Detecting the spectrum of multigene mutations in non-small cell lung cancer by Snapshot assay / 癌症

As molecular targets continue to be identified and more targeted inhibitors are developed for personalized treatment of non-small cell lung cancer (NSCLC), multigene mutation determination will be needed for routine oncology practice and for clinical trials. In this study, we evaluated the sensitivity and specificity of multigene mutation testing by using the Snapshot assay in NSCLC. We retrospectively reviewed a cohort of 110 consecutive NSCLC specimens for which epidermal growth factor receptor (EGFR) mutation testing was performed between November 2011 and December 2011 using Sanger sequencing. Using the Snapshot assay, mutation statuses were detected for EGFR, Kirsten rate sarcoma viral oncogene homolog (KRAS), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA), v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), v-ras neuroblastoma viral oncogene homolog (NRAS), dual specificity mitogen activated protein kinase kinase 1 (MEK1), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (HER2) in patient specimens and cell line DNA. Snapshot data were compared to Sanger sequencing data. Of the 110 samples, 51 (46.4%) harbored at least one mutation. The mutation frequency in adenocarcinoma specimens was 55.6%, and the frequencies of EGFR, KRAS, PIK3CA, PTEN, and MEK1 mutations were 35.5%, 9.1%, 3.6%, 0.9%, and 0.9%, respectively. No mutation was found in the HER2, NRAS, or BRAF genes. Three of the 51 mutant samples harbored double mutations: two PIK3CA mutations coexisted with KRAS or EGFR mutations, and another KRAS mutation coexisted with a PTEN mutation. Among the 110 samples, 47 were surgical specimens, 60 were biopsy specimens, and 3 were cytological specimens; the corresponding mutation frequencies were 51.1%, 41.7%, and 66.7%, respectively (P = 0.532). Compared to Sanger sequencing, Snapshot specificity was 98.4% and sensitivity was 100% (positive predictive value, 97.9%; negative predictive value, 100%). The Snapshot assay is a sensitive and easily customized assay for multigene mutation testing in clinical practice.

Inhibitory effects of selenium on telomerase activity and hTERT expression in cadmium-transformed 16HBE cells / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells.</p><p><b>METHODS</b>Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses (0.625, 1.25, 2.50, 5.00 micromol/L) for 24 hours.</p><p><b>RESULTS</b>Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of mad1 mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group.</p><p><b>CONCLUSION</b>Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing mad1 mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.</p>

Association of XAGE-1b gene expression with clinical characteristics of non-small cell lung cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association between XAGE-1b gene expression and the clinical characteristics of non-small cell lung cancer (NSCLC).</p><p><b>METHODS</b>Tumor tissue and adjacent normal lung tissue specimens were obtained surgically from 30 patients with resectable NSCLC, from which the total RNA was extracted for RT-PCR to amplify full-length XAGE-1b gene. The products of RT-PCR were identified by electrophoresis and sequencing. The expression of XAGE-1b gene and its association with the clinical characteristics of the patients were analyzed.</p><p><b>RESULTS</b>In the 30 tumor tissue specimens, the expression rate of XAGE-1b gene was 40%, but none of the normal lung tissues expressed this gene. The gene expression was not related to the patients' age, gender, tumor differentiation or clinical stages, but showed significant correlation to their pathological classification. The expression rate of XAGE-1b gene in adenocarcinoma was much higher than that in tumors of other pathological types (61.1% vs 8.3%, P=0.015). XAGE-1b gene expression tended to increase with the TNM stages, which, however, failed to find statistical data support (P>0.05).</p><p><b>CONCLUSIONS</b>XAGE-1b gene is highly expressed in lung adenocarcinoma, and can be an ideal target for tumor immunotherapy.</p>

Over-expressed genes detected by suppression subtractive hybridization in carcinoma derived from transformed 16HBE cells induced by BPDE / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To screen the over differentially expressed genes in carcinoma induced by BPDE-transformed 16HBE cells (16HBE-C cells).</p><p><b>METHODS</b>The suppression subtractive hybridization (SSH) method was performed to profile differentially expressed genes between 16HBE-C cells and 16HBE cells. The cDNA fragments of differentially expressed genes were inserted into TA cloning vector and transformed competent E. coli strain. Positive clones were randomly picked up and identified by the colony PCR method. Dot blot was used to test the same source with the tester. The differentially expressed cDNA fragments were sequenced and compared with known genes and EST database in Genbank.</p><p><b>RESULTS</b>Eight known genes were over-expressed in 16HBE-C cells including eukaryotic translation elongation factor 1 alpha 1, HIF-1 responsive RTP801, ribosomal protein L10 (RPL10), ribosomal protein S29 (RPS29), mitochondrion related genes, and laminin receptor 1. Three differentially expressed cDNA fragments could not be matched to the known genes but to the EST database.</p><p><b>CONCLUSION</b>The SSH method can detect differentially expressed genes between 16HBE-C and 16HBE cells. BPDE-induced carcinogenesis may be related to alteration of at least eight known genes and three unknown genes. These expression data provide a clue to further cloning novel genes and studying functions in BPDE-induced carcinoma.</p>