FZD7 has a critical role in cell proliferation in triple negative breast cancer

Silencing of FZD7 Inhibits Endometriotic Cell Viability, Migration, and Angiogenesis by Promoting Ferroptosis

BACKGROUND

Endometriosis (EMS) is a difficult gynecological disease to cure. Frizzled-7 (FZD7) has been shown to be associated with the development of EMS, but its specific mechanism remains unclarified. This study aims to explore the role of FZD7 in EMS.

METHODS

RT-qPCR and western blot were used to detect the expression level of FZD7 in human endometrial stromal cells (hESCs) and human ectopic endometrial stromal cell line hEM15A. The interfering plasmid of FZD7 was established. CCK-8, EdU, wound healing, transwell invasion, and cytoskeletal staining assays were applied to evaluate the role of FZD7 silencing in hEM15A cell proliferation, invasion, and migration. Tube forming ability of cells was evaluated by tube formation assay. Cellular VEGF, GSH, and MDA levels were measure by kits. Intracellular lipid ROS and Fe2+ levels were tested using C11-BODIPY (581/591) and FeRhoNox-1 probes, respectively. The ferroptosis-related protein SLC7A11, GPX4, and ACSL4 expressions were analyzed using western blot. The effects of ferroptosis on endometriotic cell viability, migration, and angiogenesis were further analyzed with the addition of an ferroptosis inhibitor (Fer-1).

RESULTS

FZD7 was upregulated in hEM15A cells, and silencing of FZD7 inhibited cell proliferation, migration, invasion, and angiogenesis abilities. Downregulation of FZD7 decreased cellular GSH level and elevated MDA level. Knockdown of FZD7 also caused an increase in intracellular ROS and Fe2+ levels, as well as the downregulation of SLC7A11 and GPX4 levels and the upregulation of ACSL4 level, which are hallmarks of ferroptosis. However, the inhibitory effects of FZD7 knockdown on hEM15A cell progression were reversed when ferroptosis inhibitor Fer-1 added.

CONCLUSION

The above indices suggest that FZD7 knockdown regulates endometriotic cell proliferation, invasion, migration, and angiogenesis via ferroptosis.

ABCG8‑mediated sterol efflux increases cancer cell progression via the LRP6/Wnt/β‑catenin signaling pathway in radiotherapy‑resistant MDA‑MB‑231 triple‑negative breast cancer cells

Expression levels of ATP‑binding cassette (ABC) transporters are known to be increased in various tumor cells, including in breast cancer, and they are responsible for mediating drug resistance, leading to treatment failure. In the present study, gene expression array analysis revealed that among ABC transporter subtypes, ABC subfamily G member 8 (ABCG8) was one of the most increased in radiotherapy‑resistant triple‑negative breast cancer (RT‑R‑TNBC) cells compared with in TNBC cells. ABCG8 is involved in sterol efflux; however, its role in cancer is not well known. Therefore, the present study investigated the effect of ABCG8 on tumor progression in RT‑R‑TNBC cells. Gene expression profiling was conducted using the QuantiSeq 3' mRNA‑Seq Service, followed by western blotting to confirm protein levels. Loss‑of‑function assays using small interfering RNA (si) transfection were performed to assess the roles of ABCG8 and its regulatory signaling pathways. RT‑R‑MDA‑MB‑231 cells exhibited increased cholesterol levels in both cells and the surrounding media via induction of sterol regulatory element binding protein 1 (mature form) and fatty acid synthase. siABCG8 transfection increased intracellular cholesterol levels but decreased cholesterol levels in the media, indicating an accumulation of cholesterol inside cells. Additionally, RT‑R‑MDA‑MB‑231 cells exhibited increased levels of β‑catenin compared with MDA‑MB‑231 cells, which was significantly reduced by ABCG8 knockdown. Furthermore, ABCG8 knockdown led to cell cycle arrest in the G2/M phase in RT‑R‑MDA‑MB‑231 cells by reducing Polo‑like kinase 1 (PLK1) and Cyclin B1 expression. RT‑R‑MDA‑MB‑231 cells also exhibited increased phosphorylated‑low‑density lipoprotein (LDL) receptor‑related protein 6 (LRP6) levels compared with MDA‑MB‑231 cells, and these were decreased by siABCG8 transfection. LRP6 siRNA transfection decreased β‑catenin, PLK1 and Cyclin B1 expression. In addition, feedback mechanisms such as liver X receptor and inducible degrader of LDL were decreased in RT‑R‑MDA‑MB‑231 cells under normal conditions compared with in MDA‑MB‑231 cells. To the best of our knowledge, the present study was the first to suggest that the cholesterol exported by ABCG8, not inside the cells, may affect cancer progression via the LRP6/Wnt/β‑catenin signaling pathway in RT‑R‑TNBC. The regulation of this pathway may offer a potential therapeutic strategy for the treatment of RT‑R‑TNBC.

Frizzled receptors: gatekeepers of Wnt signaling in development and disease

Frizzled (FZD) receptors are a subset of G-protein-coupled receptors (GPCRs), the largest class of human cell surface receptors and a major target of FDA-approved drugs. Activated by Wnt ligands, FZDs regulate key cellular processes such as proliferation, differentiation, and polarity, positioning them at the intersection of developmental biology and disease, including cancer. Despite their significance, FZD signaling remains incompletely understood, particularly in distinguishing receptor-specific roles across canonical and non-canonical Wnt pathways. Challenges include defining ligand-receptor specificity, elucidating signal transduction mechanisms, and understanding the influence of post translational modifications and the cellular context. Structural dynamics, receptor trafficking, and non-canonical signaling contributions also remain areas of active investigation. Recent advances in structural biology, transcriptomics, and functional genomics are beginning to address these gaps, while emerging therapeutic approaches-such as small-molecule modulators and antibodies-highlight the potential of FZDs as drug targets. This review synthesizes current insights into FZD receptor biology, examines ongoing controversies, and outlines promising directions for future research and therapeutic development.

Bioinformatics revealed biomarkers for diagnosis in kidney stones

Background

One of the most prevalent urinary illnesses is kidney stone formation, often known as nephrolithiasis. The precise processes of kidney stone remain poorly known after substantial investigation. In order to successfully prevent and cure stone formation and recurrence, additional research into the pathophysiology of stone formation is of paramount importance. Ferroptosis is linked to a variety of renal diseases and is a critical factor in the death of cells. However, little is known about how ferroptosis-related genes (FRGs) contribute to the development of kidney stones.

Methods

The Ferroptosis Database and the Gene Expression Omnibus (GEO) database provided us with information on kidney stones and FRGs, respectively (FerrDb).

Results

Eight DE-FRGs related to kidney stones were found in total, and they were all closely related to immune response and autophagy management. Following this, among the 8 DE-FRGs, LASSO and SVM-RFE algorithms chose FZD7, STK11, SUV39H1, and LCN2 as marker genes with suitable diagnostic capabilities. These marker genes may be involved in the control of the PPAR signaling pathway, mTOR signaling system, and fatty acid production of kidney stones, according to the functional enrichment analysis that followed. Additionally, 24 drugs that target two marker genes have been found. Despite this, the ceRNA networks have gained that the regulatory relationship between marker genes is rather complex. Additionally, the findings of the CIBERSORT investigation indicated that FZD7 and SUV39H1 may be linked to variations in the immune milieu of people who have kidney stones.

Conclusion

We developed a diagnostic tool and provided information on the development of kidney stones. In order to confirm its diagnostic applicability for kidney stones, more studies are needed before it may be used in clinical practice.

Frizzled-7-targeting antibody-derived bifunctional protein retargets NK cells against triple-negative breast cancer cells via MICA-NKG2D axis

BACKGROUND

Hypoxia is associated with the evasion of triple-negative breast cancer (TNBC) from immune surveillance. Hypoxia increases the subpopulation of putative TNBC stem-like cells (TNBCSCs) through activating Wnt/β-Catenin signaling. The shedding of MHC class I-related chain A (MICA) is particularly noteworthy in cancer stem cells (CSCs), promoting the resistance of CSCs to natural killer (NK) cell cytotoxicity. To reestablish MICA/NKG2D-mediated immunosurveillance, we proposed the design of a fusion protein (SHH002-hu1-MICA) which consists of Frizzled-7 (Fzd7)-targeting antibody and MICA, serving as an engager retargeting NK cells against TNBCs, especially TNBCSCs.

METHODS

Opal multicolor immunohistochemistry staining was used to validate the expression of membrane MICA (mMICA) and existence of NK cells in TNBC tumors; flow cytometry (FCM) assay was used to detect the expression of Fzd7/mMICA on TNBCs. Biolayer interferometry (BLI) and surface plasmon resonance (SPR) assays were executed to assess the affinity of SHH002-hu1-MICA towards rhFzd7/rhNKG2D; near-infrared imaging assay was used to evaluate the targeting capability. A cytotoxicity assay was conducted to assess the effects of SHH002-hu1-MICA on NK cell-mediated killing of TNBCs, and FCM assay to analyze the effects of SHH002-hu1-MICA on the degranulation of NK cells. Finally, TNBC cell-line-derived xenografts were established to evaluate the anti-tumor activities of SHH002-hu1-MICA in vivo.

RESULTS

The expression of mMICA is significantly downregulated in hypoxic TNBCs and TNBCSCs, leading to the evasion of immune surveillance exerted by NK cells. The expression of Fzd7 is significantly upregulated in TNBCSCs and exhibits a negative correlation with the expression of mMICA and infiltration level of NK cells. On accurate assembly, SHH002-hu1-MICA shows a strong affinity for rhFzd7/rhNKG2D, specifically targets TNBC tumor tissues, and disrupts Wnt/β-Catenin signaling. SHH002-hu1-MICA significantly enhances the cytotoxicity of NK cells against hypoxic TNBCs and TNBCSCs by inducing the degranulation of NK cells and promotes the infiltration of NK cells in CD44high regions within TNBC xenograft tumors, exhibiting superior anti-tumor activities than SHH002-hu1.

CONCLUSIONS

SHH002-hu1-MICA maintains the targeting property of SHH002-hu1, successfully activates and retargets NK cells against TNBCs, especially TNBCSCs, exhibiting superior antitumor activities than SHH002-hu1. SHH002-hu1-MICA represents a promising new engager for NK cell-based immunotherapy for TNBC.

Autophagy induced by metabolic processes leads to solid tumor cell metastatic dormancy and recurrence

A crucial cellular mechanism that has a complex impact on the biology of cancer, particularly in solid tumors, is autophagy. This review explores how metabolic processes trigger autophagy, which helps metastatic tumor cells go dormant and recur. During metastasis, tumor cells frequently encounter severe stressors, such as low oxygen levels and nutritional deprivation, which causes them to activate autophagy as a survival tactic. This process allows cancer stem cells (CSCs) to withstand severe conditions while also preserving their features. After years of dormancy, dormant disseminated tumor cells (DTCs) may reappear as aggressive metastatic cancers. The capacity of autophagy to promote resistance to treatments and avoid immune detection is intimately related to this phenomenon. According to recent research, autophagy promotes processes, such as the epithelial-to-mesenchymal transition (EMT) and helps build a pre-metastatic niche, which makes treatment strategies more challenging. Autophagy may be a promising therapeutic target because of its dual function as a tumor suppressor in early-stage cancer and a survival promoter in advanced stages. To effectively treat metastatic diseases, it is crucial to comprehend how metabolic processes interact with autophagy and affect tumor behavior. In order to find novel therapeutic approaches that can interfere with these processes and improve patient outcomes, this study highlights the critical need for additional investigation into the mechanisms by which autophagy controls tumor dormancy and recurrence.

Wnt/β-catenin signalling underpins juvenile Fasciola hepatica growth and development

Infection by the liver fluke, Fasciola hepatica, places a substantial burden on the global agri-food industry and poses a significant threat to human health in endemic regions. Widespread resistance to a limited arsenal of chemotherapeutics, including the frontline flukicide triclabendazole (TCBZ), renders F. hepatica control unsustainable and accentuates the need for novel therapeutic target discovery. A key facet of F. hepatica biology is a population of specialised stem cells which drive growth and development - their dysregulation is hypothesised to represent an appealing avenue for control. The exploitation of this system as a therapeutic target is impeded by a lack of understanding of the molecular mechanisms underpinning F. hepatica growth and development. Wnt signalling pathways govern a myriad of stem cell processes during embryogenesis and drive tumorigenesis in adult tissues in animals. Here, we identify five putative Wnt ligands and five Frizzled receptors in liver fluke transcriptomic datasets and find that Wnt/β-catenin signalling is most active in juveniles, the most pathogenic life stage. FISH-mediated transcript localisation revealed partitioning of the five Wnt ligands, with each displaying a distinct expression pattern, consistent with each Wnt regulating the development of different cell/tissue types. The silencing of each individual Wnt or Frizzled gene yielded significant reductions in juvenile worm growth and, in select cases, blunted the proliferation of neoblast-like cells. Notably, silencing FhCTNNB1, the key effector of the Wnt/β-catenin signal cascade led to aberrant development of the neuromuscular system which ultimately proved lethal - the first report of a lethal RNAi-induced phenotype in F. hepatica. The absence of any discernible phenotypes following the silencing of the inhibitory Wnt/β-catenin destruction complex components is consistent with low destruction complex activity in rapidly developing juvenile worms, corroborates transcriptomic expression profiles and underscores the importance of Wnt signalling as a key molecular driver of growth and development in early-stage juvenile fluke. The putative pharmacological inhibition of Wnt/β-catenin signalling using commercially available inhibitors phenocopied RNAi results and provides impetus for drug repurposing. Taken together, these data functionally and chemically validate the targeting of Wnt signalling as a novel strategy to undermine the pathogenicity of juvenile F. hepatica.

Antibody/siRNA Nanocarriers Against Wnt Signaling Suppress Oncogenic and Stem-Like Behavior in Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is infamous for its aggressive phenotype and poorer prognosis when compared to other breast cancer subtypes. One factor contributing to this poor prognosis is that TNBC lacks expression of the receptors that available hormonal or molecular-oriented therapies attack. New treatments that exploit biological targets specific to TNBC are desperately needed to improve patient outcomes. One promising target for therapeutic manipulation is the Wnt signaling pathway, which has been associated with many invasive breast cancers, including TNBC. This pathway is activated in TNBC cells when extracellular Wnt ligands bind to overexpressed Frizzled7 (FZD7) transmembrane receptors, leading to downstream activation of intracellular β-catenin proteins. To target and inhibit Wnt signaling in TNBC cells, polymer nanoparticles (NPs) modified with anti-FZD7 antibodies and β-catenin small interfering RNAs (siRNAs) were developed, and their impact on the oncogenic behavior of treated TNBC cells was investigated. When compared to control NPs, the Wnt-targeted NPs induced greater levels of Wnt oncogene suppression. This led to greater inhibition of oncogenic and stem-like properties, including cell proliferation, drug resistance, and spheroid formation capacity. This work demonstrates a promising approach for targeting the Wnt pathway in TNBC to counter the cellular phenotypes that drive disease progression.

A Putative Frizzled 7-Targeting Compound Acts as a Firefly Luciferase Inhibitor

The Frizzled family (FZD1-10) of G protein-coupled receptors regulates WNT signaling mediating proliferative input. Dysregulation of FZD7 and exaggerated WNT/β-catenin signaling is frequently observed in intestinal cancers. Therefore, it is attractive to develop therapeutics targeting FZD7 for cancer treatment. Structure-based virtual screening has identified compound 28, which inhibited WNT/β-catenin signaling based on the luciferase-based reporter gene TOPFlash assay. However, upon pharmacological validation, compound 28 rather acts as a potent Firefly luciferase (Fluc) inhibitor (IC50 = 30 nM), matching the reported IC50 for compound 28-mediated inhibition in the TOPFlash assay. Moreover, we employed Fluc-independent assays, a FZD7-focused bioluminescence resonance energy transfer biosensor and quantitative PCR, to emphasize the inability of compound 28 to inhibit the WNT-3A-induced conformational dynamics in FZD7 and transcription of Axin2, a WNT target gene. Thus, we underline the importance of counter screens to validate compounds that interfere with the detection technology used for compound screening.

Conjugation of Antibodies and siRNA Duplexes to Polymer Nanoparticles via Maleimide-Thiol Chemistry

Polymeric nanoparticles (NPs) have shown great promise as highly modifiable platforms that can be applied across many different disease states. They are advantageous because they can encapsulate a range of hydrophobic and hydrophilic cargoes while having customizable surface properties. Depending on the desired biointerfacing capabilities, the surface of polymeric NPs can be modified with moieties, such as antibodies, peptides, nucleic acids, and more. The work presented here is intended to provide mechanistic insight into how different parameters influence the loading of antibodies, small interfering ribonucleic acids (siRNAs), or both on the surface of poly(lactic-co-glycolic acid) (PLGA) NPs via maleimide-thiol chemistry. Some of the conjugation parameters investigated include the buffer concentration, maleimide to protein ratio, and the addition of an excipient such as Tween-20. Through variation in the concentration of FZD7 antibodies added to the reaction mixture, we established tunable conjugation and found the upper limit of their loading density under the conditions tested. We also confirmed antibody conjugation through two different mechanisms: via a thiol-modified antibody or a thiol-modified poly(ethylene glycol) (PEG) linker. Conjugation of thiolated siRNA duplexes targeting β-catenin was also investigated through variations in both Tween-20 concentration and CaCl2 buffer concentration. Finally, the coconjugation of both antibodies and siRNA duplexes was explored. Overall, this work outlines a basis for tunable biomolecule loading on polymer NPs using maleimide-thiol chemistry and reveals the incredible versatility of polymer NP platforms.

Exploring a novel four-gene system as a diagnostic and prognostic biomarker for triple-negative breast cancer, using clinical variables

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis. This research aims to find real hub genes for prognostic biomarkers of TNBC therapy. The GEO datasets GSE27447 and GSE233242 were analyzed using R package limma to explore DEGs. The PPI was generated using the STRING database. Cytoscape software plug-ins were used to screen the hub genes. Using the DAVID database, GO functional enrichment and KEGG pathway enrichment analysis were performed. Different online expression databases were employed to investigate the functions of real hub genes in tumor driving, diagnosis, and prognosis in TNBC patients with various clinicopathologic characteristics. A total of one hundred DEGs were identified between both datasets. The seven hub genes were identified after the topological parameter analysis of the PPI network. The KEGG pathway and GO analysis suggest that four genes (PSMB1, PSMC1, PSMF1, and PSMD8) are highly enriched in proteasome and were finally considered as real hub genes. Additionally, the expression analysis demonstrated that hub genes were notably up-regulated in TNBC patients compared to controls. Furthermore, correlational analyses revealed the positive and negative correlations among the expression of the real hub genes and various ancillary data, including tumor purity, promoter methylation status, overall survival (OS), genetic alterations, infiltration of CD8+ T and CD4+ immune cells, and a few more, across TNBC samples. Finally, our analysis identified a couple of significant chemotherapeutic drugs, miRNAs and transcription factors (TFS) with intriguing curative potential. In conclusion, we identified four real hub genes as novel biomarkers to overcome heterogenetic-particular challenges in diagnosis, prognosis, and therapy for TNBC patients.

Advances in the Understanding of the Pathogenesis of Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by high aggressiveness, high malignancy, and poor prognosis compared to other breast cancer subtypes.

OBJECTIVE

This review aims to explore recent advances in understanding TNBC and to provide new insights and potential references for clinical treatment.

METHODS

We examined current literature on TNBC to analyze molecular subtypes, genetic mutations, signaling pathways, mechanisms of drug resistance, and emerging therapies.

RESULTS

Findings highlight key aspects of TNBC's molecular subtypes, relevant mutations, and pathways, alongside emerging treatments that target drug resistance mechanisms.

CONCLUSION

These insights into TNBC pathogenesis may help guide future therapeutic strategies and improve clinical outcomes for patients with TNBC.

Targeting RNA helicase DDX3X with a small molecule inhibitor for breast cancer bone metastasis treatment

Patients who present with breast cancer bone metastasis only have limited palliative treatment strategies and efficacious drug treatments are needed. In breast cancer patient data, high levels of the RNA helicase DDX3 are associated with poor overall survival and bone metastasis. Consequently, our objective was to target DDX3 in a mouse breast cancer bone metastasis model using a small molecule inhibitor of DDX3, RK-33. Histologically confirmed live imaging indicated no bone metastases in the RK-33 treated cohort, as opposed to placebo-treated mice. We generated a cell line from a bone metastatic lesion in mouse and found that it along with a patient-derived bone metastasis cell line gained resistance to conventional chemotherapeutics but not to RK-33. Finally, differential levels of DDX3 were observed in breast cancer patient metastatic bone samples. Overall, this study indicates that DDX3 is a relevant clinical target in breast cancer bone metastasis and that RK-33 can be a safe and effective treatment for these patients.

Structural basis of frizzled 7 activation and allosteric regulation

Frizzleds (ten paralogs: FZD1-10) belong to the class F of G protein-coupled receptors (GPCRs), which remains poorly understood despite its crucial role in multiple key biological functions including embryonic development, stem cell regulation, and homeostasis in the adult. FZD7, one of the most studied members of the family, is more specifically involved in the migration of mesendoderm cells during the development and renewal of intestinal stem cells in adults. Moreover, FZD7 has been highlighted for its involvement in tumor development predominantly in the gastrointestinal tract. This study reports the structure of inactive FZD7, without any stabilizing mutations, determined by cryo-electron microscopy (cryo-EM) at 1.9 Å resolution. We characterize a fluctuating water pocket in the core of the receptor important for FZD7 dynamics. Molecular dynamics simulations are used to investigate the temporal distribution of those water molecules and their importance for potential conformational changes in FZD7. Moreover, we identify lipids interacting with the receptor core and a conserved cholesterol-binding site, which displays a key role in FZD7 association with a transducer protein, Disheveled (DVL), and initiation of downstream signaling and signalosome formation.

Wnt signaling and tumors (Review)

Wnt signaling is a highly conserved evolutionary pathway that plays a key role in regulation of embryonic development, as well as tissue homeostasis and regeneration. Abnormalities in Wnt signaling are associated with tumorigenesis and development, leading to poor prognosis in patients with cancer. However, the pharmacological effects and mechanisms underlying Wnt signaling and its inhibition in cancer treatment remain unclear. In addition, potential side effects of inhibiting this process are not well understood. Therefore, the present review outlines the role of Wnt signaling in tumorigenesis, development, metastasis, cancer stem cells, radiotherapy resistance and tumor immunity. The present review further identifies inhibitors that target Wnt signaling to provide a potential novel direction for cancer treatment. This may facilitate early application of safe and effective drugs targeting Wnt signaling in clinical settings. An in-depth understanding of the mechanisms underlying inhibition of Wnt signaling may improve the prognosis of patients with cancer.

Antibody and siRNA Nanocarriers to Suppress Wnt Signaling, Tumor Growth, and Lung Metastasis in Triple-Negative Breast Cancer

The paucity of targeted therapies for triple-negative breast cancer (TNBC) causes patients with this aggressive disease to suffer a poor clinical prognosis. A promising target for therapeutic intervention is the Wnt signaling pathway, which is activated in TNBC cells when extracellular Wnt ligands bind overexpressed Frizzled7 (FZD7) transmembrane receptors. This stabilizes intracellular β-catenin proteins that in turn promote transcription of oncogenes that drive tumor growth and metastasis. To suppress Wnt signaling in TNBC cells, we developed therapeutic nanoparticles (NPs) functionalized with FZD7 antibodies and β-catenin small interfering RNAs (siRNAs). The antibodies enable TNBC cell-specific binding and inhibit Wnt signaling by locking FZD7 receptors in a ligand unresponsive state, while the siRNAs suppress β-catenin through RNA interference. Compared to NPs coated with antibodies or siRNAs individually, NPs coated with both agents more potently reduce the expression of several Wnt related genes in TNBC cells, leading to greater inhibition of cell proliferation, migration, and spheroid formation. In two murine models of metastatic TNBC, the dual antibody/siRNA nanocarriers outperformed controls in terms of inhibiting tumor growth, metastasis, and recurrence. These findings demonstrate suppressing Wnt signaling at both the receptor and mRNA levels via antibody/siRNA nanocarriers is a promising approach to combat TNBC.

The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities

The evolutionarily conserved Wnt signaling pathway plays a central role in development and adult tissue homeostasis across species. Wnt proteins are secreted, lipid-modified signaling molecules that activate the canonical (β-catenin dependent) and non-canonical (β-catenin independent) Wnt signaling pathways. Cellular behaviors such as proliferation, differentiation, maturation, and proper body-axis specification are carried out by the canonical pathway, which is the best characterized of the known Wnt signaling paths. Wnt signaling has emerged as an important factor in stem cell biology and is known to affect the self-renewal of stem cells in various tissues. This includes but is not limited to embryonic, hematopoietic, mesenchymal, gut, neural, and epidermal stem cells. Wnt signaling has also been implicated in tumor cells that exhibit stem cell-like properties. Wnt signaling is crucial for bone formation and presents a potential target for the development of therapeutics for bone disorders. Not surprisingly, aberrant Wnt signaling is also associated with a wide variety of diseases, including cancer. Mutations of Wnt pathway members in cancer can lead to unchecked cell proliferation, epithelial-mesenchymal transition, and metastasis. Altogether, advances in the understanding of dysregulated Wnt signaling in disease have paved the way for the development of novel therapeutics that target components of the Wnt pathway. Beginning with a brief overview of the mechanisms of canonical and non-canonical Wnt, this review aims to summarize the current knowledge of Wnt signaling in stem cells, aberrations to the Wnt pathway associated with diseases, and novel therapeutics targeting the Wnt pathway in preclinical and clinical studies.

FZD7-Targeted Nanoparticles to Enhance Doxorubicin Treatment of Triple-Negative Breast Cancer

Doxorubicin (DOX) is a chemotherapy agent commonly used to treat triple-negative breast cancer (TNBC), but it has insufficient efficacy against the disease and considerable toxicity due to its off-target delivery. To improve the specificity of DOX for TNBC, we encapsulated it in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) coated with antibodies against Frizzled7 (FZD7), a receptor that is overexpressed on TNBC cells and which is a key activator of the Wnt signaling pathway. In vitro studies show that DOX encapsulation does not hinder its ability to localize to the nucleus in human TNBC cell cultures and that DOX delivered via NPs induces apoptosis and DNA damage via H2A.X phosphorylation to the same degree as freely delivered DOX. FZD7-targeted NPs delivering DOX caused significantly greater inhibition of metabolic activity and led to a smaller cell population following treatment when compared to freely delivered DOX or DOX-loaded NPs coated only with poly(ethylene glycol) (PEG). The FZD7 antibodies additionally provided significant levels of Wnt pathway inhibition, as demonstrated by an increase in β-catenin phosphorylation, indicative of β-catenin destruction and downregulation. These results show that FZD7-targeted platforms have great promise for improving the therapeutic window of otherwise toxic chemotherapies like DOX in TNBC and other cancers that display the overexpression of FZD7 receptors.

Unraveling Biomarker Signatures in Triple-Negative Breast Cancer: A Systematic Review for Targeted Approaches

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer, marked by poor outcomes and dismal prognosis. Due to the absence of targetable receptors, chemotherapy still represents the main therapeutic option. Therefore, current research is now focusing on understanding the specific molecular pathways implicated in TNBC, in order to identify novel biomarker signatures and develop targeted therapies able to improve its clinical management. With the aim of identifying novel molecular features characterizing TNBC, elucidating the mechanisms by which these molecular biomarkers are implicated in the tumor development and progression, and assessing the impact on cancerous cells following their inhibition or modulation, we conducted a literature search from the earliest works to December 2023 on PubMed, Scopus, and Web Of Science. A total of 146 studies were selected. The results obtained demonstrated that TNBC is characterized by a heterogeneous molecular profile. Several biomarkers have proven not only to be characteristic of TNBC but also to serve as potential effective therapeutic targets, holding the promise of a new era of personalized treatments able to improve its prognosis. The pre-clinical findings that have emerged from our systematic review set the stage for further investigation in forthcoming clinical trials.

Synthesis of the scFv fragment of anti-Frizzled-7 antibody and evaluation of its effects on triple-negative breast cancer in vitro study

OBJECTIVES

Among the most promising antibody formats in terms of inhibiting carcinogenesis are single-stranded variable fragments, whose targeted binding to the Fzd7 receptor has been proven effective at suppressing tumorigenesis. In this study, we investigated the effectiveness of an anti-Fzd7 antibody fragment against both tumor growth and metastasis of breast cancer cells.

METHODS

To develop anti-Fzd7 antibodies, bioinformatics approaches were used and the antibodies were expressed recombinantly in E. coli BL21 (DE3). The expression of anti-Fzd7 fragments was verified by Western blotting. Analysis of the antibody's binding capacity to Fzd7 was conducted by flow cytometry. Cell death and apoptosis were assessed by MTT and Annexin V/PI assays. The transwell migration and invasion assays, as well as the scratch method, were used to evaluate cell motility and invasiveness.

RESULTS

The anti-Fzd7 antibody was expressed successfully as a single band of 31 kDa. It could bind to 21.5% of MDA-MB-231 cells, as opposed to only 0.54% of SKBR-3 cells as negative control. According to MTT assay, induced apoptosis was 73.7% in MDA-MB-231 cells, compared with 29.5% in SKBR-3 cells. Also, the antibody exerted a significant inhibitory effect of 76% and 58% on migration and invasion of MDA-MB-231 cells, respectively.

CONCLUSION

The recombinantly developed anti-Fzd7 scFv of this study could exhibit significant antiproliferative and antimigratory properties, along with a high apoptosis-inducing potential, making it suitable for the immunotherapy of triple negative breast cancer.

The expression of O-linked glycosyltransferase GALNT7 in breast cancer is dependent on estrogen-, progesterone-, and HER2-receptor status, with prognostic implications

GALNT7 is a glycosyltransferase enzyme transferring N-acetylgalactosamine to initiate O-linked glycosylation in the Golgi apparatus. Breast cancer is the most common cancer in women globally. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2; ERBB2) are important biomarkers in the prognosis and molecular subtyping of breast cancer. Here, we showed that ER-positive, PR-positive or HER2-positive breast tumors have higher expression of GALNT7 compared to ER-negative, PR-negative or HER2-negative breast tumors, respectively. We found that CpG-aggregated methylation of GALNT7 gene is decreased, and in parallel, its transcript levels are increased in breast cancer compared to healthy breast tissue. We observed that the difference in the expression of GALNT7 between negative and positive status of the receptors is the highest for HER2, followed by ER and PR, pointing that HER2 might be relatively more influential than ER and PR on the expression of GALNT7 in breast cancer. We reported that basal-like breast tumors have decreased expression of GALNT7 compared to non-basal-like tumors, and that high GALNT7 expression is associated with favorable relapse-free and distant metastasis-free survival in HER2 status-dependent manner in breast cancer patients. Moreover, we showed that GALNT7 expression in breast cancer is cell type- (epithelial vs stromal cells), tumor grade- and ethnicity-dependent. Combined, we propose that GALNT7 might contribute to different clinical outcomes depending on the receptor status in breast cancer, and that a better understanding of GALNT7 and its function in the context of breast cancer is needed.

Targeted inhibition of Wnt signaling with a Clostridioides difficile toxin B fragment suppresses breast cancer tumor growth

Wnt signaling pathways are transmitted via 10 homologous frizzled receptors (FZD1-10) in humans. Reagents broadly inhibiting Wnt signaling pathways reduce growth and metastasis of many tumors, but their therapeutic development has been hampered by the side effect. Inhibitors targeting specific Wnt-FZD pair(s) enriched in cancer cells may reduce side effect, but the therapeutic effect of narrow-spectrum Wnt-FZD inhibitors remains to be established in vivo. Here, we developed a fragment of C. difficile toxin B (TcdBFBD), which recognizes and inhibits a subclass of FZDs, FZD1/2/7, and examined whether targeting this FZD subgroup may offer therapeutic benefits for treating breast cancer models in mice. Utilizing 2 basal-like and 1 luminal-like breast cancer models, we found that TcdBFBD reduces tumor-initiating cells and attenuates growth of basal-like mammary tumor organoids and xenografted tumors, without damaging Wnt-sensitive tissues such as bones in vivo. Furthermore, FZD1/2/7-positive cells are enriched in chemotherapy-resistant cells in both basal-like and luminal mammary tumors treated with cisplatin, and TcdBFBD synergizes strongly with cisplatin in inhibiting both tumor types. These data demonstrate the therapeutic value of narrow-spectrum Wnt signaling inhibitor in treating breast cancers.

Structure-Based Ligand Discovery Targeting the Transmembrane Domain of Frizzled Receptor FZD7

Despite the essential roles of Frizzled receptors (FZDs) in mediating Wnt signaling in embryonic development and tissue homeostasis, ligands targeting FZDs are rare. A few antibodies and peptide modulators have been developed that mainly bind to the family-conserved extracellular cysteine-rich domain of FZDs, while the canonical binding sites in the transmembrane domain (TMD) are far from sufficiently addressed. Based on the recent structures of FZDs, we explored small-molecule ligand discovery by targeting TMD. From the ChemDiv library with ∼1.6 million compounds, we identified compound F7H as an antagonist of FZD7 with an IC50 at 1.25 ± 0.38 μM. Focusing on this hit, the structural dissection study, together with computing studies such as molecular docking, molecular dynamics simulation, and free energy perturbation calculations, defined the binding pocket with key residue recognition. Our results revealed the structural basis of ligand recognition and demonstrated the feasibility of structure-guided ligand discovery for FZD7-TMD.

The recent progress of peptide regulators for the Wnt/β-catenin signaling pathway

Wnt signaling plays an important role in many biological processes such as stem cell self-renewal, cell proliferation, migration, and differentiation. The β-catenin-dependent signaling pathway mainly regulates cell proliferation, differentiation, and migration. In the Wnt/β-catenin signaling pathway, the Wnt family ligands transduce signals through LRP5/6 and Frizzled receptors to the Wnt/β-catenin signaling cascades. Wnt-targeted therapy has garnered extensive attention. The most commonly used approach in targeted therapy is small-molecule regulators. However, it is difficult for small-molecule regulators to make great progress due to their inherent defects. Therapeutic peptide regulators targeting the Wnt signaling pathway have become an alternative therapy, promising to fill the gaps in the clinical application of small-molecule regulators. In this review, we describe recent advances in peptide regulators for Wnt/β-catenin signaling.

Nanomedicine Technologies for Diagnosis and Treatment of Breast Cancer

Breast cancer is one of the most common cancers in women worldwide, yet conventional treatments have several shortcomings, including low specificity, systemic toxicity, and drug resistance. Nanomedicine technologies provide a promising alternative while also overcoming the limitations posed by conventional therapies. This mini-Review highlights important signaling pathways related to occurrence and development of breast cancer and current breast cancer therapies, followed by an analysis of various nanomedicine technologies developed for diagnosis and treatment of breast cancers.

Triple-negative breast cancer: epidemiology, molecular mechanisms, and modern vaccine-based treatment strategies

Long-standing scarcity of efficacious treatments and tumor heterogeneity have contributed to triple-negative breast cancer (TNBC), a subtype with a poor prognosis and aggressive behavior that accounts for 10-15% of all new cases of breast cancer. TNBC is characterized by the absence of progesterone and estrogen receptor expression and lacks gene amplification or overexpression of HER2. Genomic sequencing has detected that the unique mutational profile of both the somatic and germline modifications in TNBC is staggeringly dissimilar from other breast tumor subtypes. The clinical utility of sequencing germline BRCA1/2 genes has been well established in TNBC. Nevertheless, reports regarding the penetrance and risk of other susceptibility genes are relatively scarce. Recurring mutations (e.g., TP53 and PI3KCA mutations) occur together with rare mutations in TNBC, and the shared effects of genomic modifications drive its progression. Given the heterogeneity and complexity of this disease, a clinical understanding of the genomic modifications in TNBC can pave an innovative way toward its therapy. In this review, we summarized the most recent discoveries associated with the underlying biology of developmental signaling pathways in TNBC. We also summarize the recent advancements in genetics and epidemiology and discuss state-of-the-art vaccine-based therapeutic strategies for TNBC that will enable tailored therapeutics.

FZD7, Regulated by Non-CpG Methylation, Plays an Important Role in Immature Porcine Sertoli Cell Proliferation

The regulatory role of non-CpG methylation in mammals has been important in whole-genome bisulfite sequencing. It has also been suggested that non-CpG methylation regulates gene expression to affect the development and health of mammals. However, the dynamic regulatory mechanisms of genome-wide, non-CpG methylation during testicular development still require intensive study. In this study, we analyzed the dataset from the whole-genome bisulfite sequencing (WGBS) and the RNA-seq of precocious porcine testicular tissues across two developmental stages (1 and 75 days old) in order to explore the regulatory roles of non-CpG methylation. Our results showed that genes regulated by non-CpG methylation affect the development of testes in multiple pathways. Furthermore, several hub genes that are regulated by non-CpG methylation during testicular development-such as VEGFA, PECAM1, and FZD7-were also identified. We also found that the relative expression of FZD7 was downregulated by the zebularine-induced demethylation of the first exon of FZD7. This regulatory relationship was consistent with the results of the WGBS and RNA-seq analysis. The immature porcine Sertoli cells were transfected with RNAi to mimic the expression patterns of FZD7 during testicular development. The results of the simulation test showed that cell proliferation was significantly impeded and that cell cycle arrest at the G2 phase was caused by the siRNA-induced FZD7 inhibition. We also found that the percentage of early apoptotic Sertoli cells was decreased by transfecting them with the RNAi for FZD7. This indicates that FZD7 is an important factor in linking the proliferation and apoptosis of Sertoli cells. We further demonstrated that Sertoli cells that were treated with the medium collected from apoptotic cells could stimulate proliferation. These findings will contribute to the exploration of the regulatory mechanisms of non-CpG methylation in testicular development and of the relationship between the proliferation and apoptosis of normal somatic cells.

Coumarin derivative as a potent drug candidate against triple negative breast cancer targeting the frizzled receptor of wingless-related integration site signaling pathway

Triple negative breast cancer constitutes to about 21.8 percent of the total breast cancer related cases. Its ability to affect young ladies and in pre-menstrual stage makes this a disease of concern worldwide. The current treatment regimens involve chemotherapy which are used for treatment of other cancer types. In this regard, there is a need for specific and targeted drug candidate for its effective treatment. In the current study, assessment of coumarin derivative 2-(2-(6- Methyl-2-Oxo-2H-chromen-4-yl) acetamido)-3-phenylpropanoic acid is carried out both In-silico and In-vitro methods. Frizzled transmembrane proteins of Wingless-related integration site signaling pathway was targeted in which Frizzled-7 proved to a prospective target and showed a binding energy of -6.78 kcal/mol. The complex was subjected to molecular dynamics simulation for 200 ns and showed stable interaction with cysteine rich domain of the receptor. Cell proliferation, viability and apoptosis assay were performed on MDA-MB-231 and MDA-MB-468 cell lines with an IC₅₀ value of 81.23 and 84.68 µM, respectively. The results provide a drug candidate which is derivative of a natural compound with targeted TNBC inhibitory effect. Communicated by Ramaswamy H. Sarma.

m6 A Reader YTHDF1-Targeting Engineered Small Extracellular Vesicles for Gastric Cancer Therapy via Epigenetic and Immune Regulation

N⁶ -methyladenosine (m⁶ A) modulators decide the fate of m⁶ A-modified transcripts and drive cancer development. RNA interference targeting m⁶ A modulators promise to be an emerging cancer therapy but is challenging due to its poor tumor targeting and high systematic toxicity. Here engineered small extracellular vesicles (sEVs) with high CD47 expression and cyclic arginine-glycine-aspartic (c(RGDyC)) modification are developed for effective delivery of short interfering RNA against m⁶ A reader YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) to treat gastric cancer via epigenetic and immune regulation. This nanosystem efficiently depletes YTHDF1 expression and suppresses gastric cancer progression and metastasis through hampering frizzled7 translation and inactivating Wnt/β-catenin pathway in an m⁶ A dependent manner. Loss of YTHDF1 mediates overexpression of interferon (IFN)-γ receptor 1 and enhances IFN-γ response, promoting expression of major histocompatibility complex class I on tumor cells to achieve self-presentation of the immunogenic tumor cells to stimulate strong cytotoxic T lymphocytes responses. CD47 expression on the engineered sEVs can competitively bind with signal regulatory protein α to enhance phagocytosis of the tumor cells by tumor-associated macrophages. This versatile nanoplatform provides an efficient and low toxic strategy to inhibit epigenetic regulators and holds great potential in promoting immunotherapy.

Inferring cancer common and specific gene networks via multi-layer joint graphical model

Cancer is a complex disease caused primarily by genetic variants. Reconstructing gene networks within tumors is essential for understanding the functional regulatory mechanisms of carcinogenesis. Advances in high-throughput sequencing technologies have provided tremendous opportunities for inferring gene networks via computational approaches. However, due to the heterogeneity of the same cancer type and the similarities between different cancer types, it remains a challenge to systematically investigate the commonalities and specificities between gene networks of different cancer types, which is a crucial step towards precision cancer diagnosis and treatment. In this study, we propose a new sparse regularized multi-layer decomposition graphical model to jointly estimate the gene networks of multiple cancer types. Our model can handle various types of gene expression data and decomposes each cancer-type-specific network into three components, i.e., globally shared, partially shared and cancer-type-unique components. By identifying the globally and partially shared gene network components, our model can explore the heterogeneous similarities between different cancer types, and our identified cancer-type-unique components can help to reveal the regulatory mechanisms unique to each cancer type. Extensive experiments on synthetic data illustrate the effectiveness of our model in joint estimation of multiple gene networks. We also apply our model to two real data sets to infer the gene networks of multiple cancer subtypes or cell lines. By analyzing our estimated globally shared, partially shared, and cancer-type-unique components, we identified a number of important genes associated with common and specific regulatory mechanisms across different cancer types.

An epitope-directed selection strategy facilitating the identification of Frizzled receptor selective antibodies

The lack of incorporating epitope information into the selection process makes the conventional antibody screening method less effective in identifying antibodies with desired functions. Here, we developed an epitope-directed antibody selection method by designing a directed library favoring the target epitope and a precise "counter" antigen for clearing irrelevant binders in the library. With this method, we successfully isolated an antibody, pF7_A5, that targets the less conserved region on the FZD2/7 CRD as designed. Guided by the structure of pF7_A5-FZD2^CRD, a further round of evolution was conducted together with the "counter" antigen selection strategy, and ultimately, an FZD2-specific antibody and an FZD7-preferred antibody were obtained. Because of targeting the predefined functional site, all these antibodies exhibited the expected modulatory activity on the Wnt pathway. Together, the method developed here will be useful in antibody drug discovery, and the identified FZD antibodies will have clinical potential in FZD-related cancer therapy.

Notch signaling pathway: a comprehensive prognostic and gene expression profile analysis in breast cancer

Breast cancer is a complex disease exhibiting a great degree of heterogeneity due to different molecular subtypes. Notch signaling regulates the differentiation of breast epithelial cells during normal development and plays a crucial role in breast cancer progression through the abnormal expression of the Notch up-and down-stream effectors. To date, there are only a few patient-centered clinical studies using datasets characterizing the role of Notch signaling pathway regulators in breast cancer; thus, we investigate the role and functionality of these factors in different subtypes using publicly available databases containing records from large studies. High-throughput genomic data and clinical information extracted from TCGA were analyzed. We performed Kaplan-Meier survival and differential gene expression analyses using the HALLMARK_NOTCH_SIGNALING gene set. To determine if epigenetic regulation of the Notch regulators contributes to their expression, we analyzed methylation levels of these factors using the TCGA HumanMethylation450 Array data. Notch receptors and ligands expression is generally associated with the tumor subtype, grade, and stage. Furthermore, we showed gene expression levels of most Notch factors were associated with DNA methylation rate. Modulating the expression levels of Notch receptors and effectors can be a potential therapeutic approach for breast cancer. As we outline herein, elucidating the novel prognostic and regulatory roles of Notch implicate this pathway as an essential mediator controlling breast cancer progression.

Nanotechnological Approaches for the Treatment of Triple-Negative Breast Cancer: A Comprehensive Review

Breast cancer is the most prevalent cancer in women around the world, having a sudden spread nowadays because of the poor sedentary lifestyle of people. Comprising several subtypes, one of the most dangerous and aggressive ones is triple-negative breast cancer or TNBC. Even though conventional surgical approaches like single and double mastectomy and preventive chemotherapeutic approaches are available, they are not selective to cancer cells and are only for symptomatic treatment. A new branch called nanotechnology has emerged in the last few decades that offers various novel characteristics, such as size in nanometric scale, enhanced adherence to multiple targeting moieties, active and passive targeting, controlled release, and site-specific targeting. Among various nanotherapeutic approaches like dendrimers, lipid-structured nanocarriers, carbon nanotubes, etc., nanoparticle targeted therapeutics can be termed the best among all for their specific cytotoxicity to cancer cells and increased bioavailability to a target site. This review focuses on the types and molecular pathways involving TNBC, existing treatment strategies, various nanotechnological approaches like exosomes, carbon nanotubes, dendrimers, lipid, and carbon-based nanocarriers, and especially various nanoparticles (NPs) like polymeric, photodynamic, peptide conjugated, antibody-conjugated, metallic, inorganic, natural product capped, and CRISPR based nanoparticles already approved for treatment or are under clinical and pre-clinical trials for TNBC.

Role of microRNA/lncRNA Intertwined With the Wnt/β-Catenin Axis in Regulating the Pathogenesis of Triple-Negative Breast Cancer

Objective (s): In this mini-review, we aimed to discuss the Wnt/β-catenin signaling pathway modulation in triple-negative breast cancer, particularly the contribution of lncRNAs and miRNAs in its regulation and their possible entwining role in breast cancer pathogenesis, proliferation, migration, or malignancy.

Background: Malignant tumor formation is very high for breast cancer in women and is a leading cause of death all over the globe. Among breast cancer subtypes, triple-negative breast cancer is rife in premenopausal women, most invasive, and prone to metastasis. Complex pathways are involved in this cancer’s pathogenesis, advancement, and malignancy, including the Wnt/β-catenin signaling pathway. This pathway is conserved among vertebrates and is necessary for sustaining cell homeostasis. It is regulated by several elements such as transcription factors, enhancers, non-coding RNAs (lncRNAs and miRNAs), etc.

Methods: We evaluated lncRNAs and miRNAs differentially expressed in triple-negative breast cancer (TNBC) from the cDNA microarray data set literature survey. Using in silico analyses combined with a review of the current literature, we anticipated identifying lncRNAs and miRNAs that might modulate the Wnt/β-catenin signaling pathway.

Result: The miRNAs and lncRNAs specific to triple-negative breast cancer have been identified based on literature and database searches. Tumorigenesis, metastasis, and EMT were all given special attention. Apart from cross-talk being essential for TNBC tumorigenesis and treatment outcomes, our results indicated eight upregulated and seven downregulated miRNAs and 19 upregulated and three downregulated lncRNAs that can be used as predictive or diagnostic markers. This consolidated information could be useful in the clinic and provide a combined literature resource for TNBC researchers working on the Wnt/β-catenin miRNA/lncRNA axis.

Conclusion: In conclusion, because the Wnt pathway and miRNAs/lncRNAs can modulate TNBC, their intertwinement results in a cascade of complex reactions that affect TNBC and related processes. Their function in TNBC pathogenesis has been highlighted in molecular processes underlying the disease progression.

Recent progress in antibody-based therapeutics for triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) is a subtype of severely aggressive breast cancer that lacks the expression of oestrogen receptor (ER), progesterone receptor and human epidermal growth factor receptor 2 (HER2) and is highly metastatic and related to a poor prognosis. Current standard treatments are still limited to systemic chemotherapy, radiotherapy, and surgical resection. More effective treatments are urgently needed.

AREAS COVERED

The immunogenicity of TNBC has provided opportunities for the development of targeted immunotherapy. In this review, we focus on the recent development in antibody-based drug modalities, including angiogenesis inhibitors, immune checkpoint inhibitors, antibody-drug conjugates, immunoconjugates, T cell-redirecting bispecific antibodies and CAR-T cells, and their mechanisms of action in TNBC.

EXPERT OPINION

At present, the treatment of TNBC is still a major challenge that needs to be addressed. Novel immunotherapies are promising opportunities for improving the management of this aggressive disease.

Signaling pathways and their potential therapeutic utility in esophageal squamous cell carcinoma

Esophageal cancer is a complex gastrointestinal malignancy with an extremely poor outcome. Approximately 80% of cases of this malignancy in Asian countries including India are of squamous cell origin, termed Esophageal Squamous Cell Carcinoma (ESCC).The five-year survival rate in ESCC patients is less than 20%. Neo-adjuvant chemo-radiotherapy (NACRT) followed by surgical resection remains the major therapeutic strategy for patients with operable ESCC. However, resistance to NACRT and local recurrence after initial treatment are the leading cause of dismal outcomes in these patients. Therefore, an alternative strategy to promote response to the therapy and reduce the post-operative disease recurrence is highly needed. At the molecular level, wide variations have been observed in tumor characteristics among different populations, nevertheless, several common molecular features have been identified which orchestrate disease progression and clinical outcome in the malignancy. Therefore, determination of candidate molecular pathways for targeted therapy remains the mainstream idea of focus in ESCC research. In this review, we have discussed the key signaling pathways associated with ESCC, i.e., Notch, Wnt, and Nrf2 pathways, and their crosstalk during disease progression. We further discuss the recent developments of novel agents to target these pathways in the context of targeted cancer therapy. In-depth research of the signaling pathways, gene signatures, and a combinatorial approach may help in discovering targeted therapy for ESCC.

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.

Chemoenzymatic Synthesis of Original Stilbene Dimers Possessing Wnt Inhibition Activity in Triple-Negative Breast Cancer Cells Using the Enzymatic Secretome of Botrytis cinerea Pers

The Wnt signaling pathway controls multiple events during embryonic development of multicellular animals and is carcinogenic when aberrantly activated in adults. Breast cancer and triple-negative breast cancer (TNBC) in particular depend upon Wnt pathway overactivation. Despite this importance, no Wnt pathway-targeting drugs are currently available, which necessitates novel approaches to search for therapeutically relevant compounds targeting this oncogenic pathway. Stilbene analogs represent an under-explored field of therapeutic natural products research. In the present work, a library of complex stilbene derivatives was obtained through biotransformation of a mixture of resveratrol and pterostilbene using the enzymatic secretome of Botrytis cinerea. To improve the chemodiversity, the reactions were performed using i-PrOH, n-BuOH, i-BuOH, EtOH, or MeOH as cosolvents. Using this strategy, a series of 73 unusual derivatives was generated distributed among 6 scaffolds; 55 derivatives represent novel compounds. The structure of each compound isolated was determined by nuclear magnetic resonance and high-resolution mass spectrometry. The inhibitory activity of the isolated compounds against the oncogenic Wnt pathway was comprehensively quantified and correlated with their capacity to inhibit the growth of the cancer cells, leading to insights into structure-activity relationships of the derivatives. Finally, we have dissected mechanistic details of the stilbene derivatives activity within the pathway.

Binuclear Heteroleptic Ru(III) Dithiocarbamate Complexes: A Step towards Tunable Antiproliferative Agents

Binuclear dithiocarbamate complexes of Ru(III) are promising candidates in the search for outstanding metal-based anticancer agents. While different dithiocarbamates have shown ligand-dependent cytotoxicity in homoleptic binuclear Ru(III) complexes, the properties of heteroleptic analogues with different dithiocarbamate (DTC) ligands have yet to be explored. We herein propose the introduction of heteroleptic ligands as tunable features for the development of improved ruthenium-based antiproliferative agents and report a synthetic strategy for their synthesis as well as the evaluation of the cytotoxic activity of a selection of binuclear heteroleptic Ru(III) compounds towards MDA-MB-231 and PC3 cells.

Centrosomal Enrichment and Proteasomal Degradation of SYS-1/β-catenin Requires the Microtubule Motor Dynein

The Caenorhabditis elegans Wnt/β-catenin asymmetry (WβA) pathway utilizes asymmetric regulation of SYS-1/β-catenin and POP-1/TCF coactivators. WβA differentially regulates gene expression during cell fate decisions, specifically by asymmetric localization of determinants in mother cells to produce daughters biased toward their appropriate cell fate. Despite the induction of asymmetry, β-catenin localizes symmetrically to mitotic centrosomes in both mammals and C. elegans. Owing to the mitosis-specific localization of SYS-1 to centrosomes and enrichment of SYS-1 at kinetochore microtubules when SYS-1 centrosomal loading is disrupted, we investigated active trafficking in SYS-1 centrosomal localization. Here, we demonstrate that trafficking by microtubule motor dynein is required to maintain SYS-1 centrosomal enrichment, by dynein RNA interference (RNAi)-mediated decreases in SYS-1 centrosomal enrichment and by temperature-sensitive allele of the dynein heavy chain. Conversely, we observe depletion of microtubules by nocodazole treatment or RNAi of dynein-proteasome adapter ECPS-1 exhibits increased centrosomal enrichment of SYS-1. Moreover, disruptions to SYS-1 or negative regulator microtubule trafficking are sufficient to significantly exacerbate SYS-1 dependent cell fate misspecifications. We propose a model whereby retrograde microtubule-mediated trafficking enables SYS-1 enrichment at centrosomes, enhancing its eventual proteasomal degradation. These studies support the link between centrosomal localization and enhancement of proteasomal degradation, particularly for proteins not generally considered “centrosomal.”

The Prognostic Value of the Developmental Gene FZD6 in Young Saudi Breast Cancer Patients: A Biomarkers Discovery and Cancer Inducers OncoScreen Approach

Wnt signalling receptors, Frizzleds (FZDs), play a pivotal role in many cellular events during embryonic development and cancer. Female breast cancer (BC) is currently the worldwide leading incident cancer type that cause 1 in 6 cancer-related death. FZD receptors expression in cancer was shown to be associated with tumour development and patient outcomes including recurrence and survival. FZD6 received little attention for its role in BC and hence we analysed its expression pattern in a Saudi BC cohort to assess its prognostic potential and unravel the impacted signalling pathway. Paraffin blocks from approximately 405 randomly selected BC patients aged between 25 and 70 years old were processed for tissue microarray using an automated tissue arrayer and then subjected to FZD6 immunohistochemistry staining using the Ventana platform. Besides, Ingenuity Pathway Analysis (IPA) knowledgebase was used to decipher the upstream and downstream regulators of FZD6 in BC. TargetScan and miRabel target-prediction databases were used to identify the potential microRNA to regulate FZD6 expression in BC. Results showed that 60% of the BC samples had a low expression pattern while 40% showed a higher expression level. FZD6 expression analysis showed a significant correlation with tumour invasion (p < 0.05), and borderline significance with tumour grade (p = 0.07). FZD6 expression showed a highly significant association with the BC patients’ survival outcomes. This was mainly due to the overall patients’ cohort where tumours with FZD6 elevated expression showed higher recurrence rates (DFS, p < 0.0001, log-rank) and shorter survival times (DSS, p < 0.02, log-rank). Interestingly, the FZD6 prognostic value was more potent in younger BC patients as compared to those with late onset of the disease. TargetScan microRNA target-prediction analysis and validated by miRabel showed that FZD6 is a potential target for a considerable number of microRNAs expressed in BC. The current study demonstrates a potential prognostic role of FZD6 expression in young BC female patients and provides a better understanding of the involved molecular silencing machinery of the Wnt/FZD6 signalling. Our results should provide a better understanding of FZD6 role in BC by adding more knowledge that should help in BC prevention and theranostics.

Identification and analysis of novel endometriosis biomarkers via integrative bioinformatics

Endometriosis is a gynecological disease prevalent in women of reproductive age, and it is characterized by the ectopic presence and growth of the eutopic endometrium. The pathophysiology and diagnostic biomarkers of endometriosis have not yet been comprehensively determined. To discover molecular markers and pathways underlying the pathogenesis of endometriosis, we identified differentially expressed genes (DEGs) in three Gene Expression Omnibus microarray datasets (GSE11691, GSE23339, and GSE7305) and performed gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) network analyses. We also validated the identified genes via immunohistochemical analysis of tissues obtained from patients with endometriosis or healthy volunteers. A total of 118 DEGs (79 upregulated and 39 downregulated) were detected in each dataset with a lower (fold change) FC cutoff (log2|FC| > 1), and 17 DEGs (11 upregulated and six downregulated) with a higher FC cutoff (log2|FC| > 2). KEGG and GO functional analyses revealed enrichment of signaling pathways associated with inflammation, complement activation, cell adhesion, and extracellular matrix in endometriotic tissues. Upregulation of seven genes (C7, CFH, FZD7, LY96, PDLIM3, PTGIS, and WISP2) out of 17 was validated via comparison with external gene sets, and protein expression of four genes (LY96, PDLIM3, PTGIS, and WISP2) was further analyzed by immunohistochemistry and western blot analysis. Based on these results, we suggest that TLR4/NF-κB and Wnt/frizzled signaling pathways, as well as estrogen receptors, regulate the progression of endometriosis. These pathways may be therapeutic and diagnostic targets for endometriosis.

A FZD7-specific Antibody-Drug Conjugate Induces Ovarian Tumor Regression in Preclinical Models

Although WNT signaling is frequently dysregulated in solid tumors, drugging this pathway has been challenging due to off-tumor effects. Current clinical pan-WNT inhibitors are nonspecific and lead to adverse effects, highlighting the urgent need for more specific WNT pathway-targeting strategies. We identified elevated expression of the WNT receptor Frizzled class receptor 7 (FZD7) in multiple solid cancers in The Cancer Genome Atlas, particularly in the mesenchymal and proliferative subtypes of ovarian serous cystadenocarcinoma, which correlate with poorer median patient survival. Moreover, we observed increased FZD7 protein expression in ovarian tumors compared with normal ovarian tissue, indicating that FZD7 may be a tumor-specific antigen. We therefore developed a novel antibody-drug conjugate, septuximab vedotin (F7-ADC), which is composed of a chimeric human-mouse antibody to human FZD7 conjugated to the microtubule-inhibiting drug monomethyl auristatin E (MMAE). F7-ADC selectively binds human FZD7, potently kills ovarian cancer cells in vitro, and induces regression of ovarian tumor xenografts in murine models. To evaluate F7-ADC toxicity in vivo, we generated mice harboring a modified Fzd7 gene where the resulting Fzd7 protein is reactive with the human-targeting F7-ADC. F7-ADC treatment of these mice did not induce acute toxicities, indicating a potentially favorable safety profile in patients. Overall, our data suggest that the antibody-drug conjugate approach may be a powerful strategy to combat FZD7-expressing ovarian cancers in the clinic.

Unlocking the Wnt pathway: Therapeutic potential of selective targeting FZD7 in cancer

The Wnt signaling is of paramount pathophysiological importance. Despite showing promising anticancer activities in pre-clinical studies, current Wnt pathway inhibitors face complications in clinical trials resulting from on-target toxicity. Hence, the targeting of pathway component(s) that are essential for cancer but dispensable for normal physiology is key to the development of a safe Wnt signaling inhibitor. Frizzled₇ (FZD₇) is a Wnt pathway receptor that is redundant in healthy tissues but crucial in various cancers. FZD₇ modulates diverse aspects of carcinogenesis, including cancer growth, metastasis, maintenance of cancer stem cells, and chemoresistance. In this review, we describe state-of-the-art knowledge of the functions of FZD₇ in carcinogenesis and adult tissue homeostasis. Next, we overview the development of small molecules and biomolecules that target FZD₇. Finally, we discuss challenges and possibilities in developing FZD₇-selective antagonists.

Strategic Developments & Future Perspective on Gene Therapy for Breast Cancer: Role of mTOR and Brk/ PTK6 as Molecular Targets

Breast cancer is a serious health issue and a major concern in biomedical research. Alteration in major signaling (viz. PI3K-AKT-mTOR, Ras-Raf-MEK-Erk, NF-kB, cyclin D1, JAK-STAT, Wnt, Notch, Hedgehog signaling and apoptotic pathway) contributes to the development of major subtypes of mammary carcinoma such as HER2 positive, TNBC, luminal A and B and normal-like breast cancer. Further, mutation and expression parameters of different genes involved in the growth and development of cells play an important role in the progress of different types of carcinoma, making gene therapy an emerging new therapeutic approach for the management of life-threatening diseases like cancer. The genetic targets (oncogenes and tumor suppressor genes) play a major role in the formation of a tumor. Brk/PTK6 and mTOR are two central molecules that are involved in the regulation of numerous signaling related to cell growth, proliferation, angiogenesis, survival, invasion, metastasis, apoptosis, and autophagy. Since these two proteins are highly upregulated in mammary carcinogenesis, this can be used as targeted genes for the treatment of breast cancer. However, not much work has been done on them. This review highlights the therapeutic significance of Brk and mTOR and their associated signaling in mammary carcinogenesis, which may provide a strategy to develop gene therapy for breast cancer management.

Trending topics of SIRT1 in tumorigenicity

BACKGROUND

Carcinogenesis is governed by a series of genetic alterations and epigenetic changes that lead to aberrant patterns in neoplastic cells. Sirtuin-1(SIRT1), an NAD⁺-dependent protein deacetylase, is capable of deacetylating histones and non-histone substrates that regulate various physiological activities during tumorigenesis. Recent studies have identified the role of SIRT1 in different stages of cancer, including genome instability, tumor initiation, proliferation, metabolism, and therapeutic response. However, the action of SIRT1 has been reported to be both oncogenic and tumor suppressive during carcinogenesis. Consequently, the biological functions of SIRT1 in cancer remain controversial.

SCOPE OF REVIEW

We highlight the most recent findings on SIRT1 in different stages of tumorigenesis, and update the current status of SIRT1 small molecule modulators in clinical application of cancer treatment.

MAJOR CONCLUSION

By targeting both tumor suppressors and oncogenic proteins, SIRT1 has a bifunctional role at different stages of tumorigenesis. The impact of SIRT1 on tumorigenesis is also distinct at different stages and is dependent on its dosages. SIRT1 suppresses tumor initiation through its functions in promoting DNA repair, increasing genome stability, and inhibiting inflammation at the pre-cancer stage. However, SIRT1 enhances tumor proliferation, survival, and drug resistance through its roles in anti-apoptosis, pro-tumor metabolism, and anti-inflammation (inhibition of anti-tumor immunity) at the stages of tumor progression, metastasis, and relapse. Consequently, both SIRT1 inhibitors and activators have been explored for cancer treatment.

GENERAL SIGNIFICANCE

Better understanding the dose- and stage-dependent roles of SIRT1 in each cancer type can provide new avenues of exploration for therapy development.

Gene network analysis using SWIM reveals interplay between the transcription factor-encoding genes HMGA1, FOXM1, and MYBL2 in triple-negative breast cancer

Among breast cancer subtypes, triple-negative breast cancer (TNBC) is the most aggressive with the worst prognosis and the highest rates of metastatic disease. To identify TNBC gene signatures, we applied the network-based methodology implemented by the SWIM software to gene expression data of TNBC patients in The Cancer Genome Atlas (TCGA) database. SWIM enables to predict key (switch) genes within the co-expression network, whose perturbations in expression pattern and abundance may contribute to the (patho)biological phenotype. Here, SWIM analysis revealed an interesting interplay between the genes encoding the transcription factors HMGA1, FOXM1, and MYBL2, suggesting a potential cooperation among these three switch genes in TNBC development. The correlative nature of this interplay in TNBC was assessed by in vitro experiments, demonstrating how they may actually modulate the expression of each other.

Small-Molecule Inhibitors Targeting the Canonical WNT Signaling Pathway for the Treatment of Cancer

Canonical WNT signaling is an important developmental pathway that has attracted increased attention for anticancer drug discovery. From the production and secretion of WNT ligands, their binding to membrane receptors, and the β-catenin destruction complex to the expansive β-catenin transcriptional complex, multiple components have been investigated as drug targets to modulate WNT signaling. Significant progress in developing WNT inhibitors such as porcupine inhibitors, tankyrase inhibitors, β-catenin/coactivators, protein-protein interaction inhibitors, casein kinase modulators, DVL inhibitors, and dCTPP1 inhibitors has been made, with several candidates (e.g., LGK-974, PRI-724, and ETC-159) in human clinical trials. Herein we summarize recent progress in the drug discovery and development of small-molecule inhibitors targeting the canonical WNT pathway, focusing on their specific target proteins, in vitro and in vivo activities, physicochemical properties, and therapeutic potential. The relevant opportunities and challenges toward maintaining the balance between efficacy and toxicity in effectively targeting this pathway are also highlighted.