Optimizing Organ Preservation Strategies through Chemotherapy-Based Selection in Esophageal Squamous Cell Carcinoma: Results from the CROC Multi-Institutional Phase II Clinical Trial.

PURPOSE: This study aimed to assess the viability of definitive chemoradiotherapy (dCRT) as an organ-preservation strategy for remarkable responders who were downstaged to stage IA after receiving induction chemotherapy for resectable esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: Chemotherapy-naïve patients with resectable ESCC (stage IB-III, UICC, International Cancer Control 7th edition) were eligible for the study. All patients received three cycles of DCF therapy (docetaxel 75 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1, and 5-fluorouracil [5-FU] 750 mg/m2 on days 1-5, repeated every three weeks). A remarkable response was defined as a reduction of the tumor to T1, metastatic lymph nodes smaller than 1 cm on the short axis, and downstaging to stage IA after three cycles of DCF therapy. Remarkable responders then underwent dCRT, which included two courses of cisplatin 75 mg/m2 and 5-FU 1000 mg/m2 on days 1-4, repeated every four weeks, along with 50.4 Gy of concurrent radiotherapy. The primary endpoint was 1-year progression-free survival (PFS) in remarkable responders following DCF therapy and subsequent dCRT. Secondary endpoints included 3-year overall survival (OS) and esophagectomy-free survival (EFS). RESULTS: Of the 92 patients registered, 90 were analyzed. A remarkable response to three courses of DCF therapy was observed in 58.4% of patients. Among these responders, 89.8% achieved a complete response after dCRT. During the median follow-up period of 33 months (range: 1-85 months), the 1-year PFS was 89.8% (95% confidence interval = 77.2%-95.6%, primary endpoint), and the 3-year OS was 83.7%. The 3-year OS and EFS rates in the analysis group were 74.1% and 45.3%, respectively. An 18F-fluorodeoxyglucose-positron emission tomography response after two courses of DCF therapy was significantly associated with OS (p = 0.0049). CONCLUSIONS: In patients with resectable ESCC, dCRT for remarkable responders downstaging to stage IA after induction chemotherapy with three courses of DCF therapy is a feasible treatment option and provides an optimizing organ-preservation strategy of chemotherapy-based selection.

Dissection of the signal transduction machinery responsible for the lysyl oxidase-like 4-mediated increase in invasive motility in triple-negative breast cancer cells: mechanistic insight into the integrin-ß1-NF-κB-MMP9 axis.

Background: Triple-negative breast cancer (TNBC) cells are a highly formidable cancer to treat. Nonetheless, by continued investigation into the molecular biology underlying the complex regulation of TNBC cell activity, vulnerabilities can be exposed as potential therapeutic targets at the molecular level. We previously revealed that lysyl oxidase-like 4 (LOXL4) promotes the invasiveness of TNBC cells via cell surface annexin A2 as a novel binding substrate of LOXL4, which promotes the abundant localization of integrin-ß1 at the cancer plasma membrane. However, it has yet to be uncovered how the LOXL4-mediated abundance of integrin-ß1 hastens the invasive outgrowth of TNBC cells at the molecular level. Methods: LOXL4-overexpressing stable clones were established from MDA-MB-231 cells and subjected to molecular analyses, real-time qPCR and zymography to clarify their invasiveness, signal transduction, and matrix metalloprotease (MMP) activity, respectively. Results: Our results show that LOXL4 potently promotes the induction of matrix metalloprotease 9 (MMP9) via activation of nuclear factor-κB (NF-κB). Our molecular analysis revealed that TNF receptor-associated factor 4 (TRAF4) and TGF-ß activated kinase 1 (TAK1) were required for the activation of NF-κB through Iκß kinase kinase (IKKα/ß) phosphorylation. Conclusion: Our results demonstrate that the newly identified LOXL4-mediated axis, integrin-ß1-TRAF4-TAK1-IKKα/ß-Iκßα-NF-κB-MMP9, is crucial for TNBC cell invasiveness.

Olanzapine Plus Triple Antiemetic Therapy for the Prevention of Carboplatin-Induced Nausea and Vomiting: A Randomized, Double-Blind, Placebo-Controlled Phase III Trial.

PURPOSE: We evaluated the efficacy and safety of antiemetic therapy with olanzapine, a neurokinin-1 receptor antagonist (RA), a 5-hydroxytryptamine-3 (5-HT3) RA, and dexamethasone for preventing chemotherapy-induced nausea and vomiting in patients receiving carboplatin-containing chemotherapy. PATIENTS AND METHODS: Chemotherapy-naïve patients scheduled to receive carboplatin (AUC ≥5) were randomly assigned to receive either olanzapine 5 mg once daily (olanzapine group) or placebo (placebo group) in combination with aprepitant, a 5-HT3 RA, and dexamethasone. The primary end point was the complete response (CR; no vomiting and no rescue therapy) rate in the overall phase (0-120 hours). Secondary end points included the proportion of patients free of nausea and safety. RESULTS: In total, 355 patients (78.6% male, median age 72 years, 100% thoracic cancer), including 175 and 180 patients in the olanzapine and placebo groups, respectively, were evaluated. The overall CR rate was 86.9% in the olanzapine group versus 80.6% in the placebo group. The intergroup difference in the overall CR rate was 6.3% (95% CI, -1.3 to 13.9). The proportions of patients free of chemotherapy-induced nausea in the overall (88.6% in the olanzapine group v 75.0% in the placebo group) and delayed (89.7% v 75.6%, respectively) phases were significantly higher in the olanzapine group than in the placebo group (both P < .001). Somnolence was observed in 43 (24.6%) and 41 (22.9%) patients in the olanzapine and placebo groups, respectively, and no events were grade ≥3 in severity. CONCLUSION: The addition of olanzapine was not associated with a significant increase in the overall CR rate. Regarding the prevention of nausea, adding olanzapine provided better control in patients receiving carboplatin-containing chemotherapy, which needs further exploration.

Single Amino Acid Substitution in the Matrix Protein of Rabies Virus Is Associated with Neurovirulence in Mice.

Rabies is a fatal encephalitic infectious disease caused by the rabies virus (RABV). RABV is highly neurotropic and replicates in neuronal cell lines in vitro. The RABV fixed strain, HEP-Flury, was produced via passaging in primary chicken embryonic fibroblast cells. HEP-Flury showed rapid adaptation when propagated in mouse neuroblastoma (MNA) cells. In this study, we compared the growth of our previously constructed recombinant HEP (rHEP) strain-based on the sequence of the HEP (HEP-Flury) strain-with that of the original HEP strain. The original HEP strain exhibited higher titer than rHEP and a single substitution at position 80 in the matrix (M) protein M(D80N) after incubation in MNA cells, which was absent in rHEP. In vivo, intracerebral inoculation of the rHEP-M(D80N) strain with this substitution resulted in enhanced viral growth in the mouse brain and a significant loss of body weight in the adult mice. The number of viral antigen-positive cells in the brains of adult mice inoculated with the rHEP-M(D80N) strain was significantly higher than that with the rHEP strain at 5 days post-inoculation. Our findings demonstrate that a single amino acid substitution in the M protein M(D80N) is associated with neurovirulence in mice owing to adaptation to mouse neuronal cells.

Construction of Vero cell-adapted rabies vaccine strain by five amino acid substitutions in HEP-Flury strain.

Rabies virus (RABV) causes fatal neurological disease. Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) using inactivated-virus vaccines are the most effective measures to prevent rabies. In Japan, HEP-Flury, the viral strain, used as a human rabies vaccine, has historically been propagated in primary fibroblast cells derived from chicken embryos. In the present study, to reduce the cost and labor of vaccine production, we sought to adapt the original HEP-Flury (HEP) to Vero cells. HEP was repeatedly passaged in Vero cells to generate ten- (HEP-10V) and thirty-passaged (HEP-30V) strains. Both HEP-10V and HEP-30V grew significantly better than HEP in Vero cells, with virulence and antigenicity similar to HEP. Comparison of the complete genomes with HEP revealed three non-synonymous mutations in HEP-10V and four additional non-synonymous mutations in HEP-30V. Comparison among 18 recombinant HEP strains constructed by reverse genetics and vesicular stomatitis viruses pseudotyped with RABV glycoproteins indicated that the substitution P(L115H) in the phosphoprotein and G(S15R) in the glycoprotein improved viral propagation in HEP-10V, while in HEP-30V, G(V164E), G(L183P), and G(A286V) in the glycoprotein enhanced entry into Vero cells. The obtained recombinant RABV strain, rHEP-PG4 strain, with these five substitutions, is a strong candidate for production of human rabies vaccine.

HNF4α is required for Tkfc promoter activation by ChREBP.

Triokinase/FMN cyclase (Tkfc) is involved in fructose metabolism and is responsible for the phosphorylation of glyceraldehyde to glyceraldehyde-3-phosphate. In this study, we show that refeeding induced hepatic expression of Tkfc in mice. Luciferase reporter gene assays using the Tkfc promoter revealed the existence of two hepatocyte nuclear factor 4α (HNF4α)-responsive elements (HNF4RE1 and HNF4RE2) and one carbohydrate-responsive element-binding protein (ChREBP)-responsive element (ChoRE1). Deletion and mutation of HNF4RE1 and HNF4RE2 or ChoRE1 abolished HNF4α and ChREBP responsiveness, respectively. HNF4α and ChREBP synergistically stimulated Tkfc promoter activity. ChoRE1 mutation attenuated but maintained HNF4α responsiveness, whereas HNF4RE1 and HNF4RE2 mutations abolished ChREBP responsiveness. Moreover, Tkfc promoter activity stimulation by ChREBP was attenuated upon HNF4α knockdown. Furthermore, Tkfc expression was decreased in livers of ChREBP-/- and liver-specific HNF4-/- (Hnf4αΔHep) mice. Altogether, our data indicate that Tkfc is a target gene of ChREBP and HNF4α, and Tkfc promoter activity stimulation by ChREBP requires HNF4α.

Opinions on research involving human embryo models by researchers and the general public.

Rules and ethical considerations regarding research on embryo models have been debated across numerous countries. In this paper, we provide insights from our attitude survey conducted among Japanese researchers, including members of the Japanese Society for Regenerative Medicine, and among the general public residing in Japan, the US, the UK, Canada, and Australia. Our survey revealed that many researchers expressed the need for clear guidelines for embryo model research. Furthermore, a minority but significant portion of the general public in each country expressed opposition to research on embryo models but did not oppose research involving real embryos.

Characterization of BRAFThr599dup Mutation as a Targetable Driver Mutation Identified in Lung Adenocarcinoma by Comprehensive Genomic Profiling.

PURPOSE: Understanding the function of BRAF mutants is crucial for determining the best treatment strategy. This study aimed to characterize a rare BRAF variant, BRAFThr599dup, which was identified in a patient with lung adenocarcinoma (LUAD) by comprehensive genomic profiling. MATERIALS AND METHODS: We report a case of LUAD with BRAFThr599dup treated with dabrafenib and trametinib. We conditionally expressed wild-type BRAF, BRAFV600E, or BRAFThr599dup in Ba/F3 cells and BEAS-2B cells. Ba/F3 cells carrying double-mutant BRAF (BRAFThr599dup/R509H, BRAFV600E/R509H, or BRAFK601E/R509H) that lacked the dimerizing ability were also established. Knockout of endogenous BRAF or CRAF in Ba/F3-BRAFThr599dup cells and Ba/F3-BRAFV600E cells was performed using the CRISPR/Cas9 system. Cell viability, mitogen-activated protein kinase (MAPK) signaling activity, and sensitivity to dabrafenib and trametinib were evaluated. RESULTS: The patient was revealed to have BRAFThr599dup-positive tumor cells as a predominant clone, and dabrafenib and trametinib treatment showed modest efficacy. In Ba/F3 cells, both BRAFThr599dup and BRAFV600E similarly caused interleukin-3-independent proliferation and activated the MAPK pathway. Moreover, BRAFThr599dup and BRAFV600E similarly caused a significant increase in the anchorage-independent growth ability of BEAS-2B cells. Along with Ba/F3-BRAFV600E cells, Ba/F3-BRAFThr599dup cells were highly sensitive to a monomer-specific BRAF inhibitor, dabrafenib, with a half-maximal inhibitory concentration value of 29.7 nM. In the absence of wild-type BRAF, wild-type CRAF, or an intact dimer interface, the ability to induce oncogenic addiction and MAPK pathway activation in Ba/F3-BRAFThr599dup cells was not affected, which was in contrast to the findings in the BRAFK601E/R509H double-mutant model. CONCLUSION: BRAFThr599dup is a potent driver oncogene that activates the MAPK pathway without the requirement for dimerization in vitro. Because BRAFThr599dup has been recurrently reported across various cancer types, our findings should be further investigated both mechanistically and clinically.

Identification and epidemiological study of an uncultured flavivirus from ticks using viral metagenomics and pseudoinfectious viral particles.

During their blood-feeding process, ticks are known to transmit various viruses to vertebrates, including humans. Recent viral metagenomic analyses using next-generation sequencing (NGS) have revealed that blood-feeding arthropods like ticks harbor a large diversity of viruses. However, many of these viruses have not been isolated or cultured, and their basic characteristics remain unknown. This study aimed to present the identification of a difficult-to-culture virus in ticks using NGS and to understand its epidemic dynamics using molecular biology techniques. During routine tick-borne virus surveillance in Japan, an unknown flaviviral sequence was detected via virome analysis of host-questing ticks. Similar viral sequences have been detected in the sera of sika deer and wild boars in Japan, and this virus was tentatively named the Saruyama virus (SAYAV). Because SAYAV did not propagate in any cultured cells tested, single-round infectious virus particles (SRIP) were generated based on its structural protein gene sequence utilizing a yellow fever virus-based replicon system to understand its nationwide endemic status. Seroepidemiological studies using SRIP as antigens have demonstrated the presence of neutralizing antibodies against SAYAV in sika deer and wild boar captured at several locations in Japan, suggesting that SAYAV is endemic throughout Japan. Phylogenetic analyses have revealed that SAYAV forms a sister clade with the Orthoflavivirus genus, which includes important mosquito- and tick-borne pathogenic viruses. This shows that SAYAV evolved into a lineage independent of the known orthoflaviviruses. This study demonstrates a unique approach for understanding the epidemiology of uncultured viruses by combining viral metagenomics and pseudoinfectious viral particles.

Long-term survival and functional outcomes of laparoscopic surgery for clinical stage I ultra-low rectal cancers located within 5 cm of the anal verge: A prospective phase II trial (Ultimate trial).

OBJECTIVE: To clarify the long-term oncological outcomes and postoperative anal, urinary, and sexual functions after laparoscopic surgery for clinical stage I very low rectal carcinoma located near the anal canal. SUMMARY BACKGROUND DATA: Laparoscopic surgery is widely applied for rectal cancer; however, concerns remain, with some studies showing poorer outcomes compared to open surgery. METHODS: This single-arm, phase II trial included patients registered preoperatively from 47 institutions in Japan. The planned sample size was 300. The primary endpoint was the 3-year local recurrence rate. Anal, urinary, and sexual functions were evaluated using a prospective questionnaire. RESULTS: Three-hundred patients were registered between January 2014 and March 2017. Anus-preserving surgery was performed in 278 (93%), including 172 who underwent intersphincteric resection (58%) and 106 (36%) who underwent low anterior resection. The 3-year cumulative local recurrence rate was 6.3%. At 3 years postoperatively, 87% of patients used their own anus, and the median incontinence score improved from 12 at 3 months to 8 at 3 years. Only 5% of patients had severe incontinence (incontinence score of 16 points). Postoperative urinary function evaluation showed that International Prostate Symptom Score and Overactive Bladder Symptom Score decreased 1 week after surgery, but recovered to preoperative level 1 month after surgery. International Consultation on Incontinence Questionnaire-Sort Form remained almost stable after surgery. Sexual function evaluation using the International Index of Erectile Function-5 and International Index of Erectile Function-15 revealed that the patients had deteriorated 3 months after surgery but had recovered only slightly by 6 months. CONCLUSIONS: Laparoscopic surgery achieves feasible long-term oncological outcomes and a high rate of anus preservation with moderate anal function, and an acceptable incontinence score. While urinary function recovered rapidly, sexual function showed poor recovery.

Ex vivo expansion and activation of Vγ9Vδ2 T cells by CELMoDs in combination with zoledronic acid.

As multiple myeloma (MM) progresses, immune effector cells decrease in number and function and become exhausted. This remains an insurmountable clinical issue that must be addressed by development of novel modalities to revitalize anti-MM immunity. Human Vγ9Vδ2 T (Vδ2+ γδ T) cells serve as the first line of defense against pathogens as well as tumors and can be expanded ex vivo from peripheral blood mononuclear cells (PBMCs) upon treatment with amino-bisphosphonates in combination with IL-2. Here, we demonstrated that next-generation immunomodulators called cereblon E3 ligase modulators (CELMoDs), as well as lenalidomide and pomalidomide, expanded Th1-like Vδ2+ γδ T cells from PBMCs in the presence of zoledronic acid (ZA). However, the expansion of Th1-like Vδ2+ γδ T cells by these immunomodulatory drugs was abolished under IL-2 blockade, although IL-2 production was induced in PBMCs. BTN3A1 triggers phosphoantigen presentation to γδ T-cell receptors and is required for γδ T-cell expansion and activation. ZA but not these immunomodulatory drugs upregulated BTN3A1 in monocytes. These results suggest that immunomodulatory drugs and ZA have cooperative roles in expansion of Th1-like Vδ2+ γδ T cells, and provide the important knowledge for clinical application of human Vδ2+ γδ T cells as effector cells.

Lysyl oxidase-like 4 promotes the invasiveness of triple-negative breast cancer cells by orchestrating the invasive machinery formed by annexin A2 and S100A11 on the cell surface.

Background: Our earlier research revealed that the secreted lysyl oxidase-like 4 (LOXL4) that is highly elevated in triple-negative breast cancer (TNBC) acts as a catalyst to lock annexin A2 on the cell membrane surface, which accelerates invasive outgrowth of the cancer through the binding of integrin-ß1 on the cell surface. However, whether this machinery is subject to the LOXL4-mediated intrusive regulation remains uncertain. Methods: Cell invasion was assessed using a transwell-based assay, protein-protein interactions by an immunoprecipitation-Western blotting technique and immunocytochemistry, and plasmin activity in the cell membrane by gelatin zymography. Results: We revealed that cell surface annexin A2 acts as a receptor of plasminogen via interaction with S100A10, a key cell surface annexin A2-binding factor, and S100A11. We found that the cell surface annexin A2/S100A11 complex leads to mature active plasmin from bound plasminogen, which actively stimulates gelatin digestion, followed by increased invasion. Conclusion: We have refined our understanding of the role of LOXL4 in TNBC cell invasion: namely, LOXL4 mediates the upregulation of annexin A2 at the cell surface, the upregulated annexin 2 binds S100A11 and S100A10, and the resulting annexin A2/S100A11 complex acts as a receptor of plasminogen, readily converting it into active-form plasmin and thereby enhancing invasion.

Increased Wnt5a/ROR2 signaling is associated with chondrogenesis in meniscal degeneration.

The aim of the present study was to investigate the association between chondrogenic differentiation and Wnt signal expression in the degenerative process of the human meniscus. Menisci were obtained from patients with and without knee osteoarthritis (OA), and degeneration was histologically assessed using a grading system. Immunohistochemistry, real-time polymerase chain reaction (PCR), and Western blot analysis were performed to examine the expressions of chondrogenic markers and of the components of Wnt signaling. Histological analyses showed that meniscal degeneration involved a transition from a fibroblastic to a chondrogenic phenotype with the upregulation of SOX9, collagen type II, collagen type XI, and aggrecan, which were associated with increased Wnt5a and ROR2 and decreased TCF7 expressions. OA menisci showed significantly higher expressions of Wnt5a and ROR2 and significantly lower expressions of AXIN2 and TCF7 than non-OA menisci on real-time PCR and Western blot analysis. These results potentially demonstrated that increased expression of Wnt5a/ROR2 signaling promoted chondrogenesis with decreased expression in downstream Wnt/ß-catenin signaling. This study provides insights into the role of Wnt signaling in the process of meniscal degeneration, shifting to a chondrogenic phenotype. The findings suggested that the increased expression of Wnt5a/ROR2 and decreased expression of the downstream target of Wnt/ß-catenin signaling are associated with chondrogenesis in meniscal degeneration.

Neutrophil-lymphocyte ratio being associated with mortality risk in patients receiving antifibrotic therapy.

BACKGROUND: Antifibrotic therapy is widely used for patients with progressive fibrotic interstitial lung disease (ILD), regardless of etiology. There is an urgent need for a simple, inexpensive, and repeatable biomarker to evaluate disease severity and mortality risk. METHODS: This retrospective multicohort study assessed the neutrophil-lymphocyte ratios (NLRs) of 416 patients with ILD who received antifibrotic therapy (Hamamatsu cohort, n = 217; Seirei cohort, n = 199). The mortality risk vs. NLR relationship was evaluated at therapy initiation and 1 year. The optimal NLR cutoff of 2.7 was selected according to the mortality risk. RESULTS: Survival was shorter in patients with high NLR than with low NLR (median: 2.63 vs. 4.01 years). The NLR classification results (cutoff: 2.7) were longitudinally preserved in >70 % of the patients, and patients with consistently high NLR had a higher risk of mortality than others (median, 2.97 vs. 4.42 years). In multivariate analysis, high NLR was significantly associated with mortality independent of age, sex, forced vital capacity, lung diffusing capacity for carbon monoxide (DLCO), or the gender-age-physiology (GAP) index. A combined GAP index-NLR assessment classified mortality risk into four groups. Subset analyses revealed that NLR assessment was more applicable to patients without advanced disease, not taking steroids, and with idiopathic pulmonary fibrosis (IPF) than to patients with advanced disease, taking steroids, and patients with Non-IPF. CONCLUSION: High NLR was associated with an increased mortality risk in patients with ILDs receiving antifibrotic therapy. Assessment of NLR may help predict disease severity and mortality risk in antifibrotic therapy.

Radiological and histopathological features and treatment response by subtypes of interstitial pneumonia with autoimmune features: A prospective, multicentre cohort study.

BACKGROUND: Patients with idiopathic interstitial pneumonia (IIP) have a favourable prognosis when they have interstitial pneumonia with autoimmune features (IPAF). However, precise IPAF-related findings from high-resolution computed tomography (HRCT) and lung histopathological specimens and the treatment response have not been fully determined. Therefore, this study was conducted to evaluate the relationship between findings on HRCT or lung histopathological specimens and the progression of interstitial pneumonia in patients with IPAF. METHODS: This multicentre cohort study prospectively enrolled consecutive patients with IIP. At the diagnosis of IIP, we systematically evaluated 74 features suggestive of connective tissue diseases and followed them up. HRCT, lung specimens, serum antibodies, and the clinical course were also evaluated. RESULTS: Among 222 patients with IIP, 26 (11.7%) fulfilled the IPAF criteria. During a median observation period of 36 months, patients with IPAF showed better survival than those without IPAF (p = 0.034). While histopathological findings were not related to IPAF, nonspecific interstitial pneumonia (NSIP) with organizing pneumonia (OP) overlap was the most prevalent HRCT pattern (p < 0.001) and the consolidation opacity was the most common radiological finding in IPAF (p = 0.017). Furthermore, in patients with IPAF, the diagnosis of COP or NSIP with OP overlap was associated with a higher increase in %FVC in 1 year than in those with idiopathic pulmonary fibrosis, NSIP, or unclassifiable IIP (p = 0.002). CONCLUSIONS: This study shows the presence of consolidation opacity on HRCT and the diagnosis of COP or NSIP with OP overlap are associated with IPAF and its favourable treatment response in patients with IPAF.

CD109 Attenuates Bleomycin-induced Pulmonary Fibrosis by Inhibiting TGF-ß Signaling.

Pulmonary fibrosis is a fatal condition characterized by fibroblast and myofibroblast proliferation and collagen deposition. TGF-ß plays a pivotal role in the development of pulmonary fibrosis. Therefore, modulation of TGF-ß signaling is a promising therapeutic strategy for treating pulmonary fibrosis. To date, however, interventions targeting TGF-ß have not shown consistent efficacy. CD109 is a GPI-anchored glycoprotein that binds to TGF-ß receptor I and negatively regulates TGF-ß signaling. However, no studies have examined the role and therapeutic potential of CD109 in pulmonary fibrosis. The purpose of this study was to determine the role and therapeutic value of CD109 in bleomycin-induced pulmonary fibrosis. CD109-transgenic mice overexpressing CD109 exhibited significantly attenuated pulmonary fibrosis, preserved lung function, and reduced lung fibroblasts and myofibroblasts compared with wild-type (WT) mice. CD109-/- mice exhibited pulmonary fibrosis comparable to WT mice. CD109 expression was induced in variety types of cells, including lung fibroblasts and macrophages, upon bleomycin exposure. Recombinant CD109 protein inhibited TGF-ß signaling and significantly decreased ACTA2 expression in human fetal lung fibroblast cells in vitro. Administration of recombinant CD109 protein markedly reduced pulmonary fibrosis in bleomycin-treated WT mice in vivo. Our results suggest that CD109 is not essential for the development of pulmonary fibrosis, but excess CD109 protein can inhibit pulmonary fibrosis development, possibly through suppression of TGF-ß signaling. CD109 is a novel therapeutic candidate for treating pulmonary fibrosis.