• Proceedings of the Korean Society of Toxicology Conference
• /
• 2002.11b
• /
• pp.196-196
• /
• 2002

p16INK4a tumor suppressor gene transfer in the non-small cell lung cancer cells by transduction of recombinant adenovirus (Ad5CMV-p16) resulted in significant inhibition of cancer cell growth (Anticancer Res., 1998, 18:3257-3261). As a safety concern, we have investigated gene and protein expression after transduction of adenoviral vector (Ad5CMV-p16) in human non-small cell lung cancer (A549) cells by using microarray and 2D gel electrophoresis/ MALDI-TOF.(omitted)

• Development and Reproduction
• /
• v.26 no.3
• /
• pp.117-126
• /
• 2022

Bromodomain-containing protein 7 (BRD7) participates in many cellular processes and embryo development. BRD7 is down-regulated in various cancers and evidence of its tumor suppressor function has been accumulating. Here, we identified transforming stimulated clone 22 (TSC-22) as a novel BRD7 interacting protein and show its novel function as a positive regulator of BRD7. We found that TSC-22 expression potentiated the inactivation of the extracellular signal-regulate kinase (ERK) pathway by BRD7. Our data establishes TSC-22 as a modulator of BRD7 and unravels the molecular mechanisms that drive the synergistic tumor-suppressing effects of TSC-22 and BRD7. Our findings may open new avenues for developing novel molecular therapies for tumors exhibiting down-regulated BRD7 and/or TSC-22.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.1
• /
• pp.205-209
• /
• 2012

Background: The inhibition of tumor cell growth without toxicity to normal cells is an important target in cancer therapy. One possible way to increase the efficacy of anticancer drugs and to decrease toxicity or side effects is to develop traditional natural products, especially from medicinal plants. Paris polyphylla Smith has shown anti-tumour effects by inhibition of tumor promotion and inducement of tumor cell apoptosis, but mechanisms are still not well understood. The present study was to explore the effect of Paris polyphylla Smith extract (PPSE) on connexin26 and growth control in human esophageal cancer ECA109 cells. Methods: The effects of PPSE on Connexin26 were examined by RT-PCR, western blot and immunofluorescence; cell growth and proliferation were examined by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Results: PPSE inhibited the growth and proliferation on esophageal cancer ECA109 cells, while increasing the expression of connexin26 mRNA and protein; conversely, PPSE decreased Bcl-2 and increased Bad. Conclusion: This study firstly shows that PPSE can increase connexin26 expression at mRNA and protein level, exerting anti-tumour effects on esophageal cacner ECA109 cells via inhibiting cell proliferation and inducing cell apoptosis.

• International Journal of Oral Biology
• /
• v.33 no.1
• /
• pp.25-31
• /
• 2008

Inhibition of proteasome activity may reduce many types of cancer, so it's pathway is effective in cancer as well as in clinical fields. Here the author has carried out experiment targeting on the elevation of apoptosis in oral cancer cells by combination of proteasome inhibitor, lactacystin, and DNA replication inhibitor, etoposide. The growth of KB cells was measured by MTT methods and apoptosis was analyzed by DNA fragmentation and Hochest nucleus staining. The proteasome activity was analyzed by fluorescent tagged peptide and cellular protein expression was detected by Western hybridization. Though lactacystin and etoposide inhibited KB cell growth alone, but low combined doses inhibited cell growth more strongly and induced apoptosis. The proteasome activity was also seriously inhibited by the combination of both chemicals. Tumor suppressor proteins and apoptosis inducing proteins were highly increased under the combination of both chemicals. From above studies we can conclude that proteasome inhibitors may be used for the treatment of oral cancer and proteasome inhibitors with DNA replication inhibitors may be effective in clinical trials of oral cancer.

• Biomedical Science Letters
• /
• v.22 no.1
• /
• pp.18-23
• /
• 2016

Ultraviolet (UV) irradiation induces cellular damage. A variety of cellular responses for repairing cellular damage including DNA damage occur after UV irradiation. During the repair processes, expression and activation of various molecules are regulated depending on the types of cellular damage. Parkin is an E3 ligase and act as a tumor suppressor. Recently, it has been reported that Parkin is involved in the DNA repair process. In the current study, we investigated whether UVB irradiation influences expression of Parkin. Parkin expression transiently decreased after UVB irradiation both at the mRNA and protein levels, but returned to normal levels thereafter. Taken together with cell viability data, Parkin expression is down-regulated during UVB-induced suppression of cell growth and is increased again in accordance with recovery of UVB-induced cell growth inhibition. However, Parkin overexpression or knockdown did not influence UVB-induced cell growth inhibition and recovery. We propose that Parkin could be a useful molecular marker for evaluating conditions of cells after UVB irradiation.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.9
• /
• pp.4751-4756
• /
• 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.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.6
• /
• pp.1843-1849
• /
• 2004

Conventional medicines have usually sorted to a number of treatments such asoperation, radiotherapy, and chemotherapy. The existing anti-cancer agents, designed to eradicate cancer cells, have strong toxicities, also with leading to harmful side effects. Recently, a number of researches on natural products have been actively carried out in efforts to develop new treatments that can decrease side effects or increase anti-cancer effects. We performed this study to understand the molecular basis underlying the antitumor effects of Pharbitis nil, and Plantago asiatica, which have been used for herbal medicinal treatments against cancers in East Asia. We analyzed the effects of these medicinal herbs on proliferation and on expression of cell growth/apoptosis related molecules, with using an AGS gastric cancer cell line. The treatment of Pharbitis nil dramatically reduced cell viabilities in a dose and time-dependent manner, but Plantago asiatica didn't. FACS analysis and Annexin V staining assay also showed that Pharbitis nil induce apoptotic cell death of AGS. Expression analyses via RT-PCR and Western blots revealed that Pharbitis nil didn't increase expression of the p53 and its downstream effector p21/sup wafl/, and that the both increased expression of apoptosis related Sax and cleavage of active caspase-3 protein. We also confirmed the translocation of Sax to mitochondria. Collectively, our data demonstrate that Pharbitis nilinduce growth inhibition and apoptosis of human gastric cancer cells, and these effects are correlated with down- and up-regulation of growth-regulating apoptotic and tumor suppressor genes, respectively.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.1
• /
• pp.124-129
• /
• 2005

Resveratrol, a phytoalexin found at high levels in grapes and in grape products such as red wine, has been reported to possess a wide range of biological and pharmacological activities including anti-oxident, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects, but its molecular mechanism is poorly understood. In this study, we examined the effects of resveratrol on lipopolysaccharide (LPS)-induced growth inhibitory activity and cell growth-regulatory gene products in astroglioma C6 cells to elucidate its possible mechanism for anti-cytotoxicity. It is shown that LPS induced time-dependent growth inhibition and morphological changes of C6 cells, which were recovered by pre-treatment with resveratrol. The anti-proliferative effect of LPS was associated with the induction of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1) expression assessed by RT-PCR and Western blot analysis in time-dependent manner in C6 cells. In addition, the pro-apoptotic Bax expression was also up-regulated in LPS-treated C6 cells without alteration of anti-apoptotic Bcl-2 and Bcl-XL expression. However, resveratrol significantly inhibited LPS-induced p53, p21 and Bax levels, suggesting that the modulation of p53, p21 and Bax levels could be one of the possible pathways by which resveratrol functions as anti-cytotoxic agent.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3015-3023
• /
• 2012

The mitochondrial antioxidant protein manganese superoxide dismutase (MnSOD) may represent a new type of tumor suppressor protein. Overexpression of the cDNA of this gene by plasmid or recombinant lentiviral transfection in various types of cancer leads to growth suppression both in vitro and in vivo. We previously determined that changes in MnSOD expression had bidirectional effects on adriamycin (ADR) when combined with nitric oxide (NO). Radiation induces free radicals in a manner similar to ADR, so we speculated that MnSOD combined with NO would also have a bidirectional effect on cellular radiosensitivity. To examine this hypothesis, TE-1 human esophageal squamous carcinoma cells were stably transfected using lipofectamine with a pLenti6-DEST plasmid containing human MnSOD cDNA at moderate to high overexpression levels or with no MnSOD insert. Blastidicin-resistant colonies were isolated, grown, and maintained in culture. We found that moderate overexpression of MnSOD decreased growth rates, plating efficiency, and increased apoptosis. However, high overexpression increased growth rates, plating efficiency, and decreased apoptosis. When combined with NO, moderate overexpression of MnSOD increased the radiosensitivity of esophageal cancer cells, whereas high MnSOD overexpression had the opposite effect. This finding suggests a potential new method to kill certain radioresistant tumors and to provide radioresistance to normal cells.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.4
• /
• pp.907-915
• /
• 2007

In this study the effect of water extract of Sophora tonkinensis Gapnep (RST) was investigated on the growth of human lung carcinoma A549 cells. Exposure of A549 cells to RST resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay. The antiproliferative effect by RST treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. RST treatment did not induce the cell cycle arrest and the levels of tumor suppressor p53 as well as cyclin-dependent kinase inhibitor p21(WAF1/CIP1). It was found that RST treatment decreased the levels of cyclooxygenase (COX) -2 mRNA and protein expression without significant changes in the expression of COX-1 and inducible nitric oxide synthase (iNOS), which was correlated with a decrease in prostaglandin E2 (PGE2) synthesis. RST treatment also slightly inhibited the levels of human telomerase reverse transcriptase (hTERT) mRNA and protein expression, and the activity of telomerase. Taken together, these findings suggested that RST-induced inhibition of human lung carcinoma A549 cell growth was aoosciated with the inhibition of COX-2 expression and PGE2 production. These results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of RST.