Therapeutic potential of a 2,2’-bipyridine-based vanadium(IV) complex on HepG2 cells: cytotoxic effects and molecular targeting

Dihydroartemisinin suppresses COX-2-mediated apoptosis resistance in hepatocellular carcinoma under endoplasmic reticulum stress

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and its treatment still faces numerous challenges. Dihydroartemisinin (DHA), a derivative of artemisinin, has shown significant antitumor activity in preclinical research. Our study seeks to uncover the molecular mechanisms of DHA in HCC, potentially providing scientific evidence for its use as a supportive therapy in clinical settings. This study was conducted using various experimental approaches to systematically analyze the effects of DHA in HCC. Cell viability was evaluated by CCK-8 to determine the IC50 of DHA in HCC cells. Flow cytometry was used to measure the rates of apoptosis and reactive oxygen species (ROS) levels. Colony formation assays were performed to examine the inhibitory effects of DHA on HCC cell proliferation. The toxicity of DHA on HCC cells was evaluated through the lactate dehydrogenase release assay. Western blot was conducted to examine expression levels of proteins related to endoplasmic reticulum (ER) and apoptosis. Fluo-3 AM was utilized to label calcium ions (Ca2+), allowing for the detection of intracellular Ca2+ level changes. Additionally, ER tracker was employed to label the ER, with its morphological changes observed via immunofluorescence. DHA notably inhibited the vitality and proliferation of HCC cells and promoted cell apoptosis. Following DHA exposure, there were notable increases in ER stress markers, ROS, and Ca2+ levels. The morphology of the ER exhibited a loose and expanded state. The use of ER stress inhibitors attenuated these effects. Additionally, ER stress inducers facilitated the upregulation of COX-2, mediating apoptosis in HCC cells. Upon COX-2 knockdown, the apoptotic effect of DHA was markedly amplified. In HCC, DHA induces apoptosis in tumor cells by curbing the COX-2-mediated apoptotic resistance that arises during ER stress. This breakthrough reveals the molecular pathways through which DHA can aid in HCC treatment, offering valuable experimental data to support its clinical use as an adjuvant drug.

2,2'- Bipyridine Derivatives Exert Anticancer Effects by Inducing Apoptosis in Hepatocellular Carcinoma (HepG2) Cells

Purpose

To elucidate the therapeutic potential of 2,2'-bipyridine derivatives [NPS (1-6)] on hepatocellular carcinoma HepG2 cells.

Methods

The effects on cell survival, colony formation, cellular and nuclear morphology, generation of reactive oxygen species (ROS), change in the integrity of mitochondrial membrane potential (MMP), and apoptosis were investigated. Additionally, docking studies were conducted to analyze and elucidate the interactions between the derivatives and AKT and BRAF proteins.

Results

NPS derivatives (1, 2, 5 and 6) significantly impaired cell viability of HepG2 cell lines at nanogram range concentrations - 72.11 ng/mL, 154.42 ng/mL, 71.78 ng/mL, and 71.43 ng/mL, while other derivatives were also effective at concentrations below 1 µg/mL. These compounds reduced the colony formation capacity of HepG2 cells in a dose-dependent manner following treatment. Mechanistic studies revealed that these derivatives induce reactive oxygen species (ROS) accumulation and cause mitochondrial membrane depolarization, ultimately triggering apoptosis in HepG2 cells. In the presence of these derivatives, cells demonstrated that 75% of cells underwent apoptosis, compared to 25% in the control group. Additionally, there was a marked increase in mitochondrial depolarization (95% cells) and a threefold rise in ROS levels compared to the controls. Docking studies revealed interactions between the derivatives and the signaling proteins AKT (PDB ID: 6HHF) and BRAF (PDB ID: 8C7Y) with binding affinities ranging from -7.10 to -9.91, highlighting their pivotal role in targeting key players in hepatocellular carcinoma progression.

Conclusion

The findings of this study underscore the therapeutic potential of these derivatives against HepG2 cells and offer valuable insights for further experimental validation of their efficacy as inhibitors targeting AKT or BRAF signaling pathways.

Cytotoxic effect of Ziziphus Spina-Christi extract alone and in combination with doxorubicin on breast cancer cells

Ziziphus Spina-Christi (L.) (ZSC) is a traditional Arabian medicinal plant used to treat inflammatory symptoms, swellings and pain since long. Triple negative breast cancer (TNBC) is a form of cancer with a poor prognosis owing to the paucity of therapy alternatives. Two of the most critical pathways of TNBC development are Wnt/β-catenin signaling and autophagy. In the present study, we intended to identify the possible mechanisms of the cytotoxic effects mediated by ZSC extract on MDA-MB-231 breast cancer cells and to improve the efficacy of DOX in combination with ZSC. The MTT test was used to estimate cell viability and IC50 values. Apoptosis was detected using AnnexinV-FITC detection kit. ELISA was used to measure caspase-3 levels. Cell cycle and the level of autophagosome marker LC3-II were analysed using flow cytometry. Acidic vesicular organelle (AVOs) formation was observed by fluorescence microscopy. Real-time PCR was used to monitor changes in gene expression of β-catenin and autophagic adapter NBR1. It was shown that ZSC treatment dose-dependently inhibited MDA-MB-231 cell viability and induced apoptosis with accompanying elevation of caspase-3 level. Besides ZSC caused a significant elevation in LC3II level and downregulation of NBR1 gene expression with subsequent downregulation of β-catenin gene expression, indicating the inhibition of the oncogenic Wnt pathway. ZSC and DOX combination had synergistic cytotoxic effect by more effective suppression of Wnt pathway and induction of apoptosis and autosis. Keywords: apoptosis, autophagic adapter NBR1, autophagosome marker LC3-II, breast cancer cells, DOX, Wnt/β-catenin signaling, Ziziphus Spina-Christi