p21 Waf1/Cip1 expression by curcumin in U-87MG human glioma cells: role of early growth response-1 expression

Modern Photodynamic Glioblastoma Therapy Using Curcumin- or Parietin-Loaded Lipid Nanoparticles in a CAM Model Study

Natural photosensitizers, such as curcumin or parietin, play a vital role in photodynamic therapy (PDT), causing a light-mediated reaction that kills cancer cells. PDT is a promising treatment option for glioblastoma, especially when combined with nanoscale drug delivery systems. The curcumin- or parietin-loaded lipid nanoparticles were prepared via dual asymmetric centrifugation and subsequently characterized through physicochemical analyses including dynamic light scattering, laser Doppler velocimetry, and atomic force microscopy. The combination of PDT and lipid nanoparticles has been evaluated in vitro regarding uptake, safety, and efficacy. The extensive and well-vascularized chorioallantois membrane (CAM) of fertilized hen's eggs offers an optimal platform for three-dimensional cell culture, which has been used in this study to evaluate the photodynamic efficacy of lipid nanoparticles against glioblastoma cells. In contrast to other animal models, the CAM model lacks a mature immune system in an early stage, facilitating the growth of xenografts without rejection. Treatment of xenografted U87 glioblastoma cells on CAM was performed to assess the effects on tumor viability, growth, and angiogenesis. The xenografts and the surrounding blood vessels were targeted through topical application, and the effects of photodynamic therapy have been confirmed microscopically and via positron emission tomography and X-ray computed tomography. Finally, the excised xenografts embedded in the CAM were analyzed histologically by hematoxylin and eosin and KI67 staining.

A review of traditional Chinese medicine Curcumae Rhizoma for treatment of glioma

Glioma is the most common primary central nervous tumor and its malignant and high recurrence rate are seriously threatening patient's life. The prognosis of glioma patients is still poor with a variety of modern treatments. Traditional Chinese medicine (TCM) is widely used in the adjuvant treatment or alternative medicine of glioma. Curcumae Rhizoma is one of the most commonly used in traditional Chinese medicine prescriptions for its anti-tumor characteristics. There are also many studies that reveals the anti-tumor effect of its active ingredients and some of which have been made into drugs and have been used in clinical practice. This review summarizes the new research progress on Curcumae Rhizoma for the treatment of glioma in recent years.

Curcumin reduces paclitaxel resistance in ovarian carcinoma cells by upregulating SNIP1 and inhibiting NFκB activity

The therapeutic activity of paclitaxel against ovarian carcinoma is relatively low due to the frequent occurrence of chemoresistance and disease recurrence. We found earlier that a combination of curcumin and paclitaxel reduces cell viability and promotes apoptosis in paclitaxel-resistant (i.e., taxol-resistant, Txr) ovarian cancer cells. In the present study, we first used RNA sequencing (RNAseq) analysis to identify genes that are upregulated in Txr cell lines but downregulated by curcumin in ovarian cancer cells. The nuclear factor kappa B (NFκB) signaling pathway was shown to be upregulated in Txr cells. Furthermore, based on the protein interaction database BioGRID, we found that Smad nuclear interacting protein 1 (SNIP1) may be involved in regulating the activity of NFκB in Txr cells. Accordingly, curcumin upregulated SNIP1 expression, which in turn downregulated the pro-survival genes Bcl-2 and Mcl-1. Using shRNA-guided gene silencing, we found that SNIP1 depletion reversed the inhibitory effect of curcumin on NFκB activity. Moreover, we identified that SNIP1 enhanced NFκB protein degradation, thereby suppressing NFκB/p65 acetylation, which is involved in the inhibitory effect of curcumin on NFκB signaling. The transcription factor early growth response protein 1 (EGR1) was shown to represent an upstream transactivator of SNIP1. Consequently, we show that curcumin inhibits NFκB activity by modulating the EGR1/SNIP1 axis to attenuate p65 acetylation and protein stability in Txr cells. These findings provide a new mechanism to account for the effects of curcumin in inducing apoptosis and reducing paclitaxel resistance in ovarian cancer cells.

N6-methyladenosine reader YTHDF2 promotes multiple myeloma cell proliferation through EGR1/p21cip1/waf1/CDK2-Cyclin E1 axis-mediated cell cycle transition

Multiple myeloma (MM) is the second most common hematological malignancy. N6-methyladenosine (m⁶A) is the most abundant RNA modification. YTH domain-containing family protein 2 (YTHDF2) recognizes m⁶A-cotaining RNAs and accelerates degradation to regulate cancer progression. However, the role of YTHDF2 in MM remains unclear. We investigated the expression levels and prognostic role of YTHDF2 in MM, and studied the effect of YTHDF2 on MM proliferation and cell cycle. The results showed that YTHDF2 was highly expressed in MM and was an independent prognostic factor for MM survival. Silencing YTHDF2 suppressed cell proliferation and caused the G₁/S phase cell cycle arrest. RNA immunoprecipitation (RIP) and m⁶A-RIP (MeRIP) revealed that YTHDF2 accelerated EGR1 mRNA degradation in an m⁶A-dependent manner. Moreover, overexpression of YTHDF2 promoted MM growth via the m⁶A-dependent degradation of EGR1 both in vitro and in vivo. Furthermore, EGR1 suppressed cell proliferation and retarded cell cycle by activating p21^cip1/waf1 transcription and inhibiting CDK2-cyclinE1. EGR1 knockdown could reverse the inhibited proliferation and cell cycle arrest upon YTHDF2 knockdown. In conclusion, the high expression of YTHDF2 promoted MM cell proliferation via EGR1/p21^cip1/waf1/CDK2-cyclin E1 axis-mediated cell cycle transition, highlighting the potential of YTHDF2 as an effective prognostic biomarker and a promising therapeutic target for MM.

Phytochemicals as Chemo-Preventive Agents and Signaling Molecule Modulators: Current Role in Cancer Therapeutics and Inflammation

Cancer is one of the deadliest non communicable diseases. Numerous anticancer medications have been developed to target the molecular pathways driving cancer. However, there has been no discernible increase in the overall survival rate in cancer patients. Therefore, innovative chemo-preventive techniques and agents are required to supplement standard cancer treatments and boost their efficacy. Fruits and vegetables should be tapped into as a source of compounds that can serve as cancer therapy. Phytochemicals play an important role as sources of new medication in cancer treatment. Some synthetic and natural chemicals are effective for cancer chemoprevention, i.e., the use of exogenous medicine to inhibit or impede tumor development. They help regulate molecular pathways linked to the development and spread of cancer. They can enhance antioxidant status, inactivating carcinogens, suppressing proliferation, inducing cell cycle arrest and death, and regulating the immune system. While focusing on four main categories of plant-based anticancer agents, i.e., epipodophyllotoxin, camptothecin derivatives, taxane diterpenoids, and vinca alkaloids and their mode of action, we review the anticancer effects of phytochemicals, like quercetin, curcumin, piperine, epigallocatechin gallate (EGCG), and gingerol. We examine the different signaling pathways associated with cancer and how inflammation as a key mechanism is linked to cancer growth.

Examining the role of EGR1 during viral infections

Early growth response 1 (EGR1) is a multifunctional mammalian transcription factor capable of both enhancing and/or inhibiting gene expression. EGR1 can be activated by a wide array of stimuli such as exposure to growth factors, cytokines, apoptosis, and various cellular stress states including viral infections by both DNA and RNA viruses. Following induction, EGR1 functions as a convergence point for numerous specialized signaling cascades and couples short-term extracellular signals to influence transcriptional regulation of genes required to initiate the appropriate biological response. The role of EGR1 has been extensively studied in both physiological and pathological conditions of the adult nervous system where it is readily expressed in various regions of the brain and is critical for neuronal plasticity and the formation of memories. In addition to its involvement in neuropsychiatric disorders, EGR1 has also been widely examined in the field of cancer where it plays paradoxical roles as a tumor suppressor gene or oncogene. EGR1 is also associated with multiple viral infections such as Venezuelan equine encephalitis virus (VEEV), Kaposi's sarcoma-associated herpesvirus (KSHV), herpes simplex virus 1 (HSV-1), human polyomavirus JC virus (JCV), human immunodeficiency virus (HIV), and Epstein-Barr virus (EBV). In this review, we examine EGR1 and its role(s) during viral infections. First, we provide an overview of EGR1 in terms of its structure, other family members, and a brief overview of its roles in non-viral disease states. We also review upstream regulators of EGR1 and downstream factors impacted by EGR1. Then, we extensively examine EGR1 and its roles, both direct and indirect, in regulating replication of DNA and RNA viruses.

Identification of potential targets of the curcumin analog CCA-1.1 for glioblastoma treatment : integrated computational analysis and in vitro study

The treatment of glioblastoma multiforme (GBM) is challenging owing to its localization in the brain, the limited capacity of brain cells to repair, resistance to conventional therapy, and its aggressiveness. Curcumin has anticancer activity against aggressive cancers, such as leukemia, and GBM; however, its application is limited by its low solubility and bioavailability. Chemoprevention curcumin analog 1.1 (CCA-1.1), a curcumin analog, has better solubility and stability than those of curcumin. In this study, we explored potential targets of CCA-1.1 in GBM (PTCGs) by an integrated computational analysis and in vitro study. Predicted targets of CCA-1.1 obtained using various databases were subjected to comprehensive downstream analyses, including functional annotation, disease and drug association analyses, protein–protein interaction network analyses, analyses of genetic alterations, expression, and associations with survival and immune cell infiltration. Our integrative bioinformatics analysis revealed four candidate targets of CCA-1.1 in GBM: TP53, EGFR, AKT1, and CASP3. In addition to targeting specific proteins with regulatory effects in GBM, CCA-1.1 has the capacity to modulate the immunological milieu. Cytotoxicity of CCA-1.1 was lower than TMZ with an IC50 value of 9.8 μM compared to TMZ with an IC50 of 40 μM. mRNA sequencing revealed EGFR transcript variant 8 was upregulated, whereas EGFRvIII was downregulated in U87 cells after treatment with CCA-1.1. Furthermore, a molecular docking analysis suggested that CCA-1.1 inhibits EGFR with various mutations in GBM, which was confirmed using molecular dynamics simulation, wherein the binding between CCA-1.1 with the mutant EGFR L861Q was stable. For successful clinical translation, the effects of CCA-1.1 need to be confirmed in laboratory studies and clinical trials.

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.

Natural Compounds as Promising Adjuvant Agents in The Treatment of Gliomas

In humans, glioblastoma is the most prevalent primary malignant brain tumor. Usually, glioblastoma has specific characteristics, such as aggressive cell proliferation and rapid invasion of surrounding brain tissue, leading to a poor patient prognosis. The current therapy-which provides a multidisciplinary approach with surgery followed by radiotherapy and chemotherapy with temozolomide-is not very efficient since it faces clinical challenges such as tumor heterogeneity, invasiveness, and chemoresistance. In this respect, natural substances in the diet, integral components in the lifestyle medicine approach, can be seen as potential chemotherapeutics. There are several epidemiological studies that have shown the chemopreventive role of natural dietary compounds in cancer progression and development. These heterogeneous compounds can produce anti-glioblastoma effects through upregulation of apoptosis and autophagy; allowing the promotion of cell cycle arrest; interfering with tumor metabolism; and permitting proliferation, neuroinflammation, chemoresistance, angiogenesis, and metastasis inhibition. Although these beneficial effects are promising, the efficacy of natural compounds in glioblastoma is limited due to their bioavailability and blood-brain barrier permeability. Thereby, further clinical trials are necessary to confirm the in vitro and in vivo anticancer properties of natural compounds. In this article, we overview the role of several natural substances in the treatment of glioblastoma by considering the challenges to be overcome and future prospects.

Enhanced Anticancer Response of Curcumin- and Piperine-Loaded Lignin-g-p (NIPAM-co-DMAEMA) Gold Nanogels against U-251 MG Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most aggressive and commonly diagnosed brain cancer and is highly resistant to routine chemotherapeutic drugs. The present study involves the synthesis of Lignin-g-p (NIPAM-co-DMAEMA) gold nanogel, loaded with curcumin and piperine, to treat GBM. The ongoing study has the application potential to (1) overcome the limitations of drugs biodistribution, (2) enhance the toxicity of anticancer drugs against GBM, and (3) identify the drugs uptake pathway. Atom transfer radical polymerization was used to synthesize the Lignin-g-PNIPAM network, crosslinked with the gold nanoparticles (GNPs) to self-assemble into nanogels. The size distribution and morphological analysis confirmed that the drug-loaded gold nanogels are spherical and exist in the size of 180 nm. The single and combinatorial toxicity effects of curcumin- and piperine-loaded Lignin-g-p (NIPAM-co-DMAEMA) gold nanogels were studied against U-251 MG GBM cells. A cytotoxicity analysis displayed anticancer properties. IC₅₀ of curcumin- and piperine-loaded gold nanogels were recorded at 30 μM and 35 μM, respectively. Immunostaining and Western blot analysis confirmed the protein expression of caspase-3 and cleaved caspase-3 in cells treated with drug-loaded nanogels. Kinetic drug release revealed 86% release of hybrid curcumin–piperine from gold nanogel after 250 min at pH 4. Atomic absorption spectroscopic analysis confirmed that the drug-loaded nanogels have better internalization or association with the cancer cells than the GNPs or nano-gels alone. Morphological studies further confirmed that the curcumin and piperine nanogels penetrate the cells via endocytic pathways and induce caspase-3-related apoptosis. The experimental evidence shows the enhanced properties of combinatorial curcumin–piperine gold nanogels (IC50: 21 μM) to overcome the limitations of conventional chemotherapeutic treatments of glioma cells.

Antitumoral Activities of Curcumin and Recent Advances to ImProve Its Oral Bioavailability

Curcumin, a main bioactive component of the Curcuma longa L. rhizome, is a phenolic compound that exerts a wide range of beneficial effects, acting as an antimicrobial, antioxidant, anti-inflammatory and anticancer agent. This review summarizes recent data on curcumin's ability to interfere with the multiple cell signaling pathways involved in cell cycle regulation, apoptosis and the migration of several cancer cell types. However, although curcumin displays anticancer potential, its clinical application is limited by its low absorption, rapid metabolism and poor bioavailability. To overcome these limitations, several curcumin-based derivatives/analogues and different drug delivery approaches have been developed. Here, we also report the anticancer mechanisms and pharmacokinetic characteristics of some derivatives/analogues and the delivery systems used. These strategies, although encouraging, require additional in vivo studies to support curcumin clinical applications.

Nuclear receptor NR5A2 negatively regulates cell proliferation and tumor growth in nervous system malignancies

Nervous system malignancies are characterized by rapid progression and poor survival rates. These clinical observations underscore the need for novel therapeutic insights and pharmacological targets. To this end, here, we identify the orphan nuclear receptor NR5A2/LRH1 as a negative regulator of cancer cell proliferation and promising pharmacological target for nervous system-related tumors. In particular, clinical data from publicly available databases suggest that high expression levels of NR5A2 are associated with favorable prognosis in patients with glioblastoma and neuroblastoma tumors. Consistently, we experimentally show that NR5A2 is sufficient to strongly suppress proliferation of both human and mouse glioblastoma and neuroblastoma cells without inducing apoptosis. Moreover, short hairpin RNA-mediated knockdown of the basal expression levels of NR5A2 in glioblastoma cells promotes their cell cycle progression. The antiproliferative effect of NR5A2 is mediated by the transcriptional induction of negative regulators of the cell cycle, CDKN1A (encoding for p21cip1), CDKN1B (encoding for p27kip1) and Prox1 Interestingly, two well-established agonists of NR5A2, dilauroyl phosphatidylcholine (DLPC) and diundecanoyl phosphatidylcholine, are able to mimic the antiproliferative action of NR5A2 in human glioblastoma cells via the induction of the same critical genes. Most importantly, treatment with DLPC inhibits glioblastoma tumor growth in vivo in heterotopic and orthotopic xenograft mouse models. These data indicate a tumor suppressor role of NR5A2 in the nervous system and render this nuclear receptor a potential pharmacological target for the treatment of nervous tissue-related tumors.

Multifaceted effect of chlorpromazine in cancer: implications for cancer treatment

Since its discovery in 1951, chlorpromazine (CPZ) has been one of the most widely used antipsychotic medications for treating schizophrenia and other psychiatric disorders. In addition to its antipsychotic effect, many studies in the last several decades have found that CPZ has a potent antitumorigenic effect. These studies have shown that CPZ affects a number of molecular oncogenic targets through multiple pathways, including the regulation of cell cycle, cancer growth and metastasis, chemo-resistance and stemness of cancer cells. Here we review studies on molecular mechanisms of CPZ’s action on key proteins involved in cancer, including p53, YAP, Ras protein, ion channels, and MAPKs. We discuss common and overlapping signaling pathways of CPZ’s action, its cancer-type specificity, antitumorigenic effects of CPZ reported in animal models and population studies on the rate of cancer in psychiatric patients. We also discuss the potential benefits and limitations of repurposing CPZ for cancer treatment.

Potential Therapeutic Targets of Curcumin, Most Abundant Active Compound of Turmeric Spice: Role in the Management of Various Types of Cancer

BACKGROUND

Curcumin, an active compound of turmeric spice, is one of the most-studied natural compounds and has been widely recognized as a chemopreventive agent. Several molecular mechanisms have proven that curcumin and its analogs play a role in cancer prevention through modulating various cell signaling pathways as well as in the inhibition of the carcinogenesis process.

OBJECTIVE

To study the potential role of curcumin in the management of various types of cancer through modulating cell signalling molecules based on available literature and recent patents.

METHODS

A wide-ranging literature survey was performed based on Scopus, PubMed, PubMed Central, and Google scholar for the implication of curcumin in cancer management, along with a special emphasis on human clinical trials. Moreover, patents were searched through www.google.com/patents, www.freepatentsonline.com, and www.freshpatents.com.

RESULT

Recent studies based on cancer cells have proven that curcumin has potential effects against cancer cells as it prevents the growth of cancer and acts as a cancer therapeutic agent. Besides, curcumin exerted anti-cancer effects by inducing apoptosis, activating tumor suppressor genes, cell cycle arrest, inhibiting tumor angiogenesis, initiation, promotion, and progression stages of tumor. It was established that co-treatment of curcumin and anti-cancer drugs could induce apoptosis and also play a significant role in the suppression of the invasion and metastasis of cancer cells.

CONCLUSION

Accumulating evidences suggest that curcumin has the potential to inhibit cancer growth, induce apoptosis, and modulate various cell signaling pathway molecules. Well-designed clinical trials of curcumin based on human subjects are still needed to establish the bioavailability, mechanism of action, efficacy, and safe dose in the management of various cancers.

The Role of the Transcription Factor EGR1 in Cancer

Early growth response factor 1 (EGR1) is a transcription factor that is mainly involved in the processes of tissue injury, immune responses, and fibrosis. Recent studies have shown that EGR1 is closely related to the initiation and progression of cancer and may participate in tumor cell proliferation, invasion, and metastasis and in tumor angiogenesis. Nonetheless, the specific mechanism whereby EGR1 modulates these processes remains to be elucidated. This review article summarizes possible mechanisms of action of EGR1 in tumorigenesis and tumor progression and may serve as a reference for clinical efficacy predictions and for the discovery of new therapeutic targets.

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.

Novel Therapeutic Delivery of Nanocurcumin in Central Nervous System Related Disorders

Nutraceuticals represent complementary or alternative beneficial products to the expensive and high-tech therapeutic tools in modern medicine. Nowadays, their medical or health benefits in preventing or treating different types of diseases is widely accepted, due to fewer side effects than synthetic drugs, improved bioavailability and long half-life. Among herbal and natural compounds, curcumin is a very attractive herbal supplement considering its multipurpose properties. The potential effects of curcumin on glia cells and its therapeutic and protective properties in central nervous system (CNS)-related disorders is relevant. However, curcumin is unstable and easily degraded or metabolized into other forms posing limits to its clinical development. This is particularly important in brain pathologies determined blood brain barrier (BBB) obstacle. To enhance the stability and bioavailability of curcumin, many studies focused on the design and development of curcumin nanodelivery systems (nanoparticles, micelles, dendrimers, and diverse nanocarriers). These nanoconstructs can increase curcumin stability, solubility, in vivo uptake, bioactivity and safety. Recently, several studies have reported on a curcumin exosome-based delivery system, showing great therapeutical potential. The present work aims to review the current available data in improving bioactivity of curcumin in treatment or prevention of neurological disorders.

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.

Role of Divalent Cations in HIV-1 Replication and Pathogenicity

Divalent cations are essential for life and are fundamentally important coordinators of cellular metabolism, cell growth, host-pathogen interactions, and cell death. Specifically, for human immunodeficiency virus type-1 (HIV-1), divalent cations are required for interactions between viral and host factors that govern HIV-1 replication and pathogenicity. Homeostatic regulation of divalent cations' levels and actions appear to change as HIV-1 infection progresses and as changes occur between HIV-1 and the host. In people living with HIV-1, dietary supplementation with divalent cations may increase HIV-1 replication, whereas cation chelation may suppress HIV-1 replication and decrease disease progression. Here, we review literature on the roles of zinc (Zn2+), iron (Fe2+), manganese (Mn2+), magnesium (Mg2+), selenium (Se2+), and copper (Cu2+) in HIV-1 replication and pathogenicity, as well as evidence that divalent cation levels and actions may be targeted therapeutically in people living with HIV-1.

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.

Friend or foe, the role of EGR-1 in cancer

Early growth response-1 (EGR-1), also termed NEFI-A and Krox-24, as a multi-domain protein is implicated in several vital physiological processes, including development, metabolism, cell growth and proliferation. Previous studies have implied that EGR-1 was producing in response to the tissue injury, immune response and fibrosis. Meanwhile, emerging studies stressed the pronounced correlation of EGR-1 and human cancers. Nevertheless, the intricate mechanisms of cancer-reduce EGR-1 alteration still poorly characterized. In the review, we evaluated the effects of EGR-1 in tumor cell proliferation, apoptosis, migration, invasion and tumor microenvironment, and then, we dwell on the intricate signaling pathways that EGR-1 involved in. The aberrantly expressed of EGR-1 in cancers are expected to provide a new cancer therapy strategy or a new marker for assessing treatment efficacy.

UBN2 promotes tumor progression via the Ras/MAPK pathway and predicts poor prognosis in colorectal cancer

Background

Ubinuclein-2 (UBN2) is a nuclear protein that interacts with many transcription factors. The molecular role and mechanism of UBN2 in the development and progression of cancers, including colorectal cancer (CRC), is not well understood. The current study explored the role of UBN2 in the development and progression CRC.

Methods

Oncomine network and The Cancer Genome Atlas (TCGA) database were downloaded and Gene Set Enrichment Analysis (GSEA) was performed to compare the UBN2′s expression between normal and tumor tissues, as well as the potential correlation of UBN2 expression with signaling pathways. Immunohistochemistry (IHC), qRT-PCR and Western blotting were performed to determine the expression of UBN2 in CRC tissues or cell lines. In vitro proliferation and invasion assays, and orthotopic mouse metastatic model were used to analyze the effect of UBN2 on the development and progression of CRC.

Results

The analysis of UBN2 expression using Oncomine network showed that UBN2 was upregulated in CRC tissues compared to matched adjacent normal intestinal epithelial tissues. IHC, qRT-PCR and Western blotting confirmed that UBN2 expression is higher in CRC tissues compared with matched adjacent normal intestinal epithelial tissues. In addition, analyses of TCGA data revealed that high UBN2 expression was associated with advanced stages of lymph node metastasis, distant metastasis, and short survival time in CRC patients. IHC showed that high UBN2 expression is correlated with advanced stages of CRC. Moreover, UBN2 is highly expressed in the liver metastatic lesions. Furthermore, knockdown of UBN2 inhibited the growth, invasiveness and metastasis of CRC cells via regulation of the Ras/MAPK signaling pathway.

Conclusion

The current study demonstrates that UBN2 promotes tumor progression in CRC. UBN2 may be used as a promising biomarker for predicting the prognosis of CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0848-4) contains supplementary material, which is available to authorized users.

Modulation of Biological Activities in Glioblastoma Mediated by Curcumin

Curcumin is an alkaloid with various pharmacologic properties; numerous investigations have suggested that in the Central Nervous System, Curcumin has anti-inflammatory, antimicrobial, antioxidant, and antitumor effects. Gliomas are the most common primary intracranial tumors in adults. The prognosis of glioblastoma is still dismal. In this review, we profile that Curcumin could suppress cell proliferation and induce apoptosis of cancer cells and genomic modulation. In particular, Curcumin could exert its therapeutic effect via modulating miRNA, affecting a variety of miRNAs involved in the response to cancer therapy. The combination of Curcumin with chemotherapeutic drugs or radiotherapy could prime the sensitivity of cancer cells to chemotherapy or radiotherapy. We also discuss the use of exosomes as Curcumin delivery vehicles. In this context, exosomes containing Curcumin may change the behavior of recipient cells by targeting a sequence of cellular and molecular pathways. Hence, the application of exosomes containing Curcumin may prove to be an emerging area of research in cancer therapy.

Curcumin: a potent agent to reverse epithelial-to-mesenchymal transition

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is involved in tumor progression, invasion, migration and metastasis. EMT is a process by which polarized epithelial cells acquire motile mesothelial phenotypic features. This process is initiated by disassembly of cell-cell contacts through the loss of epithelial markers and replacement of these markers by mesenchymal markers. Reconstruction of the cytoskeleton and degradation of the tumor basement membrane ensures the spread of invasive malignant tumor cells to distant locations. Accumulating evidence indicates that curcumin, as a well-known phytochemical, can inhibit EMT/metastasis through various mechanisms and pathways in human tumors.

CONCLUSIONS

In this review, we summarize the mechanisms by which curcumin may affect EMT in cells under pathological conditions to understand its potential as a novel anti-tumor agent. Curcumin can exert chemo-preventive effects by inhibition and reversal of the EMT process through both TGF-β-dependent (e.g. in hepatoma and retinal pigment epithelial cancer) and -independent (e.g. in oral cancer, colorectal cancer, pancreatic cancer, hepatocellular carcinoma, breast cancer, melanoma, prostate cancer, bladder cancer, thyroid cancer and lung cancer) pathways. Curcumin can also mitigate chemoresistance through EMT suppression and promotion of the antiproliferative effects of conventional chemotherapeutics. Therefore, curcumin has the potential to be used as a novel adjunctive agent to prevent tumor metastasis, which may at least partly be attributed to its hampering of the EMT process.

Demethoxycurcumin: A naturally occurring curcumin analogue with antitumor properties

The eradication of cancer in a patient remains an elusive challenge despite advances in early detection and diagnosis, chemo- and immunotherapy, pinpoint radiation treatments, and expert surgical intervention. Although significant gains have been made in our understanding of cancer cell biology, a definite cure for most cancers does not exist at present. Thus, it is not surprising that the research and medical communities continue to explore the importance and therapeutic potential of natural products in their multimodality cancer treatment approach. Curcuminoids found in turmeric are one such class of natural products that have been extensively investigated for their potential to halt the progression of cancer cell proliferation and, more important, to stop metastasis from occurring. In this review, we examine one curcuminoid (demethoxycurcumin [DMC]) largely because of its increased stability and better aqueous solubility at physiological pH, unlike the more well-known curcuminoid (curcumin), which is largely unabsorbed after oral ingestion. The present review will focus on the signaling pathways that DMC utilizes to modulate the growth, invasion, and metastasis of cancer cells in an effort to provide enhanced mechanistic insight into DMC's action as it pertains to brain, ovarian, breast, lung, skin, and prostate cancer. Additionally, this review will attempt to provide an overview of DMC's mechanism of action by modulating apoptosis, cell cycle, angiogenesis, metastasis, and chemosensitivity. Lastly, it is hoped that increased understanding will be gained concerning DMC's interactive role with microRNA-551a, 5' adenosine monophosphate-activated protein kinase, nuclear factor-κB, Wnt inhibitory factor-1, and heat shock protein 70 to affect the progression of cancer.

The reversible effects of glial cell line-derived neurotrophic factor (GDNF) in the human brain

Glial cell line-derived neurotrophic factor (GDNF) is a potent survival factor, and a member of the transforming growth factor β (TGF-β) superfamily acting on different neuronal activities. GDNF was originally identified as a neurotrophic factor crucially involved in the survival of dopaminergic neurons of the nigrostriatal pathway and is currently an established therapeutic target in Parkinson's disease. However, GDNF was later reported to be highly expressed in gliomas, especially in glioblastomas, and was demonstrated as a potent proliferation factor involved in the development and migration of gliomas. Here, we review our current understanding and progress made so far by researchers in our laboratories with references to relevant articles to support our discoveries. We present past and recent discoveries on the mechanisms involved in the protection of neurons by GDNF and examine its emerging roles in gliomas, as well as reasons for the abnormal expression in Glioblastoma Multiforme (GBM). Collectively, our work establishes a paradigm by which the ability of GDNF to protect dopaminergic neurons from degradation and its corresponding effects on glioma cells points to an underlying biological vulnerability in the effects of GDNF in the normal brain which can be subverted for use by cancer cells. Hence, presenting novel opportunities for intervention in glioma therapies.

Inhibition of EGR1 inhibits glioma proliferation by targeting CCND1 promoter

Background

Gliomas are the most common primary tumors in central nervous system. The prognosis of the patients with glioma is poor regardless of the development of therapeutic strategies. Its aggressive behavior mainly depends on the potent ability of proliferation. The transcription factor EGR1 (early growth response 1) is a member of a zinc finger transcription factor family which plays an essential role in cell growth and proliferation.

Methods

EGR1 expression levels in 39 glioma tissues and 10 normal brain tissues were tested by RT-qPCR and Western-blotting. The effects of EGR1 on U251 cells, U251 stem-like cells (GSCs), and U87 cells proliferation were assessed using in vitro and in vivo cell proliferation assays. The specific binding between EGR1 and CCND1 promoter was confirmed by CHIP assay. EGF was used to improve EGR1 expression in this assay.

Results

EGR1 expression levels in human gliomas are decreased compared with normal brain tissues, however, the patients with low EGR1 expression level showed significantly enhanced patient survival in all glioma patients. EGR1 silencing inhibited proliferation and induced G1 phase arrest in glioma cells. EGR1 contributed to proliferation by directly raising CCND1. Meanwhile, EGR1 overexpression induced by EGF was able to promote the proliferation of glioma cells.

Conclusions

Our results show that stable knockdown EGR1 would inhibit glioma proliferation. The results suggest EGR1 showing lower expression in cancer tissues compared with normal tissues maybe still play an important role in tumor proliferation.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0656-4) contains supplementary material, which is available to authorized users.

Oxytocin inhibits head and neck squamous cell carcinoma cell migration by early growth response-1 upregulation

The effect of oxytocin (OXT) on cancer invasion is controversial. Few studies have examined the effect of early growth response-1 (EGR1) on the invasion of head and neck squamous cell carcinoma (HNSCC). Here, we evaluated how EGR1 affects HNSCC cell migration through the molecular mechanism of OXT in exerting anti-invasion activity. Matrigel invasion and wound-healing assays were used to measure the in-vitro cell migration. The molecular mechanism of OXT was assessed by knockdown or overexpression of EGR1 in HNSCC cells. Three-dimensional (3-D) spheroids formation, followed by the image analysis for quantification was performed. OXT at 500 nmol/l increased mRNA and protein expression of E-cadherin without cytotoxicity. OXT upregulated mRNA and protein expression of EGR1 in 6 h. p53, phosphatase and tensin, and p21 expression was increased in an EGR1-dependent manner with OXT treatment. In addition, OXT significantly downregulated 3-D spheroids' formation according to spheroids' number and size. Our data showed that OXT downregulated HNSCC cell migration by EGR1 upregulation. OXT inhibited spheroids' formation of HNSCC cells under 3-D culture conditions.

Curcumin mediates anticancer effects by modulating multiple cell signaling pathways

Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings.

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.

EGR-1/ASPP1 inter-regulatory loop promotes apoptosis by inhibiting cyto-protective autophagy

The decrease of ASPP1 (Apoptosis-Stimulating Protein of p53 1), a known p53 activator, has been linked to carcinogenesis and the cytotoxic resistance in various cancers, yet the underlying mechanisms of ASPP1 expression and its complex functions are not yet clear. Here, we report that ASPP1 forms an inter-regulatory loop with Early Growth Response 1 (EGR-1), and promotes apoptosis via inhibiting cyto-protective autophagy, independent of the well-documented p53-dependent mechanisms. We show that ASPP1 mRNA and protein were remarkably elevated by ectopic EGR-1 expression or endogenous EGR-1 activation, in cells with different tissue origins and p53 status. Conversely, RNAi-mediated EGR-1 knockdown suppressed ASPP1. The further mechanism studies revealed that ASPP1 promoter, mapped to -283/+88, which contained three conserved EGR-1 binding sites, was required for both binding and transactivity of EGR-1. In addition, we demonstrate that ASPP1 promoted EGR-1 in a positive feedback loop by preventing proteasome-mediated EGR-1 degradation or promoting EGR-1 nuclear import in response to anticancer natural compound Quercetin. Furthermore, albeit activating p53 in the nucleus is the well-studied function of ASPP1, we found that ASPP1 was predominately localized in the cytoplasm. Interestingly, the cytoplasmic ASPP1 retained its pro-apoptosis capability. Mechanistically, ASPP1 suppressed Atg5-Atg12 and also bound with Atg5-Atg12 to prevent its further complex formation with Atg16, resulting in the inhibition of cyto-protective autophagy. In conclusion, our results provide new insights into EGR-1/ASPP1 regulatory loop in sensitizing Quercetin-induced apoptosis. EGR-1/ASPP1, therefore, may be potentially used as therapeutic targets to improve cancer's response to pro-apoptosis treatments.

Binding and inhibition of the ternary complex factor Elk-4/Sap1 by the adapter protein Dok-4

The adapter protein Dok-4 (downstream of kinase-4) has been reported as both an activator and inhibitor of Erk and Elk-1, but lack of knowledge about the identity of its partner molecules has precluded any mechanistic insight into these seemingly conflicting properties. We report that Dok-4 interacts with the transactivation domain of Elk-4 through an atypical phosphotyrosine-binding domain-mediated interaction. Dok-4 possesses a nuclear export signal and can relocalize Elk-4 from nucleus to cytosol, whereas Elk-4 possesses two nuclear localization signals that restrict interaction with Dok-4. The Elk-4 protein, unlike Elk-1, is highly unstable in the presence of Dok-4, through both an interaction-dependent mechanism and a pleckstrin homology domain-dependent but interaction-independent mechanism. This is reversed by proteasome inhibition, depletion of endogenous Dok-4 or lysine-to-arginine mutation of putative Elk-4 ubiquitination sites. Finally, Elk-4 transactivation is potently inhibited by Dok-4 overexpression but enhanced by Dok-4 knockdown in MDCK renal tubular cells, which correlates with increased basal and EGF-induced expression of Egr-1, Fos and cylcinD1 mRNA, and cell proliferation despite reduced Erk activation. Thus, Dok-4 can target Elk-4 activity through multiple mechanisms, including binding of the transactivation domain, nuclear exclusion and protein destabilization, without a requirement for inhibition of Erk.

Dendrosomal nanocurcumin and p53 overexpression synergistically trigger apoptosis in glioblastoma cells

Objective(s):

Glioblastoma is the most lethal tumor of the central nervous system. Here, we aimed to evaluate the effects of exogenous delivery of p53 and a nanoformulation of curcumin called dendrosomal curcumin (DNC), alone and in combination, on glioblastoma tumor cells.

Materials and Methods:

MTT assay was exploited to measure the viability of U87-MG cells against DNC treatment. Cells were separately subjected to DNC treatment and transfected with p53-containing vector and then were co-exposed to DNC and p53 overexpression[A GA1][B2]. Annexin-V-FLUOS staining followed by flow cytometry and real-time PCR were applied to examine apoptosis and analyze the expression levels of the genes involved in cell cycle and oncogenesis, respectively.

Results:

The results of cell viability assay through MTT indicated that DNC inhibits the proliferation of U87-MG cells in a time- and dose-dependent manner. Apoptosis evaluation revealed that p53 overexpression accompanied by DNC treatment can act in a synergistic manner to significantly enhance the number of apoptotic cells (90%) compared with their application alone (15% and 38% for p53 overexpression and DNC, respectively). Also, real-time PCR data showed that the concomitant exposure of cells to both DNC and p53 overexpression leads to an enhanced expression of GADD45 and a reduced expression of NF-κB and c-Myc.

Conclusion:

The findings of the current study suggest that our combination strategy, which merges two detached gene (p53) and drug (curcumin) delivery systems into an integrated platform, may represent huge potential as a novel and efficient modality for glioblastoma treatment.

Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease

The low incidence of HIV-1 infection in patients with sickle cell disease (SCD) and inhibition of HIV-1 replication in vitro under the conditions of low intracellular iron or heme treatment suggests a potential restriction of HIV-1 infection in SCD. We investigated HIV-1 ex vivo infection of SCD peripheral blood mononuclear cells (PBMCs) and found that HIV-1 replication was inhibited at the level of reverse transcription (RT) and transcription. We observed increased expression of heme and iron-regulated genes, previously shown to inhibit HIV-1, including ferroportin, IKBα, HO-1, p21, and SAM domain and HD domain-containing protein 1 (SAMHD1). HIV-1 inhibition was less pronounced in hepcidin-treated SCD PBMCs and more pronounced in the iron or iron chelators treated, suggesting a key role of iron metabolism. In SCD PBMCs, labile iron levels were reduced and protein levels of ferroportin, HIF-1α, IKBα, and HO-1 were increased. Hemin treatment induced ferroportin expression and inhibited HIV-1 in THP-1 cells, mimicking the HIV-1 inhibition in SCD PBMCs, especially as hepcidin similarly prevented HIV-1 inhibition. In THP-1 cells with knocked down ferroportin, IKBα, or HO-1 genes but not HIF-1α or p21, HIV-1 was not inhibited by hemin. Activity of SAMHD1-regulatory CDK2 was decreased, and SAMHD1 phosphorylation was reduced in SCD PBMCs and hemin-treated THP-1 cells, suggesting SAMHD1-mediated HIV-1 restriction in SCD. Our findings point to ferroportin as a trigger of HIV-1 restriction in SCD settings, linking reduced intracellular iron levels to the inhibition of CDK2 activity, reduction of SAMHD1 phosphorylation, increased IKBα expression, and inhibition of HIV-1 RT and transcription.

Unraveling the Anticancer Effect of Curcumin and Resveratrol

Resveratrol and curcumin are natural products with important therapeutic properties useful to treat several human diseases, including cancer. In the last years, the number of studies describing the effect of both polyphenols against cancer has increased; however, the mechanism of action in all of those cases is not completely comprehended. The unspecific effect and the ability to interfere in assays by both polyphenols make this challenge even more difficult. Herein, we analyzed the anticancer activity of resveratrol and curcumin reported in the literature in the last 11 years, in order to unravel the molecular mechanism of action of both compounds. Molecular targets and cellular pathways will be described. Furthermore, we also discussed the ability of these natural products act as chemopreventive and its use in association with other anticancer drugs.

Therapeutic Potential of Curcumin for the Treatment of Brain Tumors

Brain malignancies currently carry a poor prognosis despite the current multimodal standard of care that includes surgical resection and adjuvant chemotherapy and radiation. As new therapies are desperately needed, naturally occurring chemical compounds have been studied for their potential chemotherapeutic benefits and low toxicity profile. Curcumin, found in the rhizome of turmeric, has extensive therapeutic promise via its antioxidant, anti-inflammatory, and antiproliferative properties. Preclinical in vitro and in vivo data have shown it to be an effective treatment for brain tumors including glioblastoma multiforme. These effects are potentiated by curcumin's ability to induce G2/M cell cycle arrest, activation of apoptotic pathways, induction of autophagy, disruption of molecular signaling, inhibition of invasion, and metastasis and by increasing the efficacy of existing chemotherapeutics. Further, clinical data suggest that it has low toxicity in humans even at large doses. Curcumin is a promising nutraceutical compound that should be evaluated in clinical trials for the treatment of human brain tumors.

Targeted Theranostic Approach for Glioma Using Dendrimer-Based Curcumin Nanoparticle

The delivery of anti-cancer agents to brain tumors represent a challenge because the blood-brain tumor barrier (BBTB) effectively limits the delivery of many agents. A new generation 3 (G3) dendrimer-based curcumin (Curc) conjugate was synthesized. The synthesized G3-Curc conjugate demonstrated full solubility in aqueous media. The in vitro study revealed that G3-Curc nanoparticles were internalized into glioma U-251 cells. Systemic delivery of G3-Curc conjugate led to preferentially accumulation in an orthotopic preclinical glioma model minimizing systemic toxic effect. Multicolor microscopy images of the tumor tissue showed that G3-Curc particles were internalized inside tumor cells selectively and further localized within nuclei. Enhanced bioavailability of G3-Curc conjugate was also observed with improved therapeutic efficacy against different cancers cells.

Investigating the therapeutic role and molecular biology of curcumin as a treatment for glioblastoma

OBJECTIVES

Despite the aggressive standard of care for patients with glioblastoma multiforme, survival rates typically do not exceed 2 years. Therefore, current research is focusing on discovering new therapeutics or rediscovering older medications that may increase the overall survival of patients with glioblastoma. Curcumin, a component of the Indian natural spice, turmeric, also known for its antioxidant and anti-inflammatory properties, has been found to be an effective inhibitor of proliferation and inducer of apoptosis in many cancers. The goal of this study was to investigate the expanded utility of curcumin as an antiglioma agent.

METHODS

Using the PubMed MeSH database, we conducted a systematic review of the literature to include pertinent studies on the growth inhibitory effects of curcumin on glioblastoma cell lines based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 19 in vitro and five in vivo studies were analyzed. All of the studies indicated that curcumin decreased glioblastoma cell viability through various pathways (i.e. decrease in prosurvival proteins such as nuclear factor κB, activator protein 1, and phosphoinositide 3 kinase, and upregulation of apoptotic pathways like p21, p53, and executor caspase 3). Curcumin treatment also increased animal survival compared with control groups.

CONCLUSIONS

Curcumin inhibits proliferation and induces apoptosis in certain subpopulations of glioblastoma tumors, and its ability to target multiple signaling pathways involved in cell death makes it an attractive therapeutic agent. As such, it should be considered as a potent anticancer treatment. Further experiments are warranted to elucidate the use of a bioavailable form of curcumin in clinical trials.

A Positive Feed-forward Loop Associating EGR1 and PDGFA Promotes Proliferation and Self-renewal in Glioblastoma Stem Cells

Glioblastomas are the most common primary brain tumors, highly vascularized, infiltrating, and resistant to current therapies. This cancer leads to a fatal outcome in less than 18 months. The aggressive behavior of glioblastomas, including resistance to current treatments and tumor recurrence, has been attributed to glioma stemlike/progenitor cells. The transcription factor EGR1 (early growth response 1), a member of a zinc finger transcription factor family, has been described as tumor suppressor in gliomas when ectopically overexpressed. Although EGR1 expression in human glioblastomas has been associated with patient survival, its precise location in tumor territories as well as its contribution to glioblastoma progression remain elusive. In the present study, we show that EGR1-expressing cells are more frequent in high grade gliomas where the nuclear expression of EGR1 is restricted to proliferating/progenitor cells. We show in primary cultures of glioma stemlike cells that EGR1 contributes to stemness marker expression and proliferation by orchestrating a PDGFA-dependent growth-stimulatory loop. In addition, we demonstrate that EGR1 acts as a positive regulator of several important genes, including SHH, GLI1, GLI2, and PDGFA, previously linked to the maintenance and proliferation of glioma stemlike cells.

The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo

C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma.

Induction of apoptosis by genipin inhibits cell proliferation in AGS human gastric cancer cells via Egr1/p21 signaling pathway

Natural compounds are becoming important candidates in cancer therapy due to their cytotoxic effects on cancer cells by inducing various types of programmed cell deaths. In this study, we investigated whether genipin induces programmed cell deaths and mediates in Egr1/p21 signaling pathways in gastric cancer cells. Effects of genipin in AGS cancer cell lines were observed via evaluation of cell viability, ROS generation, cell cycle arrest, and protein and RNA levels of p21, Egr1, as well as apoptotic marker genes. The cell viability of AGS cells reduced by genipin treatment via induction of the caspase 3-dependent apoptosis. Cell cycle arrest was observed at the G2/M phase along with induction of p21 and p21-dependent cyclins. As an upstream mediator of p21, the transcription factor early growth response-1 (Egr1) upregulated p21 through nuclear translocation and binding to the p21 promoter site. Silencing Egr1 expression inhibited the expression of p21 and downstream molecules involved in apoptosis. We demonstrated that genipin treatment in AGS human gastric cancer cell line induces apoptosis via p53-independent Egr1/p21 signaling pathway in a dose-dependent manner.

Urokinase-type plasminogen activator resulting from endometrial carcinogenesis enhances tumor invasion and correlates with poor outcome of endometrial carcinoma patients

The purpose of this study was to identify the dysregulated genes involved in the tumorigenesis and progression of endometrial endometrioid adenocarcinoma (EEC), and their possible mechanisms. Endometrial specimens including normal endometrial tissues, atypical endometrial hyperplasia, and EEC were analyzed. The expression profiles were compared using GeneChip Array. The gene expression levels were determined by real-time RT-PCR in the training and testing sets to correlate the clinico-pathological parameters of EEC. Immunoblotting, in vitro cell migration and invasion assays were performed in human endometrial cancer cell lines and their transfectants. In microarray analysis, seven dysregulated genes were identified. Only the levels of urokinase-type plasminogen activator (uPA) were higher in EEC with deep myometrial invasion, positive lympho-vascular space invasion, lymph node metastasis, and advanced stages. After multivariate analysis, uPA was the only independent poor prognostic factor for disease-free survival in the EEC patients (hazard ratio: 4.65, p = 0.03). uPA may enhance the migratory and invasive capabilities of endometrial tumor cells by the phosphorylation of ERK1/2, Akt and p38 molecules. uPA is a dysregulated gene involved in the tumorigenesis, bio-pathological features and outcomes of EEC. uPA may be a potential molecule and target for the detection and treatment of EEC.

The Sirt1 activator SRT3025 expands hematopoietic stem and progenitor cells and improves hematopoiesis in Fanconi anemia mice

Fanconi anemia is a genetic bone marrow failure syndrome. The current treatment options are suboptimal and do not prevent the eventual onset of aplastic anemia requiring bone marrow transplantation. We previously showed that resveratrol, an antioxidant and an activator of the protein deacetylase Sirt1, enhanced hematopoiesis in Fancd2 mutant mice and improved the impaired stem cell quiescence observed in this disease. Given that Sirt1 is important for the function of hematopoietic stem cells, we hypothesized that Sirt1 activation may improve hematopoiesis. Indeed, Fancd2(-/-) mice and wild-type mice treated with the selective Sirt1 activator SRT3025 had increased numbers of hematopoietic stem and progenitor cells, platelets and white blood cells. SRT3025 was also protective against acetaldehyde-induced hematopoietic damage. Unlike resveratrol, however, SRT3025 did not affect stem cell quiescence, suggesting distinct mechanisms of action. Conditional deletion of Sirt1 in hematopoietic cells did not abrogate the beneficial effects of SRT3025, indicating that the drug did not act by directly stimulating Sirt1 in stem cells, but must be acting indirectly via extra-hematopoietic effects. RNA-Seq transcriptome analysis revealed the down-regulation of Egr1-p21 expression, providing a potential mechanism for improved hematopoiesis. Overall, our data indicate that SRT3025 or related compounds may be beneficial in Fanconi anemia and other bone marrow failure syndromes.

Identification of egr1 direct target genes in the uterus by in silico analyses with expression profiles from mRNA microarray data

Early growth response 1 (Egr1) is a zinc-finger transcription factor to direct second-wave gene expression leading to cell growth, differentiation and/or apoptosis. While it is well-known that Egr1 controls transcription of an array of targets in various cell types, downstream target gene(s) whose transcription is regulated by Egr1 in the uterus has not been identified yet. Thus, we have tried to identify a list of potential target genes of Egr1 in the uterus by performing multi-step in silico promoter analyses. Analyses of mRNA microarray data provided a cohort of genes (102 genes) which were differentially expressed (DEGs) in the uterus between Egr1(+/+) and Egr1(–/–) mice. In mice, the frequency of putative EGR1 binding sites (EBS) in the promoter of DEGs is significantly higher than that of randomly selected non-DEGs, although it is not correlated with expression levels of DEGs. Furthermore, EBS are considerably enriched within –500 bp of DEG’s promoters. Comparative analyses for EBS of DEGs with the promoters of other species provided power to distinguish DEGs with higher probability as EGR1 direct target genes. Eleven EBS in the promoters of 9 genes among analyzed DEGs are conserved between various species including human. In conclusion, this study provides evidence that analyses of mRNA expression profiles followed by two-step in silico analyses could provide a list of putative Egr1 direct target genes in the uterus where any known direct target genes are yet reported for further functional studies.

Early growth response-1 facilitates enterovirus 71 replication by direct binding to the viral genome RNA

Enterovirus 71 (EV71) infections can cause hand, foot and mouth disease (HFMD), meningoencephalitis, neonatal sepsis, and even fatal encephalitis in children. Unfortunately, there is currently no effective treatment for EV71 infection due to the lack of understanding of viral replication and infection; and viral infections have emerged as an imperative global hazard. Thus, it is extremely important to understand the mechanism of EV71 replication in order to prevent and control the diseases associated with EV71 infections. Early growth response-1 (EGR1) is a multifunctional transcription factor that regulates diverse biological functions, including inflammation, apoptosis, differentiation, tumorigenesis, and even viral infection. Here, we provide new insight into the role of EV71 infection in regulating EGR1 production; and reveal a novel mechanism by which EGR1 facilitates EV71 replication. We demonstrate that EV71 activates EGR1 expression during infection by stimulating the protein kinase A/protein kinase Cɛ/phosphoinositide 3-kinase/Akt (PKA/PKCɛ/PI3K/Akt) cascade. We further reveal that EV71-activated EGR1, in turn, regulates the internal ribosomal entry site (IRES) of EV71 to enhance viral replication. In addition, EGR1 facilitates EV71 replication by binding directly to stem-loops I and IV of EV71 5'-untranslated region (5'UTR) with its first two zinc fingers. Moreover, EGR1 protein co-localizes with EV71 RNA in the cytoplasm of infected cells to facilitate viral replication. Our results reveal an important new role of EGR1 in viral infection, provide new insight into the novel mechanism underlying the regulation of EV71 replication, and suggest a potential application of EGR1 in the control of EV71 infection.