Thiol peroxidases are critical enzymes in the redox control of cellular processes that function by reducing low levels of hydroperoxides and regulating redox signaling. These proteins were also shown to regulate genome stability, but how their dysfunction affects the actual mutations in the genome is not known. Saccharomyces cerevisiae has eight thiol peroxidases of glutathione peroxidase and peroxiredoxin families, and the mutant lacking all these genes (∆8) is viable. In this study, we employed two independent ∆8 isolates to analyze the genome-wide mutation spectrum that results from deficiency in these enzymes. Deletion of these genes was accompanied by a dramatic increase in point mutations, many of which clustered in close proximity and scattered throughout the genome, suggesting strong mutational bias. We further subjected multiple lines of wild-type and ∆8 cells to long-term mutation accumulation, followed by genome sequencing and phenotypic characterization. ∆8 lines showed a significant increase in nonrecurrent point mutations and indels. The original ∆8 cells exhibited reduced growth rate and decreased life span, which were further reduced in all ∆8 mutation accumulation lines. Although the mutation spectrum of the two independent isolates was different, similar patterns of gene expression were observed, suggesting the direct contribution of thiol peroxidases to the observed phenotypes. Expression of a single thiol peroxidase could partially restore the growth phenotype of ∆8 cells. This study shows how deficiency in nonessential, yet critical and conserved oxidoreductase function, leads to increased mutational load and decreased fitness.

There are only a few antifungal drugs used systemically in treatment, and invasive fungal infections that are resistant to these drugs are an emerging problem in health care. In this study, we performed a high-copy-number genomic DNA (gDNA) library screening to find and characterize genes that reduce susceptibility to amphotericin B, caspofungin, and voriconazole in Saccharomyces cerevisiae. We identified the PDR16 and PMP3 genes for amphotericin B, the RMD9 and SWH1 genes for caspofungin, and the MRS3 and TRI1 genes for voriconazole. The deletion mutants for PDR16 and PMP3 were drug susceptible, but the other mutants had no apparent susceptibility. Quantitative-PCR analyses suggested that the corresponding drugs upregulated expression of the PDR16, PMP3, SWH1, and MRS3 genes. To further characterize these genes, we also profiled the global expression patterns of the cells after treatment with the antifungals and determined the genes and paths that were up- or downregulated. We also cloned Candida albicans homologs of the PDR16, PMP3, MRS3, and TRI1 genes and expressed them in S. cerevisiae. Heterologous expression of Candida homologs also provided reduced drug susceptibility to the budding yeast cells. Our analyses suggest the involvement of new genes in antifungal drug resistance.

This study aimed to synthesize a novel series of N-heterocyclic compounds and evaluate their integrated pharmacological potential by coupling in vitro selective cytotoxicity on tumor and normal cell lines with predictive in silico ADME-Tox profiling. This research highlights the anti-cancer potential of twelve synthesized compounds, five of which are new chemical entities never before described in the literature. Their detailed structural characterization (NMR ¹H, ¹³C, IR), combined with in silico predictions (ADME-Tox), confirmed their ability to cross essential biological barriers, in particular the intestinal membrane and, for certain derivatives, the BBB. Biological evaluations conducted on SH-SY5Y (neuroblastoma) and HCT116 (colorectal carcinoma) cell lines revealed several compounds with IC₅₀ values lower than those of cisplatin while exhibiting reduced cytotoxicity towards the normal human epithelial BEAS-2B cell line. In particular, the compound (1H-imidazol-1-yl)methanol (designated as Compound 6 ) stands out with IC₅₀ values of 6.97 ± 0.06 µM on SH-SY5Y and 10.70 ± 0.33 µM on HCT116, significantly lower than those of cisplatin under the same experimental conditions. This profile, combined with virtually no toxicity on normal BEAS-2B cells (IC₅₀ > 800 µM), highlights its remarkable selectivity. These results highlight optimized pharmacological properties and suggest the potential for developing selective therapeutic agents against different types of cancer, particularly neuronal and colorectal tumors. Future research will focus on in-depth mechanistic studies and in vivo validation to optimize the efficacy, pharmacokinetics, and safety of these promising molecules.