Sodium butyrate-induced histone hyperacetylation up-regulating WT1 expression in porcine kidney fibroblasts.

OBJECTIVES: Wilms' tumor 1 gene (WT1) is essential for the development of kidney and histone acetylation and is involved in its expression regulation in mice. However, whether WT1 expression is associated with histone acetylation in porcine kidney cells is unclear. Here, the effect of histone deacetylase inhibitor sodium butyrate (NaBu)-induced hyperacetylation on WT1 expression in porcine kidney fibroblasts (PKF) was examined. RESULTS: Treatments of NaBu (1, 3, 6 mM) for 24 h increased PKF viability, and 24, 48 h-treatments of 1 mM NaBu enhanced PKF proliferation. WT1 mRNA levels were significantly elevated in NaBu-treated (1, 3 mM for 24, 48 h, respectively) PKF samples. Consistently, strengthened expression of WT1 protein and histone acetylation level were detected in NaBu-treated PKF cells. CONCLUSION: Together, NaBu-induced hyperacetylation up-regulates WT1 expression in PKF, suggesting the involvement of histone acetylation in the transcriptional modulation of WT1 in porcine kidney cells.

Disulfiram/Copper Induce Ferroptosis in Triple-Negative Breast Cancer Cell Line MDA-MB-231.

BACKGROUND: The complex formed by disulfiram (DSF) and copper (Cu) is safe and effective for the prevention and treatment of triple-negative breast cancer (TNBC). Although previous studies have shown that DSF/Cu induces ferroptosis, the mechanism remains unclear. METHODS: The mitochondrial morphology of TNBC treated with DSF/Cu was observed by transmission microscopy, and intracellular levels of iron, lipid reactive oxygen species (ROS), malondialdehyde, and glutathione were evaluated to detect the presence of ferroptosis. Target genes for the DSF/Cu-activated ferroptosis signaling pathway were examined by transcriptome sequencing analysis. Expression of the target gene, HOMX1, was detected by qRT-PCR, immunofluorescence and western blot. RESULTS: The mitochondria of TNBC cells were significantly atrophied following treatment with DSF/Cu for 24 h. Addition of DSF/Cu supplement resulted in significant up-regulation of intracellular iron, lipid ROS and malondialdehyde levels, and significant down-regulation of glutathione levels, all of which are important markers of ferroptosis. Transcriptome analysis confirmed that DSF/Cu activated the ferroptosis signaling pathway and up-regulated several ferroptosis target genes associated with redox regulation, especially heme oxygenase-1 (HMOX-1). Inhibition of ferroptosis by addition of the ROS scavenger N-acetyl-L-cysteine (NAC) significantly increased the viability of DSF/Cu-treated TNBC cells. CONCLUSIONS: These results show that DSF/Cu increases lipid peroxidation and causes a sharp increase in HMOX1 activity, thereby inducing TNBC cell death through ferroptosis. DSF/Cu is a promising therapeutic drug for TNBC and could lead to ferroptosis-mediated therapeutic strategies for human cancer.

Combination of the 6-thioguanine and disulfiram/Cu synergistically inhibits proliferation of triple-negative breast cancer cells by enhancing DNA damage and disrupting DNA damage checkpoint.

Because of the lack of specific molecular targeted therapies, triple-negative breast cancer (TNBC) has high tumour recurrence and metastasis rates. It is urgent to develop novel chemotherapeutic strategies to improve patient survival. DNA damaging agents have been shown to sensitize cancer to genotoxic chemotherapies. We first found that 6-thioguanine (6-TG) can activate the NF-кB signalling pathway. Our results showed that NF-кB signalling was reduced when cells were treated with 6-TG/disulfiram (DSF)/Cu. DSF/Cu enhanced the 6-TG-mediated inhibition of proliferation. 6-TG/DSF/Cu inhibited cell cycle progression, causing cell cycle arrest in the S phase and G2/M phase. Moreover, the combined effect of 6-TG and DSF/Cu induced apoptosis, and either agent alone was able to induce apoptosis. The accumulation of γH2A indicated that DSF/Cu increased the DNA damage induced by 6-TG. Combined treatment with 6-TG and DSF/Cu synergistically reduced the levels of both phosphorylated and total ataxia-telangiectasia-mutated-and-Rad3-related kinase (ATR), suggesting that DSF/Cu promoted 6-TG-induced DNA damage by suppressing ATR protein kinases, therefore enhancing cell apoptosis. In conclusion, we demonstrate that the combination of 6-TG and DSF/Cu exerted a significant synergistic antitumour effect on human TNBC in vitro and in vivo by enhancing DNA damage and disrupting DNA damage checkpoints. We propose that this combination therapy could be a novel strategy for the treatment of TNBC.

Thioguanine Induces Apoptosis in Triple-Negative Breast Cancer by Regulating PI3K-AKT Pathway.

Triple-negative breast cancer (TNBC) is notoriously difficult to treat due to the lack of biological targets and poor sensitivity to conventional therapies. Chemotherapy is the main clinical therapy, but the effective screening strategy for chemotherapy drugs is poorly investigated. Drug repositioning has been the center of attention in recent years attracting numerous studies. Here, we firstly found multiple common features between leukemia and TNBC by analyzing the global transcriptome profiles based on the transformed comparison data from NCI60. Therefore, we investigated the role of the classic leukemia drug thioguanine (6-TG) in TNBC cancer cells. Our results indicated that 6-TG inhibited cell proliferation and tumor cell progression by suppressing PI3K-AKT pathway via downregulating the DNA methylation level of PTEN. Moreover, apoptosis was induced via the activation of PI3K-AKT downstream TSC1 and the downregulation of methylation levels of DAXX, TNF, FADD and CASP8 etc. These findings indicated 6-TG exerts its anti-tumor effects in vitro and in vivo through regulating the DNA methylation levels of genes involved in PI3K-AKT and apoptosis pathway. Meanwhile, our study suggested that transcriptome-based drug screening has potential implications for breast cancer therapy and drug selection.

Transcriptome analysis reveals that cyclophosphamide induces premature ovarian failure by blocking cholesterol biosynthesis pathway.

AIMS: The present study aimed to investigate the effects of cyclophosphamide (Cytoxan, CTX) on premature ovarian failure (POF) in mice and its regulatory mechanisms by transcriptome analysis. MAIN METHODS: Female C57BL/6 mice were treated with a single intraperitoneal injection of 70 mg/kg CTX. Serum levels of estradiol (E2) and follicle stimulating hormone (FSH) were measured by enzyme-linked immunosorbent assay (ELISA), and follicular structure differences were observed by hematoxylin and eosin (H&E) staining. The main mechanism of POF was investigated by RNA-seq data, protein-protein interaction (PPI) networks and qPCR analysis. KEY FINDINGS: The serum levels of E2 were significantly decreased and those of FSH were significantly increased compared to the control group. The ovarian weights of the mice in the CTX group were reduced, and abnormal follicular structures were also observed in the CTX group. The RNA-seq data show that the downregulated genes were related to the cholesterol biosynthesis pathway. The PPI network and qPCR analyses further confirm that the PPAR signaling pathway and the ovarian infertility genes were also involved in blocking the cholesterol biosynthesis pathway. The differences were statistically significant. SIGNIFICANCE: Our results indicate that CTX may exert its anti-tumor effects by inactivating the cholesterol biosynthesis pathway, and simultaneously reducing the supply of estrogen precursor materials, ultimately leading to the occurrence of POF. Our data provided a preliminary theoretical basis for resolving the clinical toxicity and side effects of CTX.

Differential expression of Wilms' tumour 1 gene in porcine urogenital organs during development.

Wilms' tumour 1 gene (WT1) is essential for the development of mammalian urogenital system. However, the expression pattern of WT1 in the development of porcine urogenital organs is still unclear. Here, we examined the expression of WT1 mRNA and protein in porcine kidneys, ovaries and testes from embryonic days 35 and 60 (E35d, E60d, n = 3) to the newborn (0d, n = 4) and adult (210d, n = 3) stages, using real-time PCR and immunofluorescent staining. Real-time PCR analysis showed that porcine kidneys, ovaries and testes all expressed high level of WT1 mRNAs, especially in adult testes (p < 0.05 or 0.01 vs. kidney and ovary, respectively). Morphologically, characteristic microstructures of the kidneys, ovaries and testes were observed and discerned at all four stages. Immunofluorescently, WT1 expression was detected in a dynamic and context-specific pattern during the development of these organs. Taken together, porcine urogenital organs express relatively high levels of WT1 mRNA. Dynamical and context-specific expression profile of WT1 in these organs occurs during their development, implying its close association with the development and function of porcine kidney, ovary and testis.