Survivin promotion of melanoma metastasis requires upregulation of α5 integrin

Robust aptamer-targeted CRISPR/Cas9 delivery using mesenchymal stem cell membrane -liposome hybrid: BIRC5 gene knockout against melanoma

In this study, a platform was fabricated by combining a cationic lipid, 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP) with mesenchymal stem cell membrane (MSCM) to produce a positively charged hybrid vesicle. The prepared hybrid vesicle was used to condense BIRC5 CRISPR/Cas9 plasmid for survivin (BIRC5) gene editing. The Sgc8-c aptamer (against protein tyrosine kinase 7) was then attached to the surface of the prepared NPs through electrostatic interactions. In this regard, melanoma cancer cells (B16F0 cell line) overexpressing PTK7 receptor could be targeted. Investigations were conducted on this system to evaluate its transfection efficiency, cellular toxicity, and therapeutic performance in preclinical stage using B16F0 tumor bearing C57BL/6 J mice. The results verified the superiority of the Hybrid/ BIRC5 compared to Liposome/ BIRC5 in terms of cellular toxicity and transfection efficiency. The cells exposure to Hybrid/BIRC5 significantly enhanced cytotoxicity. Moreover, Apt-Hybrid/BIRC5 showed higher anti-proliferation activity toward PTK7-positive B16F0 cancer cells than that of the PKT7-negative CHO cell line. The active tumor targeting nanoparticles increased the cytotoxicity through down-regulation of BIRC5 expression as confirmed by Western blot analysis. In preclinical stage, Apt-Hybrid/BIRC5 showed remarkable tumor growth suppression toward B16F0 tumorized mice. Thus, our study suggested that genome editing for BIRC5 through the CRISPR/Cas9 system could provide a potentially safe approach for melanoma cancer therapy and has great potential for clinical translation.

Survivin (BIRC5): Implications in cancer therapy

Inhibitors of Apoptosis proteins (IAPs) were discovered through experiments aimed at rescuing apoptosis in insects. Classically associated with the inhibition of apoptosis, the IAP member Survivin also regulates cell cycle progression and is an essential component of the Chromosomal Passenger Complex (CPC), responsible for chromosomal segregation. Although undetectable in most adult tissues, Survivin is expressed in Adult Stem Cells (ASCs) and plays a crucial role in their maintenance. Survivin is overexpressed in most cancers, contributing to their clonal expansion. As a result, it has been proposed as a possible anticancer target for nearly two decades. In this discussion, we will explore the rationale behind Survivin as a therapeutic target, focusing on common cancer types such as carcinomas, sarcomas, and leukemias. We will delve into the modulation of Survivin by cancer pro-survival cell signaling, the association between SNPs and tumorigenesis, and its regulation by miRNAs. Finally, we will compare cell growth, clonogenic capacity, and apoptosis, along with different strategies for Survivin inhibition, including gene expression and protein activity modulation.

Landscape of enhancer disruption and functional screen in melanoma cells

BACKGROUND

The high mutation rate throughout the entire melanoma genome presents a major challenge in stratifying true driver events from the background mutations. Numerous recurrent non-coding alterations, such as those in enhancers, can shape tumor evolution, thereby emphasizing the importance in systematically deciphering enhancer disruptions in melanoma.

RESULTS

Here, we leveraged 297 melanoma whole-genome sequencing samples to prioritize highly recurrent regions. By performing a genome-scale CRISPR interference (CRISPRi) screen on highly recurrent region-associated enhancers in melanoma cells, we identified 66 significant hits which could have tumor-suppressive roles. These functional enhancers show unique mutational patterns independent of classical significantly mutated genes in melanoma. Target gene analysis for the essential enhancers reveal many known and hidden mechanisms underlying melanoma growth. Utilizing extensive functional validation experiments, we demonstrate that a super enhancer element could modulate melanoma cell proliferation by targeting MEF2A, and another distal enhancer is able to sustain PTEN tumor-suppressive potential via long-range interactions.

CONCLUSIONS

Our study establishes a catalogue of crucial enhancers and their target genes in melanoma growth and progression, and illuminates the identification of novel mechanisms of dysregulation for melanoma driver genes and new therapeutic targeting strategies.

Targeting integrin α5β1 in urological tumors: opportunities and challenges

Urological tumors, such as prostate cancer, renal cell carcinoma, and bladder cancer, have shown a significant rise in prevalence in recent years and account for a significant proportion of malignant tumors. It has been established that metastasis to distant organs caused by urological tumors is the main cause of death, although the mechanisms underlying metastasis have not been fully elucidated. The fibronectin receptor integrin α5β1 reportedly plays an important role in distant metastasis and is closely related to tumor development. It is widely thought to be an important cancer mediator by interacting with different ligands, mediating tumor adhesion, invasion, and migration, and leading to immune escape. In this paper, we expound on the relationship and regulatory mechanisms of integrin α5β1 in these three cancers. In addition, the clinical applications of integrin α5β1 in these cancers, especially against treatment resistance, are discussed. Last but not least, the possibility of integrin α5β1 as a potential target for treatment is examined, with new ideas for future research being proposed.

Cloning, Expression, and Purification of the Human Synthetic Survivin Protein in Escherichia coli Using Response Surface Methodology (RSM)

Survivin is one of the novel members of the apoptosis inhibitor protein family in humans. The main activity of the Survivin protein is to suppress caspases activity resulting in negative regulation of apoptosis. Survivin protein can be a potential target for the treatment of cancers between cancerous and normal cells. In the present research, the synthetic Survivin gene with PelB secretion signal peptide was cloned into a prokaryotic expression vector pET21a. The recombinant plasmid pET21a-PelB-Surv was expressed in Escherichia coli (E.coli) BL21, and the relative molecular mass of expressed protein was calculated 34,000 g/mol, approximately. The recombinant protein was purified through chromatography column and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Response surface methodology (RSM) was used to design 20 experiments for optimization of IPTG concentration, post-induction period, and cell density of induction (OD600). The optimum levels of the selected parameters were successfully determined to be 0.28 mM for IPTG concentration, 10 h for post-induction period, and 3.40768 for cell density (OD600). These findings resulted in 4.14-fold increases in the Survivin production rate of optimum expression conditions (93.6363 mg/ml).

What Inhibits Natural Killers’ Performance in Tumour

Natural killer cells are innate lymphocytes with the ability to lyse tumour cells depending on the balance of their activating and inhibiting receptors. Growing numbers of clinical trials show promising results of NK cell-based immunotherapies. Unlike T cells, NK cells can lyse tumour cells independent of antigen presentation, based simply on their activation and inhibition receptors. Various strategies to improve NK cell-based therapies are being developed, all with one goal: to shift the balance to activation. In this review, we discuss the current understanding of ways NK cells can lyse tumour cells and all the inhibitory signals stopping their cytotoxic potential.

Identification of Core Genes and Pathways in Melanoma Metastasis via Bioinformatics Analysis

Metastasis is the leading cause of melanoma-related mortality. Current therapies are rarely curative for metastatic melanoma, revealing the urgent need to identify more effective preventive and therapeutic targets. This study aimed to screen the core genes and molecular mechanisms related to melanoma metastasis. A gene expression profile, GSE8401, including 31 primary melanoma and 52 metastatic melanoma clinical samples, was downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between melanoma metastases and primary melanoma were screened using GEO2R tool. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) analyses of DEGs were performed using the Database for Annotation Visualization and Integrated Discovery (DAVID). The Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape with Molecular Complex Detection (MCODE) plug-in tools were utilized to detect the protein–protein interaction (PPI) network among DEGs. The top 10 genes with the highest degrees of the PPI network were defined as hub genes. In the results, 425 DEGs, including 60 upregulated genes and 365 downregulated genes, were identified. The upregulated genes were enriched in ECM–receptor interactions and the regulation of actin cytoskeleton, while 365 downregulated genes were enriched in amoebiasis, melanogenesis, and ECM–receptor interactions. The defined hub genes included CDK1, COL17A1, EGFR, DSG1, KRT14, FLG, CDH1, DSP, IVL, and KRT5. In addition, the mRNA and protein levels of the hub genes during melanoma metastasis were verified in the TCGA database and paired post- and premetastatic melanoma cells, respectively. Finally, KRT5-specific siRNAs were utilized to reduce the KRT5 expression in melanoma A375 cells. An MTT assay and a colony formation assay showed that KRT5 knockdown significantly promoted the proliferation of A375 cells. A Transwell assay further suggested that KRT5 knockdown significantly increased the cell migration and cell invasion of A375 cells. This bioinformatics study provided a deeper understanding of the molecular mechanisms of melanoma metastasis. The in vitro experiments showed that KRT5 played the inhibitory effects on melanoma metastasis. Therefore, KRT5 may serve important roles in melanoma metastasis.

Neural Crest-Like Stem Cell Transcriptome Analysis Identifies LPAR1 in Melanoma Progression and Therapy Resistance

Metastatic melanoma is challenging to clinically address. Although standard-of-care targeted therapy has high response rates in patients with BRAF-mutant melanoma, therapy relapse occurs in most cases. Intrinsically resistant melanoma cells drive therapy resistance and display molecular and biologic properties akin to neural crest-like stem cells (NCLSC) including high invasiveness, plasticity, and self-renewal capacity. The shared transcriptional programs and vulnerabilities between NCLSCs and cancer cells remains poorly understood. Here, we identify a developmental LPAR1-axis critical for NCLSC viability and melanoma cell survival. LPAR1 activity increased during progression and following acquisition of therapeutic resistance. Notably, genetic inhibition of LPAR1 potentiated BRAFi ± MEKi efficacy and ablated melanoma migration and invasion. Our data define LPAR1 as a new therapeutic target in melanoma and highlights the promise of dissecting stem cell-like pathways hijacked by tumor cells. SIGNIFICANCE: This study identifies an LPAR1-axis critical for melanoma invasion and intrinsic/acquired therapy resistance.

Prognostic Significance of BIRC5/Survivin in Breast Cancer: Results from Three Independent Cohorts

Simple Summary

Survivin, coded by the BIRC5 gene, is the cell death preventing protein, which is important for cell division in normal and cancer cells. It is intensively studied as a cancer biomarker and target for antitumor therapy. In this study we asked if we could get clinically helpful information on how active BIRC5 is in breast cancer patients? We studied the BIRC5 protein level in tumor samples for breast cancer patients from a West Swedish cohort and its mRNA level in two different public gene expression databases. Survival analysis demonstrated that a higher BIRC5 protein or mRNA level was associated with poor survival in all cohorts and for different cancer subtypes. We show that BIRC5 is a promising independent cancer survival marker.

Abstract

Breast cancer (BC) histological and molecular classifications significantly improved the treatment strategy and prognosis. Inhibitor of apoptosis BIRC5/survivin is often overexpressed in cancers, however, indications of its importance in BC are inconsistent. We integrate BIRC5 protein and mRNA measures with clinical associates and long-term outcome in three independent cohorts Protein levels of BIRC5 were measured in primary lysates of 845 patients of the West Swedish BC cohort (VGR-BC) and linked to 5- and 27-years survival. The results were externally validated in transcriptomic data from METABRIC and SCAN-B cohorts. Survival analysis showed that high levels of BIRC5 were consistently associated with a poor probability of 5-year overall survival. High BIRC5 in VGR-BC contributed negatively to the disease-specific survival at 5 and 27 years. Subsets with different status by ER (estrogen receptor) expression and presence of nodal metastasis supported independent association of high BIRC5 with poor prognosis in all cohorts. In METABRIC and SCAN-B cohorts, high levels of BIRC5 mRNA were associated with the basal-like and luminal B molecular BC subtypes and with increasing histologic grade. BIRC5 is a sensitive survival marker that acts independent of ER and nodal status, and its levels need to be considered when making treatment decisions.

5-aminolevulinic-acid-mediated sonodynamic therapy improves the prognosis of melanoma by inhibiting survivin expression

BACKGROUND

This study aimed to evaluate the relationship between survivin expression and melanoma after 5-aminolevulinic acid (5-ALA)-mediated sonodynamic therapy.

METHODS

Immunohistochemistry was used to detect survivin protein expression in human melanoma clinical samples. Subsequently, the effects of 5-ALA-mediated sonodynamic therapy were determined by measuring the volume of melanoma xenografts and the bodyweights of melanoma-bearing nude mice. The MTT assay was used to detect the viability of melanoma B16-F10 cells under the action of 5-ALA-mediated sonodynamic therapy, and Western blotting and PCR were used to detect survivin expression in melanoma cells and in the melanoma-xenograft model.

RESULTS

Survivin expression was significantly upregulated in human melanoma tissues compared with that of non-melanoma tissues. In the in vivo case, 5-ALA-mediated sonodynamic therapy significantly delayed tumor growth, prolonged the survival of mice, and inhibited the expression of survivin. In the in vitro case, 5-ALA-mediated sonodynamic therapy inhibited B16-F10 cell proliferation and decreased survivin expression at both protein and mRNA levels.

CONCLUSION

Our results suggest that 5-ALA-mediated sonodynamic therapy inhibited B16-F10 cell proliferation and melanoma-xenograft growth and prolonged survival of melanoma-bearing nude mice, which might be through downregulation of survivin expression.

Survivin modulation in the antimelanoma activity of prodiginines

Melanoma is a type of skin cancer with an elevated incidence of metastasis and chemoresistance. Such features hamper treatment success of these neoplasms, demanding the search for new therapeutic options. Using a two-step resin-based approach, we recently demonstrated that cytotoxic prodiginines bind to the inhibitor of apoptosis protein, survivin. Herein, we explore the role of survivin in melanoma and whether its modulation is related to the antimelanoma properties of three cytotoxic prodiginines (prodigiosin, cyclononylprodigiosin, and nonylprodigiosin) isolated from marine bacteria. In melanoma patients and cell lines, survivin is overexpressed, and higher levels negatively impact survival. All three prodiginines caused a decrease in cell growth with reduced cytotoxicity after 24 h compared to 72 h treatment, suggesting that low concentrations promote cytostatic effects in SK-Mel-19 (BRAF mutant) and SK-Mel-28 (BRAF mutant), but not in SK-Mel-147 (NRAS mutant). An increase in G1 population was observed after 24 h treatment with prodigiosin and cyclononylprodigiosin in SK-Mel-19. Further studies indicate that prodigiosin induced apoptosis and DNA damage, as detected by increased caspase-3 cleavage and histone H2AX phosphorylation, further arguing for the downregulation of survivin. Computer simulations suggest that prodigiosin and cyclononylprodigiosin bind to the BIR domain of survivin. Moreover, knockdown of survivin increased long-term toxicity of prodigiosin, as observed by reduced clonogenic capacity, but did not alter short-term cytotoxicity. In summary, prodiginine treatment provoked cytostatic rather than cytotoxic effects, cell cycle arrest at G0/G1 phase, induction of apoptosis and DNA damage, downregulation of survivin, and decreased clonogenic capacity in survivin knockdown cells.

T cell receptor therapy against melanoma-Immunotherapy for the future?

Malignant melanoma has seen monumental changes in treatment options the last decade from the very poor results of dacarbazine treatment to the modern-day use of targeted therapies and immune checkpoint inhibitors. Melanoma has a high mutational burden making it more capable of evoking immune responses than many other tumours. Even when considering double immune checkpoint blockade with anti-CTLA-4 and anti-PD-1, we still have far to go in melanoma treatment as 50% of patients with metastatic disease do not respond to current treatment. Alternative immunotherapy should therefore be considered. Since melanoma has a high mutational burden, it is considered more immunogenic than many other tumours. T cell receptor (TCR) therapy could be a possible way forward, either alone or in combination, to improve the response rates of this deadly disease. Melanoma is one of the cancers where TCR therapy has been frequently applied. However, the number of antigens targeted remains fairly limited, although advanced personalized therapies aim at also targeting private mutations. In this review, we look at possible aspects of targeting TCR therapy towards melanoma and provide an implication of its use in the future.

Kunitz type protease inhibitor from the canine tapeworm as a potential therapeutic for melanoma

Modulating the tumor microenvironment to promote an effective immune response is critical in managing any type of tumor. Melanoma is an aggressive skin cancer and the incidence rate is increasing worldwide. Potent protease inhibitors have recently been extensively researched as potential therapeutic agents against various cancers. EgKI-1 is a potent Kunitz type protease inhibitor identified from the canine tapeworm Echinococcus granulosus that has shown anti-cancer activities in vivo. In this study we show that EgKI-1 significantly reduced the growth of melanoma in the B16-F0 mouse model and was not toxic to normal surrounding tissue. Moreover, EgKI-1 treatment significantly reduced survivin expression levels and increased the CD8+ T cell population in draining axillary lymph nodes. Therefore, EgKI-1 potentially reduces tumor growth by inducing apoptosis and modulating the tumor microenvironment, and has potential for development as an intra-lesional treatment for melanoma.

The miR-195 Axis Regulates Chemoresistance through TUBB and Lung Cancer Progression through BIRC5

Chemoresistance and metastasis are the major reasons for non-small cell lung cancer (NSCLC) treatment failure and patient deaths. We and others have shown that miR-195 regulates the sensitivity of NSCLC to microtubule-targeting agents (MTAs) in vitro and in vivo and that miR-195 represses the migration and invasion of NSCLC cells in vitro. However, the relationship between miR-195 and microtubule structure and function and whether miR-195 represses NSCLC metastasis in vivo remain unknown. We assessed the correlation between tumor levels of TUBB and patient survival, the effect of TUBB on drug response, and the effect of miR-195 on migration, invasion, and metastasis in vitro and in vivo. We found that miR-195 directly targets TUBB; knockdown of TUBB sensitizes cells to MTAs, while overexpression confers resistance; high expression of TUBB is correlated with worse survival of lung adenocarcinoma; TUBB is also regulated by CHEK1, which has been shown to regulate chemoresistance; and miR-195 targets BIRC5 to repress migration and invasion in vitro and metastasis in vivo. Our findings highlight the relevance of the miR-195/TUBB axis in regulating the response of NSCLC to MTAs and the importance of the miR-195/BIRC5 axis in regulating NSCLC metastasis.

Heterotypic CAF-tumor spheroids promote early peritoneal metastatis of ovarian cancer

The study provides insights in HGSOC by identifying that ascitic CAFs selectively recruit ITGA5^high ascitic tumor cells to form heterotypic spheroids named metastatic units (MUs), which actively engage in peritoneal metastasis, discriminates HGSOC from LGSOC, and act as therapeutic targets in hampering OC metastasis.

High-grade serous ovarian cancer (HGSOC) is hallmarked by early onset of peritoneal dissemination, which distinguishes it from low-grade serous ovarian cancer (LGSOC). Here, we describe the aggressive nature of HGSOC ascitic tumor cells (ATCs) characterized by integrin α5^high (ITGA5^high) ATCs, which are prone to forming heterotypic spheroids with fibroblasts. We term these aggregates as metastatic units (MUs) in HGSOC for their advantageous metastatic capacity and active involvement in early peritoneal dissemination. Intriguingly, fibroblasts inside MUs support ATC survival and guide their peritoneal invasion before becoming essential components of the tumor stroma in newly formed metastases. Cancer-associated fibroblasts (CAFs) recruit ITGA5^high ATCs to form MUs, which further sustain ATC ITGA5 expression by EGF secretion. Notably, LGSOC is largely devoid of CAFs and the resultant MUs, which might explain its metastatic delay. These findings identify a specialized MU architecture that amplifies the tumor–stroma interaction and promotes transcoelomic metastasis in HGSOC, providing the basis for stromal fibroblast-oriented interventions in hampering OC peritoneal propagation.

Protein 4.1B Suppresses Tumor Metastasis by Regulating Epithelial-mesenchymal Transition Progression in Melanoma Cells

Epithelial-mesenchymal transition (EMT), which involves the dramatic reorganization of the cytoskeleton, is a crucial initiating step in tumor invasion and metastasis. Protein 4.1B is a membrane-cytoskeleton cross-linker that plays an important role in tumor progression and metastasis; however, the functional roles of 4.1B in melanoma remain unclear. In this study, we aimed to investigate the effect and underlying mechanism of 4.1B on melanoma cells. Our results demonstrated that 4.1B expression was downregulated in murine B16 and B16-F10 melanoma cell lines. Ectopic 4.1B expression significantly inhibited the migration of melanoma cells and pulmonary metastasis. We further investigated the possible mechanism underlying the effect of 4.1B on EMT. The results showed that ectopic 4.1B expression altered the expression of representative EMT markers (E-cadherin, vimentin and N-cadherin), and inhibited the expression of three important transcription factors (Slug, Snail, and Twist) related to EMT in melanoma cells. Moreover, the expression of integrin α5, β3 and matrix metalloproteinase 9 (MMP-9), which is known to regulate cell adhesion, migration and invasion, were suppressed. In conclusion, our data indicate that 4.1B is an important regulator during EMT progression in melanoma cells, which may present a potential target for the prevention and treatment of melanoma.

αvβ3 Integrin Mediates Radioresistance of Prostate Cancer Cells through Regulation of Survivin

The α_vβ₃ integrin is involved in various physiologic and pathologic processes such as wound healing, angiogenesis, tumor growth, and metastasis. The impact of α_vβ₃ integrin on the radiosensitivity of prostate cancer cells and the molecular mechanism controlling cell survival in response to ionizing radiation (IR) was investigated. Both LNCaP cells stably transfected with α_vβ₃ integrin and PC-3 cells that contain endogenous β₃ integrin were used. This study demonstrated that α_vβ₃ integrin increases survival of α_vβ₃-LNCaP cells upon IR while small hairpin RNA (shRNA)-mediated knockdown of α_vβ₃ integrin in PC-3 cells sensitizes to radiation. Expression of α_vβ₃ integrin in LNCaP cells also enhances anchorage-independent cell growth while knockdown of α_vβ₃ integrin in PC-3 cells inhibits anchorage-independent cell growth. The α_vβ₃ antagonist, cRGD, significantly increases radiosensitivity in both α_vβ₃-LNCaP and PC-3 cells. Moreover, α_vβ₃ integrin prevents radiation-induced downregulation of survivin. Inhibition of survivin expression by siRNA or shRNA enhances IR-induced inhibition of anchorage-independent cell growth. Overexpression of wild-type survivin in PC-3 cells treated with α_vβ₃ integrin shRNA increases survival of cells upon IR. These findings reveal that α_vβ₃ integrin promotes radioresistance and regulates survivin levels in response to IR. IMPLICATIONS: Future translational research on targeting α_vβ₃ integrin and survivin may reveal novel approaches as an adjunct to radiotherapy for patients with prostate cancer.

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.

Aspirin Suppresses PGE2 and Activates AMP Kinase to Inhibit Melanoma Cell Motility, Pigmentation, and Selective Tumor Growth In Vivo

There are conflicting epidemiologic data on whether chronic aspirin (ASA) use may reduce melanoma risk in humans. Potential anticancer effects of ASA may be mediated by its ability to suppress prostaglandin E₂ (PGE₂) production and activate 5'-adenosine monophosphate-activated protein kinase (AMPK). We investigated the inhibitory effects of ASA in a panel of melanoma and transformed melanocyte cell lines, and on tumor growth in a preclinical model. ASA and the COX-2 inhibitor celecoxib did not affect melanoma cell viability, but significantly reduced colony formation, cell motility, and pigmentation (melanin production) in vitro at concentrations of 1 mmol/L and 20 μmol/L, respectively. ASA-mediated inhibition of cell migration and pigmentation was rescued by exogenous PGE₂ or Compound C, which inhibits AMPK activation. Levels of tyrosinase, MITF, and p-ERK were unaffected by ASA exposure. Following a single oral dose of 0.4 mg ASA to NOD/SCID mice, salicylate was detected in plasma and skin at 4 hours and PGE₂ levels were reduced up to 24 hours. Some human melanoma tumors xenografted into NOD/SCID mice were sensitive to chronic daily ASA administration, exhibiting reduced growth and proliferation. ASA-treated mice bearing sensitive and resistant tumors exhibited both decreased PGE₂ in plasma and tumors and increased phosphorylated AMPK in tumors. We conclude that ASA inhibits colony formation, cell motility, and pigmentation through suppression of PGE₂ and activation of AMPK and reduces growth of some melanoma tumors in vivo This preclinical model could be used for further tumor and biomarker studies to support future melanoma chemoprevention trials in humans. Cancer Prev Res; 11(10); 629-42. ©2018 AACR.

Efficient isolation of human metapneumovirus using MNT-1, a human malignant melanoma cell line with early and distinct cytopathic effects

Isolation of human metapneumovirus (HMPV) from clinical specimens is currently inefficient because of the lack of a cell culture system in which a distinct cytopathic effect (CPE) occurs. The cell lines LLC-MK2, Vero and Vero E6 are used for isolation of HMPV; however, the CPE in these cell lines is subtle and usually requires a long observation period and sometimes blind passages. Thus, a cell line in which an early and distinct CPE occurs following HMPV inoculation is highly desired by clinical virology laboratories. In this study, it was demonstrated that, in the human malignant melanoma cell line MNT-1, obvious syncytium formation occurs shortly after inoculation with HMPV-positive clinical specimens. In addition, the growth and efficiency of isolation of HMPV were greater using MNT-1 than using any other conventional cell line. Addition of this cell line to our routine viral isolation system for clinical specimens markedly enhanced isolation frequency, allowing isolation-based surveillance. MNT-1 has the potential to facilitate clinical and epidemiological studies of HMPV.

P-REX1 amplification promotes progression of cutaneous melanoma via the PAK1/P38/MMP-2 pathway

P-REX1 (PIP3-dependent Rac exchange factor-1) is a guanine nucleotide exchange factor that activates Rac by catalyzing exchange of GDP for GTP bound to Rac. Aberrant up-regulation of P-REX1 expression has a role in metastasis however, copy number (CN) and function of P-REX1 in cutaneous melanoma are unclear. To explore the role of P-REX1 in melanoma, SNP 6.0 and Exon 1.0 ST microarrays were assessed. There was a higher CN (2.82-fold change) of P-REX1 in melanoma cells than in melanocytes, and P-REX1 expression was significantly correlated with P-REX1 CN. When P-REX1 was knocked down in cells by P-REX1 shRNA, proliferation, colony formation, 3D matrigel growth, and migration/invasiveness were inhibited. Loss of P-REX1 inhibited cell proliferation by inhibiting cyclin D1, blocking cell cycle, and increased cell apoptosis by reducing expression of the protein survivin. Knockdown of P-REX1 expression inhibited cell migration/invasiveness by disrupting P-REX1/RAC1/PAK1/p38/MMP-2 pathway. Assessment of patient tumors and disease outcome demonstrated lower distant metastasis-free survival among AJCC stage I/II/III patients with high P-REX1 expression compared to patients with low P-REX1 expression. These results suggest P-REX1 plays an important role in tumor progression and a potential theranostic target.

The HGF/SF Mouse Model of UV-Induced Melanoma as an In Vivo Sensor for Metastasis-Regulating Gene

Cutaneous malignant melanoma is an aggressive and potentially lethal form of skin cancer, particularly in its advanced and therapy-resistant stages, and the need for novel therapeutics and prognostic tools is acute. Incidence of melanoma has steadily increased over the past few decades, with exposure to the genome-damaging effects of ultraviolet radiation (UVR) well-recognized as a primary cause. A number of genetically-engineered mouse models (GEMMs) have been created that exhibit high incidence of spontaneous and induced forms of melanoma, and a select subset recapitulates its progression to aggressive and metastatic forms. These GEMMs hold considerable promise for providing insights into advanced stages of melanoma, such as potential therapeutic targets and prognostic markers, and as in vivo systems for testing of novel therapies. In this review, we summarize how the HGF/SF transgenic mouse has been used to reveal metastasis-regulating activity of four different genes (CDK4^R24C, survivin and NME1/NME2) in the context of UV-induced melanoma. We also discuss how these models can potentially yield new strategies for clinical management of melanoma in its most aggressive forms.

For robust big data analyses: a collection of 150 important pro-metastatic genes

Metastasis is the greatest contributor to cancer-related death. In the era of precision medicine, it is essential to predict and to prevent the spread of cancer cells to significantly improve patient survival. Thanks to the application of a variety of high-throughput technologies, accumulating big data enables researchers and clinicians to identify aggressive tumors as well as patients with a high risk of cancer metastasis. However, there have been few large-scale gene collection studies to enable metastasis-related analyses. In the last several years, emerging efforts have identified pro-metastatic genes in a variety of cancers, providing us the ability to generate a pro-metastatic gene cluster for big data analyses. We carefully selected 285 genes with in vivo evidence of promoting metastasis reported in the literature. These genes have been investigated in different tumor types. We used two datasets downloaded from The Cancer Genome Atlas database, specifically, datasets of clear cell renal cell carcinoma and hepatocellular carcinoma, for validation tests, and excluded any genes for which elevated expression level correlated with longer overall survival in any of the datasets. Ultimately, 150 pro-metastatic genes remained in our analyses. We believe this collection of pro-metastatic genes will be helpful for big data analyses, and eventually will accelerate anti-metastasis research and clinical intervention.

Melanoma Cell Adhesion and Migration Is Modulated by the Uronyl 2-O Sulfotransferase

Although the vast majority of melanomas are characterized by a high metastatic potential, if detected early, melanoma can have a good prognostic outcome. However, once metastasised, the prognosis is bleak. We showed previously that uronyl-2-O sulfotransferase (Ust) and 2-O sulfation of chondroitin/dermatan sulfate (CS/DS) are involved in cell migration. To demonstrate an impact of 2-O sulfation in metastasis we knocked-down Ust in mouse melanoma cells. This significantly reduced the amount of Ust protein and enzyme activity. Furthermore, in vitro cell motility and adhesion were significantly reduced correlating with the decrease of cellular Ust protein. Single cell migration of B16V^shUst(16) cells showed a decreased cell movement phenotype. The adhesion of B16V cells to fibronectin depended on α5β1 but not αvβ3 integrin. Inhibition of glycosaminoglycan sulfation or blocking fibroblast growth factor receptor (FgfR) reduced α5 integrin in B16V cell lines. Interestingly, FgfR1 expression and activation was reduced in Ust knock-down cells. In vivo, pulmonary metastasis of B16V^shUst cells was prevented due to a reduction of α5 integrin. As a proof of concept UST knock-down in human melanoma cells also showed a reduction in ITGa5 and adhesion. This is the first study showing that Ust, and consequently 2-O sulfation of the low affinity receptor for FgfR CS/DS, reduces Itga5 and leads to an impaired adhesion and migration of melanoma cells.

Survivin: a unique target for tumor therapy

Survivin is the smallest member of the Inhibitor of apoptosis (IAP) family of proteins, involved in inhibition of apoptosis and regulation of cell cycle. These functional attributes make Survivin a unique protein exhibiting divergent functions i.e. regulating cell proliferation and cell death. Expression pattern of Survivin is also distinctive; it is prominently expressed during embryonal development, absent in most normal, terminally differentiated tissues but upregulated in a variety of human cancers. Expression of Survivin in tumours correlates with not only inhibition of apoptosis and a decreased rate of cell death, but also resistance to chemotherapy and aggressiveness of tumours. Therefore, Survivin is an important target for cancer vaccines and therapeutics. Survivin has also been found to be prominently expressed on both human and embryonic stem cells and many somatic stem cell types indicating its yet unexplored role in stem cell generation and maintenance. Overall, Survivin emerges as a molecule with much wider role in cellular homeostasis. This review will discuss various aspects of Survivin biology and its role in regulation of apoptosis, cell division, chemo-resistance and tumour progression. Various molecular and immunotherapeutic approaches targeting Survivin will also be discussed.

miR-214 and miR-148b Targeting Inhibits Dissemination of Melanoma and Breast Cancer

miR-214 and miR-148b have been proposed to antagonize the effects of each other in enabling or blocking metastasis, respectively. In this study, we provide evidence deepening their role and interrelationship in the process of metastatic dissemination. Depleting miR-214 or elevating miR-148b blocked the dissemination of melanoma or breast cancer cells, an effect that could be accentuated by dual alteration. Mechanistic investigations indicated that dual alteration suppressed passage of malignant cells through the blood vessel endothelium by reducing expression of the cell adhesion molecules ITGA5 and ALCAM. Notably, transendothelial migration in vitro and extravasation in vivo impaired by singly alternating miR-214 or miR-148b could be overridden by overexpression of ITGA5 or ALCAM in the same tumor cells. In clinical specimens of primary breast cancer or metastatic melanoma, we found a positive correlation between miR-214 and ITGA5 or ALCAM along with an inverse correlation of miR-214 and miR-148b in the same specimens. Our findings define an antagonistic relationship of miR-214 and miR-148b in determining the dissemination of cancer cells via tumor-endothelial cell interactions, with possible implications for microRNA-mediated therapeutic interventions aimed at blocking cancer extravasation. Cancer Res; 76(17); 5151-62. ©2016 AACR.

Involvement of α5 integrin in survivin-mediated osteosarcoma metastasis

OBJECTIVE

To investigate the role of survivin in osteosarcoma metastasis.

METHODS

Small interfering RNA (siRNA) was used to knockdown the expression of survivin and α5 integrin in the human osteosarcoma cell line MG63. Western blotting and immunostaining methods were used to assessed the effect of survivin knockdown on the expression of α5 integrin through flow cytometry and fluorescence microscopy detection. Meanwhile, the invasion and migration of transfected cells in Transwell and wound healing assays were probed, and the growth situation of these cells transplanted into nude mice was monitored.

RESULTS

Knockdown of survivin expression could inhibit the invasion and migration of osteosarcoma MG64 cells in vitro and the expression of α5 integrin on osteosarcoma MG64 cell surface, suggesting that survivin can inhibit the invasion and migration of osteosarcoma cells through downregulation of α5 integrin. Anti-α5 integrin antibody could also markedly decrease the capability of invasion and migration of osteosarcoma MG64 cells. Additionally, knockdown of survivin expression could slow the growth of osteosarcoma MG63 cells transplanted into nude mice.

CONCLUSIONS

Survivin-directed anti-tumor strategies might be an effective method in the treatment of osteosarcoma.

Inhibition of Vav3 gene can promote apoptosis of human gastric cancer cell line MGC803 by regulating ERK pathway

Previous studies proved that Vav3 gene was overexpressed in cancers. However, the molecular mechanism of Vav3 in apoptosis still keeps unclear; therefore, the relationship between Vav3 gene and apoptosis of gastric cancer (GC) was explored in the present study. Vav3-siRNA was transfected into MGC803 cells, and then cell activity and apoptosis rate were tested with MTT and FCM; apoptosis-related genes and proteins in MAPK signaling pathway were also tested. Results showed that Vav3 was overexpressed in GC than in adjacent normal tissues (all P < 0.05), and expression of Vav3 was related to degree of histological differentiation, cancer invasion depth, and lymphatic metastasis (Χ (2)  = 7.185, P = 0.007; Χ (2)  = 18.654, P < 0.001; Χ (2)  = 5.058, P = 0.025). Vav3 silencing inhibited activity of MGC803 cells, and apoptosis rate of cells was affected. Vav3-siRNA transfection led to changes of apoptosis-related genes such as Survivin, xIAP, Bcl-2, caspase-3, and Bax (all P < 0.01). After transfection, ratio of phosphorylation of ERK significantly reduced. We concluded that Vav3 inhibition can suppress cell activity and promote apoptosis by regulating the apoptosis-related genes through the ERK pathway.

Integrin α5β1 and p53 convergent pathways in the control of anti-apoptotic proteins PEA-15 and survivin in high-grade glioma

Integrin α5β1 expression is correlated with a worse prognosis in high-grade glioma. We previously unraveled a negative crosstalk between integrin α5β1 and p53 pathway, which was proposed to be part of the resistance of glioblastoma to chemotherapies. The restoration of p53 tumor-suppressor function is under intensive investigations for cancer therapy. However, p53-dependent apoptosis is not always achieved by p53-reactivating compounds such as Nutlin-3a, although full transcriptional activity of p53 could be obtained. Here we investigated whether integrin α5β1 functional inhibition or repression could sensitize glioma cells to Nutlin-3a-induced p53-dependent apoptosis. We discovered that α5β1 integrin-specific blocking antibodies or small RGD-like antagonists in association with Nutlin-3a triggered a caspase (Casp) 8/Casp 3-dependent strong apoptosis in glioma cells expressing a functional p53. We deciphered the molecular mechanisms involved and we showed the crucial role of two anti-apoptotic proteins, phosphoprotein enriched in astrocytes 15 (PEA-15) and survivin in glioma cell apoptotic outcome. PEA-15 is under α5β1 integrin/AKT (protein kinase B) control and survivin is a p53-repressed target. Moreover, interconnections between integrin and p53 pathways were revealed. Indeed PEA-15 repression by specific small-interfering RNA (siRNA)-activated p53 pathway to repress survivin and conversely survivin repression by specific siRNA decreased α5β1 integrin expression. This pro-apoptotic loop could be generalized to several glioma cell lines, whatever their p53 status, inasmuch PEA-15 and survivin protein levels were decreased. Our findings identify a novel mechanism whereby inhibition of α5β1 integrin and activation of p53 modulates two anti-apoptotic proteins crucially involved in the apoptotic answer of glioma cells. Importantly, our results suggest that high-grade glioma expressing high level of α5β1 integrin may benefit from associated therapies including integrin antagonists and repressors of survivin expression.

Silencing of ZNF139-siRNA induces apoptosis in human gastric cancer cell line BGC823

BACKGROUND AND PURPOSE

ZNF139, a member of zinc finger protein family, is a transcription factor. Our previous studies have showed that the over-expression of ZNF139 in gastric cancer (GC) cells was related to the differentiation of GC. However, the function of ZNF139 in GC cells' apoptosis is still unclear. In present study, endogenous ZNF139 in GC cell line BGC823 was inhibited with siRNA, and then mechanism of ZNF139 in GC cells' apoptosis was investigated.

METHODS

Expression of ZNF139 in GC tissues, adjacent normal tissues, GC cell lines MKN28, SGC7901, BGC823 and that in gastric epithelial cell line GES-1 were tested. Then ZNF139-specific siRNA was transfected into BGC823 cells. Viability, cell cycle and apoptosis of GC cells were detected. Survivin, x-IAP, caspase-3, Fas, p53, Bcl-2 and Bax genes were detected with QPCR and Western blot.

RESULTS

ZNF139 expression in GC tissues was significantly higher than that in adjacent normal tissues; ZNF139 expression in GES-1 was very weak, but it expressed in various GC cell lines, with the highest expression in BGC823. After endogenous ZNF139 was inhibited with ZNF139-siRNA, FCM indicated that after transfection, GC cells in G0/G1 phase was significantly increased, but was significantly reduced in G2/M phases; also after transfection, the apoptotic rate of BGC823 cells increased significantly. 48 h after ZNF139-siRNA was transfected, the expression of Survivin, x-IAP and Bcl-2 was significantly down-regulated, while the expression of caspase-3 and Bax was significantly up-regulated.

CONCLUSION

Our results suggest that ZNF139 functions to promote apoptosis resistance of BGC823 by regulating some apoptosis related genes.

Survivin - The inconvenient IAP

Although technically a member of the Inhibitor of Apoptosis (IAP) gene family, survivin has consistently defied assumptions, refuted predictions and challenged paradigms. Despite its more than 5500 citations currently in Medline, the biology of survivin has remained fascinatingly complex, its exploitation in human disease, most notably cancer, tantalizing, and its regulation of cellular homeostasis unexpectedly far-reaching. An inconvenient outsider that resists schemes and dogmas, survivin continues to hold great promise to unlock fundamental circuitries of cellular functions in health and disease.

Theranostic properties of a survivin-directed molecular beacon in human melanoma cells

Survivin is an inhibitor of apoptosis overexpressed in different types of tumors and undetectable in most terminally differentiated normal tissues. In the current study, we sought to evaluate the in vitro theranostic properties of a molecular beacon-oligodeoxynucleotide (MB) that targets survivin mRNA. We used laser scanning confocal microscopy to study MB delivery in living cells and real-time PCR and western blot to assess selective survivin-targeting in human malignant melanoma cells. We further assess the pro-apoptotic effect of MB by measuring internucleosomal DNA fragmentation, dissipation of mitochondrial membrane potential (MMP) and changes in nuclear morphology. Transfection of MB into A375 and 501 Mel cells generated high signal intensity from the cytoplasm, while no signal was detected in the extracellular environment and in survivin-negative cells (i.e., human melanocytes and monocytes). MB time dependently decreased survivin mRNA and protein expression in melanoma cells with the maximum effect reached at 72 h. Treatment of melanoma cells with MB induced apoptosis by significant changes in MMP, accumulation of histone-complexed DNA fragments in the cytoplasm and nuclear condensation. MB also enhanced the pro-apoptotic effect of standard chemotherapeutic drugs tested at clinically relevant concentrations. The MB tested in the current study conjugates the ability of imaging with the pharmacological silencing activity against survivin mRNA in human melanoma cells and may represent an innovative approach for cancer diagnosis and treatment.

Bortezomib-based chemotherapy regimens can improve response in newly diagnosed multiple myeloma patients with bcl-2 and survivin overexpression

OBJECTIVE

To investigate the relationship between the Bcl-2 and survivin expression and the different regimens therapeutic efficacy newly diagnosed multiple myeloma (NDMM).

METHODS

We retrospectively assessed the association of Bcl-2 and survivin expression with chemotherapeutic efficacy and prognosis in 59 NDMM patients in a single center.

RESULTS

The positive expression rate for survivin and Bcl-2 was 35% and 74%, respectively. Survivin and Bcl-2 protein expression were not associated with clinical stage, suggesting that they are not related to tumor burden in NDMM. Bortezomib-based regimens were more effective in reducing tumor burden and achieving therapeutic (complete and partial) response compared with non-bortezomib-based regimens irrespective of Bcl-2 or survivin expression (P < 0.05). In cases with both negative Bcl-2 and survivin expression (Bcl-2(-)survivin(-)), the response to bortezomib and non-bortezomib-based regimens was similar (p = 0.429). Bcl-2 and survivin expression were not correlated with overall survival (OS); however, Bcl-2-survivin- cases showed a trend towards a longer OS (P = 0.078).

CONCLUSION

We recommend bortezomib-containing regimens for NDMM with single or double-positive Bcl-2 and survivin expression.

IGF-IR promotes prostate cancer growth by stabilizing α5β1 integrin protein levels

Dynamic crosstalk between growth factor receptors, cell adhesion molecules and extracellular matrix is essential for cancer cell migration and invasion. Integrins are transmembrane receptors that bind extracellular matrix proteins and enable cell adhesion and cytoskeletal organization. They also mediate signal transduction to regulate cell proliferation and survival. The type 1 insulin-like growth factor receptor (IGF-IR) mediates tumor cell growth, adhesion and inhibition of apoptosis in several types of cancer. We have previously demonstrated that β1 integrins regulate anchorage-independent growth of prostate cancer (PrCa) cells by regulating IGF-IR expression and androgen receptor-mediated transcriptional functions. Furthermore, we have recently reported that IGF-IR regulates the expression of β1 integrins in PrCa cells. We have dissected the mechanism through which IGF-IR regulates β1 integrin expression in PrCa. Here we report that IGF-IR is crucial for PrCa cell growth and that β1 integrins contribute to the regulation of proliferation by IGF-IR. We demonstrate that β1 integrin regulation by IGF-IR does not occur at the mRNA level. Exogenous expression of a CD4 - β1 integrin cytoplasmic domain chimera does not interfere with such regulation and fails to stabilize β1 integrin expression in the absence of IGF-IR. This appears to be due to the lack of interaction between the β1 cytoplasmic domain and IGF-IR. We demonstrate that IGF-IR stabilizes the β1 subunit by protecting it from proteasomal degradation. The α5 subunit, one of the binding partners of β1, is also downregulated along with β1 upon IGF-IR knockdown while no change is observed in the expression of the α2, α3, α4, α6 and α7 subunits. Our results reveal a crucial mechanistic role for the α5β1 integrin, downstream of IGF-IR, in regulating cancer growth.