Biology subjects

Suarez-Bonnet, A.

Publications and source records attributed to Suarez-Bonnet, A..

4 recordsLinked to original sources

bioRxiv2024

Glutaminase as a metabolic target of choice to counter acquired resistance to Palbociclib by colorectal cancer cells

Several mechanisms of resistance of cancer cells to cyclin-dependent kinase inhibitors (CDKi) have been identified, including the upregulation of metabolic regulators such as glutaminase. However, whether such mechanisms and targets are optimal has not been determined. Here, we have systematically analyzed metabolic reprogramming in colorectal cancer cells exposed to Palbociclib, a CDKi selectively targeting CDK4/6, or Telaglenestat, a selective glutaminase inhibitor. Through multiple approaches, we show that Palbociclib and Telaglenestat elicit complementary metabolic responses and are thus uniquely suited to counter the metabolic reprogramming induced by the reciprocal drug. As such, while Palbociclib induced reduced tumor growth in vivo, and Telaglenestat did not show a significant effect, the drug combination displayed a strong synergistic effect on tumor growth. Likewise, initial responses to Palbociclib were followed by signs of adaptation and resistance, which were prevented by combining Palbociclib with Telaglenestat. In conclusion, combination with Telaglenestat optimally forestalls acquired resistance to Palbociclib in cancer cells.

cancer biology↗

bioRxiv2023

Blimp-1 and c-Maf regulate common and unique gene networks to protect against distinct pathways of pathobiont-induced colitis

Intestinal immune responses to commensals and pathogens are controlled by IL-10 to avoid intestinal immune pathology. We show that the transcription factors Blimp-1 (Prdm-1) and c-Maf are co-dominant regulators of Il10 in Foxp3+ regulatory T cells, but also negatively regulate proinflammatory cytokines in effector T cells. Mice with T cell-specific deletion of Prdm-1, Maf or the combination of both transcription factors did not develop inflammatory intestinal pathologies at the steady state. Double deficient Prdm1fl/flMaffl/flCd4Cre mice infected with Helicobacter hepaticus developed severe colitis with a major increase in TH1/NK/ILC1 effector genes in lamina propria leucocytes (LPLs), while Prdm1fl/flCd4Cre and Maffl/flCd4Cre mice showed mild/moderate pathology and a less-marked Type I effector response. LPLs from infected Maffl/flCd4Cre mice showed increased Il17a expression and an accompanying increase in granulocytes and myeloid cells, which was less marked in Prdm1fl/flMaffl/flCd4Cre mice, with increased T cell-myeloid-neutrophil interactions inferred from scRNA-seq analysis and confirmed by immunofluorescent analysis of colon sections. Genes over-expressed in human IBD showed differential expression in the LPL from infected mice in the absence of Prdm1 or Maf, revealing potential pathobiologic mechanisms of human disease.

immunology↗

bioRxiv2023

Palmitoyl transferase ZDHHC20 promotes pancreatic cancer metastasis

Metastasis is one of the defining features of pancreatic ductal adenocarcinoma (PDAC) that contributes to poor prognosis. In this study, the palmitoyl transferase ZDHHC20 was identified in an in vivo shRNA screen as critical for metastatic outgrowth, with no effect on proliferation and migration in vitro, or primary PDAC growth in mice. This phenotype is abrogated in immunocompromised animals, and in animals with depleted natural killer (NK) cells, indicating that ZDHHC20 affects the interaction of tumour cells and the innate immune system. Using a chemical genetics platform for ZDHHC20-specific substrate profiling, a number of novel substrates of this enzyme were identified. These results describe a role for palmitoylation in enabling distant metastasis that could not have been detected using in vitro screening approaches and identify potential effectors through which ZDHHC20 promotes metastasis of PDAC.

cancer biology↗

bioRxiv2022

USP7 inactivation suppresses APC-mutant intestinal hyperproliferation and tumor development

Truncating mutation of the tumor suppressor gene adenomatous polyposis coli (APC) is the hallmark of colorectal cancer (CRC), resulting in constitutive WNT activation. Despite decades of research, targeting WNT signaling in cancer remains challenging due to its essential role in normal stem cell maintenance. We have previously shown that the deubiquitinating enzyme USP7 is a tumor-specific WNT activator in APC-truncated cells by deubiquitinating and stabilizing {beta}-catenin, but its role in gut tumorigenesis is unknown. Here we show in vivo that deletion of Usp7 in Apc-truncated mice inhibits crypt hyperproliferation and intestinal tumor development. Importantly, intestine-specific Usp7 mutation does not yield any phenotype in wildtype animals, indicating that its loss is well tolerated. Unexpectedly, prolonged deletion of Usp7 in Apc+/- intestine induces varying degrees of colitis. Treatment with a USP7 inhibitor suppresses growth of patient-derived cancer organoids in vitro and of xenografts carrying APC truncations. We propose that USP7 inhibition may be efficacious for tumor-specific therapy of sporadic APC-mutated CRC, while patients with germline APC mutations should not receive such treatment. HighlightsO_LIUsp7 deletion in Apc-truncated mice reduces intestinal tumor development. C_LIO_LIIntestine-specific Usp7 mutation mutation has no phenotype in wildtype animals. C_LIO_LITreatment with Usp7 inhibitor suppresses growth of patient-derived cancer organoids carrying Apc truncations in vitro and of xenografts. C_LI

cancer biology↗