• Title/Summary/Keyword: molecular functions

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Silencing of NUF2 Inhibits Tumor Growth and Induces Apoptosis in Human Hepatocellular Carcinomas

  • Liu, Qiang;Dai, She-Jiao;Li, Hong;Dong, Lei;Peng, Yu-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8623-8629
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    • 2014
  • Background: As an important component of the NDC80 kinetochore complex, NUF2 is essential for kinetochore-microtubule attachment and chromosome segregation. Previous studies also suggested its involvement in development of various kinds of human cancers, however, its expression and functions in human hepatocellular carcinoma (HCC) are still unclear. Materials and Methods: In the present study, we aimed to test the hypothesis that NUF2 is aberrant in human HCCs and associated with cell growth. Results: Our results showed significantly elevated expression of NUF2 in human HCC tissues compared to adjacent normal tissues, and high expression of NUF2 in HCC cell lines. Using lentivirus-mediated silencing of NUF2 in HepG2 human HCC cells, we found that NUF2 depletion markedly suppressed proliferation and colony formation capacity in vitro, and dramatically hampered tumor growth of xenografts in vivo. Moreover, NUF2 silencing could induce cell cycle arrest and trigger cell apoptosis. Additionally, altered levels of cell cycle and apoptosis related proteins including cyclin B1, Cdc25A, Cdc2, Bad and Bax were also observed. Conclusions: In conclusion, these results demonstrate that NUF2 plays a critical role in the regulation of HCC cell proliferation and apoptosis, indicating that NUF2 may serve as a potential molecular target for therapeutic approaches.

Spatio-Temporal Expression Pattern of Grp 78, a Putative Hoxc8 Downstream Target Gene, During Murine Embryogenesis

  • Kang Jin Joo;Kwon Yunjeong;Lee Eun Young;Park Hyoung Woo;Yang Hye-Won;Kim Myoung Hee
    • Biomedical Science Letters
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    • v.11 no.3
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    • pp.311-318
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    • 2005
  • Grp78, discovered as one of the putative target genes of Hoxc8, is a highly conserved stress protein and functions as a molecular chaperone in the endoplasmic reticulum (ER). In order to see the stage-specific expression pattern of Grp78 during development, mouse embryos from day 7.5 to 17.5 p.c. were isolated, and RT-PCR as well as in situ hybridization was performed. When RT-PCR was performed using Grp78 specific primers, periodic expression pattern was detected. And also a region-specific expression pattern was detected with a strong expression in the trunk part of day 11.5 p.c. embryo, like that of Hoxc8. When in situ hybridization was performed, Grp78 was revealed to be expressed in the endoderm, somite, neuroepithelium cells of neural tube in early embryos. In the case of late embryos, Grp78 expression was detected in the liver, segmental bronchus within cranial lobe of lung, ossification center within the cartilage primordium of rib and vertebra, submandibular gland, as well as metanephros. These expression patterns are very much similar to those of Hoxc8. Since Hoxc8 has been reported to regulate apoptosis during organogenesis, it might be possible that the apoptotic function could have been conveyed through the expression of Grp78, implying that the Grp78 is one of the Hoxc8 downstream target genes.

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In Vivo Excision and Amplification of Large Human Genomic Segments Using Cre/loxP-and EBNA-1/oriP-mediated Machinery

  • Yoon, Young-Geol;Choi, Ja-Young;Kim, Jung-Min;Lee, Jun-Hyoung;Kim, Sun-Chang
    • BMB Reports
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    • v.34 no.4
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    • pp.322-328
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    • 2001
  • Excision and amplification of pre-determined, large genomic segments (taken directly from the genome of a natural host, which provides an alternative to conventional cloning in foreign vectors and hosts) was explored in human cells. In this approach, we devised a procedure for excising a large segment of human genomic DNA, the iNOS gene, by using the Cre/loxP system of bacteriophage P1 and amplifying the excised circles with the EBNA-1/oriP system of the Epstein-Barr virus. Two loxP sequences, each of which serves as a recognition site for recombinase Cre, were integrated unidirectionally into the 5'-UTR and 3'-UTR regions of the iNOS gene, together with an oriP sequence for conditional replication. The traps-acting genes cre and EBNA-1, which were under the control of a tetracycline responsive $P_{hcmv^*-1}$ promoter, were also inserted into the 5'-UTR and 3'-UTR regions of the iNOS gene, respectively, by homologous recombination. The strain carrying the inserted elements was stably maintained until the excision and amplification functions were triggered by the induction of cre and EBNA-1. Upon induction by doxycycline, Cre excised the iNOS gene that was flanked by two ZoxP sites and circularized it. The circularized iNOS gene was then amplified by the EBNA-1/oriP-system. With this procedure, approximately a 45.8-kb iNOS genomic fragment of human chromosome 17 was excised and successfully amplified in human cells. Our procedure can be used effectively for the sequencing of unclonable genes, the functional analysis of unknown genes, and gene therapy.

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Distinct mutations in MLH1 and MSH2 genes in Hereditary Non-polyposis Colorectal Cancer (HNPCC) families from China

  • Wei, Wenqian;Liu, Fangqi;Liu, Lei;Li, Zuofeng;Zhang, Xiaoyan;Jiang, Fan;Shi, Qu;Zhou, Xiaoyan;Sheng, Weiqi;Cai, Sanjun;Li, Xuan;Xu, Ye;Nan, Peng
    • BMB Reports
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    • v.44 no.5
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    • pp.317-322
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    • 2011
  • Hereditary non-polyposis Colorectal Cancer (HNPCC) is an autosomal dominant inheritance syndrome. HNPCC is the most common hereditary variant of colorectal cancer (CRC), which accounts for 2-5% CRCs, mainly due to hMLH1 and hMSH2 mutations that impair DNA repair functions. Our study aimed to identify the patterns of hMSH2 and hMLH1 mutations in Chinese HNPCC patients. Ninety-eight unrelated families from China meeting Amsterdam or Bethesda criteria were included in our study. Germline mutations in MLH1 and MSH2 genes, located in the exons and the splice-site junctions, were screened in the 98 probands by direct sequencing. Eleven mutations were found in ten patients (11%), with six in MLH1 (54.5%) and five in MSH2 (45.5%) genes. One patient had mutations in both MLH1 and MSH2 genes. Three novel mutations in MLH1 gene (c.157_160delGAGG, c.2157dupT and c.-64G>T) were found for the first time, and one suspected hotspot in MSH2 (c.1168C>T) was revealed.

Characterization of two plasma membrane protein 3 genes (PutPMP3) from the alkali grass, Puccinellia tenuiflora, and functional comparison of the rice homologues, OsLti6a/b from rice

  • Chang-Qing, Zhang;Shunsaku, Nishiuchi;Shenkui, Liu;Tetsuo, Takano
    • BMB Reports
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    • v.41 no.6
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    • pp.448-454
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    • 2008
  • Two full-length cDNAs, PutPMP3-1 and PutPMP3-2, encoding PMP3 family proteins were isolated from Puccinellia tenuiflora, a monocotyledonous halophyte. Expression of both genes was induced by low temperature, salt stress, dehydration, ABA, and $NaHCO_3$. Transcripts of PutPMP3-2 were more strongly induced by these stresses relative to those of PutPMP3-1, particularly under low temperature and dehydration conditions. Expression of PutPMP3-1 and PutPMP3-2 in yeast mutants lacking the PMP3 gene can functionally complement the membrane hyper-polarization and salt sensitivity phenotypes resulting from PMP3 deletion. To compare the functions of PutPMP3-1 and PutPMP3-2, the orthologous genes in rice (OsLti6a and OsLti6b) were isolated. Both OsLti6a and OsLti6b could functionally complement the loss of PMP3 in yeast. PutPMP3-2 and OsLti6a were more effective in reversing membrane hyperpolarization than PutPMP3-1 and OsLti6b. However, the four yeast transformants each showed similar levels of salt tolerance. These results imply that these PMP3 family members don't function identically under different stress tolerance conditions.

miR-374 promotes myocardial hypertrophy by negatively regulating vascular endothelial growth factor receptor-1 signaling

  • Lee, Jong Sub;Song, Dong Woo;Park, Jei Hyoung;Kim, Jin Ock;Cho, Chunghee;Kim, Do Han
    • BMB Reports
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    • v.50 no.4
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    • pp.208-213
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    • 2017
  • Vascular endothelial growth factor (VEGF) is an essential cytokine that has functions in the formation of new blood vessels and regression of cardiac hypertrophy. VEGF/VEGF-receptor-1 (VEGFR1) signaling plays a key role in the regression of cardiac hypertrophy, whereas VEGF/VEGFR2 signaling leads to cardiac hypertrophy. In this study, we identified the prohypertrophic role of miR-374 using neonatal rat ventricular myocytes (NRVMs). Our results showed that overexpression of miR-374 activated G protein-coupled receptor-mediated prohypertrophic pathways by the inhibition of VEGFR1-dependent regression pathways. Luciferase assays revealed that miR-374 could directly target the 3'-untranslated regions of VEGFR1 and cGMP-dependent protein kinase-1. Collectively, these findings demonstrated that miR-374 was a novel pro-hypertrophic microRNA functioning to suppress the VEGFR1-mediated regression pathway.

Molecular Characterization and Tissue Distribution of Estrogen Receptor Genes in Domestic Yak

  • Fu, Mei;Xiong, Xian-Rong;Lan, Dao-Liang;Li, Jian
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.12
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    • pp.1684-1690
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    • 2014
  • Estrogen and its receptors are essential hormones for normal reproductive function in males and females during developmental stage. To better understand the effect of estrogen receptor (ER) gene in yak (Bos grunniens), reverse transcription-polymerase chain reaction (PCR) was carried out to clone $ER{\alpha}$ and $ER{\beta}$ genes. Bioinformatics methods were used to analyze the evolutionary relationship between yaks and other species, and real-time PCR was performed to identify the mRNA expression of $ER{\alpha}$ and $ER{\beta}$. Sequence analysis showed that the ER open reading frames (ORFs) encoded 596 and 527 amino acid proteins. The yak $ER{\alpha}$ and $ER{\beta}$ shared 45.3% to 99.5% and 53.9% to 99.1% protein sequence identities with other species homologs, respectively. Real-time PCR analysis revealed that $ER{\alpha}$ and $ER{\beta}$ were expressed in a variety of tissues, but the expression level of $ER{\alpha}$ was higher than that of $ER{\beta}$ in all tissues, except testis. The mRNA expression of $ER{\alpha}$ was highest in the mammary gland, followed by uterus, oviduct, and ovary, and lowest in the liver, kidney, lung, testis, spleen, and heart. The $ER{\beta}$ mRNA level was highest in the ovary; intermediary in the uterus and oviduct; and lowest in the heart, liver, spleen, lung, kidney, mammary gland, and testis. The identification and tissue distribution of ER genes in yaks provides a foundation for the further study on their biological functions.

Transient Knock Down of Grp78 Reveals Roles in Serum Ferritin Mediated Pro-inflammatory Cytokine Secretion in Rat Primary Activated Hepatic Stellate Cells

  • Wang, Chi-Mei;Li, Shan-Jen;Wu, Chi-Hao;Hu, Chien-Ming;Cheng, Hui-Wen;Chang, Jung-Su
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.605-610
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    • 2014
  • Chronic liver diseases, including cancer, are characterized by inflammation and elevated serum ferritin (SF). However, the causal-relationship remains unclear. This study used primary rat hepatic stellate cells (HSC) as a model to investigate effects of physiological SF concentrations (10, 100 and 1000 pM) because HSCs play a central role in the development and progression of liver fibrosis. Physiological concentrations of SF, either horse SF or human serum, induced pro-inflammatory cytokine $IL1{\beta}$, IL6 and $TNF{\alpha}$ secretion in rat activated HSCs (all p<0.05). By contrast, treatment did not alter activation marker ${\alpha}SMA$ expression. The presence of SF markedly enhanced expression of Grp78 mRNA (p<0.01). Furthermore, transient knock down of Grp78 by endotoxin EGF-SubA abolished SF-induced $IL1{\beta}$ and $TNF{\alpha}$ secretion in activated HSCs (all p<0.05). In conclusion, our results showed that at physiological concentrations SF functions as a pro-inflammatory mediator in primary rat HSCs. We also provide a molecular basis for the action of SF and identified Grp78-associated ER stress pathways as a novel potential therapeutic target for resolution of fibrosis and possible prevention of liver cancer.

MicroRNA-122 Promotes Proliferation, Invasion and Migration of Renal Cell Carcinoma Cells Through the PI3K/Akt Signaling Pathway

  • Lian, Ji-Hu;Wang, Wei-Hua;Wang, Jia-Qiang;Zhang, Yu-Hong;Li, Yi
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5017-5021
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    • 2013
  • Objective: MicroRNAs (miRNAs) are a small class of non-coding, single-stranded RNAs with a critical role in genesis and maintenance of renal cancer mainly through binding to 3'-untranslated regions (3'UTR) of target mRNAs, which causes a block of translation and/or mRNA degradation. The aim of the present study was to investigate the potential effects of miR-122 in human renal cell carcinomas. Methods: The expression level of miR-122 was quantified by qRT-PCR. MTT, colony formation, invasion and migration assays were used to explore the potential functions of miR-122 in human renal cell carcinoma cells. Results: Cellular growth, invasion and migration in two A498 and 786-O cells were significantly increased after miR-122 transfection. Further experiments demonstrated that overexpression of miR-122 resulted in the increase of phospho-Akt (Ser473) and phospho-mTOR (Ser2448), then activation of mTOR targets, p70S6K and 4E-BP1. Conclusions: The up-regulation of miR-122 may play an important role in the progress of renal cancer through activating PI3K/Akt signal pathway and could be a potential molecular target for anti-cancer therapeutics.

Fatty Acid Compositions of Varying Seed Oils of Korean Origin (한국산(韓國産) 각종(各種) 종실유(種實油)의 지방산(脂肪酸)에 관(關)한 연구(硏究))

  • Mo, Su-Mi
    • Journal of Nutrition and Health
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    • v.8 no.2
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    • pp.19-26
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    • 1975
  • The role of fat is important from nutritional standpoint. The physiological functions of fat are energy yielding as well as the carrier of fat soluble vitamins, with special activities of essential fatty acids. It is fortunate that Korean families prefer to use vegetable oils rather than those from animal origin. But the problems are focused on better qaulity of food oils with attempt to exploit the available resources. This study was undertaken to inevestigate the fatty acid compositions of Korean origin both from conventional and unconventional resources of gas-liquid chromatography. The results obtained are as follows. 1. The total lipid contents of seeds of red pepper, Korean squash, sesame, perilla (var Japonica), and Korean pine nuts and walnuts were 24.3%, 56.6%, 56.4%, 46.9%, 69.8%, and 67.2%, respectively. 2. The saponification numbers of samples ranged from 190 to 200. It showed that the mean molecular weights of fatty acids composing the lipids were very much closed each other. 3. Iodine numbers of varing seed oils ranged from 96.5 of Korean squash seed oil to 124.6 of walnut oil. Oils obtained from squash seeds and sesame seeds showed significantly lower value, while others ranged from 122 to 125. 4. In the fatty acid compositions, squash seed oil was composed mainly of unsaturated fatty acids, 74.9% of which was oleic acid, whereas red pepper seed oil, pine nut oil, and sesame oil contained linoleic acid as a major component showing 64.4%, 56%, 48.8%, and 47.8%, respectively. In perilla seed oil, the amounts of linoleic and linolenic acids were 14.1% and 58%, respectively which meant nearly three-fourths of the total fatty acidsbeing the unsaturated essential fatty acids. This study will encourage the use of these conventional and unconventional vegetable oils which have highr ratios of polyunsaturated to saturated fatty acids.

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