Chemically synthesized cinobufagin suppresses nasopharyngeal carcinoma metastasis by inducing ENKUR to stabilize p53 expression

MiR-2110 induced by chemically synthesized cinobufagin functions as a tumor-metastatic suppressor via targeting FGFR1 to reduce PTEN ubiquitination degradation in nasopharyngeal carcinoma

Tumor cell metastasis is the key cause of death in patients with nasopharyngeal carcinoma (NPC). MiR-2110 was cloned and identified in Epstein-Barr virus (EBV)-positive NPC, but its role is unclear in NPC. In this study, we investigated the effect of miR-2110 on NPC metastasis and its related molecular basis. In addition, we also explored whether miR-2110 can be regulated by cinobufotalin (CB) and participate in the inhibition of CB on NPC metastasis. Bioinformatics, RT-PCR, and in situ hybridization were used to observe the expression of miR-2110 in NPC tissues and cells. Scratch, Boyden, and tail vein metastasis model of nude mouse were used to detect the effect of miR-2110 on NPC metastasis. Western blot, Co-IP, luciferase activity, colocalization of micro confocal and ubiquitination assays were used to identify the molecular mechanism of miR-2110 affecting NPC metastasis. Finally, miR-2110 induced by CB participates in CB-stimulated inhibition of NPC metastasis was explored. The data showed that increased miR-2110 significantly suppresses NPC cell migration, invasion, and metastasis. Suppressing miR-2110 markedly restored NPC cell migration and invasion. Mechanistically, miR-2110 directly targeted FGFR1 and reduced its protein expression. Decreased FGFR1 attenuated its recruitment of NEDD4, which downregulated NEDD4-induced phosphatase and tensin homolog (PTEN) ubiquitination and degradation and further increased PTEN protein stability, thereby inactivating PI3K/AKT-stimulated epithelial-mesenchymal transition signaling and ultimately suppressing NPC metastasis. Interestingly, CB, a potential new inhibitory drug for NPC metastasis, significantly induced miR-2110 expression by suppressing PI3K/AKT/c-Jun-mediated transcription inhibition. Suppression of miR-2110 significantly restored cell migration and invasion in CB-treated NPC cells. Finally, a clinical sample assay indicated that reduced miR-2110 was negatively correlated with NPC lymph node metastasis and positively related to NPC patient survival prognosis. In summary, miR-2110 is a metastatic suppressor involving in CB-induced suppression of NPC metastasis.

Immunoenhancement effect of cinobufagin on macrophages and the cyclophosphamide-induced immunosuppression mouse model

Cinobufagin (CBG) is a natural active substance. Although its various pharmacological activities have been explored, the immunomodulatory activity of CBG remains unexplored. Therefore, this study aimed to investigate the anti-inflammatory and immunomodulatory activities of CBG ex vivo and in vivo. The immunomodulatory activity of CBG was investigated in RAW 264.7 cells. CBG showed no significant toxicity to cells. Additionally, 0.5-8 μg/mL CBG significantly increased the phagocytosis ability of macrophages and the secretion levels of IL-1β and TNF-α. Thus, it exerted immunomodulatory effects. We established the immunosuppressive model induced by cyclophosphamide (CTX) in mice and studied the immunomodulatory activity of CBG in vivo. The experimental results showed that the intervention of CBG alleviated the CTX-induced weight loss, restored the lymphocyte nuclear cell number, and promoted the secretion and mRNA expression of cytokines IFN-γ, IL-4, IL-6, and IL-12. Moreover, CBG increased the immune organ index, protected the growth of the spleen and thymus, and improved the pathological changes in immunosuppressed mice. Western blot results showed that different concentrations of CBG upregulated the phosphorylation level of PI3K/Akt/mTOR in the spleen of CTX-induced immunosuppressed mice. This suggests that the immunomodulatory effect of CBG may be related to the regulation of PI3K/Akt/mTOR signaling pathway. This study provides a theoretical basis for developing CBG immune enhancers and opens up new ideas for the comprehensive utilization and development of CBG in factories.

E3 ubiquitin ligases in nasopharyngeal carcinoma and implications for therapies

Nasopharyngeal carcinoma (NPC) is one of the most common squamous cell carcinomas of the head and neck, and Epstein-Barr virus (EBV) infection is one of the pathogenic factors involved in the oncogenetic development and progression of NPC. E3 ligases, which are key members of the ubiquitin proteasome system (UPS), specifically recognize various oncogenic factors and tumor suppressors and contribute to determining their fate through ubiquitination. Several studies have demonstrated that E3 ligases are aberrantly expressed and mutated in NPC and that these changes are closely associated with the occurrence and progression of NPC. Herein, we aim to thoroughly review the specific action mechanisms by which E3 ligases participate in NPC signaling pathways and discuss their functional relationship with EBV. Moreover, we describe the current progress in and limitations for targeted therapies against E3 ligases in NPC. KEY MESSAGES: • E3 ubiquitin ligases, as members of the UPS system, determine the fate of their substrates and may act either as oncogenic or anti-tumorigenic factors in NPC. • Mutations or dysregulated expression of E3 ubiquitin ligases is closely related to the occurrence, development, and therapeutic sensitivity of NPC, as they play important roles in several signaling pathways affected by EBV infection. • As promising therapeutic targets, E3 ligases may open new avenues for treatment and for improving the prognosis of NPC patients.

FGFR families: biological functions and therapeutic interventions in tumors

There are five fibroblast growth factor receptors (FGFRs), namely, FGFR1-FGFR5. When FGFR binds to its ligand, namely, fibroblast growth factor (FGF), it dimerizes and autophosphorylates, thereby activating several key downstream pathways that play an important role in normal physiology, such as the Ras/Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase, phosphoinositide 3-kinase (PI3K)/AKT, phospholipase C gamma/diacylglycerol/protein kinase c, and signal transducer and activator of transcription pathways. Furthermore, as an oncogene, FGFR genetic alterations were found in 7.1% of tumors, and these alterations include gene amplification, gene mutations, gene fusions or rearrangements. Therefore, FGFR amplification, mutations, rearrangements, or fusions are considered as potential biomarkers of FGFR therapeutic response for tyrosine kinase inhibitors (TKIs). However, it is worth noting that with increased use, resistance to TKIs inevitably develops, such as the well-known gatekeeper mutations. Thus, overcoming the development of drug resistance becomes a serious problem. This review mainly outlines the FGFR family functions, related pathways, and therapeutic agents in tumors with the aim of obtaining better outcomes for cancer patients with FGFR changes. The information provided in this review may provide additional therapeutic ideas for tumor patients with FGFR abnormalities.

Cinobufagin: a promising therapeutic agent for cancer

OBJECTIVES

Cinobufagin is a natural active ingredient isolated from the traditional Chinese medicine Venenum Bufonis (Chinese: Chansu), which is the dried secretion of the postauricular gland or skin gland of the Bufo gargarizans Cantor or Bufo melanostictus Schneider. There is increasing evidence indicating that cinobufagin plays an important role in the treatment of cancer. This article is to review and discuss the antitumor pharmacological effects and mechanisms of cinobufagin, along with a description of its toxicity and pharmacokinetics.

METHODS

The public databases including PubMed, China National Knowledge Infrastructure and Elsevier were referenced, and 'cinobufagin', 'Chansu', 'Venenum Bufonis', 'anticancer', 'cancer', 'carcinoma', and 'apoptosis' were used as keywords to summarize the comprehensive research and applications of cinobufagin published up to date.

KEY FINDINGS

Cinobufagin can induce tumour cell apoptosis and cycle arrest, inhibit tumour cell proliferation, migration, invasion and autophagy, reduce angiogenesis and reverse tumour cell multidrug resistance, through triggering DNA damage and activating the mitochondrial pathway and the death receptor pathway.

CONCLUSIONS

Cinobufagin has the potential to be further developed as a new drug against cancer.

Regulatory network and targeted interventions for CCDC family in tumor pathogenesis

CCDC (coiled-coil domain-containing) is a coiled helix domain that exists in natural proteins. There are about 180 CCDC family genes, encoding proteins that are involved in intercellular transmembrane signal transduction and genetic signal transcription, among other functions. Alterations in expression, mutation, and DNA promoter methylation of CCDC family genes have been shown to be associated with the pathogenesis of many diseases, including primary ciliary dyskinesia, infertility, and tumors. In recent studies, CCDC family genes have been found to be involved in regulation of growth, invasion, metastasis, chemosensitivity, and other biological behaviors of malignant tumor cells in various cancer types, including nasopharyngeal carcinoma, lung cancer, colorectal cancer, and thyroid cancer. In this review, we summarize the involvement of CCDC family genes in tumor pathogenesis and the relevant upstream and downstream molecular mechanisms. In addition, we summarize the potential of CCDC family genes as tumor therapy targets. The findings discussed here help us to further understand the role and the therapeutic applications of CCDC family genes in tumors.

MYH10 Combines with MYH9 to Recruit USP45 by Deubiquitinating Snail and Promotes Serous Ovarian Cancer Carcinogenesis, Progression, and Cisplatin Resistance

The poor prognosis of serous ovarian cancer (SOC) is due to its high invasive capacity and cisplatin resistance of SOC cells, whereas the molecular mechanisms remain poorly understood. In the present study, the expression and function of non-muscle myosin heavy chain IIB (MYH10) in SOC are identified by immunohistochemistry, in vitro, and in vivo studies, respectively. The mechanism of MYH10 is demonstrated by co-immunoprecipitation, GST pull-down, confocal laser assays, and so on. The results show that the knockdown of MYH10 suppressed SOC cell proliferation, migration, invasion, metastasis, and cisplatin resistance both in vivo and in vitro. Further studies confirm that the MYH10 protein functional domain combines with non-muscle myosin heavy chain IIA (MYH9) to recruit the deubiquitinating enzyme Ubiquitin-specific proteases 45 and deubiquitinates snail to inhibit snail degradation, eventually promoting tumorigenesis, progression, and cisplatin resistance in SOC. In clinical samples, MYH10 expression is significantly elevated in SOC samples compared to the paratumor samples. And the expression of MYH10 is positively correlated with MYH9 expression. MYH10+/MYH9+ co-expression is an independent prognostic factor for predicting SOC patient survival. These findings uncover a key role of the MYH10-MYH9-snail axis in SOC carcinogenesis, progression, and cisplatin resistance, and provide potential novel therapeutic targets for SOC intervention.

Toad venom-derived bufadienolides and their therapeutic application in prostate cancers: Current status and future directions

Cancer is the second leading cause of death worldwide. Specially, the high incidence rate and prevalence of drug resistance have rendered prostate cancer (PCa) a great threat to men’s health. Novel modalities with different structures or mechanisms are in urgent need to overcome these two challenges. Traditional Chinese medicine toad venom-derived agents (TVAs) have shown to possess versatile bioactivities in treating certain diseases including PCa. In this work, we attempted to have an overview of bufadienolides, the major bioactive components in TVAs, in the treatment of PCa in the past decade, including their derivatives developed by medicinal chemists to antagonize certain drawbacks of bufadienolides such as innate toxic effect to normal cells. Generally, bufadienolides can effectively induce apoptosis and suppress PCa cells in-vitro and in-vivo, majorly mediated by regulating certain microRNAs/long non-coding RNAs, or by modulating key pro-survival and pro-metastasis players in PCa. Importantly, critical obstacles and challenges using TVAs will be discussed and possible solutions and future perspectives will also be presented in this review. Further in-depth studies are clearly needed to decipher the mechanisms, e.g., targets and pathways, toxic effects and fully reveal their application. The information collected in this work may help evoke more effects in developing bufadienolides as therapeutic agents in PCa.

Combined time-restricted feeding and cisplatin enhance the anti-tumor effects in cisplatin-resistant and -sensitive lung cancer cells

Combination therapy as an important treatment option for lung cancer has been attracting attention due to the primary and acquired resistance of chemotherapeutic drugs in the clinical application. In the present study, as a new therapy strategy, concomitant treatment with time-restricted feeding (TRF) plus cisplatin (DDP) on lung cancer growth was investigated in DDP-resistant and DDP-sensitive lung cancer cells. We first found that TRF significantly enhanced the drug susceptibility of DDP in DDP-resistant A549 (A549/DDP) cell line, illustrated by reversing the inhibitory concentration 50 (IC₅₀) values of A549/DDP cells to normal level of parental A549 cells. We also found that TRF markedly enhanced DDP inhibition on cell proliferation, migration, as well as promoted apoptosis compared to the DDP alone group in A549, H460 and A549/DDP cells lines. We further revealed that the synergistic anti-tumor effect of combined DDP and TRF was greater than that of combined DDP and simulated fasting condition (STS), a known anti-tumor cellular medium. Moreover, mRNA sequence analysis from A549/DDP cell line demonstrated the synergistic anti-tumor effect involved in upregulated pathways in p53 signaling pathway and apoptosis. Notably, compared with the DDP alone group, combination of TRF and DDP robustly upregulated the P53 protein expression without mRNA level change by regulating its stability via promoting protein synthesis and inhibiting degradation, revealed by cycloheximide and MG132 experiments. Collectively, our results suggested that TRF in combination with cisplatin might be an additional novel therapeutic strategy for patients with lung cancer.

DHW-208, A Novel Phosphatidylinositol 3-Kinase (PI3K) Inhibitor, Has Anti-Hepatocellular Carcinoma Activity Through Promoting Apoptosis and Inhibiting Angiogenesis

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide with high prevalence and lethality. Due to insidious onset and lack of early symptoms, most HCC patients are diagnosed at advanced stages without adequate methods but systemic therapies. PI3K/AKT/mTOR signaling pathway plays a crucial role in the progression and development of HCC. Aberrant activation of PI3K/AKT/mTOR pathway is involved in diverse biological processes, including cell proliferation, apoptosis, migration, invasion and angiogenesis. Therefore, the development of PI3K-targeted inhibitors is of great significance for the treatment of HCC. DHW-208 is a novel 4-aminoquinazoline derivative pan-PI3K inhibitor. This study aimed to assess the therapeutic efficacy of DHW-208 in HCC and investigate its underlying mechanism. DHW-208 could inhibit the proliferation, migration, invasion and angiogenesis of HCC through the PI3K/AKT/mTOR signaling pathway in vitro. Consistent with the in vitro results, in vivo studies demonstrated that DHW-208 elicits an antitumor effect by inhibiting the PI3K/AKT/mTOR-signaling pathway with a high degree of safety in HCC. Therefore, DHW-208 is a candidate compound to be developed as a small molecule PI3K inhibitor for the treatment of HCC, and our study provides a certain theoretical basis for the treatment of HCC and the development of PI3K inhibitors.