• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6613-6618
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• 2014

Background: The X-ray repair cross-complementing group 3 (XRCC3) is a highly suspected candidate gene for cancer susceptibility. Attention has been drawn upon associations of the XRCC3 Thr241Met polymorphism with breast cancer risk. However, the previous published findings remain controversial. Hence, we performed a meta-analysis to accurately evaluate any association between breast cancer and XRCC3 T241M (23, 812 cases and 25, 349 controls) in different inheritance models. Materials and Methods: PubMed and Web of Science databases were searched systematically until December 31, 2013 to obtain all the records evaluating the association between the XRCC3 Thr241Met polymorphism and breast cancer risk. Crude odds ratios (ORs) together with 95% confidence intervals (CIs) were used to assess the strength of associations. Results: When all eligible studies were pooled into the meta analysis of XRCC3 T241M polymorphism, a significantly increased breast cancer risk was observed in heterozygote comparison (OR=1.06, 95%CI=1.01-1.12). No significant associations were found in other models. In subgroup analysis, this polymorphism seemed to be associated with elevated breast risk in Asians. No publication bias was detected. Conclusions: This meta-analysis suggests that the T241M polymorphism confers a weakly increased breast cancer risk. A study with the larger sample size is needed to further evaluate gene-gene and gene-environment interactions of the XRCC3 T241M polymorphism with breast cancer risk.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2433-2437
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• 2013

Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis and thereby involved in the development and progression of solid tumours. Associations between three VEGF gene polymorphisms (-634 G/C, +936 C/T, and +1612 G/A) and breast cancer risk have been extensively studied, but the currently available results are inconclusive. Our aim was to investigate associations between three VEGF gene polymorphisms and breast cancer risk in Chinese Han patients. We performed a hospital-based case-control study including 680 female incident breast cancer patients and 680 female age-matched healthy control subjects. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect the three VEGF gene polymorphisms. We observed that women carriers of +936 TT genotypes [odds ratio (OR) =0.46, 95% confidence interval (CI) = 0.28, 0.76; P=0.002] or 936 T-allele (OR=0.81, 95% CI= 0.68, 0.98; P=0.03) had a protective effect concerning the disease. Our study suggested that the +1612G/A polymorphism was unlikely to be associated with breast cancer risk. The -634CC genotype was significantly associated with high tumor aggressiveness [large tumor size (OR=2.63, 95% CI=1.15, 6.02; P=0.02) and high histologic grade (OR=1.47, 95% CI= 1.06, 2.03; P=0.02)]. The genotypes were not related with other tumor characteristics such as regional or distant metastasis, stage at diagnosis, or estrogen or progesterone receptor status. Our study revealed that the VEGF -634 G/C and +936 C/T gene polymorphisms may be associated with breast cancer in Chinese Han patients.

• Genomics & Informatics
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• 제15권4호
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• pp.114-122
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• 2017

It is becoming increasingly clear that eukaryotic genomes are subjected to higher-order chromatin organization by the CCCTC-binding factor/cohesin complex. Their dynamic interactions in three dimensions within the nucleus regulate gene transcription by changing the chromatin architecture. Such spatial genomic organization is functionally important for the spatial disposition of chromosomes to control cell fate during development and differentiation. Thus, the dysregulation of proper long-range chromatin interactions may influence the development of tumorigenesis and cancer progression.

• Toxicological Research
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• 제20권2호
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• pp.109-116
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• 2004

For the safety evaluation of adenovirus-mediated gene transfer, we investigated differential gene expressions after transfecting adenoviral vector containing p16 tumor suppressor gene (Ad5CMV-p16) into human non-small cell lung cancer cells. In the previous study, we showed adenovirus-mediated $p16^{INK4a}$ gene transfer resulted in significant inhibition of cancer cell growth. We investigated gene expression changes after transfecting Ad5CMV-p16, Ad5CMV (null type, a mock vector) into A549 cells by using cDNA chip and oligonucleotide microarray chip (1200 genes) which carries genes related with signal transduction pathways, cell cycle regulations, oncogenes and tumor suppressor genes. We found that $p16^{INK4a}$ gene transfer down regulated 5 genes (cdc2, cyclin D3, cyclin B, cyclin E, cdk2) among 26 genes involved in cell cycle regulations. Compared with serum-free medium treated cells, Ad5CMV-p16 changed 27 gene expressions, two fold or more on oligonucleotide chip. In addition, Ad5CMV-p16 did not seem to increase the tumorigenicity-related gene expression in A549 cells. Further studies will be needed to investigate the effect of Ad5CMV-p16 on normal human cells and tissues for safety evaluation.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1285-1292
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• 2016

Background: It is well established that mutations in the BRCA1 gene are a major risk factor for breast cancer. Induction of cancer cell death and inhibition of survival are the main principles of cancer therapy. In this context, autophagy may have dual roles in cancer, acting on the one hand as a tumor suppressor and on the other as a mechanism of cell survival that can promote the growth of established tumors. Therefore, understanding the role of autophagy in cancer treatment is critical. Moreover, defects in apoptosis, programmed cell death, may lead to increased resistance to chemotherapy. Purpose: The aim of the present study was to detect BRCA1 gene mutations in order to throw more light on their roles as risk factors for breast cancer in Egypt. Secondly the role of autophagy and apoptosis in determining response to a fluorouracil, doxorubicin, cyclophosphamide (FAC) regimen was investigated. Materials and Methods: Forty-five female breast cancer cases and thirty apparently healthy females were enrolled in the present study. Serum levels of autophagic biomarkers, Beclin 1 and LC3 as well as the serum levels of apoptosis biomarkers Bcl-2 and Caspase-3 were measured before and after chemotherapy. Results: BRCA1 mutations were found in 5 (16.7%) and 44 (99.8%) of the controls and cancer patients, the most frequent being 5382insC followed by C61G and 185 delAG. The results revealed that chemotherapy caused elevation in serum concentration levels of the autophagic biomarkers (Beclin 1 and LC3). This elevation was associated with a significant decrease in serum concentration levels of Bcl-2 and significant increase in caspase-3 concentration levels (apoptotic markers). Conclusions: The results of the present study indicate a very high level of BRCA mutations in breast cancer cases in Egypt and point to involvement of autophagic and apoptotic machinery activation in response to FAC chemotherapy.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5233-5237
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• 2014

Epigenetic modifications of tumour suppressor genes are involved in all kinds of human cancer. Aberrant promoter methylation is also considered to play an essential role in development of lung cancer, but the pathogenesis remains unclear.We collected the data of 112 subjects, including 56 diagnosed patients with lung cancer and 56 controls without cancer. Methylation of the FHIT, RASSF1A and RAR-${\beta}$ genes in DNA from all samples and the corresponding gene methylation status were assessed using the methylation-specific polymerase chain reaction (PCR, MSP). The results showed that the total frequency of separate gene methylation was significantly higher in lung cancer compared with controls (33.9-85.7 vs 0 %) (p<0.01).Similar outcomes were obtained from the aberrant methylation of combinations of any two or three genes (p<0.01). There was a tendency that the frequency of combinations of any two or three genes was higher in stage I+II than that in stage III+IV with lung cancer. However, no significant difference was found across various clinical stages and clinic pathological gradings of lung cancer (p>0.05).These observations suggest that there is a significant association of promoter methylation of individual genes with lung cancer risk, and that aberrant methylation of combination of any two or three genes may be associated with clinical stage in lung cancer patients and involved in the initiation of lung cancer tumorigenesis. Methylation of FHIT, RASSF1A and $RAR{\beta}$ genes may be related to progression of lung oncogenesis.

• 한국정보통신학회논문지
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• 제14권10호
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• pp.2365-2370
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• 2010

마이크로어레이를 기반으로 하는 암 분류 방법은 암 종류에 따라 다르게 발현되는 유전자 양상을 통계적으로 발견함으로써 정확한 암 분류에 기여할 수 있다. 따라서 현재의 마이크로어레이 기술을 이용해서 효과적으로 암을 분류하기 위해서는 특정 암과 밀접하게 관련이 있는 정보력 있는 유전자를 선택하는 과정이 필수적이다. 본 논문에서는 난소 암 마이크로어레이 데이터를 이용하여 암에 영향을 미치는 가장 다르게 발현할 가능성이 있는 표지 유전자를 추출할 수 있는 시스템을 고안하고, 다층퍼셉트론 분류기를 이용하여 기존의 마이크로어레이 시스템과 분류 성능을 비교분석하였다. 그 결과 ANOVA를 이용하여 선택된 표지 유전자를 포함하는 마이크로어레이 데이터 셋에서 98.61%의 향상된 분류 성능을 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6945-6948
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• 2013

Background: Diosgenin, a steroidal saponin from a therapeutic herb, fenugreek (Trigonellafoenum-graceum L.), has been recognized to have anticancer properties. Telomerase activity is not detected in typical healthy cells, while in cancer cell telomerase expression is reactivated, therefore providing a promising cancer therapeutic target. Materials and Methods: We studied the inhibitory effect of diosgenin on human telomerase reverse transcriptase gene (hTERT) expression which is critical for telomerase activity. MTT- assays and qRT-PCR analysis were conducted to assess cytotoxicity and hTERT gene expression inhibition effects, respectively. Results: MTT results showed that $IC_{50}$ values for 24, 48 and 72h after treatment were 47, 44 and $43{\mu}M$, respectively. Culturing cells with diosgenin treatment caused down-regulation of hTERT expression. Discussion: These results show that diosgenin inhibits telomerase activity by down-regulation of hTERT gene expression in the A549 lung cancer cell line.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3523-3525
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• 2015

Gastric cancer is the second most common cause of cancer death worldwide. Environmental as well as genetic factors have been shown to be involved in its genesis. Among genetic factors, loss of function of a tumor suppressive gene named promyelocytic leukemia (PML) has been demonstrated in gastric cancer. In order to cast light in the mechanism by which PML protein is under-expressed in gastric cancer cells, we analyzed all exons and intron-exon boundaries of PML gene in 50 formalin-fixed paraffin-embedded tissue blocks from gastric carcinoma tumors by means of PCR-SSCP and CSGE, with direct sequencing of abnormally shifted bands. We found a novel sequence variant of unknown significance localized in intron 5 in 3 samples (c.1398+84delA). We did not detect any deleterious mutations of the PML gene. This study shows that PML mutations may not contribute to gastric adenocarcinoma development. Post-translational modifications or protein degradation might be mechanisms by which PML is not expressed in gastric tumors.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1823-1827
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• 2012

The gene encoding the Nin one binding (NOB1) protein which plays an essential role in protein degradation has been investigated for possible tumor promoting functions. The present study was focused on NOB1 as a possible therapeutic target for breast cancer treatment. Lentivirus mediated NOB1 siRNA transfection was used to silence the NOB1 gene in two established breast cancer cell lines, MCF-7 and MDA-MB-231, successful transfection being confirmed by fluorescence imaging. NOB1 deletion caused significant decline in cell proliferation was observed in both cell lines as investigated by MTT assay. Furthermore the number and size of the colonies formed were also significantly reduced in the absence of NOB1. Moreover NOB1 gene knockdown arrested the cell cycle and inhibited cell cycle related protein expression. Collectively these results indicate that NOB1 plays an essential role in breast cancer cell proliferation and its gene expression could be a therapeutic target.