Benzyl Isothiocyanate potentiates p53 signaling and antitumor effects against breast cancer through activation of p53-LKB1 and p73-LKB1 axes

Benzyl isothiocyanate suppresses development of thyroid carcinoma by regulating both autophagy and apoptosis pathway

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid cancer, characterized by rapid growth and invasion and poor prognosis. Due to its rarity and aggressive nature, ATC is a difficult condition to treat, thus knowledge of the mechanisms underlying its progression represents important research challenges. Benzyl isothiocyanate (BITC) is a natural compound that has shown promising anticancer properties. The aim of this study was to evaluate the antitumor effect of BITC in ATC, highlighting signaling pathways involved in BITC mechanism of action. This work included in vitro and in vivo studies. Results obtained indicate that BITC, both in vitro and in vivo, has the potential to slow the progression of ATC through interactions with autophagy, reduction in epithelial-mesenchymal transition (EMT) and attenuation of inflammation. In conclusion, this study identifies BITC as a compound worth further investigation for the development of new treatment strategies for this aggressive form of thyroid cancer.

Reviewing the Prospective Pharmacological Potential of Isothiocyanates in Fight against Female-Specific Cancers

Gynecological cancers are the most commonly diagnosed malignancies in females worldwide. Despite the advancement of diagnostic tools as well as the availability of various therapeutic interventions, the incidence and mortality of female-specific cancers is still a life-threatening issue, prevailing as one of the major health problems worldwide. Lately, alternative medicines have garnered immense attention as a therapeutic intervention against various types of cancers, seemingly because of their safety profiles and enhanced effectiveness. Isothiocyanates (ITCs), specifically sulforaphane, benzyl isothiocyanate, and phenethyl isothiocyanate, have shown an intriguing potential to actively contribute to cancer cell growth inhibition, apoptosis induction, epigenetic alterations, and modulation of autophagy and cancer stem cells in female-specific cancers. Additionally, it has been shown that ITCs plausibly enhance the chemo-sensitization of many chemotherapeutic drugs. To this end, evidence has shown enhanced efficacy in combinatorial regimens with conventional chemotherapeutic drugs and/or other phytochemicals. Reckoning with these, herein, we discuss the advances in the knowledge regarding the aspects highlighting the molecular intricacies of ITCs in female-specific cancers. In addition, we have also argued regarding the potential of ITCs either as solitary treatment or in a combinatorial therapeutic regimen for the prevention and/or treatment of female-specific cancers. Hopefully, this review will open new horizons for consideration of ITCs in therapeutic interventions that would undoubtedly improve the prognosis of the female-specific cancer clientele. Considering all these, it is reasonable to state that a better understanding of these molecular intricacies will plausibly provide a facile opportunity for treating these female-specific cancers.

Chemical Composition and Biological Activity of Essential Oil and Extract from the Seeds of Tropaeolum majus L. var. altum

Research background

Plant Tropaeolum majus L. (garden nasturtium) belongs to the family Tropaeolaceae and contains benzyl glucosinolate. The breakdown product of benzyl glucosinolate, benzyl isothiocyanate (BITC), exhibits various biological activities such as antiproliferative, antibacterial and antiinflammatory. In order to optimize the content of biologically active volatile compounds in plant extract and essential oil, the use of appropriate extraction technique has a crucial role.

Experimental approach

The current study investigates the effect of two modern extraction methods, microwave-assisted distillation (MAD) and microwave hydrodiffusion and gravity (MHG), on the chemical composition of volatile components present in the essential oil and extract of garden nasturtium (T. majus L. var. altum) seeds. Investigation of the biological activity of samples (essential oil, extract and pure compounds) was focused on the antiproliferative effect against different cancer cell lines: cervical cancer cell line (HeLa), human colon cancer cell line (HCT116) and human osteosarcoma cell line (U2OS), and the antibacterial activity which was evaluated against the growth and adhesion of Staphylococcus aureus and Escherichia coli to polystyrene surface.

Results and conclusions

Essential oil and extract of garden nasturtium (T. majus) seeds were isolated by two extraction techniques: MAD and MHG. BITC and benzyl cyanide (BCN) present in the extract were identified by gas chromatography-mass spectrometry. Essential oil of T. majus showed higher antiproliferative activity (IC50<5 µg/mL) than T. majus extract (IC50<27 µg/mL) against three cancer cell lines: HeLa, HCT116 and U2OS. BITC showed much higher inhibitory effect on all tested cells than BCN. The essential oil and extract of T. majus showed strong antimicrobial activity against S. aureus and E. coli.

Novelty and scientific contribution

This work represents the first comparative report on the antiproliferative activity of the essential oil and extract of T. majus seeds, BITC and BCN against HeLa, HCT116 and U2OS cells as well as their antimicrobial activity against S. aureus and E. coli. This study demonstrates that the essential oil of T. majus seeds exhibits stronger antiproliferative and antimicrobial activity than the plant extract.

Research Trend and Detailed Insights into the Molecular Mechanisms of Food Bioactive Compounds against Cancer: A Comprehensive Review with Special Emphasis on Probiotics

In an attempt to find a potential cure for cancer, scientists have been probing the efficacy of the food we eat and its bioactive components. Over the decades, there has been an exponentially increasing trend of research correlating food and cancer. This review explains the molecular mechanisms by which bioactive food components exhibit anticancer effects in several cancer models. These bioactive compounds are mainly plant based or microbiome based. While plants remain the primary source of these phytochemicals, little is known about probiotics, i.e., microbiome sources, and their relationships with cancer. Thus, the molecular mechanisms underlying the anticancer effect of probiotics are discussed in this review. The principal mode of cell death for most food bioactives is found to be apoptosis. Principal oncogenic signaling axes such as Akt/PI3K, JAK/STAT, and NF-κB seem to be modulated due to these bioactives along with certain novel targets that provide a platform for further oncogenic research. It has been observed that probiotics have an immunomodulatory effect leading to their chemopreventive actions. Various foods exhibit better efficacy as complete extracts than their individual phytochemicals, indicating an orchestrated effect of the food components. Combining bioactive agents with available chemotherapies helps synergize the anticancer action of both to overcome drug resistance. Novel techniques to deliver bioactive agents enhance their therapeutic response. Such combinations and novel approaches are also discussed in this review. Notably, most of the food components that have been studied for cancer have shown their efficacy in vivo. This bolsters the claims of these studies and, thus, provides us with hope of discovering anticancer agents in the food that we eat.

Hydrogen Sulfide Biology and Its Role in Cancer

Hydrogen sulfide (H2S) is an endogenous biologically active gas produced in mammalian tissues. It plays a very critical role in many pathophysiological processes in the body. It can be endogenously produced through many enzymes analogous to the cysteine family, while the exogenous source may involve inorganic sulfide salts. H2S has recently been well investigated with regard to the onset of various carcinogenic diseases such as lung, breast, ovaries, colon cancer, and neurodegenerative disorders. H2S is considered an oncogenic gas, and a potential therapeutic target for treating and diagnosing cancers, due to its role in mediating the development of tumorigenesis. Here in this review, an in-detail up-to-date explanation of the potential role of H2S in different malignancies has been reported. The study summarizes the synthesis of H2S, its roles, signaling routes, expressions, and H2S release in various malignancies. Considering the critical importance of this active biological molecule, we believe this review in this esteemed journal will highlight the oncogenic role of H2S in the scientific community.

The Cross Talk Between p53 and mTOR Pathways in Response to Physiological and Genotoxic Stresses

The tumor suppressor p53 is activated upon multiple cellular stresses, including DNA damage, oncogene activation, ribosomal stress, and hypoxia, to induce cell cycle arrest, apoptosis, and senescence. Mammalian target of rapamycin (mTOR), an evolutionarily conserved serine/threonine protein kinase, serves as a central regulator of cell growth, proliferation, and survival by coordinating nutrients, energy, growth factors, and oxygen levels. p53 dysfunction and mTOR pathway hyperactivation are hallmarks of human cancer. The balance between response to stresses or commitment to cell proliferation and survival is governed by various regulatory loops between the p53 and mTOR pathways. In this review, we first briefly introduce the tumor suppressor p53 and then describe the upstream regulators and downstream effectors of the mTOR pathway. Next, we discuss the role of p53 in regulating the mTOR pathway through its transcriptional and non-transcriptional effects. We further describe the complicated role of the mTOR pathway in modulating p53 activity. Finally, we discuss the current knowledge and future perspectives on the coordinated regulation of the p53 and mTOR pathways.

Inverse molecular docking reveals a novel function of thymol: Inhibition of fat deposition induced by high-dose glucose in Caenorhabditis elegans

As a natural product isolated from thyme oil in thyme, thymol (2-isopropyl-5-methylphenol) harbors antiviral, antioxidant, and other properties, and thus could be potentially used for the treatment of various diseases. However, the function of thymol has not been comprehensively studied. Here, we applied an inverse molecular docking approach to identify unappreciated functions of thymol. Potential targets of thymol in humans were identified by the server of DRAR-CPI, and targets of interest were then assessed by GO and KEGG pathway analysis. Subsequently, homologous proteins of these targets in Caenorhabditis elegans were identified by Blast tool, and their three-dimensional structures were achieved using Swiss-Model workspace. Interaction between thymol and the targeted proteins in worms was verified using AutoDock 4.0. Analyses of the targets revealed that thymol could be potentially involved in the glycolysis/gluconeogenesis and fatty acid degradation pathways. To verify the activity of thymol on lipid deposition in vivo, the C. elegans model was established. The lipid content of nematodes induced by high-dose glucose was determined by Oil Red O and Nile Red staining, and gene expression was assessed by qRT-PCR. The results showed that thymol might lead to the acceleration of β-oxidation by upregulating cpt-1, aco, fabp, and tph-1, causing the descent of lipid content in nematodes. Our findings indicated that thymol could be potentially used for the treatment of chronic metabolic diseases associated with increased fatty acid deposition.

Estrogen Receptor-Alpha and p53 Status as Regulators of AMPK and mTOR in Luminal Breast Cancer

Luminal breast cancer (LBC) driven by dysregulated estrogen receptor-alpha (ERα) signaling accounts for 70% of the breast cancer cases diagnosed. Although endocrine therapy (ET) is effective against LBC, about one-third of these patients fail to respond to therapy owing to acquired or inherent resistance mechanisms. Aberrant signaling via ERα, oncogenes, growth factor receptors, and mutations in tumor suppressors such as p53 impinge on downstream regulators such as AMPK and mTOR. While both AMPK and mTOR have been reported to play important roles in determining sensitivity of LBC to ET, how the ERα-p53 crosstalk impinges on regulation of AMPK and mTOR, thereby influencing therapeutic efficacy remains unknown. Here, we have addressed this important issue using isogenic breast cancer cell lines, siRNA-mediated RNA knockdown, and different modes of drug treatments. Interaction of p53 with ERα and AMPK was determined by in situ proximity ligation assay (PLA), and endogenous gene transcripts were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Further, the effect of concurrent and sequential administration of Fulvestrant-Everolimus combination on colony formation was determined. The studies showed that in cells expressing wild type p53, as well as in cells devoid of p53, ERα represses AMPK, whereas in cells harboring mutant p53, repression of AMPK is sustained even in the absence of ERα. AMPK is a major negative regulator of mTOR, and to our knowledge, this is the first study on the contribution of AMPK-dependent regulation of mTOR by ERα. Furthermore, the studies revealed that independent of the p53 mutation status, combination of Fulvestrant and Everolimus may be a viable first line therapeutic strategy for potentially delaying resistance of ERα+/HER2- LBC to ET.

MicroRNA-1246 by Targeting AXIN2 and GSK-3β Overcomes Drug Resistance and Induces Apoptosis in Chemo-resistant Leukemia Cells

Background and objective: Chemotherapy plays an important role in the treatment of leukemia. Multidrug resistance (MDR) induced by chemotherapy always leads to treatment failure and disease recurrence. MicroRNAs (miRNAs) have been verified as crucial components in carcinogenesis, including chemo-resistance of tumor cells, which has not been fully understood. In this study, we aimed to identify the potential candidate miRNA, miR-1246, and reveal its regulatory role in chemo-resistance of leukemia cells.

Methods: Candidate miRNAs were selected by microarray analysis, screened by bioinformatics tools and verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Chemo-resistant phenotypes, including cell viability, apoptosis, adriamycin (ADM) efflux and in vivo oncogenicity of leukemia cells following transfected with miR-1246 mimics or inhibitor were checked with or without ADM treatment to make clear the relationship between miR-1246 and chemo-resistance. RT-qPCR, western blot and dual luciferase reporter assay were performed to measure the expression of related genes and address the potential regulatory mechanism of miR-1246 in chemo-resistance.

Results: The expression of miR-1246 was significantly higher in chemo-resistant leukemia K562/ADM cells, HL-60/RS cells and recurrent primary leukemia cells. Loss of miR-1246 inhibited proliferation, induced apoptosis, altered cell cycle distribution, inhibited ADM efflux in chemo-resistant leukemia cells, while overexpression of miR-1246 showed the opposite role in chemo-sensitive leukemia cells. Both bioinformatics prediction and luciferase assay indicated that AXIN2 and glycogen synthase kinase 3 beta (GSK-3β) were the direct targets of miR-1246 in leukemia cells. Inhibition of miR-1246 could up-regulate AXIN2 and GSK-3β and inactivate Wnt/β-catenin pathway, accompanied with inhibiting the expression of β-catenin and further influencing the expression of P-glycoprotein (P-gp) in the chemo-resistant leukemia cells.

Conclusions: Chemo-resistant ability of MDR leukemia cells is attenuated by loss of miR-1246 via negatively regulating AXIN2 and GSK-3β to inactivate Wnt/β-catenin pathway and suppress P-gp expression, these mean that targeting miR-1246-AXIN2/GSK-3β-Wnt/β-catenin axis may be beneficial to overcome the chemo-resistance in relapse and refractory leukemia patients.

Anticancer activities of dietary benzyl isothiocyanate: A comprehensive review

Benzyl isothiocyanate (BITC) is one of the common isothiocyanates found in cruciferous vegetables such as broccoli, cabbage or watercress. Preclinical studies report of its effectiveness in the prevention and treatment against several cancers. This review aims to report and discuss findings on anticancer activities of BITC and its modes of action against 14 types of cancer. A literature search was conducted using the keywords "BITC" and "anticancer" from PubMed, Google Scholar and CINAHL Plus to obtain relevant research articles. This review highlights the anticancer efficacy of BITC through modulation of various signaling pathways involved in apoptosis, cell proliferation, cell cycle arrest, metastasis, angiogenesis, autophagy and the effects of BITC in combination with other drugs. With the available pharmacology evidence, we conclude that further studies are needed to validate its effectiveness in humans for further development and translation into prophylaxis or therapy by promoting optimal therapeutic effects and minimizing toxicity in cancer treatment.

p73: From the p53 shadow to a major pharmacological target in anticancer therapy

p73, along with p53 and p63, belongs to the p53 family of transcription factors. Besides the p53-like tumor suppressive activities, p73 has unique roles, namely in neuronal development and differentiation. In addition, the TP73 gene is rarely mutated in tumors. This makes p73 a highly appealing therapeutic target, particularly towards cancers with a null or disrupted p53 pathway. Distinct isoforms are transcribed from the TP73 locus either with (TAp73) and without (ΔNp73) the N-terminal transactivation domain. Conversely to TA tumor suppressors, ΔN proteins exhibit oncogenic properties by inhibiting p53 and TA protein functions. As such, p73 isoforms compose a puzzled and challenging regulatory pathway. This state-of-the-art review affords an update overview on p73 structure, biological functions and pharmacological regulation. Importantly, it addresses the relevance of p73 isoforms in carcinogenesis, highlighting their potential as drug targets in anticancer therapy. A critical discussion of major pharmacological approaches to promote p73 tumor suppressive activities, with relevant survival outcomes for cancer patients, is also provided.

OncoOmics approaches to reveal essential genes in breast cancer: a panoramic view from pathogenesis to precision medicine

Breast cancer (BC) is the leading cause of cancer-related death among women and the most commonly diagnosed cancer worldwide. Although in recent years large-scale efforts have focused on identifying new therapeutic targets, a better understanding of BC molecular processes is required. Here we focused on elucidating the molecular hallmarks of BC heterogeneity and the oncogenic mutations involved in precision medicine that remains poorly defined. To fill this gap, we established an OncoOmics strategy that consists of analyzing genomic alterations, signaling pathways, protein-protein interactome network, protein expression, dependency maps in cell lines and patient-derived xenografts in 230 previously prioritized genes to reveal essential genes in breast cancer. As results, the OncoOmics BC essential genes were rationally filtered to 140. mRNA up-regulation was the most prevalent genomic alteration. The most altered signaling pathways were associated with basal-like and Her2-enriched molecular subtypes. RAC1, AKT1, CCND1, PIK3CA, ERBB2, CDH1, MAPK14, TP53, MAPK1, SRC, RAC3, BCL2, CTNNB1, EGFR, CDK2, GRB2, MED1 and GATA3 were essential genes in at least three OncoOmics approaches. Drugs with the highest amount of clinical trials in phases 3 and 4 were paclitaxel, docetaxel, trastuzumab, tamoxifen and doxorubicin. Lastly, we collected ~3,500 somatic and germline oncogenic variants associated with 50 essential genes, which in turn had therapeutic connectivity with 73 drugs. In conclusion, the OncoOmics strategy reveals essential genes capable of accelerating the development of targeted therapies for precision oncology.

Suppression of multiple processes relevant to cancer progression by benzyl isothiocyanate may result from the inhibition of Aurora A kinase activity

The anti-cancer properties of BITC may result from the inhibition of Aurora A kinase activity.

The Diverse Functions of Mutant 53, Its Family Members and Isoforms in Cancer

The p53 family of proteins has grown substantially over the last 40 years. It started with p53, then p63, p73, isoforms and mutants of these proteins. The function of p53 as a tumour suppressor has been thoroughly investigated, but the functions of all isoforms and mutants and the interplay between them are still poorly understood. Mutant p53 proteins lose p53 function, display dominant-negative (DN) activity and display gain-of-function (GOF) to varying degrees. GOF was originally attributed to mutant p53′s inhibitory function over the p53 family members p63 and p73. It has become apparent that this is not the only way in which mutant p53 operates as a large number of transcription factors that are not related to p53 are activated on mutant p53 binding. This raises the question to what extent mutant p53 binding to p63 and p73 plays a role in mutant p53 GOF. In this review, we discuss the literature around the interaction between mutant p53 and family members, including other binding partners, the functional consequences and potential therapeutics.

Bioactive Compounds: Multi-Targeting Silver Bullets for Preventing and Treating Breast Cancer

Each cell in our body is designed with a self-destructive trigger, and if damaged, can happily sacrifice itself for the sake of the body. This process of self-destruction to safeguard the adjacent normal cells is known as programmed cell death or apoptosis. Cancer cells outsmart normal cells and evade apoptosis and it is one of the major hallmarks of cancer. The cardinal quest for anti-cancer drug discovery (bioactive or synthetic compounds) is to be able to re-induce the so called “programmed cell death” in cancer cells. The importance of bioactive compounds as the linchpin of cancer therapeutics is well known as many effective chemotherapeutic drugs such as vincristine, vinblastine, doxorubicin, etoposide and paclitaxel have natural product origins. The present review discusses various bioactive compounds with known anticancer potential, underlying mechanisms by which they induce cell death and their preclinical/clinical development. Most bioactive compounds can concurrently target multiple signaling pathways that are important for cancer cell survival while sparing normal cells hence they can potentially be the silver bullets for targeting cancer growth and metastatic progression.

Role of Phytochemicals in Cancer Prevention

The use of synthetic, natural, or biological agents to minimize the occurrence of cancer in healthy individuals is defined as cancer chemoprevention. Chemopreventive agents inhibit the development of cancer either by impeding DNA damage, which leads to malignancy or by reversing or blocking the division of premalignant cells with DNA damage. The benefit of this approach has been demonstrated in clinical trials of breast, prostate, and colon cancer. The continuous increase in cancer cases, failure of conventional chemotherapies to control cancer, and excessive toxicity of chemotherapies clearly demand an alternative approach. The first trial to show benefit of chemoprevention was undertaken in breast cancer patients with the use of tamoxifen, which demonstrated a significant decrease in invasive breast cancer. The success of using chemopreventive agents for protecting the high risk populations from cancer indicates that the strategy is rational and promising. Dietary components such as capsaicin, cucurbitacin B, isoflavones, catechins, lycopenes, benzyl isothiocyanate, phenethyl isothiocyanate, and piperlongumine have demonstrated inhibitory effects on cancer cells indicating that they may serve as chemopreventive agents. In this review, we have addressed the mechanism of chemopreventive and anticancer effects of several natural agents.

Benzyl isothiocyanate suppresses development and metastasis of murine mammary carcinoma by regulating the Wnt/β‑catenin pathway

Benzyl isothiocyanate (BITC) has been reported to exhibit antitumor properties in various cancer types; however, the underlying mechanisms of its action remain unclear. In the present study, the efficacy of BITC on murine mammary carcinoma cells was evaluated in vitro and in vivo, revealing a potential mechanism for its action. In vivo bioluminescence imaging indicated dynamic inhibition of murine mammary carcinoma cell growth and metastasis by BITC. A terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay demonstrated that BITC also induced apoptosis. BITC further exhibited antitumorigenic activity in 4T1-Luc cells in vitro via the inhibition of cell proliferation, induction of apoptosis and cell cycle arrest, and inhibition of cell migration and invasion. Furthermore, the activity of key molecules of the adenomatous polyposis coli (APC)/β-catenin complex was altered following treatment with BITC, which suggested a potential role for the APC/β-catenin complex in the BITC-mediated induction of apoptosis and inhibition of metastasis in murine mammary carcinoma. BITC upregulated the activity of glycogen synthase kinase-3β and APC proteins, whereas it downregulated β-catenin expression. The inhibition of metastasis was accompanied with the downregulation of vimentin and upregulation of E-cadherin. Conversely, BITC did not exhibit toxicity or side effects in the normal mammary epithelial cell line MCF-10A. The present study indicated that BITC exhibited anticancer properties due to the induction of breast cancer cell apoptosis and inhibition of breast cancer cell metastasis mediated by the Wnt/β-catenin signaling pathway.

Anti-Carcinogenic Glucosinolates in Cruciferous Vegetables and Their Antagonistic Effects on Prevention of Cancers

Glucosinolates (GSL) are naturally occurring β-d-thioglucosides found across the cruciferous vegetables. Core structure formation and side-chain modifications lead to the synthesis of more than 200 types of GSLs in Brassicaceae. Isothiocyanates (ITCs) are chemoprotectives produced as the hydrolyzed product of GSLs by enzyme myrosinase. Benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC) and sulforaphane ([1-isothioyanato-4-(methyl-sulfinyl) butane], SFN) are potential ITCs with efficient therapeutic properties. Beneficial role of BITC, PEITC and SFN was widely studied against various cancers such as breast, brain, blood, bone, colon, gastric, liver, lung, oral, pancreatic, prostate and so forth. Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a key transcription factor limits the tumor progression. Induction of ARE (antioxidant responsive element) and ROS (reactive oxygen species) mediated pathway by Nrf2 controls the activity of nuclear factor-kappaB (NF-κB). NF-κB has a double edged role in the immune system. NF-κB induced during inflammatory is essential for an acute immune process. Meanwhile, hyper activation of NF-κB transcription factors was witnessed in the tumor cells. Antagonistic activity of BITC, PEITC and SFN against cancer was related with the direct/indirect interaction with Nrf2 and NF-κB protein. All three ITCs able to disrupts Nrf2-Keap1 complex and translocate Nrf2 into the nucleus. BITC have the affinity to inhibit the NF-κB than SFN due to the presence of additional benzyl structure. This review will give the overview on chemo preventive of ITCs against several types of cancer cell lines. We have also discussed the molecular interaction(s) of the antagonistic effect of BITC, PEITC and SFN with Nrf2 and NF-κB to prevent cancer.

Gene prioritization, communality analysis, networking and metabolic integrated pathway to better understand breast cancer pathogenesis

Consensus strategy was proved to be highly efficient in the recognition of gene-disease association. Therefore, the main objective of this study was to apply theoretical approaches to explore genes and communities directly involved in breast cancer (BC) pathogenesis. We evaluated the consensus between 8 prioritization strategies for the early recognition of pathogenic genes. A communality analysis in the protein-protein interaction (PPi) network of previously selected genes was enriched with gene ontology, metabolic pathways, as well as oncogenomics validation with the OncoPPi and DRIVE projects. The consensus genes were rationally filtered to 1842 genes. The communality analysis showed an enrichment of 14 communities specially connected with ERBB, PI3K-AKT, mTOR, FOXO, p53, HIF-1, VEGF, MAPK and prolactin signaling pathways. Genes with highest ranking were TP53, ESR1, BRCA2, BRCA1 and ERBB2. Genes with highest connectivity degree were TP53, AKT1, SRC, CREBBP and EP300. The connectivity degree allowed to establish a significant correlation between the OncoPPi network and our BC integrated network conformed by 51 genes and 62 PPi. In addition, CCND1, RAD51, CDC42, YAP1 and RPA1 were functional genes with significant sensitivity score in BC cell lines. In conclusion, the consensus strategy identifies both well-known pathogenic genes and prioritized genes that need to be further explored.

Benzyl isothiocyanate (BITC) triggers mitochondria-mediated apoptotic machinery in human cisplatin-resistant oral cancer CAR cells

Benzyl isothiocyanate (BITC), a component of dietary food, possesses a powerful anticancer activity. Previous studies have shown that BITC produces a large number of intracellular reactive oxygen species (ROS) and increases intracellular Ca²⁺ release from endoplasmic reticulum (ER), leading to the activation of the apoptotic mechanism in tumor cells. However, there is not much known regarding the inhibitory effect of BITC on cisplatin-resistant oral cancer cells. The purpose of this study was to examine the anticancer effect and molecular mechanism of BITC on human cisplatin-resistant oral cancer CAR cells. Our results demonstrated that BITC significantly reduced cell viability of CAR cells in a concentration- and time-dependent manner. BITC was found to cause apoptotic cell shrinkage and DNA fragmentation by morphologic observation and TUNEL/DAPI staining. Pretreatment of cells with a specific inhibitor of pan-caspase significantly reduced cell death caused by BITC. Colorimetric assay analyses also showed that the activities of caspase-3 and caspase-9 were elevated in BITC-treated CAR cells. An increase in ROS production and loss of mitochondria membrane potential (ΔΨm) occurred due to BITC exposure and was observed via flow cytometric analysis. Western blotting analyses demonstrated that the protein levels of Bax, Bad, cytochrome c, and cleaved caspase-3 were up-regulated, while those of Bcl-2, Bcl-xL and pro-caspase-9 were down-regulated in CAR cells after BITC challenge. In sum, the mitochondria-dependent pathway might contribute to BITC-induced apoptosis in human cisplatin-resistant oral cancer CAR cells.

Mechanistic evaluation of phytochemicals in breast cancer remedy: current understanding and future perspectives

Breast cancer is one of the most commonly diagnosed cancers around the globe and accounts for a large proportion of fatalities in women. Despite the advancement in therapeutic and diagnostic procedures, breast cancer still represents a major challenge. Current anti-breast cancer approaches include surgical removal, radiotherapy, hormonal therapy and the use of various chemotherapeutic drugs. However, drug resistance, associated serious adverse effects, metastasis and recurrence complications still need to be resolved which demand safe and alternative strategies. In this scenario, phytochemicals have recently gained huge attention due to their safety profile and cost-effectiveness. These phytochemicals modulate various genes, gene products and signalling pathways, thereby inhibiting breast cancer cell proliferation, invasion, angiogenesis and metastasis and inducing apoptosis. Moreover, they also target breast cancer stem cells and overcome drug resistance problems in breast carcinomas. Phytochemicals as adjuvants with chemotherapeutic drugs have greatly enhanced their therapeutic efficacy. This review focuses on the recently recognized molecular mechanisms underlying breast cancer chemoprevention with the use of phytochemicals such as curcumin, resveratrol, silibinin, genistein, epigallocatechin gallate, secoisolariciresinol, thymoquinone, kaempferol, quercetin, parthenolide, sulforaphane, ginsenosides, naringenin, isoliquiritigenin, luteolin, benzyl isothiocyanate, α-mangostin, 3,3'-diindolylmethane, pterostilbene, vinca alkaloids and apigenin.

Differentiating Antiproliferative and Chemopreventive Modes of Activity for Electron-Deficient Aryl Isothiocyanates against Human MCF-7 Cells

The consumption of Brassica vegetables provides beneficial effects through organic isothiocyanates (ITCs), products of the enzymatic hydrolysis of glucosinolate secondary metabolites. The ITC l-sulforaphane (l-SFN) is the principle agent in broccoli that demonstrates several modes of anticancer action. While the anticancer properties of ITCs like l-SFN have been extensively studied and l-SFN has been the subject of multiple human clinical trials, the scope of this work has largely been limited to those derivatives found in nature. Previous studies have demonstrated that structural changes in an ITC can lead to marked differences in a compound's potency to 1) inhibit the growth of cancer cells, and 2) alter cellular transcriptional profiles. This study describes the preparation of a library of non-natural aryl ITCs and the development of a bifurcated screening approach to evaluate the dose- and time-dependence on antiproliferative and chemopreventive properties against human MCF-7 breast cancer cells. Antiproliferative effects were evaluated using a commercial MTS cell viability assay. Chemopreventive properties were evaluated using an antioxidant response element (ARE)-promoted luciferase reporter assay. The results of this study have led to the identification of 1) several key structure-activity relationships and 2) lead ITCs for continued development.

Wasabi 6-(methylsulfinyl)hexyl isothiocyanate induces apoptosis in human colorectal cancer cells through p53-independent mitochondrial dysfunction pathway

6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC), a major bioactive compound in Wasabi [Wasabia japonica (Miq.) Matsum.], has revealed the inhibitory effect on colon carcinogenesis in rat cancer model although the underlying mechanism is unclear. In this study, we used two types of human colorectal cancer cells (HCT116 p53+/+ and HCT116 p53-/- ) to investigate the anticancer activity and molecular mechanisms of 6-MSITC. Interestingly, 6-MSITC inhibited the cell proliferation in both types of cells with similar IC50 value although a light increase in the phosphorylation and accumulation of P53 protein was observed in HCT116 p53+/+ cells at 24 h after treatment. In addition, 6-MSITC increased the ratio of proapoptotic cells in both types of cells with the same fashion in a p53-independent manner. The data from mitochondrial analysis revealed that 6-MSITC enhanced the ratio of proapoptotic B-cell lymphoma-2-associated X protein/antiapoptotic myeloid cell leukemia 1, and sequentially caused mitochondrial membrane potential (ΔΨm ) loss, cytochrome c release, and caspase-3 activation in both types of cells. Taken together, Wasabi 6-MSITC induced apoptosis of human colorectal cancer cells in p53-independent mitochondrial dysfunction pathway. These findings suggest that 6-MSITC might be a potential agent for colon cancer chemoprevention although with p53 mutation. © 2018 BioFactors, 2018.

Concomitant activation of ETS-like transcription factor-1 and Death Receptor-5 via extracellular signal-regulated kinase in withaferin A-mediated inhibition of hepatocarcinogenesis in mice

Hepatocellular carcinoma (HCC) has the second lowest 5-year survival rate (~16%) of all tumor types partly owing to the lack of effective therapeutic agents. Withaferin A (WA) is a bioactive molecule derived from Withania somnifera and the present study is designed to systemically investigate the anti-HCC efficacy of WA. WA inhibited growth, migration and invasion of HCC cells. Using a phospho-kinase screening array, we discovered that WA increased phosphorylation of ERK and p38 in HCC. Further analyses revealed a key role of ERK leading to increased phosphorylation of p90-ribosomal S6 kinase (RSK) and a concomitant activation of ETS-like transcription factor-1(ELK1) and Death Receptor protein-5 (DR5) in HCC. Importantly, oral administration of WA effectively inhibited HepG2-xenografts and DEN-induced-HCC in C57BL/6 mice. Analyses of WA-treated HepG2-xenografts and DEN-induced-HCC tumors showed elevated levels of ERK, RSK, ELK1 and DR5 along with decreased expression of Ki67. In silico analyses of HCC, utilizing published profiling studies showed an inverse correlation between DR5 and Ki67. These data showed the efficacy of WA as an effective agent for HCC inhibition and provided first in vitro and in vivo evidence supporting the key role of a novel crosstalk between WA, ERK/RSK, ELK1, and DR5 in HCC inhibition.

PRAS40 signaling in tumor

The proline-rich Akt substrate of 40 kDa (PRAS40) is a substrate of Akt and a component of the mammalian target of rapamycin complex 1 (mTORC1). Locating at the crossroad of the PI3K/Akt pathway and the mTOR pathway, PRAS40 is phosphorylated by growth factors or other stimuli, and regulates the activation of these signaling pathways in turn. PRAS40 plays an important role in metabolic disorders and multiple cancers, and the phosphorylation of PRAS40 is often associated with the tumor progression of melanoma, prostate cancer, etc. PRAS40 promotes tumorigenesis by deregulating cellular proliferation, apoptosis, senescence, metastasis, etc. Herein, we provide an overview on current understandings of PRAS40 signaling in the tumor formation and progression, which suggests that PRAS40 or phospho-PRAS40 could become a novel biomarker and therapeutic target in tumor.