Suppressions of Migration and Invasion by Cantharidin in TSGH-8301 Human Bladder Carcinoma Cells through the Inhibitions of Matrix Metalloproteinase-2/-9 Signaling

Hepatotoxic mechanism of cantharidin: insights and strategies for therapeutic intervention

Cantharidin (CTD), a natural compound derived from Mylabris, is widely used in traditional Oriental medicine for its potent anticancer properties. However, its clinical application is restricted due to its high toxicity, particularly towards the liver. This review provides a concise understanding of the hepatotoxic mechanisms of CTD and highlights novel therapeutic strategies to mitigate its toxicity while enhancing its anticancer efficacy. We systematically explore the molecular mechanisms underlying CTD-induced hepatotoxicity, focusing on the involvement of apoptotic and autophagic processes in hepatocyte injury. We further discuss the endogenous and exogenous pathways implicated in CTD-induced liver damage and potential therapeutic targets. This review also summarizes the structural modifications of CTD derivatives and their impact on anticancer activity. Additionally, we delve into the advancements in nanoparticle-based drug delivery systems that hold promise in overcoming the limitations of CTD derivatives. By offering valuable insights into the hepatotoxic mechanisms of CTD and outlining potential avenues for future research, this review contributes to the ongoing efforts to develop safer and more effective CTD-based therapies.

Anticancer Attributes of Cantharidin: Involved Molecular Mechanisms and Pathways

Cancer is a preeminent threat to the human race, causing millions of deaths each year on the Earth. Traditionally, natural compounds are deemed promising agents for cancer treatment. Cantharidin (CTD)-a terpenoid isolated from blister beetles-has been used extensively in traditional Chinese medicines for healing various maladies and cancer. CTD has been proven to be protein phosphatase 2A (PP2A) and heat shock transcription factor 1 (HSF-1) inhibitor, which can be potential targets for its anticancer activity. Albeit, it harbors some toxicities, its immense anticancer potential cannot be overlooked, as the cancer-specific delivery of CTD could help to rescue its lethal effects. Furthermore, several derivatives have been designed to weaken its toxicity. In light of extensive research, the antitumor activity of CTD is evident in both in vitro as well as in vivo cancer models. CTD has also proven efficacious in combination with chemotherapy and radiotherapy and it can also target some drug-resistant cancer cells. This mini-review endeavors to interpret and summarize recent information about CTD anticancer potential and underlying molecular mechanisms. The pertinent anticancer strength of CTD could be employed to develop an effective anticarcinogenic drug.

Cantharidin alters the expression of genes associated with the NKG2D-associated immune response in TSGH-8301 human bladder carcinoma cells

Cantharidin (CTD) is a natural toxin in beetles of the Mylabris genus (blister beetle), which has been revealed to induce cell death in various types of human cancer cells. However, to the best of our knowledge, no previous studies have investigated the effect of CTD on the expression of genes and their associated signaling pathways in human bladder carcinoma cells. In the present study, CTD-induced cell morphological changes and apoptosis were observed using phase-contrast microscopy and the terminal deoxynucleotidyl transferase dUTP nick end labeling assay, respectively, in TSGH-8301 human bladder carcinoma cells. In addition, a complementary DNA microarray analysis demonstrated that CTD treatment led to a >2-fold upregulation of 269 genes. For example, the DNA damage-associated gene DNA-damage-inducible transcript 3 had a 4.75-fold upregulation. Furthermore, another 286 genes were >2-fold downregulated in response to CTD treatment. Matrix-remodeling associated 5, which is associated with cell migration and invasion, was downregulated 7.98-fold.

Role of S100A3 in human hepatocellular carcinoma and the anticancer effect of sodium cantharidinate

The fifth most common cancer worldwide is hepatocellular carcinoma (HCC), which has an annual mortality rate of ~800,000. Although surgical procedures for HCC, such as hepatic resection and liver transplantation, have progressed and the outcomes of patients have improved, HCC is still characterized by frequent recurrence, even after liver transplantation. In the present study the expression of the protein coding gene, S100 calcium binding protein A3 (S100A3), was observed in 62 HCC tissues and tumor-surrounding tissues. The present study indicated that S100A3 activation was involved in tumorigenesis and tumor aggressiveness. The protein and mRNA expression levels of S100A3 in the human HCC cell line (HepG2) were investigated using western blotting and reverse transcription-quantitative polymerase chain reaction analysis, respectively. The function of sodium cantharidinate in inducing HCC cell apoptosis was also investigated. Sodium cantharidinate inhibited the protein and gene expression of S100A3 in HepG2 cells in vitro. These data suggested that S100A3 has an important role in human HCC. The present study indicates that the functional properties of sodium cantharidinate are promising for the development of a novel drug that may control the expression of S100A3 and improve the treatment of human HCC in the near future.

Cantharidin Overcomes Imatinib Resistance by Depleting BCR-ABL in Chronic Myeloid Leukemia

Cantharidin (CTD) is an active compound isolated from the traditional Chinese medicine blister beetle and displayed anticancer properties against various types of cancer cells. However, little is known about its effect on human chronic myeloid leukemia (CML) cells, including imatinib-resistant CML cells. The objective of this study was to investigate whether CTD could overcome imatinib resistance in imatinib-resistant CML cells and to explore the possible underlying mechanisms associated with the effect. Our results showed that CTD strongly inhibited the growth of both imatinib-sensitive and imatinib-resistant CML cells. CTD induced cell cycle arrest at mitotic phase and triggered DNA damage in CML cells. The ATM/ATR inhibitor CGK733 abrogated CTD-induced mitotic arrest but promoted the cytotoxic effects of CTD. In addition, we demonstrated that CTD downregulated the expression of the BCR-ABL protein and suppressed its downstream signal transduction. Real-time quantitative PCR revealed that CTD inhibited BCR-ABL at transcriptional level. Knockdown of BCR-ABL increased the cell-killing effects of CTD in K562 cells. These findings indicated that CTD overcomes imatinib resistance through depletion of BCR-ABL. Taken together, CTD is an important new candidate agent for CML therapy.

Insect Biotechnology

For the purpose of this work, insect biotechnology, which is also known as yellow biotechnology, is the use of insects as well as insect-derived cells or molecules in medical (red biotechnology), agricultural (green biotechnology), and industrial (white) biotechnology. It is based on the application of biotechnological techniques on insects or their cells to develop products or services for human use. Such products are then applied in agriculture, medicine, and industrial biotechnology. Insect biotechnology has proven to be a useful resource in diverse industries, especially for the production of industrial enzymes including chitinases and cellulases, pharmaceuticals, microbial insecticides, insect genes, and many other substances. Insect cells (ICs), and particularly lepidopteran cells, constitute a competitive strategy to mammalian cells for the manufacturing of biotechnology products. Among the wide range of methods and expression hosts available for the production of biotech products, ICs are ideal for the production of complex proteins requiring extensive posttranslational modification. The progress so far made in insect biotechnology essentially derives from scientific breakthroughs in molecular biology, especially with the advances in techniques that allow genetic manipulation of organisms and cells. Insect biotechnology has grown tremendously in the last 30 years.

Raf/ERK/Nrf2 signaling pathway and MMP-7 expression involvement in the trigonelline-mediated inhibition of hepatocarcinoma cell migration

Background

Trigonelline occurs in many dietary food plants and has been found to have anti-carcinogenic activity. Trigonelline is also found in coffee which is one of the most widely consumed beverages. Many epidemiological studies have reported that coffee consumption has an inverse relationship with the risk of cirrhosis or hepatocellular carcinoma. It would be interesting to investigate whether trigonelline is an ideal chemoprevent agent to prevent cancer progression.

Methods

The protein expression was performed by western blotting. The trigonelline content in snow pea (Pisum sativum) was analyzed by high-performance liquid chromatography (HPLC). The migratory activity of human hepatocarcinoma cells (Hep3B) was assessed by using a wound migration assay. The percentage of each phase in the cell cycle was analyzed on a FACScan flow cytometer. Gene expression was detected by real-time reverse transcriptase-polymerase chain reaction techniques. Native gel analysis was performed to analyze the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase.

Results

According to the data of HPLC analysis, P. sativum, which is a popular vegetable, has relatively high content of trigonelline. Our findings suggest that trigonelline is an efficient compound for inhibiting Hep3B cell migration. Trigonelline inhibited the migration of hepatoma cells at concentrations of 75–100 µM without affecting proliferation. Raf/ERK/Nrf2 protein levels and further downstream antioxidative enzymes activity, such as SOD, catalase, and glutathione peroxidase, significantly decreased after treatment with 100 µM of trigonelline for 24 h. The migration inhibition of trigonelline is also related to its ability to regulate the matrix metalloproteinases 7 (MMP-7) gene expression.

Conclusions

In this study, protein kinase Cα (PKCα) and Raf/ERK/Nrf2 signaling pathway and MMP-7 gene expression were involved in the trigonelline-mediated migration inhibition of Hep3B cells. We also demonstrated that trigonelline inhibits Hep3B cell migration through downregulation of nuclear factor E2-related factor 2–dependent antioxidant enzymes activity. This study analyzed the trigonelline content in a popular vegetable, snow pea, as a representative proof to prove that trigonelline is often found in the daily intake of food. Our finding suggested that trigonelline should be a useful chemopreventive agent derived from the daily intake of food to prevent cancer progression.

Cantharidin represses invasion of pancreatic cancer cells through accelerated degradation of MMP2 mRNA

Cantharidin is an active constituent of mylabris, a traditional Chinese medicine, and is a potent and selective inhibitor of protein phosphatase 2A (PP2A) that plays an important role in cell cycle control, apoptosis, and cell-fate determination. In the present study, we found that cantharidin repressed the invasive ability of pancreatic cancer cells and downregulated matrix metalloproteinase 2 (MMP2) expression through multiple pathways, including ERK, JNK, PKC, NF-κB, and β-catenin. Interestingly, transcriptional activity of the MMP2 promoter increased after treatment with PP2A inhibitors, suggesting the involvement of a posttranscriptional mechanism. By using an mRNA stability assay, we found accelerated degradation of MMP2 mRNA after treatment of cantharidin. Microarray analyses revealed that multiple genes involved in the 3' → 5' decay pathway were upregulated, especially genes participating in cytoplasmic deadenylation. The elevation of these genes were further demonstrated to be executed through ERK, JNK, PKC, NF-κB, and β-catenin pathways. Knockdown of PARN, RHAU, and CNOT7, three critical members involved in cytoplasmic deadenylation, attenuated the downregulation of MMP2. Hence, we present the mechanism of repressed invasion by cantharidin and other PP2A inhibitors through increased degradation of MMP2 mRNA by elevated cytoplasmic deadenylation.

STAT3-mediated MMP-2 expression is required for 15-HETE-induced vascular adventitial fibroblast migration

OBJECTIVE

Vascular adventitial fibroblasts (VAFs) migration was involved in neointima formation, and increased 15-HETE levels contributed to vascular remodeling. However, how 15-HETE-induced VAF migration was not clear.

METHODS AND RESULTS

15-HETE-stimulated VAF phenotypic changes and migration as measured by the wound healing assay required STAT3 phosphorylation. JNK1 and CREB inhibition blocked 15-HETE-induced STAT3 activation and VAF changes. 15-HETE-induced MMP-2 expression and secretion were analyzed by Western blot and ELISA, respectively. MMP-2 knockdown blocked VAF migration and phenotypic alterations. JNK1, STAT3 and CREB blockade suppressed 15-HETE-induced MMP-2 expression in VAFs. MMP-2 promoter activity was assessed by chromatin immunoprecipitation using anti-STAT3 antibodies, which demonstrated that STAT3 was essential for 15-HETE-induced MMP-2 expression. Rats that suffered from hypoxia injury with or without treatment were examined. Pulmonary artery remodeling was obviously observed, and even the media was broken. MMP-2-positive staining was observed in the adventitia and intima. MMP-2 Serum secretion was enhanced as detected by ELISA, and MMP-2 and α-SMA protein expressions were increased after inducing hypoxia in the rats, which was restored in rats that had been administrated with NDGA.

CONCLUSION

These results reveal that STAT3-mediated MMP-2 expression is required for 15-HETE induced-VAF migration.

Synthesis of novel lipophilic N-substituted norcantharimide derivatives and evaluation of their anticancer activities

This research attempted to study the effect of lipophilicity on the anticancer activity of N-substituted norcantharimide derivatives. Twenty-three compounds were synthesized and their cytotoxicities against five human cancer cell lines studied. The lipophilicity of each derivative was altered by its substituent, an alkyl, alkyloxy, terpenyl or terpenyloxy group at the N-position of norcantharimide. Further, among all synthesized derivatives studied, the compounds N-farnesyloxy-7-oxabicyclo[2.2.1]heptane-2,3-dicarboximide (9), and N-farnesyl-7-oxabicyclo[2.2.1]heptane-2,3-dicarboximide (18), have shown the highest cytotoxicity, anti-proliferative and apoptotic effect against human liver carcinoma HepG2 cell lines, yet displayed no significant cytotoxic effect on normal murine embryonic liver BNL CL.2 cells. Their overall performance led us to believe that these two compounds might be potential candidates for anticancer drugs development.

Recent advances in developing insect natural products as potential modern day medicines

Except for honey as food, and silk for clothing and pollination of plants, people give little thought to the benefits of insects in their lives. This overview briefly describes significant recent advances in developing insect natural products as potential new medicinal drugs. This is an exciting and rapidly expanding new field since insects are hugely variable and have utilised an enormous range of natural products to survive environmental perturbations for 100s of millions of years. There is thus a treasure chest of untapped resources waiting to be discovered. Insects products, such as silk and honey, have already been utilised for thousands of years, and extracts of insects have been produced for use in Folk Medicine around the world, but only with the development of modern molecular and biochemical techniques has it become feasible to manipulate and bioengineer insect natural products into modern medicines. Utilising knowledge gleaned from Insect Folk Medicines, this review describes modern research into bioengineering honey and venom from bees, silk, cantharidin, antimicrobial peptides, and maggot secretions and anticoagulants from blood-sucking insects into medicines. Problems and solutions encountered in these endeavours are described and indicate that the future is bright for new insect derived pharmaceuticals treatments and medicines.

A novel cantharidin analog N-benzylcantharidinamide reduces the expression of MMP-9 and invasive potentials of Hep3B via inhibiting cytosolic translocation of HuR

Invasion and metastasis are major causes of malignant tumor-associated mortality. The present study aimed to investigate the molecular events underlying inhibitory effect of N-benzylcantharidinamide, a novel synthetic analog of cantharidin, on matrix metalloproteinase-9 (MMP-9)-mediated invasion in highly metastatic hepatocellular carcinoma Hep3B cells. In this investigation, among six analogs of cantharidin, only N-benzylcantharidinamide has the inhibitory action on MMP-9 expression at non-toxic dose. The MMP-9 expression and invasion of Hep3B cells were significantly suppressed by treatment of N-benzylcantharidinamide in a dose-dependent manner. On the other hand, the transcriptional activity of MMP-9 promoter and nuclear levels of NF-κB and AP-1 as the main transcriptional factors inducing MMP-9 expression were not affected by it although the level of MMP-9 mRNA was reduced by treatment of N-benzylcantharidinamide. Interestingly, the stability of MMP-9 mRNA was significantly reduced by N-benzylcantharidinamide-treatment. In addition, the cytosolic translocation of human antigen R (HuR), which results in the increase of MMP-9 mRNA stability through interaction of HuR with 3'-untranslated region of MMP-9 mRNA, was suppressed by treatment of N-benzylcantharidinamide, in a dose-dependent manner. Taken together, it was demonstrated, for the first time, that N-benzylcantharidinamide suppresses MMP-9 expression by reducing HuR-mediated MMP-9 mRNA stability for the inhibition of invasive potential in highly metastatic Hep3B cells.

Role of S100A3 in human colorectal cancer and the anticancer effect of cantharidinate

Colorectal cancer (CRC) is a leading cause of cancer-related mortality. The early diagnosis and treatment of CRC is the key to improving the survival of patients who may benefit from adjuvant chemotherapy. In the present study, the protein expression of S100A3 was observed in a cohort of 20 patients with cancer, which indicated that S100A3 activation was involved in tumorigenesis. In addition, the anticancer activity of cantharidinate was investigated using immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis. The protein expression of S100A3 was observed to increase by 2.4-fold in human CRC cells compared with the expression level in normal control cells (P<0.01). Cantharidinate inhibited the protein and gene expression of S100A3 in UCT-116 human CRC cells in vitro. These results suggested that S100A3 is important in human CRC. Cantharidinate has the potential to be considered as a novel adjuvant drug for controlling the expression of S100A3 in human CRC as it exhibits preventive effects.