Norcantharidin analogues: a patent review (2006 - 2010)

Nanoemulsion based lipid nanoparticles for effective demethylcantharidin delivery to cure liver cancer

Demethylcantharidin (DEM) is a widely used antitumor drug; however, its poor tumor targeting and serious organotoxicity limit its application. The aim of this study was to develop a new drug delivery system for efficient delivery of DEM. Nanoemulsion based lipid nanoparticles containing demethylcantharidin (DNLNs) were prepared by loading nanoemulsions into lipid nanoparticles. The cells proliferation, apoptosis, cycle, and uptake were investigated by Cell counting kit-8 (CCK-8), flow cytometry, and in situ fluorescence assays, respectively. Then, we established the H22 tumor-bearing mouse model to evaluate the antitumor efficacy of DNLNs and further studied its organ toxicity and distribution. DNLNs significantly inhibited the proliferation and promoted apoptosis of H22 cells, and H22 cells could take up more DNLNs. Compared with DEM, DNLNs had certain tumor-targeting properties, and the tumor inhibition rate increased by 23.24%. Moreover, DNLNs can increase white blood cell count and reduce organ toxicity. This study paves the way for nanoemulsion-based lipid nanoparticle (NLNs)-efficient DEM delivery to treat liver cancer.

Targeting the autophagy-miRNA axis in prostate cancer: toward novel diagnostic and therapeutic strategies

Since prostate cancer is one of the leading causes of cancer-related death, a better understanding of the molecular pathways guiding its development is imperative. A key factor in prostate cancer is autophagy, a cellular mechanism that affects both cell survival and death. Autophagy is essential in maintaining cellular homeostasis. Autophagy is a physiological mechanism wherein redundant or malfunctioning cellular constituents are broken down and recycled. It is essential for preserving cellular homeostasis and is implicated in several physiological and pathological conditions, including cancer. Autophagy has been linked to metastasis, tumor development, and treatment resistance in prostate cancer. The deregulation of miRNAs related to autophagy appears to be a crucial element in the etiology of prostate cancer. These miRNAs influence the destiny of cancer cells by finely regulating autophagic mechanisms. Numerous investigations have emphasized the dual function of specific miRNAs in prostate cancer, which alter autophagy-related pathways to function as either tumor suppressors or oncogenes. Notably, miRNAs have been linked to the control of autophagy and the proliferation, apoptosis, and migration of prostate cancer cells. To create customized therapy approaches, it is imperative to comprehend the dynamic interplay between autophagy and miRNAs in prostate cancer. The identification of key miRNAs provides potential diagnostic and prognostic markers. Unraveling the complex network of lncRNAs, like PCA3, also expands the repertoire of molecular targets for therapeutic interventions. This review explores the intricate interplay between autophagy and miRNAs in prostate cancer, focusing on their regulatory roles in cellular processes ranging from survival to programmed cell death.

Mechanisms of norcantharidin against renal tubulointerstitial fibrosis

Renal tubulointerstitial fibrosis (RTIF) is a common feature and inevitable consequence of all progressive chronic kidney diseases, leading to end-stage renal failure regardless of the initial cause. Although research over the past few decades has greatly improved our understanding of the pathophysiology of RTIF, until now there has been no specific treatment available that can halt the progression of RTIF. Norcantharidin (NCTD) is a demethylated analogue of cantharidin, a natural compound isolated from 1500 species of medicinal insect, the blister beetle (Mylabris phalerata Pallas), traditionally used for medicinal purposes. Many studies have found that NCTD can attenuate RTIF and has the potential to be an anti-RTIF drug. This article reviews the recent progress of NCTD in the treatment of RTIF, with emphasis on the pharmacological mechanism of NCTD against RTIF.

Intratumoral injection of norcantharidin liposome emulsion hybrid delivery system amplifies the cancer-fighting effects of oral sorafenib against hepatocellular carcinoma

Interventional therapies are increasingly used in clinical trials for hepatocellular carcinoma (HCC). Sorafenib is the front-line remedy for HCC, however, chemoresistance occurs immutably and affects the effectiveness of treatment. In a previous study, a norcantharidin liposome emulsion hybrid (NLEH) delivery system for HCC was developed. This study aims to examine the therapeutic effects of the combination of intratumoral injection of NLEH and sorafenib in treating HCC. Sorafenib combined with NLEH activated the apoptosis pathway by synergistically upregulating caspase-9, promoting cytotoxicity, apoptosis (64.57%), and G2/M cell cycle arrest (48.96%). Norcantharidin could alleviate sorafenib resistance by counteracting sorafenib-induced phosphorylation of Akt. Additionally, intratumoral injection of NLEH exhibited a sustained accumulation in the tumor within 24 h and didn't distribute to other major organs. Intratumoral injection of NLEH in combination with oral sorafenib displayed the most potent tumor growth inhibitory effect (77.91%) in vivo. H&E staining results and the indicators of the renal and liver function tests demonstrated the safety of this combination therapy. Overall, these results showed that intratumoral injection of NLEH in combination with oral sorafenib treatment represented a rational potential therapeutic option for HCC.

Review targeted drug delivery systems for norcantharidin in cancer therapy

Norcantharidin (NCTD) is a demethylated derivative of cantharidin (CTD), the main anticancer active ingredient isolated from traditional Chinese medicine Mylabris. NCTD has been approved by the State Food and Drug Administration for the treatment of various solid tumors, especially liver cancer. Although NCTD greatly reduces the toxicity of CTD, there is still a certain degree of urinary toxicity and organ toxicity, and the poor solubility, short half-life, fast metabolism, as well as high venous irritation and weak tumor targeting ability limit its widespread application in the clinic. To reduce its toxicity and improve its efficacy, design of targeted drug delivery systems based on biomaterials and nanomaterials is one of the most feasible strategies. Therefore, this review focused on the studies of targeted drug delivery systems combined with NCTD in recent years, including passive and active targeted drug delivery systems, and physicochemical targeted drug delivery systems for improving drug bioavailability and enhancing its efficacy, as well as increasing drug targeting ability and reducing its adverse effects.

Graphical Abstract

Preclinical evaluations of Norcantharidin liposome and emulsion hybrid delivery system with improved encapsulation efficiency and enhanced antitumor activity

BACKGROUND

Norcantharidin (NCTD) has a certain degree of hydrophilicity and poor lipophilicity, and has some side-effects, including short t_1/2, vascular irritation, cardiotoxicity and nephrotoxicity, which bring difficulties for formulation research. In this study, we aim to develop a novel nanocarrier to improve encapsulation efficiency, increase sterilization stability and enhance antitumor activity.

METHODS

Phospholipid complexes methods were used for increasing the lipophilicity of norcantharidin (NCTD), then NCTD phospholipid complexes were not only loaded in the oil phase and oil-water interface surface, but also encapsulated in phospholipid bilayers to obtain NCTD liposome-emulsion hybrid (NLEH) delivery system. The in vitro cytotoxicity and apoptosis, in vivo tissue distribution, tumor penetration, heterotopic and orthotopic antitumor studies were conducted to evaluate therapeutic effect.

RESULTS

NLEH exhibited an improved encapsulation efficiency (89.3%) and a better sterilization stability, compared to NCTD liposomes and NCTD emulsions. NLEH can achieve a better antitumor activity by promoting absorption (1.93-fold), prolonging blood circulation (2.08-fold), enhancing tumor-targeting accumulation (1.19 times), improving tumor penetration, and increasing antitumor immunity.

CONCLUSIONS

The liposome-emulsion hybrid (LEH) delivery system was potential carrier for NCTD delivery, and LEH could open opportunities for delivery of poorly soluble anticancer drugs, especially drugs that are more hydrophilicity than lipophilicity.

Genome of the Giant Panda Roundworm Illuminates Its Host Shift and Parasitic Adaptation

Baylisascaris schroederi, a roundworm (ascaridoid) parasite specific to the bamboo-feeding giant panda (Ailuropoda melanoleuca), represents a leading cause of mortality in wild giant panda populations. Here, we present a 293-megabase chromosome-level genome assembly of B. schroederi to infer its biology, including host adaptations. Comparative genomics revealed an evolutionary trajectory accompanied by host-shift events in ascaridoid parasite lineages after host separations, suggesting their potential for transmission and rapid adaptation to new hosts. Genomic and anatomical lines of evidence, including expansion and positive selection of genes related to the cuticle and basal metabolisms, indicate that B. schroederi undergoes specific adaptations to survive in the sharp-edged bamboo-enriched gut of giant pandas by structurally increasing its cuticle thickness and efficiently utilizing host nutrients through gut parasitism. Additionally, we characterized the secretome of B. schroederi and predicted potential drug and vaccine targets for new control strategies. Overall, this genome resource provides new insights into the host adaptation of B. schroederi to the giant panda as well as the host-shift events in ascaridoid parasite lineages. Our findings on the unique biology of B. schroederi will also aid in the development of prevention and treatment measures to protect giant panda populations from roundworm parasitism.

Metal-organic framework IRMOFs coated with a temperature-sensitive gel delivering norcantharidin to treat liver cancer

BACKGROUND

Norcantharidin (NCTD) is suitable for the treatment of primary liver cancer, especially early and middle primary liver cancer. This compound can reduce tumors and improve immune function. However, the side effects of NCTD have limited its application. There is a marked need to reduce the side effects and increase the efficacy of NCTD.

AIM

To develop a nanomaterial carrier, NCTD-loaded metal-organic framework IRMOF-3 coated with a temperature-sensitive gel (NCTD-IRMOF-3-Gel), aiming to improve the anticancer activity of NCTD and reduce the drug dose.

METHODS

NCTD-IRMOF-3-Gel was obtained by a coordination reaction. The apparent characteristics and in vitro release of NCTD-IRMOF-3-Gel were investigated. Cell cytotoxicity assays, flow cytometry, and apoptosis experiments in mouse hepatoma (Hepa1-6) cells were used to determine the anti-liver cancer activity of NCTD-IRMOF-3-Gel in in vitro models.

RESULTS

The particle size of NCTD-IRMOF-3-Gel was 50-100 nm, and the particle size distribution was uniform. The release curve showed that NCTD-IRMOF-3-Gel had an obvious sustained-release effect. The cytotoxicity assays showed that the free drug NCTD and NCTD-IRMOF-3-Gel treatments markedly inhibited Hepa1-6 cell proliferation, and the inhibition rate increased with increasing drug concentration. By flow cytometry, NCTD-IRMOF-3-Gel was observed to block the Hepa1-6 cell cycle in the S and G2/M phases, and the thermosensitive gel nanoparticles may inhibit cell proliferation by inducing cell cycle arrest. Apoptosis experiments showed that NCTD-IRMOF-3-Gel induced the apoptosis of Hepa1-6 cells.

CONCLUSION

Our results indicated that the NCTD-IRMOF-3-Gel may be beneficial for liver cancer disease treatment.

Norcantharidin-blocked ANXA2P2 inhibits fibroblast proliferation by increasing UBAP2L mRNA stability through LIN28B

AIMS

Norcantharidin (NCTD) exhibits antitumor, anti-inflammatory, and anti-fibrosis properties, which makes NCTD an attractive candidate for the treatment of pathological scars. This study was designed to investigate the potential effects of NCTD on fibroblast proliferation and explore the underlying mechanisms.

MATERIALS AND METHODS

First, cell viability and cell apoptosis were evaluated to determine the effects of NCTD on human skin fibroblasts, at 10, 50, and 100 μM. To explore the mechanism, bioinformatics analyses, chromatin immunoprecipitation, RNA immunoprecipitation, and RNA pulldown assays, and luciferase reporter assays were performed to verify the relationships among NCTD, signal transducer and activator of transcription 3 (STAT3), annexin A2 pseudogene 2 (ANXA2P2), and ubiquitin-associated protein 2-like (UBAP2L) mRNA in fibroblasts. Loss-of-function experiments were performed to investigate the roles played by STAT3, ANXA2P2, and UBAP2L in the proliferation and apoptosis of fibroblasts.

KEY FINDINGS

We found that NCTD administration induced fibroblast apoptosis and inhibited fibroblast proliferation in a dose-dependent manner. Mechanistically, NCTD inhibited ANXA2P2 transcription through the inhibition of STAT3 phosphorylation. Subsequently, ANXA2P2 was found to enhance the physical interaction between UBAP2L mRNA and lin-28 homolog B (LIN28B), which increased the stability and levels of UBAP2L mRNA. Loss-of-function assays demonstrated that ANXA2P2 and UBAP2L knockdown induced fibroblast apoptosis and suppressed fibroblast proliferation.

SIGNIFICANCE

In conclusion, we confirmed that NCTD inhibits fibroblast proliferation by inhibiting the STAT3/ANXA2P2/UBAP2L axis, which suggested that NCTD could represent a new candidate for the treatment of pathological scars.

Traditional Chinese Medicine Regulating Lymphangiogenesis: A Literature Review

Lymphatic vessels, as an important part of the lymphatic system, form a fine vascular system in humans and play an important role in regulating fluid homeostasis, assisting immune surveillance and transporting dietary lipids. Dysfunction of lymphatic vessels can cause many diseases, including cancer, cardiovascular diseases, lymphedema, inflammation, rheumatoid arthritis. Research on lymphangiogenesis has become increasingly important over the last few decades. Nevertheless, the explicit role of regulating lymphangiogenesis in preventing and treating diseases remains unclear owing to the lack of a deeper understanding of the cellular and molecular pathways of the specific and tissue-specific changes in lymphangiopathy. TCM, consisting of compound extracted from TCM, Injections of single TCM and formula, is an important complementary strategy for treating disease in China. Lots of valuable traditional Chinese medicines are used as substitutes or supplements in western countries. As one of the main natural resources, these TCM are widely used in new drug research and development in Asia. Moreover, as a historical and cultural heritage, TCM has been widely applied to clinical research on lymphangiogenesis leveraging new technologies recently. Available studies show that TCM has an explicit effect on the regulation of lymphatic regeneration. This review aims to clarify the function and mechanisms, especially the inhibitory effect of TCM in facilitating and inhibiting lymphatic regeneration.

The protective effect of L-glutamine against acute Cantharidin-induced Cardiotoxicity in the mice

Background

Cantharidin (CTD) is a compound which have the potential to be exploited as an antitumor drug, and it has been demonstrated antitumor effects in a variety of cancers. However, the use is limited due to its severe toxicity. It has reported that it can induce fatal cardiac arrhythmias. Fortunately, we found that L-glutamine can alleviate cardiac toxicity caused by cantharidin in mice.

Methods

To investigate the protective effect of L-glutamine, we used a high dose of cantharidin in mice to create a model of cardiotoxicity. In the experimental mice, glutamine was given orally half an hour before they were administrated with cantharidin. The mice of control group were intraperitoneally injected with DMSO solution. The general state of all mice, cardiac mass index, electrocardiogram change and biological markers were determined. Hematoxylin-eosin staining (HE staining) of heart tissue was carried out in each group to reflect the protective effect of glutamine. To investigate the mechanisms underlying the injury and cardio-protection, multiple oxidative stress indexes were determined and succinate dehydrogenase activity was evaluated.

Result

The results showed that L-glutamine (Gln) pretreatment reduced weight loss and mortality. It also decreased the biological markers (p < 0.05), improved electrocardiogram and histological changes that CTD induced cardiotoxicity in mice. Subsequently, the group pretreated with L-glutamine before CTD treatment increases in MDA but decreases in SOD and GSH, in comparison to the group treated with CTD alone. Besides, succinate dehydrogenase activity also was improved when L-glutamine was administrated before cantharidin compared to cantharidin.

Conclusions

This study provided evidence that L-glutamine could protect cardiac cells against the acute cantharidin-induced cardiotoxicity and the protective mechanism of glutamine may be related to the myocardial cell membrane or the tricarboxylic acid cycle in the mitochondria.

Norcantharidin inhibits the DDR of bladder cancer stem-like cells through cdc6 degradation

Introduction: Cancer stem cells (CSCs) are the main source of tumor resistance and recurrence. At present, the main treatment for patients with advanced or metastatic bladder cancer (BCa) is cisplatin-based combination chemotherapy. However, CSCs are not sensitive to DNA-damaging drugs due to their enhanced DNA damage response (DDR) activity. Materials and methods: Bladder cancer stem cell-like cells (BCSLCs) were obtained by treating UMUC3 cells with cisplatin. The characteristics of the BCSLCs were identified by qPCR, flow cytometry, scratch wound-healing assays, transwell assays, tumorigenic ability experiments, Edu assays and Western blot assays in vivo. After BCSLCs were treated with norcantharidin (NCTD), the expression of Cdc6 and activation of the ATR-Chk1 pathway were detected by Western blotting. A subcutaneous tumor model in nude mice was successfully established to assess the anti-tumor efficacy of NCTD and cisplatin either alone or in combination in vivo. The tumor tissues were detected by immunohistochemistry. Results: The derived BCSLCs showed higher expression of stemness markers, increased invasiveness, improved resistance to multiple chemotherapeutics, and higher tumorigenic capacity in vivo. The protein expression level of chromatin-binding Cdc6 was increased in BCSLCs; however, NCTD decreased the level of chromatin-binding Cdc6 and inhibited the activation of the ATR-Chk1 pathway, which ultimately led to reduction in DDR activity in BCSLCs. NCTD enhanced the killing effect of cisplatin on BCSLCs in vitro and vivo. NCTD combined with cisplatin enhanced cisplatin-induced DNA damage in BCSLCs. Conclusion: Long-term cisplatin treatment can enrich BCSLCs. However, NCTD enhanced the killing effect of cisplatin on BCSLCs in vitro and vivo. The mechanism is inhibiting the DDR activity by reducing the expression of chromatin-binding Cdc6.

Unique Responses of Hepatocellular Carcinoma and Cholangiocarcinoma Cell Lines toward Cantharidin and Norcantharidin

The present study aimed to investigate whether cell lines from human gastric and liver cancers respond differently toward cantharidin (CTD) and norcantharidin (NCTD) than other types of cancer cells. We first established the half maximal inhibitory concentrations (IC50s) of CTD for a large panel of cancer cell lines representing the 12 major types of human cancers and the mode of cell death induced by the two compounds. We next compared the growth inhibitory effects as well as the corresponding modes of action of CTD and NCTD. The IncuCyte ZOOM system was used as a semi-high throughput means to define IC50s and 90% inhibitory doses (IC90s) as a reference for the maximal tolerable doses (MTDs) for the two compounds in 72 cancer cell lines. Classical clonogenic survival assay was used to assess the anti-proliferative effect of CTD on selected cell lines of interest. In addition, DNA content-based flow was used to interrogate the modes of cell death following CTD or NCTD exposure. The results of these experiments led to several findings. 1). Cell lines representing hepatocellular carcinomas (HCCs) and cholangiocarcinomas (CCs) were among the most sensitive toward CTD, consistent with the previous clinical study of this compound and its source of origin, Mylabris. 2). Among the individual cell lines of a given cancer types, the sensitivity trends for CTD and NCTD did not exhibit a good correlation. 3) CTD and NCTD caused distinctive cytotoxic effects on HepG2 cells. Specifically, while a cytostatic effect is the primary cause of growth inhibition of CTD, cytotoxic effect is the main contributing factor for the growth inhibition of NTCD. These results indicate that liver cancer cell lines are among the most sensitive to CTD and that CTD and NCTD exhibit their effects through distinct mechanisms.

Suppression of lymphangiogenesis in human lymphatic endothelial cells by simultaneously blocking VEGF-C and VEGF-D/VEGFR-3 with norcantharidin

Lymph node metastasis of tumors is a crucial early step in the metastatic process. Tumor lymphangiogenesis plays an important role in promoting tumor metastasis to regional lymph nodes. Norcantharidin (NCTD) has been reported to possess potent anti-angiogenesis and antitumor properties in several cell lines and xenograft tumor models. However, its role in tumor-associated lymphangiogenesis and lymphatic metastasis remains unclear. Here, we investigated the effect of NCTD on proliferation, apoptosis, migration, invasion and the lymphatic tube formation, lymphangiogenesis, of human lymphatic endothelial cells (HLECs) in vitro by MTT, proliferation assay, Hoechst staining and flow cytometry, scraping line method, Matrigel invasion assay, inverted or fluorescence microscope and transmission electron microscope. Moreover, the underlying mechanisms, such as VEGF-C, VEGF-D, VEGFR-3 at protein and mRNA levels in lymphangiogenesis using 3-dimensional (3-D) culture of HLECs were measured by immunohistochemistry, western blotting and real-time polymerase chain reaction (RT-PCR). It was shown that NCTD inhibited proliferation, migration, invasion and lymphatic tube formation (forming-lymphatic and/or formed-lymphatic) of HLECs, induced HLEC apoptosis (all P<0.01) significantly, in a dose- and time-dependent manner (IC50 6.8 µg/ml); and downregulated the expression of VEGF-C, VEGF-D and VEGFR-3 at protein or/and mRNA levels (P<0.01) in HLEC lymphatic tube formation. Thus, we identified for the first time that NCTD inhibited HLEC lymphangiogenesis by simultaneously blocking VEGF-C and VEGF-D/VEGFR-3 in vitro. The present findings may be of importance to explore the therapeutical target or strategy of NCTD for tumor lymphangiogenesis and lymphatic metastasis.

Synthesis and anticancer activity of a series of norcantharidin analogues

Cantharidin (1) and norcantharidin (2) display high levels of anticancer activity against a broad range of tumour cell lines. Synthetic manipulation of norcantharidin yields (3S,3aR,4S,7R,7aS)-3-hydroxyhexahydro-4,7-epoxyisobenzofuran-1(3H)-one (3), which also displays a high level of anticancer activity against tumour cells but interestingly, shows selectivity towards HT29 (colon; GI(50) = 14 μM) and SJ-G2 (glioblastoma; GI(50) = 15 μM) cell lines. Substitution at the hydroxyl group of the cyclic lactone within (3) produces a diasteromeric pair of products that have no difference in cytotoxicity over the cell lines tested. Incorporation of an isopropyl tail at this position (16) produced the most promising compound of this series to date, with strong selectivity towards HT29 (colon; GI(50) = 19 μM) and SJ-G2 (glioblastoma; GI(50) = 21 μM) cell lines but completely void of any activity against the remaining tumour cell lines (GI(50) > 100 μM), as per the parent molecule. We also discovered that the introduction of a terminal phosphate moiety (28) at the same position produced a different trend in cytotoxicity with strong activity in BE2-C (neuroblastoma; GI(50) = 9 μM) cells; suggestive of an alternate mode of action.