Loss of TIMP-3 promotes tumor invasion via elevated IL-6 production and predicts poor survival and relapse in HPV-infected non-small cell lung cancer

The emerging role of human papillomavirus in lung cancer

Lung cancer stands as one of the most lethal diseases and is the foremost cause of cancer-related mortalities worldwide. The pathophysiology of lung cancer is multifaceted, and it includes multiple cell signaling pathways and other complex factors such as oxidative stress and genetics. The association of HPV with lung carcinogenesis was first proposed in 1979, and since then, scientists worldwide have been putting forward several hypotheses to establish a relationship between this virus and lung cancer. Although studies have reported the presence of HPV in lung cancer, the exact mechanism of entry and the route of transmission have not been elucidated clearly till date. Numerous studies across the globe have detected differentially expressed HPV oncoproteins in lung cancer patients and found their association with the critical cell signaling pathways that leads to the development and progression of lung cancer. Many reports have also provided evidence stating the involvement of HPV in determining the survival status of lung cancer patients. The present review recapitulates the studies evincing the association of HPV and lung cancer, its route of transmission and mechanism of action; the detection of the virus and treatment opportunities for HPV-positive lung cancer; and the severity associated with this disease. Therefore, this will provide an explicit idea and would help to develop preventive measures and specific as well as effective treatment for HPV-associated lung carcinogenesis.

Expression of collagenases (matrix metalloproteinase-1, -8, -13) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in naturally occurring bovine cutaneous fibropapillomas

Bovine cutaneous fibropapillomas are among the most common skin tumors in cattle; their etiology is associated with infection by bovine papillomavirus (BPV) types-1/-2 which are considered oncogenic. Degradation of the extracellular matrix (ECM), especially collagenolysis, is a key event during a series of relevant physiological processes, including tissue remodeling and repair. Various types of proteins are implicated in the regulation of ECM degradation: among these, matrix metalloproteinases (MMPs), a group of zinc-dependent endoenzymes, and tissue inhibitors of matrix metalloproteinases (TIMPs) are known to play a major role. Previous studies reported that aberrant expression of collagenolytic MMPs (MMP-1/-8/-13) and unbalancing between MMPs and TIMPs represent a critical step in tumor growth and invasion; however, studies regarding this topic in bovine cutaneous fibropapillomas are lacking. The aim of this study was to investigate the expression of the collagenases MMP-1/-8/-13 and TIMP-3 in naturally occurring fibropapillomas harboring BPV-2 DNA and normal skin samples. Here, by immunohistochemistry and western blotting analysis, we demonstrated overexpression of MMP-8/-13 along with a down-regulation of MMP-1, associated with a decrease in TIMP-3 levels in tumor compared with normal skin samples. This is the first study describing MMP-1/-8/-13 and TIMP-3 expression in bovine cutaneous fibropapillomas and our results suggest that an impaired expression of collagenases along with an imbalance between MMPs/TIMPs may contribute to an increased collagenolytic activity, which in turn could be important in ECM changes and tumors development.

Transcriptomic landscape of TIMP3 oncosuppressor activity in thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid tumor. The tissue inhibitor of metalloproteinase-3 (TIMP3) gene encodes a matrix metalloproteinases inhibitor that exerts a tumor suppressor role in several tumor types. TIMP3 is frequently downregulated in PTC by promoter methylation. We have previously functionally demonstrated that TIMP3 exerts an oncosuppressor role in PTC: TIMP3 restoration in the PTC-derived NIM1 cell line affects in vitro migration, invasion and adhesive capability, while reduces tumor growth, angiogenesis and macrophage recruitment in vivo. To get a deeper insight on the mediators of TIMP3 oncosuppressor activity in thyroid tumors, here we focused on the TIMP3 related transcriptome.

METHODS

TCGA database was used for investigating the genes differentially expressed in PTC samples with low and high TIMP3 expression. Genome wide expression analysis of clones NIM1-T23 (expressing a high level of TIMP3 protein) and NIM1-EV (control empty vector) was performed. Gene sets and functional enrichment analysis with clusterProfiler were applied to identify the modulated biological processes and pathways. CIBERSORT was used to evaluate the distribution of different immunological cell types in TCGA-PTC tumor samples with different TIMP3 expression levels. Real time PCR was performed for the validation of selected genes.

RESULTS

Thyroid tumors with TIMP3-high expression showed a down-modulation of inflammation-related gene sets, along with a reduced protumoral hematopoietic cells fraction; an enrichment of cell adhesion functions was also identified. Similar results were obtained in the TIMP3-overexpessing NIM1 cells in vitro model, where a down-regulation of immune-related function gene sets, some of which also identified in tumor samples, was observed. Interestingly, through enrichment analysis, were also recognized terms related to cell adhesion, extracellular matrix organization, blood vessel maintenance and vascular process functions that have been found modulated in our previous in vitro and in vivo functional studies.

CONCLUSIONS

Our results highlight the correlation of TIMP3 expression levels with the regulation of inflammatory functions and the immune infiltration composition associated with different PTC prognosis, thus providing a broader view on the oncosuppressor role of TIMP3 in PTC.

Human Papillomavirus Is Associated With Adenocarcinoma of Lung: A Population-Based Cohort Study

Background

Recent trends in the incidence of lung cancer have been reported despite the decreasing rate of smoking. Lung cancer is ranked among the top causes of cancer-related deaths. The ratio of adenocarcinoma to squamous cell carcinoma, as well as the ratio of women to men, is still increasing. Human papillomavirus (HPV) has been discovered in lung cancer tissues and blood specimens, particularly in Eastern countries. However, the association between HPV infection and lung adenocarcinoma remains unclear.

Methods

This population-based cohort study was conducted using data from Taiwan's single-payer national health insurance and cancer registry databases. Data on HPV infection, cancer, sex, age, comorbidities, urbanization, and occupation were collected. The cumulative incidence rates were generated using Kaplan–Meier curves and log-rank tests. COX regression analysis was used to estimate the hazard ratios of factors associated with cancer occurrence. We used data from 2007 and 2015. The cases were matched with sex and age in a 1:2 manner with 939,874 HPV+ and 1,879,748 HPV– individuals, respectively.

Results

The adjusted hazard ratios [95% confidence interval (CI)] for HPV infection in all lung cancers were 1.539 (1.436–1.649), male lung cancer 1.434 (1.312–1.566), female lung cancer 1.742 (1.557–1.948), squamous cell carcinoma (SCC) 1.092 (0.903–1.320), male SCC 1.092 (0.903–1.320), female SCC 0.949 (0.773–1.164), adenocarcinoma 1.714 (1.572–1.870), male adenocarcinoma 1.646 (1.458–1.858), and female adenocarcinoma 1.646 (1.458–1.858). The highest adjusted hazard ratio for lung cancer was chronic obstructive pulmonary disease (COPD) 1.799 (1.613–2.007), followed by male sex 1.567 (1.451–6.863) and HPV infection. The highest adjusted hazard ratio for adenocarcinoma was HPV infection 1.714 (1.572–1.870), followed by COPD 1.300 (1.102–1.533), and for SCC, male sex 5.645 (4.43–3.37), followed by COPD 2.528 (2.002–3.192).

Conclusion

Our study showed that HPV infection was associated with the occurrence of adenocarcinoma of the lung in both men and women but was not associated with SCC of the lung.

The Roles of Matrix Metalloproteinases and Their Inhibitors in Human Diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

Epigenetic signatures underlying inflammation: an interplay of nutrition, physical activity, metabolic diseases, and environmental factors for personalized nutrition

Aim and objective

Emerging translational evidence suggests that epigenetic alterations (DNA methylation, miRNA expression, and histone modifications) occur after external stimuli and may contribute to exacerbated inflammation and the risk of suffering several diseases including diabetes, cardiovascular diseases, cancer, and neurological disorders. This review summarizes the current knowledge about the harmful effects of high-fat/high-sugar diets, micronutrient deficiencies (folate, manganese, and carotenoids), obesity and associated complications, bacterial/viral infections, smoking, excessive alcohol consumption, sleep deprivation, chronic stress, air pollution, and chemical exposure on inflammation through epigenetic mechanisms. Additionally, the epigenetic phenomena underlying the anti-inflammatory potential of caloric restriction, n-3 PUFA, Mediterranean diet, vitamin D, zinc, polyphenols (i.e., resveratrol, gallic acid, epicatechin, luteolin, curcumin), and the role of systematic exercise are discussed.

Methods

Original and review articles encompassing epigenetics and inflammation were screened from major databases (including PubMed, Medline, Science Direct, Scopus, etc.) and analyzed for the writing of the review paper.

Conclusion

Although caution should be exercised, research on epigenetic mechanisms is contributing to understand pathological processes involving inflammatory responses, the prediction of disease risk based on the epigenotype, as well as the putative design of therapeutic interventions targeting the epigenome.

Possible Oncogenic Viruses Associated with Lung Cancer

Lung cancer is the most common cause of cancer death worldwide. Tobacco smoking is the most predominant etiology for lung cancer. However, only a small percentage of heavy smokers develop lung cancer, which suggests that other cofactors are required for lung carcinogenesis. Viruses have been central to modern cancer research and provide profound insights into cancer causes. Nevertheless, the role of virus in lung cancer is still unclear. In this article, we reviewed the possible oncogenic viruses associated with lung cancer.

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.

E2F1-induced ferritin heavy chain 1 pseudogene 3 (FTH1P3) accelerates non-small cell lung cancer gefitinib resistance

Long noncoding RNAs (lncRNAs) have been identified to be critical regulator for various human diseases and emerging evidence illustrate the essential function of lncRNAs in the non-small cell lung cancer (NSCLC). Here, our research team tried to identify the roles of lncRNA ferritin heavy chain 1 pseudogene 3 (FTH1P3) in the NSCLC, as well as its molecular mechanism. LncRNA microarray analysis revealed that ferritin heavy chain 1 pseudogene 3 (FTH1P3) was up-regulated in the gefitinib-resistant cells (PC9/GR). Clinically, lncRNA FTH1P3 high-expression was closely correlated with NSCLC patients' unfavorable prognosis. Gain and loss of functional experiments revealed that FTH1P3 promoted the proliferation and invasion of NSCLC cells in vitro, and FTH1P3 knockdown repressed the tumor growth in vivo. Mechanistically, transcription factor E2F1 accelerated the transcription of FTH1P3. RNA immunoprecipitation and chromatin immunoprecipitation experiments showed that FTH1P3 can recruit lysine-specific demethylase 1 (LSD1) and epigenetically repress the TIMP3, thereby accelerating the tumorigenesis of NSCLC. In summary, these findings suggest that FTH1P3 plays a critical role in the gefitinib resistance and progression of NSCLC, providing a potential novel prognostic marker for NSCLC.

Tissue inhibitor of matrix metalloproteinase-3 has both anti-metastatic and anti-tumourigenic properties

TIMP-3 is one of four tissue inhibitors of matrix metalloproteinases, the endogenous inhibitors of the matrix metalloproteinase enzymes. These enzymes have an important role in metastasis, in the invasion of cancer cells through the basement membrane and extracellular matrix. TIMP-1, -2 and -4 both promote and inhibit tumour development, in a context-dependent manner, however TIMP-3 is consistently anti-tumourigenic. TIMP-3 is also the only insoluble member of the family, being either bound to the extracellular matrix or the low density lipoprotein-related protein-1, through which it can be endocytosed. Levels of TIMP-3 have also been shown to be regulated by micro RNAs and promoter hypermethylation, resulting in frequent silencing in many tumour types, to the extent that its expression has been suggested as a prognostic marker in some tumours, being associated with lower levels of metastasis, or better response to treatment. TIMP-3 has been shown to have anti-metastatic effects, both through inhibition of matrix metalloproteinases and ADAM family members and downregulation of angiogenesis. This occurs via interactions with receptors including VEGF, via modulation of signaling pathways and due to protease inhibition. TIMP-3 has also been shown to reduce tumour growth rate, most often by inducing apoptosis by stabilisation of death receptors. A number of successful mechanisms of delivery of TIMP-3 to tumour or inflammatory sites have been investigated in vitro or in animal studies. It may therefore be worthwhile further exploring the use of TIMP-3 as a potential anti-metastatic or anti-tumorigenic therapy for many tumour types.

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.

A Novel Approach to Detect Programed Death Ligand 1 (PD-L1) Status and Multiple Tumor Mutations Using a Single Non-Small-Cell Lung Cancer (NSCLC) Bronchoscopy Specimen

Multiple biomarkers are under evaluation to guide the use of immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC), including programed death ligand 1 (PD-L1) tumor cell staining. We have developed a new approach that accurately quantifies PD-L1 status and identifies multiple mutations by using a single bronchoscopy specimen. A novel molecular marker was identified to detect the presence of malignant cells in radial endobronchial ultrasound bronchial brushings from NSCLC (n = 15) and benign (n = 13) nodules by quantitative real-time RT-PCR (RT-qPCR). The MMP9:TIMP3 transcript ratio was significantly increased in NSCLC and using receiver operating characteristic curve analysis accurately discriminated malignant and benign bronchoscopy specimens (area under the curve = 0.98; 95% CI, 0.93-1; P < 0.0001). Utilizing the same specimens, PD-L1 expression and multiple oncogenic mutations were detected by RT-qPCR and next-generation sequencing. A second archive of snap-frozen squamous cell carcinoma (n = 40) and control (n = 20) biopsies with matching formalin-fixed, paraffin-embedded slides were used to compare PD-L1 status by immunohistochemistry and RT-qPCR. The biopsy cohort confirmed that the MMP-9:TIMP3 ratio was predictive of malignancy and demonstrated that PD-L1 transcript expression was concordant with PD-L1 tumor cell membrane staining in NSCLC (Spearman r = 0.636, P < 0.0001). This rapid molecular approach can detect malignant cells and using the same single bronchoscopy specimen can generate high-quality unfixed nucleic acid that accurately quantify PD-L1 status and identify multiple oncogenic mutations.

Synergistic Action of 1,2-Epoxy-3 (3- (3,4-dimethoxyphenyl)- 4H-1-benzopiyran-4-on) Propane with Doxorubicin and Cisplatin through Increasing of p53, TIMP-3, and MicroRNA-34a in Cervical Cancer Cell Line (HeLa)

Objective: Cervical cancer is the second most common cancer among women worldwide, with a high mortality rate especially in developing countries. Insufficient treatment for cervical cancer, multiple side effects, and high drug prices encourage researchers to look for effective and selective cancer drugs with appropriate molecular targets. This study explored the cytotoxicity of (1,2-epoxy-3(3-(3,4-dimethoxyphenyl)-4H-1-benzopyran-4-on) propane (EPI) synthesized from clove leaves oil on HeLa cells, its combination with doxorubicin (DOX) and cisplatin (CIS), and also their influence on p53, TIMP-3, and miR-34a as therapeutic targets. Materials and Methods: This research was an experimental in vitro study on cervical cancer uteri culture. The cytotoxicity was analyzed by MTT assay. The drug combination synergisms were indicated by the combination index (CI) (using CompuSyn 1.4). HeLa cells in 32 wells were divided into eight groups as negative control, which were given EPI ½IC50, EPI IC50, EPI 2IC50, DOX IC50, combination of EPI+DOX, CIS, and the combination of EPI+CIS. The p53 and TIMP-3 concentrations were measured using ELISA, and expressions of miR-34a with qRT-PCR. One-way ANOVA and post hoc Tukey tests were performed to determine the mean difference of all variables between the study groups. Results: IC50 for EPI was 33.24 (±3.01) μg/ml, while DOX and CIS were 4.8 μg/ml (±0.1), and 23.34 μg/ml (±3.01), respectively, while CI values for EPI-DOX were <0.1 and for EPI-CIS <0.9. Expression of p53 in group 6 (1.67±0.31) μg/ml and 8 (1.18±0.18) μg/ml, TIMP-3 6 (3.81±0.49) μg/ml and 8 (2.93±0.42) μg/ml were significantly higher compared to the control group (p<0.05). All treatment groups showed significantly increased miR-34a expressions compared to the control group (p<0.05). Conclusion: The combinations showed a very strong synergism and a moderate slight synergism for EPI-DOX and EPI-CIS. Both combinations were able to increase the expressions of p53, TIMP-3 proteins, and MiR-34a in the HeLa cells.

TIMP3 Overexpression Improves the Sensitivity of Osteosarcoma to Cisplatin by Reducing IL-6 Production

Osteosarcoma is the most common bone cancer in children and adolescents. Tissue inhibitors of metalloproteinases (TIMPs)-3 inhibit matrix metalloproteinases to limit extracellular matrix degradation. Cisplatin is a widely used chemotherapeutic drug used to cure osteosarcoma. Interleukin (IL)-6 and TIMP3 play important roles in the drug resistance of osteosarcoma; however, their relationship in this process remains unclear. This study aimed to explore the role of TIMP3 in the cisplatin sensitivity of osteosarcoma and its underlying molecular mechanisms in vitro and in vivo. We compared TIMP3 expression levels between patients with cisplatin-sensitive and -insensitive osteosarcoma. TIMP3 was overexpressed or knocked down in the Saos2-lung cell line, which is a Saos2 subtype isolated from pulmonary metastases that has higher cisplatin chemoresistance than Saos2 cells. IL-6 expression, cell proliferation, sensitivity to cisplatin, migration, and invasion after TIMP3 overexpression or knockdown were determined. The same experiments were performed using MG63 and U2OS cells. Subsequently, luciferase-labeled Saos2-lung cells overexpressing TIMP3 were injected into the tibiae of nude mice treated with cisplatin. The results showed that IL-6 inhibited TIMP3 expression in Saos2 and Saos2-lung cells via signal transducer and activator of transcription 3 (STAT3) activation. STAT3 knockdown reversed the effect of IL-6. The expression of TIMP3 was higher in patients with cisplatin-sensitive osteosarcoma than in those with insensitive osteosarcoma. IL-6 expression was downregulated upon TIMP3 overexpression, and upregulated by TIMP3 knockdown. TIMP3 overexpression suppressed cell proliferation and enhanced cisplatin sensitivity by activating apoptosis-related signal pathways and inhibiting IL-6 expression in vitro and in vivo. In conclusion, cisplatin sensitivity correlated positively with TIMP3 expression, which is regulated by the IL-6/TIMP3/caspase pathway. The TIMP3 pathway could represent a target for new therapies to treat osteosarcoma.

Human papillomavirus infection as a prognostic marker for lung adenocarcinoma: a systematic review and meta-analysis

Although a number of studies have investigated the association between human papillomavirus (HPV) and lung cancer prognosis, the results remain inconsistent. We therefore conducted a meta-analysis of epidemiologic studies to address this issue. Searches of the MEDLINE and EMBASE electronic databases from their inception until June 30, 2016 yielded nine studies involving a total of 1,205 lung cancer cases that were used to conduct the meta-analysis. Study-specific risk estimates were pooled using a random-effects model. The pooled hazard ratio (HR) comparing HPV-positive to HPV-negative cancers 1.00 (95% confidence interval (CI): 0.78-1.28) was not significantly correlated with overall survival. However, lung adenocarcinoma patients with HPV infections exhibited a survival benefit compared to those without HPV infection (HR=0.69, 95% CI: 0.50-0.96). This meta-analysis suggests HPV infection is a prognostic marker in lung adenocarcinoma. To further elucidate the epidemiology and pathogenesis of HPV infections in lung cancer, future large prospective studies are encouraged to stratify survival analysis based on the pathological type and clinical stage of the cancer.

IL-32 gamma reduces lung tumor development through upregulation of TIMP-3 overexpression and hypomethylation

The low expression of tissue inhibitor of metalloproteinase 3 (TIMP-3) is important in inflammatory responses. Therefore, inhibition of TIMP-3 may promote tumor development. Our study showed that expression of TIMP-3 was elevated in lL-32γ mice lung tissues. In this study, we investigated whether IL-32γ mice inhibited lung tumor development through overexpression of TIMP-3 and its methylation. To explore the possible underlying mechanism, lung cancer cells were transfected with IL-32γ cDNA plasmid. A marked increase in TIMP-3 expression was caused by promoter methylation. Mechanistic studies indicated that TIMP-3 overexpression reduced NF-κB activity, which led to cell growth inhibition in IL-32γ transfected lung cancer cells. We also showed that IL-32γ inhibits expression of DNA (cytosine-5-)-methyltransferase 1 (DNMT1). Moreover, IL-32γ inhibits the binding of DNMT1 to TIMP-3 promoter, but this effect was reversed by the treatment of DNA methyltransferase inhibitor (5-Aza-CdR) and NF-κB inhibitor (PS1145), suggesting that a marked increase in TIMP-3 expression was caused by inhibition of promoter hypermethylation via decreased DNMT1 expression through the NF-κB pathway. In an in vivo carcinogen induced lung tumor model, tumor growth was inhibited in IL-32γ overexpressed mice with elevated TIMP-3 expression and hypomethylation accompanied with reduced NF-κB activity. Moreover, in the lung cancer patient tissue, the expression of IL-32 and TIMP-3 was dramatically decreased at a grade-dependent manner compared to normal lung tissue. In summary, IL-32γ may increase TIMP-3 expression via hypomethylation through inactivation of NF-κB activity, and thereby reduce lung tumor growth.

Reduction of microRNA-184 by E6 oncoprotein confers cisplatin resistance in lung cancer via increasing Bcl-2

MicroRNA-184 suppresses cell growth and survival via targeting c-Myc and Bcl- 2. We recently reported that miR-184 promotes tumor progression in non-small cell lung cancer via targeting CDC25A and c-Myc. We here hypothesized that miR-184 could be down-regulated by E6 oncoprotein to confer cisplatin resistance in NSCLC. Human papillomavirus (HPV) 16-positive lung cancer TL-1 and cervical cancer SiHa cells compared with HPV16-negative TL-10 and C33A cells were enrolled for E6 manipulation. MiR-184 expression levels were increased by E6-knockdown in TL-1 and SiHa cells, but decreased by E6-overexpression in TL-10 and C33A cells. The MTT assay showed that the inhibition concentration of cisplatin yielding for 50% cell viability was dependent on miR-184 levels. Bcl-2 de-targeted by E6-mediated miR- 184 reduction was responsible for cisplatin resistance. Luciferase reporter assay and real- time PCR analysis indicated that the miR-184 promoter activity and its expression were modulated by E6 and/or p53 manipulation. Chromatin immunoprecipitation (ChIP) assay confirmed that p53 was bound onto the miR-184 promoter and its binding activity was modulated by E6 and/or p53 manipulation. Among patients, high miR184 and high Bcl-2 mRNA expression was more commonly occurred in E6- positive tumors than in E6-negative tumors. Fifty-nine out of 136 patients receiving cisplatin-based chemotherapy were available for the retrospective study. Patients with low-mR-184, E6-positive, high-Bcl-2 tumors, and both combinations were more prevalently occurred unfavorable response to cisplatin-based chemotherapy than their counterparts. In conclusion, a decrease in miR-184 level by E6 oncoprotein may predict unfavorable response to cisplatin-based chemotherapy in HPV-infected NSCLC patients via increasing Bcl-2 expression.

A combination of anti-PD-L1 mAb plus Lm-LLO-E6 vaccine efficiently suppresses tumor growth and metastasis in HPV-infected cancers

PD‐1/PD‐L1 immunotherapy is viewed as having clinical benefits in advanced cancers but is effective in only a few patients, suggesting that an efficient combination approach is needed to improve efficacy. Immunohistochemistry analysis indicated that PD‐L1 expression was correlated with the E6 expression in tumors from 122 lung cancer patients. The poorest survival occurred in PD‐L1‐positive/E6‐positive tumor. PD‐L1 expression was increased by the expression of E6, but not the E7, oncoprotein in lung and cervical cancer cells. PD‐L1 expression was responsible for E6‐mediated colony formation and soft agar growth. Therefore, PD‐L1 secreted from tumor cells may directly promote tumor progression, particularly in E6‐positive tumors. Immune deficiency nude mice were used to test the possibility that combining anti‐PD‐L1 mAb with Lm‐LLO‐E6 vaccine could have a higher antitumor activity compared with anti‐PD‐L1 mAb or Lm‐LLO‐E6 vaccine alone. A greater antitumor activity was obtained with anti‐PD‐L1 mAb + Lm‐LLO‐E6 vaccine than with anti‐PD‐L1 mAb or Lm‐LLO‐E6 alone in subcutaneous and metastatic tumors induced by TL‐1 and SiHa cells. The longest survival time for nude mice was observed in the anti‐PD‐L1 mAb + Lm‐LLO‐E6 vaccine group. In conclusion, an anti‐PD‐L1 mAb + Lm‐LLO‐E6 vaccine may be an efficient treatment for suppression of tumor growth and metastasis induced by HPV‐infected cells.

TIMPs: versatile extracellular regulators in cancer

A compelling long-term goal of cancer biology is to understand the crucial players during tumorigenesis in order to develop new interventions. Here, we review how the four non-redundant tissue inhibitors of metalloproteinases (TIMPs) regulate the pericellular proteolysis of a vast range of matrix and cell surface proteins, generating simultaneous effects on tumour architecture and cell signalling. Experimental studies demonstrate the contribution of TIMPs to the majority of cancer hallmarks, and human cancers invariably show TIMP deregulation in the tumour or stroma. Of the four TIMPs, TIMP1 overexpression or TIMP3 silencing is consistently associated with cancer progression or poor patient prognosis. Future efforts will align mouse model systems with changes in TIMPs in patients, will delineate protease-independent TIMP function, will pinpoint therapeutic targets within the TIMP-metalloproteinase-substrate network and will use TIMPs in liquid biopsy samples as biomarkers for cancer prognosis.

MiR-30c-2* negative regulated MTA-1 expression involved in metastasis and drug resistance of HPV-infected non-small cell lung cancer

BACKGROUND

MiR-30c-2* is considered to be a tumor suppressor microRNA in various cancers and is associated with gemcitabine sensitivity of lung cancer cells. Downregulation of miR-30c-2* promotes tumor invasion via increased expression of metastasis-associated protein-1. We hypothesized that downregulated expression of miR-30c-2* was involved in human papillomavirus-associated lung tumorigenesis and drug resistance.

METHODS

We examined whether expression of human papillomavirus 16/18 oncoprotein and miR-30c-2*-associated genes could be linked to patient outcome by collecting 319 lung tumors from patients with non-small cell lung cancer to determine expression of human papillomavirus 16/18 E6 protein, miR-30c-2*, and miR-30c-2* downstream metastasis-associated protein-1 mRNA by immunohistochemical and real-time polymerase chain reaction analysis.

RESULTS

Our results showed that miR-30C-2* levels were increased 45-fold in the E6-knockdown TL-1 cells when compared with levels in the parental cells. More interestingly, metastasis-associated protein-1 expression correlated negatively with miR-30C-2* and positively with human papillomavirus 16 E6 protein expression in lung tumors from lung cancer patients. Metastasis-associated protein-1 expression levels in the tumor tissues correlated positively with tumor stage and nodal metastasis. Patients with high metastasis-associated protein-1 expression, and especially patients infected with human papillomavirus, experienced a poor clinical outcome, tumor recurrence, and a poor therapeutic response compared with those with low metastasis-associated protein-1 expression.

CONCLUSION

These results showed that miR-30C-2* and levels of downstream metastasis-associated protein-1 gene expression in the tumor tissues of patients could be useful in predicting clinical outcome and therapeutic response and in selecting useful therapeutic drugs for lung cancer patients, especially patients with human papillomavirus infection.

MiR-375 Is Epigenetically Downregulated by HPV-16 E6 Mediated DNMT1 Upregulation and Modulates EMT of Cervical Cancer Cells by Suppressing lncRNA MALAT1

Epigenetic modulation is an important mechanism of miRNA dysregulation in cervical cancer. In this study, we firstly studied how this mechanism contributes to miR-375 downregulation in cervical cancer cells. Then, we further studied the association between miR-375 and MALAT1 (metastasis associated lung adenocarcinoma transcript 1) in epithelial mesenchymal transition (EMT) of the cancer cells. HPV-16 positive SiHa and CaSki cells were used as in vitro model. Our data showed that HPV-16 E6 positively modulated DNMT1 expression in both SiHa and CaSki cells. Knockdown of DNMT1 partly restored miR-375 levels in the cells. The following methylation-specific PCR (MSP) assay and qRT-PCR analysis showed that methylation was common in the promoter region of miR-375 in both SiHa and CaSki cells and demethylation partly restored miR-375 levels in the cells. Therefore, we infer that miR-375 is downregulated partly due to promoter hypermethylation mediated by DNMT1 in HPV-16 positive cervical cancer cells. Our bioinformatics analysis showed that MALAT1 has three putative binding sites with miR-375 and the following dual luciferase assay confirmed two of them. QRT-PCR analysis showed that miR-375 overexpression significantly reduced MALAT1 expression, while MALAT1 overexpression reversely suppressed miR-375 levels. Therefore, we infer that there is a reciprocal regulation between miR-375 and MALAT1 in the cells. In SiHa cells, miR-375 overexpression or MALAT1 siRNA partly restored E-cadherin expression, significantly reduced N-cadherin and also reduced invasion capacity of SiHa cells. Therefore, these results suggest that miR-375 and MALAT1 form a functional axis modulating EMT in cervical cancer.

Aberrant expression of miR-21, miR-376c and miR-145 and their target host genes in Merkel cell polyomavirus-positive non-small cell lung cancer

Merkel Cell Polyoma Virus (MCPyV) infection has been associated with non-small cell lung cancer (NSCLC). Viruses can manipulate cellular miRNAs or have a profound impact on cellular miRNA expression to control host regulatory pathways. In this study, we evaluated the expression profiles of cancer-associated and virally affected host microRNAs miR-21, miR-145, miR-146a, miR-155, miR-302c, miR-367 and miR-376c in a series of NSCLC tissue samples as well as in samples from “healthy” sites, distant from the tumour region that were either positive or negative for MCPyV DNA. miR-21 and miR-376c were significantly upregulated whereas miR-145 was significantly downregulated in the MCPyV+ve samples compared to the MCPyV-ve tumour samples. Overall, miR-21 and miR-376c expression was higher in tumour compared to healthy tissue samples. No association was observed between the miR-155, miR-146a, miR-302c and miR-367 levels and the presence of MCPyV. The expression of miR-21 target genes (Pten, Bcl-2, Daxx, Pkr, Timp3), miR-376c (Grb2, Alk7, Mmp9) and miR-145 (Oct-4, Sox2, Fascin1) and their associated pathways (Braf, Akt-1, Akt-2, Bax, Hif1a, p53) was altered between MCPyV+ve tumor samples and their corresponding controls. These results show a novel association between miR-21, miR-376c and miR-145 and their host target genes with the presence of MCPyV, suggesting a mechanism of virus-specific microRNA signature in NSCLC.

Human papillomavirus and lung cancinogenesis: an overview

Lung cancer is the most common cause of cancer deaths worldwide. Although tobacco smoking is considered to be the main risk factor and the most well-established risk factor for lung cancer, a number of patients who do not smoke have developed this disease. This number varies between 15 % to over one-half of lung cancer cases, and the deaths from lung cancer in non-smokers are increasing every year. There are many other agents that are thought to be etiological, including diesel exhaust exposure, metals, radiation, radon, hormonal factors, cooking oil, air pollution and infectious diseases, such as human papillomavirus (HPV). Studies in various parts of the world have detected HPV DNA at different rates in lung tumors. However, the role of HPV in lung cancer is still unclear. Thus, in this review, we investigated some molecular mechanisms of HPV protein activity in host cells, the entry of HPV into lung tissue and the possible route used by the virus to reach the lung cells.

A distinct role for interleukin-6 as a major mediator of cellular adjustment to an altered culture condition

Tissue microenvironment adjusts biological properties of different cells by modulating signaling pathways and cell to cell interactions. This study showed that epithelial–mesenchymal transition (EMT)/ mesenchymal–epithelial transition (MET) can be modulated by altering culture conditions. HPV E6/E7‐transfected immortalized oral keratinocytes (IHOK) cultured in different media displayed reversible EMT/MET accompanied by changes in cell phenotype, proliferation, gene expression at transcriptional, and translational level, and migratory and invasive activities. Cholera toxin, a major supplement to culture medium, was responsible for inducing the morphological and biological changes of IHOK. Cholera toxin per se induced EMT by triggering the secretion of interleukin 6 (IL‐6) from IHOK. We found IL‐6 to be a central molecule that modulates the reversibility of EMT based not only on the mRNA level but also on the level of secretion. Taken together, our results demonstrate that IL‐6, a cytokine whose transcription is activated by alterations in culture conditions, is a key molecule for regulating reversible EMT/MET. This study will contribute to understand one way of cellular adjustment for surviving in unfamiliar conditions. J. Cell. Biochem. 116: 2552–2562, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

Environmental exposure and HPV infection may act synergistically to induce lung tumorigenesis in nonsmokers

Most studies of lung tumorigenesis have focused on smokers rather than nonsmokers. In this study, we used human papillomavirus (HPV)-positive and HPV-negative lung cancer cells to test the hypothesis that HPV infection synergistically increases DNA damage induced by exposure to the carcinogen benzo[a]pyrene (B[a]P), and contributes to lung tumorigenesis in nonsmokers. DNA adduct levels induced by B[a]P in HPV-positive cells were significantly higher than in HPV-negative cells. The DNA adduct formation was dependent on HPV E6 oncoprotein expression. Gene and protein expression of two DNA repair genes, XRCC3 and XRCC5, were lower in B[a]P-treated E6-positive cells than in E6-negative lung cancer cells. The reduced expression was also detected immunohistochemically and was caused by increased promoter hypermethylation. Moreover, mutations of p53 and epidermal growth factor receptor (EGFR) genes in lung cancer patients were associated with XRCC5 inactivation. In sum, our study indicates that HPV E6-induced promoter hypermethylation of the XRCC3 and XRCC5 DNA repair genes and the resultant decrease in their expression increases B[a]P-induced DNA adducts and contributes to lung tumorigenesis in nonsmokers.

In utero exposure to second-hand smoke activates pro-asthmatic and oncogenic miRNAs in adult asthmatic mice

Exposures to environmental pollutants contribute to dysregulated microRNA (miRNA) expression profiles, which have been implicated in various diseases. Previously, we reported aggravated asthmatic responses in ovalbumin (OVA)-challenged adult mice that had been exposed in utero to second-hand smoke (SHS). Whether in utero SHS exposure dysregulates miRNA expression patterns in the adult asthma model has not been investigated. Pregnant BALB/c mice were exposed (days 6-19 of pregnancy) to SHS (10 mg/m(3)) or HEPA-filtered air. All offspring were sensitized and challenged with OVA (19-23 weeks) before sacrifice. RNA samples extracted from lung homogenates, were subjected to RNA sequencing (RNA-seq). RNA-seq identified nine miRNAs that were most significantly up-regulated by in utero SHS exposure. Among these nine, miR-155-5p, miR-21-3p, and miR-18a-5p were also highly correlated with pro-asthmatic Th2 cytokine levels in bronchoalveolar lavage fluid. Further analysis indicated that these up-regulated miRNAs shared common chromosome locations, particularly Chr 11C, with pro-asthmatic genes. These three miRNAs have also been characterized as oncogenic miRNAs (oncomirs). We cross-referenced miRNA-mRNA expression profiles and identified 16 tumor suppressor genes that were down-regulated in the in utero-exposed offspring and that are predicted targets of the up-regulated oncomirs. In conclusion, in utero SHS exposure activates pro-asthmatic genes and miRNAs, which colocalize at specific chromosome locations, in OVA-challenged adult mice. The oncogenic characteristics of the miRNAs and putative miRNA-mRNA regulatory networks suggest that the synergistic effect of in utero SHS exposure and certain adult irritants may promote an oncogenic milieu in mouse lungs via inhibition of miRNA-regulated tumor suppressor genes.

Polymorphisms and Plasma Levels of Tissue Inhibitor of Metalloproteinase-3: Impact on Genetic Susceptibility and Clinical Outcome of Oral Cancer

Oral cancer, the fourth most common cancer among men in Taiwan, is associated with environmental carcinogens. Tissue inhibitor of metalloproteinase-3 (TIMP3), a member of the TIMP family, is the only protein that binds to the extracellular matrix for suppressing cancer cell growth, angiogenesis, migration, and invasion. The association of TIMP3 polymorphism with oral cancer susceptibility, however, has not yet been reported. In this study, 1947 participants-1200 healthy male controls and 747 male patients with oral cancer-were recruited. Allelic discrimination of TIMP3 -1296 T > C (rs9619311), TIMP3 C > T (rs9862), and TIMP3 C > T (rs11547635) polymorphisms were assessed through real-time polymerase chain reaction. The authors discovered that individuals carrying the polymorphic rs9862 allele are more susceptible to oral cancer [odds ratio (OR), 1.5; 95% confidence interval (CI), 1.2-1.9; adjusted OR (AOR), 1.6; 95% CI, 1.2-2.1] after adjustment for betel quid chewing, alcohol, and tobacco consumption. Among 601 betel quid chewers, the TIMP3 polymorphism rs9862 T/T carriers had a 32.2-fold (95% CI, 20.2-51.3) increased oral cancer risk compared with those carrying C/C and not chewing betel quid. In addition, the authors observed a significant association between rs9862 variants and large tumors (OR, 1.5; 95% CI, 1.0-2.3) development. Moreover, TIMP3 plasma levels significantly increased in oral cancer patients who have large tumor or carry T allele rs9862 polymorphism. In conclusion, these results suggest that gene-environment interactions between the TIMP3 rs9862 polymorphisms and betel quid may alter oral cancer susceptibility and tumor growth in Taiwanese men.

Paxillin confers resistance to tyrosine kinase inhibitors in EGFR-mutant lung cancers via modulating BIM and Mcl-1 protein stability

Tyrosine kinase inhibitors (TKIs) have been documented to have substantial clinical benefits to non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutation. TKI resistance occurs in nearly all patients who receive TKI-targeting therapy, resulting in a modest overall survival benefit. Therefore, establishing a biomarker for early prediction and exploring the mechanism of primary TKI resistance is essential for improving the therapeutic efficacy in non-small cell lung cancer patients. In this study, we provide evidence indicating that paxillin (PXN) overexpression may confer TKI resistance in EGFR-mutant lung cancer cells. Mechanistically, PXN-mediated extracellular signal-regulated kinases (ERK) activation is responsible for TKI resistance via decreased Bcl2-interacting mediator of cell death (BIM) and increased Mcl-1 expression due to modulating their protein stabilities by phosphorylation of BIM at serine 69 and Mcl-1 at threonine 163. The mechanistic action in the cell model was further confirmed by the observation of xenograft tumors in nude mice, revealing that the PXN-mediated TKI resistance was conquered by ERK inhibitor (AZD6244) and Bcl-2 family inhibitor (obatoclax), but the TKI resistance overcome by AZD6244 is more effective than that of obatoclax. Therefore, we suggest that PXN expression may be useful in predicting primary TKI resistance, and combining TKI with ERK inhibitors may clinically benefit EGFR-mutant non-small cell lung cancer patients whose tumors exhibit high PXN expression.

Prognostic value of tissue inhibitor of metalloproteinase-2 expression in patients with non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Tissue inhibitor of metalloproteinase-2 (TIMP-2) is a small secretory glycoprotein with anti-matrix metalloproteinase activity. Data on the value of TIMP-2 as a prognostic factor in non-small cell lung cancer (NSCLC) are discordant and remain controversial. A systematic review and meta-analysis was performed to explore this issue.

METHODS

We identified the relevant literature by searching the PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, SinoMed, and Wanfang Data databases (search terms: "non-small cell lung cancer" or "NSCLC" or "Lung Carcinoma, Non-Small-Cell", "Tissue Inhibitor of Metalloproteinase-2" or "TIMP-2", and "prognosis" or "prognostic" or "survive") for updates prior to March 1, 2014. The pooled hazard ratio (HR) of overall survival with a 95% confidence interval (95% CI) was used to evaluate the strength of the association between positive TIMP-2 expression and survival in patients with NSCLC.

RESULTS

We included 12 studies in our systematic review; five studies involving 399 patients with NSCLC were meta-analyzed. The pooled HR of all included patients was 0.57 (95% CI: 0.43-0.77), and the HRs of subgroup analysis according to stage (I-IV), testing method (immunohistochemistry) and high TIMP-2 expression percentage (<50%) were 0.63 (95% CI: 0.43-0.92), 0.55 (95% CI: 0.41-0.74), and 0.50 (95% CI: 0.28-0.88), respectively. These data suggested that high TIMP-2 expression is associated with favorable prognosis in NSCLC. The meta-analysis did not reveal heterogeneity or publication bias.

CONCLUSIONS

TIMP-2 expression indicates favorable prognosis in patients with NSCLC; as a protective factor, it could help predict outcome and may guide clinical therapy in the future.

TIMP-3 expression associates with malignant behaviors and predicts favorable survival in HCC

The tissue inhibitors of metalloproteinases (TIMPs) are proteins that specifically inhibit the proteolytic activity of the matrix metalloproteinases (MMPs). TIMP-3, the only member of the TIMPs that can tightly bind to the extracellular matrix, has been identified as a unique tumor suppressor that demonstrates the ability to inhibit tumor angiogenesis, invasion, and metastasis. This study aimed to detect the expression of TIMP-3 in hepatocellular carcinoma (HCC) and investigate the association between TIMP-3 expression and its clinicopathological significance in HCC patients. In the current study, reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting of HCC cell lines and one-step quantitative reverse transcription PCR (qPCR) and immunohistochemistry (IHC) analyses in HCC tissues were performed, to characterize the TIMP-3 expression. Kaplan-Meier survival and Cox regression analyses were utilized to evaluate the prognosis of 101 HCC patients. The results showed that the expression of TIMP-3 in HCC was significantly decreased relative to that of non-cancerous cells and tissues. Furthermore, the TIMP-3 expression was statistically associated with malignant behaviors of HCC, including portal vein invasion (p = 0.036) and lymph node metastasis (p = 0.030). Cox regression analysis revealed that TIMP-3 expression was an independent prognostic factor for disease-free survival (p = 0.039) and overall survival (p = 0.049). These data indicate that TIMP-3 expression is a valuable prognostic biomarker for HCC and that TIMP-3 expression suggests a favorable prognosis for HCC patients.

FHIT loss confers cisplatin resistance in lung cancer via the AKT/NF-κB/Slug-mediated PUMA reduction

Fragile histidine triad (FHIT) loss by the two-hit mechanism of loss of heterozygosity and promoter hypermethylation commonly occurrs in non-small cell lung cancer (NSCLC) and may confer cisplatin resistance in NSCLC cells. However, the underlying mechanisms of FHIT loss in cisplatin resistance and the response to cisplatin-based chemotherapy in NSCLC patients have not yet been reported. In the present study, inhibition concentration of 50% cell viability induced by cisplatin (IC50) and soft agar growth and invasion capability were increased and decreased in FHIT-knockdown and -overexpressing cells, respectively. Mechanistically, Slug transcription is upregulated by AKT/NF-κB activation due to FHIT loss and, in turn, Slug suppresses PUMA expression; this decrease of PUMA by FHIT loss is responsible for cisplatin resistance. In addition, cisplatin resistance due to FHIT loss can be conquered by AKT inhibitor-perifosine in xenograft tumors. Among NSCLC patients, low FHIT, high p-AKT, high Slug and low PUMA were correlated with shorter overall survival, relapse-free survival and poorer response to cisplatin-based chemotherapy. Therefore, the AKT inhibitor perifosine might potentially overcome the resistance to cisplatin-based chemotherapy in NSCLC patients with low-FHIT tumors, and consequently improve the outcome.

IL-6 enriched lung cancer stem-like cell population by inhibition of cell cycle regulators via DNMT1 upregulation

Tumors are influenced by a microenvironment rich in inflammatory cytokines, growth factors and chemokines, which may promote tumor growth. Interleukin-6 (IL-6) is a multifunctional cytokine and known as a regulator of immune and inflammation responses. IL-6 has also been reported to be associated with tumor progression and chemoresistance in different types of cancers. In our study, we demonstrated that IL-6 enriches the properties of lung cancer stem-like cells in A549 lung cancer cells cultured in spheroid medium. IL-6 also promotes sphere formation and stem-like properties of A549 cells by enhancing cell proliferation. Methylation-specific polymerase chain reaction (PCR) was performed and revealed that IL-6 increased methylation of p53 and p21 in A549 cancer cells. Western blot analysis and quantitative real-time PCR demonstrated that IL-6 increased the expression of DNA methyltransferase 1 (DNMT1) in A549 cells cultured in spheroid medium, but not the expression of DNMT3a or DNMT3b. Knockdown of DNMT1 eliminated IL-6-mediated hypermethylation of cell cycle regulators and enrichment of lung cancer stem-like properties. In conclusion, our study, for the first time, shows that the IL-6/JAK2/STAT3 pathway upregulates DNMT1 and enhances cancer initiation and lung cancer stem cell (CSC) proliferation by downregulation of p53 and p21 resulting from DNA hypermethylation. Upon blockage of the IL-6/JAK2/STAT3 pathway and inhibition of DNMT1, the proliferation of lung CSCs was reduced and their formation of spheres and ability to initiate tumor growth were decreased. These data suggest that targeting of the IL-6/JAK2/STAT3 signaling pathway and DNMT1 may become important strategies for treating lung cancer.

c-Myc suppresses microRNA-29b to promote tumor aggressiveness and poor outcomes in non-small cell lung cancer by targeting FHIT

The dual role of the microRNA-29 (miR-29) family in tumor progression and metastasis in solid tumors has been reported. Evidence for the role of miR-29 in tumor malignancy and its prognostic value in overall survival (OS) and relapse-free survival (RFS) in non-small cell lung cancer (NSCLC) remains conflicting. Mechanistic studies presented herein demonstrated that c-Myc suppressed the expression of miR-29b, promoting soft agar growth and invasion capability in lung cancer cells. Interestingly, the decrease in the expression of miR-29b by c-Myc is responsible for soft agar growth and invasiveness mediated by FHIT loss due to promoter methylation. Among patients, low expression of miR-29b and FHIT was more common in tumors with high c-Myc expression than in tumors with low c-Myc expression. Kaplan-Meier and Cox regression analysis showed that tumors with high c-Myc, low miR-29b and low FHIT expression had shorter OS and RFS periods than their counterparts. In conclusion, the decrease in the expression of miR-29b by c-Myc may be responsible for FHIT loss-mediated tumor aggressiveness and for poor outcome in NSCLC. Therefore, we suggest that restoration of the miR-29b expression using the c-Myc inhibitor might be helpful in suppressing tumor aggressiveness mediated by FHIT loss and consequently improving outcomes in NSCLC patients with tumors with low expression of FHIT.

MicroRNA-21 promotes tumour malignancy via increased nuclear translocation of β-catenin and predicts poor outcome in APC-mutated but not in APC-wild-type colorectal cancer

MiR-21 has been associated with poor prognosis in colon adenocarcinomas. However, in our preliminary data, the prognostic value of miR-21 levels was observed only in adenomatous polyposis coli (APC)-mutated tumours, not in APC-wild-type tumours. We explored whether β-catenin nuclear translocation was synergistically promoted by miR-21 in APC-mutated cells but not in APC-wild-type cells. We enrolled 165 colorectal tumour to determine APC mutation, miR-21 levels and nuclear β-catenin expression by direct sequencing, real-time PCR and immunohistochemistry. Overall survival and relapse-free survival were analysed by Kaplan-Meier and Cox regression models. The mechanistic action of β-catenin nuclear translocation modulated by miR-21 and its effect on cell invasion were evaluated in a cell model. Positive nuclear β-catenin expression was more commonly occurred in APC-mutated tumours than in APC-wild-type tumours. High miR-21 levels were relatively more common in tumours with positive nuclear β-catenin expression than in those with negative nuclear β-catenin expression. APC-mutated tumours with high miR-21 levels had shorter overall survival and relapse-free survival periods compared with others. However, the prognostic value of miR-21 levels was not observed in APC-wild-type tumours. Phosphorylation of β-catenin at Ser552 via the miR-21-mediated PTEN/AKT axis plays a critical role in β-catenin nuclear translocation in APC-mutated cells but not in APC-wild-type cells. Moreover, nuclear β-catenin expression increased by miR-21 is responsible for the capability of invasiveness. In summary, nuclear translocation of β-catenin increased by miR-21 promotes tumour malignancy and a poor outcome in APC-mutated patients but not in APC-wild-type colorectal cancer.

Regulation of interleukin-6 in head and neck squamous cell carcinoma is related to papillomavirus infection

The prevalence of head and neck squamous cell carcinoma (HNSCC) related to human papillomavirus (HPV) is increasing, unlike tobacco- and alcohol-associated cancers. To gain a clearer understanding of the molecular mechanisms implicated in HNSCC, depending on the presence or not of a viral sequence, we investigated the expression of proteins detected in the tumor regions of HNSCC patients. Twenty-two untreated HNSCC patients were selected according to the presence of HPV-16. For six patients, tumor and controlateral healthy tissues were tested for viral detection before quantitative proteomic analysis. After confirmation by Western blot, proteins were connected into a network, leading to investigate interleukin-6 (IL-6) by immunocytochemistry and ELISA. 41 ± 5% of proteins quantified by proteomics were differentially expressed in tumor compared with healthy regions. Among them, 36 proteins were retained as modulated in HPV-16 positive or negative tumors, including cytokeratins, tubulins, annexin A1, and serpin B1. Network analysis suggested a central role of IL-6, confirmed by overexpression of IL-6 in tumor tissues as in sera of HPV-negative HNSCC compared with HPV-16-positive tumors. This modulation may contribute to the survival and proliferation of cancer cells, although it was not related to tumor stage or to the level of HPV-16 DNA.

Interleukin-6 cytokine: a multifunctional glycoprotein for cancer

Interleukin 6 is a multifunctional cytokine. Its increased levels have been associated with elevated cancer risk, and also these levels have been found to be a prognostic factor for several cancer types. In addition, increased levels have been found in coronary heart disease, insulin resistant patients, advance stage cancer patients, atopy/asthma and in patients with blood circulating micrometastasis. Additionally several studies with different types of cancers have been performed to identify the correlation between interleukin-6 levels, stage, treatment response and severity of symptoms. The influence of interleukin-6 is performed mainly through the janus kinase-signal transducer and activator of transcription-zinc finger protein 1-2 signaling pathway. As a result, the increased levels of interleukin-6 are responsible for enhanced neo-angiogenesis, inhibition of cancer cell apoptosis and deregulation of the control mechanisms in the microenvironment. In addition, increased levels of inteleukin-6 have been found to increase the production of collagen and a-actin which induce interstitial lung disease. In the current mini review we will present information regarding the interleukin-6 and published results in several cancer studies and finally we will comment in future treatment approaches blocking this cytokine in cancer patients.

Hepatitis C virus core protein epigenetically silences SFRP1 and enhances HCC aggressiveness by inducing epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) is one of the most deadly cancers. Aberrant oncogenic activation of the Wnt/β-catenin signaling pathway contributes to hepatocellular carcinogenesis. Various epigenetic modifications of the Wnt antagonist secreted frizzled-related protein (SFRP) family have been implicated in regulating Wnt signaling. Here, we report that Hepatitis C virus (HCV) core protein downregulates SFRP1 expression when it is expressed in Huh7 and HepG2 cells. SFRP1 expression can be effectively restored by using either a DNA methylation inhibitor alone or in combination with a histone deacetylase inhibitor. DNA methylation analysis of the SFRP1 promoter revealed that cytosine-phosphate-guanine (CpG) islands close to the transcriptional start site (TSS) in the SFRP1 promoter were hypermethylated in core-expressing Huh7 cells, suggesting that HCV core protein may downregulate SFRP1 expression by inducing hypermethylation of the SFRP1 promoter. Chromatin immunoprecipitation revealed that HCV core protein markedly increased the expression level and binding of DNA methyltransferase-1 (Dnmt1) and histone deacetylase-1 (HDAC1) to the TSS of the SFRP1 promoter region, resulting in repression of acetyl-histone H3-binding capacity to SFRP1 promoter and the eventual epigenetic silencing of SFRP1 expression. Furthermore, the core protein-promoted cell proliferation, migration and invasiveness were effectively abrogated either by Dnmt1 knockdown or restoration of SFRP1 expression in hepatoma cells. Dnmt1 knockdown or SFRP1 overexpression also inhibited HCV core-induced epithelial-mesenchymal transition (EMT) and significantly decreased the expression levels of activated β-catenin and Wnt/β-catenin target genes, c-Myc and cyclin D1. We further showed that knockdown of Dnmt1 and restoration of SFRP1 inhibited core-induced in vivo tumor growth and aggressiveness in a xenograft HCC model. Taken together, our results strongly suggest that the HCV core-induced epigenetic silencing of SFRP1 may lead to the activation of the Wnt signaling pathway and thus contribute to HCC aggressiveness through induction of EMT.