• International Journal of Oral Biology
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• v.47 no.2
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• pp.17-24
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• 2022

Preserving intact genetic material and delivering it to the next generation are the most significant tasks of living organisms. The integrity of DNA sequences is under constant threat from endogenous and exogenous factors. The accumulation of damaged or incompletely-repaired DNA can cause serious problems in cells, including cell death or cancer development. Various DNA damage detection systems and repair mechanisms have evolved at the cellular level. Although the mechanisms of these responses have been extensively studied, the global RNA expression profiles associated with genomic instability are not well-known. To detect global gene expression changes under different DNA damage and hypoxic conditions, we performed RNA-seq after treating human cervical cancer cells with ionizing radiation (IR), hydroxyurea, mitomycin C (MMC), or 1% O₂ (hypoxia). Results showed that the expression of 184-1037 genes was altered by each stimulus. We found that the expression of 51 genes changed under IR, MMC, and hypoxia. These findings revealed damage-specific genes that varied differently according to each stimulus and common genes that are universally altered in genetic instability.

• The Korea Journal of Herbology
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• v.30 no.2
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• pp.25-30
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• 2015

Objectives : Laver (Porphyra tenera), a red algae species, is one of the most widely consumed edible seaweed in Korea. Laver contains various substances such as essential amino acid, fiber, minerals and polyphenols that benefit human health. In the present study, we prepared ethanol extracts from commercially processed product of Porphyra tenera, and evaluated the growth inhibitory effect against human oral squamous carcinoma YD-10B cells. Methods : Cell viability was measured by MTT assay. Apoptosis was confirmed by TUNEL assay and flow cytometry with the green fluorescent dye FITC annexin V entering apoptotic cells and the red fluorescent dye PI not entering. The expression of the relevant proteins was detected using Western blot. Results : Ethanol extracts of Porphyra tenera (PTE, $50-200{\mu}g/m{\ell}$) caused a significant decrease of cell viability in a dose dependant manner. The cell death occurred as a result of apoptotic process as determined by TUNEL assay and flow cytometric analysis. In line with this observation, decrease in procaspase proteins and increase in cytosolic cytochrome c were observed in cells treated with PTE. In addition, exposure to PTE decreased the expression levels of Bcl-2, and induced PARP cleavage and AIF translocation from mitochondria to nucleus. Conclusions : In conclusion, PTE exerts anti-cancer effects by inducing apoptosis via caspase activation and AIF nuclear translocation in YD-10B cells. These results provide evidence for the possible therapeutic effect of Porphyra tenera in oral cancer cells.

• Molecules and Cells
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• v.38 no.2
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• pp.112-121
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• 2015

Ectopic expression of $14-3-3{\zeta}$ has been found in various malignancies, including lung cancer, liver cancer, head and neck squamous cell carcinoma (HNSCC), and so on. However, the effect of $14-3-3{\zeta}$ in the regulation of interactions between tumor cells and the immune system has not been previously reported. In this study, we aimed to investigate whether and how $14-3-3{\zeta}$ is implicated in tumor inflammation modulation and immune recognition evasion. In oral squamous cell carcinoma (OSCC) cell lines and cancer tissues, we found that $14-3-3{\zeta}$ is overexpressed. In OSCC cells, $14-3-3{\zeta}$ knockdown resulted in the up-regulated expression of inflammatory cytokines. In contrast, $14-3-3{\zeta}$ introduction attenuated cytokine expression in human normal keratinocytes and fibroblasts stimulated with interferon-${\gamma}$ (IFN-${\gamma}$) and lipopolysaccharide (LPS). Furthermore, supernatants from $14-3-3{\zeta}$ knockdown OSCC cells dramatically altered the response of peritoneal macrophages, dendritic cells and tumor-specific T cells. Interestingly, Stat3 was found to directly interact with $14-3-3{\zeta}$ and its disruption relieved the inhibition induced by $14-3-3{\zeta}$ in tumor inflammation. Taken together, our studies provide evidence that $14-3-3{\zeta}$ may regulate tumor inflammation and immune response through Stat3 signaling in OSCC.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.334-340
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• 1998

Stimulatory effects of epidermal growth factor (EGF) and transforming growth $factor-{\alpha}$($TGF-{\alpha}$) on the growth of squamous cancer cell lines established from human oral cancer tissue with moderate differentiation were studied in vitro. After culturing in serum-free media for 24 hours, growth factors-EGF only, $TGF-{\alpha}$ only and EGF, $TGF-{\alpha}$ together-were added to the media and numbers of cells were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and compared with the control at 96, 144 hours. Each of EGF and $TGF-{\alpha}$ showed statistically significant stimulatory effects on the growth of cells respectively. Dose-dependent relationship of the stimulatory effects were not clearly demonstrated. The effects of EGF were higher than those of $TGF-{\alpha}$ and combinative administration showed higher effects than those of single uses. In conclusion, EGF may play an important and major role in differentiation and growth of human oral squamous cancer cells. $TGF-{\alpha}$, produced from cells activated by EGF, also can stimulate the cell growth and could be an alternative ligand for EGF receptor.

• Journal of Oral Medicine and Pain
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• v.30 no.2
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• pp.231-238
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• 2005

Anti-cancer drugs have been shown to target diverse cellular functions in mediation cell death in chemosensitive tumors. Most antineoplastic drugs used in chemotherapy of leukemias and solid tumors induce apoptosis in drug-sensitive target cells. However, the precise molecular requirements that are central for drug-induced cell death are largely unknown. Etoposide is used for the treatment of lung and testicular cancer. This study was performed to examine whether etoposide promote apoptosis in human oral squamous carcinoma cells (OSC9) as well as in lung and testicular cancer. Etoposide had a significant dose- and time-dependent inhibitory effect on the viability of OSC9 cells. TUNEL assay showed the positive reaction on condensed nuclei. Hoechst stain demonstrated that etoposide induced a change in nuclear morphology. The expression of p53 was increased at 48 hour, suggesting that the nuclear of OSC9 cell was damaged, thereby inducing apoptosis. Etoposide treatment induced caspase-3 cleavage and activation. Intact PARP protein 116-kDa and 85-kDa cleaved product were observed. The activated caspase-3 led cleavage of the PARP. These results demonstrate that etoposide-induced apoptosis in OSC9 cells is associated with caspase-3 activation.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.41 no.1
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• pp.1-7
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• 2017

Lycorine, a natural alkaloid extracted from the Amaryllidaceae plant family, was reported to various physiological and pharmacological effects including anti-cancer activity. Nevertheless, there is no report of the anticancer effect of lycorine in oral cancer cells. The effects of lycorine on cell proliferation and apoptosis were examined through trypan blue exclusion assay, 4'-6-diamidino-2-phenylindole (DAPI) stain, Live/Dead assay, Western blot analysis and RT-PCR. Lycorine suppressed cell viability and induced apoptosis in MC3 and HSC-3 cell lines. Lycorine decreased survivin protein but did not affect its mRNA. It regulated survivin through accelerating protein degradation in a time-dependent manner although neither proteasome nor lysosome was not associated with lycorine-mediated protein degradation. Collectively, our results suggest that lycorine may be a potential therapeutic anti-cancer drug candidate for the treatment of human oral cancer.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.284-290
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• 2022

Oral squamous cell carcinoma (OSCC) is mostly diagnosed at an advanced stage, with local and/or distal metastasis. Thus, locoregional and/or local control of the primary tumor is crucial for a better prognosis in patients with OSCC. Platelets have long been considered major players in cancer metastasis. Traditional antiplatelet agents, such as aspirin, are thought to be potential chemotherapeutics, but they need to be used with caution because of the increased bleeding risk. Podoplanin (PDPN)-expressing cancer cells can activate platelets and promote OSCC metastasis. However, the reciprocal effect of platelets on PDPN expression in OSCC has not been investigated. In this study, we found that direct contact with platelets upregulated PDPN and integrin β1 at the protein level and promoted invasiveness of human OSCC Ca9.22 cells that express low levels of PDPN. In another human OSCC HSC3 cell line that express PDPN at an abundant level, silencing of the PDPN gene reduced cell invasiveness. Analysis of the public database further supported the co-expression of PDPN and integrin β1 and their increased expression in metastatic tissues compared to normal and tumor tissues of the oral cavity. Taken together, these data suggest that PDPN is a potential target to regulate platelet-tumor interaction and metastasis for OSCC treatment, which can overcome the limitations of traditional antiplatelet drugs.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.41-44
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• 2013

Although tongcao has been reported to have anti-oxidative, anti-inflammatory and antipyretic effects, there is no report of the chemopreventive effect of tongcao in cancer cells. In the present study, we investigated the anti-proliferative activity of methanol extract of tongcao (MET) and its molecular target in HEp-2 human cervical cancer cells using MTS assay, western blot analysis, and DAPI staining. MET significantly decreases cell viability and induces apoptotic cell death. It affects Bid protein to be truncated resulting in the release of cytochrome c from mitochondria to cytosol whereas it did not affect other Bcl-2 family members. Thus, we clearly suggest that tongcao can be a potential naturally occurring plants having chemopreventive activity in cervical cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6501-6506
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• 2015

There are numerous clinical cases indicating that long-term use of bevacizumab may increase the invasiveness of tumors. However, to date, little is known about underlying molecular mechanisms. Therefore, the purpose of our study was to investigate effects of bevacizumab in four cancer cells lines (WSU-HN6, CAL27, Tca83, and HeLa). It was found to promote migration and invasion in the WSU-HN6 and Tca83 cases, while exerting inhibitory effects in CAL27 and HeLa cells. The signal transducer and activator of transcription (STAT) 3 inhibitors niclosamide and S3I-201 inhibited the STAT3 signal pathway, which is activated by bevacizumab. These inhibitors also substantially blocked bevacizumab-induced migration of WSU-HN6 and Tca83 cells. Bevacizumab upregulated interleukin (IL)-6 and phosphorylated (p)-STAT3 expression time-dependently. Therefore, we propose that bevacizumab has differential effects on the migration of different cancer cell lines and promotes migration via the IL-6/STAT3 signaling pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5495-5501
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• 2013

Background: Alu elements are one of the most common repetitive sequences that now constitute more than 10% of the human genome and potential targets for epigenetic alterations. Correspondingly, methylation of these elements can result in a genome-wide event that may have an impact in cancer. However, studies investigating the genome-wide status of Alu methylation in cancer remain limited. Objectives: Oral squamous cell carcinoma (OSCC) presents with high incidence in South-East Asia and thus the aim of this study was to evaluate the Alu methylation status in OSCCs and explore with the possibility of using this information for diagnostic screening. We evaluated Alu methylation status in a) normal oral mucosa compared to OSCC; b) peripheral blood mononuclear cells (PBMCs) of normal controls comparing to oral cancer patients; c) among oral epithelium of normal controls, smokers and oral cancer patients. Materials and Methods: Alu methylation was detected by combined bisulfite restriction analysis (COBRA) at 2 CpG sites. The amplified products were classified into three patterns; hypermethylation ($^mC^mC$), partial methylation ($^uC^mC+^mC^uC$), and hypomethylation ($^uC^uC$). Results: The results demonstrate that the $%^mC^mC$ value is suitable for differentiating normal and cancer in oral tissues (p=0.0002), but is not significantly observe in PBMCs. In addition, a stepwise decrease in this value was observed in the oral epithelium from normal, light smoker, heavy smoker, low stage and high stage OSCC (p=0.0003). Furthermore, receiver operating characteristic (ROC) curve analyses demonstrated the potential of combined $%^mC$ or $%^mC^mC$ values as markers for oral cancer detection with sensitivity and specificity of 86.7% and 56.7%, respectively. Conclusions: Alu hypomethylation is likely to be associated with multistep oral carcinogenesis, and might be developed as a screening tool for oral cancer detection.