ABSTRACT
The widespread occurrence and accumulation of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its quinone metabolite, 6PPD quinone (6PPD-Q), have been globally recognized as a critical environmental issue. However, knowledge on the adverse effects of 6PPD and 6PPD-Q on freshwater invertebrates is limited. This study investigated the effects of 6PPD and its oxidative byproduct, 6PPD-Q, on the growth and reproduction of Daphnia pulex. Through 21-day exposure experiments, we measured the uptake of 0.1, 1, and 10 µg/L 6PPD and 6PPD-Q by D. pulex and assessed the effects on growth and fecundity of D. pulex. While 6PPD and 6PPD-Q did not affect the mortality rate of D. pulex, 6PPD-Q exposure inhibited the growth of D. pulex, indicating potential ecological risks. In particular, the reproductive capacity of D. pulex remained unaffected across the tested concentrations of 6PPD and 6PPD-Q, suggesting specific toxicological pathways that warrant further investigation. This study underscored the importance of evaluating the sublethal effects of emerging contaminants such as 6PPD and 6PPD-Q on aquatic invertebrates, and highlighted the need for comprehensive risk assessments to better understand their environmental impacts.
ABSTRACT
Accumulating evidence has indicated that Complement factor H-related 3 (CFHR3) plays an essential role in various diseases. However, the biological functions of CFHR3 in hepatocellular carcinoma (HCC) remain largely unclear. Therefore, we perform a further study on CFHR3 in HCC. In this article, we report the suppressive role of CFHR3 in the proliferation and metastasis of HCC cells. CFHR3 downregulation is closely associated with large (T3-T4) HCC, tumor recurrence, and advanced (stage III-IV) clinical stage, functioning as an independent factor for the prognoses of HCC patients. Knockdown of CFHR3 promotes proliferation, migration, and invasion of HCC cells. Mechanistically, downregulation of CFHR3 is induced by miR-590-3p binding to the 3' untranslated region (UTR) of CFHR3. CFHR3 downregulation promotes the phosphorylation of STAT3 protein, thereby suppressing p53 expression. The promotional effect upon downregulation of CFHR3 induced by CFHR3 stable knockdown or miR-590-3p on HCC cell malignant phenotypes is attenuated by STAT3 inhibitor, S3I-201. In conclusion, our results reveal that CFHR3 is a protective biomarker for HCC patients, and targeting the miR-590-3p/CFHR3/p-STAT3/p53 signaling axis provides a promising strategy for HCC therapeutics.
