Here we present the first diploid genome sequence of an Asian individual. The genome was sequenced to 36-fold average coverage using massively parallel sequencing technology. We aligned the short reads onto the NCBI human reference genome to 99.97% coverage, and guided by the reference genome, we used uniquely mapped reads to assemble a high-quality consensus sequence for 92% of the Asian individual's genome. We identified approximately 3 million single-nucleotide polymorphisms (SNPs) inside this region, of which 13.6% were not in the dbSNP database. Genotyping analysis showed that SNP identification had high accuracy and consistency, indicating the high sequence quality of this assembly. We also carried out heterozygote phasing and haplotype prediction against HapMap CHB and JPT haplotypes (Chinese and Japanese, respectively), sequence comparison with the two available individual genomes (J. D. Watson and J. C. Venter), and structural variation identification. These variations were considered for their potential biological impact. Our sequence data and analyses demonstrate the potential usefulness of next-generation sequencing technologies for personal genomics.
BackgroundOesophageal cancer is one of the most deadly forms of cancer worldwide. Long non-coding RNAs (lncRNAs) are often found to have important regulatory roles.ObjectiveTo assess the lncRNA expression profile of oesophageal squamous cell carcinoma (OSCC) and identify prognosis-related lncRNAs.MethodLncRNA expression profiles were studied by microarray in paired tumour and normal tissues from 119 patients with OSCC and validated by qRT-PCR. The 119 patients were divided randomly into training (n=60) and test (n=59) groups. A prognostic signature was developed from the training group using a random Forest supervised classification algorithm and a nearest shrunken centroid algorithm, then validated in a test group and further, in an independent cohort (n=60). The independence of the signature in survival prediction was evaluated by multivariable Cox regression analysis.ResultsLncRNAs showed significantly altered expression in OSCC tissues. From the training group, we identified a three-lncRNA signature (including the lncRNAs ENST00000435885.1, XLOC_013014 and ENST00000547963.1) which classified the patients into two groups with significantly different overall survival (median survival 19.2 months vs >60 months, p<0.0001). The signature was applied to the test group (median survival 21.5 months vs >60 months, p=0.0030) and independent cohort (median survival 25.8 months vs >48 months, p=0.0187) and showed similar prognostic values in both. Multivariable Cox regression analysis showed that the signature was an independent prognostic factor for patients with OSCC. Stratified analysis suggested that the signature was prognostic within clinical stages.ConclusionsOur results suggest that the three-lncRNA signature is a new biomarker for the prognosis of patients with OSCC, enabling more accurate prediction of survival.
Esophageal cancer is the sixth leading cause of death from cancer and one of the least studied cancers worldwide. The global microRNA expression profile of esophageal cancer has not been reported previously. Here, for the first time, we have investigated expressed microRNAs in cryopreserved esophageal cancer tissues using advanced microRNA microarray techniques. Our microarray analyses identified seven microRNAs that could distinguish malignant esophageal cancer lesions from adjacent normal tissues. Some microRNAs could be correlated with the different clinicopathologic classifications. High expression of hsa-miR-103/107 correlated with poor survival by univariate analysis as well as by multivariate analysis. These results indicate that microRNA expression profiles are important diagnostic and prognostic markers of esophageal cancer, which might be analyzed simply using economical approaches such as reverse transcription-PCR.
Purpose: Recent studies have suggested that microRNA biomarkers could be useful for stratifying lung cancer subtypes, but microRNA signatures varied between different populations. Squamous cell carcinoma (SCC) is one major subtype of lung cancer that urgently needs biomarkers to aid patient management. Here, we undertook the first comprehensive investigation on microRNA in Chinese SCC patients.Experimental Design: MicroRNA expression was measured in cancerous and noncancerous tissue pairs strictly collected from Chinese SCC patients (stages I-III), who had not been treated with chemotherapy or radiotherapy prior to surgery. The molecular targets of proposed microRNA were further examined.Results: We identified a 5-microRNA classifier (hsa-miR-210, hsa-miR-182, hsa-miR-486-5p, hsamiR-30a, and hsa-miR-140-3p) that could distinguish SCC from normal lung tissues. The classifier had an accuracy of 94.1% in a training cohort (34 patients) and 96.2% in a test cohort (26 patients). We also showed that high expression of hsa-miR-31 was associated with poor survival in these 60 SCC patients by Kaplan-Meier analysis (P ¼ 0.007), by univariate Cox analysis (P ¼ 0.011), and by multivariate Cox analysis (P ¼ 0.011). This association was independently validated in a separate cohort of 88 SCC patients (P ¼ 0.008, 0.011, and 0.003 in Kaplan-Meier analysis, univariate Cox analysis, and multivariate Cox analysis, respectively). We then determined that the tumor suppressor DICER1 is a target of hsa-miR-31. Expression of hsa-miR-31 in a human lung cancer cell line repressed DICER1 activity but not PPP2R2A or LATS2.Conclusions: Our results identified a new diagnostic microRNA classifier for SCC among Chinese patients and a new prognostic biomarker, hsa-miR-31. Clin Cancer Res; 17(21); 6802-11. Ó2011 AACR.
microRNAs (miRNAs) regulate gene expression at the posttranscriptional level and play important roles in tumor initiation and progression. Recently, we examined the global miRNA expression profile of esophageal squamous cell carcinoma (ESCC) and demonstrated that miR-92a was highly expressed in tumor tissues. In this study, we found that the upregulation of miR-92a was significantly correlated with the status of lymph node metastasis and TNM stage in 107 ESCC patients. Moreover, the up-regulation of miR-92a was associated with poor survival of ESCC patients and might be used as an independent prognostic factor. Next, we investigated the role and mechanism of miR-92a in ESCC cells, and found that miR-92a modulated the migration and invasion but not apoptosis and proliferation of ESCC cells in vitro. We further demonstrated that miR-92a directly targeted the CDH1 3-UTR and repressed the expression of CDH1, a tumor metastasis suppressor. In addition, restoring of miR-92a-resistant CDH1 expression in miR-92a-overexpression cells recovered the pro-metastasis activity of miR-92a. Taken together, we demonstrated that miR-92a promotes ESCC cell migration and invasion at least partially via suppression of CDH1 expression, and patients with up-regulated miR-92a are prone to lymph node metastasis and thus have poor prognosis.Esophageal cancer is the eighth most common cancer and the sixth most common cause of cancer deaths worldwide. The incidence of esophageal cancer varies greatly by geographic location, where it is most common in China, Southeast Africa, and Japan. Compared with the high incidence of Barrett's associated adenocarcinoma in Europe and the United States (1), the incidence of esophageal squamous cell carcinoma (ESCC) 3 is prevalent in China. Despite the advances in therapy, ESCC is still one of the most lethal malignancies in China, with an overall 5-year survival rate of 20 -30% after surgery (2, 3). Tumor metastasis is primarily responsible for ESCC mortality, yet the molecular mechanism of metastatic dissemination remains unclear (4). Recent evidences suggest that miRNAs play an important role in tumor metastasis (5-8). miRNA is the noncoding RNA of ϳ22 nucleotides that regulates gene expression via degradation of target mRNAs or inhibition of protein translation. Hundreds of miRNAs have been identified, and some of them exhibit highly specific expression patterns in various tissues and species. More than 50% of annotated human miRNA genes are located in fragile chromosomal regions that are susceptible to amplification, deletion or translocation during the process of tumor development and can function either as oncogene or tumor suppressor (9). miR-92a belongs to the miR-17-92a cluster and is located on chromosome 13q32-33, a region frequently amplified in B-cell lymphoma (10, 11), lung cancer (12), and colorectal cancer (13). The polycistronic miR-17-92a cluster produces six mature miRNAs (miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1, and miR-92a-1). Up-regulation of these miRNAs were found in B-cell...
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