Relevance of the endoplasmic reticulum-mitochondria axis in cancer diagnosis and therapy

Bifenox induces hepatotoxicity and vascular toxicity in zebrafish embryos via ROS production and alterations in signaling pathways

Existing evidence shows that currently used pesticides pose toxicological risks to exposed wildlife. Chemically, bifenox belongs to diphenyl ethers, a well-known group of herbicides. Its mechanism of action primarily involves inducing lipid peroxidation and blocking protoporphyrinogen oxidases. Toxicity of diphenyl ether herbicides has been elucidated in animal cells; however, in vivo toxicological evaluations of bifenox are required to determine its unexpected effects. This study aimed to determine the negative effects of bifenox, and its effects on higher eukaryotes. We found that early stages of zebrafish embryo exposed to bifenox demonstrated increased mortality and physiological defects, based on the LC50 value. Bifenox severely inhibited blood vessel growth by reducing key elements of complex connectivity; fluorescently tagged transgenic lines (fli1a:EGFP) showed morphological changes. Additionally, transgenic lines that selectively identified hepatocytes (fabp10a:DsRed) showed reduced fluorescence, indicating that bifenox may inhibit liver development. To evaluate the level of oxidative stress, we used 2',7'-dichlorofluorescein diacetate (DCFH-DA) probes in zebrafish embryos to identify the underlying mechanisms causing developmental damage. Our findings demonstrate that exposure to bifenox causes abnormalities in the hepatic and cardiovascular systems during zebrafish embryogenesis. Therefore, this study provides new information for the evaluation of toxicological risks of bifenox in vertebrates.

Osthole Suppresses Cell Growth of Prostate Cancer by Disrupting Redox Homeostasis, Mitochondrial Function, and Regulation of tiRNAHisGTG

Prostate cancer remains a significant global health concern, posing a substantial threat to men's well-being. Despite advancements in treatment modalities, the progression of prostate cancer still presents challenges, warranting further exploration of novel therapeutic strategies. In this study, osthole, a natural coumarin derivative, inhibited cell viability in cancer cells but not in the normal prostate cell line. Moreover, osthole disrupted cell cycle progression. Furthermore, osthole reduces mitochondrial respiration with mitochondrial membrane potential (ΔΨm) depolarization and reactive oxygen species (ROS) generation, indicating mitochondrial dysfunction. In particular, osthole-induced ROS generation was reduced by N-acetyl-L-cysteine (NAC) in prostate cancer. In addition, using calcium inhibitors (2-APB and ruthenium red) and endoplasmic reticulum (ER) stress inhibitor (4-PBA), we confirmed that ER stress-induced calcium overload by osthole causes mitochondrial dysfunction. Moreover, we verified that the osthole-induced upregulation of tiRNAHisGTG expression is related to mechanisms that induce permeabilization of the mitochondrial membrane and calcium accumulation. Regarding intracellular signaling, osthole inactivated the PI3K and ERK pathways while activating the expression of the P38, JNK, ER stress, and autophagy-related proteins. In conclusion, the results suggest that osthole can be used as a therapeutic or adjuvant treatment for the management of prostate cancer.

Frequency of Gene Polymorphisms in Admixed Venezuelan Women with Recurrent Pregnancy Loss: Microsomal Epoxy Hydroxylase (rs1051740) and Enos (rs1799983)

Recurrent pregnancy loss (RPL) affects around 2% of women of reproductive age. Primary RPL is defined by ≥2 pregnancy losses and no normal birth delivery. In secondary RPL, the losses are after a normal pregnancy and delivery. Most cases have no clear aetiology, although primary cases are the most complex. Several gene single nucleotide polymorphisms (SNPs) have been associated with RPL. The frequency of some SNPs is increased in women suffering from RLP from Asian or Caucasian races; however, in admixed populations, the information on possible genetic links is scarce and contradictory. This study aimed to assess the frequency of two SNPs present in two different enzymes involved in medical conditions observed during pregnancy. It is a case-control study. Microsomal epoxy hydrolase (mEPH) is involved in detoxifying xenobiotics, is present in the ovaries, and is hormonally regulated. The endothelial nitric oxide synthase (NOS3) that forms nitric is involved in vascular tone. Two SNPs, rs1051740 (mEPH) and rs1799983 (NOS3), were assessed. The study included 50 controls and 63 primary RPL patients. The frequency of mutated alleles in both SNPs was significantly higher in patients (p < 0.05). Double-mutated homozygotes were encountered only in RPL patients (p < 0.05). Genetic polymorphisms rs1051740 and rs1799983 may be involved in primary RPL in the Venezuelan admix population. Genetic studies could provide crucial information on the aetiology of primary RPL.

Osthole impairs mitochondrial metabolism and the autophagic flux in colorectal cancer

BACKGROUND

Osthole is active constituent of Cnidium monnieri (L.) Cuss. with various physiological functions including anti-inflammation and anti-lipedemic effects. However, the regulatory activity of osthole in colorectal cancer development, focusing on mitochondrial metabolism, is not well known.

HYPOTHESIS/PURPOSE

We hypothesized that osthole may suppress progression of colorectal cancer and aimed to determine the underlying mitochondrial metabolism and the autophagic flux.

STUDY DESIGN

In this study, we elucidated the mechanism of action of osthole in colorectal cancer using an in vivo azoxymethane/dextran sodium sulfate (AOM/DSS) mouse model and an in vitro cell culture system.

METHODS

AOM/DSS mouse model was established and analyzed the effects of osthole on survival rate, diseases activity index, number of tumor and histopathology. Then, cell based assays including viability, cell cycle, reactive oxygen species (ROS), apoptosis, calcium efflux, and mitochondrial function were analyzed. Moreover, osthole-mediated signaling was demonstrated by western blot analyses.

RESULTS

Osthole effectively suppressed the growth of colorectal tumors and alleviated AOM/DSS-induced intestinal injury. Osthole restored the function of goblet cells and impaired the expression of Claudin1 and Axin1 impaired by AOM/DSS. In addition, osthole specifically showed cytotoxicity in colorectal carcinoma cells, but not in normal colon cells. Osthole decreased the ASC/caspase-1/IL-1β inflammasome pathway and induced mitochondrial dysfunction in redox homeostasis, calcium homeostasis. Furthermore, osthole inhibited both oxidative phosphorylation (OXPHOS) and glycolysis, leading to the suppression of ATP production. Moreover, via combination treatment with chloroquine (CQ), we demonstrated that osthole impaired autophagic flux, leading to apoptosis of HCT116 and HT29 cells. Finally, we elucidated that the functional role of tiRNAHisGTG regulated by osthole directly affects the cellular fate of colon cancer cells.

CONCLUSION

These results suggest that osthole has the potential to manage progression of colorectal cancer by regulating autophagy- and mitochondria-mediated signal transduction.