Biology subjects

Wenning, L.

Publications and source records attributed to Wenning, L..

3 recordsLinked to original sources

bioRxiv2025

Androgen receptor contributes to radioresistance through DNA repair and autophagy in AR-positive prostate cancer cells

Androgen receptor (AR) is a critical therapeutic target in prostate cancer (PCa), and androgen blockade is known to act synergistically with radiation therapy. However, the mechanisms through which AR modulates radiation response are not yet fully understood. In this study, we aimed to investigate the role of AR in mediating radioresistance in PCa. AR-positive LNCaP and castration-resistant C4-2 cells exhibited significantly higher radioresistance than AR-negative cells, as determined by apoptosis and cell viability assays. Following irradiation, most LNCaP cells were arrested in the G1 phase, accompanied by rapid p53 activation and p21 induction. Consistently, AR silencing significantly increased radiosensitivity and reduced DNA-PKcs expression and phosphorylation, suggesting that AR enhances DNA repair, likely through non-homologous end joining (NHEJ). At the cellular level, irradiation markedly induced macroautophagy in LNCaP and C4-2 cells, as evidenced by increased LC3B-II accumulation and autophagic vacuole formation, and the upregulation of 11 autophagy-related genes was identified by whole-transcriptomic analysis. To assess their functional relevance, we performed siRNA-mediated knockdown of selected autophagy-related genes and assessed cell viability and Annexin V/PI staining. Notably, BECN1 and LC3 knockdown significantly enhanced radiosensitivity, with BECN1 knockdown showing an effect comparable to that observed with AR silencing. These results suggest that radiation-induced autophagy promotes the survival of AR-positive prostate cancer cells. Moreover, immunohistochemical analysis of ex vivo-irradiated, patient-derived PCa tissues from patients with newly diagnosed high-Gleason score prostate cancer undergoing prostatectomy further demonstrated that radiation-induced autophagy supports the survival of high-grade AR-positive tumor cells. Collectively, our findings reveal that AR promotes radioresistance in PCa by enhancing both DNA repair and autophagy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/690226v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@3f713corg.highwire.dtl.DTLVardef@1233a11org.highwire.dtl.DTLVardef@1b94e5eorg.highwire.dtl.DTLVardef@c8338c_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2020

Production of moth sex pheromones for pest control by yeast fermentation

The use of insect sex pheromones is an alternative technology for pest control in agriculture and forestry, which, in contrast to insecticides, does not have adverse effects on human health or environment and is efficient also against insecticide-resistant insect populations.1,2 Due to the high cost of chemically synthesized pheromones, mating disruption applications are currently primarily targeting higher value crops, such as fruits.3 Here we demonstrate a biotechnological method for the production of pheromones of economically important moth pests using engineered yeast cell factories. Biosynthetic pathways towards several pheromones or their precursors were reconstructed in the oleaginous yeast Yarrowia lipolytica, which was further metabolically engineered for improved pheromone biosynthesis by decreasing fatty alcohol degradation and downregulating storage lipid accumulation. The sex pheromone of the cotton bollworm Helicoverpa armigera was produced by oxidation of fermented fatty alcohols into corresponding aldehydes. The resulting pheromone was just as efficient and specific for trapping of H. armigera male moths in cotton fields in Greece as a synthetic pheromone mixture. We further demonstrated the production of the main pheromone component of the fall armyworm Spodoptera frugiperda. Our work describes a biotech platform for the production of commercially relevant titres of moth pheromones for pest control by yeast fermentation. Significance statementAgriculture largely relies on insecticides and genetically modified crops for pest control, however alternative solutions are required due to emerging resistance, toxicity and regulatory issues, and consumer preferences. Mating disruption with sex pheromones that act by preventing insect reproduction is considered the most promising and scalable alternative to insecticides. This method is highly efficient and safe for human health and environment. The likelihood of insect resistance development is very low and can be handled by adjusting the pheromone composition. The high cost of chemically synthesized pheromones is the major barrier for the wider adoption of pheromones. A novel method based on yeast fermentation enables the production of insect sex pheromones as a lower cost from renewable feedstocks.

bioengineering↗

bioRxiv2018

Investigation of putative regulatory acetylation sites in Fas2p of Saccharomyces cerevisiae

Yeast metabolism is highly regulated, in part via coordinated reprogramming of metabolism on a transcriptional level, for example in response to environmental changes. Furthermore, regulation occurs on the protein level via posttranslational modifications directly affecting enzymatic activity - a mode of regulation that has the benefit of being very fast in response to environmental changes. One group of posttranslational modification that has been suggested to have a high impact on regulation of metabolism are acetylations. Around 4000 distinct protein acetylation sites have been found in Saccharomyces cerevisiae, many of which are located in central metabolic enzymes. However, reports on the verification of regulatory roles of specific acetylation sites on these metabolic enzymes have yet to emerge. This study investigates putative regulatory acetylation sites on Fas2p, which in concert with Fas1p is responsible for cytosolic fatty acid (FA) biosynthesis in S. cerevisiae. Fas2p stands out as one of the most highly acetylated proteins in yeast and is located at a branchpoint of acetyl-CoA metabolism. The amino acids (AAs) glutamine (Q) and arginine (R) were introduced to mimic a constitutively acetylated or non-acetylatable state at three separate lysine sites (K) (K83, K173 and K1551) confirmed to be acetylated in two independent studies, either separately or simultaneously. The results suggest that the residue replacement system in the specific case interferes with the enzymatic function of the fatty acid synthase (FAS), as QQQ and RRR triple mutants both reduce the amount of secreted free fatty acids (FFAs) in a faa1{Delta} faa4{Delta} yeast deletion mutant. The K173Q substitution significantly decreased C16 FA species at the expense of C18 FAs, while no such change could be observed for the corresponding K173R modification.

bioengineering↗