Biology subjects

Akbarzadeh, M.

Publications and source records attributed to Akbarzadeh, M..

3 recordsLinked to original sources

bioRxiv2026

An Itch Receptor Drives Melanoma

Mas-Related GPCR X4 (MRGPRX4) is a sensory neuron-restricted receptor for cholestatic itch. Here, we identify MRGPRX4 as an unexpected melanoma driver. MRGPRX4 is upregulated in melanoma and is confined to invasive, neural-crest-like and pre-EMT states associated with dedifferentiation and therapy resistance. Ectopic MRGPRX4 expression in mouse melanocytes drives 100% penetrant, highly metastatic melanoma, demonstrating oncogenic behavior. MRGPRX4 promotes melanoma cell proliferation and invasion through basal, ligand-independent, PI3K-AKT-MAPK activation. Multi-omics links MRGPRX4 expression to a mesenchymal/neural-crest-like program that defines a distinct invasive MRGPRX4? niche. Comparing transcptomics of MRGPRX4-driven tumors shows a broad overlap with BRAF/NRAS-driven tumors; however, the MRGPRX4 model also enriches an ECM-rich, invasive neural crest-like melanoma state. MRGPRX4 further remodels the tumor microenvironment toward an immunosuppressive, checkpoint-high state enriched in suppressive myeloid cells. Pharmacologic MRGPRX4 inhibition suppresses basal signaling and limits melanoma growth and invasion. In sum, melanoma exploits MRGPRX4 to acquire an invasive and immunosuppressive phenotype, nominating this somatosensory GPCR as a promising therapeutic target.

cancer biology↗

bioRxiv2024

Integrative analysis of patient-derived tumoroids and ex vivo organoid modeling of ARID1A loss in bladder cancer reveals therapeutic molecular targets

Somatic mutations in ARID1A (AT-rich interactive domain-containing protein 1A) are present in approximately 25% of bladder cancers (BC) and are associated with poor prognosis. With a view to discover effective treatment options for ARID1A-deficient BC patients, we set out to identify targetable effectors dysregulated consequent to ARID1A deficiency. Integrative analyses of ARID1A depletion in normal organoids and data mining in publicly available datasets revealed upregulation of DNA repair and cell cycle-associated genes consequent to loss of ARID1A and identified CHEK1 (Checkpoint kinase 1) and chromosomal passenger complex member BIRC5 (Baculoviral IAP Repeat Containing 5) as therapeutically drug-able candidate molecular effectors. Ex vivo treatment of patient-derived BC tumoroids with clinically advanced small molecule inhibitors targeting CHEK1 or BIRC5 was associated with increased DNA damage signalling and apoptosis, and selectively induced cell death in tumoroids lacking ARID1A protein expression. Thus, integrating public datasets with patient-derived organoid modelling and ex-vivo drug testing can uncover key molecular effectors and mechanisms of oncogenic transformation, potentially leading to novel therapeutic strategies. Our data point to ARID1A protein expression as a suitable candidate biomarker for the selection of BC patients responsive to therapies targeting BIRC5 and CHEK1.

cancer biology↗

bioRxiv2021

A two-color haploid genetic screen identifies novel host factors involved in HIV latency

To identify novel host factors as putative targets to reverse HIV latency, we performed an insertional mutagenesis genetic screen in a latently HIV-1-infected pseudo-haploid KBM7 cell line (Hap-Lat). Following mutagenesis, insertions were mapped to the genome and bioinformatic analysis resulted in the identification of 69 candidate host genes involved in maintaining HIV-1 latency. A select set of candidate genes was functionally validated using shRNA mediated depletion in latent HIV-1 infected J-Lat A2 and 11.1 T cell lines. We confirmed ADK, CHD9, CMSS1, EVI2B, EXOSC8, FAM19A, GRIK5, IRF2BP2, NF1, and USP15 as novel host factors involved in the maintenance of HIV latency. Chromatin immunoprecipitation assays indicated that CHD9, a Chromodomain Helicase DNA-binding protein, maintains HIV latency via direct association with the HIV 5LTR, and its depletion results in increased histone acetylation at the HIV-1 promoter, concomitant with HIV-1 latency reversal. FDA-approved inhibitors 5-Iodotubercidin, Trametinib, and Topiramate, targeting ADK, NF1, and GRIK5, respectively were characterized for their latency reversal potential. While 5-Iodotubercidin exhibited significant cytotoxicity in both J-Lat and primary CD4+ T cells, Trametinib reversed latency in J-Lat cells but not in latently HIV-1-infected primary CD4+ T cells. Crucially, Topiramate reversed latency in cell-line models and latently infected primary CD4+ T cells, without inducing T cell activation or significant toxicity. Thus, using an adaptation of a haploid forward genetic screen, we identified novel and druggable host factors contributing to HIV-1 latency. ImportanceA reservoir of latent HIV-1-infected cells persists in the presence of combination antiretroviral therapy (cART), representing a major obstacle for viral eradication. Reactivation of the latent HIV-1 provirus is part of curative strategies which aim to promote clearance of the infected cells. Using a two-color haploid screen, we identified 69 candidate genes as latency maintaining host factors and functionally validated a subset of 10 of those in additional T-cell based cell line models of HIV-1 latency. We further demonstrated that CHD9 is associated with HIV-1s promoter, the 5LTR while this association is lost upon reactivation. Additionally, we characterized the latency reversal potential of FDA compounds targeting ADK, NF1, and GRIK5 and identify the GRIK5 inhibitor Topiramate as a viable latency reversal agent with clinical potential.

molecular biology↗