Takaaki Sasaki

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 I2 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 I2 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. Conclusion—These findings clearly indicate that the prostaglandin I2-IP system is essential for EPCs to accomplish their function and plays a critical role in the regulation of vascular remodeling.

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 (EGFRL858R), PC9 (EGFRDel E746-A750), and H1975 (EGFRL858R+T790M), 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.

Evaluation of a Quantitative Serological Assay for Diagnosing Chronic Pulmonary Aspergillosis

ABSTRACT The purpose of this study was to evaluate the clinical utility of a quantitative Aspergillus IgG assay for diagnosing chronic pulmonary aspergillosis. We examined Aspergillus-specific IgG levels in patients who met the following criteria: (i) chronic (duration of >3 months) pulmonary or systemic symptoms, (ii) radiological evidence of a progressive (over months or years) pulmonary lesion with surrounding inflammation, and (iii) no major discernible immunocompromising factors. Anti-Aspergillus IgG serum levels were retrospectively analyzed according to defined classifications. Mean Aspergillus IgG levels were significantly higher in the proven group than those in the possible and control groups (P < 0.01). Receiver operating characteristic curve analysis revealed that the Aspergillus IgG cutoff value for diagnosing proven cases was 50 mg of antigen-specific antibodies/liter (area under the curve, 0.94; sensitivity, 0.98; specificity, 0.84). The sensitivity and specificity for diagnosing proven cases using this cutoff were 0.77 and 0.78, respectively. The positive rates of Aspergillus IgG in the proven and possible groups were 97.9% and 39.2%, respectively, whereas that of the control group was 6.6%. The quantitative Aspergillus IgG assay offers reliable sensitivity and specificity for diagnosing chronic pulmonary aspergillosis and may be an alternative to the conventional precipitin test.

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 tumor‑associated pericytes and improved intratumor hypoxia. Collectively, this study suggests that BPS attenuated vascular functional maturation in metastatic tumors.

Successful alectinib treatment after crizotinib-induced interstitial lung disease.

A 70‐year‐old woman with lung adenocarcinoma, harbouring anaplastic lymphoma kinase gene rearrangement, was treated with crizotinib as third‐line chemotherapy. After 2 months, crizotinib was discontinued because of the development of crizotinib‐induced interstitial lung disease (ILD). Steroid treatment was then introduced and tapered off. Following complete resolution of the interstitial shadow, cytotoxic chemotherapy was initiated, and continued for over 2 years, until new intrapulmonary lesions developed. Although there was a risk of drug‐induced interstitial pneumonia, alectinib was initiated as the fifth‐line therapy, without steroid supplementation, as there was no alternative treatment. No recurrence of ILD was noted at 10 months. To our knowledge, this is the first report of successful alectinib treatment after the development of crizotinib‐induced ILD without the use of prednisolone.

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.

Interstitial lung disease associated with human papillomavirus vaccination

Vaccinations against the human papillomavirus (HPV) have been recommended for the prevention of cervical cancer. HPV-16/18 AS04-adjuvanted vaccines (Cervarix) are said to have favourable safety profiles. Interstitial lung diseases (ILDs) can occur following exposure to a drug or a biological agent. We report a case of ILD associated with a Cervarix vaccination. A woman in her 40s, with a history of conisation, received three inoculations of Cervarix. Three months later, she presented with a cough and shortness of breath. Findings from a computed tomography of the chest and a transbronchial lung biopsy were consistent with non-specific interstitial pneumonia. Workup eliminated all other causes of the ILD, except for the vaccination. Over the 11 months of the follow-up period, her symptoms resolved without steroid therapy. The onset and spontaneous resolution of the ILD showed a chronological association with the HPV vaccination. The semi-quantitative algorithm revealed that the likelihood of an adverse drug reaction to Cervarix was “Probable”. The outcome was relatively good, but more attention should be paid to a potential risk for HPV vaccinations to cause ILDs. Wherever possible, chest radiographic examinations should be performed in order not to overlook any ILDs.

Neuromyelitis optica spectrum disorder secondary to treatment with anti-PD-1 antibody nivolumab: the first report

BackgroundImmune checkpoint blockade is developed as standard treatment for non-small cell lung cancer. However immune-related adverse events (irAE) have still unknown complications. Here, we report a patient with lung squamous cell carcinoma who developed neuromyelitis optica spectrum disorder with nivolumab.Case presentationA 75-year-old Japanese man with lung squamous cell carcinoma was administered nivolumab as second-line treatment. Two months after treatment with nivolumab, he presented acute paralysis in the bilateral lower limbs, sensory loss. Spinal magnetic resonance imaging showed T2 hyperintense lesions between C5-6 and Th12-L1. He was diagnosed with neuromyelitis optica spectrum disorder (NMOSD) by anti-aquaporin-4 antibody-positive in the serum and other examinations. After treatment, steroid reactivity was poor.ConclusionThis is the first patient who developed anti-AQP4 antibody-positive NMOSD as a nivolumab-induced irAE. Clinicians should be aware of this kind of potential neurological complication by using immune check point inhibitor and start the treatment of this irAE as soon as possible.

Abstract 2267: Efficacy of pemetrexed-based chemotherapy in patients with NSCLC harboring KRAS mutations

[Background] Biomarkers like epidermal growth factor receptor (EGFR) gene mutations or anaplastic lymphoma kinase (ALK) rearrangement have been discovered in lung cancer, leading to targeted therapies developed in non-small cell lung cancer (NSCLC). Several oncogenes have been reported to be negative biomarkers for response to tyrosine kinase inhibitors (TKIs), for example, NSCLC with KRAS mutations are resistant to EGFR-TKIs. A preclinical study showed that KRAS mutant lung cancer cells were sensitive to pemetrexed, while a retrospective study reported that pemetrexed-based chemotherapy didn9t show a favorable outcomes in patients with KRAS mutant NSCLC. We, therefore, studied efficacy of pemetrexed-based chemotherapy in patients with NSCLC, and compared the efficacy between KRAS and wild-type NSCLC. [Methods] We retrospectively studied the medical records of patients diagnosed with NSCLC between 2013 to 2015. Genomic DNA (gDNA) was extracted from FFPE tissue samples (QIAamp DNA FFPE Tissue Kit, QIAGEN). KRAS mutations were evaluated using Ion Torrent NGS systems (Ion PGM, Thermo Fischer Scientific) or PCR-rSSO. AmpliSeq Colon and Lung Cancer Research Panel v2 was used in the present study. We used Ion Reporter software for next-generation sequencing data analysis. [Results] We analyzed the data of 226 patients with NSCLC and successfully extracted gDNA from 94 tissue samples. Among them, mutation analysis by Ion PGM system was performed in 48 samples and PCR-rSSO in 46 samples. We will report response rate and progression free survival in the patients treated with pemetrexed-based chemotherapy. Citation Format: Shunsuke Okumura, Takaaki Sasaki, Shin-ichi Chiba, Masatoshi Sado, Naoyuki Miyokawa, Hiroshi Funakoshi, Yoshinobu Ohsaki. Efficacy of pemetrexed-based chemotherapy in patients with NSCLC harboring KRAS mutations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2267.

Abstract 2121: Src mediates acquired resistance to ALK inhibitor in ALK-rearranged non-small cell lung cancers

ALK tyrosine kinase inhibitors (TKIs) play a significant role in the treatment of ALK-rearranged non-small cell lung cancer patients.After the significant initial response to ALK-TKIs, the emergence of acquired resistance ultimately occur for all patients. Understanding the origin of resistance mechanisms within a patient is crucial to guide treatment and developing drugs/combinations to circumvent resistance. There are reported that some of the tyrosine kinases are involving by bypassing ALK signaling, but comprehensive identification of proteins that are significant for acquired resistance in ALK-TKIs is still required. Quantitative proteomic analysis provides a powerful approach in screening for alterations in protein levels. An analysis of the differential proteins expression between original cancer cell and acquired resistance cell would be useful for identification of proteins drug resistance. To investigate the changes of chaperon holding proteins, ALK rearranged-cell line H3122 were used. ALK-TKI Alectinib resistant cell lines were established by exposing increased dose of alectinib to ALK rearranged H3122 cell line (AFR). Luminespib (AUY922, Novartis Pharm.) was used as HSP90 inhibitor and Saracatinib (Selleck Chemicals.) was used as Src inhibitor in this study. We used iTRAQ (isobaric tags for relative and absolute quantitation) technology using nano-LC-MS/MS analysis, to identify alterations in H3122 protein levels of pre/post HSP90 inhibitor treatment. For further analysis, protein expression was measured by western blot. To assess the cancer cell growth inhibition for ALK and/or Src inhibitors, we used colony formation assay. Our results revealed that Crk-Src related proteins were overexpressed in ALK TKI resistance cells and had a significant protein expression changes after HSP90 inhibitor treatment. To address the impact of overcoming resistance by blocking Crk-Src pathway, Drugs/combinations with ALK inhibitor and/or Src inhibitors showed that significant treatment effect in vitro and in vivo study using tumor-bearing mouse model. Conclusion Src is one of the significant signaling pathways in the ALK-rearranged NSCLCs resistant to ALK-TKIs including alectinib, and inhibiting Src signaling could be a potential target for ALK-rearranged NSCLC after ALK-TKI resistance. Citation Format: Ryohei Yoshida, Shunsuke Okumura, Takaaki Sasaki, Yoshinobu Osaki. Src mediates acquired resistance to ALK inhibitor in ALK-rearranged non-small cell lung cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2121.