Intratumoral morphological heterogeneity can be an indicator of genetic heterogeneity in colorectal cancer

Anti-EGFR-targeted therapy is used to treat metastatic colorectal cancers with RAS wild-type. However, resistance to targeted therapy is often observed and can be primary or acquired. One reason for primary resistance is the presence of mutations that are undetected due to genetic heterogeneity, which can be expressed by differences present in primary tumor and distant metastasis or recurrence or by an intratumoral heterogeneity (presence of different subclones in the investigated tumor sample).The aim of our study was to investigate if morphological heterogeneity can be an indicator of intratumoral heterogeneity. We analysed 13 samples with homogeneous and six samples with heterogeneous morphology with NGS. We were able to demonstrate that intratumoral genetic heterogeneity is present in all studied tumor samples, independent of homogeneous or heterogeneous morphology. Moreover, one sample of our cohort with morphological and genetic heterogeneity had a genetic wild-type profile in one tumor component. Therefore, we recommend to include each morphologically identifiable tumor component in the mutational analysis to not overlook resistance-inducing or potentially targetable mutations.     

Frequency and type of KRAS mutations in routine diagnostic analysis of metastatic colorectal cancer

Mutation analysis of the KRAS oncogene is now established as a predictive biomarker in colorectal cancer (CRC). Large prospective clinical trials have shown that only CRCs with wild-type KRAS respond to anti-epidermal growth factor receptor (EGFR) treatment. Therefore, mutation analysis is mandatory before treatment, and reliable benchmarks for the frequency and types of KRAS mutations have to be established for routinely testing large numbers of metastatic CRCs.     

miR-486-5p functions as an oncogene by targeting PTEN in non-small cell lung cancer

Purpose

Lung cancer, the leading cause of cancer-related death worldwide, shows a poor 5-year overall survival rate. In our previous study, we demonstrated that miR-486-5p can be a potential blood-based biomarker for early diagnosis and recurrence prediction of non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the possible roles and related target genes of miR-486-5p in NSCLC progression.

Consistent mutation status within histologically heterogeneous lung cancer lesions

Mattsson J S M, Imgenberg‐Kreuz J, Edlund K, Botling J & Micke P
(2012) Histopathology  61, 744–748 Consistent mutation status within histologically heterogeneous lung cancer lesions Aims: Activating epidermal growth factor receptor (EGFR) and KRAS mutations characterize molecular subgroups of non‐small‐cell lung cancer (NSCLC) with a strong predictive value for response to EGFR inhibitor therapy. However, the temporal occurrence and clonal stability of these mutations during the course of cancer progression are debated. The aim of this study was to characterize the presence of EGFR and KRAS mutations in histologically different areas of primary NSCLC lesions. Methods and results: Formalin‐fixed paraffin‐embedded cancer specimens from six cases with EGFR mutations and five cases with KRAS mutations were selected from a pool of primary resected NSCLC patients. From each tumour, three morphologically distinct areas were manually microdissected and analysed for the presence of mutations. The results demonstrated consistent EGFR and KRAS mutation status in the different histological areas of all primary tumours. Conclusions: The results support the concept that activating EGFR and KRAS mutations are oncogenic events that are consistently present throughout the primary tumour independently of histological heterogeneity. Thus, for molecular diagnostics, any part of the tumour is likely to be representative for EGFR and KRAS mutation testing.     

Epidermal growth factor receptor expression status in lung cancer correlates with its mutation

The molecular mechanisms for frequent epidermal growth factor receptor (EGFR, a tyrosine kinase [TK]) and HER2 (the preferred coreceptor of EGFR) overexpression in lung cancer are poorly understood. Recent studies have shown the mutations of the TK domain in EGFR and HER2 to be present in lung cancer. The purpose of this study was to investigate the relationship between mutation status and expression of EGFR and HER2 in lung cancer. Immunostaining took place for EGFR and HER2, and mutational analyses for EGFR, HER2, and KRAS (a signaling protein) were conducted using 130 resected lung cancer specimens. Thirty-seven EGFR mutations (28%) and 8 HER2 mutations (6%), both of the TK domains, and 5 KRAS (4%) mutations were found, whereas 73 (56%) EGFR and 47 (36%) HER2 overexpressions were found. EGFR overexpression was seen more frequently in tumors with EGFR mutation (28/37, 76%) than in tumors without EGFR mutations (45/93, 48%; P = .0059). No correlation was found between HER2 mutation and HER2 expression. Multivariate regression revealed that EGFR mutation, adenocarcinoma histology, and HER2 expression were associated with EGFR expression, whereas female sex, EGFR mutation, and EGFR expression were associated with HER2 expression. In conclusion, EGFR and HER2 overexpression is frequent in lung cancer, and EGFR overexpression correlates with the EGFR TK domain mutations.     

小细胞和非小细胞肺癌晚期患者NK细胞表达的差异

目的:探索小细胞和非小细胞肺癌晚期患者NK细胞是否存在差异,并为治疗提供参考。方法:选取肺癌晚期患者共65例,其中包括小细胞肺癌14例,非小细胞肺癌51例以及20例健康对照。用流式细胞仪检测研究对象外周血淋巴细胞表面CD3-CD16+CD56+的表达情况。结果:小细胞肺癌晚期的患者较健康对照NK细胞显著升高;非小细胞肺癌晚期的患者较健康对照NK细胞无显著变化;肺癌晚期患者外周血NK细胞表达的百分比与CD4+T细胞表达的百分比呈负相关性。结论:小细胞肺癌晚期患者NK细胞升高,天然免疫可能成为已严重受损的细胞免疫的有力补充,但有待于进一步的研究。     

FER overexpression is associated with poor postoperative prognosis and cancer-cell survival in non-small cell lung cancer

Here, we show that overexpression of fer tyrosine kinase (FER), a non-receptor tyrosine kinase, predicts poor postoperative outcome and might be involved in cancer-cell survival in non-small cell lung cancer (NSCLC). Systematic screening using in silico analyses and quantitative RT-PCR revealed that FER was overexpressed in about 10% of NSCLC patients. Evaluation of FER expression using immunohistochemistry (IHC) on tissue microarrays was consistent with the mRNA level detected using quantitative RT-PCR. In analyses of 135 NSCLC patients who had undergone potential curative resection, we found that FER overexpression detected using IHC had no association with clinicopathological features such as age, sex, smoking history, histological type, disease stage, T factor, N factor, adjuvant chemotherapy history, or EGFR mutation, but was correlated with poor postoperative survival periods. A multivariate Cox regression analysis showed that this prognostic impact was independent of other clinicopathological features. In functional analyses of FER in vitro, FER exhibited a transforming activity, suggesting that it possesses oncogenic functions. We also found that human lung cancer NCI-H661 cells, which exhibited FER-outlier expression, were led to apoptosis by the knockdown of FER using RNA interference. FER overexpression might serve as a prognostic biomarker and be involved in cancer-cell survival in NSCLC.     

PGRN基因沉默对人非小细胞肺癌A549细胞增殖及迁移的影响

目的:探讨小干扰RNA(small interference RNA,si RNA)介导的颗粒蛋白前体(progranulin,PGRN)基因沉默对非小细胞肺癌A549细胞增殖、迁移和凋亡的影响及其机制。方法:分别用q PCR和Western blot法检测A549细胞和正常人支气管上皮(HBE)细胞中PGRN的m RNA和蛋白表达水平。采用脂质体转染法将PGRNsi RNA转染A549细胞,采用q PCR和Western blot法验证PGRN表达的变化;应用MTT实验检测细胞活力;活细胞计数法和结晶紫染色实验检测细胞增殖能力;划痕愈合实验和Transwell实验检测细胞迁移能力;并用Western blot法检测增殖细胞核抗原(PCNA)、细胞周期蛋白D1(cyclin D1)、Bcl-2和Bax的蛋白表达水平以及PGRN下游信号通路中细胞外信号调节激酶1/2(ERK1/2)和蛋白激酶B(Akt)的磷酸化水平。结果:PGRN在A549细胞中的m RNA和蛋白水平均明显高于HBE细胞(P0.05);转染PGRN-si RNA后A549细胞中PGRN的m RNA和蛋白水平均明显下调,细胞活力、增殖能力以及迁移能力均明显降低(P0.05)。沉默PGRN基因的表达,可下调PCNA、cyclin D1和Bcl-2的蛋白表达,而上调Bax的蛋白表达,且磷酸化的ERK1/2(p-ERK1/2)和磷酸化的Akt(p-Akt)的蛋白水平明显降低(P0.05)。结论:PGRN基因沉默能明显抑制非小细胞肺癌A549细胞的增殖和迁移能力,PI3K/Akt和MAPK/ERK信号通路可能在该过程中发挥重要作用。     

Loss of ARID1A expression is associated with poor prognosis in non-small cell lung cancer

Adenine-thymine-rich inactive domain-containing protein 1A (ARID1A) is a large subunit of the switch-sucrose nonfermenting (SWI-SNF) complex. ARID1A is considered to be a tumor suppressor in various cancers. We investigated the clinicopathological significance including prognosis of ARID1A expression in non-small cell lung cancer (NSCLC). ARID1A expression was studied by tissue microarray immunohistochemical analysis of 171 surgically resected NSCLC specimens including adenocarcinoma (ADC) and squamous cell carcinoma (SCC) on tissue microarray. Semiquantitative immunohistochemical score was obtained by multiplying the intensity and percentage scores. The overall score was further simplified by dichotomizing into either negative (score < 4) or positive (score ≥ 4) for each patient. The ARID1A-negative group revealed significantly higher correlations with male sex (p = 0.020), larger tumor size (p = 0.007), SCC than with ADC (p = 0.023) and smoking (p = 0.001). Univariate survival analysis showed that the ARID1A-negative group had a significantly shorter cancer specific survival than the ARID1A-positive group (p = 0.018). Multivariate survival analysis showed that ARID1A negativity (p = 0.022) were independent prognostic factors related with shorter cancer specific survival for NSCLC. In conclusion, Loss of ARID1A expression is a potential molecular marker to predictive of poor prognosis of NSCLC.     

福建汉族胰岛素样生长因子受体基因多态性与非小细胞肺癌易感性的关联研究

目的 探讨胰岛素样生长因子受体(insulin-like growth factor receptor,1GF-1R和IGF-2R)基因多态性与福建汉族人非小细胞肺癌(non-small-cell lung cancer,NSCLC)易感性的关系.方法 采用病例-对照研究,用聚合酶链反应-限制性片段长度多态性和DNA测序法检测福建籍汉族健康人258名和NSCLC患者260例的IGF-IR +1013和IGF-2R+1619两个位点的等位基因分布,探讨不同基因型与NSCLC发病的相关性.结果 (1) IGF-1R +1013(G/A)位点基因型和各等位基因的频率在两组中分布差异有统计学意义(P＜0.05).对于IGF-1R+ 1013(G/A)位点,与GG基因型者相比,GA基因型者NSCLC患病风险增加0.80倍(95％ CI:1.24～2.59,P=0.002),AA基因型者的风险增加2.59倍(95％ CI:1.78～7.26,P=0.000),而等位基因A携带者(GA+AA基因型)患病风险增加0.98倍(95％ CI:1.39～2.83,P=0.000).未发现IGF-2R +1619(G/A)位点各基因型和等位基因的频率分布在两组中差异有统计学意义(P＞0.05).(2)根据病理类型分层分析发现IGF-1R +1013(G/A)变异等位基因A携带者(GA+AA)患肺鳞癌的风险增加2.20倍(95％ CI:1.75～5.84,P=0.000),患肺腺癌的风险增加0.55倍(95％Ch l.00～2.41,P=0.049),患其他类型肺癌的风险增加0.96倍(95％CI:1.10～3.49,P=0.023).未发现两基因多态性与临床分期、淋巴结转移、远处转移有关(P＞0.05).(3)联合分析发现,IGF-1R+1013(G/A)和IGF-2R +1619(G/A)基因联合多态性与NSCLC的患病风险存在相关性(P=0.003).结论 IGF-IR+ 1013(G/A)位点变异等位基因A是肺癌发生的风险因素,IGF-1R+1013(G/A)和IGF-2R+1619(G/A)基因多态性对肺癌的发生有协同作用.     

Extracapsular extension is a powerful prognostic factor in stage IIA-IIIA non-small cell lung cancer patients with completely resection

The purpose of this study is to evaluate the relationship between extracapsular extension (ECE) and clinicopathology, and its influence on the prognosis in non-small cell lung cancer (NSCLC) patients. Clinical data from 388 stage IIA-IIIA NSCLC patients who underwent curative resection and confirmed ECE positive were reviewed. The Fisher’s exact or Chi-square test was used to analyze the associations between ECE and the clinical pathology. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). ECE was detected in 85 (21.9%) patients, and it had a significant correlation with advanced T stage, pathological stage and histologic type of adenocarcinoma. For the whole population, the median OS was 39.0 months, and the 5-year OS rate was 33.9%. In multivariate analysis, both ECE status and postoperative chemotherapy were significant factors for OS. The median DFS for all patients was 26.0 months, and the 5-year DFS rate was 21.7%. In multivariate analysis, pathologic stage, ECE, and postoperative chemotherapy were the independent predictor factors for DFS. Further analysis found that the locoregional recurrence-free survival and the distant recurrence-free survival rates in ECE negative group were also significantly higher than in the ECE positive group. For NSCLC patients with lymph node metastasis, the presence of ECE occurs more frequently in advanced stage and histologic type of adenocarcinoma and it may be a powerful prognostic factor which reflects the aggressive biological behavior.     

CD70在非小细胞肺癌治疗中的潜在作用

CD70是肿瘤坏死因子受体(tumor necrosis factor receptor,TNFR)超家族的成员之一,目前的研究证实CD70主要表达于B细胞、活化的T细胞及成熟的树突状细胞中.CD70还高水平表达于多种血液肿瘤和实体瘤,使其可能成为肿瘤免疫治疗的潜在靶点.在过去的几十年,免疫学的进步使免疫检查点得以确定,这使得癌症免疫治疗再度成为热点.现就CD70在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的相关研究进行回顾与总结,以期为CD70在NSCLC中的免疫治疗提供参考和研究依据.     

Cellular heterogeneity in lung cancer

Sixty-six lung carcinomas have been examined by light and electron microscopy, as well as by immunocytochemical techniques using a panel of monoclonal antibodies. There was considerable heterogeneity with regard to cell type and in only 18 cases was it possible to classify the tumour as a solely small cell, squamous or adenocarcinoma. In the remaining cases there was evidence of two or three cell types. These findings support the thesis that all lung cancers are derived from a pluripotential basal or reserve cell in the bronchial mucosa which may proliferate along one or more lines of differentiation. This view of the histogenesis of lung cancer would account for the heterogeneous appearance of many tumours and the difficulty experienced in placing them in one of the standard classifications.     

Metallothionein 1F and 2A overexpression predicts poor outcome of non-small cell lung cancer patients

Metallothioneins (MT) are intracellular, low molecular weight proteins (6–7 kDa) involved in binding of metal ions, scavenging of free radicals, cell proliferation and apoptosis and resistance to certain chemotherapeutics. Four basic families of MT proteins are distinguished: MT-I, MT-II, MT-III, MT-IV, within each of them different isoforms occur. The study aimed at examining the expression level of nine MT isoforms: MT-1A, -1B, -1E, -1F, -1G, -1H, -1X, MT-2A and MT-IV by using real-time PCR and MT-I/II expression by immunohistochemical (IHC) technique in 69 cases of non-small cell lung cancer (NSCLC) and 12 non-malignant lung tissues (NMLT) and to correlate them with patients clinicopathological data and Ki-67 antigen expression. Out of all the analyzed cases, 62 (89.9%) demonstrated an increased MT-I/II expression. MT-1B, 1F, -1G, -1H and MT-1X were significantly up-regulated, whereas MT-1E was significantly down-regulated in NSCLC as compared to NMLT. Only in two cases MT-IV mRNA expression was noted. Significant positive correlations were observed between each particular MT isoform expressions. Higher MT-1F and MT-1A mRNA expression was associated with larger primary tumor size (P = 0.0362 and P < 0.0001, respectively). Moreover, up-regulated MT-1F mRNA expression was associated with higher grade of malignancy of NSCLC (P = 0.0085). Higher MT-1B mRNA expression was associated with squamocellular and adenocarcinoma subtype of NSCLC (P = 0.0358). Univariate analysis showed, that up-regulated MT-1F and MT-2A mRNA predicted poor patients' survival (P = 0.0206 and P = 0.0097, respectively). The levels of MT-1F and MT-2A mRNA could be considered as new markers of poor prognosis of NSCLC patients.     

KRAS gene mutations in lung cancer: Particulars established and issues unresolved

Lung cancer, like other cancers, is considered to develop through the accumulation of genetic alterations. Mutation of the KRAS gene is one of the most important events in carcinogenesis of the lung. The KRAS gene, belonging to the RAS gene family, encodes a membrane‐bound 21‐kd guanosine triphosphate (GTP)‐binding protein. Single point mutations in this protein result in continuous activation to transmit excessive signals, promoting a variety of biological events. In lung cancers, the mutations concentrate at codon 12 and mostly affect adenocarcinomas (ADCs). They also affect atypical adenomatous hyperplasia, the precursor of ADCs. Therefore, mutation of the KRAS gene is suggested to confer a growth advantage to airway epithelial cells enabling them to expand clonally early in the development of ADCs. The mutation is also a reliable marker of an unfavorable response to certain molecular‐targeting therapies. Furthermore, patients with ADCs affected by mutations have been reported to exhibit a significantly higher risk of postoperative disease recurrence. Thus, the significance of KRAS gene mutations has been investigated extensively. However, not all the details emerged. In this review, particulars that have been established are introduced, and important issues remaining to be resolved are discussed, with special reference to carcinogenesis of the lung.     

Down-regulation of microRNA-124 is correlated with tumor metastasis and poor prognosis in patients with lung cancer

Introduction: MicroRNA-124 (miR-124) has been proven dysregulated in several human malignancies and correlated with tumor progression. However, its expression and clinical significance in non-small cell lung cancer (NSCLC) is still unclear. Thus, the aim of this study was to investigate the clinical significance of miR-124 expression in NSCLC. Methods: Expression levels of miR-124 in 92 pairs of NSCLC and adjacent non-tumor tissues were detected by quantitative real-time PCR (qRT-PCR). In order to determine its prognostic value, overall survival (OS) and disease-free survival (DFS) were evaluated using the Kaplan-Meier method, and multivariate analysis was performed using the Cox proportional hazard analysis. Results: miR-124 expression level was significantly lower in NSCLC tissues compared with adjacent non-tumor tissues (P < 0.05). The 5-year OS of low miR-124 expression group was significantly shorter than that of high miR-124 expression group (P < 0.05). Moreover, the 5-year DFS of low miR-124 expression group was also significantly shorter than that of high miR-124 expression group (P < 0.05). In a multivariate Cox model, we found that miR-124 expression was an independent prognostic factor for both 5-year OS and 5-year DFS in NSCLC (P < 0.05). Conclusions: Our results offer the convincing evidence that miR-124 may play key roles in the progression of lung cancer and that the down-regulated expression of miR-124 may be independently associated with shorter OS and DFS of patients, suggesting that miR-124 might be a potential marker for further risk stratification in the treatment of lung cancer.