Kayo Ijichi

Expression of TrkB and BDNF is associated with poor prognosis in non-small cell lung cancer

High expression levels of TrkB and BDNF are associated with aggressive malignant behavior in tumor cells and a poor prognosis in patients with various types of cancer. In this study, we aimed to identify the relationship between TrkB and BDNF expression and clinicopathological variables and prognosis in non-small cell lung cancer (NSCLC). We evaluated TrkB and BDNF expression in the tumor cells of 102 NSCLC patients by immunohistochemistry. Out of all clinicopathological factors examined, only vascular invasion was significantly correlated with TrkB (P=0.010) and BDNF (P=0.015) expression. TrkB-positive tumors had significantly worse disease-free survival (P=0.0094) and overall survival (P=0.0019) than TrkB-negative tumors, and TrkB expression was an independent prognostic factor for disease-free survival (HR 3.735, 95% CI 1.560-11.068, P=0.002) and overall survival (HR 4.335, 95% CI 1.534-15.963, P=0.004) in multivariate analysis. Finally, our analysis revealed that co-expression of TrkB and BDNF conferred poorer prognosis compared with overexpression of either protein alone. Our results indicate that expression of TrkB and BDNF is associated with poor prognosis in NSCLC patients.

Aurora-B overexpression is correlated with aneuploidy and poor prognosis in non-small cell lung cancer

Aurora-B is a key regulator of mitosis, and the overexpression has been detected in a variety of solid tumors. The Aurora-B overexpression has been suggested to correlate with clinical aggressiveness and aneuploidy in vitro, however, the frequency of overexpression of Aurora-B protein, the association with clinicopathologic parameters and aneuploidy remain poorly defined in non-small-cell lung cancer (NSCLC). Using 157 surgical specimens of human NSCLC, we here show that overexpression of Aurora-B proteins are significantly correlated with aneuploidy and poor outcomes in NSCLC. We examined immunohistochemical protein expression of Aurora-B, and DNA ploidy by laser scanning cytometry in 157 NSCLC cases. Aurora-B overexpression was found in 83 cases (53%) of NSCLC, and was significantly correlated with vascular invasion (p=0.012), poor differentiation (p<0.001), larger tumor size (p=0.010) and lymph node metastasis (p=0.05) and poor prognosis (p=0.011). Aneuploidy was found in 87 cases (57%), and was significantly correlated with Aurora-B overexpression (p=0.0065). Logistic multivariate analysis revealed overexpression of Aurora-B protein to be significant risk factors for aneuploidy compared with other factors. These results indicate that Aurora-B overexpression may contribute to malignant potential and increased aneuploidy in NSCLC. Thus, Aurora-B may serve as a new therapeutic target in against patients with NSCLC, although further studies will be necessary.

Nicotine Induces Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor by α1 Nicotinic Acetylcholine Receptor–Mediated Activation in PC9 Cells

Introduction: Nicotine, the major component among the 4000 identified chemicals in cigarette smoke, binds to nicotinic acetylcholine receptors (nAChRs) on non–small-cell lung cancer (NSCLC) cells and regulates cellular proliferation by activating mitogen-activated protein kinases [AQ: MAPK has been expanded to mitogen-activated protein kinases. Please approve.]and PI3K/Akt pathways. In patients with smoking-related lung cancer who continue smoking, the anticancer effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) is weaker than that in nonsmokers; however, the precise reason for this difference remains unclear. We investigated the role of &agr;1 nAChR subunit in this phenomenon. Methods: We screened for &agr;1 nAChR mRNA in three NSCLC cell lines and analyzed the protein in resected primary NSCLC tissues. We used Western blot and RNA interference (siRNA) methodology to confirm the results. Results: We determined that &agr;1 nAChR plays an essential role in nicotine-induced cell signaling and nicotine-induced resistance to EGFR-TKI. In addition, we showed that silencing of &agr;1 nAChR subunit in NSCLC may suppress the nicotine-induced resistance to EGFR-TKI. Conclusions: These results further implicate nicotine in lung carcinogenesis, and suggest that &agr;1 nAChR may be a biomarker for EGFR-TKI treatment and also a personalizing target molecule for patients with smoking-related lung cancer.

Sensitivity and kinase activity of epidermal growth factor receptor (EGFR) exon 19 and others to EGFR‐tyrosine kinase inhibitors

The presence of epidermal growth factor receptor (EGFR) somatic mutations in non‐small‐cell lung cancer patients is associated with response to treatment with EGFR‐tyrosine kinase inhibitors, such as gefitinib and erlotinib. More than 100 mutations in the kinase domain of EGFR have been identified. In particular there are many variations of deletion mutations in exon 19. In this study, using yellow fluorescent protein‐tagged fragments of the EGFR intracellular domain, we examined the differences in sensitivity to gefitinib, erlotinib and afatinib between several exon 19 mutants and other common EGFR mutations. We also used serum of patients undergoing treatment with EGFR‐tyrosine kinase inhibitors in this system. In addition, we examined the relative kinase activity of these mutants by measuring relative fluorescent intensity after immunofluorescence staining. We found that both sensitivity to EGFR‐tyrosine kinase inhibitors and relative kinase activity differed among several EGFR mutations found in the same region of the kinase domain. This study underscores the importance of reporting the clinical outcome of treatment in relation to different EGFR mutations.

Hypermethylation of the CpG dinucleotide in epidermal growth factor receptor codon 790: implications for a mutational hotspot leading to the T790M mutation in non-small-cell lung cancer.

Nearly one half of all cases of acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for non-small-cell lung cancer (NSCLC) are due to the T790M mutation in EGFR exon 20. The T790M mutation is a C→T transition mutation at a CpG dinucleotide. DNA methylation of cytosine (5-methylcytosine (5-mC)) in CpG dinucleotides is a common DNA modification; CpG dinucleotides are considered to be mutational hotspots that cause genetic diseases and cancers through spontaneous deamination of 5-mC, resulting in C→T transition mutations. This study aimed to examine the methylation level of cytosine of EGFR codon 790 and investigate whether DNA methylation was involved in acquiring the T790M mutation. We examined 18 NSCLC tumor tissues, 7 normal lymph node tissues, and 4 NSCLC cell lines (PC9, HCC827, 11-18, and A549). 5-mC was checked by bisulfite sequencing and quantified by pyrosequencing. We found that all tissue samples and cell lines had 5-mC in EGFR codon 790. The 5-mC range was 58.4-90.8%. Our results imply that hypermethylation of the CpG dinucleotide in EGFR codon 790 leads to the C→T transition mutation, causing resistance to EGFR-TKI treatment.

Spontaneous improvement of laryngeal sarcoidosis resistant to systemic corticosteroid administration

We report herein a case of laryngeal sarcoidosis that was refractory to systemic corticosteroids, but that improved spontaneously. A 49‐year‐old woman complained of dysphagia and hoarseness with accompanying edematous swellings of both arytenoid regions. She was referred to our hospital after systemic corticosteroid therapy failed to achieve any improvement. Laryngoscopy showed marked edema of the epiglottis and both arytenoid regions. The flow–volume curve on spirometry showed flattening of the expiratory flows. Histopathological examination of the arytenoid region showed non‐caseating epithelioid granulomas, and laryngeal sarcoidosis was diagnosed with the result of BAL study. She was observed without treatment as symptoms were mild. Although edema of the left arytenoid region seemed to be somewhat worsened after 6 months, she continued to be followed closely because of improvements in the flow–volume curve and increasing peak expiratory flow. By 1 year after onset, symptoms and epiglottal swelling had spontaneously improved.

CHFR aberrant methylation involves a subset of human lung adenocarcinoma associated with poor clinical outcomes

Excluding epidermal growth factor receptor (EGFR) mutation, v-Ki-ras2/Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion, the genetic alterations involved in lung adenocarcinogenesis, especially those linked to poor clinical outcomes, are still unknown. In this study, we analyzed abnormal checkpoint gene with forkhead-associated domain and ring finger (CHFR) methylation along with the above 3 mutations in 165 lung adenocarcinomas, evaluated the spectrum of each molecular abnormality, and correlated the results with clinical and pathologic variables. Reverse transcription-polymerase chain reaction assay, reverse transcription-polymerase chain reaction followed by direct DNA sequencing, and methylation-specific polymerase chain reaction were performed to detect these 3 mutations and CHFR hypermethylation. The EML4-ALK transcript or CHFR hypermethylation was found in 11 (6.7%) or 16 (10%) adenocarcinomas, respectively, whereas EGFR or KRAS mutation was detected in 48 (29%) or 13 (8%) cases, respectively. EGFR mutations occurred in patients who were negative for both CHFR hypermethylation and KRAS mutation. Among the 4 genetic or epigenetic abnormalities, only CHFR hypermethylation was significantly correlated with poor prognosis and lymphatic vessel invasion (P = .024). Histopathologically, the molecular abnormality that correlated with alveolar-destructive growth was the CHFR hypermethylation rather than the EGFR mutation (P = .03). Our results demonstrate that CHFR hypermethylation maybe one of the molecular abnormalities involved in a subset of lung adenocarcinomas with poor prognoses that might be induced by destructive growth and lymphatic vessel invasion of carcinoma cells. Thus, CHFR abnormality might be pursued as a novel therapeutic target against lung adenocarcinoma without an already-known mutation.

PD-L1 expression in lung adenocarcinoma harboring EGFR mutations or ALK rearrangements

OBJECTIVES Expression of programmed cell death-ligand 1 (PD-L1) has been associated with clinical outcome of programmed cell death-1 (PD-1) pathway blockade in non-small cell lung cancer (NSCLC). The PD-L1 IHC 22C3 pharmDx assay, the only companion diagnostic for pembrolizumab therapy, has revealed that ∼30% of all NSCLCs express PD-L1 at a high level. The frequency of high PD-L1 expression in NSCLCs with known driver oncogenes has remained unclear, however. MATERIALS AND METHODS We retrospectively evaluated PD-L1 expression with the 22C3 assay in tumor tissue of 80 lung adenocarcinoma patients including 71 with EGFR mutations and 9 with ALK rearrangements, all of whom were treated with corresponding tyrosine kinase inhibitors (TKIs). RESULTS Of the 80 tumors analyzed, 26 (32.5%) had a PD-L1 tumor proportion score (TPS) of 1%-49% and 9 (11.3%) had a PD-L1 TPS of ≥50%; 35 (43.8%) thus had a PD-L1 TPS of ≥1%. Of the 71 tumors with EGFR mutations, 23 (32.4%) had a PD-L1 TPS of 1%-49% and 7 (9.9%) had a PD-L1 TPS of ≥50%. A PD-L1 TPS of ≥1% was not associated with any clinical characteristic examined. Progression-free survival on initial TKI treatment was significantly poorer for patients with a PD-L1 TPS of ≥1% than for those with a PD-L1 TPS of <1% (p = .016). CONCLUSIONS A subset of patients with EGFR mutations or ALK rearrangements had a PD-L1 TPS of ≥50%. Prospective studies are thus warranted to examine the efficacy of PD-1/PD-L1 inhibitors in such patients.

A case of immunoglobulin G4-related respiratory disease with multiple lung cysts: A case report

A 48-year-old man was admitted for evaluation of abnormal shadows on chest radiograph. Chest computed tomography (CT) showed cysts, nodules, and cervical and axillary lymphadenopathies. Elevated serum levels of IgG4 and interleukin (IL)-6 suggested IgG4-related disease (IgG4-RD) or multicentric Castlemans disease (MCD). Histologic findings of the cervical lymph node and right lung S6 biopsies revealed numerous IgG4-positive plasma cells. Although CT findings of the lungs were atypical for IgG4-RD, consistent histologic findings, clinical symptoms, and laboratory data made us conclude IgG4-RD. Because histologic findings of IgG4-RD and MCD have similarities, differentiating between the two diseases should consider the clinical presentation.

Interstitial pneumonia caused by dabigatran

We describe the case of a 73-year-old man who experienced dry cough and exertional dyspnea after dabigatran administration. Chest radiographs revealed the development of bilateral consolidative and ground glass opacity, and transbronchial lung biopsy showed organized materials in the alveolar spaces with moderate inflammatory infiltrate and focal fibrosis. Lung opacity gradually disappeared after discontinuing dabigatran. To date, there has been only one report regarding dabigatran-induced lung injury, except for alveolar hemorrhage and eosinophilic pneumonia. Therefore, we should consider that any drug can cause various types of lung injuries.