Clinical relevance of CDH1 and CDH13 DNA-methylation in serum of cervical cancer patients

Droplet digital PCR analysis of CDH13 methylation status in Slovak women with invasive ductal breast cancer

Identifying novel epigenetic biomarkers is a promising way to improve the clinical management of patients with breast cancer. Our study aimed to determine the methylation pattern of 25 tumor suppressor genes (TSG) and select the best methylation biomarker associated with clinicopathological features in the cohort of Slovak patients diagnosed with invasive ductal carcinoma (IDC). Overall, 166 formalin-fixed, paraffin-embedded (FFPE) tissues obtained from patients with IDC were included in the study. The methylation status of the promoter regions of 25 TSG was analyzed using semiquantitative methylation-specific MLPA (MS-MLPA). We identified CDH13 as the most frequently methylated gene in our cohort of patients. Further analysis by ddPCR confirmed an increased level of methylation in the promoter region of CDH13. A significant difference in CDH13 methylation levels was observed between IDC molecular subtypes LUM A versus HER2 (P = 0.0116) and HER2 versus TNBC (P = 0.0234). In addition, significantly higher methylation was detected in HER2+ versus HER2- tumors (P = 0.0004) and PR- versus PR+ tumors (P = 0.0421). Our results provide evidence that alteration in CDH13 methylation is associated with clinicopathological features in the cohort of Slovak patients with IDC. In addition, using ddPCR as a methylation-sensitive method represents a promising approach characterized by higher precision and technical simplicity to measure the methylation of target CpGs in CDH13 compared to other conventional methods such as MS-MLPA.

Clinical applications and utility of ctDNA in cervical cancer and its precursor lesions: from screening to predictive biomarker

Cervical cancer is a leading cause of gynecological cancer death in the world. Human papillomavirus (HPV) is the most causative factor of cervical cancer. In addition, many genetic factors are involved in cervical cancer development. Most studies focus on cervical samples to do research work about cervical cancer and precancerous lesions, but no sensitive or specific biomarkers were found. High-throughput genomic technologies are able to capture information from tumors and precancerous lesions in blood, thus providing a new way for the early diagnosis of cervical precancer and cervical cancer. Blood is an ideal specimen for detecting cancer biomarkers because it contains a lot of information, such as circulating tumor cells and circulating tumor DNA (ctDNA). This article reviews the clinical use and challenges of blood ctDNA testing in patients with cervical precancer and cervical cancer.

Analysis of E-cadherin (CDH1) Gene Polymorphism and Its Association with Cervical Cancer Risk in Bangladeshi Women

BACKGROUND

E-cadherin (CDH1), a tumor suppressor gene, encodes a transmembrane glycoprotein that helps in maintaining squamous epithelium integrity of the cervix. We aimed to investigate the association between -160C/A genetic polymorphism in CDH1 and the risk of cervical cancer in Bangladeshi females.

METHOD

The present case-control study included 117 cervical cancer cases and 147 age-matched controls. The genomic DNA was extracted from peripheral blood and genotyped by using PCR-RFLP analysis.

RESULTS

Genotyping results demonstrated that the occurrences of normal homozygous (-160C/C), heterozygous (-160C/A) and variant homozygous (-160A/A) genotypes were 64.10, 27.35 and 8.55% in cases, and 77.55, 19.73 and 2.72% in controls, respectively. Compared to normal C/C genotype, variant A/A and combined (C/A+A/A) or 'any A' genotypes exhibited 3.80-fold (95% CI=1.150-12.561, P=0.029) and 1.93-fold (95% CI=1.126-3.323, P=0.017) increased risk of cervical cancer development. The -160C allele was found to be positively linked to cervical cancer incidence and raised the risk by 1.81-fold (OR= 1.814, 95% CI=1.152-2.857, p=0.01). Moreover, women carrying -160A/A variant homozygosity along with an early marital history (<18 years) were more susceptible to cervical cancer development (χ2 =6.605, p=0.037).

CONCLUSION

The study suggests that the (A/A) and combined (C/A +A/A) genotypes are associated with greater risk of cervical cancer in Bangladeshi women.

High PD-L1 expression associates with low T-cadherin expression and poor prognosis in human papillomavirus-negative head and neck squamous cell carcinoma

BACKGROUND

This study aimed at exploring the correlation between T-cadherin and programmed death-ligand 1 (PD-L1), as well as their prognostic value in patients with human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC).

METHODS

Immunohistochemical staining was used to identify the protein expression of T-cadherin and PD-L1. Spearman linear correlation analysis was used to determine their association. Kaplan-Meier analysis was utilized to plot overall survival (OS) and disease-free survival (DFS) curves. Cox proportional hazards regression was used to conduct univariate and multivariate analysis.

RESULTS

The results showed a negative association between protein expression of T-cadherin and PD-L1 (r = -0.760, p < 0.001), positive expression of T-cadherin was associated with a better OS (p < 0.001) and DFS (p < 0.001), while positive PD-L1 expression was associated with a worse OS (p = 0.002) and DFS (p < 0.001). The expression of T-cadherin and PD-L1 were independent prognostic predictors for OS and DFS.

CONCLUSIONS

In conclusion, expression of T-cadherin and PD-L1 were largely inversely correlated and independent prognostic factors for patients with HPV-negative HNSCC.

Increased ATG5 Expression Predicts Poor Prognosis and Promotes EMT in Cervical Carcinoma

Cervical cancer has the second-highest incidence and mortality of female malignancy. The major causes of mortality in patients with cervical cancer are invasion and metastasis. The epithelial–mesenchymal transition (EMT) process plays a major role in the acquisition of metastatic potential and motility. Autophagy-related genes (ARGs) are implicated in the EMT process, and autophagy exerts a dual function in EMT management at different phases of tumor progression. However, the role of specific ARGs during the EMT process has not yet been reported in cervical cancer. Based on the data from the Cancer Genome Atlas (TCGA) cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) sequencing database, we performed the prognosis analysis for those ARGs obtained from the Human Autophagy database. ATG5 was identified as the only important harmful marker influencing survival of cervical cancer patients by univariate Cox regression (HR 1.7; 95% CI: 1.0–2.8, p = 0.047), and the 5-years survival rate for the high- and low-ATG5 expression groups was 0.486 (0.375–0.631) and 0.782 (0.708–0.863), respectively. TCGA CESC methylation data showed that eight methylation sites of ATG5 could also be significantly associated with the overall survival (OS) of cervical cancer patients. Single-sample gene-set enrichment and gene functional enrichment results showed that ATG5 was correlated with some cancer-related pathways, such as phagocytosis-related genes, endocytosis-related genes, immune-related genes, EMT score, and some EMT signature-related genes. Next, cell migration and invasion assay and Western blot were applied to detect the function of ATG5 in EMT of cervical cancer. In cervical cancer cells, ATG5 knockdown resulted in attenuation of migration and invasion. The functional study showed that knockdown of ATG5 could reverse EMT process by P-ERK, P-NFκBp65, P-mTOR pathways, and so on. In conclusion, the present study implies that ATG5 was a major contributor to EMT regulation and poor prognosis in cervical cancer.

An 8-gene DNA methylation signature predicts the recurrence risk of cervical cancer

Objective

This study examined the predictive utility of DNA methylation for cervical cancer recurrence.

Methods

DNA methylation and RNA expression data for patients with cervical cancer were downloaded from The Cancer Genome Atlas. Differentially methylated genes (DMGs) and differentially expressed genes were screened and extracted via correlation analysis. A support vector machine (SVM)-based recurrence prediction model was established using the selected DMGs. Cox regression analysis and receiver operating characteristic curve analysis were used for self-evaluation. The Gene Expression Omnibus (GEO) database was applied for external validation. Functional enrichment was determined using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses.

Results

An eight-gene DNA methylation signature identified patients with a high risk of recurrence (area under the curve = 0.833). The SVM score was an independent risk factor for recurrence (hazard ratio [HR] = 0.418; 95% confidence interval [CI] = 0.26–0.67). The independent GEO database analysis further supported the result.

Conclusion

An eight-gene DNA methylation signature predictive of cervical cancer recurrence was identified in this study, and this signature may help identify patients at high risk of recurrence and improve clinical treatment.

Cadherin 13 Inhibits Pancreatic Cancer Progression and Epithelial-mesenchymal Transition by Wnt/β-Catenin Signaling

Cadherin 13 (CDH13) is an atypical cadherin that exerts tumor-suppressive effects on cancers derived from epithelial cells. Although the CDH13 promoter is frequently hypermethylated in pancreatic cancer (PC), the direct impact of CDH13 on PC is unknown. Accordingly, the expression of CDH13 in PC cell lines and paired PC tissues was examined by immunohistochemistry, quantitative real-time PCR and western blotting. Our findings showed that CDH13 was downregulated in PC tissues and cell lines. Moreover, cell proliferation, migration and invasion were detected by CCK-8 assay, transwell migration assay and transwell invasion assay, respectively. Xenograft tumor experiments were used to determine the biological function of CDH13 in vivo. As revealed by our data, CDH13 overexpression significantly inhibited the proliferation, migration and invasion of human PC cells in vitro. The inhibitory effect of CDH13 on PC was further confirmed in animal models. Mice subcutaneously or orthotopically transplanted with CDH13-overexpressing CFPAC-1 cells developed significantly smaller tumors with less liver metastases and mesenteric metastases than those of the control group. Next, transcriptomics and western blot analysis were used to identify the underlying mechanisms. Further molecular mechanism studies showed that CDH13 overexpression inhibited the activation of the Wnt/β-catenin signaling pathway and regulated the expression of epithelial-mesenchymal transition (EMT)-related markers. Our results indicated that CDH13 displayed an inhibitory effect on PC and suggested that CDH13 might be a potential biomarker and a new therapeutic target for PC.

DNA methylation data-based molecular subtype classification related to the prognosis of patients with cervical cancer

Cervical cancer is one of the leading female health-killers among all types of malignancies globally. Human papillomavirus infection combined with genetic and epigenetic alterations have been indicated to be closely associated with the pathogenesis, progression, and malignant transformation of cervical cancer. Notably, during the complex tumorigenesis process, a series of DNA methylations occurs early and is the most frequent molecular behavior. In this study, to exploit the specific DNA methylation sites influencing the prognosis of patients with cervical cancer, 275 samples were downloaded from The Cancer Genome Atlas database and further analyzed. As a result, 1253 CpGs were found to have a significant correlation with patient prognosis and were further selected for the consistent clustering of samples into six subgroups. Specifically, the samples in every subgroup were different regarding the following: race, age, tumor stage, receptor status, histological type, metastasis status, and patient prognosis. In addition, we calculated the levels of methylation sites in all subgroups, with 79 methylation sites (corresponding to 81 genes) screened as the intrasubgroup-specific methylation sites. Moreover, signaling pathway enrichment analysis was conducted on the genes of the corresponding promoter regions of the above-described specific methylation sites, revealing that these genes were enriched in biological pathways closely associated with tumors, such as the cyclic guanosine monophosphate-dependent protein kinase and focal adhesion signaling pathways. Finally, the least absolute shrinkage and selection operator algorithm was employed to establish a prognostic prediction model for cervical cancer patients, with training and test sets used for testing and validation, respectively. In summary, the specific DNA methylation site-based classification is able to reflect the heterogeneity of cervical cancer tissue, contributing to the development of personalized therapy and the accurate prediction of patient prognosis.

Targeting E-cadherin expression with small molecules for digestive cancer treatment

Digestive system cancers, mainly including gastric cancer, hepatocellular carcinoma, pancreatic cancer, and colorectal cancer, are major public health problems and lead to serious cancer-related deaths worldwide. Clinically, treatment strategies of these cancers include surgery, chemotherapy, and immunotherapy. Although successful resection and chemotherapeutic drugs have improved the treatment level, the survival rate of patients with advanced digestive system cancers remains still low primarily due to tumor metastasis. E-cadherin, the prototypical member of the type-1 classical cadherins, has been characrized as an important molecule in epithelial-mesenchymal transition (EMT) process. Loss of E-cadherin is able to induce EMT process, which is associated with cancer stem cells and drug resistance in human cancer. Therefore, restoring E-cadherin could be a useful strategy for reversal of EMT and overcoming drug resistance. In this review, we describe pharmacological small molecules targeting E-cadherin expression for the treatment of digestive system cancers, which have emerged in the recent 5 years. We hope these compounds could be potentially used for treating cancer in the near future.

Restoring E-cadherin Expression by Natural Compounds for Anticancer Therapies in Genital and Urinary Cancers

E-cadherin plays a pivotal role in cancer progression, including the epithelial-mesenchymal transition (EMT) process and tumor metastasis. Loss of E-cadherin contributes to enhanced invasion and metastasis in human cancers. Therefore, restoring E-cadherin could be a potential approach for cancer therapy. Multiple natural compounds have been shown to possess anti-tumor activities through the regulation of key molecules in signaling pathways, including E-cadherin. In this review, we describe the numerous compounds that restore the expression of E-cadherin in genital and urinary malignancies. We further discuss the potential anti-tumor molecular mechanisms of these agents as the activators of E-cadherin in genital and urinary cancers. Although these compounds exhibit their potential to inhibit the development and progression of cancers, there are several challenges to developing them as therapeutic drugs for cancer patients. Poor bioavailability in vivo is the main disadvantage of these compounds. Modification of compound structures has produced actual improvements in bioavailability. Nanoparticle-based delivery systems could be useful to deliver the agents to targeted organs. These compounds could be new promising therapeutic agents for the treatment of human genital and urinary cancers. Further investigations are required to determine the safety and side effects of natural compounds using animal models prior to clinical trials.

Garcinol exerts anti-cancer effect in human cervical cancer cells through upregulation of T-cadherin

Garcinol, a polyisoprenylated benzophenone, has been demonstrated to exert anti-cancer effects in various tumor cells. However, the effect of garcinol on cervical cancer (CC) cell progression and the related molecular mechanism remains poorly understood. Accumulating evidence has verified that downregualtion of T-cadherin is closely associated with tumorigenesis, suggesting that T-cadherin might be a potential therapeutic target for cancer treatment. In the present study, Hela and SiHa cells were treated with different concentrations of garcinol (0, 5, 10, and 25 u M), and T-cadherin siRNA was synthesized and transfected into Hela and SiHa cells combined with garcinol (25 u M) treatment. We found that garcinol dose-dependently suppressed cell viability, colony formation, invasion, migration, cell cycle progression, and promoted cell apoptosis in CC cell lines, as well as inhibited tumor growth in xenograft model. Importantly, our results showed that garcinol treatment increased the expression of T-cadherin both in vitro and in vivo, and knockdown of T-cahderin partially reversed garcinol-induced inhibition of CC development via activating P13 K/AKT signaling pathway in CC cell lines. Thus, these findings demonstrated the tumor suppressive function of garcinol on CC progression, and emphasized that the T-cadherin/P13 K/AKT was a potential mechanism involved in the antumor effects of garcinol.

Overexpression of T-cadherin inhibits the proliferation of oral squamous cell carcinoma through the PI3K/AKT/mTOR intracellular signalling pathway

OBJECTIVE

To evaluate T-cadherin gene expression in patients with oral squamous cell carcinoma(OSCC) and explore its effect on the proliferation of OSCC. Additionally, the present study aimed to determine whether the anti-proliferative effect of T-cadherin was associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway.

DESIGN

A reverse transcription-quantitative polymerase chain reaction was performed to detect T-cadherin mRNA expression. A Cell Counting Kit-8 (CCK-8) assay was used to investigate the effect of T-cadherin on cellular proliferation. The survival curves were plotted by Kaplan-Meier method, and the differences between subgroups were determined by log-rank test. The protein expression of phosphorylated (p)-PI3K, total PI3K, p-AKT, total AKT, p-mTOR, total mTOR and cyclin D1was assessed using western blot.

RESULTS

It was revealed that the expression of T-cadherin mRNA was significantly decreased in OSCC samples compared with normal adjacent ones (P = 0.007), and that low T-cadherin expression was correlated with advanced clinical stage (P = 0.0249), higher pathological grade (P = 0.0288) and poor differentiation (P = 0.0295) of OSCC. In addition, T-cadherin negative expression was revealed to be associated with a worse progression‑free survival (PFS) in patients with OSCC. Furthermore, the overexpression of T-cadherin inhibited the proliferation of OSCC cell lines and suppressed the PI3K/AKT/mTOR signaling pathway. Importantly, the combined treatment of T-cadherin with the PI3K inhibitor LY294002 enhanced the inhibitory effect of T-cadherin on cellular proliferation and the PI3K/AKT/mTOR pathway.

CONCLUSIONS

The results of the present study suggested that T-cadherin may function as a tumor suppressor gene in OSCC through suppressing the PI3K/AKT/mTOR pathway, and that it may be a potential therapeutic target for OSCC.

CDH1 promoter methylation in patients with cervical carcinoma: a systematic meta-analysis with trial sequential analysis

AIM

This study was performed to evaluate the correlation between CDH1 promoter methylation and cervical cancer.

METHODS

Trial sequential analysis was conducted to evaluate the required information size.

RESULTS

A total of 15 studies with 950 cervical cancers and 829 controls were identified. CDH1 promoter methylation was higher in cervical cancer than in cervical intraepithelial neoplasia lesions and normal cervical tissues. Subgroup analysis of ethnicity showed that CDH1 promoter methylation correlated with cervical cancer in Caucasians, but not in Asians. CDH1 promoter methylation was higher in cervical cancer cytology samples than in normal cytology samples. It was higher in squamous cell carcinoma than adenocarcinoma, but was not correlated with tumor stage, grade and overall survival.

CONCLUSION

CDH1 promoter methylation may be correlated with cervical cancer carcinogenesis, especially for Caucasians. It was associated with histological subtypes. Trial sequential analysis showed that more studies are needed.

Genetic variation in CDH13 gene was associated with non-small cell lung cancer (NSCLC): A population-based case-control study

Cadherin 13 (CDH13, T-cadherin, H-cadherin) has been identified as an anti-oncogene in various cancers. Recent studies have reported that downregulation of H-cadherin in cancers is associated with CDH13 promoter hypermethylation, which could be affected by the single nucleotide polymorphisms (SNPs) near CpG sites in the CDH13 promoter. In the current study, we investigated and analyzed the association of seven SNPs (rs11646213, rs12596316, rs3865188, rs12444338, rs4783244, rs12051272 and rs7195409) with non-small cell lung cancer (NSCLC) using logistic regression analysis. SNPs rs11646213, rs12596316, rs3865188 and rs12444338 are located in the promoter region, rs4783244 and rs12051272 are located in intron 1, and rs7195409 is located in intron 7. A total of 454 patients with NSCLC were placed into a NSCLC group and 444 healthy controls were placed into a control group, all participants were recruited to genotype the SNPs using Taqman assay. Our results showed that the allelic frequencies of rs11646213 were significantly different between NSCLC and control groups (P = 0.006). In addition, the association analysis of these SNPs stratified into NSCLC pathologic stages I+II and III+IV showed that the allelic frequencies rs7195409 had a significant difference between NSCLC pathologic stages I+II and III+IV (P = 0.006). Our results indicated that the rs11646213 and rs7195409 in CDH13 could be associated with NSCLC or its pathologic stages in the Chinese Han population.

The effect of celecoxib on DNA methylation of CDH13, TFPI2, and FSTL1 in squamous cell carcinoma of the esophagus in vivo

This study examined the in-vivo effect of the NSAID celecoxib on DNA methylation in the promoter region of the tumor-suppressor genes cadherin 13, tissue factor pathway inhibitor 12, and follistatin-like protein 1, and on apoptosis, in esophageal squamous cell carcinoma (ESCC). Forty-five patients who underwent an esophagectomy for ESCC were allocated to either a treatment group (n=22) or a control group (n=23). Patients in the treatment group were administered 800 mg/day of celecoxib for 14 days before surgery. Patients in the control group did not take any type of NSAID. Biopsies of the tumor were collected before surgery and tissue from the resection specimens after surgery. Methylation-specific PCR was used to measure DNA methylation and apoptosis was measured by flow cytometry. There was no difference in the proportion of patients with methylation for each of the genes between the patient groups before treatment. In those patients with pretreatment methylation, there was a significant reduction in the proportion with methylation and a significant increase in the corresponding messenger RNA expression after treatment with celecoxib. In those tissues in which there was a reduction in methylation following celecoxib treatment, there was a significant increase in the percentage of apoptotic cells, but not in the tissues with no change in methylation. In ESCC, in-vivo treatment with celecoxib is associated with a reduction in DNA methylation and increase in messenger RNA expression of tumor-suppressor genes, and increases in apoptosis.

Putative biomarkers for cervical cancer: SNVs, methylation and expression profiles

Cervical cancer is primarily caused by Human papillomavirus (HPV) infection, but other factors such as smoking habits, co-infections and genetic background, can also contribute to its development. Although this cancer is avoidable, it is the fourth most frequent type of cancer in females worldwide and can only be treated with chemotherapy and radical surgery. There is a need for biomarkers that will enable early diagnosis and targeted therapy for this type of cancer. Therefore, a systems biology pipeline was applied in order to identify potential biomarkers for cervical cancer, which show significant reports in three molecular aspects: DNA sequence variants, DNA methylation pattern and alterations in mRNA/protein expression levels. CDH1, CDKN2A, RB1 and TP53 genes were selected as putative biomarkers, being involved in metastasis, cell cycle regulation and tumour suppression. Other ten genes (CDH13, FHIT, PTEN, MLH1, TP73, CDKN1A, CACNA2D2, TERT, WIF1, APC) seemed to play a role in cervical cancer, but the lack of studies prevented their inclusion as possible biomarkers. Our results highlight the importance of these genes. However, further studies should be performed to elucidate the impact of DNA sequence variants and/or epigenetic deregulation and altered expression of these genes in cervical carcinogenesis and their potential as biomarkers for cervical cancer diagnosis and prognosis.

Methylation pattern of CDH1 promoter and its association with CDH1 gene expression in cytological cervical specimens

Cervical cancer is the fourth leading cause of cancer mortality in females worldwide. Infection with high-risk human papillomavirus (HPV) is essential but insufficient to cause cervical cancer, and the clearance of HPV infection is mediated by the immune system. The deficit of molecules responsible for adhesion may play a role in the development of cervical cancer. E-cadherin is encoded by the cadherin 1 (CDH1) gene, and is involved in cell adhesion by forming adherens junctions. The aim of present study was to investigate the methylation pattern of the CDH1 promoter and to identify the association between CDH1 promoter hypermethylation, CDH1 gene expression and HPV infection in cervical specimens obtained from 93 patients with low-grade squamous intraepithelial lesions (SILs), high-grade SILs or squamous cell carcinomas, and from 47 patients with normal cervical cytology (HPV-negative). The methylation pattern of the CDH1 promoter was investigated by methylation-specific polymerase chain reaction and quantitative pyrosequencing. CDH1 gene expression was measured by relative quantification. CDH1 methylation was significantly higher in both types of lesions and in cervical cancer than in normal samples, and CDH1 gene expression was significantly reduced during SIL progression (P=0.0162). However, the influence of HPV infection or HPV E6 expression on the methylation pattern of the CDH1 gene or its gene expression levels could not be confirmed. The present results support that the methylation of the CDH1 gene is age-related in patients with cervical lesions (P=0.01085), and therefore, older patients could be more susceptible to cancer than younger patients. The important methylation of the CDH1 promoter occurred near the transcription factor binding sites on nucleotides -13 and +103, which are close to the translational start codon. These results suggest that methylation at these sites may be an important event in the transcriptional regulation of E-cadherin, and in patients harboring these methylated cytosines, this event may facilitate HPV-driven carcinogenesis.

The Role of Epigenomics in the Study of Cancer Biomarkers and in the Development of Diagnostic Tools

Epigenetics plays a key role in cancer development. Genetics alone cannot explain sporadic cancer and cancer development in individuals with no family history or a weak family history of cancer. Epigenetics provides a mechanism to explain the development of cancer in such situations. Alterations in epigenetic profiling may provide important insights into the etiology and natural history of cancer. Because several epigenetic changes occur before histopathological changes, they can serve as biomarkers for cancer diagnosis and risk assessment. Many cancers may remain asymptomatic until relatively late stages; in managing the disease, efforts should be focused on early detection, accurate prediction of disease progression, and frequent monitoring. This chapter describes epigenetic biomarkers as they are expressed during cancer development and their potential use in cancer diagnosis and prognosis. Based on epigenomic information, biomarkers have been identified that may serve as diagnostic tools; some such biomarkers also may be useful in identifying individuals who will respond to therapy and survive longer. The importance of analytical and clinical validation of biomarkers is discussed, along with challenges and opportunities in this field.

Expression Level of Genes Coding for Cell Adhesion Molecules of Cadherin Group in Colorectal Cancer Patients

Background

Colorectal Cancer (CRC) is one of the most frequently diagnosed neoplasms and also one of the main death causes. Cell adhesion molecules are taking part in specific junctions, contributing to tissue integrality. Lower expression of the cadherins may be correlated with poorer differentiation of the CRC, and its more aggressive phenotype. The aim of the study is to designate the cadherin genes potentially useful for the diagnostics, prognostics, and the treatment of CRC.

Material/Method

Specimens were collected from 28 persons (14 female and 14 male), who were operated for CRC. The molecular analysis was performed using oligonucleotide microarrays, mRNA used was collected from adenocarcinoma, and macroscopically healthy tissue. The results were validated using qRT-PCR technique.

Results

Agglomerative hierarchical clustering of normalized mRNA levels has shown 4 groups with statistically different gene expression. The control group was divided into 2 groups, the one was appropriate control (C1), the second (C2) had the genetic properties of the CRC, without pathological changes histologically and macroscopically. The other 2 groups were: LSC (Low stage cancer) and HSC (High stage cancer). Consolidated results of the fluorescency of all of the differential genes, designated two coding E-cadherin (CDH1) with the lower expression, and P-cadherin (CDH3) with higher expression in CRC tissue.

Conclusions

The levels of genes expression are different for several groups of cadherins, and are related with the stage of CRC, therefore could be potentially the useful marker of the stage of the disease, also applicable in treatment and diagnostics of CRC.

Association between micronucleus frequency and cervical intraepithelial neoplasia grade in Thinprep cytological test and its significance

A micronucleus is an additional small nucleus formed due to chromosomes or chromosomal fragments fail to be incorporated into the nucleus during cell division. In this study, we assessed the utility of micronucleus counting as a screening tool in cervical precancerous lesions in Thinprep cytological test smears under oil immersion. High risk HPV was also detected by hybrid capture-2 in Thinprep cytological test smears. Our results showed that micronucleus counting was significantly higher in high-grade squamous intraepithelial lesion (HSIL) and invasive carcinoma cases compared to low-grade squamous intraepithelial lesion (LSIL) and non-neoplastic cases. Receiver operating characteristic (ROC) curve analysis revealed that micronucleus counting possessed a high degree of sensitivity and specificity for identifying HSIL and invasive carcinoma. Cut-off of 7.5 for MN counting gave a sensitivity of 89.6% and a specificity of 66.7% (P = 0.024 and AUC = 0.892) for detecting HSIL and invasive carcinoma lesions. Multiple linear regression analysis showed that only HSIL and invasive cancer lesions not age, duration of marital life and number of pregnancy are significantly associated with MN counting. The positive rate of high risk HPV was distinctly higher in LSIL, HSIL and invasive cancer than that in non-neoplstic categories. In conclusions, MN evaluation may be viewed as an effective biomarker for cervical cancer screening. The combination of MN count with HPV DNA detection and TCT may serve as an effective means to screen precancerous cervical lesions in most developing nations.

DISIS: prediction of drug response through an iterative sure independence screening

Prediction of drug response based on genomic alterations is an important task in the research of personalized medicine. Current elastic net model utilized a sure independence screening to select relevant genomic features with drug response, but it may neglect the combination effect of some marginally weak features. In this work, we applied an iterative sure independence screening scheme to select drug response relevant features from the Cancer Cell Line Encyclopedia (CCLE) dataset. For each drug in CCLE, we selected up to 40 features including gene expressions, mutation and copy number alterations of cancer-related genes, and some of them are significantly strong features but showing weak marginal correlation with drug response vector. Lasso regression based on the selected features showed that our prediction accuracies are higher than those by elastic net regression for most drugs.

Clinicopathological significance and potential drug target of T-cadherin in NSCLC

Background

Previous studies demonstrate that T-cadherin is a candidate tumor suppressor in several types of human tumors, including non-small cell lung cancer (NSCLC). Lack of protein expression of T-cadherin by hypermethylation has been found to play an important role in lung alveolar differentiation regulation and epithelial tumorigenesis. However, the correlation between T-cadherin hypermethylation and clinicopathological characteristics of NSCLC remains unclear. Here we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of T-cadherin hypermethylation on the incidence of NSCLC and clinicopathological characteristics.

Methods

A detailed literature search was carried out for related research publications. Analyses of pooled data were performed. Odds ratio (OR) and hazard ratio (HR) were calculated and summarized, respectively.

Results

Final analysis of 1,172 NSCLC patients from 15 eligible studies was performed. T-cadherin hypermethylation was observed to be significantly higher in NSCLC than in normal lung tissue, based on the pooled OR from nine studies including 532 NSCLC and 372 normal lung tissue samples (OR=8.19, 95% confidence interval [CI]=5.41–12.39, P<0.00001). T-cadherin hypermethylation may also be associated with pathological types. The pooled OR was obtained from four studies including 111patients with squamous cell carcinoma and 106 with adenocarcinoma (OR=0.35, 95% CI=0.19–0.66, P=0.001), which indicated that T-cadherin hypermethylation plays a more important role in the pathogenesis of adenocarcinoma. We did not find that T-cadherin hypermethylation was correlated with the sex or smoking status, clinical stages, or epidermal growth factor receptor (EGFR) mutation status. However, T-cadherin hypermethylation was found to be significantly higher in poorly differentiated NSCLC than in moderately and highly differentiated NSCLC, and NSCLC patients with T-cadherin hypermethylation had a lower survival rate than those without T-cadherin hypermethylation.

Conclusion

The results of this meta-analysis suggest that T-cadherin hypermethylation is associated with an increased risk and worse survival in NSCLC. T-cadherin hypermethylation, which induces the inactivation of T-cadherin gene, plays an important role in the carcinogenesis, cancer progression, as well as clinical outcome.

Prognostic significance of CDH13 hypermethylation and mRNA in NSCLC

Aberrant methylation of CpG dinucleotides is a commonly observed epigenetic modification in human cancer. Thus, detection of aberrant gene promoter methylation as a tool for diagnosis of tumors or as a prognostic marker has been widely described for many types of cancers, including nonsmall cell lung cancer (NSCLC). Emerging evidence indicates that CDH13 is a candidate tumor suppressor in several types of human tumors, including NSCLC. However, the correlation between CDH13 hypermethylation and clinicopathological characteristics of NSCLC remains unclear. In the current study, we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of CDH13 hypermethylation on the incidence of NSCLC and clinicopathological characteristics. Final analysis of 803 NSCLC patients from eleven eligible studies was performed. CDH13 hypermethylation was observed to be significantly higher in NSCLC than in normal lung tissue, with the pooled odds ratio (OR) from seven studies including 448 NSCLC and 345 normal lung tissue (OR, 7.85; 95% confidence interval, 5.12-12.03; P<0.00001). CDH13 hypermethylation was also associated with pathological types. The pooled OR was obtained from four studies, including 111 squamous cell carcinoma and 106 adenocarcinoma (OR, 0.35; 95% confidence interval, 0.19-0.66; P=0.001), which indicated that CDH13 hypermethylation plays a more important role in the pathogenesis of adenocarcinoma. NSCLC with CDH13 hypermethylation was found more frequently in poorly differentiated NSCLC patients. NSCLC patients with CDH13 hypermethylation had a lower survival rate than those without CDH13 hypermethylation. In addition, CDH13 mRNA high expression was found to correlate with better overall survival for all NSCLC patients followed for 20 years (hazard ratio, 0.81; P=0.0056). Interestingly, CDH13 mRNA overexpression was found to correlate with better overall survival only in adenocarcinoma patients (hazard ratio, 0.42; P=9.6e-09), not in squamous cell carcinoma patients (hazard ratio, 0.93; P=0.59). The results of this meta-analysis suggest that CDH13 hypermethylation is associated with an increased risk and worse survival in NSCLC. CDH13 hypermethylation and mRNA expression play an important role in carcinogenesis, progression, and development, as well as clinical outcomes.

Promoter hypermethylation of KLF4 inactivates its tumor suppressor function in cervical carcinogenesis

OBJECTIVE

The KLF4 gene has been shown to be inactivated in cervical carcinogenesis as a tumor suppressor. However, the mechanism of KLF4 silencing in cervical carcinomas has not yet been identified. DNA methylation plays a key role in stable suppression of gene expression.

METHODS

The methylation status of the KLF4 promoter CpG islands was analyzed by bisulfite sequencing (BSQ) in tissues of normal cervix and cervical cancer. KLF4 gene expression was detected by RT-PCR, immunohistochemistry and western blot. KLF4 promoter methylation in cervical cancer cell line was determined by BSQ and methylation-specific polymerase chain reaction (MS-PCR). Cell proliferation ability was detected by cell growth curve and MTT assay.

RESULTS

The methylated allele was found in 41.90% of 24 cervical cancer tissues but only in 11.11% of 11 normal cervix tissues (P<0.005). KLF4 mRNA levels were significantly reduced in cervical cancer tissues compared with normal cervix tissues (P<0.01) and KLF4 mRNA expression showed a significant negative correlation with the promoter hypermethylation (r = -0.486, P = 0.003). Cervical cancer cell lines also showed a significant negative correlation between KLF4 expression and hypermethylation. After treatment with the demethylating agent 5-Azacytidine (5-Aza), the expression of KLF4 in the cervical cancer cell lines at both mRNA and protein levels was drastically increased, the cell proliferation ability was inhibited and the chemosensitivity for cisplatin was significantly increased.

CONCLUSION

KLF4 gene is inactivated by methylation-induced silencing mechanisms in a large subset of cervical carcinomas and KLF4 promoter hypermethylation inactivates the gene's function as a tumor suppressor in cervical carcinogenesis.