Search bioRxiv⌕ Search

Biology subjects

Sule, N.

Publications and source records attributed to Sule, N..

3 recordsLinked to original sources

Sex Differences in DNA Methylation and Gene Expression Reveal Distinct Molecular Programs in Muscle-Invasive Bladder Cancer

Sex differences in muscle-invasive bladder cancer (MIBC) incidence and outcomes are well established, but the underlying epigenetic mechanisms remain poorly understood. We integrated genome-wide DNA methylation and RNA sequencing to define sex-associated epigenetic and transcriptional programs in human MIBC and evaluated their conservation in the N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) mouse model. Male tumors exhibited substantially broader DNA methylation remodeling, whereas female tumors showed prominent epithelial-mesenchymal transition (EMT) and mitotic programs. These sex-associated patterns were recapitulated in BBN tumors, with substantial conservation of human MIBC methylation changes and transcriptional programs. Cross-species integration identified conserved methylation-regulated genes, including ADAMTS12, ONECUT2, and PPP2R2C, whose expression increased following pharmacologic DNA demethylation and was associated with disease progression. Given the potential role of sex chromosomes in sex-associated molecular differences in MIBC, we evaluated X-chromosome inactivation escape and Y-linked gene expression. Reduced expression of an X-chromosome inactivation escape signature was independently associated with shorter overall survival, while reduced Y-linked gene expression was associated with immune activation. Together, these findings identify conserved sex-associated epigenetic programs in MIBC and demonstrate distinct methylation, transcriptional, and sex-chromosome features that may contribute to sex differences in bladder cancer biology and clinical outcomes.

cancer biology↗

Binary partitioning of human brain organization due to divergent human cytoskeletal evolution

CHRFAM7A is a biallelic uniquely human fusion gene present in 99.3% of humans. The direct and inverted alleles likely emerged independently in Africa and East Asia. We uncovered that the inverted allele regulates ULK4 expression through genetic epistasis. The increase in long to short ULK4 isoform ratio enhances -tubulin acetylation leading to microtubule (MT) cytoskeleton phenotypes (cell body: microtubule rich projections; neurite: de-bundling; growth cone: fanning with MT invasion). The MT cytoskeleton gain of function enhances neuronal arborization and functional connectivity in the human brain. Considering that the previously reported direct allele leads to actin cytoskeleton gain of function, we propose that CHRFAM7A alleles represent binary human genetic background through divergent evolution of the cytoskeleton. In the human brain the two alleles represent distinct brain organization: the direct allele enhances microstructure as measured by diffusion tensor imaging while the inverted allele increases functional connectivity with increased small world propensity. The two types of brain organization likely represent different susceptibility to neuropsychiatric disease and may underlie the allelic disease associations. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=195 HEIGHT=200 SRC="FIGDIR/small/725959v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@a84e75org.highwire.dtl.DTLVardef@1b712d9org.highwire.dtl.DTLVardef@367c01org.highwire.dtl.DTLVardef@1074dc4_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Syngeneic model of carcinogen-induced tumor mimics basal/squamous, stromal-rich, and neuroendocrine molecular and immunological features of muscle-invasive bladder cancer

BackgroundBladder cancer is a heterogenous disease and the emerging knowledge on molecular classification of bladder tumors could have impact to drive treatment decisions based on molecular subtype. Pre-clinical models representing each subtype are needed to test novel therapies. Carcinogen-induced bladder cancer models represent heterogeneous, immune-competent, pre-clinical testing options with many features found in the human disease. MethodsInvasive bladder tumors were induced in C57BL/6 mice when continuously exposed to N-butyl-N-(4-hydroxbutyl nitrosamine) (BBN) in the drinking water. Tumors were excised and serially passed by subcutaneous implantation into sex-matched syngeneic C57BL/6 hosts. Eight tumor lines were developed and named BBN-induced Urothelium Roswell Park (BURP) tumor lines. The BURP lines were characterized by applying consensus molecular classification to RNA expression, histopathology, and immune profiles by CIBERSORT. Two lines were further characterized for cisplatin response. ResultsEight BURP tumor lines were established with 3 male and 3 female BURP tumor lines, having the basal/squamous (BaSq) molecular phenotype and morphology. BURP-16SR was established from a male mouse and has a stromal-rich (SR) molecular phenotype and a sarcomatoid carcinoma morphology. BURP-19NE was established from a male mouse and has a neuroendocrine (NE)-like molecular phenotype and poorly differentiated morphology. The established BURP tumor lines have unique immune profiles with fewer immune infiltrates compared to their originating BBN-induced tumors. The immune profiles of the BURP tumor lines capture some of the features observed in the molecular classifications of human bladder cancer. BURP-16SR growth was inhibited by cisplatin treatment, while BURP-24BaSq did not respond to cisplatin. ConclusionsThe BURP tumor lines represent several molecular classifications, including basal/squamous, stroma-rich, and NE-like. The stroma-rich (BURP-16SR) and NE-like (BURP-19NE) represent unique immunocompetent models that can be used to test novel treatments in these less common bladder cancer subtypes. Six basal/squamous tumor lines were established from both male and female mice. Overall, the BURP tumor lines have less heterogeneity than the carcinogen-induced tumors and can be used to evaluate treatment response without the confounding mixed response often observed in heterogeneous tumors. Additionally, basal/squamous tumor lines were established and maintained in both male and female mice, thereby allowing these tumor lines to be used to compare differential treatment responses between sexes.

cancer biology↗