Epigenetic deregulation in cancer: Enzyme players and non-coding RNAs.

Data obtained from cutting-edge research have shown that deregulated epigenetic marks are critical hallmarks of cancer. Rapidly emerging scientific evidence has helped in developing a proper understanding of the mechanisms leading to control of cellular functions, from changes in chromatin accessibility, transcription and translation, and in post-translational modifications. Firstly, mechanisms of DNA methylation and demethylation are introduced, as well as modifications of DNA and RNA, with particular focus on N6-methyladenosine (m6A), discussing the effects of these modifications in normal cells and in malignancies. Then, chromatin modifying proteins and remodelling complexes are discussed. Many enzymes and accessory proteins in these complexes have been found mutated or have undergone differential splicing, leading to defective protein complexes. Epigenetic mechanisms acting on nucleosomes by polycomb repressive complexes and on chromatin by SWI/SNF complexes on nucleosome assembly/disassembly, as well as main mutated genes linked to cancers, are reviewed. Among enzymes acting on histones and other proteins erasing the reversible modifications are histone deacetylases (HDACs). Sirtuins are of interest since most of these enzymes not only deacylate histones and other proteins, but also post-translationally modify proteins adding a Mono-ADP-ribose (MAR) moiety. MAR can be read by MACRO-domain containing proteins such as histone MacroH2A1, with specific function in chromatin assembly. Finally, recent advances are presented on non-coding RNAs with a scaffold function, prospecting their role in assembly of chromatin modifying complexes, recruiting enzyme players to chromatin regions. Lastly, the imbalance in metabolites production due to mitochondrial dysfunction is presented, with the potential of these metabolites to inhibit enzymes, either writers, readers or erasers of epitranscriptome marks. In the perspectives, studies are overwied on drugs under development aiming to limit excessive enzyme activities and to reactivate chromatin modifying complexes, for therapeutic application. This knowledge may lead to novel drugs and personalised medicine for cancer patients.

Regulation of Cell Signaling Pathways by Genistein in Different Cancers: Progress, Prospects and Pitfalls.

On the translational front, integrative genomic approaches have spurred the identification of diverse mechanisms of drug resistance, tumor heterogeneity, metastasis and emerging preclinical targets. Recent breakthroughs in oncogenic cell signaling pathways have forged new links and multi-disciplinary researchers have unraveled different facets of signaling landscapes. Natural product research has witnessed breakneck developments mainly in the context of the ever-expanding list of bioactive components having significantly pharmacological properties. Genistein has gradually gained appreciation because of its multifaceted roles in the prevention and inhibition of carcinogenesis and metastasis. More importantly, the entry of genistein into various phases of clinical trials substantiates the medicinal and pharmacological significance of genistein in cancer chemoprevention. In this review, we have attempted to summarize how genistein regulated different oncogenic pathways in carcinogenesis and metastasis. Furthermore, genistein-mediated regulation of non-coding RNAs is also an interesting feature that has been included in this review to realistically analyze how genistein-mediated control of miRNAs, lncRNAs and circRNAs influence carcinogenesis. In the later sections, we have provided a summary of clinical trials related to genistein for cancer prevention/inhibition. However, apart from the optimistic approaches to further investigate genistein-mediated cancer-inhibitory effects, certain hints have emerged which underscore the pro-metastatic role of genistein. Therefore, the pro-metastatic role of genistein in different cancers should be rationally tested in a broader context because these properties in the future may reduce the enthusiasm in the quest to pursue genistein as a potent cancer chemopreventive agent.

MicroRNA regulation of TRAIL mediated signaling in different cancers: Control of micro steering wheels during the journey from bench-top to the bedside.

Large-scale sequencing methodologies have helped us identify numerous genomic alterations and we have started to scratch the surface of many new targets for treatment of cancer and the associated predictive biomarkers. TRAIL (TNF-related apoptosis-inducing ligand) is a highly appreciated anti-cancer molecule because of its ability to selectively target cancer cells. However, confluence of information suggests that cancer cells develop resistance against TRAIL-based therapeutics. It is being realized that overexpression of anti-apoptotic proteins and inactivation of pro-apoptotic proteins significantly impairs TRAIL triggered apoptosis, particularly in clinical settings. Re-balancing of pro-and anti-apoptotic proteins and upregulation of death receptors with functionally active extrinsic and intrinsic apoptotic pathways are necessary to sensitize cancer cells to TRAIL based therapeutics. microRNAs (miRNAs) are involved in regulation of myriad of molecular processes and characterized into oncogenic and tumor suppressor miRNAs. Accumulating data has identified miRNAs which positively or negatively regulate TRAIL mediated signaling in cancer cells, helping us understand different steps at which TRAIL-mediated apoptotic signaling can be targeted. Here, we assess the status of our understanding of the mechanisms related to miRNA regulation of TRAIL mediated signaling, as well as the existing gaps therein, and discuss the challenges and opportunities that will help us get closer to personalized medicine.

Interplay between epigenetic abnormalities and deregulated expression of microRNAs in cancer.

Epigenetic abnormalities and aberrant expression of non-coding RNAs are two emerging features of cancer cells, both of which are responsible for deregulated gene expression. In this review, we describe the interplay between the two. Specific themes include epigenetic silencing of tumor suppressor miRNAs, epigenetic activation of oncogenic miRNAs, epigenetic aberrations caused by miRNAs, and naturally occurring compounds which modulate miRNA expression through epigenetic mechanisms.

Oxidative stress-modulating drugs have preferential anticancer effects - involving the regulation of apoptosis, DNA damage, endoplasmic reticulum stress, autophagy, metabolism, and migration.

To achieve preferential effects against cancer cells but less damage to normal cells is one of the main challenges of cancer research. In this review, we explore the roles and relationships of oxidative stress-mediated apoptosis, DNA damage, ER stress, autophagy, metabolism, and migration of ROS-modulating anticancer drugs. Understanding preferential anticancer effects in more detail will improve chemotherapeutic approaches that are based on ROS-modulating drugs in cancer treatments.

MicroRNA-143 as a new weapon against cancer: overview of the mechanistic insights and long non-coding RNA mediated regulation of miRNA-143 in different cancers.

Central dogma of molecular biology, a term coined by Francis Crick in 1958 was considered to be the cornerstone of molecular biology unless molecular biologists challenged the idea after ground-breaking discovery of non-coding RNAs. Discovery of microRNAs marked a new era and revolutionized our understanding related to puzzling mysteries about intermediate steps between transcription and translation. Technological advancements have spawned a multitude of platforms for profiling of long-noncoding RNAs and miRNAs in different cancers. Detailed investigation of mRNA targets of miRNAs has enabled high-order analyses of interconnected networks and revealed affected pathways in different cancers. miR-143 has emerged as a multi-talented tumor suppressor microRNA having considerable ability to inhibit and prevent cancer via regulation of myriad of oncogenes. In this review, we will summarize most recent evidence related to characteristically unique ability of miR-143 to target different oncogenic mRNAs in different cancers. We will also comprehensively discuss how scientists have identified multiple long non-coding RNAs reportedly involved in promoting the expression of oncogenes by interfering with miR-143 mediated targeting of these oncogenes. Because of excellent ability of miR-143 to effectively target oncogenic mRNAs, researchers have started to focus on use of miR-143 mimics to restore expression of miR-143 in various cancers.

Regulation of signaling pathways by Ampelopsin (Dihydromyricetin) in different cancers: exploring the highways and byways less travelled.

Ampelopsin or Dihydromyricetin is gradually emerging as a high-quality natural product because of its ability to modulate wide-ranging signaling pathways. Ampelopsin (Dihydromyricetin) has been reported to effectively modulate growth factor receptor (VEGFR2 and PDGFRß) mediated signaling,  TRAIL/TRAIL-R pathway, JAK/STAT and mTOR-driven signaling in different cancers. Ampelopsin (Dihydromyricetin) has also been shown to exert inhibitory effects on the versatile regulators which trigger EMT (Epithelial-to-Mesenchymal Transition). Findings obtained from in-vitro studies are encouraging and there is a need to comprehensively analyze how Ampelopsin (Dihydromyricetin) inhibits tumor growth in different cancer models. Better knowledge of efficacy of Ampelopsin (Dihydromyricetin) in tumor bearing mice will be helpful in maximizing its translational potential.

Interplay of long non-coding RNAs and TGF/SMAD signaling in different cancers.

Based on the exciting insights gleaned from decades of ground-breaking research, it has become evident that deregulated signaling pathways play instrumental role in cancer development and progression. Interestingly discovery of non-coding RNAs has revolutionized our understanding related to transcription, post-transcription and translation. Modern era has witnessed landmark discoveries in the field of molecular cancer and non-coding RNA biology has undergone tremendous broadening. There has been an exponential growth in the list of publications related to non-coding RNAs and overwhelmingly increasing classes of non-coding RNAs are adding new layers of complexity to already complicated nature of cancer. Regulation of TGF/SMAD signaling by miRNAs and LncRNAs has opened new horizons for therapeutic targeting of TGF/SMAD pathway. In this review we have set spotlight on central role of LncRNAs in modulation of TGF/SMAD pathway. Major proportion of the available evidence is underlining positive role of LncRNAs in contextual regulation of TGF/SMAD pathway. LncRNAs are vital to these regulatory networks because they provide a background support to make the TGF/SMAD mediated intracellular signaling more smooth or make transduction cascade more flexible in response to cues from extracellular environment. Therefore, in accordance with this notion, MALAT1, OIP5-AS1, MIR100HG, HOTAIR, ANRIL, PVT1, AFAP1-AS1, SPRY4-IT, ZEB2NAT, TUG1 and Lnc-SNHG1 have been reported to positively regulate TGF/SMAD signaling. In this review, we have focused on the regulation of TGF/SMAD signaling by LncRNAs and how these non-coding RNAs can be therapeutically exploited. Short-interfering RNA (siRNA) and natural products are currently being tested for efficacy against different LncRNAs. Nanotechnological strategies to efficiently deliver LncRNA-targeting siRNAs are also currently being investigated in different cancers.

Restoring TRAIL Induced Apoptosis Using Naturopathy. Hercules Joins Hand with Nature to Triumph Over Lernaean Hydra.

Cancer is a multifaceted disease. Our deepened knowledge about genetic and biological mechanisms of cancer cells presents an opportunity to explore the inter-individual differences in the body's ability to metabolize and respond to different nutrients. It is becoming progressively more understandable that the deregulation of several signaling pathways and the alterations in apoptotic response are some of the major determinants that underpin carcinogenesis. Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL)-mediated signaling has gained a remarkable appreciation because of its ability to selectively induce apoptosis in cancer cells leaving normal cells intact. However, technological advances have started to shed light on underlying mechanisms of resistance against TRAIL-induced apoptosis in cancer cells. The impairment of TRAIL-mediated apoptosis includes various factors ranging from the loss or down regulation of TRAIL receptors or pro-apoptotic proteins to the up regulation of anti-apoptotic proteins. Intriguingly to mention that there is an ever-increasing number of natural herbal extracts (phytometabolites), which have been explored to date for their potential action in restoring apoptosis TRAIL-mediated in cancer cells. In this review, we will highlight the progress in understanding the mechanisms opted by phenolic compounds in overcoming TRAIL resistance.

TRAIL, Wnt, Sonic Hedgehog, TGFß, and miRNA Signalings Are Potential Targets for Oral Cancer Therapy.

Clinical studies and cancer cell models emphasize the importance of targeting therapies for oral cancer. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is highly expressed in cancer, and is a selective killing ligand for oral cancer. Signaling proteins in the wingless-type mouse mammary tumor virus (MMTV) integration site family (Wnt), Sonic hedgehog (SHH), and transforming growth factor ß (TGFß) pathways may regulate cell proliferation, migration, and apoptosis. Accordingly, the genes encoding these signaling proteins are potential targets for oral cancer therapy. In this review, we focus on recent advances in targeting therapies for oral cancer and discuss the gene targets within TRAIL, Wnt, SHH, and TGFß signaling for oral cancer therapies. Oncogenic microRNAs (miRNAs) and tumor suppressor miRNAs targeting the genes encoding these signaling proteins are summarized, and the interactions between Wnt, SHH, TGFß, and miRNAs are interpreted. With suitable combination treatments, synergistic effects are expected to improve targeting therapies for oral cancer.

Oleuropein and Cancer Chemoprevention: The Link is Hot.

Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

Anticancer drugs for the modulation of endoplasmic reticulum stress and oxidative stress.

Prior research has demonstrated how the endoplasmic reticulum (ER) functions as a multifunctional organelle and as a well-orchestrated protein-folding unit. It consists of sensors which detect stress-induced unfolded/misfolded proteins and it is the place where protein folding is catalyzed with chaperones. During this folding process, an immaculate disulfide bond formation requires an oxidized environment provided by the ER. Protein folding and the generation of reactive oxygen species (ROS) as a protein oxidative byproduct in ER are crosslinked. An ER stress-induced response also mediates the expression of the apoptosis-associated gene C/EBP-homologous protein (CHOP) and death receptor 5 (DR5). ER stress induces the upregulation of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) receptor and opening new horizons for therapeutic research. These findings can be used to maximize TRAIL-induced apoptosis in xenografted mice. This review summarizes the current understanding of the interplay between ER stress and ROS. We also discuss how damage-associated molecular patterns (DAMPs) function as modulators of immunogenic cell death and how natural products and drugs have shown potential in regulating ER stress and ROS in different cancer cell lines. Drugs as inducers and inhibitors of ROS modulation may respectively exert inducible and inhibitory effects on ER stress and unfolded protein response (UPR). Reconceptualization of the molecular crosstalk among ROS modulating effectors, ER stress, and DAMPs will lead to advances in anticancer therapy.

Penetrance and phenotypic effects of C/T polymorphism at 1595 position in exon 5 of the TRAIL gene among prostate cancer patients in Pakistani population.

It is becoming progressively more understandable that variations within the sequence of tumor suppressor genes and oncogenes may contribute to cancer progression. Increasingly it is being realized that cancer cells get resistant to pro-apoptotic signals and evidence has started to shed light on the fact that nucleotide polymorphisms may lead to suboptimal apoptotic capacity and therefore increased cancer risk. It has previously been shown that there is a relationship between C/T polymorphism at 1595 position in exon 5 of the TRAIL gene and cancer however rapidly accumulating data cannot be extrapolated to other populations due to intra- and inter-ethnic variability. The study is focused on the C/T polymorphism at 1595 position in exon 5 of the TRAIL gene in prostate cancer patients diagnosed in local population in Pakistan. 126 prostate cancer patients and 91 control subjects participated in this study. 5ml venous blood was taken from participants with informed consent. DNA was extracted using standard organic methods. PCR-RFLP analysis was done for C/T polymorphism at 1595 position in exon 5 of the TRAIL gene using site specific primers and restriction enzyme. The results were statistically evaluated in SPSS14. In this particular study it was found that there was no significant difference in major allele C genotype between patients and controls, p value > 0.05. Similar statistically non-significant difference was observed for T allele genotype in the patient and control groups. However the heterozygous genotype CT was significantly higher, p value 0.053 (-0.05), in prostate cancer patients as compared to controls. This is the first study providing a clue of relationship of C/T polymorphism role in prostate cancer development and progression in our population.

Rutin mediated targeting of signaling machinery in cancer cells.

Progress in our understanding of molecular oncology has started to shed light on dysregulation of spatio-temporally controlled signaling pathways, inactivation of tumor suppressor genes, tumour and normal stem cell quiescence, overexpression of oncogenes, extracellular and stromal microenvironments, epigenetics and autophagy. Sequentially and characteristically it has been shown that cancer cells acquire the ability to escape from apoptotic cell death, proliferate uncontrollably, sustain angiogenesis and tactfully reconstitute intracellular pathways to avoid immune surveillance. We have attempted to provide a recent snapshot of most recent progress with emphasis on how rutin modulates wide ranging intracellular signaling cascades as evidenced by in-vitro and in-vivo research. It is worth describing that 'single-cell proteomics' analysis has further improved our understanding regarding intracellular signaling pathways frequently activated in cancer cells resistant to therapeutics and can provide biomarkers for cancer diagnosis and prognosis. Data obtained from preclinical studies will prove to be helpful for scientists to bridge basic and translational studies.

Hepatocellular carcinoma: targeting of oncogenic signaling networks in TRAIL resistant cancer cells.

Apoptotic response in hepatocellular carcinoma (HCC) cells is impaired because of interconnectivity of proteins into complexes and signaling networks that are highly divergent in time and space. TNF-related apoptosis-inducing ligand (TRAIL) has emerged as an attractive anticancer agent reported to selectively induce apoptosis in cancer cells. Although diametrically opposed roles of TRAIL are reported both as an inducer of apoptosis and regulator of metastasis, overwhelmingly accumulating experimental evidence highlighting apoptosis inducing activity of TRAIL is directing TRAIL into clinical trials. Insights from TRAIL mediated signaling in HCC research are catalyzing new lines of study that should not only explain molecular mechanisms of disease but also highlight emerging paradigms in restoration of TRAIL mediated apoptosis in resistant cancer cells. It is becoming progressively more understandable that phytochemicals derived from edible plants have shown potential in modelling their interactions with their target proteins. Rapidly accumulating in vitro and in-vivo evidence indicates that phytonutrients have anticancer activity in rodent models of hepatocellular carcinoma. In this review we bring to limelight how phytonutrients restore apoptosis in hepatocellular carcinoma cells by rebalancing pro-apoptotic and anti-apoptotic proteins. Evidence has started to emerge, that reveals how phytonutrients target pharmacologically intractable proteins to suppress cancer. Target-based small-molecule discovery has entered into the mainstream research in the pharmaceutical industry and a better comprehension of the genetics of patients will be essential for identification of responders and non-responders.

Reactive oxygen species and autophagy modulation in non-marine drugs and marine drugs.

It is becoming more understandable that an existing challenge for translational research is the development of pharmaceuticals that appropriately target reactive oxygen species (ROS)-mediated molecular networks in cancer cells. In line with this approach, there is an overwhelmingly increasing list of many non-marine drugs and marine drugs reported to be involved in inhibiting and suppressing cancer progression through ROS-mediated cell death. In this review, we describe the strategy of oxidative stress-based therapy and connect the ROS modulating effect to the regulation of apoptosis and autophagy. Finally, we focus on exploring the function and mechanism of cancer therapy by the autophagy modulators including inhibitors and inducers from non-marine drugs and marine drugs.

miRNA and TMPRSS2-ERG do not mind their own business in prostate cancer cells.

Oncogenic fusion proteins belong to an important class that disrupts gene expression networks in a cell. Astonishingly, fusion-positive prostate cancer cells enable the multi-gene regulatory capability of miRNAs to remodel the signal transduction landscape, enhancing or antagonizing the transmission of information to downstream effectors. Accumulating evidence substantiates the fact that miRNAs translate into dose-dependent responsiveness of cells to signaling regulators in transmembrane protease serine 2:ETS-related gene (TMPRSS2-ERG)-positive cells. Wide ranging signaling proteins are the targets for the degree of quantitative fluctuations imposed by miRNAs. miRNA signatures are aberrantly expressed in fusion-positive cancer cells, suggesting that they have a cumulative effect on tumor aggressiveness. It seems attractive to note that TMPRSS2:ERG fusion has a stronger effect as tumors positive for the oncogenic TMPRSS2:ERG have dysregulated oncomirs and tumor suppressor miRNA signature. It is undeniable that a comprehensive analysis of the prostate cancer microRNAome is necessary to uncover novel microRNAs and pathways associated with prostate cancer. Moreover, the identification and validation of miRNA signature in TMPRSS2-ERG-positive prostate cancer cells may help to identify novel molecular targets and pathways for personalized therapy.

Re-evaluating the FGFR4 (G388R) germline mutation in different cancers in Pakistani population.

BACKGROUND: Cancer is a life threatening complicated diseasethatarises because of wide-ranging environmental and cellular factors. These external and internal stresses disrupt the spatio-temporally controlled mechanisms of the cellular signalings. Accumulating evidence suggests that signal transductions are misrepresented in carcinogenesis and FGFR4 is reported to be involved in carcinogenesis. Although there is considerable evidence emphasizing the relationship between FGFR4 (G388R) mutation and carcinogenesis however rapidly accumulating data cannot be extrapolated to Pakistani population due to intra- and inter-ethnic variability. OBJECTIVE: The study is focused on the trans-membrane mutation G388R of FGFR4 genes among different types of cancers diagnosed in local population in Pakistan. METHODS: 103 breast cancer patients, 56 Lung cancer patients (both Small Cell and Non Small Cell) and 45 control subjects participated in this study. Sample of 5-ml venous blood was taken from participants with informed consent. DNA was extracted and PCR-RFLP analysis was done for G388R mutation in FGFR4 gene using site specific primers and restriction enzyme. The results were statistically evaluated in SPSS14. RESULTS: The genotypes of G388R in FGFR4 gene were in Hardy-Weinberg equilibrium. The percentage of normal homozygotes GG was found to be (48.5%) in breast cancer, (51.8%) in lung cancer. Glycine/arginine was (36.9%) in breast cancer, (42.9%) in lung cancer. CONCLUSION: We were unable to find a possible correlation between FGFR4 G388R mutation and different cancers in local population.

Breast cancer proteome takes more than two to tango on TRAIL: beat them at their own game.

Breast carcinogenesis is a multidimensional disease that has resisted drug-related solutions to date because of heterogeneity, disorganized spatiotemporal behavior of signal transduction cascades, cell cycle checkpoints, cell transition, plasticity, and impaired pro-apoptotic response. These synchronized oncogenic events, including protein-protein interaction, transcriptional-regulatory, and signaling networks, trigger genomic and transcriptional disturbances in TRAIL-mediated signaling network neighborhoods. Therefore, tumor cells often acquire the ability to escape death by suppressing cell death pathways that normally function to eliminate damaged and harmful cells. This review describes the TRAIL-mediated cell death signaling pathways, the interactions between these pathways, and the ways in which these pathways are deregulated in breast cancer.

Upon the tightrope in prostate cancer: two acrobats on the same tightrope to cross the finishline.

Prostate cancer is a multifactorial, multistep progressive disorder that is undruggable to date because of stumbling blocks in the standardization of therapy. It is triggered by a broad range of proteins, signaling networks and DNA damage response modulators. It is becoming increasingly apparent that DNA repair mediators have split personalities, as they are instrumental in suppressing and promoting carcinogenesis. In this article, we discuss on post-transcriptional processing of regulators of DNA damage response, and how DNA repair proteins trigger shuttling of androgen receptor. Substantial fraction of information has been added into the existing literature of ATM biology; however, the particular area of post-transcriptional processing errors and gene therapy for reprogramming of ATM has been left unaddressed in prostate cancer. It is therefore noteworthy that the facet of targeting strategy, antisense morpholino oligonucleotides chemistry, and systematic delivery of AOs has promising outlook in splice-targeted antisense-mediated therapy.