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Biology subjects

Gonzalez-Fernandez, M.

Publications and source records attributed to Gonzalez-Fernandez, M..

3 recordsLinked to original sources

Aurora kinase A is a synthetic lethal target in FANCA-deficient cancers

Loss-of-function genomic alterations in FANCA occur across multiple cancer types, yet no molecularly tailored therapies have successfully exploited this potential vulnerability. Using complementary unbiased approaches, including a genome-wide CRISPR/Cas9 loss-of-function screen and a high-throughput drug screen in isogenic cancer cell-based models, we identified Aurora kinase A (AURKA) as a reproducible synthetic lethal target of FANCA-deficient cancers. Inhibition of AURKA induced chromosomal instability, micronucleation, and early G2/M arrest selectively in FANCA-deficient cells, consistent with an increased reliance on mitotic checkpoint control. Mechanistically, FANCA deficiency is associated with an elevated AURKA expression at both the transcriptomic and protein levels, and with an upregulation of mitotic spindle and G2/M checkpoint gene signatures. Analysis of large-scale cancer genomics datasets, including over 650,000 clinically sequenced tumors, confirms that FANCA is the most frequently altered Fanconi anemia pathway gene across cancers, and that Fanconi anemia-defective tumors exhibit an increased tumor mutational burden and genomic instability. Collectively, our findings point to AURKA inhibition as a promising precision treatment strategy in FANCA-deficient cancers and provide a rationale to further explore this strategy in the clinic.

cancer biology↗

TAOK1 regulates chemo- and radiosensitivity in BRCA1/2-deficient tumors

BRCA1/2-deficient cells are hypersensitive to replication stress- and DNA-damage-inducing agents such as poly(ADP-ribose) polymerase inhibitors (PARPi), platinum drugs, and ionizing radiation (IR), largely due to impaired homologous recombination repair and replication fork (RF) protection. The precise mechanisms underlying RF vulnerability in the absence of BRCA1/2 remain incompletely understood, however. Here, we identify Thousand And One Amino Acid Kinase 1 (TAOK1) as a novel regulator of RF dynamics that sensitizes BRCA1/2-deficient cells to both PARPi and IR. Unlike established DNA repair factors, such as PARG or the 53BP1-RIF1-shieldin-CST pathway, which mediate PARPi sensitivity while protecting cells against IR, TAOK1 promotes RF degradation and suppresses post-replicative damage repair. TAOK1 depletion stabilizes RFs and reduces replication-associated DNA damage in BRCA1/2-deficient cells, thereby conferring therapy resistance. Interestingly, we found that TAOK1 functions in RF regulation to be independent of its kinase activity. Instead, it interacts with PCNA and regulates ISG15 levels and thereby affects RF stability. Our findings reveal TAOK1 as a non-canonical mediator of therapy sensitivity in BRCA1/2-deficient tumors. TeaserTAOK1 controls replication fork stability through PCNA and ISG15, affecting therapy response in BRCA1/2-deficient cancers.

cancer biology↗

Harnessing homeostatically active RhoC at cell junctions preserves human endothelial barrier function during inflammation

Rho GTPases are molecular targets of bacterial toxins that modulate their enzymatic activity. RhoA, RhoB and RhoC are almost identical and play critical roles in generating actomyosin-mediated contractile forces that cause endothelial hyperpermeability during inflammation. Searching for new treatments to modulate endothelial integrity, we demonstrate that the specific and simultaneous activation of these three Rho GTPases with a chimeric recombinant toxin does not induce cell contraction but enhances homeostatic endothelial barrier function, increases reticular adherens junctions and preserves the microvascular endothelium in response to pathological inflammatory challenges in vitro and in vivo. This pro-barrier effect is specifically mediated by RhoC, whose activity is increased by cell confluence. The uniqueness of RhoC relies on an arginine 188 within its hypervariable region that determines its junctional localization, high homeostatic activity, and barrier-protective function. Quantitative proteomics revealed that RhoC regulates the expression of myosin light chain proteins and junction-stabilizing actomyosin. Thus, harnessing the activity of RhoC represents a potential therapy for strengthening endothelial barriers during pathological inflammation.

cell biology↗