Biology subjects

Gamez-Valero, A.

Publications and source records attributed to Gamez-Valero, A..

3 recordsLinked to original sources

bioRxiv2024

MITF Targets in Gastrointestinal Stromal Tumors: Implication in Autophagy and Extracellular Vesicle Secretion

Previous studies have identified Microphthalmia-associated Transcription Factor (MITF) involvement in regulating Gastrointestinal Stromal Tumors (GIST) growth and cell cycle progression. This study uses Chromatin Immunoprecipitation combined with high-throughput sequencing (ChIP-seq) and RNA sequencing to explore MITF-modulated genes in GIST. Our findings reveal that MITF regulates genes involved in lysosome biogenesis, vesicle generation, autophagy, and mTOR signaling pathways. Comparative transcriptome analysis following MITF silencing in GIST cells shows differential enrichment in mTOR signaling, impacting tumor growth and autophagy. In the context of cancer, the interplay between autophagy and extracellular vesicle release can influence tumor progression and metastasis. We examined MITFs role in autophagy and extracellular vesicle (EV) production in GIST, finding that MITF overexpression increases autophagy, as shown by elevated LC3II levels while silencing MITF disrupts autophagosome and autolysosome formation. Despite no significant changes in EV size or number, MITF silencing notably reduces KIT expression in EV content. KIT secretion in EVs has been linked to GIST metastasis, suggesting that MITF is a crucial target for managing tumor growth and metastasis in GIST.

cancer biology↗

bioRxiv2023

Small RNAs in plasma extracellular vesicles define biomarkers of premanifest changes in Huntington's disease

Despite the advances in the understanding of Huntingtons disease (HD), there is the need for molecular biomarkers to categorize mutation-carriers during the preclinical stage of the disease preceding the functional decline. Small RNAs (sRNAs) are a promising source of biomarkers since their expression levels are highly sensitive to pathobiological processes. Here, using an optimized method for plasma extracellular vesicles (EVs) purification and an exhaustive analysis pipeline of sRNA sequencing data, we show that EV-sRNAs are early downregulated in mutation-carriers, and that this deregulation is associated with premanifest cognitive performance. Seven candidate sRNAs (tRF-Glu-CTC, tRF-Gly-GCC, miR-451a, miR-21-5p, miR-26a-5p, miR-27a-3p, and let7a-5p) were validated in additional subjects, showing a significant diagnostic accuracy at premanifest stages. Of these, miR - 21-5p was significantly decreased over time in a longitudinal study; and miR-21-5p and miR-26a-5p levels correlated with cognitive changes in the premanifest cohort. In summary, the present results suggest that deregulated plasma EV-sRNAs define an early biosignature in mutation carriers with specific species sensing the progression and cognitive changes occurring at the premanifest stage.

neuroscience↗

bioRxiv2020

Platelet miRNA bio-signature discriminates between dementia with Lewy bodies and Alzheimer disease

Dementia with Lewy bodies (DLB) is one of the most common causes of degenerative dementia after Alzheimers disease (AD) and presents pathological and clinical overlap with both AD and Parkinsons disease (PD). Consequently, only one in three DLB cases is diagnosed correctly. Platelets, previously related to neurodegeneration, contain microRNAs (miRNAs) whose analysis may provide disease biomarkers. Here, we profiled the whole platelet miRNA transcriptome from DLB patients and healthy controls. Differentially expressed miRNAs were further validated in three consecutive studies from 2017 to 2019 enrolling 162 individuals, including DLB, AD, and PD patients, and healthy controls. Results comprised a 7-miRNA biosignature, showing the highest diagnostic potential for the differentiation between DLB and AD. Additionally, compared to controls, two miRNAs were down-regulated in DLB, four miRNAs were up-regulated in AD, and two miRNAs were down-regulated in PD. Predictive target analysis identified three disease-specific clusters of pathways as a result of platelet-miRNA deregulation. Our cross-sectional study assesses the identification of a novel, highly specific and sensitive platelet-associated miRNA-based bio-signature, which distinguishes DLB from AD. The paper explainedO_ST_ABSProblemC_ST_ABSDementia with Lewy bodies (DLB) presents pathological and clinical overlap with both Alzheimers (AD) and Parkinsons disease (PD), which impairs its correct diagnosis. Although numerous papers report peripheral biomarkers for AD, well-established biomarkers for DLB distinguishing it from AD are still missing. Platelet miRNA transcriptome was analyzed in several works, but their putative role as disease biomarkers for neurological disorders has not been assessed. It would be of paramount importance to establish a blood-based bio-signature as a minimally invasive mean for DLB diagnosis, improving differentiation of DLB patients from controls and AD. ResultsOur study revealed that platelet miRNAs might be promising biomarkers for the correct diagnosis of DLB stratifying patients in comparison with overlapping disorders, especially AD, and may help to highlight possible disease-related processes. In this cross-sectional study, which includes 162 individuals (DLB, AD, PD and healthy controls), platelet-associated miRNA content was disease group-specific. Three different miRNA sets together with their predicted targeted pathways were defined. ImpactThis study suggests that platelet miRNA may serve as DLB biomarker allowing the correct diagnosis and stratification in an easily-applied manner in clinical settings, and may help to highlight possible disease-related processes.

neuroscience↗