Notch-1 knockdown suppresses proliferation, migration and metastasis of salivary adenoid cystic carcinoma cells

Association between Single Nucleotide Polymorphisms in Monoamine Oxidase and the Severity of Addiction to Betel Quid

Betel quid (BQ) is the fourth most popular psychoactive substance in the world, and BQ use disorder (BUD) is prevalent in Asian countries. Although the mechanisms underlying BUD remain unclear, studies have reported influences from monoamine oxidase inhibitor. We enrolled 50 patients with BUD and assessed their BQ consumption habits, emotional conditions, and the clinical severity of addiction-assessed using the Diagnostic and Statistical Manual of Mental Disorders [Fifth Edition] (DSM-5) criteria, Substance Use Severity Rating Scale, and Yale-Brown Obsessive Compulsive Disorder Rating Scale for BQ. Patients were categorized into the severe group when showing six or more symptoms defined by DSM-5. A genome-wide association study was conducted for single nucleotide polymorphisms in BRCA1, COL9A1, NOTCH1, HSPA13, FAT1, and MAOA by using patients' blood samples. More severe BUD symptoms were associated with younger age of using BQ and poor oral hygiene and with severe craving for and more anxiety toward BQ use. The MAOA rs5953210 polymorphism was significantly associated with severe BUD (odds ratio, 6.43; 95% confidence interval, 5.12-7.74; p < 0.01) and might contribute to BQ-associated cancer risk. Further studies are required to investigate the addictive properties of BQ and the development of novel diagnostic tools and pharmacotherapeutic alternatives to BUD treatment.

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.

Systemic and Targeted Therapies in Adenoid Cystic Carcinoma

OPINION STATEMENT

Adenoid cystic carcinoma (ACC) is an often-indolent type of salivary gland cancer (SGC). A subset of patients develops progression or aggressive disease warranting systemic therapy in the recurrent/metastatic (R/M) setting. We recommend genomic testing for all patients with R/M disease to aid with prognostication and eligibility for potential experimental therapies. Here, we review the currently available treatment options (cytotoxic chemotherapies and vascular endothelial growth factor receptor (VEGFR)-targeting tyrosine kinase inhibitors (TKIs)). Based on limited data, we nominate regimens which may have more favorable efficacy profiles. Among the cytotoxic chemotherapies, several regimens are acceptable when incorporating a platinum agent. Among the VEGFR-targeting TKIs, lenvatinib and axitinib are the preferred options. Larger, randomized studies prioritizing combinations with mechanistic synergism are needed. Predictive biomarkers are critical, as there is currently little evidence to guide sequencing of available options for individual patients. Immunotherapy is an available option, but has been associated with only modest benefit in ACC. We go on to review other therapies that have been studied and nominate those with promise based on early clinical data.

Reconstruction and analysis of the aberrant lncRNA-miRNA-mRNA network based on competitive endogenous RNA in adenoid cystic carcinoma of the salivary gland

Background

The aim of this work was to investigate the competing endogenous RNA (ceRNA) network in adenoid cystic carcinoma of the salivary gland (SACC).

Methods

Differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) between cancer tissues and normal salivary gland (NSG) in ACC were identified using data from the Gene Expression Omnibus (GEO) database. Functional annotation and pathway enrichment analysis of DEmRNAs were performed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The miRNAs that are targeted by lncRNAs were predicted using miRanda and PITA, while the target mRNAs of miRNAs were retrieved from miRanda, miRWalk, and TargetScan. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and then we constructed the lncRNA-miRNA-mRNA networks of ACC.

Results

Differentially expressed RNAs were identified in SACC. Upon comparing cancer tissues and NSG tissues, 103 upregulated and 52 downregulated lncRNAs and 745 upregulated and 866 downregulated mRNAs were identified in GSE88804; in addition, 39 upregulated and 43 downregulated miRNAs were identified in GSE117275. GO enrichment analyses revealed that the most relevant GO terms were regulation of transcription DNA-templated, transcription DNA-templated, and cell division. KEGG pathway enrichment analysis showed that differentially expressed genes (DEGs) were mainly enriched in the cell cycle, pathways in cancer, PI3K-Akt signaling pathway, breast cancer, and microRNAs in cancer. The PPI network consisted of 27 upregulated and 54 downregulated mRNAs. By constructing ceRNA network, NONHSAT251752.1-hsa-miR-6817-5p-NOTCH1, NONHSAT251752.1-hsa-miR-204-5p/hsa-miR-138-5p-CDK6 regulatory axises were identified and all genes in the network were verified by qRT-PCR.

Conclusions

The present study constructed ceRNA networks in SACC and provided a novel perspective of the molecular mechanisms for SACC.

Oral Cancer Stem Cells: Therapeutic Implications and Challenges

Head and neck squamous cell carcinoma (HNSCC) is currently one of the 10 most common malignancies worldwide, characterized by a biologically highly diverse group of tumors with non-specific biomarkers and poor prognosis. The incidence rate of HNSCC varies widely throughout the world, with an evident prevalence in developing countries such as those in Southeast Asia and Southern Africa. Tumor relapse and metastasis following traditional treatment remain major clinical problems in oral cancer management. Current evidence suggests that therapeutic resistance and metastasis of cancer are mainly driven by a unique subpopulation of tumor cells, termed cancer stem cells (CSCs), or cancer-initiating cells (CICs), which are characterized by their capacity for self-renewal, maintenance of stemness and increased tumorigenicity. Thus, more understanding of the molecular mechanisms of CSCs and their behavior may help in developing effective therapeutic interventions that inhibit tumor growth and progression. This review provides an overview of the main signaling cascades in CSCs that drive tumor repropagation and metastasis in oral cancer, with a focus on squamous cell carcinoma. Other oral non-SCC tumors, including melanoma and malignant salivary gland tumors, will also be considered. In addition, this review discusses some of the CSC-targeted therapeutic strategies that have been employed to combat disease progression, and the challenges of targeting CSCs, with the aim of improving the clinical outcomes for patients with oral malignancies. Targeting of CSCs in head and neck cancer (HNC) represents a promising approach to improve disease outcome. Some CSC-targeted therapies have already been proven to be successful in pre-clinical studies and they are now being tested in clinical trials, mainly in combination with conventional treatment regimens. However, some studies revealed that CSCs may not be the only players that control disease relapse and progression of HNC. Further, clinical research studying a combination of therapies targeted against head and neck CSCs may provide significant advances.

Metastatic Breast Cancer, Organotropism and Therapeutics: A Review

The final stage of breast cancer involves spreading breast cancer cells to the vital organs like the brain, liver lungs and bones in the process called metastasis. Once the target organ is overtaken by the metastatic breast cancer cells, its usual function is compromised causing organ dysfunction and death. Despite the significant research on breast cancer metastasis, it's still the main culprit of breast cancer-related deaths. Exploring the complex molecular pathways associated with the initiation and progression of breast cancer metastasis could lead to the discovery of more effective ways of treating the devastating phenomenon. The present review article highlights the recent advances to understand the complexity associated with breast cancer metastases, organotropism and therapeutic advances.

Molecular Markers that Matter in Salivary Malignancy

Despite aggressive initial interventions, recurrent/metastatic salivary gland cancer is not uncommon. Standard chemotherapy has not been shown to have durable clinical benefits. Several potential molecular markers have been identified in different histologic subtypes of salivary cancers. The objective of this review is to highlight the molecular markers that have been targeted in clinical trials for salivary gland cancers.

MIR137/MIR2682 locus is associated with perineural invasiveness in head and neck cancer

BACKGROUND

Head and neck cancer (HNSCC) is one of the most lethal cancers characterized by high relapse and poor prognosis. Several miRNAs have been implicated in HNSCC, including the tumor suppressor miR-137. A large CpG island (CpG73) spans most of the miR-137 gene sequence and stretches 659-bp downstream, ending just upstream of miR-2682 in the same host gene. Here, we assessed the role of the MIR137/MIR2682 locus in HNSCC.

METHODS

MiRNA expression was analyzed in paired cancerous and normal tissues from 77 HNSCC patients by Quantitative Reverse-Transcription PCR. CpG73 methylation in paired tissues from 48 patients was determined by combined bisulfite restriction analysis. Associations between expression and methylation levels and patient clinicopathological parameters were investigated.

RESULTS

Decreased expression of miR-137 (P<0.01) and miR-2682 (P<0.01) precursors was observed in cancerous tissues, most significantly in oropharyngeal tumors. Lower miR-137 levels correlated with increased perineural invasiveness (P = 0.04). Predicted common miRNA targets MTDH and Notch1 were upregulated in tumor tissues. The CpG73 region between miR-137 and miR-2682 was hypermethylated in tumors. Methylation was observed in 60.4% of cancerous compared to 31.6% of normal tissues, and methylation levels were significantly higher (P<0.01) in tumors. Increased methylation correlated with decreased disease-free patient survival (P = 0.024).

CONCLUSION

The MIR137/MIR2682 locus correlated with HNSCC perineural invasiveness. This is the first report showing miR-2682 downregulation in head and neck cancer. Our results support the tumor suppressive role of miR-137 and miR-2682. The inverse correlation between CpG73 hypermethylation and disease-free survival suggests this epigenetic mark may have prognostic value in HNSCC.

miR-5191 acts as a tumor suppressor in salivary adenoid cystic carcinoma by targeting Notch-2

OBJECTIVE

This study sought to investigate the effect of miR-5191 on proliferation, invasion and metastasis in salivary adenoid cystic carcinoma (SACC).

MATERIALS AND METHODS

The differential expression level of miR-5191 between 5 primary tumor and adjacent non-neoplastic samples, and in two SACC cell lines was detected by quantitative real-time PCR. Cell proliferation, invasion, and migration were performed, followed by luciferase reporter assay and western analysis. The effect of miR-5191 on cell proliferation and apoptosis was evaluated by cell growth and apoptosis assay. The function of miR-5191 in SACC tumorigenesis and metastasis in vivo was investigated by nude mice experiment. The associations between miR-5191/Notch-2 expression and clinicopathological features were analyzed.

RESULTS

miR-5191 was downregulated in primary tumor tissues and SACC-LM cells. By targeting Notch-2, miR-5191 expression level affected the migration, invasion, and proliferation of SACC cells. Overexpression of miR-5191 inhibited the expression levels of Notch-2, followed by the decreased expression of c-Myc, Bcl-2, Hes-1, Hey-1, and Cyclin D1. In vivo, miR-5191 overexpression suppressed the SACC tumorigenesis and pulmonary metastasis in mice. In SACC patients, higher expression of miR-5191 was related to better prognoses and lower possibility of metastasis.

CONCLUSIONS

miR-5191 acts as a tumor suppressor in SACC by targeting Notch-2.

DNA damage response as a prognostic indicator in metastatic breast cancer via mutational analysis

Background

High tumor heterogeneity contributes to breast cancer recurrence and metastasis. However, the lack of indicators to serve as precise and reliable means of predicting breast cancer prognosis has yet to be addressed. This study aims to reveal the prognostic relevance of mutations in metastatic breast cancer (MBC) by large-scale circulating tumor DNA (ctDNA) analysis in China.

Methods

We performed ctDNA panel-captured sequencing of 958 blood samples from MBC patients including 494 hormone receptor (HR)-positive cases, 130 human epidermal growth factor receptor 2-positive cases, and 177 triple-negative breast cancer (TNBC) cases. The somatic mutations and potential targets were assessed. Progression-free survival (PFS) was analyzed using the Kaplan-Meier method.

Results

In 801 of the 958 MBC blood samples, 663 mutated genes and 5,829 nonsynonymous alterations were identified. Mutated genes of the highest frequency were tumor protein p53 (TP53, 54%), phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA, 41%), estrogen receptor 1 (ESR1, 12%), myeloid/lymphoid or mixed-lineage leukemia protein 3 (MLL3, 11%), DNA (cytosine-5)-methyltransferase 3A (DNMT3A, 10%), erb-b2 receptor tyrosine kinase 2 (ERBB2, 10%), GATA binding protein 3 (GATA3, 8%), FAT atypical cadherin 1 (FAT1, 7%), phosphatase and tensin homolog (PTEN, 6%), and mitogen-activated protein kinase kinase kinase 1 (MAP3K1, 6%). Enriched mutations and driver genes in MBC varied across stages and in multiple subtypes. Moreover, TP53, ERBB2, or coexisting TP53/PIK3CA mutations in MBC were remarkably related with shorter PFS. Mutated DNA damage response (DDR) genes were significantly associated with tumor mutation burden and mutant-allele tumor heterogeneity score, as well as with worse clinical outcome.

Conclusions

Our findings indicate that the mutations of TP53, PIK3CA, ERBB2, and in particular, DDR genes, in MBC might be relevant indicators of unfavorable prognosis in MBC.

Notch Signaling in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system with a steadily rising incidence. The term "thyroid cancer" encompasses a spectrum of subtypes, namely papillary thyroid cancer, follicular thyroid cancer, anaplastic thyroid cancer, and medullary thyroid cancer. Each subtype differs histopathologically and in degrees of cellular differentiation, which may be in part due to signaling of the Notch pathway. The Notch pathway is an evolutionarily conserved signal transduction mechanism that regulates cell proliferation, differentiation, survival, stem cell maintenance, embryonic and adult development, epithelial-mesenchymal transition, and angiogenesis. Its role in cancer biology is controversial, as it has been shown to play both an oncogenic and tumor-suppressive role in many different types of cancers. This discordance holds true for each subtype of thyroid cancer, indicating that Notch signaling is likely cell type and context dependent. Whether oncogenic or not, Notch signaling has proven to be significantly involved in the tumorigenesis of thyroid cancer and has thus earned interest as a therapeutic target. Advancement in the understanding of Notch signaling in thyroid cancer holds great promise for the development of novel treatment strategies to benefit patients.

Extract Derived From Black Rice Functions as a Photothermal Agent for Suppressing Tumor Growth and Metastasis

It remains a challenge to develop an effective therapeutic agent with low cost and good biocompatibility for cancer therapy. Based on its dark color, we hypothesized that, the extraction from black rice grains, denoted BRE, could serve as a photothermal conversion agent. The results showed that BRE confers a high photothermal conversion efficiency up to 54.13%. The combination of BRE and near infrared (NIR) treatment enables effective photothermal tumor ablation, and suppress tumor metastasis via inhibiting the epithelial-mesenchymal transition (EMT) pathway. In addition, BRE exhibits no obvious toxicity in vivo. Therefore, BRE could serve as a promising photothermal therapy agent with a low toxicity to treat cancer.

Cutaneous Effects of Notch Inhibitor Therapy: A Report of Two Cases

As aberrant Notch signaling has been linked to cancerous growth, Notch inhibitors represent a novel category of targeted oncological therapy. Notch pathways in tumor cells may contribute to proliferation or limit apoptosis and differentiation. Healthy skin differentiation and homeostasis are reliant on normal Notch expression, and disruption of this signaling has been implicated in dermatological conditions such as hidradenitis suppurativa, psoriasis, atopic dermatitis, and lichen planus. Here, we describe two cases of patients with cutaneous side effects from Notch inhibitor treatment for adenoid cyst carcinoma (ACC) and review the role of Notch signaling in skin disease. By illuminating connections between medication side effects and disease pathogenesis, our goal is to increase awareness of the cutaneous side effects of Notch inhibitor treatment.

JAG2/Notch2 inhibits intervertebral disc degeneration by modulating cell proliferation, apoptosis, and extracellular matrix

Background

Intervertebral disc degeneration (IVDD)-related disorders are the major causes of low back pain. A previous study suggested that Notch activation serves as a protective mechanism and is a part of the compensatory response that maintains the necessary resident nucleus pulposus (NP) cell proliferation to replace lost or non-functional cells. However, the exact mechanism remains to be determined. In this study, we aimed to investigate the role of JAG2/Notch2 in NP cell proliferation and apoptosis.

Methods

Recombinant JAG2 or Notch2, Hes1, and Hey2 siRNAs were used to activate or inhibit Notch signaling. Cell proliferation, apoptosis, cell cycle regulatory factors, and pathways associated with Notch-mediated proliferation were examined. In vivo experiments involving an intradiscal injection of Sprague-Dawley rats were performed.

Results

Recombinant JAG2 induced Notch2 and Hes1/Hey2 expression together with NP cell proliferation. Downregulation of Notch2/Hes1/Hey2 induced G0/G1 phase cell cycle arrest in NP cells. Moreover, Notch2 mediated NP cell proliferation by regulating cyclin D1 and by activating PI3K/Akt and Wnt/β-catenin signaling. Furthermore, Notch signaling inhibited TNF-α-promoted NP cell apoptosis by suppressing the formation of the RIP1-FADD-caspase-8 complex. Finally, we found that intradiscal injection of JAG2 alleviated IVDD and that sh-Notch2 aggravated IVDD in a rat model. These results indicated that JAG2/Notch2 inhibited IVDD by modulating cell proliferation, apoptosis, and extracellular matrix. The JAG2/Notch2 axis regulated NP cell proliferation via PI3K/Akt and Wnt/β-catenin signaling and inhibited TNF-α-induced apoptosis by suppressing the formation of the RIP1-FADD-caspase-8 complex.

Conclusions

The current and previous results shed light on the therapeutic implications of targeting the JAG2/Notch2 axis to inhibit or reverse IVDD.

Physiology, Pathology and Regeneration of Salivary Glands

Salivary glands are essential structures in the oral cavity. A variety of diseases, such as cancer, autoimmune diseases, infections and physical traumas, can alter the functionality of these glands, greatly impacting the quality of life of patients. To date, no definitive therapeutic approach can compensate the impairment of salivary glands, and treatment are purely symptomatic. Understanding the cellular and molecular control of salivary glands function is, therefore, highly relevant for therapeutic purposes. In this review, we provide a starting platform for future studies in basic biology and clinical research, reporting classical ideas on salivary gland physiology and recently developed technology to guide regeneration, reconstruction and substitution of the functional organs.

RETRACTED: MicroRNA-34 suppresses proliferation of human ovarian cancer cells by triggering autophagy and apoptosis and inhibits cell invasion by targeting Notch 1

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors. The substance of the retraction is as follows: Attention has been drawn by Dr Elisabeth Bik to the fact that similar images representing the results of different experiments are shown in Figures 1G and 3F. She also points to the remarkable similarity between the legend text and line graphs of Figure 1 of the Biochimie article, Jia et al (2019), and Figure 1 of a publication in Eur Rev Med Pharmacol Sci (2019), Xu et al (2019). The latter article has since been retracted. An anomymous reader has observed that Figures 1G and 3F show three rows of images shared with Figure 4 of the first-published version of a manuscript in the Journal of the Balkan Union of Oncology (J BUON), Tan et al (2019), submitted and accepted for publication before the submission of the Biochimie article, though it has since publication undergone unexplained modification to Figure 4. Furthermore, the panels shared between the Biochimie and J BUON articles are similar to panels in Figure 7 of a much earlier manuscript, published in October 2017 in Science Reports (Dai et al), as well as to a figure in a later article, Li et al (2020). In addition, the top panel of Figure 3G in Jia et al (2019) as well as the two lower panels is also similar to a part of Figure 7, Dia et al (2017). Further unexplained anomalies concern Figure 3C of Jia et al (2019). The editors would like to thank Dr Bik and the anonymous reader for their valuable insight in this matter. The above observations cast serious doubt on the scientific integrity of the Biochimie article. Confronted with the observation that panels in Figures 1G and 3F were similar though representing different experiments, the authors replied to the editors that the bottom panel in Figure 3F was a mistake and would be corrected. They were not able to produce the raw data when requested, and proposed to the editors to repeat the experiments. However, no new data have been received by the editors at the time of writing, and would not change the serious doubts that they harbour concerning the integrity of the work published in Biochimie. Therefore, the editorial team has opted for retraction irrespective of any new results. This decision has been accepted by the authors.

Highly Tumorigenic Diffuse Large B Cell Lymphoma Cells Are Produced by Coculture with Stromal Cells

BACKGROUND/AIMS

Diffuse large B cell lymphoma (DLBCL) is heterogeneous. We aimed to explore how tumor microenvironment promotes lymphoma cell aggressiveness and heterogeneity.

METHODS

We created a coculture system using human DLBCL cells and mouse bone marrow stromal cells. Proliferative capacity, drug resistance, clonogenicity, and tumorigenicity were compared in lymphoma cells from the coculture system and lymphoma cells cultured alone. Expression of Notch signaling associated genes was evaluated using real-time reverse transcriptase PCR and Western blot.

RESULTS

Lymphoma cells in the coculture system differentiated into a suspended cell group and an adherent cell group. They acquired a stronger proliferative capacity and drug resistance than lymphoma cells cultured alone, and differences existed between the adherent cell and suspended cell groups. The suspended cell group acquired the most powerful clonogenic and tumorigenic potential. However, Notch3 was exclusively expressed in the adherent lymphoma cell group and the use of N-[N-(3, 5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester, an inhibitor of Notch pathway, could abolish the emergence of highly aggressive lymphoma cells.

CONCLUSION

Highly tumorigenic lymphoma cells could be generated by coculture with stromal cells, and it was dependent on Notch3 expression in the adjacent lymphoma cells through interaction with stromal cells.

Autophagy negatively regulates tumor cell proliferation through phosphorylation dependent degradation of the Notch1 intracellular domain

Autophagy is a highly conserved mechanism that degrades long-lived proteins and dysfunctional organelles, and contributes to cell fate. In this study, autophagy attenuates Notch1 signaling by degrading the Notch1 intracellular domain (Notch1-IC). Nutrient-deprivation promotes Notch1-IC phosphorylation by MEKK1 and phosphorylated Notch1-IC is recognized by Fbw7 E3 ligase. The ubiquitination of Notch1-IC by Fbw7 is essential for the interaction between Notch1-IC and p62 and for the formation of aggregates. Inhibition of Notch1 signaling prevents the transformation of breast cancer cells, tumor progression, and metastasis. The expression of Notch1 and p62 is inversely correlated with Beclin1 expression in human breast cancer patients. These results show that autophagy inhibits Notch1 signaling by promoting Notch1-IC degradation and therefore plays a role in tumor suppression.

Genomics of mucoepidermoid and adenoid cystic carcinomas

Objective

To report on the current state of the literature on the genetics of mucoepidermoid and adenoid cystic carcinomas of the salivary glands with a focus on genomic screens and recently discovered genetic translocations.

Methods

A PubMed based literature review was performed to query for genetics related basic science and preclinical studies about mucoepidermoid and adenoid cystic carcinomas of the salivary glands.

Results and conclusions

Genetic translocations between CRTC1 and MAML2 in mucoepidermoid carcinoma and between MYB and NFIB in adenoid cystic carcinoma have been recently discovered and have therapeutic implications. Key signaling pathways such as the EGFR pathway in mucoepidermoid carcinoma and the Notch pathway, chromatin regulation, and c‐kit mediated epithelial‐mesenchymal transitions in adenoid cystic carcinoma have recently been elucidated, pointing to possible therapeutic targets in both cancers.

Breast cancer lung metastasis: Molecular biology and therapeutic implications

Distant metastasis accounts for the vast majority of deaths in patients with cancer. Breast cancer exhibits a distinct metastatic pattern commonly involving bone, liver, lung, and brain. Breast cancer can be divided into different subtypes based on gene expression profiles, and different breast cancer subtypes show preference to distinct organ sites of metastasis. Luminal breast tumors tend to metastasize to bone while basal-like breast cancer (BLBC) displays a lung tropism of metastasis. However, the mechanisms underlying this organ-specific pattern of metastasis still remain to be elucidated. In this review, we will summarize the recent advances regarding the molecular signaling pathways as well as the therapeutic strategies for treating breast cancer lung metastasis.

Overexpression of Musashi-1 protein is associated with progression and poor prognosis of gastric cancer

Musashi-1, an evolutionally conserved RNA-binding protein, has been implicated in the promotion of pathological stem cell proliferation, including tumorigenesis. The objective of the present study was to evaluate the expression of Musashi-1 protein and its implications in the progression and prognosis of gastric cancer. The expression level of Musashi-1 protein in gastric cancer was determined by western blotting and immunohistochemistry, and compared with the clinicopathological parameters. The present study revealed that the expression level of Musashi-1 protein in gastric cancer was significantly upregulated and correlated with the tumor size, tumor-node-metastasis (TNM) stage, Lauren classification, depth of invasion, vessel invasion, lymph node metastasis and distant metastasis. The mean survival time for patients with low expression levels of Musashi-1 was significantly longer compared with patients with high expression levels of Musashi-1. For each TNM stage, the mean survival time for patients with a low Musashi-1 expression levels was also significantly longer compared with patients with a high Musashi-1 expression level. Notably, TNM stage II patients with a low Musashi-1 expression level demonstrated a longer mean survival time compared with TNM stage I patients with high Musashi-1 expression level (56.8 vs. 42.3 months; P=0.001), and TNM stage III patients with low Musashi-1 expression level exhibited a longer mean survival time compared with TNM stage II patients with a high Musashi-1 expression level (44.0 vs. 33.8 months; P=0.034). Multivariate Cox's regression test demonstrated that Musashi-1 protein expression level was an independent prognostic indicator for the survival rate of the patients with gastric cancer. The results of the present study highlighted an important role for Musashi-1 protein in the progression of gastric cancer. The detection of the Musashi-1 protein expression level alone or in combination with TNM staging may aid the prediction of the prognosis of patients with gastric cancer.

Down-regulation of miR-125a-5p is associated with salivary adenoid cystic carcinoma progression via targeting p38/JNK/ERK signal pathway

Salivary adenoid cystic carcinoma (SACC) is a relatively uncommon epithelial-like malignancy that can occur in the head and neck region. Despite its slow growth, this aggressive salivary gland tumor frequently recurs and metastasizes to distant organs since lacking effective chemotherapy treatment. MicroRNAs are key regulators in tumor metastasis and progression, but their roles during SACC progression have not been illustrated. In current study, we demonstrate that miR-125a-5p is down-regulated in SACC and closely related to the metastasis and progression in human SACC specimens. In vitro, miR-125a-5p mimic can suppress SACC cell migration and invasion; while blocking miR-125a-5p can relieve the inhibition effect. By using dual-luciferase assay, we confirmed that miR-125a-5p directly targeted to p38 and tissue samples of patients indicated the negative correlation between miR-125a-5p and p38; clinical analysis also showed that low level expression of miR-125a-5p is closely associated with poor prognosis of SACC. Furthermore, down-regulation of miR-125a-5p triggered downstream p38/JNK/ERK activation. Taken together, our results indicate that down-regulation of miR-125a-5p promotes SACC progression through p38 signal pathway and miR-125a-5p can be a potential therapeutic target of SACC.

The Role of Notch1 Signaling in Anaplastic Thyroid Carcinoma

PURPOSE

The Notch signaling pathway is widely expressed in normal, reactive, and neoplastic tissues; however, its role in thyroid tissues has not been fully elucidated. Therefore, this study was conducted to characterize the expression of the Notch signaling pathway in papillary thyroid cancer (PTC) cells and anaplastic thyroid cancer (ATC) cells.

MATERIALS AND METHODS

Expression of activated Notch1 in ATC and PTC paraffin-embedded tissues was determined by immunohistochemistry. The small interfering RNA techniquewas employed to knock down Notch1 expression in ATC and PTC cell lines.

RESULTS

The expression of activated Notch1 was higher in ATC cases than in PTC cases. Inhibition of Notch1 significantly reduced proliferation and migration of ATC cells, but not PTC cells. In addition, inhibition of Notch1 in ATC cells significantly reduced the expression of key markers of epithelial-mesenchymal transition and cancer stem cells. Conversely, changes in the expression of these proteins were not observed in PTC cells.

CONCLUSION

The results of this study suggest that Notch1 expression plays different roles in tumor progression in ATC and PTC cells. We also found that Notch1 expression was significantly related to the highly invasive or proliferative activity of ATC cells.

microRNA-30b inhibits cell invasion and migration through targeting collagen triple helix repeat containing 1 in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the largest histological subgroup of lung cancer and has increased in prevalence in China over the past 5 years. The 5-year survival rate has remained at 15-20 %, with a median survival of 8-12 months. The tumorigenesis and progression of NSCLC is orchestrated by numerous oncogene and anti-oncogene mutations and insights into microRNA function have increased our understanding of the process. Here, we investigated the effects of miR-30b on NSCLC cell invasion and migration and explored the underlying molecular mechanisms involved.

METHODS

Quantitative reverse transcription PCR, wound healing assay, trans-well assays, western blotting and dual luciferase assays were performed to investigate the molecular mechanisms of miR-30b in NSCLC cells.

RESULTS

MiR-30b was down-regulated and Cthrc1 up-regulated in NSCLC tissues. Both were associated with tumor differentiation, TNM stage and lymph node metastases. Up-regulation of miR-30b restricted A549 and Calu-3 cell invasion and migration. Additionally, the expression of Cthrc1, matrix metalloproteinase-9 and matrix metalloproteinase-2 was reduced, while metallopeptidase inhibitor-1 expression increased. Bioinformatics analysis identified Cthrc1 as a target of miR-30b and western blotting and luciferase reporter assays confirmed that miR-30b regulates Cthrc1 by directly binding to its 3'UTR. Transfection of Cthrc1 without the 3'UTR restored the miR-30b inhibiting cell invasion. Up-regulation of miR-30b or down-regulation of Cthrc1 had potential significance in the invasion and metastasis of NSCLC.

CONCLUSIONS

MiR-30b was down-regulated and Cthrc1 up-regulated in NSCLC tissues. Both of them were related to tumor differentiation, TNM stage and lymph node metastases. MiR-30b affected NSCLC cells invasion and migration by regulating Cthrc1.