Label-free-based quantitative proteomic analysis of the inhibition of cisplatin-resistant ovarian cancer cell proliferation by cucurbitacin B

Cucurbitacin B suppresses hepatocellular carcinoma progression through inducing DNA damage-dependent cell cycle arrest

BACKGROUND

The mortality rate of liver cancer ranks third in the world, and hepatocellular carcinoma (HCC) is a malignant tumor of the digestive tract. Cucurbitacin B (CuB), a natural compound extracted from Cucurbitaceae spp., is the main active component of Chinese patent medicine the Cucurbitacin Tablet, which has been widely used in the treatment of various malignant tumors in clinics, especially HCC.

PURPOSE

This study explored the role and mechanism of CuB in the suppression of liver cancer progression.

METHODS

Cell Counting Kit-8 (CCK-8) and colony formation assays were used to detect the inhibitory function of CuB in Huh7, Hep3B, and Hepa1/6 hepatoma cells. Calcein-AM/propidium iodide (PI) staining and lactate dehydrogenase (LDH) measurement assays were performed to determine cell death. Mitochondrial membrane potential (Δψm) was measured, and flow cytometry was performed to evaluate cell apoptosis and cell cycle. Several techniques, such as proteomics, Western blotting (WB), and ribonucleic acid (RNA) interference, were utilized to explore the potential mechanism. The animal experiment was performed to verify the results of in vitro experiments.

RESULTS

CuB significantly inhibited the growth of Huh7, Hep3B, and Hepa1/6 cells and triggered the cell cycle arrest in G2/M phage without leading to cell death, especially apoptosis. Knockdown of insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), a target of CuB, did not reverse CuB elicited cell cycle arrest. CuB enhanced phosphorylated ataxia telangiectasia mutated (p-ATM) and phosphorylated H2A histone family member X (γ-H2AX) levels. Moreover, CuB increased p53 and p21 levels and decreased cyclin-dependent kinase 1 (CDK1) expression, accompanied by improving phosphorylated checkpoint kinase 1 (p-CHK1) level and suppressing cell division cycle 25C (CDC25C) protein level. Interestingly, these phenomena were partly abolished by a deoxyribonucleic acid (DNA) protector methylproamine (MPA). Animal studies showed that CuB also significantly suppressed tumor growth in BALB/c mice bearing Hepa1/6 cells. In tumor tissues, CuB reduced the expression levels of proliferating cell nuclear antigen (PCNA) and γ-H2AX but did not change the terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) level.

CONCLUSION

This study demonstrated for the first time that CuB could effectively impede HCC progression by inducing DNA damage-dependent cell cycle arrest without directly triggering cell death, such as necrosis and apoptosis. The effect was achieved through ataxia telangiectasia mutated (ATM)-dependent p53-p21-CDK1 and checkpoint kinase 1 (CHK1)-CDC25C signaling pathways. These findings indicate that CuB may be used as an anti-HCC drug, when the current findings are confirmed by independent studies and after many more clinical phase 1, 2, 3, and 4 testings have been done.

Essential oil from Fructus Alpiniae zerumbet ameliorates vascular endothelial cell senescence in diabetes by regulating PPAR-γ signalling: A 4D label-free quantitative proteomics and network pharmacology study

ETHNOPHARMACOLOGICAL RELEVANCE

Vascular endothelial cell senescence is associated with cardiovascular complications in diabetes. Essential oil from Fructus Alpiniae zerumbet (Pers.) B.L.Burtt & R.M.Sm. (EOFAZ) has potentially beneficial and promising diabetes-related vascular endothelial cell senescence-mitigating effects; however, the underlying molecular mechanisms remain unclear.

AIM OF THE STUDY

To investigate the molecular effects of EOFAZ on vascular endothelial cell senescence in diabetes.

MATERIALS AND METHODS

A diabetes mouse model was developed using a high-fat and high-glucose diet (HFD) combined with intraperitoneal injection of low-dose streptozotocin (STZ, 30 mg/kg) and oral treatment with EOFAZ. 4D label-free quantitative proteomics, network pharmacology, and molecular docking techniques were employed to explore the molecular mechanisms via which EOFAZ alleviates diabetes-related vascular endothelial cell senescence. A human aortic endothelial cells (HAECs) senescence model was developed using high palmitic acid and high glucose (PA/HG) concentrations in vitro. Western blotting, immunofluorescence, SA-β-galactosidase staining, cell cycle, reactive oxygen species (ROS), cell migration, and enzyme linked immunosorbent assays were performed to determine the protective role of EOFAZ against vascular endothelial cell senescence in diabetes. Moreover, the PPAR-γ agonist rosiglitazone, inhibitor GW9662, and siRNA were used to verify the underlying mechanism by which EOFAZ combats vascular endothelial cell senescence in diabetes.

RESULTS

EOFAZ treatment ameliorated abnormal lipid metabolism, vascular histopathological damage, and vascular endothelial aging in diabetic mice. Proteomics and network pharmacology analysis revealed that the differentially expressed proteins (DEPs) and drug-disease targets were associated with the peroxisome proliferator-activated receptor gamma (PPAR-γ) signalling pathway, a key player in vascular endothelial cell senescence. Molecular docking indicated that the small-molecule compounds in EOFAZ had a high affinity for the PPAR-γ protein. Western blotting and immunofluorescence analyses confirmed the significance of DEPs and the involvement of the PPAR-γ signalling pathway. In vitro, EOFAZ and rosiglitazone treatment reversed the effects of PA/HG on the number of senescent endothelial cells, expression of senescence-related proteins, the proportion of cells in the G0/G1 phase, ROS levels, cell migration rate, and expression of pro-inflammatory factors. The protective effects of EOFAZ against vascular endothelial cell senescence in diabetes were aborted following treatment with GW9662 or PPAR-γ siRNA.

CONCLUSIONS

EOFAZ ameliorates vascular endothelial cell senescence in diabetes by activating PPAR-γ signalling. The results of the present study highlight the potential beneficial and promising therapeutic effects of EOFAZ and provide a basis for its clinical application in diabetes-related vascular endothelial cell senescence.

Antitumor Effect of Poplar Propolis on Human Cutaneous Squamous Cell Carcinoma A431 Cells

Propolis is a gelatinous substance processed by western worker bees from the resin of plant buds and mixed with the secretions of the maxillary glands and beeswax. Propolis has extensive biological activities and antitumor effects. There have been few reports about the antitumor effect of propolis against human cutaneous squamous cell carcinoma (CSCC) A431 cells and its potential mechanism. CCK-8 assays, label-free proteomics, RT-PCR, and a xenograft tumor model were employed to explore this possibility. The results showed that the inhibition rate of A431 cell proliferation by the ethanol extract of propolis (EEP) was dose-dependent, with an IC50 of 39.17 μg/mL. There were 193 differentially expressed proteins in the EEP group compared with the control group (p < 0.05), of which 103 proteins (53.37%) were upregulated, and 90 proteins (46.63%) were downregulated. The main three activated and suppressed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were extracellular matrix (ECM)-receptor interaction, amoebiasis, cell adhesion molecules (CAMs), nonalcoholic fatty liver disease (NAFLD), retrograde endocannabinoid signaling, and Alzheimer's disease. The tumor volume of the 100 mg/kg EEP group was significantly different from that of the control group (p < 0.05). These results provide a theoretical basis for the potential treatment of human CSCC A431 cell tumors using propolis.