Biology subjects

Szachnowski, U.

Publications and source records attributed to Szachnowski, U..

4 recordsLinked to original sources

bioRxiv2023

A novel lncRNA PROCA11 regulates cell plasticity in response to androgen deprivation of prostate cancer cells

Long non-coding RNAs (lncRNAs) represent vast and yet poorly characterized family of genes that can fine tune cellular plasticity, thereby allowing the emergence of aggressive therapy-resistant and metastatic cancers. Androgen deprivation therapies (ADT) are commonly used to treat prostate cancer by inactivating the Androgen Receptor (AR). However, castration-resistant prostate cancer (CRPC) with neuroendocrine subtypes (NEPC) often emerge. In this study, we explore the role of lncRNAs in response to androgen deprivation. Using a dynamic prostate cancer cell system mimicking the CRPC and NEPC onset, we identified 15 novel lncRNAs, with PROCA11 standing out as a first-choice candidate, being also highly abundant in high-risk prostate cancer tumors. This majorly nuclear lncRNA is expressed at low levels in androgen-dependent conditions of growth and strongly activated upon hormone withdrawal, preceding neuroendocrine genes and persisting at high levels in neuroendocrine cells. Extensive computational analysis of clinical data and functional studies in cells revealed PROCA11 association with basal-to-luminal transformation of the transcriptomic landscape and activation of metabolic and signaling pathways reminiscent of neurogenesis and of maintenance of AR signaling. We propose that PROCA11 is involved in the intricate circuits regulating cellular plasticity enabling cell survival and proliferation and emergence of the NE phenotype in response to ADT.

cancer biology↗

bioRxiv2022

Transcriptomic landscapes of SARS-CoV-2-infected and bystander lung cells reveal a selective upregulation of NF-κB-dependent coding and non-coding proviral transcripts

Investigations of cellular responses to viral infection are commonly performed on mixed populations of infected and uninfected cells or using single-cell RNA sequencing, leading to inaccurate and low-resolution gene expression interpretations. Here, we performed deep polyA+ transcriptome analyses and novel RNA profiling of SARS-CoV-2 infected lung epithelial cells, sorted based on the expression of the viral spike (S) protein. Infection caused a massive reduction in mRNAs and lncRNAs, including transcripts coding for antiviral factors, such as interferons (IFN). This absence of IFN signaling probably explained the poor transcriptomic response of bystander cells co-cultured with S+ ones. NF-{kappa}B pathway and the inflammatory response escaped the global shutoff in S+ cells. Functional investigations revealed the proviral function of the NF-{kappa}B pathway and the antiviral activity of CYLD, a negative regulator of the pathway. Thus, our transcriptomic analysis on sorted cells revealed additional genes that modulate SARS-CoV-2 replication in lung cells.

microbiology↗

bioRxiv2020

The INO80 remodeler couples premature termination of mRNA synthesis with transcription elongation

Co-transcriptional RNA quality control is essential for gene expression. However, its regulation remains poorly understood. Here, we report that the evolutionarily conserved ATP-dependent chromatin remodelling INO80 complex promotes transcription termination by the non-coding RNA quality control pathway in S. cerevisiae. Loss of INO80 leads to accumulation of stalled RNA Polymerase II preferentially at promoter-proximal pausing sites, compromising Pol II processivity and hindering transcription elongation. We reveal that binding of RNA surveillance and non-coding transcription termination factors to promoter-proximal mRNA regions is associated with increased promoter-proximal pausing. INO80 counteracts promoter-proximal stalling of genes attenuated by the Nrd1-Nab3-Sen1 (NNS) non-coding transcription termination complex, promoting their expression. We show that INO80 interacts with Nrd1 and the Nab2 RNA surveillance factor in vivo. Absence of INO80 leads to defective transcription termination by the Nrd1-Nab3-Sen1 (NNS) complex. We demonstrate that INO80 facilitates the recruitment of Nab2 at non-coding transcription termination sites and its association with promoter-proximally terminated mRNA transcripts. Finally, we provide evidence that INO80 promotes the release of stalled RNA Polymerase II from a non-coding transcription termination site. Collectively, our work suggests that the INO80 complex regulates transcription by removal of stalled Polymerase, implicating a chromatin-based mechanism for non-coding and premature transcription termination in gene expression.

molecular biology↗

bioRxiv2019

Endogenous RNAi pathway evolutionarily shapes the destiny of the antisense lncRNAs transcriptome

Antisense (as)lncRNAs are extensively degraded by the nuclear exosome and the cytoplasmic exoribonuclease Xrn1 in the budding yeast Saccharomyces cerevisiae, lacking RNA interference (RNAi). Whether the ribonuclease III Dicer affects aslncRNAs in close RNAi-capable relatives remains unknown. Using genome-wide RNA profiling, here we show that aslncRNAs are primarily targeted by the exosome and Xrn1 in the RNAi-capable budding yeast Naumovozyma castellii, Dicer only affecting Xrn1-sensitive lncRNAs (XUTs) levels in Xrn1-deficient cells. The dcr1 and xrn1 mutants display synergic growth defects, indicating that Dicer becomes critical in the absence of Xrn1. Small RNA sequencing showed that Dicer processes aslncRNAs into small RNAs, with a preference for asXUTs. Consistently, Dicer localizes into the cytoplasm. Finally, we observed an expansion of the exosome-sensitive antisense transcriptome in N. castellii compared to S. cerevisiae, suggesting that the presence of cytoplasmic RNAi has reinforced the nuclear RNA surveillance machinery to temper aslncRNAs expression. Our data provide fundamental insights into aslncRNAs metabolism and open perspectives into the possible evolutionary contribution of RNAi in shaping the aslncRNAs transcriptome.

genomics↗