Involvement of the TGF-beta and beta-catenin pathways in pelvic lymph node metastasis in early-stage cervical cancer

Integrative machine learning analysis of multiple gene expression profiles in cervical cancer

Although most of the cervical cancer cases are reported to be closely related to the Human Papillomavirus (HPV) infection, there is a need to study genes that stand up differentially in the final actualization of cervical cancers following HPV infection. In this study, we proposed an integrative machine learning approach to analyse multiple gene expression profiles in cervical cancer in order to identify a set of genetic markers that are associated with and may eventually aid in the diagnosis or prognosis of cervical cancers. The proposed integrative analysis is composed of three steps: namely, (i) gene expression analysis of individual dataset; (ii) meta-analysis of multiple datasets; and (iii) feature selection and machine learning analysis. As a result, 21 gene expressions were identified through the integrative machine learning analysis which including seven supervised and one unsupervised methods. A functional analysis with GSEA (Gene Set Enrichment Analysis) was performed on the selected 21-gene expression set and showed significant enrichment in a nine-potential gene expression signature, namely PEG3, SPON1, BTD and RPLP2 (upregulated genes) and PRDX3, COPB2, LSM3, SLC5A3 and AS1B (downregulated genes).

Identification of differentially expressed genes in cervical cancer by bioinformatics analysis

Cervical cancer is the most common gynecological malignancy. In recent years, the incidence of cervical cancer has had a younger trend. Cervical cancer morbidity and mortality rates have been significantly reduced due to recent decades of cervical cytology screening leading to the early detection and treatment of cervical cancer and precancerous lesions. There are a number of methods used to treat cervical cancer and improve the survival rate. However, the prevalence and recurrence rates of cervical cancer are increasing every year. There is an urgent requirement for a better understanding of the molecular mechanism cervical cancer development. The present study used scientific information retrieval from the Gene Expression Omnibus database to download the GSE26511 dataset, which contained 39 samples, including 19 cervical cancer lymph node-positive samples and 20 cervical cancer lymph node-negative samples. Using Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, and weighted gene co-expression network analysis, 1,263 differentially expressed genes were found that affected the biological processes, including 'cell cycle process', 'signaling pathways', 'immune response', 'cell activation', 'regulation of immune system process' and 'inflammatory response'. These areas should be the focus of study for cervical cancer in the future.

Long non-coding RNA HOTAIR promotes cervical cancer progression through regulating BCL2 via targeting miR-143-3p

BACKGROUND

HOX transcript antisense RNA (HOTAIR) is a long non-coding RNA (lncRNA) widely involved in the progression of numerous malignancies. Whereas, the potential molecular mechanism of HOTAIR involved in cervical cancer progression is still needed to be elaborated.

METHODS

The expression of HOTAIR and miR-143-3p were detected in cervical cancer tissues and cells by qRT-PCR. MTT and flow cytometry analysis were performed to measure cell proliferation and apoptosis. Bioinformatics, Dual-Luciferase reporter and RIP were used to analyze the possible correlation between HOTAIR, miR-143-3p and BCL2. The expression of Bax and BCL2 was detected by western blot. Mice xenograft model was established to confirm the role of HOTAIR on tumor growth in vivo.

RESULTS

HOTAIR expression was elevated while miR-143-3p expression was reduced in cervical cancer tissues and cell lines. HOTAIR knockdown suppressed proliferation and enhanced apoptosis in cervical cancer cells. Moreover, HOTAIR could function as a sponge for miR-143-3p. The inhibitory effect of HOTAIR knockdown on cervical cancer cells growth was abolished following decrease of miR-143-3p expression. Furthermore, HOTAIR promoted BCL2 expression by modulating miR-143-3p. BCL2 overexpression attenuated the tumor-suppressive effect of miR-143-3p in cervical cancer. Finally, the carcinogenicity of HOTAIR was validated in mice.

CONCLUSIONS

HOTAIR promoted cervical cancer cell growth by modulating BCL2 via miR-143-3p, hinting a novel regulatory mechanism and potential therapeutic target in cervical cancer.

Dkk3 dependent transcriptional regulation controls age related skeletal muscle atrophy

Age-related muscle atrophy (sarcopenia) is the leading cause for disability in aged population, but the underlying molecular mechanisms are poorly understood. Here we identify a novel role for the secreted glycoprotein Dickkopf 3 (Dkk3) in sarcopenia. Forced expression of Dkk3 in muscles in young mice leads to muscle atrophy. Conversely, reducing its expression in old muscles restores both muscle size and function. Dkk3 induces nuclear import of β-catenin and enhances its interaction with FoxO3, which in turn activates the transcription of E3 ubiquitin ligase Fbxo32 and Trim63, driving muscle atrophy. These findings suggest that Dkk3 may be used as diagnostic marker and as therapeutic target for age-related muscle atrophy, and reveal a distinct transcriptional control of Fbxo32 and Trim63.

The long noncoding RNA HOXA11 antisense induces tumor progression and stemness maintenance in cervical cancer

Recent research has focused on the impact of long noncoding RNA (lncRNA) in cervical carcinogenesis. However, whether HOXA11 antisense (HOXA11-AS) is involved in cervical cancer remains to be elucidated. In the present study, we examined HOXA11-AS expression levels in cervical cancer patients and determined the relationships between HOXA11-AS expression and clinicopathological factors. We also investigated the bio-functional consequences of HOXA11-AS overexpression both in vitro and in vivo. HOXA11-AS expression was significantly greater in tissues from patients with cervical cancer than in control patients (P<0.001). Multivariate analysis showed that high HOXA11-AS was an independent prognosticator of overall survival (Hazard ratio=2.450, P=0.032). HOXA11-AS overexpression enhanced cell proliferation, migration, and tumor invasion in vitro, whereas HOXA11-AS knockdown inhibited these biologic aggressive features. These adverse changes were accompanied by characteristics of epithelial-mesenchymal transition (EMT). In vivo xenograft experiments using the siHOXA11-AS-transfected HeLa cells revealed that HOXA11-AS strongly induced tumor growth. Furthermore, we found that HOXA11-AS knockdown decreased cancer stemness and triggered the EMT program. In conclusion, HOXA11-AS overexpression correlated with poor survival in patients with cervical cancer. Thus, HOXA11-AS may be a pivotal target for exploring novel cervical cancer therapeutics.

Systematic assessment of cervical cancer initiation and progression uncovers genetic panels for deep learning-based early diagnosis and proposes novel diagnostic and prognostic biomarkers

Although many outstanding achievements in the management of cervical cancer (CxCa) have obtained, it still imposes a major burden which has prompted scientists to discover and validate new CxCa biomarkers to improve the diagnostic and prognostic assessment of CxCa. In this study, eight different gene expression data sets containing 202 cancer, 115 cervical intraepithelial neoplasia (CIN), and 105 normal samples were utilized for an integrative systems biology assessment in a multi-stage carcinogenesis manner. Deep learning-based diagnostic models were established based on the genetic panels of intrinsic genes of cervical carcinogenesis as well as on the unbiased variable selection approach. Survival analysis was also conducted to explore the potential biomarker candidates for prognostic assessment. Our results showed that cell cycle, RNA transport, mRNA surveillance, and one carbon pool by folate were the key regulatory mechanisms involved in the initiation, progression, and metastasis of CxCa. Various genetic panels combined with machine learning algorithms successfully differentiated CxCa from CIN and normalcy in cross-study normalized data sets. In particular, the 168-gene deep learning model for the differentiation of cancer from normalcy achieved an externally validated accuracy of 97.96% (99.01% sensitivity and 95.65% specificity). Survival analysis revealed that ZNF281 and EPHB6 were the two most promising prognostic genetic markers for CxCa among others. Our findings open new opportunities to enhance current understanding of the characteristics of CxCa pathobiology. In addition, the combination of transcriptomics-based signatures and deep learning classification may become an important approach to improve CxCa diagnosis and management in clinical practice.

Long non-coding RNA, steroid receptor RNA activator (SRA), induces tumor proliferation and invasion through the NOTCH pathway in cervical cancer cell lines

Contemporary research has focused on the function of long non-coding RNAs (lncRNAs) in carcinogenesis. However, the involvement of the lncRNA, steroid receptor RNA activator (SRA), in cervical carcinogenesis remains to be elucidated. In the present study, we investigated the bio-functional consequences of lncRNA SRA knockdown in vitro. To verify the role of lncRNA SRA in cell proliferation, migration, and invasion, lncRNA RNA interference was utilized to knock down lncRNA SRA expression in cervical cancer cell lines, resulting in our discovery that lncRNA SRA knockdown inhibited cell proliferation, cell migration and tumor invasion in the cervical cancer cell lines. Additionally, in vitro experiments using the lncRNA SRA-knockdown cervical cancer cell lines revealed that lncRNA SRA is a strong inducer and modulator of the expression of genes related to epithelial-mesenchymal transition and the NOTCH signaling pathway. In conclusion, our findings demonstrated that lncRNA SRA is highly correlated with cancer progression and cervical cancer cell proliferation and migration. Furthermore, these results indicate that lncRNA SRA may be a potential therapeutic target and prognostic marker for cervical malignancy.

Experimental Therapy of Advanced Breast Cancer: Targeting NFAT1-MDM2-p53 Pathway

Advanced breast cancer, especially advanced triple-negative breast cancer, is typically more aggressive and more difficult to treat than other breast cancer phenotypes. There is currently no curable option for breast cancer patients with advanced diseases, highlighting the urgent need for novel treatment strategies. We have recently discovered that the nuclear factor of activated T cells 1 (NFAT1) activates the murine double minute 2 (MDM2) oncogene. Both MDM2 and NFAT1 are overexpressed and constitutively activated in breast cancer, particularly in advanced breast cancer, and contribute to its initiation, progression, and metastasis. MDM2 regulates cancer cell proliferation, cell cycle progression, apoptosis, migration, and invasion through both p53-dependent and -independent mechanisms. We have proposed to target the NFAT1-MDM2-p53 pathway for the treatment of human cancers, especially breast cancer. We have recently identified NFAT1 and MDM2 dual inhibitors that have shown excellent in vitro and in vivo activities against breast cancer, including triple-negative breast cancer. Herein, we summarize recent advances made in the understanding of the oncogenic functions of MDM2 and NFAT1 in breast cancer, as well as current targeting strategies and representative inhibitors. We also propose several strategies for inhibiting the NFAT1-MDM2-p53 pathway, which could be useful for developing more specific and effective inhibitors for breast cancer therapy.

HPIP: a predictor of lymph node metastasis and poor survival in cervical cancer

Background

The aim of this study was to explore the relationships of HPIP expression status with the clinicopathological variables and survival outcomes of patients with cervical cancer (CC).

Methods

We compared the HPIP expression of 119 samples from CC tissues, 20 from cervical intraepithelial tissues, and 20 from normal cervical tissues by using immunohistochemical staining.

Results

It was observed that the ratio of elevated HPIP expression was higher in CC tissues than in cervical intraepithelial neoplasia (P=0.017) and normal cervical tissues (P=0.001). In addition, there was an association between HPIP and clinicopathological factors, such as histological grade (P<0.001), stromal infiltration (P=0.015), lymph node metastasis (P<0.001), lymphovascular space invasion (LVSI; P=0.026), and recurrence (P=0.029). Furthermore, multivariate Cox regression analysis revealed that high HPIP expression (P=0.027 and P=0.042) as well as the International Federation of Gynaecology and Obstetrics stage (P=0.003 and P=0.009), lymph node metastasis (P=0.031 and P=0.017), and LVSI (P=0.024 and P=0.046) were independent prognostic factors. In addition, we demonstrated that high HPIP expression (P=0.003) and LVSI (P<0.001) were independently related to lymph node metastasis.

Conclusion

Elevated HPIP expression may contribute to the progression and metastasis of CC and may also serve as a new biomarker to predict the prognosis of CC.

Increased CCL19 expression is associated with progression in cervical cancer

Cervical cancer is the third most common cancer and the fourth leading cause of malignancy related mortality in women worldwide. CCL19 is highly expressed in human cancer cells, and ligand CCL19 binding to CCR7 induces actin polymerization and pseudopodia formation. However, whether or not CCL19 is involved in EMT of human cervical cancer needs further investigation. Using quantitative PCR and western blot analyses, we found that CCL19 is overexpressed in cervical cancer cell lines and tissues. Knockdown of CCL19 via siRNA inhibited the proliferation of cervical cancer cells by increasing apoptosis. Further analyses showed that inhibitory effects of CCL19 on cell migration and invasion were partly associated with EMT process. In conclusion, these data indicate that CCL19 is abnormally expressed in cervical cancer, indicating a novel and important role for CCL19 in cervical cancer malignant transformation.

GINS2 is a novel prognostic biomarker and promotes tumor progression in early-stage cervical cancer

GINS complex subunit 2 (GINS2), a member of the GINS complex, is involved in DNA replication. GINS2 is upregulated in a variety of aggressive tumors. However, its role in cervical cancer carcinogenesis remains to be elucidated. We investigated the clinical significance of GINS2 in patients with early-stage cervical cancer and its biological functions in cervical cancer progression. GINS2 expression was analyzed in cervical cancer cell lines and in 8 matched cervical cancer samples at the mRNA and protein levels using real-time PCR and western blotting, respectively. GINS2 protein expression in 155 paraffin-embedded cervical cancer specimens was validated using immunohistochemistry. Statistical analysis was used to evaluate its clinicopathological significance. Short hairpin RNA interference, anchorage-independent growth ability, colony formation assay, wound healing ability, Transwell assays and western blotting were used to determine the effects of GINS2 on the aggressive phenotype of cervical cancer cells. There was obvious upregulation of GINS2 in the cervical cancer cell lines and tumor specimens compared to that in the normal cervical tissues. Significant correlations were identified between GINS2 expression and squamous cell carcinoma antigen (SCC-Ag; P<0.001), deep stromal invasion (P=0.021), vital status (P<0.001), recurrence (P<0.001) and pelvic lymph node metastasis (PLNM; P<0.001). Moreover, patients with higher GINS2 expression had shorter overall survival (OS) compared to patients with low GINS2 expression. Multivariate analysis revealed that GINS2 may serve as an independent risk factor of poor prognosis in early-stage cervical cancer. In addition, GINS2 downregulation markedly suppressed cell proliferation and tumorigenic ability, as well as cell migration and invasion. Our findings suggest that GINS2 is a novel indicator of PLNM and a valuable prognostic biomarker in early-stage cervical cancer, and subsequently is a valuable molecular target for cervical cancer diagnosis and treatment.

MiR-211 inhibits invasion and epithelial-to-mesenchymal transition (EMT) of cervical cancer cells via targeting MUC4

The dysregulated molecules and their involvement in lymph node metastases of cervical cancer are far from been fully revealed. In this study, by reviewing MUC4 expression in The Human Protein Atlas and retrieving gene microarray data in GEO dataset (No. GDS4664), we found that MUC4 upregulation is associated with lymph node metastasis in cervical cancer. Knockdown of MUC4 in Hela and SiHa cells significantly reduced their invasion and also reduced the mesenchymal properties. By performing bioinformatics analysis, we observed that miR-211 is a potential suppressor of MUC4, which has a predicted highly conserved binding site in the 3'UTR of MUC among mammals. The following assays confirmed that miR-211 can directly target the 3'UTR of MUC4 and inhibit its expression at both mRNA and protein levels. In addition, enforced miR-211 expression phenocopies the effects of MUC4 siRNA in inhibiting cervical cancer cell invasion and reversing EMT properties. Therefore, we infer that miR-211 is a novel miRNA with suppressive effect on MUC4 expression and can inhibit cervical cancer cell invasion and EMT.

Tripartite motif containing 62 is a novel prognostic marker and suppresses tumor metastasis via c-Jun/Slug signaling-mediated epithelial-mesenchymal transition in cervical cancer

Background

TRIM62 (tripartite motif containing 62) has been found to act as a tumor suppressor of several cancers. However, its precise biological role and related mechanism remain unknown in cervical cancer (CC).

Methods

Quantitative Real-time PCR and western blot were adopted to detect the mRNA and protein expression level of TRIM62 in both human CC cell lines and tissues. Immunohistochemistry was used to measure the TRIM62 expression in 30 normal cervical and 189 CC tissues. Univariate and multivariate Cox regression analyses and Kaplan–Meier survival analyses performed to investigate the association between TRIM62 expression and CC patients’ prognosis. The effect of TRIM62 on CC growth and metastasis was studied in vitro and in vivo. Multi-pathway reporter array were utilized to identify the potential signaling manipulated by TRIM62.

Results

TRIM62 was frequently down-regulated in both human CC cells and tissues. Low expression of TRIM62 in CC tissues was associated with aggressive clinicopathological features of CC patients. In addition, TRIM62 was also an independent poor prognostic factor for overall and disease-free survival of CC patients after surgery. Moreover, enforced expression of TRIM62 in CC cells significantly inhibited their abilities of proliferation, migration and invasion in vitro. Besides, subcutaneous xenograft tumor model and xenograft mouse metastatic model respectively displayed that TRIM62 impeded the growth and metastasis of CC in vivo. Furthermore, mechanism study exhibited that TRIM62 could suppress epithelial-mesenchymal transition (EMT) by inhibiting c-Jun/Slug signaling. The inhibitory role of TRIM62 in tumor proliferation might be through regulating cell cycle related proteins CyclinD1 and P27 by targeting c-Jun.

Conclusion

TRIM62 is a potential prognostic biomarker in CC and suppresses metastasis of CC via inhibiting c-Jun/Slug signaling-mediated EMT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0445-5) contains supplementary material, which is available to authorized users.

Opening the door to the development of novel Abl kinase inhibitors

The discovery of the importance of kinase activity and its relationship to the emergence and proliferation of cancer cells, due to changes in normal physiology, opened a remarkable pathway for the treatment of chronic myelogenous leukemia through intense search of drug candidates. Six Abl kinase inhibitors have received the US FDA approval as chronic myelogenous leukemia treatment, and continuous efforts in obtaining new, more effective and selective molecules are being carried out. Herein we discuss the mechanisms of Abl inhibition, structural features and ligand/protein interactions that are important for the design of new Abl kinase inhibitors. This review provides a broad overview of binding mode predictions, through molecular docking, which can be an approach to discover novel Abl kinase inhibitors.

Tumor-Suppressor Gene NBPF1 Inhibits Invasion and PI3K/mTOR Signaling in Cervical Cancer Cells

The purpose of this study was to assess the effects of NBPF1 expression on cervical cancer cell invasion and apoptosis and to illustrate its potential mechanism. Human cervical cancer HeLa cells were transfected with the constructed siNBPF1 or pcDNA3.1-NBPF1 vectors. Effects of NBPF1 expression on cell invasion ability and cell apoptosis were analyzed using the Matrigel method and an Annexin V-FITC cell apoptosis kit, respectively. In addition, cell apoptosis-related proteins involved with the PI3K/mTOR signaling pathway were analyzed using Western blot. Remediation experiments were conducted to verify the effects of NBPF1 expression on cell invasion and apoptosis. Compared to the control, mRNA and protein expressions of NBPF1 were significantly decreased when cells were transfected with siNBPF1 (p < 0.05), which was contrary to the results of cells transfected with pcDNA3.1-NBPF1. Overexpression of NBPF1 significantly suppressed HeLa cell invasion but promoted cell apoptosis (p < 0.05). Overexpression of NBPF1 performed a significant inhibitory role on PI3K/mTOR signal pathway expression, while NBPF1 was silenced, showing contrary results. Our data suggested that NBPF1 overexpression may be a suppressor for cervical cancer via affecting cell invasion and apoptosis through regulating PI3K/mTOR signaling pathway. NBPF1 may be a potential therapeutic target for cervical cancer treatment.

NR2F6 Expression Correlates with Pelvic Lymph Node Metastasis and Poor Prognosis in Early-Stage Cervical Cancer

Background: There is an abnormal expression of nuclear receptor subfamily 2 group F member 6 (NR2F6) in human cancers such as breast cancer, colon cancer, and acute myelogenous leukemia. However, its clinical significance in cervical cancer has not been established. We explored NR2F6 expression and its clinicopathological significance in early-stage cervical cancer. Methods: NR2F6 expression in cervical cancer cell lines and cervical cancer tissues was determined by Western blotting, real-time PCR, and immunochemistry (IHC). NR2F6 expression in 189 human early-stage cervical cancer tissue samples was evaluated using IHC. The relevance between NR2F6 expression and early-stage cervical cancer prognosis and clinicopathological features was determined. Results: There was marked NR2F6 mRNA and protein overexpression in the cervical cancer cells and clinical tissues compared with an immortalized squamous cell line and adjacent noncancerous cervical tissues, respectively. In the 189 cervical cancer samples, NR2F6 expression was positively related to International Federation of Gynecology and Obstetrics (FIGO) stage (p = 0.006), squamous cell carcinoma antigen (p = 0.006), vital status (p < 0.001), tumor recurrence (p = 0.001), chemotherapy (p = 0.039), and lymph node metastasis (p < 0.001). Overall and disease-free survival was shorter in patients with early-stage cervical cancer and higher NR2F6 levels than in patients with lower levels of NR2F6. Univariate and multivariate analysis determined that NR2F6 was an independent prognostic factor of survival in early-stage cervical cancer. Conclusions: Taken together, our findings suggest that high NR2F6 expression predicts pelvic lymph node metastasis, tumor recurrence and poor prognosis in early-stage cervical cancer. NR2F6 might be a novel prognostic biomarker and potential therapeutic target of cervical cancer.

Role of the teneurins, teneurin C-terminal associated peptides (TCAP) in reproduction: clinical perspectives

In humans, the teneurin gene family consists of four highly conserved paralogous genes that are the result of early vertebrate gene duplications arising from a gene introduced into multicellular organisms from a bacterial ancestor. In vertebrates and humans, the teneurins have become integrated into a number of critical physiological systems including several aspects of reproductive physiology. Structurally complex, these genes possess a sequence in their terminal exon that encodes for a bioactive peptide sequence termed the 'teneurin C-terminal associated peptide' (TCAP). The teneurin/TCAP protein forms an intercellular adhesive unit with its receptor, latrophilin, an Adhesion family G-protein coupled receptor. It is present in numerous cell types and has been implicated in gamete migration and gonadal morphology. Moreover, TCAP is highly effective at reducing the corticotropin-releasing factor (CRF) stress response. As a result, TCAP may also play a role in regulating the stress-associated inhibition of reproduction. In addition, the teneurins and TCAP have been implicated in tumorigenesis associated with reproductive tissues. Therefore, the teneurin/TCAP system may offer clinicians a novel biomarker system upon which to diagnose some reproductive pathologies.

Prognostic significance of circulating laminin gamma2 for early-stage non-small-cell lung cancer

Background

Laminin gamma2 (Ln-γ2) chain, a distinctive subunit of heterotrimeric laminin-332, is frequently upregulated in carcinomas and is of great importance in cell migration and invasion. Despite this, the status of circulating Ln-γ2 in lung cancer patients is still uncertain.

Patients and methods

In this retrospective study, serum samples from 538 all-stage (stages I–IV) patients with non-small-cell lung cancer (NSCLC) and 94 age-matched healthy volunteers were investigated by enzyme-linked immunosorbent assay. Data were statistically analyzed in combination with clinicopathological information.

Results

Circulating Ln-γ2 was markedly increased in NSCLC, even in stage I cases (P<0.01), reflecting the progression of lung cancer. Survival analysis on 370 eligible patients indicated that serum Ln-γ2-negative patients survived much longer compared with Ln-γ2-positive individuals (P=0.028), and it was especially the case for stage I (P<0.001), stage T1 (P=0.001), and stage N0 patients (P=0.038), all of whom represented early-stage cases. For the advanced patients, however, overall survivals were not significantly different among stages II–IV (P=0.830), stages T2–T4 (P=0.575), stages N1–N3 (P=0.669), and stage M1 (P=0.849). Cox analysis subsequently defined serum Ln-γ2 as an independent prognostic indicator of NSCLC, particularly for early-stage patients. Furthermore, we demonstrated the association of serum Ln-γ2 with smoking behavior, but its association with tumor progression and early prognostic significance were not altered in the nonsmoking cohort.

Conclusion

Our study demonstrated that elevation of circulating Ln-γ2 was an early-emerging event in NSCLC and was significantly associated with poor prognosis in NSCLC, especially for early-stage cases.

Long non-coding RNA HOTAIR modulates HLA-G expression by absorbing miR-148a in human cervical cancer

The long non-coding RNA HOX transcript antisense RNA (HOTAIR) has been found overexpressed in many human malignancies and involved in tumor progression and metastasis. However, little is known about the potential biological roles of HOTAIR in tumor escape. In the present study, the expression of HOTAIR was detected in 59 paired cervical cancer tissue samples by real-time PCR and then subjected to correlation analysis with clinical features. The effects of HOTAIR on cervical cancer cells as well as the expression of human leukocyte antigen (HLA)-G were studied by overexpression and RNA interference approaches. Insight into the mechanism of HOTAIR acting as competitive endogenous RNAs (ceRNAs) was gained from bioinformatic analysis and luciferase assays. HOTAIR expression was obviously increased in cervical cancer tissue. HOTAIR upregulation was associated with advanced pathological stage, histology, lymph node invasion and lymphatic metastasis, and also correlated with shorter overall survival of cervical cancer patients. Furthermore, HOTAIR overexpression promoted the proliferation, migration and invasion of cervical cancer cells, while HOTAIR knockdown inhibited cell invasion and cell viability, induced apoptosis and inhibited growth in vitro and in vivo. Moreover, HOTAIR modulated human leucocyte antigen-G (HLA-G) expression by competitively binding miR-148a. Our data suggest that HOTAIR plays an important oncogenic role in cervical cancer and might serve as a marker for cervical cancer prognosis and a potential target for therapeutic intervention.

Identification of methylation markers for the prediction of nodal metastasis in oral and oropharyngeal squamous cell carcinoma

Hypermethylation is an important mechanism for the dynamic regulation of gene expression, necessary for metastasizing tumour cells. Our aim is to identify methylation tumour markers that have a predictive value for the presence of regional lymph node metastases in patients with oral and oropharyngeal squamous cell carcinoma (OOSCC). Significantly differentially expressed genes were retrieved from four reported microarray expression profiles comparing pN0 and pN+ head-neck tumours, and one expression array identifying functionally hypermethylated genes. Additional metastasis-associated genes were included from the literature. Thus genes were selected that influence the development of nodal metastases and might be regulated by methylation. Methylation-specific PCR (MSP) primers were designed and tested on 8 head-neck squamous cell carcinoma cell lines and technically validated on 10 formalin-fixed paraffin-embedded (FFPE) OOSCC cases. Predictive value was assessed in a clinical series of 70 FFPE OOSCC with pathologically determined nodal status. Five out of 28 methylation markers (OCLN, CDKN2A, MGMT, MLH1 and DAPK1) were frequently differentially methylated in OOSCC. Of these, MGMT methylation was associated with pN0 status (P = 0.02) and with lower immunoexpression (P = 0.02). DAPK1 methylation was associated with pN+ status (P = 0.008) but did not associate with protein expression. In conclusion, out of 28 candidate genes, two (7%) showed a predictive value for the pN status. Both genes, DAPK1 and MGMT, have predictive value for nodal metastasis in a clinical group of OOSCC. Therefore DNA methylation markers are capable of contributing to diagnosis and treatment selection in OOSCC. To efficiently identify additional new methylation markers, genome-wide methods are needed.

Characterization of long non-coding RNA expression profiles in lymph node metastasis of early-stage cervical cancer

Pelvic lymph node metastasis (PLNM) is an independent prognostic parameter and determines the treatment strategies of cervical cancer. Increasing evidence indicates that long non-coding RNAs (lncRNAs) play a crucial role in the process of tumor biological functions. This study aimed to mine lymph node metastasis-associated lncRNAs and investigate their potential pathophysiological mechanism in cervical cancer lymph node metastasis. We applied the lncRNA-mining approach to identify lncRNA transcripts represented on Affymetrix human genome U133 plus 2.0 microarrays from Gene Expression Omnibus (GEO) and then by validation in clinical specimens. The biological role and molecular mechanism of these lncRNAs were predicted by bioinformatic analysis. Subsequently, a receiver operating characteristic (ROC) curve and survival curve were conducted to evaluate the diagnostic and prognostic value of candidate lncRNAs. In total, 234 differentially expressed lncRNAs were identified to significantly associate with pelvic lymph node metastasis in early-stage cervical cancer. Our qRT-PCR results were consistent with the mining analysis (P<0.05). The functional enrichment analysis suggested that these lncRNAs may be involved in the biological process of lymph node metastasis. The ROC curves demonstrated satisfactory discrimination power of MIR100HG and AC024560.2 with areas under the curve of 0.801 and 0.837, respectively. Survival curve also indicated that patients with high MIR100HG expression had a tendency of poor prognosis. This is the first study to successfully mine the lncRNA expression patterns in PLNM of early-stage cervical cancer. MIR100HG and AC024560.2 may be a potential biomarkers of PLNM and these lncRNAs may provide broader perspective for combating cervical cancer metastasis.

Transforming growth factor-β1 in carcinogenesis, progression, and therapy in cervical cancer

Transforming growth factor β1 (TGF-β1) is a multifunctional cytokine that plays important roles in cervical tumor formation, invasion, progression, and metastasis. TGF-β1 functions as a tumor inhibitor in precancerous lesions and early stage cancers of cervix whereas as a tumor promoter in later stage. This switch from a tumor inhibitor to a tumor promoter might be due to various alterations in TGF-β signaling pathway, such as mutations or loss of expression of TGF-β receptors and SMAD proteins. Additionally, the oncoproteins of human papillomaviruses have been shown to stimulate TGF-β1 expression, which in turn suppresses host immune surveillance. Thus, in addition to driving tumor cell migration and metastasis, TGF-β1 is believed to play a key role in promoting human papillomavirus infection by weakening host immune defense. In this article, we will discuss the role of TGF-β1 in the expression, carcinogenesis, progression, and therapy in cervical cancers. A better understanding of this cytokine in cervical carcinogenesis is essential for critical evaluation of this cytokine as a potential prognostic marker and therapeutic target.

MiR-519d facilitates the progression and metastasis of cervical cancer through direct targeting Smad7

Background

MicroRNAs (miRNAs) play pivotal roles in the development of various cancer types, including cervical cancer.

Methods and results

In this study, we showed that miR-519d, a miRNA within the chromosome 19 miRNA cluster, was significantly upregulated in cervical cancer tissues, compared with non-tumorous cervical samples. Suppression of miR-519d markedly attenuated the migration and invasion of HeLa and SiHa cervical cancer cells. Additionally, miR-519d inhibited the apoptosis of cervical cancer cells, and the proliferation of cervical cancer cells was also affected following transfection of miR-519d inhibitor. Moreover, we identified Smad7 to be a novel target of miR-519d in cervical cancer cells. MiR-519d matched the 3′-UTR of Smad7 mRNA. Transfection with miR-519d mimics led to apparent downregulation of Smad7 both at the mRNA and protein levels. Luciferase reporter analysis revealed that miR-519d reduced the luciferase activity of Smad7 mRNA 3′-UTR through matching site-dependent manner. And more notably, suppression of Smad7 remarkably restored the migration and invasion of miR-519d-depleted cervical cancer cells.

Conclusion

Taken together, these findings implicated that miR-519d promoted the progression and metastasis of cervical cancer through targeting Smad7.

Interleukin-33 in tumorigenesis, tumor immune evasion, and cancer immunotherapy

Interleukin-33 (IL-33) is a member of the IL-1 gene family and mainly expressed in the nucleus of tissue lining cells, stromal cells, and activated myeloid cells. IL-33 is considered a damage-associated molecular pattern (DAMP) molecule and plays an important role in many physiological and pathological settings such as tissue repair, allergy, autoimmune disease, infectious disease, and cancer. The biological functions of IL-33 include maintaining tissue homeostasis, enhancing type 1 and 2 cellular immune responses, and mediating fibrosis during chronic inflammation. IL-33 exerts diverse functions through signaling via its receptor ST2, which is expressed in many types of cells including regulatory T cells (Treg), group 2 innate lymphoid cells (ILC2s), myeloid cells, cytotoxic NK cells, Th2 cells, Th1 cells, and CD8(+) T cells. Tumor development results in downregulation of IL-33 in epithelial cells but upregulation of IL-33 in the tumor stroma and serum. The current data suggest that IL-33 expression in tumor cells increases immunogenicity and promotes type 1 antitumor immune responses through CD8(+) T cells and NK cells, whereas IL-33 in tumor stroma and serum facilitates immune suppression via Treg and myeloid-derived suppressor cell (MDSC). Understanding the role of IL-33 in cancer immunobiology sheds lights on targeting this cytokine for cancer immunotherapy.

Prognostic Value of SMAD4 in Pancreatic Cancer: A Meta-Analysis

PURPOSE: The prognostic value of SMAD4 in pancreatic cancer has been evaluated in several studies. However, the conclusions remain controversial. Therefore, we aimed to evaluate the association between SMAD4 expression and the outcome of pancreatic cancer patients by performing a meta-analysis. METHODS: We systematically searched for relevant studies evaluating the relationship between SMAD4 expression and the outcome of pancreatic cancer patients until May 2015. A meta-analysis was performed using STATA 12.0, and pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate the strength of the association between SMAD4 expression and the prognosis of pancreatic cancer patients. RESULTS: The analysis included 1762 patients from 14 studies, with 1401 patients from 11 studies and 927 patients from 8 studies included in the univariate and multivariate analyses, respectively. Loss of SMAD4 expression was found to be significantly correlated with poor overall survival, with the combined HR (95% CI) of 1.20 (1.03-1.40). After adjusting for potential confounders using the Cox regression model, the pooled HR (95% CI) was 1.88 (1.31-2.70). In subgroup analysis, study region, number of patients, follow-up duration, and cutoff value were found to affect the significance of the association between loss of SMAD4 expression and poor prognosis. In addition, there was no evidence of publication bias, as suggested by Begg’s and Egger’s test. CONCLUSIONS: Loss of SMAD4 was associated with poor survival and was a negative prognostic indicator in patients with pancreatic cancer.

Acylglycerol kinase is over-expressed in early-stage cervical squamous cell cancer and predicts poor prognosis

Acylglycerol kinase (AGK) had been shown to contribute to cancer progression and unfavorable clinical outcomes of patients. Our study aimed to investigate the expression pattern and clinical significance of AGK in patients with early-stage cervical squamous cell cancer (CSCC). The protein and messenger RNA (mRNA) expression of AGK was analyzed in six cervical cancer cell lines and four paired early-stage CSCC specimens and normal cervical tissues (NCT), using Western blotting and real-time PCR (RT-PCR). And we investigated the AGK protein expression in paraffin-embedded specimens from 140 patients with early-stage CSCC and 30 cases of NCT by immunohistochemistry (IHC). Statistical analyses were performed to evaluate the clinicopathological significance of AGK expression. The expressions of AGK protein and mRNA were significantly up-regulated in cervical cancer cell lines and cancer tissues. IHC analyses revealed that AGK was highly expressed in 93 (66.4 %) of 140 early-stage CSCC specimens, but in none of the NCT. Moreover, AGK expression in early-stage CSCC was significantly correlated with tumor stage (P < 0.001), tumor size (P < 0.001), and tumor type (P < 0.001). Early-stage CSCC patients with high AGK expression level had shorter progress-free survival (PFS) and overall survival (OS) time compared with patients with low AGK expression levels. Univariate and multivariate analyses identified AGK expression level as an independent prognostic factor for survival of early-stage CSCC patients. We showed that AGK was over-expressed in cervical cancer cell lines and clinical tissues, and over-expression of AGK was associated with poor survival outcomes of early-stage CSCC patients. AGK can be used as an independent prognostic marker for early-stage CSCC.

DLL4 as a predictor of pelvic lymph node metastasis and a novel prognostic biomarker in patients with early-stage cervical cancer

Delta-like ligand 4 (DLL4), one of the five Notch signaling ligands in mammals, has an important function in proliferation, invasion, metastasis, progression, and angiogenesis of malignancies. This study aimed to investigate DLL4 expression level in early-stage cervical carcinoma and to evaluate its clinical significance. We used fresh frozen and paraffin-embedded cervical cancer tissues to analyze DLL4 expression and its clinical significance. DLL4 expression at both mRNA and protein levels in cervical cancer tissues was significantly higher than that in normal cervical tissues. High DLL4 protein level was clearly correlated with high International Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.044), lymphovascular space involvement (LVSI) (P = 0.015), pelvic lymph node metastasis (PLNM) (P = 0.001), and recurrence (P < 0.001). Univariate and multivariate logistic regression analyses demonstrated that DLL4 overexpression was strongly associated with lymph node metastasis (odds ratio, 2.790; 95 % CI, 1.344-5.791; P = 0.006). Moreover, survival analysis revealed that DLL4 expression was an independent factor of unfavorable overall survival (hazard ratio, 2.130; 95 % CI, 1.108-4.097; P = 0.023) and disease-free survival (hazard ratio, 1.965; 95 % CI, 1.085-3.560; P = 0.026) in patients with cervical cancer. Overall, our data indicate that high DLL4 expression predicts pelvic lymph node metastasis and poor survival in cervical cancer. Therefore, DLL4 may be a potential clinical diagnostic marker for patients with early-stage cervical cancer.

Network Topologies Decoding Cervical Cancer

According to the GLOBOCAN statistics, cervical cancer is one of the leading causes of death among women worldwide. It is found to be gradually increasing in the younger population, specifically in the developing countries. We analyzed the protein-protein interaction networks of the uterine cervix cells for the normal and disease states. It was found that the disease network was less random than the normal one, providing an insight into the change in complexity of the underlying network in disease state. The study also portrayed that, the disease state has faster signal processing as the diameter of the underlying network was very close to its corresponding random control. This may be a reason for the normal cells to change into malignant state. Further, the analysis revealed VEGFA and IL-6 proteins as the distinctly high degree nodes in the disease network, which are known to manifest a major contribution in promoting cervical cancer. Our analysis, being time proficient and cost effective, provides a direction for developing novel drugs, therapeutic targets and biomarkers by identifying specific interaction patterns, that have structural importance.

C14ORF166 overexpression is associated with pelvic lymph node metastasis and poor prognosis in uterine cervical cancer

C14ORF166 (chromosome 14 open reading frame 166) is a transcriptional repressor related to the regulation of centrosome architecture. However, the role of C14ORF166 in the development and progression of cancer remains largely unknown. The aim of this study was to investigate the expression and clinicopathological significance of C14ORF166 in cervical cancer. C14ORF166 expression was analyzed using quantitative real-time PCR (RT-PCR) and Western blotting in cervical cancer cell lines and eight paired cervical cancer samples and the adjacent normal tissues. Immunohistochemistry was used to analyze C14ORF166 protein expression in 148 clinicopathologically characterized cervical cancer specimens. Statistical analyses were performed to evaluate the relationship between the expression of C14ORF166 and clinicopathologic features and prognosis. C14ORF166 mRNA and protein expression were significantly upregulated in cervical cancer cell lines and tissue samples (P < 0.05). Immunohistochemical analysis revealed a high expression of C14ORF166 was observed in 39.9 % (59/148) of the cervical cancer specimens; the remaining samples expressed low levels or did not express any detectable C14ORF166. The chi-square test indicated that high-level expression of C14ORF166 was significantly associated with International Federation of Gynecology and Obstetrics (FIGO) stage (P < 0.001), vital status (P = 0.026), tumor size (P = 0.034), serum squamous cell carcinoma antigen level (SCC-Ag; P = 0.035), and pelvic lymph node metastasis (P < 0.001). Patients with highly expressed C14ORF166 showed a tendency to receive postoperative chemotherapy (P = 0.005) and postoperative radiation (P = 0.008). Furthermore, high C14ORF166 expression was associated with poorer overall survival compared to low C14ORF166 expression, and C14ORF166 was a significant prognostic factor in univariate and multivariate analysis (P < 0.05). High C14ORF166 expression had prognostic value for poor outcome in cervical cancer. C14ORF166 may represent a biomarker of pelvic lymph node metastasis and enable the identification of high-risk patients along with selection of appropriate treatment strategies.

c.29C>T polymorphism in the transforming growth factor-β1 (TGFB1) gene correlates with increased risk of urinary bladder cancer

TGF-β1 is a pleiotropic cytokine, which plays a dual role in tumor development. In the early stages, it inhibits the growth of tumor while in the late stages of carcinoma, it promotes tumor growth. The purpose of this study was to analyze the distribution of the TGFB1 gene polymorphisms between cases and controls so as to assess their correlation with bladder cancer risk. This study included 237 cases of urinary bladder cancer and 290 age matched controls from the same ethnic background. Three polymorphisms in the TGFB1 gene, c.29C>T (rs-1800470), c.74G>C (rs-1800471) and +140A>G (rs-13447341), were analyzed by direct DNA sequencing. Statistical analyses revealed no significant differences in the demographical data, except that the frequencies of smokers and non-vegetarians were higher in the cases. Eighty percent of the bladder cancer patients had superficial transitional cell carcinoma, and 53.16% and 26.31% of the patients were in grade I and grade II, respectively. We found that c.29C>T substitution increased the risk of bladder cancer significantly and recessive model of analysis was the best fitted model (p=0.004; OR=1.72 95% CI 1.18-2.50). A significantly higher risk in the recessive form was also suggested by co-dominant analysis showing that the homozygous form (TT) was a significant risk factor in comparison to CC and CT genotypes. The other two polymorphisms, c.74G>C (p=0.18, OR=0.67 95% CI 0.37-1.21) and +140A>G (p=0.416, OR=0.77 95% CI 0.41-1.45) did not affect the risk of urinary bladder cancer. In conclusion, we found that the TGFB1 c.29C>T substitution increases the risk of bladder cancer significantly while c.74G>C and +140A>G polymorphisms do not affect the risk.

Curcumin and emodin down-regulate TGF-β signaling pathway in human cervical cancer cells

Cervical cancer is the major cause of cancer related deaths in women, especially in developing countries and Human Papilloma Virus infection in conjunction with multiple deregulated signaling pathways leads to cervical carcinogenesis. TGF-β signaling in later stages of cancer is known to induce epithelial to mesenchymal transition promoting tumor growth. Phytochemicals, curcumin and emodin, are effective as chemopreventive and chemotherapeutic compounds against several cancers including cervical cancer. The main objective of this work was to study the effect of curcumin and emodin on TGF-β signaling pathway and its functional relevance to growth, migration and invasion in two cervical cancer cell lines, SiHa and HeLa. Since TGF-β and Wnt/β-catenin signaling pathways are known to cross talk having common downstream targets, we analyzed the effect of TGF-β on β-catenin (an important player in Wnt/β-catenin signaling) and also studied whether curcumin and emodin modulate them. We observed that curcumin and emodin effectively down regulate TGF-β signaling pathway by decreasing the expression of TGF-β Receptor II, P-Smad3 and Smad4, and also counterbalance the tumorigenic effects of TGF-β by inhibiting the TGF-β-induced migration and invasion. Expression of downstream effectors of TGF-β signaling pathway, cyclinD1, p21 and Pin1, was inhibited along with the down regulation of key mesenchymal markers (Snail and Slug) upon curcumin and emodin treatment. Curcumin and emodin were also found to synergistically inhibit cell population and migration in SiHa and HeLa cells. Moreover, we found that TGF-β activates Wnt/β-catenin signaling pathway in HeLa cells, and curcumin and emodin down regulate the pathway by inhibiting β-catenin. Taken together our data provide a mechanistic basis for the use of curcumin and emodin in the treatment of cervical cancer.

Invasion of uterine cervical squamous cell carcinoma cells is facilitated by locoregional interaction with cancer-associated fibroblasts via activating transforming growth factor-beta

OBJECTIVE

Local invasion is a common pattern of spread in uterine cervical squamous cell carcinoma (CSCC). Although transforming growth factor-beta (TGF-β) facilitates invasion of various types of cancer cells, the role of the TGF-β pathway in CSCC is unclear. In this study, we analyzed the role of TGF-β signaling in the progression of CSCC.

METHODS

Immunohistochemistry was used to examine the expression of TGF-β pathway molecules in 67 CSCC samples with clinicopathological data. Activation of the TGF-β pathway was investigated following co-culture of CSCC cells and cervical cancer-associated fibroblasts (CCAFs).

RESULTS

Clinicopathological analysis of CSCC samples revealed that prominent expression of TGF-β receptor-2 was more frequent in CSCC with lymphovascular space invasion (LVSI) than without LVSI (p < 0.01). Lymph node metastasis was more frequent in cases in which phosphorylated SMAD3 (pSMAD3) was localized exclusively at the boundary of tumor clusters (n = 9, p < 0.05). Recombinant TGF-β1 increased pSMAD3 expression and enhanced cellular invasion (p < 0.005) in CSCC cells, which was attenuated by an inhibitor of the TGF-β receptor (p < 0.005). Enhanced pSMAD3 expression and invasion was also observed when conditioned media from CSCC cells co-cultured with CCAFs were administered. Luciferase assays showed that this medium contained a large amount of active TGF-β. Along with TGF-β activation, thrombospondin-1 was upregulated in both CSCC cells and CCAFs, while thrombospondin-1 silencing in either CSCC cells or CCAFs repressed the activity of TGF-β. Thrombospondin-1 was prominently expressed in cases with pSMAD3 boundary staining (p < 0.05).

CONCLUSIONS

These results suggest that interaction between CSCC cells and surrounding CCAFs activates TGF-β via thrombospondin-1 secretion to facilitate CSCC invasion.

Up-regulation of FOXM1 by E6 oncoprotein through the MZF1/NKX2-1 axis is required for human papillomavirus-associated tumorigenesis

PURPOSE

Foxhead box M1 (FOXM1) expression has been shown to be linked with human papillomavirus (HPV) 16/18-infected cervical cancer. However, the mechanism underlying the induction of FOXM1 in HPV 16/18-infected cancers remains elusive.

EXPERIMENTAL DESIGN

The mechanistic actions of FOXM1 induced by the E6/NKX2-1 axis in tumor aggressiveness were elucidated in cellular and animal models. The prognostic value of FOXM1 for overall survival (OS) and relapse-free survival (RFS) in HPV-positive oral and lung cancers was assessed using Kaplan-Meier and Cox regression models.

RESULTS

Herein, FOXM1 expression is upregulated by E6-mediated NKX2-1 in HPV-positive cervical, oral, and lung cancer cells. Induction of FOXM1 by E6 through the MZF1/NKX2-1 axis is responsible for HPV-mediated soft agar growth, invasiveness, and stemness through activating Wnt/β-catenin signaling pathway. In a nude mice model, metastatic lung tumor nodules in HPV 18 E6-positive GNM or HPV 16 E6-positive TL-1-injected nude mice were markedly decreased in both cell types with E6 knockdown, FOXM1 knockdown, or treatment with FOXM1 inhibitor (thiostrepton). Among the four subgroup patients, the worst FOXM1 prognostic value for OS and RFS was observed in HPV 16/18-positive patients with tumors with high-expressing FOXM1.

CONCLUSIONS

Induction of FOXM1 by E6 oncoprotein through the MZF1/NKX2-1 axis may be responsible for HPV 16/18-mediated tumor progression and poor outcomes in HPV-positive patients.

Long non-coding RNA HOTAIR is associated with human cervical cancer progression

The functions of many long non-coding RNAs (lncRNAs) in human cancers remain to be clarified. The lncRNA Hox transcript antisense intergenic RNA (HOTAIR) has been reported to reprogram chromatin organization and promote breast and colorectal cancer metastasis, the involvement of lncRNAs in cervical cancer is just beginning to be studied. In the present study, we examined the expression and the functional role of HOTAIR in cervical cancer. HOTAIR expression was determined in cervical cancer tissues (n=111) and corresponding normal tissues (n=40) by using real-time polymerase chain reaction, and its correlation with clinical parameters and prognosis were analyzed. To determine the effect of HOTAIR knockdown and overexpression in cervical cancer cell lines, we used the CCK-8 assay, wound healing migration and Matrigel invasion assay. The expression level of HOTAIR in cervical cancer tissues was higher than that in corresponding non-cancerous tissues. High HOTAIR expression correlated with lymph node metastasis, and reduced overall survival. A multivariate analysis showed that HOTAIR was a prognostic factor for predicting cervical cancer recurrence. Knockdown of HOTAIR reduced cell proliferation, migration, and invasion in cervical cancer cell lines. Moreover, HOTAIR regulated the expression of vascular endothelial growth factor, matrix metalloproteinase-9 and epithelial-to-mesenchymal transition (EMT)-related genes, which are important for cell motility and metastasis. Therefore, HOTAIR may promote tumor aggressiveness through the upregulation of VEGF and MMP-9 and EMT-related genes. These findings indicate that HOTAIR may represent a novel biomarker for predicting recurrence and prognosis and serve as a promising therapeutic target in cervical cancer.

Six1 overexpression at early stages of HPV16-mediated transformation of human keratinocytes promotes differentiation resistance and EMT

Previous studies in our laboratory discovered that SIX1 mRNA expression increased during in vitro progression of HPV16-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. In this study, we explored the role of Six1 at early stages of HPV16-mediated transformation by overexpressing Six1 in HKc/HPV16. We found that Six1 overexpression in HKc/HPV16 increased cell proliferation and promoted cell migration and invasion by inducing epithelial-mesenchymal transition (EMT). Moreover, the overexpression of Six1 in HKc/HPV16 resulted in resistance to serum and calcium-induced differentiation, which is the hallmark of the HKc/DR phenotype. Activation of MAPK in HKc/HPV16 overexpressing Six1 is linked to resistance to calcium-induced differentiation. In conclusion, this study determined that Six1 overexpression resulted in differentiation resistance and promoted EMT at early stages of HPV16-mediated transformation of human keratinocytes.

Meta-analysis of the prognostic value of smad4 immunohistochemistry in various cancers

Background

Accumulating evidence indicates that Smad4 (DPC4) plays a fundamental role in the development and prognosis of several types of cancer. The objective of this study was to conduct a meta-analysis to evaluate whether the loss of Smad4 staining could serve as a prognostic marker.

Methods

A comprehensive meta-analysis was conducted using major useful databases to determine the relationship between the immunohistochemical detection of Smad4 and the survival of patients with various cancers. We used hazard ratios (HRs) with 95% confidence interval (CIs) as the effect estimation to evaluate the association of Smad4 with overall survival (OS), cancer-specific survival (CSS) or recurrence-free survival (RFS). The relationship between the clinical characteristics of patients and Smad4 was also evaluated using the odds ratio (OR).

Results

A total of 7570 patients from 26 studies were included in the analysis. The pooled results showed that loss of Smad4 staining was a negative predictor of OS with an HR of 1.97 (95% CI: 1.55–2.51; P_{heterogeneity}<0.001) and CSS/RFS (HR = 1.81; 95% CI: 1.30–2.54; P_{heterogeneity}<0.001). In addition, loss of Smad4 staining was more likely to be found in older (OR = 1.69, 95% CI: 1.09–2.61; P_{heterogeneity} = 0.648) colorectal cancer patients with a late tumor stage (OR = 2.31, 95% CI: 1.71–3.10; P_{heterogeneity} = 0.218) and in gastric cancer patients with lymph node metastasis (OR = 2.11, 95% CI: 1.03–4.34; P_{heterogeneity} = 0.038).

Conclusion

Based on these results, our meta-analysis provided evidence that loss of Smad4 staining could act as an unfavorable biomarker in the prognosis of various cancers and should be used as a powerful tool in future clinical trials.

CISD2 expression is a novel marker correlating with pelvic lymph node metastasis and prognosis in patients with early-stage cervical cancer

The CDGSH iron sulfur domain2 (CISD2) is an evolutionarily conserved gene. It functions to control mammalian life span and regulate human breast cancer cells proliferation. However, the characteristics of CISD2 expression and its clinical/prognostic significance are unclear in human tumor. Our study aimed to investigate the expression pattern and clinicopathological significance of CISD2 in patients with early-stage cervical cancer. The mRNA and protein expression levels of CISD2 were analyzed in eight cervical cancer cell lines and eight paired cervical cancer tumors by real-time PCR and Western blotting, respectively. Immunohistochemistry was performed to examine CISD2 protein expression in paraffin-embedded tissues from 149 early-stage cervical cancer patients. Statistical analyses were used to evaluate the clinicopathological significance of CISD2 expression. CISD2 expression was significantly upregulated in cervical cancer cells at both the mRNA and protein levels. Statistical analysis showed a significant correlation of CISD2 expression with the squamous cell carcinoma antigen (P = 0.000), myometrium invasion (P = 0.003), recurrence (P = 0.012), lymphovascular space involvement (P = 0.019) and especially pelvic lymph node metastasis (PLNM; P = 0.000). Patients with higher CISD2 expression had shorter overall survival duration than patients with lower CISD2 expression. Multivariate analysis suggested that CISD2 expression might be an independent prognostic indicator for the survival of patients with early-stage cervical cancer. Our results for the first time suggested that high CISD2 expression was closely correlated with PLNM and poor prognosis in early-stage cervical cancer patients. CISD2 protein might be a novel biomarker for early-stage cervical cancer progression.

MicroRNA‑10a enhances the metastatic potential of cervical cancer cells by targeting phosphatase and tensin homologue

Cervical cancer is one of the leading causes of cancer‑related mortality worldwide. Previously, the upregulation of microRNA (miR)‑10a has been identified in human cervical cancer. The present study firstly demonstrated that miR‑10a was markedly upregulated in primary tumor tissues in patients with positive lymph node metastasis (LN+) compared with negative (LN‑) by quantitative polymerase chain reaction. miR‑10a mimics markedly enhanced cervical cancer cell migration and invasion abilities, and accordingly the miR‑10a inhibitor suppressed those functions. Furthermore, these data suggested that the phosphatase and tensin homologue (PTEN) was inhibited by miR‑10a through an miR‑10a binding site within the 3'‑untranslated region of PTEN at the posttranscriptional level, and that miR‑10a mimics promoted nuclear translocation of β‑catenin. Therefore, it was concluded that the overexpression of miR‑10a contributes to metastasis in cervical cancer by targeting PTEN. miR‑10a may therefore be used clinically as a molecular marker for patients with cervical cancer lymph node metastasis.

TBLR1 is a novel prognostic marker and promotes epithelial-mesenchymal transition in cervical cancer

BACKGROUND

Invasion and metastasis remain a critical issue in cervical cancer. However, the underlying mechanism of it in cervical cancer remains unclear. The newly discovered protein, TBLR1, plays a crucial role in regulating various key cellular functions.

METHODS

In this study, western blot, real-time RT-PCR, immunohistochemical staining, 3D morphogenesis Matrigel culture, wound healing and Boyden chamber invasion assays, xenografted tumour model, luciferase assays, and chromatin immunoprecipitation assays were used.

RESULTS

The expression of TBLR1 in cervical cancer cell lines and tissues was significantly upregulated at both the RNA and protein levels compared with that in normal cervical cells. Statistical analysis suggested that TBLR1 as an independent prognostic factor was significantly correlated with the clinical stage, survival time and recurrence. Moreover, overexpression of TBLR1 in Hela and Siha cell lines promoted invasion in vitro and in vivo with the increases of the mesenchymal factors vimentin and fibronectin and decreases of the epithelial marker α-catenin. In contrast, RNAi-mediated knockdown of TBLR1 inhibited epithelial-mesenchymal transition in vitro and in vivo. Further study indicated that this might be mediated via the NF-κB and Wnt/β-Catenin signalling pathway, and involve regulation of Snail and Twist.

CONCLUSIONS

The TBLR1 protein may be a prognostic marker in cervical cancer and play an important role in the invasion and metastasis of human cervical cancer.

Six1 promotes epithelial-mesenchymal transition and malignant conversion in human papillomavirus type 16-immortalized human keratinocytes

Six1, a member of the Six family of homeodomain transcription factors, is overexpressed in various human cancers, and SIX1 overexpression is associated with tumor progression and metastasis. Six1 messenger RNA levels increase during in vitro progression of human papillomavirus type 16 (HPV16)-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. In this study, we show that HKc/DR-overexpressing Six1 exhibited a more mesenchymal phenotype, as characterized by a fibroblastic appearance and increased invasion. We utilized Whole Human Genome Microarrays to explore the gene expression changes associated with Six1 overexpression in HKc/DR. We found that overexpression of Six1 downregulated epithelial-related genes and upregulated mesenchymal-related genes, which suggests that Six1 overexpression induces epithelial-mesenchymal transition (EMT). Pathway analysis of the microarray data showed alterations in the transforming growth factor-beta (TGF-β) pathway, including enhanced expression of the TGF-β receptor type II (TβRII), and activation of the mitogen-activated protein kinase (MAPK) pathway in HKc/DR-overexpressing Six1, suggesting that Smad-independent pathways of TGF-β signaling may be involved in Six1-mediated EMT. p38 MAPK activation was required for sustained Six1-induced EMT and TβRII overexpression. Finally, we determined that Six1 overexpression in HKc/DR resulted in malignant conversion and increased the cancer stem cell (CSC)-like population. Thus, Six1 overexpression promotes EMT, CSCs properties and malignant conversion in HKc/DR through MAPK activation, which supports the possible use of p38-TβRII inhibitors for the treatment of cancers overexpressing Six1.

miR-135a leads to cervical cancer cell transformation through regulation of β-catenin via a SIAH1-dependent ubiquitin proteosomal pathway

Human papillomaviruses (HPVs) is the principal etiological agent of cervical cancer (CC). However, exposure to the high-risk type HPV alone is insufficient for tumor formation, and additional factors are required for the HPV-infected cells to become tumorigenic. Dysregulated microRNAs (miRNAs) expression is frequently observed in cancer but their roles in the formation of CC have not been fully revealed. In this study, we compared the expression of miR-135a in laser capture microdissected cervical specimens and confirmed overexpression of the miRNA in malignant cervical squamous cell carcinoma compared with precancerous lesions. Transient force-expression of miR-135a induced growth in low-density culture, anchorage-independent growth, proliferation and invasion of a HPV-16 E6/E7-immortalized cervical epithelial cell line, NC104-E6/E7. The observed effects were due to the inhibitory action of miR-135a on its direct target seven in absentia homolog 1 (SIAH1) leading to upregulation of β-catenin/T cell factor signaling. miR-135a force-expression enhanced the growth of HeLa- and NC104-E6/E7-derived tumor in vivo. The effect of miR-135a could be partially nullified by SIAH1 force-expression. More importantly, the expression of SIAH1 and β-catenin correlated with that of miR-135a in precancerous and cancerous lesions of cervical biopsies. By comparing the tumorigenic activities of miR-135a in E6/E7 positive/negative cell lines and in NC104-E6/E7 with or without E6/E7 knockdown, we demonstrated that HPV E6/E7 proteins are prerequisite for miR-135a as an oncomiR. Taken together, miR-135a/SIAH1/β-catenin signaling is important in the transformation and progression of cervical carcinoma.

Deregulation of the miRNAs expression in cervical cancer: human papillomavirus implications

MicroRNAs (miRNAs) are a class of small non coding RNAs of 18-25 nucleotides in length. The temporal or short-lived expression of the miRNAs modulates gene expression post transcriptionally. Studies have revealed that miRNAs deregulation correlates and is involved with the initiation and progression of human tumors. Cervical cancer (CC) displays notably increased or decreased expression of a large number of cellular oncogenic or tumor suppressive miRNAs, respectively. However, understanding the potential role of miRNAs in CC is still limited. In CC, the high-risk human papillomaviruses (HR-HPVs) infection can affect the miRNAs expression through oncoprotein E6 and E7 that contribute to viral pathogenesis, although other viral proteins might also be involved. This deregulation in the miRNAs expression has an important role in the hallmarks of CC. Interestingly, the miRNA expression profile in CC can discriminate between normal and tumor tissue and the extraordinary stability of miRNAs makes it suitable to serve as diagnostic and prognostic biomarkers of cancer. In this review, we will summarize the role of the HR-HPVs in miRNA expression, the role of miRNAs in the hallmarks of CC, and the use of miRNAs as potential prognostic biomarkers in CC.

Pharmacological modulation of beta-catenin and its applications in cancer therapy

Beta-catenin (β-catenin) is a multifunction protein with a central role in physiological homeostasis. Its abnormal expression leads to various diseases including cancer. In normal physiology, β-catenin either maintains integrity of epithelial tissues or controls transcription of various genes on extracellular instigations. In epithelial tissues, β-catenin functions as a component of the cadherin protein complex and regulates epithelial cell growth and intracellular adhesion. In Wnt signalling, β-catenin is a major transcriptional modulator and plays a crucial role in embryogenesis, stem cell renewal and organ regeneration. Aberrant expression of β-catenin can induce malignant pathways in normal cells and its abnormal activity is also exploited by existing malignant programmes. It acts as an oncogene and modulates transcription of genes to drive cancer initiation, progression, survival and relapse. Abnormal expression and function of β-catenin in cancer makes it a putative drug target. In the past decade, various attempts have been made to identify and characterize various pharmacological inhibitors of β-catenin. Many of these inhibitors are currently being investigated for their anticancer activities in a variety of cancers. The first half of this review will focus on the role of β-catenin in cancer initiation, maintenance, progression and relapse whereas the second half will briefly summarize the recent progress in development of agents for the pharmacological modulation of β-catenin activity in cancer therapeutics.

Genetic variations in the transforming growth factor beta pathway as predictors of bladder cancer risk

Bladder cancer is the fifth most common cancer in the United States, and identifying genetic markers that may predict susceptibility in high-risk population is always needed. The purpose of our study is to determine whether genetic variations in the transforming growth factor-beta (TGF-β) pathway are associated with bladder cancer risk. We identified 356 single-nucleotide polymorphisms (SNPs) in 37 key genes from this pathway and evaluated their association with cancer risk in 801 cases and 801 controls. Forty-one SNPs were significantly associated with cancer risk, and after adjusting for multiple comparisons, 9 remained significant (Q-value ≤0.1). Haplotype analysis further revealed three haplotypes within VEGFC and two haplotypes in EGFR were significantly associated with increased bladder cancer risk compared to the most common haplotype. Classification and regression tree analysis further revealed potential high-order gene-gene interactions, with VEGFC: rs3775194 being the initial split, which suggests that this variant is responsible for the most variation in risk. Individuals carrying the common genotype for VEGFC: rs3775194 and EGFR: rs7799627 and the variant genotype for VEGFR: rs4557213 had a 4.22-fold increase in risk, a much larger effect magnitude than that conferred by common genotype for VEGFR: rs4557213. Our study provides the first epidemiological evidence supporting a connection between TGF-β pathway variants and bladder cancer risk.