Akira Orimo
Research interests
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InterestsCancer Biology, Cancer Cells, Stromal tumour interaction, carcinoma-associated fibroblasts
Publications
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Emerging roles of the tumor-associated stroma in promoting tumor metastasis.
Cell adhesion & migration. 05/2012; 6(3).
The stroma in human carcinomas consists of extracellular matrix and various types of non-carcinoma cells, mainly leukocytes, endothelial cells, fibroblasts, myofibroblasts and bone marrow-derived progenitors. The tumor-associated stroma actively supports tumor growth by stimulating neo-angiogenesis,... [more] The stroma in human carcinomas consists of extracellular matrix and various types of non-carcinoma cells, mainly leukocytes, endothelial cells, fibroblasts, myofibroblasts and bone marrow-derived progenitors. The tumor-associated stroma actively supports tumor growth by stimulating neo-angiogenesis, as well as proliferation and invasion of apposed carcinoma cells. It has long been accepted that alterations within carcinoma cells mediate metastasis in a cell-autonomous fashion. Recent studies have, however, suggested an additional notion that cancer cells instigate local and systemic changes in the tumor microenvironment and contribute to niche formation for metastasis. Research, aiming to establish the roles of the tumor-associated stroma in facilitating the spread of carcinoma cells into distant organs, has provided an abundance of data and greater knowledge of the biology of metastatic carcinoma cells and associated stromal cells. This has stimulated further advances in the development of novel therapeutic approaches targeting tumor metastasis.
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Experimental generation of carcinoma-associated fibroblasts (CAFs) from human mammary fibroblasts.
Journal of visualized experiments : JoVE. 01/2011;
Carcinomas are complex tissues comprised of neoplastic cells and a non-cancerous compartment referred to as the 'stroma'. The stroma consists of extracellular matrix (ECM) and a variety of mesenchymal cells, including fibroblasts, myofibroblasts, endothelial cells, pericytes and leukocytes (... [more] Carcinomas are complex tissues comprised of neoplastic cells and a non-cancerous compartment referred to as the 'stroma'. The stroma consists of extracellular matrix (ECM) and a variety of mesenchymal cells, including fibroblasts, myofibroblasts, endothelial cells, pericytes and leukocytes (1-3). The tumour-associated stroma is responsive to substantial paracrine signals released by neighbouring carcinoma cells. During the disease process, the stroma often becomes populated by carcinoma-associated fibroblasts (CAFs) including large numbers of myofibroblasts. These cells have previously been extracted from many different types of human carcinomas for their in vitro culture. A subpopulation of CAFs is distinguishable through their up-regulation of α-smooth muscle actin (α-SMA) expression(4,5). These cells are a hallmark of 'activated fibroblasts' that share similar properties with myofibroblasts commonly observed in injured and fibrotic tissues (6). The presence of this myofibroblastic CAF subset is highly related to high-grade malignancies and associated with poor prognoses in patients. Many laboratories, including our own, have shown that CAFs, when injected with carcinoma cells into immunodeficient mice, are capable of substantially promoting tumourigenesis (7-10). CAFs prepared from carcinoma patients, however, frequently undergo senescence during propagation in culture limiting the extensiveness of their use throughout ongoing experimentation. To overcome this difficulty, we developed a novel technique to experimentally generate immortalised human mammary CAF cell lines (exp-CAFs) from human mammary fibroblasts, using a coimplantation breast tumour xenograft model. In order to generate exp-CAFs, parental human mammary fibroblasts, obtained from the reduction mammoplasty tissue, were first immortalised with hTERT, the catalytic subunit of the telomerase holoenzyme, and engineered to express GFP and a puromycin resistance gene. These cells were coimplanted with MCF-7 human breast carcinoma cells expressing an activated ras oncogene (MCF-7-ras cells) into a mouse xenograft. After a period of incubation in vivo, the initially injected human mammary fibroblasts were extracted from the tumour xenografts on the basis of their puromycin resistance (11). We observed that the resident human mammary fibroblasts have differentiated, adopting a myofibroblastic phenotype and acquired tumour-promoting properties during the course of tumour progression. Importantly, these cells, defined as exp-CAFs, closely mimic the tumour-promoting myofibroblastic phenotype of CAFs isolated from breast carcinomas dissected from patients. Our tumour xenograft-derived exp-CAFs therefore provide an effective model to study the biology of CAFs in human breast carcinomas. The described protocol may also be extended for generating and characterising various CAF populations derived from other types of human carcinomas.
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9.43Impact points
Autocrine TGF-beta and stromal cell-derived factor-1 (SDF-1) signaling drives the evolution of tumor-promoting mammary stromal myofibroblasts.
Proceedings of the National Academy of Sciences of the United States of America. 11/2010; 107(46):20009-14.
Much interest is currently focused on the emerging role of tumor-stroma interactions essential for supporting tumor progression. Carcinoma-associated fibroblasts (CAFs), frequently present in the stroma of human breast carcinomas, include a large number of myofibroblasts, a hallmark of activated fib... [more] Much interest is currently focused on the emerging role of tumor-stroma interactions essential for supporting tumor progression. Carcinoma-associated fibroblasts (CAFs), frequently present in the stroma of human breast carcinomas, include a large number of myofibroblasts, a hallmark of activated fibroblasts. These fibroblasts have an ability to substantially promote tumorigenesis. However, the precise cellular origins of CAFs and the molecular mechanisms by which these cells evolve into tumor-promoting myofibroblasts remain unclear. Using a coimplantation breast tumor xenograft model, we show that resident human mammary fibroblasts progressively convert into CAF myofibroblasts during the course of tumor progression. These cells increasingly acquire two autocrine signaling loops, mediated by TGF-β and SDF-1 cytokines, which both act in autostimulatory and cross-communicating fashions. These autocrine-signaling loops initiate and maintain the differentiation of fibroblasts into myofibroblasts and the concurrent tumor-promoting phenotype. Collectively, these findings indicate that the establishment of the self-sustaining TGF-β and SDF-1 autocrine signaling gives rise to tumor-promoting CAF myofibroblasts during tumor progression. This autocrine-signaling mechanism may prove to be an attractive therapeutic target to block the evolution of tumor-promoting CAFs.
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6.34Impact points
Carcinoma-associated fibroblasts are a rate-limiting determinant for tumour progression.
Seminars in cell & developmental biology. 10/2009;
Tumours are highly complex tissues composed of carcinoma cells and surrounding stroma, which is constructed by various different types of mesenchymal cells and an extracellular matrix (ECM). Carcinoma-associated fibroblasts (CAFs), which consist of both fibroblasts and myofibroblasts, are frequently... [more] Tumours are highly complex tissues composed of carcinoma cells and surrounding stroma, which is constructed by various different types of mesenchymal cells and an extracellular matrix (ECM). Carcinoma-associated fibroblasts (CAFs), which consist of both fibroblasts and myofibroblasts, are frequently observed in the stroma of human carcinomas, and their presence in large numbers is often associated with the development of high-grade malignancies and poor prognoses. Moreover, in human tumour xenograft models, CAFs extracted from the tumour are more capable of promoting tumour growth through their interactions with carcinoma cells, when compared to those isolated from non-cancerous stroma. Taken together, these observations strongly suggest that CAFs actively contribute to tumour progression. In this review, we highlight the emerging roles of these cells in promoting tumourigenesis, and we discuss the molecular mechanisms underlying their tumour-promoting capabilities and their cellular origin.
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2.71Impact points
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4.09Impact points
Stromal fibroblasts in cancer: a novel tumor-promoting cell type.
Cell cycle (Georgetown, Tex.). 09/2006; 5(15):1597-601.
Tumors are highly complex tissues composed of neoplastic cells and, in the case of carcinomas, stromal cell compartments containing a variety of mesenchymal cells, notably fibroblasts, myofibroblasts, endothelial cells, pericytes, and a variety of inflammatory cells associated with the immune system... [more] Tumors are highly complex tissues composed of neoplastic cells and, in the case of carcinomas, stromal cell compartments containing a variety of mesenchymal cells, notably fibroblasts, myofibroblasts, endothelial cells, pericytes, and a variety of inflammatory cells associated with the immune system. Fibroblasts and myofibroblasts often represent the majority of the stromal cells within various types of human carcinomas, yet the specific contributions of these cells to tumor growth are poorly understood. Recent work has demonstrated that stromal fibroblast fractions, named carcinoma-associated fibroblasts (CAFs), that have been extracted from a number of invasive human breast carcinomas are more competent to promote the growth of mammary carcinoma cells and to enhance tumor angiogenesis than are comparable cells derived from outside of these tumor masses. CAFs include large populations of myofibroblasts that secrete elevated levels of stromal cell-derived factor 1 (SDF-1), also called CXCL12, which plays a central role in the promotion of tumor growth and angiogenesis; CAF-derived SDF-1 not only stimulates carcinoma cell growth directly through the CXCR4 receptor displayed on tumor cells but also serves to recruit endothelial progenitor cells (EPCs) into tumors, thereby furthering neoangiogenesis. In this review, we highlight the importance of this SDF-1-CXCR4 signaling pathway in the tumor microenvironment and discuss the mechanisms by which stromal fibroblasts within mammary carcinomas enhance tumor growth.
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31.15Impact points
Stromal fibroblasts present in invasive human breast carcinomas promote tumor growth and angiogenesis through elevated SDF-1/CXCL12 secretion.
Cell. 06/2005; 121(3):335-48.
Fibroblasts often constitute the majority of the stromal cells within a breast carcinoma, yet the functional contributions of these cells to tumorigenesis are poorly understood. Using a coimplantation tumor xenograft model, we demonstrate that carcinoma-associated fibroblasts (CAFs) extracted from h... [more] Fibroblasts often constitute the majority of the stromal cells within a breast carcinoma, yet the functional contributions of these cells to tumorigenesis are poorly understood. Using a coimplantation tumor xenograft model, we demonstrate that carcinoma-associated fibroblasts (CAFs) extracted from human breast carcinomas promote the growth of admixed breast carcinoma cells significantly more than do normal mammary fibroblasts derived from the same patients. The CAFs, which exhibit the traits of myofibroblasts, play a central role in promoting the growth of tumor cells through their ability to secrete stromal cell-derived factor 1 (SDF-1); CAFs promote angiogenesis by recruiting endothelial progenitor cells (EPCs) into carcinomas, an effect mediated in part by SDF-1. CAF-secreted SDF-1 also stimulates tumor growth directly, acting through the cognate receptor, CXCR4, which is expressed by carcinoma cells. Our findings indicate that fibroblasts within invasive breast carcinomas contribute to tumor promotion in large part through the secretion of SDF-1.
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6.75Impact points
Cancer-associated myofibroblasts possess various factors to promote endometrial tumor progression.
Clinical cancer research : an official journal of the American Association for Cancer Research. 11/2001; 7(10):3097-105.
Myofibroblastic invasion associated with malignant epithelial cells of endometrial cancer as well as other cancers is often found in the interstitium. To assess the myofibroblastic-epithelial interaction, frozen sections from a total of 10 endometrial cancers with or without invasive myofibroblasts ... [more] Myofibroblastic invasion associated with malignant epithelial cells of endometrial cancer as well as other cancers is often found in the interstitium. To assess the myofibroblastic-epithelial interaction, frozen sections from a total of 10 endometrial cancers with or without invasive myofibroblasts were immunohistochemically examined. Interestingly, the invasive myofibroblasts adjacent to malignant epithelial cells showed frequently intensive positive staining of several growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor I, and epidermal growth factor, the cognate receptors such as Fetal liver kinase-1/Kinase Insert Domain-containing receptor/VEGF receptor-2, fms-like tyrosine kinase-1/VEGF receptor-1, and epidermal growth factor receptor, several cell cycle regulators such as cyclins and cyclin dependent kinases, and estrogen receptor alpha. Moreover, we indicated that the majority of the myofibroblasts as well as cancer epithelial cells are proliferating because of their positive staining of proliferating cell nuclear antigen and Ki-67. Furthermore, the myofibroblasts were also positive of hypoxia-inducible factor 1 alpha, which is a marker protein of hypoxia, probably followed by activation of VEGF-Flk-1 and VEGF-fms-like tyrosine kinase-1 signals, which could initiate angiogenesis. These findings suggest directly that the myofibroblasts might participate in the progression of tumor cells in terms of cancer cell growth stimulation and also activated initiation of angiogenesis.
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3.33Impact points
Molecular cloning of ring finger protein 21 (RNF21)/interferon-responsive finger protein (ifp1), which possesses two RING-B box-coiled coil domains in tandem.
Genomics. 11/2000; 69(1):143-9.
We have cloned the full length of a novel cDNA, named ring finger protein 21 (RNF21), composed of the RING finger-B box-coiled coil (RBCC) domain and the B30.2 domain, which are characteristic of the RBCC-B30.2 family. As a structural feature, the RNF21 cDNA possessed at least three kinds of isoform... [more] We have cloned the full length of a novel cDNA, named ring finger protein 21 (RNF21), composed of the RING finger-B box-coiled coil (RBCC) domain and the B30.2 domain, which are characteristic of the RBCC-B30.2 family. As a structural feature, the RNF21 cDNA possessed at least three kinds of isoforms, due to alternative splicing, consisting of the long form with the RBCC-RBCC-B30.2 domain, the medium form with the RBCC-B30.2 domain, and the short form with only the RBCC domain. Moreover, respective transcripts corresponding to the three isoforms were detected in various human organs by reverse transcription-PCR and Northern blot analyses. Interestingly, the medium form of the RNF21 mRNA expressed most predominantly was dramatically up-regulated within 8-16 h by interferon stimulation of HeLa cells. These findings suggest that RNF21 is a downstream gene that may mediate interferon's biological action.
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2.55Impact points
Molecular cloning of testis-abundant finger Protein/Ring finger protein 23 (RNF23), a novel RING-B box-coiled coil-B30.2 protein on the class I region of the human MHC.
Biochemical and biophysical research communications. 10/2000; 276(1):45-51.
We have identified a genomic DNA fragment, using the PCR method with degenerate oligonucleotide primers which contain the conserved sequence of the RING finger domain. Using the DNA fragment as a probe, a novel cDNA was cloned from human and mouse testis. The cDNA had a domain structure of the typic... [more] We have identified a genomic DNA fragment, using the PCR method with degenerate oligonucleotide primers which contain the conserved sequence of the RING finger domain. Using the DNA fragment as a probe, a novel cDNA was cloned from human and mouse testis. The cDNA had a domain structure of the typical RING-B box-coiled coil (RBCC)-B30.2 domain and therefore was named testis-abundant finger protein (tfp). Indeed, the transcript was highly expressed in the testis, although it was also found ubiquitously in various organs by Northern blot analysis. The tfp gene was mapped at the class I region of the human MHC (major histocompatibility complex), within which some known RBCC-B30.2 proteins such as RFP, RFB30/HERF1, AFP, and HZF had been localized. These findings demonstrate that several RBCC-B30.2 proteins including tfp, which are non-HLA proteins, are clustered within the class I region of the human MHC.
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5.33Impact points
Impaired estrogen sensitivity in bone by inhibiting both estrogen receptor alpha and beta pathways.
The Journal of biological chemistry. 08/2000; 275(28):21372-9.
Although it is well established that estrogen deficiency causes osteoporosis among the postmenopausal women, the involvement of estrogen receptor (ER) in its pathogenesis still remains uncertain. In the present study, we have generated rats harboring a dominant negative ERalpha, which inhibits the a... [more] Although it is well established that estrogen deficiency causes osteoporosis among the postmenopausal women, the involvement of estrogen receptor (ER) in its pathogenesis still remains uncertain. In the present study, we have generated rats harboring a dominant negative ERalpha, which inhibits the actions of not only ERalpha but also recently identified ERbeta. Contrary to our expectation, the bone mineral density (BMD) of the resulting transgenic female rats was maintained at the same level with that of the wild-type littermates when sham-operated. In addition, ovariectomy-induced bone loss was observed almost equally in both groups. Strikingly, however, the BMD of the transgenic female rats, after ovariectomized, remained decreased even if 17beta-estradiol (E(2)) was administrated, whereas, in contrast, the decrease of littermate BMD was completely prevented by E(2). Moreover, bone histomorphometrical analysis of ovariectomized transgenic rats revealed that the higher rates of bone turnover still remained after treatment with E(2). These results demonstrate that the prevention from the ovariectomy-induced bone loss by estrogen is mediated by ER pathways and that the maintenance of BMD before ovariectomy might be compensated by other mechanisms distinct from ERalpha and ERbeta pathways.
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3.54Impact points
Efp as a primary estrogen-responsive gene in human breast cancer.
FEBS letters. 05/2000; 472(1):9-13.
We have previously isolated the efp (estrogen-responsive finger protein) that is required for the normal estrogen-induced cell proliferation. Here, we show the genomic organization of the human efp gene which consists of nine exons. The efp mRNA was expressed in human breast tumors and the estrogen-... [more] We have previously isolated the efp (estrogen-responsive finger protein) that is required for the normal estrogen-induced cell proliferation. Here, we show the genomic organization of the human efp gene which consists of nine exons. The efp mRNA was expressed in human breast tumors and the estrogen-induced expression of the efp was found in MCF-7 human breast cancer cells. Moreover, efp promoter activity was enhanced through the estrogen-responsive element dependent on estrogen and estrogen receptor. These results suggest that the efp can mediate estrogen actions such as cell growth in human breast cancer as a primary responsive gene.
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Chromosome mapping of RNF16 and rnf16, human, mouse and rat genes coding for testis RING finger protein (terf), a member of the RING finger family.
Cytogenetics and cell genetics. 02/2000; 89(1-2):56-8.
RNF16 (ring finger protein 16; alias terf), a member of the RING finger family, has been shown to be exclusively expressed in the testis. Human RNF16 is located at 1q42 based on PCR-assisted analysis of both a human/rodent mono-chromosomal hybrid cell panel and a radiation hybrid-mapping panel. On t... [more] RNF16 (ring finger protein 16; alias terf), a member of the RING finger family, has been shown to be exclusively expressed in the testis. Human RNF16 is located at 1q42 based on PCR-assisted analysis of both a human/rodent mono-chromosomal hybrid cell panel and a radiation hybrid-mapping panel. On the other hand, chromosomal mapping of the RNF16 gene by fluorescence in situ hybridization reveals that mouse Rnf16 is located at 11B1.2-B1.3 and rat Rnf16 at 10q22. These results provide additional evidence that the mouse 11B region displays conserved linkage homology with the rat 10q22 region, whereas in the case of RNF16, this homology is only conserved among rodents, distinct from the 1q42 region of the human genome.
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9.43Impact points
Underdeveloped uterus and reduced estrogen responsiveness in mice with disruption of the estrogen-responsive finger protein gene, which is a direct target of estrogen receptor alpha.
Proceedings of the National Academy of Sciences of the United States of America. 11/1999; 96(21):12027-32.
The biological roles of estrogen-responsive finger protein (efp) in vivo were evaluated in mice carrying a loss-of-function mutation in efp by gene-targeted mutagenesis. Although efp homozygous mice were viable and fertile in both sexes, the uterus that expressed abundant estrogen receptor alpha exh... [more] The biological roles of estrogen-responsive finger protein (efp) in vivo were evaluated in mice carrying a loss-of-function mutation in efp by gene-targeted mutagenesis. Although efp homozygous mice were viable and fertile in both sexes, the uterus that expressed abundant estrogen receptor alpha exhibited significant underdevelopment. When the ovariectomized homozygotes were subjected to 17beta-estradiol treatment, they showed remarkably attenuated responses to estrogen, as exemplified by decreased interstitial water imbibition and retarded endometrial cell increase, at least, attributable to the lower ratio of G1 to S-phase progression in epithelial cells. These results suggest that efp is essential for the normal estrogen-induced cell proliferation and uterine swelling as one of the direct targets of estrogen receptor alpha.
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2.55Impact points
Molecular cloning of rat efp: expression and regulation in primary osteoblasts.
Biochemical and biophysical research communications. 09/1999; 261(2):412-8.
We have previously identified an estrogen-responsive gene, efp (estrogen-responsive finger protein), by genomic binding-site cloning method. Here, we isolated a rat homologue of efp cDNA that encodes an open reading frame of 644 amino acids sharing high homology with human efp (69% identity at the p... [more] We have previously identified an estrogen-responsive gene, efp (estrogen-responsive finger protein), by genomic binding-site cloning method. Here, we isolated a rat homologue of efp cDNA that encodes an open reading frame of 644 amino acids sharing high homology with human efp (69% identity at the protein level) and mouse efp (80% identity at the protein level). The efp protein has a RING finger, a variant type of zinc finger motif, B1 box and B2 box, each having a pair of zinc fingers, and coiled-coil domain, belonging to the RING finger-B box-Coiled Coil (RBCC) family. Several members of RBCC family including efp have characteristic C-terminal domain, forming a subfamily. Next, we detected efp mRNA in primary osteoblasts, one of estrogen target cells, derived from the calvariae of rat fetus. An anti-efp antibody revealed the efp protein is expressed and regulated by estrogen in the primary osteoblasts. Interestingly, the efp protein in primary osteoblasts is down-regulated by 1alpha,25-dihydroxyvitamin D(3) treatment that promotes the differentiation of the cells, whereas it is up-regulated by TGF-beta1 treatment that inhibits the differentiation of the cells. These findings suggest the possible involvement of the efp in the differentiation of osteoblastic cells.
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3.29Impact points
Successful germ-line transmission of chimeras generated by coculture aggregation with J1 ES cells and eight-cell embryos.
Analytical biochemistry. 05/1999; 269(1):204-7.
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3.22Impact points
Differential immunolocalization of estrogen receptor alpha and beta in rat ovary and uterus.
Journal of molecular endocrinology. 03/1999; 22(1):37-44.
In order to investigate the localization of estrogen receptor (ER) alpha and ERbeta in the reproductive organs in the rat, polyclonal antibodies were raised to each specific amino acid sequence. The Western blot with anti-ERalpha antibody showed a 66 kDa band in rat ovary and uterus, while that with... [more] In order to investigate the localization of estrogen receptor (ER) alpha and ERbeta in the reproductive organs in the rat, polyclonal antibodies were raised to each specific amino acid sequence. The Western blot with anti-ERalpha antibody showed a 66 kDa band in rat ovary and uterus, while that with anti-ERbeta antibody detected a 55 kDa band in rat ovary, uterus and prostate. The ligand-independent nuclear localization of the two receptors was verified by immunocytochemistry. By immunohistochemistry, the nuclei of glandular and luminal epithelial cells in the uterus were stained with anti-ERalpha antibody, whereas only the nuclei of glandular epithelium cells were stained with anti-ERbeta antibody. In rat ovary, positive signals were shown with anti-ERbeta antibody in the nuclei of granulosacells. No specific immunostaining was observed with anti-ERalpha antibody. Although ERbeta was immunostained at the proestrous, metestrous and diestrous stages, the immunoreactivity of ERbeta was hardly detected at the estrous stage in rat ovary. Thus, we show differential expression of ERalpha and ERbeta in rat uterus and ovary at the protein level, which may provide a clue for understanding the roles of the two receptors in reproductive organs.
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[The molecular mechanisms of estrogen action against senile disease]
Nippon Ronen Igakkai zasshi. Japanese journal of geriatrics. 03/1999; 36(2):95-8.
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2.00Impact points
NMDA receptor type 2D gene as target for estrogen receptor in the brain.
Brain research. Molecular brain research. 02/1999; 63(2):375-9.
Although it is well known that estrogen exerts its effect in the brain, the direct target genes transcriptionally regulated by estrogen or rather estrogen receptor (ER) are almost unknown. During the search for estrogen receptor-binding sites from human CpG island library, we found one genomic DNA f... [more] Although it is well known that estrogen exerts its effect in the brain, the direct target genes transcriptionally regulated by estrogen or rather estrogen receptor (ER) are almost unknown. During the search for estrogen receptor-binding sites from human CpG island library, we found one genomic DNA fragment corresponding to the putative 3'-untranslated region of human NMDA receptor subunit 2D (NR2D) gene. It contained at least four half palindromic estrogen responsive elements (hEREs) within two hundred nucleotides, which was conserved also in the rat. Interestingly, the NR2D mRNA is co-localized with ERalpha and/or ERbeta mRNA in a number of regions of rat brain. We have also demonstrated that NR2D mRNA is up-regulated in rat hypothalamus by estrogen possibly via hEREs identified here. Thus, we suggest that NR2D is one of the direct targets of estrogen receptors which are involved in reproductive as well as non-reproductive actions in the brain.
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3.33Impact points
Molecular cloning, localization, and developmental expression of mouse brain finger protein (Bfp)/ZNF179: distribution of bfp mRNA partially coincides with the affected areas of Smith-Magenis syndrome.
Genomics. 12/1998; 54(1):59-69.
Bfp (brain finger protein) is a member of the RING finger protein family, which is highly expressed in the brain. We have previously shown that one copy of the human bfp gene, mapped at 17p11.2, was actually deleted in six of six Smith-Magenis syndrome (SMS) patients. Now we have isolated the mouse ... [more] Bfp (brain finger protein) is a member of the RING finger protein family, which is highly expressed in the brain. We have previously shown that one copy of the human bfp gene, mapped at 17p11.2, was actually deleted in six of six Smith-Magenis syndrome (SMS) patients. Now we have isolated the mouse bfp cDNA. Using in situ hybridization and immunohistochemistry, the distribution of mouse bfp mRNA and protein was identified especially in neural cells of the cerebral cortex, hippocampus, lateral amygdaloid nucleus, and ventromedial hypothalamus. In primary culture of the whole brain in a neonatal mouse, the Bfp protein was detected in both neuron and glial cells, and its subcellular localization was predominantly in the nucleus, but some amounts were also found in the cytoplasm. The bfp mRNA was also expressed strongly in the marginal zone of brain vesicles, optic stalk, and cartilage primordium, which are part of the critical tissues frequently involved in SMS patients, and in such tissues as nasal epithelium and primordium of follicles in a 13. 5-dpc embryo. Subsequently, its amount in the developing brain further increased during embryogenesis, reaching the highest level in the adult brain. These findings suggest a possibility that Bfp might be involved in the pathogenesis of Smith-Magenis syndrome as a regulator protein related to neural differentiation and function.
Following (2)
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Tamer Onder
Harvard Medical School -
Urszula M Polanska
Paterson Institute for Cancer Research
Topics (2)
