Itraconazole induces apoptosis and cell cycle arrest via inhibiting Hedgehog signaling in gastric cancer cells

Experimental and network pharmacology certify itraconazole mitigates fluorouracil-induced intestinal damage by inhibiting mTOR-mediated intestinal senescence

Fluorouracil (Fu) is one of the first-line drugs for colorectal cancer, but severe intestinal damage limits its clinical application. The intestinal damage caused by Fu is closely related to cellular senescence. Itraconazole (Itr) is primarily used to treat fungal infections. At present, the effects of Itr on intestinal senescence and damage have not been the subject of extensive study. In this study, NCM460 cells were utilized to establish a model of Fu-induced senescence and inflammation. Treatment of NCM460 cells with Fu resulted in increased senescence-associated beta-galactosidase (SA-β-Gal) activity, elevated p21 expression, and the upregulation of p16 and p53. Additionally, there was enhanced Senescence-Associated Secretory Phenotype (SASP) and an increase in inflammatory factors IL-1β and IL-6. The present study demonstrated that the treatment of Itr effectively alleviated the changes caused by Fu in NCM460 cells. Moreover, it was observed that Itr was efficacious in mitigating intestinal damage induced by Fu in Balb/c mice. Network pharmacology analysis and experimental validation identified the mTOR signaling pathway as a key target of Itr in treating Fu-induced intestinal aging and inflammation. Our findings demonstrate that Itr significantly inhibited the mTOR pathway, while the mTOR activator MHY1485 restored mTOR activity and promoted senescence. Moreover, it was observed that Itr could effectively enhance the tumor-killing effect of Fu in HCT116 and SW480 cells, as well as in Balb/c nude mice. In conclusion, Itr is a promising candidate for reducing intestinal side effects and enhancing Fu's efficacy in the treatment of colorectal cancer.

Itraconazole promotes melanoma cells apoptosis via inhibiting hedgehog signaling pathway-mediated autophagy

Background

Itraconazole, a widely used antifungal medication, has shown potential in inhibiting tumor growth and reducing angiogenesis. However, its role in melanoma tumor growth remains insufficiently explored. This study investigates the inductive effect of itraconazole on autophagy-mediated apoptosis in melanoma cells.

Method

Potential drug targets were identified using the PMF machine learning algorithm. Apoptosis and cell cycle in melanoma cell lines A375 and A2058 were assessed via flow cytometry. Western blot analysis was performed to examine autophagy and associated signaling proteins, while autophagy flux and autophagosome formation were visualized using fluorescence microscopy. A melanoma cell xenograft mouse model was established to evaluate the inhibitory mechanisms of itraconazole on tumor cell proliferation.

Result

Using the PMF machine learning algorithm, SQSTM1 was identified as the primary target of itraconazole. Itraconazole inhibited melanoma cell proliferation by inducing G1 phase arrest and autophagy-mediated apoptosis in A375 and A2058 cells. Furthermore, itraconazole suppressed Hedgehog signaling and counteracted the activation of the Hedgehog agonist recombinant human Sonic Hedgehog (rhShh). In vivo, itraconazole significantly reduced tumor growth in A375 and A2058 xenograft models.

Conclusion

Itraconazole induces autophagy-mediated apoptosis in melanoma cells by inhibiting Hedgehog signaling, underscoring its potential as a therapeutic option for melanoma treatment.

IC Regimen: Delaying Resistance to Lorlatinib in ALK Driven Cancers by Adding Repurposed Itraconazole and Cilostazol

Lorlatinib is a pharmaceutical ALK kinase inhibitor used to treat ALK driven non-small cell lung cancers. This paper analyses the intersection of past published data on the physiological consequences of two unrelated drugs from general medical practice-itraconazole and cilostazol-with the pathophysiology of ALK positive non-small cell lung cancer. A conclusion from that data analysis is that adding itraconazole and cilostazol may make lorlatinib more effective. Itraconazole, although marketed worldwide as a generic antifungal drug, also inhibits Hedgehog signaling, Wnt signaling, hepatic CYP3A4, and the p-gp efflux pump. Cilostazol, marketed worldwide as a generic thrombosis preventative drug, acts by inhibiting phosphodiesterase 3, and, by so doing, lowers platelets' adhesion, thereby partially depriving malignant cells of the many tumor trophic growth factors supplied by platelets. Itraconazole may enhance lorlatinib effectiveness by (i) reducing or stopping a Hedgehog-ALK amplifying feedback loop, by (ii) increasing lorlatinib's brain levels by p-gp inhibition, and by (iii) inhibiting growth drive from Wnt signaling. Cilostazol, surprisingly, carries minimal bleeding risk, lower than that of aspirin. Risk/benefit assessment of the combination of metastatic ALK positive lung cancer being a low-survival disease with the predicted safety of itraconazole-cilostazol augmentation of lorlatinib favors a trial of this drug trio in ALK positive lung cancer.

Therapeutic potential of hedgehog signaling in advanced cancer types

In this chapter, we have made an attempt to elucidate the relevance of hedgehog signaling pathway in tumorigenesis. Here, we have described different types of hedgehog signaling (canonical and non-canonical) with emphasis on the different mechanisms (mutation-driven, autocrine, paracrine and reverse paracrine) it adopts during tumorigenesis. We have discussed the role of hedgehog signaling in regulating cell proliferation, invasion and epithelial-to-mesenchymal transition in both local and advanced cancer types, as reported in different studies based on preclinical and clinical models. We have specifically addressed the role of hedgehog signaling in aggressive neuroendocrine tumors as well. We have also elaborated on the studies showing therapeutic relevance of the inhibitors of hedgehog signaling in cancer. Evidence of the crosstalk of hedgehog signaling components with other signaling pathways and treatment resistance due to tumor heterogeneity have also been briefly discussed. Together, we have tried to put forward a compilation of the studies on therapeutic potential of hedgehog signaling in various cancers, specifically aggressive tumor types with a perspective into what is lacking and demands further investigation.

Itraconazole halts hepatocellular carcinoma progression by modulating sonic hedgehog signaling in rats: A novel therapeutic approach

Liver cancer stands as the fourth leading global cause of death, and its prognosis remains grim due to the limited effectiveness of current medical interventions. Among the various pathways implicated in the development of hepatocellular carcinoma (HCC), the hedgehog signaling pathway has emerged as a crucial player. Itraconazole, a relatively safe and cost-effective antifungal medication, has gained attention for its potential as an anticancer agent. Its primary mode of action involves inhibiting the hedgehog pathway, yet its impact on HCC has not been elucidated. The main objective of this study was to investigate the effect of itraconazole on diethylnitrosamine-induced early-stage HCC in rats. Our findings revealed that itraconazole exhibited a multifaceted arsenal against HCC by downregulating the expression of key components of the hedgehog pathway, shh, smoothened (SMO), and GLI family zinc finger 1 (GLI1), and GLI2. Additionally, itraconazole extended survival and improved liver tissue structure, attributed mainly to its inhibitory effects on hedgehog signaling. Besides, itraconazole demonstrated a regulatory effect on Notch1, and Wnt/β-catenin signaling molecules. Consequently, itraconazole displayed diverse anticancer properties, including anti-inflammatory, antiangiogenic, antiproliferative, and apoptotic effects, as well as the potential to induce autophagy. Moreover, itraconazole exhibited a promise to impede the transformation of epithelial cells into a more mesenchymal-like phenotype. Overall, this study emphasizes the significance of targeting the hedgehog pathway with itraconazole as a promising avenue for further exploration in clinical studies related to HCC treatment.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Repurposing antifungal drugs for cancer therapy

BACKGROUND

Repurposing antifungal drugs in cancer therapy has attracted unprecedented attention in both preclinical and clinical research due to specific advantages, such as safety, high-cost effectiveness and time savings compared with cancer drug discovery. The surprising and encouraging efficacy of antifungal drugs in cancer therapy, mechanistically, is attributed to the overlapping targets or molecular pathways between fungal and cancer pathogenesis. Advancements in omics, informatics and analytical technology have led to the discovery of increasing "off-site" targets from antifungal drugs involved in cancerogenesis, such as smoothened (D477G) inhibition from itraconazole in basal cell carcinoma.

AIM OF REVIEW

This review illustrates several antifungal drugs repurposed for cancer therapy and reveals the underlying mechanism based on their original target and "off-site" target. Furthermore, the challenges and perspectives for the future development and clinical applications of antifungal drugs for cancer therapy are also discussed, providing a refresh understanding of drug repurposing.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review may provide a basic understanding of repurposed antifungal drugs for clinical cancer management, thereby helping antifungal drugs broaden new indications and promote clinical translation.

Zinc Finger Proteins in the War on Gastric Cancer: Molecular Mechanism and Clinical Potential

According to the 2020 global cancer data released by the World Cancer Research Fund (WCRF) International, gastric cancer (GC) is the fifth most common cancer worldwide, with yearly increasing incidence and the second-highest fatality rate in malignancies. Despite the contemporary ambiguous molecular mechanisms in GC pathogenesis, numerous in-depth studies have demonstrated that zinc finger proteins (ZFPs) are essential for the development and progression of GC. ZFPs are a class of transcription factors with finger-like domains that bind to Zn²⁺ extensively and participate in gene replication, cell differentiation and tumor development. In this review, we briefly outline the roles, molecular mechanisms and the latest advances in ZFPs in GC, including eight principal aspects, such as cell proliferation, epithelial-mesenchymal transition (EMT), invasion and metastasis, inflammation and immune infiltration, apoptosis, cell cycle, DNA methylation, cancer stem cells (CSCs) and drug resistance. Intriguingly, the myeloid zinc finger 1 (MZF1) possesses reversely dual roles in GC by promoting tumor proliferation or impeding cancer progression via apoptosis. Therefore, a thorough understanding of the molecular mechanism of ZFPs on GC progression will pave the solid way for screening the potentially effective diagnostic indicators, prognostic biomarkers and therapeutic targets of GC.

Solanine Represses Gastric Cancer Growth by Mediating Autophagy Through AAMDC/MYC/ATF4/Sesn2 Signaling Pathway

Purpose

Solanine is the main component of the plant Solanum, which has been shown to provide growth-limiting activities in a variety of human cancers. However, little is known about its function in gastric cancer (GC).

Methods

We investigated the effect of solanine on GC in vivo and in vitro. The inhibition rate of solanine on the tumor was observed by constructing a subcutaneous tumor in nude mice. Morphological changes were analyzed with H&E staining. The expression of ATF4 was detected by IF analysis. MTT assays, EdU staining, and colony formation assays were used to detect the inhibition rate of solanine on GC cells. Matrigel transwells were used to detect the invasion of GC cells. Cell migration was measured using the wound healing assay. The flow cytometric analysis was used to monitor changes in the cell cycle and cell apoptosis. Western blotting was used to detect major proteins in cells and tumors.

Results

Solanine suppressed gastric tumorigenesis. Solanine also inhibited the proliferation, invasion and mitigation of GC cells, and induced cell cycle arrest and apoptosis in vitro. Moreover, the growth-limiting activities of solanine in gastric cancer were related to the suppression of the AAMDC/MYC/ATF4/Sesn2 pathway-mediated autophagy. Overexpression of AAMDC reversed the inhibitory effect of solanine on autophagy and gastric cancer.

Conclusion

In summary, our findings indicate that solanine confers growth-limiting activities by deactivating the AAMDC-regulated autophagy in gastric cancer.

Ciclopirox drives growth arrest and autophagic cell death through STAT3 in gastric cancer cells

Ciclopirox (CPX), an antifungal drug, has recently been identified as a promising agent for cancer treatment. However, the effects and underlying mechanism of CPX as an antitumor agent of gastric cancer (GC) remain largely unknown. Here, we found that CPX dramatically suppresses GC xenograft growth in vitro via inhibiting proliferation and stimulating autophagic cell death rather than apoptosis. Moreover, CPX (20 mg/kg, intraperitoneally) substantially inhibits GC xenograft tumor growth in vivo. Mechanistically, CPX promotes growth arrest and autophagic cell death through suppressing the phosphorylation of signal transducers and activators of transcription 3 (STAT3) at tyrosine 705 (Tyr705) and serine 727 (Ser727) sites, respectively. Additionally, CPX induces STAT3 ubiquitination, which subsequently leads to a decrease in the p-STAT3 (Ser727) level. On the other hand, CPX represses the p-STAT3 (Tyr705) level via p-Src (Tyr416) inhibition. Collectively, our findings unmask a novel mechanism by which CPX regulates growth and autophagic cell death in GC cells via regulating the phosphorylation of STAT3 both at Tyr705 and Ser727 residues, and suggest that CPX may be a potential treatment for GC.

Repurposed itraconazole for use in the treatment of malignancies as a promising therapeutic strategy

Understanding cancer biology and the development of novel agents for cancer treatment has always been the goal of cancer researchers. However, the research and development of new drugs is hindered by its long development time, exorbitant cost, high regulatory hurdles, and staggering failure rates. Given the challenges involved drug development for cancer therapies, alternative strategies, in particular the repurposing of 'old' drugs that have been approved for other indications, are attractive. Itraconazole is an FDA-approved anti-fungal drug of the triazole class, and has been used clinically for more than 30 years. Recent drug repurposing screens revealed itraconazole exerts anti-cancer activity via inhibiting angiogenesis and multiple oncogenic signaling pathways. To explore the potential utilization of itraconazole in different types of malignancies, we retrieved the published literature relating to itraconazole in cancer and reviewed the mechanisms of itraconazole in preclinical and clinical cancer studies. Current research predicts the hedgehog signaling pathway as the main target by which itraconazole inhibits a variety of solid and hematological cancers. As clinical trial results become available, itraconazole could emerge as a new antitumor drug that can be used in combination with first-line antitumor drugs.

A minimalist and robust chemo-photothermal nanoplatform capable of augmenting autophagy-modulated immune response against breast cancer

Previously used in anti-fungal therapy, itraconazole has now been shown to be successful in treating advanced breast cancer (NCT00798135). However, its poor solubility still restricts its application in clinical treatment. There is therefore an urgent need for combined methods to enhance the therapeutic effect of itraconazole (IC) in breast cancer treatment. With this goal, co-assembled IC/IR820 NPs with synergistic photonic hyperthermia and itraconazole payloads have been constructed to overcome these shortcomings. The IC/IR820 NPs show an enhanced therapeutic effect on breast cancer by inducing reactive oxygen species (ROS)-mediated apoptosis and autophagic death. Further evaluation in a mouse model has shown impressive effects of the IC/IR820 NPs on both inhibiting tumor metastasis and activating immunity to prevent tumor recurrence. Mechanistically, itraconazole may promote both tumor cell antigen presentation through autophagy and the activation of dendritic cells to induce an immune response, which displays a synergistic effect with the immune response generated by photothermal therapy to inhibit tumor recurrence. This strategy of combining itraconazole and IR820 into one minimalist and robust nanoplatform through co-assembly results in excellent therapeutic efficacy, suggesting its potential application as an alternative method for the clinical treatment of breast cancer.

Induced Cell Cycle Arrest in Triple-Negative Breast Cancer by Combined Treatment of Itraconazole and Rapamycin

Triple-negative breast cancer (TNBC) is the aggressive molecular type of breast carcinoma, with a high metastasis/relapse incidence and cancer-related death rate, due to lack of specific therapeutic targets in the clinic. Exploring potential therapeutic targets or developing novel therapeutic strategies are the focus of intense research to improve the survival and life quality of patients with TNBC. The current study focused on drugs targeting the mTOR signaling pathway by investigating the potential utilization of itraconazole (ITZ) combined with rapamycin in the treatment of TNBC. CCK-8, colony formation and transwell assays were conducted to evaluate the effect of ITZ with rapamycin in combination on MDA-MB-231 and BT-549 TNBC cells. Synergistic inhibition was found in terms of proliferation and motility of TNBC cells. However, apoptosis was not enhanced by the combined treatment of ITZ and rapamycin. Flow cytometry analysis showed that ITZ and/or rapamycin arrested cells in G0/G1 phase and prevented G1/S phase transition. Reduced cyclin D1 protein levels were consistent with G0/G1 phase arrest, especially when resulting from the combination of ITZ with rapamycin. In conclusion, the combination of ITZ with rapamycin is a promising therapeutic strategy for patients with TNBC through synergistically arresting cells in the G0/G1 phase of the cell cycle, rather than inducing apoptosis.

Itraconazole improves survival outcomes in patients with colon cancer by inducing autophagic cell death and inhibiting transketolase expression

The incidence of colon cancer continues to increase annually, and it is the leading cause of cancer-associated mortality worldwide. Altering cell metabolism and inducing autophagic cell death have recently emerged as novel strategies in preventing tumor growth. Autophagy plays an essential role in energy production by degrading damaged cellular components and is also associated with tumor proliferation suppression. Itraconazole is an FDA-approved drug used as an antifungal medication and has been reported to induce autophagic cell death in breast cancer. However, the effects of itraconazole on cell metabolism and induction of apoptosis in colon cancer remain unclear. The present study analyzed extensive data from patients diagnosed with colon cancer using itraconazole between January 2011 and December 2015, from the Taiwanese National Health Insurance Research Database. The underlying molecular mechanisms of itraconazole in autophagy-induced cell death were also investigated. The results demonstrated that the 5-year survival rate was significantly higher in patients with colon cancer who received itraconazole treatment. In addition, itraconazole decreased the viability and cell colony formation, and induced cleaved caspase-3 expression and G₁ cell cycle arrest of COLO 205 and HCT 116 cells. Notably, itraconazole induced autophagy by enhancing LC3B and p62 expression. Following LC3 knockdown, the viability of itraconazole-treated COLO 205 and HCT 116 cells notably improved. Taken together, the results of the present study suggest that itraconazole may have a beneficial effect on patients with colon cancer, and its underlying molecular mechanisms may be associated with the induction of autophagic cell death.

Itraconazole Exerts Its Antitumor Effect in Esophageal Cancer By Suppressing the HER2/AKT Signaling Pathway

Itraconazole, an FDA-approved antifungal, has antitumor activity against a variety of cancers. We sought to determine the effects of itraconazole on esophageal cancer and elucidate its mechanism of action. Itraconazole inhibited cell proliferation and induced G1-phase cell-cycle arrest in esophageal squamous cell carcinoma and adenocarcinoma cell lines. Using an unbiased kinase array, we found that itraconazole downregulated protein kinase AKT phosphorylation in OE33 esophageal adenocarcinoma cells. Itraconazole also decreased phosphorylation of downstream ribosomal protein S6, transcriptional expression of the upstream receptor tyrosine kinase HER2, and phosphorylation of upstream PI3K in esophageal cancer cells. Lapatinib, a tyrosine kinase inhibitor that targets HER2, and siRNA-mediated knockdown of HER2 similarly suppressed cancer cell growth in vitro Itraconazole significantly inhibited growth of OE33-derived flank xenografts in mice with detectable levels of itraconazole and its primary metabolite, hydroxyitraconazole, in esophagi and tumors. HER2 total protein and phosphorylation of AKT and S6 proteins were decreased in xenografts from itraconazole-treated mice compared to xenografts from placebo-treated mice. In an early phase I clinical trial (NCT02749513) in patients with esophageal cancer, itraconazole decreased HER2 total protein expression and phosphorylation of AKT and S6 proteins in tumors. These data demonstrate that itraconazole has potent antitumor properties in esophageal cancer, partially through blockade of HER2/AKT signaling.

Drug Repurposing in Oncology: Current Evidence and Future Direction

BACKGROUND

Drug repurposing, the application of known drugs and compounds with a primary non-oncology purpose, might be an attractive strategy to offer more effective treatment options to cancer patients at a low cost and reduced time.

METHODS

This review described a total of 10 kinds of non-oncological drugs from more than 100 mechanical studies as well as evidence from population-based studies. The future direction of repurposed drug screening is discussed by using patient-derived tumor organoids.

RESULTS

Many old drugs showed previously unknown effects or off-target effects and can be intelligently applied for cancer chemoprevention and therapy. The identification of repurposed drugs needs to combine evidence from mechanical studies and population-based studies. Due to the heterogeneity of cancer, patient-derived tumor organoids can be used to screen the non-oncological drugs in vitro.

CONCLUSION

These identified old drugs could be repurposed in oncology and might be added as adjuvants and finally benefit patients with cancers.

Unfolding antifungals: as a new foe to pancreatic ductal adenocarcinoma-a mini-review

Increased deaths caused due to pancreatic cancer (PC) is drawing much attention towards an immediate need for therapeutics that could possibly control this disease and increase the patients' survival rate. Despite the long list of well-established chemotherapeutic drugs in several cancers none have proved to be efficient against PC, and the increasing chemoresistance to the gold standard drug gemcitabine calls a need to search for solutions in other categories of drug. To the rescue, antifungals have shown themselves to be effective against PC and can increase gemcitabine sensitivity against PC. In this mini-review, we reported how antifungals have targeted PC and helped to reduce its lethality. Additionally, it is emphasized that how the antifungals show new mechanisms that could be triggered by using either monotherapy or combination therapy of these antifungals with chemotherapeutic drugs in PC. Moreover it shows an approach of using other drugs with possible same or other mechanism to know their effect on PC.

Itraconazole synergistically increases therapeutic effect of paclitaxel and 99mTc-MIBI accumulation, as a probe of P-gp activity, in HT-29 tumor-bearing nude mice

P-glycoprotein (P-gp), is an important efflux pump involved in chemotherapy resistance in human colon cancer. We investigated the efficacy of itraconazole as a P-gp inhibitor and its therapeutic synergistic relationship to paclitaxel through 99mTc-MIBI accumulation in HT-29 tumor-bearing nude mice. Histopathological screening along with in vitro experiments was done for further assessment. Itraconazole successfully inhibited P-gp mediated 99mTc-MIBI efflux, increasing its in vitro accumulation in itraconazole-receiving dishes. Notably, the co-administration of itraconazole with paclitaxel significantly enhanced the in vitro cytotoxicity effect of paclitaxel in itraconazole + paclitaxel wells containing HT-29 cells. Compared to the control, tumor volume in mice treated with itraconazole, paclitaxel and itraconazole +paclitaxel showed growth suppression approximately by 36.21, 60.02, and 73.3% respectively. And compared to paclitaxel group, the nude mice co-treated with paclitaxel and itraconazole showed suppression of tumor growth by about 33.31 % at the end of the treatment period. Also the biodistribution result showed that the co-administration of itraconazole with paclitaxel raised the mean tumor radioactivity accumulation compared to control and paclitaxel group. When given paclitaxel alone, the ID% of hepatic and cardiac tissue was reduced while co-administration of itraconazole with paclitaxel increased 99mTc-MIBI accumulation in these organs. Furthermore, the histopathological findings confirmed the biodistribution results. These results demonstrate that although monotherapy with itraconazole or paclitaxel has anti-tumor activity against HT-29 human colorectal cancer, a synergistic anti-tumor activity can be achieved when itraconazole is co-administered with paclitaxel. Also, 99mTc-MIBI is an effective radiotracer for monitoring response to treatment in MDR tumors.

CircNEIL3 regulatory loop promotes pancreatic ductal adenocarcinoma progression via miRNA sponging and A-to-I RNA-editing

Background

A growing number of studies have focused on investigating circRNAs as crucial regulators in the progression of multiple cancer types. Nevertheless, the biological effects and underlying mechanisms of circRNAs in pancreatic ductal adenocarcinoma (PDAC) remain unclear.

Methods

Differentially expressed circRNAs between cancerous tissue and adjacent normal tissues were identified by RNA sequencing in PDAC. Subsequently, in vitro and in vivo functional experiments were performed to investigate the functional roles of circNEIL3 in PDAC tumour growth and metastasis. Furthermore, RNA pull-down, dual-luciferase reporter assays, RNA immunoprecipitation (RIP) assays, fluorescent in situ hybridization (FISH) and Sanger sequencing assays were performed to examine the circular interaction among circNEIL3, miR-432-5p and adenosine deaminases acting on RNA 1 (ADAR1).

Results

CircNEIL3 was upregulated in PDAC and promoted the progression of PDAC cells both in vitro and in vivo. Mechanistically, circNEIL3 was shown to regulate the expression of ADAR1 by sponging miR-432-5p to induce RNA editing of glioma-associated oncogene 1 (GLI1), ultimately influencing cell cycle progression and promoting epithelial-to-mesenchymal transition (EMT) in PDAC cells. Moreover, we discovered that the circNEIL3/miR-432-5p/ADAR1 axis was correlated with the PDAC clinical stage and overall survival of PDAC patients, while ADAR1 may reduce the biogenesis of circNEIL3.

Conclusions

Our findings reveal that circNEIL3 facilitates the proliferation and metastasis of PDAC through the circNEIL3/miR-432-5p/ADAR1/GLI1/cell cycle and EMT axis and that its expression is regulated by ADAR1 through a negative feedback loop. Therefore, circNEIL3 may serve as a prognostic marker and a therapeutic target for PDAC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01333-7.

Hedgehog signaling in gastrointestinal carcinogenesis and the gastrointestinal tumor microenvironment

The Hedgehog (HH) signaling pathway plays important roles in gastrointestinal carcinogenesis and the gastrointestinal tumor microenvironment (TME). Aberrant HH signaling activation may accelerate the growth of gastrointestinal tumors and lead to tumor immune tolerance and drug resistance. The interaction between HH signaling and the TME is intimately involved in these processes, for example, tumor growth, tumor immune tolerance, inflammation, and drug resistance. Evidence indicates that inflammatory factors in the TME, such as interleukin 6 (IL-6) and interferon-γ (IFN-γ), macrophages, and T cell-dependent immune responses, play a vital role in tumor growth by affecting the HH signaling pathway. Moreover, inhibition of proliferating cancer-associated fibroblasts (CAFs) and inflammatory factors can normalize the TME by suppressing HH signaling. Furthermore, aberrant HH signaling activation is favorable to both the proliferation of cancer stem cells (CSCs) and the drug resistance of gastrointestinal tumors. This review discusses the current understanding of the role and mechanism of aberrant HH signaling activation in gastrointestinal carcinogenesis, the gastrointestinal TME, tumor immune tolerance and drug resistance and highlights the underlying therapeutic opportunities.

Clinical and prognostic significances of cancer stem cell markers in gastric cancer patients: a systematic review and meta-analysis

Background

Gastric cancer (GC) is considered one of the most lethal malignancies worldwide, which is accompanied by a poor prognosis. Although reports regarding the importance of cancer stem cell (CSC) markers in gastric cancer progression have rapidly developed over the last few decades, their clinicopathological and prognostic values in gastric cancer still remain inconclusive. Therefore, the current meta-analysis aimed to quantitatively re-evaluate the association of CSC markers expression, overall and individually, with GC patients’ clinical and survival outcomes.

Methods

Literature databases including PubMed, Scopus, ISI Web of Science, and Embase were searched to identify the eligible articles. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were recorded or calculated to determine the relationships between CSC markers expression positivity and overall survival (OS), disease-free survival (DFS)/relapse-free survival (RFS), disease-specific survival (DSS)/ cancer-specific survival (CSS), and clinicopathological features.

Results

We initially retrieved 4,425 articles, of which a total of 66 articles with 89 studies were considered as eligible for this meta-analysis, comprising of 11,274 GC patients. Overall data analyses indicated that the overexpression of CSC markers is associated with TNM stage (OR = 2.19, 95% CI 1.84–2.61, P = 0.013), lymph node metastasis (OR = 1.76, 95% CI 1.54–2.02, P < 0.001), worse OS (HR = 1.65, 95% CI 1.54–1.77, P < 0.001), poor CSS/DSS (HR = 1.69, 95% CI 1.33–2.15, P < 0.001), and unfavorable DFS/RFS (HR = 2.35, 95% CI 1.90–2.89, P < 0.001) in GC patients. However, CSC markers expression was found to be slightly linked to tumor differentiation (OR = 1.25, 95% CI 1.01–1.55, P = 0.035). Sub-analysis demonstrated a significant positive relationship between most of the individual markers, specially Gli-1, Oct-4, CD44, CD44V6, and CD133, and clinical outcomes as well as the reduced survival, whereas overexpression of Lgr-5, Nanog, and sonic hedgehog (Shh) was not found to be related to the majority of clinical outcomes in GC patients.

Conclusion

The expression of CSC markers is mostly associated with worse outcomes in patients with GC, both overall and individual. The detection of a combined panel of CSC markers might be appropriate as a prognostic stratification marker to predict tumor aggressiveness and poor prognosis in patients with GC, which probably results in identifying novel potential targets for therapeutic approaches.

Tumor microenvironment pathways: Cross regulation in breast cancer metastasis

The tumor microenvironment (TME) is heterogeneous and contains a multiple cell population with surrounded immune cells, which plays a major role in regulating metastasis. The multifunctional pathways, Hedgehog (Hh), Wnt, Notch, and NF-kB, cross-regulates metastasis in breast cancer. This review presents substantial evidence for cross-regulation of TME components and signaling pathways, which makes breast TME more heterogeneous and complex, promoting breast cancer progression and metastasis as a highly aggressive form. We discoursed the importance of stromal and immune cells as well as their crosstalk in bridging the metastasis. We also discussed the role of Hh and Notch pathways in the intervention between breast cancer cells and macrophages to support TME; Notch signaling in the bidirectional communication between cancer cells and components of TME; Wnt signal pathway in controlling the factors responsible for EMT and NF-κB pathway in the regulation of genes controlling the inflammatory response. We also present the role of exosomes and their miRNAs in the cross-regulation of TME cells as well as pathways in the reprogramming of breast TME to support metastasis. Finally, we examined and discussed the targeted small molecule inhibitors and natural compounds targeting developmental pathways and proposed small molecule natural compounds as potential therapeutics of TME based on the multitargeting ability. In conclusion, the understanding of the molecular basis of the cross-regulation of TME pathways and their inhibitors helps identify molecular targets for rational drug discovery to treat breast cancers.

Triptolidenol, isolated from Tripterygium wilfordii, disrupted NF-κB/COX-2 pathway by targeting ATP-binding sites of IKKβ in clear cell renal cell carcinoma

Triptolidenol (TPD) is an epoxy diterpene lactone from Tripterygium wilfordii, which has been used for chronic nephritis in China，and possessed various pharmacological properties, such as anti-inflammatory and anti-cancer activities. However, the precise molecular antitumor mechanism of TPD remains to be elucidated. In this study, we investigated the effects of TPD on human clear cell renal cell carcinoma (ccRCC) and investigated its precise anti-tumor mechanisms. It was showed that TPD significantly suppressed ccRCC cell proliferation, cell migration, and induced cell cycle arrest at S phase. Furthermore, TPD also induced apoptosis by activating the cytochrome c (cyt c)/caspase cascade signaling pathway. Moreover, using confocal immunofluorescence, a dual-luciferase reporter assay and molecular docking study, the results showed that TPD obviously reduced the expression of COX-2 by inhibiting the kinase activity of IKKβ via targeting its ATP-binding domain, and then attenuating the transactivation of NF-κB. Collectively, our study demonstrated that TPD suppressed renal cell carcinoma growth through disrupting NF-κB/COX-2 pathway by targeting ATP-binding sites of IKKβ, and provided pharmacological evidence that TPD exhibits potential use in the treatment of COX-2-mediated diseases such as ccRCC.

Galectin-1 promotes vasculogenic mimicry in gastric adenocarcinoma via the Hedgehog/GLI signaling pathway

Background: Galectin-1 (GAL-1), which is encoded by LGALS1, promotes vasculogenic mimicry (VM) in gastric cancer (GC) tissue. However, the underlying mechanism remains unclear.

Methods: Immunohistochemical (IHC) and CD34-periodic acid-Schiff (PAS) double staining were used to investigate Glioma-associated oncogene-1(GLI1) expression and VM in paraffin-embedded sections from 127 patients with GC of all tumor stages. LGALS1 or GLI1 were stably transduced into MGC-803 cells and AGS cells, and western blotting, IHC, CD34-PAS double staining and three-dimensional culture in vitro, and tumorigenicity in vivo were used to explore the mechanisms of GAL-1/ GLI1 promotion of VM formation in GC tissues.

Results: A significant association between GAL-1 and GLI1 expression was identified by IHC staining, as well as a significant association between GLI1 expression and VM formation. Furthermore, overexpression of LGALS1 enhanced expression of GLI1 in MGC-803 and AGS cells. GLI1 promoted VM formation both in vitro and in vivo. The effects of GLI1 on VM formation were independent of LGALS1. Importantly, the expression of VM-related molecules, such as MMP2, MMP14 and laminin5γ2, was also affected upon GLI1 overexpression or silencing in GC cell lines. Conclusion: GAL-1 promotes VM in GC through the Hh/GLI pathway, which has potential as a novel therapeutic target for treatment of VM in GC.

Inhibition of CAL27 Oral Squamous Carcinoma Cell by Targeting Hedgehog Pathway With Vismodegib or Itraconazole

Oral Squamous Cell Carcinoma (OSCC) presents an important challenge for the health systems worldwide. Thus, unraveling the biological mechanisms involved in OSCC pathogenesis is essential to the discovery of new drugs with anticancer potential. The Hedgehog (HH) pathway has shown promising results as a therapeutic target both in vitro and in vivo. This study aimed to investigate the effects of vismodegib and itraconazole on the expression of Hedgehog (HH) genes (PTCH1, SMO, and GLI1), cell cycle and cell death in OSCC cells. Alamar Blue assay was used to assess the cytotoxicity of vismodegib and itraconazole in a panel of oral cancer cell lines, including CAL27. The expression of HH signaling components after treatment with vismodegib and itraconazole, at concentrations of 25 or 50 μg/ml was evaluated by qPCR. Cell cycle and apoptosis were evaluated by flow cytometry after 72 h treatment with 50 μg/ml of vismodegib or itraconazole. HH signaling was activated in OSCC cell lines CAL27, SCC4, SCC9, and HSC3. Vismodegib and itraconazole significantly reduced CAL27 cell viability after 48 h of treatment. Gene expression of PTCH1, SMO, and GLI1 decreased in response to 24 h of treatment with vismodegib or itraconazole. Furthermore, CAL27 cells exhibited alterations in morphology, cell size, and cellular granularity. An increase in the DNA fragmentation was observed after treatment and both inhibitors induced apoptosis after 72 h. In conclusion, SMO inhibitors vismodegib and itraconazole demonstrably reduced the expression of HH genes in CAL27 OSCC cell line. In addition, treatment with vismodegib and itraconazole reduced cellular viability and altered the morphology of CAL27 cells, and also induced apoptosis.

Recycling the Purpose of Old Drugs to Treat Ovarian Cancer

The main challenge in ovarian cancer treatment is the management of recurrences. Facing this scenario, therapy selection is based on multiple factors to define the best treatment sequence. Target therapies, such as bevacizumab and polymerase (PARP) inhibitors, improved patient survival. However, despite their achievements, ovarian cancer survival remains poor; these therapeutic options are highly costly and can be associated with potential side effects. Recently, it has been shown that the combination of repurposed, conventional, chemotherapeutic drugs could be an alternative, presenting good patient outcomes with few side effects and low costs for healthcare institutions. The main aim of this review is to strengthen the importance of repurposed drugs as therapeutic alternatives, and to propose an in vitro model to assess the therapeutic value. Herein, we compiled the current knowledge on the most promising non-oncological drugs for ovarian cancer treatment, focusing on statins, metformin, bisphosphonates, ivermectin, itraconazole, and ritonavir. We discuss the primary drug use, anticancer mechanisms, and applicability in ovarian cancer. Finally, we propose the use of these therapies to perform drug efficacy tests in ovarian cancer ex vivo cultures. This personalized testing approach could be crucial to validate the existing evidences supporting the use of repurposed drugs for ovarian cancer treatment.

Itraconazole inhibits the Hedgehog signaling pathway thereby inducing autophagy-mediated apoptosis of colon cancer cells

Itraconazole is as an antifungal medication used to treat systemic fungal infections. Recently, it has been reported to be effective in suppressing tumor growth by inhibiting the Hedgehog signaling pathway and angiogenesis. In the present study, we investigated whether itraconazole induces autophagy-mediated cell death of colon cancer cells through the Hedgehog signaling pathway. Cell apoptosis and cell cycle distribution of the colon cancer cell lines SW-480 and HCT-116 were detected by flow cytometry and terminal TUNEL assay. Autophagy and signal proteins were detected by western blotting and cell proliferation-associated antigen Ki-67 was measured using immunohistochemistry. The images of autophagy flux and formation of autophagosomes were observed by laser scanning confocal and/or transmission electron microscopy. Colon cancer cell xenograft mouse models were also established. Itraconazole treatment inhibited cell proliferation via G1 cell cycle arrest as well as autophagy-mediated apoptosis of SW-480 and HCT-116 colon cancer cells. In addition, the Hedgehog pathway was found to be involved in activation of itraconazole-mediated autophagy. After using the Hedgehog agonist recombinant human Sonic Hedgehog (rhshh), itraconazole could counteract the activation of rhshh. Moreover, treatment with itraconazole produced significant cancer inhibition in HCT-116-bearing mice. Thus, itraconazole may be a potential and effective therapy for the treatment of colon cancer.

Anti-fungal drug itraconazole exerts anti-cancer effects in oral squamous cell carcinoma via suppressing Hedgehog pathway

AIMS

To investigate the therapeutic potential of itraconazole in oral squamous cell carcinoma (OSCC) and its molecular mechanism.

MATERIALS AND METHODS

The in vitro anti-cancer effects of itraconazole was determined by CCK-8 assay and colony formation assay. Transwell and wound healing assays were used to examine cell invasion and migration. The in vivo therapeutic efficacy of itraconazole was assessed by OSCC patient-derived xenograft (PDX) model. Western blot was performed to explore the anti-cancer mechanism.

KEY FINDINGS

Itraconazole inhibited cell proliferation and colony formation of OSCC cells in a time and concentration dependent manner; induced cell cycle arrest and apoptosis, as well as inhibited cell invasion and migration. In the OSCC PDX model, itraconazole impeded tumor growth, reduced Ki-67 expression and induced apoptosis. Itraconazole downregulated the protein expression of Hedgehog pathway to inhibit proliferation and migration of oral squamous cell carcinoma cells, which can be revised by recombinant human sonic hedgehog protein (rSHH).

SIGNIFICANCE

Itraconazole showed anti-cancer effects on OSCC via inhibiting the Hedgehog pathway.

"Hedgehog pathway": a potential target of itraconazole in the treatment of cancer

PURPOSE

Itraconazole is an antifungal drug that has been clinically used for over 30 years. In recent years, scholars have discovered that it possesses an anticancer effect. Moreover, its mechanism has been clarified to some degree. What deserves to be mentioned is that itraconazole acting on the Hedgehog pathway has made a new progress in the treatment of cancers. While interestingly, studies have demonstrated that the Hedgehog pathway is largely activated in different cancer cells.

RESULT

This review tries to highlight the effect of itraconazole on smoothened receptor (SMO) in the Hedgehog pathway, thereby reducing the glioma-associated oncogene homolog (GLI) release and finally exhibiting a range of anticancer effects, promoting apoptosis of cancer cells, and inhibiting proliferation by indirect inhibition of NF-κB pathway and inflammation, moreover, promoting the expression of cyclin-dependent kinase inhibitors, inhibiting the expression of target genes transcribed by GLI such as BCL-2 and Cyclin-D1. Besides, itraconazole increases the number of Bnip3, subsequently, inducing the dissociation of the Beclin-1/BCL-2 binding complex, as a result of ultimately promoting autophagy of cancer cells.

CONCLUSION

As a new anticancer drug, whether itraconazole eventually entering clinical application requires the joint eforts of all scholars. In any case, an in-depth study on itraconazole will bring new hope for cancer patients in the near future.

The role of hedgehog signaling in gastric cancer: molecular mechanisms, clinical potential, and perspective

Patients with advanced gastric cancer usually have a poor prognosis and limited therapeutic options. Overcoming this challenge requires novel targets and effective drugs. The Hedgehog (Hh) signaling pathway plays a crucial role in the development of the gastrointestinal tract and maintenance of the physiologic function of the stomach. Aberrantly activated Hh signaling is implicated in carcinogenesis as well as maintenance of cancer stem cells. Somatic mutations in the components of Hh signaling (PTCH1 and SMO) have been shown to be a major cause of basal cell carcinoma, and dozens of Hh inhibitors have been developed. To date, two inhibitors (GDC-0449 and LDE225) have been approved by the U.S. Food and Drug Administration to treat basal cell carcinoma and medulloblastoma. Here, we review the role of the Hh signaling in the carcinogenesis and progression of gastric cancer and summarize recent findings on Hh inhibitors in gastric cancer. Hedgehog signaling is often aberrantly activated and plays an important role during inflammation and carcinogenesis of gastric epithelial cells. Further study of the precise mechanisms of Hh signaling in this disease is needed for the validation of therapeutic targets and evaluation of the clinical utility of Hh inhibitors for gastric cancer.

Inhibition of the hedgehog pathway for the treatment of cancer using Itraconazole

Itraconazole (ITZ) is an anti-fungal drug that has been used in clinical practice for nearly 35 years. Recently, numerous experiments have shown that ITZ possesses anti-cancer properties. The Hedgehog (Hh) pathway plays a pivotal role in fundamental processes, including embryogenesis, structure, morphology and proliferation in various species. This pathway is typically silent in adult cells, and inappropriate activity is linked to various tumor types. The most important mechanism of ITZ in the treatment of cancer is inhibition of the Hh pathway through the inhibition of smoothened receptors (SMO), glioma-associated oncogene homologs (GLI), and their downstream targets. In this review, we discuss the mechanisms of ITZ in the treatment of cancer through inhibition of the Hh pathway, which includes anti-inflammation, prevention of tumor growth, induction of cell cycle arrest, induction of apoptosis and autophagy, prevention of angiogenesis, and drug resistance. We also discuss the clinical use of ITZ in many types of cancers. We hope this review will provide more information to support future studies on ITZ in the treatment of various cancers.

Physicochemical and pathohistological changes in experimental fibrosarcoma tumors of hamsters treated with metformin and itraconazole

The anticancer effects of metformin (an antihyperglycaemic agent) and itraconazole (an antifungal agent), which are established non-oncologic drugs, were investigated in the present study. The weight, diameter, volume, density, surface, surface to volume ratio and immunohistochemistry of experimental fibrosarcoma tumors were investigated in hamsters treated with metformin and itraconazole. Briefly, the hamsters were injected with BHK-21/C13 cells in order to induce fibrosarcoma, and the animals were treated daily with metformin, itraconazole or a combination of the two drugs. Subsequently, blood samples were obtained for biochemical analyses and the tumors were excised, weighed and measured. The tumor samples were pathohistologically and immunohistochemically assessed for proliferation marker protein Ki-67, hematopoietic progenitor cell antigen CD34, cytochrome c oxidase subunit 4 (COX4), glucose transporter 1 (GLUT1) and inducible nitric oxide synthase (iNOS), and vital organs were toxicologically tested. Ki-67-positivity and cytoplasmic marker (CD34, COX4, GLUT1, iNOS) immunoexpression in the tumor samples were quantified. The results revealed that the combination of metformin and itraconazole significantly altered the physicochemical and pathohistological characteristics of the hamster fibrosarcoma tumors, including absolute and relative weight, volume, density, length, surface area, surface to volume ratio, Ki-67-positivity and the immunoexpression of cytoplasmic markers, without indications of toxicity. Furthermore, metformin with itraconazole demonstrated antiproliferative functions in cervical carcinoma HeLa, colon carcinoma HT-29, lung carcinoma A549 and fibrosarcoma BHK-21/C13 cells, with markedly lower cytotoxicity in the normal fetal lung MRC-5 cells. In conclusion, the administration of metformin in combination with itraconazole may inhibit the growth of fibrosarcoma tumors in vivo and the proliferation of various malignant cell lines in vitro, suggesting that this may be an effective and safe approach as a nontoxic anticancer adjuvant and relapse prevention therapy.

Isoalantolactone inhibits IKKβ kinase activity to interrupt the NF-κB/COX-2-mediated signaling cascade and induces apoptosis regulated by the mitochondrial translocation of cofilin in glioblastoma

Isoalantolactone (IATL), a sesquiterpene lactone compound, possesses many pharmacological and biological activities, but its role in glioblastoma (GBM) treatment is still unknown. The aim of the current study was to investigate the antiglioma effects of IATL and to explore the underlying molecular mechanisms. In the current study, the biological functions of IATL were examined by MTT, cell migration, colony formation, and cell apoptosis assays. Confocal immunofluorescence techniques, chromatin immunoprecipitation, and pull‐down assays were used to explore the precise underlying molecular mechanisms. To examine IATL activity and the molecular mechanisms by which it inhibits glioma growth in vivo, we used a xenograft tumor mouse model. Furthermore, Western blotting was used to confirm the changes in protein expression after IATL treatment. According to the results, IATL inhibited IKKβ phosphorylation, thus inhibiting both the binding of NF‐κB to the cyclooxygenase 2 (COX‐2) promoter and the recruitment of p300 and eventually inhibiting COX‐2 expression. In addition, IATL induced glioma cell apoptosis by promoting the conversion of F‐actin to G‐actin, which in turn activates the cytochrome c (Cyt c) and caspase‐dependent apoptotic pathways. In the animal experiments, IATL reduced the size and weight of glioma tumors in xenograft mice and inhibited the expression of COX‐2 and phosphorylated NF‐κB p65 in the transplanted tumors. In conclusion, the current study indicated that IATL inhibited the expression of COX‐2 through the NF‐κB signaling pathway and induced the apoptosis of glioma cells by increasing actin transformation. These results suggested that IATL could be greatly effective in GBM treatment.

Study of New Therapeutic Strategies to Combat Breast Cancer Using Drug Combinations

Cancer is a disease that affects and kills millions of people worldwide. Breast cancer, especially, has a high incidence and mortality, and is challenging to treat. Due to its high impact on the health sector, oncological therapy is the subject of an intense and very expensive research. To improve this therapy and reduce its costs, strategies such as drug repurposing and drug combinations have been extensively studied. Drug repurposing means giving new usefulness to drugs which are approved for the therapy of various diseases, but, in this case, are not approved for cancer therapy. On the other hand, the purpose of combining drugs is that the response that is obtained is more advantageous than the response obtained by the single drugs. Using drugs with potential to be repurposed, combined with 5-fluorouracil, the aim of this project was to investigate whether this combination led to therapeutic benefits, comparing with the isolated drugs. We started with a screening of the most promising drugs, with verapamil and itraconazole being chosen. Several cellular viability studies, cell death and proliferation studies, mainly in MCF-7 cells (Michigan Cancer Foundation-7, human breast adenocarcinoma cells) were performed. Studies were also carried out to understand the effect of the drugs at the level of possible therapeutic resistance, evaluating the epithelial-mesenchymal transition. Combining all the results, the conclusion is that the combination of verapamil and itraconazole with 5-fluorouracil had benefits, mainly by decreasing cell viability and proliferation. Furthermore, the combination of itraconazole and 5-fluorouracil seemed to be the most effective, being an interesting focus in future studies.

RAB31 Targeted by MiR-30c-2-3p Regulates the GLI1 Signaling Pathway, Affecting Gastric Cancer Cell Proliferation and Apoptosis

Background: Gastric cancer (GC), one of the most common cancers worldwide, is highly malignant and fatal. Ras-related protein in brain 31 (RAB31), a member of the RAB family of oncogenes, participates in the process of carcinogenesis and cancer development; however, its role in GC progression is unknown.

Methods: In our study, 90 pairs of tissue microarrays were used to measure the levels of RAB31 protein by immunochemistry, and 22 pairs of fresh tissue were used to measure the levels of RAB31 mRNA by quantitative PCR. We also investigated the effects of RAB31 on tumor growth both in vitro and in vivo.

Results: RAB31 was overexpressed in GC tissues, and its overexpression predicted poor survival in patients. In a nude mouse model, depletion of RAB31 inhibited tumor growth. In vitro, silencing of RAB31 suppressed cell viability, promoted cell cycle arrest, enhanced apoptosis, and affected the expression of cell cycle and apoptotic proteins; these effects were mediated by glioma-associated oncogene homolog 1 (GLI1). Co-immunoprecipitation and immunofluorescence assays confirmed that RAB31 interacted with GLI1. In addition, luciferase reporter assays and Western blotting showed that microRNA-30c-2-3p modulated the RAB31/GLI1 pathway by targeting the 3′-untranslated region of RAB31.

Conclusions: Collectively, these data show that RAB31 is regulated by microRNA-30c-2-3p, and functions as an oncogene in GC tumorigenesis and development by interacting with GLI1. Therefore, targeting the miR-30c-2-3p/RAB31/GLI1 axis may be a therapeutic intervention for gastric cancer.

Cytotoxic and Genotoxic Effects of Fluconazole on African Green Monkey Kidney (Vero) Cell Line

Fluconazole is a broad-spectrum triazole antifungal that is well-established as the first-line treatment for Candida albicans infections. Despite its extensive use, reports on its genotoxic/mutagenic effects are controversial; therefore, further studies are needed to better clarify such effects. African green monkey kidney (Vero) cells were exposed in vitro to different concentrations of fluconazole and were then evaluated for different parameters, such as cytotoxicity (MTT/cell death by fluorescent dyes), genotoxicity/mutagenicity (comet assay/micronucleus test), and induction of oxidative stress (DCFH-DA assay). Fluconazole was used at concentrations of 81.6, 163.2, 326.5, 653, 1306, and 2612.1μM for the MTT assay and 81.6, 326.5, and 1306μM for the remaining assays. MTT results showed that cell viability reduced upon exposure to fluconazole concentration of 1306μM (85.93%), being statistically significant (P<0.05) at fluconazole concentration of 2612.1μM (35.25%), as compared with the control (100%). Fluconazole also induced necrosis (P<0.05) in Vero cell line when cells were exposed to all concentrations (81.6, 326.5, and 1306μM) for both tested harvest times (24 and 48 h) as compared with the negative control. Regarding genotoxicity/mutagenicity, results showed fluconazole to increase significantly (P<0.05) DNA damage index, as assessed by comet assay, at 1306μM versus the negative control (DI=1.17 vs DI=0.28, respectively). Micronucleus frequency also increased until reaching statistical significance (P<0.05) at 1306μM fluconazole (with 42MN/1000 binucleated cells) as compared to the negative control (13MN/1000 binucleated cells). Finally, significant formation of reactive oxygen species (P<0.05) was observed at 1306μM fluconazole vs the negative control (OD=40.9 vs OD=32.3, respectively). Our experiments showed that fluconazole is cytotoxic and genotoxic in the assessed conditions. It is likely that such effects may be due to the oxidative properties of fluconazole and/or the presence of FMO (flavin-containing monooxygenase) in Vero cells.

Hedgehog Signaling Pathway and Autophagy in Cancer

Hedgehog (Hh) pathway controls complex developmental processes in vertebrates. Abnormal activation of Hh pathway is responsible for tumorigenesis and maintenance of multiple cancers, and thus addressing this represents promising therapeutic opportunities. In recent years, two Hh inhibitors have been approved for basal cell carcinoma (BCC) treatment and show extraordinary clinical outcomes. Meanwhile, a series of novel agents are being developed for the treatment of several cancers, including lung cancer, leukemia, and pancreatic cancer. Unfortunately, Hh inhibition fails to show satisfactory benefits in these cancer types compared with the success stories in BCC, highlighting the need for better understanding of Hh signaling in cancer. Autophagy, a conserved biological process for cellular component elimination, plays critical roles in the initiation, progression, and drug resistance of cancer, and therefore, implied potential to be targeted. Recent evidence demonstrated that Hh signaling interplays with autophagy in multiple cancers. Importantly, modulating this crosstalk exhibited noteworthy capability to sensitize primary and drug-resistant cancer cells to Hh inhibitors, representing an emerging opportunity to reboot the efficacy of Hh inhibition in those insensitive tumors, and to tackle drug resistance challenges. This review will highlight recent advances of Hh pathway and autophagy in cancers, and focus on their crosstalk and the implied therapeutic opportunities.

Epoxymicheliolide, a novelguaiane-type sesquiterpene lactone, inhibits NF‑κB/COX‑2 signaling pathways by targeting leucine 281 and leucine 25 in IKKβ in renal cell carcinoma

Parthenolide (PTL) is a sesquiterpene lactone compound obtained from Tanacetum parthenium (feverfew) and inhibits the activation of nuclear factor (NF)-κB. Epoxymicheliolide (EMCL) is a compound which is structurally related to PTL; however, EMCL is more stable under acidic and alkaline conditions. As a biologically active molecule, the detailed mechanism by which EMCL inhibits tumor activity remains to be elucidated. The present study evaluated the effect of EMCL on renal cell carcinoma (RCC) cells and identified the underlying mechanisms. It was found that treatment with EMCL significantly inhibited the proliferation of RCC cells in vitro and increased the induction of apoptosis by activating the mitochondria- and caspase-dependent pathway. Simultaneously, EMCL suppressed cell invasion and metastasis by inhibiting epithelial-mesenchymal transition, as observed in a microfluidic chip assay. Furthermore, using immunofluorescence analysis, an electrophoretic mobility shift assay and a dual-luciferase reporter assay, it was shown that treatment with EMCL significantly suppressed the expression of cyclooxygenase-2 by inhibiting the translocation of NF-κB p50/p65 and the activity of NF-κB. Collectively, the results indicated that EMCL suppressed tumor growth by inhibiting the activation of NF-κB and suggested that EMCL may be a novel anticancer agent in the treatment of RCC.

NOX4-driven ROS formation regulates proliferation and apoptosis of gastric cancer cells through the GLI1 pathway

NADPH Oxidase 4 (NOX4), a member of the NOX family, has emerged as a significant source of reactive oxygen species, playing an important role in tumor cell proliferation, apoptosis, and other physiological processes. However, the potential function of NOX4 in gastric cancer (GC) cell proliferation is yet unknown. The aim of this study was to illustrate whether NOX4 plays a role in regulating gastric cancer cell growth. First, the clinical information from 90 patients was utilized to explore the clinical value of NOX4 as a predictive tool for tumor size and prognosis. Results showed that NOX4 expression was correlated with tumor size and prognosis. In vitro assays confirmed that knockdown of NOX4 expression blocked cell proliferation and the expression of Cyclin D1, BAX, and so on. Interestingly, NOX4 promoted cell proliferation via activation of the GLI1 pathway. GLI1, a well-known transcription factor in the Hedgehog signaling pathway, was overexpressed to test whether NOX4 activates downstream signaling via GLI1. Overexpression of GLI1 reversed the inhibition of proliferation induced by NOX4 knockdown. In addition, overexpression of NOX4 increased GLI1 expression, and depletion of GLI1 expression decreased the effects induced by NOX4 overexpression. Further, ROS generated by NOX4 was required for GLI1 expression, as shown by use of the ROS inhibitor, diphenylene iodonium (DPI). In summary, the findings indicate that NOX4 plays an important role in gastric cancer cell growth and apoptosis through the generation of ROS and subsequent activation of GLI1 signaling. Hence, the targeting of NOX4 may be an attractive therapeutic strategy for blocking gastric cancer cell proliferation.

Reactive oxygen species modulate itraconazole-induced apoptosis via mitochondrial disruption in Candida albicans

Itraconazole (ITC), a well-known fungistatic agent, has potent fungicidal activity against Candida albicans. However, its mechanism of fungicidal activity has not been elucidated yet, and we aimed to identify the mechanism of ITC against C. albicans. ITC caused cell shrinkage via potassium leakage through the ion channel. Since shrunken cells could indicate apoptosis, we investigated apoptotic features. Annexin V-FITC and TUNEL assays indicated that fungicidal activity of ITC was involved in apoptosis. Subsequently, we confirmed an intracellular factor that could cause apoptosis. ITC treatment caused reactive oxygen species (ROS) accumulation. To confirm whether ROS is related with ITC-triggered cell death, cell viability was examined using the ROS scavenger N-acetylcysteine (NAC). NAC pretreatment recovered ITC-induced cell death, indicating that antifungal activity of ITC is associated with ROS, which is also confirmed by impaired glutathione-related antioxidant system and oxidized intracellular lipids. Moreover, ITC-induced mitochondrial dysfunction, in turn, triggered cytochrome c release and metacaspase activation, leading to apoptosis. Unlike the only ITC-treatment group, cells with NAC pretreatment did not show significant damage to mitochondria, and attenuated apoptotic features. Therefore, our results suggest that ITC induces apoptosis as fungicidal mechanism, and intracellular ROS is major factor to trigger the apoptosis by ITC in C. albicans.

Alantolactone, a natural sesquiterpene lactone, has potent antitumor activity against glioblastoma by targeting IKKβ kinase activity and interrupting NF-κB/COX-2-mediated signaling cascades

Background

Glioblastoma multiforme (GBM) is one of the most refractory and palindromic central nervous system (CNS) neoplasms, and current treatments have poor effects in GBM patients. Hence, the identification of novel therapeutic targets and the development of effective treatment strategies are essential. Alantolactone (ATL) has a wide range of pharmacological activities, and its anti-tumor effect is receiving increasing attention. However, the molecular mechanism underlying the anti-GBM activity of ATL remains poorly understood.

Methods

The biological functions of ATL in GBM cells were investigated using migration/invasion, colony formation and cell cycle/apoptosis assays. The localization of nuclear factor kappa B (NF-κB) p50/p65 and its binding to the cyclooxygenase 2 (COX-2) promoter were determined using confocal immunofluorescence, a streptavidin-agarose pulldown assay and a chromatin immunoprecipitation (ChIP) assay. IKKβ kinase activity was determined using a cell IKKβ kinase activity spectrophotometry quantitative detection kit and a molecular docking study. LC-MS/MS analysis was performed to determine the ability of ATL to traverse the blood-brain barrier (BBB). The in vivo anti-tumor efficacy of ATL was also analyzed in xenografted nude mice. Western blot analysis was performed to detect the protein expression levels.

Results

ATL significantly suppressed the growth of GBM in vivo and in vitro. ATL significantly reduced the expression of COX-2 by inhibiting the kinase activity of IKKβ by targeting the ATP-binding site and then attenuating the binding of NF-κB to the COX-2 promoter region. Furthermore, ATL induced apoptosis by activating the cytochrome c (cyt c)/caspase cascade signaling pathway. Moreover, ATL could penetrate the BBB.

Conclusions

ATL exerts its anti-tumor effects in human GBM cells at least in part via NF-κB/COX-2-mediated signaling cascades by inhibiting IKKβ kinase activity. ATL, which is a natural small molecule inhibitor, is a promising candidate for clinical applications in the treatment of CNS tumors.