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Marques, R. B.

Publications and source records attributed to Marques, R. B..

2 recordsLinked to original sources

Reduced levels of inositol hexakisphosphate kinase (IP6K) impair life-cycle transitions and the intracellular development of Trypanosoma cruzi within human cardiomyocytes

Trypanosoma cruzi is the etiological agent of Chagas disease. During its life cycle, T. cruzi undergoes several key differentiation processes that are essential for its survival. The precise mechanisms that regulate these processes remain elusive, and any interference in this cycle would represent a breakthrough in the development of effective therapy against Chagas disease. Here, after depleting a single IP6K allele of T. cruzi, we observed that key differentiation processes (metacyclogenesis, amastigogenesis and trypomastigogenesis) were profoundly impaired. Epimastigote forms of IP6K-deficient T. cruzi exhibited morphological alterations and reduced metacyclogenesis. IP6K-deficient metacyclic forms had reduced infective potential in human cardiomyocytes. IP6K-deficient amastigote forms showed impaired ability to transform into trypomastigotes, with most of the population egressing from human cardiomyocytes without completing trypomastigogenesis. Together, our results suggest that IP6K is critical to sustain the T. cruzi life cycle. Since disruption of both IP6K alleles was lethal and the primary structure of IP6K shares only [~]25% similarity with its human homolog, this kinase emerges as a promising target for drug development against Chagas disease. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=153 HEIGHT=200 SRC="FIGDIR/small/700787v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1cb37f0org.highwire.dtl.DTLVardef@c59fb8org.highwire.dtl.DTLVardef@791cb7org.highwire.dtl.DTLVardef@14c68fd_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

LncRNA LINC00941 Links Oncogenic KRAS Signaling to Aggressiveness and Chemoresistance in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, driven largely by oncogenic KRAS, yet effective targeted therapies remain unavailable. Long noncoding RNAs (lncRNAs) are emerging as key regulators of tumor biology, but their role in KRAS-driven PDAC is not well defined. To address this gap, we integrated RNA sequencing, exome, and clinical data from The Cancer Genome Atlas (TCGA) and identified 49 long intergenic noncoding RNAs (lincRNAs) differentially expressed according to KRAS status. Among the ten most abundant, LINC00941 and AC006262.5 showed the strongest differential expression in an independent PDAC cohort from the International Cancer Genome Consortium (ICGC). Experimental validation in KRAS-mutant PDAC cell lines and isogenic pancreatic epithelial models confirmed KRAS-dependent regulation of LINC00941, which was consistently upregulated in patient tumors and correlated with poor prognosis in both TCGA and ICGC datasets. Single-cell transcriptomic analysis further demonstrated that LINC00941 is enriched in malignant epithelial populations. Functional assays revealed that LINC00941 silencing impaired migration and invasion, reduced DNA repair capacity, and sensitized PDAC cells to gemcitabine, while having little effect on viability. Supporting these findings, co-expression and enrichment analyses linked LINC00941 to pathways regulating cell adhesion, motility, extracellular matrix organization, and DNA repair. Together, these findings demonstrate that oncogenic KRAS reshapes the lncRNA landscape in PDAC and identify LINC00941 as a KRAS-regulated oncogenic lncRNA that promotes aggressiveness and chemoresistance, highlighting its prognostic value and potential as a therapeutic target.

cancer biology↗