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Biology subjects

Dang, T. V. T.

Publications and source records attributed to Dang, T. V. T..

3 recordsLinked to original sources

Spatial analysis of HPV associated cervical intraepithelial neoplastic tissues demonstrate distinct immune signatures associated with cervical cancer progression

Cervical cancer remains the fourth most common cancer affecting women worldwide, and incidences of other HPV-related cancers continue to rise. For the development of effective prevention strategies in high-risk patients, we aimed to better understand the roles of inflammatory pathways and the tumour microenvironment as the main driver of progression to malignancy in HPV-infected tissues. We analysed the spatial organisation of seven samples of HPV+ high-grade squamous intraepithelial lesion (HSIL) and cervical intraepithelial neoplasia 3 (CIN3), comparing tumour heterogeneity and immune microenvironments between pre-malignant (neoplastic) and adjacent cervical tissues. We observed evidence of immune suppression within the neoplastic regions across all samples and identified distinct immune clusters for each dysplastic lesion. Previous single-cell data analyses in an HPV16 E7 oncoprotein-driven transgenic mouse model suggested a potential role for IL34-CSF1R signalling in immune modulation, where low IL34 expression was associated with Langerhans cell dysfunction, and, in cervical cancer, with poor patient outcome. Here, we observed that IL34-CSF1R co-expression was absent within HPV-associated neoplastic tissues but present in adjacent normal tissue regions. Additionally, we identified enrichment of an M2 gene signature in neoplastic tissue, while adjacent tissue was enriched with a pro-inflammatory M1 gene signature. Our findings provide bio-pathological insights into the spatial cellular and molecular mechanisms underlying HPV-associated cervical cancer immune regulation and suggest a strategy to modulate the immune system in HPV-positive neoplastic cervical and other tissues.

genomics↗

SnRK1 inhibits anthocyanin biosynthesis through both transcriptional regulation and direct phosphorylation and dissociation of the MYB/bHLH/TTG1 MBW complex.

Plants have evolved an extensive specialized secondary metabolism. The colorful flavonoid anthocyanins, for example, not only stimulate flower pollination and seed dispersal but also protect different tissues against high light, UV- and oxidative stress. Their biosynthesis is highly regulated by environmental and developmental cues and induced by high sucrose levels. Expression of the biosynthetic enzymes involved is controlled by a transcriptional MBW complex, comprising (R2R3) MYB- and bHLH-type transcription factors (TF) and the WD40 repeat protein TTG1. Anthocyanin biosynthesis is obviously useful but also carbon- and energy-intensive and non-vital. Consistently, the SnRK1 protein kinase, a metabolic sensor activated in carbon- and energy-depleting stress conditions, represses anthocyanin biosynthesis. Here we show that Arabidopsis SnRK1 represses MBW complex activity both at the transcriptional and post-translational level. In addition to repressing expression of the key transcription factor MYB75/PAP1, SnRK1 activity triggers MBW complex dissociation, associated with loss of target promoter binding, MYB75 protein degradation and nuclear export of TTG1. We also provide evidence for direct interaction with and phosphorylation of multiple MBW complex proteins. These results indicate that repression of expensive anthocyanin biosynthesis is an important strategy to save energy and redirect carbon flow to more essential processes for survival in metabolic stress conditions.

plant biology↗

HEAT SHOCK FACTOR BINDING PROTEIN limits meiotic crossovers by repressing HEI10 transcription

The number of meiotic crossovers is tightly controlled and most depend on pro-crossover ZMM proteins, such as the E3 ligase HEI10. Despite the importance of HEI10 dosage for crossover formation, how HEI10 transcription is controlled remains unexplored. In a forward genetic screen using a sensitive fluorescent seed crossover reporter in Arabidopsis thaliana we identify heat shock factor binding protein (HSBP) as a repressor of HEI10 transcription and crossover numbers. Using genome-wide crossover mapping and cytogenetics, we show that hsbp mutations or meiotic HSBP knockdowns increase ZMM-dependent crossovers towards the telomeres, mirroring the effects of HEI10 overexpression. Through RNA sequencing, DNA methylome and chromatin immunoprecipitation analysis, we reveal that HSBP directly represses HEI10 transcription by binding with heat shock factors (HSFs) at the HEI10 promoter and maintaining DNA methylation over the HEI10 5' untranslated region. Our findings provide insights into how the temperature response regulator HSBP restricts meiotic HEI10 transcription and crossover number by attenuating HSF activity.

plant biology↗