Publications by authors named "SunHwa Hong"

32 Publications

HDAC7 regulates histone 3 lysine 27 acetylation and transcriptional activity at super-enhancer-associated genes in breast cancer stem cells.

Oncogene 2019 09 2;38(39):6599-6614. Epub 2019 Aug 2.

Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Biomedical Research Building, Miami, FL, 33136, USA.

Chromatin regulation through histone modifications plays an essential role in coordinated expression of multiple genes. Alterations in chromatin induced by histone modifiers and readers regulate critical transcriptional programs involved in both normal development and tumor differentiation. Recently, we identified that histone deacetylases HDAC1 and HDAC7 are necessary to maintain cancer stem cells (CSCs) in both breast and ovarian tumors. Here, we sought to investigate the CSC-specific function of HDAC1 and HDAC7 mechanistically by using a stem-like breast cancer (BrCa) cell model BPLER and matched nonstem tumor cell (nsTC)-like HMLER, along with conventional BrCa cell lines with different CSC enrichment levels. We found that HDAC1 and HDAC3 inhibition or knockdown results in HDAC7 downregulation, which is associated with a decrease in histone 3 lysine 27 acetylation (H3K27ac) at transcription start sites (TSS) and super-enhancers (SEs) prominently in stem-like BrCa cells. Importantly, these changes in chromatin landscape also correlate with the repression of many SE-associated oncogenes, including c-MYC, CD44, CDKN1B, SLUG, VDR, SMAD3, VEGFA, and XBP1. In stem-like BrCa cells, HDAC7 binds near TSS and to SEs of these oncogenes where it appears to contribute to both H3K27ac and transcriptional regulation. These results suggest that HDAC7 inactivation, directly or through inhibition of HDAC1 and HDAC3, can result in the inhibition of the CSC phenotype by downregulating multiple SE-associated oncogenes. The CSC selective nature of this mechanism and the prospect of inhibiting multiple oncogenes simultaneously makes development of HDAC7 specific inhibitors a compelling objective.
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http://dx.doi.org/10.1038/s41388-019-0897-0DOI Listing
September 2019

Anti- activity and inhibition of gastritis by extract.

Lab Anim Res 2018 Jun 18;34(2):75-79. Epub 2018 Jun 18.

Center for Animal Resource Development, Wonkwang University, Iksan, Korea.

is widely consumed plant as a vegetable and herbal medicine in southeastern Asia. has been reported antioxidant, improvement of bone health and antidiabetic effects. In the present study, we investigated the potential inhibitory effect of extract (AHE) on . The anti-bacterial activities of AHE were determined by disk agar diffusion method. Also, the inhibition effect of the AHE on infection was investigated using a mouse model. colonization was confirmed by rapid urease tests, as described previously. Mucosal damage was evaluated grossly and histologically according to previously described criteria. As the results of the disk agar diffusion assay, CLR, AMX and MTZ inhibited the bacterial growth with inhibition zone of 19.2, 15.2 and 7.5 mm, respectively. AHE 100 µg/mL showed an inhibition zone value of 20.6 mm. Rapid urease tests of the mice stomachs demonstrated a significant reduction in colonization. In addition to the therapeutic effect against infection, the AHE reduced mucosal inflammation and epithelial damages in the stomach of -infected mice. These results demonstrate that the AHE successfully cured an infection and treated the infection. This AHE could be a promising treatment for patients with gastric complaints including gastritis caused by .
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http://dx.doi.org/10.5625/lar.2018.34.2.75DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010401PMC
June 2018

Anti-coccidial activity of the ethanol extract of fruits on .

Lab Anim Res 2018 Mar 22;34(1):44-47. Epub 2018 Mar 22.

Center for Animal Resource Development, Wonkwang University, Iksan, Korea.

Anti-coccidial effects of the fruits of (Tribuli fructus) ethanol extract (TTE) were studied with animal experiment following per oral administration with (.) . This experiment was performed on the 3-day-old chicks (n=30). The animals were divided with 3 groups; TFE 15mg per animal+infected (n=10), TTE untreated+infected (n=10) and non-infected control (n=10). Animals were administrated with or without TTE during 1 week, and then inoculated with . The anti-coccidial activity were evaluated with oocysts shedding numbers in stools, body weights changes and food intake changes. The TTE-inoclated animals revealed significantly decreased stool oocysts numbers (<0.05) when compared to the TTE untreated animals. Also, TTE-treated animals showed more increased body weight gains (<0.05) than the TTE untreated animals. These results demonstrate that TTE produce anticoccidial activities against . TTE could be a promising treatment for the coccidiosis.
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http://dx.doi.org/10.5625/lar.2018.34.1.44DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5876163PMC
March 2018

Detection of Helicobacter felis in a cat with gastric disease in laboratory animal facility.

Lab Anim Res 2016 Jun 24;32(2):122-7. Epub 2016 Jun 24.

Center for Animal Resource Development, Wonkwang University, 460 Iksandae-ro, Iksan, Korea.; Graduate School of Applied Animal Science, Wonkwang University, 460 Iksandaero, Iksan, Korea.

A 3-month-old male cat in the animal facility was presented for investigation of anorexia and occasional vomiting. We collected the specimens from gastroscopic biopsy and stool collection. The gastroscopic biopsy specimens were tested using a rapid urease test, CLO Helicobacter-detection kits. Stool specimens were gathered and evaluated using the commercially available SD Bioline H. pylori Ag kit according to the manufacturer's instructions. Genomic DNAs from gastroscopic biopsy and stool specimens of the cat were extracted and submitted to the consensus PCR to amplify Helicobacter rpoB gene. Then the DNAs from gastroscopic biopsy and stool specimens were conducted a multiplex species-specific PCR to amplify urease B gene for H. heilmannii, H. pylori and H. felis. As the results, the rapid urease test with gastroscopic biopsy was revealed positive reaction. The result of H. pylori Stool Ag assay was one red line, negative for H. pylori. The gastroscopic biopsy and stool specimen were positive reactions by the consensus PCR reaction using the RNA polymerase beta-subunit-coding gene (rpoB) to detect Helicobacter species. By multiplex species-specific PCR with gastroscopic biopsy and stool specimens, no amplification products corresponding to either H. heilmannii or H. pylori were detected, but the specimens tested were positive for H. felis. This case was confirmed as gastroenteric disease induced by H. felis infection. On our knowledge, this is a very rare report about H. felis-induced gastroenteric disease in cat and may provide a valuable data on the study of feline Helicobacter infection.
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http://dx.doi.org/10.5625/lar.2016.32.2.122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931036PMC
June 2016

Anticoccidial effects of the Plantago asiatica extract on experimental Eimeria tenella infection.

Lab Anim Res 2016 Mar 24;32(1):65-9. Epub 2016 Mar 24.

Center for Animal Resource Development, Animal Disease Research Unit, Wonkwang University, 460 Iksandaero, Iksan 54538, Korea.

Anticoccidial effects of the Plantago asiatica extract (PAE) were evaluated in chickens following oral infection with Eimeria (E.) tenella. This study was conducted on the 3-day-old chickens (n=30). Those animals were divided with 3 groups; PAE 0.1% treated/infected (n=10), PAE untreated/infected (n=10) and non-infected control (n=10). Chickens were fed a standard diet supplemented with or without PAE for 1 week prior to infection with E. tenella (10,000 sporulated oocysts per chicken). The effects of PAE on E. tenella infection were assessed by two parameters; fecal oocysts shedding and body weights gain. The PAE-fed chickens produced significantly reduced fecal oocysts (P<0.05) when compared to the E. tenella-infected group fed standard diet. Also, PAE-based diet, improved body weight loss caused by E. tenella infection. Our data demonstrated that PAE had remarkable anticoccidial activities against E. tenella. This finding might have implications for the development of anticoccidial drug. This study is the first to demonstrate anticoccidial effect of PAE on Eimeria parasites.
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http://dx.doi.org/10.5625/lar.2016.32.1.65DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816998PMC
March 2016

Comparison of three diagnostic assays for the identification of Helicobacter spp. in laboratory dogs.

Lab Anim Res 2015 Jun 26;31(2):86-92. Epub 2015 Jun 26.

Center for Animal Resource Development, Wonkwang University, Iksan, Korea. ; Graduate School of Applied Animal Science, Wonkwang University, Iksan, Korea.

A number of Helicobacter species may confound experimental data because of their association with disease progressing in various kinds of laboratory animals. Screening of Helicobacter species is particularly desirable, because they are prevalent in commercial and research animal facilities. The aim of the present study was to compare three diagnostic methods [e.g. Helicobacter stool antigen kit (HpSA), polymerase chain reaction (PCR) and rapid urease test (RUT)] for the identification of Helicobacter spp. in stools or gastric biopsy specimens collected from eight dogs suffering from gastritis. The gastroscopic biopsy specimens were tested using RUT and PCR, while stool specimens were evaluated using both HpSA and PCR. DNAs from the gastric biopsies and stool specimens were analyzed by both a consensus PCR that amplified the RNA polymerase beta-subunit-coding gene (rpoB) of Helicobacter spp. and a species-specific PCR to amplify the urease B gene of Helicobacter heilmannii, Helicobacter pylori, and Helicobacter felis. Helicobacter spp. were detected in 62.5% of the dogs, while H. heilmannii and H. felis were identified in 37.5 and 25% of the dogs, respectively. The HpSA did not efficiently detect Helicobacter spp. in the stool samples compared to the RUT and PCR assays, both of which successfully detected Helicobacter spp. in the two sample types. Finally, we recommend that consensus PCR with stool specimens could be used before the species-specific PCR for identifying Helicobacter species in laboratory dogs.
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http://dx.doi.org/10.5625/lar.2015.31.2.86DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4490150PMC
June 2015

Anticoccidial effects of the root bark of Dictamnus dasycarpus Turcz extract on experimental Eimeria tenella infection.

Lab Anim Res 2014 Dec 24;30(4):169-73. Epub 2014 Dec 24.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea. ; Institute of Animal Experiment & Efficacy Evaluation, Wonkwang University, Iksan, Korea.

Anticoccidial effects of the root bark of Dictamnus dasycarpus Turcz (Rutaceae) extract (DDE) were evaluated in chickens following oral infection with Eimeria (E.) tenella. Three-day-old chickens (n=30) were assigned to three groups (control, untreated, and DDE 0.1% treated). Chickens were fed a standard diet supplemented with or without DDE for 1 week prior to infection with E. tenella (10,000 sporulated oocysts per chicken). The effects of DDE on E. tenella infection were assessed by two parameters; fecal oocysts shedding and body weights gain. The DDE-fed chickens produced significantly reduced fecal oocysts (P<0.05) when compared to the E. tenella-infected group fed standard diet. Also, DDE-based diet, improved body weight loss caused by E. tenella infection. Our data demonstrated that DDE had remarkable anticoccidial activities against E. tenella. This finding might have implications for the development of anticoccidial drug. This study is the first to demonstrate anticoccidial effect of DDE on Eimeria parasites.
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http://dx.doi.org/10.5625/lar.2014.30.4.169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306704PMC
December 2014

Onion peel water extracts enhance immune status in forced swimming rat model.

Lab Anim Res 2014 Dec 24;30(4):161-8. Epub 2014 Dec 24.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea. ; Institute of Animal Experiment & Efficacy Evaluation, Wonkwang University, Iksan, Korea.

Onion peel contains a high concentration of quercetin and other flavonoids. In this study, the potential immune-enhancing effects of an onion peel water extract (OPE) supplement were investigated by the rat forced swimming test. OPE was prepared using hot water. Thirty-six male Sprague Dawley rats were fed a pellet diet for 1 week and were then randomly divided into six groups: normal control (NC), forced swimming control (FSC), positive control (quercetin 20 mg/kg), and three groups administered 4, 20, or 100 mg/kg of OPE. Oral drug administration was conducted daily for 4 weeks. All rats, except those of NC group, were forced to swim in water and were considered exhausted when they failed to rise to the water surface to breathe within a 7-s period. Blood lymphocyte counts, immune organ weights, histopathological analysis, and serum interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-12 levels were determined. OPE-treated rats consumed more food and had an increased thymic cortex to medulla ratio than that observed in FSC group rats (P<0.05). The area of the white pulp in the spleens of OPE-treated group rats was increased compared with that in FSC group rats (P<0.05). Furthermore, blood lymphocyte numbers and IFN-γ, TNF-α, and IL-12 concentrations were significantly higher in OPE-fed groups than in FSC group (P<0.05). These results suggest that an OPE supplement can improve the immune status by increasing the number of immune-related cells and specific cytokine levels.
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http://dx.doi.org/10.5625/lar.2014.30.4.161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306703PMC
December 2014

Granulopoiesis requires increased C/EBPα compared to monopoiesis, correlated with elevated Cebpa in immature G-CSF receptor versus M-CSF receptor expressing cells.

PLoS One 2014 21;9(4):e95784. Epub 2014 Apr 21.

Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America.

C/EBPα is required for the formation of granulocyte-monocyte progenitors; however, its role in subsequent myeloid lineage specification remains uncertain. Transduction of murine marrow with either of two Cebpa shRNAs markedly increases monocyte and reduces granulocyte colonies in methylcellulose or the monocyte to neutrophil ratio in liquid culture. Similar findings were found after marrow shRNA transduction and transplantation and with CEBPA knockdown in human marrow CD34+ cells. These results apparently reflect altered myeloid lineage specification, as similar knockdown allowed nearly complete 32Dcl3 granulocytic maturation. Cebpa knockdown also generated lineage-negative blasts with increased colony replating capacity but unchanged cell cycle parameters, likely reflecting complete differentiation block. The shRNA having the greatest effect on lineage skewing reduced Cebpa 3-fold in differentiating cells but 6-fold in accumulating blasts. Indicating that Cebpa is the relevant shRNA target, shRNA-resistant C/EBPα-ER rescued marrow myelopoiesis. Cebpa knockdown in murine marrow cells also increased in vitro erythropoiesis, perhaps reflecting 1.6-fold reduction in PU.1 leading to GATA-1 derepression. Global gene expression analysis of lineage-negative blasts that accumulate after Cebpa knockdown demonstrated reduction in Cebpe and Gfi1, known transcriptional regulators of granulopoiesis, and also reduced Ets1 and Klf5. Populations enriched for immature granulocyte or monocyte progenitor/precursors were isolated by sorting Lin-Sca-1-c-Kit+ cells into GCSFR+MCSFR- or GCSFR-MCSFR+ subsets. Cebpa, Cebpe, Gfi1, Ets1, and Klf5 RNAs were increased in the c-Kit+GCSFR+ and Klf4 and Irf8 in the c-Kit+MCSFR+ populations, with PU.1 levels similar in both. In summary, higher levels of C/EBPα are required for granulocyte and lower levels for monocyte lineage specification, and this myeloid bifurcation may be facilitated by increased Cebpa gene expression in granulocyte compared with monocyte progenitors.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095784PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994156PMC
June 2015

Usefulness of a Helicobacter pylori stool antigen test for diagnosing H. pylori infected C57BL/6 mice.

Lab Anim Res 2013 Mar 25;29(1):27-32. Epub 2013 Mar 25.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea. ; Huvet. Inc., Iksan, Korea.

Among several diagnostic tests, a Helicobacter pylori stool antigen (HpSA) test may offer a useful noninvasive method for diagnosing infection without sacrificing animals. In this study, male C57BL/6 mice (n=6) were infected with H. pylori ATCC 49503 (1×10(8) CFU/mouse) by intragastric inoculation three times at 2-day intervals, and H. pylori infected stool specimens were collected 1, 3, 5, 7, 14, 21 days after infection to assess reliability of the HpSA test. Five of six specimens were positive at 5-21 days after infection, and the sensitivity of the HpSA test was 83.33%. The presence of H. pylori infection was confirmed by the rapid urease test and genomic DNA polymerase chain reaction (PCR), and showed the same results as the HpSA. However, the rapid urease test and genomic DNA PCR are invasive tests and require animal sacrifice to detect H. pylori in gastric biopsy samples. We suggest that an HpSA test kit would be useful and effective for monitoring H. pylori in various laboratory animals, as H. pylori can be easily monitored without sacrificing animals.
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http://dx.doi.org/10.5625/lar.2013.29.1.27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616206PMC
March 2013

Anticoccidial effects of Galla rhois extract on Eimeria tenella-infected chicken.

Lab Anim Res 2012 Sep 26;28(3):193-7. Epub 2012 Sep 26.

Korean Medicine (KM)-Based Herbal Drug Research Group, Korea Institute of Oriental Medicine, Dajeon, Korea.

Anticoccidial effects of Galla rhois (GR) extract were evaluated in chickens after oral infection with Eimeria tenella. This study was performed using 3-day-old chickens (n=30). The animals were divided into 3 groups as follows: GR 0.5%/infected (n=10), untreated/infected (n=10), and non-infected control (n=10). The chickens were fed a standard diet supplemented with or without GR for 1 week before infection with E. tenella (10,000 sporulated oocysts per chicken). The effects of GR on E. tenella infection were assessed by 2 parameters, number of fecal oocysts and body weight gain, and the results of the polymerase chain reaction (PCR). The GR-fed chickens produced significantly lower number of fecal oocysts (P<0.05) than the E. tenella-infected chickens who were fed the standard diet. In addition, GR-based diet improved the loss of body weight caused by E. tenella infection. Positive findings of PCR were identified by distinct bands in the samples of E. tenella-inoculated chickens. However, PCR analysis revealed no E. tenella oocysts in the feces of GR-fed chickens. Our data showed that GR extracts had remarkable anticoccidial activities against E. tenella. This finding might have implications for the development of novel anticoccidial drugs.
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http://dx.doi.org/10.5625/lar.2012.28.3.193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3469847PMC
September 2012

Molecular identification of Mycoplasma cynos from laboratory beagle dogs with respiratory disease.

Lab Anim Res 2012 Mar 21;28(1):61-6. Epub 2012 Mar 21.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea.

In this study, we examined a colony of 20 beagle dogs in a laboratory animal facility. Mycoplasma was detected by consensus PCR assay in 1 dog with respiratory and constitutional symptoms. None of the other dogs were affected. The dog was euthanized and necropsied. In postmortem examinations, gray or plum-colored gross lesions were found on the lung, most commonly in the apical and cardiac lobes. Some lesions showed clear demarcation and consolidation. Microscopic examination showed peribronchiolar lymphoid hyperplasia and interstitial thickening, lesions pathognomonic for mycoplasma pneumonia. To identify canine Mycoplasma species, we used species-specific PCR reactions for M. arginini, M. canis, M. cynos, M. edwardii, M. felis, M. gateae, M. maculosum, M. molare, M. opalescens, M. spumans, Mycoplasma sp. HRC 689, and M. collis. As the result, we identified Mycoplasma cynos by amplification of DNA extracted from lung tissue of the laboratory beagle dog with respiratory disease.
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http://dx.doi.org/10.5625/lar.2012.28.1.61DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3315197PMC
March 2012

Uterine adenocarcinoma with feline leukemia virus infection.

Lab Anim Res 2011 Dec 19;27(4):347-51. Epub 2011 Dec 19.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea.

Feline endometrial adenocarcinomas are uncommon malignant neoplasms that have been poorly characterized to date. In this study, we describe a uterine adenocarcinoma in a Persian cat with feline leukemia virus infection. At the time of presentation, the cat, a female Persian chinchilla, was 2 years old. The cat underwent surgical ovariohystectomy. A cross-section of the uterine wall revealed a thickened uterine horn. The cat tested positive for feline leukemia virus as detected by polymerase chain reaction. Histopathological examination revealed uterine adenocarcinoma that had metastasized to the omentum, resulting in thickening and the formation of inflammatory lesions. Based on the histopathological findings, this case was diagnosed as a uterine adenocarcinoma with abdominal metastasis. To the best of our knowledge, this is the first report of a uterine adenocarcinoma with feline leukemia virus infection.
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http://dx.doi.org/10.5625/lar.2011.27.4.347DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3251767PMC
December 2011

Affinity purification of MLL3/MLL4 histone H3K4 methyltransferase complex.

Methods Mol Biol 2012 ;809:465-72

Nuclear Receptor Biology Section, NIDDK, NIH, Bethesda, MD, USA.

Methylation on histone H3 lysine 4 (H3K4) correlates with actively transcribed genes. In mammalian cells, there exist multiple Set1-like histone H3K4 methyltransferase complexes, which have overlapping but distinct subunit compositions. Developing methods to isolate each of these histone H3K4 methyltransferase complexes would help understand the molecular mechanisms by which histone H3K4 methylation regulates mammalian gene expression. In this chapter, we provide a one-step affinity purification protocol on isolation of the MLL3/MLL4 histone H3K4 methyltransferase complex using FLAG-tagged PA1, a unique subunit of the MLL3/MLL4 complex.
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http://dx.doi.org/10.1007/978-1-61779-376-9_30DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3467094PMC
March 2012

Sensitive and specific identification by polymerase chain reaction of Eimeria tenella and Eimeria maxima, important protozoan pathogens in laboratory avian facilities.

Lab Anim Res 2011 Sep 30;27(3):255-8. Epub 2011 Sep 30.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea.

Eimeria tenella and Eimeria maxima are important pathogens causing intracellular protozoa infections in laboratory avian animals and are known to affect experimental results obtained from contaminated animals. This study aimed to find a fast, sensitive, and efficient protocol for the molecular identification of E. tenella and E. maxima in experimental samples using chickens as laboratory avian animals. DNA was extracted from fecal samples collected from chickens and polymerase chain reaction (PCR) analysis was employed to detect E. tenella and E. maxima from the extracted DNA. The target nucleic acid fragments were specifically amplified by PCR. Feces secreting E. tenella and E. maxima were detected by a positive PCR reaction. In this study, we were able to successfully detect E. tenella and E. maxima using the molecular diagnostic method of PCR. As such, we recommended PCR for monitoring E. tenella and E. maxima in laboratory avian facilities.
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http://dx.doi.org/10.5625/lar.2011.27.3.255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3188734PMC
September 2011

Spontaneous osteosarcoma of the femur in a non-obese diabetic mouse.

Lab Anim Res 2011 Sep 30;27(3):251-4. Epub 2011 Sep 30.

Center for Animal Resources Development, Wonkwang University, Iksan, Korea.

An abnormal swelling was identified in the distal portion of the right femur in a 1-year-old non-obese diabetic (NOD) mouse. Grossly, a large mass of the distal femur was observed in the right femur. Lesions were poorly marginated, associated with destruction of the cancellous and cortical elements of the bone, and showed ossification within the soft tissue component. Histologically, the tumor was identified as a poorly differentiated sarcoma. Histopathologic examination of the bone masses revealed invasive proliferation of poorly differentiated neoplastic mesenchymal cells forming streams, bundles, and nests, which resulted in destruction of normal bone. Neoplastic cells exhibited random variation in cellular appearance and arrangement, as well as matrix composition and abundance. Haphazard and often intermingling patterns of osteogenic, chondroblastic, lipoblastic, and angiogenic tissues were present. Larger areas of neoplastic bone and hyaline cartilage contained multiple large areas of hemorrhage and necrosis bordered by neoplastic cells. The mass was diagnosed as an osteosarcoma. To our knowledge, this is the first spontaneous osteosarcoma in an NOD mouse.
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http://dx.doi.org/10.5625/lar.2011.27.3.251DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3188733PMC
September 2011

Spontaneous sertoli cell tumor with cryptorchism in a beagle dog.

Lab Anim Res 2011 Jun 22;27(2):177-8. Epub 2011 Jun 22.

Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea.

A male one year-old beagle dog with unilateral cryptorchism was presented for investigation of reduced appetite. Abdominal sonography and radiography demonstrated abnormal enlargement of the left testicle in the abdominal cavity. Both the retroperitoneal cryptorchid testicle and the other contralateral testicle were removed surgically. The retroperitoneal cryptorchid testicle was an enlarged, firm and bulging sphere mass. The cut surface revealed a homogeneous white color. The contralateral testicle in the scrotum showed an almost normal appearance. Histopathologically, the retroperitoneal cryptorchid testicle was diagnosed as a Sertoli cell tumor. This report describes a case of Sertoli cell tumor with cryptorchism in a beagle dog.
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http://dx.doi.org/10.5625/lar.2011.27.2.177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3146002PMC
June 2011

Sensitive and Specific Detection of Mycoplasma species by Consensus Polymerase Chain Reaction and Dot Blot Hybridization.

Lab Anim Res 2011 Jun 22;27(2):141-5. Epub 2011 Jun 22.

Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea.

Mycoplasmas are highly fastidious bacteria, difficult to culture and slow growing. Many species of mycoplasmas are important pathogens that cause respiratory infection in laboratory animals and that are known to affect experimental results obtained with contaminated animals. The aim of the present study was to develop a sensitive and specific assay for the detection of mycoplasma species. To this end, we developed a polymerase chain reaction and dot blot hybridization assay (PCR/DBH) for detecting mycoplasma DNA and evaluated it for its sensitivity and specificity. Mycoplasma consensus primer pairs were used for the amplification of target DNA. When PCR product was visually detected, the limit of detection of the PCR test was 10(2) pg of mycoplasma purified DNA. For DBH, the amplified DNA was labeled by incorporation of digoxigenin (DIG). This DIG-labeled probe was capable of detecting 10(4) pg of purified mycoplasma DNA by DBH. PCR/DBH was more sensitive than PCR or DBH alone and was also very specific. Our PCR/DBH assay can be applied efficiently to confirm the presence of mycoplasma species on clinical samples and to differentiate between mycoplasma species infection and other bacterial infections.
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http://dx.doi.org/10.5625/lar.2011.27.2.141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145997PMC
June 2011

Mural folliculitis and alopecia with cutaneous candidiasis in a beagle dog.

Lab Anim Res 2011 Mar 25;27(1):63-5. Epub 2011 Mar 25.

Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea.

A one-year-old male Beagle dog showed dermatitis, alopecia and scales. Examination of the affected dog revealed generalized alopecia, patchy erythema, and superficial erosions with histological evidence of mural folliculitis. External tests for parasites in scraped skin samples were negative. However, fungal culture tests and polymerase chain reaction revealed the existence of Candida in the lesion. These results suggest that cutaneous candidiasis may induce mural folliculitis and alopecia in dogs.
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http://dx.doi.org/10.5625/lar.2011.27.1.63DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145986PMC
March 2011

Cronobacter sakazakii Infection Induced Fatal Clinical Sequels Including Meningitis in Neonatal ICR Mice.

Lab Anim Res 2011 Mar 25;27(1):59-62. Epub 2011 Mar 25.

Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea.

Cronobacter sakazakii (C. sakazakii), formerly Enterobacter sakazakii, is an emerging pathogen associated with the ingestion of contaminated reconstituted formula that causes serious illnesses such as bacteremia, septicemia, necrotizing enterocolitis, meningitis and death in low-birth-weight preterm neonatal infants. The objective of this study was to develop an animal model for human neonatal C. sakazakii infections. We acquired timed-pregnant ICR mice and allowed them to give birth naturally. On postnatal day 3.5, each pup was administered orally a total dose of approximately 10(7) CFU C. sakazakii strain 3439. Mice were observed twice daily for morbidity and mortality. At postnatal day 10.5, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of C. sakazakii. C. sakazakii was isolated from cecum and other tissues in inoculated mice. In the tissues of C. sakazakii infected mice, meningitis and gliosis were detected in brain. In this study, we confirmed the neonatal ICR mice may be used a very effective animal model for human neonatal C. sakazakii infections.
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http://dx.doi.org/10.5625/lar.2011.27.1.59DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145988PMC
March 2011

AP-1 protein induction during monopoiesis favors C/EBP: AP-1 heterodimers over C/EBP homodimerization and stimulates FosB transcription.

J Leukoc Biol 2011 Oct 4;90(4):643-51. Epub 2011 May 4.

Division of Pediatric Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.

AP-1 proteins heterodimerize via their LZ domains to bind TGACGTCA or TGACTCA, whereas C/EBPs dimerize to bind ATTGCGCAAT. We demonstrate that intact C/EBPα also heterodimerizes with c-Jun or c-Fos to bind a hybrid DNA element, TGACGCAA, or more weakly to TGATGCAA. A 2:1 ratio of c-Jun:C/EBPα or c-Fos:C/EBPα was sufficient for preferential binding. Semiquantitative Western blot analysis indicates that the summation of c-Jun, JunB, and c-Fos levels in differentiating myeloid cells is similar to or exceeds the entirety of C/EBPα and C/EBPβ, indicating the feasibility of heterodimer formation. Induction of AP-1 proteins during monocytic differentiation favored formation of C/EBP:AP-1 heterodimers, with C/EBPα homodimers more evident during granulopoiesis. Approximately 350 human and 300 murine genes contain the TGACGCAA motif between -2 kb and +1 kb of their transcription start sites. We focused on the murine Fosb promoter, which contains a C/EBP:AP-1 cis element at -56 and -253, with the hFOSB gene containing an identical site at -253 and a 1-bp mismatch at -56. C/EBPα:AP-1 heterodimers bound either site preferentially in a gel-shift assay, C/EBPα:c-Fos ER fusion proteins induced endogenous Fosb mRNA but not in the presence of CHX, C/EBP and AP-1 proteins bound the endogenous Fosb promoter, mutation of the -56 cis element reduced reporter activity fivefold, and endogenous FosB protein was expressed preferentially during monopoiesis versus granulopoiesis. Increased expression of Jun/Fos proteins elevates C/EBP:AP-1 heterodimer formation to potentially activate novel sets of genes during monopoiesis and potentially during other biologic processes.
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http://dx.doi.org/10.1189/jlb.0111043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3177697PMC
October 2011

UTX mediates demethylation of H3K27me3 at muscle-specific genes during myogenesis.

EMBO J 2010 Apr 18;29(8):1401-11. Epub 2010 Mar 18.

Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

Polycomb (PcG) and Trithorax (TrxG) group proteins act antagonistically to establish tissue-specific patterns of gene expression. The PcG protein Ezh2 facilitates repression by catalysing histone H3-Lys27 trimethylation (H3K27me3). For expression, H3K27me3 marks are removed and replaced by TrxG protein catalysed histone H3-Lys4 trimethylation (H3K4me3). Although H3K27 demethylases have been identified, the mechanism by which these enzymes are targeted to specific genomic regions to remove H3K27me3 marks has not been established. Here, we demonstrate a two-step mechanism for UTX-mediated demethylation at muscle-specific genes during myogenesis. Although the transactivator Six4 initially recruits UTX to the regulatory region of muscle genes, the resulting loss of H3K27me3 marks is limited to the region upstream of the transcriptional start site. Removal of the repressive H3K27me3 mark within the coding region then requires RNA Polymerase II (Pol II) elongation. Interestingly, blocking Pol II elongation on transcribed genes leads to increased H3K27me3 within the coding region, and formation of bivalent (H3K27me3/H3K4me3) chromatin domains. Thus, removal of repressive H3K27me3 marks by UTX occurs through targeted recruitment followed by spreading across the gene.
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http://dx.doi.org/10.1038/emboj.2010.37DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2868576PMC
April 2010

Histone methylation regulator PTIP is required for PPARgamma and C/EBPalpha expression and adipogenesis.

Cell Metab 2009 Jul;10(1):27-39

Nuclear Receptor Biology Section, CEB, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

PPARgamma and C/EBPalpha cooperate to control preadipocyte differentiation (adipogenesis). However, the factors that regulate PPARgamma and C/EBPalpha expression during adipogenesis remain largely unclear. Here, we show PTIP, a protein that associates with histone H3K4 methyltransferases, regulates PPARgamma and C/EBPalpha expression in mouse embryonic fibroblasts (MEFs) and during preadipocyte differentiation. PTIP deletion in MEFs leads to marked decreases of PPARgamma expression and PPARgamma-stimulated C/EBPalpha expression. Further, PTIP is essential for induction of PPARgamma and C/EBPalpha expression during preadipocyte differentiation. Deletion of PTIP impairs the enrichment of H3K4 trimethylation and RNA polymerase II on PPARgamma and C/EBPalpha promoters. Accordingly, PTIP(-/-) MEFs and preadipocytes all show striking defects in adipogenesis. Rescue of the adipogenesis defect in PTIP(-/-) MEFs requires coexpression of PPARgamma and C/EBPalpha. Finally, deletion of PTIP in brown adipose tissue significantly reduces tissue weight. Thus, by regulating PPARgamma and C/EBPalpha expression, PTIP plays a critical role in adipogenesis.
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http://dx.doi.org/10.1016/j.cmet.2009.05.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2732027PMC
July 2009

Identification of JmjC domain-containing UTX and JMJD3 as histone H3 lysine 27 demethylases.

Proc Natl Acad Sci U S A 2007 Nov 14;104(47):18439-44. Epub 2007 Nov 14.

Nuclear Receptor Biology Section, Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Covalent modifications of histones, such as acetylation and methylation, play important roles in the regulation of gene expression. Histone lysine methylation has been implicated in both gene activation and repression, depending on the specific lysine (K) residue that becomes methylated and the state of methylation (mono-, di-, or trimethylation). Methylation on K4, K9, and K36 of histone H3 has been shown to be reversible and can be removed by site-specific demethylases. However, the enzymes that antagonize methylation on K27 of histone H3 (H3K27), an epigenetic mark important for embryonic stem cell maintenance, Polycomb-mediated gene silencing, and X chromosome inactivation have been elusive. Here we show the JmjC domain-containing protein UTX (ubiquitously transcribed tetratricopeptide repeat, X chromosome), as well as the related JMJD3 (jumonji domain containing 3), specifically removes methyl marks on H3K27 in vitro. Further, the demethylase activity of UTX requires a catalytically active JmjC domain. Finally, overexpression of UTX and JMJD3 leads to reduced di- and trimethylation on H3K27 in cells, suggesting that UTX and JMJD3 may function as H3K27 demethylases in vivo. The identification of UTX and JMJD3 as H3K27-specific demethylases provides direct evidence to indicate that similar to methylation on K4, K9, and K36 of histone H3, methylation on H3K27 is also reversible and can be dynamically regulated by site-specific histone methyltransferases and demethylases.
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http://dx.doi.org/10.1073/pnas.0707292104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2141795PMC
November 2007

PTIP associates with MLL3- and MLL4-containing histone H3 lysine 4 methyltransferase complex.

J Biol Chem 2007 Jul 11;282(28):20395-406. Epub 2007 May 11.

Nuclear Receptor Biology Section, Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

PTIP, a protein with tandem BRCT domains, has been implicated in DNA damage response. However, its normal cellular functions remain unclear. Here we show that while ectopically expressed PTIP is capable of interacting with DNA damage response proteins including 53BP1, endogenous PTIP, and a novel protein PA1 are both components of a Set1-like histone methyltransferase (HMT) complex that also contains ASH2L, RBBP5, WDR5, hDPY-30, NCOA6, SET domain-containing HMTs MLL3 and MLL4, and substoichiometric amount of JmjC domain-containing putative histone demethylase UTX. PTIP complex carries robust HMT activity and specifically methylates lysine 4 (K4) on histone H3. Furthermore, PA1 binds PTIP directly and requires PTIP for interaction with the rest of the complex. Moreover, we show that hDPY-30 binds ASH2L directly. The evolutionarily conserved hDPY-30, ASH2L, RBBP5, and WDR5 likely constitute a subcomplex that is shared by all human Set1-like HMT complexes. In contrast, PTIP, PA1, and UTX specifically associate with the PTIP complex. Thus, in cells without DNA damage agent treatment, the endogenous PTIP associates with a Set1-like HMT complex of unique subunit composition. As histone H3 K4 methylation associates with active genes, our study suggests a potential role of PTIP in the regulation of gene expression.
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http://dx.doi.org/10.1074/jbc.M701574200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729684PMC
July 2007

Coactivator ASC-2 mediates heat shock factor 1-mediated transactivation dependent on heat shock.

FEBS Lett 2004 Feb;559(1-3):165-70

Department of Molecular Biology, Pusan National University, Busan 609-735, South Korea.

Upon exposure to elevated temperatures, mammalian cells increase the expression of the heat shock proteins (HSP) through activation of the heat shock factor 1 (HSF1). Since most transcription factors require coactivators for efficient transcriptional activity, we tried to identify the coactivator(s) that interacts with and modulates the activities of HSF1. In vitro glutathione S-transferase (GST) pull-down assay revealed that HSF1 strongly interacts with activating signal cointegrator (ASC)-2 and weakly with cyclic adenosine monophosphate responsive element binding protein (CBP). We also show that cotransfection of ASC-2, but not CBP, potentiates HSF1-mediated transactivation based on its cognate element (heat shock element, HSE) linked to luciferase reporter. The molecular interaction of HSF1 and ASC-2 was stimulated by heat shock in cells and the overexpression of HSF1-interacting domain of ASC-2 inhibited the specific induced protein association and HSF1-mediated transactivation. Taking these results together, we suggest that ASC-2 in a novel coactivator for HSF1 and heat shock stress may contribute the strong active transcription complex through sequential recruitment of HSF1 and ASC-2.
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http://dx.doi.org/10.1016/S0014-5793(04)00028-6DOI Listing
February 2004

Activation and interaction of ATF2 with the coactivator ASC-2 are responsive for granulocytic differentiation by retinoic acid.

J Biol Chem 2004 Apr 20;279(17):16996-7003. Epub 2004 Jan 20.

Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 609-735, Korea.

Terminal differentiation of hematopoietic cells follows a precisely orchestrated program of transcriptional regulatory events at the promoters of both lineage-specific and ubiquitous genes. Here we show that the transcription factor ATF2 is associated with the induction of granulocytic differentiation, and the molecular interaction of ATF2 with a tissue-specific coactivator activating signal cointegator-2 (ASC-2) potentiates the differentiation procedure. All-trans retinoic acid (RA) induced the phosphorylation and expression of ATF2 in the early and middle phase of granulocyte differentiation, respectively. The activation of granulocyte-specific gene expression is increased with the concerted action of another basic regionleucine zipper factor, CCAAT/enhancer-binding protein (C/EBPalpha), and ASC-2, which function in a cooperative manner. The interaction between ATF2 and C/EBPalpha in RA-treated cells was enhanced by the ectopic expression of ASC-2. ATF2-mediated transactivation was also increased by co-transfection of ASC-2. This resulted from the direct protein interaction that the N-terminal transactivation domain of ATF2 interacts with the central region of ASC-2. Furthermore, the molecular interaction of ATF2 and ASC-2 was stimulated by RA treatment and inhibited by p38beta kinase inhibitor. Taking these results together, these results suggest that the differentiation-dependent expression and phosphorylation of ATF2 protein physically and functionally interacts with C/EBPalpha and coativator ASC-2 and synergizes to induce target gene transcription during granulocytic differentiation.
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http://dx.doi.org/10.1074/jbc.M311752200DOI Listing
April 2004

Interactions between activating signal cointegrator-2 and the tumor suppressor retinoblastoma in androgen receptor transactivation.

J Biol Chem 2004 Feb 25;279(8):7131-5. Epub 2003 Nov 25.

Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.

Activating signal cointegrator-2 (ASC-2), a cancer-amplified transcription coactivator of nuclear receptors and numerous other transcription factors, was previously shown to contain two LXXLL motifs, each of which interacts with a distinct set of nuclear receptors. In this work, we showed that ASC-2 has an indirect, separate binding site for androgen receptor (AR). Interestingly, this region overlapped with the direct interaction interfaces with the tumor suppressor retinoblastoma (Rb). Although ASC-2 alone stimulated AR transactivation in cotransfections of HeLa cells, ectopic expression of Rb effected ASC-2 to act as a transcription coactivator of AR in Rb-null Saos2 cells. These results, along with the previous report in which AR was shown to directly interact with Rb (Yeh, S., Miyamoto, H., Nishimura, K., Kang, H., Ludlow, J., Hsiao, P., Wang, C., Su, C., and Chang C. (1998) Biochem. Biophys. Res. Commun. 248, 361-367), suggest that the AR-ASC-2 interactions in vivo may involve Rb. Thus, ASC-2 appears to contain at least three distinct nuclear receptor interaction domains.
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http://dx.doi.org/10.1074/jbc.M312563200DOI Listing
February 2004

Interaction and functional cooperation of the cancer-amplified transcriptional coactivator activating signal cointegrator-2 and E2F-1 in cell proliferation.

Mol Cancer Res 2003 Nov;1(13):948-58

Laboratory of Molecular Growth Regulation, National Institute of Health, Bethesda, MD, USA.

Activating signal cointegrator-2 (ASC-2), a novel coactivator, is amplified in several cancer cells and known to interact with mitogenic transcription factors, including serum response factor, activating protein-1, and nuclear factor-kappaB, suggesting the physiological role of ASC-2 in the promotion of cell proliferation. Here, we show that the expression pattern of ASC-2 was correlated with that of E2F-1 for protein increases at G(1) and S phase. Furthermore, cells stably overexpressing ASC-2 had an increased cell proliferation profile. These results prompted us to examine the functional interaction of ASC-2 and E2F-1. Biochemical evidence of protein interaction indicated that the transactivation domain of E2F-1 interacted with the COOH-terminal region of ASC-2. The importance of the E2F-1-ASC-2 interaction was supported by the demonstration that the coexpression of ASC-2 and E2F-1 synergistically transactivated E2F-1-driven gene transcription and the acetylation of E2F-1 protein was necessary for ASC-2-mediated transcriptional coactivation. Interestingly, overexpression of ASC-2 increased the endogenous protein level of E2F-1 in cells, resulting from the prolonged protein stability of E2F-1. Taken together, these results suggest that the cancer-amplified transcriptional coactivator ASC-2 may promote cell proliferation through enhancement of E2F-1-dependent transactivation of the expression of genes associated with cell cycle progression that may be available to favor tumor growth in vivo.
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November 2003

Hepatitis B virus X protein regulates transactivation activity and protein stability of the cancer-amplified transcription coactivator ASC-2.

Hepatology 2003 Nov;38(5):1258-66

Department of Molecular Biology, Pusan National University, Busan, Korea.

Hepatitis B virus X protein (HBx) is a transcriptional coactivator that plays a significant role in the regulation of genes involved in inflammation and cell survival. A recently identified cellular coactivator, activating signal cointegrator 2 (ASC-2), is enriched in liver cancer cells and associates with many transcription factors that are active in hepatocytes. The tissue colocalization of these 2 proteins, in view of their similar regulatory functions, led us to examine whether HBx and ASC-2 cooperate in transcriptional activation of gene expression. Glutathione S-transferase (GST) pull-down assays and mammalian 2-hybrid analysis show that the transactivation domain of HBx interacts with the C-terminal domain of ASC-2. In fact, these 2 proteins associated in a ternary complex that included the transcriptional activator retinoid X receptor (RXR). Mechanistically, on expression of HBx, the half-life of the ASC-2 coactivator is observed to increase in concordance with the observed increase in ASC-2-dependent coactivation of transcription. In conclusion, these results show that HBx stabilizes the cellular coactivator ASC-2 through direct protein-protein interaction, affecting the regulation of genes actively transcribed in liver cancer cells.
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http://dx.doi.org/10.1053/jhep.2003.50451DOI Listing
November 2003