Methylation profiling of archived non-small cell lung cancer: a promising prognostic system.

PURPOSE: Enhanced prognostication power is becoming more desirable in clinical oncology. In this study, we explored the prognostic potential of multigene hypermethylation profiling in non-small-cell lung cancer. EXPERIMENTAL DESIGN: We evaluated a panel of eight genes (p16, APC, ATM, hMLH1, MGMT, DAPK, ECAD, and RASSF1A) using methylation-specific PCR in 105 archived specimens of non-small-cell lung cancer representing all stages of the illness. We analyzed the effect of gene methylation status on outcome individually in a cumulative manner and in a combinatorial approach using recursive partitioning to identify methylation profiles, which affect overall survival. RESULTS: In this data set, tumors harboring promoter hypermethylation at two or more genes exhibit similar survival trends to others in the cohort. Using recursive partitioning, three genes (APC, ATM, and RASSF1A) emerged as determinants of prognostic groups. This designation retained its statistical significance even when disease stage and age were entered into a multivariate analysis. Using this approach, patients whose tumors were hypermethylated at APC and those hypermethylated at only ATM (not also at APC or RASSF1A) enjoyed substantially longer 1- and 2-year survival than patients in the remaining groups. In 32 adjacent histologically normal lung tissue specimens, we detected similar methylation abnormalities. CONCLUSION: Assessment of promoter hypermethylation aberrations may facilitate prognostic profiling of lung tumors, but validation in independent data sets is needed to verify these profiles. This system uses material that is abundantly available with linked outcome data and can be used to generate reliable epigenetic determinants.     

Gene expression profiling of non-small cell lung cancer

Functional genomics has emerged over the past 10 years as a novel technology to study genetic alterations. Gene expression arrays are one genomic technique employed to discover changes in the DNA expression that occur in neoplastic transformation. Microarrays have been applied to investigating lung cancer. Specific applications include discovering novel genetic changes that occur in lung tumors. Microarrays can also be applied to improve diagnosis, staging and discover prognostic markers. The eventual goal of this technology is to discover new markers for therapy and to customize therapy based on an individual tumor genetic composition. In this review, we present the current state of gene expression array technology in its application to lung cancer.     

Gene expression profiling in non-small cell lung cancer: from molecular mechanisms to clinical application.

Non-small cell lung cancer (NSCLC) is the most common cause of premature death from malignant disease in western countries. A better understanding of the molecular mechanisms underlying NSCLC etiology, pathogenesis, and therapeutics will lead to improved clinical outcomes. Recent technological advances in gene expression profiling (in particular, with cDNA and oligonucleotide microarrays) allow the simultaneous analysis of the expression of thousands of genes. In this review, the technology of global gene expression profiling is discussed, and the progress made thus far with it in NSCLC is reviewed. A new molecular classification of NSCLC has been developed, which has provided important insights into etiology and pathogenesis. Other studies have found potential biomarkers for NSCLC that may be of use in diagnosis, screening, and assessing the effectiveness of therapy. Finally, advances have been made in the understanding of the molecular mechanisms of NSCLC progression and the molecular mechanisms of action of currently used cytotoxic drugs. This may facilitate the improvement of current therapeutics and the identification of novel targets. Taken together, these advances hold the promise of an improved understanding of the molecular biology of NSCLC and its treatment, which in turn will lead to improved outcomes for this deadly disease.     

非小细胞肺癌组织中3p区抑癌基因启动子的甲基化

目的：探讨3p位点上3个抑癌基因RASSF1α、RAR-β和FHIT启动子甲基化在非小细胞肺癌（non-smallcelllungcancer．NSCLC）组织中的作用。方法：应用甲基化特异的PCR（methyl-specific PCR,MSP）和RTPCR方法分别测定53例NSCLC组织中RASSF1α、RAR-β和FHIT的甲基化率与转录水平。结果：NSCLC癌组织和癌旁组织中的甲基化率分别是FHIT为53％和8％,RAR-β为42％和6％,RASSF1α为57％和9％;FHIT、RASSF1α的甲基化率在吸烟指数〉400年支组高于≤400年支组（P值分别为0．004与0．008）;FHIT、RASSF1α的甲基化率Ⅱ期高于Ⅰ期（P值分别为0．016与0．008）,Ⅲ期高于Ⅱ期（P值分别为0．033与0．029）。结论：3P位点RASSF1α、RAR-β和FHIT基因甲基化的发生与NSCLC的病理生理密切相关,而启动子CpG岛甲基化是导致转录沉默的重要机制。     

非小细胞肺癌组织中低表达microRNA表达谱

  目的  检测非小细胞肺癌患者手术标本组织中低表达microRNA的表达谱,为进一步阐述肿瘤的发生发展机制和提供诊断或治疗的新策略提供基础,积累以国内患者为数据来源的microRNA资料。  方法  利用芯片技术初步筛选在非小细胞肺癌组织中低表达microRNA,进而利用实时荧光定量PCR验证癌组织和正常肺组织表达水平的差异。  结果  芯片结果发现有20种microRNA在非小细胞肺癌组织中发生明显下调。实时荧光定量PCR验证发现其中的13种microRNA表达量显著降低,分别是hsa-miR-125a-5p、hsa-miR-143、hsa-miR-519a、hsa-miR-223-5p、hsa-miR-1、hsa-miR-520c-3p、hsa-miR-489、hsa-miR-27a、hsa-miR-373、hsa-miR-125b、hsa-miR-27b、hsa-miR-142-5p、hsa-miR-206。  结论  在非小细胞肺癌组织中发现一些表达水平显著下调的mciroRNA,这些microRNA可能与肿瘤的发生发展或某些功能相关。      

Methylation of multiple genes as a candidate biomarker in non-small cell lung cancer

Aberrant DNA methylation is a common phenomenon in human cancer. The aims of this study were to investigate the methylation profiles of non-small cell lung cancer (NSCLC) in the Chinese population. Twenty tumor suppressor genes (TSGs) were determined of the methylation status using methylation-specific PCR in 78 paired NSCLC specimens and adjacent normal tissues, as well as in 110 Stage I/II NSCLC and 50 cancer-free plasmas. The results showed that, nine genes (APC, CDH13, KLK10, DLEC1, RASSF1A, EFEMP1, SFRP1, RARβ and p16(INK4A)) demonstrated a significantly higher frequency of methylation in NSCLC compared with the normal tissues (P≤0.001), while the others (RUNX3, hMLH1, DAPK, BRCA1, p14(ARF), MGMT, NORE1A, FHIT, CMTM3, LSAMP and OPCML) showed relatively low sensitivity or specificity. Furthermore, methylation of multiple genes was more frequentin cancerous tissue, CpG island methylator phenotype positive (CIMP+) cases were detected in 65.38% of (51/78) NSCLC while only in 1.28% (1/78) of adjacent normal tissues (P<0.001), and CIMP+ was associated with advanced stage (P=0.017), lymphatic metastasis (P=0.001) and adverse 2-year progression-free survival (P=0.027). The nine genes validated in tissues also showed a significantly higher frequency of tumor-specific hypermethylation in NSCLC plasma, as compared with the cancer-free plasmas, and a 5-gene set (APC, RASSF1A, CDH13, KLK10 and DLEC1) achieved a sensitivity of 83.64% and a specificity of 74.0% for cancer diagnosis. Thus, the results indicated that methylated alteration of multiple genes plays an important role in NSCLC pathogenesis and a panel of candidate epigenetic biomarkers for NSCLC detection in the Chinese population was identified.     

ATP citrate lyase: activation and therapeutic implications in non-small cell lung cancer

Enhanced glucose and lipid metabolism is one of the most common properties of malignant cells. ATP citrate lyase (ACLY) is a key enzyme of de novo fatty acid synthesis responsible for generating cytosolic acetyl-CoA and oxaloacetate. To evaluate its role in lung cancer progression, we here analyzed ACLY expression in a subset of human lung adenocarcinoma cell lines and showed a relationship with the phosphatidyl-inositol-3 kinase-Akt pathway. The introduction of constitutively active Akt into cells enhanced the phosphorylation of ACLY, whereas dominant-negative Akt caused attenuation. In human lung adenocarcinoma samples, ACLY activity was found to be significantly higher than in normal lung tissue. Immunohistochemical analysis further showed phosphorylated ACLY overexpression in 162 tumors, well-correlating with stage, differentiation grade, and a poorer prognosis. Finally, to show the therapeutic potential and mechanism of ACLY inhibition for lung cancer treatment, we assessed the effect of RNA interference targeting ACLY on lipogenesis and cell proliferation in A549 cells. ACLY inhibition resulted in growth arrest in vitro and in vivo. Interestingly, increased intracellular lipids were found in ACLY knockdown cells, whereas de novo lipogenesis was inhibited. Supplementation of insulin could rescue the proliferative arrest elicited by ACLY inhibition; however, in contrast, fatty acid palmitate induced cell death. Taken together, these findings suggest that ACLY is involved in lung cancer pathogenesis associated with metabolic abnormality and might offer a novel therapeutic target.     

Molecular profiling of non-small cell lung cancer and correlation with disease-free survival

Recent studies have suggested that information from gene expression profiles could be used to develop molecular classifications of cancer. We hypothesized that expression levels of specific genes in operative specimens could be correlated to recurrence risk in non-small cell lung cancer (NSCLC). We performed expression profiling using 19.2 K cDNA microarrays on tumor specimens from a total of 39 NSCLC patients with known clinical follow-up information. Statistical analysis and clustering approaches were used to determine patterns of gene expression segregating with clinical outcome. The results provide evidence that molecular subtyping of NSCLC can identify distinct profiles of gene expression correlating with disease-free survival.     

DNA repair pathways and non-small cell lung cancer: clinical perspectives

The role of DNA repair pathways is to maintain cellular integrity. However, genetic instability is a driving force in the development of tumor cells and many tumors are characterized by the loss of functionality in one or several DNA repair pathways. However, if genetic instability trespasses a certain point, it will induce cell death. Therefore, the dysfunctionality of several DNA repair pathways could represent an Achille's heel for the tumor, if such pathways could be pharmacologically targeted. For instance, the inhibition of PARP1, a protein in the base excision repair pathway (BER) is sufficient to induce cell death in cancer cells bearing BRCA1 or BRCA2 mutations, which are essential proteins in the homologous recombination repair pathway (HR). This phenomenon called "synthetic letality" constitutes recent knowledge and we discuss here the possibility that this strategy might be applied to innovative treatment options in lung cancer. Further, several DNA repair proteins could be used in lung cancer as prognostic and/or predictive biomarkers of response to chemotherapy or radiation. Indeed, specific biomarkers of each DNA repair pathway do exist and could guide oncologists in therapeutic decisions (e.g. ERCC1 and cisplatin). Finally, pharmacologic modulation of DNA repair proteins might also be interesting as it might increase therapeutic efficacy of anticancer strategies (DNA-interacting chemotherapy and radiotherapy). Here, we will present the principal DNA repair pathways and associated biomarkers (ERCC1, MSH2, PARP1 and BRCA1/2), and discuss their status in non-small call lung cancer (NSCLC).     

Differential impact of p16 inactivation by promoter methylation in non-small cell lung and colorectal cancer: clinical implications

Inactivation of p16 has been reported as one of the more frequent events in human carcinogenesis. In order to contribute to the knowledge of the impact of p16 silencing by promoter methylation, we have investigated p16 expression and inactivation of p16 by methylation in two of the major types of human cancer, non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). p16 expression was evaluated by Western blot, and p16 promoter methylation by a methylation-specific PCR procedure (MSP). Clinical correlations were established using the chi-square test, and distributions of disease-free survival (DFS) were estimated with the Kaplan-Meier method. Analyses for p16 revealed that 61.22% (60 of 98) of NSCLCs, and 32.9% (26 of 79) of CRCs here considered, lacked p16 expression. Moreover, 36.7% (22/60) of the non-small cell lung tumours without p16 expression showed p16 promoter methylation, detecting a significant correlation between p16 methylation and the histological subtype of squamous cell carcinomas (SCC) (P=0.04). With respect to CRCs, p16 promoter methylation was observed in 26.9% of tumours that lacked p16 expression (7/26), all tumours studied showing partial methylation. Survival studies demonstrated a clear correlation between p16 negative expression and poor prognosis in NSCLC patients. Moreover, we found a trend toward poor clinical evolution in the group of patients with tumours showing total p16 methylation, in NSCLC, without statistically significant differences in CRC. In conclusion, our results indicate that p16 alterations constitute a major molecular abnormality in NSCLC with a considerable prognosis impact, promoter methylation being an important mechanism involved in p16 silencing. In CRC, however, p16 promoter methylation could be considered as a less definitive molecular factor without prognostic implication, since partial methylation constitutes a prevalent mechanism.     

Molecular profiling of breast cancer: clinical implications

Breast cancers are routinely subcategorised on the basis of clinical stage, cellular morphology and immunohistochemical analysis of a small number of markers. The recent development of gene expression microarray and related technologies provides an opportunity to perform more detailed profiling of the disease. It is anticipated that the molecular classification arising from such studies will be more powerful than its pathological predecessor at confining treatment to those patients who are most likely to benefit. It is likely that this will result in a much less frequent use of adjuvant chemotherapy. Furthermore, of those who do receive it, a higher proportion will benefit. If adopted, this will offer considerable patient benefits in terms of reducing unnecessary toxicity and have major health economic implications.     

Targeting NTRK fusion in non-small cell lung cancer: rationale and clinical evidence

In the era of personalized medicine, the identification of targetable genetic alterations represented a major step forward in anticancer therapy. NTRK rearrangements represent the molecular driver of a subset of solid tumors, including 3% of non-small-cell lung cancers (NSCLCs). Preliminary data indicate that molecularly selected NSCLC patients harboring NTRK fusions derive an unprecedented clinical benefit from Trk-directed targeted therapies. The aim of this review is to describe the molecular biology of NTRK signaling pathway and to summarize the preclinical data on novel Trk inhibitors, touching upon the clinical development of these inhibitors for the treatment of advanced NSCLC, which have already shown encouraging anticancer activity and acceptable safety profile in early phase I clinical trials.     

Bioelectrical impedance phase angle in clinical practice: implications for prognosis in stage IIIB and IV non-small cell lung cancer

Background  

A frequent manifestation of advanced lung cancer is malnutrition, timely identification and treatment of which can lead to improved patient outcomes. Bioelectrical impedance analysis (BIA) is an easy-to-use and non-invasive technique to evaluate changes in body composition and nutritional status. We investigated the prognostic role of BIA-derived phase angle in advanced non-small cell lung cancer (NSCLC).     

Pokemon蛋白在非小细胞肺癌中的表达及临床意义

背景与目的 原癌基因Pokemon是ARF特异性转录抑制剂,通过ARF-P53途径调节细胞生长和分化.Pokemon是多种肿瘤抑制基因和原癌基因的上游基因,因此有望成为重要的肿瘤监视靶点.本研究旨在探讨Pokemon基因在非小细胞肺癌(NSCLC)中表达的临床意义及其对预后的影响.方法 应用SP免疫组化方法检测Pokemon蛋白在92例NSCLC肿瘤组织及20例癌旁组织中的表达,分析其与NSCLC临床病理学特征及预后的关系.结果 Pokemon在癌旁组织中不表达,92例肺癌组织中66例呈阳性表达(占71.7%).Pokemon表达与肺癌患者TNM分期有密切关系(P=0.011).Pokemon阴性表达者生存率显著高于Pokemon阳性表达者(P=0.0015).Pokemon表达是影响患者预后的独立因素.结论 NSCLC中存在Pokemon的表达,它有望作为NSCLC新的诊断标志.Pokemon高表达可能预示NSCLC患者预后较差.     

Erlotinib in non-small cell lung cancer

Erlotinib and gefitinib are quinazoline derivatives that selectively and reversibly inhibit the tyrosine kinase activity of the EGFR. Activating mutations in the EGFR confer hypersensitivity to the tyrosine kinase inhibitors gefitinib and erlotinib in patients with advanced non-small-cell lung cancer. Erlotinib has been developed in EGFR mutation-positive patients as a firstline treatment, and results from recently completed phase III studies have shown superior progression-free survival and response rates for erlotinib, compared to chemotherapy.     

Integrated mutation,copy number and expression profiling in resectable non-small cell lung cancer

Background  

The aim of this study was to identify critical genes involved in non-small cell lung cancer (NSCLC) pathogenesis that may lead to a more complete understanding of this disease and identify novel molecular targets for use in the development of more effective therapies.     

Operative results of clinical stage I non-small cell lung cancer

BACKGROUND: Clinical stage (c-stage) I non-small cell lung cancer (NSCLC) is generally indicated for surgery, however, surgical exploration sometimes reveals advanced disease, thus resulting in incomplete resection. PATIENTS AND METHODS: A total of 645 consecutive patients were investigated in which 347 were diagnosed to have c-stage IA in 347 and 298 were diagnosed to have IB disease. All cases underwent operation and were investigated for resectability and the cause of an incomplete resection. RESULTS: The c-Stage IA patients included 16.6% of T3/4 and 10.4% of N2 whereas clinical stage IB patients included 14.4% of T3/4 and 18.8% of N2/3. A complete resection was performed in 594 patients (91%). In 347 c-stage IA patients, the complete resection rates were 93% in adenocarcinomas (235/252), 100% in squamous cell carcinomas (76/76), and 89% in others (17/19). In 298 c-stage IB patients, the complete resection rates were 86% in adenocarcinomas (141/164), 90% in squamous cell carcinomas (90/100), and 94% in others (31/33). The 5-year survival rates of the c-stage IA and IB patients who underwent a complete resection were 66.4 and 48.3%, respectively. However, the same rates were 18.4 and 14.7% for c-stage IA and IB patients who underwent an incomplete resection. The reasons for an incomplete resection in 54 patients were malignant pleurisy in 38 (70.4%), extranodal invasion of mediastinal nodal metastasis in ten (19%), an incomplete bronchial margin in three (5.6%), and ipsilateral pulmonary metastases in two (3.7%), and ipsilateral adrenal metastasis in one (1.3%). In 13% of the c-stage IB adenocarcinomas, pleural metastasis was discovered during thoracotomy. CONCLUSIONS: Pleural dissemination was the most frequent cause of an incomplete resection, and its prevalence was high in c-stage IB adenocarcinomas.