• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.476-486
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• 2008

Background: TRAIL (TNF-related apoptosis inducing ligand) is a newly identified member of the TNF gene family which appears to have tumor-selective cytotoxicity due to the distinct decoy receptor system. TRAIL has direct access to caspase machinery and induces apoptosis regardless of p53 phenotype. Therefore, TRAIL has a therapeutic potential in lung cancer which frequently harbors p53 mutation in more than 50% of cases. However, it was shown that TRAIL also could activates $NF-{\kappa}B$ in some cell lines which might inhibit TRAIL-induced apoptosis. This study was designed to investigate whether TRAIL can activate $NF-{\kappa}B$ in lung cancer cell lines relatively resistant to TRAIL-induced apoptosis and inhibition of $NF-{\kappa}B$ activation using proteasome inhibitor MG132 which blocks $I{\kappa}B{\alpha}$ degradation can sensitize lung cancer cells to TRAIL-induced apoptosis. Methods: A549 (wt p53) and NCI-H1299 (null p53) lung cancer cells were used and cell viability test was done by MTT assay. Apoptosis was confirmed with Annexin V assay followed by FACS analysis. To study $NF-{\kappa}B$-dependent transcriptional activation, a luciferase reporter gene assay was used after making A549 and NCI-H1299 cells stably transfected with IgG ${\kappa}-NF-{\kappa}B$ luciferase construct. To investigate DNA binding of $NF-{\kappa}B$ activated by TRAIL, electromobility shift assay was used and supershift assay was done using anti-p65 antibody. Western blot was done for the study of $I{\kappa}B{\alpha}$ degradation. Results: A549 and NCI-H1299 cells were relatively resistant to TRAIL-induced apoptosis showing only 20~30% cell death even at the concentration 100 ng/ml, but MG132 ($3{\mu}M$) pre-treatment 1 hour prior to TRAIL addition greatly increased cell death more than 80%. Luciferase assay showed TRAIL-induced $NF-{\kappa}B$ transcriptional activity in both cell lines. Electromobility shift assay demonstrated DNA binding complex of $NF-{\kappa}B$ activated by TRAIL and supershift with p65 antibody. $I{\kappa}B{\alpha}$ degradation was proven by western blot. MG132 completely blocked both TRAIL-induced $NF-{\kappa}B$ dependent luciferase activity and DNA binding of $NF-{\kappa}B$. Conclusion: This results suggest that inhibition of $NF-{\kappa}B$ can be a potentially useful strategy to enhance TRAIL-induced tumor cell killing in lung cancer.

• Journal of Life Science
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• v.27 no.9
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• pp.1020-1030
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• 2017

Epidemiology studies have reported a reduced incidence of colon cancer among populations that consume a large quantity of ${\omega}3-polyunsaturated$ fatty acids (${\omega}3-PUFAs$) of marine origin. Herein, we demonstrated a mechanism of anticancer action of ${\omega}3-PUFAs$, showing that they suppressed invasion and tumorigenicity in colon cancer cells. Docosahexaenoic acids (DHA) inhibited the cell growth of HT29 cells. This action likely involved apoptosis, given that the DHA treatment increased the cleaved form of PARP and sub G1 cells. Moreover, the invasiveness of HT29 cells was inhibited following DHA treatment, whereas arachidonic acid (AA) had no effect. The levels of Matrix-metalloproteinase-9 (MMP-9) and MMP-2 mRNA decreased after DHA pretreatment. DHA treatment inhibited MMP-9 and MMP-2 promoter activities and reduced VEGF promoter activity. DHA pretreatment also inhibited the activities of prostaglandin-2 (PGE2)-induced MMPs and the VEGF promoter. Cyclooxygenase-2 (COX-2) overexpression increased the activity of MMPs and that of the Vascular endotherial growth factor (VEGF) promoter in HT29 cells, and DHA inhibited NF-kB and COX-2 promoter reporter activities. As shown by in vivo experiments, when mouse colon cancer cells (MCA38) were implanted into Fat-1 and wild-type mice, both the tumoral size and volume were dramatically inhibited in Fat-1 transgenic mice. Furthermore, TUNEL-positive cells increased in tumors from Fat-1 mice compared with wild mice. In immunohistochemistry, the intensity of CD31 in Fat-1 tumors was weaker. These findings suggest that ${\omega}3-PUFAs$ may inhibit tumorigenicity and angiogenesis as well as cancer cell invasion by suppression of COX-2, MMPs and VEGF via the reduction of NF-kB in colon cancer.

• Journal of Life Science
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• v.23 no.10
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• pp.1230-1238
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• 2013

The regulatory effect of the tumor-suppressor protein p53 on the apoptogenic activity of $17{\alpha}$-estradiol ($17{\alpha}-E_2$) was compared between HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells. When the HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells were treated with $2.5{\sim}10{\mu}M$ $17{\alpha}-E_2$ for 48 h or with $10{\mu}M$for various time periods, cytotoxicity and an apoptotic sub-$G_1$ peak were induced in the HCT116 ($p53^{+/+}$) cells in a dose- and time-dependent manner. However, the HCT116 ($p53^{-/-}$) cells were much less sensitive to the apoptotic effect of $17{\alpha}-E_2$. Although $17{\alpha}-E_2$ induced aberrant mitotic spindle organization and incomplete chromosome congregation at the equatorial plate, $G_2/M$ arrest was induced to a similar extent in both cell types. In addition, $17{\alpha}-E_2$-induced activation of Bak and Bax, ${\Delta}{\Psi}m$ loss, and PARP degradation were more dominant in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells. In accordance with enhancement of p53 phosphorylation (Ser-15) and p53 levels, p21 and Bax levels were elevated in the HCT116 ($p53^{+/+}$) cells treated with $17{\alpha}-E_2$. The HCT116 ($p53^{-/-}$) cells exhibited barely or undetectable levels of p21 and Bax, regardless of $17{\alpha}-E_2$ treatment. On the other hand, although the level of Bcl-2 was slightly lower in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells, it remained relatively constant after the $17{\alpha}-E_2$ treatment. Together, these results show that among the components of the $17{\alpha}-E_2$-induced apoptotic-signaling pathway, which proceeds through mitotic spindle defects causing mitotic arrest, subsequent activation of Bak and Bax and the mitochondria-dependent caspase cascade, leading to PARP degradation, $17{\alpha}-E_2$-induced activation of Bak and Bax is the upstream target of proapoptotic action of p53.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.181-185
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• 2001

The naturally occurring chemical indole-3-carbinol (13C), found in vegetables of the Brassica genus, is a promising anticancer agent that was shown previ- ously to induce a Gl cell cycle arrest of human breast cancer cell lines, independent of estrogen receptor signaling. The anticancer activity of 13C and the possible mechanisms of its action were explored in a human hepatocellular carcinoma cell line, HepG2. Treatment of HepG2 cells with 13C suppressed the growth of the cells. The growth sup- pression caused by 13C ($IC_{50}$/: 444$\mu$M) was found to be partially due to its ability to stop the cell cycle in HepG2 cells. Western blot analysis for the Gl phase artiest demonstrated that the expression-levels of cyclin-dependent kinase (Cdk4, Cdk6) and cyclic D were reduced strongly after treatment of Hep72 cells with 13C (4007M) for 24- 72 hrs. Furthermore, I3C selectively abolished the expression of Cdk6 in a dose- and time-dependent manner, and accordingly, inhibited the phosphorylation of retinoblastoma. Interestingly, after the HepG2 cells reached their max- imal growth arrest, the level of the p21, a well-known Cdk inhibitor, increased significantly. Therefore, it could be considered that the Gl arrest of HepG2 cells treated with 13C was due to the indirect inhibition of Cdk4/6 activities by p21 Western blot analysis for G2/M phase arrest of demonstrated the levels of Cdc2 and cyclin Bl werer reduced dramatically after the treatment of HepG2 cells with 13C ($40\mu$M) for 24-72 hrs. flow cytometry of propidium iodide-stained HepG2 cells revealed that 13C induces a Gl (53%,72hr incubation) and G2 (25%,24hr incubation) cell cycle arrest. Thus, our observations have uncovered a previously undefined antiproliferative pathway for r3C that implicates Cdk4/6 and Cdc2 as a target for cell cycle control in human HepG2 cells. However, the 13C-medi- ated cell cycle arrest and repression of Cdk4/6 production did not affect the apoptotic induction of HepG2 cell.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.426-436
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• 2007

Oral cancer take up 2-6% of all carcinomas and squamous cell carcinoma, which is the most common type in oral cancer, has a poor prognosis due to its high metastasis and recurrence rates. In treating oral cancer, chemotherapy to the primary, metastasized and recurrent lesion is a very important and useful treatment, even though its widespread usage is limited due to high general toxicity and local toxicity to other organs. Taxol, a microtubule stabilizing agent, is an anticancer drug that induces cell apoptosis by inhibiting depolymerization of microtubules in between the metaphase and anaphase of the cell mitosis. Recently, its effectiveness and mechanism on various tumor has been reported. However, not much research has been done on the application of Taxol to oral squamous cell carcinoma. Cyclosporin A, which is an immunosuppressant, is being used on cancers and when co-administered with Taxol, effectiveness of Taxol is enhanced by inhibition of Taxol induced multidrug resistance. In this study, Cyclosporin A with different concentration of Taxol was co-administered to HN22, the oral squamous cell carcinomacell line. To observe the cell apoptosis and the mechanisms that take part in this process, mortality evaluation of tumor cell using wortmannin, c-DNA microarray, RT-PCR analysis, cytometry analysis and western blotting were used, and based upon the observation on the effect and mechanism of the agent, the following results were obtained: 1. The HN22 cell line viability was lowest when $100{\mu}M$ of Wortmannin and $5{\mu}g/ml$ of Taxol were co-administered, showing that Taxol participates in P13K-AKT1 pathway. 2. In c-DNA microarray, where $1{\mu}g/ml$ of cyclosporine A and 3mg/ml of Taxol were co-administered, no up regulation of AKT1, PTEN and BAD c-DNA that participate in cell apoptosis was observed. 3. When $1{\mu}g/ml$ of Cyclosporin A was applied alone to HN22 cell line, no difference was found in AKT1, PTEN and BAD mRNA expression. 4. Increased AKT1, mRNA expression was observed when $3{\mu}g/ml$ of Taxol was applied alone to HN22 cell line. 5. When $1{\mu}g/ml$ of Cyclosporin A and Taxol($3{\mu}g/ml\;and\;5{\mu}g/ml$) were co-administered to HN22 cell line, PTEN mRNA expression increased, whereas AKT1 and BAD mRNA decreased. 6. As a result of cytometry analysis, in the group of Cyclosporin A($1{\mu}g/ml$) and Taxol($3{\mu}g/ml$) co-administration, increased Annxin V was observed, which shows that apoptosis occurred by deformation of plasma membrane. However, no significant difference was observed with vary ing concentration. 7. In western blot analysis, no caspase 3 was observed in the group of Cyclosporin A($1{\mu}g/ml$) and Taxol($3{\mu}g/ml$) co-administration. From the results of this study, it can be concluded that synergistic effect can be observed in combination therapy of Taxol and Cyclosporin A on oral squamous cell carcinoma cell line, where decreased activity of the cell line was observed. This resulted in decreased AKT1 and BAD mRNA and increased PTEN mRNA expression and when wortmannin and Taxol were co-administered, the viability decreased which confirms that Taxol decreases the viability of tumor cell line. Hence, when Taxol and cyclosporine A are co-administered, it can be assumed that cell apoptosis occurs through AKt1 pathway.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.267-277
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• 2021

To evaluate hepatoprotective effects, the antioxidant capacities of matcha green tea extract (Camellia sinenesis) were compared to those of green leaf tea and the anti-inflammatory activities in HepG2 cells were investigated. Evaluation of the total phenolic and total flavonoid content, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibitory effect on lipid peroxidation indicated that the aqueous extract of matcha green tea presented significant catechin content and antioxidant capacity compared to those of green leaf tea. In addition, the extract had considerable inhibitory effects on α-glucosidase, α-amylase, and advanced glycation end-products. The matcha green tea extract significantly increased cell viability and reduced reactive oxygen species in H₂O₂- and high-glucose-treated HepG2 cells. Furthermore, in response to oleic acid-induced HepG2 cell injury, treatment with matcha green tea aqueous extract inhibited lipid accumulation and regulated the expression of inflammatory proteins such as p-JNK, p-Akt, p-GSK-3β, caspase-3, COX-2, iNOS, and TNF-α. Matcha green tea could be used as a functional material to ameliorate hepatic lipid accumulation and inflammation.