Loss of expression of TIMP3 in clear cell renal cell carcinoma

Identification of chemoresistance associated key genes-miRNAs-TFs in docetaxel resistant breast cancer by bioinformatics analysis

The present study aimed to identify the differentially expressed genes (DEGs) and enriched pathways in docetaxel (DTX) resistant breast cancer cell lines by bioinformatics analysis. The microarray dataset GSE28784 was obtained from gene expression omnibus (GEO) database. The differentially expressed genes (DEGs), gene ontology (GO), and Kyoto Encyclopedia of gene and genome (KEGG) pathway analyses were performed with the help of GEO2R and DAVID tools. Furthermore, the protein-protein interaction (PPI) and hub-gene network of DEGs were constructed using STRING and Cytohubba tools. The prognostic values of hub genes were calculated with the help of the Kaplan-Meier plotter database. From the GEO2R analysis, 222 DEGs were identified of which 120 are upregulated and 102 are downregulated genes. In the PPIs network, five up-regulated genes including CCL2, SPARC, CYR61, F3, and MFGE8 were identified as hub genes. It was observed that low expression of six hub genes CXCL8, CYR61, F3, ICAM1, PLAT, and THBD were significantly correlated with poor overall survival of BC patients in survival analysis. miRNA analysis identified that hsa-mir-16-5p, hsa-mir-335-5p, hsa-mir-124-3p, hsa-mir-20a-5p, and hsa-mir-155-5p are the top 5 interactive miRNAs that are commonly interacting with more hub genes with degree score of greater than five. Additionally, drug-gene interaction analysis was performed to identify drugs which are could potentially elevate/lower the expression levels of hub genes. In summary, the gene-miRNAs-TFs network and subsequent correlation of candidate drugs with hub genes may improve individualized diagnosis and help select appropriate combination therapy for DTX-resistant BC in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03971-2.

TIMP3/Wnt axis regulates gliosis of Müller glia

BACKGROUND

Previous studies have confirmed the expression of tissue inhibitor of metalloproteinase-3 (TIMP3) in Müller glia (MG). However, the role of TIMP3 in MG remains unknown.

METHODS

A mouse model of laser-induced retinal damage and gliosis was generated using wild-type C57BL/6 mice. TIMP3 and associated proteins were detected using Western blotting and immunofluorescence microscopy. RNA sequencing (GSE132140) of mouse laser-induced gliosis was utilized for pathway analysis. TIMP3 overexpression was induced in human MG. Human vitreous samples were obtained from patients with proliferative diabetic retinopathy (PDR) and healthy controls for protein analysis.

RESULTS

TIMP3 levels increased in mouse eyes after laser damage. Morphology and spatial location of TIMP3 indicated its presence in MG. TIMP3-overexpressing MG showed increased cellular proliferation, migration, and cell nuclei size, suggesting TIMP3-induced gliosis for retinal repair. Glial fibrillary acidic protein (GFAP) and vimentin levels were elevated in TIMP3-overexpressing MG and laser-damaged mouse retinas. RNA sequencing and Western blotting suggested a role for β-catenin in mediating TIMP3 effects on the retina. Human vitreous samples from patients with PDR showed a positive correlation between TIMP3 and GFAP levels, both of which were elevated in patients with PDR.

CONCLUSIONS

TIMP3 is associated with MG gliosis to enhance the repair ability of damaged retinas and is mediated by the canonical Wnt/β-catenin. Changes in TIMP3 could potentially be used to control gliosis in a range of retinal diseases However, given the multifaceted nature of TIMP3, care must be taken when developing treatments that aim solely to boost the function of TIMP3.

FUNDING

National Cheng Kung University Hospital, Taiwan (NCKUH-10604009 and NCKUH-11202007); the Ministry of Science and Technology (MOST 110-2314-B-006-086-MY3).

Biomarkers in renal cell carcinoma and their targeted therapies: a review

Renal cell carcinoma (RCC) is one of the most life-threatening urinary malignancies displaying poor response to radiotherapy and chemotherapy. Although in the recent past there have been tremendous advancements in using targeted therapies for RCC, despite that it remains the most lethal urogenital cancer with a 5-year survival rate of roughly 76%. Timely diagnosis is still the key to prevent the progression of RCC into metastatic stages as well as to treat it. But due to the lack of definitive and specific diagnostic biomarkers for RCC and its asymptomatic nature in its early stages, it becomes very difficult to diagnose it. Reliable and distinct molecular markers can not only refine the diagnosis but also classifies the tumors into thier sub-types which can escort subsequent management and possible treatment for patients. Potential biomarkers can permit a greater degree of stratification of patients affected by RCC and help tailor novel targeted therapies. The review summarizes the most promising epigenetic [DNA methylation, microRNA (miRNA; miR), and long noncoding RNA (lncRNA)] and protein biomarkers that have been known to be specifically involved in diagnosis, cancer progression, and metastasis of RCC, thereby highlighting their utilization as non-invasive molecular markers in RCC. Also, the rationale and development of novel molecular targeted drugs and immunotherapy drugs [such as tyrosine kinase inhibitors and immune checkpoint inhibitors (ICIs)] as potential RCC therapeutics along with the proposed implication of these biomarkers in predicting response to targeted therapies will be discussed.

Integrated analysis to identify the prognostic and immunotherapeutic roles of coagulation-associated gene signature in clear cell renal cell carcinoma

The coagulation system is closely related to the physiological status and immune response of the body. Recent years, studies focusing on the association between coagulation system abnormalities and tumor progression have been widely reported. In clear cell renal cell carcinoma (ccRCC), poor prognosis often occurs in patients with venous tumor thrombosis and coagulation system abnormalities, and there is a lack of research in related fields. Significant differences in coagulation function were also demonstrated in our clinical sample of patients with high ccRCC stage or grade. Therefore, in this study, we analyzed the biological functions of coagulation-related genes (CRGs) in ccRCC patients using single-cell sequencing and TCGA data to establish the 5-CRGs based diagnostic signature and predictive signature for ccRCC. Univariate and multivariate Cox analyses suggested that prognostic signature could be an independent risk factor. Meanwhile, we applied CRGs for consistent clustering of ccRCC patients, and the two classes showed significant survival and genotype differences. The differences in individualized treatment between the two different subtypes were revealed by pathway enrichment analysis and immune cell infiltration analysis. In summary, we present the first systematic analysis of the significance of CRGs in the diagnosis, prognosis, and individualized treatment of ccRCC patients.

The Repertoire of Tissue Inhibitors of Metalloproteases: Evolution, Regulation of Extracellular Matrix Proteolysis, Engineering and Therapeutic Challenges

Tissue inhibitors of metalloproteases (TIMPs) belong to a fascinating protein family expressed in all Metazoa. They act as regulators of the turnover of the extracellular matrix, and they are consistently involved in essential processes. Herein, we recapitulate the main activities of mammalian TIMPs (TIMP1-4) in the control of extracellular-matrix degradation and pathologies associated with aberrant proteostasis. We delineate the activity of TIMPs in the control of extracellular matrix (ECM) homeostasis and discuss the diversity of TIMPs across metazoans taking into account the emergence of the components of the ECM during evolution. Thus, the TIMP repertoire herein analysed includes the homologues from cnidarians, which are coeval with the origins of ECM components; protostomes (molluscs, arthropods and nematodes); and deuterostomes (echinoderms and vertebrates). Several questions, including the maintenance of the structure despite low sequence similarity and the strategies for TIMP engineering, shed light on the possibility to use recombinant TIMPs integrating unique features and binding selectivity for therapeutic applications in the treatment of inflammatory pathologies.

Spatially Resolved Transcriptomes of Mammalian Kidneys Illustrate the Molecular Complexity and Interactions of Functional Nephron Segments

Available transcriptomes of the mammalian kidney provide limited information on the spatial interplay between different functional nephron structures due to the required dissociation of tissue with traditional transcriptome-based methodologies. A deeper understanding of the complexity of functional nephron structures requires a non-dissociative transcriptomics approach, such as spatial transcriptomics sequencing (ST-seq). We hypothesize that the application of ST-seq in normal mammalian kidneys will give transcriptomic insights within and across species of physiology at the functional structure level and cellular communication at the cell level. Here, we applied ST-seq in six mice and four human kidneys that were histologically absent of any overt pathology. We defined the location of specific nephron structures in the captured ST-seq datasets using three lines of evidence: pathologist's annotation, marker gene expression, and integration with public single-cell and/or single-nucleus RNA-sequencing datasets. We compared the mouse and human cortical kidney regions. In the human ST-seq datasets, we further investigated the cellular communication within glomeruli and regions of proximal tubules–peritubular capillaries by screening for co-expression of ligand–receptor gene pairs. Gene expression signatures of distinct nephron structures and microvascular regions were spatially resolved within the mouse and human ST-seq datasets. We identified 7,370 differentially expressed genes (p_adj < 0.05) distinguishing species, suggesting changes in energy production and metabolism in mouse cortical regions relative to human kidneys. Hundreds of potential ligand–receptor interactions were identified within glomeruli and regions of proximal tubules–peritubular capillaries, including known and novel interactions relevant to kidney physiology. Our application of ST-seq to normal human and murine kidneys confirms current knowledge and localization of transcripts within the kidney. Furthermore, the generated ST-seq datasets provide a valuable resource for the kidney community that can be used to inform future research into this complex organ.

GABPA-activated TGFBR2 transcription inhibits aggressiveness but is epigenetically erased by oncometabolites in renal cell carcinoma

Background

The ETS transcription factor GABPA has long been thought of as an oncogenic factor and recently suggested as a target for cancer therapy due to its critical effect on telomerase activation, but the role of GABPA in clear cell renal cell carcinoma (ccRCC) is unclear. In addition, ccRCC is characterized by metabolic reprograming with aberrant accumulation of L-2-hydroxyglurate (L-2HG), an oncometabolite that has been shown to promote ccRCC development and progression by inducing DNA methylation, however, its downstream effectors remain poorly defined.

Methods

siRNAs and expression vectors were used to manipulate the expression of GABPA and other factors and to determine cellular/molecular and phenotypic alterations. RNA sequencing and ChIP assays were performed to identify GABPA target genes. A human ccRCC xenograft model in mice was used to evaluate the effect of GABPA overexpression on in vivo tumorigenesis and metastasis. ccRCC cells were incubated with L-2-HG to analyze GABPA expression and methylation. We carried out immunohistochemistry on patient specimens and TCGA dataset analyses to assess the effect of GABPA on ccRCC survival.

Results

GABPA depletion, although inhibiting telomerase expression, robustly enhanced proliferation, invasion and stemness of ccRCC cells, whereas GABPA overexpression exhibited opposite effects, strongly inhibiting in vivo metastasis and carcinogenesis. TGFBR2 was identified as the GABPA target gene through which GABPA governed the TGFβ signaling to dictate ccRCC phenotypes. GABPA and TGFBR2 phenocopies each other in ccRCC cells. Higher GABPA or TGFBR2 expression predicted longer survival in patients with ccRCC. Incubation of ccRCC cells with L-2-HG mimics GABPA-knockdown-mediated phenotypic alterations. L-2-HG silenced the expression of GABPA in ccRCC cells by increasing its methylation.

Conclusions

GABPA acts as a tumor suppressor by stimulating TGFBR2 expression and TGFβ signaling, while L-2-HG epigenetically inhibits GABPA expression, disrupting the GABPA-TGFβ loop to drive ccRCC aggressiveness. These results exemplify how oncometabolites erase tumor suppressive function for cancer development/progression. Restoring GABPA expression using DNA methylation inhibitors or other approaches, rather than targeting it, may be a novel strategy for ccRCC therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02382-6.

FKBP51 promotes invasion and migration by increasing the autophagic degradation of TIMP3 in clear cell renal cell carcinoma

The occurrence of metastasis is a serious risk for renal cell carcinoma (RCC) patients. In order to develop novel therapeutic approaches to control the progression of metastatic RCC, it is of urgent need to understand the molecular mechanisms underlying RCC metastasis and identify prognostic markers of metastatic risk. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been known to be closely associated with extracellular matrix (ECM) turnover, which plays a highly active role in tumor metastasis. Recent studies have shown that immunophilin FK-506-binding protein 51 (FKBP51) may be important for the regulation of ECM function, and exert effects on the invasion and migration of tumor cells. However, the mechanisms underlying these activities remain unclear. The present study detected the role of FKBP51 in clear cell renal cell carcinoma (ccRCC), the most common subtype of RCC, and found that FKBP51 significantly promotes ccRCC invasion and migration by binding with the TIMP3, connecting TIMP3 with Beclin1 complex and increasing autophagic degradation of TIMP3. Given the important roles that TIMPs/MMPs play in ECM regulation and remodeling, our findings will provide new perspective for future investigation of the regulation of metastasis of kidney cancer and other types of cancer.

Assessment of prognostic value of tissue inhibitors of metalloproteinase 3 (TIMP3) protein in ovarian cancer

Background: TIMP3 is a multifunctional proteolytic enzyme belonging to TIMPs family and acts as a potent inhibitor of matrix metalloproteinases (MMPs). TIMP3 possesses a tumor suppresive function by directly promoting tumor cell apoptosis, preventing angiogenesis and extracellular matrix remodelling. The lower expression of TIMP3 was associated with poor prognosis and overall survival in various cancer types. The aim of this study was to evaluate the association of TIMP3 protein expression with ovarian cancer (OC) clinicopathological features and survival outcomes.Patients and Methods: One hundred forty four of OC FFPE samples were collected from King Abdulaziz University Hospital, Saudi Arabia and constructed in tissue microarray (TMA) slides. Automated Ventana immunostainer platform was used to evaluate TIMP3 protein expression patterns.Results: The study showed that TIMP3 exhibits cytoplasmic localisation. This TIMP3 protein expression was not associated with age, tumor size and the involvement of lymph nodes (p > 0.05). However, it was significantly correlated with tumor stage (p < 0.05) and borderline significant with endpoint status (p = 0.07). Interestingly, the Kaplan-Meier analysis of disease specific survival (DSS) outcomes showed a significant association (p = 0.02, log rank) between OC patients with higher TIMP3 expression compared to those with lower expression. In fact, OC patients with high TIMP3 expression had longer survivals. Multivariate Cox’s regression analysis suggests that low TIMP3 protein expression pattern is an independent poor survival marker (p = 0.025).Conclusion: Cytoplasmic TIMP3 protein expression could be used as a good prognosticator to stratify poorly prognostic OC patients in order to personlaize their disease management.

Salivary DNA Methylation as an Epigenetic Biomarker for Head and Neck Cancer. Part II: A Cancer Risk Meta-Analysis

Aberrant methylation of tumor suppressor genes has been reported as an important epigenetic silencer in head and neck cancer (HNC) pathogenesis. Here, we performed a comprehensive meta-analysis to evaluate the overall and specific impact of salivary gene promoter methylation on HNC risk. The methodological quality was assessed using the Newcastle–Ottawa scale (NOS). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association and Egger’s and Begg’s tests were applied to detect publication bias. The frequency of salivary DNA promoter methylation was significantly higher in HNC patients than in healthy controls (OR: 8.34 (95% CI = 6.10–11.39; p < 0.01). The pooled ORs showed a significant association between specific tumor-related genes and HNC risk: p16 (3.75; 95% CI = 2.51–5.60), MGMT (5.72; 95% CI = 3.00–10.91), DAPK (5.34; 95% CI = 2.18–13.10), TIMP3 (3.42; 95% CI = 1.99–5.88), and RASSF1A (7.69; 95% CI = 3.88–15.23). Overall, our meta-analysis provides precise evidence on the association between salivary DNA promoter hypermethylation and HNC risk. Thus, detection of promoter DNA methylation in saliva is a potential biomarker for predicting HNC risk.

miR‑122‑5p suppresses the oncogenesis of PTC by inhibiting DUSP4 expression

MicroRNAs (miRNAs or miRs) play an important role in regulating the occurrence and development of papillary thyroid carcinoma (PTC). miR‑122‑5p is widely considered a tumour inhibitor, which has not been fully explored in PTC. Bioinformatics analysis identified dual specificity phosphatase 4 (DUSP4), a tumour promoter gene for PTC, as a downstream target of miR‑122‑5p. The aim of the present study was to investigate the role and molecular mechanism of miR‑122‑5p in PTC oncogenesis. In this study, the expression pattern of miR‑122‑5p in PTC cancer tissues and PTC cell lines was investigated via reverse transcription‑quantitative PCR. Furthermore, the roles of miR‑122‑5p in PTC were explored using gain‑of‑function and loss‑of‑function assays. The results revealed that the expression of miR‑122‑5p was significantly lower in PTC cancer tissues, especially in cancer tissues with significant invasion or metastasis. Overexpression of miR‑122‑5p caused by miR‑122‑5p mimics inhibited the proliferation, invasion, and migration of the PTC cell line K1, while knockdown of miR‑122‑5p by miR‑122‑5p inhibitors exhibited the opposite effect. Furthermore, in vivo assays revealed that miR‑122‑5p overexpression inhibited tumour growth. In addition, miR‑122‑5p was negatively correlated with DUSP4 expression in PTC cancer tissues. miR‑122‑5p overexpression inhibited DUSP4 expression in K1 cells, while miR‑122‑5p downregulation produced the inverse effect. Specifically, a luciferase reporter assay confirmed the binding sites of miR‑122‑5p on the 3'‑UTR of DUSP4, demonstrating the targeting effect of miR‑122‑5p on DUSP4. miR‑122‑5p inhibited the oncogenesis of PTC by targeting DUSP4, revealing the potential application value of miR‑122‑5p in the diagnosis and treatment of PTC.

CircCSNK1G3 up-regulates miR-181b to promote growth and metastasis via TIMP3-mediated epithelial to mesenchymal transitions in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common form of kidney cancer, with a high recurrence rate and metastasis capacity. Circular RNAs (circRNAs) have been suggested to act as the critical regulator in several diseases. This study is designed to investigate the role of circCSNK1G3 on RCC progression. We observed a highly expression of circCSNK1G3 in RCC tissues compared with normal tissues. The aberrantly circCSNK1G3 promoted the tumour growth and metastasis in RCC. In the subsequent mechanism investigation, we discovered that the tumour‐promoting effects of circCSNK1G3 were, at least partly, achieved by up‐regulating miR‐181b. Increased miR‐181b inhibits several tumour suppressor gene, including CYLD, LATS2, NDRG2 and TIMP3. Furthermore, the decreased TIMP3 leads to the enhanced epithelial to mesenchymal transition (EMT) process, thus promoting the cancer metastasis. In conclusion, we identified the oncogenic role of circCSNK1G3 in RCC progression and demonstrated the regulatory role of circCSNK1G3 induced miR‐181b expression, which leads to TIMP3‐mediated EMT process, thus resulting in tumour growth and metastasis in RCC. This study reveals the promise of circCSNK1G3 to be developed as a potential diagnostic and prognostic biomarker in the clinic. And the roles of circCSNK1G3 in cancer research deserve further investigation.

The anti-inflammatory protein MCPIP1 inhibits the development of ccRCC by maintaining high levels of tumour suppressors

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. It is highly vascularized and largely resistant to traditional chemo- and radiotherapy. Decreases in tumour suppressors and low levels of the anti-inflammatory Monocyte Chemoattractant Protein-Induced Protein 1 (MCPIP1) play important roles in the development and progression of ccRCC. MCPIP1, also called Regnase-1, possesses endonuclease activity and degrades the mRNA of proinflammatory cytokines such as IL-6, IL-1β, IL-12 and IL-2. We previously showed that the level of MCPIP1 decreases with ccRCC progression. In this study, we explored the role of MCPIP1 in regulating the levels of tumour suppressors. We found low levels of the suppressors PTEN, RECK and TIMP3 and high levels of MMPs in patients with ccRCC who had already been shown to have low MCPIP1 expression. We demonstrated that MCPIP1 regulates the expression levels of PTEN, RECK and TIMP3 in ccRCC cell lines as well as in vivo models of ccRCC. MCPIP1 overexpression increased the expression of tumour suppressors. Moreover, we observed that the RNase activity of MCPIP1 is responsible for the modulation of apoptosis and activation of prometastatic signalling pathways. Furthermore, we found a negative correlation between high levels of IL6, a direct target of MCPIP1 RNase activity, and TIMP3 in patients, indicating that MCPIP1 and TIMP3 might collectively cause the high levels of IL6 in ccRCC patients. Taken together, our results show the importance of MCPIP1 in regulating the level of tumour suppressors and, consequently, in ccRCC development and progression.

CircFNDC3B sequestrates miR-937-5p to derepress TIMP3 and inhibit colorectal cancer progression

Circular RNA (circRNA) are single‐stranded RNA with covalently closed 3′ and 5′ ends, with many recognized to be involved in human diseases as gene regulators, typically by interacting with other RNA. CircFNDC3B is a circRNA formed by back‐splicing of exons 5 and 6 of the FNDC3B gene. CircFNDC3B was recently implicated in renal carcinoma, gastric and bladder cancer. However, the expression levels of circFNDC3B and its role in colorectal cancer (CRC) remain unclear. Expression of circFNDC3B and TIMP3 levels in CRC tissues and cell lines were found to be low, whereas microRNA (miR)‐937‐5p expression was high in CRC. MicroRNA‐937‐5p downregulated TIMP3, thereby promoting tumor cell proliferation, invasion, migration and angiogenesis. Moreover, CircFNDC3B was shown to bind to miR‐937‐5p. CircFNDC3B and circFNDC3B‐enriched exosomes inhibited tumorigenic, metastatic and angiogenic properties of CRC, and miR‐937‐5p overexpression or TIMP3 knockdown could reverse these effects. In vivo CRC tumor growth, angiogenesis and liver metastasis were suppressed by circFNDC3B overexpression, circFNDC3B‐enriched exosomes or miR‐937‐5p knockdown. In conclusion, our work reports a tumor‐suppressing role for the circFNDC3B–miR‐97‐5p–TIMP3 pathway and suggests that circFNDC3B‐enriched exosomes can inhibit angiogenesis and CRC progression.

Timp3 deficiency affects the progression of DEN-related hepatocellular carcinoma during diet-induced obesity in mice

AIM

Obesity and low-grade inflammation are associated with an increased risk of hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The tissue inhibitor of metalloproteinase (TIMP) 3, an endogenous inhibitor of protease activity that represents a key mediator of inflammation, is reduced in inflammatory metabolic disorders and cancer. In contrast, Timp3-deficient mice (Timp3^-/-) are highly resistant to developing HCC in response to a diethylnitrosamine (DEN); therefore, we aimed to elucidate the biological role of genetic loss of Timp3 in obesity-related hepatocarcinogenesis.

METHODS

Fourteen-day-old male wild-type (wt) and Timp3^-/- mice were injected with 25 mg/kg DEN or an equal volume of saline. After 4 weeks, mice were randomized into two dietary groups and fed either normal or high-fat diet and allowed to grow until 32 weeks of age. Liver histological features were analyzed, and differentially expressed genes in the liver were quantified.

RESULTS

In Timp3^-/- mice fed with the obesogenic diet, despite the increase in liver steatosis and inflammation, both the number of tumors and the total tumor size are significantly reduced 30 weeks post-DEN injection, compared to control mice. Moreover, Timp3 deletion in hepatocarcinogenesis during obesity is associated with a reduction in FoxM1 transcriptional activity through H19/miR-675/p53 pathway.

CONCLUSIONS

This study suggests that Timp3 ablation leads to cell cycle perturbation, at least in part by repressing FoxM1 transcriptional activity through H19/miR-675/p53 pathway.

Loss of TIMP3 by promoter methylation of Sp1 binding site promotes oral cancer metastasis

The tissue inhibitor of metalloproteinase-3 (TIMP3) is the only member of the TIMP family that binds to the extracellular matrix and suppresses cancer cell growth, angiogenesis, migration, and invasion. However, whether the abnormal expression and promoter methylation of TIMP3 facilitates oral cancer metastasis remain unclear. In this study, the DNA methylation levels of TIMP3 CpG islands were assessed through pyrosequencing. Artificial modulation of TIMP3 was performed to explore the role of TIMP3 in tumor metastasis in vitro and in vivo. Our results showed that the suppression of TIMP3 transcription by DNA methylation involves the inhibition of the binding of the transcription factor Sp1 to the TIMP3 promoter as well as the upregulation of DNMT1 and DNMT3B. Functional analyses revealed that TIMP3 overexpression reduced migration and invasion abilities in oral cancer cells and inhibited lymph node metastasis in vivo. Moreover, TIMP3 regulated epithelial-mesenchymal transition by increasing the expression of the epithelial markers and reducing the expression of the mesenchymal markers. In conclusion, our findings suggested that the suppression of TIMP3 by DNA methylation contributes to oral cancer metastasis.

TIMP-3 as a therapeutic target for cancer

Tissue inhibitor of metalloproteinase-3 (TIMP-3), a secreted glycoprotein, plays an important role in carcinogenesis. It can bind to many proteinases to suppress their activity and thus protect the extracellular matrix from degradation. TIMP-3 may have many anticancer properties, including apoptosis induction and antiproliferative, antiangiogenic, and antimetastatic activities. This review summarizes the structure, proteinase inhibition ability, genetic and epigenetic regulation, cancer therapy potential, and contribution to cancer development of TIMP-3. Furthermore, in this review we discuss its potential as a biomarker for predicting cancer progression and the current state of drugs that target TIMP-3, either alone or in combination with clinical treatment. In conclusion, TIMP-3 can be a biomarker of cancer and a potential target for cancer therapy. This review article can serve as a basis to understand how to modulate TIMP-3 levels as a drug target of cancers.

RETRACTED: Down-regulation of microRNA-21 reduces inflammation and podocyte apoptosis in diabetic nephropathy by relieving the repression of TIMP3 expression

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concerns were raised about suspected duplicated features between the 'DN' and 'DN+anti-miR-NC' groups within Figure 2I, as detailed here: https://pubpeer.com/publications/FB14889727E5CF2651E012EEA10225#1. A journal investigation confirmed the presence of these suspected duplicated features. The journal asked the authors to provide an explanation to these concerns and the associated raw data. All authors were contacted on several occasions, but the journal did not receive a response. The Editor-in-Chief assessed the case and decided to retract the article.

The Association of BRAF V600E Mutation With Tissue Inhibitor of Metalloproteinase-3 Expression and Clinicopathological Features in Papillary Thyroid Cancer

BACKGROUND

Papillary thyroid cancer (PTC) is the most common endocrine malignancy. The aim of this study was to investigate the association of tissue inhibitor metalloproteinase-3 (TIMP3) mRNA and protein levels in thyroid tissues, based on BRAF V600E status with the clinicopathologic characteristics of PTC.

METHODS

A total of 60 fresh frozen tissue samples of PTC patients (15 male and 45 female) were collected during thyroidectomy. All clinicopathological information was obtained and samples were reviewed as well as confirmed by a pathologist; exon 15 of the BRAF gene was genotyped by sequencing, TIMP3 mRNA level was assessed using SYBR-Green Real-Time PCR, and TIMP3 protein level was measured using ELISA.

RESULTS

Of 60 cases, BRAF mutation was found in 24 (40%). Larger tumor size and higher lymph node metastasis frequency were observed, significant in BRAF (+), compared to the BRAF (-) PTC group (P = 0.039 and P = 0.03, respectively). No significant difference was seen in the tumoral tissues of the TIMP3 mRNA level in BRAF (+), compared to BRAF (-) PTC samples. However, the mean TIMP3 protein level was significantly lower in tumoral tissues, compared to matched non-tumoral tissues in BRAF (+) PTC (P=0.003); TIMP3 protein level was significantly lower in tumoral tissues compared to matched non-tumoral tissues in BRAF (+), in subjects who had no lymph node metastasis and also in subjects with lymph node metastasis in both BRAF positive and negative PTC cases.

CONCLUSION

Our results showed that BRAF mutation was associated with a larger tumor size, higher frequency of lymph node metastasis, and lower TIMP3 protein levels. Lower TIMP3 protein level was associated with the lymph node metastasis in PTC patients.

Effects of cell-cell crosstalk on gene expression patterns in a cell model of renal cell carcinoma lung metastasis

The median survival rate of patients with metastatic renal carcinoma is approximately 10 to 12 months, with up to 50% of patients developing metastases in the lung parenchyma. The molecular basis for metastatic development remains unclear. In the present study, we used renal cell carcinoma (RCC) cells and bronchial epithelial cells, representing metastasis target organ cells, conditioned medium and co-culture models to identify specific gene expression changes responsible for cancer cell viability in a metastatic microenvironment. RCC cell proliferation and migration increased when the culture was supplemented with conditioned medium from lung fibroblasts or pleural epithelial cells. Healthy epithelial cells were, in turn, also stimulated with conditioned medium from RCC cell lines. The mitogen-activated protein kinase (MAPK), interleukin (IL)-6, and phosphatidylinositol 4,5-bisphosphate (PIP2) signaling pathways were identified as deregulated upon cell‑cell interaction. Thus, cell-cell communication may contribute to the development of the metastatic niche. The identified deregulated signaling pathways may be considered as potential therapeutic targets in metastatic renal carcinoma.

Plasma levels of the tissue inhibitor matrix metalloproteinase-3 as a potential biomarker in oral cancer progression

Oral cancer is the most common malignancy with poor prognosis and is the fourth most common cancer in men in Taiwan. The tissue inhibitor of metalloproteinase-3 (TIMP3) acts as a tumor suppressor gene by inhibiting the growth, angiogenesis, migration, and invasion of cancer cells. However, few studies have examined the association of plasma TIMP3 levels with oral squamous cell carcinoma (OSCC), and the role of plasma TIMP3 levels in OSCC progression is still unclear. We measured the plasma TIMP3 levels of 450 OSCC patients and 64 healthy controls by using a commercial enzyme-linked immunosorbent assay. We also analyzed TIMP3 mRNA levels of 328 OSCC patients and 32 normal tissues from The Cancer Genome Atlas (TCGA) dataset. Our results revealed that plasma TIMP3 levels were significantly lower in patients with OSCC than in healthy controls (p < 0.001). Moreover, plasma TIMP3 levels in patients with OSCC were significantly associated with the tumor stage and tumor status but not with the lymph node status, metastasis, and cell differentiation. To verify our findings, we also examined TCGA bioinformatics database and discovered similar results for the association with the pathological stage of OSCC. In conclusion, our results suggest that plasma TIMP3 is a potential biomarker for predicting the tumor stage and T status in patients with OSCC.

The epigenetic landscape of renal cancer

The majority of kidney cancers are associated with mutations in the von Hippel-Lindau gene and a small proportion are associated with infrequent mutations in other well characterized tumour-suppressor genes. In the past 15 years, efforts to uncover other key genes involved in renal cancer have identified many genes that are dysregulated or silenced via epigenetic mechanisms, mainly through methylation of promoter CpG islands or dysregulation of specific microRNAs. In addition, the advent of next-generation sequencing has led to the identification of several novel genes that are mutated in renal cancer, such as PBRM1, BAP1 and SETD2, which are all involved in histone modification and nucleosome and chromatin remodelling. In this Review, we discuss how altered DNA methylation, microRNA dysregulation and mutations in histone-modifying enzymes disrupt cellular pathways in renal cancers.

Tissue inhibitor of metalloproteinase-3 (TIMP3) expression decreases during melanoma progression and inhibits melanoma cell migration

AIMS

Malignant melanoma is the most aggressive form of skin cancer, and metastatic dissemination to regional and visceral sites is responsible for the majority of melanoma-related mortalities. In a recent study by our group, we observed reduced expression of tissue inhibitor of metalloproteinase-3 (TIMP3) in the majority of stage III melanoma samples studied. TIMP3 has been reported as a tumour suppressor in several human malignancies, with reduced expression correlating with poor clinical outcome. In this study, we investigated the changes in TIMP3 expression during melanoma progression.

PATIENTS AND METHODS

TIMP3 expression was analysed by immunohistochemistry in sequential archived tumour material from stage I/II, stage III and stage IV samples from melanoma patients (n = 33). Protein expression was investigated for associations with disease-free survival and overall survival. Methylation status of the gene promoter was determined using methylation-specific PCR. In vitro assays were used to investigate the functional consequences of TIMP3 expression on behavioural aspects of melanoma cells.

RESULTS

We show that TIMP3 expression decreases with melanoma progression although no significant clinical associations were obtained. Analysis of the status of promoter methylation using methylation-specific PCR revealed it to be a low-frequency event in melanoma. Additionally, through gene modulation experiments in melanoma cell lines, we show that TIMP3 negatively regulates cell migration, invasion and anoikis resistance.

CONCLUSIONS

Collectively, our data suggests that TIMP3 functions as a tumour suppressor in melanoma and negatively regulates several aspects of the metastatic cascade.

Lack of Correlation between Aberrant p16, RAR-β2, TIMP3, ERCC1, and BRCA1 Protein Expression and Promoter Methylation in Squamous Cell Carcinoma Accompanying Candida albicans-Induced Inflammation

Hyperplastic candidiasis is characterized by thickening of the mucosal epithelia with Candida albicans infection with occasional progression to squamous cell carcinoma (SCC). C. albicans is a critical factor in tumor development; however, the oncogenic mechanism is unclear. We have previously produced an animal model for hyperplastic candidiasis in the rat forestomach. In the present study, we investigate whether impaired DNA methylation and associated protein expression of tumor suppressor and DNA repair genes are involved in the SCC carcinogenesis process using this hyperplastic candidiasis model. Promoter methylation and protein expression were analyzed by methylation specific PCR and immunohistochemical staining, respectively, of 5 areas in the forestomachs of alloxan-induced diabetic rats with hyperplastic candidiasis: normal squamous epithelia, squamous hyperplasia, squamous hyperplasia adjacent to SCC, squamous hyperplasia transitioning to SCC, and SCC. We observed nuclear p16 overexpression despite increases in p16 gene promoter methylation during the carcinogenic process. TIMP3 and RAR-β2 promoter methylation progressed until the precancerous stage but disappeared upon malignant transformation. In comparison, TIMP3 protein expression was suppressed during carcinogenesis and RAR-β2 expression was attenuated in the cytoplasm but enhanced in nuclei. ERCC1 and BRCA1 promoters were not methylated at any stage; however, their protein expression disappeared beginning at hyperplasia and nuclear protein re-expression in SCC was observed only for ERCC1. These results suggest that aberrant p16, RAR-β2, TIMP3, ERCC1, and BRCA1 expression might occur that is inconsistent with the respective gene promoter methylation status, and that this overexpression might serve to promote the inflammatory carcinogenesis caused by C. albicans infection.

Association of TIMP3 expression with vessel density, macrophage infiltration and prognosis in human malignant melanoma

AIMS

Several anti-tumour properties have been ascribed to the tissue inhibitor of matrix metalloproteinases-3 (TIMP3) gene, including inhibition of neovascularisation in tumour xenografts. Reduced protein expression has been linked to promoter hypermethylation and allelic loss of heterozygosity in various human malignancies. In melanoma-positive lymph nodes from patients, we evaluated the association between TIMP3 expression, vessel density, macrophage infiltration and potential correlations with disease-free survival (DFS) and overall survival (OS).

PATIENTS AND METHODS

TIMP3 expression was analysed by immunohistochemistry (IHC) in melanoma lymph node biopsies of stage III melanoma patients (n = 43). Blood vessel density and macrophage infiltration were quantitatively assessed and correlation with TIMP3 expression was investigated. Methylation status of the gene promoter was determined using methylation-specific polymerase chain reaction (MSP). Protein expression and promoter methylation status were investigated for associations with DFS and OS.

RESULTS

Reduced expression of TIMP3, as determined by IHC, was observed in 74% of the cases (32 in 43). A significant inverse correlation was observed between TIMP3 expression and vessel density (p = 0.031). Correlation between TIMP3 expression and macrophage infiltration was not statistically significant (p = 0.369). MSP analysis revealed methylation of the gene promoter in 18% (7 in 38) of the analysed cases. No differences in OS and DFS were observed between cases with high and low TIMP3 expression. Gene promoter methylation was significantly associated with both poor 5-year DFS (p = 0.024) and OS (p = 0.034).

CONCLUSIONS

Our data indicate that TIMP3 is a dominant negative regulator of angiogenesis in cutaneous melanoma and gene silencing by promoter methylation is associated with poor outcome.

Interleukin-6 as an emerging regulator of renal cell cancer

BACKGROUND

Our knowledge on the molecular basis of kidney cancer metastasisis still relatively low. About 25-30% of patients suffering from clear cell renal cell carcinoma (ccRCC)present metastatic disease at the time of primary diagnosis. Only 10% of patients diagnosed with stage IV disease survive 5 years and 20-50% of patients diagnosed with localized tumor develop metastases within 3 years. High mortality of patients with this cancer is associated with a large potential for metastasis and resistance to oncologic treatments such as chemo- and radiotherapy. Literature data based on studies conducted on other types of cancers suggest that in metastatic ccRCC, the complex of interleukin-6 (IL-6) and its soluble receptor (sIL-6R; complex IL-6/sIL-6R) and the signal transduction pathway (gp130/STAT3) might play a key role in this process.

PURPOSE

Therefore, in this review we focus on the role of IL-6 and its signaling pathways as a factor for development and spread of RCC. Analyzing the molecular basis of cancer spreading will enable the development of prognostic tests, evaluate individual predisposition for metastasis, and produce drugs that target metastases. As the development of effective systemic treatments evolve from advancements in molecular biology, continued studies directed at understanding the genetic and molecular complexities of this disease are critical to improve RCC treatment options.

Role of DNA methylation in renal cell carcinoma

Alterations in DNA methylation are seen in cancers and have also been examined in clear cell renal cell carcinoma (ccRCC). Numerous tumor suppressor genes have been reported to be partially or completely silenced due to hypermethylation of their promoters in single-locus studies, and the use of hypomethylating agents has been shown to restore the expression of many of these genes in vitro. In particular, members of the Wnt and TGF-beta pathways, pro-apoptotic genes such as APAF-1 and negative cell-cycle regulators such as KILLIN have been shown to be epigenetically silenced in numerous studies in ccRCC. Recently, TCGA analysis of a large cohort of ccRCC samples demonstrated that aberrant hypermethylation correlated with the stage and grade in kidney cancer. Our genome-wide studies also revealed aberrant widespread hypermethylation that affected regulatory regions of the kidney genome in ccRCC. We also observed that aberrant enhancer hypermethylation was predictive of adverse prognosis in ccRCC. Recent discovery of mutations affecting epigenetic regulators reinforces the importance of these changes in the pathophysiology of ccRCC and points to the potential of epigenetic modulators in the treatment of this malignancy.

TIMP3 controls cell fate to confer hepatocellular carcinoma resistance

Inflammation enables human cancers and is a critical promoter of hepatocellular carcinoma (HCC). TIMP3 (Tissue inhibitor of metalloproteinase 3), a natural metalloproteinase inhibitor, controls cytokine and growth factor bioavailability to keep inflammation in check and regulate cell survival in the liver. TIMP3 is also found silenced in human cancers. We therefore tested whether Timp3 affects HCC predisposition. Remarkably, genetic loss of Timp3 protected from carcinogen-induced HCC through the immediate engagement of several tumor suppressor pathways, while tumor necrosis factor (TNF) signaling was dispensable for this protection. All wild-type mice developed HCC by 12 months, whereas HCC incidence was reduced to 33% at 12 months and 57% at 15 months in Timp3 null mice. Upon acute carcinogen treatment the deficient livers exhibited greater cytokine expression, but lower cell death and higher hepatocyte senescence. We found that precocious activation of p53, p38 and Notch preceded senescence and hepatic cell differentiation, and these events were conserved throughout tumorigenesis. Timp3-deficient mouse embryo fibroblasts also responded to carcinogen by favoring senescence over apoptosis. We conclude that Timp3 status determines p53, p38 and Notch coactivation to instruct hepatic cell fate and transformation and uncover mechanisms that are protective even within a pro-inflammatory microenvironment.

Tpl2 knockout keratinocytes have increased biomarkers for invasion and metastasis

Skin cancer is the most common form of cancer in the USA, with an estimated two million cases diagnosed annually. Tumor progression locus 2 (Tpl2), also known as MAP3K8, is a serine/threonine protein kinase in the mitogen-activated protein kinase signal transduction cascade. Tpl2 was identified by our laboratory as having a tumor suppressor function in skin carcinogenesis, with the absence of this gene contributing to heightened inflammation and increased skin carcinogenesis. In this study, we used gene expression profiling to compare expression levels between Tpl2 (+/+) and Tpl2 (-) (/-) keratinocytes. We identified over 2000 genes as being differentially expressed between genotypes. Functional annotation analysis identified cancer, cell growth/proliferation, cell death, cell development, cell movement and cell signaling as the top biological processes to be differentially regulated between genotypes. Further microarray analysis identified several candidate genes, including Mmp1b, Mmp2, Mmp9 and Mmp13, involved in migration and invasion to be upregulated in Tpl2 (-) (/-) keratinocytes. Moreover, Tpl2 (-/-) keratinocytes had a significant downregulation in the matrix metalloproteinase (MMP) inhibitor Timp3. Real-time PCR validated the upregulation of the MMPs in Tpl2 (-/-) keratinocytes and zymography confirmed that MMP2 and MMP9 activity was higher in conditioned media from Tpl2 (-/-) keratinocytes. Immunohistochemistry confirmed higher MMP9 staining in 12-O-tetradecanoylphorbol-13-acetate-treated skin from Tpl2 (-/-) mice and grafted tumors formed from v-ras(Ha) retrovirus-infected Tpl2 (-/-) keratinocytes. Additionally, Tpl2 (-/-) keratinocytes had significantly higher invasion, malignant conversion rates and increased endothelial cell tube formation when compared with Tpl2 (+/+) keratinocytes. In summary, our studies reveal that keratinocytes from Tpl2 (-/-) mice demonstrate a higher potential to be invasive and metastatic.

Genomics and epigenomics of clear cell renal cell carcinoma: recent developments and potential applications

Majority of clear cell renal cell carcinomas (ccRCCs) are diagnosed in the advanced metastatic stage resulting in dramatic decrease of patient survival. Thereby, early detection and monitoring of the disease may improve prognosis and treatment results. Recent technological advances enable the identification of genetic events associated with ccRCC and reveal significant molecular heterogeneity of ccRCC tumors. This review summarizes recent findings in ccRCC genomics and epigenomics derived from chromosomal aberrations, DNA sequencing and methylation, mRNA, miRNA expression profiling experiments. We provide a molecular insight into ccRCC pathology and recapitulate possible clinical applications of genomic alterations as predictive and prognostic biomarkers.

Promoter hypermethylation contributes to TIMP3 down-regulation in high stage endometrioid endometrial carcinomas

AIMS

Expression of tissue inhibitor of metalloproteinases-3 (TIMP-3) has been found to be decreased in several types of cancer by promoter gene hypermethylation. However, little is known regarding the silencing effect of TIMP3 promoter hypermethylation on gene and protein expression in endometrial carcinomas and its prognostic significance.

METHODS AND RESULTS

TIMP3 promoter hypermethylation and gene copy number variations were evaluated using a methylation-specific multiplex ligation-dependent probe amplification approach in 60 cases of endometrioid endometrial carcinomas. TIMP3 expression was also evaluated at the transcript and protein levels. Loss of TIMP-3 protein expression was found in 44 (73%) of 60 carcinomas. Promoter hypermethylation was identified in 25% (15 of 60); was more frequent in stages II-IV (55%, six of 11) than in stage I (18%, nine of 49; P = 0.021); and was found more commonly in tumours with deep myometrial invasion. MLH1 and TIMP3 promoters were hypermethylated simultaneously in the same group of tumours (P < 0.001). A correlation between TIMP3 methylation and microsatellite instability (MSI) was found (P = 0.005). TIMP3 copy number changes were frequently a loss (35%), whereas a gain was detected in only 5%.

CONCLUSIONS

TIMP3 promoter hypermethylation was associated with high stage endometrioid endometrial tumours with extrauterine spread. Nevertheless, promoter hypermethylation and loss of heterozygosity are not the only mechanisms for TIMP3 inactivation.

Regulation of Th1/Th2 polarization by tissue inhibitor of metalloproteinase-3 via modulating dendritic cells

Tissue inhibitor of metalloproteinase-3 (TIMP-3) is one of a family of proteins inhibiting matrix metalloproteinases, which has also been identified as a mediator for checking inflammation. Meanwhile, it is well known that inflammation causes the activation of the immune response. However, it is not clear whether TIMP-3 plays a role in the immune system. In the present study, we demonstrated a novel function of TIMP-3 in Th1/Th2 polarization through its influence on the antigen-presenting cells. First, TIMP-3 was found strikingly up-regulated by IL-4 during the differentiation of human dendritic cells via the p38MAPK pathway. Second, the expression of costimulatory molecule-CD86 was repressed by TIMP-3. Besides, the induction of IL-12 in matured dendritic cells was significantly inhibited in a PI3K-dependent manner. Furthermore, dendritic cells matured in the presence of TIMP-3 could stimulate allogeneic naive T helper (Th) cells to display a prominent Th2 polarization. Importantly, in an autoimmune disorder-primary immune thrombocytopenia, TIMP-3 showed a statistically positive correlation with IL-4 and platelet count, but a negative correlation with IFN-γ in patient blood samples. Collectively, these in vitro and in vivo data clearly suggested a novel role of TIMP-3 in Th1/Th2 balance in humans.

Use of the MLPA assay in the molecular diagnosis of gene copy number alterations in human genetic diseases

Multiplex Ligation-dependent Probe Amplification (MLPA) assay is a recently developed technique able to evidence variations in the copy number of several human genes. Due to this ability, MLPA can be used in the molecular diagnosis of several genetic diseases whose pathogenesis is related to the presence of deletions or duplications of specific genes. Moreover, MLPA assay can also be used in the molecular diagnosis of genetic diseases characterized by the presence of abnormal DNA methylation. Due to the large number of genes that can be analyzed by a single technique, MLPA assay represents the gold standard for molecular analysis of all pathologies derived from the presence of gene copy number variation. In this review, the main applications of the MLPA technique for the molecular diagnosis of human diseases are described.

Epigenetic regulation of matrix metalloproteinases and their collagen substrates in cancer

Our review covers the recent epigenetic data that are focused on matrix metalloproteinases (MMPs), their inhibitors (tissue inhibitors of MMPs; TIMPs) and collagen substrates. Twenty-four MMPs, four TIMPs and at least 28 collagen types are known in humans. The MMP activity regulates the functionality of multiple extracellular matrix proteins, cytokines, growth factors and cell signaling and adhesion receptors. Aberrantly enhanced MMP proteolysis affects multiple cell functions, including proliferation, migration and invasion. This aberrant MMP proteolysis is frequently recorded in cancer. Recent evidence, however, indicates that several MMPs function as tumor suppressors in cancer. Their inhibition could have pro-tumorigenic effects (making them anti-targets), counterbalancing the benefits of target inhibition and leading to adverse effects in cancer patients. The current epigenetic data suggest that there are distinct multi-layered epigenetic mechanisms that regulate MMPs, TIMPs and collagens. We show that in certain cancer types, epigenetic signatures of selected MMPs exhibit stem cell-like characteristics. Epigenetic mechanisms appear to play an especially important role in glioblastoma multiforme. Glioblastomas/gliomas synthesize de novo and then deposit collagens into the brain parenchyma. The collagen deposition, combined with an enhanced MMP activity in glioblastomas/gliomas, facilitates rapid invasion of tumor cells through the brain. It is tempting to hypothesize that the epigenetic mechanisms which control MMPs, TIMPs and collagens and, consequently, tumor cell invasion, represent promising drug targets and that in the near future these targets will be challenged pharmacologically.

Genetic and epigenetic control of UNC5C expression in human renal cell carcinoma

Inappropriate gene silencing and subsequent promiscuous activity define the transformation of many solid tumours including renal cell carcinoma (RCC). Here, we report that UNC5C, one of the Netrin-1 receptors, was frequently inactivated in RCC cell lines and primary tumours. UNC5C protein was expressed in the proximal convoluted tubules of the human kidney, the presumed origin of clear cell RCC (ccRCC) and papillary RCC (pRCC). Compared to paired adjacent non-malignant tissues, both UNC5C mRNA and protein expression were significantly down-regulated in RCC. Immunohistochemical analysis showed that UNC5C was inactivated in 94.3% of the samples and the loss of UNC5C occurred at the early stage of RCC. Methylation specific PCR showed that UNC5C promoter was methylated in two renal carcinoma cell lines. Pharmacologic demethylation alone or in combination with inhibition of deacetylation dramatically induced UNC5C expression. Furthermore, bisulfite genomic sequencing (BGS) confirmed that dense methylation existed in UNC5C promoter. In paired tumour samples, UNC5C methylation was observed in 12 out of 44 patients (27.3%). Moreover, we analysed the loss of heterozygosity (LOH) of UNC5C in renal cell carcinoma, the LOH was observed in 27 out of 44 patients (61.4%). Finally, restoration of UNC5C expression suppressed the colony formation of renal carcinoma cells. In addition, UNC5C inhibited tumour cell proliferation, migration and enhanced chemosensitivity to cisplatin and etoposide. Therefore, UNC5C acts as a tumour suppressor in RCC and is down-regulated in RCC. Loss of heterozygosity and DNA methylation contribute to the inactivation of UNC5C in renal cell carcinoma.

TIMP3 regulates migration, invasion and in vivo tumorigenicity of thyroid tumor cells

Papillary thyroid carcinoma (PTC) arises from the thyroid follicular epithelium and represents the most frequent thyroid malignancy. PTC is associated with gene rearrangements generating RET/PTC and TRK oncogenes, and to the BRAFV600E activating point mutation. A role of tumor-suppressor genes in the pathogenesis of PTC has not been assessed yet. The tissue inhibitor of metalloproteinase-3 (TIMP3) gene, encoding a metalloproteinases inhibitor and capable of inhibiting growth, angiogenesis, invasion and metastasis of several cancers, was found to be silenced by promoter methylation in a consistent fraction of PTCs, in association with tumor aggressiveness and BRAFV600E mutation, thus suggesting an oncosuppressor role. To explore this possibility, in this study we performed gene expression and functional studies. Analysis of gene expression data produced in our laboratory as well as meta-analysis of publicly available data sets confirmed the downregulation of TIMP3 gene expression in PTC with respect to normal thyroid. The functional consequences of TIMP3 downregulation were investigated in the PTC-derived NIM1 cell line, in which the expression of TIMP3 is silenced. Restoration of TIMP3 expression by exposure to soluble TIMP3 protein or by complementary DNA transfection had no effect on the growth rate of NIM1 cells. Instead, it affected the adhesive, migratory and invasive capabilities of NIM1 cells by modulating several proteins involved in these processes. A striking effect was observed in vivo, as TIMP3 reduced the tumorigenicity of NIM1 cells by repressing angiogenesis and macrophage infiltration. Our data indicate that the loss of TIMP3 expression exerts a functional role in the pathogenesis of PTC.