFC projections severely impaired switching behavior, establishing the critical role of the LC-mPFC circuit in supporting attentional switching. To uncover the neurophysiological substrates of the behavioral deficits, we paired endoscopic calcium imaging of the mPFC with chemogenetic inhibition of the LC in task-performing mice. We found that mPFC prominently responded to attentional switching and that LC inhibition not only enhanced the engagement of mPFC neurons but also broadened single-neuron tuning in the task. At the population level, LC inhibition disrupted mPFC dynamic changes and impaired the encoding capacity for switching. Our results highlight the profound impact of the ascending LC input on modulating prefrontal dynamics and provide new insights into the cellular and circuit-level mechanisms that support behavioral flexibility.

neuroscience↗