Efferocytosis by bone marrow mesenchymal stromal cells disrupts osteoblastic differentiation via mitochondrial remodeling

The efficient clearance of dead and dying cells, efferocytosis, is critical to maintain tissue homeostasis. In the bone marrow microenvironment (BMME), this role is primarily fulfilled by professional bone marrow macrophages, but recent work has shown that mesenchymal stromal cells (MSCs) act as a non-professional phagocyte within the BMME. However, little is known about the mechanism and impact of efferocytosis on MSCs and on their function. To investigate, we performed flow cytometric analysis of neutrophil uptake by ST2 cells, a murine bone marrow-derived stromal cell line, and in murine primary bone marrow-derived stromal cells. Transcriptional analysis showed that MSCs possess the necessary receptors and internal processing machinery to conduct efferocytosis, with Axl and Tyro3 serving as the main receptors, while MerTK was not expressed. Moreover, the expression of these receptors was modulated by efferocytic behavior, regardless of apoptotic target. MSCs derived from human bone marrow also demonstrated efferocytic behavior, showing that MSC efferocytosis is conserved. In all MSCs, efferocytosis impaired osteoblastic differentiation. Transcriptional analysis and functional assays identified downregulation in MSC mitochondrial function upon efferocytosis. Experimentally, efferocytosis induced mitochondrial fission in MSCs. Pharmacologic inhibition of mitochondrial fission in MSCs not only decreased efferocytic activity but also rescued osteoblastic differentiation, demonstrating that efferocytosis-mediated mitochondrial remodeling plays a critical role in regulating MSC differentiation. This work describes a novel function of MSCs as non-professional phagocytes within the BMME and demonstrates that efferocytosis by MSCs plays a key role in directing mitochondrial remodeling and MSC differentiation. Efferocytosis by MSCs may therefore be a novel mechanism of dysfunction and senescence. Since our data in human MSCs show that MSC efferocytosis is conserved, the consequences of MSC efferocytosis may impact the behavior of these cells in the human skeleton, including bone marrow remodeling and bone loss in the setting of aging, cancer and other diseases.

Vitamin D Receptor Antagonist MeTC7 Inhibits PD-L1

Small-molecule inhibitors of PD-L1 are postulated to control immune evasion in tumors similar to antibodies that target the PD-L1/PD-1 immune checkpoint axis. However, the identity of targetable PD-L1 inducers is required to develop small-molecule PD-L1 inhibitors. In this study, using chromatin immunoprecipitation (ChIP) assay and siRNA, we demonstrate that vitamin D/VDR regulates PD-L1 expression in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) cells. We have examined whether a VDR antagonist, MeTC7, can inhibit PD-L1. To ensure that MeTC7 inhibits VDR/PD-L1 without off-target effects, we examined competitive inhibition of VDR by MeTC7, utilizing ligand-dependent dimerization of VDR-RXR, RXR-RXR, and VDR-coactivators in a mammalian 2-hybrid (M2H) assay. MeTC7 inhibits VDR selectively, suppresses PD-L1 expression sparing PD-L2, and inhibits the cell viability, clonogenicity, and xenograft growth of AML cells. MeTC7 blocks AML/mesenchymal stem cells (MSCs) adhesion and increases the efferocytotic efficiency of THP-1 AML cells. Additionally, utilizing a syngeneic colorectal cancer model in which VDR/PD-L1 co-upregulation occurs in vivo under radiation therapy (RT), MeTC7 inhibits PD-L1 and enhances intra-tumoral CD8+T cells expressing lymphoid activation antigen-CD69. Taken together, MeTC7 is a promising small-molecule inhibitor of PD-L1 with clinical potential.

Tfl deletion induces extraordinary Cxcl13 secretion and cachexia in VavP-Bcl2 transgenic mice

STATEMENT OF SIGNIFICANCE

Loss of TFL, found in several types of lymphoma, induces excessive CXCL13 secretion through RNA dysregulation contributing to body weight loss and early death in lymphoma model mice. Follicular lymphoma (FL) is associated with overexpressed BCL-2 and other genetic aberrations, including 6q-. We identified a novel gene on 6q25, "Transformed follicular lymphoma (TFL)," from a transformed FL. TFL regulates several cytokines via mRNA degradation, which has been suggested to underlie resolving inflammation. Fluorescence in situ hybridization revealed a deletion of TFL occurred in 13.6% of various B-cell lymphoma samples. We developed VavP-bcl2 transgenic, TFL deficit mice (Bcl2-Tg/Tfl -/-) to seek how TFL affects disease progression in this lymphoma model. While Bcl2-Tg mice developed lymphadenopathy and died around 50 weeks, Bcl2-Tg/Tfl -/- mice lost body weight around 30 weeks and died about 20 weeks earlier than Bcl2-Tg mice. Furthermore, we found a unique B220-IgM+ cell population in the bone marrow of Bcl2-Tg mice. cDNA array in this population revealed that Cxcl13 mRNA in Bcl2-Tg/Tfl -/- mice expressed significantly higher than Bcl2-Tg mice. In addition, bone marrow extracellular fluid and serum showed an extremely high Cxcl13 concentration in Bcl2-Tg/Tfl -/- mice. Among bone marrow cells, the B220-IgM+ fraction was the main producer of Cxcl13 in culture. A reporter assay demonstrated TFL regulates CXCL-13 via induction of 3'UTR mRNA degradation in B lineage cells. These data suggest Tfl regulates Cxcl13 in B220-IgM+ cells in the bone marrow, and a very high concentration of serum Cxcl13 arising from these cells may contribute to early death in lymphoma-bearing mice. Since several reports have suggested the association of CXCL13 expression with lymphoma, these findings provide new insights into cytokine regulation via TFL in lymphoma.

Mitochondrial Transfer to Host Cells from Ex Vivo Expanded Donor Hematopoietic Stem Cells

Mitochondrial dysfunction is observed in various conditions, from metabolic syndromes to mitochondrial diseases. Moreover, mitochondrial DNA (mtDNA) transfer is an emerging mechanism that enables the restoration of mitochondrial function in damaged cells. Hence, developing a technology that facilitates the transfer of mtDNA can be a promising strategy for the treatment of these conditions. Here, we utilized an ex vivo culture of mouse hematopoietic stem cells (HSCs) and succeeded in expanding the HSCs efficiently. Upon transplantation, sufficient donor HSC engraftment was attained in-host. To assess the mitochondrial transfer via donor HSCs, we used mitochondrial-nuclear exchange (MNX) mice with nuclei from C57BL/6J and mitochondria from the C3H/HeN strain. Cells from MNX mice have C57BL/6J immunophenotype and C3H/HeN mtDNA, which is known to confer a higher stress resistance to mitochondria. Ex vivo expanded MNX HSCs were transplanted into irradiated C57BL/6J mice and the analyses were performed at six weeks post transplantation. We observed high engraftment of the donor cells in the bone marrow. We also found that HSCs from the MNX mice could transfer mtDNA to the host cells. This work highlights the utility of ex vivo expanded HSC to achieve the mitochondrial transfer from donor to host in the transplant setting.

Myelodysplastic syndromes disable human CD271+VCAM1+CD146+ niches supporting normal hematopoietic stem/progenitor cells

Mesenchymal stem/stromal cells (MSCs) within the bone marrow microenvironment (BMME) support normal hematopoietic stem and progenitor cells (HSPCs). However, the heterogeneity of human MSCs has limited the understanding of their contribution to clonal dynamics and evolution to myelodysplastic syndromes (MDS). We combined three MSC cell surface markers, CD271, VCAM-1 (Vascular Cell Adhesion Molecule-1) and CD146, to isolate distinct subsets of human MSCs from bone marrow aspirates of healthy controls (Control BM). Based on transcriptional and functional analysis, CD271+CD106+CD146+ (NGFR+/VCAM1+/MCAM+/Lin-; NVML) cells display stem cell characteristics, are compatible with murine BM-derived Leptin receptor positive MSCs and provide superior support for normal HSPCs. MSC subsets from 17 patients with MDS demonstrated shared transcriptional changes in spite of mutational heterogeneity in the MDS clones, with loss of preferential support of normal HSPCs by MDS-derived NVML cells. Our data provide a new approach to dissect microenvironment-dependent mechanisms regulating clonal dynamics and progression of MDS.

Abstract 74: Osteoblasts efferocytosis in bone marrow microenvironment induces osteoblasts’ senescence and apoptosis

Increased cellular apoptosis is commonly seen in myelodysplastic syndrome (MDS), but how clearance of apoptotic cells, especially neutrophils, impacts disease progression is unknown. Moreover, while dysfunction of bone marrow (BM) stromal cell populations has been described in patients with MDS, the mechanisms inducing stromal defects are not well understood. Our laboratory found that BM macrophages are defective in a murine model of MDS (Vav-Nup98 HoxD13, aka NHD13), with decreased efferocytotic rates and increased inflammatory mediators. The increased apoptotic burden and defective macrophages would be expected to recruit non-professional phagocytes (osteoblasts) in the bone and bone marrow. Based on these data, we hypothesize that OBs (osteoblasts) participate in the clearance of apoptotic cells in the bone marrow microenvironment (BMME) to maintain BM homeostasis. However, the increased osteoblastic efferocytosis burden in MDS contributes to OBs’ dysfunction as a mechanism of MDS-dependent BMME disruption that may lead to MDS progression.

We isolated from wild-type (B6) mice bone-associated cells (BAC), which are enriched with OBs. In vitro co-culture with labeled human end-stage neutrophils at 1:1 and 1:10 (OB: PMN) increased OB apoptosis, while senescence was increased only in high-dose PMN co-culture. We found that these changes were cell-autonomous. In vivo injection of neutrophils into WT mice showed around 5-10% efferocytosis rate in OBs. In efferocytotic OBs, apoptosis rates were significantly increased. Together, these data show that OBs participate in efferocytosis and that efferocytosis disrupts OBs, causing apoptosis and senescence.

To mimic the MDS microenvironment, we used a genetic model where one of the Isocitrate dehydrogenase 2 (IDH2) mutations found in MDS (R140Q) is targeted to hematopoietic cells via the Vav promoter (IDH2R140Q mice) as well as NHD13 mice, representing early and late MDS BMME respectively. We observed that 6-to-8 months old NHD13 mice experienced more end-stage neutrophils[CL1] in the BMME (4.6% rate of end-stage neutrophils in WT compared to 9.5% rate in NHD13 mice), where OB apoptosis was also increased in vivo. In IDH2R140Q mice at 3 months of age, we confirmed the presence of mutated IDH2 in bone marrow cells by increased intracellular levels of the oncometabolite 2-hydroxyglutarate. At this early time point, IDH2R140Q mice did not have increased rates of apoptosis in CD45+ cells, and we found no increase in OB apoptosis. Analysis of IDH2R140Q mice at later time points is ongoing.

Our data identify novel mechanisms to explain the relationship between defective myeloid cells and OB apoptosis in MDS that may contribute to the inflammatory MDS microenvironment, impact disease progression, and serve as future therapeutic approaches for MDS patients.

Citation Format: Chunmo Chen, Emily R. Quarato, Yuko Kawano, Noah A. Salama, Hiroki Kawano, Michael W. Becker, Jeevisha Bajaj, Laura Calvi. Osteoblasts efferocytosis in bone marrow microenvironment induces osteoblasts’ senescence and apoptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 74.

Dersimelagon, a novel oral melanocortin 1 receptor agonist, demonstrates disease-modifying effects in preclinical models of systemic sclerosis

Background

Activation of melanocortin 1 receptor (MC1R) is known to exert broad anti-inflammatory and anti-fibrotic effects. The purpose of this study is to investigate the potential of dersimelagon, a novel oral MC1R agonist, as a therapeutic agent for systemic sclerosis (SSc).

Methods

The effects of dersimelagon phosphoric acid (MT-7117) on skin fibrosis and lung inflammation were evaluated in bleomycin (BLM)-induced SSc murine models that were optimized for prophylactic and therapeutic evaluation. Microarray-based gene expression analysis and serum protein profiling were performed in the BLM-induced SSc models. The effect of MT-7117 on transforming growth factor-β (TGF-β)-induced activation of human dermal fibroblasts was evaluated in vitro. Immunohistochemical analyses of MC1R expression in the skin of SSc patients were performed.

Results

Prophylactic treatment with MT-7117 (≥ 0.3 mg/kg/day p.o.) significantly inhibited skin fibrosis and lung inflammation, and therapeutic treatment with MT-7117 (≥ 3 mg/kg/day p.o.) significantly suppressed the development of skin fibrosis in the BLM-induced SSc models. Gene array analysis demonstrated that MT-7117 exerts an anti-inflammatory effect via suppression of the activation of inflammatory cells and inflammation-related signals; additionally, vascular dysfunction was extracted as the pathology targeted by MT-7117. Serum protein profiling revealed that multiple SSc-related biomarkers including P-selectin, osteoprotegerin, cystatin C, growth and differentiation factor-15, and S100A9 were suppressed by MT-7117. MT-7117 inhibited the activation of human dermal fibroblasts by suppressing TGF-β-induced ACTA2 (encoding α-smooth muscle actin) mRNA elevation. MC1R was expressed by monocytes/macrophages, neutrophils, blood vessels (endothelial cells), fibroblasts, and epidermis (keratinocytes) in the skin of SSc patients, suggesting that these MC1R-positive cells could be targets for MT-7117.

Conclusions

MT-7117 demonstrates disease-modifying effects in preclinical models of SSc. Investigations of its mechanism of action and target expression analyses indicate that MT-7117 exerts its positive effect by affecting inflammation, vascular dysfunction, and fibrosis, which are all key pathologies of SSc. The results of the present study suggest that MT-7117 is a potential therapeutic agent for SSc. A phase 2 clinical trial investigating the efficacy and tolerability of MT-7117 in patients with early, progressive diffuse cutaneous SSc is currently in progress.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02899-3.

POS0467 DERSIMELAGON, A NOVEL ORAL MELANOCORTIN 1 RECEPTOR AGONIST, DEMONSTRATES DISEASE-MODIFYING EFFECTS IN PRECLINICAL MODELS OF SYSTEMIC SCLEROSIS

Background

Activation of melanocortin 1 receptor (MC1R) is known to have broad anti-inflammatory and anti-fibrotic effects. The bleomycin (BLM)-induced skin fibrosis murine model is well-established for systemic sclerosis (SSc). α-melanocyte-stimulating hormone, an endogenous ligand of MC1R, inhibits skin fibrosis and MC1R knock-out enhances skin fibrosis in this model. These pieces of evidence suggest that MC1R agonism has potential in the treatment of SSc.

Objectives

Dersimelagon phosphate (MT-7117) is an investigational small molecule that is an orally administered, selective agonist for MC1R. The purpose of this study is to investigate the potential of MT-7117 as a therapeutic agent for SSc by evaluating its efficacy and mechanism of action in complementary preclinical models. The expression and distribution of MC1R in the skin of SSc patients was investigated.

Methods

The effects of MT-7117 on skin fibrosis and lung inflammation were evaluated in BLM-induced SSc murine models that were optimized for prophylactic and therapeutic evaluation. Microarray-based gene expression analysis and serum protein profiling were performed to investigate the mechanism of action of MT-7117 in the BLM-induced SSc models. The effect of MT-7117 on TGF-β-induced activation of human dermal fibroblasts was evaluated in vitro. Immunohistochemical analyses of MC1R expression in skin samples from SSc patients were performed.

Results

Prophylactic treatment with MT-7117 (≥0.3 mg/kg/day p.o.) significantly inhibited the increase in collagen content of the skin, the serum level of surfactant protein D, and the weight of the lungs from BLM-induced skin fibrosis and lung inflammation model. Therapeutic treatment with MT-7117 (≥3 mg/kg/day p.o.) significantly suppressed skin thickening and the numbers of myofibroblasts in pre-established BLM-induced skin fibrosis model. Gene array analysis using the BLM-induced SSc model demonstrated changes in numerous categories related to macrophages, monocytes, and neutrophils, followed by endothelial cell-related categories after treatment with MT-7117. In the analysis that focused on biological functions, categories of inflammatory response, activation of antigen-presenting cells, angiogenesis, atherosclerosis, vasculogenesis, and vaso-occlusion were suppressed by MT-7117. In the analysis that focused on molecular signaling pathways, triggering receptor expressed on myeloid cells-1, IL-6, and oncostatin M involved in inflammation, and peroxisome proliferator-activated receptor that is related to fibrosis were all affected by MT-7117. Serum protein profiling using BLM-induced SSc model revealed that multiple SSc-related biomarkers including P-selectin, osteoprotegerin, cystatin C, growth and differentiation factor-15 and S100A9 were suppressed by MT-7117. MT-7117 inhibited the activation of human dermal fibroblasts by suppressing TGF-β-induced ACTA2 (encoding α-smooth muscle actin) mRNA elevation in vitro. Immunohistochemical analyses showed that MC1R positivity was observed in 40 of 50 diffuse cutaneous SSc patients. MC1R was expressed by monocytes/macrophages, neutrophils, blood vessels (endothelial cells), fibroblasts, and epidermis (keratinocytes) in the skin of SSc patients.

Conclusion

MT-7117 demonstrates disease-modifying effects in preclinical models of SSc. Investigations of its mechanism of action and target expression analyses indicate that MT-7117 exerts its positive effects by affecting the pathologies of inflammation, vascular dysfunction, and fibrosis through inflammatory cells, endothelial cells, and fibroblasts. In view of its potent beneficial impact on all these three main pathologies of SSc, MT-7117 is a potential therapeutic agent for the treatment of clinically challenging SSc, which has diverse and difficult to treat symptoms. A phase 2 clinical trial investigating the efficacy and tolerability of MT-7117 in patients with early, progressive diffuse cutaneous SSc is currently in progress.

Disclosure of Interests

Masahiro Kondo Employee of: Mitsubishi Tanabe Pharma Corporation, Tsuyoshi Suzuki Employee of: Mitsubishi Tanabe Pharma Corporation, Yuko Kawano Employee of: Mitsubishi Tanabe Pharma Corporation, Shinji Kojima Employee of: Mitsubishi Tanabe Pharma Corporation, Masahiko Miyashiro Employee of: Mitsubishi Tanabe Pharma Corporation, Atsuhiro Matsumoto Employee of: Mitsubishi Tanabe Pharma Corporation, Gabriela Kania: None declared, Przemyslaw Blyszczuk: None declared, rebecca ross: None declared, Panji Mulipa: None declared, Francesco Del Galdo Grant/research support from: Prof. F. Del Galdo received fees and research support from Abbvie, AstraZeneca, Boehringer-Ingelheim, Capella, Chemomab, Kymab, Janssen and Mitsubishi-Tanabe., Yun Zhang: None declared, Jörg H.W. Distler Grant/research support from: Prof. J.H.W. Distler received consulting fees, lecture fees, and/or honoraria from Actelion, Active Biotech, Anamar, ARXX, aTyr, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, Sanofi-Aventis, RedX, RuiYi and UCB. J. H. W. Distler is stock owner of 4D Science and Scientific head of FibroCure.

Melanogenic effect of dersimelagon (MT-7117), a novel oral melanocortin 1 receptor agonist

Background

The activation of melanocortin 1 receptor (MC1R) on melanocytes stimulates the production of eumelanin. A tridecapeptide α melanocyte‐stimulating hormone (αMSH) is known to induce skin pigmentation.

Objectives

We characterised the properties of a novel oral MC1R agonist dersimelagon (MT‐7117) with respect to its specific binding to MC1R, downstream signalling and eumelanin production in experimental models.

Methods

The competitive binding and production of intracellular cyclic adenosine 3′, 5′‐monophosphate in cells expressing recombinant melanocortin receptors were examined. A mouse melanoma cell line B16F1 was used for the evaluation of in vitro melanin production. The in vitro activity of MT‐7117 was determined with αMSH and [Nle⁴, D‐Phe⁷]‐αMSH (NDP‐αMSH) as reference comparators. The change of coat colour and skin pigmentation were evaluated after repeat administration of MT‐7117 by oral gavage to C57BL/6J‐A^y/+ mice and cynomolgus monkeys, respectively.

Results

MT‐7117 showed the highest affinity for human MC1R compared to the other melanocortin receptors evaluated and agonistic activity for human, cynomolgus monkey and mouse MC1R, with EC₅₀ values in the nanomolar range. In B16F1 cells, MT‐7117 increased melanin production in a concentration‐dependent manner. In vivo, MT‐7117 (≥0.3 mg/kg/day p.o.) significantly induced coat colour darkening in mice. MT‐7117 (≥1 mg/kg/day p.o.) induced significant skin pigmentation in monkeys and complete reversibility was observed after cessation of its administration.

Conclusions

MT‐7117 is a novel oral MC1R agonist that induces melanogenesis in vitro and in vivo, suggesting its potential application for the prevention of phototoxic reactions in patients with photodermatoses, such as erythropoietic protoporphyria and X‐linked protoporphyria.

[A Case of Liver Abscess during Treatment for Abemaciclib-Induced Interstitial Lung Disease]

The patient was a 64-year-old woman. The patient was operated for left breast cancer(pT2N0M0, stage ⅡA, Luminal A). Eight years after surgery, CT findings revealed lung metastasis in the S8 and S9 areas of the left lung. The patient was treated with a combination of abemaciclib and letrozole, which resulted in a partial response(PR). One year after treatment, the lung metastases remained small, but multiple interstitial shadows appeared in both lower lung fields. The patient was diagnosed with drug-induced interstitial lung disease(Grade 1), and abemaciclib withdrawal and steroid therapy were initiated. After 3 months of treatment with prednisolone at 30 mg/day, the interstitial shadows tended to improve on CT, but a liver abscess was found in the S8 area of the right lobe of the liver. Prednisolone was tapered and abemaciclib was resumed at a dose of 200 mg/day, resulting in scarring of the lung injury and resolution of the liver abscess. The patient's PR was maintained for 18 months after relapse. We report a case of liver abscess during treatment of abemaciclib-induced interstitial lung disease.

IgG4-related mastitis requiring differentiation from breast cancer: a case report

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a group of chronic relapsing inflammatory conditions. Although IgG4-RD can occur in various organs, it is rarely observed in mammary glands. Here, we report a case of IgG4-related mastitis (IgG4-RM) that needed to be differentiated from breast cancer. A 54-year-old woman was examined for a tumor in her left breast. Mammary ultrasonography revealed an irregular hypoechoic tumor measuring 45.0 × 43.0 × 32.0 mm in size. A core-needle biopsy of the left breast tissue revealed a high degree of mixed T and B lymphocytic and plasma cell infiltration, as well as interstitial fibrosis. IgG4-RD was diagnosed based on hematological examination that revealed an abnormal IgG4 value of 332 mg/dl. All the clinical diagnostic criteria for IgG4 were met, resulting in a definitive diagnosis of IgG4-RM.

[Experience with BD EleVationTM in Vacuum-Assisted Biopsy]

For qualitative diagnosis of breast mass, core needle biopsy(CNB)and fine-needle aspiration biopsy cytology(FNAC)are widely used. Overseas, vacuum-assisted biopsy(VAB)is often the first choice for qualitative diagnosis, and its proper use has become a clinical issue. In addition, with the progress of diagnostic imaging in recent years, the chances of finding micro-lesions such as ductal carcinoma in situ(DCIS)are increasing. Since a sufficient amount of tissue sample is required for these diagnoses and abundant biopsy materials are required, tissue biopsy by VAB may be desirable. The advantage of tissue biopsy with VAB is that accurate definitive diagnosis is possible by collecting a sufficient amount of tissue to obtain pretreatment tissue information. On the other hand, there is concern that patient stress may occur, such as hematoma formation after puncture and invasion by a thick puncture needle. It is lightweight and has an ergonomic design that provides stable grip. New technological innovations in this device may contribute to the reduction of patient stress, and are expected to be used in the future. We outline the experience of using BD EleVationTM in breast suction tissue biopsy at our institution.

Pathological Complete Response following Neoadjuvant Chemotherapy in Invasive Ductal Carcinoma with Mammary Paget's Disease: A Case Report

Mammary Paget's disease is a rare malignancy. Mastectomy or breast-conserving surgery has been considered as the standard treatment, while there have been few reports of neoadjuvant chemotherapy (NAC). A 53-year-old woman with erythema and skin ulceration of the left breast was admitted to our institution. Breast examinations revealed left invasive ductal carcinoma (cT1bN0M0, cStage I), and a punch biopsy of the left mammary erythema indicated Paget's disease (cTisN0M0, cStage0). The patient received NAC because of multiple lesions. Consequently, the breast tumor clinically disappeared, and the erythema improved. These outcomes made it easier to perform surgery (left mastectomy and sentinel node biopsy). Histopathological examination revealed no residual cancer cells in either the mammary gland or breast skin, and no metastasis was found in the sentinel lymph node. Therefore, NAC may be a useful treatment for mammary Paget's disease.

Mobilization efficiency is critically regulated by fat via marrow PPARδ

The mobilization efficiency of hematopoietic stem/progenitor cells from bone marrow (BM) to circulation by granulocyte colony-stimulating factor (G-CSF) is dramatically dispersed in humans and mice with no mechanistic lead for poor mobilizers. The regulatory mechanism for mobilization efficiency by dietary fat was assessed in mice. Fat-free diet (FFD) for 2 weeks greatly increased mobilization compared to normal diet (ND). The BM mRNA level of peroxisome proliferator-activated receptor δ (PPARδ), a receptor for lipid mediators, was markedly up-regulated by G-CSF in mice fed with ND and displayed strong positive correlation with widely scattered mobilization efficiency. It was hypothesized that BM fat ligand for PPARδ might inhibit mobilization. The PPARδ agonist inhibited mobilization in mice fed with ND and enhanced mobilization by FFD. Treatment with the PPARδ antagonist and chimeric mice with PPARδ+/- BM showed enhanced mobilization. Immunohistochemical staining and flow cytometry revealed that BM PPARδ expression was enhanced by G-CSF mainly in mature/immature neutrophils. BM lipid mediator analysis revealed that G-CSF treatment and FFD resulted in the exhaustion of ω3-polyunsaturated fatty acids such as eicosapentaenoic acid (EPA). EPA induced the up-regulation of genes downstream of PPARδ, such as carnitine palmitoyltransferase-1α and angiopoietin-like protein 4 (Angptl4), in mature/immature neutrophils in vitro and inhibited enhanced mobilization in mice fed with FFD in vivo. Treatment of wild-type mice with the anti-Angptl4 antibody enhanced mobilization together with BM vascular permeability. Collectively, PPARδ signaling in BM mature/immature neutrophils induced by dietary fatty acids negatively regulates mobilization, at least partially, via Angptl4 production.

FGF-23 from erythroblasts promotes hematopoietic progenitor mobilization

Fibroblast growth factor 23 (FGF-23) hormone is produced by bone-embedded osteocytes and regulates phosphate homeostasis in kidneys. We found that administration of granulocyte colony-stimulating factor (G-CSF) to mice induced a rapid, substantial increase in FGF-23 messenger RNA in bone marrow (BM) cells. This increase originated mainly from CD45-Ter119+CD71+ erythroblasts. FGF-23 protein in BM extracellular fluid was markedly increased during G-CSF-induced hematopoietic progenitor cell (HPC) mobilization, but remained stable in the blood, with no change in the phosphate level. Consistent with the BM hypoxia induced by G-CSF, low oxygen concentration induced FGF-23 release from human erythroblast HUDEP-2 cells in vitro. The efficient mobilization induced by G-CSF decreased drastically in both FGF-23-/- and chimeric mice with FGF-23 deficiency, only in hematopoietic cells, but increased in osteocyte-specific FGF-23-/- mice. This finding suggests that erythroblast-derived, but not bone-derived, FGF-23 is needed to release HPCs from BM into the circulation. Mechanistically, FGF-23 did not influence CXCL-12 binding to CXCR-4 on progenitors but interfered with their transwell migration toward CXCL-12, which was canceled by FGF receptor inhibitors. These results suggest that BM erythroblasts facilitate G-CSF-induced HPC mobilization via FGF-23 production as an intrinsic suppressor of chemoattraction.

[Effectiveness of Atezolizumab Combination Therapy for PD-L1(SP142)Positive Lung and Breast Double Cancer-A Case Report]

The anti-PD-L1 antibody atezolizumab has become the standard of immunochemotherapy with the results of the international phase Ⅲ trials in lung cancer and breast cancer. We report a case in which atezolizumab was efficiency in PD-L1 (SP142)-positive lung and breast double cancer. A 56-years-old woman. She noticed a lump in her right breast and visited a nearby doctor, who referred her to our hospital for close examination and treatment. Ultrasonography revealed about 5 cm mass on the right mammary gland and axillary lymph nodes swelling. Core-needle biopsy was confirmed invasive ductal carcinoma( ER negative, PgR negative, HER2 negative, Ki-67 high expression). CT findings showed right mammary mass, right axillary lymph nodes swelling, liver mass, and lung tumor with mediastinal lymph nodes swelling. Therefore, a bronchoscopic biopsy was performed and a diagnosis of primary lung cancer was obtained. Pretreatment diagnosis was lung adenocarcinoma, cT2a, N2/3, M1b/1c(HEP, OSS), Stage ⅢA/B or ⅣA/B(PD-L1 positive), and right breast cancer, T4b, N2, M0/1 (HEP, OSS, LYM), Stage ⅢB or Ⅳ triple-negative(PD-L1 positive)double cancer. We underwent surgery(mastectomy with axillar lymph nodes dissection), followed by immunochemotherapy(atezolizumab, carboplatin, paclitaxel)and it was efficiency.

[A Case of Dermatitis Caused by Metronidazole Gel That Needed to Be Differentiated from Breast Cancer Skin Metastasis]

Seventy years old woman noticed a mass in her right breast before 3 years. Since she had ulcer bleeding, she visited our hospital. In physical findings, a hemorrhagic about 8 cm mass with an ulcer was found in the upper right breast. Breast ultrasonography revealed a large tumor of approximately 8 cm in the right A area, and needle biopsy revealed invasive ductal carcinoma(ER positive, PgR positive, HER2 positive, Ki-67 low expression). Right axillary lymph node metastasis was confirmed, but no clear distant metastasis was observed. Pretreatment diagnosis was right breast cancer, cT4bN1M0, Stage ⅢB, Luminal HER. Chemotherapy was started with pertuzumab, trastuzumab, and docetaxel, and the tumor was reduced after 6 cycles. Due to side effects, the drug was changed to a molecular targeted drug only and the treatment was continued. However, redness was observed in the entire right breast, and breast cancer skin metastasis was suspected. Since the dermatitis caused by metronidazole gel was also distinguished, the redness was improved when the application was stopped. When confirmed by a patch test, a reaction to metronidazole gel was observed, leading to the diagnosis of dermatitis caused by metronidazole gel.

[A Case of Cervical Metastasis from Breast Cancer]

A 59-year-old female was performed a left mastectomy with axillary lymph node dissection. Final diagnosis of the surgical specimen was left breast cancer pT2N1M0, Stage ⅡB, Luminal type. She was treated with adjuvant endocrine therapy, however, chest wall recurrence was identified at 1 year and 3 months after surgery, and curative resection of this tumor and radiotherapy were performed. Nine months later, she was admitted to the hospital for cervical pain and dyspnea, and magnetic resonance imaging showed bone metastasis in cervical vertebra which compressed spinal cord. Although cervical fusion therapy was performed, she died 39 days later. Metastasis spinal cord compression in breast cancer patients may result in irreversible spinal cord injury if treatment is delayed. Rapid diagnosis and systemic treatment for oncologic emergency are significant.

[Clinical Significance of Inflammatory Markers in Recombinant Human-Soluble Thrombomodulin Therapy for DIC in Solid Tumors]

BACKGROUND

The peripheral blood neutrophil-lymphocyte ratio(NLR), platelet-lymphocyte ratio(PLR), and lymphocyte- monocyte ratio(LMR)of cancer patients have been proposed as indicators of systemic inflammatory response. Recombinant human-soluble thrombomodulin(rTM)has also been reported its efficacy in DIC associated with solid tumors. In this study, we investigated the clinical significance of inflammatory markers in rTM therapy for DIC associated with solid tumors.

PATIENTS AND METHOD

A retrospective study of 63 patients with solid tumors with DIC was performed. We examined the correlation between NLR, LMR, PLR and DIC withdrawal rate and 28-day survival rate.

RESULTS

The DIC withdrawal rate was not correlated in LMR(p=0.655), and significantly higher in low NLR and low PLR cases(p=0.037, p=0.024). Furthermore, 28-day survival rate was not correlated in LMR(p=0.632), and significantly higher in low NLR and low PLR cases(p= 0.046, p=0.014).

CONCLUSIONS

It was suggested that NLR and PLR may be useful as predictive markers of DIC withdrawal rate and 28-day survival rate in rTM therapy for DIC associated with solid tumors.

[A Case in Which Re-Administration of Pertuzumab/Trastuzumab with Eribulin Therapy Was Useful for Recurrent HER2 Breast Cancer]

Pertuzumab plus trastuzumab plus docetaxel regimen is the first choice for the initial treatment of HER2-positive recurrent breast cancer. However, docetaxel causes many adverse events. A 48-year-old woman was admitted to our hospital for a left breast tumor and was diagnosed with left breast cancer(T1N0M0, Stage Ⅰ, Luminal A). We performed a breast-conserving surgery and sentinel lymph node biopsy, followed by irradiation of the remaining parts of the mammary gland and adjuvant therapy with tamoxifen. Three and a half years after the first surgery, she underwent local resection due to chest wall recurrence of breast cancer. The recurrent tumor was HER2-positive, and we administered fluorouracil, epirubicin, cyclophosphamide( FEC)and paclitaxel plus trastuzumab. Liver metastases were confirmed on completion of cycle 11 of trastuzumab administration, and the regimen was changed to pertuzumab plus trastuzumab plus docetaxel. A partial response was seen following this regimen. The next line of treatment was the administration of 5 cycles of T-DM1, which resulted in stabilizing the disease. The liver metastases progressed, and the regimen was changed to pertuzumab plus trastuzumab plus eribulin. Partial response was seen following this regimen for liver metastases without serious adverse events(20 cycles).

Repeated social defeat stress induces neutrophil mobilization in mice: maintenance after cessation of stress and strain-dependent difference in response

BACKGROUND AND PURPOSE

Inflammation has been associated with stress-related mental disturbances. Rodent studies have reported that blood-borne cytokines are crucial for stress-induced changes in emotional behaviours. However, the roles and regulation of leukocytes in chronic stress remain unclear.

EXPERIMENTAL APPROACH

Adult male C57BL/6N mice were subjected to repeated social defeat stress (R-SDS) with two protocols which differed in stress durations, stress cycles, and housing conditions, followed by the social interaction test. The numbers of leukocyte subsets in the bone marrow, spleen, and blood were determined by flow cytometry shortly after or several days after R-SDS. These leukocyte changes were studied in two strains of mice with different stress susceptibility, C57BL/6N and BALB/c mice.

KEY RESULTS

R-SDS with both protocols similarly induced social avoidance in C57BL/6N mice. In the bone marrow, neutrophils and monocytes were increased, and T cells, B cells, NK cells, and dendritic cells were decreased with both protocols. In the blood, neutrophils and monocytes were increased with both protocols, whereas T cells, B cells, NK cells, and dendritic cells were decreased with one of these. Neutrophils and monocytes were also increased in the spleen. Changes in the bone marrow and increased levels of circulating neutrophils were maintained for 6 days after R-SDS. BALB/c mice showed greater social avoidance and increase in circulating neutrophils than C57BL/6N mice.

CONCLUSION AND IMPLICATIONS

In two strains of mice, chronic stress induced neutrophil mobilization and its maintenance. These effects were strain-related and may contribute to the pathology of mental illness.

LINKED ARTICLES

This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.4/issuetoc.

P767Survey of palliative sedation at the end-of-life in terminally ill heart failure patients - a five year experience in national cardiovascular center

Background

Palliative sedation is a therapeutic option when symptom relief is difficult to achieve at the end-of-life. However, little is known regarding palliative sedation in terminally ill heart failure (HF) patients.

Purpose

To survey the practice of palliative sedation in terminally ill HF patients at a tertiary referral cardiovascular center, and to investigate the efficacy and safety of sedative agents in HF patients.

Methods

We retrospectively reviewed consecutive patients who were referred to palliative care team at our institution between September 2013 and August 2018. Patients who were hospitalized for HF and died during hospitalization despite optimal medical therapy were selected and defined as terminally ill HF. We investigated the practice of palliative sedation in terminally ill HF patients and analysed the vital signs and sedation scale before starting sedative agents and about 1 hour afterward.

Results

Among 95 terminally ill HF patients, 37 were prescribed palliative sedation at the end-of-life (Picture). Of 37 patients (mean age: 70 years, median B-type natriuretic peptide: 1018 pg/ml, median creatinine: 3.0 mg/dl, intravenous inotrope: 81%), 25 were prescribed dexmedetomidine, and 12 were prescribed midazolam as first agent for sedation. Patient's backgrounds were comparable between the two groups. Richmond Agitation-Sedation Scale was significantly reduced (P<0.01), whereas blood pressure and heart rate were not altered after treatments in both groups. In midazolam group, significant decreases were noted regarding respiratory rate (P=0.01) and oxygen saturation (P=0.02); however, these parameters were not changed in dexmedetomidine group (Table).

Table 1. Vital signs and sedation scale Dexmedetomidine group (n=25) Midazolam group (n=12) Baseline After P value Baseline After P value Richmond Agitation-Sedation Scale 1 (0, 1) −1 (−2, 0) <0.01 1 (0, 1) −2 (−3, −1) <0.01 Vital signs   Systolic blood pressure (mmHg) 90±15 89±16 0.51 89±21 84±23 0.33   Diastolic blood pressure (mmHg) 52±13 54±11 0.34 60±14 56±23 0.48   Heart rate (beats per minute) 95±20 91±22 0.17 90±21 90±19 0.70   Respiratory rate (breaths per minute) 22±5 20±5 0.24 21±5 17±2 0.01   Oxygen saturation (%) 97±3 96±6 0.59 96±5 94±5 0.02

Picture. Study flowchart

Conclusions

Dexmedetomidine and midazolam were commonly used in real-word practice for HF patients at the end-of-life. Although impact on respiratory system differed by treatments, both agents could be prescribed effectively and safely in terminally ill HF patients.

Influence of the trapeziometacarpal joint fusion on thumb muscles and thumb-tip movement: A cadaveric study

BACKGROUND

Trapeziometacarpal (TMC) arthrodesis provides stability and strength of the thumb, whereas fixation of the TMC joint restricts motion of the thumb, which may consequently impair the activity of daily living. The objective of our study was to investigate how length and area of the thumb-tip trajectory were reduced after the TMC joint fusion.

METHODS

Six fresh, frozen cadavers were used for this study. Tension was applied to the distal tendons of 4 extrinsic thumb muscles (extensor pollicis longus, flexor pollicis longus, abductor pollicis longus, and extensor pollicis brevis) by servomotor, whereas tension was applied to 4 intrinsic muscles (abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and adductor pollicis) using static weights. The thumb-tip trajectory was examined using a motion capture system without tension and with 5 different weights to induce intrinsic muscle tension before and after the TMC joint fusion.

FINDINGS

When tension was applied to the intrinsic muscles, the length of the thumb-tip trajectory decreased in all conditions compared with that before the TMC joint fusion, whereas the trajectory decreased only when the abductor pollicis longus was pulled. The overall thumb-tip trajectory area was reduced to approximately 30% compared with that before the TMC joint fusion.

INTERPRETATION

Thumb-tip trajectory was restricted by the TMC joint fusion to approximately 30%. However, the reduced area was found tolerable for performing daily activities. Thus, arthrodesis can be the first-line treatment in patients who wish to engage in activities of daily living without difficulties.

Updated survival date of phase I/II study of carboplatin plus nab-paclitaxel and concurrent radiotherapy for patients with locally advanced non-small cell lung cancer

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Background: Chemoradiation regimens of greater efficacy are needed for patients with locally advanced non–small cell lung cancer (NSCLC). Methods: Patients between 20 and 74 years of age with unresectable NSCLC of stage IIIA or IIIB and a performance status of 0 or 1 were eligible for the study. In the phase II part of the study, patients received weekly nab-paclitaxel at 50 mg/m2 together with weekly carboplatin at an area under the curve (AUC) of 2 mg mL–1 min and concurrent radiotherapy with 60 Gy in 30 fractions. This concurrent phase was followed by a consolidation phase consisting of two 3-week cycles of nab-paclitaxel plus carboplatin. The primary end point of the phase II part of the study was progression-free survival (PFS). Results: Between October 2014 and November 2016, 58 patients were enrolled at 14 institutions in Japan, with 56 of these individuals being evaluable for treatment efficacy and safety. At the median follow-up time of 26.0 months (range, 4.0 to 49.6 months), the median overall survival (OS) was not reached (95% confidence interval [CI], 25.3 months to not reached) and the 2-year OS rate was 66.1% (95% CI, 52.1% to 76.8 %). The median PFS was 11.8 months (60% CI, 10.6 to 16.8 months; 95% CI, 8.2 to 21.0 months). The overall response rate was 76.8% (95% CI, 64.2% to 85.9%), and the disease control rate was 94.6% (95% CI, 85.4% to 98.2%). Subgroup analysis according to histology or age revealed no significant differences in median PFS or OS. Common toxicities of grade 3 or 4 in the concurrent phase included leukopenia (60.7%) and neutropenia (28.6%). Pneumonitis of grade 3 was observed in two patients during the study period. No treatment-related deaths occurred. Conclusions: Our results reveal encouraging feasibility and activity for concurrent chemoradiation with nab-paclitaxel at 50 mg/m2 and carboplatin at an AUC of 2 mg mL–1 min in patients with locally advanced NSCLC. Clinical trial information: UMIN000012719.

Transition of Spleen Volume Long After Pediatric Living Donor Liver Transplantation for Biliary Atresia

PURPOSE

After undergoing the Kasai procedure for biliary atresia (BA), most patients develop severe splenomegaly that tends to be improved by liver transplantation. However, fluctuations in splenic volume long after transplantation remain to be elucidated.

PATIENTS AND METHODS

Seventy-one consecutive patients who had undergone pediatric living donor liver transplantation (LDLT) for BA were followed up in our outpatient clinic for 5 years. They were classified into 3 groups according to their clinical outcomes: a good course group (GC, n = 41) who were maintained on only 1 or without an immunosuppressant, a liver dysfunction group (LD, n = 18) who were maintained on 2 or 3 types of immunosuppressants, and a vascular complication group (VC, n = 11). Splenic and hepatic volumes were calculated by computed tomography in 464 examinations and the values compared before and after the treatment, especially in the VC group.

RESULTS

Splenic volume decreased exponentially in the GC group, with splenic volume to standard spleen volume ratio (SD) being 1.59 (0.33) 5 years after liver transplantation. Splenic volume to standard spleen volume ratios were greater in the VC and LD groups than in the GC group. Patients in the VC group with portal vein stenosis developed liver atrophy and splenomegaly, whereas those with hepatic vein stenosis developed hepatomegaly and splenomegaly. Interventional radiation therapy tended to improve the associated symptoms.

CONCLUSIONS

Fluctuations in splenic volume long after pediatric LDLT for BA may reflect various clinical conditions. Evaluation of both splenic and hepatic volumes can facilitate understanding clinical conditions following pediatric LDLT.

Sensitivity of epidermal growth factor receptor with single or double uncommon mutations to afatinib confirmed by a visual assay

Patients with non‐small cell lung cancer (NSCLC) harboring common mutations of the epidermal growth factor receptor (EGFR) are sensitive to EGFR‐tyrosine kinase inhibitors (TKI). Although forms of EGFR harboring single uncommon mutations such as G719X or L861Q are thought to be less sensitive to EGFR‐TKI, the efficacy of these drugs in patients with double uncommon mutations has remained unclear. We here present an NSCLC patient found to be positive for double uncommon EGFR mutations (G719X and L861Q) by clinical genomic sequencing analysis of a pleural effusion specimen who showed a durable response to the EGFR‐TKI afatinib. The sensitivity of EGFR with single or double uncommon mutations to afatinib and the EGFR‐TKI erlotinib was also evaluated in vitro with a visual assay based on HEK293 cells transiently transfected with expression plasmids for yellow fluorescent protein (YFP)‐tagged fragments of the EGFR intracellular domain (ICD). Whereas forms of EGFR with double uncommon mutations were more sensitive to erlotinib than were those with single uncommon mutations, those with single or double uncommon mutations were similarly sensitive to afatinib, consistent with the patient's clinical outcome. Our data support the notion that afatinib is the most suitable EGFR‐TKI for NSCLC harboring uncommon mutations of EGFR. Furthermore, the YFP‐EGFR‐ICD assay is potentially applicable to prediction of EGFR‐TKI efficacy in patients with such mutations.

Quantitative Estimation of Dietary Intake in Patients on Hemodialysis

A simple method to calculate the amount of dietary (protein, sodium and potassium) intake in hemodialyzed patients was developed. In 8 nutritionally stable patients, the amount of dietary intake was monitored conventionally by a dietary record method. In contrast, assuming that the amount of dietary intake was equal to the amount of accumulation in the body, the former was calculated as the change in the product of serum concentrations and total body fluid volume, which was estimated based on the sex and body build of each patient. The urea accumulation was converted to the protein intake. The interdialytic dietary protein and sodium intake calculated by this method, 120 ± 10 g and 240 ± 40 mEq, respectively, was not significantly different from that obtained by the dietary record, while the interdialytic potassium accumulation, 60 ± 7 mEq, was significantly smaller than the dietary intake, 110 + 9 mEq, obtained by the record method, though the correlation was significant. Thus, the amount of protein and sodium intake can be calculated simply without diet research or body fluid volume measurements. Although potassium intake can not be calculated exactly because of intestinal loss, this simple method gives us a rough estimate. In addition, multiple regression analysis showed that the amount of energy intake obtained by the record method may be explained by the protein and sodium intake estimated by simple calculation.

Expression of brain-derived neurotrophic factor and its receptor TrkB is associated with poor prognosis and a malignant phenotype in small cell lung cancer

OBJECTIVES

TrkB is a receptor for brain-derived neurotrophic factor (BDNF) and is highly expressed in various cancers, with BDNF-TrkB signaling having been implicated in tumor progression and metastasis. The role of the BDNF-TrkB system in small cell lung cancer (SCLC), a neuroendocrine cancer, has remained unclear, however. We examined BDNF and TrkB expression in SCLC patients as well as the function of BDNF-TrkB signaling in SCLC cell lines.

MATERIALS AND METHODS

BDNF and TrkB expression in tumor specimens of 58 SCLC patients and 20 non-small cell lung cancer (NSCLC) patients was examined by immunohistochemistry and was scored on the basis of the distribution and intensity of staining. TrkB-overexpressing SCLC (SBC5^TrkB) cells were established by retrovirus transduction and were examined for the effects of BDNF on intracellular signaling, cell proliferation, and cell migration in vitro.

RESULTS

The staining score for TrkB in NSCLC and SCLC specimens was 2.80 ± 0.19 and 3.60 ± 0.15, respectively, whereas that for BDNF was 1.95 ± 0.32 and 2.76 ± 0.14, respectively. High levels of both TrkB and BDNF expression in SCLC tumors were significantly associated with poor overall survival in multivariate analysis (hazard ratio = 1.821, P = 0.036). BDNF activated AKT and ERK signaling pathways in and promoted the migration of SBC5^TrkB cells, and these effects were attenuated by the pan-Trk inhibitor GNF-5837. GNF-5837 also inhibited the proliferation of SBC5^TrkB cells in the presence of BDNF.

CONCLUSION

Coexpression of BDNF and TrkB was associated with poor prognosis in SCLC patients, and BDNF promoted the migration of TrkB-overexpressing SCLC cells. TrkB is thus a potential therapeutic target for SCLC.

Total Body Fluid Volume Determination Based on Urea Kinetics in Hemofiltration as an Index of Basal Body Weight in Uremic Patients

Assuming that urea is distributed uniformly within the total body water, urea-space or total body fluid volume was determined in six uremic patients based on urea kinetics in hemofiltration.

The total body fluid volume before hemofiltration was 36.0 ± 3.6 L (61.8 ± 2.6% BW) and after hemofiltration 32.5 ± 3.4 L (59.3 ± 2.8% BW), suggesting that the total body fluid volume was nearly normalized by hemofiltration. It is concluded that urea-space, easily measurable based on urea kinetics during hemofiltration, is useful in evaluating the fluid balance in patients undergoing artificial kidney therapy.

CD44 variant-dependent regulation of redox balance in EGFR mutation-positive non-small cell lung cancer: A target for treatment

OBJECTIVES

The regulation of redox balance in cancer cells is an important factor in tumor development and chemoresistance, with oncogene activation having been shown to induce the generation of reactive oxygen species (ROS). Activating mutations of the epidermal growth factor receptor gene (EGFR) are oncogenic drivers in non-small cell lung cancer (NSCLC), but it has remained unknown whether ligand-independent EGFR signaling conferred by EGFR mutation triggers ROS generation in NSCLC cells.

MATERIALS AND METHODS

HEK293T cells were transfected with an expression vector for mutant EGFR. The expression of CD44 variant (CD44v) isoforms in NSCLC cell lines was evaluated by flow cytometry. Cells were depleted of CD44v by RNA interference and assayed for ROS and glutathione (GSH) levels. The effect of CD44v on cisplatin sensitivity was evaluated in vitro with the MTS assay.

RESULTS

EGFR signaling due to EGFR mutation increased ROS levels in transfected HEK293T cells. The expression of CD44v isoforms was found to be inversely correlated with basal ROS levels in EGFR mutation-positive NSCLC cell lines. Knockdown of CD44v induced depletion of intracellular GSH and increased ROS levels in EGFR-mutated NSCLC cells that express CD44v at a high level (CD44v^high). In addition, depletion of GSH by treatment with buthionine-[S, R]-sulfoximine induced marked accumulation of ROS and enhanced the cytotoxicity of cisplatin in CD44v^highEGFR-mutated NSCLC cells but not in corresponding CD44v^low cells. This enhancement of cisplatin cytotoxicity by GSH depletion was prevented by treatment with the antioxidant N-acetyl-l-cysteine. Knockdown of CD44v also enhanced cisplatin cytotoxicity in CD44v^highEGFR mutation-positive NSCLC cells but not in CD44v^low cells.

CONCLUSION

Our results thus implicate CD44v in redox adaptation and as a potential target for treatment in CD44v^highEGFR-mutated NSCLC cells.

Note: Optimization of magnifying a polarization angle with Littrow layout blazed gratings

Magnification of a polarization angle with Littrow layout gratings has been developed. High magnification with a factor of 7.7 using two gratings in Littrow layout was experimentally proved. The magnification range was investigated by calculation at a wavelength of 10.6 μm. The method can be applied for a high magnification factor >30. Larger groove numbers and smaller blaze angles are suitable for the large magnification. Statistical fluctuation of the diffracted polarization angle is compared with that of the incident polarization angle.

Complementary Indicators for Diagnosis of Hepatic Vein Stenosis After Pediatric Living-donor Liver Transplantation

INTRODUCTION

Although hepatic vein stenosis after liver transplantation is a rare complication, the complication rate of 1% to 6% is higher in pediatric living-donor liver transplantation than that in other liver transplantation cases. Diagnosis is very important because this complication can cause hepatic congestion that develops to liver cirrhosis, graft loss, and patient loss. However, this is unlikely in cases where there are no ascites or hypoalbuminemia.

OBJECTIVES

Eleven of 167 patients who had undergone pediatric living-donor liver transplantation were identified in the outpatient clinic at Jichi Medical University as having suffered from hepatic vein stenosis, and were enrolled in the study.

METHODS

We conducted a retrospective study in which we reviewed historical patient records to investigate the parameters for diagnosis and examine treatment methods and outcomes.

RESULTS

The 11 patients were treated with 16 episodes of balloon dilatation. Three among these received retransplantation and another 2 cases required the placement of a metallic stent at the stenosis. Histological examination revealed severe fibrosis in four of nine patients who had a liver biopsy, with mild fibrosis revealed in the other five grafts. Furthermore, hepatomegaly and splenomegaly diagnosed by computed tomography, elevated levels of hyarulonic acid, and/or a decrease in calcineurin inhibitor clearance were found to be pathognomonic at diagnosis, and tended to improve after treatment.

CONCLUSIONS

Diagnosis of hepatic vein stenosis after liver transplantation can be difficult, so careful observation is crucial to avoid the risk of acute liver dysfunction. Comprehensive assessment using volumetry of the liver and spleen and monitoring of hyarulonic acid levels and/or calcineurin inhibitor clearance, in addition to some form of imaging examination, is important for diagnosis and evaluation of the effectiveness of therapy.