The NOTCH1-HEY1 pathway regulates self-renewal and epithelial-mesenchymal transition of salivary adenoid cystic carcinoma cells

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.

Impact of NOTCH1 expression in primary breast adenoid cystic carcinoma

AIMS

Adenoid cystic carcinoma (AdCC) originates from salivary-type like glands in the head and neck, lung, and breast. AdCC shows chromosomal translocation, resulting in MYB::NFIB fusion and overexpression of MYB. Recently, NOTCH1 pathway alteration has been recognised in a subset of patients with salivary gland AdCC and has been shown to be associated with poor survival. In this study, we investigated the correlation of NOTCH1 pathway alteration with the clinical outcome of patients with primary breast AdCC by examining NOTCH1 immunoreactivity in attempts to better predict clinical outcomes.

METHODS

We identified 25 cases of breast AdCC, reviewed the clinical outcome and performed immunohistochemical (IHC) staining for NOTCH1 on FFPE sections.

RESULTS

IHC evaluation of NOTCH1 expression in 25 cases of primary breast AdCCs revealed a positive correlation between NOTCH1 expression and primary tumour size. All cases with NOTCH1 expression were greater than 15 mm in size at presentation but only 50% of NOTCH1 negative tumours were greater than 15 mm. We demonstrated a positive correlation between NOTCH1 positive AdCCs and recurrence/metastases. 63.6% of NOTCH1 positive AdCCs had either metastases or recurrence. On the contrary, only 21.5% of NOTCH1 negative AdCCs had recurrence or metastases. AdCCs with NOTCH1 positivity correlated with inferior relapse free survival (median 33 vs 129 months).

CONCLUSIONS

Our study demonstrates that in patients with breast AdCC, overexpression of NOTCH1 ≥20% is associated with larger tumour size and aggressive clinical outcomes. Importantly, NOTCH1 inhibitors may have potential therapeutic effect in patients with breast AdCC.

Anti-NOTCH1 therapy with OMP-52 M51 inhibits salivary adenoid cystic carcinoma by depressing epithelial-mesenchymal transition (EMT) process and inducing ferroptosis

Salivary adenoid cystic carcinoma (ACC) is a common type of salivary gland cancer, and the mechanisms underlying its progression still remain poorly understood without efficient therapies. NOTCH1, an evolutionally conserved cell-cell signaling pathway, is involved in the progression of ACC. In our study, we attempted to explore whether NOTCH1 suppression using the monoclonal anti-NOTCH1 antibody OMP-52 M51 could be of potential for ACC treatment. Here, we identified NOTCH1 elevation in human ACC tissues compared with the matched normal samples. Patients with metastasis expressed much higher NOTCH1. We then found that OMP-52 M51 markedly reduced the expression of NOTCH1 and its intracellular active form NICD1 (NOTCH1 intracellular domain). Importantly, OMP-52 M51 markedly reduced the proliferation, migration and invasion of ACC cells. RNA-Seq and in vitro studies further showed that OMP-52 M51 significantly induced ferroptosis in ACC cells, indicated by the increased cellular malondialdehyde (MDA), iron contents and lipid ROS production, and decreased glutathione (GSH) levels. Further, remarkable glutathione peroxidase 4 (GPX4) reduction was detected in ACC cells with OMP-52 M51 treatment. However, promoting NOTCH1 expression markedly abolished the function of OMP-52 M51 to induce ferroptosis. Intriguingly, low-dose OMP-52 M51 strongly facilitated the capacity of ferroptosis inducer erastin to trigger ferroptotic cell death, revealing that OMP-52 M51 could improve the sensitivity of ACC cells to ferroptosis. In vivo, OMP-52 M51 administration suppressed tumor growth and induced ferroptosis in the constructed ACC xenograft mouse model. Collectively, our findings demonstrated that NOTCH1 inhibition by OMP-52 M51 represses the proliferation and epithelial-mesenchymal transition (EMT) in ACCs, and promotes ferroptosis, revealing the potential therapeutical application of OMP-52 M51 in ACC.

NCoR1 limits angiogenic capacity by altering Notch signaling

Corepressors negatively regulate gene expression by chromatin compaction. Targeted regulation of gene expression could provide a means to control endothelial cell phenotype. We hypothesize that by targeting corepressor proteins, endothelial angiogenic function can be improved. To study this, the expression and function of nuclear corepressors in human umbilical vein endothelial cells (HUVEC) and in murine organ culture was studied. RNA-seq revealed that nuclear receptor corepressor 1 (NCoR1), silencing mediator of retinoid and thyroid hormone receptors (SMRT) and repressor element-1 silencing transcription factor (REST) are the highest expressed corepressors in HUVECs. Knockout and knockdown strategies demonstrated that the depletion of NCoR1 increased the angiogenic capacity of endothelial cells, whereas depletion of SMRT or REST did not. Interestingly, the effect was VEGF signaling independent. NCoR1 depletion significantly upregulated angiogenesis-associated genes, especially tip cell genes, including ESM1, DLL4 and NOTCH4, as observed by RNA- and ATAC-seq. Confrontation assays comparing cells with and without NCoR1-deficiency revealed that loss of NCoR1 promotes a tip-cell position during spheroid sprouting. Moreover, a proximity ligation assay identified NCoR1 as a direct binding partner of the Notch-signaling-related transcription factor RBPJk. Luciferase assays showed that siRNA-mediated knockdown of NCOR1 promotes RBPJk activity. Furthermore, NCoR1 depletion prompts upregulation of several elements in the Notch signaling cascade. Downregulation of NOTCH4, but not NOTCH1, prevented the positive effect of NCOR1 knockdown on spheroid outgrowth. Collectively, these data indicate that decreasing NCOR1 expression is an attractive approach to promote angiogenic function.

Meta-analysis of microarray data to determine gene indicators involved in cisplatin resistance in non-small cell lung cancer

BACKGROUND

Lung cancer is a major cause of cancer-related mortality worldwide, with a 5-year survival rate of approximately 22%. Cisplatin is one of the standard first-line chemotherapeutic agents for non-small cell lung cancer (NSCLC), but its efficacy is often limited by the development of resistance. Despite extensive research on the molecular mechanisms of chemoresistance, the underlying causes remain elusive and complex.

AIMS

We analyzed three microarray datasets to find the gene signature and key pathways related to cisplatin resistance in NSCLC.

METHODS AND RESULTS

We compared the gene expression of sensitive and resistant NSCLC cell lines treated with cisplatin. We found 274 DEGs, including 111 upregulated and 163 downregulated genes, in the resistant group. Gene set enrichment analysis showed the potential roles of several DEGs, such as TUBB2B, MAPK7, TUBAL3, MAP2K5, SMUG1, NTHL1, PARP3, NTRK1, G6PD, PDK1, HEY1, YTHDF2, CD274, and MAGEA1, in cisplatin resistance. Functional analysis revealed the involvement of pathways, such as gap junction, base excision repair, central carbon metabolism, and Notch signaling in the resistant cell lines.

CONCLUSION

We identified several molecular factors that contribute to cisplatin resistance in NSCLC cell lines, involving genes and pathways that regulate gap junction communication, DNA damage repair, ROS balance, EMT induction, and stemness maintenance. These genes and pathways could be targets for future studies to overcome cisplatin resistance in NSCLC.

Regulation of the Notch signaling pathway by natural products for cancer therapy

The Notch signaling pathway is an evolutionarily conserved pathway that modulates normal biological processes involved in cellular differentiation, apoptosis, and stem cell self-renewal in a context-dependent fashion. Attributed to its pleiotropic physiological roles, both overexpression and silencing of the pathway are associated with the emergence, progression, and poorer prognosis in various types of cancer. To decrease disease incidence and promote survival, targeting Notch may have chemopreventive and anti-cancer effects. Natural products with profound historical origins have distinguished themselves from other therapies due to their easy access, high biological compatibility, low toxicity, and reliable effects at specific physiological sites in vivo. This review describes the Notch signaling pathway, particularly its normal activation process, and some main illnesses related to Notch signaling pathway dysregulation. Emphasis is placed on the effects and mechanisms of natural products targeting the Notch signaling pathway in diverse cancer types, including curcumin, ellagic acid (EA), resveratrol, genistein, epigallocatechin-3-gallate (EGCG), quercetin, and xanthohumol and so on. Existing evidence indicates that natural products are feasible solution to fight against cancer by targeting Notch signaling, either alone or in combination with current therapeutic agents.

Cytotoxic Imidazolyl-Mesalazine Ester-Based Ru(II) Complexes Reduce Expression of Stemness Genes and Induce Differentiation of Oral Squamous Cell Carcinoma

The aggressiveness and recurrence of cancer is linked to cancer stem cells (CSCs), but drugs targeting CSCs may not succeed in the clinic due to the lack of a distinct CSC subpopulation. Clinical Pt(II) drugs can increase stemness. We screened 15 RuII or IrIII complexes with mesalazine or 3-aminobenzoate Schiff bases of the general formulas [Ru(p-cym)L]+, [Ru(p-cym)L], and [Ir(Cp*)L]+ (L = L1-L9) and found three complexes (2, 12, and 13) that are active against oral squamous cell carcinoma (OSCC) CSCs. There is a putative oncogenic role of transcription factors (viz. NOTCH1, SOX2, c-MYC) to enhance the stemness. Our work shows that imidazolyl-mesalazine ester-based RuII complexes inhibit growth of CSC-enriched OSCC 3D spheroids at low micromolar doses (2 μM). Complexes 2, 12, and 13 reduce stemness gene expression and induce differentiation markers (Involucrin, CK10) in OSCC 3D cultures. The imidazolyl-mesalazine ester-based RuII complex 13 shows the strongest effect. Downregulating c-MYC suggests that RuII complexes may target c-MYC-driven cancers.

Salivary glands adenoid cystic carcinoma: a molecular profile update and potential implications

Adenoid cystic carcinoma (ACC) is an aggressive tumor with a high propensity for distant metastasis and perineural invasion. This tumor is more commonly found in regions of the head and neck, mainly the salivary glands. In general, the primary treatment modality for ACC is surgical resection and, in some cases, postoperative radiotherapy. However, no effective systemic treatment is available for patients with advanced disease. Furthermore, this tumor type is characterized by recurrent molecular alterations, especially rearrangements involving the MYB, MYBL1, and NFIB genes. In addition, they also reported copy number alterations (CNAs) that impact genes. One of them is C-KIT, mutations that affect signaling pathways such as NOTCH, PI3KCA, and PTEN, as well as alterations in chromatin remodeling genes. The identification of new molecular targets enables the development of specific therapies. Despite ongoing investigations into immunotherapy, tyrosine kinase inhibitors, and anti-angiogenics, no systemic therapy is approved by the FDA for ACC. In this review, we report the genetic and cytogenetic findings on head and neck ACC, highlighting possible targets for therapeutic interventions.

Increased retinoic acid signaling decreases lung metastasis in salivary adenoid cystic carcinoma by inhibiting the noncanonical Notch1 pathway

MYB-NFIB fusion and NOTCH1 mutation are common hallmark genetic events in salivary gland adenoid cystic carcinoma (SACC). However, abnormal expression of MYB and NOTCH1 is also observed in patients without MYB-NFIB fusion and NOTCH1 mutation. Here, we explore in-depth the molecular mechanisms of lung metastasis through single-cell RNA sequencing (scRNA-seq) and exome target capture sequencing in two SACC patients without MYB-NFIB fusion and NOTCH1 mutation. Twenty-five types of cells in primary and metastatic tissues were identified via Seurat clustering and categorized into four main stages ranging from near-normal to cancer-based on the abundance of each cell cluster in normal tissue. In this context, we identified the Notch signaling pathway enrichment in almost all cancer cells; RNA velocity, trajectory, and sub-clustering analyses were performed to deeply investigate cancer progenitor-like cell clusters in primary tumor-associated lung metastases, and signature genes of progenitor-like cells were enriched in the "MYC_TARGETS_V2" gene set. In vitro, we detected the NICD1-MYB-MYC complex by co-immunoprecipitation (Co-IP) and incidentally identified retinoic acid (RA) as an endogenous antagonist of genes in the "MYC_TARGETS_V2" gene set. Following this, we confirmed that all-trans retinoic acid (ATRA) suppresses the lung metastasis of SACC by correcting erroneous cell differentiation mainly caused by aberrant NOTCH1 or MYB expression. Bioinformatic, RNA-seq, and immunohistochemical (IHC) analyses of primary tissues and metastatic lung tissues from patients with SACC suggested that RA system insufficiency partially promotes lung metastasis. These findings imply the value of the RA system in diagnosis and treatment.

PMN-MDSCs modulated by CCL20 from cancer cells promoted breast cancer cell stemness through CXCL2-CXCR2 pathway

Our previous studies have showed that C-C motif chemokine ligand 20 (CCL20) advanced tumor progression and enhanced the chemoresistance of cancer cells by positively regulating breast cancer stem cell (BCSC) self-renewal. However, it is unclear whether CCL20 affects breast cancer progression by remodeling the tumor microenvironment (TME). Here, we observed that polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were remarkably enriched in TME of CCL20-overexpressing cancer cell orthotopic allograft tumors. Mechanistically, CCL20 activated the differentiation of granulocyte-monocyte progenitors (GMPs) via its receptor C-C motif chemokine receptor 6 (CCR6) leading to the PMN-MDSC expansion. PMN-MDSCs from CCL20-overexpressing cell orthotopic allograft tumors (CCL20-modulated PMN-MDSCs) secreted amounts of C-X-C motif chemokine ligand 2 (CXCL2) and increased ALDH⁺ BCSCs via activating CXCR2/NOTCH1/HEY1 signaling pathway. Furthermore, C-X-C motif chemokine receptor 2 (CXCR2) antagonist SB225002 enhanced the docetaxel (DTX) effects on tumor growth by decreasing BCSCs in CCL20^high-expressing tumors. These findings elucidated how CCL20 modulated the TME to promote cancer development, indicating a new therapeutic strategy by interfering with the interaction between PMN-MDSCs and BCSCs in breast cancer, especially in CCL20^high-expressing breast cancer.

Adenoid Cystic Carcinoma of Salivary Glands: A Ten-Year Review and an Assessment of the Current Management, Surgery, Radiotherapy, and Chemotherapy

Adenoid cystic carcinoma (ACC) is a rare cancer that arises from the salivary glands and other sites in the body, such as the lung and breast. Although the tumor accounts for 10% of all salivary gland malignancies, it only accounts for 1% of head and neck malignancies. It can affect both major and minor salivary glands; here, it is called salivary gland adenoid cystic carcinoma or SACC, with a slight predilection to the latter, and commonly manifests between the 6_th and 7_th decades of life. The disease also shows a slight female predilection, with a reported female to male ratio of 3 : 2. Lesions of SACC are often insidious and slow-growing, and symptoms such as pain and altered sensation are frequently associated with advanced stages of the disease. Salivary adenoid cystic carcinoma is characterized by perineural invasion (PNI), a distinctive feature that potentially plays a significant role in the tumor's relapse and recurrence, which is approximately 50%. The disease is not prevalent, and its etiopathogenesis is poorly understood, although several genetic patterns and biomarkers have been linked to its initiation and/or progression. The discovery of these mutations and biomarkers has encouraged several clinical studies to use therapeutic agents to target the specific receptors on the cancer cells to potentially prevent further proliferation of the tumor cells and metastasis of the disease. Diagnosis of SACC is often challenging and frequently requires a combination of clinical examination, imaging, and histopathology. Management of SACC is primarily surgical excision, while radiotherapy has shown to be effective in improving local control in cases with microscopic residual disease. However, treatment of recurrent or metastatic tumors by radiotherapy with or without chemotherapy has so far shown limited success. The aim of this thesis is to provide an update of literature on SACC with a particular focus on the latest management approaches and future trends.

Single-cell transcriptomic analysis of the tumor ecosystem of adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a malignant tumor that originates from exocrine gland epithelial cells. We profiled the transcriptomes of 49,948 cells from paracarcinoma and carcinoma tissues of three patients using single-cell RNA sequencing. Three main types of the epithelial cells were identified into myoepithelial-like cells, intercalated duct-like cells, and duct-like cells by marker genes. And part of intercalated duct-like cells with special copy number variations which altered with MYB family gene and EN1 transcriptomes were identified as premalignant cells. Developmental pseudo-time analysis showed that the premalignant cells eventually transformed into malignant cells. Furthermore, MYB and MYBL1 were found to belong to two different gene modules and were expressed in a mutually exclusive manner. The two gene modules drove ACC progression into different directions. Our findings provide novel evidence to explain the high recurrence rate of ACC and its characteristic biological behavior.

Roles of transducin-like enhancer of split (TLE) family proteins in tumorigenesis and immune regulation

Mammalian transducin-like enhancer of split family proteins (TLEs) are homologous to Drosophila Groucho (Gro) and are essential transcriptional repressors. Seven TLE family members, TLE1-7, have been identified to date. These proteins do not bind DNA directly; instead, they bind a set of transcription factors and thereby inhibit target gene expression. Loss of TLEs in mice usually leads to defective early development; however, TLE functions in developmentally mature cells are unclear. Recent studies have revealed that TLEs are dysregulated in certain human cancer types and may function as oncogenes or tumor suppressors in different contexts. TLE levels also affect the efficacy of cancer treatments and the development of drug resistance. In addition, TLEs play critical roles in the development and function of immune cells, including macrophages and lymphocytes. In this review, we provide updates on the expression, function, and mechanism of TLEs; discuss the roles played by TLEs in tumorigenesis and the inflammatory response; and elaborate on several TLE-associated signaling pathways, including the Notch, Wnt, and MAPK pathways. Finally, we discuss potential strategies for targeting TLEs in cancer therapy.

A γ-Secretase Inhibitor Attenuates Cell Cycle Progression and Invasion in Human Oral Squamous Cell Carcinoma: An In Vitro Study

Notch signaling is associated with many human malignancies, including oral squamous cell carcinoma (OSCC). However, the exact function of Notch signaling in OSCC remains unclear. Here, we investigated the effect of Notch signaling inhibition using a γ-secretase inhibitor (DAPT) on OSCC behaviours in vitro. Bioinformatic analysis of public-available gene expression profiles revealed the dysregulation of the Notch signaling pathway in OSCC compared with normal tissues, indicating the role of Notch signaling in OSCC regulation. RNA sequencing analysis of DAPT-treated human OSCC cells revealed the dysregulation of genes related to cell cycle-related pathways. Blocking Notch signaling significantly inhibited cell proliferation. DAPT-induced G0/G1 cell cycle arrest induced cell apoptosis. Furthermore, cell migration and invasion were also reduced in DAPT-treated cells. These findings indicate that Notch signaling activation participates in OSCC regulation by promoting cell growth, cell cycle progression, cell migration, and invasion. These mechanisms could facilitate OSCC progression. These results imply the potential use of Notch signaling inhibitors as a candidate adjuvant treatment in OSCC patients.

General Transcription Factor IIF Polypeptide 2: A Novel Therapeutic Target for Depression Identified Using an Integrated Bioinformatic Analysis

Depression currently affects 4% of the world’s population; it is associated with disability in 11% of the global population. Moreover, there are limited resources to treat depression effectively. Therefore, we aimed to identify a promising novel therapeutic target for depression using bioinformatic analysis. The GSE54568, GSE54570, GSE87610, and GSE92538 gene expression data profiles were retrieved from the Gene Expression Omnibus (GEO) database. We prepared the four GEO profiles for differential analysis, protein–protein interaction (PPI) network construction, and weighted gene co-expression network analysis (WGCNA). Gene Ontology functional enrichment and Kyoto Encyclopedia of Genes and Genomes metabolic pathway analyses were conducted to determine the key functions of the corresponding genes. Additionally, we performed correlation analyses of the hub genes with transcription factors, immune genes, and N6-methyladenosine (m6A) genes to reveal the functional landscape of the core genes associated with depression. Compared with the control samples, the depression samples contained 110 differentially expressed genes (DEGs), which comprised 56 downregulated and 54 upregulated DEGs. Moreover, using the WGCNA and PPI clustering analysis, the blue module and cluster 1 were found to be significantly correlated with depression. GTF2F2 was the only common gene identified using the differential analysis and WGCNA; thus, it was used as the hub gene. According to the enrichment analyses, GTF2F2 was predominantly involved in the cell cycle and JAK-STAT, PI3K-Akt, and p53 signaling pathways. Furthermore, differential and correlation analyses revealed that 9 transcription factors, 12 immune genes, and 2 m6A genes were associated with GTF2F2 in depression samples. GTF2F2 may serve as a promising diagnostic biomarker and treatment target of depression, and this study provides a novel perspective and valuable information to explore the molecular mechanism of depression.

Transcription Factor HEY1 Improves Brain Vascular Endothelial Cell Function and Alleviates Ischemic Stroke by Upregulating NOTCH3

To investigate the function of hairy/enhancer-of-split related with YRPW motif protein 1 (HEY1) and Notch receptor 3 (NOTCH3) in ischemic stroke. Stroke models were established by middle cerebral artery occlusion (MCAO) and oxygen glucose deprivation (OGD) in rats and rat brain microvascular endothelial cells (BMVECs), respectively. Neurological deficit evaluation and 2,3,5-triphenyltetrazolium chloride staining were used to assess cerebral injury. The expression of HEY1 and NOTCH3 was manipulated using gain and loss of function approaches. Terminal deoxynucleotidyl transferase dUTP nick end labeling and Western blotting analysis of cleaved caspase-3 and B-cell lymphoma-2 (Bcl2) were used to evaluate apoptosis. Enzyme-linked immunosorbent assay was performed to measure the expression levels of interleukin (IL)-1β, IL-6 and IL-18. The proliferation and migration of BMVECs were analyzed by Ki-67 immunofluorescence and scratch assay, respectively. Tube formation assay was conducted to measure the length of capillary-like tubes formed by BMVECs. Co-immunoprecipitation was used to testify the relationship between HEY1 and NOTCH3. HEY1 and NOTCH3 were upregulated in MCAO and OGD models. HEY1 ameliorated ischemic injuries in MCAO rats. Knockdown of HEY1 or NOTCH3 promoted OGD-induced apoptosis and inflammation and inhibited proliferation and migration in BMVECs. NOTCH3 was a binding protein of HEY1. Overexpression of HEY1 offset the disease-promoting effect of NOTCH3 silencing. HEY1 suppresses apoptosis and inflammation and promotes proliferation and migration in BMVECs by upregulating NOTCH3, thereby ameliorating ischemic stroke.

MicroRNA-34a Promotes Ischemia-Induced Cardiomyocytes Apoptosis through Targeting Notch1

Myocardial apoptosis occurs during myocardial ischemia. This study aimed to determine the effect of microRNA-34a (miR-34a) in ischemia-induced myocardial apoptosis. Mainly, SD rats were subjected to myocardial ischemia by ligaturing the left anterior descending branch of coronary artery. After rats had myocardial infarction, HE staining and TUNEL staining confirmed a significant increase in apoptosis. The expression of miR-34a was noticeably upregulated, while the expression of Notch1 was downregulated. An increase in caspase-3 and a decrease in Bcl-2/Bax ratio were observed in myocardium. Similar results were observed in the in vitro model of cardiomyocyte ischemia and anoxia of this study. When rat cardiomyocytes were administered with serum starvation and microaerophilic system, apoptosis-related proteins were significantly increased. However, transfecting the miR-34a inhibitor into the cardiomyocyte before the serum starvation and hypoxia treatment could increase the ratio of Bcl-2/Bax and downregulate the expression of caspase-3, as well as prevent cardiomyocytes from apoptosis. As opposed to the abovementioned points, the upregulation of miR-34a expression by transfecting miR-34a mimics induced Notch1 reduce and apoptosis-related proteins increase apparently, while upregulation of Notch1 could stimulate apoptosis attributed to miR-34a. Mechanistically, we demonstrated that Notch1 is a direct target of miR-34a. In conclusion, our current results suggested that miR-34a significantly stimulates ischemia-induced cardiomyocytes apoptosis by targeting Notch1.

Hey1 promotes migration and invasion of melanoma cells via GRB2/PI3K/AKT signaling cascade

Increasing evidence indicates that Notch signaling regulates multiple intracellular biological processes in malignant melanoma. Whereas how Notch signaling is transduced to influence melanoma cell behaviors remains largely elusive. Here we show that the Notch signaling downstream target Hey1 promotes migration and invasion of melanoma cells via the GRB2/PI3K/AKT pathway. First, bioinformatics tools, immunohistochemistry, and Western blotting analysis showed that the expression of Hey1 is increased in melanoma. Then, both in vivo and in vitro experiments showed that Hey1 promotes the malignant behaviour of the melanoma cells. High-throughput RNA-sequencing analysis revealed that inhibition of Hey1 results in decreased GRB2 expression in melanoma cells. Last, functional experiments confirmed that Hey1 positively regulates GRB2/PI3K/AKT pathway to influence migration and invasion of melanoma cells. In summary, our results suggest that Hey1 promotes the invasion and metastasis of melanoma cells by regulating GRB2/PI3K/AKT pathway. Our study provides potential therapeutics in tumor biology.

Molecular insights of metastasis and cancer progression derived using 3D cancer spheroid co-culture in vitro platform

The multistep metastasis process is carried out by the combinatorial effect of the stromal cells and the cancerous cells and plays vital role in the cancer progression. The scaffold/physical cues aided 3D cancer spheroid imitates the spatiotemporal organization and physiological properties of the tumor. Understanding the role of the key players in different stages of metastasis, the molecular cross-talk between the stromal cells and the cancer cells contributing in the advancement of the metastasis through 3D cancer spheroid co-culture in vitro platform is the center of discussion in the present review. This state-of-art in vitro platform utilized to study the cancer cell host defence and the role of exosomes in the cross talk leading to cancer progression has been critically examined here. 3D cancer spheroid co-culture technique is the promising next-generation in vitro approach for exploring potent treatments and personalized medicines to combat cancer metastasis leading to cancer progression.

MicroRNA-34a Alleviates Gemcitabine Resistance in Pancreatic Cancer by Repression of Cancer Stem Cell Renewal

OBJECTIVES

This study aimed to enhance the sensitivity of pancreatic ductal adenocarcinoma cells by microRNA-34a (miR-34a)-mediated targeting of Notch 1.

METHODS

Cell viability was determined by using an MTT (3-(4,5)-dimethylthiahiazo(-2)-3,5-diphenytetrazoliumromide) assay. The expression levels of miR-34a and relevant mRNAs were determined using quantitative polymerase chain reaction. Protein levels were measured by Western blotting. Cellular stemness was assessed by cell invasiveness and sphere formation assays. A transplanted tumor model was established for in vivo experiments.

RESULTS

MicroRNA-34a enhanced gemcitabine sensitivity both in vivo and in vitro. MicroRNA-34a suppressed the stemness and proliferation of pancreatic cancer stem cells. MicroRNA-34a directly associated with Notch 1, which lies upstream of epithelial-mesenchymal transition signaling pathways.

CONCLUSIONS

MicroRNA-34a sensitized pancreatic cancer cells to gemcitabine treatment by inhibiting Notch 1 signaling in pancreatic cancer stem cells, indicating that miR-34a has the potential to be developed as a novel therapeutic agent for the treatment of gemcitabine-resistant pancreatic ductal adenocarcinoma cells.

Quantitative ubiquitylomics reveals the ubiquitination regulation landscape in oral adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is an extremely rare salivary gland tumor with a poor prognosis and needs attention on molecular mechanisms. Protein ubiquitination is an evolutionarily conserved post-translational modification (PTM) for substrates degradation and controls diverse cellular functions. The broad cellular function of ubiquitination network holds great promise to detect potential targets and identify respective receptors. Novel technologies are discovered for in-depth research and characterization of the precise and dynamic regulation of ubiquitylomics in multiple cellular processes during cancer initiation, progression and treatment. In the present study, 4D label-free quantitative techniques of ubiquitination proteomics were used and we identified a total of 4152 ubiquitination sites in 1993 proteins. We also performed a systematic bioinformatics analysis for differential modified proteins and peptides containing quantitative information through the comparation between oral ACC (OACC) tumor with adjacent normal tissues, as well as the identification of eight protein clusters with motif analysis. Our findings offered an important reference of potential biomarkers and effective therapeutic targets for ACC.

Characteristics of the PI3K/AKT and MAPK/ERK pathways involved in the maintenance of self-renewal in lung cancer stem-like cells

Lung cancer is the leading cause of cancer-related mortality worldwide due to its early asymptomatic and late metastasis. While cancer stem cells (CSCs) may play a vital role in oncogenesis and development of lung cancer, mechanisms underlying CSCs self-renewal remain less clear. In the present study, we constructed a clinically relevant CSCs enrichment recognition model and evaluated the potential functions of phosphatidylinositol 3-kinase (PI3K)/AKT pathway (PI3K/AKT) and mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) pathways in lung cancer via bioinformatic analysis, providing the basis for in depth mechanistic inquisition. Experimentally, we confirmed that PI3K/AKT pathway predominantly promotes proliferation through anti-apoptosis in lung adenocarcinoma cells, while MAPK/ERK pathway has an overwhelming superiority in regulating the proliferation in lung CSCs. Further, utilizing stemness score model, LLC-Symmetric Division (LLC-SD) cells and mouse orthotopic lung transplantation model, we elucidated an intricate cross-talk between the oncogenic pathway and the stem cell reprograming pathway that impact stem cell characteristics as well as cancer biology features of lung CSCs both in vitro and in vivo. In summary, our findings uncovered a new insight that PI3K/AKT and MAPK/ERK pathways as oncogenic signaling pathway and/or stem cell signaling pathway act distinctively and synergistically to regulate lung CSCs self-renewal.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

Ginsenoside Rg3 Suppresses Epithelial-Mesenchymal Transition via Downregulating Notch-Hes1 Signaling in Colon Cancer Cells

Invasion and metastasis are the major causes leading to the high mortality of colon cancer. Ginsenoside Rg3 (Rg3), as a bioactive ginseng compound, is suggested to possess antimetastasis effects in colon cancer. However, the underlying molecular mechanisms remain unclear. In this study, we reported that Rg3 could effectively inhibit colon cancer cell invasion and metastasis through in vivo and in vitro studies. In addition, Rg3 suppressed the epithelial-mesenchymal transition (EMT) of HCT15 cells and SW48 cells evidenced by detecting EMT related markers E-cadherin, vimentin, and snail expression. Furthermore, inhibition of Notch signaling by LY411,575 or specific Hes1 siRNA obviously repressed colon cancer cell migration and metastasis, and induced increase in E-cadherin and decrease in vimentin and snail. Meanwhile, the expression of NICD and Hes1 was obviously decreased in the presence of Rg3. However, Rg3 failed to suppress EMT in Hes1 overexpressed colon cancer cells. In particular, Rg3 significantly reversed IL-6-induced EMT promotion and blocked IL-6- induced NICD and Hes1 upregulations. Overall, these findings suggested that Rg3 could inhibit colon cancer migration and metastasis via suppressing Notch-Hes1-EMT signaling.

Natural cordycepin induces apoptosis and suppresses metastasis in breast cancer cells by inhibiting the Hedgehog pathway

In the study, we investigated the role of the hedgehog (Hh) pathway in cordycepin's effects on human breast cancer cells, with respect to cell growth, apoptosis and metastasis. We found cordycepin to have low toxicity but significant anticancer effects. Cordycepin-induced apoptosis led to increased PUMA, CYTO-C, FAS, DR4/5, and cleaved caspase-3; and decreased BCL-2, XIAP and PDGFR-α. Cordycepin inhibited metastasis, which was associated with up-regulated E-cadherin, and down-regulated N-cadherin, SNAIL, SLUG and ZEB1. Cordycepin also inhibited expression of Hh pathway components and GLI transcriptional activity. Inversely, knockout of GLI blocked cordycepin-mediated effects on the apoptotic, epithelial-mesenchymal transition (EMT) and Notch pathways, which indicates that GLI is crucial for cordycepin's effects against breast cancer. Inhibition of GLI enhanced cordycepin's effect on breast cancer cell growth. To our knowledge, this is the first study of cordycepin's effect on the Hh pathway in breast cancer, and provides preliminary data for the in vivo study, and possible therapeutic use, of cordycepin.

Molecular and Cellular Modelling of Salivary Gland Tumors Open New Landscapes in Diagnosis and Treatment

Salivary gland tumors are neoplasms affecting the major and minor salivary glands of the oral cavity. Their complex pathological appearance and overlapping morphological features between subtypes, pose major challenges in the identification, classification, and staging of the tumor. Recently developed techniques of three-dimensional culture and organotypic modelling provide useful platforms for the clinical and biological characterization of these malignancies. Additionally, new advances in genetic and molecular screenings allow precise diagnosis and monitoring of tumor progression. Finally, novel therapeutic tools with increased efficiency and accuracy are emerging. In this review, we summarize the most common salivary gland neoplasms and provide an overview of the state-of-the-art tools to model, diagnose, and treat salivary gland tumors.