Biology subjects

Canarutto, G.

Publications and source records attributed to Canarutto, G..

3 recordsLinked to original sources

bioRxiv2024

The DNA-repair protein APE1 participates with hnRNPA2B1 to motif-enriched and prognostic miRNA secretion

The base excision repair (BER) Apurinic/apyrimidinic endonuclease 1 (APE1) enzyme is endowed with several non-repair activities including miRNAs processing. APE1 is overexpressed in many cancers but its causal role in the tumorigenic processes is largely unknown. We recently described that APE1 can be actively secreted by mammalian cells through exosomes. However, APE1 role in EVs or exosomes is still unknown, especially regarding a putative regulatory function on small non-coding RNAs vesicular secretion. Through dedicated transcriptomic analysis on cellular and vesicular small RNAs of different APE1-depleted cancer cell lines, we found that miRNAs loading into EVs is a regulated process, dependent on APE1, distinctly conveying RNA subsets into vesicles. We identified APE1-dependent secreted miRNAs characterized by enriched sequence motifs and possible binding sites for APE1. In 33 out of 34 APE1-dependent-miRNA precursors, we surprisingly found EXO-motifs and proved that APE1 cooperates with hnRNPA2B1 for the EV-sorting of a subset of miRNAs, including miR-1246, through direct binding to GGAG stretches. Using TCGA-datasets, we showed that these miRNAs identify a signature with high prognostic significance in cancer. In summary, we provided evidence that APE1 is part of the protein cargo of secreted EVs, suggesting a novel post-transcriptional role for this ubiquitous DNA-repair enzyme that could explain its role in cancer progression.

molecular biology↗

bioRxiv2023

A common druggable signature of oncogenic CMYC, mutant KRAS and mutant p53 reveals functional redundancy and competition of the oncogenes in cancer

Major driver oncogenes CMYC, mutant KRAS and mutant TP53 often co-exist and cooperate in promoting human neoplasia. By CRISPR-Cas9-mediated downregulation we determined their proteomics and transcriptomics downstream programs in a panel of cell lines with activated either single or three oncogenes - in cancers of lung, colon and pancreas. This allowed to define and screen the oncogenes common functional program for anti-cancer target candidates, and find protocols which efficiently kill cancer cells and organoids by targeting pathways represented by a signature of three genes: RUVBL1, HSPA9 and XPO1. We found that these genes were controlled by the driver oncoproteins in a redundant or competitive manner, rather than by cooperation. Each oncoprotein individually was able to upregulate the three target genes, while upon oncogene co-expression each target was controlled preferably by a specific oncoprotein which reduced the influence of the others. Mechanistically this redundancy was mediated by parallel routes of the target gene activation - as in the case of mutant KRAS signaling to C-JUN and GLI-2 transcription factors bypassing CMYC, and by competition - as in the case of mutant p53 and CMYC competing for biding to the target promoters. The transcriptomics data from the cell lines and patient samples indicate that the redundancy of the oncogenic programs is a broad phenomenon which may comprise even a majority of the genes dependent on the oncoprotein, as shown for mutant p53 in colon and lung cancer cell lines. Nevertheless, we demonstrate that the redundant oncogene programs harbor targets of efficient anti-cancer drug combinations, bypassing limitations of a direct oncoprotein inhibition.

cancer biology↗

bioRxiv2023

HuR modulation with tanshinone mimics impairs LPS response in murine macrophages

Lipopolysaccharide exposure to macrophages induces an inflammatory response that is heavily regulated at the transcriptional and post-transcriptional levels. HuR (ELAVL1) is an RNA binding protein that binds and regulates the maturation and half-life of AU/U rich elements (ARE) containing cytokines and chemokines transcripts, mediating the LPS-induced response. Here we investigated how and to what extent small molecule tanshinone mimics (TMs) inhibiting HuR-RNA interaction counteract LPS stimulus in macrophages. We show TMs exist in solution in keto-enolic tautomerism and that, by molecular dynamic calculations, the orto quinone form is the bioactive species interacting with HuR and inhibiting its binding mode vs mRNA targets. A chemical blockage of the diphenolic, reduced form as a diacetate caused the loss of activity of TMs in vitro but resulted to prodrug-like activity in vivo. The murine macrophage cell line RAW264.7 was treated with LPS and TMs, and the modulation of cellular LPS-induced response was monitored by RNA and Ribonucleoprotein immunoprecipitation sequencing. Correlation analyses indicated that LPS induced a strong coupling between differentially expressed genes and HuR-bound genes, and that TMs reduced such interactions. Functional annotation addressed a specific set of genes involved in chemotaxis and immune response, such as Cxcl10, Il1b, Cd40, and Fas, with a decreased association with HuR, a reduction of their expression and protein secretion. The same effect was observed in primary murine bone marrow-derived macrophages, and in vivo in an LPS induced peritonitis model, in which the serum level of Cxcl10 and Il1b was strongly reduced, endowing TMs such as TM7nox with remarkable anti-inflammatory properties in vivo.

molecular biology↗