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Background The epidermal growth factor receptor (EGFR) is a therapeutic target for patients with non-small cell lung cancer (NSCLC). Cetuximab is an anti-EGFR monoclonal antibody that inhibits EGFR signaling and proliferation of colorectal cancer and head and neck cancers. Since only few NSCLC patients benefit from cetuximab therapy, we evaluated a novel combination treatment using cetuximab and EGFR small interfering RNA (siRNA) to strongly suppress EGFR signaling and searched for a biomarker in NSCLC cell lines harboring wild-type EGFR. Methods Alterations in EGFR and its downstream genes in five NSCLC cell lines (A549, Lu99, 86-2, Sq19 and Ma10) were assessed through sequencing. The protein expression levels of these molecules were assessed through western blotting. The effect of combination treatment was determined through cell proliferation assay, caspase-3/7 assay, invasion assay, and migration assay. Results All cell lines were harboring wild-type EGFR, whereas KRAS, PTEN, TP53 and TP53 were mutated in A549 and Lu99; Lu99 and Sq19; Lu99, 86-2, Sq19 and Ma10; and A549, 86-2, and Sq19 cell lines, respectively. PTEN was not expressed in Sq19, and LKB1 was not expressed in both A549 and Sq19. TP53 was not expressed in both A549 and Lu99. The combination of cetuximab and EGFR siRNA significantly suppressed cell proliferation in 86-2, Sq19 and Ma10, which express wild-type KRAS. It induced apoptosis in A549, 86-2 and Ma10 cells, which express wild type PTEN. The combination treatment had no effect either on cell invasion nor migration in all cell lines. Conclusion EGFR targeted therapy using the combination of cetuximab and EGFR siRNA is effective in NSCLC cell lines harboring wild-type EGFR. Wild-type KRAS may act as a potential biomarker for response to combination treatment by the induction of apoptosis in cells with wild-type PTEN.

We present a case report of a 35-year-old woman who had splenic infarction. She had persistent high fever, systemic joint pain, and abnormal liver function. She was diagnosed with cytomegalovirus and human parvovirus B19 concomitant infection. Her coagulopathy test revealed no abnormal results. She was treated with intravenous ganciclovir for 13 days; consequently, her splenic infarction improved after 7 weeks. As per our knowledge, this is the first case of cytomegalovirus and parvovirus B19 coinfection complicated by splenic infarction. Cytomegalovirus and parvovirus B19 may induce a hypercoagulation state during the acute phase.

Epidermal growth factor receptor (EGFR) gene mutation testing is essential for choosing appropriate treatment options in patients with advanced non-small cell lung cancer (NSCLC). However, a time delay occurs between histological diagnosis and molecular diagnosis in clinical situations. To minimize this delay, we developed a novel point-of-care test for EGFR mutations, based on a high-speed real-time polymerase chain reaction (PCR) system designated here as ultrarapid PCR combined with highly accurate bronchoscopic sampling. We investigated whether our system for detecting EGFR mutations was valid by comparing test results with those obtained using a commercialized EGFR mutation test. We obtained small amounts of bronchial lavage fluids after transbronchial biopsies (TBBs) were performed on enrolled patients (n=168) who underwent endobronchial ultrasonography using a guide sheath (EBUS-GS). EGFR mutation analysis was performed by ultrarapid PCR immediately after EBUS-GS-TBBs were obtained (on the same day). After pathological diagnoses of NSCLC, EGFR mutation status in formalin-fixed, paraffin- embedded samples was confirmed by the PCR-invader method, and the concordance rates between the PCR methods were compared. The total diagnostic yield of EBUS-GS-TBB was 91.0%. The positive concordance rates for detecting 19del and L858R with the ultrarapid PCR and PCR-invader methods were both 100%. Negative concordance rates were 97.2 and 98.1%, respectively. We also demonstrated a dramatic effect of early erlotinib administration, based on ultrarapid PCR results, for a 52-year-old woman suffering from respiratory failure due to severe intrapulmonary metastases with poor performance status. In conclusion, ultrarapid PCR combined with EBUS-GS-TBB enabled rapid and reliable point-of-care testing for EGFR mutations.

Mutations in the epidermal growth factor receptor (EGFR) gene are associated with a favorable clinical response to the EGFR tyrosine kinase inhibitors gefitinib and erlotinib in non-small cell lung cancer (NSCLC). We present here, a new method for the rapid detection of the two most common EGFR mutations (delE746-A750 and L858R) from clinical samples. The methodology involves the combination of newly designed mutation-specific primers and a novel real-time PCR machine with an innovative thermo-control mechanism that enables ultrarapid PCR. We evaluated this method using a cell mixture composed of various ratios of lung cancer cells harboring mutated or wild-type EGFR, lung cancer tissues obtained by surgery, and a cytology sample obtained by bronchoscopy from a lung cancer patient. In the cell mixture analysis, our method detected 0.1% of cells with delE746-A750 and 1% of cells with L858R among cells with wild-type EGFR. In 143 lung cancer tissues, the result of this assay was concordant with those of direct sequencing in 138 samples. The five samples with discordant results were tested using a PCR-Invader assay and the result matched those of our method at 100%. We also successfully detected EGFR mutations in the lavage obtained from a lung cancer patient. The turnaround time for this method was

A 75-year-old woman with aplastic anemia was admitted to our university hospital because of a dry cough that had persisted for a month. Chest computed tomography showed a mass shadow with a central low attenuation area in the lower lobe of the left lung. Filamentous fungus resembling Aspergillus fumigatus was cultured from the specimens obtained by transthoracic needle aspiration biopsy and bronchoalveolar lavage. The initial diagnosis was a lung abscess due to A. fumigatus, although the patient did not respond well to antifungal agents. Subsequently, the filamentous fungus was identified as Aspergillus viridinutans by sequence analysis of the β-tubulin gene, and the patient was successfully treated with combination therapy along with granulocyte colony-stimulating factor. The incidence of A. viridinutans infection is very rare. A. viridinutans is morphologically similar to A. fumigatus; however, the response to antifungal agents is generally worse than that observed in A. fumigatus infections. Therefore, the selection of agents and supplemental therapy is of vital importance in cases of A. viridinutans infection.

Germline LKB1 mutations cause Peutz-Jeghers syndrome, a hereditary disorder that predisposes to gastrointestinal hamartomatous polyposis and several types of malignant tumors. Somatic LKB1 alterations are rare in sporadic cancers, however, a few reports showed the presence of somatic alterations in a considerable fraction of lung cancers. To determine the prevalence and the specificity of LKB1 alterations in lung cancers, we examined a large number of lung cancer cell lines and lung adenocarcinoma (AdC) specimens for the alterations. LKB1 genetic alterations were frequently detected in the cell lines (21/70, 30%), especially in non-small cell lung cancers (NSCLCs) (20/51, 39%), and were significantly more frequent in cell lines with KRAS mutations. Point mutations were detected only in AdCs and large cell carcinomas, whereas homozygous deletions were detected in all histological types of lung cancer. Among lung AdC specimens, LKB1 mutations were found in seven (8%) of 91 male smokers but in none of 64 females and/or nonsmokers, and were significantly more frequent in poorly differentiated tumors. The difference in the frequency of LKB1 alterations between cell lines and tumor specimens was likely to be owing to masking of deletions by the contamination of noncancerous cells in the tumor specimens. These results indicate that somatic LKB1 genetic alterations preferentially occur in a subset of poorly differentiated lung AdCs that appear to correlate with smoking males.

The mammalian target of rapamycin (mTOR) is a key kinase acting downstream of growth factor receptor PI3K and AKT signaling, leading to processes resulting in increased cell size and proliferation through translation control. Rapamycin, a specific inhibitor of mTOR, results predominately in G1 cell cycle arrest through translation control and occasionally, cell type-dependent apoptosis by an unknown mechanism. In this study, we investigated the effect and mechanism of action of rapamycin on non-small cell lung cancer (NSCLC) cell lines with p53 mutations. Cell proliferation was evaluated by modified MTT assay. The apoptotic effect of rapamycin was measured by caspase-3 activation and flow cytometric analysis of Annexin V binding. The expression of Bcl-2 and the release of cytochrome c from mitochondria were evaluated by western blotting. We found that rapamycin induced apoptosis in NSCLC cell lines with p53 mutations. Western blot analysis demonstrated that rapamycin downregulates the expression levels of Bcl-2, which leads to increased cytochrome c release from mitochondria and subsequent activation of caspase cascades. These findings suggest that rapamycin induces p53-independent apoptosis through downregulation of Bcl-2 and the mitochondrial pathway in NSCLC cell lines as a novel antitumor mechanism.

Paternally expressed imprinted gene 1/mesoderm-specific transcript (PEG1/MEST) is an imprinted gene expressed from the paternal allele. Recently, frequent loss of imprinting (LOI) of PEG1/MEST has been reported in lung adenocarcinomas. It is suggested that the LOI may be involved in pathogenesis of lung adenocarcinoma. In the present study, incidence of LOI of PEG1/MEST was examined in lung cancer cell lines, including small cell lung cancer (SCLC). Among 50 cell lines tested, 20 cell lines were heterozygous for the AflIII site of the PEG1/MEST gene. In these heterozygotes, biallelic expression was observed in 9 cell lines (45%), monoallelic in 11 (55%). In cell lines of non-small cell lung cancer (NSCLC), 62% (8 of 13) exhibited biallelic expression. In SCLC, only 1 of 7 cell lines (14%) showed biallelic expression. LOI of PEG1/MEST in the NSCLC cell line is significantly frequent compared with that in SCLC cell lines (p=0.043). This result supports the possibility that LOI may be related to tumorigenesis and malignant transformation, especially in NSCLC.

To identify genes whose expression is upregulated in lung adenocarcinoma (AdC) cells in comparison with noncancerous peripheral lung epithelial cells, type II alveolar cells and bronchiolar epithelial cells, as well as AdC cells, were isolated by laser capture microdissection, and subjected to cDNA microarray analysis of 637 human cancer-related genes. Each of the component cells was obtained from several different individuals and analysed independently. As a comparison, two lung AdC cell lines and two primarily cultured normal lung epithelial cell lines were also subjected to cDNA microarray analysis. Four genes, TOP2A, MMP15, MX2 and KOC1, were commonly upregulated in microdissected AdC cells in comparison with microdissected epithelial cells. Hierarchical clustering analysis revealed that differences in gene-expression profiles were more evident between cultured and uncultured cells than between cancerous and noncancerous cells. To further identify the common molecular targets of AdC cells in vivo, quantitative real-time RT–PCR was performed against the four genes upregulated by cDNA microarray analysis. The TOP2A, MMP15, MX2 and KOC1 genes were overexpressed in 10/10 (100%), 8/10 (80%), 5/10 (50%) and 3/10 (30%) microdissected AdC cell samples, respectively, in comparison with any of nine independently microdissected noncancerous epithelial cell samples. The TOP2A gene was commonly overexpressed in lung AdC cells, as previously reported. In addition, the MMP15 and MX2 genes were identified, for the first time, as being commonly overexpressed in lung AdC cells. These results strongly indicate that the MMP15 and MX2 genes could be novel markers for molecular diagnosis and therapy of lung AdC.

Retinoblastoma (RB) protein and antibody against RB protein in sera from 45 lung cancer patients and 30 healthy volunteers were examined using bacterially synthesized glutathione S-transferase (GST) RB fusion protein and immunoblot analysis. RB protein was not detected in sera from any individuals with lung cancer or in any healthy volunteers. Sera from 6 patients, including 4 with non-small cell carcinoma and 2 with small cell carcinoma, reacted to a GST-RB fusion protein but not with a GST protein. Sera from 30 normal volunteers reacted to neither GST-RB fusion protein nor GST protein. The backgrounds such as age, gender, performance status, histology, stage, smoking history, and prior treatment were not significantly different between the patients with and without anti-RB antibodies. This is the first report describing the presence of anti-RB antibody in patients with malignant tumors. Further studies are needed to establish clinical significance for anti-RB antibody.

Mutations of the Kristen ras (K-ras) gene have been implicated in the pathogenesis of human lung cancer, especially adenocarcinoma, and have been proposed to be a prognostic factor. The K-ras mutation in codon 12 is detectable even in cell-free fluids by using the enriched polymerase chain reaction (PCR) technique. On the other hand, based on experimental results, the rho A mutation in codon 14 is also proposed to be oncogenic as observed in the K-ras mutation. Malignant pleural effusion is a common complication of lung cancer. We studied the point mutation of K-ras codon 12 and rho A codon 14 using enriched PCR in specimens of pleural effusion. Forty patients with pleural effusion were enrolled in this study. The causes of pleural effusion were non-small cell lung cancer (18 cases), small cell lung cancer (6 cases), malignant mesothelioma (2 cases), metastatic lung tumor (5 cases), thymoma (1 case), malignant lymphoma (1 case), and pleuritis tuberculosa (7 cases). The K-ras mutation was detected in 4 of 14 cases with adenocarcinoma, 1 of 3 cases with squamous cell carcinoma, 1 of 1 case with large cell carcinoma, and 1 of 5 cases with metastatic lung tumor, respectively. The rho A mutation was not detected in any pleural effusion examined in this study. Our study demonstrates the usefullness of pleural effusion as a clinical specimen for a search of point mutation of oncogenes. The K-ras codon 12 mutation is readily detected in pleural effusion, and the demonstration of this mutation has potentially important implications for the diagnosis of malignant pleural effusion.

NKG2D is an activating receptor that is expressed in immune effector cells, and the ligands for which are expressed in transformed cells. NKG2D-NKG2D ligand system might play an essential role in the tumor immunity of host cells. We have previously reported that a member of NKG2D ligand family, UL-16-binding protein 2 (ULBP2), is predominantly expressed on the surface of lung cancer cells, and is shed and solubilized into the sera of the lung cancer patients. In addition, we showed that the soluble form of ULBP2 (sULBP2) aggravates the cytotoxicity of host immune effector cells. Therefore, shedding of ULBP2 from the surface of cancer cells might be a critical component of the immune escape mechanisms employed in lung cancer. In this study, we investigated the mechanism of ULBP2 shedding from the cell surfaces in human lung cancer cell lines. First, we compared the amount of ULBP2 expression on the surface of normal cells and that in the culture medium of various lung cancer cell lines. We observed a significant correlation among non-small-cell lung cancer (NSCLC) cell lines (r=0.835, P Citation Format: Kosuke Yamaguchi, Hiroki Hikumi, Shinji Matsumaga, Miyako Takata, Naoki Kinoshita, Kiyoshi Hashimoto, Masaki Nakamoto, Jun Kurai, Masanari Watanabe, Akira Yamasaki, Tadashi Igishi, Naoto Burioka, Eiji Shimizu. ADAM proteases shed UL-16-binding protein 2 in human lung cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 454. doi:10.1158/1538-7445.AM2013-454

An epidermal growth factor receptor (EGFR) mutation is the best marker of sensitivity to the EGFR tyrosine kinase inhibitors gefitinib and erlotinib. Polymerase chain reaction (PCR)-based methods combined with the use of fluorescence probes, such as the Scorpion Amplification Refractory Mutation System (ARMS) or the PCR-Invader method, are frequently used to detect EGFR mutations before therapy. The sensitivities and specificities of these methods are satisfactory; however, there is potential to further improve the cost and detection time. We developed a new method for the rapid and reliable detection of EGFR mutations by using a combination of mutation-specific primers and the newly developed ultra-rapid real-time PCR (Hyper-PCR) amplification method that can be accomplished in Citation Format: Hiroki Chikumi, Miyako Takata, Keiji Matsunami, Shingo Matsumoto, Masahiro Kotani, Tomohiro Sakamoto, Hirokazu Touge, Kosuke Yamaguchi, Jun Kurai, Naomi Miyake, Masaki Nakamoto, Tadashi Igishi, Eiji Shimizu. A new rapid diagnostic test to identify epidermal growth factor receptor mutations in non-small cell lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-88. doi:10.1158/1538-7445.AM2013-LB-88

Rho GTPases play an essential role in the control of various cellular functions. Accumulating evidence suggests that RhoA overexpression contributes to human cancer development. However, the activation states of RhoA are poorly defined in cancer cells. In this study, we examined both the expression levels and the activation states of RhoA in various lung cancer cells by quantitative real-time reverse transcriptase-polymerase chain reaction and in vivo Rho guanine nucleotide exchange assay, respectively. Moreover, we dissected the signaling pathway from the cell surface receptors to RhoA using a broad-spectrum G protein coupled receptor (GPCR) antagonist, [D-Arg1,D-Trp5,7,9,Leu11]Substance P (SP), and a recently reported Galphaq/11-selective inhibitor, YM-254890. We found that RhoA was expressed highly in large cell carcinoma cells but only weakly in adenocarcinoma cells. The activation states of RhoA are considerably different from its expression profiles. We found that four of six small cell lung carcinoma (SCLC) cell lines exhibited a moderate to high activation rate of RhoA. The addition of [D-Arg1,D-Trp5,7,9,Leu11]SP reduced RhoA activity by almost 60% in H69 SCLC cells. The addition of YM-254890 had no effect on RhoA activity in H69 cells. Our results suggest that RhoA is activated in various lung cancer cells independent of its expression levels, and the high activation state of RhoA in SCLC cells mainly depends on a neuroendocrine peptide autocrine system which signals through Galpha12 coupled GPCR to RhoA. This study provides new insights into RhoA signaling in lung cancer cells and may help in developing novel therapeutic strategies against lung cancer.