仲矢 丈雄

Castration-resistant prostate cancer (CRPC) is a big challenge in managing prostate cancer patients. The androgen receptor (AR) pathway is a major driver even in CRPC under androgen deprivation. The mechanism in maintaining of the AR pathway under androgen deprivation remains elusive. The recent discovery of biomolecular condensate, a membrane-less intracellular construct formed by liquid-liquid phase separation (LLPS), that facilitate molecular assembly, encouraged the re-screening of our previous microarray data list. We selected Rbm14 as a target molecule for further analysis because it works as a coactivator of nuclear receptors as well as it facilitates formation of biomolecular condensates via its intrinsically disordered region. GFP-tagged Rbm14 transfected into HEK293T cells formed droplet-like puncta, which diminished following treatment with 1,6-hexanediol. Droplet-like structures were also observed in immunofluorescence for endogenous RBM14 of PC-3 and DU145 cells. Luciferase assay revealed that Rbm14 enhanced androgen-responsive element (ARE)-mediated reporter activity in all conditions with or without testosterone and AR. Co-immunoprecipitation confirmed the Rbm14-AR interaction. Long non-coding RNAs, including NEAT1, SRA1, and HOTAIR, were also interacted with Rbm14. Small interfering RNAs of NEAT1 reduced ARE-mediated reporter activity, while transfection of SRA1 and HOTAIR enhance the reporter activity. Treatment with 1,6-hexanediol as well as transfection with a dominant-negative splice variant of Rbm14 reduced expression of prostate specific antigen (PSA), a prototype of androgen-regulated gene, in LNCaP, PC-3, and DU145 cells under androgen deprivation. Immunohistochemically, RBM14 expression was substantially upregulated in prostate cancer tissues after androgen deprivation therapy than in untreated tumors. In conclusion, RBM14 is a novel factor involved in maintenance of PSA expression via phase separation under androgen deprivation in prostate cancer.

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

Abstract Myofibroblasts cause tissue fibrosis by producing extracellular matrix proteins, such as collagens. Humoral factors like TGF-β, and matrix stiffness are important for collagen production by myofibroblasts. However, the molecular mechanisms regulating their ability to produce collagen remain poorly characterised. Here, we show that vestigial-like family member 3 (VGLL3) is specifically expressed in myofibroblasts from mouse and human fibrotic hearts and promotes collagen production. Further, substrate stiffness triggers VGLL3 translocation into the nucleus through the integrin β1-Rho-actin pathway. In the nucleus, VGLL3 undergoes liquid-liquid phase separation via its low-complexity domain and is incorporated into non-paraspeckle NONO condensates containing EWS RNA-binding protein 1 (EWSR1). VGLL3 binds EWSR1 and suppresses miR-29b, which targets collagen mRNA. Consistently, cardiac fibrosis after myocardial infarction is significantly attenuated in Vgll3-deficient mice, with increased miR-29b expression. Overall, our results reveal an unrecognised VGLL3-mediated pathway that controls myofibroblasts’ collagen production, representing a novel therapeutic target for tissue fibrosis.

RATIONALE: Phagocytosis is an important physiological process for eliminating unnecessary substances or dead cells after tissue damage, such as inflammation or infarction. Phagocytosis was previously considered to be mainly performed by professional phagocytotic cells, such as macrophages. In contrast, we previously demonstrated that the phagocytosis of dead cells and unnecessary substances by myofibroblasts is as important as that by professional phagocytotic cells in myocardial infarction. Based on our discovery, we speculated that phagocytosis by myofibroblasts may be a more common pathological phenomenon also in other diseases than previously believed. PATIENT CONCERNS: A 44-year-old male patient with atopic dermatitis developed a cutaneous reddish nodule with an underlying induration on his thigh. INTERVENTIONS: The cutaneous lesion was surgically removed. DIAGNOSES: Histopathological examination demonstrated that the cutaneous lesion had solid infiltration by inflammatory cells, namely, plasma cells, histiocytes, and lymphocytes, in the dermis. The cutaneous lesion included mucinosis in the dermis. Inside the mucinosis, we detected cells with clear areas of mucinous substances. Some of the cells were α-smooth muscle actin-positive myofibroblasts. Electron microscopic images demonstrated that there were collagen bands in the cells with mucinous engulfment. Based on these pieces of evidence, we conclude that these mucinous phagocytotic cells were myofibroblasts, not professional phagocytotic cells, such as macrophages. OUTCOMES: There was no recurrence of the lesion. LESSONS: The clinical appearance of this case resembled that of previously reported solitary cutaneous focal mucinoses. However, our case had distinctive characteristics, such as the phagocytosis of mucinous substances by myofibroblasts, multiple mucinous lesions in a single eruption, and the presence of inflammatory cells, which have not been previously reported. For this distinct cutaneous lesion, a clear dermatological and pathological name has yet to be determined. We propose "myofibroblast phagocytic cutaneous mucinosis" as a candidate name. In addition, our discoveries suggest that phagocytosis by myofibroblasts is not rare but rather is a common pathological phenomenon that has been undetected or unrecognized.

Leukotriene B4 receptor 1 (BLT1), a high-affinity G-protein-coupled receptor for leukotriene B4 (LTB4 ), is expressed on various inflammatory cells and plays critical roles in several inflammatory diseases. In myocardial infarction (MI), various inflammatory cells are known to be recruited to the infarcted area, but the function of BLT1 in MI is poorly understood. Here, we investigated the role of BLT1 in MI and the therapeutic effect of a BLT1 antagonist, ONO-4057, on MI. Mice with infarcted hearts showed increased BLT1 expression and LTB4 levels. BLT1-knockout mice with infarcted hearts exhibited attenuated leukocyte infiltration, proinflammatory cytokine production, and cell death, which led to reduced mortality and improved cardiac function after MI. Bone-marrow transplantation studies showed that BLT1 expressed on bone marrow-derived cells was responsible for the exacerbation of inflammation in infarcted hearts. Furthermore, ONO-4057 administration attenuated the inflammatory responses in hearts surgically treated for MI, which resulted in reduced mortality and improved cardiac function after MI. Our study demonstrated that BLT1 contributes to excessive inflammation after MI and could represent a new therapeutic target for MI.

RATIONALE: Primary carcinosarcoma of the upper urinary tract is rare. Ureteral duplication is one of the most common urinary tract malformations. Additionally, the association between ureteral duplication and malignancy is unknown. To the best of our knowledge, no cases of malignant tumors diagnosed as carcinosarcoma with ureteral duplication have been reported. We herein report the case of a patient with carcinosarcoma of the ureteropelvic junction associated with incomplete ureteral duplication. PATIENT CONCERNS: A 60-year-old Japanese woman presented with painless gross hematuria. She had a history of total hysterectomy and chemotherapy for endometrioid carcinoma 5 years before. She had no history of occupational chemical exposure. DIAGNOSES: Radiographic imaging revealed right incomplete ureteral duplication, hydronephrosis, and a polypoid tumor in the ureteropelvic junction of the lower moiety of the right kidney. Urine cytology showed a small amount of degenerated atypical epithelial and nonepithelial cells. The transureteral biopsy specimen showed dysplastic urothelial cells and atypical myoid spindle cells. These findings were indefinite for malignancy. INTERVENTIONS: The patient underwent right nephroureterectomy. Pathological examination of the resected tumor showed a biphasic neoplasm composed of carcinomatous and sarcomatous components. The sarcomatous component was immunohistochemically positive for vimentin, desmin, h-caldesmon, and α-SMA and negative for pancytokeratin (AE1/AE3), low molecular weight cytokeratin (CAM 5.2), EMA, E-cadherin, GATA3, uroplakin 2, and p63. Based on these findings, we diagnosed the tumor as carcinosarcoma. OUTCOMES: The postoperative course was uneventful. No additional therapy was administered. The patient has remained alive without recurrence for 21 months since surgery. LESSONS: Carcinosarcoma can arise from ureteral duplication. Although the majority of carcinosarcomas of the upper urinary tract are diagnosed at an advanced stage and have a poor prognosis, some can have a less aggressive course. Further studies are needed to determine the association between ureteral duplication and malignancy.

RATIONALE: Suppression and of cancer metastasis is one of the most important issues in cancer care. Considering the typical clinical course of metastases, cancer cells might prefer certain environments or conditions. However, favorable environments for cancer metastasis have not been clearly identified. We had previously described a case of dual, yet separate, pancreatic and colon cancer, in which the metastatic pancreatic cancer was localized at the invasive portion of the colon cancer. We hypothesized that metastatic pancreatic cancer took over the colon cancer microenvironment. PATIENT CONCERNS: We experienced an another case of double cancer in a 65-year-old man who had lung squamous cell carcinoma and an independent pancreatic adenocarcinoma that metastasized to the liver as well as to the lung cancer lesion and pulmonary fibrotic regions associated with pneumothorax and bronchiolization. INTERVENTIONS: The pneumothorax could not be controlled by conservative treatment. Thus, an emergency surgery with partial resection of the lower lobe of right lung was performed. DIAGNOSES: We found multiple pancreatic cancer metastases in the lung cancer and fibrotic lesions in the surgical specimen. However, we detected no metastasis in normal lung tissues except inside small arteries, although the lung cancer and fibrotic tissue areas were smaller than the normal lung tissue areas in the surgical specimen. OUTCOMES: The patient died 50 days after the surgery. LESSONS: This case may thus provide evidence to strengthen our hypothesis that pancreatic cancer prefers to metastasize to other independent cancer lesions, overtaking the cancer microenvironment constructed by other independent cancers. The lung cancer microenvironment, rich in myofibroblasts and/or cancer-associated fibroblasts, might be suitable for pancreatic carcinoma metastasis. In addition, we propose the hypothesis that compared with normal tissues, noncancerous fibrotic lesions are preferable destinations for cancer metastasis. Furthermore, metastasis of pancreatic carcinoma to lung cancer and fibrotic tissues might be more common, although such cases have not been previously reported.

Background: Renal dysplasia is the most important cause of end-stage renal disease in children. The histopathological characteristic of dysplasia is primitive tubules with fibromuscular disorganization. Renal dysplasia often includes metaplastic cartilage. Metaplastic cartilage in renal dysplasia has been explained as occurring secondary to vesicoureteral reflux (VUR). Additionally, renal dysplasia is observed in renal dysplasia-associated syndromes, which are combinations of multiple developmental malformations and include VACTERL association. Case presentation: We observed the following multiple developmental malformations in a 108-day-old male infant during a nephrectomy: a nonfunctioning right kidney with VUR, hemidiaphragmatic eventration, a ventricular septal defect (VSD) with tetralogy of Fallot in the heart, cryptorchidism, and hyperdactylia. These developmental anomalies satisfied the diagnostic criteria for VACTERL association. A surgical specimen of the right nonfunctioning kidney revealed prominent cartilaginous metaplasia in the renal dysplasia with VUR. The densities of the ectopic cartilaginous lesions in this nonfunctioning kidney were extraordinarily high compared with other renal dysplasia cases. Giemsa banding of his genome produced normal results. The patient has not undergone further detailed genomic investigation. Conclusion: This case might be a novel type of VACTERL association, that is, renal dysplasia combined with prominent cartilaginous metaplasia, tetralogy of Fallot and VSD of the heart, hemidiaphragmatic eventration, and hyperdactylia.

<p>症例は39歳男性．37歳時に食道静脈瘤破裂で他院入院の際，両側肺門リンパ節腫脹および肺野粒状影を認め，リンパ節生検で非乾酪性肉芽腫を認めたため，肺サルコイドーシスの診断となった．食道静脈瘤のフォローアップと門脈圧亢進症の原因精査目的に当科紹介となった．腹腔鏡検査では肝表面は広範に凹凸不整で辺縁は鈍であった．また肝表面には粒状の白色結節が多数見られ，肝辺縁で一部癒合し斑状であった．同時に施行した肝生検では，非乾酪性肉芽腫を認め，肝表面の所見と合わせて，肝サルコイドーシスの診断に至った．肉芽腫は門脈域に認めており，門脈の壁外性圧迫や閉塞により門脈圧亢進症を来したと推定された．ステロイドによる加療を開始し，1年近く経過しているが，肝障害は軽度改善し，食道静脈瘤は増悪なく経過している．肝サルコイドーシスに門脈圧亢進症を合併することは稀であり，腹腔鏡検査にて合併症なく診断できたので報告する．</p>

Endocrine resistance is a major problem in prostate cancer. Recent studies suggest that cellular plasticity plays a key role in therapy resistance. Yet little is known about the cellular changes of human prostate cancer after androgen deprivation therapy (ADT). In this study, we investigated cellular senescence, senescence-associated secretory phenotypes (SASPs), and anti-oxidant responses. Hormone ablation upregulated senescence-associated (SA)-beta-Gal activity in prostate glands, as well as the expressions of p27(KIP1) and p53, in a mouse castration model. In line with this, the expressions of p21(CIP1) and p27(KIP1) were significantly more upregulated in human non-pathological prostatic glands after ADT than in untreated specimens. In a study of SASP markers, the expressions of IL6 and IL8 were also more upregulated in human non-pathological prostatic glands after ADT than in untreated specimens. IL6, IL8, and MMP2 were expressed more strongly in human prostate cancer specimens resected after ADT than in untreated tumors. Of note, treatment with the anti-oxidant reagent NAC significantly suppressed SA-beta-Gal activity in androgen-sensitive human prostate cancer LNCaP cells. In immunohistochemical analyses on anti-oxidant response genes, NRF2 and NQO1 were more upregulated after hormone ablation in human prostate gland and carcinoma specimens after ADT than in untreated specimens or in murine prostate glands after castration. Taken together, these findings suggest that ADT induces cellular senescence processes accompanied by secretory phenotypes and anti-oxidant responses in prostate. These cellular changes may be attractive targets for preventing endocrine resistance in prostate cancer. (C) 2016 Elsevier Ltd. All rights reserved.

Myocardial infarction (MI) results in the generation of dead cells in the infarcted area. These cells are swiftly removed by phagocytes to minimize inflammation and limit expansion of the damaged area. However, the types of cells and molecules responsible for the engulfment of dead cells in the infarcted area remain largely unknown. In this study, we demonstrated that cardiac myofibroblasts, which execute tissue fibrosis by producing extracellular matrix proteins, efficiently engulf dead cells. Furthermore, we identified a population of cardiac myofibroblasts that appears in the heart after MI in humans and mice. We found that these cardiac myofibroblasts secrete milk fat globule-epidermal growth factor 8 (MFG-E8), which promotes apoptotic engulfment, and determined that serum response factor is important for MFG-E8 production in myofibroblasts. Following MFG-E8-mediated engulfment of apoptotic cells, myofibroblasts acquired antiinflammatory properties. MFG-E8 deficiency in mice led to the accumulation of unengulfed dead cells after MI, resulting in exacerbated inflammatory responses and a substantial decrease in survival. Moreover, MFG-E8 administration into infarcted hearts restored cardiac function and morphology. MFG-E8-producing myofibroblasts mainly originated from resident cardiac fibroblasts and cells that underwent endothelial-mesenchymal transition in the heart. Together, our results reveal previously unrecognized roles of myofibroblasts in regulating apoptotic engulfment and a fundamental importance of these cells in recovery from MI.

We experienced the giant seminoma with 18 × 10 × 10 cm sized and about 2.6 kg weight of 25 year old patient. We intensively examined the histological tissue type distributions in this giant seminoma. Most of the tumor consisted of seminoma components. In addition, the tumor included the very small fragments of yolk sac tumor and embryonal carcinoma component at the root part of the seminoma mass. This shows that intensive histological examination may contribute to the finding of other embryonic component of the large seminoma. This may show that leaving the seminoma growing may generate the other embryonic tumor component, not always big enough to find out in a routine procedure, during the growth, in the different way from the original mixed cell germ tumor.

BACKGROUND: Lymphatic stomata are small lymphatic openings in the serosal membrane that communicate with the serosal cavity. Although these stomata have primarily been studied in experimental mammals, little is known concerning the presence and properties of lymphatic stomata in the adult human pleura. Thus, adult human pleurae were examined for the presence or absence of lymphatic stomata. METHODS AND RESULTS: A total of 26 pulmonary ligaments (13 left and 13 right) were obtained from 15 adult human autopsy cases and examined using electron and light microscopy. The microscopic studies revealed the presence of apertures fringed with D2-40-positive, CD31-positive, and cytokeratin-negative endothelial cells directly communicating with submesothelial lymphatics in all of the pulmonary ligaments. The apertures' sizes and densities varied from case to case according to the serial tissue section. The medians of these aperture sizes ranged from 2.25 to 8.75 μm in the left pulmonary ligaments and from 2.50 to 12.50 μm in the right pulmonary ligaments. The densities of the apertures ranged from 2 to 9 per mm(2) in the left pulmonary ligaments and from 2 to 18 per mm(2) in the right pulmonary ligaments. However, no significant differences were found regarding the aperture size (p=0.359) and density (p=0.438) between the left and the right pulmonary ligaments. CONCLUSIONS: Our study revealed that apertures exhibit structural adequacy as lymphatic stomata on the surface of the pulmonary ligament, thereby providing evidence that lymphatic stomata are present in the adult human pleura.

Kaposiform hemangioendothelioma is a vascular tumor categorized as intermediate malignancy. We experienced an autopsy of a female baby with kaposiform hemangioendothelioma with Kasabach-Men-itt syndrome. She died of systemic bleeding tendency following disseminated intravascular coagulation at the age of 9 days. At autopsy, a huge main tumor, histologically kaposiform hemangioendothelioma, was discovered in the mediastinum between the right chest cavity and pericardium. Furthermore, kaposiform hemangioendothelioma with the same histology involved the lungs, heart, liver, subserosa of cardial part of the stomach, retroperitoneum around the right adrenal gland, broad ligament of the uterus, and muscular tissue around the thyroid. To date, a few previously reported cases of multifocal kaposiform hemangioendothelioma have demonstrated locally aggressive distributions mainly in bone and soft tissues. The present case with extensive distribution including visceral organs implies that kaposiform hemangioendothelioma may have higher potential to spread than considered before. (C) 2014 Elsevier Inc. All rights reserved.

Apical neural progenitors (aNPs) drive neurogenesis by means of a program consisting of self-proliferative and neurogenic divisions. The balance between these two manners of division sustains the pool of apical progenitors into late neurogenesis, thereby ensuring their availability to populate the brain with terminal cell types. Using knockout and in utero electroporation mouse models, we report a key role for the microtubule-associated protein 600 (p600) in the regulation of spindle orientation in aNPs, a cellular event that has been associated with cell fate and neurogenesis. We find that p600 interacts directly with the neurogenic protein Ndel1 and that aNPs knockout for p600, depleted of p600 by shRNA or expressing a Ndel1-binding p600 fragment all display randomized spindle orientation. Depletion of p600 by shRNA or expression of the Ndel1-binding p600 fragment also results in a decreased number of Pax6-positive aNPs and an increased number of Tbr2-positive basal progenitors destined to become neurons. These Pax6-positive aNPs display a tilted mitotic spindle. In mice wherein p600 is ablated in progenitors, the production of neurons is significantly impaired and this defect is associated with microcephaly. We propose a working model in which p600 controls spindle orientation in aNPs and discuss its implication for neurogenesis.

The intestinal epithelium maintains homeostasis by a self-renewal process involving resident stem cells, including Lgr5(+) crypt-base columnar cells, but core mechanisms and their contributions to intestinal cancer are not fully defined. In this study, we examined a hypothesized role for KLF5, a zinc-finger transcription factor that is critical to maintain the integrity of embryonic and induced pluripotent stem cells, in intestinal stem-cell integrity and cancer in the mouse. Klf5 was indispensable for the integrity and oncogenic transformation of intestinal stem cells. In mice, inducible deletion of Klf5 in Lgr5(+) stem cells suppressed their proliferation and survival in a manner associated with nuclear localization of beta-catenin (Catnb), generating abnormal apoptotic cells in intestinal crypts. Moreover, production of lethal adenomas and carcinomas by specific expression of an oncogenic mutant of beta-catenin in Lgr5(+) stem cells was suppressed completely by Klf5 deletion in the same cells. Given that activation of the Wnt/beta-catenin pathway is the most frequently altered pathway in human colorectal cancer, our results argue that KLF5 acts as a fundamental core regulator of intestinal oncogenesis at the stem-cell level, and they suggest KLF5 targeting as a rational strategy to eradicate stem-like cells in colorectal cancer. (C) 2014 AACR.

Shwachman-Diamond syndrome, which is characterized by pancreatic fatty degeneration, skeletal growth retardation, and hematological dysfunction, is a congenital disease caused by SBDS gene mutations. Although hematological disorders often accompany this syndrome, carcinomas associated with this syndrome have not been reported except in one breast cancer and one moderately differentiated pancreatic cancer case. We report on an autopsy of a 24-year-old case of pancreatoduodenal carcinoma in Shwachman-Diamond syndrome. The histology of the tumor was undifferentiated carcinoma, which seems to have originated from either the pancreatic duct or the duodenal epithelium. The tumor was intermingled with two pathological changes characteristic of Shwachman-Diamond syndrome: fatty degeneration of the pancreas and inflammation of the villous stroma of the duodenum. Considering that SBDS protein regulates mitosis and its suppression causes genomic instability, this case might provide an example of carcinogenesis based on genomic instability, together with degenerative changes and chronic inflammation, at a very young age.

p600 is a multifunctional protein implicated in cytoskeletal organization, integrin-mediated survival signaling, calcium-calmodulin signaling and the N-end rule pathway of ubiquitin-proteasome-mediated proteolysis. While push, the Drosophila counterpart of p600, is dispensable for development up to adult stage, the role of p600 has not been studied during mouse development. Here we generated p600 knockout mice to investigate the in vivo functions of p600. Interestingly, we found that homozygous deletion of p600 results in lethality between embryonic days 11.5 and 13.5 with severe defects in both embryo and placenta. Since p600 is required for placental development, we performed conditional disruption of p600, which deletes selectively p600 in the embryo but not in the placenta. The conditional mutant embryos survive longer than knockout embryos but ultimately die before embryonic day 14.5. The mutant embryos display severe cardiac problems characterized by ventricular septal defects and thin ventricular walls. These anomalies are associated with reduced activation of FAK and decreased expression of MEF2, which is regulated by FAK and plays a crucial role in cardiac development. Moreover, we observed pleiotropic defects in the liver and brain. In sum, our study sheds light on the essential roles of p600 in fetal development. © 2013 Nakaya et al.

Epstein-Barr virus (EBV) is a representative human oncogenic virus that causes malignancies of various cell lineages. LMP2A, an EBV-encoded latent membrane protein, is expressed in EBV-associated malignancies of various cell lineages. LMP2A caused visible tumor formation transplanted in nude mice when transferred to immortalized non-transformed fibroblasts, NIH3T3. LMP2A-expressing cells showed higher ability of colony formation in soft agar than empty vector-transfected control cells, although the expression of LMP2A did not cause focus transformation in low serum concentrations. LMP2A expression increased the size of Hoechst 33,342 dye excreting side population (SP), in which cancer-initiating cells or cancer stem-like cells were enriched. SP increase by LMP2A was also responsible for colony formation in soft agar. The LMP2A-mediated SP increase depended on the activations of Stat3, MEK/ERK, and PI3K pathways, and on upregulation of HMGA2. Enrichment of SP, stem-like cells, by LMP2A promoted the transformation capability of LMP2A from non-transformed cells. The enrichment of stem-like cell population by a virus-encoded factor might explain the oncogenic functions of oncogenic viruses. (C) 2013 Elsevier B.V. All rights reserved.

Efficient engulfment of apoptotic cells is critical for maintaining tissue homoeostasis. When phagocytes recognize 'eat me' signals presented on the surface of apoptotic cells, this subsequently induces cytoskeletal rearrangement of phagocytes for the engulfment through Rac1 activation. However, the intracellular signalling cascades that result in Rac1 activation remain largely unknown. Here we show that G-protein-coupled receptor kinase 6 (GRK6) is involved in apoptotic cell clearance. GRK6 cooperates with GIT1 to activate Rac1, which promotes apoptotic engulfment independently from the two known DOCK180/ELMO/Rac1 and GULP1/Rac1 engulfment pathways. As a consequence, GRK6-deficient mice develop an autoimmune disease. GRK6-deficient mice also have increased iron stores in splenic red pulp in which F4/80(+) macrophages are responsible for senescent red blood cell clearance. Our results reveal previously unrecognized roles for GRK6 in regulating apoptotic engulfment and its fundamental importance in immune and iron homoeostasis.

CpG island promoter methylation of tumor suppressor genes is one of the most characteristic abnormalities in EBV-associated gastric carcinoma (GC). Aberrant promoter methylation and expression loss of PTEN were evaluated in cancer tissues of GC by methylation-specific PCR and immunohistochemistry, respectively, showing that both abnormalities occurred concurrently in EBV-associated GC. PTEN abnormalities were reiterated in GC cell tines MKN-1 and MKN-7 infected with recombinant EBV, and DNA methyltransferase I (DNMT1) was commonly overexpressed in both cell lines. Stable and transient transfection systems in MKN-1 similarly showed that viral latent membrane protein 2A (LMP2A) up-regulated DNMT1, leading to an increase in methylation of the PTEN promoter. Importantly, the level of phosphorylate signal transducer and activator of transcription 3 (pSTAT3) increased in the nuclei of LMP2A-expressing GC cells, and knockdown of STAT3 counteracted LMP2A-mediated DNMT1 overexpression. Immunohistochemistry for both pSTAT3 and DNMT1 showed diffuse labeling in the nuclei of the cancer cells in GC tissues, especially in EBV-associated GC. Taken together, LMP2A induces the phosphorylation of STAT3, which activates DNMT1 transcription and causes PTEN expression loss through CpG island methylation of the PTEN promoter in EBV-associated GC. LMP2A plays an essential role in the epigenetic abnormalities in host stomach cells and in the development and maintenance of EBV-associated cancer. [Cancer Res 2009;69(7):2766-74]

During viral infection, interferon-alpha/beta (IFN-alpha/beta) and many IFN-inducible genes are induced to elicit antiviral responses of the host. Using cells with a gene disruption(s) for the IRF family of transcription factors, we provide evidence that these genes, containing similar IRF-binding cis-elements, are classified into distinct groups, based on the gene induction pathway(s), The IFN-beta gene induction is dependent on either IRF-3 or IRF-7, whereas induction of the IFN-alpha gene family is IRF-7-dependent. On the other hand, ISG15, ISG54 and IP-10 are induced by either IRF-3 or IFN stimulated gene factor 3 (ISGF3). We also show that another group of genes is totally dependent on ISGF3, Thus, during viral infection, a given gene responds either directly to a virus or virus-induced IFN-alpha/beta or both through distinct pathways, The differential utilization of these induction pathways for these genes during viral infection may reflect their distinct functional roles in the efficient antiviral response. (C) 2001 Academic Press.

Induction of the interferon (IFN)-alpha/beta gene transcription in virus-infected cells is an event central to innate immunity. Mice lacking the transcription factor IRF-3 are more vulnerable to virus infection. In embryonic fibroblasts, virus-induced IFN-alpha/beta gene expression levels are reduced and the spectrum of the IFN-alpha mRNA subspecies altered. Furthermore, cells additionally defective in IRF-7 expression totally fail to induce these genes in response to infections by any of the virus types tested. In these cells, a normal profile of IFN-alpha/beta mRNA induction can be achieved by coexpressing both IRF-3 and IRF-7. These results demonstrate the essential and distinct roles of the two factors, which together ensure the transcriptional efficiency and diversity of IFN-alpha/beta genes for the antiviral response.

The interferon regulatory factor (IRF) family of transcription factors regulate the interferon (IFN) system, among which IRF-3 is involved in the virus-induced IFN-beta gene expression. Here me show that another member IRF-7 is critical for the IFN-alpha gene induction. Unlike the IRF-3 gene, the IRF-7 gene is induced by IFNs through activation of the ISGF3 transcription factor, and IRF-7 undergoes virus-induced nuclear translocation. In cells lacking p48, an essential component of IFN stimulated gene factor 3 (ISGF3), ectopic expression of IRF-7 but not IRF-3 can rescue the deficiency to induce IFN-alpha genes. These results indicate that IRF-7 is a key factor in the positive feedback regulation of IFN-alpha/beta production. (C) 1998 Federation of European Biochemical Societies.