Mechanistic role of pyroptosis in tumor microenvironment and tumor immunotherapy.

In recent decades, extraordinary attention has been devoted to cell death pathways principally because of multifaceted regulatory roles in normal developmental and pathophysiological processes. The removal of functionally defective, infected or potentially malignant cells is regulated by programmed cell death (PCD) cascades.  Pyroptotic cell death is a highly complicated pro-inflammatory form of cell death. Pyroptosis is characterized by the formation of pores in the plasma membrane by oligomerization of the N-terminal fragment of gasdermins (gasdermin-NT) following the cleavage of gasdermin. Pyroptosis plays a pivotal role in the innate immune responses and mechanistically steered by inflammasome-mediated and inflammasome-independent cascades. In this review, we have comprehensively analyzed how different signaling pathways regulated pyroptosis in cancer inhibition and metastatic spread of cancer cells to the secondary sites. Comprehensive understanding of the interconnection between signaling pathways and pyroptosis will enable us to reap maximum benefits from the exciting mechanistic insights gained from pioneering studies related to pyroptosis.

Role of melatonin in carcinogenesis and metastasis: From mechanistic insights to intermeshed networks of noncoding RNAs.

In recent years, seminal studies have been devoted to unraveling the puzzling mysteries associated with the cancer preventive/inhibitory role of melatonin. Our current knowledge of the translational mechanisms and the detailed structural insights have highlighted the characteristically exclusive role of melatonin in the inhibition of carcinogenesis and metastatic dissemination. This mini-review outlines recent discoveries related to mechanistic role of melatonin in prevention of carcinogenesis and metastasis. Moreover, another exciting facet of this mini-review is related to phenomenal breakthroughs linked with regulation of noncoding RNAs by melatonin in wide variety of cancers.

Regulatory role of circular RNAs in oral squamous cell carcinoma.

OSCC is a genomically complicated disease and advancements in the modern era of molecular oncology have enabled researchers to portray near-to-complete resolution of signaling landscape. Over the last two decades, overwhelming proof-of-concept has established mechanistic regulatory role of non-coding RNAs in carcinogenesis, including OSCC. Circular RNAs demonstrate a burgeoning facet of oncology research and molecular biologists are only beginning to appreciate and recognize the significance of circRNAs in the pathogenesis of OSCC. Regulatory roles of non-coding RNAs in the re-shaping of signaling pathways offer plausible strategies for prevention/inhibition of OSCC. Circular RNAs have mechanistic roles in OSCC and "sponge effects" mediated by a wider variety of circRNAs need to be rationally targeted for effective cancer prevention. Phenomenal and cutting-edge research works in different types of animal models will further refine our knowledge for selection of most promising circRNAs as pharmacologically valuable targets.

Multifunctional role of Nobiletin in cancer chemoprevention.

The diversity of highly bioactive and pharmacologically active natural products which recognize essential biological targets having exquisite specificity, constitutes a massive pharmacological database for discovery of valuable drugs. The rapid accumulation of information has revealed chemopreventive role of nobiletin against wide variety of cancers. Recent efforts are now being expanded and new integrative omics technologies have illuminated continuously upgrading list of molecular mechanisms which underlie carcinogenesis and metastasis. In this mini-review, we explore the progress that has been made in the identification of promising molecular targets of nobiletin.

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.

Frontiers of Ferroptosis in Cancer Treatment.

Recent phenomenal advancements in genomic and proteomic technologies and rapid breakthroughs in the interpretation of large gene expression datasets have enabled scientists to comprehensively characterize the gene signatures involved in ferroptosis. Ferroptosis is an iron-dependent form of non-apoptotic cell death that has gained the worthwhile attention of both basic and clinical researchers. Ferroptosis has dichotomous, context-dependent functions both as a tumor suppressor and promoter of carcinogenesis. Essentially, pharmacological modulation of ferroptosis by its induction as well as its inhibition holds enormous potential to overcome drug resistance and to improve the therapeutic potential of chemotherapeutic drugs in a wide variety of cancers.

Overview of the signaling pathways involved in metastasis: An intriguing story-tale of the metastatic journey of ovarian cancer cells.

Wealth of information has revolutionized our understanding related to the genetics and functional genomics of this heterogeneous disease. Keeping in view the heterogeneity of ovarian cancer, long-term survival might be achieved by translation of recently emerging mechanistic insights at the cellular and molecular levels to personalize individual strategies for treatment and to identify biomarkers for early detection. Importantly, the motility and invasive properties of ovarian cancer cells are driven by a repertoire of signaling cascades, many components of which have been experimentally verified as therapeutic targets in preclinical models as well as in clinical trials. Scientific evidence garnered over decades of research has deconvoluted the highly intricate intertwined network of intracellular signaling pathways which played fundamental role in carcinogenesis and metastasis. In this review we have provided a compendium of myriad of signaling cascades which have been documented to play critical role in the progression and metastasis of ovarian cancer. We have partitioned this multi-component review into different sections to individually discuss and summarize the roles of TGF/SMAD, JAK/STAT, Wnt/ß-Catenin, NOTCH, SHH/GLI, mTORC1/mTORC2, VEGFR and Hippo/YAP pathways in ovarian cancer metastasis.

Apigenin as an effective anticancer natural product: Spotlight on TRAIL, WNT/ß-catenin, JAK-STAT pathways, and microRNAs.

Wealth of information gleaned from decades of high-impact research work; scientists have disentangled the complicated web of versatile regulators that underlie cancer development and progression. Use of structural biology approaches and functional genomics have helped us to gain new insights into complex nature of cancer, and it is now clear that genetic/epigenetic mutations, overexpression of oncogenes, inactivation of tumor suppressors, loss of apoptosis, and versatility of protein binding partners have contributory roles in carcinogenesis and metastatic spread. It is becoming progressively more understandable that reprogramming of gene expression during and nontranscriptional changes during cancer development and progression are initiated and controlled by deregulated signal transduction cascades, all of which collectively create an incalculable complexity. Data obtained through preclinical and clinical trials revealed that alterations in the targeted oncogenes and other downstream, and parallel pathways played a central role in the development of resistance against different therapeutics. Phytochemicals have regained limelight, and different natural products are currently being tested for efficacy in preclinical studies. Apigenin, a plant-derived flavonoid has considerable pharmacological value and is reportedly involved in the regulation of different signaling cascades. In this review, we have attempted to summarize rapidly evolving understanding of molecular biologists and pharmacologists about the potential of apigenin in the regulation of deregulated signaling pathways in different cancers. We have emphasized on the regulation of WNT/ß-catenin and janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. We also comprehensively discuss how apigenin restored apoptosis in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant cancers. The review also gives a snapshot of microRNAs (miRNAs) that regulate wide-ranging biological processes, and it is now clear that each miRNA can control hundreds of gene targets. Apigenin was noted to upregulate miR-520b and miR-101 in different cancers to inhibit tumor growth. Moreover, apigenin-induced apoptotic rate was significantly higher when used in combination with miR-423-5p inhibitors or miR-138 mimics. Better comprehension of linear and integrated signaling pathways will be helpful in effective therapeutic targeting of deregulated signaling pathways to inhibit/prevent cancer.

NEDD4 Family of E3 Ubiquitin Ligases in Breast Cancer: Spotlight on SMURFs, WWPs and NEDD4.

Massively parallel sequencing, genomic and proteomic technologies have provided near complete resolution of signaling landscape of breast cancer (BCa). NEDD4 family of E3-ubiquitin ligases comprises a large family of proteins particularly, SMURFs (SMURF1, SMURF2), WWPs and NEDD4 which are ideal candidates for targeted therapy. However, it is becoming progressively more understandable that SMURFs and NEDD4 have "split-personalities". These molecules behave dualistically in breast cancer and future studies must converge on detailed identification of context specific role of these proteins in BCa. Finally, we provide scattered clues of regulation of SMURF2 by oncogenic miRNAs, specifically considering longstanding questions related to regulation of SMURF1 and WWPs by miRNAs in BCa. SMURFS, WWPs and NEDD4 are versatile regulators and represent a fast-growing field in cancer research and better understanding of the underlying mechanisms will be helpful in transition of our knowledge from a segmented view to a more conceptual continuum.

Role of Autophagy in Breast Cancer Development and Progression: Opposite Sides of the Same Coin.

The term "autophagy", which means "self (auto) - eating (phagy)", describes a catabolic process that is evolutionarially conserved among all eukaryotes. Although autophagy is mainly accepted as a cell survival mechanism, it also modulates the process known as "type II cell death". AKT/mTOR pathway is an upstream activator of autophagy and it is tightly regulated by the ATG (autophagy-related genes) signaling cascade. In addition, wide ranging cell signaling pathways and non-coding RNAs played essential roles in the control of autophagy. Autophagy is closely related to pathological processes such as neurodegenerative diseases and cancer as well as physiological conditions. After the Nobel Prize in Physiology or Medicine 2016 was awarded to Yoshinori Ohsumi "for his discoveries of mechanisms for autophagy", there was an explosion in the field of autophagy and molecular biologists started to pay considerable attention to the mechanistic insights related to autophagy in different diseases. Since autophagy behaved dualistically, both as a cell death and a cell survival mechanism, it opened new horizons for a deeper analysis of cell type and context dependent behavior of autophagy in different types of cancers. There are numerous studies showing that the induction of autophagy mechanism will promote survival of cancer cells. Since autophagy is mainly a mechanism to keep the cells alive, it may protect breast cancer cells against stress conditions such as starvation and hypoxia. For these reasons, autophagy was noted to be instrumental in metastasis and drug resistance. In this chapter we have emphasized on role of role of autophagy in breast cancer. Additionally we have partitioned this chapter into exciting role of microRNAs in modulation of autophagy in breast cancer. We have also comprehensively summarized how TRAIL-mediated signaling and autophagy operated in breast cancer cells.

Emerging themes of regulation of oncogenic proteins by Solanum nigrum and its bioactive molecules in different cancers.

Research over the decades has sequentially and systematically provided a near-complete resolution of multifaceted and therapeutically challenging nature of cancer. Drug discovery from plants has enjoyed a renaissance in the past few years. Natural products have provided many of the lead structures, which are currently being used as templates for the design and synthesis of novel compounds with biologically enhanced properties. With the maturity and diversification of technologies, there is a growing need to design high-throughput functional assays for the evaluation of the myriad of compounds being catalogued. This review sheds light on the tumor suppressive properties of Solanum nigrum and its bioactive ingredients. Several worthy of mention include uttroside B, solanine, solamargine, and physalins, which have been tested for efficacy in cancer cell lines and xenografted mice. We have summarized the most recent findings related to S. nigrum-mediated regulation of intracellular protein network in different cancers. α-Solanine, an active component of S. nigrum, is involved in the regulation of microRNA-21 (miRNA-21) (oncogenic) and miRNA-138 (tumor suppressor) in prostate cancer. However, this is the only available evidence that gives us a clue related to the tumor suppressive effects exerted by components of S. nigrum at a posttranscriptional level. More interestingly, S. nigrum and its components exerted inhibitory effects on different pathways including PI3K/AKT, JAK-STAT, VEGF/VEGFR, and matrix metalloproteinases in different cancers. We also provide an overview of new tools, methodologies, and approaches, which will allow researchers to extract as much information as possible out of the tremendous data sets currently being generated. The use of computational tools will be helpful in processing structurally complex natural products and also in prediction of their macromolecular targets.

Prostate Cancer Stem Cells: Viewing Signaling Cascades at a Finer Resolution.

It is becoming characteristically more understandable that within tumor cells, there lies a sub-population of tumor cells with "stem cell" like properties and remarkable ability of self-renewal. Many features of these self-renewing cells are comparable with normal stem cells and are termed as "cancer stem cells". Accumulating experimentally verified data has started to scratch the surface of spatio-temporally dysregulated intracellular signaling cascades in the biology of prostate cancer stem cells. We partition this multicomponent review into how different signaling cascades operate in cancer stem cells and how bioactive ingredients isolated from natural sources may modulate signaling network.

TRAIL and Bortezomib: killing cancer with two stones.

Cancer genomics and proteomics have undergone considerable broadening in the past decades and increasingly it is being realized that solid/liquid phase microarrays and high-throughput resequencing have provided platforms to improve our existing knowledge of determinants of cancer development, progression and survival. Loss of apoptosis is a widely and deeply studied process and different approaches are being used to restore apoptosis in resistant cancer phenotype. Modulating the balance between pro-apoptotic and anti-apoptotic proteins is essential to induce apoptosis. It is becoming more understood that pharmacological inhibition of the proteasome might prove to be an effective option in improving TRAIL induced apoptosis in cancer cells. Keeping in view rapidly accumulating evidence of carcinogenesis, metastasis, resistance against wide ranging therapeutics and loss of apoptosis, better knowledge regarding tumor suppressors, oncogenes, pro-apoptotic and anti-apotptic proteins will be helpful in translating the findings from benchtop to bedside.

Recently emerging signaling landscape of ataxia-telangiectasia mutated (ATM) kinase.

Research over the years has progressively and sequentially provided near complete resolution of regulators of the DNA repair pathways which are so important for cancer prevention. Ataxia-telangiectasia mutated kinase (ATM), a high-molecular-weight PI3K-family kinase has emerged as a master regulator of DNA damage signaling and extensive cross-talk between ATM and downstream proteins forms an interlaced signaling network. There is rapidly growing scientific evidence emphasizing newly emerging paradigms in ATM biology. In this review, we provide latest information regarding how oxidative stress induced activation of ATM can be utilized as a therapeutic target in different cancer cell lines and in xenografted mice. Moreover, crosstalk between autophagy and ATM is also discussed with focus on how autophagy inhibition induces apoptosis in cancer cells.