Biology subjects

Blanco, M. A.

Publications and source records attributed to Blanco, M. A..

7 recordsLinked to original sources

bioRxiv2025

Combinatorial inhibition of LSD1 and Menin induces therapeutic differentiation in AML

Acute myeloid leukemia (AML) is characterized by differentiation arrest and uncontrolled proliferation. Differentiation therapy aims to treat AML by de-repressing latent myeloid maturation programs to induce cell cycle arrest and subsequent cell death. This approach is curative in the promyelocytic AML subtype, but has met with limited success in other subtypes. Genes such as LSD1 have emerged as intriguing non-APL AML differentiation therapy targets, but results as monoagents in clinical trials have been mixed. Here, we performed differentiation-specific CRISPR screens to identify targets whose inhibition synergizes with LSD1 inhibition to induce terminal differentiation of non-APL AML cells. Intriguingly, the MLL co-factor Menin scored as the top hit. Using cell lines, primary patient samples, and mouse AML models, we find that dual inhibition of LSD1 and Menin is a highly promising approach for differentiation therapy. Mechanistically, we determine that inhibition of Menin downregulates drivers of proliferation and stemness such as MEIS1, and inhibition of LSD1 induces inflammatory and interferon-related pro-myeloid differentiation expression programs. Surprisingly, we find that this combination is effective in selected AML models without mutations in MLL or NPM1, thus nominating dual inhibition of LSD1 and Menin as an attractive therapeutic approach for a mutationally diverse set of non-APL AMLs. HighlightsO_LIInhibition of LSD1 and Menin synergizes to induce differentiation of MLL-r and MLL-WT AMLs. C_LIO_LIInhibition of Menin downregulates drivers of proliferation and stemness. C_LIO_LIInhibition of LSD1 induces differentiation-associated inflammatory and interferon responses. C_LIO_LILSD1 and Menin occupy different areas of the genome. C_LI

cancer biology↗

bioRxiv2024

APC coordinates GSK3 phosphorylation of SETD8 to suppress colorectal cancer

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths with increasing incidence globally. Mutations in the tumor suppressor APC initiate CRC at least in part by preventing the GSK3 kinase from phosphorylating {beta}-CATENIN, leading to its constitutive stabilization and transactivation of mitogenic target genes. While the importance of {beta}-CATENIN phosphorylation by GSK3 is well-established, APC regulation of GSK3 activity upon other targets with potential oncogenic relevance are not understood. Here, we identify the H4K20 methyltransferase SETD8 as target of APC-coordinated GSK3 phosphorylation in the intestinal epithelium. We found that phosphorylation by GSK3 restrains the oncogenic activity of SETD8, with loss of phosphorylation sensitizing mice to oncogenic insults. Mechanistically, phosphorylation alters the role of SETD8 in transcriptional regulation, most notably by preventing it from activating oncogenic YAP signaling and a fetal-like transcriptional program. These results underscore the importance of SETD8 in CRC and represent a novel {beta}-CATENIN -independent oncogenic consequence of APC loss. SignificanceGSK3 is thought to restrain colorectal cancer primarily by phosphorylation of {beta}-CATENIN. We show that GSK3 also phosphorylates SETD8, preventing SETD8 activation of oncogenic programs including YAP-driven fetal-like gene expression.

cancer biology↗

bioRxiv2024

Exploring symbiotic legume-rhizobia relationships across tropical species

O_LIThe nitrogen-fixing symbiosis with rhizobia significantly contributes to the successful establishment of legumes in tropical environments. Here, we explored the symbiotic interactions between legumes and rhizobia across 109 tropical species. C_LIO_LIWe evaluated the presence of root nodules in 72 genera spanning four Fabaceae subfamilies, encompassing 53% of the genera in Costa Rica and approximately 9.4% globally. Our analysis revealed root nodules in 78% of the species belonging to Caesalpinioideae (67%) and Papilionoideae (84%). Also, we formulated a predictive model for nodulation in legumes, with fine-root color and flower symmetry as the main predictor criteria. C_LIO_LINodulating taxa consistently presented higher N levels in tissues, thinner roots, and a pronounced phylogenetic influence on nodulation. We also identified the bacterial genera associated with all nodulating legumes. Caesalpinioideae formed symbiotic relationships with ten rhizobial genera, whereas Papilionoideae were associated with only four. Bradyrhizobium emerged as the predominant symbiont in nodules, while Rhizobium, Mesorhizobium, Agrobacterium, Paraburkholderia, and Cupriavidus exhibited a more restricted host range. Furthermore, genomic analysis suggests that 15 out of the 22 sequenced rhizobial strains may represent novel species. C_LIO_LIOur study enhances the understanding of the different dimensions that comprise legume-rhizobia interactions, incorporating a diverse array of previously unexamined tropical forest legume taxa. C_LI

plant biology↗

bioRxiv2023

Forward genetic screening in engineered colorectal cancer organoids identifies novel regulators of metastasis

Cancer is the second leading cause of death globally, due primarily to metastatic dissemination and colonization of distal sites. Recurrent genetic drivers of metastasis are elusive, suggesting that, unlike the stereotyped mutations promoting primary tumor development, drivers of metastasis may be variable. Here, we interrogate pathways governing metastasis through CRISPR/Cas9-based forward genetic screening in a genetically defined colorectal adenocarcinoma tumor organoid (tumoroid) model using ex vivo invasion screens and orthotopic, in vivo screens for gain of metastatic potential. We identify Ctnna1 and Bcl2l13 as bona fide metastasis suppressors. CTNNA1 loss promotes carcinoma cell invasion and migration through an atypical EMT-like mechanism, whereas BCL2L13 loss promotes cell survival after extracellular matrix detachment and non-cell-autonomous macrophage polarization. Ultimately, this study provides a proof-of-principle that high-content forward genetic screening can be performed in tumor-organoid models in vivo and identifies novel regulators of colon cancer metastasis.

cancer biology↗

bioRxiv2022

APC and P53 mutations synergize to create a therapeutic vulnerability to NOTUM inhibition in advanced colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer-related deaths globally, with the majority of cases initiated by inactivation of the APC tumor suppressor. This results in the constitutive transcriptional activation of the canonical WNT signal transduction pathway effector {beta}-Catenin, along with induction of WNT feedback inhibitors, including the extracellular palmitoleoyl-protein carboxylesterase NOTUM. Here, we show that NOTUM retains cell-autonomous tumor suppressive activity in APC-null adenomatous lesions despite constitutive {beta}-Catenin activation. Strikingly, we find that NOTUM becomes an obligate oncogene upon subsequent P53 inactivation during the adenoma-adenocarcinoma transition, and that these phenotypes are WNT-independent, resulting from differential activity of NOTUM upon its enzymatic targets Glypican 1 and 4 in early vs. late-stage disease, respectively. Ultimately, preclinical mouse models of CRC and human tumoroid cultures demonstrate that pharmacological inhibition of NOTUM is highly effective in arresting primary adenocarcinoma growth and inhibiting metastatic colonization of distal organs. The finding that a single agent targeting an extracellular enzyme is effective in treating highly aggressive tumors make NOTUM a novel therapeutic vulnerability in advanced colorectal adenocarcinomas.

cancer biology↗

bioRxiv2022

CRISPR loss of function screening to identify genes involved in human primordial germ cell-like cells development

Despite our increasing knowledge of molecular mechanisms guiding various aspects of human reproduction, those underlying human primordial germ cell (PGC) development remain largely unknown. Here, we conducted custom CRISPR screening in an in vitro system of hPGC-like cells (hPGCLCs) to identify genes required for acquisition and maintenance of PGC fate in humans. Amongst our candidates, we identified TCL1A, an AKT coactivator. Functional assessment in our in vitro hPGCLCs system revealed that TCL1A played a critical role in later stages of hPGCLC development. Moreover, we found that TCL1A loss reduced AKT-mTOR signaling, downregulated expression of genes related to translational control, and subsequently led to a reduction in global protein synthesis and proliferation. Together, our study identifies novel regulators critical for hPGCLC development and demonstrates the importance of translational control in human reproduction.

developmental biology↗

bioRxiv2021

Chromatin state barriers enforce an irreversible mammalian cell fate decision

Stem and progenitor cells have the capacity to balance self-renewal and differentiation. Hematopoietic myeloid progenitors replenish more than 25 billion terminally differentiated neutrophils every day under homeostatic conditions and can increase this output in response to stress or infection. At what point along the spectrum of maturation do progenitors lose capacity for self-renewal and become irreversibly committed to differentiation? Using a system of conditional myeloid development that can be toggled between self-renewal and differentiation, we interrogated determinants of this point of no return in differentiation commitment. Irreversible commitment is due primarily to loss of open regulatory site access and disruption of a positive feedback transcription factor activation loop. Restoration of the transcription factor feedback loop extends the window of cell plasticity and alters the point of no return. These findings demonstrate how the chromatin state enforces and perpetuates cell fate and identifies potential avenues for manipulating cell identity. HighlightsO_LIThere exists a point of irreversible commitment in granulocytic differentiation C_LIO_LIChromatin state dynamics establish the transition from self-renewal to differentiation commitment C_LIO_LIReduced chromatin accessibility underlies an irreversible loss of regulatory site access C_LIO_LIRestoration of a transcription factor feedback loop alters the differentiation commitment point C_LI

molecular biology↗