Author of

• 17398

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  P2.01 - Poster Session with Presenters Present (ID 461)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Biology/Pathology
  • Presentations: 2
  • Moderators:
  • Coordinates: 12/06/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 17405

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    P2.01-007 - Detection of Promoter DNA Methylation of APC, DAPK, and GSTP1 Genes in Tissue Biopsy and Matched Serum of Advanced Stage Lung Cancer Patients (ID 5595)

    14:30 - 14:30  |  Author(s): S. Kumar
    • Abstract

    Background:
    Promoter DNA hypermethylation is a well characterized epigenetic event and has been linked with early stages of lung carcinogenesis through inactivation of tumor suppressor genes. In this study, we studied the methylation status of APC, DAPK, and GSTP1 genes in tissue biopsy and serum of lung cancer patients and cancer-free controls.
    
    Methods:
    In this prospective study, 160 primary lung cancer patients and 70 cancer-free controls undergoing bronchoscopy for benign disease were recruited. DNA was isolated from tissue biopsy and serum of all the subjects and methylation-specific PCR of APC, DAPK, and GSTP1 was carried out after bisulfite conversion. Association of DNA methylation with various clinico-pathological parameters and survival was determined in lung cancer patients.
    
    Results:
    The methylation rates of APC, DAPK, and GSTP1 in tissue biopsy were 83.1%, 83.1%, and 78.1% for lung cancer patients and 72.9%, 70%, and 70% for cancer-free controls. The methylation rates of APC, DAPK, and GSTP1 in serum were 52.5%, 30.6%, and 65.6% for lung cancer patients and 14.3%, 18.6%, and 30% for cancer-free controls. In lung cancer patients, all three genes were methylated at significantly higher frequency in tissue biopsy than matched serum samples. No significant correlation was observed between methylation of any of three genes with clinico-pathological parameters, including survival.
    
    Conclusion:
    Present study did not demonstrating any evidence suggesting the role of promoter DNA methylation of APC, DAPK, and GSTP1 in lung carcinogenesis. However, follow-up of cancer-free controls, who were positive for DNA methylation, is required to confirm their role in early stages of lung carcinogenesis.
    
    

  • 17409

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    P2.01-011 - Identification of Differentially Expressed Circulating miRNAs in the Serum of NSCLC Patients Using next Generation Sequencing (ID 4016)

    14:30 - 14:30  |  Author(s): S. Kumar
    • Abstract

    Background:
    Aberrant expression of miRNAs has been found in human cancers and has not only been used as diagnostic, prognostic, and predictive biomarkers, but also as potential therapeutic target. In this study, we compared the expression profile of miRNAs in the serum of NSCLC patients with that of non-malignant respiratory disease patients and healthy controls.
    
    Methods:
    For this prospective pilot study, a total of 10 subjects were recruited, 2 each of lung adenocarcinoma (ADC), squamous cell carcinoma (SQC), pulmonary tuberculosis (TB), chronic obstructive pulmonary disease (COPD), and healthy controls, from Outpatient Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi. Approximately 5 ml. of peripheral blood was collected; serum was separated and total RNA was isolated using miRNeasy serum/plasma kit (QIAGEN). Small RNAs were purified from total RNA; libraries of 18 to 50 nt small RNAs were prepared with the TruSeq RNA Library Prep Kit (Illumina), and mature miRNAs were profiled using illumina TruSeq Sequencing Chemistry on illumina HiSeq 2000 next generation sequencing (NGS) platform. Quality check was performed and high quality raw data was mapped on to miRBase database. The expression profile of miRNAs in each subject was analyzed using miRNAkey software and fold change was performed to identify differentially expressed miRNAs in NSCLC as compared to controls.
    
    Results:
    Using NGS, we were able to detect 1074, 1013, 299, 268, and 907 known miRNAs in the serum of lung ADC, SQC, TB, COPD and healthy controls, respectively. A number of miRNAs, such as let-7, miR-10b-5p, miR-15a-5p, miR-23b-5p, miR-92a-3p, miR-148b-3p, miR-185-3p, miR-192-5p, miR-320a, miR-329-3p, miR-342-3p, miR-375, miR-449a, miR-486-5p, miR-497-5p, miR-584-3p, miR-1908-5p, and miR-3195 were found to be downregulated, while miR-10a-5p, miR-148a-3p, and miR-197-3p were found to be upregulated in NSCLC as compared to non-malignant respiratory disease controls and healthy controls (>2 fold change; p<0.05). Further, few miRs, including miR-93-3p, miR-130b-5p, miR-196b-5p, miR-337-3p, miR-378f, miR-382-5p, miR-424-3p, and miR-1271-3p were found to be specifically expressed in NSCLC.
    
    Conclusion:
    A number of miRNAs were found to be dysregulated in the serum of NSCLC patients than controls. The present study is being continued in a larger set of subjects to validate the findings & also the expression patterns of target genes of differentially expressed miRNAs is being analyzed by real-time reverse-transcriptase PCR to find their relevance in lung carcinogenesis. This may prove to be useful for developing non-invasive diagnostic and prognostic tools as well as tools to monitor therapeutic efficacy in NSCLC.