• Title/Summary/Keyword: heterogeneous gene expression

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Identification of Heterogeneous Prognostic Genes and Prediction of Cancer Outcome using PageRank (페이지랭크를 이용한 암환자의 이질적인 예후 유전자 식별 및 예후 예측)

  • Choi, Jonghwan;Ahn, Jaegyoon
    • Journal of KIISE
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    • v.45 no.1
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    • pp.61-68
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    • 2018
  • The identification of genes that contribute to the prediction of prognosis in patients with cancer is one of the challenges in providing appropriate therapies. To find the prognostic genes, several classification models using gene expression data have been proposed. However, the prediction accuracy of cancer prognosis is limited due to the heterogeneity of cancer. In this paper, we integrate microarray data with biological network data using a modified PageRank algorithm to identify prognostic genes. We also predict the prognosis of patients with 6 cancer types (including breast carcinoma) using the K-Nearest Neighbor algorithm. Before we apply the modified PageRank, we separate samples by K-Means clustering to address the heterogeneity of cancer. The proposed algorithm showed better performance than traditional algorithms for prognosis. We were also able to identify cluster-specific biological processes using GO enrichment analysis.

Renal Lymphoma with Mesenteric Lymphomatosis in a Cat

  • Jeon, Jin-ha;Song, Doo-won;Ro, Woong-bin;Kim, Heyong-seok;Lee, Ga-won;Cho, Jun-ho;Jeong, Woo-chang;Kim, Soo-hyeon;Sur, Jung-hyang;Park, Hee-myung
    • Journal of Veterinary Clinics
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    • v.37 no.4
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    • pp.208-212
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    • 2020
  • A 6-year-old castrated male Russian Blue cat was presented for evaluation of dyschezia. Abdominal ultrasound revealed hyperechoic nodules in both kidneys, heterogeneous mass in abdomen, and extensive mesenteric thickening with multiple hypoechoic nodules. Computed tomography showed multiple hypodense lesions in both kidneys and diffuse nodular infiltration around the mesentery. Fine needle aspirates (FNA) acquired under ultrasound guidance from the mesentery consisted of large lymphocytes which have round to irregular nuclei with granular chromatin, prominent nucleoli and a small amount of basophilic cytoplasm. Polymerase chain reaction (PCR) for antigen receptor gene rearrangement result of FNA sample revealed a T-cell malignancy. The cat died from acute renal failure after 1 cycle of modified Madison-Wisconsin L-CHOP protocol. Postmortem examination revealed bilaterally enlarged lumpy-bumpy shaped kidneys. Histopathologic examination showed an infiltration of malignant lymphocytes into the renal parenchyma and mesentery. Immunohistochemical staining of the renal sample displayed a negative expression of CD3, PAX5, MUM-1, and CD79. The clinical features and prognosis of the cat with renal lymphoma with mesenteric lymphomatosis have been described in this report.

A new type of oculocutaneous albinism with a novel OCA2 mutation

  • Lee, Sang Yoon;Lee, Eun Joo;Byun, Jun Chul;Jang, Kyung Mi;Kim, Sae Yoon;Hwang, Su-Kyeong
    • Journal of Yeungnam Medical Science
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    • v.38 no.2
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    • pp.160-164
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    • 2021
  • Oculocutaneous albinism (OCA) is a group of rare genetically heterogeneous disorders, characterized by hypopigmentation of the eyes, skin, and hair, which result in ocular abnormalities and a risk of developing skin cancer. Currently, there is no ophthalmologic procedure or drug that prevents the clinical features of OCA. Here, we report a new type of OCA in two, unrelated Korean families with the same OCA2 mutation. Affected individuals in this study are different from those of previous reports in two aspects: an inheritance pattern and clinical presentation. All reported patients with OCA have shown an autosomal recessive inheritance pattern, while our patients showed an autosomal dominant inheritance pattern. Small amounts of pigment can be acquired with age in OCA, but there is no substantial variation from adolescence to adulthood in this regard. A case where the patient attained normal pigmentation levels has never been reported. However, our patients displayed completely normal pigmentation in their late twenties. Whole exome sequencing and in-silico analysis revealed a novel mutation, OCA2 c.2338G>A p.(G780S) (NM_000275) with a high likelihood of pathogenicity. Sanger sequencing of p.G780S identified the same mutation in the affected individuals, which was not found in the family members with normal phenotype. We hypothesize that OCA2 G780S not only acts as a pathogenic variant of OCA but also induces pigmentation by enhancing the melanogenesis gene expression of other modifier genes, such as SLC45A2 and TPC2. These findings may provide further understanding of melanin biosynthesis and new treatment methods for OCA.

Spinocerebellar ataxia 7 (SCA7) (척수소뇌성 운동실조증 제7형)

  • Seon-Yong, Jeong;Seok-Hun, Jang;Hyon-J., Kim
    • Journal of Genetic Medicine
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    • v.4 no.1
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    • pp.22-37
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    • 2007
  • The autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases, clinically and genetically heterogeneous, characterized by degeneration of spinocerebellar pathways with variable involvement of other neural systems. At present, 27 distinct genetic forms of SCAs are known: SCA1-8, SCA10-21, SCA23, SCA25-28, DRPLA (dentatorubral-pallidoluysian atrophy), and 16q-liked ADCA (autosomal dominant cerebellar ataxia). Epidemiological data about the prevalence of SCAs are restricted to a few studies of isolated geographical regions, and most do not reflect the real occurrence of the disease. In general a prevalence of about 0.3-2 cases per 100,000 people is assumed. As SCA are highly heterogeneous, the prevalence of specific subtypes varies between different ethnic and continental populations. Most recent data suggest that SCA3 is the commonest subtype worldwide; SCA1, SCA2, SCA6, SCA7, and SCA8 have a prevalence of over 2%, and the remaining SCAs are thought to be rare (prevalence <1%). In this review, we highlight and discuss the SCA7. The hallmark of SCA7 is the association of hereditary ataxia and visual loss caused by pigmentary macular degeneration. Visual failure is progressive, bilateral and symmetrical, and leads irreversibly to blindness. This association represents a distinct disease entity classified as autosomal dominant cerebellar ataxia (ADCA) type II by Harding. The disease affectsprimarily the cerebellum and the retina by the moderate to severe neuronal loss and gliosis, but also many other central nervous system structures as the disease progresses. SCA7 is caused by expansion of an unstable trinucleotide CAG repeat in the ATXN7 gene encoding a polyglutamine (polyQ) tract in the corresponding protein, ataxin-7. Normal ATXN7 alleles contain 4-35 CAG repeats, whereas pathological alleles contain from 36->450 CAG repeats. Immunoblott analysis demonstrated that ataxin-7 is widely expressed but that expression levels vary among tissues. Instability of expanded repeats is more pronounced in SCA7 than in other SCA subtypes and can cause substantial lowering of age at onset in successive generations termed ‘anticipation’ so that children may become diseased even before their parents develop symptoms. The strong anticipation in SCA7 and the rarity of contractions should have led to its extinction within a few generations. There is no specific drug therapy for this neurodegenerative disorder. Currently, therapy remains purely symptomatic. Cellular models and SCA7 transgenic mice have been generated which constitute valuable resources for studying the disease mechanism. Understanding the pathogenetic mechanisms of neurodegeneration in SCAs should lead to the identification of potential therapeutic targets and ultimately facilitate drug discovery. Here we summarize the clinical, pathological, and genetic aspects of SCA7, and review the current understanding of the pathogenesis of this disorder. Further, we also review the potential therapeutic strategies that are currently being explored in polyglutamine diseases.

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Novel Low-Temperature-Active Phytase from Erwinia carotovora var. carotovota ACCC 10276

  • Huang, Huoqing;Luo, Huiying;Wang, Yaru;Fu, Dawei;Shao, Na;Yang, Peilong;Meng, Kun;Yao, Bin
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1085-1091
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    • 2009
  • A phytase with high activity at low temperatures has great potential for feed applications, especially in aquaculture. Therefore, this study used a degenerate PCR and TAIL PCR to clone a phytase gene from Erwinia carotovora var. carotovota, the cause of soft rot of vegetables in the ground or during cold storage. The full-length 2.5-kb fragment included an open reading frame of 1,302 bp and encoded a putative phytase of 45.3 kDa with a 50% amino acid identity to the Klebsiella pneumoniae phytase. The phytase contained the active site RHGXRXP and HD sequence motifs that are typical of histidine acid phosphatases. The enzyme was expressed in Escherichia coli, purified, and displayed the following characteristics: a high catalytic activity at low temperatures (retaining over 24% activity at $5^{\circ}C$) and remarkably thermal lability (losing >96% activity after incubation at $60^{\circ}C$ for 2 min). The optimal phytase activity occurred at pH 5.5 and ${\sim}49^{\circ}C$, and the enzyme activity rapidly decreased above $40^{\circ}C$. When compared with mesophilic counterparts, the phytase not only exhibited a high activity at a low temperature, but also had a low $K_m$ and high $k_{cat}$. These temperature characteristics and kinetic parameters are consistent with low-temperature-active enzymes. To our knowledge, this would appear to be the first report of a low-temperature-active phytase and its heterogeneous expression.

Identification of Matrix Mineralization-Related Genes in Human Periodontal Ligament Cells Using cDNA Microarray (cDNA microarray에 의한 치주인대세포의 광물화 결절형성에 관여하는 유전자들의 분석)

  • Shin, Jae-Hee;Park, Jin-Woo;Yeo, Shin-Il;Noh, Woo-Chang;Kim, Moon-Kyu;Kim, Jung-Chul;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.37 no.sup2
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    • pp.447-463
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    • 2007
  • Periodontal ligament (PDL) cells have been known as multipotential cells, and as playing an important rolesin periodontal regeneration. The PDL cells are composed of heterogeneous cell populations which have the capacity to differentiate into either cementoblasts or osteoblasts, depending on needs and conditions. Therefore, PDL cells have the capacity to produce mineralized nodules in vitro in mineralization medium which include ascorbic acid, ${\beta}$-glycerophosphate and dexamethasone. In spite of these well-known osteoblast like properties of PDL cells, very little is known about the molecules involved in the formation of the mineralized nodules in the PDL cells. In the present study, we analysed gene-expression profiles during the mineralization process of cultured PDL cells by means of a cDNA microarray consisting of 3063 genes. Nodules of mineralized matrix were strongly stained with alizarin red S on the PDL cells cultured in the media with mineralization supplements. Among 3,063 genes analyzed, 35 were up-regulated more than two-fold at one or more time points in cells that developed matrix mineralization nodules, and 38 were down-regulated to less than half their normal level of expression. In accord with the morphological change we observed, several genes related to calcium-related or mineral metabolism were induced in PDL cells during osteogenesis, such as IGF-II and IGFBP-2. Proteogycan 1, fibulin-5, keratin 5, ,${\beta}$-actin, ${\alpha}$-smooth muscle actin and capping protein, and cytoskeleton and extracellular matrix proteins were up-regulated during mineralization. Several genes encoding proteins related to apoptosis weredifferentially expressed in PDL cells cultured in the medium containing mineralization supplements. Dkk-I and Nip3, which are apoptosis-inducing agents, were up-regulated, and Btf and TAXlBP1, which have an anti-apoptosis activity, were down-regulated during mineralization. Also periostin and S100 calciumbinding protein A4 were down-regulated during mineralization.