Jinfang Jiang

Inactivation of miR-34a by aberrant CpG methylation in Kazakh patients with esophageal carcinoma

BackgroundEsophageal squamous cell carcinoma (ESCC) is an aggressive tumor with dismal prognosis and high incidence and mortality in Kazakh population. MiR-34a, a direct p53 target gene, possesses tumor-suppressive properties as they mediate apoptosis, cell cycle arrest, and senescence. The reduced expression of miR-34a by methylation in various cancers has been reported.MethodsTo determine whether aberrant miR-34a methylation occurs in esophageal cancer, the DNA methylation of 23 CpGs sites in the miR-34a promoter was quantitatively analyzed in relation to the translation initiation site by MALDI -TOF mass spectrometry in 59 ESCC tissues and 34 normal tissues from the Kazakh population. Real-time PCR was used to detect the inhibition of miR-34a expression levels and to evaluate their association with methylation.ResultsWe found that miR-34a is more frequently methylated in ESCC (0.133 ± 0.040) than in controls (0.066 ± 0.045, P < 0.01). A nearly two-fold increase in miR-34a expression for the hypomethylated promoter was found in normal esophageal tissues than ESCC with hypermethylation (P <0.0001), pointing to a negative relationship between miR-34a CpG sites methylation and expression(r = −0.594, P = 0.042). The hypermethylation of miR-34a CpG_8.9 was associated with the advanced UICC stage III/IV of the esophageal cancers, and the hypermethylation of CpG_8.9 and CpG_5 of miR-34a was significantly correlated with lymph node metastasis.ConclusionsOur findings suggest that miR-34a is involved in the etiology of ESCC and that hypermethylated miR-34a is a potential biomarker for ESCC diagnosis and prognosis. Moreover, targeting miR-34a methylation by demethylating agents may offer a novel strategy for anticancer therapy of ESCC.

Multiple polymorphisms within the PLCE1 are associated with esophageal cancer via promoting the gene expression in a Chinese Kazakh population.

Although recent genome-wide association studies of esophageal squamous cell carcinoma (ESCC) identified a susceptibility locus in phospholipase C epsilon 1 (PLCE1) in Chinese Han populations, few studies further confirmed these findings in pure Kazakh population in which there are higher incidence and mortality of ESCC. Here, we investigated the potential associations between 19 SNPs of PLCE1 and susceptibility to ESCC in 222 cases and 326 controls from a pure ethnic population of Kazakh. Real-time PCR and immunohistochemistry were performed to detect the PLCE1 expression levels and evaluate their association with PLCE1 polymorphism. We found that only 4 SNPs (rs753724, rs11187842, rs2274223, and rs12263737) with moderate linkage disequilibrium (LD) confer significantly increased risk of ESCC, with the ORs ranging from 1.43 to 2.04, and there was a risk allele dose-dependent increase in ESCC risk (P-trend=0.043). Especially, the risk effects of rs2274223 were more evident in poor differentiation and advanced clinical stages of Kazakh ESCC. Additionally, the significantly lowest PLCE1 mRNA expression was found in the KYSE-150 cell line having no risk alleles compared with other three cell lines having risk alleles, and the normal tissues of both homozygous mutant type of PLCE1 rs12263737 and rs2274223 had a higher PLCE1 staining score than that of homozygous wild type. Our findings suggested that genetic variants in PLCE1 might serve as candidate markers for Kazakh ESCC susceptibility, and these LD variants might influence ESCC risk individually and jointly by promoting the messenger RNA and protein expression of the gene.

Analysis of PTEN Methylation Patterns in Soft Tissue Sarcomas by MassARRAY Spectrometry

Soft tissue sarcomas (STSs) are a rare and fascinating group of diseases that can be subdivided into specific reciprocal translocations in STSs (SRTSs) and nonspecific reciprocal translocations in STSs (NRTSs). PTEN mutations are rare in STSs, suggesting that PTEN expression may be lost by alternative mechanisms such as methylation. In order to reveal whether aberrant PTEN methylation occurs in STSs, MassARRAY Spectrometry was carried to detect methylation patterns of PTEN in STSs. We evaluated methylation levels in 41 CpG sites from −2,515 to −2,186 bp (amplicon A) and −1,786 to −1,416 bp (amplicon B) relative to the translation initiation site in 110 different cases (46 cases of SRTSs, 40 cases of NRTSs, and 24 cases of normal controls). In addition, immunohistochemistry (IHC) was used to detect the loss of PTEN to determine whether PTEN alterations were responsible for decreased PTEN expression. Our data showed that expression of PTEN was diminished in 49 (57%) STSs, whereas the remaining cases (43%) were classified as high expression. Our previous results found that only 2 of 86 cases (2.3%) had a PTEN mutation suggesting that PTEN may be mainly downregulated in STSs by methylation, but not by mutation of PTEN itself. We observed that amplicon A was hypermethylated in STSs with low PTEN expression, whereas normal controls had low methylation levels (P<0.0001), which was not present in amplicon B (P>0.05), nor were there significant differences in the methylation levels in PTEN between SRTS and NRTS cases. The majority of individual CpG units within two amplicons was demonstrated to be hypermethylated. These findings indicate that PTEN hypermethylation is a common event in STSs suggesting that the inactivation of PTEN may be due to hypermethylation in the promoter of PTEN. The aberrant methylation of the CpG sites within PTEN promoter may serve as a potential candidate biomarker for STSs.

Targeting oncogenic PLCE1 by miR-145 impairs tumor proliferation and metastasis of esophageal squamous cell carcinoma

Phospholipase C epsilon 1 (PLCE1) is a susceptibility gene in esophageal squamous cell carcinoma (ESCC). Nevertheless, the role of PLCE1 in ESCC tumorigenesis has not been elucidated. In this study, we determined the function of PLCE1 and its regulatory microRNA (miRNA) in ESCC. PLCE1 protein was excessively expressed in ESCC and precancerous lesions compared with that in normal tissues. High PLCE1 expression levels in ESCC were significantly linked with poor overall survival. Knockdown of PLCE1 promoted the apoptosis, cytokine-induced apoptosis, and sensitivity of cancer cells to chemotherapeutic drugs but abrogated the proliferation and EMT phenotype of ESCC in vitro. Notably, miR-145 was newly identified as a potent repressor of PLCE1 expression by directly targeting the 3′UTR of PLCE1. MiR-145 also inhibited cell proliferation, migration, and metastasis, as well as controlled the cytoskeleton dynamics of esophageal cancer. Moreover, miR-145 was expressed at low levels in a large cohort of patients with ESCC and was inversely correlated with PLCE1 protein expression in cancer cells and tissues. These findings demonstrate that PLCE1 functions as tumor promoter in ESCC and can be suppressed by miR-145 through inhibition of PLCE1 translation. Hence, delivery of PLCE1-targeting miR-145 is a potential therapeutic approach for esophageal cancer.

Prognostic value of PLCE1 expression in upper gastrointestinal cancer: a systematic review and meta-analysis.

BACKGROUND A number of studies have identified a shared susceptibility locus in phospholipase C epsilon 1 (PLCE1) for esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinomas (GCA). However, the results of PLCE1 expression in esophageal and gastric cancer remain inconsistent and controversial. Moreover, the effects on clinicopathological features remain undetermined. This study aimed to provide a precise quantification of the association between PLCE1 expression and the risk of ESCC and GCA through meta-analysis. MATERIALS AND METHODS Eligible studies were identified from PubMed, Wanfang Data, ISI Web of Science, and the Chinese National Knowledge Infrastructure databases. Using RevMan5.2 software, pooled odds ratios (ORs) with 95% confidence intervals (CIs) were employed to assess the association of PLCE1 expression with clinicopathological features relative to ESCC or GCA. RESULTS Seven articles were identified, including 761 esophageal and gastric cancer cases and 457 controls. Overall, we determined that PLCE1 expression was associated with tumor progression in both esophageal cancers (pooled OR=5.93; 95%CI=3.86 to 9.11) and gastric cancers (pooled OR=9.73; 95%CI=6.46 to 14.7). Moreover, invasion depth (pooled OR=3.62; 95%CI=2.30 to 5.70) and lymph node metastasis (pooled OR=4.21; 95%CI=2.69 to 6.59) were linked with PLCE1 expression in gastric cancer. However, no significant associations were determined between PLCE1 overexpression and the histologic grade, invasion depth, and lymph node metastasis in esophageal cancer. CONCLUSIONS Our meta- analysis results indicated that upregulated PLCE1 is significantly associated with an increased risk of tumor progression in ESCC and GCA. Therefore, PLCE1 expression can be appropriately regarded as a promising biomarker for ESCC and GCA patients.

Effect of TGF-β1 on the Migration and Recruitment of Mesenchymal Stem Cells after Vascular Balloon Injury: Involvement of Matrix Metalloproteinase-14.

Restenosis or occlusion after vascular procedures is ascribed to intimal hyperplasia. Transforming growth factor (TGF)-β1 is involved in recruitment of mesenchymal stem cells (MSCs) following arterial injury, and its release from latent TGF-binding protein by matrix metalloproteinase (MMP)-14-induced proteolysis contributes to neointima formation. However, the relationship between MMP-14 and TGF-β1 activation in restenosis is unknown. This study investigated the relationship using a rat model of balloon-induced injury. Rats were assigned to vehicle-, SB431542 (SB)-, or recombinant human (rh)TGF-β1-treated groups and examined at various time points after balloon-induced injury for expression of TGF-β1/Smad signalling pathway components, MMP-14 and MSCs markers including Nestin, CD29, and Sca1+CD29+CD11b/c−CD45−. Intimal hyperplasia was reduced in SB- and rhTGF-β1-treated rats. The expression of TGF-β1, TGF-β1RI, and Smad2/3 was decreased, but the levels of phosphorylated Smad2/3 were higher in SB-treated rats than vehicle-treated after 7 days to 14 days. rhTGF-β1 administration decreased the expression of TGF-β1/Smad pathway proteins, except for TGF-β1RI. Nestin and CD29 expression and the number of Sca1+CD29+CD11b−CD45− cells were reduced, whereas MMP-14 expression was increased after SB431542 and rhTGF-β1 administration. These results suggest that TGF-β1/Smad signalling and MMP-14 act to recruit MSCs which differentiate to vascular smooth muscle cells and mesenchymal-like cells that participate in arterial repair/remodelling.

Analysis of Molecular Cytogenetic Alteration in Rhabdomyosarcoma by Array Comparative Genomic Hybridization

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma with poor prognosis. The genetic etiology of RMS remains largely unclear underlying its development and progression. To reveal novel genes more precisely and new therapeutic targets associated with RMS, we used high-resolution array comparative genomic hybridization (aCGH) to explore tumor-associated copy number variations (CNVs) and genes in RMS. We confirmed several important genes by quantitative real-time polymerase chain reaction (QRT-PCR). We then performed bioinformatics-based functional enrichment analysis for genes located in the genomic regions with CNVs. In addition, we identified miRNAs located in the corresponding amplification and deletion regions and performed miRNA functional enrichment analysis. aCGH analyses revealed that all RMS showed specific gains and losses. The amplification regions were 12q13.12, 12q13.3, and 12q13.3–q14.1. The deletion regions were 1p21.1, 2q14.1, 5q13.2, 9p12, and 9q12. The recurrent regions with gains were 12q13.3, 12q13.3–q14.1, 12q14.1, and 17q25.1. The recurrent regions with losses were 9p12–p11.2, 10q11.21–q11.22, 14q32.33, 16p11.2, and 22q11.1. The mean mRNA level of GLI1 in RMS was 6.61-fold higher than that in controls (p = 0.0477) by QRT-PCR. Meanwhile, the mean mRNA level of GEFT in RMS samples was 3.92-fold higher than that in controls (p = 0.0354). Bioinformatic analysis showed that genes were enriched in functions such as immunoglobulin domain, induction of apoptosis, and defensin. Proto-oncogene functions were involved in alveolar RMS. miRNAs that located in the amplified regions in RMS tend to be enriched in oncogenic activity (miR-24 and miR-27a). In conclusion, this study identified a number of CNVs in RMS and functional analyses showed enrichment for genes and miRNAs located in these CNVs regions. These findings may potentially help the identification of novel biomarkers and/or drug targets implicated in diagnosis of and targeted therapy for RMS.

HLA-DRB1 and HLA-DQB1 methylation changes promote the occurrence and progression of Kazakh ESCC

Human leukocyte antigen II (HLA-II) plays an important role in host immune responses to cancer cells. Changes in gene methylation may result in aberrant expression of HLA-II, serving a key role in the pathogenesis of Kazakh esophageal squamous cell carcinoma (ESCC). We analyzed the expression level of HLA-II (HLA-DP, -DQ, and -DR) by immunohistochemistry, as well as the methylation status of HLA-DRB1 and HLA-DQB1 by MassARRAY spectrometry in Xinjiang Kazakh ESCC. Expression of HLA-II in ESCC was significantly higher than that in cancer adjacent normal (ACN) samples (P < 0.05). Decreased HLA-II expression was closely associated with later clinical stages of ESCC (P < 0.05). Hypomethylation of HLA-DRB1 and hypermethylation of HLA-DQB1 was significantly correlated with occurrence of Kazakh ESCC (P < 0.01), and mainly manifested as hypomethylation of CpG9, CpG10-11, and CpG16 in HLA-DRB1 and hypermethylation of CpG6-7 and CpG16-17 in HLA-DQB1 (P < 0.01). Moreover, hypomethylation of HLA-DQB1 CpG6-7 correlated with poor differentiation in ESCCs, whereas hypermethylation of HLA-DRB1 CpG16 and hypomethylation of HLA-DQB1 CpG16-17 were significantly associated with later stages of ESCC (P < 0.05). A significant inverse association between HLA-DRB1 CpG9 methylation and HLA-II expression was found in ESCC (P < 0.05). These findings suggest aberrant HLA-DRB1 and HLA-DQB1 methylation contributes to the aberrant expression of HLA-II. These molecular changes may influence the immune response to specific tumor epitopes, promoting the occurrence and progression of Kazakh ESCC.

SLC39A6: a potential target for diagnosis and therapy of esophageal carcinoma

BackgroundEsophageal squamous cell carcinoma (ESCC) is a highly lethal cancer, and its underlying molecular mechanisms are poorly understood. Recent large-scale genome-wide association studies in Chinese Han populations have identified an ESCC susceptibility locus within the SLC39A6 gene. Here, we sought to explore the expression and biological function of SLC39A6 in ESCC.MethodsMultiethnic validation of SLC39A6 protein expression was performed in different cohorts of patients from Chinese Han and Kazakh populations in the Xinjiang region by immunohistochemistry. The associations among SLC39A6 expression, clinicopathological parameters, and prognosis outcomes of ESCC were analyzed. And the effects of SLC39A6 silencing by siRNA on cell proliferation, apoptosis, and invasiveness, as well as the proteins involved in epithelial-to-mesenchymal transition (EMT) of esophageal cancer cells, were studied.ResultsSLC39A6 protein expression increased progressively from normal esophageal epithelium (NEE) to low-grade intraepithelial neoplasia to ESCC, and finally reached the highest in high-grade intraepithelial neoplasia from Han ethnic. Similarly, SLC39A6 protein was significantly overexpressed in Kazakh ethnic ESCC compared with that in NEE. Increased expression of SLC39A6 was found to be closely correlated with histological grade and early Tumor-Node-Metastasis stage I/II. High tumorous SLC39A6 expression was significantly correlated with shorter overall survival (OS). Cox regression analysis confirmed that SLC39A6 expression was an independent prognostic factor for poor OS in ESCC. Experimentally, the suppression of SLC39A6 expression promoted ESCC cell apoptosis but abrogated proliferation and invasion, and induced an EMT phenotype that included enhanced expression of E-cadherin, loss of vimentin, and morphological changes in ESCC cells in vitro.ConclusionsCombined, our findings highlight a tumor-promoting role for SLC39A6 in ESCC, suggesting that SLC39A6 could serve as an early detector of high-risk subjects and prognostic biomarker. The targeting of SLC39A6 might be a potential therapeutic strategy for blocking ESCC.

BRCA1 Gene Exon 11 Mutations in Uighur and Han Women with Early-onset Sporadic Breast Cancer in the Northwest Region of China

The prevalence of BRCA1 gene mutations in breast cancer differs between diverse ethnic groups. Relatively little information is known about patterns of BRCA1 mutations in early-onset breast cancer in women of Uighur or Han descent, the major ethnic populations of the Xinjiang region in China. The aim of this study was to identify BRCA1 mutations in Uighur and Han patients with early-onset (age <35 years), and sporadic breast cancer for genetic predisposition to breast cancer. For detection of BRCA1 mutations, we used a polymerase chain reaction single-stranded conformation polymorphism approach, followed by direct DNA sequencing in 22 Uighur and 13 Han women with early-onset sporadic breast cancer, and 32 women with benign breast diseases. The prevalence of BRCA1 mutations in this population was 22.9% (8/35) among early-onset sporadic breast cancer cases. Of these, 31.8% (7/22) of Uighur patients and 7.69% (1/13) of Han patients were found to have BRCA1 mutations. In 7 Uighur patients with BRCA1 mutations, there were 11 unique sequence alterations in the BRCA1 gene, including 4 clearly disease-associated mutations on exon 11 and 3 variants of uncertain clinical significance on exon 11, meanwhile 4 neutral variants on intron 20 or 2. None of the 11 BRCA1 mutations identified have been previously reported in the Breast Cancer Information Core database. These findings reflect the prevalence of BRCA1 mutations in Uighur women with early-onset and sporadic breast cancer, which will allow for provision of appropriate genetic counseling and treatment for Uighur patients in the Xinjiang region.