Language：English  

Here, we report a 57-year-old female patient with HER2-positive recurrent gastric cancer who experienced drug-induced thrombocytopenia associated with trastuzumab, a humanized anti-HER2 monoclonal antibody. Shortly after the initiation of S-1, oxaliplatin, and trastuzumab chemotherapy, the patient experienced severe thrombocytopenia and did not respond to platelet transfusions. Based on the findings of increased numbers of polynuclear megakaryocytes in the bone marrow and an elevated level of platelet-associated IgG (PA-IgG), the patient was diagnosed with drug-induced thrombocytopenia (DITP). The platelet count recovered rapidly with oral prednisolone (1 mg/kg). Since we initially suspected oxaliplatin as the causal agent, S-1 was restarted as a monotherapy, followed by trastuzumab after a 3-week interval, without oxaliplatin. On the second day after the addition of trastuzumab, severe thrombocytopenia occurred again, which suggests that trastuzumab was responsible for the DITP. The patient no longer experienced severe thrombocytopenia during the subsequent S-1 and oxaliplatin chemotherapy, which supports this hypothesis.

DOI： 10.1007/s13691-021-00520-z

Open Access

Web of Science

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Fibroblasts synthesise the extracellular matrix (ECM) such as collagen and elastin, the excessive accumulation of which can lead to fibrosis and organ dysfunction under pathological conditions. Cancer-associated fibroblasts (CAFs) are major constituents of the tumour microenvironment (TME) that accompany the desmoplastic reaction responsible for anti-cancer treatment resistance. Thus, it is important to dissect the roles of CAFs in the TME to develop new therapeutic strategies for refractory cancers. Recent progress in the studies of CAF biology suggests that the functions of CAFs are complicated and that they are composed of functionally distinct populations, including cancer-promoting CAFs (pCAFs) and cancer-restraining CAFs (rCAFs). We recently identified a new cell surface marker for rCAFs in pancreatic and colon cancers, designated as Meflin (mesenchymal stromal cell- and fibroblast-expressing Linx paralogue)/Islr (immunoglobulin super family containing leucine-rich repeat). Based on the distribution of Meflin/Islr-positive cells, we also considered it a specific candidate marker for mesenchymal stroma/stem cells. Meflin/Islr-positive CAFs have been shown to suppress cancer progression by being involved in regulating collagen structures and BMP signalling in the TME. This review describes the function of Meflin/Islr in cancer fibrosis as well as in cardiac and lung fibrosis and its potential in the development of new cancer therapeutics.

DOI： 10.3389/fcell.2021.749924

Open Access

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Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

At the early stage of cancer development, oncogenic mutations often cause multilayered epithelial structures. However, the underlying molecular mechanism still remains enigmatic. By performing a series of screenings targeting plasma membrane proteins, we have found that collagen XVII (COL17A1) and CD44 accumulate in RasV12-, Src-, or ErbB2-transformed epithelial cells. In addition, the expression of COL17A1 and CD44 is also regulated by cell density and upon apical cell extrusion. We further demonstrate that the expression of COL17A1 and CD44 is profoundly upregulated at the upper layers of multilayered, transformed epithelia in vitro and in vivo. The accumulated COL17A1 and CD44 suppress mitochondrial membrane potential and reactive oxygen species (ROS) production. The diminished intracellular ROS level then promotes resistance against ferroptosis-mediated cell death upon cell extrusion, thereby positively regulating the formation of multilayered structures. To further understand the functional role of COL17A1, we performed comprehensive metabolome analysis and compared intracellular metabolites between RasV12 and COL17A1-knockout RasV12 cells. The data imply that COL17A1 regulates the metabolic pathway from the GABA shunt to mitochondrial complex I through succinate, thereby suppressing the ROS production. Moreover, we demonstrate that CD44 regulates membrane accumulation of COL17A1 in multilayered structures. These results suggest that CD44 and COL17A1 are crucial regulators for the clonal expansion of transformed cells within multilayered epithelia, thus being potential targets for early diagnosis and preventive treatment for precancerous lesions.

DOI： 10.1016/j.cub.2021.04.078

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Mesenchymal stem cells (MSCs) are the likely precursors of multiple lines of mesenchymal cells. The existence of bona fide MSCs with self-renewal capacity and differentiation potential into all mesenchymal lineages, however, has been unclear because of the lack of MSC-specific marker(s) that are not expressed by the terminally differentiated progeny. Meflin, a glycosylphosphatidylinositol-anchored protein, is an MSC marker candidate that is specifically expressed in rare stromal cells in all tissues. Our previous report showed that Meflin expression becomes down-regulated in bone marrow-derived MSCs cultured on plastic, making it difficult to examine the self-renewal and differentiation of Meflin-positive cells at the single-cell level. Here, we traced the lineage of Meflin-positive cells in postnatal and adult mice, showing that those cells differentiated into white and brown adipocytes, osteocytes, chondrocytes and skeletal myocytes. Interestingly, cells derived from Meflin-positive cells formed clusters of differentiated cells, implying the in situ proliferation of Meflin-positive cells or their lineage-committed progenitors. These results, taken together with previous findings that Meflin expression in cultured MSCs was lost upon their multilineage differentiation, suggest that Meflin is a useful potential marker to localize MSCs and/or their immature progenitors in multiple tissues.

DOI： 10.1111/gtc.12855

Open Access

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Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

The standard chemotherapy regimen for unresectable or recurrent biliary tract cancer is gemcitabine combined with cisplatin (GC). To evaluate the effectiveness and safety of chemotherapy in patients with unresectable or recurrent biliary tract cancer in the real world, we retrospectively analyzed the clinical courses of patients who underwent chemotherapy with GC from January 2015 to November 2019. Forty-eight patients underwent the GC regimen. One patient (2.1%) achieved a complete response, seven patients (14.6%) achieved a partial response, 26 patients (54.2) achieved stable disease, 11 patients (22.9%) achieved progressive disease, and 3 patients (6.3%) were not evaluable. The overall response rate was 16.7%. The median overall survival was 14.2 months (95% CI: 13.8-14.6), and the median progression-free survival was 7.7 months (95% CI: 4.2-11.2). Thirty-nine patients (81.3%) experienced grade 3 or higher severe adverse events as follows: 54.2% experienced neutropenia, 20.8% experienced anemia, 12.5% experienced thrombocytopenia and 20.8% experienced biliary tract infection. As a second-line chemotherapy, S-1 was used in seventeen patients, and stable disease was achieved in three patients (17.6%). The GC regimen for biliary tract cancer is effective and safe for unresectable or recurrent biliary tract cancer in routine clinical practice.

DOI： 10.18999/nagjms.82.4.725

Open Access

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Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Malignant mesothelioma is an aggressive neoplasm for which effective treatments are lacking. We often encounter mesothelioma cases with a profound desmoplastic reaction, suggesting the involvement of cancer‑associated fibroblasts (CAFs) in mesothelioma progression. While the roles of CAFs have been extensively studied in other tumors and have led to the view that the cancer stroma contains heterogeneous populations of CAFs, their roles in mesothelioma remain unknown. We previously showed that connective tissue growth factor (CTGF), a secreted protein, is produced by both mesothelioma cells and fibroblasts and promotes the invasion of mesothelioma cells in vitro. In this study, we examined the clinical relevance of CAFs in mesothelioma. Using surgical specimens of epithelioid malignant pleural mesothelioma, we evaluated the clinicopathological significance of the expression of α‑smooth muscle actin (αSMA), the most widely used marker of CAFs, the expression of CTGF, and the extent of fibrosis by immunohistochemistry and Elastica‑Masson staining. We also analyzed the expression of mesenchymal stromal cell‑ and fibroblast‑expressing Linx paralogue (Meflin; ISLR), a recently reported CAF marker that labels cancer‑restraining CAFs and differ from αSMA‑positive CAFs, by in situ hybridization. The extent of fibrosis and CTGF expression in mesothelioma cells did not correlate with patient prognosis. However, the expression of αSMA and CTGF, but not Meflin, in CAFs correlated with poor prognosis. The data suggest that CTGF+ CAFs are involved in mesothelioma progression and represent a potential molecular target for mesothelioma therapy.

DOI： 10.3892/or.2020.7669

Open Access

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PubMed

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

The roles of cancer-associated fibroblasts (CAF) in the progression of various types of cancers are well established. CAF promote cancer progression through pleiotropic mechanisms, including the secretion of soluble factors and extracellular matrix, physical interactions with cancer cells, and the regulation of angiogenesis, immunity and metabolism. Their contribution to therapeutic resistance is also well appreciated. Therefore, CAF have been considered as a therapeutic target in cancer. However, recent studies in autochthonous pancreatic cancer models suggest that specific subset(s) of CAF exhibit cancer-restraining roles, indicating that CAF are functionally and molecularly heterogeneous, which is supported by recent single-cell transcriptome analyses. While cancer-promoting CAF (pCAF) have been extensively studied, the nature and specific marker(s) of cancer-restraining CAF (rCAF) have remained uncharacterized. Interestingly, a recent study provided insight into the nature of rCAF and suggested that they may share molecular properties with pancreatic stellate cells (PSC) and mesenchymal stem/stromal cells (MSC). Complicating this finding is that PSC and MSC have been shown to promote the formation of a tumor-permissive and tumor-promoting environment in xenograft tumor models. However, these cells undergo significant transcriptional and epigenetic changes during ex vivo culture, which confounds the interpretation of experimental results based on the use of cultured cells. In this short review, we describe recent studies and hypotheses on the identity of rCAF and discuss their analogy to fibroblasts that suppress fibrosis in fibrotic diseases. Finally, we discuss how these findings can be exploited to develop novel anticancer therapies in the future.

DOI： 10.1111/cas.14346

Open Access

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PubMed

Language：English   Publishing type：Research paper (scientific journal)  

RATIONALE: Myofibroblasts have roles in tissue repair following damage associated with ischemia, aging, and inflammation and also promote fibrosis and tissue stiffening, causing organ dysfunction. One source of myofibroblasts is mesenchymal stromal/stem cells that exist as resident fibroblasts in multiple tissues. We previously identified meflin (mesenchymal stromal cell- and fibroblast-expressing Linx paralogue), a glycosylphosphatidylinositol-anchored membrane protein, as a specific marker of mesenchymal stromal/stem cells and a regulator of their undifferentiated state. The roles of meflin in the development of heart disease, however, have not been investigated. OBJECTIVE: We examined the expression of meflin in the heart and its involvement in cardiac repair after ischemia, fibrosis, and the development of heart failure. METHODS AND RESULTS: We found that meflin has an inhibitory role in myofibroblast differentiation of cultured mesenchymal stromal/stem cells. Meflin expression was downregulated by stimulation with TGF (transforming growth factor)-β, substrate stiffness, hypoxia, and aging. Histological analysis revealed that meflin-positive fibroblastic cells and their lineage cells proliferated in the hearts after acute myocardial infarction and pressure-overload heart failure mouse models. Analysis of meflin knockout mice revealed that meflin is essential for the increase in the number of cells that highly express type I collagen in the heart walls after myocardial infarction induction. When subjected to pressure overload by transverse aortic constriction, meflin knockout mice developed marked cardiac interstitial fibrosis with defective compensation mechanisms. Analysis with atomic force microscopy and hemodynamic catheterization revealed that meflin knockout mice developed stiff failing hearts with diastolic dysfunction. Mechanistically, we found that meflin interacts with bone morphogenetic protein 7, an antifibrotic cytokine that counteracts the action of TGF-β and augments its intracellular signaling. CONCLUSIONS: These data suggested that meflin is involved in cardiac tissue repair after injury and has an inhibitory role in myofibroblast differentiation of cardiac fibroblastic cells and the development of cardiac fibrosis.

DOI： 10.1161/CIRCRESAHA.119.314806

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PubMed

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(一社)日本内科学会  

J-GLOBAL

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(一社)日本病理学会  

J-GLOBAL

Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (bulletin of university, research institution)   Publisher：トヨタ自動車(株)トヨタ記念病院  

J-GLOBAL

Authorship：Lead author   Language：English   Publishing type：Research paper, summary (national, other academic conference)  

Web of Science

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本超音波医学会  

J-GLOBAL

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本超音波医学会  

J-GLOBAL

Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本超音波医学会  

J-GLOBAL

Event date： 2019.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Event date： 2018.7

Language：English   Presentation type：Poster presentation