Major vault protein is a direct target of Notch1 signaling and contributes to chemoresistance in triple-negative breast cancer cells

Tiron enhances the anti-cancer activity of doxorubicin in DMBA-induced breast cancer: Role of Notch signaling/apoptosis/autophagy/oxidative stress

Existing work intended to investigate the outcomes of the localized mitochondrial antioxidant tiron (TR) alone or in combination with doxorubicin (DOX) in 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis in rats and the mechanistic pathways behind these effects. Also, to examine the preventive role of TR against DOX-related cardiotoxicity. 64 female Sprague-Dawley rats were randomly assigned into 8 groups: CTRL, DOX, TR, DMBA, DMBA + DOX, DMBA + TR100, DMBA + TR200, and DMBA + DOX + TR200. Rats received TR (100 and 200 mg/kg), DOX (2mg/kg), and DMBA (7.5 mg/kg) for four consecutive weeks. TR alone or combined with DOX not only inhibited oxidative status-related parameters and Notch pathway proteins but also attenuated proliferation markers, and enhanced apoptosis, and autophagy-related genes. Consistently, the histopathological analysis showed better scores in mammary tissues isolated from groups treated with TR only or combined with DOX. Additionally, TR dramatically decreased relative heart weight, myocardial injury biomarkers, and heart oxidative stress parameters while maintaining the myocardial histological integrity. Here we provided evidence that TR acts via modulating Notch signaling/apoptosis/autophagy/oxidative stress to elicit anti-tumor activity and combination with DOX revealed a higher efficacy as a novel anticancer strategy. Moreover, TR could be a potential cardio-protective candidate during DOX-chemotherapy, possibly via its antioxidant activity.

Furin, ADAM, and γ-secretase: Core regulatory targets in the Notch pathway and the therapeutic potential for breast cancer

The activation of the Notch pathway promotes the occurrence and progression of breast cancer. The Notch signal plays different roles in different molecular subtypes of breast cancer. In estrogen receptor-positive (ER+) breast cancer, the Notch pathway regulates the activity of estrogen receptors. In human epidermal growth factor receptor 2-positive (HER2+) breast cancer, crosstalk between Notch and HER2 enhances HER2 signal expression. In triple-negative breast cancer (TNBC), Notch pathway activation is closely linked to tumor invasion and drug resistance. This article offers a comprehensive review of the structural domains, biological functions, and key targets of Notch with a specific focus on the roles of Furin protease, ADAM metalloprotease, and γ-secretase in breast cancer and their potential as therapeutic targets. We discuss the functions and mutual regulatory mechanisms of these proteinases in the Notch pathway as well as other potential targets in the Notch pathway, such as the glycosylation process and key transcription factors. This article also introduces new approaches in the treatment of breast cancer, with a special focus on the molecular characteristics and treatment response differences of different subtypes. We propose that the core regulatory molecules of the Notch pathway may become key targets for development of personalized treatment, which may significantly improve treatment outcomes and prognosis for patients with breast cancer.

MiR-338-5p, a novel metastasis-related miRNA, inhibits triple-negative breast cancer progression by targeting the ETS1/NOTCH1 axis

Breast cancer ranks as the most prevalent cancer globally, surpassing lung cancer, with recurrence/metastasis to be its main account for the cancer-related mortality. MicroRNAs (miRNAs) participate critically in various physiological and pathological processes through posttranscriptional regulation of downstream genes. Our preliminary findings identified miR-338-5p, potentially linked to metastasis in breast cancer, a previously unexplored area. Analysis of the GSE38867 dataset revealed the decreased miR-338-5p expression in metastatic breast cancer compared to normal tissues. Cellular function experiments and a xenograft tumor model demonstrated the inhibitory function of miR-338-5p on the progression of breast cancer in vitro and in vivo. Furthermore, it downregulated the expression of mesenchymal biomarkers and NOTCH1 significantly. With the predicting targets of miR-338-5p and transcription factors of the NOTCH1 gene, coupled with dual luciferase reporter assays, it is identified ETS1 as the interactor between miR-338-5p and NOTCH1. In breast cancer tissues, as well as in our xenograft tumor model, expression of ETS1 and NOTCH1 was positively correlated using immunohistochemical staining. This study reports, for the first time, on the miR-338-5p/ETS1/NOTCH1 axis and its pivotal role in breast cancer proliferation and metastasis. These findings propose a novel therapeutic strategy for breast cancer patients and lays a foundation for its clinical detection and treatment evaluation.

Exploiting Matrix Stiffness to Overcome Drug Resistance

Drug resistance is arguably one of the biggest challenges facing cancer research today. Understanding the underlying mechanisms of drug resistance in tumor progression and metastasis are essential in developing better treatment modalities. Given the matrix stiffness affecting the mechanotransduction capabilities of cancer cells, characterization of the related signal transduction pathways can provide a better understanding for developing novel therapeutic strategies. In this review, we aimed to summarize the recent advancements in tumor matrix biology in parallel to therapeutic approaches targeting matrix stiffness and its consequences in cellular processes in tumor progression and metastasis. The cellular processes governed by signal transduction pathways and their aberrant activation may result in activating the epithelial-to-mesenchymal transition, cancer stemness, and autophagy, which can be attributed to drug resistance. Developing therapeutic strategies to target these cellular processes in cancer biology will offer novel therapeutic approaches to tailor better personalized treatment modalities for clinical studies.

Seedless black Vitis vinifera polyphenols suppress hepatocellular carcinoma in vitro and in vivo by targeting apoptosis, cancer stem cells, and proliferation

Hepatocellular carcinoma (HCC) is an aggressive tumor and one of the most challenging cancers to treat. Here, we evaluated the in vitro and in vivo ameliorating impacts of seedless black Vitis vinifera (VV) polyphenols on HCC. Following the preparation of the VV crude extract (VVCE) from seedless VV (pulp and skin), three fractions (VVF1, VVF2, and VVF3) were prepared. The anticancer potencies of the prepared fractions, compared to 5-FU, were assessed against HepG2 and Huh7 cells. In addition, the effects of these fractions on p-dimethylaminoazobenzene-induced HCC in mice were evaluated. The predicted impacts of selected phenolic constituents of VV fractions on the activity of essential HCC-associated enzymes (NADPH oxidase "NADPH-NOX2", histone deacetylase 1 "HDAC1", and sepiapterin reductase "SepR") were analyzed using molecular docking. The results showed that VVCE and its fractions induced apoptosis and collapsed CD133+ stem cells in the studied cancer cell lines with an efficiency greater than 5-FU. VVF1 and VVF2 exhibited the most effective anticancer fractions in vitro; therefore, we evaluated their influences in mice. VVF1 and VVF2 improved liver morphology and function, induced apoptosis, and lowered the fold expression of various crucial genes that regulate cancer stem cells and other vital pathways for HCC progression. For most of the examined parameters, VVF1 and VVF2 had higher potency than 5-FU, and VVF1 showed more efficiency than VVF2. The selected phenolic compounds displayed competitive inhibitory action on NADPH-NOX2, HDAC1, and SepR. In conclusion, these findings declare that VV polyphenolic fractions, particularly VVF1, could be promising safe anti-HCC agents.

Notch signaling pathway in cancer: from mechanistic insights to targeted therapies

Notch signaling, renowned for its role in regulating cell fate, organ development, and tissue homeostasis across metazoans, is highly conserved throughout evolution. The Notch receptor and its ligands are transmembrane proteins containing epidermal growth factor-like repeat sequences, typically necessitating receptor-ligand interaction to initiate classical Notch signaling transduction. Accumulating evidence indicates that the Notch signaling pathway serves as both an oncogenic factor and a tumor suppressor in various cancer types. Dysregulation of this pathway promotes epithelial-mesenchymal transition and angiogenesis in malignancies, closely linked to cancer proliferation, invasion, and metastasis. Furthermore, the Notch signaling pathway contributes to maintaining stem-like properties in cancer cells, thereby enhancing cancer invasiveness. The regulatory role of the Notch signaling pathway in cancer metabolic reprogramming and the tumor microenvironment suggests its pivotal involvement in balancing oncogenic and tumor suppressive effects. Moreover, the Notch signaling pathway is implicated in conferring chemoresistance to tumor cells. Therefore, a comprehensive understanding of these biological processes is crucial for developing innovative therapeutic strategies targeting Notch signaling. This review focuses on the research progress of the Notch signaling pathway in cancers, providing in-depth insights into the potential mechanisms of Notch signaling regulation in the occurrence and progression of cancer. Additionally, the review summarizes pharmaceutical clinical trials targeting Notch signaling for cancer therapy, aiming to offer new insights into therapeutic strategies for human malignancies.

The prognostic value and immunological role of MVP in pan-cancer study

Major Vault Protein (MVP) has emerged as a potential prognostic and immunological biomarker in various cancer types. This pan-cancer study aimed to investigate expression of MVP and its correlation with clinical outcomes and immune infiltration across diverse cancer types. We conducted an analysis of extensive transcriptomic and clinical data from publicly available databases. Our findings unveiled a significant association between MVP expression and cancer progression, with higher expression levels predicting poorer overall survival in multiple cancer types. Importantly, MVP expression demonstrated a close relationship with immune infiltration in the tumor microenvironment, showing that higher expression levels were associated with increased immune cell infiltration. We further validated expression of MVP and function in cancer cell lines A549 and AGS. These compelling results suggest that MVP holds promise as a valuable biomarker for prognostic assessment and the development of immunotherapeutic strategies across various cancer types. Consequently, targeting MVP may offer a compelling therapeutic approach in the treatment of human cancers.

A molecular approach to triple-negative breast cancer: targeting the Notch signaling pathway

INTRODUCTION

Triple-negative breast cancer is an aggressive subtype of breast cancer characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression. This phenotype renders triple-negative breast cancer cells refractory to conventional therapies, resulting in poor clinical outcomes and an urgent need for novel therapeutic approaches. Recent studies have implicated dysregulation of the Notch receptor signaling pathway in the development and progression of triple-negative breast cancer.

OBJECTIVE

This study aimed to conduct a comprehensive literature review to identify potential therapeutic targets of the Notch pathway. Our analysis focused on the upstream and downstream components of this pathway to identify potential therapeutic targets.

RESULTS

Modulating the Notch signaling pathway may represent a promising therapeutic strategy to treat triple-negative breast cancer. Several potential therapeutic targets within this pathway are in the early stages of development, including upstream (such as Notch ligands) and downstream (including specific molecules involved in triple-negative breast cancer growth). These targets represent potential avenues for therapeutic intervention in triple-negative breast cancer.

COMMENTS

Additional research specifically addressing issues related to toxicity and improving drug delivery methods is critical for the successful translation of these potential therapeutic targets into effective treatments for patients with triple-negative breast cancer.

Differential Expression of NOTCH-1 and Its Molecular Targets in Response to Metronomic Followed by Conventional Therapy in a Patient with Advanced Triple-Negative Breast Cancer

A group of 27 patients diagnosed with metastatic triple-negative breast cancer (mTNBC) was randomly distributed into two groups and underwent different lines of metronomic treatment (mCHT). The former group (N 14) received first-line mCHT and showed a higher overall survival rate than the second group (N 13), which underwent second-line mCHT. Analysis of one patient still alive from the first group, diagnosed with mTNBC in 2019, showed a complete metabolic response (CMR) after a composite approach implicating first-line mCHT followed by second-line epirubicin and third-line nab-paclitaxel, and was chosen for subsequent molecular characterization. We found altered expression in the cancer stemness-associated gene NOTCH-1 and its corresponding protein. Additionally, we found changes in the expression of oncogenes, such as MYC and AKT, along with their respective proteins. Overall, our data suggest that a first-line treatment with mCHT followed by MTD might be effective by negatively regulating stemness traits usually associated with the emergence of drug resistance.

Notch1 promotes resistance to cisplatin by up-regulating Ecto-5'-nucleotidase (CD73) in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is an aggressive molecular subtype that due to lack of druggable targets is treated with chemotherapy as standard of care. However, TNBC is prone to chemoresistance and associates with poor survival. The aim of this study was to explore the molecular mechanisms of chemoresistance in TNBC. Firstly, we found that the mRNA expression of Notch1 and CD73 in cisplatin-treated patient material associated with poor clinical outcome. Further, both were upregulated at the protein level in cisplatin-resistant TNBC cell lines. Overexpression of Notch1 intracellular domain (termed N1ICD) increased expression of CD73, whereas knockdown of Notch1 decreased CD73 expression. Using chromatin immunoprecipitation and Dual-Luciferase assay it was identified that N1ICD directly bound the CD73 promoter and activated transcription. Taken together, these findings suggest CD73 as a direct downstream target of Notch1, providing an additional layer to the mechanisms underlying Notch1-mediated cisplatin resistance in TNBC.

Cancer-Associated Adipocytes and Breast Cancer: Intertwining in the Tumor Microenvironment and Challenges for Cancer Therapy

Adipocytes are the main components in breast tissue, and cancer-associated adipocytes (CAAs) are one of the most important components in the tumor microenvironment of breast cancer (BC). Bidirectional regulation was found between CAAs and BC cells. BC facilitates the dedifferentiation of adjacent adipocytes to form CAAs with morphological and biological changes. CAAs increase the secretion of multiple cytokines and adipokines to promote the tumorigenesis, progression, and metastasis of BC by remodeling the extracellular matrix, changing aromatase expression, and metabolic reprogramming, and shaping the tumor immune microenvironment. CAAs are also associated with the therapeutic response of BC and provide potential targets in BC therapy. The present review provides a comprehensive description of the crosstalk between CAAs and BC and discusses the potential strategies to target CAAs to overcome BC treatment resistance.

CHD4 promotes acquired chemoresistance and tumor progression by activating the MEK/ERK axis

AIMS

Chemoresistance remains a major challenge in gastric cancer (GC). Chromodomain helicase DNA-binding protein 4 (CHD4) mediated chromatin remodeling plays critical roles in various tumor types, but its role in chemoresistance in GC remains uncharacterized.

METHODS

CHD4 expression was examined by immunohistochemistry and Western blotting. The role of CHD4 on cell proliferation and chemoresistance of GC was examined in vitro and in vivo. Immunoprecipitation and liquid chromatography-mass spectrometry were used to identify CHD4-binding proteins and a proximity ligation assay was used to explore protein-protein interaction.

RESULTS

Chemoresistance is associated with upregulation of CHD4 in the tumor tissues of GC patients. Overexpression of CHD4 increased chemoresistance and cell proliferation. Knockdown of CHD4 induced cell apoptosis and cell cycle arrest. CHD4 mediates the decrease of the intracellular concentration of cisplatin by inducing drug efflux. Additionally, CHD4 promotes the interaction between ERK1/2 and MEK1/2, resulting in continuous activation of MEK/ERK pathway. Knockdown of CHD4 in GC increased sensitivity to chemotherapy and suppressed tumor growth in a mouse xenograft model.

CONCLUSIONS

This study identifies CHD4 dominated multi-drug efflux as a promising therapeutic target for overcoming acquired chemoresistance in GC.

Multiplexed and reproducible high content screening of live and fixed cells using Dye Drop

High-throughput measurement of cells perturbed using libraries of small molecules, gene knockouts, or different microenvironmental factors is a key step in functional genomics and pre-clinical drug discovery. However, it remains difficult to perform accurate single-cell assays in 384-well plates, limiting many studies to well-average measurements (e.g., CellTiter-Glo®). Here we describe a public domain Dye Drop method that uses sequential density displacement and microscopy to perform multi-step assays on living cells. We use Dye Drop cell viability and DNA replication assays followed by immunofluorescence imaging to collect single-cell dose-response data for 67 investigational and clinical-grade small molecules in 58 breast cancer cell lines. By separating the cytostatic and cytotoxic effects of drugs computationally, we uncover unexpected relationships between the two. Dye Drop is rapid, reproducible, customizable, and compatible with manual or automated laboratory equipment. Dye Drop improves the tradeoff between data content and cost, enabling the collection of information-rich perturbagen-response datasets.

Overcoming therapeutic resistance to platinum-based drugs by targeting Epithelial–Mesenchymal transition

Platinum-based drugs (PBDs), including cisplatin, carboplatin, and oxaliplatin, have been widely used in clinical practice as mainstay treatments for various types of cancer. Although there is firm evidence of notable achievements with PBDs in the management of cancers, the acquisition of resistance to these agents is still a major challenge to efforts at cure. The introduction of the epithelial-mesenchymal transition (EMT) concept, a critical process during embryonic morphogenesis and carcinoma progression, has offered a mechanistic explanation for the phenotypic switch of cancer cells upon PBD exposure. Accumulating evidence has suggested that carcinoma cells can enter a resistant state via induction of the EMT. In this review, we discussed the underlying mechanism of PBD-induced EMT and the current understanding of its role in cancer drug resistance, with emphasis on how this novel knowledge can be exploited to overcome PBD resistance via EMT-targeted compounds, especially those under clinical trials.

Wharton jelly-derived mesenchymal stem cell exosomes induce apoptosis and suppress EMT signaling in cervical cancer cells as an effective drug carrier system of paclitaxel

Mesenchymal stem cells can be obtained and multiplied from various sources and have a very high capacity to release exosomes. Exosomes are nano-sized extracellular vesicles containing biological signaling molecules. This study aimed to determine the effect of MSC-derived exosomes as a drug delivery system for paclitaxel in cervical cancer cells. In this study, human MSC were isolated from wharton jelly of umbilical cord tissue (WJ-MSC), and cells were characterized by CD44, CD90, CD105, and CD34 staining. Exosomes were released in WJ-MSC cells with serum-starved conditions for 48 hours, and particle sizes and structures were examined with zeta-sizer and TEM. In addition, exosomes CD9, CD63, and CD81 markers were checked by western blot. Paclitaxel was loaded into exosomes (Exo-PAC) by electroporation and then incubated with Hela cervical cancer cells for 24 hours. TGF-β, SMAD, Snail, Slug, β-catenin, Notch, Caspase-3, Caspase-9, Bax, Bcl-2 protein and gene expression levels were analyzed in Hela cells. As a result, low concentration Exo-PAC induced apoptosis, and suppressed epithelial-mesenchymal transition proteins in Hela cells. In this study, it has been demonstrated that WJ-MSCs can be used as drug delivery systems for cervical cancer if exosomes are produced scalably in the future.

Recent Trends in Nanomedicine-Based Strategies to Overcome Multidrug Resistance in Tumors

Cancer is the leading cause of economic and health burden worldwide. The commonly used approaches for the treatment of cancer are chemotherapy, radiotherapy, and surgery. Chemotherapy frequently results in undesirable side effects, and cancer cells may develop resistance. Combating drug resistance is a challenging task in cancer treatment. Drug resistance may be intrinsic or acquired and can be due to genetic factors, growth factors, the increased efflux of drugs, DNA repair, and the metabolism of xenobiotics. The strategies used to combat drug resistance include the nanomedicine-based targeted delivery of drugs and genes using different nanocarriers such as gold nanoparticles, peptide-modified nanoparticles, as well as biomimetic and responsive nanoparticles that help to deliver payload at targeted tumor sites and overcome resistance. Gene therapy in combination with chemotherapy aids in this respect. siRNA and miRNA alone or in combination with chemotherapy improve therapeutic response in tumor cells. Some natural substances, such as curcumin, quercetin, tocotrienol, parthenolide, naringin, and cyclosporin-A are also helpful in combating the drug resistance of cancer cells. This manuscript summarizes the mechanism of drug resistance and nanoparticle-based strategies used to combat it.

Extracellular Vesicles and Resistance to Anticancer Drugs: A Tumor Skeleton Key for Unhinging Chemotherapies

Although surgical procedures and clinical care allow reaching high success in fighting most tumors, cancer is still a formidable foe. Recurrence and metastatization dampen the patients’ overall survival after the first diagnosis; nevertheless, the large knowledge of the molecular bases drives these aspects. Chemoresistance is tightly linked to these features and is mainly responsible for the failure of cancer eradication, leaving patients without a crucial medical strategy. Many pathways have been elucidated to trigger insensitiveness to drugs, generally associated with the promotion of tumor growth, aggressiveness, and metastatisation. The main mechanisms reported are the expression of transporter proteins, the induction or mutations of oncogenes and transcription factors, the alteration in genomic or mitochondrial DNA, the triggering of autophagy or epithelial-to-mesenchymal transition, the acquisition of a stem phenotype, and the activation of tumor microenvironment cells. Extracellular vesicles (EVs) can directly transfer or epigenetically induce to a target cell the molecular machinery responsible for the acquisition of resistance to drugs. In this review, we resume the main body of knowledge supporting the crucial role of EVs in the context of chemoresistance, with a particular emphasis on the mechanisms related to some of the main drugs used to fight cancer.

Small but Powerful: The Human Vault RNAs as Multifaceted Modulators of Pro-Survival Characteristics and Tumorigenesis

Simple Summary

Small non-protein-coding RNAs have been recognized as valuable regulators of gene expression in all three domains of life. Particularly in multicellular organisms, ncRNAs-mediated gene expression control has evolved as a central principle of cellular homeostasis. Thus, it is not surprising that non-coding RNA misregulation has been linked to various diseases. Here, we review the contributions of the four human vault RNAs to cellular proliferation, apoptosis and cancer biology.

Abstract

The importance of non-coding RNAs for regulating gene expression has been uncovered in model systems spanning all three domains of life. More recently, their involvement in modulating signal transduction, cell proliferation, tumorigenesis and cancer progression has also made them promising tools and targets for oncotherapy. Recent studies revealed a class of highly conserved small ncRNAs, namely vault RNAs, as regulators of several cellular homeostasis mechanisms. The human genome encodes four vault RNA paralogs that share significant sequence and structural similarities, yet they seem to possess distinct roles in mammalian cells. The alteration of vault RNA expression levels has frequently been observed in cancer tissues, thus hinting at a putative role in orchestrating pro-survival characteristics. Over the last decade, significant advances have been achieved in clarifying the relationship between vault RNA and cellular mechanisms involved in cancer development. It became increasingly clear that vault RNAs are involved in controlling apoptosis, lysosome biogenesis and function, as well as autophagy in several malignant cell lines, most likely by modulating signaling pathways (e.g., the pro-survival MAPK cascade). In this review, we discuss the identified and known functions of the human vault RNAs in the context of cell proliferation, tumorigenesis and chemotherapy resistance.

GRWD1 affects the proliferation, apoptosis, invasion and migration of triple negative breast cancer through the Notch signaling pathway

Breast cancer is a highly heterogeneous tumor, among which triple negative breast cancer (TNBC) is the most invasive and prone to recurrence and metastasis. The present study aimed to investigate the regulatory mechanisms of glutamate-rich WD-repeat-containing protein 1 (GRWD1) in TNBC cells. The expression of GRWD1 in the normal human breast epithelial cells and human breast cancer cells was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The transfection effects of small interfering RNA (siRNA)-GRWD1 and overexpression (Ov)-Notch1 were also confirmed by RT-qPCR and western blotting. The proliferation, apoptosis, invasion and migration of transfected cells were in turn analyzed by Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine, Matrigel and wound healing assays. The expression of proteins related to proliferation, apoptosis, metastasis, epithelial-mesenchymal transition and the Notch signaling pathway was detected by western blotting. As a result, GRWD1 expression was upregulated in breast cancer cells and was revealed to be highest in MDA-MB-231 and HCC1937 cells. GRWD1 knockdown suppressed TNBC cell proliferation, invasion and migration and promoted TNBC cell apoptosis. Furthermore, the expression of Notch1 and Notch4 was inhibited by GRWD1 knockdown. The expression of downstream genes of the Notch signaling pathway Hes1, Hes5, Hey1, Hey2, p21, c-Myc, cyclin D1, human epidermal growth factor 2 receptor and NF-κB were all suppressed after siRNA-GRWD1 transfection. However, Notch1 overexpression reversed the effect of GRWD1 knockdown on biological behaviors of TNBC cells. In conclusion, GRWD1 knockdown could suppress the proliferation, invasion and migration and promoted apoptosis of TNBC cells through inhibiting the Notch signaling pathway.

Notch signaling in female cancers: a multifaceted node to overcome drug resistance

Drug resistance is one of the main challenges in cancer therapy, including in the treatment of female-specific malignancies, which account for more than 60% of cancer cases among women. Therefore, elucidating the underlying molecular mechanisms is an urgent need in gynecological cancers to foster novel therapeutic approaches. Notably, Notch signaling, including either receptors or ligands, has emerged as a promising candidate given its multifaceted role in almost all of the hallmarks of cancer. Concerning the connection between Notch pathway and drug resistance in the afore-mentioned tumor contexts, several studies focused on the Notch-dependent regulation of the cancer stem cell (CSC) subpopulation or the induction of the epithelial-to-mesenchymal transition (EMT), both features implicated in either intrinsic or acquired resistance. Indeed, the present review provides an up-to-date overview of the published results on Notch signaling and EMT- or CSC-driven drug resistance. Moreover, other drug resistance-related mechanisms are examined such as the involvement of the Notch pathway in drug efflux and tumor microenvironment. Collectively, there is a long way to go before every facet will be fully understood; nevertheless, some small pieces are falling neatly into place. Overall, the main aim of this review is to provide strong evidence in support of Notch signaling inhibition as an effective strategy to evade or reverse resistance in female-specific cancers.

Pediatric T-ALL type-1 and type-2 relapses develop along distinct pathways of clonal evolution

The mechanisms underlying T-ALL relapse remain essentially unknown. Multilevel-omics in 38 matched pairs of initial and relapsed T-ALL revealed 18 (47%) type-1 (defined by being derived from the major ancestral clone) and 20 (53%) type-2 relapses (derived from a minor ancestral clone). In both types of relapse, we observed known and novel drivers of multidrug resistance including MDR1 and MVP, NT5C2 and JAK-STAT activators. Patients with type-1 relapses were specifically characterized by IL7R upregulation. In remarkable contrast, type-2 relapses demonstrated (1) enrichment of constitutional cancer predisposition gene mutations, (2) divergent genetic and epigenetic remodeling, and (3) enrichment of somatic hypermutator phenotypes, related to BLM, BUB1B/PMS2 and TP53 mutations. T-ALLs that later progressed to type-2 relapses exhibited a complex subclonal architecture, unexpectedly, already at the time of initial diagnosis. Deconvolution analysis of ATAC-Seq profiles showed that T-ALLs later developing into type-1 relapses resembled a predominant immature thymic T-cell population, whereas T-ALLs developing into type-2 relapses resembled a mixture of normal T-cell precursors. In sum, our analyses revealed fundamentally different mechanisms driving either type-1 or type-2 T-ALL relapse and indicate that differential capacities of disease evolution are already inherent to the molecular setup of the initial leukemia.

Major Vault Protein (MVP) Associated With BRAF V600E Mutation Is an Immune Microenvironment-Related Biomarker Promoting the Progression of Papillary Thyroid Cancer via MAPK/ERK and PI3K/AKT Pathways

Papillary thyroid cancer (PTC) is the most common malignancy of the endocrine system, with an increase in incidence frequency. Major vault protein (MVP) is the main structural protein of the vault complex that has already been investigated in specific cancers. Yet the underlying biological functions and molecular mechanisms of MVP in PTC still remain considerably uncharacterized. Comprehensive analyses are predicated on several public datasets and local RNA-Seq cohort. Clinically, we found that MVP was upregulated in human PTC than in non-cancerous thyroid tissue and was correlated with vital clinicopathological parameters in PTC patients. MVP expression was associated with BRAF V600E, RAS, TERT, and RET status, and it was correlated with worse progression-free survival in PTC patients. Functionally, enrichment analysis provided new clues for the close relationship between MVP with cancer-related signaling pathways and the immune microenvironment in PTC. In PTC with high MVP expression, we found CD8+ T cells, regulatory T cells, and follicular helper T cells have a higher infiltration level. Intriguingly, MVP expression was positively correlated with multiple distinct phases of the anti-cancer immunity cycle. MVP knockdown significantly suppressed cell viability and colony formation, and promoted apoptosis. In addition, downregulated MVP markedly inhibited the migration and invasion potential of PTC cells. The rescue experiments showed that MVP could reverse the level of cell survival and migration. Mechanistically, MVP exerts its oncogenic function in PTC cells through activating PI3K/AKT/mTOR and MAPK/ERK pathways. These results point out that MVP is a reliable biomarker related to the immune microenvironment and provide a basis for elucidating the oncogenic roles of MVP in PTC progression.

Novel antitumor activity of the combined treatment of galloylquinic acids from Copaifera lucens and doxorubicin in solid Ehrlich carcinoma-bearing mice via the modulation of the Notch signaling pathway

AIMS

This study aims to investigate the potential synergistic effect of the combined treatment of galloylquinic acids compounds from Copaifera lucens with doxorubicin via the modulation of the Notch pathway in Ehrlich carcinoma-bearing mice model.

MAIN METHODS

The solid tumor model was induced in mice by s.c. injection of Ehrlich cancerous cells in the right hind limb. Sixty mice were allocated into five different groups which included treated groups with galloylquinic acids compounds, doxorubicin and their combination. Normal and tumor control groups were also used. Different biological samples were collected to measure the levels of Notch1, Hes1, Jagged1, TNF-α, IL-6, and VEGF. Histopathological and immunohistochemical examinations of tumor tissues using specific anti-NF-kβ and anti-cyclin D1 antibodies were also performed.

KEY FINDINGS

Our results showed that the combined treatment of galloylquinic acids compounds with doxorubicin significantly inhibited Notch1, Hes1, Jagged1, TNF-α, IL-6, VEGF, NF-kβ, and cyclin D1 activities.

SIGNIFICANCE

Galloylquinic acids compounds exhibited promising synergistic chemotherapeutic and oncostatic effects and promoted the chemosensitivity of doxorubicin, mainly by inhibiting the Notch signaling pathway and its downstream effectors. These compounds may be considered in cancer therapy exhibiting improved efficacy and reduced side effects of chemotherapeutic agents.

Cancer Stem Cells Contribute to Drug Resistance in Multiple Different Ways

Many tumors are resistant to conventional cancer therapies because a tumor is composed of heterogeneous cell population. Especially, subpopulation of cancer stem cells, which have self-renewal and differentiation properties and responsible for the tumor initiation, is generally considered resistant to chemo-, radio-, and immune therapy. Understanding the mechanism of drug resistance in cancer stem cells should lead to establish more effective therapeutic strategies. Actually, different molecular mechanisms are conceivable for cancer stem cells acquiring drug resistance. These mechanisms include not only cytoplasmic signaling pathways but also the intercellular communications in the tumor microenvironment. Recently, a great deal of successful reports challenged to elucidate the mechanisms of drug resistance and to develop novel treatments targeting cancer stem cells.

Novel cancer stem cell marker MVP enhances temozolomide-resistance in glioblastoma

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MVP level were up-regulated in temozolomide-resistant glioblastoma cells and glioblastoma stem cells.

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MVP decreased the sensitization to temozolomide of glioblastoma cells and glioblastoma stem cells.

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Knockdown of MVP reduced temozolomide-resistance, sphere formation ability and invasive capacity.

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Negative correlation between MVP expression and prognosis of glioblastoma patients

The resistance of highly aggressive glioblastoma multiforme (GBM) to chemotherapy is a major clinical problem resulting in a poor prognosis. GBM contains a rare population of self-renewing cancer stem cells (CSCs) that proliferate, spurring the growth of new tumors, and evade chemotherapy. In cancer, major vault protein (MVP) is thought to contribute to drug resistance. However, the role of MVP as CSCs marker remains unknown and whether MVP could sensitize GBM cells to Temozolomide (TMZ) also is unclear. We found that sensitivity to TMZ was suppressed by significantly increasing the MVP expression in GBM cells with TMZ resistance. Also, MVP was associated with the expression of other multidrug-resistant proteins in tumorsphere of TMZ-resistant GBM cell, and was highly co-expressed with CSC markers in tumorsphere culture. On the other hands, knockdown of MVP resulted in reduced sphere formation and invasive capacity. Moreover, high expression of MVP was associated with tumor malignancy and survival rate in glioblastoma patients. Our study describes that MVP is a potentially novel maker for glioblastoma stem cells and may be useful as a target for preventing TMZ resistance in GBM patients.

Inhibition of the notch signaling pathway overcomes resistance of cervical cancer cells to paclitaxel through retardation of the epithelial-mesenchymal transition process

Use of paclitaxel as monotherapy or in combination with other therapeutic agents is a widely employed front-line chemotherapeutic strategy for cervical cancer. However, previous reports have shown that approximately 70% of the patients with cervical cancer develop resistance to paclitaxel. Epithelial-mesenchymal transition (EMT) contributes to the occurrence of chemoresistance in several types of cancer, including cervical cancer. Identification of the critical signaling pathway that regulates the EMT process may provide a novel strategy for avoiding or delaying the emergence of paclitaxel resistance during the treatment of cervical cancer. Herein, we established a paclitaxel-resistant cervical cancer cell line (HeLa-229PTR cells) by culturing parental HeLa-229 cells with increasing concentrations of paclitaxel. We observed elevated expression of Notch1 in HeLa-229PTR cells compared with their parental HeLa-229 cells, indicating its potential involvement in the EMT phenotype of the paclitaxel-resistant cells. Furthermore, silencing of the NOTCH1 gene, as well as treatment with a γ-secretase inhibitor (DAPT) partially reversed the EMT phenotype and significantly enhanced the sensitivity of HeLa-229PTR cells to paclitaxel. Moreover, we found that DAPT could significantly inhibit invasiveness, reduce colony formation activity, and promote apoptosis of HeLa-229PTR cells. Taken together, these results indicated that HeLa-229PTR cells develop the EMT phenotype partly through activation of Notch1 signaling. Thus, inhibition of Notch1 signaling can be a strategy for the reversal of the EMT phenotype and may increase the sensitivity of cervical cancer cells to treatment with paclitaxel.

Mechanisms of Drug Resistance and Use of Nanoparticle Delivery to Overcome Resistance in Breast Cancers

Breast cancer is the leading cancer type diagnosed among women in the world. Unfortunately, drug resistance to current breast cancer chemotherapeutics remains the main challenge for a higher survival rate. The recent progress in the nanoparticle platforms and distinct features of nanoparticles that enhance the efficacy of therapeutic agents, such as improved delivery efficacy, increased intracellular cytotoxicity, and reduced side effects, hold great promise to overcome the observed drug resistance. Currently, multifaceted investigations are probing the resistance mechanisms associated with clinical drugs, and identifying new breast cancer-associated molecular targets that may lead to improved therapeutic approaches with the nanoparticle platforms. Nanoparticle platforms including siRNA, antibody-specific targeting and the role of nanoparticles in cellular processes and their effect on breast cancer were discussed in this article.

Notch Signalling in Breast Development and Cancer

The Notch signalling pathway is a highly conserved developmental signalling pathway, with vital roles in determining cell fate during embryonic development and tissue homeostasis. Aberrant Notch signalling has been implicated in many disease pathologies, including cancer. In this review, we will outline the mechanism and regulation of the Notch signalling pathway. We will also outline the role Notch signalling plays in normal mammary gland development and how Notch signalling is implicated in breast cancer tumorigenesis and progression. We will cover how Notch signalling controls several different hallmarks of cancer within epithelial cells with sections focussed on its roles in proliferation, apoptosis, invasion, and metastasis. We will provide evidence for Notch signalling in the breast cancer stem cell phenotype, which also has implications for therapy resistance and disease relapse in breast cancer patients. Finally, we will summarise the developments in therapeutic targeting of Notch signalling, and the pros and cons of this approach for the treatment of breast cancer.

Constitutive GLI1 expression in chondrosarcoma is regulated by major vault protein via mTOR/S6K1 signaling cascade

Hedgehog signaling plays a pivotal role in embryonic pattern formation and diverse aspects of the postnatal biological process. Perturbation of the hedgehog pathway and overexpression of GLI1, a downstream transcription factor in the hedgehog pathway, are highly relevant to several malignancies including chondrosarcoma (CS). We previously found that knocking down expression of GLI1 attenuates the disrupted Indian hedgehog (IHH) signal pathway and suppresses cell survival in human CS cells. However, the underlying mechanisms regulating the expression of GLI1 are still unknown. Here, we demonstrated the implication of GLI1 in SMO-independent pathways in CS cells. A GLI1 binding protein, major vault protein (MVP), was identified using the affinity purification method. MVP promoted the nuclear transport and stabilization of GLI1 by compromising the binding affinity of GLI1 with suppressor of fused homolog (SUFU) and increased GLI1 expression via mTOR/S6K1 signaling cascade. Functionally, knockdown of MVP suppressed cell growth and induced apoptosis. Simultaneous inhibition of MVP and GLI1 strongly inhibits the growth of CS in vitro and in vivo. Moreover, IHC results showed that MVP, GLI1, and P-p70S6K1 were highly expressed and positively correlated with each other in 71 human CS tissues. Overall, our findings revealed a novel regulating mechanism for HH-independent GLI1 expression and provide a rationale for combination therapy in patients with advanced CS.

Notch3 inhibits cell proliferation and tumorigenesis and predicts better prognosis in breast cancer through transactivating PTEN

Notch receptors (Notch1-4) play critical roles in tumorigenesis and metastasis of malignant tumors, including breast cancer. Although abnormal Notch activation is related to various tumors, the importance of single receptors and their mechanism of activation in distinct breast cancer subtypes are still unclear. Previous studies by our group demonstrated that Notch3 may inhibit the emergence and progression of breast cancer. PTEN is a potent tumor suppressor, and its loss of function is sufficient to promote the occurrence and progression of tumors. Intriguingly, numerous studies have revealed that Notch1 is involved in the regulation of PTEN through its binding to CBF-1, a Notch transcription factor, and the PTEN promoter. In this study, we found that Notch3 and PTEN levels correlated with the luminal phenotype in breast cancer cell lines. Furthermore, we demonstrated that Notch3 transactivated PTEN by binding CSL-binding elements in the PTEN promoter and, at least in part, inhibiting the PTEN downstream AKT-mTOR pathway. Notably, Notch3 knockdown downregulated PTEN and promoted cell proliferation and tumorigenesis. In contrast, overexpression of the Notch3 intracellular domain upregulated PTEN and inhibited cell proliferation and tumorigenesis in vitro and in vivo. Moreover, inhibition or overexpression of PTEN partially reversed the promotion or inhibition of cell proliferation induced by Notch3 alterations. In general, Notch3 expression positively correlated with elevated expression of PTEN, ER, lower Ki-67 index, and incidence of involved node status and predicted better recurrence-free survival in breast cancer patients. Therefore, our findings demonstrate that Notch3 inhibits breast cancer proliferation and suppresses tumorigenesis by transactivating PTEN expression.

The Role of Notch, Hedgehog, and Wnt Signaling Pathways in the Resistance of Tumors to Anticancer Therapies

Resistance to therapy is the major hurdle in the current cancer management. Cancer cells often rewire their cellular process to alternate mechanisms to resist the deleterious effect mounted by different therapeutic approaches. The major signaling pathways involved in the developmental process, such as Notch, Hedgehog, and Wnt, play a vital role in development, tumorigenesis, and also in the resistance to the various anticancer therapies. Understanding how cancer utilizes these developmental pathways in acquiring the resistance to the multi-therapeutic approach cancer can give rise to a new insight of the anti-therapy resistance mechanisms, which can be explored for the development of a novel therapeutic approach. We present a brief overview of Notch, Hedgehog, and Wnt signaling pathways in cancer and its role in providing resistance to various cancer treatment modalities such as chemotherapy, radiotherapy, molecular targeted therapy, and immunotherapy. Understanding the importance of these molecular networks will provide a rational basis for novel and safer combined anticancer therapeutic approaches for the improvement of cancer treatment by overcoming drug resistance.

Immunoediting role for major vault protein in apoptotic signaling induced by bacterial N-acyl homoserine lactones

The major vault protein (MVP) mediates diverse cellular responses, including cancer cell resistance to chemotherapy and protection against inflammatory responses to Pseudomonas aeruginosa Here, we report the use of photoactive probes to identify MVP as a target of the N-(3-oxo-dodecanoyl) homoserine lactone (C12), a quorum sensing signal of certain proteobacteria including P. aeruginosa. A treatment of normal and cancer cells with C12 or other N-acyl homoserine lactones (AHLs) results in rapid translocation of MVP into lipid raft (LR) membrane fractions. Like AHLs, inflammatory stimuli also induce LR-localization of MVP, but the C12 stimulation reprograms (functionalizes) bioactivity of the plasma membrane by recruiting death receptors, their apoptotic adaptors, and caspase-8 into LR. These functionalized membranes control AHL-induced signaling processes, in that MVP adjusts the protein kinase p38 pathway to attenuate programmed cell death. Since MVP is the structural core of large particles termed vaults, our findings suggest a mechanism in which MVP vaults act as sentinels that fine-tune inflammation-activated processes such as apoptotic signaling mediated by immunosurveillance cytokines including tumor necrosis factor-related apoptosis inducing ligand (TRAIL).

Drug resistance and Cancer stem cells

Therapy resistance is a major problem when treating cancer patients as cancer cells develop mechanisms that counteract the effect of therapeutic compounds, leading to fit and more aggressive clones that contribute to poor prognosis. Therapy resistance can be both intrinsic and/or acquired. These are multifactorial events, and some are related to factors including adaptations in cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), deregulation of key signaling pathways, drug efflux through ABC transporters, acquired mutations, evading apoptosis, and activation of DNA damage response among others. Among these factors, CSCs represent the major source of therapy resistance. CSCs are a subset of tumor cells that are capable of self-renewal and multilineage progenitor expansion that are known to be intrinsically resistant to anticancer treatments. Multiple clones of CSCs pre-exist, and some can adopt and expand easily to changes in the tumor microenvironment (TME) and/or in response to radio- and chemotherapy. A combination of both intrinsic and extrinsic factors contributes to CSC-mediated therapy resistance. In this review, we will focus on CSCs and therapy resistance as well as suggest strategies to eliminate CSCs and, therefore, overcome resistance. Video abstract.

The Vault Nanoparticle: A Gigantic Ribonucleoprotein Assembly Involved in Diverse Physiological and Pathological Phenomena and an Ideal Nanovector for Drug Delivery and Therapy

Simple Summary

In recent decades, a molecular complex referred to as vault nanoparticle has attracted much attention by the scientific community, due to its unique properties. At the molecular scale, it is a huge assembly consisting of 78 97-kDa polypeptide chains enclosing an internal cavity, wherein enzymes involved in DNA integrity maintenance and some small noncoding RNAs are accommodated. Basically, two reasons justify this interest. On the one hand, this complex represents an ideal tool for the targeted delivery of drugs, provided it is suitably engineered, either chemically or genetically; on the other hand, it has been shown to be involved in several cellular pathways and mechanisms that most often result in multidrug resistance. It is therefore expected that a better understanding of the physiological roles of this ribonucleoproteic complex may help develop new therapeutic strategies capable of coping with cancer progression. Here, we provide a comprehensive review of the current knowledge.

Abstract

The vault nanoparticle is a eukaryotic ribonucleoprotein complex consisting of 78 individual 97 kDa-“major vault protein” (MVP) molecules that form two symmetrical, cup-shaped, hollow halves. It has a huge size (72.5 × 41 × 41 nm) and an internal cavity, wherein the vault poly(ADP-ribose) polymerase (vPARP), telomerase-associated protein-1 (TEP1), and some small untranslated RNAs are accommodated. Plenty of literature reports on the biological role(s) of this nanocomplex, as well as its involvement in diseases, mostly oncological ones. Nevertheless, much has still to be understood as to how vault participates in normal and pathological mechanisms. In this comprehensive review, current understanding of its biological roles is discussed. By different mechanisms, vault’s individual components are involved in major cellular phenomena, which result in protection against cellular stresses, such as DNA-damaging agents, irradiation, hypoxia, hyperosmotic, and oxidative conditions. These diverse cellular functions are accomplished by different mechanisms, mainly gene expression reprogramming, activation of proliferative/prosurvival signaling pathways, export from the nucleus of DNA-damaging drugs, and import of specific proteins. The cellular functions of this nanocomplex may also result in the onset of pathological conditions, mainly (but not exclusively) tumor proliferation and multidrug resistance. The current understanding of its biological roles in physiological and pathological processes should also provide new hints to extend the scope of its exploitation as a nanocarrier for drug delivery.

Y-box binding protein 1 (YB-1) promotes gefitinib resistance in lung adenocarcinoma cells by activating AKT signaling and epithelial-mesenchymal transition through targeting major vault protein (MVP)

PURPOSE

Gefitinib is a first-line treatment option for epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma. However, most patients inevitably develop gefitinib resistance. The mechanism underlying this resistance is not fully understood. Y-box binding protein 1 (YB-1) has been reported to play a role in modulating drug sensitivity, but its role in gefitinib resistance is currently unknown. Here, we investigated the role of YB-1 in gefitinib resistance of lung adenocarcinoma.

METHODS

We determined the expression of YB-1, epithelial-mesenchymal transition (EMT) and AKT signaling markers, as well as the viability of lung adenocarcinoma cell lines bearing mutant (HCC827, PC-9) or wild-type (H1299) EGFR. We also evaluated PC-9 cell migration and invasion using transwell assays. The clinical importance of YB-1 and major vault protein (MVP) was evaluated using primary lung adenocarcinoma patient samples.

RESULTS

We found that YB-1 was significantly upregulated in gefitinib-resistant lung adenocarcinoma cells compared to gefitinib-sensitive cells. YB-1 augmented gefitinib resistance by activating the AKT pathway and promoting EMT. Decreased migration and invasion was observed upon MVP silencing in YB-1-overexpressing PC-9 cells, as well as restored gefitinib sensitivity. A retrospective analysis of 85 patients with lung adenocarcinoma revealed that YB-1 levels were significantly increased in tyrosine kinase inhibitor (TKI)-resistant patients compared to those in TKI-sensitive patients, indicating that YB-1 may serve as a biomarker to clinically predict acquired gefitinib resistance.

CONCLUSION

YB-1 activates AKT signaling and promotes EMT at least in part by directly activating MVP. Hence, targeting the YB-1/MVP axis may help to overcome gefitinib resistance in lung adenocarcinoma patients.

Resveratrol Promotes Tumor Microvessel Growth via Endoglin and Extracellular Signal-Regulated Kinase Signaling Pathway and Enhances the Anticancer Efficacy of Gemcitabine against Lung Cancer

The synergistic anticancer effect of gemcitabine (GEM) and resveratrol (RSVL) has been noted in certain cancer types. However, whether the same phenomenon would occur in lung cancer is unclear. Here, we uncovered the molecular mechanism by which RSVL enhances the anticancer effect of GEM against lung cancer cells both in vitro and in vivo. We established human lung adenocarcinoma HCC827 xenografts in nude mice and treated them with GEM and RSVL to detect their synergistic effect in vivo. Tumor tissue sections from nude mice were subjected to hematoxylin and eosin staining for blood vessel morphological observation, and immunohistochemistry was conducted to detect CD31-positive staining blood vessels. We also established the HCC827-human umbilical vein endothelial cell (HUVEC) co-culture model to observe the tubule network formation. Human angiogenesis antibody array was used to screen the angiogenesis-related proteins in RSVL-treated HCC827. RSVL suppressed the expression of endoglin (ENG) and increased tumor microvessel growth and blood perfusion into tumor. Co-treatment of RSVL and GEM led to more tumor growth suppression than treatment of GEM alone. Mechanistically, using the HCC827-HUVEC co-culture model, we showed that RSVL-suppressed ENG expression was accompanied with augmented levels of phosphorylated extracellular signal-regulated kinase (ERK) 1/2 and increased tubule network formation, which may explain why RSVL promoted tumor microvessel growth in vivo. RSVL promoted tumor microvessel growth via ENG and ERK and enhanced the anticancer efficacy of GEM. Our results suggest that intake of RSVL may be beneficial during lung cancer chemotherapy.

Identification of microRNAs and their Endonucleolytic Cleavaged target mRNAs in colorectal cancer

Background

Colorectal cancer (CRC) ranks the third among the most common malignancies globally. It is well known that microRNAs (miRNAs) play vital roles in destabilizing mRNAs and repressing their translations in this disease. However, the mechanism of miRNA-induced mRNA cleavage remains to be investigated.

Method

In this study, high-throughput small RNA (sRNA) sequencing was utilized to identify and profile miRNAs from six pairs of colorectal cancer tissues (CTs) and adjacent tissues (CNs). Degradome sequencing (DS) was employed to detect the cleaved target genes. The Database for Annotation, Visualization and Integrated Discovery (DAVID) software was used for GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis.

Results

In total, 1278 known miRNAs (clustered into 337 families) and 131 novel miRNAs were characterized in the CT and CN libraries, respectively. Of those, 420 known and eight novel miRNAs were defined as differentially expressed miRNAs (DEmiRNAs) by comparing the expression levels observed in the CT and CN libraries. Furthermore, through DS, 9685 and 202 potential target transcripts were characterized as target genes for 268 known and 33 novel miRNAs, respectively. It was further predicted that a total of 264 targeted genes for the 85 DEmiRNAs are involved in proteoglycans in cancer and the AMP-activated protein kinase signaling pathway. After systemic analysis of prognosis-related miRNA targets in those cancer-related signal pathways, we found that two targets ezrin (EZR) and hematopoietic cell-specific Lyn substrate 1 (HCLS1) had the potential prognostic characteristics with CRC regarding over survival (OS) or recurrence.

Conclusion

In total, we found that endonucleolytic miRNA-directed mRNA cleavage occurs in CRC. A number of potential genes targeted by CRC-related miRNAs were identified and some may have the potential as prognosis markers of CRC. The present findings may lead to an improved better appreciation of the novel interaction mode between miRNAs and target genes in CRC.

Thymoquinone and pentoxifylline enhance the chemotherapeutic effect of cisplatin by targeting Notch signaling pathway in mice

AIMS

Notch signaling is highly implicated in several cancers and chemoresistance. Therefore, Notch-targeted therapies might be beneficial in enhancing chemotherapeutic effect and cancer regression. This study aimed to investigate implication of Notch in development and progression of solid Ehrlich carcinoma (SEC) and enhancement of anticancer effect of cisplatin (CIS) by addition of thymoquinone (TQ) and pentoxifylline (PTX) through modulation of Notch.

MAIN METHODS

SEC was induced in mice as model for mammary carcinoma by s.c. injection of 1 × 10⁶ Ehrlich cells into back of the mice. On 12^th day, solid tumor was developed and mice were divided into seven groups; tumor control, early CIS (ECIS), ECIS + ETQ, ECIS + ETQ + EPTX, late CIS (LCIS), LCIS + LTQ, and LCIS + LTQ + LPTX. Early treatment was started on 12^th day, whereas late treatment was begun on 19^th day from tumor inoculation. At the endpoint, samples were collected for detection of Notch1, Hes1, Jagged1, β-catenin, TNF-α, IL-6, IFN-γ, IL-2, VEGF, apoptosis, CD4, and CD8.

KEY FINDINGS

Adding PTX and TQ to CIS significantly reduced Notch1, Hes1, Jagged1, β-catenin, TNF-α, IL-6, IFN-γ, and VEGF with increment in IL-2, CD4, CD8, and apoptotic cells. Moreover, early treated groups showed remarkable attenuation in tumor growth and the relevant parameters compared to their counterpart later groups.

SIGNIFICANCE

Addition of PTX with TQ to CIS showed a synergistic chemotherapeutic action and induced better oncostatic effect mainly through Notch suppression. Consequently, shutting Notch could be of great interest in promoting chemosensetivity and cancer control.

PRKD2 Promotes Progression and Chemoresistance of AML via Regulating Notch1 Pathway

Introduction

Progression and chemoresistance of acute myeloid leukemia (AML) contribute to most of the treatment failure. Notch pathway has been proven to be involved in many biological processes and diseases, especially AML. In this study, we aimed to explore genes correlated with Notch1 pathway in AML and determine their roles in the regulation of AML progression and chemoresistance.

Methods

TCGA database was used to explore Notch1 associated genes. Kaplan-Meier survival analysis was performed to evaluate the prognostic significance of genes. Quantitative RT-PCR (qRT-PCR) and Western blot were performed to examine the expression of genes. The expression of PRKD2 was up-regulated or knocked down in AML cell lines by lentivirus or siRNAs. CCK-8 and flow cytometry were used to analyze the effect of PRKD2 on cell proliferation and chemoresistance.

Results

Based on TCGA database, PRKD2 was found to be positively correlated with Notch1 expression, cytogenetic risk status and poorer prognosis in AML. Moreover, the expression level of PRKD2 was higher in AML chemo-resistant cells than in chemo-sensitive cells. Functionally, knockdown of PRKD2-induced apoptosis and increased chemosensitivity of AML cells. PRKD2 overexpression promoted proliferation and chemoresistance of AML cells. Furthermore, we found PRKD2 could regulate Notch1 pathway. Besides, high PRKD2 expression was correlated with higher risk group of AML patients which indicated that PRKD2 was an independent prognostic marker for AML.

Conclusion

Taken together, our results showed that PRKD2 could promote the proliferation and chemoresistance of AML cells by regulating Notch1 pathway. The study broadened our insights into the underlying mechanisms in chemoresistance and proliferation of AML, and provided a new prognostic marker and treatment target for AML.

Notch Signaling Activation as a Hallmark for Triple-Negative Breast Cancer Subtype

Triple-negative breast cancer (TNBC) is a subgroup of 15%-20% of diagnosed breast cancer patients. It is generally considered to be the most difficult breast cancer subtype to deal with, due to the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), which usually direct targeted therapies. In this scenario, the current treatments of TNBC-affected patients rely on tumor excision and conventional chemotherapy. As a result, the prognosis is overall poor. Thus, the identification and characterization of targets for novel therapies are urgently required. The Notch signaling pathway has emerged to act in the pathogenesis and tumor progression of TNBCs. Firstly, Notch receptors are associated with the regulation of tumor-initiating cells (TICs) behavior, as well as with the aetiology of TNBCs. Secondly, there is a strong evidence that Notch pathway is a relevant player in mammary cancer stem cells maintenance and expansion. Finally, Notch receptors expression and activation strongly correlate with the aggressive clinicopathological and biological phenotypes of breast cancer (e.g., invasiveness and chemoresistance), which are relevant characteristics of TNBC subtype. The purpose of this up-to-date review is to provide a detailed overview of the specific role of all four Notch receptors (Notch1, Notch2, Notch3, and Notch4) in TNBCs, thus identifying the Notch signaling pathway deregulation/activation as a pathognomonic feature of this breast cancer subtype. Furthermore, this review will also discuss recent information associated with different therapeutic options related to the four Notch receptors, which may be useful to evaluate prognostic or predictive indicators as well as to develop new therapies aimed at improving the clinical outcome of TNBC patients.