[Effectiveness of EGFR-TKIs versus chemotherapy as first-line treatment for advanced non-small cell lung cancer: a meta-analysis]

Assessment of Resistance to Tyrosine Kinase Inhibitors by an Interrogation of Signal Transduction Pathways by Antibody Arrays

Cancer patients with an aberrant regulation of the protein phosphorylation networks are often treated with the tyrosine kinase inhibitors. Response rates approaching 85% are common. Unfortunately, patients often become refractory to the treatment by altering their signal transduction pathways. An implementation of the expression profiling with microarrays can identify the overall mRNA-level changes, and proteomics can identify the overall changes in protein levels or can identify the proteins involved, but the activity of the signal transduction pathways can only be established by interrogating post-translational modifications of the proteins. As a result, the ability to identify whether a drug treatment is successful or whether resistance arose, or the ability to characterize any alterations in the signaling pathways, is an important clinical challenge. Here, we provide a detailed explanation of antibody arrays as a tool which can identify system-wide alterations in various post-translational modifications (e.g., phosphorylation). One of the advantages of using antibody arrays includes their accessibility (an array does not require either an expert in proteomics or costly equipment) and speed. The availability of arrays targeting a combination of post-translational modifications is the primary limitation. In addition, unbiased approaches (phosphoproteomics) may be more suitable for the novel discovery, whereas antibody arrays are ideal for the most widely characterized targets.

[Intercalated Combination of Chemotherapy and EGFR-TKIs versus Chemotherapy Alone in the First-line Treatment of Advanced Non-small Cell Lung Cancer: A Meta-analysis]

背景与目的

化疗与表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs)联合疗法一直是许多研究的焦点，其中间插联合疗法受到了更多研究者的关注。本研究旨在系统评价化疗与EGFR-TKIs间插联合疗法对比单独化疗一线治疗晚期非小细胞肺癌(non-small cell lung cancer, NSCLC)的有效性及安全性。

方法

检索The Cochrane Library、PubMed、EMBASE、中国生物医学文献数据库(CBM)、知网和万方等数据库关于化疗间插联合EGFR-TKIs疗法和单独化疗一线治疗晚期NSCLC的随机对照试验(randomized controlled trial, RCT)，分析如下结局指标：无进展生存期(progression-free survival, PFS)、总体生存期(overall survival, OS)、客观缓解率(objective response rate, ORR)、疾病控制率(disease control rate, DCR)以及不良反应发生率。由两名研究者根据Cochrane系统评价手册筛选文献、进行质量评价以及提取并交叉核对数据。应用Stata12.0软件进行meta分析。

结果

本研究共纳入6个RCT，共计933例晚期NSCLC患者。Meta分析结果表明，在晚期NSCLC患者一线治疗中，与单独化疗相比，间插联合疗法虽然延长了患者的PFS(HR=0.72, 95%CI: 0.53-0.98, P=0.037)，但并不能提高其OS(HR=0.85, 95%CI: 0.72-1.01, P=0.060)、ORR(OR=1.59, 95%CI: 0.86-2.95, P=0.142)和DCR(OR=1.09, 95%CI: 0.95-1.25, P=0.226)。进一步的亚组分析发现，间插联合疗法提高了女性、腺癌、从不吸烟和EGFR突变等患者的PFS，差异具有统计学意义。在安全性方面，间插联合疗法的主要不良反应为皮疹(OR=7.81, 95%CI: 3.74-16.34, P < 0.001)和腹泻(OR=2.73, 95%CI: 1.92-3.89, P < 0.001)。

结论

一线接受化疗间插联合EGFR-TKIs治疗的NSCLC患者的PFS明显高于接受单独化疗者，其主要不良事件是皮疹和腹泻。因此，间插联合治疗具有一定优势，但仍需要更多大样本、高质量的RCT进一步验证。

[Ionizing Radiation Reduces TKI Resistance Caused by T790M Mutation in NSCLC Cell Lines]

背景与目的

以表皮生长因子受体（epidermal growth factor receptor, EGFR）为靶点的分子靶向治疗在非小细胞肺癌（non-small cell lung cancer, NSCLC）的治疗中发挥重要的作用。EGFR突变的患者对EGFR酪氨酸激酶抑制剂（EGFR-tyrosine kinase inhibitor, EGFR-TKI）治疗敏感、疗效显著，但无论近期疗效如何，患者最终都不可避免地产生耐药。大量研究证实，EGFR基因的二次突变（T790M）是患者耐药的主要原因。本研究旨在探讨电离辐射对NSCLC细胞株T790M突变所致EGFR-TKI耐药的影响。

方法

选择NSCLC细胞株H1975和H3255为研究对象，实时荧光定量PCR法检测两株细胞的突变状态、克隆形成实验观察两株细胞的放射敏感性，MTT法检测各处理组两株细胞对EGFR-TKI的抗药性。

结果

H1975为T790M+L858R双突变株、H3255是仅有L858R的单突变株；各处理组H1975及H3255的存活分数未见明显差异（P=0.952），提示T790M突变对NSCLC细胞株的放射敏感性无影响；2.5 Gy X线辐射组，H1975的IC₅₀为（0.678, 2±0.373）μmol/L，较0 Gy对照组的（3.520±0.821）μmol/L明显下降，差异有统计学意义（P=0.008），H1975相较于H3255的抗药性也从85.9倍下降为39.2倍。

结论

电离辐射可降低NSCLC细胞株T790M突变所致的TKI耐药，本实验的研究结果为后续的体内和临床研究提供了研究依据；EGFR-TKI治疗期间联合放射治疗对克服T790M突变介导的耐药性有望成为一种有希望的治疗策略。