• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.835-840
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• 2013

Accumulating evidence has shown that microRNAs are involved in cancer development and progression. However, it remains unknown about the potential role of miR-19a in the pathogenesis of gastric cancer. Here, we report that suppressor of cytokine signaling 1 (SOCS1) is a novel target of miR-19a in gastric cancer cells and that miR-19a expression is inversely correlated with SOCS1 expression in gastric cancer cells and a subset of gastric cancer tissues. Ectopic expression of miR-19a dramatically promoted proliferation and tumorigenicity of gastric cancer cells both in vitro and in vivo. Moreover, we showed that silencing of SOCS1 promoted cell growth and colony formation resembling that of miR-19a overexpression, whereas re-introduction of SOCS1 (without the 3'-UTR) attenuated the pro-tumorigenic functions. Taken together, our findings suggest that the SOCS1 gene is a direct target of miR-19a, which functions as an oncogenic miRNA in gastric cancer by repressing the expression of tumor suppressor SOCS1.

• 미생물학회지
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• 제46권2호
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• pp.122-126
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• 2010

RAD53은 효모의 검문지점 경로가 DNA 손상을 감지하여 여러 가지 후속적인 세포 내 반응을 일으키는 데 핵심적인 역할을 하는 인산화 효소일 뿐만 아니라, dNTP 생성에 중요한 RNR 유전자 등의 전사 활성화 과정에도 관여하는 효모의 생존에 필수적인 유전자이다. 본 연구에서는 rad53${\Delta}$ 돌연변이의 hydroxyurea에 대한 민감성을 억제하는 억제자로서 CYC8을 동정하였다. CYC8 유전자가 많은 사본으로 존재할 때 rad53${\Delta}$ 균주의 hydroxyurea에 대한 내성이 증가하였으나, CYC8과 복합체로 작용하는 TUP1은 다사본 억제자로 작용하지 못하였다. 반면, 삭제 돌연변이의 경우, cyc8${\Delta}$과 tup1${\Delta}$ 모두 억제자로 작용하였다. CYC8은 효모에서 프리온 단백질로 작용하기 때문에 과량 발현되면 정상적인 CYC8 단백질의 잘못된 접힘을 유발하게 되고, 결과적으로 우성의 $cyc8^-$ 표현형이 나타나게 된다. 따라서 CYC8이 다사본 억제자로 작용하는 이유는 이러한 프리온의 특성 때문으로 추측된다. CYC8이 다사본이거나 cyc8${\Delta}$ 돌연변이일 경우 모두 RNR 유전자의 전사가 증가되는 것을 관찰하였다. 따라서 CYC8에 의한 rad53${\Delta}$ 돌연변이의 억제는 RNR 증가에 따른 세포 내 dNTP 증가 때문으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권8호
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• pp.1072-1079
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• 2013

The NLRP12 (NLR family, pyrin domain containing 12) serves as a suppressor factor in the inflammatory response and protects the host against inflammation-induced damage. In the present study, we aimed to study the polymorphisms of NLRP12 gene and its association with susceptibility to non-specific digestive disorder (NSDD) in rabbits. We re-sequenced the entire coding region of the rabbit NLRP12 gene and detected a total of 19 SNPs containing 14 synonymous and five non-synonymous variations. Among them, the coding SNP (c.1682A>G), which would carry a potential functional implication, was subsequently subjected to genotyping for case-control association study (272 cases and 267 controls). The results revealed that allele A was significantly protective against NSDD with an odds ratio value of 0.884 (95% confidence interval, 0.788 to 0.993; p = 0.038). We also experimentally induced NSDD in growing rabbits by feeding a fibre-deficient diet and subsequently investigated NLRP12 mRNA expression. The mRNA expression of NLRP12 in healthy status was significantly higher than that in severe NSDD (p = 0.0016). The highest expression was observed in individuals carrying the protective genotype AA (p = 0.0108). These results suggested that NLRP12 was significantly associated with the NSDD in rabbits. However, the precise molecular mechanism of NLRP12 involving in the development of rabbit NSDD requires further research.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4363-4368
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• 2012

The epidermal differentiation complex (EDC) contains a large number of gene products which are crucial for the maturation of the human epidermis and can contribute to skin diseases, even carcinogenesis. It is generally accepted that activation of oncogenes and/or inactivation of tumor suppressor genes play pivotal roles in the process of carcinogenesis. Here, NICE-3, a novel EDC gene, was found to be up-regulated in human hepatocellular carcinoma (HCC) by quantitative real-time RT-PCR. Furthermore, overexpression of exogenous NICE-3 by recombinant plasmids could significantly promote cell proliferation, colony formation and soft agar colony formation in Focus and WRL-68 HCC cell lines. Reversely, NICE-3 silencing by RNA interference could markedly inhibit these malignant phenotypes in YY-8103 and MHCC-97H cells. Moreover, cell cycle analysis of MHCC-97H transfected with siRNA by flow cytometry showed that NICE-3 knockdown may inhibit cell growth via arrest in G0/G1 phase and hindering entry of cells into S phase. All data of our findings indicate that NICE-3 may contribute to human hepatocellular carcinoma by promoting cell proliferation.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4751-4756
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• 2012

Colon cancer continues to be one of the most common cancers, and the importance and necessity of new therapies needs to be stressed. The most important proto-oncogen factors for colon cancer appear to be epidermal growth factor receptor, EGFR, and c-Src with high expression and activity leading to tumor growth and ultimately to colon cancer progression. Application of c-Src and EGFR antisense agents simultaneously should theoretically therefore have major benefit. In the present study, anti-EGFR and c-Src specific antisense oligodeoxynucleotides were combined in a formulation using PAMAM dendrimers as a carrier. Nano drug entry into cells was confirmed by flow cytometry and fluorescence microscopy imaging and real time PCR showed gene expression of c-Src and EGFR, as well as downstream STAT5 and MAPK-1 with the tumor suppressor gene P53 to all be downregulated. EGFR and c-Src protein expression was also reduced when assessed by western blotting techniques. The effect of the antisense oligonucleotide on HT29 cell proliferation was determined by MTT assay, reduction beijng observed after 48 hours. In summary, nano-drug, anti-EGFR and c-Src specific antisense oligodeoxynucleotides were effectively transferred into HT-29 cells and inhibited gene expression in target cells. Based on the results of this study it appears that the use of antisense EGFR and c-Src simultaneously might have a significant effect on colon cancer growth by down regulation of EGFR and its downstream genes.

• 대한화학회지
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• 제47권5호
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• pp.460-465
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• 2003

p53 유전자의 변이는 다양한 인체암 중 가장 일반적인 유전자적 변화로 알려져 있으며, 양성에서 악성 대장암으로 전이되는 과정에서 연관이 있는 것으로 알려져 있다. 본 연구에서는 PCR-SSCP와 DHPLC를 이용하여 대장암 환자의 조직에서 p53 유전자의 엑손 5-8에서 돌연변이를 분석하였다. SSCP에서는 50개의 샘플중 엑손 5에서 C13109>T 형태의 돌연변이가 7례가(14%) 발견되었고, DHPLC에서는 C13109>T 7례와 C13202>A, C13204>G 형태의 돌연변이 2례, 모두 9례의(18%) 변이가 검출되었다. DHPLC 분석법을 이용하여 SSCP에서 발견하지 못했던 2례(4%)의 변이를 더 발견하였다. 최종적으로 염기서열분석법을 통해 위의 결과를 확인하였고, p53 돌연변이 검출법으로 SSCP보다 DHPLC가 더 감도가 좋고 효과적인 검출법임을 확인하였다.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.370-378
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• 2009

N-myc downstream-regulated gene 2 (NDRG2) has recently been found to be a tumor suppressor gene. Although it has been reported that NDRG2 expression in breast cancer cells decreases cell proliferation by inhibiting STAT3 activation via SOCS1 induction, the molecular mechanism of chemotherapeutic agent-induced apoptosis is not well known. To elucidate the effect of NDRG2 on the apoptotic pathway induced by doxorubicin, we established stable cell lines expressing NDRG2 and investigated the effect of NDRG2 expression on the doxorubicin-induced apoptosis. While STAT3 activation was remarkably inhibited by NDRG2 overexpression, the expression level of p21 was increased by NDRG2 expression. We confirmed that NDRG2-expressing cells treated with doxorubicin suppressed STAT3 activation and upregulated p21 expression. NDRG2 expression considerably enhanced TUNEL positive apoptotic cells, poly-ADP ribose polymerase (PARP) cleavage, release of cytochrome c to cytosol, and caspase-3 activity in doxorubicin-induced apoptosis. Bid expression in a resting state and after treatment with doxorubicin increased in MDA-MB-231-NDRG2 cells compared to MDA-MB-231-mock cells. Meanwhile, Bcl-$x_L$ expression decreased in MDA-MB-231-NDRG2 cells compared to MDA-MB-231-mock cells in a resting state and in doxorubicin-treated cells. Collectively, these data suggest that suppression of STAT3 activation by NDRG2 influences the sensitivity to doxorubicin-induced apoptosis of breast cancer cells and this may provide a potential therapeutic benefit to overcome the resistance against doxorubicin in breast cancer.

• 동의생리병리학회지
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• 제18권2호
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• pp.553-560
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• 2004

In the present study, we investigated the anti-proliferative effects of aqueous extract of Wikyung-tang(WKT) on the growth of human lung carcinoma cell line A549. WKT treatment declined the cell viability and proliferation of A549 cells in a concentration-dependent manner. The anti-proliferative effects by WKT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. WKT treatment induced an inhibition and/or degradation of apoptotic target proteins such poly(ADP-ribose) polymerase (PARP) and phospholipase C-γ1 (PLC-γ1). WKT treatment did not affect the levels of other Bcl-2 family gene products, such as Bcl-2, Bax and Bad. Western blot analysis and RT-PCT data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 were induced by WKT treatment in A549 cells. Additionally, WKT treatment induced the down-regulation of telomerase reverse transcriptase mRNA (hTERT) expression of A549 cells, however, the levels of other telomere-regulatory gene products were not affected. Taken together, these findings suggest that WKT-induced inhibition of human lung cancer cell proliferation is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products and WKT may have therapeutic potential in human lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.239-244
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• 2014

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9171-9176
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• 2014

Aim: P53, the most commonly mutated tumor suppressor gene in all types of human cancer, is involved in cell cycle arrest and control of apoptosis. Although p53 contains several polymorphic sites, the codon 72 polymorphism is by far more common. There are divergent reports but many studies suggest p53 pro/pro SNP may be associated with susceptibility to developing various cancers in different regions of the world. The present study aimed to find any correlation between H. pylori infection and progression of carcinogenesis, by studying apoptosis and the p53 gene in gastric biopsies from north Indian population. Materials and Methods: A total of 921 biopsies were collected and tested for prevalence of H. pylori by rapid urease test (RUT), imprint cytology and histology. Apoptosis was studied by the TUNEL method. Analysis of p53 gene polymorphism at codon 72 was accomplished by PCR using restriction enzyme BstU1. Observation: Out of 921 samples tested 56.7% (543) were H. pylori positive by the three techniques. The mean apoptotic index (AI) in the normal group was 2.12, while gastritis had the maximum 4.24 followed by gastric ulcer 2.28, gastropathy 2.22 and duodenal ulcer 2.08. Mean AI in cases with gastric cancer (1.72) was less than the normal group. The analysis of p53 72 SNP revealed that p53 (Arg/Arg), (Pro /Arg) variant are higher (40.59% & 33.66%) as compared to p53 pro/pro variant (25.74%) inthe healthy population. Conclusions: The North Indian population harbors Arg or Pro/Arg SNP that is capable of withstanding stress conditions; this may be the reason of low incidence of gastric disease in spite of high infection with H. pylori. There was no significant association with H. pylori infection and AI. However, there is increased apoptosis in gastritis which may occur independent of H. pylori or p53 polymorphism.