The Wnt signaling pathway: a potential therapeutic target against cancer

Unraveling the crosstalk: circRNAs and the wnt signaling pathway in cancers of the digestive system

Circular RNA (circRNA) is a unique type of noncoding RNA molecule characterized by its closed-loop structure. Functionally versatile, circRNAs play pivotal roles in gene expression regulation, protein activity modulation, and participation in cell signaling processes. In the context of cancers of the digestive system, the Wnt signaling pathway holds particular significance. Anomalous activation of the Wnt pathway serves as a primary catalyst for the development of colorectal cancer. Extensive research underscores the notable participation of circRNAs associated with the Wnt pathway in the progression of digestive system tumors. These circRNAs exhibit pronounced dysregulation across esophageal cancer, gastric cancer, liver cancer, colorectal cancer, pancreatic cancer, and cholangiocarcinoma. Furthermore, the altered expression of circRNAs linked to the Wnt pathway correlates with prognostic factors in digestive system tumors. Additionally, circRNAs related to the Wnt pathway showcase potential as diagnostic, therapeutic, and prognostic markers within the realm of digestive system tumors. This comprehensive review outlines the interplay between circRNAs and the Wnt signaling pathway in cancers of the digestive system. It seeks to provide a comprehensive perspective on their association while delving into ongoing research that explores the clinical applications of circRNAs associated with the Wnt pathway.

FOXP4-mediated induction of PTK7 activates the Wnt/β-catenin pathway and promotes ovarian cancer development

Ovarian cancer (OV) poses a significant challenge in clinical settings due to its difficulty in early diagnosis and treatment resistance. FOXP4, belonging to the FOXP subfamily, plays a pivotal role in various biological processes including cancer, cell cycle regulation, and embryonic development. However, the specific role and importance of FOXP4 in OV have remained unclear. Our research showed that FOXP4 is highly expressed in OV tissues, with its elevated levels correlating with poor prognosis. We further explored FOXP4's function through RNA sequencing and functional analysis in FOXP4-deficient cells, revealing its critical role in activating the Wnt signaling pathway. This activation exacerbates the malignant phenotype in OV. Mechanistically, FOXP4 directly induces the expression of protein tyrosine kinase 7 (PTK7), a Wnt-binding receptor tyrosine pseudokinase, which causes abnormal activation of the Wnt signaling pathway. Disrupting the FOXP4-Wnt feedback loop by inactivating the Wnt signaling pathway or reducing FOXP4 expression resulted in the reduction of the malignant phenotype of OV cells, while restoring PTK7 expression reversed this effect. In conclusion, our findings underscore the significance of the FOXP4-induced Wnt pathway activation in OV, suggesting the therapeutic potential of targeting this pathway in OV treatment.

Glioma Stem Cells-Features for New Therapy Design

On a molecular level, glioma is very diverse and presents a whole spectrum of specific genetic and epigenetic alterations. The tumors are unfortunately resistant to available therapies and the survival rate is low. The explanation of significant intra- and inter-tumor heterogeneity and the infiltrative capability of gliomas, as well as its resistance to therapy, recurrence and aggressive behavior, lies in a small subset of tumor-initiating cells that behave like stem cells and are known as glioma cancer stem cells (GCSCs). They are responsible for tumor plasticity and are influenced by genetic drivers. Additionally, GCSCs also display greater migratory abilities. A great effort is under way in order to find ways to eliminate or neutralize GCSCs. Many different treatment strategies are currently being explored, including modulation of the tumor microenvironment, posttranscriptional regulation, epigenetic modulation and immunotherapy.

GRIK1-AS1 deficiency accelerates endometriosis progression by boosting DNMT1-dependent SFRP1 promoter methylation in endometrial stromal cells

BACKGROUND

Endometriosis, a gynecological disease that affects up to 10% of women, is a major cause of pain and infertility. Deregulation of the epigenome is accountable for the onset and progression of endometriosis, although its exact mechanism is unknown. The purpose of the current study is to examine the role of the long non-coding RNA (lncRNA) GRIK1-AS1 in the epigenetic regulation of endometrial stromal cell proliferation and the development of endometriosis.

METHODS

Endometriosis datasets were screened to identify GRIKI-AS1 as dramatically declining in endometriosis. Gain or loss of function endometrial stromal cell (ESC) models were established. The anti-proliferation phenotype was investigated using in vitro and in vivo experiments. Epigenetic regulatory network analyses were conducted to suggest the intrinsic molecular mechanism.

RESULTS

With bioinformatic and clinical data, we observed that GRIK1-AS1 and SFRP1 were expressed at low levels in endometriosis. Overexpressed GRIK1-AS1 inhibited ESC proliferation, while SFRP1 knockdown rescued the antiproliferative ability of GRIK1-AS1. Specifically, methylation-dependent expression inhibition of SFRP1 was revealed in ESCs. Mechanistically, GRIK1-AS1 hampers the occupancy of DNMT1 in SRFP1 promoter, leading to hypomethylation of SFRP1 and upregulated SFRP1 expression, thereby potentially suppressing Wnt signaling and its adverse proliferative effect. Therapeutically, lentivirus-mediated upregulation of GRIK1-AS1 inhibited endometriosis disease progression in vivo.

CONCLUSIONS

Our study is a proof-of-concept demonstration for GRIKI-AS1-associated endometriosis pathogenesis and highlights a potential intervention target.

Abnormal activation of the Wnt3a/β-catenin signaling pathway promotes the expression of T-box transcription factor 3(TBX3) and the epithelial-mesenchymal transition pathway to mediate the occurrence of adenomyosis

BACKGROUND

T-box transcription factor 3(TBX3) is a transcription factor that can regulate cell proliferation, apoptosis, invasion, and migration in different tumor cells; however, its role in adenomyosis (ADM) has not been previously studied. Some of ADM's pathophysiological characteristics are similar to those of malignant tumors (e.g., abnormal proliferation, migration, and invasion).

METHODS AND RESULTS

We hypothesized that TBX3 might have a role in ADM. We used tamoxifen-induced Institute of Cancer research (ICR) mice to establish ADM disease model. The study procedure included western blotting and immunohistochemistry to analyze protein levels; additionally, we used intraperitoneal injection of Wnt/β-catenin pathway inhibitor XAV-939 to study the relationship between TBX3 and Wnt/β-catenin pathway as well as Anti-proliferation cell nuclear antigen( PCNA) and TUNEL to detect cell proliferation and apoptosis, respectively. TBX3 overexpression and epithelial-to-mesenchymal transition (EMT) in ADM mice was found to be associated with activation of the Wnt3a/β-catenin pathway. Treatment with XAV-939 in ADM mice led to the inhibition of both TBX3 and EMT; moreover, abnormal cell proliferation was suppressed, the depth of invasion of endometrium cells was limited. Thus, the use of XAV-939 effectively inhibited further invasion of endometrial cells.

CONCLUSION

These findings suggest that TBX3 may play an important role in the development of ADM. The expression of TBX3 in ADM was regulated by the Wnt3a/β-catenin pathway. The activation of the Wnt3a/β-catenin pathway in ADM promoted TBX3 expression and induced the occurrence of EMT, thus promoting cell proliferation and inhibiting apoptosis, ultimately accelerating the development of ADM. The study provides a reference for the diagnosis of ADM.

β-catenin inhibitors in cancer therapeutics: intricacies and way forward

β-catenin is an evolutionary conserved, quintessential, multifaceted protein that plays vital roles in cellular homeostasis, embryonic development, organogenesis, stem cell maintenance, cell proliferation, migration, differentiation, apoptosis, and pathogenesis of various human diseases including cancer. β-catenin manifests both signaling and adhesive features. It acts as a pivotal player in intracellular signaling as a component of versatile WNT signaling cascade involved in embryonic development, homeostasis as well as in carcinogenesis. It is also involved in Ca2+ dependent cell adhesion via interaction with E-cadherin at the adherens junctions. Aberrant β-catenin expression and its nuclear accumulation promote the transcription of various oncogenes including c-Myc and cyclinD1, thereby contributing to tumor initiation, development, and progression. β-catenin's expression is closely regulated at various levels including its stability, sub-cellular localization, as well as transcriptional activity. Understanding the molecular mechanisms of regulation of β-catenin and its atypical expression will provide researchers not only the novel insights into the pathogenesis and progression of cancer but also will help in deciphering new therapeutic avenues. In the present review, we have summarized the dual functions of β-catenin, its role in signaling, associated mutations as well as its role in carcinogenesis and tumor progression of various cancers. Additionally, we have discussed the challenges associated with targeting β-catenin molecule with the presently available drugs and suggested the possible way forward in designing new therapeutic alternatives against this oncogene.

Signaling pathways and targeted therapeutic strategies for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. Although promising strides have been made in the field of PCOS over the past decades, the distinct etiologies of this syndrome are not fully elucidated. Prenatal factors, genetic variation, epigenetic mechanisms, unhealthy lifestyles, and environmental toxins all contribute to the development of this intricate and highly heterogeneous metabolic, endocrine, reproductive, and psychological disorder. Moreover, interactions between androgen excess, insulin resistance, disruption to the hypothalamic-pituitary-ovary (HPO) axis, and obesity only make for a more complex picture. In this review, we investigate and summarize the related molecular mechanisms underlying PCOS pathogenesis from the perspective of the level of signaling pathways, including PI3K/Akt, TGF-β/Smads, Wnt/β-catenin, and Hippo/YAP. Additionally, this review provides an overview of prospective therapies, such as exosome therapy, gene therapy, and drugs based on traditional Chinese medicine (TCM) and natural compounds. By targeting these aberrant pathways, these interventions primarily alleviate inflammation, insulin resistance, androgen excess, and ovarian fibrosis, which are typical symptoms of PCOS. Overall, we hope that this paper will pave the way for better understanding and management of PCOS in the future.

Secreted frizzled-related proteins: A promising therapeutic target for cancer therapy through Wnt signaling inhibition

The Wnt signaling system is a critical pathway that regulates embryonic development and adult homeostasis. Secreted frizzled-related proteins (SFRPs) are extracellular inhibitors of Wnt signaling that act by binding directly to Wnt ligands or Frizzled receptors. SFRPs can act as anti-Wnt agents and suppress cancer growth by blocking the action of Wnt ligands. However, SFRPs are often silenced by promoter methylation in cancer cells, resulting in hyperactivation of the Wnt pathway. Epigenetic modifiers can reverse this silencing and restore SFRPs expression. Despite the potential of SFRPs as a therapeutic target, the effects of SFRPs on tumor development remain unclear. Therefore, a review of the expression of various members of the SFRPs family in different cancers and their potential as therapeutic targets is warranted. This review aims to summarize the current knowledge of SFRPs in cancer, focusing on their expression patterns and their potential as novel therapeutic targets.

Utility of Wnt family member 9b (Wnt9b) immunohistochemistry in the cytologic diagnosis of metastatic breast carcinoma

Wnt family member 9b (Wnt9b) has been demonstrated as a valuable marker for breast cancer diagnosis in surgical pathology. In this study, we examined the utility of Wnt9b in diagnosing metastatic breast carcinoma in cytology samples. Cell blocks from fine needle aspirations (FNA) and fluid specimens of 96 metastatic breast carcinomas and 123 primary and metastatic non-breast neoplasms from various organ systems were evaluated by Wnt9b and GATA3 immunohistochemistry (IHC). Wnt9b and GATA3 were positive in 81.3% and 92.7% of metastatic breast carcinomas, respectively. Conversely, 93.5% and 90.0% of non-breast, non-urothelial carcinomas were negative for Wnt9b and GATA3, respectively. Wnt9b expression was positive in rare gastrointestinal, gynecological, lung, pancreas, and salivary gland tumors. All twenty-eight urothelial carcinomas were negative for Wnt9b, while twenty-six (92.9%) were positive for GATA3. Wnt9b was slightly less sensitive but more specific than GATA3 in diagnosing metastatic breast cancer in cytology samples. Particularly, Wnt9b shows higher specificity in differentiating breast and urothelial primaries. The combined use of Wnt9b and GATA3 may increase diagnostic accuracy.

Amphibian-Derived Natural Anticancer Peptides and Proteins: Mechanism of Action, Application Strategies, and Prospects

Cancer is one of the major diseases that seriously threaten human life. Traditional anticancer therapies have achieved remarkable efficacy but have also some unavoidable side effects. Therefore, more and more research focuses on highly effective and less-toxic anticancer substances of natural origin. Amphibian skin is rich in active substances such as biogenic amines, alkaloids, alcohols, esters, peptides, and proteins, which play a role in various aspects such as anti-inflammatory, immunomodulatory, and anticancer functions, and are one of the critical sources of anticancer substances. Currently, a range of natural anticancer substances are known from various amphibians. This paper aims to review the physicochemical properties, anticancer mechanisms, and potential applications of these peptides and proteins to advance the identification and therapeutic use of natural anticancer agents.

The potential role of miRNAs in the pathogenesis of adrenocortical carcinoma - A focus on signaling pathways interplay

Adrenocortical carcinoma (ACC) is a highly malignant infrequent tumor with a dismal prognosis. microRNAs (miRNAs, miRs) are crucial in post-transcriptional gene expression regulation. Due to their ability to regulate multiple gene networks, miRNAs are central to the hallmarks of cancer, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, reprogramming of cellular metabolism, and avoidance of immune destruction. ACC represents a singular form of neoplasia associated with aberrations in the expression of evolutionarily conserved short, non-coding RNAs. Recently, the role of miRNAs in ACC has been examined extensively despite the disease's rarity. Hence, the current review is a fast-intensive track elucidating the potential role of miRNAs in the pathogenesis of ACC besides their association with the survival of ACC.

MicroRNA-21 in gynecological cancers: From molecular pathogenesis to clinical significance

Ovarian, cervical, and endometrial cancers are the three most common gynecological cancer types (GCs). They hold a significant position as the leading causes of mortality among women with cancer-related death. However, GCs are often diagnosed late, severely limiting the efficacy of current treatment options. Thus, there is an urgent, unmet need for innovative experimentation to enhance the clinical treatment of GC patients. MicroRNAs (miRNAs) are a large and varied class of short noncoding RNAs (22 nucleotides in length) that have been shown to play essential roles in various biological processes involved in development. Recent research has shown that miR-211 influences tumorigenesis and cancer formation, adding to our knowledge of the miR-21 dysregulation in GCs. Furthermore, current research that sheds light on the crucial functions of miR-21 may provide supporting evidence for its potential prognostic, diagnostic, and therapeutic applications in the context of GCs. This review will thus focus on the most recent findings concerning miR-21 expression, miR-21 target genes, and the processes behind GCs. In addition, the latest findings that support miR-21's potential use as a non-invasive biomarker and therapeutic agent for detecting and treating cancer will be elucidated in this review. The roles played by various lncRNA/circRNA-miRNA-mRNA axis in GCs are also comprehensively summarized and described in this study, along with any possible implications for how these regulatory networks may contribute to the pathogenesis of GCs. Also, it is crucial to recognize the complexity of the processes involved in tumour therapeutic resistance as a significant obstacle in treating GCs. Furthermore, this review provides an overview of the current state of knowledge regarding the functional significance miR-21 in therapeutic resistance within the context of GCs.

Epithelial cell dysfunction in chronic rhinosinusitis: the epithelial-mesenchymal transition

INTRODUCTION

Epithelial-mesenchymal transition (EMT) is a type of epithelial cell dysfunction, which is widely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS), especially CRS with nasal polyps, and contributes to pathogenesis of the disease. EMT is mediated via complex mechanisms associated with multiple signaling pathways.

AREAS COVERED

We have summarized the underlying mechanisms and signaling pathways promoting EMT in CRS. Strategies or drugs/agents targeting the genes and pathways related to the regulation of EMT are also discussed for their potential use in the treatment of CRS and asthma. A literature search of studies published in English from 2000 to 2023 was conducted using the PubMed database, employing CRS, EMT, signaling, mechanisms, targeting agents/drugs, as individual or combinations of search terms.

EXPERT OPINION

EMT in nasal epithelium not only leads to epithelial cell dysfunction but also plays an important role in nasal tissue remodeling in CRS. A comprehensive understanding of the mechanisms underlying EMT and the development of drugs/agents targeting these mechanisms may provide new treatment strategies for CRS.

Isorhamnetin exerts anti-tumor activity in DEN + CCl4-induced HCC mice

BACKGROUND

Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer and the main cause of cancer death globally. The use of medicinal herbs as chemotherapeutic agents in cancer treatment is receiving attention as they possess no or minimum side effects. Isorhamnetin (IRN), a flavonoid, has been under attention for its anti-inflammatory and anti-proliferative properties in a number of cancers, including colorectal, skin, and lung cancers. However, the in vivo mechanism of isorhamnetin to suppress liver cancer has yet to be explored.

METHODS AND RESULT

HCC was induced by N-diethylnitrosamine (DEN) and carbon tetrachloride (CCL₄) in Swiss albino mice. Isorhamnetin (100 mg/kg body weight) was given to examine its anti-tumor properties in HCC mice model. Histological analysis and liver function assays were performed to assess changes in liver anatomy. Probable molecular pathways were explored using immunoblot, qPCR, ELISA, and immunohistochemistry techniques. Isorhamnetin inhibited various pro-inflammatory cytokines to suppress cancer-inducing inflammation. Additionally, it regulated Akt and MAPKs to suppress Nrf2 signaling. Isorhamnetin activated PPAR-γ and autophagy while suppressing cell cycle progression in DEN + CCl₄-administered mice. Additionally, isorhamnetin regulated various signaling pathways to suppress cell proliferation, metabolism, and epithelial-mesenchymal transition in HCC.

CONCLUSION

Regulating diverse cellular signaling pathways makes isorhamnetin a better anti-cancer chemotherapeutic candidate in HCC. Importantly, the anti-TNF-α properties of isorhamnetin could prove it a valuable therapeutic agent in sorafenib-resistant HCC patients. Additionally, anti-TGF-β properties of isorhamnetin could be utilized to reduce the EMT-inducing side effects of doxorubicin.

RYK Gene Expression Associated with Drug Response Variation of Temozolomide and Clinical Outcomes in Glioma Patients

Temozolomide (TMZ) chemotherapy is an important tool in the treatment of glioma brain tumors. However, variable patient response and chemo-resistance remain exceptionally challenging. Our previous genome-wide association study (GWAS) identified a suggestively significant association of SNP rs4470517 in the RYK (receptor-like kinase) gene with TMZ drug response. Functional validation of RYK using lymphocytes and glioma cell lines resulted in gene expression analysis indicating differences in expression status between genotypes of the cell lines and TMZ dose response. We conducted univariate and multivariate Cox regression analyses using publicly available TCGA and GEO datasets to investigate the impact of RYK gene expression status on glioma patient overall (OS) and progression-free survival (PFS). Our results indicated that in IDH mutant gliomas, RYK expression and tumor grade were significant predictors of survival. In IDH wildtype glioblastomas (GBM), MGMT status was the only significant predictor. Despite this result, we revealed a potential benefit of RYK expression in IDH wildtype GBM patients. We found that a combination of RYK expression and MGMT status could serve as an additional biomarker for improved survival. Overall, our findings suggest that RYK expression may serve as an important prognostic or predictor of TMZ response and survival for glioma patients.

Wnt Signaling Inhibitors and Their Promising Role in Tumor Treatment

In a continuous search for the improvement of antitumor therapies, the inhibition of the Wnt signaling pathway has been recognized as a promising target. The altered functioning of the Wnt signaling in human tumors points to the strategy of the inhibition of its activity that would impact the clinical outcomes and survival of patients. Because the Wnt pathway is often mutated or epigenetically altered in tumors, which promotes its activation, inhibitors of Wnt signaling are being intensively investigated. It has been shown that knocking down specific components of the Wnt pathway has inhibitory effects on tumor growth in vivo and in vitro. Thus, similar effects are expected from the application of Wnt inhibitors. In the last decades, molecules acting as inhibitors on the pathway’s specific molecular levels have been identified and characterized. This review will discuss the inhibitors of the canonical Wnt pathway, summarize knowledge on their effectiveness as therapeutics, and debate their side effects. The role of the components frequently mutated in various tumors that are principal targets for Wnt inhibitors is also going to be brought to the reader’s attention. Some of the molecules identified as Wnt pathway inhibitors have reached early stages of clinical trials, and some have only just been discovered. All things considered, inhibition of the Wnt signaling pathway shows potential for the development of future therapies.

Extracellular Vesicles Act as Carriers for Cargo Delivery and Regulate Wnt Signaling in the Hepatocellular Carcinoma Tumor Microenvironment

As the primary type of liver cancer, hepatocellular carcinoma (HCC) causes a large number of deaths every year. Despite extensive research conducted on this disease, the prognosis of HCC remains unclear. Recently, research has largely focused on extracellular vesicles (EVs), and they have been found to participate in various ways in the development of various diseases, including HCC, such as by regulating cell signaling pathways. However, recent studies have reported the mechanisms underlying the regulation of Wnt signaling by EVs in HCC, primarily focusing on the regulation of the canonical pathways. This review summarizes the current literature on the regulation of Wnt signaling by EVs in HCC and their underlying mechanisms. In addition, we also present future research directions in this field. This will deepen the understanding of HCC and provide new ideas for its treatment.

Molecular mechanisms targeting drug-resistance and metastasis in colorectal cancer: Updates and beyond

Colorectal cancer (CRC) is the third most diagnosed malignancy and a major leading cause of cancer-related deaths worldwide. Despite advances in therapeutic regimens, the number of patients presenting with metastatic CRC (mCRC) is increasing due to resistance to therapy, conferred by a small population of cancer cells, known as cancer stem cells. Targeted therapies have been highly successful in prolonging the overall survival of patients with mCRC. Agents are being developed to target key molecules involved in drug-resistance and metastasis of CRC, and these include vascular endothelial growth factor, epidermal growth factor receptor, human epidermal growth factor receptor-2, mitogen-activated extracellular signal-regulated kinase, in addition to immune checkpoints. Currently, there are several ongoing clinical trials of newly developed targeted agents, which have shown considerable clinical efficacy and have improved the prognosis of patients who do not benefit from conventional chemotherapy. In this review, we highlight recent developments in the use of existing and novel targeted agents against drug-resistant CRC and mCRC. Furthermore, we discuss limitations and challenges associated with targeted therapy and strategies to combat intrinsic and acquired resistance to these therapies, in addition to the importance of implementing better preclinical models and the application of personalized therapy based on predictive biomarkers for treatment selection.

Wnt signaling pathway-related gene PRICKLE1 is a prognostic biomarker for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) has become a major health risk to human health. Although significant clinical progress has been made in the treatment of ESCC, the prognosis of patients still needs to be improved. Therefore, it is important to screen effective molecular indicators for the prognosis of ESCC. In this study, the intersection of up-regulated genes, down-regulated genes, and Wnt signaling pathway-related genes in ESCC was taken, and 47 overlapping genes were found. PRICKLE1 was determined to be an independent prognostic factor in ESCC based on univariate and multifactorial COX risk regression models. Kaplan-Meier survival curves showed that patients in the PRICKLE1 high expression group had significantly better overall survival. In addition, we performed various experiments to examine the effects of PRICKLE1 overexpression on proliferation, migration, and apoptosis of ESCC cells. The experimental results showed that the PRICKLE1-OE group had reduced cell viability, significantly lower migration ability and significantly higher apoptosis rate compared to the NC group.Therefore, we hypothesized that high PRICKLE1 expression could be used to predict the survival rate of ESCC patients, which could be used as an independent prognostic indicator for ESCC patients and provide potential applications for ESCC clinical treatment.

pH-responsive and targeted delivery of chrysin via folic acid-functionalized mesoporous silica nanocarrier for breast cancer therapy

Cancer is a disease of global importance. In order to mitigate conventional chemotherapy-related side effects, phytochemicals with inherent anticancer efficacy have been opted. However, the use of nanotechnology is essential to enhance the bioavailability and therapeutic efficacy of these phytochemicals. Herein, we have formulated folic acid conjugated polyacrylic acid capped mesoporous silica nanoparticles (∼47.6 nm in diameter) for pH-dependent targeted delivery of chrysin to breast cancer (MCF-7) cells. Chrysin loaded mesoporous silica nanoparticles (Chr- mSiO2@PAA/FA) have been noted to induce apoptosis in MCF-7 cells through oxidative insult and mitochondrial dysfunction with subsequent G1 arrest. Further, in tumor bearing mice, intravenous incorporation of Chr-mSiO2@PAA/FA has been noticed to enhance the anti-neoplastic effects of chrysin via tumor site-specific accumulation. Enhanced cytotoxicity of chrysin contributed towards in vivo tumor regression, restoration of normalized tissue architecture and maintenance of healthy body weight. Besides, no serious systemic toxicity was manifested in response to Chr-mSiO2@PAA/FA administration in vivo. Thus, the study evokes about the anticancer potentiality of chrysin and its increased therapeutic activity via incorporation into folic acid conjugated mesoporous silica nanoparticles, which may hold greater impact in field of future biomedical research.

Glycobiology of cellular expiry: Decrypting the role of glycan-lectin regulatory complex and therapeutic strategies focusing on cancer

Often the outer leaflets of living cells bear a coat of glycosylated proteins, which primarily regulates cellular processes. Glycosylation of such proteins occurs as part of their post-translational modification. Within the endoplasmic reticulum, glycosylation enables the attachment of specific oligosaccharide moieties such as, 'glycan' to the transmembrane receptor proteins which confers precise biological information for governing the cell fate. The nature and degree of glycosylation of cell surface receptors are regulated by a bunch of glycosyl transferases and glycosidases which fine-tune attachment or detachment of glycan moieties. In classical death receptors, upregulation of glycosylation by glycosyl transferases is capable of inducing cell death in T cells, tumor cells, etc. Thus, any deregulated alternation at surface glycosylation of these death receptors can result in life-threatening disorder like cancer. In addition, transmembrane glycoproteins and lectin receptors can transduce intracellular signals for cell death execution. Exogenous interaction of lectins with glycan containing death receptors signals for cell death initiation by modulating downstream signalings. Subsequently, endogenous glycan-lectin interplay aids in the customization and implementation of the cell death program. Lastly, the glycan-lectin recognition system dictates the removal of apoptotic cells by sending accurate signals to the extracellular milieu. Since glycosylation has proven to be a biomarker of cellular death and disease progression; glycans serve as specific therapeutic targets of cancers. In this context, we are reviewing the molecular mechanisms of the glycan-lectin regulatory network as an integral part of cell death machinery in cancer to target them for successful therapeutic and clinical approaches.

Review targeted drug delivery systems for norcantharidin in cancer therapy

Norcantharidin (NCTD) is a demethylated derivative of cantharidin (CTD), the main anticancer active ingredient isolated from traditional Chinese medicine Mylabris. NCTD has been approved by the State Food and Drug Administration for the treatment of various solid tumors, especially liver cancer. Although NCTD greatly reduces the toxicity of CTD, there is still a certain degree of urinary toxicity and organ toxicity, and the poor solubility, short half-life, fast metabolism, as well as high venous irritation and weak tumor targeting ability limit its widespread application in the clinic. To reduce its toxicity and improve its efficacy, design of targeted drug delivery systems based on biomaterials and nanomaterials is one of the most feasible strategies. Therefore, this review focused on the studies of targeted drug delivery systems combined with NCTD in recent years, including passive and active targeted drug delivery systems, and physicochemical targeted drug delivery systems for improving drug bioavailability and enhancing its efficacy, as well as increasing drug targeting ability and reducing its adverse effects.

Graphical Abstract

The roles of metabolic profiles and intracellular signaling pathways of tumor microenvironment cells in angiogenesis of solid tumors

Innate and adaptive immune cells patrol and survey throughout the human body and sometimes reside in the tumor microenvironment (TME) with a variety of cell types and nutrients that may differ from those in which they developed. The metabolic pathways and metabolites of immune cells are rooted in cell physiology, and not only provide nutrients and energy for cell growth and survival but also influencing cell differentiation and effector functions. Nowadays, there is a growing awareness that metabolic processes occurring in cancer cells can affect immune cell function and lead to tumor immune evasion and angiogenesis. In order to safely treat cancer patients and prevent immune checkpoint blockade-induced toxicities and autoimmunity, we suggest using anti-angiogenic drugs solely or combined with Immune checkpoint blockers (ICBs) to boost the safety and effectiveness of cancer therapy. As a consequence, there is significant and escalating attention to discovering techniques that target metabolism as a new method of cancer therapy. In this review, a summary of immune-metabolic processes and their potential role in the stimulation of intracellular signaling in TME cells that lead to tumor angiogenesis, and therapeutic applications is provided. Video abstract.

Binding of DEP domain to phospholipid membranes: More than just electrostatics

Over the past decades an extensive effort has been made to provide a more comprehensive understanding of Wnt signaling, yet many regulatory and structural aspects remain elusive. Among these, the ability of Dishevelled (DVL) protein to relocalize at the plasma membrane is a crucial step in the activation of all Wnt pathways. The membrane binding of DVL was suggested to be mediated by the preferential interaction of its C-terminal DEP domain with phosphatidic acid (PA). However, due to the scarcity and fast turnover of PA, we investigated the role on the membrane association of other more abundant phospholipids. The combined results from computational simulations and experimental measurements with various model phospholipid membranes, demonstrate that the membrane binding of DEP/DVL constructs is governed by the concerted action of generic electrostatics and finely-tuned intermolecular interactions with individual lipid species. In particular, while we confirmed the strong preference for PA lipid, we also observed a weak but non-negligible affinity for phosphatidylserine, the most abundant anionic phospholipid in the plasma membrane, and phosphatidylinositol 4,5-bisphosphate. The obtained molecular insight into DEP-membrane interaction helps to elucidate the relation between changes in the local membrane composition and the spatiotemporal localization of DVL and, possibly, other DEP-containing proteins.

WNT5A in tumor development and progression: A comprehensive review

The investigation of tumor microenvironment (TME) is essential to better characterize the complex cellular crosstalk and to identify important immunological phenotypes and biomarkers. The niche is a crucial contributor to neoplasm initiation, maintenance and progression. Therefore, a deeper analysis of tumor surroundings could improve cancer diagnosis, prognosis and assertive treatment. Thus, the WNT family exerts a critical action in tumorigenesis of different types of neoplasms due to dysregulations in the TME. WNT5A, an evolutionary WNT member, is involved in several cellular and physiopathological processes, in addition to tissue homeostasis. The WNT5A protein exerts paradoxical effects while acting as both an oncogene or tumor suppressor by regulating several non-canonical signaling pathways, and consequently interfering in cell growth, cytoskeletal remodeling, migration and invasiveness. This review focuses on a thorough characterization of the role of WNT5A in neoplastic transformation and progression, which may help to understand the prognostic potentiality of WNT5A and its features as a therapeutic target in several cancers. Additionally, we herein summarized novel findings on the mechanisms by which WNT5A might favor tumorigenesis or suppression of cancer progression and discussed the recently developed treatment strategies using WNT5A as a protagonist.

Countering Triple Negative Breast Cancer via Impeding Wnt/β-Catenin Signaling, a Phytotherapeutic Approach

Triple negative breast cancer (TNBC) is characterized as a heterogeneous disease with severe malignancy and high mortality. Aberrant Wnt/β-catenin signaling is responsible for self-renewal and mammosphere generation, metastasis and resistance to apoptosis and chemotherapy in TNBC. Nonetheless, in the absence of a targeted therapy, chemotherapy is regarded as the exclusive treatment strategy for the treatment of TNBC. This review aims to provide an unprecedented overview of the plants and herbal derivatives which repress the progression of TNBC through prohibiting the Wnt/β-catenin pathway. Herbal medicine extracts and bioactive compounds (alkaloids, retinoids. flavonoids, terpenes, carotenoids and lignans) alone, in combination with each other and/or with chemotherapy agents could interrupt the various steps of Wnt/β-catenin signaling, i.e., WNT, FZD, LRP, GSK3β, Dsh, APC, β-catenin and TCF/LEF. These phytotherapy agents diminish proliferation, metastasis, breast cancer stem cell self-renewal and induce apoptosis in cell and animal models of TNBC through the down-expression of the downstream target genes of Wnt signaling. Some of the herbal derivatives simultaneously impede Wnt/β-catenin signaling and other overactive pathways in triple negative breast cancer, including: mTORC1; ER stress and SATB1 signaling. The herbal remedies and their bioactive ingredients perform essential roles in the treatment of the very fatal TNBC via repression of Wnt/β-catenin signaling.

Pharmacologic Manipulation of Late SV40 Factor Suppresses Wnt Signaling and Inhibits Growth of Allogeneic and Syngeneic Colon Cancer Xenografts

Aberrant hyperactivation of Wnt signaling, driven by nuclear β-catenin in the colonic epithelium, represents the seminal event in the initiation and progression of colorectal cancer (CRC). Despite its established role in CRC tumorigenesis, clinical translation of Wnt inhibitors remains unsuccessful. Late SV40 factor (LSF; encoded by TFCP2) is a transcription factor and a potent oncogene. The current study identified a chemotype, named factor quinolinone inhibitors (FQIs), that specifically inhibits LSF DNA-binding, partner protein-binding, and transactivation activities. The role of LSF and FQIs in CRC tumor growth was examined. Herein, the study showed that LSF and β-catenin interacted in several CRC cell lines irrespective of their mutational profile, which was disrupted by FQI2-34. FQI2-34 suppressed Wnt activity in CRC cells in a dose-dependent manner. Leveraging both allogeneic and syngeneic xenograft models showed that FQI2-34 suppressed CRC tumor growth, significantly reduced nuclear β-catenin, and down-regulated Wnt targets such as axis inhibition protein 2 (AXIN-2) and SRY-box transcription factor 9, in the xenograft cells. FQI2-34 suppressed the proliferation of xenograft cells. Adenocarcinomas from a series of stage IV CRC patients revealed a positive correlation between LSF expression and Wnt targets (AXIN-2 and SRY-box transcription factor 9) within the CRC cells. Collectively, this study uncovers the Wnt inhibitory and CRC growth-suppressive effects of these LSF inhibitors in CRC cells, revealing a novel target in CRC therapeutics.

Wnt Signaling in the Breast: From Development to Disease

The Wnt cascade is a primordial developmental signaling pathway that plays a myriad of essential functions throughout development and adult homeostasis in virtually all animal species. Aberrant Wnt activity is implicated in embryonic and tissue morphogenesis defects, and several diseases, most notably cancer. The role of Wnt signaling in mammary gland development and breast cancer initiation, maintenance, and progression is far from being completely understood and is rather shrouded in controversy. In this review, we dissect the fundamental role of Wnt signaling in mammary gland development and adult homeostasis and explore how defects in its tightly regulated and intricated molecular network are interlinked with cancer, with a focus on the breast.

The roles of HOXB8 through activating Wnt/β-catenin and STAT3 signaling pathways in the growth, migration and invasion of ovarian cancer cells

Ovarian cancer is one of the gynecological malignancies ranked third in incidence and first in mortality in the world. Homoboxb8 (HOXB8) has been demonstrated to play crucial roles in various tumors. However, the function of HOXB8 in ovarian cancer remains to be addressed. Quantitative real-time polymerase chain reaction, immunohistochemistry staining and western blot assays demonstrated that HOXB8 expression was up-regulated in human ovarian cancer tissues and cells. The results of CCK-8 and colony formation assays indicated that HOXB8 promoted the proliferation of ovarian cancer cells. Transwell and immunofluorescence (IF) staining assay demonstrated that HOXB8 promoted the migration and invasion of ovarian cancer cells. Importantly, mechanism analysis implied that HOXB8 increased the expression of β-catenin and phosphorylation of STAT3, and the downstream target molecules of Cyclin D1, c-Myc, TWIST1, MMP7 and MMP9, indicating that HOXB8 could promote the activation of Wnt/β-catenin and STAT3 pathways. Moreover, HOXB8 knockdown suppressed xenograft tumor growth, and inhibited the levels of HOXB8 and Ki-67, while increasing the level of E-cadherin in mice. In conclusion, HOXB8 promotes cell proliferation, migration and invasion through modulating Wnt/β-catenin and STAT3 signaling pathways in ovarian cancer, suggesting that HOXB8 may provide a promising target for the therapy of ovarian cancer.

GRAPHICAL ABSTRACT

Canonical Wnt Signaling in the Pathology of Iron Overload-Induced Oxidative Stress and Age-Related Diseases

Iron accumulates in the vital organs with aging. This is associated with oxidative stress, inflammation, and mitochondrial dysfunction leading to age-related disorders. Abnormal iron levels are linked to neurodegenerative diseases, liver injury, cancer, and ocular diseases. Canonical Wnt signaling is an evolutionarily conserved signaling pathway that regulates many cellular functions including cell proliferation, apoptosis, cell migration, and stem cell renewal. Recent evidences indicate that iron regulates Wnt signaling, and iron chelators like deferoxamine and deferasirox can inhibit Wnt signaling and cell growth. Canonical Wnt signaling is implicated in the pathogenesis of many diseases, and there are significant efforts ongoing to develop innovative therapies targeting the aberrant Wnt signaling. This review examines how intracellular iron accumulation regulates Wnt signaling in various tissues and their potential contribution in the progression of age-related diseases.

Wnt Family Member 9b (Wnt9b) Is a New Sensitive and Specific Marker for Breast Cancer

Confirming the tumor origin is often a diagnostic challenge in pathology and carries significant therapeutic impacts. Cytokeratin 7, estrogen receptor, and GATA binding protein 3 (GATA3) are well-established diagnostic markers frequently used to support a tumor's breast origin. However, their specificities still have room to improve. Many nonbreast tumors express cytokeratin 7 and estrogen receptor, and urothelial tumors frequently express GATA3. There is a practical need for a new breast lineage marker that is sensitive and specific. Wnt family member proteins play critical roles in embryo development, tissue homeostasis and tumor development through β-catenin dependent and independent pathways. The current study evaluated Wnt9b and GATA3 expression in 163 primary breast cancers, 63 metastatic breast cancers, and 525 nonbreast epithelial tumors. The positive rates of Wnt9b and GATA3 in primary breast cancer were both 98.7%. The positive rates in metastatic breast cancer were 87.3% for Wnt9b and 96.8% for GATA3. For nonbreast tumors, including 64 cases of urothelial carcinoma, Wnt9b was negative in all except salivary gland carcinomas. The study demonstrated that Wnt9b is a breast cancer marker with similar sensitivity as GATA3 but with greater specificity than GATA3 and may ultimately become a useful diagnostic tool in routine surgical pathology practice.

Clinical Importance of Wnt5a in the Pathogenesis of Colorectal Cancer

Wnt5a is one of the potent signaling molecules that initiates responses involved in cancer through activation of both canonical and noncanonical signaling cascades. Wnt5a both directly and indirectly triggers cancer-associated signaling pathways based on the cancer type. In colorectal cancer (CRC), altering Wnt5a expression can influence several cellular processes of tumor cells, including proliferation, differentiation, migration, invasion, and metastasis. This review summarizes the molecular mechanisms and clinical importance of Wnt5a in the pathogenesis of CRC for better understanding the pathogenesis and its potential role as a prognostic marker and as an appropriate therapeutic target in the treatment of this disease in the future.

The Interaction between microRNAs and the Wnt/β-Catenin Signaling Pathway in Osteoarthritis

Osteoarthritis (OA) is a chronic disease affecting the whole joint, which still lacks a disease-modifying treatment. This suggests an incomplete understanding of underlying molecular mechanisms. The Wnt/β-catenin pathway is involved in different pathophysiological processes of OA. Interestingly, both excessive stimulation and suppression of this pathway can contribute to the pathogenesis of OA. microRNAs have been shown to regulate different cellular processes in different diseases, including the metabolic activity of chondrocytes and osteocytes. To bridge these findings, here we attempt to give a conclusive overview of microRNA regulation of the Wnt/β-catenin pathway in bone and cartilage, which may provide insights to advance the development of miRNA-based therapeutics for OA treatment.

Implications of viral infection in cancer development

Since the identification of the first human oncogenic virus in 1964, viruses have been studied for their potential role in aiding the development of cancer. Through the modulation of cellular pathways associated with proliferation, immortalization, and inflammation, viral proteins can mimic the effect of driver mutations and contribute to transformation. Aside from the modulation of signaling pathways, the insertion of viral DNA into the host genome and the deregulation of cellular miRNAs represent two additional mechanisms implicated in viral oncogenesis. In this review, we will discuss the role of twelve different viruses on cancer development and how these viruses utilize the abovementioned mechanisms to influence oncogenesis. The identification of specific mechanisms behind viral transformation of human cells could further elucidate the process behind cancer development.

Phospho-β-catenin expression in primary and metastatic melanomas and in tumor-free visceral tissues, and associations with expression of PD-L1 and PD-L2

β-catenin (βcat) is an important downstream effector in the Wnt signaling pathway and plays important roles in the development and progression of many cancers including melanoma. βcat expression is regulated by GSK-3β-mediated phosphorylation at positions 33, 37 and 41. In normal cells, phosphorylation at these sites triggers proteasomal degradation, which prevents accumulation of free cytoplasmic βcat. In cancer cells, stabilized β-catenin translocates into the nucleus, where it associates with TCF/Lef proteins to activate transcription of genes that promote tumorigenesis and metastasis, including PD-L1. It has been suggested that nuclear phospho-βcat (pβcat) staining may be diagnostically useful in differentiating primary from metastatic melanoma. Also, a pβcat peptide (residues 30-39, with only S33 phosphorylated) is naturally presented by melanoma cells as a T-cell target. We evaluated expression of pS33-βcat in primary and metastatic melanomas by immunohistochemistry and found its expression varied widely but was most commonly cytoplasmic. Nuclear staining was identified in only 18% of metastatic melanomas. Staining with antibodies to pS33-βcat and pS33/37/T41-βcat was most intense in mitotic melanoma cells; however, pS33-βcat intensity was not significantly associated with AJCC stage, tumor location, BRAF mutation status, or immune infiltrates. Yet, PD-L1 and PD-L2 expression by tumor cells were significantly higher in tumors with high pS33-βcat expression. The low rate of nuclear pS33-βcat expression suggests that pS33-βcat may have limited utility for identifying metastatic melanomas. However, high expression in dividing cells and strong associations with PD-L1 and PD-L2 expression may inform future personalized therapies for tumors with high pS33-βcat expression.

Generation of the tumor-suppressive secretome from tumor cells

Rationale: The progression of cancer cells depends on the soil and building an inhibitory soil might be a therapeutic option. We previously created tumor-suppressive secretomes by activating Wnt signaling in MSCs. Here, we examined whether the anti-tumor secretomes can be produced from tumor cells. Methods: Wnt signaling was activated in tumor cells by overexpressing β-catenin or administering BML284, a Wnt activator. Their conditioned medium (CM) was applied to cancer cells or tissues, and the effects of CM were evaluated. Tumor growth in the mammary fat pad and tibia in C57BL/6 female mice was also evaluated through μCT imaging and histology. Whole-genome proteomics analysis was conducted to determine and characterize novel tumor-suppressing proteins, which were enriched in CM. Results: The overexpression of β-catenin or the administration of BML284 generated tumor-suppressive secretomes from breast, prostate and pancreatic cancer cells. In the mouse model, β-catenin-overexpressing CM reduced tumor growth and tumor-driven bone destruction. This inhibition was also observed with BML284-treated CM. Besides p53 and Trail, proteomics analysis revealed that CM was enriched with enolase 1 (Eno1) and ubiquitin C (Ubc) that presented notable tumor-suppressing actions. Importantly, Eno1 immunoprecipitated CD44, a cell-surface adhesion receptor, and its silencing suppressed Eno1-driven tumor inhibition. A pan-cancer survival analysis revealed that the downregulation of MMP9, Runx2 and Snail by CM had a significant impact on survival outcomes (p < 0.00001). CM presented a selective inhibition of tumor cells compared to non-tumor cells, and it downregulated PD-L1, an immune escape modulator. Conclusions: The tumor-suppressive secretome can be generated from tumor cells, in which β-catenin presented two opposing roles, as an intracellular tumor promoter in tumor cells and a generator of extracellular tumor suppressor in CM. Eno1 was enriched in CM and its interaction with CD44 was involved in Eno1's anti-tumor action. Besides presenting a potential option for treating primary cancers and metastases, the result indicates that aggressive tumors may inhibit the growth of less aggressive tumors via tumor-suppressive secretomes.

Natural-Derived Molecules as a Potential Adjuvant in Chemotherapy: Normal Cell Protectors and Cancer Cell Sensitizers

BACKGROUND

Cancer is a global threat to humans and a leading cause of death worldwide. Cancer treatment includes, among other things, the use of chemotherapeutic agents, compounds that are vital for treating and preventing cancer. However, chemotherapeutic agents produce oxidative stress along with other side effects that would affect the human body.

OBJECTIVE

To reduce the oxidative stress of chemotherapeutic agents in cancer and normal cells by naturally derived compounds with anti-cancer properties, and protect normal cells from the oxidation process. Therefore, the need to develop more potent chemotherapeutics with fewer side effects has become increasingly important.

METHOD

Recent literature dealing with the antioxidant and anticancer activities of the naturally naturally-derived compounds: morin, myricetin, malvidin, naringin, eriodictyol, isovitexin, daidzein, naringenin, chrysin, and fisetin has been surveyed and examined in this review. For this, data were gathered from different search engines, including Google Scholar, ScienceDirect, PubMed, Scopus, Web of Science, Scopus, and Scifinder, among others. Additionally, several patient offices such as WIPO, CIPO, and USPTO were consulted to obtain published articles related to these compounds.

RESULT

Numerous plants contain flavonoids and polyphenolic compounds such as morin, myricetin, malvidin, naringin, eriodictyol, isovitexin, daidzein, naringenin, chrysin, and fisetin, which exhibit ‎antioxidant, anti-inflammatory, and anti-carcinogenic actions via several mechanisms. These compounds show sensitizers of cancer cells and protectors of healthy cells. Moreover, these compounds can reduce oxidative stress, which is accelerated by chemotherapeutics and exhibit a potent anticancer effect on cancer cells.

CONCLUSIONS

Based on these findings, more research is recommended to explore and evaluate such flavonoids and polyphenolic compounds.

Comprehensive evaluation of two Astragalus species (A. campylosema and A. hirsutus) based on biological, toxicological properties and chemical profiling

Astragalus L. (Fabaceae) is an important genus with numerous species having various traditional medicinal uses making them of interest for scientific investigations to ascertain their therapeutic benefits. In the present study, the quantitative polyphenolic profiles of methanolic extracts from different parts (leaves, flowers, and roots) of two endemic Astragalus species growing in Turkey, i.e. A. campylosema Boiss. and A. hirsutus Vahl were determined, along with their antioxidant and enzyme inhibitory properties. A. campylosema and A. hirsutus extracts showed varying total phenolic (25.80-40.60 and18.59-29.46 mg GAE/g, respectively) and total flavonoid (11.21-105.91 and 16.06-131.91 mg RE/g, respectively) contents. HPLC-MS/MS revealed rutin to be the predominant phenolic compound in all the extracts of A. campylosema and leaf extract of A. hirsutus (133.53-752.42 μg g^-1), while hyperoside was the major one in the flower and root extracts of A. hirsutus (2014.07 and 123.13 μg g^-1, respectively). In DPPH and ABTS assays, radical scavenging capacity was demonstrated by all extracts of A. campylosema (47.13-48.10 and 87.03-115.36 mg TE/g, respectively) and A. hirsutus (17.82-38.67 and 47.84-57.29 mg TE/g, respectively). Reducing activity was also displayed by the extracts in CUPRAC and FRAP assays (A. campylosema: 83.06-135.20 and 59.15-90.19 mg TE/g, respectively; A. hirsutus: 53.02-83.42 and 31.25-43.25 mg TE/g, respectively). All extracts were also found to act as metal chelators (12.32-21.45 mg EDTAE/g) and exhibited total antioxidant capacity ranging from 1.16 to 1.60 mmol TE/g, in phosphomolybdenum assay. Acetyl- and butyryl-cholinesterase inhibitory effects were observed by all the extracts of the two species (1.56-4.99 mg GALAE/g). Anti-hyperpigmentation potential by inhibiting tyrosinase (54.55-67.35 mg KAE/g) was reported as well. Carbohydrate hydrolyzing enzymes, amylase and glucosidase were also inhibited (0.22-1.03 mmol ACAE/g). Overall, A. campylosema extracts showed relatively better antioxidant and enzyme inhibitory potentials compared to A. hirsutus extracts. Strikingly, A. hirsutus extracts was found to have higher AGE inhibition activity than A. campylosema. Although the cytotoxic effect of three different organs obtained from A. campylosema and A. hirsutus increased depending on the dose (from 10 to 200 μg/mL), it was found that both plant extracts did not show a genotoxic effect at the highest concentration of 200 μg/mL. Indeed, data amassed from this current scientific work showed the two selected Astragalus species to be rich in bioactive polyphenols that could be responsible for the various pharmacological activities and hence demands to be further explored for their possible applications as natural health promoting agents.

HDAC6 suppresses microRNA-199a transcription and augments HPV-positive cervical cancer progression through Wnt5a upregulation

High-risk human papillomavirus (HR-HPV) infection is a major risk factor for the initiation and progression of cervical cancer (CC). This study aimed to explore the role of histone deacetylase 6 (HDAC6) in HPV-positive CC and the molecules implicated. Differentially expressed genes between HPV-positive and HPV-negative tissues, and differentially expressed microRNAs (miRNAs) in cells after HDAC6 downregulation were identified using microarray analyses. The expression profiles of HDAC6 and miR-199a and their cellular functions were investigated via loss-of-function studies. Xenograft tumors were induced in mice for in vivo studies. HDAC6 and Wnt5a were highly expressed, whereas miR-199a was poorly expressed in HPV-positive CC tissues. Downregulation of HDAC6 reduced proliferation, migration, invasion, and resistance to apoptosis of HPV-positive CC cells. HDAC6 suppressed the transcription of miR-199a, and miR-199a targeted Wnt5a to inactivate the Wnt signaling pathway. Further downregulation of miR-199a blocked the inhibitory effect of HDAC6 silencing on CC cell growth both in vivo and in vitro, whereas further artificial inhibition of Wnt5a inactivated Wnt signaling and blocked the malignant behaviors of CC cells. This study showed that HDAC6 suppresses the transcription of miR-199a and enhances the progression of HPV-positive cervical cancer through upregulation of Wnt5a.

Cell signaling pathways as molecular targets to eliminate AML stem cells

Acute myeloid leukemia (AML) remains the most lethal of leukemias and a small population of cells called leukemic stem cells (LSCs) has been associated with disease relapses. Some cell signaling pathways play an important role in AML survival, proliferation and self-renewal properties and are abnormally activated or suppressed in LSCs. This includes the NF-κB, Wnt/β-catenin, Hedgehog, Notch, EGFR, JAK/STAT, PI3K/AKT/mTOR, TGF/SMAD and PPAR pathways. This review aimed to discuss these pathways as molecular targets for eliminating AML LSCs. Herein, inhibitors/activators of these pathways were summarized as a potential new anti-AML therapy capable of eliminating LSCs to guide future researches. The clinical use of cell signaling pathways data can be useful to enhance the anti-AML therapy.

Contribution of RAGE axis activation to the association between metabolic syndrome and cancer

Far beyond the compelling proofs supporting that the metabolic syndrome represents a risk factor for diabetes and cardiovascular diseases, a growing body of evidence suggests that it is also a risk factor for different types of cancer. However, the involved molecular mechanisms underlying this association are not fully understood, and they have been mainly focused on the individual contributions of each component of the metabolic syndrome such as obesity, hyperglycemia, and high blood pressure to the development of cancer. The Receptor for Advanced Glycation End-products (RAGE) axis activation has emerged as an important contributor to the pathophysiology of many clinical entities, by fueling a chronic inflammatory milieu, and thus supporting an optimal microenvironment to promote tumor growth and progression. In the present review, we intend to highlight that RAGE axis activation is a crosswise element on the potential mechanistic contributions of some relevant components of metabolic syndrome into the association with cancer.

Upregulation of SDHA inhibited proliferation, migration, and invasion of clear cell renal cell carcinoma cells via inactivation of the Wnt/β-catenin pathway

Clear cell renal cell carcinoma (ccRCC) is a common genitourinary malignancy with high mortality. Recent findings suggest that the succinate dehydrogenase complex subunit A (SDHA) is lowly expressed in many types of cancers and involved in tumorigenesis. However, the potential regulatory roles and molecular mechanisms by which SDHA affects the development and progression of ccRCC remain largely unknown. In this study, our results showed that there was significant downregulation of SDHA in ccRCC tissue relative to corresponding non-cancerous tissue, and low expression of SDHA was associated with Fuhrman pathological grade, tumor size, TNM stage, metastasis, and poor prognosis in ccRCC patients. Moreover, overexpression of SDHA inhibited the proliferation, invasion, and migration capacities of ccRCC cells. Mechanistically, SDHA impeded the proliferation and metastasis of ccRCC cells by inactivation of the Wnt/β-catenin pathway. In vivo experiments, SDHA suppressed ccRCC growth in a nude mouse model. In conclusion, our study results indicated that SDHA may act as a new molecular marker for judging the occurrence and development of ccRCC and serve as a therapeutic target for the treatment of human ccRCC.

Mining Natural Compounds to Target WNT Signaling: Land and Sea Tales

WNT signaling plays paramount roles in organism development, physiology, and disease, representing a highly attractive target for drug development. However, no WNT-modulating drugs have been approved, with several candidates trudging through the early clinical trials. This delay instigates alternative approaches to discover WNT-modulating drugs. Natural products were the source of therapeutics for centuries, but the chemical diversity they offer, especially when looking at different taxonomic groups and habitats, is still to a large extent unexplored. These considerations urge researchers to screen natural compounds for the WNT-modulatory activities. Since several reviews on such endeavors exist, we here have attempted to present these efforts as "Land and sea tales" (citing the book title by Rudyard Kipling) superimposing them onto the traditional pipeline of drug discovery and early development. In doing so, we illustrate each step of the pipeline with case studies stemming from our own research. It will become obvious that several steps of the pipeline need to be modified when applied to natural products rather than to synthetic libraries. Yet the main message of this chapter is that natural compounds represent a powerful source for the WNT signaling modulators and can be developed towards drug candidates against WNT-dependent maladies.

Molecular Mechanisms of Colon Cancer Progression and Metastasis: Recent Insights and Advancements

Colorectal cancer (CRC), the third most common type of cancer, is the second leading cause of cancer-related mortality rates worldwide. Although modern research was able to shed light on the pathogenesis of CRC and provide enhanced screening strategies, the prevalence of CRC is still on the rise. Studies showed several cellular signaling pathways dysregulated in CRC, leading to the onset of malignant phenotypes. Therefore, analyzing signaling pathways involved in CRC metastasis is necessary to elucidate the underlying mechanism of CRC progression and pharmacotherapy. This review focused on target genes as well as various cellular signaling pathways including Wnt/β-catenin, p53, TGF-β/SMAD, NF-κB, Notch, VEGF, and JAKs/STAT3, which are associated with CRC progression and metastasis. Additionally, alternations in methylation patterns in relation with signaling pathways involved in regulating various cellular mechanisms such as cell cycle, transcription, apoptosis, and angiogenesis as well as invasion and metastasis were also reviewed. To date, understanding the genomic and epigenomic instability has identified candidate biomarkers that are validated for routine clinical use in CRC management. Nevertheless, better understanding of the onset and progression of CRC can aid in the development of early detection molecular markers and risk stratification methods to improve the clinical care of CRC patients.

Beyond TNBC: Repositioning of Clofazimine Against a Broad Range of Wnt-Dependent Cancers

Wnt signaling plays key roles in oncogenic transformation and progression in a number of cancer types, including tumors in the breast, colon, ovaries, liver, and other tissues. Despite this importance, no therapy targeting the Wnt pathway currently exists. We have previously shown that the anti-mycobacterium drug clofazimine is a specific inhibitor of Wnt signaling and cell proliferation in triple-negative breast cancer (TNBC). Here, we expand the applicability of clofazimine to a set of other Wnt-dependent cancers. Using a panel of cell lines from hepatocellular carcinoma, glioblastoma, as well as colorectal and ovarian cancer, we show that the efficacy of clofazimine against a given cancer type correlates with the basal levels of Wnt pathway activation and the ability of the drug to inhibit Wnt signaling in it, being further influenced by the cancer mutational spectrum. Our study establishes the basis for patient stratification in the future clinical trials of clofazimine and may ultimately contribute to the establishment of the Wnt pathway-targeted therapy against a diverse set of cancer types relying on the oncogenic Wnt signaling.

Analysis of N6-Methyladenosine Methyltransferase Reveals METTL14 and ZC3H13 as Tumor Suppressor Genes in Breast Cancer

Objectives

Recently, an increasing number of studies have revealed that N6-methyladenosine (m6A) functions as a significant post-transcriptional modification which plays a critical role in the occurrence and progression of enriched tumors by regulating coding and non-coding RNA biogenesis. However, the biological function of m6A in breast cancer remains largely unclear.

Materials and Methods

In this study, we used a series of bioinformatic databases and tools to jointly analyze the expression of m6A methylation transferases (METTL3, METTL14, WTAP, RBM15, RBM15B and ZC3H13) and investigate the prognostic value of METTL14 and ZC3H13 in breast cancer. Besides, we analyzed the downstream carcinogenic molecular mechanisms related to METTL14 and ZC3H13 and their relationship with immune infiltration in breast tumor tissues.

Results

The results showed that METTL14 and ZC3H13 were the down-regulated m6A methylation transferases in breast cancer. Survival outcome analysis suggested that abnormally low expression of METTL14 and ZC3H13 could predict unfavorable prognosis in four breast cancer subtypes. Moreover, their down-regulation was associated with ER-, PR- and triple-negative breast cancer patients, as well as tumor progression (increased Scarff, Bloom and Richardson grade status and Nottingham Prognostic Index classification). Co-expression analysis revealed that METTL14 and ZC3H13 had a strong positive correlation with APC, an antagonist of the Wnt signaling pathway, indicating they might cooperate in regulating proliferation, invasion, and metastasis of tumor cells. METTL14, ZC3H13, and APC expression levels had significant positive correlation with infiltrating levels of CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells, and negative correlation with Treg cells in breast cancer.

Conclusions

This study demonstrated that down-regulation of METTL14 and ZC3H13 which act as two tumor suppressor genes was found in breast cancer and predicted poor prognosis. Their abnormal expression promoted breast cancer invasion by affecting pathways related to tumor progression and mediating immunosuppression.

Angiogenesis-Related Functions of Wnt Signaling in Colorectal Carcinogenesis

Simple Summary

Angiogenesis belongs to the most clinical characteristics of colorectal cancer (CRC) and is strongly linked to the activation of Wnt/β-catenin signaling. The most prominent factors stimulating constitutive activation of this pathway, and in consequence angiogenesis, are genetic alterations (mainly mutations) concerning APC and the β-catenin encoding gene (CTNNB1), detected in a large majority of CRC patients. Wnt/β-catenin signaling is involved in the basic types of vascularization (sprouting and nonsprouting angiogenesis), vasculogenic mimicry as well as the formation of mosaic vessels. The number of known Wnt/β-catenin signaling components and other pathways interacting with Wnt signaling, regulating angiogenesis, and enabling CRC progression continuously increases. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Abstract

Aberrant activation of the Wnt/Fzd/β-catenin signaling pathway is one of the major molecular mechanisms of colorectal cancer (CRC) development and progression. On the other hand, one of the most common clinical CRC characteristics include high levels of angiogenesis, which is a key event in cancer cell dissemination and distant metastasis. The canonical Wnt/β-catenin downstream signaling regulates the most important pro-angiogenic molecules including vascular endothelial growth factor (VEGF) family members, matrix metalloproteinases (MMPs), and chemokines. Furthermore, mutations of the β-catenin gene associated with nuclear localization of the protein have been mainly detected in microsatellite unstable CRC. Elevated nuclear β-catenin increases the expression of many genes involved in tumor angiogenesis. Factors regulating angiogenesis with the participation of Wnt/β-catenin signaling include different groups of biologically active molecules including Wnt pathway components (e.g., Wnt2, DKK, BCL9 proteins), and non-Wnt pathway factors (e.g., chemoattractant cytokines, enzymatic proteins, and bioactive compounds of plants). Several lines of evidence argue for the use of angiogenesis inhibition in the treatment of CRC. In the context of this paper, components of the Wnt pathway are among the most promising targets for CRC therapy. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

GABRD promotes progression and predicts poor prognosis in colorectal cancer

Little is known about the functional roles of gamma-aminobutyric acid type A receptor subunit delta (GABRD) in colorectal cancer (CRC). The expression of GABRD between CRCs and adjacent normal tissues (NTs), metastasis and primary tumors was compared using public transcriptomic datasets. A tissue microarray and immunohistochemical staining (IHC) were used to determine the clinical and prognostic significance of the GABRD in CRC. We used gain-of-function and loss-of-function experiments to investigate the in vitro roles of GABRD in cultured CRC cells. We characterized the potential mechanism of GABRD’s activities in CRC using a Gene Set Enrichment Analysis (GSEA) with The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD) dataset. We found that the GABRD expression was significantly increased in CRCs compared to that in NTs, but was similar between metastasis and primary tumors. Overexpression of GABRD was significantly associated with later pTNM stages and unfavorable patient survival. Overexpression of GABRD accelerated while knock-down of GABRD inhibited cell growth and migration. Mechanistically, the function of GABRD might be ascribed to its influence on major oncogenic events such as epithelial–mesenchymal transition (EMT), angiogenesis, and hedgehog signaling. Collectively, GABRD could be a novel prognostic predictor for CRC that deserves further investigation.

Circular RNA hsa_circ_0005114-miR-142-3p/miR-590-5p-adenomatous polyposis coli protein axis as a potential target for treatment of glioma

Glioma is the most common type of brain tumor and is associated with a high mortality rate. Despite recent advances in treatment options, the overall prognosis in patients with glioma remains poor. Studies have suggested that circular (circ)RNAs serve important roles in the development and progression of glioma and may have potential as therapeutic targets. However, the expression profiles of circRNAs and their functions in glioma have rarely been studied. The present study aimed to screen differentially expressed circRNAs (DECs) between glioma and normal brain tissues using sequencing data collected from the Gene Expression Omnibus database (GSE86202 and GSE92322 datasets) and explain their mechanisms based on the competing endogenous (ce)RNA regulatory hypothesis. In total, 424 commonly downregulated DECs (with the Gene_symbol annotated in the circBase database) in these two datasets were identified. Using the CircInteractome and Starbase databases, 18 micro (mi)RNAs (miRs) were predicted to interact with DECs, while 22 glioma-related genes obtained from the Comparative Toxicogenomics Database were predicted to be regulated by 15 miRNAs via the miRwalk 2.0 database. A ceRNA network was established based on 115 DECs, 15 miRNAs and 22 mRNAs. LinkedOmics online analysis using The Cancer Genome Atlas (TCGA) data showed that hsa-miR-142-3p/hsa-miR-590-5p and their target gene adenomatous polyposis coli protein (APC) were all significantly associated with overall survival rate and their prognosis trend was opposite, revealing that high expression levels of hsa-miR-142-3p/hsa-miR-590-5 were associated with a poor overall survival rate, while high APC expression with a good overall survival rate. UALCAN analysis using TCGA data of glioblastoma multiforme and the GSE25632 and GSE103229 microarray datasets showed that hsa-miR-142-3p/hsa-miR-590-5p was upregulated and APC was downregulated. Thus, hsa-miR-142-3p/hsa-miR-590-5p-APC-related circ/ceRNA axes may be important in glioma, and hsa_circ_0005114 interacted with both of these miRNAs. Functional analysis showed that hsa_circ_0005114 was involved in insulin secretion, while APC was associated with the Wnt signaling pathway. In conclusion, hsa_circ_0005114-miR-142-3p/miR-590-5p-APC ceRNA axes may be potential targets for the treatment of glioma.