Biology subjects

Facanha, A. R.

Publications and source records attributed to Facanha, A. R..

3 recordsLinked to original sources

bioRxiv2026

Tumour metabolic heterogeneity discrimination by video thermometry and concanamycin-sensitive proton pump measurements: Old tools integrated into advanced preclinical studies

AO_SCPLOWBSTRACTC_SCPLOWPhenotypic, genetic and metabolic tumour heterogeneity is a major factor contributing to cancer progression, metastasis, and resistance to therapy. Distinctive thermal and proton flux patterns can occur in cancer cells as a function of variations in the metabolic rate of the tumour mass, tumour margins, and normal tissues, which can be detected by video thermometry (VTM) as well as by Scanning Ion-selective Electrode Techniques (SIET). This study presents distinct thermal patterns associated with tumour heterogeneity observed in canine mammary cancer using VTM and investigate the correlation between these thermometric signatures with metabolic changes related to V-ATPase activity by comparing real-time VTM data with that from concanamycin-sensitive ATP hydrolysis and cell proton flux measurements. The results demonstrate that integrating SIET and VTM data sets can reveal metabolic signatures to assist the diagnosis, surgery and therapeutic monitoring. Considering the breast cancer hallmarks conservation in human, canines and other mammals, this study provides a first bioenergetic proof-of-concept for the potential of the integration of the VTM technology with enzymatic and electrophysiological analyses sensitive to concanamycin for the development of more effective diagnostic, prognostic and therapeutic approaches in veterinary as well as in preclinical medical studies.

cancer biology↗

bioRxiv2021

Molecular Prognosis of Endometrial Adenocarcinoma by Expression Patterns of the V-ATPase C1 Subunit

O_LIComparative analysis of expression patterns of ATP6V1C1 encoding C1 subunit of V-H+-ATPase revealed that molecular alterations correlated with endometrial cancer of better prognosis were grouped with low ATP6V1C1 expression while those correlated with worse prognosis were clustered with high ATP6V1C1 expression levels. C_LIO_LIExpression patterns of C1 subunit in endometrial adenocarcinoma are associated with molecular malignancy signatures shared by histological subtypes of highest mortality rate suggesting that G3 adenocarcinoma exhibits molecular changes resembling endometrial serous carcinoma. C_LIO_LIATP6V1C1 might serve as novel prognostic marker allowing identification of targetable pathways for high-risk endometrial cancer. C_LI

cancer biology↗

bioRxiv2019

Mitochondrial ascorbate synthesis acts as a pro-oxidant pathway and down-regulate energy supply in plants

Attempts to improve the ascorbate (AsA) content of plants are still dealing with the limited understanding of why exists a wide variability of this powerful anti-oxidant molecule in different plant sources, species and environmental situations. In plant mitochondria, the last step of AsA synthesis is catalyzed by the enzyme L-galactone-1,4-lactone dehydrogenase (L-GalLDH). By using GalLDH-RNAi silencing plant lines, biochemical and proteomic approaches, we here discovered that, in addition to accumulate this antioxidant, mitochondria synthesize AsA to down-regulate the respiratory activity and the cellular energy provision. The work reveals that the AsA synthesis pathway within mitochondria is a branched electron transfer process that channels electrons towards the alternative oxidase, interfering with conventional electron transport. It was unexpectedly found that significant hydrogen peroxide is generated during AsA synthesis, which affects the AsA level. The induced AsA synthesis shows proteomic alterations of mitochondrial and extra-mitochondrial proteins related to oxidative and energetic metabolism. The most identified proteins were known components of plant responses to high light acclimation, programmed cell death, oxidative stress, senescence, cell expansion, iron and phosphorus starvation, different abiotic stress/pathogen attack responses and others. We propose that changing the electron flux associated with AsA synthesis might be part of a new mechanism by which the L-GalLDH enzyme would adapt plant mitochondria to fluctuating energy demands and redox status occurring under different physiological contexts.

plant biology↗