Correlation of epidermal growth factor receptor mutations and HER2/3 protein expression with clinical outcome in advanced non-small cell lung cancer patients treated with gefitinib / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>The effect of gefitinib on advanced non-small cell lung cancer (NSCLC) was various. How to choose the sensitive patients and improve the effect was difficulty in clinic. This study was to assess the correlation of epidermal growth factor receptor (EGFR) mutations and HER2/3 protein expression with the effect of gefitinib on Chinese patients with advanced NSCLC.</p><p><b>METHODS</b>From May 2002 to February 2005, a total of 106 Chinese NSCLC patients who had failed at least one chemotherapy regimen were treated with gefitinib 250 mg once a day. The mutations in the exons 18-24 of EGFR gene were detected in the tumor tissues from 106 patients before the treatment of gefitinib, and HER2/3 expression in 84 tumor samples were detected by immunohistochemistry.</p><p><b>RESULTS</b>Mutation was identified in 32 (30.2%) tumor tissues. Overall remission rate was significantly higher in the HER2 high expression patients than in the HER2 low expression patients (36.8% vs 17.4%, P=0.044). HER2 and HER3 expression levels were not associated with time to progression (TTP) and overall survival (OS). The patients with HER2/3 single high expression had relatively longer TTP and OS than those with HER2/3 single low expression (6.1 vs 9.1 months, P=0.725; 6.1 vs 9.0 months, P=0.862), while those with concomitant HER2/3 high expression had significant longer TTP and OS. EGFR-mutated patients with HER2 expression or high HER2 and HER3 expressions were more sensitive to gefitinib.</p><p><b>CONCLUSION</b>EGFR mutations combined with HER2/3 expressions is a significant predictor for gefitinib efficacy on Chinese patients with advanced NSCLC.</p>

EGFR mutation predicts response and prognosis in iressa-treated advanced-stage non-small cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation between mutation in EGFR tyrosine kinase domain and tumor response as well as prognosis in advanced stage non-small cell lung cancer (NSCLC) treated with iressa.</p><p><b>METHODS</b>From May 2002 to Feb. 2005, iressa was orally administered at a dose of 250 mg once daily for 106 advanced stage NSCLC patients until occurrence of disease progression or intolerable toxicity. Cancer tissue was obtained from these patients, and DNA was extracted for analysis of mutation in exon 18 to 24 of EGFR. Exon 18 to 24 of EGFR were amplified by nest PCR, sequenced and analyzed from both sense and antisence directions.</p><p><b>RESULTS</b>Primary NSCLC tissue specimens consisted of 25 frozen tissue blocks and 81 paraffin-embedded tumor tissue blocks from 106 consecutive NSCLC patients. Mutation was found to be more frequent in the adenocarcinoma than in the squamous cell carcinoma (35.9% vs 14.3%, P =0.033). Mutation was identified in 32 patients (30.2%). Response rate to iressa was 71.9% in the patients with EGFR mutation versus 13.5% in those without mutation (P <0.01). Compared with the patients without EGFR mutation, those with mutation had longer overall survival (median, 13.45 vs. 5.25 months; P<0.01) and median time to progression (median, 8.35 vs. 3.0 months; P <0.01).</p><p><b>CONCLUSION</b>EGFR mutation may be positively correlated with the response and survival in advanced stage Chinese NSCLC patient treated with iressa.</p>

Expression of human mu-opioid receptor cDNA in CHO cell / 生物工程学报

Opioid receptor, is classified into three subtypes, mu, kappa and delta, with the mu-type receptor plays important roles in opioid analgesia and opioid addiction. The cDNA encoding mu-type receptor was obtained by RT-PCR from human brain RNA and was cloned into pcDNA3.1(+). The resultant recombinant plasmid pcDNAMORs were transfected into CHO cells by liposome. After PCR identification, the positive clone were treated with agonist and antiagonist were tested for their competence of signal transduction. CHO cells that contained mu-opioid receptor in the expression vector pcDNA3.1(+) acquired naloxone-blockable high-affinity specific binding of morphine and DAMGO. The concentration of cAMP in CHO cells transfected with pcDNAMOR was reduced after binding to morphine and DAMGO, and increased after binding naloxone. These results indicate that the mu-type receptor expreesd on the CHO cell has similar biological property as the nature receptor. The availability of these specific cell lines will facilitate the drug development and promote our understanding the mechanism underlying opiate addiction.

A QUICK AND PRECISION METHOD TO CONSTRUCT ESCHERICHIA COLI HISTIDINE AUXOTROPH / 微生物学通报

Red in vivo recombination is a new kind of genetic engineering technique based on homologous recombination. In this work, plasmid pKD46 which expresses Red recombination proteins is transferred into Escherichia coli strain DH5?.The kanamycine resistant gene is generated by PCR by using primers with homology to hisDCB gene of E.coli chromosome. Thus, the hisDCB gene was replaced with kanamycine resistant gene by the plasmid recombination system, then the resistant gene was eliminated by a helper plasmid encoding the FLP recombinase. At last, a E.coli histidine auxotroph which is sensitive to kanamycine was got. The results indicate that Red in vivo recombination is a convenient method to construct auxotrophs.