Harmine induces apoptosis and inhibits tumor cell proliferation, migration and invasion through down-regulation of cyclooxygenase-2 expression in gastric cancer

Harmine inhibits the proliferation and migration and promotes the apoptosis of colon cancer cells via inhibition of the FAK/AKT and ERK1/2/CREB signaling pathways

Harmine is present in a variety of medicinal plants, and its effects on colon cancer cells remain unclear. Here, we found that harmine exhibited significant inhibitory effects on the proliferation of colon cancer cells by inhibiting the phosphorylation levels of the FAK/AKT and ERK1/2/CREB. Furthermore, harmine also inhibited the migration of colon cancer cells and suppressed the expression levels of MMP-2, MMP-9, and VEGF. Additionally, harmine-induced apoptosis in colon cancer cells by regulating the expression of Bcl-2 and Bax. In conclusion, our findings suggest that harmine exerts a significant inhibitory effect on the development of colon cancer cells.

The role of ayahuasca in cell viability and oxidative stress in gastric adenocarcinoma cell line

Ayahuasca, a psychoactive beverage native to the Amazon, originally derived from Banisteriopsis caapi stem scrapings and Psychotria viridis leaves, exhibits hallucinogenic properties due to N,N-dimethyltryptamine. When combined with β-carbolines, it enters the bloodstream and central nervous system, inhibiting monoamine oxidase-A. Over time, therapeutic effects have been associated to ayahuasca consumption. This study assessed the impact of extracts from three plant decoctions used in ayahuasca preparation on the gastric adenocarcinoma cell line (AGS). MTT reduction assays selected B. caapi, Mimosa hostilis, and Peganum harmala samples as most effective. Lactate dehydrogenase activity evaluated membrane integrity loss, while oxidative stress induction was measured using dihydroethidium and 2',7'-dichlorodihydrofluorescein diacetate probes. Results revealed apoptosis induction in AGS cells, with all three samples significantly reducing oxidative stress.

The Role of Ayahuasca in Colorectal Adenocarcinoma Cell Survival, Proliferation and Oxidative Stress

The psychedelic beverage ayahuasca is originally obtained by Banisteriopsis caapi (B. caapi) (BC) and Psychotria viridis (P. viridis) (PV). However, sometimes these plant species are replaced by others that mimic the original effects, such as Mimosa hostilis (M. hostilis) (MH) and Peganum harmala (P. harmala) (PH). Its worldwide consumption and the number of studies on its potential therapeutic effects has increased. This study aimed to evaluate the anticancer properties of ayahuasca in human colorectal adenocarcinoma cells. Thus, the maximum inhibitory concentration (IC50) of decoctions of MH, PH, and a mixture of these (MHPH) was determined. The activities of caspases 3 and 9 were evaluated, and the cell proliferation index was determined through immunocytochemical analysis (Ki-67). Two fluorescent probes were used to evaluate the production of oxidative stress and the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) was also evaluated. It was demonstrated that exposure to the extracts significantly induced apoptosis in Caco-2 cells, while decreasing cell proliferation. MH and MHPH samples significantly reduced oxidative stress and significantly increased glutathione peroxidase activity. No significant differences were found in SOD activity. Overall, it was demonstrated that the decoctions have a potential anticancer activity in Caco-2 cells.

Research progress on the antitumor effects of harmine

Harmine is a naturally occurring β-carboline alkaloid originally isolated from Peganum harmala. As a major active component, harmine exhibits a broad spectrum of pharmacological properties, particularly remarkable antitumor effects. Recent mechanistic studies have shown that harmine can inhibit cancer cell proliferation and metastasis through epithelial-to-mesenchymal transition, cell cycle regulation, angiogenesis, and the induction of tumor cell apoptosis. Furthermore, harmine reduces drug resistance when used in combination with chemotherapeutic drugs. Despite its remarkable antitumor activity, the application of harmine is limited by its poor solubility and toxic side effects, particularly neurotoxicity. Novel harmine derivatives have demonstrated strong clinical application prospects, but further validation based on drug activity, acute toxicity, and other aspects is necessary. Here, we present a review of recent research on the action mechanism of harmine in cancer treatment and the development of its derivatives, providing new insights into its potential clinical applications and strategies for mitigating its toxicity while enhancing its efficacy.

Role and regulation of FOXO3a: new insights into breast cancer therapy

Breast cancer is the most common malignancy in the world, particularly affecting female cancer patients. Enhancing the therapeutic strategies for breast cancer necessitates identifying molecular drug targets that effectively eliminate tumor cells. One of these prominent targets is the forkhead and O3a class (FOXO3a), a member of the forkhead transcription factor subfamily. FOXO3a plays a pivotal role in various cellular processes, including apoptosis, proliferation, cell cycle regulation, and drug resistance. It acts as a tumor suppressor in multiple cancer types, although its specific role in cancer remains unclear. Moreover, FOXO3a shows promise as a potential marker for tumor diagnosis and prognosis in breast cancer patients. In addition, it is actively influenced by common anti-breast cancer drugs like paclitaxel, simvastatin, and gefitinib. In breast cancer, the regulation of FOXO3a involves intricate networks, encompassing post-translational modification post-translational regulation by non-coding RNA (ncRNA) and protein-protein interaction. The specific mechanism of FOXO3a in breast cancer urgently requires further investigation. This review aims to systematically elucidate the role of FOXO3a in breast cancer. Additionally, it reviews the interaction of FOXO3a and its upstream and downstream signaling pathway-related molecules to uncover potential therapeutic drugs and related regulatory factors for breast cancer treatment by regulating FOXO3a.

Harmine Hydrochloride Induces G2/M Cell Cycle Arrest and Apoptosis in SK-Hep1 Hepatocellular Carcinoma Cells by Regulating Mitogen-Activated Protein Kinases and the PI3K/AKT Pathway

Liver cancer is a globally common form of cancer. Thus, novel drugs derived from natural products are needed to reduce the side effects of chemotherapy. The present study aimed to analyze the anticancer properties and effects of harmine hydrochloride (HMH), a water-soluble metabolite of harmine that can be easily absorbed into tissues, in treating liver cancer cells. HMH dose-dependently inhibited cell growth, migration, invasion, and colony formation in SK-Hep1 cells. It also induced G2/M arrest by reducing the expression of p-cdc2, cyclin B1, and Rb (G2/M phase regulatory proteins) in a dose-dependent manner. HMH treatment reduced the expression of caspase-9, caspase-3, PARP, and Bcl-2 and increased the expression of Bax (a proapoptotic protein). Moreover, it increased the production of reactive oxygen species and decreased the intracellular uptake of rhodamine 123 due to mitochondrial dysfunction because of oxidative stress. HMH treatment also upregulated the phosphorylation of JNK, p38, and FOXO3a in SK-Hep1 cells and downregulated the PI3K/AKT signaling pathway. Our findings suggest that HMH may activate the compounds responsible for anticancer effects in hepatocellular carcinoma cells.

Postbiotics: Functional Food Materials and Therapeutic Agents for Cancer, Diabetes, and Inflammatory Diseases

Postbiotics are (i) "soluble factors secreted by live bacteria, or released after bacterial lysis, such as enzymes, peptides, teichoic acids, peptidoglycan-derived muropeptides, polysaccharides, cell-surface proteins and organic acids"; (ii) "non-viable metabolites produced by microorganisms that exert biological effects on the hosts"; and (iii) "compounds produced by microorganisms, released from food components or microbial constituents, including non-viable cells that, when administered in adequate amounts, promote health and wellbeing". A probiotic- and prebiotic-rich diet ensures an adequate supply of these vital nutrients. During the anaerobic fermentation of organic nutrients, such as prebiotics, postbiotics act as a benevolent bioactive molecule matrix. Postbiotics can be used as functional components in the food industry by offering a number of advantages, such as being added to foods that are harmful to probiotic survival. Postbiotic supplements have grown in popularity in the food, cosmetic, and healthcare industries because of their numerous health advantages. Their classification depends on various factors, including the type of microorganism, structural composition, and physiological functions. This review offers a succinct introduction to postbiotics while discussing their salient features and classification, production, purification, characterization, biological functions, and applications in the food industry. Furthermore, their therapeutic mechanisms as antibacterial, antiviral, antioxidant, anticancer, anti-diabetic, and anti-inflammatory agents are elucidated.

Activation of endoplasmic reticulum stress by harmine suppresses the growth of esophageal squamous cell carcinoma

The worldwide overall 5-year survival rate of esophageal squamous cell carcinoma (ESCC) patients is less than 20%, and novel therapeutic strategies for these patients are urgently needed. Harmine is a natural β-carboline alkaloid, which received great interest in cancer research because of its biological and anti-tumor activities. The aim of this study is to examine the effects of harmine on ESCC and its mechanism. We investigated the effects of harmine on proliferation, cell cycle, apoptosis, and tumor growth in vivo. RNA sequencing (RNA-seq), real-time PCR, and western blotting were used to detect the mechanism. Harmine inhibited ESCC cell growth in vitro and tumor growth in vivo. Differentially expressed genes in harmine-treated ESCC cells were mainly involved in protein processing in the endoplasmic reticulum (ER). Real-time PCR and western blotting confirmed harmine-induced cellular ER stress. CRISPR-Cas9 knockout of C/EBP homologous protein (CHOP) abolished harmine-induced expression of death receptor 5 and apoptosis. Harmine also induced the expression of CHOP-mediated sestrin-2, which in turn contributes to autophagosome formation via suppressing the AMP-activated protein kinase-protein kinase B-mammalian target of rapamycin signaling pathway. In conclusion, our results demonstrate that harmine inhibits the growth of ESCC through its regulation of ER stress, suggesting that it is a promising candidate for ESCC treatment.

Naturally derived indole alkaloids targeting regulated cell death (RCD) for cancer therapy: from molecular mechanisms to potential therapeutic targets

Regulated cell death (RCD) is a critical and active process that is controlled by specific signal transduction pathways and can be regulated by genetic signals or drug interventions. Meanwhile, RCD is closely related to the occurrence and therapy of multiple human cancers. Generally, RCD subroutines are the key signals of tumorigenesis, which are contributed to our better understanding of cancer pathogenesis and therapeutics. Indole alkaloids derived from natural sources are well defined for their outstanding biological and pharmacological properties, like vincristine, vinblastine, staurosporine, indirubin, and 3,3′-diindolylmethane, which are currently used in the clinic or under clinical assessment. Moreover, such compounds play a significant role in discovering novel anticancer agents. Thus, here we systemically summarized recent advances in indole alkaloids as anticancer agents by targeting different RCD subroutines, including the classical apoptosis and autophagic cell death signaling pathways as well as the crucial signaling pathways of other RCD subroutines, such as ferroptosis, mitotic catastrophe, necroptosis, and anoikis, in cancer. Moreover, we further discussed the cross talk between different RCD subroutines mediated by indole alkaloids and the combined strategies of multiple agents (e.g., 3,10-dibromofascaplysin combined with olaparib) to exhibit therapeutic potential against various cancers by regulating RCD subroutines. In short, the information provided in this review on the regulation of cell death by indole alkaloids against different targets is expected to be beneficial for the design of novel molecules with greater targeting and biological properties, thereby facilitating the development of new strategies for cancer therapy.

Synthesis of harmine-nitric oxide donor derivatives as potential antitumor agents

To further improve the anti-tumor activity of Harmine (HM), we took the hybridization approach and synthesized harmine derivatives-furoxan hybrids containing nitric oxide (NO) releasing parts by connecting NO donors with anti-tumor active fragments to harmine. Then, the synthesized compounds were evaluated for their in vitro cytotoxicity against five human cancer cell lines. Among them, compound 10 was found to have the strongest antiproliferative activity against HepG2 (IC₅₀ = 1.79 µM). In addition, compound 10 produced high levels of NO in vitro, verifying that the release of NO was closely correlated to the antiproliferative activity. In addition, Compound 10 also showed good plasma stability. Finally, we also preliminarily investigated the acute toxicity of compound 10 in mice and assessed the absorption of compound 10 by Caco-2 cell permeability assay. In brief, the remarkable biological characteristics of the new harmine derivatives-furoxan hybrids may make them promising candidates for human cancer intervention.

Harmine Hydrochloride Mediates the Induction of G2/M Cell Cycle Arrest in Breast Cancer Cells by Regulating the MAPKs and AKT/FOXO3a Signaling Pathways

Breast cancer (BC) is one of the most common causes of death among women worldwide. Recently, interest in novel approaches for BC has increased by developing new drugs derived from natural products with reduced side effects. This study aimed to treat BC cells with harmine hydrochloride (HMH) to identify its anticancer effects and mechanisms. HMH treatment suppressed cell growth, migration, invasion, and colony formation in MCF-7 and MDA-MB-231 cells, regardless of the hormone signaling. It also reduced the phosphorylation of PI3K, AKT, and mTOR and increased FOXO3a expression. Additionally, HMH treatment increased p38 phosphorylation in MCF-7 cells and activated c-Jun N-terminal kinase (JNK) phosphorylation in MDA-MB-231 cells in a dose-dependent manner, where activated p38 and JNK increased FOXO3a expression. Activated FOXO3a increased the expression of p53, p21, and their downstream proteins, including p-cdc25, p-cdc2, and cyclin B1, to induce G2/M cell cycle arrest. Furthermore, HMH inhibited the PI3K/AKT/mTOR pathway by significantly reducing p-AKT expression in combination with LY294002, an AKT inhibitor. These results indicate that mitogen-activated protein kinases (MAPKs) and AKT/FOXO3a signaling pathways mediate the induction of cell cycle arrest following HMH treatment. Therefore, HMH could be a potential active compound for anticancer bioactivity in BC cells.

Current Advances and Outlook in Gastric Cancer Chemoresistance: A Review

BACKGROUND

Surgical resection of the lesion is the standard primary treatment of gastric cancer. Unfortunately, most patients are already in the advanced stage of the disease when they are diagnosed with gastric cancer. Alternative therapies, such as radiation therapy and chemotherapy, can achieve only very limited benefits. The emergence of cancer drug resistance has always been the major obstacle to the cure of tumors. The main goal of modern cancer pharmacology is to determine the underlying mechanism of anticancer drugs.

OBJECTIVE

Here, we mainly review the latest research results related to the mechanism of chemotherapy resistance in gastric cancer, the application of natural products in overcoming the chemotherapy resistance of gastric cancer, and the new strategies currently being developed to treat tumors based on immunotherapy and gene therapy.

CONCLUSION

The emergence of cancer drug resistance is the main obstacle in achieving alleviation and final cure for gastric cancer. Mixed therapies are considered to be a possible way to overcome chemoresistance. Natural products are the main resource for discovering new drugs specific for treating chemoresistance, and further research is needed to clarify the mechanism of natural product activity in patients. .

Harmine Augments the Cytotoxic and Anti-invasive Potential of Temozolomide Against Glioblastoma Multiforme Cells

Background: Glioblastoma multiforme (GBM) is considered the deadliest human cancer. Temozolomide is now a part of postresection standard chemotherapy for this type of cancer. Unfortunately, resistance to temozolomide is a major obstacle to treatment success. Combination therapy with natural anticancer agents increases the activity of temozolomide against cancer cells. Objectives: This study aimed to assess the effects of temozolomide in combination with harmine against GBM cells. Methods: Cancer cells were treated with temozolomide and/or harmine. After 24, 48, 72, and 96 h, the viability of the cells was assessed by the MTT test. The combination index and dose reduction index were determined by CompuSyn software. Tumor invasion potential was investigated by evaluating cell migration, invasion, and adhesion. The real-time PCR technique was done to study the expression pattern of two genes involved in cancer cell invasion. Statistical analysis was performed using one-way analysis of variance and Tukey’s post-hoc test, and differences were considered non-significant at P > 0.05. Results: After treatment with temozolomide, cell viability showed a concentration- and time-dependent decrease, and the cells’ survival rate decreased. The combination of temozolomide and harmine had a synergistic effect. Also, temozolomide and/or harmine treatment decreased cancer cells’ migration, invasion, and adhesion potentials, as well as the expression of metalloproteinases 2 and 9 in T98G cells. Conclusions: The combination of temozolomide and harmine can be promising for the successful treatment of GBM.

In vitro effects of harmine against Echinococcus granulosus protoscoleces by stimulating DNA damage

Cystic echinococcosis (CE), a parasitic larval cystic stage of a small taeniid-type tapeworm (Echinococcus granulosus), causes illness in intermediate hosts and has become a threat to global public health. Currently, chemical compounds recommended by the WHO targeting CE are albendazole and mebendazole, however, none of them shows enhanced efficacy. Novel molecular compounds are urgently required to treat this disease. Our group uncover a drug, termed harmine (HM), that may be capable of treating CE. In this study, we aim to evaluate the anti-parasitic efficacy and the mechanism of DNA damage of HM against E. granulosus. In vitro, the results indicated that, within two and three days of treatment, ABZ killed 30.4% and 35.3% of protoscoleces, whereas HM killed 52.7% and 100% of protoscoleces, respectively. Furthermore, the presence of abnormalities in the internal structure of protoscoleces was examined by ultrastructural images of TEM, and the result showed that there were scattered nucleoli and heterochromatin margination phenomenon by HM treatment. DNA damage of protoscoleces was examined by using the comet assay, and results showed the DNA of protoscoleces was damaged. Moreover, EgATM, EgP53, EgTopo2a and EgRad54 genes were used to support the DNA damage by HM treatment, and results showed that all four genes were upregulated expression. In further, the result of HM treatment was tested by using designed siRNA to inhibit the expression of EgTopo2a and EgRad54. The results demonstrated that the viability was 88.75 ± 2.11% after suppressing the expression of EgTopo2a, which was significantly higher than that for HM alone group (P < 0.01). The viability was 10.11 ± 2.60% after transfected with EgRad54 siRNA, which was significantly lower compared with the HM alone group (P < 0.01). Based on our preliminary data, HM demonstrated significant parasiticidal activity against E. granulosus in vitro without obvious toxicity towards its host cells, suggesting that HM can be a potential anti-echinococcosis drug. HM was found to induce DNA damages of CE by activating the EgATM-EgP53-EgTopo2a signaling pathway. We therefore surmise that DNA damage response may be one of the mechanisms of HM against the parasite.

Pharmacological effects of harmine and its derivatives: a review

Harmine is isolated from the seeds of the medicinal plant, Peganum harmala L., and has been used for thousands of years in the Middle East and China. Harmine has many pharmacological activities including anti-inflammatory, neuroprotective, antidiabetic, and antitumor activities. Moreover, harmine exhibits insecticidal, antiviral, and antibacterial effects. Harmine derivatives exhibit pharmacological effects similar to those of harmine, but with better antitumor activity and low neurotoxicity. Many studies have been conducted on the pharmacological activities of harmine and harmine derivatives. This article reviews the pharmacological effects and associated mechanisms of harmine. In addition, the structure-activity relationship of harmine derivatives has been summarized.

Circumstantial Overdose Management of an Efficient Cancer Cell Photosensitizer with Preclinical Evidence: A Biophysical Study

In this article, pharmacological management of circumstantial overdose of an anticancer drug, Harmine (HM), under in vitro and in vivo conditions is described and further validated by employing in silico methods. HM, an efficient cancer cell photosensitizer, interacts extensively with nontoxic β-cyclodextrin (β-CD). Steady-state fluorescence studies and molecular docking analysis established differential nature of molecular inclusion depending on the relative concentrations of β-CD. Presently, β-CD is commonly used as a standard drug-delivery vehicle but its application for controlled drug withdrawal is rarely explored. Flow cytometric results and in vivo investigations on a zebrafish model showed that conditional overdose of preadministered drug molecules can be efficiently removed by encapsulating successfully within nontoxic β-CDs, albeit by controlled application of the same. This is an approach to manage the cytotoxicity of a drug in a safe way that is already administered. We believe that this β-CD-mediated withdrawal of drugs may find possible applications in controlled capturing of excess or unused drug inside living systems and reducing the unwanted toxicity associated with chemotherapeutics.

Flavokawain B and Doxorubicin Work Synergistically to Impede the Propagation of Gastric Cancer Cells via ROS-Mediated Apoptosis and Autophagy Pathways

Simple Summary

Among various kinds of treatment strategies for cancers, combination therapy has attracted significant attention due to its beneficial effects than the individual effects of the same compounds. Based on this idea, this study has investigated the synergistic effects of combination treatment of a natural anti-cancer agent flavokawain B (FKB) and a chemotherapeutic agent Doxorubicin on human gastric cancer cells and the underlying molecular mechanisms were deciphered through in vitro and in vivo approaches. Experimental data obtained in this study provided promising application prospects of FKB + Doxrubicin combination treatment in human gastric cancer cells.

Abstract

Chalcone flavokawain B (FKB) possesses a chemopreventive and anti-cancer activity. Doxorubicin is a chemotherapeutic DNA intercalating agent widely used in malignancy treatment. The present study investigated whether synergistic effects exist between the combination of FKB (1.25–5 µg/mL) and doxorubicin (0.5 µg/mL) on the apoptosis and autophagy in human gastric cancer (AGS) cells, and the possible in vitro and in vivo mechanisms. The MTT assay measured cell viability. Various apoptotic-, autophagy-associated protein expression was determined by the Western blot technique. FKB+doxorubicin synergy was estimated by the Chou-Talalay combination index (CI) method. In vivo studies were performed on BALB/c mice. Results showed that compared to FKB/doxorubicin treatments, low doses of FKB+doxorubicin suppressed AGS cell growth. FKB potentiated doxorubicin-induced DNA fragmentation, apoptotic cell death, and enhanced doxorubicin-mediated mitochondrial, death receptor pathways. FKB+doxorubicin activated increased LC3-II accumulation, p62/SQSTM1 expression, and AVO formation as compared to the FKB/doxorubicin alone treatments indicating autophagy in these cells. The death mechanism in FKB+doxorubicin-treated AGS cells is due to the activation of autophagy. FKB+doxorubicin-mediated dysregulated Bax/Bcl-2, Beclin-1/Bcl-2 ratios suggested apoptosis, autophagy induction in AGS cells. FKB+doxorubicin-induced LC3-II/AVOs downregulation was suppressed due to an apoptotic inhibitor Z-VAD-FMK. Whereas, 3-methyladenine/chloroquine weakened FKB+doxorubicin-induced apoptosis (decreased DNA fragmentation/caspase-3). Activation of ERK/JNK may be involved in FKB+doxorubicin-induced apoptosis and autophagy. FKB+doxorubicin-triggered ROS generation, but NAC attenuated FKB+doxorubicin-induced autophagic (LC3 accumulation) and apoptotic (caspase-3 activation and PARP cleavage) cell death. FKB+doxorubicin blocked gastric cancer cell xenografts in nude mice in vivo as compared to FKB/doxorubicin alone treatments. FKB and doxorubicin wielded synergistic anti-tumor effects in gastric cancer cells and is a promising therapeutic approach.

Myrrh induces the apoptosis and inhibits the proliferation and migration of gastric cancer cells through down-regulating cyclooxygenase-2 expression

OBJECTIVE

The present study is designed to evaluate the anti-tumor effects of myrrh on human gastric cancer both in vitro and in vivo.

METHODS

The gastric cancer cell proliferation was determined by MTT assay. Apoptosis was measured by flow cytometry and Hoechst 33342 staining. Wound healing was performed to evaluate the effects of myrrh on the migration. COX-2, PCNA, Bcl-2, and Bax expressions were detected by Western blot analysis. A xenograft nude mice model of human gastric cancer was established to evaluate the anti-cancer effect of myrrh in vivo.

RESULTS

Myrrh significantly inhibited cellular proliferation, migration, and induced apoptosis in vitro as well as inhibited tumor growth in vivo. In addition, myrrh inhibited the expression of PCNA, COX-2, and Bcl-2 as well as increased Bax expression in gastric cancer cells.

CONCLUSION

Myrrh may inhibit the proliferation and migration of gastric cancer cells, as well as induced their apoptosis by down-regulating the expression of COX-2.

Repurposing of plant alkaloids for cancer therapy: Pharmacology and toxicology

Drug repurposing (or repositioning) is an emerging concept to use old drugs for new treatment indications. Phytochemicals isolated from medicinal plants have been largely neglected in this context, although their pharmacological activities have been well investigated in the past, and they may have considerable potentials for repositioning. A grand number of plant alkaloids inhibit syngeneic or xenograft tumor growth in vivo. Molecular modes of action in cancer cells include induction of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, inhibition of angiogenesis and glycolysis, stress and anti-inflammatory responses, regulation of immune functions, cellular differentiation, and inhibition of invasion and metastasis. Numerous underlying signaling processes are affected by plant alkaloids. Furthermore, plant alkaloids suppress carcinogenesis, indicating chemopreventive properties. Some plant alkaloids reveal toxicities such as hepato-, nephro- or genotoxicity, which disqualifies them for repositioning purposes. Others even protect from hepatotoxicity or cardiotoxicity of xenobiotics and established anticancer drugs. The present survey of the published literature clearly demonstrates that plant alkaloids have the potential for repositioning in cancer therapy. Exploitation of the chemical diversity of natural alkaloids may enrich the candidate pool of compounds for cancer chemotherapy and -prevention. Their further preclinical and clinical development should follow the same stringent rules as for any other synthetic drug as well. Prospective randomized, placebo-controlled clinical phase I and II trials should be initiated to unravel the full potential of plant alkaloids for drug repositioning.

A new potential anti-cancer beta-carboline derivative decreases the expression levels of key proteins involved in glioma aggressiveness: A proteomic investigation

Gliomas remain highly fatal due to their high resistance to current therapies. Deregulation of protein synthesis contributes to cancer onset and progression and is a source of rising interest for new drugs. CM16, a harmine derivative with predicted high blood-brain barrier penetration, exerts antiproliferative effects partly through translation inhibition. We evaluated herein how CM16 alters the proteome of glioma cells. The analysis of the gel-free LC/MS and auto-MS/MS data showed that CM16 induces time- and concentration-dependent significant changes in the total ion current chromatograms. In addition, we observed spontaneous clustering of the samples according to their treatment condition and their proper classification by unsupervised and supervised analyses, respectively. A two-dimensional gel-based approach analysis allowed us to identify that treatment with CM16 may downregulate four key proteins involved in glioma aggressiveness and associated with poor patient survival (HspB1, BTF3, PGAM1, and cofilin), while it may upregulate galectin-1 and Ebp1. Consistently with the protein synthesis inhibition properties of CM16, HspB1, Ebp1, and BTF3 exert known roles in protein synthesis. In conclusion, the downregulation of HspB1, BTF3, PGAM1 and cofilin bring new insights in CM16 antiproliferative effects, further supporting CM16 as an interesting protein synthesis inhibitor to combat glioma.

Harmine suppresses the proliferation of pancreatic cancer cells and sensitizes pancreatic cancer to gemcitabine treatment

Purpose

Pancreatic carcinoma is one of the most deadliest types of cancer, and relatively insensitive to the currently available chemotherapy. Thus, the discovery of novel therapeutic agents to prolong the survival times of patients with pancreatic cancer is urgently required.

Methods

Cell proliferation was assessed using the sulforhodamine B and cell clone formation assay, apoptosis was analyzed through Annexin V/PI staining, analysis of cell cycle distribution was determined by PI staining, and the expression of proteins was detected via Western blotting.

Results

Our data showed that harmine exerted an anti-proliferative effect and cell cycle arrest at G2/M in pancreatic cancer cells. Meanwhile, harmine plus gemcitabine showed strong synergy in inhibiting the proliferation of pancreatic cancer cells. Furthermore, harmine induced apoptosis and enhanced the gemcitabine-induced apoptosis in pancreatic cancer cells. The AKT/mTOR pathway is involved in mechanisms of gemcitabine resistance in pancreatic cancer cells, our data demonstrated that harmine plus gemcitabine significantly suppressed the AKT/mTOR signaling pathway.

Conclusion

Harmine may be a potential candidate for the treatment of pancreatic cancer. Morever, the combination of harmine with gemcitabine appears to be an attractive option for the treatment of patients with pancreatic cancer.

Harmine suppresses hyper-activated Ras-MAPK pathway by selectively targeting oncogenic mutated Ras/Raf in Caenorhabditis elegans

Background

Mutationally activated Ras proteins are closely linked to a wide variety of human cancers. Hence, there has been an intensive search for anti-Ras therapies for cancer treatment. The sole Ras gene, which encodes LET-60, in Caenorhabditis elegans regulates vulval development. While the loss of let-60 function leads to failure of vulva formation, the let-60(n1046gf) allele, which contains a missense mutation mimicking a Ras codon 13 mutation found in human cancers, results in extra vulval tissue, a phenotype named Muv (multiple vulvas).

Methods

By taking advantage of the easy-to-score Muv phenotype of let-60(n1046gf), we used a step-by-step screening approach (from crude extract to active fraction to active natural compound) to search for inhibitors of oncogenic Ras. Mutants of other key components in the Ras-mitogen-activated protein kinase (MAPK) pathway were used to identify other candidate targets.

Results

The natural compound harmine, isolated from the plant Peganum harmala, was found to suppress the Muv phenotype of let-60(n1046gf). In addition, harmine targets the hyper-activation of the Ras/MAPK pathway specifically caused by overexpression or mutated forms of LET-60/Ras and its immediate downstream molecule LIN-45/Raf. Finally, harmine can be absorbed into the worm body and probably functions in its native form, rather than requiring metabolic activation.

Conclusion

In sum, we have revealed for the first time the anti-Ras activity of harmine in a C. elegans model system. Our results revealed the potential anti-cancer mechanism of harmine, which may be useful for the treatment of specific human cancers that are associated with oncogenic Ras mutations.

Harmine-loaded galactosylated pluronic F68-gelucire 44/14 mixed micelles for liver targeting

Harmine (HM), a phytoconstituent has wide range of pharmacological activities including antimicrobial, antifungal, antioxidative, and anticancer. HM has shown promising anticancer activity against liver cancer cells. However, poor aqueous solubility, multidrug pump P-gp efflux, extensive in vivo metabolism, and rapid elimination due to glucuronidation/sulfation limit clinical utility of HM. In order to overcome the drawbacks of HM, the current work reports preparation of HM-loaded galactosylated pluronic F-68 (PF68)-Gelucire^® 44/14 (GL44) mixed micelles (HM-MM). 3² factorial design was used to investigate the effect of formulation variables on formation HM-loaded mixed micelles. Solvent evaporation method was used for preparation of HM-MM. The optimized HM-MM was evaluated for size, percent drug entrapped (EE), in vitro HM release, oral bioavailability, and biodistribution in rats. HM-MM with an average size 277.5 ± 3.24 nm had an EE of 86.5 ± 1.51% w/w. HM-MM released HM in a controlled manner. Additionally, HM-MM showed significant enhancement in oral bioavailability (around six-folds) of HM when compared to HM alone. Further, HM-MM showed around sevenfold higher amount of HM in the liver when compared to HM alone revealing efficient drug targeting capability. Such significant improvement in oral bioavailability of HM when formulated into mixed micelles could be attributed to solubilization of hydrophobic HM into micellar core along with P-gp inhibition effect of both galactosylated PF68 and GL44. Thus, the present work highlights galactosylated PF68 and GL44 mixed micelles as an efficient carrier system having drug targeting capability and potential to enhance bioavailability of BCS class II drugs.

Harmine induces anticancer activity in breast cancer cells via targeting TAZ

Harmine (HM) is a β-carboline alkaloid found in multiple medicinal plants. It has been used in folk medicine for anticancer therapy; however, the molecular mechanism of HM on human breast cancer remains unclear. Transcriptional co-activator with PDZ-binding motif (TAZ), also known as WW domain-containing transcription regulator 1, serves an important role in the carcinogenesis and progression of breast cancer. The aim of the present study was to elucidate the potential anticancer activity and mechanism of HM in breast cancer, in vitro and in vivo. Cell proliferation was measured using a CCK-8 assay, apoptotic activity was detected by flow cytometry and DAPI staining, and cell migration was examined using a wound healing assay. The expression of proteins, including extracellular signal-regulate kinase (Erk), phosphorylated (p-) Erk, protein kinase B (Akt), p-Akt, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax), were determined by western blotting. The mRNA expression of TAZ was detected using reverse transcription-quantitative polymerase chain reaction analysis. The expression of proteins in mouse tumor tissues were examined by immunohistochemistry. HM significantly suppressed cellular proliferation and migration, promoted apoptosis in vitro and inhibited tumor growth in vivo. In addition, HM significantly decreased the expression of TAZ, p-Erk, p-Akt and Bcl-2, but increased that of Bax. The overexpression of TAZ in breast cancer cells inhibited the antitumor effect of HM. In conclusion, HM was found to induce apoptosis and prevent the proliferation and migration of human breast cancer cell lines, possibly via the downregulation of TAZ.

Design and Synthesis of a New Soluble Natural β-Carboline Derivative for Preclinical Study by Intravenous Injection

Harmine is a natural β-carboline compound showing several biological activities, including antiproliferative properties, but this soluble natural molecule lacks selectivity. Harmine derivatives were reported to overcome this problem, but they are usually poorly soluble. Here, we designed and synthesized a new 2, 7, 9-trisubstituted molecule (1-methyl-7-(3-methylbutoxy)-9-propyl-2-[(pyridin-2-yl)methyl]-9H-pyrido[3,4-b]indol-2-ium bromide) with a solubility of 1.87 ± 0.07 mg/mL in a simulated injection vehicle. This compound is stable for at least 72 h in acidic and physiological conditions (pH 1.1 and 7.4) as well as in a simulated injection vehicle (physiological liquid + 0.1% Tween80®). Solubility in those media is 1.06 ± 0.08 mg/mL and 1.62 ± 0.13 mg/mL at pH 7.4 and 1. The synthesized molecule displays a significant activity on five different cancer cell lines (IC₅₀ range from 0.2 to 2 µM on A549, MDA-MB-231, PANC-1, T98G and Hs683 cell lines). This compound is also more active on cancer cells (MDA-MB-231) than on normal cells (MCF-10a) at IC₅₀ concentrations. Due to its high activity at low concentration, such solubility values should be sufficient for further in vivo antitumoral activity evaluation via intravenous injection.

Super-enhancers: novel target for pancreatic ductal adenocarcinoma

Super-enhancers (SEs) are unique areas of the genome which drive high-level of transcription and play a pivotal role in the cell physiology. Previous studies have established several important genes in cancer as SE-driven oncogenes. It is likely that oncogenes may hack the resident tissue regenerative program and interfere with SE-driven repair networks, leading to the specific pancreatic ductal adenocarcinoma (PDAC) phenotype. Here, we used ChIP-Seq to identify the presence of SE in PDAC cell lines. Differential H3K27AC marks were identified at enhancer regions of genes including c-MYC, MED1, OCT-4, NANOG, and SOX2 that can act as SE in non-cancerous, cancerous and metastatic PDAC cell lines. GZ17-6.02 affects acetylation of the genes, reduces transcription of major transcription factors, sonic hedgehog pathway proteins, and stem cell markers. In accordance with the decrease in Oct-4 expression, ChIP-Seq revealed a significant decrease in the occupancy of OCT-4 in the entire genome after GZ17-6.02 treatment suggesting the possible inhibitory effect of GZ17-6.02 on PDAC. Hence, SE genes are associated with PDAC and targeting their regulation with GZ17-6.02 offers a novel approach for treatment.

Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1A (DYRK1A) Inhibitors as Potential Therapeutics

Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is a member of an evolutionarily conserved family of protein kinases that belongs to the CMGC group of kinases. DYRK1A, encoded by a gene located in the human chromosome 21q22.2 region, has attracted attention due to its association with both neuropathological phenotypes and cancer susceptibility in patients with Down syndrome (DS). Inhibition of DYRK1A attenuates cognitive dysfunctions in animal models for both DS and Alzheimer's disease (AD). Furthermore, DYRK1A has been studied as a potential cancer therapeutic target because of its role in the regulation of cell cycle progression by affecting both tumor suppressors and oncogenes. Consequently, selective synthetic inhibitors have been developed to determine the role of DYRK1A in various human diseases. Our perspective includes a comprehensive review of potent and selective DYRK1A inhibitors and their forthcoming therapeutic applications.

Harmine enhances type H vessel formation and prevents bone loss in ovariectomized mice

Recently, researchers identified a distinct vessel subtype called type H vessels that couple angiogenesis and osteogenesis. We previously found that type H vessels are reduced in ovariectomy (OVX)-induced osteoporotic mice, and preosteoclasts are able to secrete platelet-derived growth factor-BB (PDGF-BB) to stimulate type H vessel formation and thereby to promote osteogenesis. This study aimed to explore whether harmine, a β-carboline alkaloid, is capable of preventing bone loss in OVX mice by promoting preosteoclast PDGF-BB-induced type H vessel formation.

METHODS

The impact of harmine on osteoclastogenesis of RANKL-stimulated RAW264.7 cells was verified by gene expression analysis and tartrate-resistant acid phosphatase (TRAP) staining. Enzyme-linked immunosorbent assay (ELISA) was conducted to test PDGF-BB production by preosteoclasts. A series of angiogenesis-related assays in vitro were performed to assess the pro-angiogenic effects of the conditioned media from RANKL-stimulated RAW264.7 cells treated with or without harmine. Meanwhile, the role of PDGF-BB in this process was determined. In vivo, OVX mice were intragastrically administrated with harmine emulsion or an equal volume of vehicle. 2 months later, bone samples were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to evaluate bone mass, osteogenic and osteoclastic activities, as well as the numbers of type H vessels. Bone marrow PDGF-BB concentrations were assessed by ELISA.

RESULTS

Exposure of RANKL-stimulated RAW264.7 cells to harmine enhanced the formation of preosteoclasts and the production of PDGF-BB. Harmine augmented the ability of RANKL-stimulated RAW264.7 cells to promote angiogenesis of endothelial cells, whereas the effect was blocked by PDGF-BB inhibition. In vivo, the oral administration of harmine emulsion to OVX mice resulted in enhanced trabecular bone mass and osteogenic responses, increased numbers of preosteoclasts, as well as reduced numbers of osteoclasts and fat cells. Moreover, OVX mice treated with harmine exhibited higher levels of bone marrow PDGF-BB and much more type H vessels in bone.

CONCLUSION

Harmine may exert bone-sparing effects by suppression of osteoclast formation and promotion of preosteoclast PDGF-BB-induced angiogenesis.

Anti HSV-2 activity of Peganum harmala (L.) and isolation of the active compound

Genital herpes is a sexually transmitted disease caused by herpes simplex virus type 2 (HSV-2). Nucleoside analogues such as acyclovir (ACV) are the usual therapy for treating HSV infection. However, the overuse of this drug has led to the emergence of resistant strains. Therefore, the search for new alternative or complementary molecules to overcome this obstacle is needed. In this objective, Peganum harmala was investigated for its HSV-2 activity. The organic extracts of the different plant organs were evaluated for their cytotoxicity on Vero cells by the MTT test and anti HSV-2 activity by plaque reduction assay. Only the methanol seeds extract was active with a 50% inhibitory concentration (IC₅₀) and a selectivity index (SI) of 161 and 13.2 μg/mL, respectively. In addition, the study of the antiviral mode of action revealed that this extract exerts a virucidal action both during the entry of viruses and the release of the newly formed virions, whereas no cell protection effect was observed. The active compound was isolated by bio-guided purification using thin layer chromatography (TLC) and identified by GC-MS and HPLC-DAD-ESI-MSⁿ as harmine. The combination of harmine standard compound with ACV showed a combination index (CI) of 0.5 indicating that these two compounds have a synergic effect. This data suggests that harmine could be associated to ACV to improve the treatment of genital herpes essentially for the immunocompromised patients.

The inhibitory effects of compound Muniziqi granule against B16 cells and harmine induced autophagy and apoptosis by inhibiting Akt/mTOR pathway

Background

Compound Muniziqi granule (MNZQ) is a multi-component herbal preparation and a popular traditional Uighur medicine used in China for treating endocrine disorder-induced acne, chloasma, dysmenorrhea, menopausal syndrome, and melanoma. Harmine presented in MNZQ has been confirmed potential anticancer effect on the B16 cells among others. The purpose of this study is to explore the inhibitory effects of MNZQ against B16 cells and mechanism of autophagy and apoptosis induced by harmine in B16 cells.

Methods

The cell viability was calculated by CCK8 assay. The in vitro tyrosinase activity was determined by spectrophotometry. The harmine-induced autophagy was demonstrated by electron microscopy and MDC staining. Flow cytometry was used to measure cell death and cell cycle distribution. All proteins expression was assessed by western blot.

Results

MNZQ and some herb extracts contained in preparation displayed inhibitory effects on B16 cells but without inhibition on mushroom tyrosinase compared with kojic acid. The formation of autophagosome was markedly induced by harmine with the accretion of LC3-II and the degeneration of p62 in B16 cells, which indicated that harmine was an autophagy inducer. Cell death and sub-G2 population suggested that harmine could induce cell death. Particularly, 3-MA, an autophagy inhibitor, was discovered to prevent harmine-induced decrease of the cell viability and cell cycle arrest on G2 phase, indicating that autophagy was vital to the cell death. In addition, the results indicated that harmine could inhibit the phosphorylation of Akt and mTOR, which might mediate autophagy.

Conclusion

Harmine could induce autophagy and apoptosis by inhibiting Akt/mTOR pathway in B16 cells. Harmine might be a promising therapeutic agent for treatment of melanoma in MNZQ.

Comprehensive evaluation of clinical efficacy and safety of celecoxib combined with chemotherapy in management of gastric cancer

BACKGROUND

To evaluate the clinical efficacy and safety of celecoxib combined with chemotherapy in the treatment of gastric cancer.

METHODS

In total, 240 gastric cancer patients undergoing radical gastrectomy followed by adjuvant chemotherapy were randomly assigned into 2 groups. In the experimental group (n = 120), patients were administered with celecoxib-based chemotherapy, and chemotherapy alone was performed in the control group. Disease-free survival (DFS) and progression-free survival (PFS) were considered as the primary efficacy parameters, and objective response rate (ORR), overall survival (OS), quality of life (QOL), and safety as the secondary efficacy parameters.

RESULTS

The 3-year OS did not significantly differ between the experimental (72%) and control groups (68%, P = .67). The 3-year DFS in the experimental group was 64%, which did not significantly differ from 51% in the control group (P = .41). In patients with positive cyclooxygenase-2 (COX-2) from the experimental group, the 3-year OS was 78%, significantly higher compared with 66% in the control group (P = .02), and the 3-year DFS was 70%, considerably >50% in the control group (P = .01). No statistical significance was identified in the incidence of nausea, neutropenia, anorexia, peripheral neurotoxicity, diarrhea, vomiting, asthenia, and thrombocytopenia, etc. The EORTC quality of life questionnaire (QLQ)-C30 questionnaire revealed that the global QOL in the experimental group was significantly higher than that in the control group (P < .05). No statistical significance was noted in the scores of functioning scale between 2 groups, whereas the scores of the symptom scale, especially pain and fatigue in the experimental group were remarkably higher than that in the control group (P < .05). The global score of EORTC QLQ-STO22 in the experimental group was considerably higher compared with that in the control group (P < .05). No statistical significance was identified in term of the domains of restrictions on feeding, dysphagia, anxiety, reflux, sense of taste, dry mouth, hair loss, and body shape between groups (all P > .05).

CONCLUSION

Celecoxib combined with chemotherapy yields clinical benefits for gastric cancer patients with positive COX-2, which not only enhances the OS, DFS, PFS, QOL, and short-term clinical efficacy, but also does not increase the risk of adverse events.

MitoKATP channels promote the proliferation of hypoxic human pulmonary artery smooth muscle cells via the ROS/HIF/miR-210/ISCU signaling pathway

Previous results have indicated that mitochondrial ATP-sensitive potassium (mitoK_ATP) channels are associated with the hypoxic proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the mechanism underlying the promotive effects of mitoK_ATP channels on cell proliferation in response to hypoxia remains unknown. mitoK_ATP channel opening results in a collapse of mitochondrial membrane potential and generation of mitochondrial reactive oxygen species (ROS). As hypoxia-inducible factor-1α (HIF-1α) is a critical oxygen sensor and major transcriptional regulator of the hypoxic adaptive response, the current study assessed whether mitoK_ATP opening contributes to the chronic proliferation of human PASMCs (hPASMCs) in collaboration with HIF-1α and its downstream targets under hypoxic conditions. The present study demonstrated that there was crosstalk between mitoK_ATP channels and HIF-1α signaling in PASMCs under hypoxic conditions. The results suggest that mitoK_ATP channels are involved in the proliferation of PASMCs during hypoxia through upregulation of the ROS/HIF/microRNA-210/iron-sulfur cluster protein signaling pathway.

Multidrug-resistant cancer cells and cancer stem cells hijack cellular systems to circumvent systemic therapies, can natural products reverse this?

Chemotherapy is one of the most effective and broadly used approaches for cancer management and many modern regimes can eliminate the bulk of the cancer cells. However, recurrence and metastasis still remain a major obstacle leading to the failure of systemic cancer treatments. Therefore, to improve the long-term eradication of cancer, the cellular and molecular pathways that provide targets which play crucial roles in drug resistance should be identified and characterised. Multidrug resistance (MDR) and the existence of tumor-initiating cells, also referred to as cancer stem cells (CSCs), are two major contributors to the failure of chemotherapy. MDR describes cancer cells that become resistant to structurally and functionally unrelated anti-cancer agents. CSCs are a small population of cells within cancer cells with the capacity of self-renewal, tumor metastasis, and cell differentiation. CSCs are also believed to be associated with chemoresistance. Thus, MDR and CSCs are the greatest challenges for cancer chemotherapy. A significant effort has been made to identify agents that specifically target MDR cells and CSCs. Consequently, some agents derived from nature have been developed with a view that they may overcome MDR and/or target CSCs. In this review, natural products-targeting MDR cancer cells and CSCs are summarized and clustered by their targets in different signaling pathways.

Potential Antitumor Effect of Harmine in the Treatment of Thyroid Cancer

Thyroid cancer is one of the most common types of cancer in endocrine system. In latest studies, harmine has been proved to inhibit the growth of several cancers in vitro and in vivo. In the current study, we evaluated the in vitro and in vivo anticancer efficiency of harmine against thyroid cancer cell line TPC-1. The in vitro cytotoxicity of harmine evaluated by XTT assay indicated that harmine suppressed the proliferation of TPC-1 cells in a dose- and time-dependent manner. Moreover, harmine dose-dependently induced apoptosis of TPC-1 cells through regulating the ratio of Bcl-2/Bax. The colony forming ability of TPC-1 cells was also time-dependently inhibited by harmine. The inhibitory effects of harmine on migration and invasion of TPC-1 cells were studied by wound scratching and Transwell assays. In vivo evaluation showed that harmine effectively inhibited the growth of thyroid cancer in a dose-dependent manner in nude mice. Therefore, harmine might be a promising herbal medicine in the therapy of thyroid cancer and further efforts are needed to explore this therapeutic strategy.

A synergistic antitumor effect of polyphyllin I and formosanin C on hepatocarcinoma cells

Polyphyllin I (PPI) and formosanin C (FC) were regarded as effective and imperative components isolated from Rhizoma Paridis saponins (RPS) and exhibited strong anti-tumor effects on a variety of cancers. With the wide application of complex mixtures in clinics, synergistic interactions are of vital importance in phytomedicine. Therefore, it is of inherent importance to study whether there is a synergistic anti-tumor effect on PPI and FC from one herb. In this study, the viability was detected by MTT assay. The combination index (CI) analysis was used to assess their synergistic effect. Consequently, there was a synergistic anti-tumor effect between PPI and FC at a ratio of 1:1. The CI value was less than 1.0. Their combination significantly increased their single G1 phase arrest and mitochondria-dependent apoptotic pathway. Meanwhile, PPI and FC reduced the ability of cell migration. In conclusion, polyphyllin I and formosanin C showed a synergistic anti-tumor effect on hepatocarcinoma cells. The findings would provide the foundation for the use of RPS in the future.

MiR-203 inhibits tumor invasion and metastasis in gastric cancer by ATM

Gastric cancer is one of the most common malignancies in the world. A number of miRNAs are aberrantly expressed during the progression of gastric cancer. In this study, we aimed to investigate the role of miR-203 in the invasion and metastasis of gastric cancer and the potential mechanism of the effect of miR-203 on the tumor progression of gastric cancer. Our results showed that miR-203 was significantly downregulated in gastric cancer tissues and cells, while ataxia telangiectasia mutated kinase (ATM) was upregulated in gastric cancer tissues and cells and was directly regulated by miR-203. Ectopic overexpression of miR-203 inhibited the colony formation, migration, and invasion of gastric cancer cells. In addition, miR-203 overexpression significantly suppressed the protein level of Snail and obviously promoted the protein level of E-cadherin in gastric cancer cells. ATM knockdown phenocopied the effect of miR-203 overexpression. These results suggested that miR-203 suppressed the migration and invasion of gastric cancer through regulating the level of ATM-mediated-Snail and E-cadherin. MiR-203 might be a novel therapeutic strategy for the treatment of gastric cancer.

Harmine combined with paclitaxel inhibits tumor proliferation and induces apoptosis through down-regulation of cyclooxygenase-2 expression in gastric cancer

Cyclooxygenase-2 (COX-2) serves an important role in the carcinogenesis and progression of gastric cancer. Harmine (HM) and paclitaxel (PTX) are reported as promising drug candidates for cancer therapy, but whether a synergistic anti-tumor effect of HM combined with PTX exists in human gastric cancer remains unknown. The present study evaluated the effects of HM and/or PTX on cell proliferation and apoptosis in a gastric cancer cell line, SGC-7901. HM and PTX inhibited cell proliferation in a dose-dependent manner. Both HM and PTX alone induced apoptosis in gastric cancer cells. The combination of HM and PTX exerted synergistic effects on proliferation inhibition and apoptosis induction in SGC-7901 cells, with down-regulation of COX-2, PCNA and Bcl-2 and up-regulation of Bax expression. The results indicated that combination chemotherapy using HM with PTX exerts an anti-tumor effect for treating gastric cancer. The combination of the two drugs inhibits gastric cancer development more effectively than each drug alone through down-regulation of COX-2 expression.

Expression of APPL1 is correlated with clinicopathologic characteristics and poor prognosis in patients with gastric cancer

BACKGROUND

Although appl1 is overexpressed in many cancers, its status in gastric cancer (gc) is not known. In the present study, we used relevant pathologic and clinical data to investigate appl1 expression in patients with gc.

METHODS

In 47 gc and 27 non-gc surgical specimens, immunohistochemistry was used to detect the expression of appl1, and reverse-transcriptase polymerase chain reaction (rt-pcr) was used to detect messenger rna (mrna). A scatterplot visualized the relationship between survival time and mrna expression in gc patients. The log-rank test and other survival statistics were used to determine the association of appl1 expression with the pathologic features of the cancer and clinical outcomes.

RESULTS

In gc, appl1 was expressed in 28 of 47 specimens (59.6%), and in non-gc, it was expressed in 7 of 23 specimens (30.4%, p < 0.05). The expression of mrna in gc was 0.82 [95% confidence interval (ci): 0.78 to 0.86], and in non-gc, it was 0.73 (95% ci: 0.69 to 0.77; p < 0.05). Immunohistochemistry demonstrated that, in gc, appl1 expression was correlated with depth of infiltration (p = 0.005), lymph node metastasis (p = 0.017), and TNM stage (p = 0.022), but not with pathologic type (p = 0.41). Testing by rt-pcr demonstrated that, in gc, appl1 mrna expression was correlated with depth of infiltration (p = 0.042), lymph node metastasis (p = 0.031), and TNM stage (p = 0.04), but again, not with pathologic type (p = 0.98). The correlation coefficient between survival time and mrna expression was -0.83 (p < 0.01). Overexpression of appl1 protein (hazard ratio: 3.88; 95% ci: 1.07 to 14.09) and mrna (hazard ratio: 4.23; 95% ci: 3.09 to 15.11) was a risk factor for death in patients with gc.

CONCLUSIONS

Expression of appl1 is increased in gc. Overexpression is prognostic for a lethal outcome.

Liposomes coated with N-trimethyl chitosan to improve the absorption of harmine in vivo and in vitro

In this study, harmine liposomes (HM-lip) were prepared through the thin-film hydration-pH-gradient method and then coated with N-trimethyl chitosan (TMC). Particle size, zeta potential, entrapment efficiency, and in vitro release of HM-lip and TMC-coated harmine liposomes (TMC-HM-lip) were also determined. Sprague Dawley rats were further used to investigate the pharmacokinetics in vivo. Retention behavior in mouse gastrointestinal tract (GIT) was studied through high-performance liquid chromatography and near-infrared imaging. Degradation was further evaluated through incubation with Caco-2 cell homogenates, and a Caco-2 monolayer cell model was used to investigate the uptake and transport of drugs. HM-lip and TMC-HM-lip with particle size of 150-170 nm, an entrapment efficiency of about 81%, and a zeta potential of negative and positive, respectively, were prepared. The release of HM from HM-lip and TMC-HM-lip was slower than that from HM solution and was sensitive to pH. TMC-HM-lip exhibited higher oral bioavailability and had prolonged retention time in GIT. HM-lip and TMC-HM-lip could also protect HM against degradation in Caco-2 cell homogenates. The uptake amount of TMC-HM-lip was higher than that of HM and HM-lip. TMC-HM-lip further demonstrated higher apparent permeability coefficient (P(app)) from the apical to the basolateral side than HM and HM-lip because of its higher uptake and capability to open tight junctions in the cell monolayers. TMC-HM-lip can prolong the retention time in the GIT, protect HM against enzyme degradation, and improve transport across Caco-2 cell monolayers, thus enhancing the oral bioavailability of HM.

Design, synthesis, and in vivo evaluations of benzyl Nω-nitro-Nα-(9H-pyrido[3,4-b]indole-3-carbonyl)-l-argininate as an apoptosis inducer capable of decreasing the serum concentration of P-selectin

A series of findings suggest that the discovery of in vivo apoptosis inducers for chemotherapy is of clinical importance.

Peganum harmala L.'s anti-growth effect on a breast cancer cell line

This research was done to evaluate the induction of apoptosis in MDA-MB-231 breast cancer cell line by Peganum harmala's extract, in which a significant amount of ß-carbolines is included. The apoptosis incidence was assessed through Annexin-V-Flous kit. The expressions of genes through which intrinsic apoptosis pathway are involved, Bax, Bcl-2, Bid, and Puma, over the genes the expressions of which are linked to extrinsic apoptosis pathway, TRAIL, Caspase8, p21, and p53, were examined by RT-PCR and Real-time PCR. The results demonstrate that the extract decreases the growth rate of the cancer cell line through inducing apoptosis mechanism. As long as the expression of anti-apoptosis Bcl-2 gen reduced dramatically, an over-expression in Bax and Puma genes was monitored indicating activation of intrinsic apoptosis pathway. A notable over-expression observed with TRAIL and Caspase8 genes as well as Bid gene. The latter is an intermediate for both intrinsic and extrinsic pathways of apoptosis.

Effects of harmine, an acetylcholinesterase inhibitor, on spatial learning and memory of APP/PS1 transgenic mice and scopolamine-induced memory impairment mice

Harmine, a β-carboline alkaloid present in Peganum harmala with a wide spectrum of pharmacological activities, has been shown to exert strong inhibition against acetylcholinesterase in vitro. However, whether it can rescue the impaired cognition has not been elucidated yet. In current study, we examined its effects on scopolamine-induced memory impairment mice and APP/PS1 transgenic mice, one of the models for Alzheimer's disease, using Morris Water Maze test. In addition, whether harmine could penetrate blood brain barrier, interact with and inhibit acetylcholinesterase, and activate downstream signaling network was also investigated. Our results showed that harmine (20mg/kg) administered by oral gavage for 2 weeks could effectively enhance the spatial cognition of C57BL/6 mice impaired by intraperitoneal injection of scopolamine (1mg/kg). Meanwhile, long-term consumption of harmine (20mg/kg) for 10 weeks also slightly benefited the impaired memory of APP/PS1 mice. Furthermore, harmine could pass through blood brain barrier, penetrate into the brain parenchyma shortly after oral administration, and modulate the expression of Egr-1, c-Jun and c-Fos. Molecular docking assay disclosed that harmine molecule could directly dock into the catalytic active site of acetylcholinesterase, which was partially confirmed by its in vivo inhibitory activity on acetylcholinesterase. Taken together, all these results suggested that harmine could ameliorate impaired memory by enhancement of cholinergic neurotransmission via inhibiting the activity of acetylcholinesterase, which may contribute to its clinical use in the therapy of neurological diseases characterized with acetylcholinesterase deficiency.

Role of cancer-associated fibroblasts in invasion and metastasis of gastric cancer

Cancer-associated fibroblasts (CAFs) are important components of various types of tumors, including gastric cancer (GC). During tumorigenesis and progression, CAFs play critical roles in tumor invasion and metastasis via a series of functions including extracellular matrix deposition, angiogenesis, metabolism reprogramming and chemoresistance. However, the mechanism of the interaction between gastric cancer cells and CAFs remains largely unknown. MicroRNAs (miRNAs) are a class of non-coding small RNA molecules, and their expression in CAFs not only regulates the expression of a number of target genes but also plays an essential role in the communication between tumor cells and CAFs. In this review, we provide an overview of recent studies on CAF miRNAs in GC and the relevant signaling pathways in gastrointestinal tumors. Focusing the attention on these signaling pathways may help us better understand their role in tumor invasion and metastasis and identify new molecular targets for therapeutic strategies.

Paclitaxel combined with harmine inhibits the migration and invasion of gastric cancer cells through downregulation of cyclooxygenase-2 expression

Cyclooxygenase-2 (COX-2) has a critical role in the invasiveness and metastasis of gastric cancer. In addition, paclitaxel (PTX) and harmine (HM) were reported to be potential therapeutic drug candidates for cancer therapy; however, the synergistic antitumor effect of PTX and HM combined treatment on the human gastric cancer cells remains to be elucidated. The aim of the present study was to evaluate the effects of PTX and/or HM on the cell migration and invasion in two human gastric cancer cell lines, SGC-7901 and MKN-45. MTT assay was used to detect the growth inhibition induced by PTX and HM. The Transwell assay was employed to assess the effects of PTX and HM on the cell migration and invasion. The expression levels of COX-2 and matrix metalloproteinase-9 (MMP-9) were analyzed by western blot analysis. The results demonstrated that PTX and HM inhibited cell proliferation in a dose-dependent manner. Individually PTX and HM were able to inhibit the migration and invasion of two human gastric cancer cells; however, the combination of PTX and HM exerted synergistic effects on migration and invasion inhibition, with downregulation of COX-2 and matrix metalloproteinase (MMP)-9. In conclusion, the results of the present study indicated that combination chemotherapy using PTX with HM exerted an antitumor effect, which may be implicated for the treatment of gastric cancer. Of note, the combination of the two drugs inhibited migration and invasion more effectively compared with each drug alone, the mechanism of which proceeded via the downregulation of COX-2 expression.

A network model for angiogenesis in ovarian cancer

Background

We recently identified two robust ovarian cancer subtypes, defined by the expression of genes involved in angiogenesis, with significant differences in clinical outcome. To identify potential regulatory mechanisms that distinguish the subtypes we applied PANDA, a method that uses an integrative approach to model information flow in gene regulatory networks.

Results

We find distinct differences between networks that are active in the angiogenic and non-angiogenic subtypes, largely defined by a set of key transcription factors that, although previously reported to play a role in angiogenesis, are not strongly differentially-expressed between the subtypes. Our network analysis indicates that these factors are involved in the activation (or repression) of different genes in the two subtypes, resulting in differential expression of their network targets. Mechanisms mediating differences between subtypes include a previously unrecognized pro-angiogenic role for increased genome-wide DNA methylation and complex patterns of combinatorial regulation.

Conclusions

The models we develop require a shift in our interpretation of the driving factors in biological networks away from the genes themselves and toward their interactions. The observed regulatory changes between subtypes suggest therapeutic interventions that may help in the treatment of ovarian cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-015-0551-y) contains supplementary material, which is available to authorized users.