Biphasic function of GSK3ß in gefitinib­resistant NSCLC with or without EGFR mutations.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, are effective in the treatment of non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, the mechanism underlying acquired resistance to EGFR-TKIs remains largely unknown. Therefore, the present study generated gefitinib-resistant PC-9 (PC-9G) cells, which were revealed to be more resistant to gefitinib-induced reductions in proliferation, migration and invasion, and increases in apoptosis, and had no detectable EGFR mutations compared with the control PC-9 cell line. In addition, the present study performed genome-wide transcriptomic analysis of differentially expressed genes between PC-9 and PC-9G cell lines. Cell proliferation, colony formation, invasion, migration and flow cytometry analyses were also performed. The genome-wide transcriptomic analysis revealed that glycogen synthase kinase 3ß (GSK3ß) was downregulated in PC-9G cells compared with that in PC-9 cells. Furthermore, GSK3ß overexpression increased the proliferation, migration and invasion of PC-9 and H1975 gefitinib-resistant cells. Conversely, overexpression of GSK3ß suppressed the proliferation, migration and invasion of PC-9G cells. Furthermore, AKT inhibition reduced the proliferation, migration and invasion, and induced the apoptosis of PC-9, PC-9G and H1975 cells, the effects of which were reversed following AKT activation; notably, the tumor suppressor function of GSK3ß was inconsistent with the tumor promotor role of the AKT pathway in PC-9G cells without EGFR mutation. The present study may provide novel insights into the distinctive role of GSK3ß in gefitinib-resistant NSCLC with or without EGFR mutations, suggesting that a more detailed investigation on GSK3ß as a therapeutic target for gefitinib-resistant NSCLC may be warranted.

Altered Wnt5a expression affects radiosensitivity of non-small cell lung cancer via the Wnt/ß-catenin pathway.

It has been reported that upregulation of wingless-type protein 5a (Wnt5a) is associated with poor prognosis in patients with non-small cell lung cancer (NSCLC). Wnt5a expression is often upregulated in radiation-resistant NSCLC cells. However, the biological functions or molecular mechanisms of radiosensitivity in NSCLC remain unknown. In the present study, MTT assay and flow cytometric analysis were performed to assess the effect of overexpression or knockdown of Wnt5a and/or radiation on the proliferation and apoptosis of NSCLC cells. Furthermore, western blot analysis was performed to detect canonical Wnt signaling (ß-catenin) in H1650 and A549 cells. The results demonstrated that Wnt5a knockdown combined with irradiation inhibited proliferation and induced apoptosis in NSCLC cells compared with Wnt5a knockdown or radiotherapy alone. In addition, the combination of Wnt5a knockdown and irradiation decreased nuclear and increased cytoplasmic ß-catenin expression in H1650 and A549 cells, the effects of which were reversed following overexpression of Wnt5a. The combination of overexpressing Wnt5a and irradiation resulted in significant tumor regression, while ß-catenin knockdown reversed Wnt5a overexpression-induced NSCLC cell proliferation. Taken together, these results suggest that Wnt5a may be involved in the activation of ß-catenin-dependent canonical Wnt signaling, and thus may influence the effectiveness of radiation therapy in NSCLC.

Overexpression of Wnt7a enhances radiosensitivity of non-small-cell lung cancer via the Wnt/JNK pathway.

The Wingless-type protein 7a (Wnt7a) plays an antiproliferative role in non-small-cell lung cancer (NSCLC). Previous studies have indicated that Wnt7a expression was downregulated in radiation-resistant NSCLC cells. However, little is known about its biological functions and molecular mechanisms in radiosensitivity of NSCLC. Thus, NSCLC cell proliferation and apoptosis in response to Wnt7a overexpression and/or radiation were determined by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-tertazolium bromide (MTT) assay and flow cytometry, respectively. The activation of the Wnt/cJun N-terminal kinase (JNK) and Wnt/ß-catenin signaling pathways were further examined by western blot in NSCLC cell lines H1650 and A549. Wnt7a overexpression combined with radiation-inhibited cell proliferation and induced apoptosis in NSCLC cell lines compared to Wnt7a overexpression or radiotherapy alone. In addition, the phosphorylation of JNK, but not ß-catenin, was congruent with the changes in Wnt7a overexpression and/or radiation. Moreover, the Wnt/JNK pathway could induce the apoptosis of NSCLC cells through the mitochondrial pathway. Inhibition of the Wnt/JNK signaling pathway by SP600125, a JNK inhibitor, contributed to proliferation induction in NSCLC cells. Taken together, these results showed that Wnt7a overexpression sensitized NSCLC cell lines to radiotherapy through the Wnt/JNK signaling pathway.

Wnt7a inhibits transformed cell proliferation while promoting migration and invasion in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most important cause of lung cancer death. Wnt7a is a known tumor suppressor gene which is often downregulated in NSCLC, and restoration of Wnt7a leads to decreased NSCLC cell proliferation. However, the biological role of Wnt7a in the migration and invasion in NSCLC remains unclear. METHODS: We examined whether overexpression of Wnt7a transfected by pcDNA6-Wnt7a could induce the proliferation, migration and invasion of NSCLC H1650 and A549 cell lines. Wnt7a signaling pathway, such as canonical (ß-catenin) or non-canonical (c-Jun N-terminal kinase, JNK) pathways, were also assessed. RESULTS: We found that re-expression of Wnt7a led to reduced cell growth in NSCLC cell lines. In spite of the antiproliferative effect, Wnt7a overexpression could affect the migration and invasion of NSCLC cells. In the Wnt7a signaling pathway, the phosphorylation of JNK (Thr-183/Tyr-185) and c-Jun (Ser-63) were increased by re-expression of Wnt7a in both H1650 and A549 cell lines. The phosphorylation of ß-catenin (Thr-41/Ser-45, Ser-552, Ser-675, and Ser-45) were not altered by restoration of Wnt7a. In NSCLC cells, Wnt7a overexpression was accompanied by parallel changes in the JNK pathway but not in the ß-catenin pathway. CONCLUSIONS: These results help to understand that Wnt7a may play a two-sided role in NSCLC, suggesting that restoration of Wnt7a expression is not always suitable as therapeutic strategy for NSCLC.

Comparison of the effects of nimodipine and deferoxamine on brain injury in rat with subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) may lead to brain atrophy and cognitive dysfunction. This study aimed to compare the efficacy of nimodipine and deferoxamine on these sequelae of SAH. A rat model of SAH was established by the double-hemorrhage method. These rats were injected with saline (intraperitoneal, IP), nimodipine (IP), or deferoxamine (IP and intranasal) every 12 h for 5 days after SAH. The MRI scanning, including magnetic resonance angiography, diffusion tensor imaging, T2-weighted imaging, was performed to detect the brain structure. The levels of iron metabolism-related proteins were examined by Western blot analysis. The Morris water maze (MWM) test was used to assess the cognitive function. Then, then neurons in the cortex and hippocampus were counted on hematoxylin and eosin-stained brain sections. Significant cerebral vasospasm (CVS) was found in the saline and deferoxamine groups, but not in the nimodipine group. Cerebral peduncle injury was detected in the saline and nimodipine groups, but not significantly in the deferoxamine group. Compared with nimodipine, deferoxamine reduced transferrin (Tf), Tf receptor, and ferritin levels after SAH. The MWM performances were significantly worse in the saline and nimodipine groups than that in the deferoxamine group. Brain atrophy and neuronal losses were more significant in the saline and nimodipine groups than in the deferoxamine group. Nimodipine significantly ameliorated CVS, but it did not improve the late changes in brain structure and cognitive function. Deferoxamine effectively reduced neuronal cell death and ameliorated cognitive function after SAH.

Brain structure alterations and cognitive impairment following repetitive mild head impact: An in vivo MRI and behavioral study in rat.

Mild traumatic brain injury (mTBI) or concussion is a common health issue. Several people repeatedly experience head impact milder than that causing concussion. The present study aimed to confirm the effects of such repeated impact on the brain structure and cognitive abilities. Rat models were established by closed skull weight-drop injury. The animals were anesthetized, subjected to single (s)-sham, s-mTBI, repetitive (r)-sham, and r-mTBI, and recovery times were recorded. MRI, including T2-weighted and diffusion tensor imaging (DTI), as well as, neurological severity scores (mNSS) were assessed for the dynamics of the brain structure and neurological function. Morris water maze (MWM) was used to evaluate the cognitive function. The histological examination of r-mTBI rats revealed the basis of structural changes in the brain. There was no significant difference in the recovery time, MRI, mNSS, and MWM between the s-sham and the s-mTBI groups. Compared with r-sham, r-mTBI induced significant differences in the following aspects. The recovery time was prolonged and beam balance test (BBT) in mNSS increased from day 5. MWM performances were worse even after the BBT was recovered. The volumes of the cortex (CT), hippocampus (HP), and lateral ventricle had changed from day 5, which reached a maximum at day 14. Abnormal DTI parameters were observed in CT, corpus callosum, and HP. Histological analyses showed that both in CT and HP, neuron counts reduced at the end of the experiment. Altogether, these findings indicate that non-symptomatic head injury may result in brain atrophy and cognitive impairment when occurred repeatedly.

Cerebral vasospasm and corticospinal tract injury induced by a modified rat model of subarachnoid hemorrhage.

OBJECTIVE: Double-hemorrhage rat models of subarachnoid hemorrhages (SAH) are most effective at simulating delayed cerebral vasospasms (CVS). The present study modified the models to minimize additional trauma and investigated injury of the corticospinal tract (CST) using diffusion tensor imaging (DTI). METHODS: On the first day, 0.3ml of autologous arterial blood was collected by puncturing the caudal artery and injected into the cisterna magna via percutaneous puncture; and the operation was repeated on the third day. The diameters of the basilar artery (BA), middle cerebral artery (MCA), and anterior cerebral artery (ACA) were measured by magnetic resonance angiography on days 3, 5, 7, 9, and 11 post-SAH. Meanwhile, on days 3, 7, 11, 15 and 19, DTI was performed to evaluate the injury of the CST at cerebral peduncle (CP) and pyramidal tract (Py) by measuring fractional anisotropy (FA) value. RESULTS: Blood was deposited mainly in the basal cistern. Diameters of BA, MCA, and ACA were significantly reduced. FA value of the CP was lower in the SAH group than in the control group; but FA value of Py wasn't different between the two groups. CONCLUSION: This is a minimally-invasive and high performance rat model of SAH. Additionally, the occurrence of CVS is firm and the axons in CP are injured.

Immunohistochemical demonstration of alteration of ß-catenin during tumor metastasis by different mechanisms according to histology in lung cancer.

The protein ß-catenin exhibits a dual function in cells, by acting as a major structural component of cell-cell adherens junctions and as a central signaling molecule in the Wnt signaling pathway. However, how the regulation of ß-catenin expression during tumor metastasis in non-small cell lung cancer (NSCLC) varies according to histological type remains unclear. To investigate the regulatory mechanism of ß-catenin on tumor metastasis, the present study compared the expression of Wnt1, ß-catenin and E-cadherin in 41 primary NSCLC tumors and their corresponding metastatic lesions by immunohistochemistry. Altered expression of ß-catenin was more frequent in the metastatic tumors (34/41, 82.9%) than in the corresponding primary tumors (24/41, 58.5%; P<0.05). There were 12 cases [nine of adenocarcinoma (ADC) and three of squamous cell carcinoma (SqCC)] that revealed discordant ß-catenin expression between the primary tumors and the corresponding metastatic lesions. Of these, 11 cases (11/12, 91.7%; nine ADCs and two SqCCs) demonstrated acquired ß-catenin alterations in the metastatic lesions. Subgroup analysis of these nine ADCs revealed that six cases (6/9, 66.7%) were accompanied by E-cadherin loss but no Wnt1 overexpression. Subgroup analysis of the three SqCCs revealed discordant ß-catenin expression. Two cases (2/3, 66.7%) demonstrated acquired ß-catenin expression during metastatic progression with Wnt1 overexpression but no change in E-cadherin expression. One case of SqCC revealed normal ß-catenin expression in the metastasis although the expression was aberrant in the primary tumor. The results of the present study revealed that the changes in ß-catenin expression occurred during tumor metastasis by different mechanisms, depending on histological type. The alterations in ß-catenin expression may be regulated by a cadherin-catenin system in ADCs with reduced membranous expression of E-cadherin, but mediated by Wnt1 overexpression in SqCCs with cytoplasmic or nuclear transition types.

Multiple low doses of erythropoietin delay the proliferation of hepatocytes but promote liver function in a rat model of subtotal hepatectomy.

PURPOSE: The impact of various doses of erythropoietin (EPO) on liver regeneration after partial hepatectomy (PH) in different animal models is still under debate. We investigated the impact of low doses of EPO on liver regeneration in a rat model of subtotal hepatectomy. METHODS: We established a 90 % PH rat model with perioperative injections of low-dose EPO (1,000 IU/kg). We analyzed survival and hepatocyte proliferation in animals treated with or without EPO and assessed liver function by blood ammonia measurement and the indocyanine green 15-min retention test. RESULTS: Low doses of EPO treatment improved the survival of rats after 90 % PH. Unexpectedly, during the first 24 h after the operation, liver regeneration in the EPO-treated rats was inhibited. DNA synthesis, cell proliferation, and the expression of cyclins and p-STAT3 peaked 48 h after PH, which was delayed by about 24 h vs. the control rats. Furthermore, EPO treatment increased the serum level of IL-6 and protected the hepatocytes from apoptosis. CONCLUSION: Low doses of EPO do not stimulate early hepatocyte proliferation in the regenerating liver, but contribute to liver protection by inducing IL-6 and inhibiting apoptosis.

Aberration of the Wnt signaling pathway in pulmonary fatal adenocarcinoma: a case report.

We report a case of a 58-year-old woman showed a homogeneous well-defined perihilar mass in the right upper lobe and fully surrounded by aerated parenchyma at computed tomography (CT). A right upper lobectomy with mediastinal lymph node sampling was performed. A pathologic diagnosis of well-differentiated fetal adenocarcinoma of the lung was made and staged as T2bN0M0. For the expression of Wnt signaling pathway molecules, positive expressions of Wnt1, ß-catenin, c-Myc, Cyclin D1and MMP7 were especially prominent in budding solid nests, but not in glandular structures. The nuclear/cytoplasmic localization of ß-catenin accompanied upregulation of Wnt signaling pathway molecules in budding solid nests. These results demonstrated that elevated nuclear/cytoplasmic expression of ß-catenin in fatal adenocarcinoma might be regulated by the Wnt signaling pathway.

Analysis of protein-protein interaction network and functional modules on primary osteoporosis.

BACKGROUND: Primary osteoporosis is an age-related disease, and the main cause of this disease is the failure of bone homeostasis. Previous studies have shown that primary osteoporosis is associated with gene mutations.To explore the functional modules of the PPI (protein-protein interaction) network of differentially expressed genes (DEGs), and the related pathways participating in primary osteoporosis. METHODS: The gene expression profile of primary osteoporosis GSE35956 was downloaded from the GEO (Gene Expression Omnibus) database and included five MSC (mesenchymal stem cell) specimens of normal osseous tissue and five MSC specimens of osteoporosis. The DEGs between the two types of MSC specimens were identified by the samr package in R language. In addition, the functions and pathways of DEGs were enriched. Then the DEGs were mapped to String to acquire PPI pairs and the PPI network was constructed with by these PPI pairs. Topological properties of the network were calculated by Network Analyzer, and modules in the network were screened by Cluster ONE software. Subsequently, the fronting five modules whose P-value was less than 1.0e-05 were identified and function analysis was conducted. RESULTS: A total of 797 genes were filtered as DEGs from these ten specimens of GSE35956 with 660 up-regulated genes and 137 down-regulated genes. Meanwhile, up-regulated DEGs were mainly enriched in functions and pathways related to cell cycle and DNA replication. Furthermore, there were 4,135 PPI pairs and 377 nodes in the PPI network. Four modules were enriched in different pathways, including cell cycle and DNA replication pathway in module 2. CONCLUSIONS: In this paper, we explored the genes and pathways involved in primary osteoporosis based on gene expression profiles, and the present findings have the potential to be used clinically for the future treatment of primary osteoporosis.

Entecavir plus adefovir rescue therapy for chronic hepatitis B patients after multiple treatment failures in real-life practice.

AIM: To evaluate the efficacy and safety of Entecavir (ETV) plus adefovir (ADV) for chronic hepatitis B (CHB) patients after multiple nucleos(t)ide analogue (NAs) failure treatment. METHODS: Hepatitis B e antigen (HBeAg)-positive patients who had a suboptimal response or developed resistance to two or more previous NAs treatments were included, and all subjects were treated with ETV in combination with ADV for ≥ 24 months. Complete virologic response (CVR) was defined as an undetectability of serum hepatitis B virus (HBV) DNA level during treatment. Safety assessment was based on the increasing of serum creatinine and creatine kinase levels. RESULTS: A total of 45 eligible patients were included. Twenty-five patients had been treated with lamivudine (LAM) or telbivudine (LdT) and developed genotypic resistance. Resistance to ADV was present in 18 patients and 4 patients had a suboptimal response to ETV. Two patients had a resistance to both LAM and ADV. The cumulative probabilities of CVR at 12 and 24 months of ETV + ADV treatment were 88.9% (40/45) and 97.8% (44/45), respectively. Although one patient failed to achieve CVR, its serum HBV DNA level decreased by 3.3 log copies/mL after 24 months of combination therapy. The cumulative probability of HBeAg seroconversion was 15.6% (7/45) and 26.7% (12/45) at 12 and 24 months of treatment, respectively. History of prior exposure to specific NAs did not make a difference to ETV + ADV treatment outcome. There were no significant adverse events related to ETV + ADV therapy observed in the study subjects. CONCLUSION: ETV + ADV can be used as an effective and safe rescue therapy in patients after multiple NA therapy failures, especially in the areas where tenofovir is not yet available.

Comparison of Direct Sequencing, PNA Clamping-Real Time Polymerase Chain Reaction, and Pyrosequencing Methods for the Detection of EGFR Mutations in Non-small Cell Lung Carcinoma and the Correlation with Clinical Responses to EGFR Tyrosine Kinase Inhibitor Treatment.

BACKGROUND: The aims of this study were to evaluate the abilities of direct sequencing (DS), peptide nucleic acid (PNA) clamping, and pyrosequencing methods to detect epidermal growth factor receptor (EGFR) mutations in formalin-fixed paraffin-embedded (FFPE) non-small cell lung carcinoma (NSCLC) samples and to correlate EGFR mutational status as determined by each method with the clinical response to EGFR tyrosine kinase inhibitors (TKIs). METHODS: Sixty-one NSCLC patients treated with EGFR TKIs were identified to investigate somatic mutations in the EGFR gene (exons 18-21). RESULTS: Mutations in the EGFR gene were detected in 38 of the 61 patients (62%) by DS, 35 (57%) by PNA clamping and 37 (61%) by pyrosequencing. A total of 44 mutations (72%) were found by at least one of the three methods, and the concordances among the results were relatively high (82-85%; kappa coefficient, 0.713 to 0.736). There were 15 discordant cases (25%) among the three different methods. CONCLUSIONS: All three EGFR mutation tests had good concordance rates (over 82%) for FFPE samples. These results suggest that if the DNA quality and enrichment of tumor cells are assured, then DS, PNA clamping, and pyrosequencing are appropriate methods for the detection of EGFR mutations.

Discordance between anaplastic lymphoma kinase status in primary non-small-cell lung cancers and their corresponding metastases.

AIMS: The anaplastic lymphoma kinase gene (ALK) has attracted considerable attention as a potential molecular target in non-small-cell lung cancer (NSCLC). However, it is unclear whether ALK alterations are acquired during the metastatic progression of NSCLC. METHODS AND RESULTS: ALK status and ALK expression were evaluated in a series of 67 primary NSCLCs and their corresponding metastatic lesions using fluorescence in-situ hybridization and immunohistochemistry. ALK rearrangement was detected in 7.5% (5/67) of the primary tumours and in 9.0% (6/67) of the metastases (P < 0.001). ALK copy number gain (CNG) was detected in 1.5% (1/67) of the primary tumours and in 35.8% (24/67) of the metastases. Whereas ALK rearrangement was detected only in adenocarcinomas, CNG was identified in various histological subtypes of NSCLC. ALK expression was detected in 11.9% (8/67) of the primary tumours and in 25.4% (17/67) of the metastatic lesions. CONCLUSIONS: ALK alteration and ALK expression can be acquired during metastatic progression in NSCLC, and ALK CNG is associated with ALK expression.

Overexpression of epithelial-mesenchymal transition-related markers according to cell dedifferentiation: clinical implications as an independent predictor of poor prognosis in cholangiocarcinoma.

Although increased evidence has suggested that epithelial-mesenchymal transition has been implicated in cancer invasion and is associated with poor prognosis, its significance in cholangiocarcinoma remains unclear. We evaluated the levels of expression of epithelial-mesenchymal transition-related genes and proteins in 2 established human cholangiocarcinoma cell lines with different morphological characteristics and performed transwell cell invasion assays. Furthermore, we investigated the association between altered expression of 6 epithelial-mesenchymal transition-related proteins and clinical outcomes in human cholangiocarcinoma patients (n = 119) by immunohistochemistry using a tissue microarray approach. Comparative analysis of protein and messenger RNA expression revealed that the cell line with less differentiation (JCK) showed increased expression of mesenchymal markers and zinc-finger proteins and decreased expression of epithelial markers. The invasion activity of JCK cells was significantly higher than that of cells from OZ cell lines. Tissue microarray analysis revealed that the combined expression pattern of 6 epithelial-mesenchymal transition-related proteins predicted shortened disease-free survival (13.0 versus 22.0 months, P = .033) and overall survival (23.0 versus 63.0 months, P = .003) and was confirmed as an independent unfavorable prognostic factor for survival in multivariate survival analysis (disease-free survival, P = .028 for the 3 epithelial-mesenchymal transition-related markers; overall survival, P = .010 for the 6 epithelial-mesenchymal transition-related markers). In conclusion, our results suggest that altered expression of a number of epithelial-mesenchymal transition-related genes in tumor cells with poor differentiation may explain their increased invasive ability. Our results also suggest that altered expression of a suite of epithelial-mesenchymal transition-related proteins could be used as a tool to predict poor outcomes in human cholangiocarcinoma patients.

Clinicopathological correlations of mTOR and pAkt expression in non-small cell lung cancer.

The Akt/mammalian target of rapamycin (mTOR) pathway is up-regulated in many human cancers, and agents targeting the mTOR pathway are in various stages of clinical development and application. Expression of pAkt and mTOR was studied by immunohistochemical analysis of 574 surgically resected non-small cell lung cancer (NSCLC) specimens on a tissue microarray. The results were correlated with clinicopathological features. Expression of mTOR showed a strong correlation with the expression of pAkt (p < 0.001) and was significantly associated with female gender, tumor size of ≤3 cm, adenocarcinoma (ADC), non-smoker status, and lower pathological stage. Expression of pAkt was correlated with older age (≥65), ADC, non-smoker status, and lower T stage. Univariate survival analysis revealed that the mTOR- and pAkt-positive group had a significantly longer cancer-specific survival than the mTOR- and pAkt-negative group (p = 0.038 and 0.024, respectively). Coexpression of pAkt and mTOR correlated with better prognosis than either single- or double-negative pAkt and mTOR groups (p = 0.016). However, multivariate analysis proved that mTOR and pAkt expression are not independent prognostic factors for cancer-specific survival. Expression of pAkt and mTOR expression is more significantly associated with ADC than squamous cell carcinoma. Although pAkt/mTOR expression is not an independent prognostic marker, expression of these proteins is associated with better prognosis.

High incidence of EGFR mutations in Korean men smokers with no intratumoral heterogeneity of lung adenocarcinomas: correlation with histologic subtypes, EGFR/TTF-1 expressions, and clinical features.

INTRODUCTION: Epidermal growth factor receptor (EGFR) mutation has been known to be associated with adenocarcinoma with bronchioloalveolar carcinoma (BAC; lepidic) feature. This study was aimed to characterize the frequency of EGFR mutations and their association with histologic subtypes in Korean nonsmall cell lung cancer (NSCLC) patients. METHODS: Three hundred eighty-two (88 biopsies and 294 resections) NSCLC patients were investigated for EGFR mutations (exons 18-21) by polymerase chain reaction and direct sequencing method. For the resected adenocarcinoma specimens, histologic subtypes were classified according to both 2004 World Health Organization classification and 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. The results were correlated with EGFR mutation and clinicopathologic features. RESULTS: EGFR mutations were detected in 196 of 382 NSCLCs (51.3%) and were more frequent in women than in men (65.7% versus 34.3%, p < 0.001) and in nonsmokers than in smokers (63.4% versus 32.0%, p < 0.001). Regarding histologic subtypes of adenocarcinoma, mixed acinar and BAC pattern showed the most frequent EGFR mutation (67.6%), followed by mixed papillary and acinar (65.2%), mixed solid and acinar (38.2%), micropapillary and acinar (30.4%), and acinar and mucinous BAC (13.3%). In addition, EGFR mutations were more frequently observed in tumors with BAC or papillary components than those with mucinous BAC or solid components. Identical EGFR mutations were detected in a single tumor showing mixed histological features. EGFR protein expression was seen more frequently in tumors with EGFR mutations than those without EGFR mutations (75.3% versus 24.7%, p=0.003). EGFR mutations were significantly more common in tumors with thyroid transcription factor-1 (TTF-1) expression than those without TTF-1 (p < 0.001), and almost all (92.7%) mutated adenocarcinomas were TTF-1 positive. CONCLUSIONS: The incidence of EGFR mutations is variable according to histologic subtypes, gender, and smoking history. The mixed acinar and BAC and papillary and acinar subtypes, the presence of BAC (lepidic) or papillary components, EGFR, and TTF-1 protein expression can predict higher EGFR mutation in lung adenocarcinoma. However, intratumoral heterogeneity of EGFR mutation was not found. In addition, relatively high incidence of EGFR mutations in Korean men who smoked with adenocarcinoma histology suggests that these patients should not be left behind EGFR mutation test.

Detection of ALK gene rearrangement in non-small cell lung cancer: a comparison of fluorescence in situ hybridization and chromogenic in situ hybridization with correlation of ALK protein expression.

INTRODUCTION: Accurate determination of ALK rearrangement is important in lung cancer patients, especially in determining their eligibility for crizotinib therapy. Fluorescence in situ hybridization (FISH) has been regarded as the gold standard method for detecting ALK rearrangement. However, FISH requires a fluorescence microscope, and the signals are labile and rapidly fade over time. This study evaluates the concordance between ALK gene rearrangement in non-small cell lung cancer assessed by ALK FISH and a newly developed ALK chromogenic in situ hybridization (CISH) and correlates the results with ALK protein expression assessed by immunohistochemistry. METHODS: A total of 465 formalin-fixed, paraffin-embedded non-small cell lung cancer samples were analyzed by ALK FISH (PathVysion, Vysis, Abbott) and ALK CISH. For comparison, all specimens were stained by immunohistochemistry (clone 5A4, Novocastra) and interobserver reproducibility was assessed. RESULTS: We found that agreement between the pathologists on the CISH-determined ALK status was achieved in 449 patients (96.6%), and ALK rearrangement was identified in 18 patients (4.0%) in CISH method. Among these cases, 443 cases (95.3%) had results matching the corresponding FISH results: 17 rearranged, 425 wild types, and 1 discordant case. There was high concordance in the assessment of ALK gene rearrangement between FISH and CISH techniques (κ = 0.92) and between observers (κ = 0.97). In addition, there was high concordance in the ALK gene status and ALK protein expression between CISH and IHC tests (κ = 0.82). CONCLUSIONS: CISH is a highly reproducible and practical method to detect ALK gene rearrangement and correlated well with ALK protein expression. Here, we present a diagnostic algorithm (Chung's SNUBH ALK protocol) to detect lung cancer with ALK rearrangements using IHC, FISH and CISH. Because CISH allows a concurrent analysis of histological features of the tumors and gene rearrangement, it appears to be a useful method in determining ALK gene rearrangement.