• Title/Summary/Keyword: p16 genes

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Epigenetic Regulation of miR-129-2 Leads to Overexpression of PDGFRa and FoxP1 in Glioma Cells

  • Tian, Xiang-Yang;Zhang, Ling;Sun, Lai-Guang;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6129-6133
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    • 2015
  • miR-129-2 is frequently downregulated in multiple cancers. However, how it is silenced in cancers remains unclear. Here we investigated the expression profile and potential biological function of miR-129-2 in glioblastoma (GBM), the most common and lethal form of brain tumors in adults. We showed that miR-129-2 is lost in GBM patient specimens and cultured cell lines. miR-129-2 expression could be restored upon treatment with a histone deadetylase inhibitor (trichostatin A) but not a DNA methylation inhibitor (5-Aza-2'-deoxycytidine), and more profound effect was observed with the treatment of these two drugs in combination. Furthermore, forced expression of miR-129-2 repressed the expression of major oncogenic genes such as PDGFRa and Foxp1 in GBMs. Consistently, expression of miR-129-2 significantly inhibits GBM cell proliferation in vitro. These results reveal that miR-129-2 is epigenetically regulated and functions as a tumor suppressor gene in GBMs, suggesting it may serve as a potential therapeutic target for GBM treatment.

Mutation Spectrum of Manganese (II) Peroxidase Gene in the Pleurotus ostreatus Mutants Induced by Gamma Radiation

  • Chang, Hwa-Hyoung;Lee, Young-Keun;Kim, Jae-Sung;Lee, Ki-Sung;Cho, Kyu-Seong
    • Journal of Microbiology
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    • v.41 no.1
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    • pp.52-57
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    • 2003
  • The mutational spectra in the manganese (II) peroxidase gene (mnp) of the Pleurotus ostreatus mutants induced by gamma radiation (Co$\^$60/) give evidence to prove the effect of gamma radiation on the gene. mnp of each mutant was cloned, sequenced and analyzed. Among the 1941 base pairs of the sequenced region of the mnP genes of 4 mutants (PO-5,-6,-15 and -16), nine mutational hotspots on which the same base was mutated simultaneously were found, additionally 6 mutations were also found at different positions in the mnp gene. These mutation-spectra were predominantly A:T\longrightarrowG:C transitions (50.1%). By the analysis of putative amino acid sequences, PO-5 and PO-16 mutants have 3 and 1 mutated residues, respectively. Since the mutational spectra reported herein are specific to the mnp gene, we propose that the mutational hotspots for the gamma radiation could be in the gene(5) within cells.

Integration Sites and Genotype Distributions of Human Papillomavirus in Cervical Intraepithelial Neoplasia

  • Wang, Li;Dai, Shu-Zhen;Chu, Hui-Jun;Cui, Hong-Fei;Xu, Xiao-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3837-3841
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    • 2013
  • Objectives: To analyse HPV integration prevalence and genotype distributions in cervical intraepithelial neoplasia (CIN) in east part of China, furthermore to assess preferential sites for common HPV integrations and provide baseline information for cervical abnormality screening and prevention. Methods: Integration of HPV in 113 paraffin-embedded cervical intraepithelial neoplasia samples was assessed using Gencap technology in Key Laboratory of Biotechnologies in BGI-Shenzhen. Results: 64 samples were HPV-integrated and as the cervical lesions increased, the integration rate became higher significantly (P=0.002). Fifteen different HPV genotypes were detected, 14 high-risk (16, 18, 31, 33, 51, 52, 56, 58, 66, 68) and 1 low-risk (11). The most common genotypes were HPV-16, 58, 33, 52, 66, and 56. Thirteen patients had co-integration involving mainly HPV-16 and 58. The frequency of HPV gene disruption was higher in L1 and E1 genes than in other regions of the viral genomes. Conclusion: Some 56.6% of CIN lesions in Qingdao had HPV integrations, and 67.2% of HPV-integrated patients were HPV-16 and 58, more prone to be integrated in younger patients below 45 years old. There exist preferential sites for HPV-16 and HPV-58 integration, and they are more likely to be disrupted in the L1 and E1 loci.

Mutation Detection of E6 and LCR Genes from HPV 16 Associated with Carcinogenesis

  • Mosmann, Jessica P.;Monetti, Marina S.;Frutos, Maria C.;Kiguen, Ana X.;Venezuela, Raul F.;Cuffini, Cecilia G.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1151-1157
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    • 2015
  • Human papillomavirus (HPV) is responsible for one of the most frequent sexually transmitted infections. The first phylogenetic analysis was based on a LCR region fragment. Nowadays, 4 variants are known: African (Af-1, Af-2), Asian-American (AA) and European (E). However the existence of sub-lineages of the European variant havs been proposed, specific mutations in the E6 and LCR sequences being possibly related to persistent viral infections. The aim of this study was a phylogenetic study of HPV16 sequences of endocervical samples from C${\acute{o}}$rdoba, in order to detect the circulating lineages and analyze the presence of mutations that could be correlated with malignant disease. The phylogenetic analysis determined that 86% of the samples belonged to the E variant, 7% to AF-1 and the remaining 7% to AF-2. The most frequent mutation in LCR sequences was G7521A, in 80% of the analyzed samples; it affects the binding site of a transcription factor that could contribute to carcinogenesis. In the E6 sequences, the most common mutation was T350G (L83V), detected in 67% of the samples, associated with increased risk of persistent infection. The high detection rate of the European lineage correlated with patterns of human migration. This study emphasizes the importance of recognizing circulating lineages, as well as the detection of mutations associated with high-grade neoplastic lesions that could be correlated to the development of carcinogenic lesions.

Analysis of p53 and Retinoblasoma(Rb) Gene Polymorphisms in Relation to Lung Cancer in Koreans (한국인 폐암 환자에 대한 p53 및 Rb유전자의 다형성 분석)

  • Lee, Kyung-Sang;Sohn, Jang-Won;Yang, Suck-Chul;Yoon, Ho-Joo;Shin, Dong-Ho;Park, Sung-Soo;Lee, Jung-Hee;Lee, Chun-Geun;Cho, Youl-Hee
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.3
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    • pp.534-546
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    • 1997
  • Background : The p53 and retinoblastoma(Rb) tumor suppressor genes are associated with the pathogenesis of several types of human cancer. Substantial proportion of the primary lung cancers or cell lines have been reported to have the p53 and/or the Rb gene mutations. But, so far there is no report on the analysis of the Rb gene polymorphism as one of the genetic susceptibility marker. This study was undertaken to establish the gene frequencies of the polymorphic genotypes of the p53 and Rb genes in Koreans to evaluate the possible involvement of these genotypes as a risk factor of lung cancer. Methods : In this study 145 controls without previous and present tumor history and 128 lung cancer patients were subjected to analysis. The two intragenic polymorphisms of the p53 gene(exon 4/ AccII, intron 6/MspI) and one intron 17/XbaI polymorphism of the Rb gene were analysed by the method of polymersae chain reaction- restriction fragment length polymorphisms(PCR-RFLPs). The genotype of the intron 3/16 bp repeat polymorphism of p53 was determined by PCR and direct gel electrophoresis. Results : There were no significant differences in the genotype distributions of the p53 gene between lung cancer patients and controls. But heterozygotes(Arg/Pro) of the exon 4/AccII polymorphisms were slightly over-represented than controls, especially in the Kreyberg type I cancer, which was known to be associated with smoking. The intron 3/16 bp duplication and the intron 6/MspI polymorphisms were in complete linkage disequilibrium. About 95% of the individuals were homozygotes of the common alleles both in the 16 duplication and MspI polymorphisms, and no differences were deteced in the genotype distributions between lung cancer patients and controls. Overall genotype distributions of the Rb gene polymorphisms between lung cancer patients and controls were not significantly different However, the genotype distributions in the Kreyberg type I cancer were significantly different from those of controls(p = 0.0297) or adenocarcinomas(p = 0.0008). It was noticeable that 73.4% of the patients with adenocarcinomas were heterozygotes(r1/r2) whereas 39.2% of the Kreyberg type I cancer were heterozygous at this polymorphisms. In the lung cancer patients, significant differences were also noted between the high dose smokers and low dose smokers including non-smokers(p = 0.0258). The relative risk to Kreyberg type I cancer was significantly reduced in the individuals with the genotype of r1/r2(odds ratio = 0.46, 95% C.I. = 0.25-0.86, p = 0.0124). The combined genotype distribution of the exon 4 AccII of the p53 and the intron 17 Rb gene polymorphisms in Kreyberg type I cancers were significantly different from dose of controls or adenocarcinomas. The highest odds ratio were observed in the individuals with the genotypes of Arg/Pro and r2/r2(odds ratio = 1.97,95% C.I. = 0.84-4.59) and lowest one was in the patients with Arg/Arg, r1/r2 genotype(odds ratio = 0.54, 95% C.I. = 0.25-1.14). Conclusion : The p53 and the Rb gene polymorphisms modulate the risk of smoking induced lung cancer development in Koeans. However, the exact mechanism of risk modulation by these polymorphism remains to be determined. For more discrete clarification of associations between specific genotypes and lung cancer risk, the evaluations of these polymorphisms in other ethnics and more number of patients will be needed.

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The Study of anti-cancer mechanism with Cobrotoxin on Human prostatic cancer cell line(PC-3) (전립선 암세포에 대한 Cobrotoxin의 항암(抗癌) 기전(機轉) 연구(硏究))

  • Chae, Sang-jin;Song, Ho-seup
    • Journal of Acupuncture Research
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    • v.22 no.3
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    • pp.169-183
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    • 2005
  • Objective : The purpose of this study was to investigate the anti-caner effect of cobrotoxin on the prostatic cancer cell line (PC-3).The goal of study is to ascertain whether cobrotoxin inhibits tile cell growth and cell cycle of PC-3, or the expression of relative genes and whether the regression of PC-3 cell growth is due to cell death or the expression of gene related to apoptosis. Methods : After the treatment of Pc-3 cells with cobrotoxin, we performed 형광현미경, MTT assay, Western blotting, Flow cytometry, PAGE electrophoresis and Surface plasmon resonance analysis to identify the cell viability, cell death, apoptosis, the changes of cell cycle and the related protein, Adk, MAP kinase. Results : 1. Compared with normal cell, the inhibition of cell growth reduced in proportion with the dose of cobrotoxin(0-16nM) in PC-3. 2. Cell viabilities of 0.1, 1, 4nM cobrotoxin treatment were decreased and those of 8, 16nM were decreased significantly. 3. S phase of cell cycle was decreased at the group of 1, 2, 4, 8, 16nM cobrotoxin, but M phase was increased at 0.1, 1, 2, 4, 8, 16nM cobrotoxin. 4. Cox-2 expression after cobrotoxin was peaked at 12hours and was decreased significantly after 6, 12, 24 hours. 5. The expression of Cdk4 was decreased dose-dependently at 1, 2, 4, 8nM cobrotoxin and was decreased siginificantly at 4, 8nM Cyclin D1 was decreased at 1, 2, 4, 8nM and Cycline E was not changed. Cycline B was decreased at 1, 2, 4, 8nM dose-dependently and was decreased siginificanlty at 2, 4, 8nM. 6. The expression of Akt was decreased at 1, 2, 4, 8nM dose-dependently and was decreased significantly at 2, 4, 8nM. 7. ERK was increased at 1, 2nM and decreased at 4, 8nM, p-ERK was increased at 1, 2, 4 nM, but decreased at 8nM. JNK and p-JNK were increased at 1, 4, 8 nM. p38 was increased at 2nM p-p38 was increased at lnM but decreased significantly at 2, 4, 8nM. 8. The nucli of normal cells were stained round and homogenous in DAPI staining, but those of PC-3 were stained condense and splitted. Apoptosis was increased dose-dependently at 2, 4, 8, 16nM and increased significantly at 2, 4, 8, 16nM. 9. Bax wasn`t changed at 1, 2, 4, 8nM and Bcl-2 was decreased significantly at 1, 2, 4, 8nM. Caspase 3 and 9 weren`t changed at 1, 2, 4nM but were decreased significantly at 8nM. Conclusions : These results indicate that cobrotoxin inhibits the growth of prostate Cancer cells, has anti-cancer effects by inducing apoptosis.

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RAPD Analysis on the Species of Pinelliae Tuber (RAPD 방법을 이용한 반하류 한약재의 감별 연구)

  • 배명효;김규열;정유헌;최호영
    • The Journal of Korean Medicine
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    • v.20 no.4
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    • pp.16-22
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    • 2000
  • This study intends to report the significance of several experimental results obtained from analysing the genes extracted from the plants and herbal medicine such as P. temalta (Thunb.) Breit, A. amurense var serratum Nakai, A. erubescens (Wall.) Schott, Pinelliae Tuber and Arisaematis Tuber, mainly by the method of RAPD(randomly amplified polymorphic DNA) and the method of RFLP(restriction fragment length polymorphism) on ITS(internal transcribed spacer) region. Genomic DNA could be extracted from both original plants and dried materials. DNA fragments of P. temata kind and A. amurense kind showed the same aspect separately within the same species under the method of RAPD using random primer, while various aspects(polymorphism) were discovered among different species. In RAPD analysis by uniprimer, common bands were extracted from all types of P. temata in the case of uniprimer #4, which were distinguished from the kind of A. amurense. Other polymorphic bands appeared in between different A. amurense species as well. In the case of uniprimer #11, particular band came out in the kind of P. temata. On the other hand, in the case of uniprimer #5, #6, and #8, various bands(polymorhism) were revealed in both kinds of P. temata and A. amurense. Although further study is needed to ascertain whether these results are due to the differences of species, kinds, or growing place, the results could be used as a scientific method of identifying the substitutes for A. amurense genus. The author believes that as if P. temata class of plants used in this experiment are different among themselves in terms of the shape, size and property, those are clearly a class of P. temata or belong to the same genus.

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Decolorization of Acid Green 25 by Surface Display of CotA laccase on Bacillus subtilis Spores

  • Park, Jong-Hwa;Kim, Wooil;Lee, Yong-Suk;Kim, June-Hyung
    • Journal of Microbiology and Biotechnology
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    • v.29 no.9
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    • pp.1383-1390
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    • 2019
  • In this study, we expressed cotA laccase from Bacillus subtilis on the surface of B. subtilis spores for efficient decolorization of synthetic dyes. The cotE, cotG, and cotY genes were used as anchoring motifs for efficient spore surface display of cotA laccase. Moreover, a $His_6$ tag was inserted at the C-terminal end of cotA for the immunological detection of the expressed fusion protein. Appropriate expression of the CotE-CotA (74 kDa), CotG-CotA (76 kDa), and CotY-CotA (73 kDa) fusion proteins was confirmed by western blot. We verified the surface expression of each fusion protein on B. subtilis spore by flow cytometry. The decoloration rates of Acid Green 25 (anthraquinone dye) for the recombinant DB104 (pSDJH-EA), DB104 (pSDJH-GA), DB104 (pSDJH-YA), and the control DB104 spores were 48.75%, 16.12%, 21.10%, and 9.96%, respectively. DB104 (pSDJH-EA) showed the highest decolorization of Acid Green 25 and was subsequently tested on other synthetic dyes with different structures. The decolorization rates of the DB104 (pSDJH-EA) spore for Acid Red 18 (azo dye) and indigo carmine (indigo dye) were 18.58% and 43.20%, respectively. The optimum temperature for the decolorization of Acid Green 25 by the DB104 (pSDJH-EA) spore was found to be $50^{\circ}C$. Upon treatment with known laccase inhibitors, including EDTA, SDS, and $NaN_3$, the decolorization rate of Acid Green 25 by the DB104 (pSDJH-EA) spore decreased by 23%, 80%, and 36%, respectively.

STUDY ON MUTATION OF RAS GENE IN DMBA INDUCED CARCINOMA OF HAMSTER BUCCAL POUCH (DMBA로 유도된 햄스터 협낭암종에서 ras 유전자 변이에 관한 연구)

  • Song, Sun-Chul;Kim, Kyung-Wook;Lee, Jae-Hoon;Kim, Chang-Jin
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.26 no.6
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    • pp.581-590
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    • 2000
  • Alterations in the cellular genome affecting the expression or function of genes controlling cell growth and differentiation are considered to be the main cause of cancer. Over 30 oncogenes can be activated by insertional mutagenesis, single point mutations, chromosomal translocations and gene amplification. The ras oncogenes have been detected in $15{\sim}20%$ of human tumors that include some of the most common forms of human neoplasia and are known to acquire their transforming properties by single point mutations in two domains of their coding sequences, most commonly in codons 12 and 61. The ras gene family consists of three functional genes, N-ras, K-ras and H-ras which encode highly similar proteins of 188 or 189 amino acid residues generically known as P21. ras proteins have been shown to bind GTP and GTP, and possess intrinsic GTPase activity. Experimental study was performed to observe the mutational change of the ras gene family and apply the results to the clinical activity. 36 Golden Syrian Hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek (control side) was treated with mineral oil as the same manner of the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were completely dissected by microdissection and DNA from both tissue were isolated by proteinase K/phenol/chloroform extraction. Segments of the K-ras and H-ras gene were amplified by PCR using the oligonucleotide primers corresponding to the homologous region (codon 12 and 61) of the hamster gene, and then confirmational change of ras genes was observed by SSCP and autosequencing analysis. The results were as follows : 1. Malignant lesion could be found in the experimental side from the experimental six weeks. 2. One hamster among six showed point mutation of the H-ras codon 12($G{\rightarrow}A$ transition) at the experimental 10 and 14 weeks. 3. One of six at 6 weeks, two of six at 8 weeks and one of six at 12 weeks revealed the confirmational change of the H-ras codon 61($A{\rightarrow}T$ transversion). 4. The incidence of point mutation of H-ras codon 12 and 61 were 5.5%(2 of 36) and 11%(4 of 36) respectively. 5. Point mutation of the K-ras could not be seen during the whole experimental period. Form the above results, these findings strongly support the concept that H-ras oncogenes may have the influence of the DMBA induced carcinoma of hamster buccal pouch.

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Anti-proliferation Effects of Isorhamnetin on Lung Cancer Cells in Vitro and in Vivo

  • Li, Qiong;Ren, Fu-Qiang;Yang, Chun-Lei;Zhou, Li-Ming;Liu, Yan-You;Xiao, Jing;Zhu, Ling;Wang, Zhen-Grong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.3035-3042
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    • 2015
  • Background: Isorhamnetin (Iso), a novel and essential monomer derived from total flavones of Hippophae rhamnoides that has long been used as a traditional Chinese medicine for angina pectoris and acute myocardial infarction, has also shown a spectrum of antitumor activity. However, little is known about the mechanisms of action Iso on cancer cells. Objectives: To investigate the effects of Iso on A549 lung cancer cells and underlying mechanisms. Materials and Methods: A549 cells were treated with $10{\sim}320{\mu}g/ml$ Iso. Their morphological and cellular characteristics were assessed by light and electronic microscopy. Growth inhibition was analyzed by MTT, clonogenic and growth curve assays. Apoptotic characteristics of cells were determined by flow cytometry (FCM), DNA fragmentation, single cell gel electrophoresis (comet) assay, immunocytochemistry and terminal deoxynucleotidyl transferase nick end labeling (TUNEL). Tumor models were setup by transplanting Lewis lung carcinoma cells into C57BL/6 mice, and the weights and sizes of tumors were measured. Results: Iso markedly inhibited the growth of A549 cells with induction of apoptotic changes. Iso at $20{\mu}g/ml$, could induce A549 cell apoptosis, up-regulate the expression of apoptosis genes Bax, Caspase-3 and P53, and down-regulate the expression of Bcl-2, cyclinD1 and PCNA protein. The tumors in tumor-bearing mice treated with Iso were significantly smaller than in the control group. The results of apoptosis-related genes, PCNA, cyclinD1 and other protein expression levels of transplanted Lewis cells were the same as those of A549 cells in vitro. Conclusions: Iso, a natural single compound isolated from total flavones, has antiproliferative activity against lung cancer in vitro and in vivo. Its mechanisms of action may involve apoptosis of cells induced by down-regulation of oncogenes and up-regulation of apoptotic genes.