Intratumoral injection of hemagglutinating virus of Japan-envelope vector yielded an antitumor effect for advanced melanoma: a phase I/IIa clinical study.

Hemagglutinating virus of Japan (HVJ; Sendai virus) is an RNA virus that has cell fusion activity. HVJ-envelope (HVJ-E) is a UV-irradiated HVJ particle that loses viral replication and protein synthesis activity but retains cell fusion activity. We recently reported that HVJ-E has antitumor effects on several types of tumors. Here, we describe the results of a first-in-human phase I/IIa study in patients with advanced melanoma, receiving intratumoral administration of HVJ-E. The primary aim was to evaluate the safety and tolerability of HVJ-E, and the secondary aim was to examine the objective tumor response and antitumor immunity. Six patients with stage IIIC or IV progressive malignant melanoma with skin or lymph metastasis were enrolled. Patients were separated into two groups (n = 3 each) and received low and high doses of HVJ-E. Five of the six patients completed 4 weeks of follow-up evaluation; one patient discontinued treatment owing to progressive disease. Complete or partial responses were observed in 3 of 6 (50%) injected target lesions, 7 of 15 (47%) noninjected target lesions, and 10 of 21 (48%) target lesions. Induction of antitumor immunity was observed: activation of natural killer cells, a marked increase in interferon-γ levels in the peripheral blood, and infiltration of cytotoxic T cells into both injected and noninjected tumor lesions. Thus, intratumoral injection of HVJ-E in advanced melanoma patients showed safety and tolerability with local regression of the tumor mediated by antitumor immunity. The results suggest that HVJ-E might be a new treatment approach in patients with advanced melanoma.

EGFR tyrosine kinase inhibition worsens acute lung injury in mice with repairing airway epithelium.

RATIONALE: Epidermal growth factor receptor (EGFR) and its ligands play important roles in the regeneration of damaged epithelium and proliferation of various epithelial tumors. Although the EGFR-tyrosine kinase inhibitor gefitinib is effective against advanced non-small cell lung cancer with EGFR mutations, some patients treated with this agent develop severe acute interstitial pneumonia. Characteristics of patients who develop interstitial pneumonia include older age, smoking history, and preexisting interstitial pneumonia suggesting a connection between airway injury and alveolar dysfunction. OBJECTIVES: The purpose of this study was to investigate the effects of gefitinib on airway repair after injury. METHODS: C57BL/6J mice received intraperitoneally naphthalene at Day 0. Gefitinib (20, 90, or 200 mg/kg) was given daily at Days--1 to 13 after naphthalene administration. Bronchoalveolar lavage fluid and lung tissue were obtained at Days 7 and 14. Terminal bronchial epithelial cells from Days 7 and 14 were retrieved with laser capture microdissection, and gene expression analyzed using microarray. MEASUREMENTS AND MAIN RESULTS: Gefitinib treatment after naphthalene prolonged neutrophil sequestration and worsened acute lung injury. We found 17 genes with more than a threefold increase in bronchiolar epithelial cells from mice treated with 200 mg/kg of gefitinib after naphthalene at Day 14 compared with those treated with naphthalene alone. Up-regulated genes included S100A8, S100A6, and StefinA3. These genes are known to participate in neutrophil sequestration, acute inflammation, and airway remodeling. CONCLUSIONS: EGFR inhibition in repairing airway epithelial cells modulated significant expression of genes involved in the airway microenvironment, prolonged inflammation, and potentiated acute lung injury.

Recombinant human erythropoietin reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice.

BACKGROUND AND OBJECTIVE: Erythropoietin (EPO) has recently been demonstrated to have a tissue protective role by acting as an anti-apoptotic agent in various tissues, such as brain, spinal cord, heart and kidney. The purpose of this study was to determine whether human recombinant EPO reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice. METHODS: Bleomycin was instilled intratracheally into C57BL/6 mice. Recombinant human EPO or saline was injected intraperitoneally, daily from day 5 to day 13 after bleomycin instillation. RESULTS: EPO receptor was expressed in bronchiolar and alveolar type II cells. At 14 days after instillation, the number of terminal uridine deoxynucleotidyl transferase nick end-labelled positive cells in the lung was decreased, and the histological degree of inflammation and fibrosis was attenuated in mice injected with EPO compared with controls. Expression of phosphorylated Akt and Erk, which are thought to mediate the survival signalling pathway induced by EPO, tended to be increased in lung tissues from mice treated with EPO compared with those from mice treated with saline after bleomycin instillation. CONCLUSIONS: As it is likely that EPO protects epithelial cells from injury and apoptosis, EPO administration could be a potential therapeutic strategy for the prevention of lung injury.

The role of high mobility group box1 in pulmonary fibrosis.

High mobility group box1 protein (HMGB1) was originally discovered as a nuclear binding protein, and is known to play an important role in acute lung injury. However, the role of HMGB1 in pulmonary fibrosis has not been addressed. Therefore, we measured the HMGB1 levels in serum and bronchoalveolar lavage fluids (BALF) from patients with idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia, interstitial pneumonia associated with collagen vascular diseases, and hypersensitivity pneumonitis (HP) by enzyme-linked immunosorbent assay. We also assessed the HMGB1 expression in bleomycin-induced pulmonary fibrosis in mice, and examined the effect of anti-HMGB1 antibody and ethyl pyluvate, which inhibits the HMGB1 secretion from alveolar macrophages. In addition, we examined the effect of HMGB1 on fibroblast proliferation, apoptosis, and collagen synthesis in vitro. Serum HMGB1 levels were not significantly increased in interstitial lung diseases compared with control subjects. BALF HMGB1 levels were significantly increased in IPF and HP compared with control subjects. HMGB1 protein was predominantly detected in inflammatory cells and hyperplasic epithelial cells in IPF. In bleomycin-induced pulmonary fibrosis in mice, HMGB1 protein was predominantly up-regulated in bronchiolar epithelial cells at early phase and in alveolar epithelial and inflammatory cells in fibrotic lesions at later phase. Intraperitoneal injection of anti-HMGB1 antibody or ethyl pyluvate significantly attenuated lung inflammation and fibrosis in this model. HMGB1 significantly induced proliferation, but not apoptosis or collagen synthesis on cultured fibroblasts. HMGB1 may be a promising target against pulmonary fibrosis as well as acute lung injury.

Dual-immunohistochemistry provides little evidence for epithelial-mesenchymal transition in pulmonary fibrosis.

Epithelial-mesenchymal transition (EMT) has been considered to be involved in organ fibrogenesis. However, there is few direct evidence of this process in the pathophysiology of pulmonary fibrosis in vivo. Therefore, we tried to verify the involvement of this process in the development of pulmonary fibrosis. Since the co-expressions of epithelial and mesenchymal markers are thought to be a marker of EMT, we performed dual-immuunohistochemistry to assess the co-expressions of these proteins in lung tissues from bleomycin-induced pulmonary fibrosis in mice, and from patients with idiopathic pulmonary fibrosis, and nonspecific interstitial pneumonia. Double positive cells for epithelial markers including E-cadherin, T1alpha, or aquaporin 5, and a mesenchymal markers alpha-smooth muscle actin or vimentin were not found in bleomycin-induced pulmonary fibrosis in mice. Double positive cells for E-cadherin, ICAM-1, LEA, CD44v9, or SP-A and alpha-smooth muscle actin or vimentin were not found in lung tissues from normal lung parenchyma, idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia. These results offer at least two possibilities. One is that EMT does not occur in IPF or bleomycin-induced pulmonary fibrosis in mice. Another is that EMT may occur in pulmonary fibrosis but the time during this transition in which cells express detectable levels of epithelial and mesenchymal markers is too small to be detected by double immunohistochemistry.

Gene transfer of soluble transforming growth factor type II receptor by in vivo electroporation attenuates lung injury and fibrosis.

BACKGROUND: Transforming growth factor-beta1 (TGF-beta1) has the potential to induce acute inflammation and apoptosis in lung epithelial cells and plays a central role in subsequent fibrosis. AIMS: To examine a new anti-TGF-beta1 therapy against lung injury and fibrosis, which comprises the transfection of soluble TGF type II receptor (sTGFRII) gene into skeletal muscles by in vivo electroporation. METHODS: Soluble TGFRII was detectable between 1 and 14 days in the serum and significantly increased between 3 and 10 days after gene transfer into muscles. Based on these findings, the sTGFRII gene was injected at 3 days before or 4 days after the bleomycin instillation in order to examine the significance of TGF-beta1 on the early inflammatory phase (day 0 to day 7) or the fibrotic phase (day 7 to day 14) in this model. RESULTS: Transfection of sTGFRII gene at 3 days before or 4 days after bleomycin instillation significantly attenuated apoptosis, injury, and fibrosis at 7 or 14 days, respectively. This method does not require the use of viral vector or neutralising antibody, and it is therefore possible to avoid problems regarding the pathogenicity of the viral vector or immunocomplex. CONCLUSIONS: This novel anti-TGF-beta1 strategy may have clinical application in the treatment of lung injury and fibrosis.

Anti-vascular endothelial growth factor gene therapy attenuates lung injury and fibrosis in mice.

Vascular endothelial growth factor (VEGF) is an angiogenesis factor with proinflammatory roles. Flt-1 is one of the specific receptors for VEGF, and soluble flt-1 (sflt-1) binds to VEGF and competitively inhibits it from binding to the receptors. We examined the role of VEGF in the pathophysiology of bleomycin-induced pneumopathy in mice, using a new therapeutic strategy that comprises transfection of the sflt-1 gene into skeletal muscles as a biofactory for anti-VEGF therapy. The serum levels of sflt-1 were significantly increased at 3-14 days after the gene transfer. Transfection of the sflt-1 gene at 3 days before or 7 days after the intratracheal instillation of bleomycin decreased the number of inflammatory cells, the protein concentration in the bronchoalveolar lavage fluid and with von Willebrand factor expression at 14 days. Transfection of the sflt-1 gene also attenuated pulmonary fibrosis and apoptosis at 14 days. Since the inflammatory cell infiltration begins at 3 days and is followed by interstitial fibrosis, it is likely that VEGF has important roles as a proinflammatory, a permeability-inducing, and an angiogenesis factor not only in the early inflammatory phase but also in the late fibrotic phase. Furthermore, this method may be beneficial for treating lung injury and fibrosis from the viewpoint of clinical application, since it does not require the use of a viral vector or neutralizing Ab.