Biology subjects

Vilas, J. M.

Publications and source records attributed to Vilas, J. M..

4 recordsLinked to original sources

bioRxiv2024

Transcriptional repression of SOX2 by p53 in cancer cells regulates cell identity and migration

During cancer development and progression, many genetic alterations lead to the acquisition of novel features that confer selective advantage to cancer cells and that resemble developmental programs. SOX2 is one of the key pluripotency transcription factors, expressed during embryonic development and active in adult stem cells. In cancer, SOX2 is frequently dysregulated and associated with tumor stemness and poor patient survival. SOX2 expression is suppressed in differentiated cells by tumor suppressor proteins that form a transcriptional repressive complex. We previously identified some of these proteins and found that their absence combined with deficiency in Trp53, leads to maximal dysregulated expression of Sox2. Using cancer cell lines of different origin and with different p53 status, we show here that manipulating TP53 to restore or decrease its activity results in repression or induction of SOX2, respectively. Mechanistically, we observed that the regulation of SOX2 expression by TP53 is transcriptional and identified Trp53 bound to the promoter region and the SRR2 enhancer of Sox2. Forcing high levels of SOX2 in cancer cells leads to morphological changes that molecularly correspond to the acquisition of a more mesenchymal phenotype correlating with an increased migratory capacity. Finally, the analysis of human breast cancer samples shows that this correlation between TP53 status, levels of expression of SOX2 and a more metastatic phenotype is also observed in cancer patients. Our results support the notion that lack of TP53 in tumor cells results in deregulated expression of developmental gene SOX2 with phenotypic consequences related with increased malignization. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/623640v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@15e8df8org.highwire.dtl.DTLVardef@baa5e5org.highwire.dtl.DTLVardef@1e181aaorg.highwire.dtl.DTLVardef@7c3f0_HPS_FORMAT_FIGEXP M_FIG C_FIG Novelty and ImpactOur work demonstrates that TP53 regulates transcriptionally SOX2 through binding to its promoter and the SRR2 enhancer. Increased expression of SOX2 promotes an EMT and increased migration. Breast cancer patients with genetic alteration of TP53 show increased levels of SOX2 and a more metastatic phenotype. This work is a key demonstration of an additional effect of genetic alterations of TP53, leading to de-repression of SOX2 and alteration of cancer cell plasticity with important phenotypic consequences.

cancer biology↗

bioRxiv2023

Field and genetic evidence support the photosynthetic performance index (PIABS) as an indicator of rice grain yield

The effective increase of the rice breeding process for grain yield could be sustained by developing efficient tools to accelerate plant selection through the rapid determination of reliable predictors. Here, we have described different associations between grain yield and photosynthetic parameters simply and fast obtainable by a non-invasive technique in flag leaf during the anthesis stage. Among the analyzed photosynthetic parameters, the photosynthetic performance index (PIABS) stood out for its strong association with grain yield. A genome-wide association analysis determined in plants from a rice diversity panel at tillering stage indicated the presence of a quantitative trait locus on chromosome 9 characterized by a set of candidate chloroplastic genes with contrasting haplotypes for PIABS. An analysis of these haplotypes indicated a separation into two groups. One with haplotypes linked to high values of PIABS, which were associated almost exclusively with Japonica spp. subpopulations, and another with haplotypes linked to low values of PIABS, which were associated exclusively with Indica spp. subpopulations. Genotypes of the Japonica spp. subpopulations showed high values in panicle weight, a yield components parameter, compared with the Indica spp. subpopulations genotypes. The results of this work suggested that PIABS could be an early predictor of grain yield at the tillering stage in rice breeding processes.

plant biology↗

bioRxiv2020

Genetic structure of Photosystem II functionality in rice unraveled by GWAS analysis

Rice production is a particularly important crop for the half-world population. Therefore, knowledge about which genes are implicated in the functionality of the Photosystem II, that are still poorly explored could collaborate in the assisted selection of rice improving. In the present study, we applied Genome wide Association Studies of PSII chlorophyll fluorescence under two contrasting environmental conditions in 283 rice accessions highly diverse. A total of 110 significant association SNP-phenotype were observed, and 69 quantitative trait loci identified with a total of 157 genes, of which 38 were highly significant, mapped spread out through rice genome. These underlying regions are enriched in genes related to biotic and abiotic stresses, transcription factors, Calvin cycle, senescence, and grain characters. The correlations analyses PSII chlorophyll fluorescence parameters and some panicle characteristics found here suggest the possibility of developing molecular markers to assist the breeding programs that improve photosynthesis and yield in rice. HighlightThe genetic structure of the Photosystem II functionality in rice was studied by using genome-wide association through chlorophyll fluorescence.

plant biology↗

bioRxiv2019

The fungal endophyte Fusarium solani provokes differential effects on the energy balance of two Lotus species

Background and aimsThe interactions established between plants and endophytic fungi span a continuum from beneficial to pathogenic associations. The aim of this work was to explore the mechanisms underlying the potentially beneficial effects provoked by a fungal strain in legume species of the genus Lotus.\n\nMethodsThe ability to solubilise phosphorous was evaluated in nine fungal strains isolated from roots of L. tenuis. A selected strain was further assessed for its ability to colonize plant roots in different Lotus species. The effects of the two interactions were assessed by analysis of the photosynthesis, sugar amount, and macronutrient status of leaves and roots.\n\nResultsA fungal isolate identified as Fusarium solani shows the highest phosphate-solubilisation activity and grows endophytically in roots of L. japonicus and L. tenuis. Fungal invasion enhances plant growth in L. japonicus but provokes a contrasting effect in L. tenuis. Photosynthesis, sugars and K content showed a differential effect in both plant species.\n\nConclusionsOur results indicate neither of the plant species evaluated in this work were significantly stressed by F. solani. Thus, the differential responses observed are due to distinct mechanisms involving photosynthesis, potassium homeostasis, and carbohydrate metabolism that are employed by plants to maintain fitness during the endophytic interaction.

microbiology↗