A systematic analysis of fractional contributions of various growth signals on the proliferation of lung cancer cells

背景：吉非替尼是一种表皮生长因子受体(EGFR)酪氨酸激酶活性的抑制剂，最近被引入治疗晚期肺癌。吉非替尼对一些患者非常有效，而对另一些患者则完全无效。此外，已知吉非替尼会导致严重的药物性肺炎。最近发现，EGFR突变的存在与吉非替尼的疗效有很好的对应关系。标本、支气管冲洗、胸腔积液)含有许多正常细胞和癌细胞。此外，EGFR显示了10多种不同的突变。结果：建立了一种新的检测EGFR突变的方法，命名为PNA-LNA聚合酶链式反应钳。这种方法可以在100倍的野生型EGFR存在的情况下检测突变。我们筛选了30个来自日本的肺癌细胞系，发现有9个细胞系存在突变。接下来对56例临床标本(1例活检标本、16例胸腔积液标本、1例针吸活检标本、14例支气管冲洗液标本、5例痰标本、35例石蜡包埋标本和3例心包积液标本)进行了检测。10例标本中发现有EGFR突变的细胞。讨论：临床标本中有关EGFR突变的信息提供了宝贵的信息，以避免患者不必要地使用gefinitib。PNA-LNA聚合酶链式反应钳能在1小时内高灵敏度地检测到EGFR突变。PNA-LNA聚合酶链式反应钳将为非小细胞肺癌的诊断或治疗提供一种良好的临床检测方法。

Background : Gefitinib is an inhibitor of tyrosine kinase activity of the epidermal growth factor receptor (EGFR) and has recently been introduced in the treatment of advanced lung cancers. Gefitinib is dramatically effective in some patients, whereas it is completely ineffective in others. In addition, gefitinib is known to cause serious drug-induced pneumonitis. Recently, it has been found that the presence of EGFR mutation well corresponds with the effectiveness of gefitinib.Method : Clinical specimens isolated from patients (i.g. specimen, bronchial washing, pleural effusion) contain many normal cells as well as cancer cells. In addition, EGFR shows more than 10 different mutations. These make the identification of EGFR mutations in clinical specimen difficult.Results : We have established a novel detection method for EGFR mutations and named it as PNA-LNA PCR clamp. This method can detect mutations in the presence of 100-fold amount of wild type EGFR. We screened 30 lung cancer cell lines established from Japanese, and found 9 cell lines have mutations. We next investigated 56 clinical specimens (1 biopsy specimen, 16 pleural effusion specimens, 1 needle biopsy specimens, 14 bronchial washing fluid specimens, 5 sputum specimens, 35 paraffin embedded specimens and 3 pericardial effusion specimens). 10 specimens were found to contain cells with EGFR mutations.Discussion : To avoid unnecessary administration of gefinitib to patients, information on EGFR mutation in the clinical specimens gives an invaluable information. PNA-LNA PCR clamp can detect EGFR mutations with a high sensitivity within an hour. PNA-LNA PCR clamp will establish an excellent clinical test beneficial for the diagnosis or treatment of non-small cell lung cancers.