Epithelial-Mesenchymal Expression Phenotype of Primary Melanoma and Matched Metastases and Relationship with Overall Survival

Role of PLK1/NUMB/NOTCH in epithelial-mesenchymal transition in human melanoma

Polo-like kinase 1 (PLK1), a serine/threonine kinase, is overexpressed in melanoma and its expression has been associated with poor disease prognosis. PLK1 has been shown to interact with NUMB, a NOTCH antagonist. However, the exact role of PLK1, NUMB, and NOTCH signaling in epithelial-mesenchymal transition (EMT) in melanoma progression is unclear. In this study, Affymetrix microarray analysis was performed to determine differentially expressed genes following shRNA-mediated knockdown of PLK1 in human melanoma cells that showed significant modulations in EMT and metastasis-related genes. Using multiple PLK1-modulated melanoma cell lines, we found that PLK1 is involved in the regulation of cell migration, invasion, and EMT via its kinase activity and NOTCH activation. In vitro kinase assay and mass spectrometry analysis demonstrated a previously unknown PLK1 phosphorylation site (Ser413) on NUMB. Overexpression of non-phosphorylatable (S413A) and phosphomimetic (S413D) mutants of NUMB in melanoma cells implicated the involvement of NUMB-S413 phosphorylation in cell migration and invasion, which was independent of NOTCH activation. To determine the clinical relevance of these findings, immunohistochemistry was performed using melanoma tissue microarray, which indicated a strong positive correlation between PLK1 and N-cadherin, a protein required for successful EMT. These findings were supported by TCGA analysis, where expression of high PLK1 with low NUMB or high NOTCH or N-cadherin showed a significant decrease in survival of melanoma patients. Overall, these results suggest a potential role of PLK1 in EMT, migration, and invasion of melanoma cells. Our findings support the therapeutic targeting of PLK1, NUMB, and NOTCH for melanoma management.

Sphingolipid paracrine signaling impairs keratinocyte adhesion to promote melanoma invasion

Melanoma is the deadliest form of skin cancer due to its propensity to metastasize. It arises from melanocytes, which are attached to keratinocytes within the basal epidermis. Here, we hypothesize that, in addition to melanocyte-intrinsic modifications, dysregulation of keratinocyte functions could initiate early-stage melanoma cell invasion. We identified the lysolipid sphingosine 1-phosphate (S1P) as a tumor paracrine signal from melanoma cells that modifies the keratinocyte transcriptome and reduces their adhesive properties, leading to tumor invasion. Mechanistically, tumor cell-derived S1P reduced E-cadherin expression in keratinocytes via S1P receptor dependent Snail and Slug activation. All of these effects were blocked by S1P2/3 antagonists. Importantly, we showed that epidermal E-cadherin expression was inversely correlated with the expression of the S1P-producing enzyme in neighboring tumors and the Breslow thickness in patients with early-stage melanoma. These findings support the notion that E-cadherin loss in the epidermis initiates the metastatic cascade in melanoma.

E-cadherin expression in the tumor microenvironment of advanced epidermal growth factor receptor-mutant lung adenocarcinoma and the association with prognosis

BACKGROUND

The expression of programmed death-ligand 1 (PD-L1), tumor-infiltrating lymphocytes (TILs), E-cadherin, and vimentin in lung cancer tumor microenvironment is known to impact patient survival or response to therapy. The expression of these biomarkers may also differ between primary lung tumors and brain metastatic tumors. In this study, we investigated the interaction between these biomarkers in lung tumors with or without concomitant brain metastasis and the interaction with paired brain metastatic tumors.

METHODS

The study included 48 patients with stage IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma. Sixteen of the forty-eight patients were diagnosed with brain metastasis, while the remaining thirty-two were not. All sixteen patients with brain metastasis had brain tumors. The expression of PD-L1, TILs (CD8⁺ T lymphocytes and FOXP3⁺ regulatory T lymphocytes), E-cadherin, and vimentin were evaluated using immunohistochemical (IHC) staining.

RESULTS

Patients with brain metastasis exhibited a higher frequency of exon 19 deletion and uncommon EGFR mutations, a higher lung tumor vimentin score, worse progression-free survival (PFS), and overall survival (OS) than patients without brain metastasis. IHC staining showed no difference between paired lung and brain tumors. Patients with low PD-L1 expression had better PFS and OS. After multivariate analysis, higher body mass index, the presence of brain metastasis, bone metastasis, and uncommon EGFR mutations were correlated with worse PFS, while the presence of brain metastasis and high lung tumor E-cadherin score was associated with worse OS.

CONCLUSIONS

In patients with stage IV EGFR-mutant lung adenocarcinoma, high E-cadherin expression in the lung tumor might be associated with worse OS. Vimentin expression in the lung tumor was positively related to the risk of brain metastasis.

Therapeutic targeting of anoikis resistance in cutaneous melanoma metastasis

The acquisition of resistance to anoikis, the cell death induced by loss of adhesion to the extracellular matrix, is an absolute requirement for the survival of disseminating and circulating tumour cells (CTCs), and for the seeding of metastatic lesions. In melanoma, a range of intracellular signalling cascades have been identified as potential drivers of anoikis resistance, however a full understanding of the process is yet to be attained. Mechanisms of anoikis resistance pose an attractive target for the therapeutic treatment of disseminating and circulating melanoma cells. This review explores the range of small molecule, peptide and antibody inhibitors targeting molecules involved in anoikis resistance in melanoma, and may be repurposed to prevent metastatic melanoma prior to its initiation, potentially improving the prognosis for patients.

GLUT1 and ASCT2 Protein Expression in Papillary Thyroid Carcinoma Patients and Relation to Hepatitis C Virus: A Propensity-Score Matched Analysis

Purpose

Recently, glucose and amino acid transporters have gradually become a hot topic in thyroid gland biology and cancer research. We aimed to investigate the expressions of glucose transporter 1 (GLUT1) and glutamine transporter 2 (ASCT2) in papillary thyroid carcinoma (PTC) and their clinical significance and relation to HCV-related hepatitis.

Patients and Methods

Screening 202 TC tissue samples against the selection criteria using a propensity-score matched analysis to adjust for age, sex, side of tumor, histopathological variants, TNM staging system, and the positivity for HCV yielded 51 matched (17 HCV positive and 34 HCV negative) PTC samples. The expressions of GLUT1 and ASCT2 expressions were detected by immunohistochemical staining. Kaplan–Meier survival curves were generated for disease-free and overall survival, and multivariate Cox regression analysis was applied to identify predictors for mortality.

Results

Of 51 thyroid cancer tissues, 85% showed positive GLUT1 cytoplasmic staining, and 26% had a high expression score. All thyroid cancer specimens demonstrated ASCT2 cytoplasmic staining with membranous accentuation. Of these, 78% showed a high expression score, and 22% showed weak staining. On stratifying the study cohort based on the HCV status, HCV negative cohort showed a significantly higher immunoreactivity score for GLUT1 (p = 0.004) but not ASCT2 (p = 0.94) than HCV positive group. The expressions of the studied transporters showed no significant associations with the prognostic features of PTC nor the disease-free/overall survival.

Conclusion

GLUT1 and ASCT2 immunohistochemical staining showed positive expression with variable intensity in nearly 85% and 100% of PTC tissue samples compared to normal ones, respectively. Furthermore, GLUT1 protein expression, not ASCT2, showed a higher immunoreactivity score in PTC patients who are negative for HCV than cancer patients with positive HCV. Meanwhile, the expression of both protein markers was not associated with the clinicopathological characteristics of the studied PTC patients. Further large-scale multicenter studies are recommended to validate the present findings.

Nanotechnology Addressing Cutaneous Melanoma: The Italian Landscape

Cutaneous melanoma is one of the most aggressive solid tumors, with a low survival for the metastatic stage. Currently, clinical melanoma treatments include surgery, chemotherapy, targeted therapy, immunotherapy and radiotherapy. Of note, innovative therapeutic regimens concern the administration of multitarget drugs in tandem, in order to improve therapeutic efficacy. However, also, if this drug combination is clinically relevant, the patient's response is not yet optimal. In this scenario, nanotechnology-based delivery systems can play a crucial role in the clinical treatment of advanced melanoma. In fact, their nano-features enable targeted drug delivery at a cellular level by overcoming biological barriers. Various nanomedicines have been proposed for the treatment of cutaneous melanoma, and a relevant number of them are undergoing clinical trials. In Italy, researchers are focusing on the pharmaceutical development of nanoformulations for malignant melanoma therapy. The present review reports an overview of the main melanoma-addressed nanomedicines currently under study in Italy, alongside the state of the art of melanoma therapy. Moreover, the latest Italian advances concerning the pre-clinical evaluation of nanomedicines for melanoma are described.

NudCD1 Promotes the Proliferation and Metastasis of Non-Small Cell Lung Cancer Cells through the Activation of IGF1R-ERK1/2

BACKGROUND

NudC domain containing 1 (NudCD1) is an oncoprotein related to diverse cancers. This study aims to investigate the expression, role, and regulatory mechanism of NudCD1 in non-small cell lung cancer (NSCLC).

METHODS

qRT-PCR, Western blot, and immunohistochemistry were performed to detect the expressions of NudCD1 in NSCLC tissues and cell lines. The correlation between NudCD1 expression and clinical features was determined by the χ2 test. Besides, shRNA was used to construct the NudCD1 low expression model of NCI-H1299 and NCI-H460 cells, and CCK-8 and transwell assay were conducted to monitor the changes of proliferation, migration, and invasion of cancer cells. The expression levels of epithelial-mesenchymal transition markers and IGF1R-ERK1/2 signaling pathway proteins were detected by Western blot.

RESULTS

The expression of NudCD1 in NSCLC was higher than that in normal tissues, and the increased expression of NudCD1 was significantly correlated with increased T stage and lymph node metastasis. Moreover, patients with high expression of NudCD1 had worse prognosis. NudCD1 knockdown was proven to impede the proliferation but facilitate the migration and invasion of cancer cells. Furthermore, knockdown of NudCD1 resulted in an increase in the expression of E-cadherin and a decrease in the expression of vimentin. We also observed that NudCD1 overexpression promoted the phosphorylation of IGF1R and ERK1/2 proteins.

CONCLUSION

NudCD1 promotes the proliferation and metastasis of NSCLC cells via activation of IGF1R-ERK1/2, which indicates that NudCD1 may be a potential therapy target of NSCLC.

Significance of epithelial-to-mesenchymal transition inducing transcription factors in predicting distance metastasis and survival in patients with colorectal cancer: A systematic review and meta-analysis

Background:

The clinical relevance of epithelial-to-mesenchymal transition (EMT) in colorectal cancer (CRC) progression has been highlighted over the last decade. Several EMT-inducing transcription factors (EMT-TFs) have been implicated in the regulation of EMT, including Twist, Snail1, Slug, ZEB1, and ZEB2. Here, this meta-analysis aimed to predict the risk of distance metastasis and overall survival in CRC patients with high expression of EMT-TFs.

Materials and Methods:

All eligible studies were searched in PubMed, Scopus, and Web of Science databases. The search was carried out to include literatures published as late as September 1, 2018. In overall, 16 studies that investigated the relationship between EMT-TFs with distance metastasis and survival in CRC patients were included. In meta-analysis, a pooled hazard ratio (HR) and odds ratio (OR) were estimated for associations.

Results:

The results of this review indicated that expressions of all EMT-TFs are significantly correlated with poor overall survival in CRC. Moreover, there are a significant association between Twist (OR, 1.46; 95% confidence interval [CI], 1.03–2.09), Slug (OR, 3.43; 95% CI, 1.98–5.93), and ZEB2 (OR, 2.42; 95% CI, 1.09–5.40) expression with distance metastatic in CRC patients.

Conclusion:

These findings suggest that the overexpression of EMT-TFs plays a key role in increasing the risk of distance metastasis as well as decreasing overall survival in CRC patients.

Cancer stem cells, epigenetics, tumor microenvironment and future therapeutics in cutaneous malignant melanoma: a review

This review provides an overview of the current understanding of the ontogeny and biology of melanoma stem cells in cutaneous malignant melanoma. This article also summarizes and evaluates the current knowledge of the underlying epigenetic mechanisms, the regulation of melanoma progress by the tumor microenvironment as well as the therapeutic implications and applications of these novel insights, in the setting of personalized medicine. Unraveling the complex ecosystem of cutaneous malignant melanoma and the interplay between its components, aims to provide novel insights into the establishment of efficient therapeutic strategies.

Mass Spectrometry-Based Proteomic Characterization of Cutaneous Melanoma Ectosomes Reveals the Presence of Cancer-Related Molecules

Cutaneous melanoma (CM) is an aggressive type of skin cancer for which effective biomarkers are still needed. Recently, the protein content of extracellular vesicles (ectosomes and exosomes) became increasingly investigated in terms of its functional role in CM and as a source of novel biomarkers; however, the data concerning the proteome of CM-derived ectosomes is very limited. We used the shotgun nanoLC-MS/MS approach to the profile protein content of ectosomes from primary (WM115, WM793) and metastatic (WM266-4, WM1205Lu) CM cell lines. Additionally, the effect exerted by CM ectosomes on recipient cells was assessed in terms of cell proliferation (Alamar Blue assay) and migratory properties (wound healing assay). All cell lines secreted heterogeneous populations of ectosomes enriched in the common set of proteins. A total of 1507 unique proteins were identified, with many of them involved in cancer cell proliferation, migration, escape from apoptosis, epithelial-mesenchymal transition and angiogenesis. Isolated ectosomes increased proliferation and motility of recipient cells, likely due to the ectosomal transfer of different cancer-promoting molecules. Taken together, these results confirm the significant role of ectosomes in several biological processes leading to CM development and progression, and might be used as a starting point for further studies exploring their diagnostic and prognostic potential.

Comparative Study of Transcriptomics-Based Scoring Metrics for the Epithelial-Hybrid-Mesenchymal Spectrum

The Epithelial-mesenchymal transition (EMT) is a cellular process implicated in embryonic development, wound healing, and pathological conditions such as cancer metastasis and fibrosis. Cancer cells undergoing EMT exhibit enhanced aggressive behavior characterized by drug resistance, tumor-initiation potential, and the ability to evade the immune system. Recent in silico, in vitro, and in vivo evidence indicates that EMT is not an all-or-none process; instead, cells can stably acquire one or more hybrid epithelial/mesenchymal (E/M) phenotypes which often can be more aggressive than purely E or M cell populations. Thus, the EMT status of cancer cells can prove to be a critical estimate of patient prognosis. Recent attempts have employed different transcriptomics signatures to quantify EMT status in cell lines and patient tumors. However, a comprehensive comparison of these methods, including their accuracy in identifying cells in the hybrid E/M phenotype(s), is lacking. Here, we compare three distinct metrics that score EMT on a continuum, based on the transcriptomics signature of individual samples. Our results demonstrate that these methods exhibit good concordance among themselves in quantifying the extent of EMT in a given sample. Moreover, scoring EMT using any of the three methods discerned that cells can undergo varying extents of EMT across tumor types. Separately, our analysis also identified tumor types with maximum variability in terms of EMT and associated an enrichment of hybrid E/M signatures in these samples. Moreover, we also found that the multinomial logistic regression (MLR)-based metric was capable of distinguishing between "pure" individual hybrid E/M vs. mixtures of E and M cells. Our results, thus, suggest that while any of the three methods can indicate a generic trend in the EMT status of a given cell, the MLR method has two additional advantages: (a) it uses a small number of predictors to calculate the EMT score and (b) it can predict from the transcriptomic signature of a population whether it is comprised of "pure" hybrid E/M cells at the single-cell level or is instead an ensemble of E and M cell subpopulations.

Comparative Study of Transcriptomics-Based Scoring Metrics for the Epithelial-Hybrid-Mesenchymal Spectrum

The Epithelial-mesenchymal transition (EMT) is a cellular process implicated in embryonic development, wound healing, and pathological conditions such as cancer metastasis and fibrosis. Cancer cells undergoing EMT exhibit enhanced aggressive behavior characterized by drug resistance, tumor-initiation potential, and the ability to evade the immune system. Recent in silico, in vitro, and in vivo evidence indicates that EMT is not an all-or-none process; instead, cells can stably acquire one or more hybrid epithelial/mesenchymal (E/M) phenotypes which often can be more aggressive than purely E or M cell populations. Thus, the EMT status of cancer cells can prove to be a critical estimate of patient prognosis. Recent attempts have employed different transcriptomics signatures to quantify EMT status in cell lines and patient tumors. However, a comprehensive comparison of these methods, including their accuracy in identifying cells in the hybrid E/M phenotype(s), is lacking. Here, we compare three distinct metrics that score EMT on a continuum, based on the transcriptomics signature of individual samples. Our results demonstrate that these methods exhibit good concordance among themselves in quantifying the extent of EMT in a given sample. Moreover, scoring EMT using any of the three methods discerned that cells can undergo varying extents of EMT across tumor types. Separately, our analysis also identified tumor types with maximum variability in terms of EMT and associated an enrichment of hybrid E/M signatures in these samples. Moreover, we also found that the multinomial logistic regression (MLR)-based metric was capable of distinguishing between "pure" individual hybrid E/M vs. mixtures of E and M cells. Our results, thus, suggest that while any of the three methods can indicate a generic trend in the EMT status of a given cell, the MLR method has two additional advantages: (a) it uses a small number of predictors to calculate the EMT score and (b) it can predict from the transcriptomic signature of a population whether it is comprised of "pure" hybrid E/M cells at the single-cell level or is instead an ensemble of E and M cell subpopulations.

The Effects of MiR-214-3p and Irisin/FNDC5 on the Biological Behavior of Osteosarcoma Cells

Background: Irisin/fibronectin type III domain-containing protein 5 (FNDC5) has important effects on breast cancer and liver cancer, however, its role in osteosarcoma is poorly understood. This study explored the effects of irisin/FNDC5 in osteosarcoma cells, aiming to provide a direction for treating osteosarcoma. Material and Methods: The expression levels of irisin/FNDC5 in serums and tissues of osteosarcoma patients and the expression characteristics of FNDC5 in osteosarcoma cell lines were measured. The effects of irisin, at different concentrations (0, 25, 50, 100, and 200 ng/mL), and FNDC5 on the viability, migration, and invasion of U2OS cells were analyzed. The target gene regulating FNDC5 was predicted, and its effects on irisin/FNDC5 and osteosarcoma cells were further explored. Results: The authors found that irisin/FNDC5 was significantly downregulated in the serums and tissues of osteosarcoma patients, and FNDC5 was also lowly expressed in osteosarcoma cell lines, especially in U2OS cells. Irisin/FNDC5 could not only inhibit the viability of U2OS cell in a concentration- and time-dependent manner but could also suppress cell migration and invasion. Furthermore, miR-214-3p inhibited the expression of irisin/FNDC5, and promoted the migration, invasion, and epithelial/mesenchymal transition (EMT) of U2OS cell through targeting FNDC5. Conclusions: Irisin/FNDC5 could inhibit the viability, migration, invasion, and EMT of osteosarcoma cells, and miR-214-3p could target FNDC5 to release its antitumor effects. Thus, irisin/FNDC5 and miR-214-3p might become a new direction for the treatment of osteosarcoma patients in the future.

Melanoma Metabolism: Cell Survival and Resistance to Therapy

Cutaneous melanoma is one of the most aggressive types of cancer, presenting the highest potential to form metastases, both locally and distally, which are associated with high death rates of melanoma patients. A high somatic mutation burden is characteristic of these tumours, with most common oncogenic mutations occurring in the BRAF, NRAS and NF1 genes. These intrinsic oncogenic pathways contribute to the metabolic switch between glycolysis and oxidative phosphorylation metabolisms of melanoma, facilitating tumour progression and resulting in a high plasticity and adaptability to unfavourable conditions. Moreover, melanoma microenvironment can influence its own metabolism and reprogram several immune cell subset functions, enabling melanoma to evade the immune system. The knowledge of the biology, molecular alterations and microenvironment of melanoma has led to the development of new targeted therapies and the improvement of patient care. In this work, we reviewed the impact of melanoma metabolism in the resistance to BRAF and MEK inhibitors and immunotherapies, emphasizing the requirement to evaluate metabolic alterations upon development of novel therapeutic approaches. Here we summarized the current understanding of the impact of metabolic processes in melanomagenesis, metastasis and microenvironment, as well as the involvement of metabolic pathways in the immune modulation and resistance to targeted and immunocheckpoint therapies.

MiR-214-3p regulates the viability, invasion, migration and EMT of TNBC cells by targeting ST6GAL1

MiR-214-3p is concerned with the outcomes of various tumors, such as liver cancer, bladder cancer, etc. However, the role and target of miR-214-3p in triple negative breast cancer (TNBC) is not fully understood. This study took this as the entry point, with a view to find a potential target for TNBC. The expressions of miR-214-3p in TNBC tissues and cell lines were detected, and the effects of miR-214-3p inhibitor on the viability, migration, invasion and epithelial mesenchymal transition (EMT) of TNBC cells were further analyzed. The potential target of miR-214-3p were predicted and verified, as well as the effects of target silencing on the TNBC cells were also measured. MiR-214-3p was abnormally elevated in both TNBC tissues and cell lines, especially in MDA-MB-468 cells. Low-expression of miR-214-3p restrained the survival, migration, invasion and EMT of TNBC cells. ST6GAL1 was the target gene of miR-214-3p, and its expression level increased with the low-expression of miR-214-3p. ST6GAL1 expression was abnormally reduced in both TNBC tissues and cell lines. The silence of ST6GAL1 promoted the viability, migration, invasion and EMT of TNBC cells, which could be reversed by miR-214-3p inhibitor. The down-regulation of miR-214-3p could suppress the viability, migration, invasion and EMT of TNBC cells though targeting ST6GAL1, which might be a potential target for future treatment of TNBC. Up-regulation of miR-214-3p could promote the EMT of non-TNBC cells.

Zebrafish modeling reveals that SPINT1 regulates the aggressiveness of skin cutaneous melanoma and its crosstalk with tumor immune microenvironment

BACKGROUND

Skin cutaneous melanoma (SKCM) is the most lethal form of skin cancer and while incidence rates are declining for most cancers, they have been steadily rising for SKCM. Serine protease inhibitor, kunitz-type, 1 (SPINT1) is a type II transmembrane serine protease inhibitor that has been shown to be involved in the development of several types of cancer, such as squamous cell carcinoma and colorectal cancer.

METHODS

We used the unique advantages of the zebrafish to model the impact of Spint1a deficiency in early transformation, progression and metastatic invasion of SKCM together with in silico analysis of the occurrence and relevance of SPINT1 genetic alterations of the SKCM TCGA cohort.

RESULTS

We report here a high prevalence of SPINT1 genetic alterations in SKCM patients and their association with altered tumor immune microenvironment and poor patient survival. The zebrafish model reveals that Spint1a deficiency facilitates oncogenic transformation, regulates the tumor immune microenvironment crosstalk, accelerates the onset of SKCM and promotes metastatic invasion. Notably, Spint1a deficiency is required at both cell autonomous and non-autonomous levels to enhance invasiveness of SKCM.

CONCLUSIONS

These results reveal a novel therapeutic target for SKCM.

FAM3B promotes progression of oesophageal carcinoma via regulating the AKT-MDM2-p53 signalling axis and the epithelial-mesenchymal transition

FAM3B has been suggested to play important roles in the progression of many cancers, such as gastric, oral, colon and prostate cancer. However, little is known about the role of FAM3B in human esophageal squamous cell carcinoma (ESCC). In the present study, we found that FAM3B expression was higher in ESCC tissues than in adjacent normal tissues. Using quantitative real-time polymerase chain reaction, we found similar results in cell lines. FAM3B expression was significantly related to T/TNM stage. Importantly, Kaplan-Meier analysis revealed that a high expression level of FAM3B predicted a poor outcome for ESCC patients. Overexpression of FAM3B inhibits ESCC cell death, increases oesophageal tumour growth in xenografted nude mice, and promotes ESCC cell migration and invasion. Further studies confirmed that FAM3B regulates the AKT-MDM2-p53 pathway and two core epithelial-to-mesenchymal transition process markers, Snail and E-cadherin. Our results provide new insights into the role of FAM3B in the progression of ESCC and suggest that FAM3B may be a promising molecular target and diagnostic marker for ESCC.

Claudin-7 downregulation induces metastasis and invasion in colorectal cancer via the promotion of epithelial-mesenchymal transition

The dysregulation of the tight junctions (TJs) protein claudin-7 is closely related to the development and metastasis of colorectal cancer (CRC). The aim of this study was to investigate the expression of claudin-7 and characterize the relationship between claudin-7 expression and epithelial-mesenchymal transition (EMT) in CRC. In this study, the expression of claudin-7, E-cadherin, vimentin and snail-1 was detected by immunohistochemistry (IHC) in a set of 80 CRC specimens comprising 20 specimens each of well-differentiated, moderately differentiated, poorly differentiated and liver metastases tissues. The correlation between claudin-7 and EMT-related proteins in the stably transfected claudin-7 knockdown HCT116 cell line was analyzed by IHC, immunofluorescence (IF), Western blotting (WB) and nude mouse xenograft models. The results revealed that the expression of claudin-7 was downregulated as CRC tissue differentiation grade decreased, and that low claudin-7 expression corresponded to the downregulation of E-cadherin (r = 0.725, p < 0.001) and upregulation of vimentin (r = -0.376, p = 0.001) and snail-1 (r = -0.599, p < 0.001). Additionally, in the claudin-7 knockdown HCT116 cell line, the staining intensity and expression of E-cadherin was decreased, while the immunoreactivity and expression of vimentin and snail-1 was increased. Futhermore, the result of tumor formation experiment was consistent with CRC tissues. In conclusion, the expression of claudin-7 in CRC is downregulated as differentiation grade decreases. Claudin-7 downregulation may promote the invasion and metastasis of CRC by regulating EMT. Our results provide new perspectives for a potential therapeutic target for CRC.

Resveratrol analogue, trans-4,4'-dihydroxystilbene (DHS), inhibits melanoma tumor growth and suppresses its metastatic colonization in lungs

The prevalence of melanoma and the lack of effective therapy for metastatic melanoma warrant extensive and systematic evaluations of small molecules in cellular and pre-clinical models. We investigated, herein, the antitumor and anti-metastatic effects of trans-4,4'-dihydroxystilbene (DHS), a natural product present in bark of Yucca periculosa, using in vitro and in vivo melanoma murine models. DHS showed potent melanoma cytotoxicity, as determined by MTT and clonogenic assay. Further, DHS induced cytotoxicity was mediated through apoptosis, which was assessed by annexin V-FITC/PI, sub-G1 and caspase activation assays. In addition, DHS inhibited cell proliferation by inducing robust cell cycle arrest in G1-phase. Imperatively, these inhibitory effects led to a significant reduction of melanoma tumor in pre-clinical murine model. DHS also inhibited cell migration and invasion of melanoma cells, which were examined using wound healing and Transwell migration/invasion assays. Mechanistically, DHS modulated the expressions of several key metastasis regulating proteins e.g., MMP-2/9, N-cadherin, E-cadherin and survivin. We also showed the anti-metastatic effect of DHS in a melanoma mediated lung metastasis model in vivo. DHS significantly reduced large melanoma nodule formation in the parenchyma of lungs. Therefore, DHS may represent a promising natural drug in the repertoire of treatment against melanoma tumor growth and metastasis.

Upregulated N-cadherin expression is associated with poor prognosis in epithelial-derived solid tumours: A meta-analysis

BACKGROUND

N-cadherin is an important molecular in epithelial-mesenchymal transition (EMT) and has been reported to be associated with aggressive behaviours of tumours. However, prognostic value of N-cadherin in solid malignancies remains controversially.

MATERIALS AND METHODS

The Pubmed/MELINE and EMBASE databases were used for a comprehensive literature searching. Pooled risk ratio (RR) and hazard ratio (HR) with their corresponding 95% confidence intervals (CIs) were employed to quantify the prognostic role.

RESULTS

Involving 36 studies with 5705 patients were performed to investigate relationships between N-cadherin upregulation and clinicopathological features, survival. Results suggested upregulated N-cadherin was associated with lymph node metastasis (RR = 1.16, 95% CI [1.00, 1.35]), higher histological grade (RR = 1.36, 95%CI [1.14, 1.62]), angiolymphatic invasion (RR = 1.19, 95% CI [1.06, 1.34]) and advanced clinical stage (RR = 1.32, 95% CI [1.06, 1.64]), while upregulated N-cadherin was apt to be associated with distant metastasis (RR = 1.43, 95% CI [0.99, 2.05]). Moreover, N-cadherin was correlated with poor prognosis of 3-year survival (HR = 1.78, 95% CI [1.51, 2.10]), 5-year survival (HR = 1.57, 95% CI [1.17, 2.10]) and overall survival (OS) (HR = 1.32, 95% CI [1.20, 1.44]). Subgroup analyses according to cancer types were also conducted for applying these conclusions to some tumours more properly. No publication bias was found except subgroup analysis of distant metastasis (P = .652 for Begg's test and 0.023 for Egger's test).

CONCLUSIONS

Taken together, upregulation of N-cadherin is associated with more aggressive behaviours of epithelial-derived solid malignancies and can be regarded as a predictor of poor survival.

Neural crest and cancer: Divergent travelers on similar paths

Neural crest cells are multipotent progenitors that dynamically interpret diverse microenvironments to migrate significant distances as a loosely associated collective and contribute to many tissues in the developing vertebrate embryo. Uncovering details of neural crest migration has helped to inform a general understanding of collective cell migration, including that which occurs during cancer metastasis. Here, we discuss several commonalities and differences of neural crest and cancer cell migration and behavior. First, we focus on some of the molecular pathways required for the initial specification and potency of neural crest cells and the roles of many of these pathways in cancer progression. We also describe epithelial-to-mesenchymal transition, which plays a critical role in initiating both neural crest migration and cancer metastasis. Finally, we evaluate studies that demonstrate myriad forms of cell-cell and cell-environment communication during neural crest and cancer collective migration to highlight the remarkable similarities in their molecular and cell biological regulation.