• Title/Summary/Keyword: Proto-oncogene

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Targeting SHCBP1 Inhibits Cell Proliferation in Human Hepatocellular Carcinoma Cells

  • Tao, Han-Chuan;Wang, Hai-Xiao;Dai, Min;Gu, Cheng-Yu;Wang, Qun;Han, Ze-Guang;Cai, Bing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5645-5650
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    • 2013
  • Src homology 2 domain containing (SHC) is a proto-oncogene which mediates cell proliferation and carcinogenesis in human carcinomas. Here, the SHC SH2-domain binding protein 1 (SHCBP1) was first established to be up-regulated in human hepatocellular carcinoma (HCC) tissues by array-base comparative genome hybridization (aCGH). Meanwhile, we examine and verify it by quantitative real-time PCR and western blot. Our current data show that SHCBP1 was up-regulated in HCC tissues. Overexpression of SHCBP1 could significantly promote HCC cell proliferation, survival and colony formation in HCC cell lines. Furthermore, knockdown of SHCBP1 induced cell cycle delay and suppressed cell proliferation. Furthermore, SHCBP1 could regulate the expression of activate extracellular signal-regulated kinase 1/2 (ERK1/2) and cyclin D1. Together, our findings indicate that SHCBP1 may contribute to human hepatocellular carcinoma by promoting cell proliferation and may serve as a molecular target of cancer therapy.

CK2 Enzyme Affinity Against c-myc424-434 Substrate in Human Lung Cancer Tissue

  • Yaylim, Ilhan;Ozkan, Nazli Ezgi;Isitmangil, Turgut;Isitmangil, Gulbu;Turna, Akif;Isbir, Turgay
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.5233-5236
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    • 2012
  • CK2 is a serine threonine kinase that participates in a variety of cellular processes with more than 300 defined substrates. This critical enzyme is known to be upregulated in cancers, but the role of this upregulation in carcinogenesis is not yet fully understood but c-myc, one of the defined CK2 substrates, is a well-known proto-oncogene that is normally essential in developmental process but is also involved in tumor development. We evaluated the optimal enzyme and substrate concentrations for CK2 activity in both neoplastic and non-neoplastic human lung tissues using the c-$myc^{424-434}$ peptide (EQKLISEEDL) as a substrate. The activities measured for the neoplastic tissue were 600-750 U/mg protein while those for the control tissue was in the range of 650-800 U/mg. $K_m$ value for c-myc peptide was determined as $0.33{\mu}M$ in non-neoplastic tissue and $0.18{\mu}M$ in neoplastic tissue. In this study, we did not observe an increased activity in the neoplastic tissue when compared with the non-neoplastic lung tissue, but we recorded two times higher affinity for c-$myc^{424-434}$ in cancer tissue. Considering the metabolic position of c-$myc^{424-434}$, our results suggest that phosphorylation by CK2 may be important in dimerization and thus it might affect the regulation of c-myc in cancer tissues.

MDM2 Expression in Serous and Mucinous Epithelial Tumours of the Ovary

  • Abdelaal, Shereen E;Habib, Fahima M;el Din, Amina A Gamal;Gabal, Samia M;Hassan, Nabila S;Ibrahim, Nihad A
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3295-3300
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    • 2016
  • Background: Different types of cancer exhibit abnormalities in cell cycle regulators. The murine double minute-2(MDM2) cell cycle regulator is a proto-oncogene that negatively regulates the P53 tumour suppressor gene. Surface epithelial tumours constitute approximately two thirds of ovarian neoplasms. Each histologic type can be classified as benign, borderline and malignant. This study aimed to examine immunohistochemical expression of the MDM2 protein in ovarian serous and mucinous epithelial tumours (benign, borderline and malignant). Materials and Methods: This study included forty five ovarian tumours, subdivided into fifteen cystadenomas (5 serous and 10 mucinous), fifteen borderline tumours (11 serous and 4 mucinous) and fifteen cystadenocarcinomas (9 serous and 6 mucinous). Paraffin sections were stained with haematoxylin and eosin for histopathologic study, and with mouse monoclonal anti-MDM2 antibody for immunohistochemistry. Results: MDM2 positivity was detected in 28.9% of the studied ovarian tumours. All benign tumours were negative and positivity was significantly higher in malignant than borderline tumours (P value of chi-square test =0.000). Significantly, all MDM2 positive mucinous tumours were malignant with no positive mucinous borderline tumours. Malignant tumours showed positive MDM2 expression in 83.3% of mucinous type and in 55.6% of serous type. Borderline serous tumours showed negative MDM2 in 72.7% of cases (P value of Z test =0.04). Conclusions: Alterations in the expression of the cell cycle regulator (MDM2) occur early in the process of tumourigenesis in serous and mucinous ovarian tumours. We suggest that MDM2 may be used in those tumours as a marker for risk stratification and identification of cases with cancer development and progression. We recommend further studies on MDM2 immunohistochemistry, in conjunction with adjuvant methods as DNA ploidy and FISH gene amplification, focusing on the mucinous tumours and differentiating between the three tumour categories, benign, borderline and malignant.

Analysis of the Role of STAT Binding Site in the Drosophila raf Promoter Region Using Transgenic Flies (형질전환 초파리를 이용한 Drosophila raf 유전자 발현조절영역에 존재하는 STAT결합부위의 역할에 관한 연구)

  • Park, Hyun Sook;Kim, Young Shin;Kwon, Eun Jeong;Yoo, Mi Ae
    • Journal of Life Science
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    • v.9 no.1
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    • pp.50-57
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    • 1999
  • STATs activated by various cytokine and growth factors trigger a quick response in the nucleus and induce changes in gene expression. We have found the sequences homologous to STAT binding site in the 5'-flanking region of the D-raf gene. In this study, we examined role of the STAT binding site in D-raf gene promoter activity in vivo by using transgenic flies. The reporter plasmid pDraf-STATmut-lacZ was constructed by fusing D-raf promoter fragment having the base-substituted STAT binding site with the lacZ gene in a P-element vector. Transgenic flies bearing the Draf-STATmut-lacZ fusion genes were established by P-element mediated transformation. The expression of lacZ in transgenic flies bearing Draf-STATmut-lacZ fusion genes carrying base substitution in STAT site throughout various developmental stages was extensively reduced in comparison with that in transgenic flies bearing wild type Draf-lacZ fusion gene. These results show that the STAT binding site plays an important role in regulation of the D-raf gene.

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Expression patterns of innate immunity-related genes in response to polyinosinic:polycytidylic acid (poly[I:C]) stimulation in DF-1 chicken fibroblast cells

  • Jang, Hyun-Jun;Song, Ki-Duk
    • Journal of Animal Science and Technology
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    • v.62 no.3
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    • pp.385-395
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    • 2020
  • Polyinosinic:polycytidylic acid (poly[I:C]) can stimulate Toll-like receptor 3 (TLR3) signaling pathways. In this study, DF-1 cells were treated with poly(I:C) at various concentrations and time points to examine the comparative expression patterns of innate immune response genes. The viability of DF-1 cells decreased from 77.41% to 38.68% when cells were treated different dose of poly(I:C) from 0.1 ㎍/mL to 100 ㎍/mL for 24 h respectively. The expressions of TLR3, TLR4, TLR7, TLR15, TLR21, IL1B, and IL10 were increased in dose- and time-dependent manners by poly(I:C) treatment. On the contrary, the expression patterns of interferon regulatory factors 7 (IRF7), Jun proto-oncogene, AP-1 transcription factor subunit (JUN), Nuclear Factor Kappa B Subunit 1 (NF-κB1), and IL8L2 were varied; IRF7 and IL8L2 were increasingly expressed whereas the expressions of JUN and NF-κB1 were decreased in a dose-dependent manner after they were early induced. In time-dependent analysis, IRF7 expression was significantly upregulated from 3 h to 24 h, whereas JUN and NF-κB1 expressions settled down from 6 h to 24 h after poly(I:C) treatment although they were induced at early time from 1 h to 3 h. Poly(I:C) treatment rapidly increased the expression of IL8L2 from 3 h to 6 h with a plateau at 6 h and then the expression of IL8L2 was dramatically decreased until 24 h after poly(I:C) treatment although the expression level was still higher than the non-treated control. These results may provide the basis for understanding host response to viral infection and its mimicry system in chickens.

$p19^{ras}$ Accelerates $p73{\beta}$-mediated Apoptosis through a Caspase-3 Dependent Pathway

  • Jang, Sang-Min;Kim, Jung-Woong;Choi, Kyung-Hee
    • Animal cells and systems
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    • v.13 no.4
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    • pp.399-403
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    • 2009
  • $p19^{ras}$ is an alternative splicing variant of the proto-oncogene c-H-ras pre-mRNA of $p21^{ras}$. In contrast to $p21^{ras}$, $p19^{ras}$ does not have a C-terminal CAAX motif that targets the plasma membrane and is localized to both the cytoplasm and nucleus. We found that $p19^{ras}$ activated the transcriptional activity of $p73{\beta}$ through protein-protein interactions in the nucleus. p73 is known to play an important role in cellular damage responses such as apoptosis. Although p73 is a structural and functional homologue of p53, p73-mediated apoptosis has not yet been clearly elucidated. In this study, we demonstrate that the interaction between $p19^{ras}$ and $p73{\beta}$ accelerated $p73{\beta}$-induced apoptosis through a caspase-3 dependent pathway. Treatment with DEVD-CHO, a caspase inhibitor, also strengthened $p73{\beta}$-mediated apoptosis through a caspase-3 dependent pathway. Furthermore, the enhanced transcriptional activity of endogenous $p73{\beta}$ by treatment with Taxol was amplified by $p19^{ras}$ overexpression, which markedly increased caspase-3 dependent apoptosis in the p53-null SAOS2 cancer cell line. Our findings indicate a functional linkage between $p19^{ras}$ and p73 in caspase-3 mediated apoptosis of cancer cells.

Transcriptional Regulation of the Drosophila Proliferating Cell Nuclear Antigen Gene and raf Proto-oncogene by Ursolic Acid in Drosophila Cultured Kc Cells

  • Park, Thae-Yeong;Rhee, Sang-Hoon;Kim, Han-Do;Kim, Chong-Rak;Kang, Ho-Sung;Yoo, Mi-Ae
    • Animal cells and systems
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    • v.1 no.1
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    • pp.151-155
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    • 1997
  • Promoter of the Drosophila proliferating cell nuclear antigen (PCNA) gene contains DRE (Drosophila DNA replication-related element) required for the high level expression of replication-related genes. Recently, we found that promoter region of the D-raf (a Drosophila homolog of the human c-raf-1) contains two sequences homologous to the DRE and demonstrated the DRE/DREF (DRE-binding factor) involvement in regulation of the D-raf gene. In this study, using ursolic acid (UA), a pentacyclic triterpene acid reported to possess antitumor activities, we examined effects of UA on proliferation of the Drosophila cultured Kc cells and on expression of the PCNA and D-raf genes. UA showed an inhibitory effect on proliferation of the Kc cells in a concentration-dependent manner in DNA content assays and [3H]thymidine incorporation assays. The IC50 value of anti-proliferative effects of UA in DNA content assays was about 7.5uM. UA showed inhibitory effects on expression of the PCNA as well as on that of the D-raf, which were examined with the reporter plasmic p5'-168DPCNACAT or p5'-878DrafCAT, respectively. The results obtained in the present study suggest that expression of the PCNA and D-raf genes is coordinately regulated in at least UA-treated Kc cells and that down-regulation of expression of the PCNA and D-raf genes might be related with the antitumor activities of UA.

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Expression of c-Jun in pancreatic islet $\alpha$-cells of nonobese diabetic(NOD) mice

  • Park, Sang-Joon;Lee, Sae-Bom;Choi, Yang-Kyu;Lee, Chul-Ho;Hyun, Byung-Hwa;Lee, Keun-Joa;Ryu, Si-Yun;Cho, Sung-Whan;Song, Jae-Chan;Lee, Cha-Soo;Jeong, Kyu-Shik
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.17-24
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    • 1998
  • This is the first report of c-Jun protein expression and mRNA in a pancreatic islet in a nonobese diabetic(NOD) state mice. In this experiment NOD mice with insulin-dependent diabetes mellitus type I at age 16 weeks(n=7) just before death(n=4) were used. The control group consist of prediabetic NOD(8 weeks n=7) and ICR(8 weeks n=7 and 16 weeks n=7) mice. c-Jun positive cells in the pancreatic islet of NOD mice were localized in the same positions as a-glucagon producing cells. immunoreactivity was negative in the prediabetic NOD(8 weeks) and ICR(8 weeks and 16 weeks) mice. The number of c-Jun positive cells in mice with severe diabetic state just before death were significantly decreased when compared to NOD(16 weeks) mice. Expression of c-Jun in mRNA level was assessed by RT-PCR method. The levels of mRNA in NOD(16 weeks) mice group were elevated in total pancreatic tissues. The present results suggest that the induction of proto-oncogene protein may be of significance in assessing cell specific injury and may play a functional role between pancretic islet $\alpha$-cells and $\beta$-cells in the diabetic state.

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Inducing apoptosis by the inhibition of c-myb in oral squamous carcinoma cell line, KB cell

  • Lee, Jung-Chang;Moon, Hyun-Ju;Lee, Young-Hee;Jung, Ji-Eun;Sharma, Manju;Jhee, Eun-Jung;Yi, Ho-Keun
    • International Journal of Oral Biology
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    • v.32 no.4
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    • pp.127-133
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    • 2007
  • Oral squamous cell carcinoma (OSCC) is the most common malignancy and is a major cause of worldwide cancer mortality. The proto-oncogene c-myb plays an important role in regulation of cell growth and differentiation, and it is expressed at high levels in hematopoietic cells and many other types of cancers. However, the function of c-myb is not well known in OSCC. The present study aimed to reveal the function of c-myb and to test the alternation of cell growth and signaling by c-myb in OSCC. In this study, c-myb and dominant-negatibe myb(DNmyb) were expressed in an adenovirus-mediated gene delivery system to KB cells. The over-expressed c-myb brought increased cellular proliferation compared with control cells. However, DN-myb infected KB cells showed significant reduction of cell growth and enhanced induction of apoptosis to activate PARP and caspase 9. c-myb induced increase of IGF-I, -II and IGF-IR expressions while DN-myb down-regulated these expression. Activation of ERK and Akt/PKB pathway was shown only in c-myb transduced cells. These findings suggest that the role of c-myb in cell growth of oral cancer cells is partially mediated through the modulation of IGFs, ERK and Akt/PKB. From this results, DN-myb is strongly recommended as a curable gene for the treatment of c-myb dependent malignancies such as OSCC.

Biological Evaluation of Bone Marrow-Derived Stem Cells onto Different Wettability by RT-PCR (역전사 중합효소 연쇄반응을 이용한 표면 적심성에 따른 골수유래 줄기세포의 생물학적 평가)

  • 김은정;박종수;김문석;조선행;이종문;이해방;강길선
    • Polymer(Korea)
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    • v.28 no.3
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    • pp.218-224
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    • 2004
  • The adhesion and proliferation of mammalian cells on polymeric biomaterials depend on the surface characteristics such as wettability, chemistry, charge and roughness. In order to recognize the correlation between the adhesion and proliferation of human bone marrow derived stem cells (BMSCs) and surface property, radio frequency generated plasma treatment on low density polyethylene (LDPE) has been carried out. The modified LDPE surfaces were characterized by measuring the static water contact angle. The adhesion and proliferation of cells on LDPE films were characterized by cell counting and reverse transcription-polymerase chain reaction (RT-PCR). The water contact angle of the film surface decreased with plasma treatment time. Proto-oncogenes (c-myc, c-fos) and tumor suppressor gene (p153) showed maximum expression with contact angle of 60 ∼ 70$^{\circ}$ range of LDPE film. By cell counting, we confirmed that the rate of cell proliferation appeared the higher on the film surface of the contact angle of 60∼70$^{\circ}$ We concluded that the surface wettability is an important role for the growth and differentiation of BMSCs.