• Asian Pacific Journal of Cancer Prevention
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• 제16권4호
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• pp.1599-1603
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• 2015

Background: Epigenetic silencing of tumor suppressor genes due to promoter hypermethylation is one of the frequent mechanisms observed in cancers. Hypermethylation of several tumor suppressor genes involved in cell cycle regulation has been reported in many types of tumors including oral squamous cell carcinomas. LATS1 (Large Tumor Suppressor, isoform 1) is a novel tumor suppressor gene that regulates cell cycle progression by forming complexes with the cyclin dependent kinase, CDK1. Promoter hypermethylation of the LATS1 gene has been observed in several carcinomas and also has been linked with prognosis. However, the methylation status of LATS1 in oral squamous cell carcinomas is not known. As oral cancer is one of the most prevalent forms of cancer in India, the present study was designed to investigate the methylation status of LATS1 promoter and associate it with histopathological findings in order to determine any associations of the genetic status with stage of differentiation. Materials and Methods: Tumor chromosomal DNA isolated from biopsy tissues of thirteen oral squamous cell carcinoma biopsy tissues were subjected to digestion with methylation sensitive HpaII enzyme followed by amplification with primers flanking CCGG motifs in promoter region of LATS1 gene. The PCR amplicons were subsequently subjected to agarose gel electrophoresis along with undigested amplification control. Results: HpaII enzyme based methylation sensitive PCR identified LATS1 promoter hypermethylation in seven out of thirteen oral squamous cell carcinoma samples. Conclusions: The identification of LATS1 promoter hypermethylation in seven oral squamous cell carcinoma samples (54%), which included one sample with epithelial dysplasia, two early invasive and one moderately differentiated lesions indicates that the hypermethylation of this gene may be one of the early event during carcinogenesis. To the best of our knowledge, this is the first study to have explored and identified positive association between LATS1 promoter hypermethylation with histopathological features in oral squamous cell carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4435-4438
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• 2015

p21 is a cyclin-dependent kinase inhibitor, which can arrest cell proliferation and serve as a tumor suppressor. Though many studies were published to assess the relationship between p21 rs1059234 polymorphism and various cancer risks, there was no definite conclusion on this association. To derive a more precise quantitative assessment of the relationship, a large scale meta-analysis of 5,963 cases and 8,405 controls from 16 eligible published case-control studies was performed. Our analysis suggested that rs1059234 was not associated with the integral cancer risk for both dominant model [(T/T+C/T) vs C/C, OR=1.00, 95% CI: 0.84-1.18] and recessive model [T/T vs (C/C+C/T), OR=1.03, 95% CI: 0.93-1.15)]. However, further stratified analysis showed rs1059234 was greatly associated with the risk of squamous cell carcinoma of head and neck (SCCHN). Thus, larger scale primary studies are still required to further evaluate the interaction of p21 rs1059234 polymorphism and cancer risk in specific cancer subtypes.

• 동의생리병리학회지
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• 제19권3호
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• pp.671-676
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• 2005

In this study, we investigated the antioxidant effect of extract from Monascus pillosus, on the human wild-type p53 and p21 expressing A549 lung epithelial cell line and MCF-7 mammary adenocarcinoma cell line stimulated by NO. $P21^{waf/cip1}$ was identified as a gene induced in senescent cells. It is a cyclin-dependent kinase inhibitor and has been shown to cause cell cycle arrest and apoptosis. While p53-regulated stimulation of p21 appears to be central for the permanent growth-arrest, the role of p21 in p53-triggered cell death is unclear. Low dose of sodium nitroprusside (SNP) induced the development of senescence associated with increased expression of p53 and p21 in A549 cells. Inhibition of p21 transactivating activity requires high level correlates with the amount of p53 necessary to cause cell death. Association of p21 and p53 results in inhibition of p21-stimulated transcription. This requires a higher p53 level than is necessary for transcriptional activation of endogenous p53-responsive gene but correlates well with the level of p53 necessary to cause cell death. Exposure to W-1 inhibited oxidative stresses-induced senescence-like arrest, resulting in a significant reduction in p53 and p21 steady state levels. These results suggest that p53 and p21 play a central role in the onset of senescence. Thus, it is important to emphasize control of oxidative balance in tumor prevention and aging.

• Journal of Ginseng Research
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• 제39권2호
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• pp.148-154
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• 2015

Background: Ginseng is known to have antiapoptotic, anti-inflammatory, and antioxidant effects. The present study investigated a possible role of Korean Red Ginseng (KRG) in suppressing dopaminergic neuronal cell death and the cleavage of p35 to p25 in the substantia nigra (SN) and striatum (ST) using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. Methods: Ten-week-old male C57BL/6 mice were injected intraperitoneally with 30 mg/kg of MPTP at 24-h intervals for 5 d, and then administered KRG (1 mg/kg, 10 mg/kg, or 100 mg/kg) once a day for 12 consecutive days from the first injection. Pole tests were performed to assess the motor function of the mice, dopaminergic neuronal survival in the SN and ST was evaluated using tyrosine hydroxylase-immunohistochemistry, and the expressions of cyclin-dependent kinase 5 (Cdk5), p35, and p25 in the SN and ST were measured using Western blotting. Results: MPTP administration caused behavioral impairment, dopaminergic neuronal death, increased Cdk5 and p25 expression, and decreased p35 expression in the nigrostriatal system of mice, whereas KRG dose-dependently alleviated these MPTP-induced changes. Conclusion: These results indicate that KRG can inhibit MPTP-induced dopaminergic neuronal death and suppress the cleavage of p35 to p25 in the SN and the ST, suggesting a possible role for KRG in the treatment of Parkinson's disease.

• 환경생물
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• 제23권1호
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• pp.21-26
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• 2005

Cell response to genotoxic agents is complex and involves the participation of different classes of genes including cell cycle control, DNA repair and apoptosis. In this report, we presented a approach to characterize the cellular functions associated with the altered transcript profiles of MCF-7 exposed to low-dose in vitro gamma-irradiation. We used the method of human 2.4 k cDNA microarrays containing apoptosis, cell cycle, chromatin, repair, stress and chromosome genes to analyze the differential gene expression characterization that were displayed by radiation-exposed cell, human breast carcinoma MCF-7 cell line, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. Among these genes, 66 were up-regulated and 49 were down-regulated. Specific genes were concomitantly induced in the results. Cyclin dependent kinase 4 (Cdk4) is induced for starting the cell cycle. This regulation is required for a DNA damage­induced G1 arrest. In addition to, an apoptotic pathways gene Bcl-w was concomitantly induced. Mismatch repair protein homologue-l (hMLH1), a necessary component of DNA mismatch protein repair (MMR), in G2-M cell cycle checkpoint arrest. The present study provides new information on the molecular mechanism underlying the cell response to genotoxic stress, with relevance to basic and clinical research.

• 동의생리병리학회지
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• 제38권1호
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• pp.38-45
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• 2024

To compare and analyze the improvement effects of white ginseng extract, red ginseng extract, and black ginseng extract on cognitive dysfunction and memory impairment caused by scopolamine in rats. In the cognitive behavioral test, the tendency of the SCOP+B group to overcome the escape time delay induced by scopolamine administration was observed, unlike the SCOP group. The frequency on plat form was significantly increased in the group treated with ginseng extracts compared to the SCOP group. As a result of measuring the duration time on goal quadrant, the time spent in the quadrant was significantly increased in the SCOP+B group compared to the SCOP group. In the hippocampus, the SCOP-treated group significantly decreased the activity of AChE compared to the normal group, but the ginseng extract-treated groups significantly increased it compared to the SCOP group. After sacrificing the rats after the behavioral test, the expression of PSD95 protein in the excised brain was significantly decreased in the SCOP group compared to normal, but it was observed that the SCOP+R and SCOP+B groups were significantly increased compared to the SCOP group. CREB1 protein expression was significantly increased in the SCOP+R group, and the expression of Cdk5 was significantly increased in the SCOP+B group. Ginseng extracts significantly restored the memory damaged by scopolamine suggesting that red ginseng increased the expression of CREB1 and PSD95 proteins, and black ginseng increased the protein expression of Cdk5 and PSD95 to induce memory recovery.

• Clinical and Experimental Pediatrics
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• 제51권1호
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• pp.73-77
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• 2008

목 적 : p16 유전자는 염색체 9p21에 위치하는데 종양억제 유전자 중 하나로 cyclin-dependent kinase의 억제제로 작용하며 Rb 인산화를 억제한다. 다양한 종류의 종양에서 p16 유전자의 결실 또는 과메틸화가 발견되고 있는데 이는 급성림프구성백혈병에서도 흔히 발견되는 이상 소견으로 높은 빈도로 나타나고 있지만 급성림프구성백혈병의 예후와 p16 유전자의 연관성에 대해서는 아직 논란의 여지가 있다. 본 연구에서는 면역조직화학염색으로 확인한 p16 단백질의 소실과 급성림프구성백혈병 환아들의 임상 경과와의 연관성에 대하여 조사하고자 하였다. 방 법 : 1998년 1월부터 2006년 12월까지 급성림프구성백혈병으로 진단된 74명의 진단 시 골수 슬라이드에서 p16 단백질 면역조직화학염색을 하였다. 환아들의 임상 양상, 검사실 소견, 치료 후 경과에 대해서 후향적으로 조사하였다. 결 과 : 74명 중 12명에서 p16 단백질이 면역화학염색 결과 음성이었다. 이들 중 남아가 7명 여아가 5명이었으며 진단 시 연령의 중앙값은 5.8(1.3-18.8)세였다. 백혈구 수의 중앙값은 17,225 $(500-403,300)/{\mu}L$ 이었으며 면역표현형은 early pre-B CALLA (+)형이 7명, T 세포형은 5명이었다. 진단 시 예후 중간군이었던 두 명의 환아들에서 골수 재발 하였으며 3명의 환아들이 유방암의 가족력이 있었다. 4명이 사망하여 8년 생존율은 $53.5{\pm}18.7%$였다. 결 론 : p16 단백질의 소실은 소아 급성림프구성백혈병에서 불량한 예후와 연관된 인자로 추정되며 임상에서 진단 시 p16에 대한 유전자 검사뿐만 아니라 단백질에 대해서도 검사가 필요할 것으로 생각된다. 하지만 좀더 많은 환자들에 대한 분석이 더 정확한 연관성을 밝히는데 도움이 될 것으로 사료된다.

• Journal of Acupuncture Research
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• 제21권2호
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• pp.41-55
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• 2004

Objective : To investigate the possible molecular mechanism (s) of melittin as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Methods : Growth inhibitory study, flow cytometry analysis, SDS-polyacrylamide gel electrophoresis and Western blot analysis, RT-PCR and in vitro caspases activity assay were performed. Results : Melittin treatment declined the cell viability of A549 cells in a concentration-dependent manner, which was associated with induction of apoptotic cell death. Melittin treatment down-regulated the levels of Bcl-XS/L mRNA and protein expression of A549 cells, an anti-apoptotic gene, however, the those of Bax, a pro-apoptotic gene, were up-regulated. Melittin induced the proteolytic cleavage and activation of caspase-3 and caspase-9 protease in a dose-dependent manner without alteration of inhibitor of apoptosis proteins family and Akt expression. Western blot analysis and RT-PCR data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 were also remained unchanged. Conclusions : Taken together, these findings suggest that melittin-induced inhibition of human lung cancer cell growth is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and melittin may have therapeutic potential in human lung cancer.

• 생명과학회지
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• 제19권12호
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• pp.1787-1793
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• 2009

파이토케미칼의 일종인 CAPE가 암세포 생장에 미치는 영향과 유전자 발현을 연구하기 위하여, 인간 대장암 세포주 HCT116에 CAPE를 처리하였다. CAPE의 처리는 농도 의존적으로 암 세포 생존율을 감소시키고, 세포사멸을 유도함을 확인하였다. CAPE에 의해 차별적으로 발현되는 유전자를 분석하기 위하여, oligo DNA microarray 실험을 수행하였다. 그 결과, $20{\mu}M$ CAPE를 24시간 동안 처리한 경우, 2배 이상 발현이 증가되는 유전자 266개, 2배 이상 발현이 감소되는 유전자 143개를 확인하였다. 발현이 증가되는 유전자중 3개(NAG-1, p21, GADD45A)를 선택하여, RT-PCR을 수행하였다. 그 결과, 모든 유전자의 발현이 마이크로어레이 실험결과와 일치하였다. 또한, CAPE를 농도 의존적으로 처리한 후, NAG-1 유전자와 단백질의 발현을 확인한 결과, mRNA 수준과 단백질 수준에서의 발현양상이 동일함을 확인하였다. 게다가, CAPE를 포함한 5개의 다른 종류의 파이토케미칼(resveratrol, genistein, daidzein, capsaicin)을 처리한 경우, 처리한 모든 파이토케미칼에 의해 NAG-1 유전자의 발현이 증가됨을 확인하였다. 이중 CAPE가 가장 낮은 농도의 처리임에도 불구하고 NAG-1의 발현을 가장 강하게 유도하였다. 결론적으로 이러한 연구결과는 CAPE에 의한 세포사멸은 항암유전자인 NAG-1의 과대발현과 밀접한 관련이 있음을 의미한다.

• 생명과학회지
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• 제15권3호
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• pp.323-331
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• 2005

남미지역에서 자생하는 Tabebuia avellanedae라는 나무의 수피에서 동정된 quinone계 물질이며, DNA topoisomeras억제제로 알려진 $\beta-lapachone$의 항암작용에 관한 부가적인 자료를 얻기 위하여 인체 간암(HepG2) 및 방광암(T24)세포를 대상으로 조사한 결과 다음과 같은 결과를 얻게 되었다. MTT assay 및 flow cytometry 분석 등의 결과에서, $\beta-lapachone$의 처리에 따라 조사된 두 가지 암세포에서 $\beta-lapachone$처리 농도의존적으로 암세포의 심한 형태적 변형이 동반되면서 암세포의 증식이 억제되었으며, 생존율이 저하되었고 이는 apoptosis유발과 상관성이 있음을 알 수 있었다. $\beta-lapachone$처리에 의한 두 암세포의 증식억제는 종양억제 유전자 p53 및 Cdk inhibitor p21의 발현과는 큰 연관성이 없음을 RT-PCR 및 Western blot analysis를 통하여 확인하였다. 그러나 전사조절인자 Sp-1 및 세포증식 주요조절인자인 PCNA의 단백질 발현은 $\beta-lapachone$처리에 따라 매우 감소되었으며, telomere조절에 중요한 인자들의 선택적 발현 저하 현상도 관찰되었다. 이상의 결과들은 인체 암세포에서 $\beta-lapachone$의 항암작용을 이해하는 중요한 자료가 될 것이며, $\beta-lapachone$과 유사한 화학적 구조 및 성질을 가지는 항암제 후보물질들의 항암기전 비교 및 항암제 개발을 위한 기초 자료로서 응용될 것이다.