Biology subjects

Vicente, M. M.

Publications and source records attributed to Vicente, M. M..

2 recordsLinked to original sources

bioRxiv2023

Neolactotetraosylceramide: A novel non-invasive urinary biomarker for bladder cancer

There is an urgent need to identify noninvasive biomarkers for bladder cancer. Here, we applied glycan analytics by multiplex capillary gel electrophoresis coupled to laser-induced fluorescence detection (xCGE-LIF) to unravel the global glycosphingolipid (GSL)-glycan profile of primary tumor tissues and urine samples from bladder cancer patients. Thereby, we detected neolactotetraosylceramide (Gal{beta}1-4GlcNAc{beta}1-3Gal{beta}1-4Glc-Cer, nLc4) at significantly increased levels from tumorigenic regions of bladder tissues compared to non-malignant adjacent material (n = 30). Specific expression of nLc4 in cancer tissue was confirmed by immunofluorescence staining. GSL-glycan profiling by xCGE-LIF of urinary exosomes showed that nLc4 is increased in bladder cancer patients (n = 16) when compared to controls (n = 50), with an overall sensitivity of 57% and specificity of 90%. We set-up an ELISA targeting nLc4-containing urinary exosomes from bladder cancer patients (n = 9) and cancer-free individuals (n = 9) demonstrating an overall sensitivity and specificity of 89% and 78%, respectively. SIGNFICANCEThis study shows that levels of nLc4 are significantly elevated in bladder cancer tissue and urinary exosomes of bladder cancer patients. Urinary detection of nLc4 by glycan analytics or ELISA outperforms standard diagnostic modalities, facilitating noninvasive bladder cancer diagnosis. Furthermore, nLc4 bears the potential of being a target for bladder cancer therapy.

cancer biology↗

bioRxiv2019

A CyclinB2-Cas9 fusion promotes the homology-directed repair of double-strand breaks

The discovery of clustered regularly interspaced palindromic repeats (CRISPR), a defense system against viruses found in bacteria, launched a new era in gene targeting. The key feature of this technique is the guiding of the endonuclease Cas9 by single guide RNAs (sgRNA) to specific sequences, where a DNA lesion is introduced to trigger DNA repair. The CRISPR/Cas9 system may be extremely relevant for gene therapy, but the technique needs improvement to become a safe and fully effective tool. The Cas9-induced double-strand break (DSB) is repaired by one of two pathways, the error-prone Non-homologous end joining (NHEJ) or the high-fidelity Homology Direct Repair (HDR). Shifting the repair of the DSB to HDR is challenging, given the efficiency of NHEJ. Here we describe an engineered protein approach to increase knock-in efficiency by promoting the relative increase in Cas9 activity in G2, the phase of the cell cycle where HDR is more active. Cas9 was fused to the degradation domain of proteins known to be degraded in G1. The activity of two chimeric proteins, Geminin-Cas9 and CyclinB2-Cas9, is demonstrated, as well as their cell-cycle-dependent degradation. The chimeras shifted the repair of the DSBs to the HDR repair pathway compared to the commonly used Cas9. The application of cell cycle specific degradation tags could pave the way for more efficient and secure gene editing applications of the CRISPR/Cas9 system.

molecular biology↗