Drug Screening of Potential Multiple Target Inhibitors for Estrogen Receptor-α-positive Breast Cancer

Investigating antioxidant effects of hamamelitannin-conjugated zinc oxide nanoparticles on oxidative stress-Induced neurotoxicity in zebrafish larvae model

BACKGROUND

An excessive amount of reactive oxygen species triggers oxidative stress, leading to an imbalance in cellular homeostasis. Antioxidant therapy is an effective tool for lowering the oxidative stress and associated ailments. Recently, green nano-based drug formulations have demonstrated promising antioxidant activity and neutralizing oxidative stress. In this study, a tannin molecule Hamamelitannin (HAM), was utilized to synthesize zinc oxide nanoparticles HAM-ZnO NPs, to mitigate oxidative stress and associated ailments .

METHODOLOGY

The HAM-ZnO NPs were synthesized and characterized by XRD, SEM, and FTIR. The antioxidant potentials of HAM-ZnO NPs were analyzed by in vitro antioxidant assays. Zebrafish embryos and larvae were used as in-vivo models to assess the toxicity and antioxidant protective mechanism. Hydrogen peroxide (1mM) was employed to induce oxidative stress and treated with HAM-ZnO NPs to study the cognitive impairment and antioxidant enzyme levels. Levels of reactive oxygen species and cell death due to oxidative stress induction were studied by 2',7'-dichlorodihydrofluorescein diacetate and Acridine orange staining methods. Additionally, expression of Antioxidant genes such as SOD, CAT, GPx, and GSR were studied. .

RESULTS

HAM-ZnO NPs exhibited a spherical morphology and size ranges between 48 and 53 nm. In vitro antioxidant studies revealed the antioxidant properties of HAM-ZnO NPs. Furthermore, in vivo studies indicated that HAM-ZnO NPs don't possess any cytotoxic effects in zebrafish larvae at concentrations between (5-25 µg/ml), The study also observed that HAM-ZnO NPs significantly reduced Hydrogen Peroxide-induced stress and increased antioxidant activity in zebrafish larvae. Also, the antioxidant gene expression was upregulated in the HAM-ZnO NPs zebrafish larvae.

CONCLUSION

Findings in this study showed that HAM-ZnO NPs might be a potential intervention for diseases linked to oxidative stress.

From Hamamelitannin Synthesis to the Study of Enzymatic Acylations of D-Hamamelose

The bioactive natural substance, hamamelitannin, was effectively synthesized in two ways. The chemical acylation of 2,3-O-isopropylidene-α,β-D-hamamelofuranose promoted by Bu2SnO using 3,4,5-tri-O-acetylgalloyl chloride, followed by the deprotection provided hamamelitannin in 79%. Pilot enzymatic benzoylation of D-hamamelose using vinyl benzoate (4 equiv.) and Lipozyme TL IM as a biocatalyst in t-butyl methyl ether (t-BuMeO) gave mainly benzoylated furanoses (89%), of which tribenzoates reached (52%). Enzymatic galloylation of 2,3-O-isopropylidene-α,β-D-hamamelofuranose with vinyl gallate under the catalysis of Lipozyme TL IM in t-butyl alcohol (t-BuOH) or t-BuMeO provided only the 5-O-galloylated product. The reaction in t-BuMeO proceeded in a shorter reaction time (61 h) and higher yield (82%). The more hydrophobic vinyl 3,4,5-tri-O-acetylgallate in the same reactions gave large amounts of acetylated products. Vinyl gallate and triacetylgallate in the enzymatic acylation of D-hamamelose with Lipozyme TL IM in t-BuMeO yielded 2′,5-diacylated hamamelofuranoses in a yield below 20%. The use of other vinyl gallates hydrophobized by methylation or benzylation provided 2′,5-diacylated hamamelofuranoses in good yields (65–84%). The reaction with silylated vinyl gallate did not proceed. The best results were obtained with vinyl 2,3,5-tri-O-benzyl gallate, and the only product, 2′,5-diacylated hamamelofuranoside precipitated from the reaction mixture (84% in 96 h). After debenzylation, hamamelitannin was obtained an 82% yield from hamamelose in two steps. This synthesis is preparatively undemanding and opens the way to multigram preparations of bioactive hamamelitannin and its analogues.

Identification of miRNA biomarkers for breast cancer by combining ensemble regularized multinomial logistic regression and Cox regression

BACKGROUND

Breast cancer is one of the most common cancers in women. It is necessary to classify breast cancer subtypes because different subtypes need specific treatment. Identifying biomarkers and classifying breast cancer subtypes is essential for developing appropriate treatment methods for patients. MiRNAs can be easily detected in tumor biopsy and play an inhibitory or promoting role in breast cancer, which are considered promising biomarkers for distinguishing subtypes.

RESULTS

A new method combing ensemble regularized multinomial logistic regression and Cox regression was proposed for identifying miRNA biomarkers in breast cancer. After adopting stratified sampling and bootstrap sampling, the most suitable sample subset for miRNA feature screening was determined via ensemble 100 regularized multinomial logistic regression models. 124 miRNAs that participated in the classification of at least 3 subtypes and appeared at least 50 times in 100 integrations were screened as features. 22 miRNAs from the proposed feature set were further identified as the biomarkers for breast cancer by using Cox regression based on survival analysis. The accuracy of 5 methods on the proposed feature set was significantly higher than on the other two feature sets. The results of 7 biological analyses illustrated the rationality of the identified biomarkers.

CONCLUSIONS

The screened features can better distinguish breast cancer subtypes. Notably, the genes and proteins related to the proposed 22 miRNAs were considered oncogenes or inhibitors of breast cancer. 9 of the 22 miRNAs have been proved to be markers of breast cancer. Therefore, our results can be considered in future related research.