• BMB Reports
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• 제30권3호
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• pp.205-210
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• 1997

p53 tumor suppressor plays an important role in the regulation of cellular proliferation. To identify proteins regulating the expression of p53 in rat liver, we analyzed p53 promoter by electrophoretic mobility shift assay (EMSA) and DNase I footprinting assay. We found that a protein binds the sequence CACGTG, bHLH consensus sequence in rat p53 promoter. Southwestern blotting analysis with oligonucleotides containing this sequence shows that the molecular weight of the protein is 100 kDa. This size is not compatible with the bHLH family such as USF or c-Myc/Max which is known to regulate the expression of the human and mouse p53 gene. Therefore this 100 kDa protein may be a new protein regulating basal transcription of rat p53. We purified this 100 kDa protein through sequence-specific DNA affinity chromatogaphy.

• Toxicological Research
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• 제32권1호
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• pp.73-80
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• 2016

Chronic exposure to cadmium (Cd) is known to adversely affect renal function. Our previous studies indicated that Cd induces p53-dependent apoptosis by inhibiting gene expression of the ubiquitin-conjugating enzyme (Ube) 2d family in both human and rat proximal tubular cells. In this study, the effects of Cd on protein expression of p53 and apoptotic signals in the kidney and liver of mice exposed to Cd for 12 months were examined, as well as the effects of Cd on p53 protein levels and gene expression of the Ube2d family in various cell lines. Results showed that in the kidney of mice exposed to 300 ppm Cd for 12 months, there was overaccumulation of p53 proteins in addition to the induction of apoptosis, which was triggered specifically in the proximal tubules. Interestingly, the site of apoptosis was the same as that of p53 accumulation in the proximal tubules. In the liver of mice chronically exposed to Cd, gene expression of the Ube2d family tended to be slightly decreased, together with slight apoptosis without the accumulation of p53 protein. In rat small intestine epithelial (IEC-6) cells, Cd decreased not only the p53 protein level but also gene expression of Ube2d1, Ube2d2 and Ube2d4. In human brain microvascular endothelial cells (HBMECs), Cd did not suppress gene expression of the Ube2d family, but increased the p53 protein level. In human brain astrocytes (HBASTs), Cd only increased gene expression of UBE2D3. These results suggest that Cd-induced apoptosis through p53 protein is associated with renal toxicity but not hepatic toxicity, and the modification of p53 protein by Cd may vary depending on cell type.

• BMB Reports
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• 제48권2호
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• pp.81-90
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• 2015

p73 is a structural and functional homologue of the p53 tumor suppressor protein. Like p53, p73 induces apoptosis and cell cycle arrest and transactivates p53-responsive genes, conferring its tumor suppressive activity. In addition, p73 has unique roles in neuronal development and differentiation. The importance of p73-induced apoptosis lies in its capability to substitute the pro-apoptotic activity of p53 in various human cancer cells in which p53 is mutated or inactive. Despite the great importance of p73-induced apoptosis in cancer therapy, little is known about the molecular basis of p73-induced apoptosis. In this review, we discuss the p73 structures reported to date, detailed structural comparisons between p73 and p53, and current understanding of the transcription-dependent and -independent mechanisms of p73-induced apoptosis.

• 한국자기공명학회논문지
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• 제22권3호
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• pp.64-70
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• 2018

Human Tid1, belonging to the family of the Hsp40/DnaJ, functions as a co-chaperone of cytosolic and mitochondrial Hsp70 proteins. In addition, the conserved J-domain and G/F-rich region of Tid1 has been suggested to interact with the p53 tumor suppressor protein, to translocate it to the mitochondria. Here, backbone NMR assignments were achieved for the putative p53-binding domain of Tid1. The obtained chemical shift information identified five ${\alpha}$-helices including four helices characteristic of J-domain, which are connected to a short ${\alpha}$-helix in the G/F-rich region via a flexible loop region. We expect that this structural information would contribute to our progressing studies to elucidate atomic structure and molecular interaction of the domain with p53.

• Molecules and Cells
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• 제43권2호
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• pp.176-181
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• 2020

The RUNX transcription factors serve as master regulators of development and are frequently dysregulated in human cancers. Among the three family members, RUNX3 is the least studied, and has long been considered to be a tumor-suppressor gene in human cancers. This idea is mainly based on the observation that RUNX3 is inactivated by genetic/epigenetic alterations or protein mislocalization during the initiation of tumorigenesis. Recently, this paradigm has been challenged, as several lines of evidence have shown that RUNX3 is upregulated over the course of tumor development. Resolving this paradox and understanding how a single gene can exhibit both oncogenic and tumor-suppressive properties is essential for successful drug targeting of RUNX. We propose a simple explanation for the duality of RUNX3: p53 status. In this model, p53 deficiency causes RUNX3 to become an oncogene, resulting in aberrant upregulation of MYC.

• Toxicological Research
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• 제20권1호
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• pp.21-29
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• 2004

We used cDNA microarray to assess gene expression profiles in hematopoetic cell line, U-937, exposed to low doses of ionizing irradiation. The 1,000 DNA elements on this array were PCR-amplified cDNAs selected from named human cancer related genes. According to the strength of irradiation, the levels of some gene expression were increased or decreased as dose-dependent manner. The gene expressions of Tubulin alpha, protein kinase, interferon-alpha, -beta, -omega receptor and ras homolog gene family H were significantly increased. Especially, Tubulin gene was shown 2.5 fold up-regulated manner under stress of 500 rad irradiation than 200 rad. On the other hand, fibroblast growth factor 12 and four and a half LIM domains, etc. were significantly down-regu-lated. Also, tumor protein 53(TP53) related genes that p53 inducible protein, tumor protein 53-binding protein looks of little significance as radiation sensitive manner. The radio-sensitivity of tubulin gene etc. that we proposed could be useful to rapid and correct survey for the bio-damage by exposure to low dose irradiation.

• 한국식품영양과학회지
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• 제44권3호
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• pp.338-346
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• 2015

본 연구에서는 최근 식생활의 서구화로 인해 발병률이 급증하고 있는 대장암의 진행을 억제하거나 감소시키고 인체 대장암 세포인 HT-29의 증식을 억제하며, 세포사멸을 유도하는 천연소재를 알아보기 위해서 flavonoid가 HT-29 인체 대장암 세포의 apoptosis 유도 및 기전에 미치는 영향을 알아보았다. MTT assay 결과 apigenin, rutin, naringenin, myricetin을 $100{\mu}M$ 농도로 처리하였을 때 62.71, 75.78, 74.24, 77.61%로 이 중 naringenin이 대장암 세포 성장에 억제 효과가 가장 높은 실험 결과를 나타내었다. Caspase-3 activity에서는 naringenin이 241.46%로 가장 높은 활성을 나타내었다. 이를 바탕으로 세포사멸과 관련된 유전자를 확인하고자 대장암 세포에 flavonoid인 apigenin, rutin, naringenin, myricetin에 $100{\mu}M$ 농도로 처리한 후 RTPCR을 실시한 결과, 세포사멸의 주요한 조절인자인 Bcl-2 family 단백질 중 Bcl-2는 rutin에 의해 감소되었고 Bax는 myricetin에 의해 증가하였으며, p53은 naringenin이 높게 발현되었다. 또한 western blotting을 통해 flavonoid인 apigenin, rutin, naringenin, myricetin에 $100{\mu}M$ 농도로 처리한 결과, Bcl-2 family 단백질과 더불어 세포사멸 조절에 중요한 역할을 하는 활성형인 cleaved caspase-3은 모두 증가하였고, 그중 myricetin이, PARP은 naringenin, E-cadherin은 rutin이 각각 높은 발현 양상을 나타내었다. 이번 실험 결과를 통해 flavonoid가 세포사멸의 주요한 조절 인자인 Bcl-2 family 단백질의 발현이나 caspase의 활성 등을 조절하여 암세포 사멸인자인 Bcl-2의 발현은 감소시키고 Bax, p53, PARP의 발현을 증가시키는 것을 통해 대장암 세포의 apoptosis를 유도하였다. 또한 암세포의 전이와 관련된 E-cadherin의 발현도 조절하는 것을 관찰하였다. 이상의 연구를 통해 flavonoid가 대장암 세포의 증식을 억제하는 효과가 있음을 확인하였으며, 세포사멸과 관련된 기전을 규명하였다. 이를 기초자료로 일상에서 쉽게 섭취할 수 있는 식품에 많이 존재하며 비교적 독성과 부작용이 적은 flavonoid를 이용한 천연 항암제 개발 가능성을 제시하였고, 추후 대장암의 암예방제 및 암치료제로 개발될 수 있도록 추가 연구 수행이 필요할 것으로 사료된다.

• BMB Reports
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• 제51권12호
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• pp.642-647
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• 2018

Ubiquitin-conjugating enzyme E2S (UBE2S), a family of E2 protein in the ubiquitination process, is involved in development of various cancers. However, its role in lung adenocarcinoma, has not been well elucidated. In this report, we attempted to investigate expression and function of UBE2S in lung adenocarcinoma. Up-regulation of UBE2S at mRNA, and protein level, was observed in human cancer tissues and lung adenocarcinoma cells. Higher UBE2S expression correlated with poorer prognosis of lung adenocarcinoma patients. UBE2S expression was efficiently suppressed by lentivirus-mediated shRNA strategy in A549 cells, and UBE2S silencing led to reduced cell proliferation, colony formation, and enhanced apoptosis. Inverse results were observed, in UBE2S over-expressed H1299 cells. Microarray analysis indicated that a large number of genes were regulated by UBE2S, and p53 signaling pathway may be critical, to the role of UBE2S in cancer development. Together, UBE2S could be a potential target for lung adenocarcinoma.

• Journal of Gastric Cancer
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• 제1권1호
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• pp.10-16
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• 2001

Purpose: The p53 protein is a tumor supressor gene, and its mutation is associated with biologic aggressiveness. CD44v6, one of the CD44 family, is a cell surface glycoprotein that plays a role in cancer invasion and metastasis. Vascular endothelial growth factor (VEGF) is another recently identified growth factor with significant angiogenic properties. The purpose of this study was to investigate p53, CD44v6, and VEGF expressions to determine whether degree of expression was related to pathological parameters such as Lauren's classification, depth of invasion, and lymph node metastasis. Materials and Methods: Immunohistochemical stains of p53, CD44v6, and VEGF in formalin-fixed paraffin-embedded tissue sections of 125 gastric adenocarcinomas were done. Results: The overall expression rates of p53, CD44v6, and VEGF were $54.4\%$ (68/125), $36.8\%$ (46/125), and $48.0\%$ (60/125), respectively. The p53, not CD44v6 and VEGF was higher in intestinal-type gastric carcinomas by Lauren's classification. The expressions of p53, CD44v6, and VEGF were statistically correlated with depth of tumor invasion. The expression of CD44v6 was higher in the lymph node metastatic group than in the negative group. The p53 expression was significantly associated with VEGF expression. Conclusions: These data suggest that the expressions of p53, CD44v6, and VEGF are biologically related to malignancy. The p53 and CD44v6 expressions are independent; however, p53 gene mutation is one of the contributing factors to VEGF expression in gastric adenocarcinoma.

• Radiation Oncology Journal
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• 제17권1호
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• pp.70-77
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• 1999

목적 : 연구자들은 배양 배지의 산성환경이 SCK 선암세포에서 apoptosis를 유도하는 것과 산성환경이 SCK 선암 세포주에서 방사선에 의해 유도되는 apoptosis를 억제시킨다고 관찰하고 apoptosis 관련 유전자들인 p53, p21/WAF/CIP, Bcl-2 및 Bax 들의 발현과 배양 배지 pH 환경과의 연관성을 관찰하였다. 대상 및 방법 : SCK 선암 세포주를 체외 방사선 조사기를 이용하여 방사선 120Gy 조사 후 규정된 시간에 DNA fragmentation을 전기 영동으로 관찰하였다. 실험 조작으로 apoptosis가 유발된 세포군을 정량적으로 분석하고 세포주기 분석을 위하여 FACScan을 이용하였다. Apoptosis 관련 유전자들인 p53, P21/WAF/CIP, Bcl-2 및 Bax 들의 발현은 western blot으로 관찰하였다. 결과 : SCK 선암 세포주에서 방사선에 의해 유도되는 apoptosis는 산성환경(pH 6.6)에서는 apoptosis의 유발이 억제 된다는 사실을 관찰할 수 있었다. 세포주기 분석에서는 방사선조사 후 apoptosis가 뚜렷히 관찰된 pH 7.5 배양 배지 조건에 비하여 pH 6.6 배양 배지 조건에서 현저한 G2/M arrest가 관찰 되었다. apoptosis 관련 유전단백 분석에서는 Bcl-2 유전단백은 두 군 공히 발현의 차이를 관찰할 수 없었고, p53 및 p21은 pH 7.5 배양 배지 환경에서 뚜렷한 발현의 증가를 관찰하였고, p21은 pH 6.6 배양 배지 환경에서는 발현을 관찰할 수 없었다. Bax는 pH 7.5 배양 배지 환경에서 pH 6.6 환경에 비해 경미한 발현의 증가 및 지속성을 관찰하였다. 결론 . 저자들은 SCK 선암 세포주를 대상으로 방사선조사 후 상이한 pH 7.5 와 6.6의 배양 배지 조건에 따른 apoptosis의 관찰에 영향을 주는 유전자 발현에 관한 연구에서 Bcl-2 family의 발현에 비해 세포주기 관련 유전단백들인 p53 발현과 이에 따른 p21의 발현차이가 확연한 p53-dependent apoptotic pathway를 확인하였다. 방사선 조사 후 pH 6.6의 배양 배지 조건에서의 apoptosis 현상을 관찰할 수 없었던 이유는 pH 6.6의 경우 50-60$\%$의 세포가 G2/M arrest에서 세포주기를 순환하지 못함을 확인하였기에 G2/M arrest의 해지와 더불어 순환되는 세포주기의 결과에 따른 post-mitotic apoptosis 현상의 장애로 추론하였다.