LFZ-4-46, a tetrahydroisoquinoline derivative, induces apoptosis and cell cycle arrest via induction of DNA damage and activation of MAPKs pathway in cancer cells

Novel tetrahydroisoquinolines as DHFR and CDK2 inhibitors: synthesis, characterization, anticancer activity and antioxidant properties

In this study, we synthesized new 5,6,7,8-tetrahydroisoquinolines and 6,7,8,9-tetrahydrothieno[2,3-c]isoquinolines based on 4-(N,N-dimethylamino)phenyl moiety as expected anticancer and/or antioxidant agents. The structure of all synthesized compounds were confirmed by spectral date (FT-IR, 1H NMR, 13C NMR) and elemental analysis. We evaluated the anticancer activity of these compounds toward two cell lines: A459 cell line (lung cancer cells) and MCF7 cell line (breast cancer cells). All tested compounds showed moderate to strong anti-cancer activity towards the two cell lines. Compound 7e exhibited the most potent cytotoxic activity against A549 cell line (IC50: 0.155 µM) while compound 8d showed the most potent one against MCF7 cell line (IC50: 0.170 µM) in comparison with doxorubicin. In addition, we examined the effect of compounds 7e and 8d regarding the growth of A549 and MCF7 cell lines, employing flow cytometry and Annexin V-FITC apoptotic assay. Our results showed that compound 7e caused cell cycle arrest at the G2/M phase with a 79-fold increase in apoptosis of A459 cell line. Moreover, compound 8d caused cell cycle arrest at the S phase with a 69-fold increase in apoptosis of MCF7 cell line. Furthermore, we studied the activity of these compounds as enzyme inhibitors against several enzymes. Our findings by docking and experimental studies that compound 7e is a potent CDK2 inhibitor with IC50 of 0.149 µM, compared to the Roscovitine control drug with IC50 of 0.380 µM. We also found that compound 8d is a significant DHFR inhibitor with an IC50 of 0.199 µM, compared to Methotrexate control drug with IC50 of 0.131 µM. Evaluation of the antioxidant properties of ten compounds was also studied in comparison with Vitamin C. Compounds 1, 3, 6, 7c and 8e have higher antioxidant activity than Vitamin C which mean that these compounds can used as potent antioxidant drugs.

MiR-302a Regenerates Human Corneal Endothelial Cells against IFN-γ-Induced Cell Death

Damage to human corneal endothelial cells (hCECs) leads to bullous keratopathy because these cells cannot be regenerated in vivo. In this study, we investigated the protective role of microRNA (miR)-302a against interferon-γ (IFN-γ)-induced senescence and cell death of hCECs. Cultured hCECs were transfected with miR-302a and treated with IFN-γ (20 ng/mL) to evaluate the protective effect of miR-302a on IFN-γ-induced cell death. Senescence was evaluated by the senescence-associated β-galactosidase (SA-β-gal) assay, and the secretion of senescence-associated secretory phenotype (SASP) factors was analyzed. Mitochondrial function and endoplasmic reticulum (ER) stress were assessed. We revealed that miR-302a enhanced the cell viability and proliferation of hCECs and that IFN-γ increased the cell size, the number of SA-β-gal-positive cells, and SASP factors, and arrested the cell cycle, which was eliminated by miR-302a. miR-302a ameliorated mitochondrial oxidative stress and ER stress levels which were induced by IFN-γ. IFN-γ decreased the mitochondrial membrane potential and promoted autophagy, which was eliminated by miR-302a. The in vivo study showed that regeneration of rat CECs was promoted in the miR-302a group by inhibiting IFN-γ and enhancing mitochondrial function. In conclusion, miR-302a eliminated IFN-γ-induced senescence and cellular damage by regulating the oxidative and ER stress, and promoting the proliferation of CECs. Therefore, miR-302a may be a therapeutic option to protect hCECs against IFN-γ-induced stress.

Apigenin sensitizes radiotherapy of mouse subcutaneous glioma through attenuations of cell stemness and DNA damage repair by inhibiting NF-κB/HIF-1α-mediated glycolysis

The radioresistance of glioma is related to the presence of glioma stem cells. Apigenin, a natural flavonoid compound present in numerous health foods and edible plants, has inhibitory effects on a variety of glioma cells. However, the effects of apigenin on glioma and radiotherapy remain unclear. Here, we used radioresistant SU3-5R stem cells-inoculated subcutaneous glioma model to investigate the effects of apigenin and potential mechanisms. The results showed that after treatment of mouse subcutaneous glioma with apigenin 20 mg/kg for 12 days, irradiation 8 Gray twice or their combination, the tumor volume and weight were significantly decreased, especially in the combined treatment group. Apigenin treatment inhibited the activities of glycolytic related enzymes and expressions of nuclear factor kappa B (NF-κB) p65, hypoxia inducible factor-lα (HIF-1α), glucose transporter (GLUT)-1/3 and pyruvate kinase isozyme type M2 (PKM2) proteins in tumor tissues. After treatment of SU3-5R cells with apigenin 7.5 μM, the fluorescence intensity of CD133 positive cells was decreased, the percentage of cells with comet tails caused by irradiation was increased, and the expressions of lipopolysaccharide-induced NF-κB p65, HIF-1α, GLUT-3 and PKM2 proteins were reduced. These results demonstrate that apigenin can sensitize the radiotherapy of subcutaneous glioma in nude mice, and its mechanisms may result from the attenuations of cell stemness and DNA damage repair by inhibiting NF-κB/HIF-1α-mediated glycolytic related enzymes and protein expressions. In conclusion, our findings suggest that apigenin and apigenin-rich health foods can be used in the radiotherapy of glioma as a radiosensitizer.