A novel recombinant human Frizzled-7 protein exhibits anti-tumor activity against triple negative breast cancer via abating Wnt/β-catenin pathway

CtBP2 Regulates Wnt Signal Through EGR1 to Influence the Proliferation and Apoptosis of DLBCL Cells

Diffuse large B-cell lymphoma (DLBCL) is the most prevalent form of lymphoma. The overexpression of CtBP2 in tissues may contribute to tumor occurrence and progression. The expression of EGR1 in DLBCL is elevated, suggesting its potential role as an oncogene that promotes the proliferation of DLBCL cells. Database predictions indicate that CtBP2 can bind to EGR1. The objective of the present study was to investigate whether CtBP2 can influence the proliferation and apoptosis of DLBCL cells by regulating the Wnt signaling pathway through EGR1. Western blot assay showed that CtBP2 expression was upregulated in DLBCL cells. Cell proliferation level was detected by CCK8 assay and EdU staining, and the apoptosis level and cycle distribution were analyzed through flow cytometry. Our data indicated that interference with CtBP2 and EGR1 can inhibit the proliferation and cell cycle progression of DLBCL cells while promoting apoptosis. The predictions from the HDOCK server, along with the results of Co-IP experiments, suggested that EGR1 and CtBP2 can effectively bind to each other, with EGR1 positioned downstream of CtBP2 and regulated by it. Furthermore, interference with CtBP2 could also inhibit the expression of the Wnt/β-catenin signaling pathway. Overexpression of EGR1 counteracted the effects of siRNA-CtBP2, promoting cell proliferation and cycle, inhibiting apoptosis and upregulating the expression of the Wnt/β-catenin signaling pathway. From the above experiments, we found that CtBP2 can regulate the Wnt/β-catenin signaling pathway through EGR1 to influence the proliferation and apoptosis of DLBCL cells. Therefore, EGR1 may be one of the key contributors involved in the regulation of Wnt/β-catenin signaling by CtBP2.

Targeting Triple-Negative Breast Cancer: Resistance Mechanisms and Therapeutic Advancements

BACKGROUND

Triple-negative breast cancer (TNBC) is one of the most heterogeneous and menacing forms of breast cancer, with no sustainable cure available in the current treatment landscape. Its lack of targets makes it highly unresponsive to various treatment modalities, which is why chemotherapy continues to be the primary form of treatment, despite the high rates of patients developing chemoresistance. In recent years, however, there has been significant progress in identifying and understanding the role of several aspects that might contribute to genomic instability and other hallmarks of cancer, including cellular proteins, immune targets, and epigenetic mechanisms, which are desirable as they permit reversibility easier than the often-adamant genetic changes.

METHODS

A literature review was conducted on the role of various TNBC associated biomarkers, their therapeutic applications, and their role in tumorigenesis and tumor maintenance, with a focus on linking both the driving biological mechanisms and emerging treatment options for TNBC.

CONCLUSIONS

Shifting the focus of treatment to identify crucial tumor cell subpopulations and associated biomarkers, such as local immune cell populations and cancer stem cells, could potentially solve or simplify decades' worth of problems that are associated with TNBC, bolstering early detection and the evolution of precision medicine and treatment. The techniques that can be used here are epigenetic analysis and RNA sequencing. Biomarkers, such as PD-L1, survivin, and ABC transporters, are implicated in several crucial processes that maintain tumors, such as cell proliferation, metastasis, immunosuppression, and stemness. Complex treatment options such as, immunotherapy, pathway inhibition, PARP inhibition, virotherapy, and RNA targeting have been considered for TNBC. Phytochemicals are also being considered as a treatment modality for TNBC, as a supplement to chemotherapy and radiation therapy, or as sole treatment.

Divide and Conquer-Targeted Therapy for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive and malignant type of breast cancer with limited treatment options and poor prognosis. One of the most significant impediments in TNBC treatment is the high heterogeneity of this disease, as highlighted by the detection of several molecular subtypes of TNBC. Each subtype is driven by distinct mutations and pathway aberrations, giving rise to specific molecular characteristics closely connected to clinical behavior, outcomes, and drug sensitivity. This review summarizes the knowledge regarding TNBC molecular subtypes and how it can be harnessed to devise tailored treatment strategies instead of blindly using targeted drugs. We provide an overview of novel targeted agents and key insights about new treatment modalities with an emphasis on the androgen receptor signaling pathway, cancer stem cell-associated pathways, phosphatidylinositol 3-kinase (PI3K)/AKT pathway, growth factor signaling, and immunotherapy.

N-glycosylation of Wnt3 regulates the progression of hepatocellular carcinoma by affecting Wnt/β-catenin signal pathway

BACKGROUND

Wnt/FZD-mediated signaling pathways are activated in more than 90% of hepatocellular carcinoma (HCC) cell lines. As a well-known secretory glycoprotein, Wnt3 can interact with FZD receptors on the cell surface, thereby activating the Wnt/β-catenin signaling pathway. However, the N-glycosylation modification site of Wnt3 and the effect of this modification on the biological function of the protein are still unclear.

AIM

To investigate the effect of Wnt3 N-glycosylation on the biological function of HCC cells.

METHODS

Site-directed mutagenesis was used to verify the Wnt3 N-glycosylation sites, actinomycin D treatment was used to detect the stability of Wnt3 after site-directed mutation, the binding of the N-glycosylation site-directed mutant Wnt3 to FZD7 was observed by laser confocal microscopy, and the effects of the N-glycosylation site-directed mutation of Wnt3 on the Wnt/β-catenin signaling pathway and the progression of HCC cells were detected by western blot and cell function experiments.

RESULTS

Wnt3 has two N-glycosylation-modified sites (Asn90 and Asn301); when a single site at amino acid 301 is mutated, the stability of Wnt3 is weakened; the binding ability of Wnt3 to FZD7 decreases when both sites are mutated simultaneously; and the level of proteins related to the Wnt/β-catenin signaling pathway is downregulated. Cell proliferation, migration and invasion are also weakened in the case of single 301 site and double-site mutations.

CONCLUSION

These results indicate that by inhibiting the N-glycosylation of Wnt3, the proliferation, migration, invasion and colony formation abilities of liver cancer cells can be weakened, which might provide new therapeutic strategies for clinical liver cancer in the future.

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.

Facts and prospects of peptide in targeted therapy and immune regulation against triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Due to the lack of specific therapeutic targets, treatment options are limited, and the recurrence and metastasis rate is high, the overall survival of patients is poor. However, with the discovery of some new targets and the corresponding immune regulation after targeting these targets, TNBC has a new hope in treatment. The peptide has a simple structure, strong binding affinity, and high stability, and has great potential in targeted therapy and immune regulation against TNBC. This review will discuss how single peptides and peptide combinations target triple-negative breast cancer to exert immunomodulatory effects. Among them, single peptides target specific receptors on TNBC cells, act as decoys to target key ligands in the regulatory pathway, and target TME-related cells. The combinations of peptides work in the form of cancer vaccines, engineered exosomes, microRNAs and other immune-related molecular pathways, immune checkpoint inhibitors, chimeric antigen receptor T cells, and drug-peptide conjugates. This article is mainly dedicated to exploring new treatment methods for TNBC to improve the curative effect and prolong the survival time of patients.

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.

Combined treatment with Alhagi maurorum and docetaxel inhibits breast cancer progression via targeting HIF-1α/VEGF mediated tumor angiogenesis in vivo

Breast cancer is a challenging disease and leading cause of cancer death in women. There is no effective agent for metastatic breast cancer after surgery and chemotherapy. Alhagi maurorum (A.m) has been reported to exhibit an anticancer effect on various types of cancer cells in vitro. This study aimed to examine the suppressive effect of A.m alone and combined with docetaxel (DTX) on the breast cancer growth in mice models and the possible underlying mechanisms. In the present study, the mice were inoculated subcutaneously with the injections of 4T1 cells. Then, A.m, DTX, and their combination were administered intraperitoneally. The expressions of β-catenin (β-cat), FZD7, MMP2, HIF1-α, and VEGF A (vascular endothelial growth factor A) were investigated using RT-PCR method. Also, plasma alkaline phosphatase (ALP), alanine aminotransferase (GPT or ALT), aspartate transaminase (GOT or AST), serum creatinine, and urea were examined, and histological analyses of the tissues were conducted. The results demonstrated that A.m (500 mg/kg) combined with DTX significantly decreased the expression of β-cat, MMP2, and FZD7 as compared with the negative control group and monotherapies. Also, the mRNA levels of HIF1-α and VEGF A were suppressed significantly by DTX + A.m (500 mg/kg). Tumor weights and sizes were significantly lower and tumor inhibition rate was significantly higher in the DTX + A.m group. The A.m 500 mg/kg + DTX also suppressed the serum GPT level in tumor-bearing mice and decreased the serum urea level. Taken together, our findings suggest that DTX combined with A.m at an optimal dose of 500 mg/kg as the optimal dose can inhibit β-cat, FZD7, MMP2, and breast cancer growth via interrupting HIF-1α/VEGF signaling and might be used as a promising antiangiogenic agent for breast cancer treatment.

Frizzled-7-targeting antibody (SHH002-hu1) potently suppresses non-small-cell lung cancer via Wnt/β-catenin signaling

Non-small-cell lung cancer (NSCLC) is one of the deadliest cancers worldwide, and metastasis is considered one of the leading causes of treatment failure in NSCLC. Wnt/β-catenin signaling is crucially involved in epithelial-mesenchymal transition (EMT), a crucial factor in promoting metastasis, and also contributes to resistance developed by NSCLC to targeted agents. Frizzled-7 (Fzd7), a critical receptor of Wnt/β-catenin signaling, is aberrantly expressed in NSCLC and has been confirmed to be positively correlated with poor clinical outcomes. SHH002-hu1, a humanized antibody targeting Fzd7, was previously successfully generated by our group. Here, we studied the anti-tumor effects of SHH002-hu1 against NSCLC and revealed the underlying mechanism. First, immunofluorescence (IF) and near-infrared (NIR) imaging assays showed that SHH002-hu1 specifically binds Fzd7⁺ NSCLC cells and targets NSCLC tissues. Wound healing and transwell invasion assays indicated that SHH002-hu1 significantly inhibits the migration and invasion of NSCLC cells. Subsequently, TOP-FLASH/FOP-FLASH luciferase reporter, IF, and western blot assays validated that SHH002-hu1 effectively suppresses the activation of Wnt/β-catenin signaling, and further attenuates the EMT of NSCLC cells. Finally, the subcutaneous xenotransplanted tumor model of A549/H1975, as well as the popliteal lymph node (LN) metastasis model, was established, and SHH002-hu1 was demonstrated to inhibit the growth of NSCLC xenografts and suppress LN metastasis of NSCLC. Above all, SHH002-hu1 with selectivity toward Fzd7⁺ NSCLC and the potential of inhibiting invasion and metastasis of NSCLC via disrupting Wnt/β-catenin signaling, is indicated as a good candidate for the targeted therapy of NSCLC.

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.

Molecular Mechanisms, Biomarkers and Emerging Therapies for Chemotherapy Resistant TNBC

Triple-negative breast cancer (TNBC) is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival (OS). Taxane and anthracycline-containing chemotherapy (CT) is currently the main systemic treatment option for TNBC, while platinum-based chemotherapy showed promising results in the neoadjuvant and metastatic settings. An early arising of intrinsic or acquired CT resistance is common and represents the main hurdle for successful TNBC treatment. Numerous mechanisms were uncovered that can lead to the development of chemoresistance. These include cancer stem cells (CSCs) induction after neoadjuvant chemotherapy (NACT), ATP-binding cassette (ABC) transporters, hypoxia and avoidance of apoptosis, single factors such as tyrosine kinase receptors (EGFR, IGFR1), a disintegrin and metalloproteinase 10 (ADAM10), and a few pathological molecular pathways. Some biomarkers capable of predicting resistance to specific chemotherapeutic agents were identified and are expected to be validated in future studies for a more accurate selection of drugs to be employed and for a more tailored approach, both in neoadjuvant and advanced settings. Recently, based on specific biomarkers, some therapies were tailored to TNBC subsets and became available in clinical practice: olaparib and talazoparib for BRCA1/2 germline mutation carriers larotrectinib and entrectinib for neurotrophic tropomyosin receptor kinase (NTRK) gene fusion carriers, and anti-trophoblast cell surface antigen 2 (Trop2) antibody drug conjugate therapy for heavily pretreated metastatic TNBC (mTNBC). Further therapies targeting some pathologic molecular pathways, apoptosis, miRNAS, epidermal growth factor receptor (EGFR), insulin growth factor 1 receptor (IGF-1R), and androgen receptor (AR) are under investigation. Among them, phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and EGFR inhibitors as well as antiandrogens showed promising results and are under evaluation in Phase II/III clinical trials. Emerging therapies allow to select specific antiblastics that alone or by integrating the conventional therapeutic approach may overcome/hinder chemoresistance.

The Wnt/β-catenin pathway in breast cancer therapy: a pre-clinical perspective of its targeting for clinical translation

INTRODUCTION

Despite various treatments available, there is still a high mortality rate in breast cancer patients. Thus, there exists an unmet need for new therapeutic interventions. Studies show that the Wnt/β-catenin signaling pathway is involved in breast cancer metastasis because of its transcriptional control on epithelial to mesenchymal transition.

AREAS COVERED

This comprehensive review explores the Wnt signaling pathway as a potential target for treating breast cancer and other breast cancer subtypes. We discuss the Wnt signaling pathway, its role in breast cancer metastasis, and its effect on breast cancer stem cells. Further, endogenous agents that cause Wnt pathway inactivation are outlined. Finally, various natural and chemical compounds modulating the Wnt pathway used in pre-clinical or clinical trials for breast cancer treatment are discussed.

EXPERT OPINION

In vitro and in vivo studies indicate an immense potential of agents targeting the Wnt signaling pathway to prevent and manage breast cancer. Still, more clinical studies are required to support their use in humans. Apart from the agents already in clinical trials, several drug combinations discussed may be translated into clinical practice in a few years.

Cancer chemoprevention through Frizzled receptors and EMT

Frizzled (FZD) transmembrane receptors are well known for their role in β-catenin signaling and development and now understanding of their role in the context of cancer is growing. FZDs are often associated with the process of epithelial to mesenchymal transition (EMT) through β-catenin, but some also influence EMT through non-canonical pathways. With ten different FZDs, there is a wide range of activity from oncogenic to tumor suppressive depending on the tissue context. Alterations in FZD signaling can occur during development of premalignant lesions, supporting their potential as targets of chemoprevention agents. Agonizing or antagonizing FZD activity may affect EMT, which is a key process in lesion progression often targeted by chemoprevention agents. Recent studies identified a specific FZD as important for activity of an EMT inhibiting chemopreventive agent and other studies have highlighted the previously unrecognized potential for targeting small molecules to FZD receptors. This work demonstrates the value of investigating FZDs in chemoprevention and here we provide a review of FZDs in cancer EMT and their potential as chemoprevention targets.

Targeting Different Pathways Using Novel Combination Therapy in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer accounting for 15-20% of cases and is defined by the lack of hormonal receptors viz., estrogen receptor (ER), progesterone receptor (PR) and expression of human epidermal growth receptor 2 (HER2). Treatment of TNBC is more challenging than other subtypes of breast cancer due to the lack of markers for the molecularly targeted therapies (ER, PR, and HER-2/ Neu), the conventional chemotherapeutic agents are still the mainstay of the therapeutic protocols of its patients. Despite, TNBC being more chemo-responsive than other subtypes, unfortunately, the initial good response to the chemotherapy eventually turns into a refractory drug-resistance. Using a monotherapy for the treatment of cancer, especially high-grade tumors like TNBC, is mostly worthless due to the inherent genetic instability of tumor cells to develop intrinsic and acquired resistance. Thus, a cocktail of two or more drugs with different mechanisms of action is more effective and could successfully control the disease. Furthermore, combination therapy reveals more, or at least the same, effectiveness with lower doses of every single agent and decreases the likelihood of chemoresistance. Herein, we shed light on the novel combinatorial approaches targeting PARP, EGFR, PI3K pathway, AR, and wnt signaling, HDAC, MEK pathway for efficient treatment of high-grade tumors like TNBC and decreasing the onset of resistance.

Expression and prognostic impact of FZDs in pancreatic adenocarcinoma

Background

Despite the high number of researches on pancreatic adenocarcinoma (PAAD) over past decades, little progress had been made due to lack of effective treatment regimens. We aimed to investigate the expression level, mutation, and clinical significance of the Frizzled (FZD) family in PAAD so as to establish a sufficient scientific evidence for clinical decisions and risk management.

Methods

PAAD samples were extracted from The Cancer Genome Atlas (TCGA). Oncomine, Gene expression profiling interactive analysis (GEPIA), human protein atlas (HPA), Kaplan–Meier Plotter, cBioPortal, LinkedOmics, DAVID database, and R software (× 64 3.6.2) were used to comprehensively analyze the roles of FZDs. p value below to 0.05 was considered as significant difference.

Results

In total, 179 PAAD tissues and 171 paracancerous tissues were included. The expression levels of FZD1, 2, 6, 7, and 8 were higher in PAAD tissues than those in normal pancreatic tissue. The higher the expression levels of FZD2 and FZD7, the higher the clinical stage. The overall survival (OS) time was significantly different between low FZD3, 4, 5, 6, and 9 expression group and high expression group. Multivariable analysis showed that FZD3 and FZD6 were independent prognostic factors. The recurrence free survival (RFS) time was significantly different between low FZD4 and FZD8 expression group and high expression group. The RFS difference between low FZD6 expression group and high expression group had not reached statistical significance (p = 0.067), which might be due to the small sample size. However, multivariable analysis showed that FZD6 was the only independent factor for RFS. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that FZDs played a critical role in the Wnt signaling pathway, which was further confirmation that FZDs were transmembrane receptors of Wnt signaling pathway.

Conclusions

Our results strongly indicated a crucial role of the FZD family in PAAD. FZD3 and FZD6 could be potential prognostic and predictive markers, and FZD6 might also function as a potential therapeutic target in PAAD by blocking Wnt/β-catenin pathway.

Regulation of Wnt Signaling Pathways at the Plasma Membrane and Their Misregulation in Cancer

Wnt signaling is one of the key signaling pathways that govern numerous physiological activities such as growth, differentiation and migration during development and homeostasis. As pathway misregulation has been extensively linked to pathological processes including malignant tumors, a thorough understanding of pathway regulation is essential for development of effective therapeutic approaches. A prominent feature of cancer cells is that they significantly differ from healthy cells with respect to their plasma membrane composition and lipid organization. Here, we review the key role of membrane composition and lipid order in activation of Wnt signaling pathway by tightly regulating formation and interactions of the Wnt-receptor complex. We also discuss in detail how plasma membrane components, in particular the ligands, (co)receptors and extracellular or membrane-bound modulators, of Wnt pathways are affected in lung, colorectal, liver and breast cancers that have been associated with abnormal activation of Wnt signaling. Wnt-receptor complex components and their modulators are frequently misexpressed in these cancers and this appears to correlate with metastasis and cancer progression. Thus, composition and organization of the plasma membrane can be exploited to develop new anticancer drugs that are targeted in a highly specific manner to the Wnt-receptor complex, rendering a more effective therapeutic outcome possible.

A novel humanized Frizzled-7-targeting antibody enhances antitumor effects of Bevacizumab against triple-negative breast cancer via blocking Wnt/β-catenin signaling pathway

BACKGROUND

Anti-angiogenic therapy has been widely applied to the clinical treatment of malignant tumors. However, the efficacy of such treatments has been called into question, especially in triple-negative breast cancer (TNBC). Bevacizumab, the first anti-angiogenic agent approved by FDA, actually increases invasive and metastatic properties of TNBC cells, resulting from the activation of Wnt/β-catenin signaling in response to hypoxia. As a critical receptor of Wnt/β-catenin signaling, Frizzled-7 (Fzd7) is aberrantly expressed in TNBC, indicating Fzd7 a potential target for developing drugs to be combined with anti-angiogenic agents.

METHODS

Hybridoma technique and antibody humanization technique were utilized to generate a Fzd7-targeting antibody (SHH002-hu1). Biolayer interferometry (BLI) assay and near infrared (NIR) imaging were conducted to detect the affinity and targeting ability of SHH002-hu1. Next, whether SHH002-hu1 could suppress the invasion and migration of TNBC cells induced by Bevacizumab were validated, and the underlying molecular mechanisms were elucidated by luciferase reporter and western blot assays. The nude-mice transplanted TNBC models were established to assess the anti-TNBC activities of SHH002-hu1 when combined with Bevacizumab. Then, the effects on putative TNBC stem-like cells and Wnt/β-catenin signaling were evaluated by immunofluorescence (IF). Further, the tumor-initiating and self-renew capacity of TNBC cells were studied by secondary nude mouse xenograft model and sphere formation assay. In addition, the effects of SHH002-hu1 on the adaptation of TNBC cells to hypoxia were evaluated by the detection of vasculogenic mimicry (VM) and hypoxia-inducible factor-1α (HIF-1α) transcriptional activity.

RESULTS

The novel humanized antibody targeting Fzd7 (SHH002-hu1) exhibited extremely high affinity with Fzd7, and specifically targeted to Fzd7⁺ cells and tumor tissues. SHH002-hu1 repressed invasion, migration and epithelial-mesenchymal cell transformation (EMT) of TNBC cells induced by Bevacizumab through abating Wnt/β-catenin signaling. SHH002-hu1 significantly enhanced the capacity of Bevacizumab to inhibit the growth of TNBC via reducing the subpopulation of putative TNBC stem-like cells, further attenuating Bevacizumab-enhanced tumor-initiating and self-renew capacity of TNBC cells. Moreover, SHH002-hu1 effectively restrained the adaptation of TNBC cells to hypoxia via disrupting Wnt/β-catenin signaling.

CONCLUSION

SHH002-hu1 significantly enhances the anti-TNBC capacity of Bevacizumab, and shows the potential of preventing TNBC recurrence, suggesting SHH002-hu1 a good candidate for the synergistic therapy together with Bevacizumab.

LncRNA HOTAIR promotes breast cancer progression through regulating the miR-129-5p/FZD7 axis

Breast cancer is the most common malignancies worldwide. LncRNA HOX transcript antisense intergenic RNA (HOTAIR) has been shown to promote progression and metastasis of various cancers, including breast cancer. This reasearch aimed to investigate the downstream regulatory pathways of HOTAIR in breast cancer. The levels of HOTAIR and miR-129-5p were examined in breast cancer tissues and SKBR3 and MCF7 cells by quantitative real-time PCR (qRT-PCR). Cell proliferation was examined by Cell Counting Kit-8 (CCK-8) assay. Cell migration and invasion were estimated by transwell assay. Epithelial-to-mesenchymal transition (EMT)-related markers (E-cadherin, N-cadherin and Vimentin) were measured by Western blot assay. The expression of Frizzled 7 (FZD7) was detected using qRT-PCR or Western blot assay. Bioinformatics analysis, luciferase reporter assay or RNA Immunoprecipitation (RIP) assay was performed to explore the molecular mechanism of HOTAIR in breast cancer. Xenograft analysis was utilized to evaluate the tumor growth in vivo. HOTAIR and FZD7 were upregulated, while miR-129-5p was down-regulated in breast cancer tissues and cells. Knockdown of miR-129-5p reversed the effect of HOTAIR knockdown on cell proliferation, migration, invasion and EMT. FZD7 restored the inhibition of miR-129-5p on breast cancer progression. Furthermore, HOTAIR was a sponge of miR-129-5p and FZD7 was a target of miR-129-5p. Knockdown of HOTAIR inhibited the tumor growth in vivo. HOTAIR facilitated breast cancer progression by regulating the miR-129-5p/FZD7 axis, indicating that HOTAIR may be a potential biomarker and therapeutic target for breast cancer.

Inhibition of the Wnt Signalling Pathway: An Avenue to Control Breast Cancer Aggressiveness

Breast cancer (BC) is the most common tumour in women. Although the introduction of novel therapeutic approaches in clinical practice has dramatically improved the clinical outcome of BC patients, this malignant disease remains the second leading cause of cancer-related death worldwide. The wingless/integrated (Wnt) signalling pathway represents a crucial molecular node relevantly implicated in the regulation of normal somatic stem cells as well as cancer stem cell (CSC) traits and the epithelial-mesenchymal transition cell program. Accordingly, Wnt signalling is heavily dysregulated in BC, and the altered expression of different Wnt genes is significantly associated with cancer-related aggressive behaviours. For all these reasons, Wnt signalling represents a promising therapeutic target currently under clinical investigation to achieve cancer eradication by eliminating CSCs, considered by most to be responsible for tumour initiation, relapse, and drug resistance. In this review, we summarized the current knowledge on the Wnt signalling pathway in BC and have presented evidence implicating the suitability of Wnt targeting in an attempt to improve the outcome of patients without affecting the normal somatic stem cell population.

Identification and Characterization of a Novel Protein ASP-3 Purified from Arca subcrenata and Its Antitumor Mechanism

Diverse bioactive substances derived from marine organisms have been attracting growing attention. Besides small molecules and polypeptides, numerous studies have shown that marine proteins also exhibit antitumor activities. Small anticancer proteins can be expressed in vivo by viral vectors to exert local and long-term anticancer effects. Herein, we purified and characterized a novel protein (ASP-3) with unique antitumor activity from Arca subcrenata Lischke. The ASP-3 contains 179 amino acids with a molecular weight of 20.6 kDa. The spectral characterization of ASP-3 was elucidated using Fourier Transform infrared spectroscopy (FTIR) and Circular Dichroism (CD) spectroscopy. Being identified as a sarcoplasmic calcium-binding protein, ASP-3 exhibited strong inhibitory effects on the proliferation of Human hepatocellular carcinoma (HepG2) cells with an IC50 value of 171.18 ± 18.59 μg/mL, measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The RNA-seq analysis showed that ASP-3 regulated the vascular endothelial growth factor receptor (VEGFR) signaling pathway in HepG2 cells. Immunofluorescence results indicated that ASP-3 effectively reduced VEGFR2 phosphorylation in HepG2 cells and affected the downstream components of VEGF signaling pathways. The surface plasmon resonance (SPR) analysis further demonstrated that ASP-3 direct interacted with VEGFR2. More importantly, the therapeutic potential of ASP-3 as an anti-angiogenesis agent was further confirmed by an in vitro model using VEGF-induced tube formation assay of human umbilical vein endothelial cells (HUVECs), as well as an in vivo model using transgenic zebrafish model. Taken together, the ASP-3 provides a good framework for the development of even more potent anticancer proteins and provides important weapon for cancer treatment using novel approaches such as gene therapy.

Mechanisms of Chemotherapy Resistance in Triple-Negative Breast Cancer-How We Can Rise to the Challenge

Triple-negative (TNBC) is the most lethal subtype of breast cancer owing to high heterogeneity, aggressive nature, and lack of treatment options. Chemotherapy remains the standard of care for TNBC treatment, but unfortunately, patients frequently develop resistance. Accordingly, in recent years, tremendous effort has been made into elucidating the mechanisms of TNBC chemoresistance with the goal of identifying new molecular targets. It has become evident that the development of TNBC chemoresistance is multifaceted and based on the elaborate interplay of the tumor microenvironment, drug efflux, cancer stem cells, and bulk tumor cells. Alterations of multiple signaling pathways govern these interactions. Moreover, TNBC's high heterogeneity, highlighted in the existence of several molecular signatures, presents a significant obstacle to successful treatment. In the present, in-depth review, we explore the contribution of key mechanisms to TNBC chemoresistance as well as emerging strategies to overcome them. We discuss novel anti-tumor agents that target the components of these mechanisms and pay special attention to their current clinical development while emphasizing the challenges still ahead of successful TNBC management. The evidence presented in this review outlines the role of crucial pathways in TNBC survival following chemotherapy treatment and highlights the importance of using combinatorial drug strategies and incorporating biomarkers in clinical studies.

MicroRNA-645 targets urokinase plasminogen activator and decreases the invasive growth of MDA-MB-231 triple-negative breast cancer cells

Background

Urokinase plasminogen activator (uPA) promotes the in vivo invasive growth of HCC cells by cleaving and activating matrix metalloproteinases (MMPs) to induce the destruction of the extracellular matrix of triple-negative breast cancer (TNBC) cells. The identification of microRNAs that target uPA and decrease uPA expression would be useful for attenuating the in vivo invasive growth of TNBC cells.

Materials and methods

MicroRNA-645 (miR-645) was identified using an online tool (miRDB) as potentially targeting uPA; miR-645 inhibition of uPA was confirmed by western blot experiments. The effects of miR-645 on the in vivo invasive growth of TNBC cells were examined using an intrahepatic tumor model in nude mice, and the miR-645 mechanism of action was explored with MMP cleaving experiments.

Results

Through virtual screening, we discovered that miR-645 potentially targeted the uPA 3′ untranslated region. This targeting was confirmed by western blot experiments and miR-645 lentiviral particle (LV-645) transduction that inhibited uPA expression in MDA-MB-231 TNBC cells. The LV-645 inhibition of uPA led to the decreased invasive growth of TNBC cells in nude mice. The mechanism data indicated that the uPA inhibition resulted in a decreased cleaving of the pro-MMP-9 protein.

Conclusion

Targeting uPA with miR-645 decreased the in vivo invasive growth of TNBC cells. These results suggest that miR-645 may represent a promising treatment strategy for TNBC.