Curcumin suppresses malignant glioma cells growth and induces apoptosis by inhibition of SHH/GLI1 signaling pathway in vitro and vivo

Repurposing synthetic and natural derivatives induces apoptosis in an orthotopic glioma-induced xenograft model by modulating WNT/β-catenin signaling

BACKGROUND

Glioblastomas arise from multistep tumorigenesis of the glial cells. Despite the current state-of-art treatment, tumor recurrence is inevitable. Among the innovations blooming up against glioblastoma, drug repurposing could provide profound premises for treatment enhancement. While considering this strategy, the efficacy of the repurposed drugs as monotherapies were not up to par; hence, the focus has now shifted to investigate the multidrug combinations.

AIM

To investigate the efficacy of a quadruple-combinatorial treatment comprising temozolomide along with chloroquine, naringenin, and phloroglucinol in an orthotopic glioma-induced xenograft model.

METHODS

Antiproliferative effect of the drugs was assessed by immunostaining. The expression profiles of WNT/β-catenin and apoptotic markers were evaluated by qRT-PCR, immunoblotting, and ELISA. Patterns of mitochondrial depolarization was determined by flow cytometry. TUNEL assay was performed to affirm apoptosis induction. In vivo drug detection study was carried out by ESI-Q-TOF MS analysis.

RESULTS

The quadruple-drug treatment had significantly hampered glioma proliferation and had induced apoptosis by modulating the WNT/β-catenin signaling. Interestingly, the induction of apoptosis was associated with mitochondrial depolarization. The quadruple-drug cocktail had breached the blood-brain barrier and was detected in the brain tissue and plasma samples.

CONCLUSION

The quadruple-drug combination served as a promising adjuvant therapy to combat glioblastoma lethality in vivo and can be probed for translation from bench to bedside.

Forkhead box transcription factors (FOXOs and FOXM1) in glioma: from molecular mechanisms to therapeutics

Glioma is the most aggressive and malignant type of primary brain tumor, comprises the majority of central nervous system deaths, and is categorized into different subgroups according to its histological characteristics, including astrocytomas, oligodendrogliomas, glioblastoma multiforme (GBM), and mixed tumors. The forkhead box (FOX) transcription factors comprise a collection of proteins that play various roles in numerous complex molecular cascades and have been discovered to be differentially expressed in distinct glioma subtypes. FOXM1 and FOXOs have been recognized as crucial transcription factors in tumor cells, including glioma cells. Accumulating data indicates that FOXM1 acts as an oncogene in various types of cancers, and a significant part of studies has investigated its function in glioma. Although recent studies considered FOXO subgroups as tumor suppressors, there are pieces of evidence that they may have an oncogenic role. This review will discuss the subtle functions of FOXOs and FOXM1 in gliomas, dissecting their regulatory network with other proteins, microRNAs and their role in glioma progression, including stem cell differentiation and therapy resistance/sensitivity, alongside highlighting recent pharmacological progress for modulating their expression.

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.

Photodynamic Therapy for Glioblastoma: Illuminating the Path toward Clinical Applicability

Glioblastoma (GBM) is the most common adult brain cancer. Despite extensive treatment protocols comprised of maximal surgical resection and adjuvant chemo-radiation, all glioblastomas recur and are eventually fatal. Emerging as a novel investigation for GBM treatment, photodynamic therapy (PDT) is a light-based modality that offers spatially and temporally specific delivery of anti-cancer therapy with limited systemic toxicity, making it an attractive option to target GBM cells remaining beyond the margins of surgical resection. Prior PDT approaches in GBM have been predominantly based on 5-aminolevulinic acid (5-ALA), a systemically administered drug that is metabolized only in cancer cells, prompting the release of reactive oxygen species (ROS), inducing tumor cell death via apoptosis. Hence, this review sets out to provide an overview of current PDT strategies, specifically addressing both the potential and shortcomings of 5-ALA as the most implemented photosensitizer. Subsequently, the challenges that impede the clinical translation of PDT are thoroughly analyzed, considering relevant gaps in the current PDT literature, such as variable uptake of 5-ALA by tumor cells, insufficient tissue penetrance of visible light, and poor oxygen recovery in 5-ALA-based PDT. Finally, novel investigations with the potential to improve the clinical applicability of PDT are highlighted, including longitudinal PDT delivery, photoimmunotherapy, nanoparticle-linked photosensitizers, and near-infrared radiation. The review concludes with commentary on clinical trials currently furthering the field of PDT for GBM. Ultimately, through addressing barriers to clinical translation of PDT and proposing solutions, this review provides a path for optimizing PDT as a paradigm-shifting treatment for GBM.

AL-Johani N, Alarifi S, Afzal M. Cytotoxicity Mechanisms of Blue-Light-Activated Curcumin in T98G Cell Line: Inducing Apoptosis through ROS-Dependent Downregulation of MMP Pathways

We examined the photodynamic activation of Curcumin under blue light in glioblastoma T98G cells. The therapeutic effect of Curcumin, in both the absence and presence of blue light, was measured by the MTT assay and apoptosis progression using flow cytometry. Fluorescence imaging was carried out to evaluate Curcumin uptake. Photodynamic activation of Curcumin (10 µM), in the presence of blue light, enhanced its cytotoxic effect, resulting in the activation of ROS-dependent apoptotic pathways in T98G cells. The gene expression studies showed the expression of matrixes metalloproteinase 2 (MMP2) and 9 (MMP9) decrease with Curcumin (10 µM) under blue light exposure, indicating possible proteolytic mechanisms. Moreover, the cytometric appearance displayed that the expressions of NF-κB and Nrf2 were found to be increased upon exposure to blue light, which revealed a significant induction of expression of nuclear factor as a result of blue-light-induced oxidative stress and cell death. These data further demonstrate that Curcumin exhibited a photodynamic effect via induction of ROS-mediated apoptosis in the presence of blue light. Our results suggest that the application of blue light enhances the therapeutic efficacy of Curcumin in glioblastoma because of the phototherapeutic effect.

Combined treatments with AZD5363, AZD8542, curcumin or resveratrol induce death of human glioblastoma cells by suppressing the PI3K/AKT and SHH signaling pathways

Glioblastoma (GBM) is a very aggressive tumor that presents vascularization, necrosis and is resistant to chemotherapy and radiotherapy. Current treatments are not effective eradicating GBM, thus, there is an urgent need to develop novel therapeutic strategies against GBM. AZD5363, AZD8542, curcumin and resveratrol, are widely studied for the treatment of cancer and in the present study we explored the effects of the administration of combined treatments with AZD5363, AZD8542, curcumin or resveratrol on human GBM cells. We found that the combined treatments with AZD5363+AZD8542+Curcumin and AZD8542+Curcumin+Resveratrol inhibit the PI3K/AKT and SHH survival pathways by decreasing the activity of AKT, the reduction of the expression of SMO, pP70S6k, pS6k, GLI1, p21 and p27, and the activation of caspase-3 as a marker of apoptosis. These results provide evidence that the combined treatments AZD5363+AZD8542+Curcumin and AZD8542+Curcumin+Resveratrol have the potential to be an interesting option against GBM.

Design and validation of a flowless gradient generating microfluidic device for high-throughput drug testing

Drug testing is a vital step in the identification of the potential efficacy of any new/existing drug and/or combinations of drugs. The conventional methods of testing the efficacy of new drugs using multiwell plates are time consuming and prone to evaporation loss and manual error. Microfluidic devices with automated generation of concentration gradients provide a promising alternative. The implementation of such microfluidic devices is still limited owing to the additional expertise and facilities required to fabricate and run these devices. Conventional microfluidic devices also need pumps, tubing, valves, and other accessories, making them bulky and non-portable. To address these problems, we have developed a method for fabricating microfluidic structures using a nonconventional technique by exploiting the Saffman-Taylor instability in lifted Hele-Shaw cells. Multi-channel structure molds with varying dimensions were fabricated by shaping ceramic polymer slurry and retaining the shape. Further using the mold thus made, polydimethyl siloxane (PDMS) devices offering static, stable, diffusion-based gradients were casted using soft lithography. We have demonstrated with COMSOL simulation, as well as using fluorescein isothiocyanate (FITC), a fluorescent dye, that the concentration gradient can be generated in this device, which remains stable for at least 5 days. Using this multichannel device, in vitro drug efficacy was validated with two drugs namely, temozolomide (TMZ) and curcumin, one FDA approved and one under research, on glioblastoma cells (U87MG). The resulting IC50 values were consistent with those reported in the literature. We have also demonstrated the possibility of conducting molecular assays post-drug testing in the device by microtubule staining after curcumin treatment on cervical cancer cells (HeLa). In summary, we have demonstrated a i) user-friendly, ii) portable, static drug testing platform that iii) does not require further accessories and can create iv) a stable gradient for a long duration. Such a device can reduce the time, manual errors, fabrication and running expenditure, and resources needed to a great extent in drug testing.

Natural compounds as a potential modifier of stem cells renewal: Comparative analysis

Cancer stem cells (CSCs) are indispensable for development, progression, drug resistance, and tumor metastasis. Current cancer-directed interventions target targeting rapidly dividing cancer cells and slow dividing CSCs, which are the root cause of cancer origin and recurrence. The most promising targets include several self-renewal pathways involved in the maintenance and renewal of CSCs, such as the Wnt/β-Catenin, Sonic Hedgehog, Notch, Hippo, Autophagy, and Ferroptosis. In view of safety, natural compounds are coming to the front line of treatment modalities for modifying various signaling pathways simultaneously involved in maintaining CSCs. Therefore, targeting CSCs with natural compounds is a promising approach to treating various types of cancers. In view of this, here we provide a comprehensive update on the current status of natural compounds that effectively tune key self-renewal pathways of CSCs. In addition, we highlighted surface expression markers in several types of cancer. We also emphasize how natural compounds target these self-renewal pathways to reduce therapy resistance and cancer recurrence properties of CSCs, hence providing valuable cancer therapeutic strategies. The inclusion of nutraceuticals is believed to enhance the therapeutic efficacy of current cancer-directed interventions significantly.

Exosomes as Novel Delivery Systems for Application in Traditional Chinese Medicine

Exosomes, as gifts of nature derived from various cell types with a size range from ~40 to 160 nm in diameter, have gained attention recently. They are composed of a lipid membrane bilayer structure containing different constituents, such as surface ligands and receptors, from the parental cells. Originating from a variety of sources, exosomes have the ability to participate in a diverse range of biological processes, including the regulation of cellular communication. On account of their ideal native structure and characteristics, exosomes are taken into account as drug delivery systems (DDSs). They can provide profound effects on conveying therapeutic agents with great advantages, including specific targeting, high biocompatibility, and non-toxicity. Further, they can also be considered to ameliorate natural compounds, the main constituents of traditional Chinese medicine (TCM), which are usually ignored due to the complexity of their structures, poor stability, and unclear mechanisms of action. This review summarizes the classification of exosomes as well as the research progress on exosome-based DDSs for the treatment of different diseases in TCM. Furthermore, this review discusses the advantages and challenges faced by exosomes to contribute to their further investigation and application.

Radiosensitizing effect of dendrosomal nanoformulation of curcumin on cancer cells

BACKGROUND

Curcumin was found to possess numerous pharmacological activities in clinical research, however, its biological effects together with radiation are yet to be addressed. The present study investigated whether the combined treatment of dendrosomal nanoformulation of curcumin (DNC) and gamma radiation can enhance the radiosensitivity of U87MG and MDA-MB-231 cell lines.

METHODS

U87MG and MDA-MB-231 cell lines were exposed to 2 Gray (Gy) and 10 μM DNC determined by MTT assay, then subjected to clonogenic assay, cell cycle assay, and flow cytometric apoptosis analysis. Acridine Orange/Ethidium Bromide (AO/EB) and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) stained cells were used to study morphologic changes. The expression evaluation of putative cell cycle genes, i.e., P53, P21, CCND1, and CCNB1 was carried out by RT-qPCR.

RESULTS

Our findings indicated that the combined treatment with DNC and radiation might cooperatively augment the efficacy of ionizing radiation in the cancer cells and notably decrease the survival and viability of the cells in a time- and concentration-dependent manner. In addition to a synergistic effect deducted by sensitizer enhancement ratio (SER) assessment, co-treatment resulted in greater apoptotic cells than the individual treatments. Further experiments then indicated that DNC could effectively induce G2/M phase cell cycle arrest and apoptosis following irradiation. Conformably, there was a decrement of CCND1 and CCNB1 expression, and an increment of P53, P21 expression.

CONCLUSIONS

The data implied that DNC as a radiosensitizer can enhance the lethal effect of ionizing radiation on cancer cells which could be a promising adjuvant therapy in clinical treatments.

Small Interfering RNA for Gliomas Treatment: Overcoming Hurdles in Delivery

Gliomas are central nervous system tumors originating from glial cells, whose incidence and mortality rise in coming years. The current treatment of gliomas is surgery combined with chemotherapy or radiotherapy. However, developing therapeutic resistance is one of the significant challenges. Recent research suggested that small interfering RNA (siRNA) has excellent potential as a therapeutic to silence genes that are significantly involved in the manipulation of gliomas’ malignant phenotypes, including proliferation, invasion, metastasis, therapy resistance, and immune escape. However, it is challenging to deliver the naked siRNA to the action site in the cells of target tissues. Therefore, it is urgent to develop delivery strategies to transport siRNA to achieve the optimal silencing effect of the target gene. However, there is no systematic discussion about siRNAs’ clinical potential and delivery strategies in gliomas. This review mainly discusses siRNAs’ delivery strategies, especially nanotechnology-based delivery systems, as a potential glioma therapy. Moreover, we envisage the future orientation and challenges in translating these findings into clinical applications.

Curcumin analogue BDDD-721 exhibits more potent anticancer effects than curcumin on medulloblastoma by targeting Shh/Gli1 signaling pathway

Medulloblastoma (MB) is a malignant tumor in the fourth ventricle of children. The clinical treatment is mainly surgical resection combined with radiotherapy and chemotherapy, but the curative effect is not ideal, and the 3-year survival rate is very low. Previous study confirmed that curcumin attenuated the proliferation of medulloblastoma both in vitro and in vivo. In present study, we found a curcumin analogue named BDDD-721, exhibited more potent anti-tumor activity than curcumin. Compared with curcumin, BDDD-721 more effectively inhibited the proliferation, migration, invasion, and increased apoptosis of medulloblastoma cells. Furthermore, BDDD-721 treatment led to activation of glioma-associated oncogene homolog (Gli), reduced expression of Shh and its downstream target Smo, Gli1 and Ptch1. In addition, SAG (Shh signaling pathway agonist) antagonized the pro-apoptotic effects of BDDD-721 on medulloblastomas as confirmed by CCK8 assays and flow cytometry; while cyclopamine (Shh signaling pathway inhibitor) enhanced its effects on medulloblastomas. In conclusion, these results indicate that curcumin analogue BDDD-721 has more potent anticancer effects than curcumin on medulloblastomas by targeting Shh/Gli1 signaling pathway.

Review on the Therapeutic Potential of Curcumin and its Derivatives on Glioma Biology

Gliomas are common and aggressive brain tumors that carry a poor prognosis. The current multimodal therapeutic option for glioma includes surgery subsequently temozolomide chemotherapy and/or radiation; but gliomas are often associated with multidrug resistance, intensive adverse events, and tumor relapse. Thus, novel interventions that can enhance successful chemo-prevention and overcome therapeutic resistance are urgently needed. Phytochemicals have several biological properties with multi-target sites and relatively limited degrees of toxicity. Curcumin is a natural polyphenolic compound with several anti-tumor effects which potentially inhibit tumor growth, development, proliferation, invasion, dissemination, and angiogenesis in different human malignancies. Experimental model studies have demonstrated that curcumin attenuates glioma cell viability by G2/M cell cycle arrest, apoptosis, induction of autophagy, gene expression alteration, and disruption of multi-molecular pathways. Moreover, curcumin has been reported to re-sensitize cancer to chemotherapeutics as well as augment the effect of radiotherapy on glioma cells. In this review, we have provided an update on the in vitro and in vivo effects of curcumin-based therapy on gliomas. We have also discussed the use of curcumin in combination therapies, its effectiveness on drug-resistant cells, and new formulations of curcumin in the treatment of gliomas.

Anticancer effects of veratramine via the phosphatidylinositol-3-kinase/serine-threonine kinase/mechanistic target of rapamycin and its downstream signaling pathways in human glioblastoma cell lines

AIMS

Antitumor effects of veratramine in prostate and liver cancers has been investigated, but it is still unclear whether veratramine can be used as an effective therapeutic agent for glioma. The aim of this study was to evaluate the potential pharmacological mechanism of veratramine in glioma.

MAIN METHODS

Using four types of human glioblastoma cell lines, including A172, HS-683, T98G, and U-373-MG the dose-dependent antitumor effect of veratramine was evaluated. The cytotoxicity and cell proliferation were examined by CCK-8, and cell proliferation was further confirmed by anchorage-independent colony formation assay. The cell cycle distribution and apoptotic rate was assessed by flow cytometry, and apoptosis was further evaluated by apoptosis assay. The migration and invasiveness capacity were analyzed by using transwell. Protein and mRNA levels of related factors were determined by western blotting and RT-qPCR, respectively.

KEY FINDINGS

Veratramine markedly induced apoptosis, suppressed the cell proliferation via the cell cycle G₀/G₁ phase arrest, and reduced the capacity for the migration and invasion in human glioblastoma multiforme cell lines. Moreover, veratramine was sufficient to affect the phosphatidylinositol-3-kinase/serine-threonine kinase/mechanistic target of rapamycin signaling pathway and its downstream Mdm2/p53/p21 pathway in human glioblastoma cell lines.

SIGNIFICANCE

Antitumor effects of veratramine in suppression of glioma progression was mediated by the regulation of PI3K/Akt/mTOR and Mdm2/p53/p21 signaling pathway.

The multifaceted NF-kB: are there still prospects of its inhibition for clinical intervention in pediatric central nervous system tumors?

Despite advances in the understanding of the molecular mechanisms underlying the basic biology and pathogenesis of pediatric central nervous system (CNS) malignancies, patients still have an extremely unfavorable prognosis. Over the years, a plethora of natural and synthetic compounds has emerged for the pharmacologic intervention of the NF-kB pathway, one of the most frequently dysregulated signaling cascades in human cancer with key roles in cell growth, survival, and therapy resistance. Here, we provide a review about the state-of-the-art concerning the dysregulation of this hub transcription factor in the most prevalent pediatric CNS tumors: glioma, medulloblastoma, and ependymoma. Moreover, we compile the available literature on the anti-proliferative effects of varied NF-kB inhibitors acting alone or in combination with other therapies in vitro, in vivo, and clinical trials. As the wealth of basic research data continues to accumulate, recognizing NF-kB as a therapeutic target may provide important insights to treat these diseases, hopefully contributing to increase cure rates and lower side effects related to therapy.

Naringenin attenuates cell viability and migration of C6 glioblastoma cell line: a possible role of hedgehog signaling pathway

OBJECTIVE

Gliomas are the most prevalent type of malignant primary brain tumors. Despite the availability of several treatment modalities, these tumors have poor prognostic features. Aberrant Hedgehog (Hh) signaling has been found to be implicated in the development of numerous malignancies including gliomas. Naringenin appears to have anti-proliferative and anti-cancer properties. However, there is no report describing its effects via the Hh signaling pathway on the C6 glioblastoma cell line. The current study was set to examine the anti-cancer effects of naringenin on C6 cells in order to determine the effect of this compound on the Hh signaling pathway.

METHODS

The anti-proliferative and apoptotic effects of naringenin against C6 and 3T3 fibroblast cells were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin-V/PI dual staining assay, respectively. The effect of naringenin on the migration of C6 cells was evaluated by the migration scratch assay. To assess the anti-cancer effect of naringenin on the Hh signaling pathway, the expression of Gli-1, Smo, and Sufu at protein levels in C6 cells was analyzed using western blotting.

RESULTS

The obtained data indicated that naringenin exerted higher cytotoxicity against C6 cells (IC50 value of 114 ± 3.4 µg/mL) than normal 3T3 fibroblasts (IC50 value of 290 ± 7 µg/mL). Naringenin (114 µg/mL) also induced stronger apoptotic effects on C6 cells than 3T3 cells after 24 h of incubation. Furthermore, naringenin at a concentration of 114 µg/mL and a lower concentration of 60 µg/mL inhibited the migration of the C6 cell line. In addition, naringenin at a concentration of 114 µg/mL significantly decreased the expression of Gli-1 and Smo and elevated the expression of Sufu at the protein level in the C6 cell line.

CONCLUSION

These data represent that naringenin may have a potential effect on the management of the proliferation and metastasis of malignant gliomas by inhibiting the Hh signaling pathway.

New insights of structural activity relationship of curcumin and correlating their efficacy in anticancer studies with some other similar molecules

Recently, Cancer is the widespread category of different diseases in human beings, and its progress is linked with a number of factors such as estrogen level, diet, hereditary etc. Curcumin is a naturally occurring compound which appears to be significant clinical for applications in vitro as well as in vivo studies. Many of the research groups have been paying attention towards natural products for the development of anticancer drugs. Curcumin, Rosmarinic acid and Chalcone are the naturally occurring compounds, which are chemopreventive and chemotherapeutic. In present review the anticancer activity of curcumin and similar analogues in vitro has been discussed on the basis of inhibitory concentration (IC50). Also this data is compared with the inhibitory concentration of chalcone, its derivatives and rosmarinic acid.

Two Worlds Colliding: The Interplay Between Natural Compounds and Non-Coding Transcripts in Cancer Therapy

Cancer is a devastating disease and has recently become the leading cause of death in western countries, representing an immense public health burden. When it comes to cancer treatment, chemotherapy is one of the main pillars, especially for advanced stage tumors. Over the years, natural compounds have emerged as one of the most valuable resources for new chemotherapies. It is estimated that more than half of the currently used chemotherapeutic agents are derived from natural compounds. Usually, natural compounds are discovered empirically and an important limitation of introducing new anti-cancer natural products is lack of knowledge with regard to their mechanism of action. Recent data has proven that several natural compounds may function via modulating the expression and function of non-coding RNAs (ncRNAs). NcRNAs are a heterogenous class of RNA molecules which are usually not translated into proteins but have an important role in gene expression regulation and are involved in multiple tumorigenic processes, including response/resistance to pharmacotherapy. In this review, we will discuss how natural compounds function via ncRNAs while summarizing the available data regarding their effects on over 15 types of cancer. Moreover, we will critically analyze the current advances and limitations in understanding the way natural compounds exert these health-promoting effects by acting on ncRNAs. Finally, we will propose several hypotheses that may open new avenues and perspectives regarding the interaction between natural compounds and ncRNAs, which could lead to improved natural compound-based therapeutic strategies in cancer.

Identification of harmine and β-carboline analogs from a high-throughput screen of an approved drug collection; profiling as differential inhibitors of DYRK1A and monoamine oxidase A and for in vitro and in vivo anti-cancer studies

DYRK1A (dual-specificity tyrosine phosphorylation-regulated kinase 1a) is highly expressed in glioma, an aggressive brain tumor, and has been proposed as a therapeutic target for cancer. In the current study, we have used an optimized and validated time-resolved fluorescence energy transfer (TR-FRET)-based DYRK1A assay for high-throughput screening (HTS) in 384-well format. A small-scale screen of the FDA-approved Prestwick drug collection identified the β-carboline, harmine, and four related analogs as DYRK1A inhibitors. Hits were confirmed by dose response and in an orthogonal DYRK1A assay. Harmine's potential therapeutic use has been hampered by its off-target activity for monoamine oxidase A (MAO-A) which impacts multiple nervous system targets. Selectivity profiling of harmine and a broader collection of analogs allowed us to map some divergent SAR (structure-activity relationships) for the DYRK1A and MAO-A activities. The panel of harmine analogs had varying activities in vitro in glioblastoma (GBM) cell lines when tested for anti-proliferative effects using a high content imaging assay. In particular, of the identified analogs, harmol was found to have the best selectivity for DYRK1A over MAO-A and, when tested in a glioma tumor xenograft model, harmol demonstrated a better therapeutic window compared to harmine.

Anticancer Mechanism of Curcumin on Human Glioblastoma

Glioblastoma (GBM) is the most malignant brain tumor and accounts for most adult brain tumors. Current available treatment options for GBM are multimodal, which include surgical resection, radiation, and chemotherapy. Despite the significant advances in diagnostic and therapeutic approaches, GBM remains largely resistant to treatment, with a poor median survival rate between 12 and 18 months. With increasing drug resistance, the introduction of phytochemicals into current GBM treatment has become a potential strategy to combat GBM. Phytochemicals possess multifarious bioactivities with multitarget sites and comparatively marginal toxicity. Among them, curcumin is the most studied compound described as a potential anticancer agent due to its multi-targeted signaling/molecular pathways properties. Curcumin possesses the ability to modulate the core pathways involved in GBM cell proliferation, apoptosis, cell cycle arrest, autophagy, paraptosis, oxidative stress, and tumor cell motility. This review discusses curcumin’s anticancer mechanism through modulation of Rb, p53, MAPK, P13K/Akt, JAK/STAT, Shh, and NF-κB pathways, which are commonly involved and dysregulated in preclinical and clinical GBM models. In addition, limitation issues such as bioavailability, pharmacokinetics perspectives strategies, and clinical trials were discussed.

Examining the developmental toxicity of piperonyl butoxide as a Sonic hedgehog pathway inhibitor

Piperonyl butoxide (PBO) is a semisynthetic chemical present in hundreds of pesticide formulations used in agricultural, commercial, and residential settings. PBO acts as a pesticide synergist by inhibiting insect cytochrome P450 enzymes and is often present at much higher concentrations than active insecticidal ingredients. PBO was recently discovered to also inhibit Sonic hedgehog (Shh) signaling, a key molecular pathway in embryonic development and in brain and face morphogenesis. Recent animal model studies have shown that in utero PBO exposure can cause overt craniofacial malformations or more subtle neurodevelopmental abnormalities. Related adverse developmental outcomes in humans are etiologically heterogeneous, and, while studies are limited, PBO exposure during pregnancy has been linked to neurodevelopmental deficits. Contextualized in PBO's newly recognized mechanism as a Shh signaling inhibitor, these findings support more rigorous examination of the developmental toxicity of PBO and its potential contribution to etiologically complex human birth defects. In this review, we highlight environmental sources of human PBO exposure and summarize existing animal studies examining the developmental impact of prenatal PBO exposure. Also presented are critical knowledge gaps in our understanding of PBO's pharmacokinetics and potential role in gene-environment and environment-environment interactions that should be addressed to better understand the human health impact of environmental PBO exposure.

The Multi-Faceted Effect of Curcumin in Glioblastoma from Rescuing Cell Clearance to Autophagy-Independent Effects

The present review focuses on the multi-faceted effects of curcumin on the neurobiology glioblastoma multiforme (GBM), with a special emphasis on autophagy (ATG)-dependent molecular pathways activated by such a natural polyphenol. This is consistent with the effects of curcumin in a variety of experimental models of neurodegeneration, where the molecular events partially overlap with GBM. In fact, curcumin broadly affects various signaling pathways, which are similarly affected in cell degeneration and cell differentiation. The antitumoral effects of curcumin include growth inhibition, cell cycle arrest, anti-migration and anti-invasion, as well as chemo- and radio-sensitizing activity. Remarkably, most of these effects rely on mammalian target of rapamycin (mTOR)-dependent ATG induction. In addition, curcumin targets undifferentiated and highly tumorigenic GBM cancer stem cells (GSCs). When rescuing ATG with curcumin, the tumorigenic feature of GSCs is suppressed, thus counteracting GBM establishment and growth. It is noteworthy that targeting GSCs may also help overcome therapeutic resistance and reduce tumor relapse, which may lead to a significant improvement of GBM prognosis. The present review focuses on the multi-faceted effects of curcumin on GBM neurobiology, which represents an extension to its neuroprotective efficacy.

Fanconi Anemia Pathway Activation by FOXM1 Is Critical to Bladder Cancer Recurrence and Anticancer Drug Resistance

Although the 5-year survival rate of patients diagnosed with nonmuscle invasive bladder cancer (NMIBC) has reached 85%, more than 50% of patients suffer from frequent recurrences. To identify molecular targets associated with recurrence of NMIBC, we analyzed gene expression data and found that FOXM1 and FANCD2 were involved in recurrence. Therefore, we investigated how these genes were involved in the mechanism of recurrence and confirmed their usefulness as biomarkers. Investigation have shown that FOXM1 directly regulated the transcription of FANCD2, which is the key gene of the Fanconi anemia (FA) pathway. Depletion of FOXM1 resulted in DNA repair defects in the FA pathway and in decreased resistance to chemotherapy. Thus, the FANCD2-associated FA pathway activated by FOXM1 is an important mechanism involved in chemotherapy-related recurrence. In conclusion, FOXM1 and FANCD2 can be used as prognostic factors that are associated with high risk of recurrence and with anticancer drug resistance properties in NMIBC patients.

Curcumin Affects Gastric Cancer Cell Migration, Invasion and Cytoskeletal Remodeling Through Gli1-β-Catenin

Purpose

The function of curcumin on the gastric cancer cell line, SGC-7901 is unknown. The present study aimed to observe the effects of curcumin on gastric cancer cells through the Shh and Wnt signaling pathways.

Methods

SGC-7901 cells were transfected with si-Gli1 and si-β-catenin siRNA, then cells were stimulated with curcumin and its effects on cell migration, invasion, cytoskeleton remodeling, EMT, apoptosis and cell cycle were investigated by transwell assays, immunofluorescence and flow cytometry assays. The interaction between Gli1 and β-catenin was observed by co-immunoprecipitation.

Results

We show that curcumin suppressed the expression of Shh, Gli1 and Foxm1 in the Shh signaling pathway, and the expression of β-catenin in the Wnt signaling pathway in SGC-7901 cells, both in mRNA and protein. As a result, cellular migration, invasion and cytoskeletal remodeling ability decreased. Our results revealed that when stimulated with curcumin, cells showed decreased cellular migration and invasion, while enhanced apoptosis. In addition, curcumin induced cytoskeletal remodeling and S phase cell cycle arrest. The inhibition of Shh and Wnt signaling pathway and the addition of curcumin also inhibited the epithelial–mesenchymal transition process. Furthermore, a physical interaction was observed between Gli1 of the Shh signaling and β-catenin of the Wnt signaling in these cells, but curcumin inhibited the interaction of these two proteins.

Conclusion

The present study indicated that curcumin plays an anti-tumor role through Gli1-β-catenin pathway in gastric cancer SGC-7901 cells.

Therapeutic Potential of Curcumin in the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor. Despite standard multimodality treatment, the highly aggressive nature of GBM makes it one of the deadliest human malignancies. The anti-cancer effects of dietary phytochemicals like curcumin provide new insights to cancer treatment. Evaluation of curcumin's efficacy against different malignancies including glioblastoma has been a motivational research topic and widely studied during the recent decade. In this review, we discuss the recent observations on the potential therapeutic effects of curcumin against glioblastoma. Curcumin can target multiple signaling pathways involved in developing aggressive and drug-resistant features of glioblastoma, including pathways associated with glioma stem cell activity. Notably, combination therapy with curcumin and chemotherapeutics like temozolomide, the GBM standard therapy, as well as radiotherapy has shown synergistic response, highlighting curcumin's chemo- and radio-sensitizing effect. There are also multiple reports for curcumin nanoformulations and targeted forms showing enhanced therapeutic efficacy and passage through blood-brain barrier, as compared with natural curcumin. Furthermore, in vivo studies have revealed significant anti-tumor effects, decreased tumor size and increased survival with no notable evidence of systemic toxicity in treated animals. Finally, a pharmacokinetic study in patients with GBM has shown a detectable intratumoral concentration, thereby suggesting a potential for curcumin to exert its therapeutic effects in the brain. Despite all the evidence in support of curcumin's potential therapeutic efficacy in GBM, clinical reports are still scarce. More studies are needed to determine the effects of combination therapies with curcumin and importantly to investigate the potential for alleviating chemotherapy- and radiotherapy-induced adverse effects.

Therapeutic potentials of curcumin in the treatment of glioblstoma

Glioblastoma multiforme (GBM), a greatly aggressive malignancy of the brain, is correlated with a poor prognosis and low rate of survival. Up to now, chemotherapy and radiation therapy after surgical approaches have been the treatments increasing the survival rates. The low efficacy of mentioned therapies as well as their side-effects has forced researchers to explore an appropriate alternative or complementary treatment for glioblastoma. In experimental models, it has been shown that curcumin has therapeutic potentials to fight against GBM. Given that curcumin has pharmacological effects against cancer stem cells, as major causes of resistance to therapy in glioblastoma cells. Moreover, it has been showed that curcumin exerts its therapeutic effects on GBM cells via affecting on apoptosis, oxidant system, and inflammatory pathways. Curcumin would possess a synergistic impact with chemotherapeutic agents. Herein, we summarized the current findings on curcumin as therapeutic agent in the treatment of GBM.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Arsenic trioxide and curcumin attenuate cisplatin-induced renal fibrosis in rats through targeting Hedgehog signaling

Renal fibrosis is a progressive process resulting from a sustained injury that may ultimately cause renal failure. Cisplatin is an antitumor drug that induces renal injury and nephrotoxicity and is widely employed as a model for acute and chronic renal injury. Several signaling pathways are implicated in fibrogenic cell activation among which is Hedgehog (Hh) signaling. We here investigated the effects of arsenic trioxide (Ars) and curcumin in ameliorating cisplatin-induced kidney fibrosis via regulating Hh signaling. Cisplatin (4.5 mg/kg) was administered in Sprague-Dawley rats for two consecutive days and renal fibrosis was induced after 21 days. Once renal fibrosis was confirmed, Ars (3.5 mg/kg/day, orally) and curcumin (200 mg/kg/day, orally) were administered daily for another 21 days. Ars and curcumin corrected kidney function markers as creatinine clearance and urea nitrogen. Both agents ameliorated fibrosis as shown by lowered TGF-β1 mRNA levels, α-SMA protein levels, and hydroxylproline content. Cisplatin-activated Hh signaling which was blocked by both Ars and curcumin as demonstrated by decreased mRNA levels of Shh, Smo, and Ptch and suppressed renal Gli1 and Gli2 protein levels. Our results indicate new therapeutic roles for Ars and curcumin and suggest that blocking Hh signaling may be a promising approach for alleviating renal fibrosis. Symbols indicate α-SMA, alpha-smooth muscle actin; TGF-β, transforming growth factor-beta; Ptch, patched; Smo, smoothened; Shh, sonic hedgehog; Ihh, Indian hedgehog; Dhh, desert hedgehog; and SUFU, suppressor of fused.

Complementary and integrative health interventions and their association with health-related quality of life in the primary brain tumor population

BACKGROUND AND PURPOSE

Little is known about complementary and integrative health intervention usage in the primary brain tumor population. We aimed to identify the percentage of patients using these practices and explore the impact on quality of life.

MATERIALS AND METHODS

Clinical records from patients seen in clinic between December 16, 2013 and February 28, 2014 were reviewed retrospectively. The questionnaires used were a modified version of the International Complementary and Alternative Medicine Questionnaire, the Functional Assessment of Cancer Therapy- Brain Cancer and the Functional Assessment of Chronic Illness Therapy- Fatigue.

RESULTS

76% of patients utilized a complementary and integrative health modality. The most frequently reported modalities used were vitamins, massage, and spiritual healing, prayer, diet and meditation.

CONCLUSION

These results confirm the usage of complementary and integrative health practices within the primary brain tumor population; however, there was no evidence of association between use and quality of life.

Dietary Phytochemicals Targeting Cancer Stem Cells

There is an increasing awareness of the importance of a diet rich in fruits and vegetables for human health. Cancer stem cells (CSCs) are characterized as a subpopulation of cancer cells with aberrant regulation of self-renewal, proliferation or apoptosis leading to cancer progression, invasiveness, metastasis formation, and therapy resistance. Anticancer effects of phytochemicals are also directed to target CSCs. Here we provide a comprehensive review of dietary phytochemicals targeting CSCs. Moreover, we evaluate and summarize studies dealing with effects of dietary phytochemicals on CSCs of various malignancies in preclinical and clinical research. Dietary phytochemicals have a significant impact on CSCs which may be applied in cancer prevention and treatment. However, anticancer effects of plant derived compounds have not yet been fully investigated in clinical research.

Targeting the Notch1 oncogene by miR-139-5p inhibits glioma metastasis and epithelial-mesenchymal transition (EMT)

BACKGROUND

Glioma metastasis, invasion, epithelial-mesenchymal transition (EMT) and chemoresistance indicate poor prognosis. Accumulating evidence reveals that Notch1 is an important factor in tumour progression. However, the role of Notch1 in glioma EMT and associated microRNAs (miRNAs) with the Notch pathway remain controversial.

METHODS

Utilizing cBioPortal database to examine the gene signature of NOTCH1 (encoding Notch1), CDH2 (encoding N-cadherin) and SNAI1 (encoding Snail-1) in disease-free survival (DFS) and overall survival (OS). We analyzed the Notch1 expression from Oncomine. We used Western blot (WB), immunohistochemistry (IHC) and immunofluorescence to determine protein levels. Transcription was evaluated by quantitative real-time (qRT)-PCR. siRNA and lentivirus were used to knock down Notch1 and overexpress miR-139-5p, respectively. The migration and invasion of glioma cells were assessed by wound healing and transwell assays. Luciferase reporter assays were utilized to verify the relationship between Notch1 and miR-139-5p. A U87-implanted intracranial model was used to study the effect of miR-139-5p on tumour growth and Notch1 suppression efficacy or EMT reversion.

RESULTS

It revealed the association of NOTCH1, CDH2, SNAI1 genomic alterations with decreases in DFS and OS. Notch1 was upregulated in classical and proneural subtypes of GBM, and associated with tumour grade. Notch1 inhibition suppressed the biological behaviours of metastasis, invasion and EMT. Notch1 was identified as a novel direct target of miR-139-5p. MiR-139-5p overexpression partially phenocopied Notch1 siRNA, whereas the forced expression of Notch1 reversed the effects of miR-139-5p on the invasion of glioma. Moreover, intracranial tumourigenicity and EMT behaviours were reduced by the introduction of miR-139-5p and partially mediated by the decreased Notch1 expression.

CONCLUSIONS

miR-139-5p was identified as a tumour suppressor by negatively targeting Notch1, and this work suggests a possible molecular mechanism of the miR-139/Notch1/EMT axis for glioma treatment.

Delivery siRNA with a novel gene vector for glioma therapy by targeting Gli1

Background

Gene therapy has recently shown considerable clinical benefit in cancer therapy during the past few years, and the application of this choice in cancer treatments is increasing continually. Gli1 is an ideal candidate target for cancer gene therapy and is important for tumorigenesis.

Methods

In this study, we developed a novel gene delivery system with a self-assembly method by using a 1,2-dioleoyl-3-trimethylammonium-propane and methoxy poly (ethylene glycol)-poly(lactide) copolymer (DMP), with zeta potential of 32.7 mV and measuring 35.6 nm. The effect of this delivery system was tested in vitro and in vivo.

Results

DMP showed good performance in delivering siRNA to glioma cells in vitro with high transfection performance (98%). Moreover, DMP–Gli1si shows a satisfactory anti-glioma effect via induction of cell apoptosis and cell growth inhibition in vitro. Furthermore, for subcutaneous tumor-bearing mice, treatment with the DMP–Gli1si complex significantly inhibited tumor growth by inhibiting Gli1 protein expression, promoting apoptosis, and reducing proliferation.

Conclusion

The complex of Gli1 siRNA and DMP may potentially play an important role as a new drug in the clinical treatment of gliomas.

NRP-1 targeted and cargo-loaded exosomes facilitate simultaneous imaging and therapy of glioma in vitro and in vivo

Currently, glioma treatment is limited by two main factors: timely detection at onset or relapse and restriction of drugs by the blood-brain barrier (BBB) from entering the brain and influencing tumor growth. However, a safe BBB-traversing drug delivery system has brought new hope to glioma treatment. Exosomes have strong cargo-loading capacity and have the ability to cross the BBB. They can also be conferred with the ability for targeted delivery. Therefore, exosomes have great promise to be a targeted drug delivery vehicles. In this study, we firstly loaded superparamagnetic iron oxide nanoparticles (SPIONs) and curcumin (Cur) into exosomes and then conjugated the exosome membrane with neuropilin-1-targeted peptide (RGERPPR, RGE) by click chemistry to obtain glioma-targeting exosomes with imaging and therapeutic functions. When administered to glioma cells and orthotopic glioma models, we found that these engineered exosomes could cross the BBB smoothly and provided good results for targeted imaging and therapy of glioma. Furthermore, SPION-mediated magnetic flow hyperthermia (MFH) and Cur-mediated therapy also showed a potent synergistic antitumor effect. Therefore, the diagnostic and therapeutic effects on glioma were significantly improved, while reducing the side effects. We have designed a new type of glioma-targeting exosomes, which can carry nanomaterials and chemical agents for simultaneous diagnosis and treatment of glioma, thus providing a potential approach for improving the diagnosis and treatment effects of intracranial tumors.

Nano-delivery systems for encapsulation of dietary polyphenols: An experimental approach for neurodegenerative diseases and brain tumors

Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.

Bioinformatic Analysis of GLI1 and Related Signaling Pathways in Chemosensitivity of Gastric Cancer

Background

This study assessed the prognostic value of GLI1 in gastric cancer and analyzed the possible GLI1-related signaling network in chemosensitivity.

Material/Methods

Bioinformatic data mining was performed by using data in the TCGA-Stomach Cancer (TCGA-STAD) and the Kaplan-Meier plotter. GLI1 co-expressed genes in TCGA-STAD were subjected to KEGG pathway analysis. The genes enriched in the KEGG pathways were further subjected to Protein-Protein Interaction (PPI) analysis.

Results

In TCGA-STAD, high GLI1 gene/exon expression was associated with significantly worse survival (p=0.016 and 0.0023 respectively). In the Kaplan-Meier plotter, high GLI1 expression was associated with unfavorable overall survival (OS) (HR: 1.68, 95%CI: 1.42–2, p<0.0001) and first progression-free survival (FPS) (HR: 1.72, 95%CI: 1.4–2.11, p<0.0001). In TCGA-STAD, 600 GLI1 co-expressed genes were identified (absolute Pearson’s r ≥0.5). The most significant pathways were pathways in cancer (p=230.0E-12) and the Hedgehog signaling pathway (p=6.9E-9). PI3K-AKT pathway (p=17.0E-9) has the largest proportion of gene enrichment. Some GLI1 co-expressed genes in the PI3K-AKT pathway are central nodes in the PPI network and also play important roles in chemosensitivity of gastric cancer. Nevertheless, the mechanisms underlying their co-expression are still largely unexplored.

Conclusions

High GLI1 expression is associated with unfavorable OS and FPS in patients with gastric cancer. As a member of the Hedgehog signaling pathway, GLI1 co-expressed genes are also largely enriched in PI3K/AKT pathway in gastric cancer, which is closely related to chemoresistance. The underlying mechanisms are still largely unexplored and need further study.

Curcumin on the "flying carpets" to modulate different signal transduction cascades in cancers: Next-generation approach to bridge translational gaps

Curcumin, a bioactive and pharmacologically efficient component isolated from Curcuma longa has attracted considerable attention because of its ability to modulate diverse cellular and physiological pathways. WNT, TGF/SMAD, NOTCH, and SHH are fundamentally different signaling cascades, but their choreographed activation is strongly associated with cancer development and progression. In this review we have attempted to set spotlight on regulation of different cell signaling pathways by curcumin in different cancers. We partition this multi-component review into in-depth biological understanding of various signal transduction cascades and how curcumin targets intracellular signal transducers of deregulated pathways to inhibit cancer development and progression. Rapidly broadening landscape of both established and candidate oncogenic driver mutations identified in different cancers is a major stumbling block in the standardization of drugs having significant clinical outcome. Intra and inter-tumor heterogeneity had leveraged the complexity of therapeutic challenges to another level. Multi-pronged approach and molecularly guided treatments will be helpful in improving the clinical outcome.

MicroRNA-326 sensitizes human glioblastoma cells to curcumin via the SHH/GLI1 signaling pathway

Glioblastoma multiforme is the most malignant and common brain tumor in adults and is characterized by poor survival and high resistance to chemotherapy and radiotherapy. Among the new chemotherapy drugs, curcumin, a popular dietary supplement, has proven to have a potent anticancer effect on a variety of cancer cell types; however, it remains difficult to achieve a satisfactory therapeutic effect with curcumin using the traditional single-drug treatment. In this study, we found that expression of miR-326, a tumor suppressor microRNA in various tumor types, resulted in a marked increase of curcumin-induced cytotoxicity and apoptosis and a decrease of proliferation and migration in glioma cells. Moreover, we found that combination treatment of miR-326 and curcumin caused significant inhibition of the SHH/GLI1 pathway in glioma cells compared with either treatment alone, independent of p53 status. Furthermore, in vivo, the curcumin-induced increase in miR-326 expression altered the anti-glioma mechanism of this combination treatment, which further reduced tumor volume and prolonged the survival period compared to either treatment alone. Taken together, our data strongly support an important role for miR-326 in enhancing the chemosensitivity of glioma cells to curcumin.

Aspirin inhibits the SHH/GLI1 signaling pathway and sensitizes malignant glioma cells to temozolomide therapy

Aberrant activation of sonic hedgehog (SHH)/glioma-associated oncogene homolog 1 (GLI1) pathway plays an important role in the tumorigenicity of malignant glioma cells and resistance to temozolomide (TMZ). Here we investigated the aspirin's antineoplastic molecular route by targeting SHH/GLI1 pathway and examined the feasibility of aspirin combined with TMZ therapy. Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) revealed that the activity of the SHH/GLI1 pathway was strongly inhibited by aspirin. Aspirin acted as the glioma growth-inhibitory and pro-apoptosis roles by inhibiting the SHH/GLI1 pathway and reprogramming the epithelial to mesenchymal transition (EMT). The immunofluorescence assay showed aspirin could prevent the nuclear translocation of GLI1 to inhibit its transcriptional regulation. The stable lentiviral overexpression of GLI1 reversed the DNA double strand breaks (DSBs) caused by the GANT61 and TMZ. Furthermore, aspirin combined with TMZ enhanced chemosensitivity and GLI1-induced chemoprotection was partly blocked by aspirin in vitro and in vivo. Collectively, aspirin has a therapeutic potential for SHH/GLI1 targeted therapy against glioma cells. Acquired activation of GLI1 protects glioma cells against TMZ therapy. Impairment of DNA DSBs repair activity might be involved in the route of aspirin-induced chemosensitivity. Combined aspirin with TMZ may be a promising strategy against malignant glioma.

Targeting oncogenic transcription factors by polyphenols: A novel approach for cancer therapy

Inflammation is one of the major causative factor of cancer and chronic inflammation is involved in all the major steps of cancer initiation, progression metastasis and drug resistance. The molecular mechanism of inflammation driven cancer is the complex interplay between oncogenic and tumor suppressive transcription factors which include FOXM1, NF-kB, STAT3, Wnt/β- Catenin, HIF-1α, NRF2, androgen and estrogen receptors. Several products derived from natural sources modulate the expression and activity of multiple transcription factors in various tumor models as evident from studies conducted in cell lines, pre-clinical models and clinical samples. Further combination of these natural products along with currently approved cancer therapies added an additional advantage and they considered as promising targets for prevention and treatment of inflammation and cancer. In this review we discuss the application of multi-targeting natural products by analyzing the literature and future directions for their plausible applications in drug discovery.

Regulation of Hedgehog Signaling in Cancer by Natural and Dietary Compounds

The aberrant Hedgehog (Hh) signaling induced by mutations or overexpression of the signaling mediators has been implicated in cancer, associated with processes including inflammation, tumor cell growth, invasion, and metastasis, as well as cancer stemness. Small molecules targeting the regulatory components of the Hh signaling pathway, especially Smoothened (Smo), have been developed for the treatment of cancer. However, acquired resistance to a Smo inhibitor vismodegib observed in clinical trials suggests that other Hh signaling components need to be explored as potential anticancer targets. Natural and dietary compounds provide a resource for the development of potent agents affecting intracellular signaling cascades, and numerous studies have been conducted to evaluate the efficacy of natural products in targeting the Hh signaling pathway. In this review, we summarize the role of Hh signaling in tumorigenesis, discuss results from recent studies investigating the effect of natural products and dietary components on Hh signaling in cancer, and provide insight on novel small molecules as potential Hh signaling inhibitors.

Lentivirus-mediated silencing of the PTC1 and PTC2 genes promotes recovery from spinal cord injury by activating the Hedgehog signaling pathway in a rat model

This study aimed to investigate the effect of Patched-1 (PTC1) and PTC2 silencing in a rat model, on Hedgehog (Hh) pathway-mediated recovery from spinal cord injury (SCI). An analytical emphasis on the relationship between the sonic hedgehog (Shh) pathway and nerve regeneration was explored. A total of 126 rats were divided into normal, sham, SCI, negative control (NC), PTC1-RNAi, PTC2-RNAi and PTC1/PTC2-RNAi groups. The Basso, Beattie and Bresnahan (BBB) scale was employed to assess hind limb motor function. Quantitative real-time polymerase chain reaction and western blotting were performed to examine the mRNA and protein levels of PTC1, PTC2, Shh, glioma-associated oncogene homolog 1 (Gli-1), Smo and Nestin. Tissue morphology was analyzed using immunohistochemistry, and immunofluorescent staining was conducted to detect neurofilament protein 200 (NF-200) and glial fibrillary acidic protein (GFAP). The PTC1/PTC2-RNAi group displayed higher BBB scores than the SCI and NC groups. Shh, Gli-1, Smo and Nestin expression levels were elevated in the PTC1/PTC2-RNAi group. PTC1 and PTC2 mRNA and protein expression was lower in the PTC1/PTC2-RNAi group than in the normal, sham and SCI groups. Among the seven groups, the PTC1/PTC2-RNAi group had the largest positive area of NF-200 staining, whereas the SCI group exhibited a larger GFAP-positive area than both the normal and the sham groups. The Shh pathway may provide new insights into therapeutic indications and regenerative recovery tools for the treatment of SCI. Activation of the Hh signaling pathway by silencing PTC1 and PTC2 may reduce inflammation and may ultimately promote SCI recovery.

Curcumin-lipoic acid conjugate as a promising anticancer agent on the surface of gold‑iron oxide nanocomposites: A pH-sensitive targeted drug delivery system for brain cancer theranostics

Brain tumor is a lethal, fast growing cancer and a difficult case for treatment. Receptor-mediated endocytosis has been recognized as one of the most effective methods for drug delivery to brain tissue by overcoming obstacles associated with conventional therapeutics. In this work, a targeted theranostic drug delivery system (DDS) was prepared based on gold‑iron oxide nanocomposites (Fe₃O₄@Au NCs). Lipoic acid-curcumin (LA-CUR) was synthesized and introduced as a novel anticancer drug, and glutathione (GSH) was exploited as the targeting ligand. Both LA-CUR and GSH were easily attached to Fe₃O₄@Au NCs via Au-S interaction. As a negatively charged nanocarrier, the prepared DDS showed relatively less protein adsorption. Accordingly, hemocompatibility assays (complement, platelet, and leucocyte activation) revealed its hemocompatible virtue, especially in respect of free LA-CUR. GSH functionalization led to 2-fold increase of cellular uptake in GSH receptor-positive astrocyte cells which could primarily indicate the probable ability of the DDS to bypass BBB. Cytotoxicity and apoptosis assays together showed the noticeably enhanced cytotoxicity of LA-CUR against cancerous U87MG cells (IC50=2.69μg/ml) in comparison with curcumin (IC50=21.31μg/ml); moreover, the DDS demonstrated relatively higher cytotoxicity against cancerous U87MG cells than normal astrocyte cells which was in accordance with pH sensitive mechanism of LA-CUR release. Besides, the results of in vitro magnetic resonance imaging (MRI) (relaxation rate (r₂)=80.73 (s^-1·mM^-1)) primarily revealed that the DDS can be applied as a negative MRI contrast agent. In sum, the prepared DDS appeared to be a promising candidate for brain cancer treatment and a favorable MRI contrast agent.

The interference of Notch1 target Hes1 affects cell growth, differentiation and invasiveness of glioblastoma stem cells through modulation of multiple oncogenic targets

The invasive and lethal nature of Glioblastoma multiforme (GBM) necessitates the continuous identification of molecular targets and search of efficacious therapies to inhibit GBM growth. The GBM resistance to chemotherapy and radiation it is attributed to the existence of a rare fraction of cancer stem cells (CSC) that we have identified within the tumor core and in peritumor tissue of GBM. Since Notch1 pathway is a potential therapeutic target in brain cancer, earlier we highlighted that pharmacological inhibition of Notch1 signalling by γ-secretase inhibitor-X (GSI-X), reduced cell growth of some c-CSC than to their respective p-CSC, but produced negligible effects on cell cycle distribution, apoptosis and cell invasion. In the current study, we assessed the effects of Hes1-targeted shRNA, a Notch1 gene target, specifically on GBM CSC refractory to GSI-X. Depletion of Hes1 protein induces major changes in cell morphology, cell growth rate and in the invasive ability of shHes1-CSC in response to growth factor EGF. shHes1-CSC show a decrease of the stemness marker Nestin concurrently to a marked increase of neuronal marker MAP2 compared to pLKO.1-CSC. Those effects correlated with repression of EGFR protein and modulation of Stat3 phosphorylation at Y705 and S727 residues. In the last decade Stat3 has gained attention as therapeutic target in cancer but there is not yet any approved Stat3-based glioma therapy. Herein, we report that exposure to a Stat3/5 inhibitor, induced apoptosis either in shHes1-CSC or control cells. Taken together, Hes1 seems to be a favorable target but not sufficient itself to target GBM efficaciously, therefore a possible pharmacological intervention should provide for the use of anti-Stat3/5 drugs either alone or in combination regimen.

Curcumin exerts its tumor suppressive function via inhibition of NEDD4 oncoprotein in glioma cancer cells

Glioblastoma is the most common brain cancer in adults. It represents one of the top ten malignant tumors with an average survival time of nine months despite treatments with surgery, radiotherapy and chemotherapy. Curcumin is a phytochemical turmeric isolated from root of the Curcuma longa plant. Accumulating evidence have proved that curcumin targets numerous cancer signaling pathways. The E3 ubiquitin ligase NEDD4, neural precursor cell expressed developmentally downregulated protein 4, is frequently overexpressed in various cancers. However, whether curcumin regulates NEDD4 expression has not been described in human cancers. Therefore, in this study, we explored the roles of NEDD4 in glioma cell proliferation, apoptosis and mobility. We further investigated whether curcumin exerts its antitumor activities via suppressing NEDD4 expression. We found that curcumin reduced the expression of NEDD4 and Notch1 and pAKT, leading to glioma cell growth inhibition, apoptosis, and suppression of migration and invasion. Moreover, deletion of NEDD4 expression enhanced the sensitivity of glioma cells to curcumin treatment. Thus, inactivation of NEDD4 by curcumin could be a promising approach for therapeutic intervention.

Curcumin increases efficiency of γ-irradiation in gliomas by inhibiting Hedgehog signaling pathway

It was reported that γ-irradiation had a controversial therapeutic effect on glioma cells. We aimed to investigate the cytotoxic effect on the glioma cells induced by γ-irradiation and explore the treatment to rescue the phenotype alteration of remaining cells. We used transwell assay to detect the glioma cell invasion and migration capacity. Cell proliferation and apoptosis were tested by the CCK-8 assay and flow cytometry respectively. Western Blot was used to detect the activity of Hedgehog signaling pathway and Epithelial-to-Mesenchymal Transition (EMT) status. γ-irradiation showed cytotoxic effect on LN229 cells in vitro, whereas this contribution was limited in U251 cells. However, it could significantly stimulated EMT process in both LN229 and U251. Curcumin (CCM) could rescue EMT process induced by γ-irradiation via the suppression of Gli1 and the upregulation of Sufu. The location and expression of EMT markers were also verified by Immunofluorescence. Immunohistochemistry assay was used on intracranial glioma tissues of nude mice. The capacities of cell migration and invasion were suppressed with combined therapy. This research showed Curcumin could rescue the EMT process induced by γ-irradiation via inhibiting the Hedgehog signaling pathway and potentiate the cell cytotoxic effect in vivo and in vitro.

Selective Targeting of Cancer Cells by Oxidative Vulnerabilities with Novel Curcumin Analogs

Recently, research has focused on targeting the oxidative and metabolic vulnerabilities in cancer cells. Natural compounds like curcumin that target such susceptibilities have failed further clinical advancements due to the poor stability and bioavailability as well as the need of high effective doses. We have synthesized and evaluated the anti-cancer activity of several monocarbonyl analogs of curcumin. Interestingly, two novel analogs (Compound A and I) in comparison to curcumin, have increased chemical stability and have greater anti-cancer activity in a variety of human cancer cells, including triple-negative, inflammatory breast cancer cells. In particular, the generation of reactive oxygen species was selective to cancer cells and occurred upstream of mitochondrial collapse and execution of apoptosis. Furthermore, Compound A in combination with another cancer-selective/pro-oxidant, piperlongumine, caused an enhanced anti-cancer effect. Most importantly, Compound A was well tolerated by mice and was effective in inhibiting the growth of human triple-negative breast cancer and leukemia xenografts in vivo when administered intraperitoneally. Thus, exploiting oxidative vulnerabilities in cancer cells could be a selective and efficacious means to eradicate malignant cells as demonstrated by the curcumin analogs presented in this report with high therapeutic potential.

Diarylheptanoids suppress proliferation of pancreatic cancer PANC-1 cells through modulating shh-Gli-FoxM1 pathway

Pancreatic cancer is one of the leading causes of cancer, and it has the lowest 5-year survival rates. It is necessary to develop more potent anti-pancreatic cancer drugs to overcome the fast metastasis and resistance to surgery, radiotherapy, chemotherapy, and combinations of these. We have identified several diarylheptanoids as anti-pancreatic cancer agents from Alpinia officinarum (lesser galangal) and Alnus japonica. These diarylheptanoids suppressed cell proliferation and induced the cell cycle arrest of pancreatic cancer cells (PANC-1). Among them, the most potent compounds 1 and 7 inhibited the shh-Gli-FoxM1 pathway and their target gene expression in PANC-1 cells. Furthermore, they suppressed the expression of the cell cycle associated genes that were rescued by the overexpression of exogenous FoxM1. Taken together, (E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (1) from Alpinia officinarum (lesser galangal) and platyphyllenone (7) from Alnus japonica inhibit PANC-1 cell proliferation by suppressing the shh-Gli-FoxM1 pathway, and they can be potential candidates for anti-pancreatic cancer drug development.