Observation of Zn-photoprotoporphyrin red Autofluorescence in human bronchial cancer using color-fluorescence endoscopy.

BACKGROUND: We observed red autofluorescence emanating from bronchial cancer lesions using a sensitive color-fluorescence endoscopy system. We investigated to clarify the origin of the red autofluorescence. METHODS: The wavelengths of the red autofluorescence emanating from lesions were measured in eight patients using a spectrum analyzer and compared based on pathologic findings. Red autofluorescence at 617.3, 617.4, 619.0, and 617.1 nm was emitted by normal bronchus, inflamed tissue, tissue exhibiting mild dysplasia, and malignant lesions, respectively. Protoporphyrin, uroporphyrin, and coproporphyrin, the major porphyrin derivatives in human blood, were purchased to determine which porphyrin derivative is the source of red fluorescence when acquired de novo. We synthesized photoporphyrin, Zn-protoporphyrin and Zn-photoprotoporphyrin from protoporphyrin. RESULTS: Coproporphyrin and uroporphyrin emitted only weak fluorescence. Fluorescence was emitted by our synthesized Zn-photoprotoporphyrin at 625.5 nm and by photoprotoporphyrin at 664.0 nm. CONCLUSIONS: From these results, we conclude that Zn-photoprotoporphyrin was the source of the red autofluorescence observed in bronchial lesions. Zn-protoporphyrin is converted to Zn-photoprotoporphyrin by radiation with excitation light. Our results suggest that red autofluorescence emanating from Zn-photoprotoporphyrin in human tissues could interfere with photodynamic diagnosis using porphyrin derivatives such as Photofrin® and Lazerphyrin® with a sensitive endoscopy system, because color cameras cannot differentiate Zn-photoprotoporphyrin red fluorescence from that of other porphyrin derivatives.

Prostacyclin stimulated integrin-dependent angiogenic effects of endothelial progenitor cells and mediated potent circulation recovery in ischemic hind limb model.

BACKGROUND: Prostacyclin (PGI2) enhances angiogenesis, especially in cooperation with bone marrow (BM)-derived endothelial progenitor cells (EPCs). However, the mechanisms of PGI2 in EPC-mediated angiogenesis in vivo remain unclear. The purpose of this study was to clarify the role of PGI2 in EPC-mediated angiogenesis using BM-specific IP deletion mice. METHODS AND RESULTS: Hind limb ischemia (HLI) was induced in wild-type (WT) mice transplanted with IP-deleted BM (WT/BM(IP(-/-)). Recovery of blood flow (RBF) in WT/BM(IP(-/-)) was impaired for 28 days after HLI, whereas RBF in IP(-/-)/BM(WT) was attenuated for up to 7 days compared with WT/BM(WT). The impaired RBF in WT/BM(IP(-/-)) was completely recovered by intramuscular injection of WT EPCs but not IP(-/-) EPCs. The impaired effects of IP(-/-) EPCs were in accordance with reduced formation of capillary and arterioles in ischemic muscle. An ex vivo aortic ring assay revealed that microvessel formation was enhanced by accumulation/adhesion of EPCs to perivascular sites as pericytes. IP(-/-)EPCs, in which expression of integrins was decreased, had impaired production of angiogenic cytokines, adhesion to neovessels and their angiogenic effects. The small-interfering RNA (siRNA)-mediated knockdown of integrin ß1 in WT EPCs attenuated adhesion to microvessels and their in vivo and in vitro angiogenic effects. CONCLUSIONS: PGI2 may induce persistent angiogenic effects in HLI through adhesion of EPCs to perivascular sites of neovessels via integrins in addition to paracrine effects.

Detection of resistance mutations in patients with anaplastic lymphoma kinase-rearranged lung cancer through liquid biopsy.

Background: Tyrosine kinase inhibitors (TKIs) significantly improve clinical outcomes in patients with non-small cell lung cancer due to anaplastic lymphoma kinase (ALK) gene rearrangement. However, the rate of relapse with TKIs is high owing to the development of resistance mutations during treatment. Repeated biopsies during disease progression are crucial for elucidating the molecular mechanisms underlying the development of resistance to ALK inhibitors. Analysis of cell-free DNA (cfDNA) obtained from plasma is a novel approach for tumor genotyping. Methods: In this mixed prospective and retrospective observational cohort study, we investigated the clinical feasibility of continuous quantitative monitoring of ALK-acquired mutations in plasma obtained from patients with ALK+ non-small cell lung cancer by using a highly sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay. We enrolled nine patients, including three treatment-naïve patients recently diagnosed with ALK+ non-small cell lung cancer via tissue biopsy and expected to receive ALK TKIs and six patients already receiving ALK TKIs. Plasma samples were collected from these patients every 3 months. cfDNA was extracted from 66 samples during the study period, and 10 ALK mutations were simultaneously evaluated. Results: The numbers of samples showing the G1202R, C1156Y, G1269A, F1174L, T1151ins, and I1171T mutations were 32, 16, 5, 4, 1, and 1, respectively. The L1196M, L1152R, V1180L, and S1206Y mutations were not detected. Correlation analyses between progression-free survival and the time from treatment initiation (or treatment modification) to the detection of resistance mutations revealed that although resistance mutations may occur before a drug change becomes necessary, there is a duration during which the disease does not progress. Conclusions: Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.

Demarcation Line Determination for Diagnosis of Gastric Cancer Disease Range Using Unsupervised Machine Learning in Magnifying Narrow-Band Imaging.

BACKGROUND AND AIMS: It is important to determine an accurate demarcation line (DL) between the cancerous lesions and background mucosa in magnifying narrow-band imaging (M-NBI)-based diagnosis. However, it is difficult for novice endoscopists. We aimed to automatically determine the accurate DL using a machine learning method. METHODS: We used an unsupervised machine learning approach to determine the DLs. Our method consists of the following four steps: (1) an M-NBI image is segmented into superpixels using simple linear iterative clustering; (2) the image features are extracted for each superpixel; (3) the superpixels are grouped into several clusters using the k-means method; and (4) the boundaries of the clusters are extracted as DL candidates. The 23 M-NBI images of 11 cases were used for performance evaluation. The evaluation investigated the similarity of the DLs identified by endoscopists and our method, and the Euclidean distance between the two DLs was calculated. For the single case of 11 cases, the histopathological examination was also conducted to evaluate the proposed system. RESULTS: The average Euclidean distances for the 11 cases were 10.65, 11.97, 7.82, 8.46, 8.59, 9.72, 12.20, 9.06, 22.86, 8.45, and 25.36. The results indicated that the proposed method could identify similar DLs to those identified by experienced doctors. Additionally, it was confirmed that the proposed system could generate pathologically valid DLs by increasing the number of clusters. CONCLUSIONS: Our proposed system can support the training of inexperienced doctors as well as enrich the knowledge of experienced doctors in endoscopy.

Prostaglandin I2 promotes recruitment of endothelial progenitor cells and limits vascular remodeling.

OBJECTIVE: Endothelial progenitor cells (EPCs) play an important role in the self-healing of a vascular injury by participating in the reendothelialization that limits vascular remodeling. We evaluated whether prostaglandin I(2) plays a role in the regulation of the function of EPCs to limit vascular remodeling. METHODS AND RESULTS: EPCs (Lin(-)cKit(+)Flk-1(+) cells) were isolated from the bone marrow (BM) of wild-type (WT) mice or mice lacking the prostaglandin I(2) receptor IP (IP(-/-) mice). Reverse transcription-polymerase chain reaction analysis showed that EPCs among BM cells specifically express IP. The cellular properties of EPCs, adhesion, migration, and proliferation on fibronectin were significantly attenuated in IP-deficient EPCs compared with WT EPCs. In contrast, IP agonists facilitated these functions in WT EPCs, but not in IP-deficient EPCs. The specific deletion of IP in BM cells, which was performed by transplanting BM cells of IP(-/-) mice to WT mice, accelerated wire injury-mediated neointimal hyperplasia in the femoral artery. Notably, transfused WT EPCs, but not IP-deficient EPCs, were recruited to the injured vessels, participated in reendothelialization, and efficiently rescued the accelerated vascular remodeling. CONCLUSIONS: These findings clearly indicate that the prostaglandin I(2)-IP system is essential for EPCs to accomplish their function and plays a critical role in the regulation of vascular remodeling.

Cyclin-dependent kinase 4 upregulation mediates acquired resistance of dabrafenib plus trametinib in BRAF V600E-mutated lung cancer.

BACKGROUND: Combination therapy with the B-Raf inhibitor, dabrafenib, and the MEK inhibitor, trametinib (DT) is commonly used to treat patients with B-Raf proto-oncogene, serine/threonine kinase V600E (BRAF V600E)-mutated non-small cell lung cancer (NSCLC). However, the mechanisms through which cancer develops DT resistance are unclear. Here, we investigated new mechanisms underlying acquired DT-resistant NSCLC with the BRAF V600E mutation. METHODS: We compared genomic signatures before and after DT treatment in patients with NSCLC. RESULTS: Two of four patients treated with DT developed carcinomatous pleuritis within 3 months. Target DNA sequencing and quantitative polymerase chain reaction (PCR) analyses revealed the increased expression level of cyclin-dependent kinase 4 (CDK4). We also found prominent protein expression of CDK4 after DT treatment. Induction of CDK4 expression in a cell line derived from a patient with the BRAF V600E mutation resulted in partial resistance to dabrafenib. CONCLUSIONS: Our findings suggest a possible relationship between CDK4 upregulation and acquired resistance to DT therapy.

The feasibility of circulating tumor DNA analysis as a marker of recurrence in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) has a poorer prognosis than other breast cancer subtypes; therefore, identifying markers of early recurrence is important. The present study aimed to establish a liquid biopsy protocol for droplet digital PCR-based detection of frequently mutated genes in patients with TNBC. Tumor DNA from 36 patients with TNBC who relapsed within 2 years after surgical resection was retrospectively analyzed. Somatic mutational profiles were evaluated using targeted sequencing to identify frequently mutated genes and genes associated with molecularly targeted therapies. The association between genetic alterations and associated protein phosphorylation was investigated using immunohistochemical analysis. Recurrent hot spot mutations in the plasma were monitored over time. Mutation-specific probes were used to successfully detect mutations in the blood samples of patients who were positive for PIK3CA H1047R and AKT1 E17K mutations. Somatic mutations in AKT1 (14.9%) and PIK3CA (25.5%) were frequently identified in the data. Robust phosphorylation of AKT and S6RP was more common in tumors with PIK3CA H1047R and AKT1 E17K mutational background than in tumors with wild-type PIK3CA and AKT1. In conclusion, the present study evaluated a high-sensitivity detection system for frequently mutated genes that was also applicable for cell-free DNA. The PI3K/AKT pathway was revealed to be activated in patients harboring PIK3CA H1047R and AKT1 E17K mutations; therefore, the PI3K/AKT pathway may be a promising candidate for targeted therapy in these patients.

Monomerization of ALK Fusion Proteins as a Therapeutic Strategy in ALK-Rearranged Non-small Cell Lung Cancers.

Objective: Oncogenic echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) (EML4-ALK) fusion proteins found in non-small cell lung cancers (NSCLC) are constitutively phosphorylated and activated by dimerization via the coiled-coil domain (cc) within EML4. Here, we investigated whether disruption of ALK fusion protein oligomerization via competitive cc mimetic compounds could be a therapeutic strategy for EML4-ALK NSCLC. Methods: A Ba/F3 cell model was created that expressed an ALK intracellular domain in which the dimer/monomer state is ligand-regulated. This novel cell model was used to investigate the effect of disrupting ALK fusion protein oligomerization on tumor cell growth in vitro and in vivo using nude mice. Subsequently, the antiproliferative effects of endogenous cc domain co-expression and mimetic cc peptides were assayed in EML4-ALK cancer cell lines. Results: Cells induced to express monomeric ALK in vitro did not survive. When transplanted into mice, induction of monomers abrogated tumor formation. Using a fluorescent protein system to quantify protein-protein interactions of EML4-ALK and EML4cc, we demonstrated that co-expression of EML4cc suppressed EML4-ALK assembly concomitant with decreasing the rate of tumor growth in vitro and in vivo. In EML4-ALK cancer cell lines, administration of synthetic EML4cc peptide elicited a decrease of phosphorylation of ALK leading to reduction in tumor cell growth. Conclusions: Our findings support the monomerization of ALK fusion proteins using EML4cc peptides for competitive inhibition of dimerization as a promising therapeutic strategy for EML4-ALK NSCLC. Further studies are warranted to explore the use of specific cc peptide as a therapeutic option for other lung cancers harboring driver fusion genes containing a cc or oligomerization domain within the fusion partner.

Acute eosinophilic pneumonia following inhalation of turpentine oil: A case report.

Acute eosinophilic pneumonia (AEP) is an eosinophilic lung disease associated with environmental substances including smoking. Although the etiology of AEP has not been fully elucidated, it has been hypothesized that IL-33 plays a central role in the pathogenesis of AEP. Turpentine oil, from resins of pine trees, is not only used in paints, but also utilized in experimental animal models of inflammation because it leads to the production of inflammatory cytokines including IL-33. Here, we report the first case of AEP following turpentine oil inhalation. A 67-year-old woman reported using urushiol with turpentine oil to repair home goods. She had fever and persistent cough after turpentine inhalation over a very short period of time. The chest X-ray image showed consolidation in the upper right lung field. Laboratory findings indicated that there was no evidence of infection, collagen vascular diseases, and other allergic diseases that cause pneumonia, but analysis of the bronchoalveolar lavage fluid revealed 29% eosinophils with a small number of lipid-laden macrophages. With these findings, the diagnostic criteria of AEP was met. We rendered a diagnosis of AEP by inhalation of turpentine because no other cause for AEP was identified even with a structured questionnaire survey. The manifestations resolved immediately after steroid therapy. This is the first report of a case of AEP caused by the inhalation of turpentine oil.

Novel ALK-specific mRNA in situ hybridization assay for non-small-cell lung carcinoma.

BACKGROUND: A recent technical advance in mRNA in situ hybridization (mRNA-ISH) assays provides simultaneous signal amplification and background suppression with a unique probe design that enables single-molecule visualization. We assessed the utility of the mRNA-ISH assay as a diagnostic tool for detecting anaplastic lymphoma receptor tyrosine kinase (ALK) mRNA in non-small-cell lung carcinoma (NSCLC). We compared the mRNA-ISH assay with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). METHODS: The study included 279 surgically resected lung adenocarcinomas and 44 transbronchial-biopsied (TBB) adenocarcinomas. mRNA-ISH was conducted using the RNAscope 2.0 system, which includes pre-designed probes for detecting the tyrosine kinase domain encoded in ALK mRNA. IHC was conducted on all 323 samples using ALK-specific antibodies. mRNA-ISH was performed on 279 surgical samples and 6 TBB samples. Break-apart FISH was used to examine samples that were mRNA-ISH-positive or IHC-positive. RESULTS: ALK protein expression was detected in 11 of 279 specimens (3.9%). ALK mRNA was also detected with mRNA-ISH in ALK-positive samples, and 9 of the 11 specimens (81%) were also positive for ALK using break-apart FISH. Using the IHC results as a reference, the sensitivity and specificity of mRNA-ISH was 100%. In the TBB cohort, ALK protein expression was observed in 3 of 44 specimens (6.8%), in which ALK mRNA expression was also detected. CONCLUSIONS: The ALK mRNA-ISH data were highly correlated with the IHC data, and ALK mRNA-ISH detected ALK mRNA expression in every FISH-positive sample. We conclude that mRNA-ISH could serve as an alternative or complementary method for diagnosing ALK rearrangements in NSCLC.

Activation of Src signaling mediates acquired resistance to ALK inhibition in lung cancer.

Anaplastic lymphoma kinase (ALK) fusion oncogenes occur in approximately 3-5% of non-small cell lung cancer (NSCLC) cases. Various ALK inhibitors are in clinical use for the treatment of ALK-NSCLC, including the first generation ALK inhibitor, crizotinib, and recently the more highly potent alectinib and ceritinib. However, most tumors eventually become resistant to ALK specific inhibitors. To address the mechanisms underlying the development of ALK inhibitor resistance, we used iTRAQ quantitative mass spectrometry and phosphor-receptor tyrosine kinase arrays to investigate intracellular signaling alterations in ALK inhibitor resistant NSCLC cell lines. Src signaling was identified as an alectinib resistance mechanism, and combination treatment with ALK and Src inhibitors was highly effective for inhibiting the growth of ALK inhibitor resistant cells in vitro and in mouse xenograft models. Furthermore, phospho-receptor tyrosine kinase activation and downstream PI3K/AKT signaling was effectively blocked by inhibiting Src in alectinib resistant cells. Finally, we showed that the combined use of ALK and Src inhibitors inhibited the growth of other ALK-NSCLC cell lines, including those that were ceritinib or lorlatinib resistant. Our data suggest that targeting Src signaling may be an effective approach to the treatment of ALK-NSCLC with acquired resistance to ALK inhibitors.

Rikkunshito for Preventing Chemotherapy-Induced Nausea and Vomiting in Lung Cancer Patients: Results from 2 Prospective, Randomized Phase 2 Trials.

The herbal medicine rikkunshito has the potential to improve chemotherapy-induced nausea and vomiting (CINV) by stimulating ghrelin secretion. We aimed to evaluate the efficacy and safety of rikkunshito in preventing CINV for patients with lung cancer. Two separate prospective, randomized, phase II parallel design studies were conducted in patients with lung cancer. Fifty-eight and sixty-two patients scheduled to receive highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC), respectively, were randomized 1:1 to receive either standard antiemetic therapy in accordance with international guidelines (S group) or standard antiemetic therapy plus oral rikkunshito (R group). The primary endpoint was overall complete response (CR)-that is, no emesis and rescue medication in the first 120 h post-chemotherapy. Secondary endpoints included CR in the acute (0-24 h) and delayed (>24-120 h) phases and safety. Fifty-seven patients (S group, 28; R group, 29) receiving HEC and sixty-two patients (S group, 30; R group, 32) receiving MEC with comparable characteristics were evaluated. The CR rates were similar across the S and R groups for the HEC study in the overall (67.9% vs. 62.1%), acute (96.4% vs. 89.6%), and delayed (67.9% vs. 62.1%) phases, respectively, and for the MEC study in the overall (83.3% vs. 84.4%), acute (100% vs. 100%), and delayed (83.3% vs. 84.4%) phases, respectively. No severe adverse events were observed. Although rikkunshito was well tolerated, it did not demonstrate an additional preventative effect against CINV in lung cancer patients receiving HEC or MEC. Clinical Trial Registry Information: This study is registered with the University Hospital Medical Information Network (UMIN) Clinical Trial Registry, identification numbers UMIN 000014239 and UMIN 000014240.

Histamine H1 antagonist levocetirizine as a potential cause of lung injury.

Histamine H1 antagonists rarely cause drug-induced lung injury (DLI). A woman in her 60s, who had been taking antihistaminic levocetirizine for 2 months, presented with progressive cough and shortness of breath. A chest radiograph showed patchy infiltrations on both lower lung fields. Chest computed tomography findings were consistent with non-specific interstitial pneumonia. Serum markers associated with interstitial pneumonias were elevated. Room air arterial blood gas analysis revealed hypoxemia. Restrictive ventilatory impairment was noted with reduced diffusing capacity. Transbronchial lung biopsy specimens demonstrated unclassifiable alveolitis. Steroid pulse therapy was introduced for respiratory distress, but the initial response to treatment was poor. A drug lymphocyte stimulation test was positive for levocetirizine. The interstitial pneumonia improved following withdrawal of levocetirizine. Her illness has not recurred under steroid therapy and the discontinuation of levocetirizine. Antihistaminics may have a potential risk of DLI.

Prostaglandin I2 analog suppresses lung metastasis by recruiting pericytes in tumor angiogenesis.

Prostaglandin I2 (PGI2) agonist has been reported to reduce tumor metastasis by modifying tumor angiogenesis; however, the mechanisms of how PGI2 affects the endothelial cells or pericytes in tumor vessel maturation are still unclear. The purpose of this study was to clarify the effects of PGI2 on tumor metastasis in a mouse lung metastasis model using Lewis lung carcinoma (LLC) cells. The mice were treated continuously with beraprost sodium (BPS), a PGI2 analog, for 3 weeks and then examined for lung metastases. The number and size of lung metastases were decreased significantly by BPS treatment. In addition, scanning electron microscopy and immunohistochemistry revealed that BPS increased the number of tumor­associated pericytes and improved intratumor hypoxia. Collectively, this study suggests that BPS attenuated vascular functional maturation in metastatic tumors.

Molecular pathways: the basis for rational combination using MEK inhibitors in KRAS-mutant cancers.

Mutations in RAS oncogenes are frequently observed in human cancers, and the mutations result in activation of the RAS-RAF-MEK-ERK pathway, leading to cell proliferation and survival. The pathway is, therefore, a potent therapeutic target in the RAS-mutant cancers. MEK inhibitors can specifically block the pathway and are one of the key types of drugs for the treatment of the RAS-mutant cancers. As RAS proteins activate other downstream signaling proteins in addition to the RAS-RAF-MEK-ERK pathway, combination therapeutic approaches with MEK inhibitors are also being evaluated. Moreover, MEK inhibitors can arrest cancer cells in G1 phase and repress prosurvival Bcl2 family proteins such as MCL1 and BCL2/BCLXL, and increase expression of Bim, a proapoptotic BH3-only family protein. This mechanism may explain the efficacy of the combination of MEK inhibitors with cytotoxic agents or other targeted inhibitors. A better understanding of the pathway will help us with development of rational combinations for the treatment of the RAS-mutant cancers.

Feasibility of adjuvant chemotherapy with S-1 consisting of a 4-week administration and a two-week rest period in patients with completely resected non-small cell lung cancer.

The efficacy of adjuvant chemotherapy with S-1 in patients with completely resected non-small cell lung cancer (NSCLC) has yet to be clarified, and the appropriate schedule for the adjuvant chemotherapy with S-1 remains unknown. A phase II study was conducted to evaluate the feasibility and efficacy of adjuvant chemotherapy with S-1. Patients enrolled in this study were 20-75 years old, had pathological stage IB-IIIA NSCLC, and had received complete resection of NSCLC. S-1 (80 mg/m2) was administered orally to the patients for four weeks followed by a two-week rest period (conventional schedule), for a maximum of eight cycles. The primary endpoint was relative dose intensity (RDI), while the secondary endpoints were safety and 1 year of disease-free survival (1y-DFS). Between May 2007 and October 2009, 28 patients were enrolled. The RDI was 63.1% (95% CI, 48.6-77.7). No grade 3 or worse hematological toxicity was observed. Grade 3 non-hematological toxicities were observed in four patients. No grade 4 or worse hematological toxicity was detected. The probability of 1y-DFS was 85.7% (95% CI, 72.8-98.6). In the subgroup analysis, the median RDI of patients over 65 years old was lower compared to the other patients (44.8 vs. 100%; P=0.013; Mann-Whitney U test). Creatinine clearance (CCr) was lower in the older group, with more grade 2 or 3 non-hematological toxicities in the elderly patients. These results suggest that the conventional schedule of adjuvant chemotherapy with S-1 is not likely to be feasible in older patients with completely resected NSCLC.

Nicotinamide phosphoribosyltransferase: a potent therapeutic target in non-small cell lung cancer with epidermal growth factor receptor-gene mutation.

BACKGROUND: Non-small cell lung cancer (NSCLC) often has an epidermal growth factor receptor (EGFR) gene mutation. Growth of EGFR-gene-mutated NSCLC depends predominantly on EGFR signaling and requires a large amount of intracellular ATP to activate EGFR signal transduction. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in nicotinamide adenine dinucleotide biosynthesis, and it regulates intracellular ATP levels in mammalian cells. The effect of NAMPT inhibition on NSCLC has not been completely understood. METHODS: We aimed to clarify the hypothesis that NAMPT inhibition suppresses growth of EGFR-gene-mutated NSCLC through reduction of intracellular ATP levels, using NAMPT-siRNA transfection and NAMPT inhibitor FK866. We used four lung adenocarcinoma cell lines, including H358 (Wild type EGFR), LC2 (EGFR), PC9 (EGFR), and H1975 (EGFR), and evaluated the effect of FK866 on these cells and its mechanisms, using cell proliferation, Western blot, ATP, and apoptosis assay. RESULTS: We found that (1) H358, LC2, and H1975 cell lines highly expressed NAMPT-mRNA; (2) NAMPT-specific siRNA and FK866 suppressed proliferation of these NSCLCs; (3) FK866 reduced intracellular ATP levels in H1975 cells; (4) FK866 dephosphorylated EGFR signal proteins, including EGFR, Akt, Map kinase kinase 1/2, and extracellular signal-regulated kinase 1/2 (ERK 1/2); (5) FK866 induced apoptosis of H1975 cells; and (6) FK866 suppressed growth of H1975 xenograft tumors and attenuated expression of phospho-ERK 1/2 in the tumors in a tumor-bearing mouse model. CONCLUSION: These findings indicate that NAMPT is a potent therapeutic target in the treatment of EGFR-gene-mutated NSCLC.

Pharmacokinetics of garenoxacin in elderly patients with respiratory tract infections.

The pharmacokinetics of the new oral des-fluoroquinolone antimicrobial garenoxacin (GRNX) was investigated in elderly patients with respiratory tract infections. Patients were treated with GRNX (200 mg or 400 mg) once daily for 7 days. Plasma GRNX concentrations were determined and pharmacokinetic parameters were estimated by Bayesian predictions using reported population pharmacokinetic parameters. At each dose, the maximum plasma concentration (C(max)) and the area under the concentration-time curve (AUC) were comparable with those reported in young subjects, except that the estimated C(max) and AUC values in one patient receiving the 200 mg dose whose body weight and creatinine clearance rate (CL(Cr)) were 38 kg and 17 mL/min, respectively, were higher than those of the other patients given 200 mg GRNX and were comparable with those of patients who received the 400mg dose. These results suggest that the recommended dose of GRNX should be 400 mg for most elderly and young patients, but only 200 mg in patients whose body weight and CL(Cr) are < 40 kg and < 30 mL/min, respectively.