Path of Silibinin from diet to medicine: A dietary polyphenolic flavonoid having potential anti-cancer therapeutic significance.

In the last few decades, targeting cancer by the use of dietary phytochemicals has gained enormous attention. The plausible reason and believe or mind set behind this fact is attributed to either lesser or no side effects of natural compounds as compared to the modern chemotherapeutics, or due to their conventional use as dietary components by mankind for thousands of years. Silibinin is a naturally derived polyphenol (a flavonolignans), possess following biochemical features; molecular formula C25H22O10, Molar mass: 482.44 g/mol, Boiling point 793 °C, with strikingly high antioxidant and anti-tumorigenic properties. The anti-cancer properties of Silibinin are determined by a variety of cellular pathways which include induction of apoptosis, cell cycle arrest, inhibition of angiogenesis and metastasis. In addition, Silibinin controls modulation of the expression of aberrant miRNAs, inflammatory response, and synergism with existing anti-cancer drugs. Therefore, modulation of a vast array of cellular responses and homeostatic aspects makes Silibinin an attractive chemotherapeutic agent. However, like other polyphenols, the major hurdle to declare Silibinin a translational chemotherapeutic agent, is its lesser bioavailability. After summarizing the chemistry and metabolic aspects of Silibinin, this extensive review focuses on functional aspects governed by Silibinin in chemoprevention with an ultimate goal of summarizing the evidence supporting the chemopreventive potential of Silibinin and clinical trials that are currently ongoing, at a single platform.

Deguelin targets multiple oncogenic signaling pathways to combat human malignancies.

Cancer is an anomalous growth and differentiation of cells known to be governed by oncogenic factors. Plant-based natural metabolites have been well recognized to possess chemopreventive properties. Deguelin, a natural rotenoid, is among the class of bioactive phytoconstituents from a diverse range of plants with potential antineoplastic effects in different cancer subtypes. However, the precise mechanisms of how deguelin inhibits tumor progression remains elusive. Deguelin has shown promising results in targeting the hallmarks of tumor progression via inducing tumor apoptosis, cell cycle arrest, and inhibition of angiogenesis and metastasis. Based on initial scientific excerpts, deguelin has been reported to inhibit tumor growth via different signaling pathways, including mitogen-activated protein kinase, phosphoinositide 3-kinase, serine/threonine protein kinase B (also known as Akt), mammalian target of rapamycin, nuclear factor-κB, matrix metalloproteinase (MMP)-2, MMP-9 and caspase-3, caspase-8, and caspase-9. This review summarizes the mechanistic insights of antineoplastic action of deguelin to gain a clear understanding of its therapeutic effects in cancer. The anticancer potential of deguelin with respect to its efficacy in targeting tumorigenesis via nanotechnological approaches is also investigated. The initial scientific findings have presented deguelin as a promising antitumorigenic agent which can be used for monotherapy as well as synergistically to augment efficacy of chemotherapeutic treatment regimes.

Genomic analysis of a novel species Halomonas shambharensis isolated from hypersaline lake in Northwest India.

Genome analysis of Halomonas shambharensis, a novel species, was performed to understand the osmoprotectant strategies used by the strain to overcome the salinity stress and to explore the prospective industrial uses. It will also help to better understand the ecological roles of Halomonas species in hypersaline habitats. Ultrastructure of the cell was determined by using transmission electron microscopy. Standard microbiological methods were used to find out growth parameters and heterotrophic mode of nutrition. For Genome analysis, complete bacterial genome sequencing was performed using the Oxford Nanopore MinION DNA Sequencer. Assembly, annotation and finishing of the obtained sequence were done by using a Prokaryotic Genome Annotation Pipeline (PGAP) (SPAdes v. 3.10.1). Predicted Coading sequences (CDSs) obtained through the PGAP were used for functional annotation using Clusters of Orthologous Groups and Kyoto Encyclopedia of Genes and Genomes (KEGG) platforms. The H. shambharensis was found to be a Gram-stain-negative, rod-shaped bacterium, motile with a peritrichous flagella. The H. shambharensis bacterium can grow in a wide range of temperature (from 25 to 65 °C), pH (pH 4 to pH 12.0) and salt concentration (5.0% NaCl to 30.0% NaCl). After annotation and assembly, the total genome size obtained was 1,533,947 bp, which revealed 146 subsystems, 3847 coding sequences, and 19RNAs with G+C content of 63.6%. Gene annotation identified the genes related to various metabolic pathways, including carbohydrate metabolism, fatty acid metabolism and stress tolerance. The genomic dataset of H. shambharensis will be useful for analysis of protein-coding gene families and how these coding genes are significant for the survival and metabolism among the different species of Halomonas. The complete genome sequence presented here will help to unravel the biotechnological potential of H. shambharensis for production of the high-value products such as betaine, or as a source of gene-mining for individual enzymes.

Molecular mechanisms of action of quercetin in cancer: recent advances.

In the last few decades, the scientific community has discovered an immense potential of natural compounds in the treatment of dreadful diseases such as cancer. Besides the availability of a variety of natural bioactive molecules, efficacious cancer therapy still needs to be developed. So, to design an efficacious cancer treatment strategy, it is essential to understand the interactions of natural molecules with their respective cellular targets. Quercetin (Quer) is a naturally occurring flavonol present in many commonly consumed food items. It governs numerous intracellular targets, including the proteins involved in apoptosis, cell cycle, detoxification, antioxidant replication, and angiogenesis. The weight of available synergistic studies vigorously fortifies the utilization of Quer as a chemoprevention drug. This extensive review covers various therapeutic interactions of Quer with their recognized cellular targets involved in cancer treatment.

Isothiocyanates: a class of bioactive metabolites with chemopreventive potential.

In recent years, growing interest has been focused on the field of chemoprevention using natural therapies. The reason to turn toward "natural" remedies is associated with diverse beneficial pharmacological properties of natural compounds. Isothiocyanates (ITCs), the major pharmacological active constituents of cruciferous vegetables, are derived from the enzymatic hydrolysis of glucosinolates (GSLs). ITCs govern many intracellular targets including cytochrome P 450 (CYP) enzymes, proteins involved in antioxidant response, tumorigenesis, apoptosis, cell cycle, and metastasis. Investigation of the mechanisms of anti-cancer drugs has given important information regarding the use of natural chemopreventive compounds. This extensive review covers various molecular aspects of the interactions of ITCs with their recognized cellular targets involved in cancer treatment in order to enhance anti-tumor outcome with decreased toxicity to patients.

Protocol for the isolation of tumor cell-derived extracellular vesicles followed by in vivo metastasis assessment in a murine ovarian cancer model.

Extracellular vesicles (EVs) play a crucial role in facilitating communication between cancer cells and their immediate or remote microenvironments, thereby promoting the extensive spread of cancer throughout the body. In this context, we present a protocol for the isolation of tumor cell-derived EVs followed by in vivo metastasis assessment in a murine ovarian cancer model. We describe steps for the isolation and characterization of EVs from ID8 cells, development of a metastatic mouse model, and sample preparation for flow cytometry. For complete details on the use and execution of this protocol, please refer to Gupta et al.1.

Blocking Oncostatin M receptor abrogates STAT3 mediated integrin signaling and overcomes chemoresistance in ovarian cancer.

Chemotherapy such as cisplatin is widely used to treat ovarian cancer either before or after surgical debulking. However, cancer relapse due to chemotherapy resistance is a major challenge in the treatment of ovarian cancer. The underlying mechanisms related to chemotherapy resistance remain largely unclear. Therefore, identification of effective therapeutic strategies is urgently needed to overcome therapy resistance. Transcriptome-based analysis, in vitro studies and functional assays identified that cisplatin-resistant ovarian cancer cells express high levels of OSMR compared to cisplatin sensitive cells. Furthermore, OSMR expression associated with a module of integrin family genes and predominantly linked with integrin αV (ITGAV) and integrin ß3 (ITGB3) for cisplatin resistance. Using ectopic expression and knockdown approaches, we proved that OSMR directly regulates ITGAV and ITGB3 gene expression through STAT3 activation. Notably, targeting OSMR using anti-OSMR human antibody inhibited the growth and metastasis of ovarian cancer cells and sensitized cisplatin treatment. Taken together, our results underscore the pivotal role of OSMR as a requirement for cisplatin resistance in ovarian cancer. Notably, OSMR fostered the expression of a distinct set of integrin genes, which in turn resulted into a crosstalk between OSMR and integrins for signaling activation that is critical for cisplatin resistance. Therefore, targeting OSMR emerges as a promising and viable strategy to reverse cisplatin-resistance in ovarian cancer.

Preclinical activity of selinexor in combination with eribulin in uterine leiomyosarcoma.

Leiomyosarcoma (LMS) is a rare soft tissue sarcoma (STS) that begins in smooth muscle tissue and most often initiates in the abdomen or uterus. Compared with other uterine cancers, uterine LMS (ULMS) is an aggressive tumor with poor prognosis and a high risk of recurrence and death, regardless of the stage at presentation. Selinexor is a first-in-class selective inhibitor of nuclear export (SINE) compound that reversibly binds to exportin 1 (XPO1), thereby reactivating tumor suppressor proteins and downregulating the expression of oncogenes and DNA damage repair (DDR) proteins. In this study, we evaluated the effects of selinexor in combination with doxorubicin and eribulin in the LMS tumor model in vitro and in vivo. Treatment of selinexor combined with eribulin showed synergistic effects on tumor growth inhibition in SK-UT1 LMS-derived xenografts. Immunohistochemical assessment of the tumor tissues showed a significantly reduced expression of proliferation (Ki67) and XPO1 markers following combination therapy compared to the control group. Global transcriptome analyses on tumor tissue revealed that the combination therapy regulates genes from several key cancer-related pathways that are differentially expressed in ULMS tumors. To our knowledge, this is the first preclinical study demonstrating the anti-cancer therapeutic potential of using a combination of selinexor and eribulin in vivo. Results from this study further warrant clinical testing a combination of chemotherapy agents with selinexor to reduce the morbidity and mortality from ULMS.

Establishment of In Vivo Ovarian Cancer Mouse Models Using Intraperitoneal Tumor Cell Injection.

Mouse models-xenograft models, syngeneic models (directly implanted or chemically or virally induced), and genetically engineered mice (including transgenic and knockout methods) are invaluable for preclinical studies of ovarian cancer as they recapitulate the structures and microenvironments of tumors, which in vitro studies are unable to accomplish.This chapter describes the methodology and approaches for generating various murine models currently employed in ovarian cancer research. It covers the implantation of cells from ovarian cancer cell lines into mice by intraperitoneal injection.

Optimized proximity ligation assay (PLA) for detection of RNA-protein complex interactions in cell lines.

Conventional proximity ligation assay (PLA) suffers from target specificity issues that curtail their accuracy on interpreting proximal interactions in cell biology. Here, we present a reliable and sensitive approach by including a fluorochrome-labeled mRNA fragment along with biotin-labeled RNA probe and a target-specific antibody, which were used to generate proximal ligation signals through linear connectors in intact cells. This protocol will be particularly useful for studying the proximal interactions between RNA binding proteins (RBPs) and their target mRNAs in cells. For complete details on the use and execution of this protocol, please refer to George et al. (2021).

Metabolic Reprogramming in Tumor-Associated Macrophages in the Ovarian Tumor Microenvironment.

The interaction between tumor cells and macrophages in the tumor microenvironment plays an essential role in metabolic changes in macrophages and reprograms them towards a pro-tumorigenic phenotype. Increasing evidence indicates that macrophage metabolism is a highly complex process and may not be as simple as previously thought. Pro-inflammatory stimuli switch macrophages towards an M1-like phenotype and rely mainly on aerobic glycolysis and fatty acid synthesis, whereas anti-inflammatory stimuli switch macrophages towards an M2-like phenotype. M2-like macrophages depend more on oxidative phosphorylation (OXPHOS) and fatty acid oxidation. However, this metabolically reprogrammed phenotypic switch in macrophages remained a mystery for a while. Therefore, through this review, we tend to describe how macrophage immunometabolism determines macrophage phenotypes and functions in tumor microenvironments (TMEs). Furthermore, we have discussed how metabolic reprogramming in TAM can be used for therapeutic intervention and drug resistance in ovarian cancer.

Gallic Acid: A Dietary Polyphenol that Exhibits Anti-neoplastic Activities by Modulating Multiple Oncogenic Targets.

Phytochemicals are being used for thousands of years to prevent dreadful malignancy. Side effects of existing allopathic treatment have also initiated intense research in the field of bioactive phytochemicals. Gallic acid, a natural polyphenolic compound, exists freely as well as in polymeric forms. The anti-cancer properties of gallic acid are indomitable by a variety of cellular pathways such as induction of programmed cell death, cell cycle apprehension, reticence of vasculature and tumor migration, and inflammation. Furthermore, gallic acid is found to show synergism with other existing chemotherapeutic drugs. Therefore, the antineoplastic role of gallic acid suggests its promising therapeutic candidature in the near future. The present review describes all these aspects of gallic acid at a single platform. In addition nanotechnology-mediated approaches are also discussed to enhance bioavailability and therapeutic efficacy.

Correction: Parashar et al. Patient-Derived Ovarian Cancer Spheroids Rely on PI3K-AKT Signaling Addiction for Cancer Stemness and Chemoresistance. Cancers 2022, 14, 958.

The authors would like to correct the author byline to include Dr [...].

Patient-Derived Ovarian Cancer Spheroids Rely on PI3K-AKT Signaling Addiction for Cancer Stemness and Chemoresistance.

Ovarian cancer is the most lethal gynecological malignancy among women worldwide and is characterized by aggressiveness, cancer stemness, and frequent relapse due to resistance to platinum-based therapy. Ovarian cancer cells metastasize through ascites fluid as 3D spheroids which are more resistant to apoptosis and chemotherapeutic agents. However, the precise mechanism as an oncogenic addiction that makes 3D spheroids resistant to apoptosis and chemotherapeutic agents is not understood. To study the signaling addiction mechanism that occurs during cancer progression in patients, we developed an endometrioid subtype ovarian cancer cell line named 'MCW-OV-SL-3' from the ovary of a 70-year-old patient with stage 1A endometrioid adenocarcinoma of the ovary. We found that the cell line MCW-OV-SL-3 exhibits interstitial duplication of 1q (q21-q42), where this duplication resulted in high expression of the PIK3C2B gene and aberrant activation of PI3K-AKT-ERK signaling. Using short tandem repeat (STR) analysis, we demonstrated that the cell line exhibits a unique genetic identity compared to existing ovarian cancer cell lines. Notably, the MCW-OV-SL-3 cell line was able to form 3D spheroids spontaneously, which is an inherent property of tumor cells when plated on cell culture dishes. Importantly, the tumor spheroids derived from the MCW-OV-SL-3 cell line expressed high levels of c-Kit, PROM1, ZEB1, SNAI, VIM, and Twist1 compared to 2D monolayer cells. We also observed that the hyperactivation of ERK and PI3K/AKT signaling in these cancer cells resulted in resistance to cisplatin. In summary, the MCW-OV-SL3 endometrioid cell line is an excellent model to study the mechanism of cancer stemness and chemoresistance in endometrioid ovarian cancer.

Tumor Derived Extracellular Vesicles Drive T Cell Exhaustion in Tumor Microenvironment through Sphingosine Mediated Signaling and Impacting Immunotherapy Outcomes in Ovarian Cancer.

SPHK1 (sphingosine kinase-1) catalyzes the phosphorylation of sphingosine to sphingosine-1-phosphate (S1P), is found to be highly expressed in solid tumors. Here, extracellular vesicles (EVs) are identified as the key transporters of SPHK1 to the tumor microenvironment. Consequently, SPHK1-packaged EVs elevate S1P levels in the tumor microenvironment, where S1P appears as an immunosuppressive agent. However, the exact mechanism of how S1P mediates its immunosuppressive effects in cancer is not understood. It is investigated that S1P can induce T cell exhaustion. S1P can also upregulate programmed death ligand-1 (PDL-1) expression through E2F1-mediated transcription. Notably, an SPHK1 inhibitor PF543 improves T cell-mediated cytotoxicity. Furthermore, combining PF543 with an anti-PD-1 antibody reduces tumor burden and metastasis more effectively than PF543 alone in vivo. These data demonstrate a previously unrecognized mechanism of how SPHK1-packaged EVs contribute to the progression of ovarian cancer and thus present the potential clinical application of inhibiting SPHK1/S1P signaling to improve immune checkpoint blockage (anti-PD-1 antibody) therapy in ovarian cancer.

Emodin: A metabolite that exhibits anti-neoplastic activities by modulating multiple oncogenic targets.

Oncogenic transformation has been the major cause of global mortality since decades. Despite established therapeutic regimes, majority of cancer patients either present with tumor relapse, refractory disease or therapeutic resistance. Numerous drug candidates are being explored to tap the key reason being poor tumor remission rates, from novel chemotherapy agents to immunotherapy to exploring natural compound derivatives with effective anti-cancer potential. One of these natural product metabolites, emodin has present with significant potential to target tumor oncogenic processes: induction of apoptosis and cell cycle arrest, tumor angiogenesis, and metastasis to chemoresistance in malignant cells. Based on the present scientific excerpts on safety and effectiveness of emodin in targeting hallmarks of tumor progression, emodin is being promisingly explored using nanotechnology platforms for long-term sustained treatment and management of cancer patients. In this review, we summarize the up-to-date scientific literature supporting the anti-neoplastic potential of emodin. We also provide an insight into toxicity and safety profile of emodin and how emodin has emerged as an effective therapeutic alternative in synergism with established conventional chemotherapeutic regimes for management and treatment of tumor progression.

RNA-binding protein FXR1 drives cMYC translation by recruiting eIF4F complex to the translation start site.

Fragile X-related protein-1 (FXR1) gene is highly amplified in patients with ovarian cancer, and this amplification is associated with increased expression of both FXR1 mRNA and protein. FXR1 expression directly associates with the survival and proliferation of cancer cells. Surface sensing of translation (SUnSET) assay demonstrates that FXR1 enhances the overall translation in cancer cells. Reverse-phase protein array (RPPA) reveals that cMYC is the key target of FXR1. Mechanistically, FXR1 binds to the AU-rich elements (ARE) present within the 3' untranslated region (3'UTR) of cMYC and stabilizes its expression. In addition, the RGG domain in FXR1 interacts with eIF4A1 and eIF4E proteins. These two interactions of FXR1 result in the circularization of cMYC mRNA and facilitate the recruitment of eukaryotic translation initiation factors to the translation start site. In brief, we uncover a mechanism by which FXR1 promotes cMYC levels in cancer cells.

Heat shock proteins as biomarkers of lung cancer.

Heat shock proteins are known to be associated with a wide variety of human cancers including lung cancer. Overexpression of these molecular chaperones is linked with tumor survival, metastasis and anticancer drug resistance. In recent years, heat shock proteins are gaining much importance in the field of cancer research owing to their potential to be key determinants of cell survival and apoptosis. Lung cancer is one of the most common cancers diagnosed worldwide and the association of heat shock proteins in lung cancer diagnosis, prognosis and as drug targets remains unresolved. The aim of this review is to draw the importance of heat shock protein members; Hsp27, Hsp70, Hsp90, Hsp60 and their diagnostic and prognostic implications in lung cancer. Based on the available literature heat shock proteins can serve as biomarkers and anticancer drug targets in the management of lung cancer patients.

PLCγ1­dependent invasion and migration of cells expressing NSCLC­associated EGFR mutants.

The increased tyrosine kinase activity of non­small cell lung cancer (NSCLC)­associated epidermal growth factor receptor (EGFR) mutants results in deregulated pathways that contribute to malignant cell survival, tumor progression and metastasis. Previous studies investigating lung cancer­associated EGFR have focused on the prognostic implications of receptor kinase mutations in patients with NSCLC; however, the role of EGFR mutations in tumor cell invasion and migration remains undetermined. The present study was designed to investigate the role of NSCLC­associated mutant EGFR­driven signaling pathways in cell proliferation and invasion. Non­endogenous EGFR­expressing 293 cells stably expressing EGFR mutants that are sensitive or resistant to Food and Drug Administration (FDA)­approved EGFR­targeted tyrosine kinase inhibitors (TKIs) were used in the present study. The experiments demonstrated an increased phosphorylation of phospholipase (PLC)γ1, c­Cbl, signal transducer and activator of transcription (Stat), extracellular regulated kinase (Erk)1/2, Akt, Shc and Gab1 proteins in cells expressing a mutant form, rather than the wild­type receptor. As PLCγ1 is a known regulator of metastatic development, mutant receptor­mediated PLCγ1 activation was further evaluated. To examine the effects of EGFR and PLCγ1 phosphorylation, the metastatic potential of cells expressing mutants was investigated using wound healing, Transwell cell migration and invasion assays. The inhibition of receptor phosphorylation with the 1st, 2nd and 3rd generation TKIs, gefitinib, afatinib, osimertinib, respectively, reduced PLCγ1 phosphorylation, and reduced the invasive and migratory potential of 293 cells, confirming PLCγ1 as one of the probable downstream effectors of mutant EGFR signaling. However, the PLC inhibitor, U73122, inhibited cell migration and invasion without affecting EGFR signaling and PLCγ1 phosphorylation. Notably, U73122 reduced Akt and Erk1/2 phosphorylation within 25 min of its application; however, 100% cell viability was recorded even after 48 h. Upon further investigation, proliferative signaling pathways remained active at 48 h, in accordance with cell viability. Therefore, the present study concludes that mutant receptor­mediated PLCγ1 activation may play a significant role in the migration and invasion of NSCLC tumors; however, its regulatory role in tumor cell proliferation warrants further investigation and validation in lung tumor cell lines harboring EGFR mutations.

Emerging Role of Extracellular Vesicles in Immune Regulation and Cancer Progression.

The development of effective therapies for cancer treatment requires a better understanding of the tumor extracellular environment and a dynamic interaction between tumor cells, the cells of the immune system, and the tumor stroma. Increasing evidence suggests that extracellular vesicles play an important role in this interaction. Extracellular vesicles are nanometer-sized membrane-bound vesicles secreted by various types of cells that facilitate intracellular communication by transferring proteins, various lipids, and nucleic acids, especially miRNAs, between cells. Extracellular vesicles play discrete roles in the immune regulatory functions, such as antigen presentation, and activation or suppression of immune cells. Achieving therapeutic intervention through targeting of extracellular vesicles is a crucial area of research now. Thus, a deeper knowledge of exosome biology and the molecular mechanism of immune regulation is likely to provide significant insight into therapeutic intervention utilizing extracellular vesicles to combat this dreadful disease. This review describes the recent updates on immune regulation by extracellular vesicles in cancer progression and possible use in cancer therapy.