Deguelin attenuates non-small cell lung cancer cell metastasis through inhibiting the CtsZ/FAK signaling pathway

Deguelin Restores Paclitaxel Sensitivity in Paclitaxel-Resistant Ovarian Cancer Cells via Inhibition of the EGFR Signaling Pathway

Background

Ovarian cancer is one of women's malignancies with the highest mortality among gynecological cancers. Paclitaxel is used in first-line ovarian cancer chemotherapy. Research on paclitaxel-resistant ovarian cancer holds significant clinical importance.

Methods

Cell viability and flow cytometric assays were conducted at different time and concentration points of deguelin and paclitaxel treatment. Immunoblotting was performed to assess the activation status of key signaling molecules important for cell survival and proliferation following treatment with deguelin and paclitaxel. The fluo-3 acetoxymethyl assay for P-glycoprotein transport activity assay and cell viability assay in the presence of N-acetyl-L-cysteine were also conducted.

Results

Cell viability and flow cytometric assays demonstrated that deguelin resensitized paclitaxel in a dose- and time-dependent manner. Cotreatment with deguelin and paclitaxel inhibited EGFR and its downstream signaling molecules, including AKT, ERK, STAT3, and p38 MAPK, in SKOV3-TR cells. Interestingly, cotreatment with deguelin and paclitaxel suppressed the expression level of EGFR via the lysosomal degradation pathway. Cotreatment did not affect the expression and function of P-glycoprotein. N-acetyl-L-cysteine failed to restore cell cytotoxicity when used in combination with deguelin and paclitaxel in SKOV3-TR cells. The expression of BCL-2, MCL-1, and the phosphorylation of the S155 residue of BAD were downregulated. Moreover, inhibition of paclitaxel resistance by deguelin was also observed in HeyA8-MDR cells.

Conclusion

Our research showed that deguelin effectively suppresses paclitaxel resistance in SKOV3-TR ovarian cancer cells by downregulating the EGFR and its downstream signaling pathway and modulating the BCL-2 family proteins. Furthermore, deguelin exhibits inhibitory effects on paclitaxel resistance in HeyA8-MDR ovarian cancer cells, suggesting a potential mechanism for paclitaxel resensitization that may not be cell-specific. These findings suggest that deguelin holds promise as an anticancer therapeutic agent for overcoming chemoresistance in ovarian cancer.

Deguelin inhibits the proliferation of human multiple myeloma cells by inducing apoptosis and G2/M cell cycle arrest: Involvement of Akt and p38 MAPK signalling pathway

Deguelin exhibits antiproliferative activity against various cancer cell types. Previous studies have reported that deguelin exhibits pro-apoptotic activity against human cancer cells. The current study aimed at further elaborating the anticancer effects of deguelin against multiple myeloma cells. Cell growth estimations were made through MTT assay. Phase contrast microscopy was used for the analysis of the viability of multiple myeloma cells. Colony formation from multiple myeloma cells was studied using a clonogenic assay. Antioxidative assays for determining levels of glutathione (GSH) and superoxide dismutase (SOD) were carried out after treating multiple myeloma cells with deguelin. The apoptosis of multiple myeloma cells was studied using AO/EB and Annexin V-FITC/PI staining methods. Multiple myeloma cell cycle analysis was performed through flow cytometry. mRNA expression levels were depicted using qRT-PCR. Migration and invasion of multiple myeloma cells were determined with the wound-healing and transwell assays, respectively. Deguelin specifically inhibited the multiple myeloma cell growth while the normal plasma cells were minimally affected. Multiple myeloma cells when treated with deguelin exhibited remarkably lower viability and colony-forming ability. Multiple myeloma cells treated with deguelin produced more SOD and had higher GSH levels. The multiple myeloma cell growth, migration, and invasion were significantly declined by in vitro administration of deguelin. In conclusion, deguelin treatment, when applied in vitro, induced apoptotic cell death and resulted in mitotic cessation at the G2/M phase through modulation of cell cycle regulatory mRNAs in multiple myeloma cells.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

Bergenin Inhibits Tumor Growth and Overcomes Radioresistance by Targeting Aerobic Glycolysis

Hexokinase 2 (HK2), the first glycolytic rate-limiting enzyme, is closely correlated with the occurrence and progression of tumors. Effective therapeutic agents targeting HK2 are urgently needed. Bergenin has exhibited various pharmacological activities, such as antitumor properties. However, the effects of bergenin on the abnormal glucose metabolism of cancer cells are yet unclear. In this study, HK2 was overexpressed in OSCC tissues, and the depletion of HK2 inhibited the growth of OSCC cells in vitro and in vivo. Moreover, these results showed that the natural compound, bergenin, exerted a robust antitumor effect on OSCC cells. Bergenin inhibited cancer cell proliferation, suppressed glycolysis, and induced intrinsic apoptosis in OSCC cells by downregulating HK2. Notably, bergenin restored the antitumor efficacy of irradiation in the radioresistant OSCC cells. A mechanistic study revealed that bergenin upregulated the protein level of phosphatase and the tensin homolog deleted on chromosome 10 (PTEN) by enhancing the interaction between PTEN and ubiquitin-specific protease 13 (USP13) and stabilizing PTEN; this eventually inhibited AKT phosphorylation and HK2 expression. Bergenin was identified as a novel therapeutic agent against glycolysis to inhibit OSCC and overcome radioresistance. Targeting PTEN/AKT/HK2 signaling could be a promising option for clinical OSCC treatment.

Defective cathepsin Z affects EGFR expression and causes autosomal dominant palmoplantar keratoderma

BACKGROUND

The abnormal function of epidermal growth factor receptor (EGFR) has recently been shown to underlie various disorders of cornification.

OBJECTIVES

To delineate the genetic basis of a novel dominant form of palmoplantar keratoderma (PPK).

METHODS

Whole-exome (WES) and direct sequencing, quantitative real-time polymerase chain reaction, protein modelling, confocal immunofluorescence microscopy, immunoblotting, three-dimensional skin equivalents and an enzyme activity assay were used to delineate the genetic basis of a novel dominant form of PPK.

RESULTS

WES revealed heterozygous variants (c.274T > C and c.305C > T) in CTSZ (encoding cathepsin Z) in four individuals (belonging to three unrelated families) with focal PPK. Bioinformatics and protein modelling predicted the variants to be pathogenic. Previous studies have suggested that EGFR expression may be subject to cathepsin regulation. Immunofluorescence revealed reduced cathepsin Z expression in the upper epidermal layers and concomitant increased epidermal EGFR expression in patients harbouring CTSZ variants. Accordingly, human keratinocytes transfected with constructs expressing PPK-causing variants in CTSZ displayed reduced cathepsin Z enzymatic activity, as well as increased EGFR expression. In line with the role played by EGFR in the regulation of keratinocyte proliferation, human keratinocytes transfected with the PPK-causing variants showed significantly increased proliferation that was abolished upon exposure to erlotinib, an EGFR inhibitor. Similarly, downregulation of CTSZ resulted in increased EGFR expression and increased proliferation in human keratinocytes, suggestive of a loss-of-function effect of the pathogenic variants. Finally, three-dimensional organotypic skin equivalents grown from CTSZ-downregulated cells showed increased epidermal thickness and EGFR expression as seen in patient skin; here, too, erlotinib was found to rescue the abnormal phenotype.

CONCLUSIONS

Taken collectively, these observations attribute to cathepsin Z a hitherto unrecognized function in epidermal differentiation.

Skp2-mediated MLKL degradation confers cisplatin-resistant in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the most prevalent type of cancer and the leading cause of cancer-related death. Chemotherapeutic resistance is a major obstacle in treating NSCLC patients. Here, we discovered that the E3 ligase Skp2 is overexpressed, accompanied by the downregulation of necroptosis-related regulator MLKL in human NSCLC tissues and cell lines. Knockdown of Skp2 inhibited viability, anchorage-independent growth, and in vivo tumor development of NSCLC cells. We also found that the Skp2 protein is negatively correlated with MLKL in NSCLC tissues. Moreover, Skp2 is increased and accompanied by an upregulation of MLKL ubiquitination and degradation in cisplatin-resistant NSCLC cells. Accordingly, inhibition of Skp2 partially restores MLKL and sensitizes NSCLC cells to cisplatin in vitro and in vivo. Mechanistically, Skp2 interacts and promotes ubiquitination-mediated degradation of MLKL in cisplatin-resistant NSCLC cells. Our results provide evidence of an Skp2-dependent mechanism regulating MLKL degradation and cisplatin resistance, suggesting that targeting Skp2-ubiquitinated MLKL degradation may overcome NSCLC chemoresistance.

The Role of Paxillin Aberrant Expression in Cancer and Its Potential as a Target for Cancer Therapy

Paxillin is a multi-domain adaptor protein. As an important member of focal adhesion (FA) and a participant in regulating cell movement, paxillin plays an important role in physiological processes such as nervous system development, embryonic development, and vascular development. However, increasing evidence suggests that paxillin is aberrantly expressed in many cancers. Many scholars have also recognized that the abnormal expression of paxillin is related to the prognosis, metastases, invasion, survival, angiogenesis, and other aspects of malignant tumors, suggesting that paxillin may be a potential cancer therapeutic target. Therefore, the study of how aberrant paxillin expression affects the process of tumorigenesis and metastasis will help to develop more efficacious antitumor drugs. Herein, we review the structure of paxillin and its function and expression in tumors, paying special attention to the multifaceted effects of paxillin on tumors, the mechanism of tumorigenesis and progression, and its potential role in tumor therapy. We also hope to provide a reference for the clinical prognosis and development of new tumor therapeutic targets.

Potential Focal Adhesion Kinase Inhibitors in Management of Cancer: Therapeutic Opportunities from Herbal Medicine

Focal adhesion kinase (FAK) is a multifunctional protein involved in cellular communication, integrating and transducing extracellular signals from cell-surface membrane receptors. It plays a central role intracellularly and extracellularly within the tumor microenvironment. Perturbations in FAK signaling promote tumor occurrence and development, and studies have revealed its biological behavior in tumor cell proliferation, migration, and adhesion. Herein we provide an overview of the complex biology of the FAK family members and their context-dependent nature. Next, with a focus on cancer, we highlight the activities of FAK signaling in different types of cancer and how knowledge of them is being used for screening natural compounds used in herbal medicine to fight tumor development.

Overview of the multifaceted resistances toward EGFR-TKIs and new chemotherapeutic strategies in non-small cell lung cancer

The role of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) has been vastly studied over the last decade. This has led to the rapid development of many generations of EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, patients treated with third-generation TKIs (osimertinib, avitinib and rociletinib) targeting the EGFR T790M mutation have shown emerging resistances and relapses. Therefore, further molecular understanding of NSCLC mutations, bypass signalling, tumour microenvironment and the existence of cancer stem cells to overcome such resistances is warranted. This will pave the way for designing novel and effective chemotherapies to improve patients' overall survival. In this review, we provide an overview of the multifaceted mechanism of resistances towards EGFR-TKIs, as well as the challenges and perspectives that should be addressed in strategising chemotherapeutic treatments to overcome the ever evolving and adaptive nature of NSCLC.

Modern aspects of the use of natural polyphenols in tumor prevention and therapy

Polyphenols are secondary plant metabolites or organic compounds synthesized by them. In other words, these are molecules that are found in plants. Due to the wide variety of polyphenols and the plants in which they are found, these compounds are divided according to the source of origin, the function of the polyphenols, and their chemical structure; where the main ones are flavonoids. All the beneficial properties of polyphenols have not yet been studied, since this group of substances is very extensive and diverse. However, most polyphenols are known to be powerful antioxidants and have anti-inflammatory effects. Polyphenols help fight cell damage caused by free radicals and immune system components. In particular, polyphenols are credited with a preventive effect that helps protect the body from certain forms of cancer. The onset and progression of tumors may be related directly to oxidative stress, or inflammation. These processes can increase the amount of DNA damage and lead to loss of control over cell division. A number of studies have shown that oxidative stress uncontrolled by antioxidants or an uncontrolled and prolonged inflammatory process increases the risk of developing sarcoma, melanoma, and breast, lung, liver, and prostate cancer. Therefore, a more in-depth study of the effect of polyphenolic compounds on certain signaling pathways that determine the complex cascade of oncogenesis is a promising direction in the search for new methods for the prevention and treatment of tumors.

Deguelin Attenuates Non-Small-Cell Lung Cancer Cell Metastasis by Upregulating PTEN/KLF4/EMT Signaling Pathway

Non-small-cell lung cancer (NSCLC) is the most common lung cancer and a major cause of cancer mortality worldwide. Deguelin plays a vital inhibitory role in NSCLC initiation and development. However, the downstream mechanism of deguelin-suppressed metastasis of NSCLC cells is still not completely understood. Interestingly, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and Krüppel-like factor 4 (KLF4) also contribute to inhibition of metastasis in NSCLC cells. Here, we demonstrated that deguelin significantly upregulated PTEN and KLF4 expressions and PTEN positively upregulated KLF4 expression in NSCLC cells including A549 and PC9 cells. Moreover, overexpressions of PTEN and KLF4 inhibited the migration and invasion of NSCLC cells, an effect similar to that of deguelin. Furthermore, overexpressions of PTEN and KLF4 could suppress the epithelial-mesenchymal transition (EMT), an effect also similar to that of deguelin. Additionally, deguelin displayed a significant antitumor ability by upregulating PTEN and KLF4 expressions in mice model with NSCLC cells. Together, these results indicated that deguelin could be a potential therapeutic agent through upregulating PTEN and KLF4 expressions for NSCLC therapy.

The microRNA-520a-3p inhibits invasion and metastasis by targeting NF-kappaB signaling pathway in non-small cell lung cancer

PURPOSE

To identify the expression of miR-520a-3p and AKT1 in non-small cell lung cancer cells (NSCLC) and the mechanism in inhibiting cell invasion and metastasis by targeting NF-kappaB signaling pathway.

METHODS

Bioinformatics analysis and dual luciferase reporter gene assay were used to predict and verify the targeting relationship between miR-520a-3p and AKT1. EdU assay was used to detect the proliferation of NSCLC cells. Flow cytometry detected the apoptosis of NSCLC cells. Transwell assay tested the invasion ability of NSCLC cells. qRT-PCR measured the expression of miR-520a-3p and AKT1 mRNA in NSCLC cells; while western blotting was adopted to detect the protein expressions of AKT1, Ki67, CyclinD1, Bax, Bcl-2, MMP-2, MMP-9, NF-kB p65, IkBs kinase (IKK), NF-kB inducing kinase (NIK).

RESULTS

Bioinformatics analysis suggested that miR-520a-3p could target AKT1. miR-520a-3p could regulate the expression of AKT1 negatively. Compared to mimic-NC group, miR-520a-3p mimic group had increased expressions of miR-520a-3p and Bax, while decreased expressions of AKT1, Ki67, CyclinD1, Bcl-2, MMP-2, MMP-9, NF-kB p65, IKK and NIK, reduced cell proliferation, invasion, and increased cell apoptosis rate (all P < 0.05). Compared to inhibitor NC group, miR-520a-3p inhibitor group had decreased expressions of miR-520a-3p and Bax, but increased expressions of AKT1, Ki67, CyclinD1, Bcl-2, MMP-2, MMP-9, NF-kB p65, IKK and NIK, promoted cell proliferation, invasion, and suppressed cell apoptosis rate (all P < 0.05).

CONCLUSION

Overexpression of miR-520a-3p can target and downregulate the expression of AKT1 to inhibit the invasion and metastasis of NSCLC via suppressing the activation of NF-kappaB signaling pathway.

Lysosomal peptidases – Intriguing roles in cancer progression and neurodegeneration

Lysosomal peptidases are hydrolytic enzymes capable of digesting waste proteins that are targeted to lysosomes via endocytosis and autophagy. Besides intracellular protein catabolism, they play more specific roles in several other cellular processes and pathologies, either within lysosomes, upon secretion into the cell cytoplasm or extracellular space, or bound to the plasma membrane. In cancer, lysosomal peptidases are generally associated with disease progression, as they participate in crucial processes leading to changes in cell morphology, signaling, migration, and invasion, and finally metastasis. However, they can also enhance the mechanisms resulting in cancer regression, such as apoptosis of tumor cells or antitumor immune responses. Lysosomal peptidases have also been identified as hallmarks of aging and neurodegeneration, playing roles in oxidative stress, mitochondrial dysfunction, abnormal intercellular communication, dysregulated trafficking, and the deposition of protein aggregates in neuronal cells. Furthermore, deficiencies in lysosomal peptidases may result in other pathological states, such as lysosomal storage disease. The aim of this review was to highlight the role of lysosomal peptidases in particular pathological processes of cancer and neurodegeneration and to address the potential of lysosomal peptidases in diagnosing and treating patients.

Extracellular cathepsin Z signals through the α5 integrin and augments NLRP3 inflammasome activation

Respiratory silicosis is a preventable occupational disease that develops secondary to the aspiration of crystalline silicon dioxide (silica) into the lungs, activation of the NLRP3 inflammasome, and IL-1β production. Cathepsin Z has been associated with the development of inflammation and IL-1β production; however, the mechanism of how cathepsin Z leads to IL-1β production is unknown. Here, the requirement for cathepsin Z in silicosis was determined using WT mice and mice deficient in cathepsin Z. The activation of the NLRP3 inflammasome in macrophages was studied using WT and cathepsin Z-deficient bone marrow-derived murine dendritic cells and the human monocytic cell line THP-1. The cells were activated with silica, and IL-1β release was determined using enzyme-linked immunosorbent assay or IL-1β bioassays. The relative contribution of the active domain or integrin-binding domain of cathepsin Z was studied using recombinant cathepsin Z constructs and the α₅ integrin neutralizing antibody. We report that the lysosomal cysteine protease cathepsin Z potentiates the development of inflammation associated with respiratory silicosis by augmenting NLRP3 inflammasome-derived IL-1β expression in response to silica. The secreted cathepsin Z functions nonproteolytically via the internal integrin-binding domain to impact caspase-1 activation and the production of active IL-1β through integrin α₅ without affecting the transcription levels of NLRP3 inflammasome components. This work reveals a regulatory pathway for the NLRP3 inflammasome that occurs in an outside-in fashion and provides a link between extracellular cathepsin Z and inflammation. Furthermore, it reveals a level of NLRP3 inflammasome regulation that has previously only been found downstream of extracellular pathogens.

Pharmacological basis and new insights of deguelin concerning its anticancer effects

Deguelin is a rotenoid of the flavonoid family, which can be extracted from Lonchocarpus, Derris, or Tephrosia. It possesses the inhibition of cancer cell proliferation by inducing apoptosis through regulating the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, the NF-κB signaling pathway, the Wnt signaling pathway, the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway and epidermal growth factor receptor (EGFR) signaling, activating the p38 mitogen-activated protein kinase (MAPK) pathway, repression of Bmi1, targeting cyclooxygenase-2 (COX-2), targeting galectin-1, promotion of glycogen synthase kinase-3β (GSK3β)/FBW7-mediated Mcl-1 destabilization and targeting mitochondria via down-regulating Hexokinases II-mediated glycolysis, PUMA-mediation, which are some crucial molecules which modulate closely cancer cell growth and metastasis. Deguelin inhibits tumor cell propagation and malignant transformation through targeting angiogenesis, targeting lymphangiogenesis, targeting focal adhesion kinase (FAK), inhibiting the CtsZ/FAK signaling pathway, targeting epithelial-mesenchymal transition (EMT), the NF-κB signaling pathway, regulating NIMA-related kinase 2 (NEK2). In addition, deguelin possesses other biological activities, such as targeting cell cycle arrest, modulation of autophagy, inhibition of hedgehog pathway, inducing differentiation of mutated NPM1 acute myeloid leukemia etc. Therefore, deguelin is a promising chemopreventive agent for cancer therapy.

Whole-Genome Methylation Study of Congenital Lung Malformations in Children

Background and Objectives

The treatment of asymptomatic patients with congenital pulmonary malformations (CPMs) remains controversial, partially because the relationship between congenital lung malformations and malignancy is still undefined. Change in methylation pattern is a crucial event in human cancer, including lung cancer. We therefore studied all differentially methylated regions (DMRs) in a series of CPMs in an attempt to find methylation anomalies in genes already described in association with malignancy.

Methods

The DNA extracted from resected congenital lung malformations and control lung tissue was screened using Illumina MethylationEPIC arrays. Comparisons between the group of malformed samples or the malformed samples of same histology or each malformed sample and the controls and between a pleuropulmonary blastoma (PPB) and controls were performed. Moreover, each malformed sample was pairwise compared with its respective control. All differentially methylated regions (DMRs) with an adjusted p-value <0,05 were studied.

Results

Every comparison highlighted a number of DMRs closed to genes involved either in cell proliferation or in embryonic development or included in the Cancer Gene Census. Their abnormal methylation had been already described in lung tumors.

Conclusions

Methylation anomalies already described in lung tumors and also shared by the PPB were found in congenital lung malformations, regardless the histology. The presence of methylation abnormalities is suggestive of a correlation between congenital lung malformations and some step of malignant transformation.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

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.

RIP1/RIP3/MLKL-mediated necroptosis contributes to vinblastine-induced myocardial damage

Vinblastine (VBL) has been considered as a first-line anti-tumor drug for many years. However, vinblastine-caused myocardial damage has been continually reported. The underlying molecular mechanism of the myocardial damage remains unknown. Here, we show that vinblastine induces myocardial damage and necroptosis is involved in the vinblastine-induced myocardial damage both in vitro and in vivo. The results of WST-8 and flow cytometry analysis show that vinblastine causes damage to H9c2 cells, and the results of animal experiments show that vinblastine causes myocardial cell damage. The necrosome components, receptor-interacting protein 1 (RIP1) receptor-interacting protein 3 (RIP3), are significantly increased in vinblastine-treated H9c2 cells, primary neonatal rat ventricular myocytes and rat heart tissues. And the downstream substrate of RIP3, mixed lineage kinase domain like protein (MLKL) was also increased. Pre-treatment with necroptosis inhibitors partially inhibits the necrosome components and MLKL levels and alleviates vinblastine-induced myocardial injury both in vitro and in vivo. This study indicates that necroptosis participated in vinblastine-evoked myocardial cell death partially, which would be a potential target for relieving the chemotherapy-related myocardial damage.

Single-cell transcriptome analysis demonstrates inter-patient and intra-tumor heterogeneity in primary and metastatic lung adenocarcinoma

In this study, we performed single-cell transcriptome data analysis of fifty primary and metastatic lung adenocarcinoma (LUAD) samples from the GSE123902 and GSE131907 datasets to determine the landscape of inter-patient and intra-tumoral heterogeneity. The gene expression profiles and copy number variations (CNV) showed significant heterogeneity in the primary and metastatic LUAD samples. We observed upregulation of pathways related to translational initiation, endoplasmic reticulum stress, exosomes, and unfolded protein response in the brain metastasis samples as compared to the primary tumor samples. Pathways related to exosomes, cell adhesion and metabolism were upregulated and the epithelial-to-mesenchymal-transition (EMT) pathway was downregulated in brain metastasis samples from chemotherapy-treated LUAD patients as compared to those from the untreated LUAD patients. Tumor cell subgroups in the brain metastasis samples showed differential expression of genes related to type II alveolar cells, chemoresistance, glycolysis and oxidative phosphorylation (metabolic reprogramming), and EMT. Thus, single-cell transcriptome analysis demonstrated intra-patient and intra-tumor heterogeneity in the regulation of pathways related to tumor progression, chemoresistance and metabolism in the primary and metastatic LUAD tissues. Moreover, our study demonstrates that single cell transcriptome analysis is a potentially useful tool for accurate diagnosis and personalized targeted treatment of LUAD patients.

Emerging role of phytochemicals in targeting predictive, prognostic, and diagnostic biomarkers of lung cancer

Lung-cancer is the foremost cause of cancer in humans worldwide, of which 80-85% cases are composed of non-small cell lung carcinoma. All treatment decisions depend on the pattern of biomarkers selection to enhance the response to the targeted therapies. Although advanced treatments are available for lung-cancer, the disease treatment remains not adequate. There are several synthetic chemotherapeutic agents available for the treatment of lung cancer. However, due to their toxic effect, survival rate is still 15-18%. Besides, medicinal plants are a huge reservoir of natural products that provide protective effects against lung cancer. Likewise, successful studies of potential phytochemicals in targeting lung-cancer biomarkers have created a novel paradigm for the discovery of potent drugs against lung-cancer. Hence, to defeat severe toxicity and resistance towards the synthetic drugs, detailed studies are required regarding the available phytochemicals and targets responsible for the treatment of lung-cancer. The present review provides a comprehensive information about the lung-cancer biomarkers under the classification of predictive, prognostic, and diagnostic type. Moreover, it discusses and enlists the phytochemicals with mode of action against different biomarkers, effective doses in in vitro, in vivo, and clinical studies, the limitations associated with usage of phytochemicals as a drug to prevent/cure lung-cancer and the latest techniques employed to overcome such issues.

Inhibition of ERKs/Akt-Mediated c-Fos Expression Is Required for Piperlongumine-Induced Cyclin D1 Downregulation and Tumor Suppression in Colorectal Cancer Cells

Background

Deregulation of Cyclin D1 and cell cycle progression plays a critical role in tumorigenesis. The natural compound piperlongumine (PL) exhibits potential anticancer effects in various cancer models, but the underlying mechanism needs further elucidation.

Methods

The inhibitory effect of PL on colorectal cancer (CRC) cells was determined by anchorage-dependent and -independent assays. The protein level of Cyclin D1 was examined by immunoblot (IB) and immunohistochemical staining (IHC). The mRNA level was determined by qRT-PCR. Phosphorylation of histone H3 was analyzed by immunofluorescence (IF). The cell cycle was examined by flow cytometry. The in vivo antitumor effect was validated by the xenograft mouse model.

Results

Cyclin D1 was overexpressed in CRC tissues and cells, and was required for maintaining cell growth, colony formation, and in vivo tumorigenesis. PL decreased the protein level of c-Fos, which eventually reduced the transcriptional activity of AP-1 and the mRNA level of Cyclin D1. Mechanism study showed that PL impaired EGF-induced activation of ERK1/2 and Akt signalings, which resulted in a reduction of c-Fos transcription. Furthermore, PL reduced the half-life of c-Fos and caused the ubiquitination-dependent degradation of c-Fos. Finally, the in vivo antitumor effect of PL on CRC cells was examined using a xenograft mouse model.

Conclusion

Our data indicate that PL is a promising antitumor agent that deserves further study for CRC treatment.

Tanshinone IIA inhibits oral squamous cell carcinoma via reducing Akt-c-Myc signaling-mediated aerobic glycolysis

Aerobic glycolysis is one of the hallmarks of human cancer cells. Overexpression of hexokinase 2 (HK2) plays a crucial role in the maintaining of unlimited tumor cell growth. In the present study, we found that the oral squamous cell carcinoma (OSCC) cells exhibited an aerobic glycolysis phenotype. Moreover, HK2 is highly expressed in OSCC patient derived-tissues and cell lines. Depletion of HK2 inhibited OSCC cell growth in vitro and in vivo. With a natural product screening, we identified Tanshinone IIA (Tan IIA) as a potential anti-tumor compound for OSCC through suppressing HK2-mediated glycolysis. Tan IIA decreased glucose consumption, lactate production, and promoted intrinsic apoptosis in OSCC cells. The mechanism study revealed that Tan IIA inhibited the Akt-c-Myc signaling and promoted E3 ligase FBW7-mediated c-Myc ubiquitination and degradation, which eventually reduced HK2 expression at the transcriptional level. In summary, these results indicate that targeting HK2-mediated aerobic glycolysis is a promising anti-tumor strategy for OSCC treatment.

Promotion of ubiquitination-dependent survivin destruction contributes to xanthohumol-mediated tumor suppression and overcomes radioresistance in human oral squamous cell carcinoma

Background

Overexpression of survivin plays a crucial role in tumorigenesis and correlates with poor prognosis in human malignancies. Thus, survivin has been proposed as an attractive target for new anti-tumor interventions.

Methods

A natural product library was used for natural compound screening through MTS assay. The expression of survivin in oral squamous cell carcinoma (OSCC) and the inhibitory effect of xanthohumol (XN) on OSCC were examined by anchorage-dependent and -independent growth assays, immunoblot, immunofluorescence, immunohistochemical staining, ubiquitination analysis, co-immunoprecipitation assay, CRISPR-Cas9-based gene knockout, and xenograft experiment.

Results

Survivin is highly expressed in OSCC patient-derived tissues and cell lines. Knockout of survivin reduced the tumorigenic properties of OSCC cells in vitro and in vivo. With a natural compound screening, we identified that xanthohumol inhibited OSCC cells by reducing survivin protein level and activating mitochondrial apoptotic signaling. Xanthohumol inhibited the Akt-Wee1-CDK1 signaling, which in turn decreased survivin phosphorylation on Thr34, and facilitated E3 ligase Fbxl7-mediated survivin ubiquitination and degradation. Xanthohumol alone or in combination with radiation overcame radioresistance in OSCC xenograft tumors.

Conclusion

Our findings indicate that targeting survivin for degradation might a promising strategy for OSCC treatment.

Xanthohumol suppresses glioblastoma via modulation of Hexokinase 2 -mediated glycolysis

Deregulation of aerobic glycolysis is a common phenomenon in human cancers, including glioblastoma (GBM). In the present study, we demonstrated that the natural compound xanthohumol has a profound anti-tumor effect on GBM via direct inhibition of glycolysis. Xanthohumol suppressed cell proliferation and colony formation of GBM cells, and significantly impaired glucose metabolism via inhibiting Hexokinase 2 (HK2) expression. We demonstrated that down-regulation of c-Myc was required for xanthohumol-induced decrease of HK2. Xanthohumol destabilization of c-Myc, and promoted FBW7-mediated ubiquitination of c-Myc. Xanthohumol attenuated Akt activity and inhibited the activation of GSK3β, resulted in c-Myc degradation. Overexpression of Myr-Akt1 significantly rescued xanthohumol-mediated c-Myc inhibition and glycolysis suppression. Finally, the xanthohumol-mediated down-regulation of the PI3-K/Akt-GSK3beta-FBW7 signaling axis promoted the destabilization of c-Myc. Finally, the animal results demonstrated that xanthohumol substantially inhibited tumor growth in vivo. Collectively, xanthohumol appears to be a promising new anti-tumor agent with the therapeutic potential for GBM.

Deguelin suppresses non-small cell lung cancer by inhibiting EGFR signaling and promoting GSK3β/FBW7-mediated Mcl-1 destabilization

Activating mutations of epidermal growth factor receptor (EGFR) play crucial roles in the oncogenesis of human non-small cell lung cancer (NSCLC). By screening 79 commercially available natural products, we found that the natural compound deguelin exhibited a profound anti-tumor effect on NSCLC via directly down-regulating of EGFR-signaling pathway. Deguelin potently inhibited in vitro EGFR kinase activity of wild type (WT), exon 19 deletion, and L858R/T790M-mutated EGFR. The in silico docking study indicated that deguelin was docked into the ATP-binding pocket of EGFRs. By suppression of EGFR signaling, deguelin inhibited anchorage-dependent, and independent growth of NSCLC cell lines, and significantly delayed tumorigenesis in vivo. Further study showed that deguelin inhibited EGFR and downstream kinase Akt, which resulted in the activation of GSK3β and eventually enhanced Mcl-1 phosphorylation at S159. Moreover, deguelin promoted the interaction between Mcl-1 and E3 ligase SCF^FBW7, which enhanced FBW7-mediated Mcl-1 ubiquitination and degradation. Additionally, phosphorylation of Mcl-1 by GSK3β is a prerequisite for FBW7-mediated Mcl-1 destruction. Depletion or pharmacological inactivation of GSK3β compromised deguelin-induced Mcl-1 ubiquitination and reduction. Taken together, our data indicate that enhancement of ubiquitination-dependent Mcl-1 turnover might be a promising approach for cancer treatment.

Xanthohumol inhibits colorectal cancer cells via downregulation of Hexokinases II-mediated glycolysis

Deregulation of glycolysis is a common phenomenon in human colorectal cancer (CRC). In the present study, we reported that Hexokinase 2 (HK2) is overexpressed in human CRC tissues and cell lines, knockout of HK2 inhibited cell proliferation, colony formation, and xenograft tumor growth. We demonstrated that the natural compound, xanthohumol, has a profound anti-tumor effect on CRC via down-regulation of HK2 and glycolysis. Xanthohumol suppressed CRC cell growth both in vitro and in vivo. Treatment with xanthohumol promoted the release of cytochrome C and activated the intrinsic apoptosis pathway. Moreover, our results revealed that xanthohumol down-regulated the EGFR-Akt signaling, exogenous overexpression of constitutively activated Akt1 significantly impaired xanthohumol-induced glycolysis suppression and apoptosis induction. Our results suggest that targeting HK2 appears to be a new approach for clinical CRC prevention or treatment.

Cysteine Cathepsins in Tumor-Associated Immune Cells

Cysteine cathepsins are key regulators of the innate and adaptive arms of the immune system. Their expression, activity, and subcellular localization are associated with the distinct development and differentiation stages of immune cells. They promote the activation of innate myeloid immune cells since they contribute to toll-like receptor signaling and to cytokine secretion. Furthermore, they control lysosomal biogenesis and autophagic flux, thus affecting innate immune cell survival and polarization. They also regulate bidirectional communication between the cell exterior and the cytoskeleton, thus influencing cell interactions, morphology, and motility. Importantly, cysteine cathepsins contribute to the priming of adaptive immune cells by controlling antigen presentation and are involved in cytotoxic granule mediated killing in cytotoxic T lymphocytes and natural killer cells. Cathepins'aberrant activity can be prevented by their endogenous inhibitors, cystatins. However, dysregulated proteolysis contributes significantly to tumor progression also by modulation of the antitumor immune response. Especially tumor-associated myeloid cells, such as tumor-associated macrophages and myeloid-derived suppressor cells, which are known for their tumor promoting and immunosuppressive functions, constitute the major source of excessive cysteine cathepsin activity in cancer. Since they are enriched in the tumor microenvironment, cysteine cathepsins represent exciting targets for development of new diagnostic and therapeutic moieties.

Skp2-mediated ubiquitination and mitochondrial localization of Akt drive tumor growth and chemoresistance to cisplatin

The E3 ligase S-phase kinase-associated protein 2(Skp2) is overexpressed in human cancers and correlated with poor prognosis, but its contributions to tumorigenesis and chemoresistance in nasopharyngeal carcinoma (NPC) are not evident. Herein we show that Skp2 is highly expressed in NPC tumor tissues and cell lines. Knockdown of Skp2 suppresses tumor cell growth, colony formation, glycolysis, and in vivo tumor growth. Skp2 promotes Akt K63-mediated ubiquitination and activation, which is required for EGF-induced Akt mitochondrial localization. Importantly, K63-linked ubiquitination enhances the interaction between Akt and HK2 and eventually increases HK2 phosphorylation on Thr473 and mitochondrial localization. Overexpression of Skp2 impaired the intrinsic apoptotic pathway and confers cisplatin resistance. Moreover, ectopic expression of Myr-Akt1 or phosphomimetic HK2-T473D rescued cisplatin-induced tumor suppression in Skp2 knockdown stable cells. Also, depletion of Akt ubiquitination enhances the antitumor efficacy of cisplatin in vitro and in vivo. Finally, we demonstrated that Skp2 is positively correlated with p-Akt and HK2 in NPC tumor tissues. This study highlights the clinical value of Skp2 targeting in NPC treatment.

Repression of Hexokinases II-Mediated Glycolysis Contributes to Piperlongumine-Induced Tumor Suppression in Non-Small Cell Lung Cancer Cells

Deregulation of glycolysis is a common phenomenon in human non-small cell lung cancer (NSCLC). In the present study, we reported the natural compound, piperlongumine, has a profound anti-tumor effect on NSCLC via regulation of glycolysis. Piperlongumine suppressed the proliferation, colony formation and HK2-mediated glycolysis in NSCLC cells. We demonstrated that exposure to piperlongumine disrupted the interaction between HK2 and VDAC1, induced the activation of the intrinsic apoptosis signaling pathway. Moreover, our results revealed that piperlongumine down-regulated the Akt signaling, exogenous overexpression of constitutively activated Akt1 in HCC827 and H1975 cells significantly rescued piperlongumine-induced glycolysis suppression and apoptosis. The xenograft mouse model data demonstrated the pivotal role of suppression of Akt activation and HK2-mediated glycolysis in mediating the in vivo antitumor effects of piperlongumine. The expression of HK2 was higher in malignant NSCLC tissues than that of the paired adjacent tissues, and was positively correlated with poor survival time. Our results suggest that HK2 could be used as a potential predictor of survival and targeting HK2 appears to be a new approach for clinical NSCLC prevention or treatment.

Cathepsins: Potent regulators in carcinogenesis

Cathepsins (CTS) are mainly lysosomal acid hydrolases extensively involved in the prognosis of different diseases, and having a distinct role in tumor progression by regulating cell proliferation, autophagy, angiogenesis, invasion, and metastasis. As all these processes conjunctively lead to cancer progression, their site-specific regulation might be beneficial for cancer treatment. CTS regulate activation of the proteolytic cascade and protein turnover, while extracellular CTS is involved in promoting extracellular matrix degradation and angiogenesis, thereby stimulating invasion and metastasis. Despite cancer regulation, the involvement of CTS in cellular adaptation toward chemotherapy and radiotherapy augments their therapeutic potential. However, lysosomal permeabilization mediated cytosolic translocation of CTS induces programmed cell death. This complex behavior of CTS generates the need to discuss the different aspects of CTS associated with cancer regulation. In this review, we mainly focused on the significance of each cathepsin in cancer signaling and their targeting which would provide noteworthy information in the context of cancer biology and therapeutics.

The Natural Flavonoid Compound Deguelin Inhibits HCMV Lytic Replication within Fibroblasts

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus for which there is no vaccine or cure. This viral infection, once acquired, is life-long, residing latently in hematopoietic cells. However, latently infected individuals with weakened immune systems often undergo HCMV reactivation, which can cause serious complications in immunosuppressed and immunocompromised patients. Current anti-viral therapies target late stages of viral replication, and are often met with therapeutic resistance, necessitating the development of novel therapeutics. In this current study, we identified a naturally-occurring flavonoid compound, deguelin, which inhibits HCMV lytic replication. Our findings reveal that nanomolar concentrations of deguelin significantly suppress the production of the infectious virus. Further, we show that deguelin inhibits the lytic cycle during the phase of the replication cycle consistent with early (E) gene and protein expression. Importantly, our data reveal that deguelin inhibits replication of a ganciclovir-resistant strain of HCMV. Together, our findings identify a novel, naturally occurring compound that may prove useful in the treatment of HCMV replication.

Pectolinarigenin inhibits non‑small cell lung cancer progression by regulating the PTEN/PI3K/AKT signaling pathway

Lung cancer is the principal cause of cancer-associated mortality. Pectolinarigenin (Pec) reportedly has effective antitumor activity against certain cancer types. Phosphatase and tensin homolog (PTEN) is a well-known tumor suppressor and serves a vital role in cancer progression. However, the effect of Pec on non-small cell lung cancer (NSCLC) cell proliferation and metastasis, and the underlying mechanism, has not yet been elucidated. In the present study, it was demonstrated that Pec inhibited the proliferation of A549 and Calu-3 cells in dose- and time-dependent manners. The apoptosis rate significantly increased with increasing doses of Pec. Apoptosis-associated protein expression was additionally altered by Pec exposure. Pec was able to suppress the metastasis of NSCLC cells; it upregulated the mRNA and protein expression levels of E-cadherin, and downregulated the mRNA and protein expression levels of vimentin. Additionally, Pec was able to activate PTEN and subsequently downregulate the PI3K/protein kinase B (AKT) signaling pathway. In summary, Pec was able to inhibit cell proliferation, promote apoptosis and suppress metastasis in NSCLC cells through the PTEN/PI3K/AKT signaling pathway, indicating that Pec is a potential agent for NSCLC therapy.