Lentiviral miR30-based RNA interference against heparanase suppresses melanoma metastasis with lower liver and lung toxicity

Hsa-let-7c-5p, hsa-miR-130b-3p, and hsa-miR-142-3p as Novel miRNA Biomarkers for Melanoma Progression

This study aimed to screen miRNA biomarkers for melanoma progression. Raw melanoma data were downloaded from the Gene Expression Omnibus (GSE34460, GSE35579, GSE18509, and GSE24996) and the Cancer Genome Atlas (TCGA). Then, all differentially expressed miRNAs (DEmiRNAs) between benign vs. primary, metastatic vs. benign, and metastatic vs. primary groups were obtained in the GSE34460 and GSE35579 datasets, and the miRNAs related to disease progression were further screened. Then, the miRNA-gene network was constructed, followed by enrichment, survival, and cluster analyses. Differentially expressed genes (DEGs), tumor-infiltrating immune cells, and tumor mutation burden (TMB) between subtypes were analyzed. miRNAs were verified in the GSE18509 and GSE24996 datasets. A total of 132 and 209 DEmiRNAs were obtained in the GSE34460 and GSE35579 datasets, respectively, and 27 DEmiRNAs related to disease progression were screened. hsa-miR-106b-5p, hsa-miR-27b-3p, and hsa-miR-141-3p had a higher degree and were regulated by numerous genes in the miRNA-gene network. Moreover, four miRNAs were associated with prognosis: hsa-let-7c-5p, hsa-miR-130b-3p, hsa-miR-142-3p, and hsa-miR-509-3p. Furthermore, the bidirectional hierarchical clustering of 27 miRNAs was classified into three subtypes, and TMB and four types of immune cells, including activated dendritic cells, naïve CD4 T cells, M1 macrophages, and plasma cells, showed significant differences among the three subtypes. The expression levels of most miRNAs in the GSE18509 and GSE24996 datasets were consistent with those in the training dataset. These miRNAs, including hsa-let-7c-5p, hsa-miR-130b-3p, and hsa-miR-142-3p, and activated dendritic cells, naïve CD4 T cells, M1 macrophages, and plasma cells may play vital roles in the pathogenesis of melanoma.

The Role and Therapeutic Value of Syndecan-1 in Cancer Metastasis and Drug Resistance

Metastasis and relapse are major causes of cancer-related fatalities. The elucidation of relevant pathomechanisms and adoption of appropriate countermeasures are thus crucial for the development of clinical strategies that inhibit malignancy progression as well as metastasis. An integral component of the extracellular matrix, the type 1 transmembrane glycoprotein syndecan-1 (SDC-1) binds cytokines and growth factors involved in tumor microenvironment modulation. Alterations in its localization have been implicated in both cancer metastasis and drug resistance. In this review, available data regarding the structural characteristics, shedding process, and nuclear translocation of SDC-1 are detailed with the aim of highlighting strategies directly targeting SDC-1 as well as SDC-1-mediated carcinogenesis.

MicroRNA-1252-5p Associated with Extracellular Vesicles Enhances Bortezomib Sensitivity in Multiple Myeloma Cells by Targeting Heparanase

INTRODUCTION

Multiple myeloma (MM) remains an incurable disease, and patient survival requires a better understanding of this malignancy's molecular aspects. Heparanase (HPSE) is highly expressed in aggressive MM cells and related to tumor growth, metastasis, and bortezomib (BTZ) resistance. Thus, targeting HPSE seems to be a promising approach for MM treatment, and because microRNAs (miRNAs) have emerged as potential regulators of HPSE expression, the use of extracellular vesicles (EVs) can allow the efficient delivery of therapeutic miRNAs.

METHODS

We used prediction algorithms to identify potential miRNAs that regulate negatively HPSE expression. RT-qPCR was performed to assess miRNAs and HPSE expression in MM lines (U266 and RPMI-8226). Synthetic miRNA mimics were electroporated in MM cells to understand the miRNA contribution in HPSE expression, glycosaminoglycans (GAGs) profile, cell proliferation, and cell death induced by BTZ. EVs derived from HEK293T cells were engineered with miRNAs to evaluate their therapeutic potential combined with BTZ.

RESULTS

It revealed a direct association between BTZ sensitivity, HPSE, and miR-1252-5p expressions. Moreover, overexpression of miR-1252-5p significantly reduced HPSE expression and HPSE enzymatic activity in MM cells. The higher level of miR-1252-5p was correlated with a reduction of cell viability and higher sensitivity to BTZ. Further, EVs carrying miR-1252-5p increased MM cells' sensitivity to BTZ treatment.

CONCLUSION

These results showed that miR-1252-5p could negatively regulate HPSE in MM, indicating the use of EVs carrying miR-1252-5p as a potential novel BTZ sensitization approach in MM cells.

[Heparanase promotes trans-endothelial migration of hepatocarcinoma cells by inducing apoptosis of microvascular endothelial cells]

OBJECTIVE

To explore the effect of heparanase (HPSE) on apoptosis of microvascular endothelial cells (MVECs) and trans-endothelial migration of hepatocellular carcinoma (HCC) cells.

METHODS

A HCC cell line with high HPSE expression was selected by real-time quantitative PCR (qRT-PCR) and Western blotting and transefected with a lentiviral vector containing an interfering RNA sequence of HPSE. Transwell migration assay was performed to detect the trans-endothelial migration (TEM) rate of the transfected HCC cells across human umbilical vein endothelial cells (HUVECs). In a Transwell indirect co-culture system, the effect of HPSE silencing in the HCC cells was determined on apoptosis of HUVECs in vitro. A nude mouse model of HCC was used to verify the effect of HPSE on apoptosis of MVECs and liver metastasis of the tumor.

RESULTS

HCCLM3 cell line highly expressing HPSE was selected for the experiment. Transfection of the HCC cells with the lentiviral vector for HPSE interference the HCC cells resulted in significantly lowered TEM rate as compared with the cells transfected with the control vector (P < 0.01). In the indirect co-culture system, the survival rate of HUVECs co-cultured with HCCLM3 cells with HPSE interference was significantly higher and their apoptotic index was significantly lower than those in the control group (P < 0.05). Ultrastructural observation showed no obvious apoptosis of HUVECs co-cultured with HCCLM3 cells with HPSE interference but revealed obvious apoptotic changes in the control group. In the animal experiment, the tumor formation rate in the liver was 100% (6/6) in the control group, significantly higher than that in RNAi group (33.3%, 2/6) (P < 0.05). Under optical microscope, necrosis and apoptosis of the MVECs was detected in the liver of the control mice, while the endothelial cells remained almost intact in RNAi group.

CONCLUSIONS

HPSE promotes the metastasis of HCC cells by inducing apoptosis of MVECs.

The prognostic significance of heparanase expression in metastatic melanoma

BACKGROUND

Heparanase expression is induced in many types of cancers, including melanoma, and promotes tumor growth, angiogenesis and metastasis. However, there is insufficient data regarding heparanase expression in the metastatic lesions that are the prime target for anti-cancer therapeutics. To that end, we examined heparanase expression in metastatic melanoma and its correlation with clinical parameters.

RESULTS

Heparanase staining was detected in 88% of the samples, and was strong in 46%. For the entire cohort of metastatic melanoma patients, no apparent correlation was found between heparanase staining intensity and survival. However, in a sub group of 46 patients diagnosed as stage IVc melanoma, strong heparanase staining was associated with reduced survival rates [hazard ratio=2.1; 95%CI 1.1-4.1, p=0.025].

MATERIAL AND METHODS

Paraffin sections from 69 metastatic melanomas were subjected to immunohistochemical analysis, applying anti-heparanase antibody. The clinical and pathological data, together with heparanase staining intensity, were evaluated in a logistic regression model for site of metastasis and survival. Slides were also stained for the heparanase-homolog, heparanase-2 (Hpa2).

CONCLUSIONS

Heparanase is highly expressed in metastatic melanoma and predicts poor survival of stage IVc melanoma patients, justifying the development and implementation of heparanase inhibitors as anti-cancer therapeutics.

MicroRNA-Directed Cancer Therapies: Implications in Melanoma Intervention

Acquired tumor resistance to cancer therapies poses major challenges in the treatment of cancers including melanoma. Among several signaling pathways or factors that affect neocarcinogenesis, cancer progression, and therapies, altered microRNAs (miRNAs) expression has been identified as a crucial player in modulating the key pathways governing these events. While studies in the miRNA field have grown exponentially in the last decade, much remains to be discovered, particularly with respect to their roles in cancer therapies. Since immune and nonimmune signaling cascades prevail in cancers, identification and evaluation of miRNAs, their molecular mechanisms and cellular targets involved in the underlying development of cancers, and acquired therapeutic resistance would help in devising new strategies for the prognosis, treatment, and an early detection of recurrence. Importantly, in-depth validation of miRNA-targeted molecular events could lead to the development of accurate progression-risk biomarkers, improved effectiveness, and improved patient responses to standard therapies. The current review focuses on the roles of miRNAs with recent updates on regulated cell cycle and proliferation, immune responses, oncogenic/epigenetic signaling pathways, invasion, metastasis, and apoptosis, with broader attention paid to melanomagenesis and melanoma therapies.

Heparanase Upregulation Contributes to Porcine Reproductive and Respiratory Syndrome Virus Release

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause substantial economic losses to the pig industry worldwide. Heparan sulfate (HS) is used by PRRSV for initial attachment to target cells. However, the role of HS in the late phase of PRRSV infection and the mechanism of virus release from host cells remain largely unknown. In this study, we showed that PRRSV infection caused a decrease in HS expression and upregulated heparanase, the only known enzyme capable of degrading HS. We subsequently demonstrated that the NF-κB signaling pathway and cathepsin L protease were involved in regulation of PRRSV infection-induced heparanase. In addition, we found that ablation of heparanase expression using small interfering RNA duplexes increased cell surface expression of HS and suppressed PRRSV replication and release, whereas overexpression of heparanase reduced HS surface expression and enhanced PRRSV replication and release. These data suggest that PRRSV activates NF-κB and cathepsin L to upregulate and process heparanase, and then the active heparanase cleaves HS, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes great economic losses each year to the pig industry worldwide. The molecular mechanism of PRRSV release from host cells largely remains a mystery. In this study, we demonstrate that PRRSV activates NF-κB and cathepsin L to upregulate and process heparanase, and then the active heparanase is released to the extracellular space and exerts enzymatic activity to cleave heparan sulfate, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.

MicroRNA-30a regulates cell proliferation and tumor growth of colorectal cancer by targeting CD73

Background

MicroRNAs are non-coding RNAs which regulate a variety of cellular functions in the development of tumors. Among the numerous microRNAs, microRNA-30a (miR-30a) is thought to play an important role in the processes of various human tumors. In this study, we aimed to explore the role of miR-30a in the process of colorectal cancer (CRC).

Methods

The quantitative real-time PCR and western blot analysis were used to detect the expressions of miR-30a and CD73 in CRC cell lines and clinical tissues. The luciferase reporter assay was conducted to validate the association between miR-30a and CD73. The CCK-8, terminal deoxynucleotidyl transferase dUTP -biotin nick end labeling (TUNEL) assays and cell cycle flow cytometry were carried out to verify the biological functions of miR-30a in vitro. The nude mouse tumorigenicity experiment was used to clarify the biological role of miR-30a in vivo.

Results

The expression of miR-30a was significantly reduced in tumor cells and tissues of CRC. The proliferation ability of CRC cells was suppressed and the apoptosis of cells was promoted when miR-30a is over-regulated, however, the biological effects would be inverse since the miR-30a is down-regulated. CD73 is thought to be a target binding gene of miR-30a because miR-30a can bind directly to the 3′-UTR of CD73 mRNA, subsequently reducing its expression. The proliferation suppression of the CRC cells mediated by miR-30a could be rescued after up-regulating the expression of CD73.

Conclusions

MiR-30a plays an important role on regulating the cell proliferation and apoptosis, thus affecting the growth of the tumor in CRC. And it may participate in the disease process of CRC by regulating the expression of CD73.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3291-8) contains supplementary material, which is available to authorized users.

Mechanisms of heparanase inhibitors in cancer therapy

Heparanase is an endo-β-D-glucuronidase capable of cleaving heparan sulfate side chains contributing to breakdown of the extracellular matrix. Increased expression of heparanase has been observed in numerous malignancies and is associated with a poor prognosis. It has generated significant interest as a potential antineoplastic target because of the multiple roles it plays in tumor growth and metastasis. The protumorigenic effects of heparanase are enhanced by the release of heparan sulfate side chains, with subsequent increase in bioactive fragments and cytokine levels that promote tumor invasion, angiogenesis, and metastasis. Preclinical experiments have found heparanase inhibitors to substantially reduce tumor growth and metastasis, leading to clinical trials with heparan sulfate mimetics. In this review, we examine the role of heparanase in tumor biology and its interaction with heparan surface proteoglycans, specifically syndecan-1, as well as the mechanism of action for heparanase inhibitors developed as antineoplastic therapeutics.

Serpine2, a potential novel target for combating melanoma metastasis

Early stages of melanoma can be treated by surgical resection of tumor, but there is still no effective treatment once it is progressed to metastatic phases. Although growing family of both metastasis promoting and metastasis suppressor genes have been reported, the molecular mechanisms governing melanoma metastatic cascade are still not completely understood. Therefore, defining the molecules that govern melanoma metastasis may aid the development of more effective therapeutic strategies for combating cancer. In the present study, we found that Serpin Peptidase Inhibitor 2, Serpine2 was involved in the metastasis of melanoma cells. The requirement of Serpine2 in the migration of melanoma cells was confirmed by gene silencing and over-expression in vitro. Moreover, down-regulation of Serpine2 expression strikingly inhibited melanoma cellular metastasis in vivo. Finally, we found that Serpine2 promotes melanoma metastasis through the glycogen synthesis kinase 3β, GSK-3β signaling pathway. To conclude, our findings suggested a novel mechanism underlying the metastasis of melanoma cells which might serve as a new intervention target for the treatment of melanoma.

HBxAg suppresses apoptosis of human placental trophoblastic cell lines via activation of the PI3K/Akt pathway

The aim of this study is to investigate the effect of hepatitis B virus X (HBx) protein on the apoptosis of placental trophoblastic cells and its potential mechanism. A pcDNA3.1 expression vector of HBx gene was built and transfected into JEG-3 and HTR-8 human placental trophoblastic cell lines, respectively. After transfection for 48 h, RT-PCR and immunofluorescence analyses showed that HBx mRNA and protein expression was detected in JEG-3 and HTR-8 cells. Flow cytometry revealed that early apoptosis of JEG-3 and HTR-8 cells was reduced by pcDNA-HBx transfection. Immunofluorescence and Western blotting showed that PI3K and p-Akt were significantly upregulated in HTR-8 cells. HBx ectopic expression did not change the viability of JEG-3 and HTR-8 cells when the PI3K/Akt pathway was blocked by its specific inhibitor LY294002. Moreover, the pcDNA-PI3K expression vector and pcDNA-HBx were transfected individually or co-transfected into the cells. The results showed that pcDNA-PI3K/pcDNA-HBx co-transfection promoted the expression of PI3K protein compared with the pcDNA-PI3K transfection group but did not increase the expression of HBx protein compared with pcDNA-HBx transfection group. In conclusion, HBx gene can be transferred into JEG-3 and HTR-8 human placental trophoblastic cell lines and cause inhibition of cell apoptosis. Its effect of apoptosis inhibition is related to the activation of the PI3K/Akt signaling pathway.

Heparanase: a rainbow pharmacological target associated to multiple pathologies including rare diseases

In recent years, heparanase has attracted considerable attention as a promising target for innovative pharmacological applications. Heparanase is a multifaceted protein endowed with enzymatic activity, as an endo-β-D-glucuronidase, and nonenzymatic functions. It is responsible for the cleavage of heparan sulfate side chains of proteoglycans, resulting in structural alterations of the extracellular matrix. Heparanase appears to be involved in major human diseases, from the most studied tumors to chronic inflammation, diabetic nephropathy, bone osteolysis, thrombosis and atherosclerosis, in addition to more recent investigation in various rare diseases. The present review provides an overview on heparanase, its biological role, inhibitors and possible clinical applications, covering the latest findings in these areas.

Synthetic Bax-Anti Bcl2 combination module actuated by super artificial hTERT promoter selectively inhibits malignant phenotypes of bladder cancer

BACKGROUND

The synthetic biology technology which enhances the specificity and efficacy of treatment is a novel try in biomedical therapy during recent years. A high frequency of somatic mutations was shown in the human telomerase reverse transcriptase (hTERT) promoter in bladder cancer, indicating that a mutational hTERT promoter might be a tumor-specific element for bladder cancer therapy. In our study, we aimed to construct a synthetic combination module driven by a super artificial hTERT promoter and to investigate its influence on the malignant phenotypes of bladder cancer.

METHODS

The dual luciferase assay system was used to verify the driven efficiency and tumor-specificity of the artificial hTERT promoter and to confirm the relationship between ETS-1 and the driven efficiency of the artificial hTERT promoter. CCK-8 assay and MTT assay were used to test the effects of the Bax-Anti Bcl2 combination module driven by the artificial hTERT promoter on cell proliferation. Simultaneously, the cell apoptosis was detected by the caspase 3ELISA assay and the flow cytometry analysis after transfection. The results of CCK-8 assay and MTT assay were analyzed by ANOVA. The independent samples t-test was used to analyze other data.

RESULTS

We demonstrated that the artificial hTERT promoter had a higher driven efficiency which might be regulated by transcription factor ETS-1 in bladder cancer cells, compared with wild-type hTERT promoter. Meanwhile, the artificial hTERT promoter showed a strong tumor-specific effect. The cell proliferation inhibition and apoptosis induction were observed in artificial hTERT promoter- Bax-Anti Bcl2 combination module -transfected bladder cancer 5637 and T24 cells, but not in the module -transfected normal human fibroblasts.

CONCLUSION

This module offers us a useful synthetic biology platform to inhibit the malignant phenotypes of bladder cancer in a more specific and effective way.

Synthetic Tet-inducible artificial microRNAs targeting β-catenin or HIF-1α inhibit malignant phenotypes of bladder cancer cells T24 and 5637

Ribonucleic acid interference (RNAi) based on microRNA (miRNA) may provide efficient and safe therapeutic opportunities. However, natural microRNAs can not easily be regulated and usually cause few phenotypic changes. Using the engineering principles of synthetic biology, we provided a novel and standard platform for the generation of tetracycline (Tet)-inducible vectors that express artificial microRNAs in a dosage-dependent manner. The vector generates a Pol II promoter-mediated artificial microRNA which was flanked by ribozyme sequences. In order to prove the utility of this platform, we chose β-catenin and HIF-1α as the functional targets and used the bladder cancer cell lines 5637 and T24 as the test models. We found that the Tet-inducible artificial microRNAs can effectively silence the target genes and their downstream genes, and induce anti-cancer effects in the two bladder cancer cell lines. These devices can inhibit proliferation, induce apoptosis, and suppress migration of the bladder cancer cell lines 5637 and T24. The Tet-inducible synthetic artificial microRNAs may represent a kind of novel therapeutic strategies for treating human bladder cancer.

Synthetic Tet-inducible small hairpin RNAs targeting hTERT or Bcl-2 inhibit malignant phenotypes of bladder cancer T24 and 5637 cells

Small hairpin RNA (shRNA) can inhibit the malignant phenotypes of tumor cell through ribonucleic acid interference (RNAi). However, it is hardly to be regulated and it may induce few phenotypic changes. Here, we build a type of tetracycline (Tet)-inducible vectors which can achieve regulatable expression of shRNA in a time-dependent manner by using synthetic biology approach. In order to prove the effectiveness of this device, we chose hTERT and Bcl-2 as target genes and test the utility of the device on 5637 and T24 cell lines. The experiments show that the Tet-inducible small hairpin RNA can effectively suppress their target genes and generate anti-cancer effects on both 5637 and T24 cell lines. The device we build not only can inhibit proliferation but also can induce apoptosis and suppress migration of the bladder cancer cell lines 5637 and T24. The Tet-inducible small hairpin RNAs may provide a novel strategy for the treatment of human bladder cancer in the future.

Scaffolds for Artificial miRNA Expression in Animal Cells

Artificial miRNAs (amiRNAs) are molecules that have been developed to promote gene silencing in a similar manner to naturally occurring miRNAs. amiRNAs are generally constructed by replacing the mature miRNA sequence in the pre-miRNA stem-loop with a sequence targeting a gene of interest. These molecules offer an interesting alternative to silencing approaches that are based on shRNAs and siRNAs because they present the same efficiency as these options and are less cytotoxic. amiRNAs have mostly been applied to gene knockdown in plants; they have been examined to a lesser extent in animal cells. Therefore, this article reviews the amiRNAs that have been developed for animal cells and focuses on the miRNA scaffolds that can already be applied to construct the artificial counterparts, as well as on the different approaches that have been described to promote amiRNA expression and silencing efficiency. Furthermore, the availability of amiRNA libraries and other tools that can be used to design and construct these molecules is briefly discussed, along with an overview of the therapeutic applications for which amiRNAs have already been evaluated.

Lentiviral vector-mediated doxycycline-inducible USP39 shRNA or cDNA expression in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC), characterized by distinct biological and clinicopathological features, has a poor prognosis due to lack of effective therapeutic targets. Our previous data revealed that high levels of USP39 were selectively present in TNBC samples compared with their normal breast tissue samples and USP39 was also expressed at different levels in cultured TNBC cells and normal breast cells. Yet, the underlying cellular and molecular mechanisms of USP39 remain unclear. In the present study, we describe a doxycycline (DOX)-regulated lentiviral vector system expressing shRNA or cDNA of the USP39 gene in the TNBC cell line MDA-MB-231. USP39 expression was knocked down by the miR-30-based inducible lentiviral short hairpin RNA (shRNA) delivery system or overexpressed by the inducible cDNA system. The inducible shRNA-mediated downregulation of USP39 expression markedly reduced the proliferation and colony-forming ability of MDA-MB-231 cells, while overexpression of USP39 by the inducible system did not promote cancer cell proliferation. The lentiviral vector-mediated Tet-on system demonstrated efficient and inducible knockdown of USP39 or overexpression of USP39 in TNBC cells, facilitating a wide variety of applications for gene knockdown and overexpression experiments in gene functional studies in vitro and in vivo.

Nuclear heparanase-1 activity suppresses melanoma progression via its DNA-binding affinity

Heparanase-1 (HPSE) plays a pivotal role in structural remodeling of the ECM and the glycocalyx, thus conferring protumorigenic, proangiogenic and prometastatic properties to many cancer entities. In addition to its extracellular function, recent studies suggest an intracellular activity of HPSE with a largely unknown significance during tumor progression. Therefore, we investigated the relevance of the dual functions of HPSE to malignant melanoma in vitro, as well as in different mouse melanoma models based on the intradermal or intravenous injection of melanoma cells. Consistent with its extracellular action, an HPSE deficiency led to a reduced shedding of the glycocalyx accompanied by a reduced availability of vascular endothelial growth factor, affecting tumor growth and vascularization. In contrast, we measured an elevated expression of the protumorigenic factors pentraxin-3, tissue factor, TNF-α and most prominently, MMP-9, upon HPSE knockdown. In vivo, an HPSE deficiency was related to increased lymph node metastasis. Since the inhibition of its extracellular function with heparin was unable to block the gene regulatory impact of HPSE, we proposed an intracellular mechanism. Immunostaining revealed a counter-staining of HPSE and NF-κB in the nucleus, suggesting a close relationship between both proteins. This finding was further supported by the discovery of a direct charge-driven molecular interaction between HPSE and DNA by using atomic force microscopy and a co-precipitation approach. Our findings are novel and point towards a dual function for HPSE in malignant melanoma with a protumorigenic extracellular activity and a tumor-suppressive nuclear action. The identification of molecular strategies to shuttle extracellular HPSE into the nuclei of cancer cells could provide new therapeutic options.

Synthetic artificial microRNAs targeting UCA1-MALAT1 or c-Myc inhibit malignant phenotypes of bladder cancer cells T24 and 5637

We provided a platform for constructing artificial microRNAs that can silence both protein-coding genes and non-coding genes.

MicroRNAs: novel players in cancer diagnosis and therapies

First discovered in 1993, microRNAs (miRNAs) have been one of the hottest research areas over the past two decades. Oftentimes, miRNAs levels are found to be dysregulated in cancer patients. The potential use of miRNAs in cancer therapies is an emerging and promising field, with research finding miRNAs to play a role in cancer initiation, tumor growth, and metastasis. Therefore, miRNAs could become an integral part from cancer diagnosis to treatment in future. This review aims to examine current novel research work on the potential roles of miRNAs in cancer therapies, while also discussing several current challenges and needed future research.

Heparan sulfate proteoglycans and heparin regulate melanoma cell functions

BACKGROUND

The solid melanoma tumor consists of transformed melanoma cells, and the associated stromal cells including fibroblasts, endothelial cells, immune cells, as well as, soluble macro- and micro-molecules of the extracellular matrix (ECM) forming the complex network of the tumor microenvironment. Heparan sulfate proteoglycans (HSPGs) are an important component of the melanoma tumor ECM. Importantly, there appears to be both a quantitative and a qualitative shift in the content of HSPGs, in parallel to the nevi-radial growth phase-vertical growth phase melanoma progression. Moreover, these changes in HSPG expression are correlated to modulations of key melanoma cell functions.

SCOPE OF REVIEW

This review will critically discuss the roles of HSPGs/heparin in melanoma development and progression.

MAJOR CONCLUSIONS

We have correlated HSPGs' expression and distribution with melanoma cell signaling and functions as well as angiogenesis.

GENERAL SIGNIFICANCE

The current knowledge of HSPGs/heparin biology in melanoma provides a foundation we can utilize in the ongoing search for new approaches in designing anti-tumor therapy. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.

MicroRNA-dependent targeting of the extracellular matrix as a mechanism of regulating cell behavior

BACKGROUND

MicroRNAs are small noncoding RNAs which regulate gene expression at the posttranscriptional level by inducing mRNA degradation or translational repression. MicroRNA-dependent modulation of the extracellular matrix and its cellular receptors has emerged as a novel mechanism of regulating numerous matrix-dependent processes, including cell proliferation and apoptosis, cell adhesion and migration, cell differentiation and stem cell properties.

SCOPE OF REVIEW

In this review, we will present different mechanisms by which microRNAs and extracellular matrix constituents mutually regulate their expression, and we will demonstrate how these expression changes affect cell behavior. We will also highlight the importance of dysregulated matrix-related microRNA expression for the pathogenesis of inflammatory and malignant disease, and discuss the potential for diagnostic and therapeutic applications.

MAJOR CONCLUSIONS

MicroRNAs and matrix-dependent signal transduction processes form novel regulatory circuits, which profoundly affect cell behavior. As misexpression of microRNAs targeting extracellular matrix constituents is observed in a variety of diseases, a pharmacological intervention with these processes has therapeutic potential, as successfully demonstrated in vitro and in advanced animal models. However, a deeper mechanistic understanding is required to address potential side effects prior to clinical applications in humans.

GENERAL SIGNIFICANCE

A full understanding of the role and function of microRNA-dependent regulation of the extracellular matrix may lead to new targeted therapies and new diagnostics for malignant and inflammatory diseases in humans. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.