• Journal of Life Science
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• v.21 no.1
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• pp.89-95
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• 2011

p53 is tumor suppressor gene that regulates apoptosis such as caspase-dependent and p21-mediated signaling pathways. PI3K/Akt is known to be over-activated in cancer cells. Akt activates many survival-related signals such as mTOR and COX-2. Inactivation of Akt would result in non-inhibition of p53 as well as induced apoptosis. In this study, we showed that curcumin and EGCG activate p53 via inhibition of the Akt signaling pathway. Treatments using curcumin and EGCG in different concentrations for 24 hr and 48 hr inhibited proliferation of HCT116 colon cancer cells and increased apoptotic cell death. Also, our data showed that curcumin and EGCG increased the p53 expression and decreased the p-Akt. Treatment of LY294002 (Akt inhibitor) resulted in decreased cell proliferation of cancer cells, while LY294002 treated with curcumin or EGCG showed a greater decrease of cell proliferation. In addition, inhibition of Akt induced p53 activation in HCT116 colon cancer cells. These results suggest that curcumin and EGCG induce apoptosis by inhibiting Akt and increase p53 in HCT116 colon cancer cells.

• Journal of Convergence for Information Technology
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• v.10 no.5
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• pp.134-142
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• 2020

This study aimed to determine whether there was a difference in lung functions of smokers according to the presence of carcinogenic genetic-metabolizing enzymes by comparing the results of lung functions and the presence of genetic metabolizing enzymes that metabolize tobacco substances. To achieve this, 31 smokers without no illness and no psychiatric history were selected (28 males and 3 females); they were aged 20 to 27 years and were physically and mentally healthy students attending K University. Their lung functions were measured, and gene polymorphisms of cytochrome P-450 1A1 (CYP1A1) related to metabolic activation of tobacco components and gene polymorphism of tumor protein 53 (TP53) related to lung cancer were analyzed. As a result, the mean values of lung function of TT and Arg / Arg without genetic mutations were the highest, and ANOVA analysis of CYP1A1 and lung functions showed that the P-value of FVC was 0.049, which was different between groups. In other words, there is no high mutation in Cytochrome P-450 1A1 (CYP1A1) gene, which is associated with the metabolic activation of tobacco components. In other words, In the absence of the mutant Cytochrome P-450 1A1 (CYP1A1) gene, which is associated with the metabolic activation of tobacco components, the value of FVC was high.

• Journal of Life Science
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• v.28 no.11
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• pp.1316-1320
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• 2018

The effects of a green tea extract (GTE) were examined using the MCF-7 human breast cancer cell line. Cell viability assays using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that GTE had a significant cytotoxic effect on MCF-7 cells, depending on the concentration of GTE. Western blotting of p53 and its related proteins, p21/cip1 and CDK2, after GTE treatment revealed that a significant and concentration dependent increase in p53 protein in response to GTE. The levels of p21/cip1 proteins were also increased at low GTE concentrations were significantly increased even at the highest GTE concentrations. However, the level of CDK2 was significantly decreased by treatment with high concentrations of GTE. These results indicate that treatment with GTE increased the p53 level in MCF-7 cells, and this activation of p53 markedly elevated the levels of p21/cip1proteins, which, in turn, inhibited CDK2 expression in the MCF-7 cells. The inhibition of CDK2 expression might then affect cell cycle progression. Subsequent FACS analysis indicated that GTE treatment the gradually increased progression of the MCF-7 to the G1 phase. These results clearly demonstrate that the anti-tumor effect of GTE in MCF-7 cells is regulated by p53 arrest of the MCF-7 cells at the G1 stage of cell cycle.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1200-1205
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• 1998

Background: Lung cancer formation is a multistage process involving activation of protooncogene and inactivation of tumor suppressor genes. We evaluate the significance of cyclin D1, p53, bcl-2 gene mutations in patients with curatively resected stage IIIA non-small cell lung cancer(NSCLC). Material and Method: One hundred consecutive cases of stage IIIA lung cancers from patients operated on curatvely between 1990 and 1995 for which adequate paraffin blocks and clinical history were available. Immunohistochemical studies were performed on the representative tissue sections from each case by the labelled streptovidin- biotin method. Sections for cyclin D1, p53, Bcl-2 immunostaining were pretreated in a microwave oven for 10 to 20 minutes in citrate buffer before immunostaining. The overnight incubation with NCL-cyclin D1-GM for cyclin D1, with clone DO-7 for p53, with clone 124 for bcl-2 was done. Mean follow-up was 24.1 months (range 2-84 months) after operation. Result: One hundred cases of lung cancers were composed of 56 cases of squamous cell carcinoma, 37 cases of adenocarcinoma, 5 cases of adenosquamous cell carcinoma, and 2 cases of large cell carcinoma. The 5-year survival was 32.1%. The positive expression rate of cyclin D1 was 35%, p53 was 56%, and bcl-2 was 17%. But there were no correlation between cyclin D1, p53, Bcl-2 protein expression and survival. Conclusion: These observation indicate that cyclin D1, p53, bcl-2 protein overexpression might be implicated in the oncogenesis of non-small cell lung carcinomas but they have no usefulness as a prognostic marker.

• Reproductive and Developmental Biology
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• v.35 no.2
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• pp.159-165
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• 2011

To explore the role of histone deactylase (HDAC) activation in an in vivo model of hypertrophy, we studied the effects of Trichostatin A (TSA). TSA subjected to thoracic aortic banding (TAB)-induced pressure stress in mice. In histological observations, TAB in treated mice showed a significant hypertrophic response, whereas the sham operation remained nearly normal structure with partially blunted hypertrophy. TSA treatment had no effect (measured as HW/BW) on sham-operated animals. TAB animals treated with vehicle manifested a robust ~50% hypertrophic response (p<0.05 vs sham). TAB mice treated with 2 mg/kg/day TSA manifested a blunted growth responses, which was significantly diminished (p<0.05) compared with vehicle-treated TAB mice. TAB mice treated with a lower dose of TSA (0.5 mg/kg/day) manifested a similar blunting of hypertrophic growth (~25% increase in heart mass). Furthermore, to determine activity duration of TSA in vitro, 1 nM TSA was added to H9c2 cells. Histone acetylation was initiated at 4 hr after treatment, and it was peak up to 18 hr, then followed by significantly reduced to 30 hr. We also analyzed the expression of p53 following TSA treatment, wherein p53 expression was elevated at 4 hr, and it was maintained to 24 hr after treatment. ERK was activated at 8 hr, and maintained till 30 hr after treatment suggesting an intracellular signaling interaction between TSA and p53 expression Taken together, it is suggested that HDAC activation is required for pressure-overload growth of the heart. Eventually, these data suggest that histone acetylation may be a novel target for therapeutic intervention in pressure-overloaded cardiac hypertrophy.

• BMB Reports
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• v.52 no.2
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• pp.157-162
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• 2019

Our previous study found that two novel cancer-related genes, PRR11 and SKA2, constituted a classic gene pair that was regulated by p53 and NF-Y in lung cancer. However, their role and regulatory mechanism in breast cancer remain elusive. In this study, we found that the expression levels of PRR11 and SKA2 were upregulated and have a negative prognotic value in breast cancer. Loss-of-function experiments showed that RNAi-mediated knockdown of PRR11 and/or SKA2 inhibited proliferation, migration, and invasion of breast cancer cells. Mechanistic experiments revealed that knockdown of PRR11 and/or SKA2 caused dysregulation of several downstream genes, including CDK6, TPM3, and USP12, etc. Luciferase reporter assays demonstrated that wild type p53 significantly repressed the PRR11-SKA2 bidirectional promoter activity, but not NF-Y. Interestingly, NF-Y was only essential for and correlated with the expression of PRR11, but not SKA2. Consistently, adriamycin-induced (ADR) activation of endogenous p53 also caused significant repression of the PRR11 and SKA2 gene pair expression. Notably, breast cancer patients with lower expression levels of either PRR11 or SKA2, along with wild type p53, exhibited better disease-free survival compared to others with p53 mutations and/or higher expression levels of either PRR11 or SKA2. Collectively, our study indicates that the PRR11 and SKA2 transcription unit might be an oncogenic contributor and might serve as a novel diagnostic and therapeutic target in breast cancer.

• Animal cells and systems
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• v.5 no.4
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• pp.267-274
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• 2001

Calpains are a family of cysteine proteases existing primarily in two forms designated by the $Ca^{2+}$ concentration needed for activation in vitro, $\mu$-calpain (calpain-I) and m-calpain (calpain-II). The physiologica1 roles of calpains remain unclear. Many groups have proposed a role for calpains In apoptosis, but their patterns of activation are not well characterized. Calpains have been implicated in neutrophil apoptosis, glucocorticoid-induced thymocyte apoptosis, as well as many other apoptotic pathways. Calpain activation in apoptosis is usually linked upstream or downstream to caspase activation, or in a parallel pathway alongside caspase activation. Calpains have been suggested to be involved in DNA fragmentation (via endonuclease activation), but also as effector proteases that cleave cellular proteins involved in DNA repair, membrane associated proteins and other homeostatic regulatory proteins. Recently, our laboratory demonstrated $\mu$-calpain activation in NAD(P)H: quinone oxidoreducatse 1 (NQO1)-expressing cells after exposure to $\beta$-lapachone, a novel quinone and potential chemo- and radio-therapeutic agent. Increased cytosolic $Ca^{2+}$ in NQO1-expressing cells after $\beta$-lapachone exposures were shown to lead to $\mu$-calpain activation. In turn, $\mu$-calpain activation was important for substrate proteolysis and DNA fragmentation associated with apoptosis. Upon activation, $\mu$-calpain translocated to the nucleus where it could proteolytically cleave PARP and p53. We provided evidence that $\beta$-lapachone-induced, $\mu$-calpain stimulated, apoptosis did not involve any of the known caspases; known apoptotic caspases were not activated after $\beta$-lapachone treatment of NQO1-expressing cells, nor did caspase inhibitors have any effect on $\beta$-1apachone-induced cell death. Elucidation of processes by which $\beta$-1apachone-stimulated $\mu$-calpain activation and calpains ability to activate endonucleases and induce apoptosis independent of caspase activity will be needed to further develop/modulate $\beta$-lapachone for treatment of human cancers that over-express NQO1.

• BMB Reports
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• v.29 no.1
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• pp.88-91
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• 1996

The anaerobically expressed gene aeg-46.5, which had been identified by the operon fusion technique with a hybrid bacteriophage of ${\lambda}$ and Mu, ${\lambda}$placMu53, was studied for its expression pattern and growth. The expression of aeg-46.5 was studied in the wild-type cell and mutant cells that have mutation (s) in the control gene of anaerobic respiration (fnr) and nitrate response (narL and narP). The ${\beta}$-galactosidase reporter gene showed maximum expression in narL host after two hours of aerobic to anaerobic switch in M9-Glc-nitrate medium. Both 40 mM and 100 mM concentrations of nitrate ion in the medium had little effect on expression level. We propose that aeg-46.5 is subject to multiple regulations of anaerobic activation by Fnr, nitrate activation by NarP and repression mediated by NarL.

• Molecules and Cells
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• v.43 no.10
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• pp.889-897
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• 2020

K-RAS is frequently mutated in human lung adenocarcinomas (ADCs), and the p53 pathway plays a central role in cellular defense against oncogenic K-RAS mutation. However, in mouse lung cancer models, oncogenic K-Ras mutation alone can induce ADCs without p53 mutation, and loss of p53 does not have a significant impact on early K-Ras-induced lung tumorigenesis. These results raise the question of how K-Ras-activated cells evade oncogene surveillance mechanisms and develop into lung ADCs. RUNX3 plays a key role at the restriction (R)-point, which governs multiple tumor suppressor pathways including the p14^ARF-p53 pathway. In this study, we found that K-Ras activation in a very limited number of cells, alone or in combination with p53 inactivation, failed to induce any pathologic lesions for up to 1 year. By contrast, when Runx3 was inactivated and K-Ras was activated by the same targeting method, lung ADCs and other tumors were rapidly induced. In a urethane-induced mouse lung tumor model that recapitulates the features of K-RAS-driven human lung tumors, Runx3 was inactivated in both adenomas (ADs) and ADCs, whereas K-Ras was activated only in ADCs. Together, these results demonstrate that the R-point-associated oncogene surveillance mechanism is abrogated by Runx3 inactivation in AD cells and these cells cannot defend against K-Ras activation, resulting in the transition from AD to ADC. Therefore, K-Ras-activated lung epithelial cells do not evade oncogene surveillance mechanisms; instead, they are selected if they occur in AD cells in which Runx3 has been inactivated.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.139-148
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• 1999

Oral cancer is a common neoplasm in humans and etiologic mechanism is not well known, so treatment and evaluation of oral cancer is difficult problem. Traditional TNM classification between prognosis of tumors and classification of histopathologic differentiation has problem like lack of objectivity through operators. In molecular biology, cancer is developed by alteration of activation of oncogene and/or inactivation of tumor suppressor gene. The p53 gene, one of the tumor suppresor genes, is believed to play an important role through mutation and overexpression in the progression of human cancers. The p53 mutation is most frequent genetic disorder in humans. The Cyclin D1 has tumor suppresion activity by regulation of cell cycle. The Cyclin D1 regulate activity of Rb tumor suppresor gene by stimulation of CDK4 The purpose of this study was to observe the expression of p53 protein and Cyclin D1 in oral squamous cell carcinoma, and to get expectation of the malignancy and prognosis of oral squamous cell carcinoma. Using the 15 cases of squamous cell carcinoma and the microscopic H&E and immunohistochemical stain. We divided it into 3 groups according to the stain extent, clinical stage and histologic differentiation. The results were as follows1.In the features of immunohistochemical stain of 15 cases of squamous cell carcinoma, positive reaction of p53 was identified in 8 cases (53.3%) and positive reaction of cyclin D1 was identified in 3 cases (20%). Both positive reaction of p53 protein and Cyclin D1 was show in only one case. 2.8 of p53 positive cases were linked in 87.5% of the end stage tumor, 62.5% of neck node involvement, 87.5% of poorly and moderately histopathplogic differentiation. 3. All 3 of Cyclin D1 positive cases were linked in the end stage tumor, neck node involvement, poorly and moderately histopathologic differentiation. From above results, expression of p53 protein was identified in 53.3% of 15 cases and these results mean oral squamous cell carcinoma was drived by mutation of p53 protein. Especially, highly positive reaction of p53 protein and Cyclin D1 was identified in cases that involvement of neck lymph node and the end stage tumors and it means that the evaluation of p53 protein and Cyclin D1 was useful for evaluation of malignant tumor as specific tumor marker.