• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.35 no.2
• /
• pp.66-73
• /
• 2009

Tumor angiogenesis is a process leading to formation of blood vessels within tumors and is crucial for maintaining a supply of oxygen and nutrients to support tumor growth and metastasis. Vascular endothelial growth factor(VEGF) plays a key role in tumor angiogenesis including induction of endothelial cell proliferation, migration, survival and capillary tube formation. VEGF binds to two distinct receptors on endothelial cells. VEGFR-2 is considered to be the dominant signaling receptor for endothelial cell permeability, proliferation, and differentiation. Bevacizumab(Avastin, Genetech, USA) is a monoclonal antibody against vascular endothelial growth factor. It is used in the treatment of cancer, where it inhibits tumor growth by blocking the formation of new blood vessels. The goal of this study is to identify the anti-tumor effect of Bevacizumab(Avastin) for oral squamous cell carcinoma cell lines. Human squamous cell carcinoma cell line(HN4) was used in this study. We examined the sensitivity of HN4 cell line to Bevacizumab(Avastin) by using in vitro proliferation assays. The results were as follows. 1. In the result of MTT assay according to concentration of Bevacizumab(Avastin), antiproliferative effect for oral squamous cell carcinoma cell lines was observed. 2. The growth curve of cell line showed the gradual growth inhibition of oral squamous cell carcinoma cell lines after exposure of Bevacizumab(Avastin). 3. In the apoptotic index, groups inoculated Bevacizumab(Avastin) were higher than control groups. 4. In condition of serum starvation, VEGFR-2 did not show any detectable autophosphorylation, whereas the addition of VEGF activated the receptor. Suppression of phosphorylated VEGFR-2 and phosphorylated MAPK was observed following treatment with Bevacizumab(Avastin) in a dose-dependent manner. 5. In TEM view, dispersed nuclear membrane, scattered many cytoplasmic vacuoles and localized chromosomal margination after Bevacizumab(Avastin) treatment were observed. These findings suggest that Bevacizumab(Avastin) has the potential to inhibit MAPK pathway in proliferation of oral squamous cell carcinoma cell lines via inhibition of VEGF-dependent tumor growth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.2
• /
• pp.103-108
• /
• 2007

Cyclooxygenase-2 (Cox-2) is known as one of the critical factor in carcinomas of various organs. However, the importance of Cox-2 in oral squamous cell carcinoma has not been fully described yet. The purpose of this study is to evaluate the anti-cancer effect of selective cox-2 inhibitor, celecoxib in an oral squamous cell carcinoma cell line, KB with respect to cytotoxicity test, in vitro invasion and MMP-2 expression. In cytotoxicity test, celecoxib treated group showed definitely concentration dependent cytotoxicity. In addition, administration of celecoxib reduced the invasive potential of KB cell line significantly in invasion assay. However, there was no remarkable difference of the MMP-2 expression between the celecoxib treated group and the control group. Considering these data, celecoxib had a potential cytotoxic agent to oral squamous cell carcinoma cells. Also, it had anti-invasive property without acting on the MMP-2 expression mechanism. Therefore, it was postulated that celecoxib had the possibility of anti-cancer agent in treatment strategies of oral squamous cell carcinoma.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.5
• /
• pp.394-404
• /
• 2007

Oral squamous cell carcinoma is the most prevalent oral cancer, which is characterized by its high metastasis and recurrent rates and poor prognosis. Taxol is an anticancer agent which is microbial products extracted from jew tree. It combines with the tubulin and induces apoptosis by inhibiting mitosis of cell with microtubule stabilization. Recently, it was reported to be effective in various solid tumors, but only very slight effect has been seen in oral squamous cell carcinomas due to its cell-specific potencies. Cyclosporin A is used as immune suppressant and is being applied in anticancer therapy as its mechanism of induction of change of apoptotic process in various cells have been known. In this study, oral squamous cell carcinoma HN22 cell line was used for in vitro experiment and as for the experimental group taxol and cyclosporin A were applied alone and to observe the synergistic effect of apoptosis, Taxol and cyclosporin A were coadministered with different concentration of taxol for comparison. The results were obtained as follow: 1. There was no difference in Bcl-2, Bax, caspase 3, 8, 9 mRNA expression when cyclosprin A or taxol was applied alone to HN 22 cell line. 2. Caspase 3, 9 mRNA expression was prominently increased when cyclosprin A and taxol were applied together to cancer cell. 3. No significant difference was observed when cyclosporin A and taxol($1{\mu}g/ml$ and $3{\mu}g/ml$) were applied together to cancer cell line. 4. No significant difference was seen in Bcl-2, Bax, and caspase 8 mRNA expression in all the groups of in vitro experiments. 5. When cyclosporin A was applied alone in vivo study on the nude mice, histopathologi cal findings was similar to those of the control group. Oral squamous cell carcinoma induced by inoculation of HN 22 cell line was not reduced after treatment of cyclosporin A. 6. When taxol was applied alone, the islands of squamous cell carcinoma still remained, which meant insignificant healing effect. There was a lesser volume increase compared with the cyclosporin A alone. 7. When taxol and cyclosporin A were applied together, the connective tissue and calcification were seen in the histopathologic findings. Oral squamous cell carcinoma was decreased and cancer cell was disappeared. In observing the tumor mass change with time, there was a gradual decreased size and healing features. As the results of the in vitro experiment, it could conclud that only when the two agents are applied together, mitochondria-mediated apoptosis occurred by considerable increase of caspase 3, 9 mRNA expression, irrespectable of the concentration of taxol. In vivo experiment, there was a discrete synergistic effect when the two agents were applied together. But single use of cyclosporin A was not effective in this study. Based on the results of this experiment, if further clinical studies are done, taxol and cyclosporin A could be effectively used in treatment of oral squamous cell carcinomas.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.1
• /
• pp.30-40
• /
• 2008

The objectives of this study was to check up the effect of celecoxib, COX-2 inhibitor, on the pathogenesis of oral squamous cell carcinoma. After mefenamic acid, aspirin and celecoxib, COX-2 inhibitor, were inoculated to HN 22 cell line, the following results were obtained through tumor cell viability by wortmannin, growth curve of tumor cell line, apoptotic index, PGE2 synthesis, total RNA extraction, RT-PCR analysis and TEM features. 1. When wortmannin and celecoxib were given together, the survival rate of tumor cells was lowest about 47 %. So wortmannin had an effect on the decrease of survival rate of tumor cells. 2. In growth curve, the slowest growth was observed in celecoxib inoculated group. 3. The synthesis of PGE2 was decreased in all group and the obvious suppression and highest apoptotic index was observed in celecoxib inoculated group. 4. Suppression of expression of COX-2 mRNA was evident in celecoxib inoculated group. But that of COX-1,2 mRNA was observed in mefenamic acid inoculated group and aspirin inoculated group. 5. In celecoxib inoculated group, mRNA expression of AKT1 was decreased and that of PTEN & expression of caspase 3 and 9 was evidently increased. Depending on above results, when celecoxib was inoculated to oral squamous cell carcinoma cell line, an increase of mRNA expression of caspase 3,9 and PTEN is related to a decrease of mRNA expression of AKT1. Wortmannin had an effect on the decrease of survival rate of tumor cells. Celecoxib might induce apoptosis of tumor cell by suppression of AKT1 pathway and COX-2 inhibition. This results suggested that COX-2 inhibitor might be significantly effective in chemoprevention of oral squamous cell carcinoma.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.28 no.4
• /
• pp.339-347
• /
• 2006

Oral leukoplakia is the most common premalignant lesion and malignant transformation has been reported from verrucal lekoplakia. Homogenous, benign leukoplakia develops into a line of squamous cell carcinoma such as verrrucous carcinoma, papillary squamous cell carcinoma and invasive squamous cell carcinoma. Early diagnosis and intervention of premalignant leukoplakia is up-most important to prevent transformation into a oral squamous cell carcinoma. Any change in surface, size and color warrants repeated biopsy. If verrucous carcinoma is evidently derived from the previous leukoplakia, wide surgical excision and periodic follow up is needed. Surgically removed lesion of leukoplakia has the tendency to recur. Follow-up is very important to patient and clinician. Although many therapies have been reported to oral leukoplakia and verrucal carcinoma, accepted treatment principle is not exist so far. But surgical removal is recommended as the treatment of choice.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.4
• /
• pp.333-344
• /
• 2008

The objectives of this study was to explore the growth pattern of the oral squamous cell carcinoma when overexpressed COX was inhibited, explore the pathway that COX inhibitors suppressed the proliferation of cancer cells, and then hereafter investigate the potential of COX as chemopreventive target for oral squamous cell carcinoma. For confirming the COX-dependent effect and mechanisms on growth of the oral cancer cells, we treated the nonselective NSAID, Mefenamic acid and COX-2 selective inhibitor, Celecoxib in HN4 cell line. And then the cell line was evaluated with MTT assay and growth curve, the production of PGE2, total RNA extraction and RT-PCR analysis, and TEM The results were obtained as follows: 1. After administration of medication, in the result of MTT assay, Celecoxib inoculated group inhibit the cell growth rather than Mefenamic acid inoculated group. 2. The growth curve of cell line showed as time passes by there was a dramatic cell growth in the control group, and gradual growth inhibition was found in medication inoculated group and, in Celecoxib inoculated group there was more inhibition of cell growth. 3. After the administration of medication, Celecoxib tend to inhibit the synthesis of PGE2 more than Mefenamic acid. Mefenamic acid inhibit the synthesis of PGE2 more as the concentration gets high, but Celecoxib inhibited the synthesis of PGE2 even in low concentration. 4. After the administration of medication, the revelation of COX mRNA in cell line, there was a 50% decrease in COX-1, 60% decrease in COX-2 as in $50{\mu}M$ Mefenamic acid, and in Celecoxib $50{\mu}M$ there was not much difference in COX-1 and 90% decrease in COX-2 was found. 5. HN4 cell line showed broken nucleus and tangled cytoskeleton bundles in cytoplasm which meant apoptotic features after the treatment of Celecoxib in TEM view. Depending on the above results, we estimate that the inhibition of the expression of COX-2 cause the growth suppression of the oral squamous cell carcinoma, and it get achieved through pathway of reduced PGE2 production and increased apoptosis. In addition to, because COX-2 selective inhibitor specifically act to COX-2, it is considered that COX-2 selective inhibitor has the adequate potential as chemopreventive agent for oral squamous cell carcinoma.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.22 no.2
• /
• pp.50-59
• /
• 2009

Objectives : The aim of this study was conducted that CRE (Coptidis Rhizoma Extract) induces apoptosis in YD-10B cells, human oral squamous carcinoma cell line. Methods : In this study, YD-10B cells were exposed to CRE (0.03-0.30 mg/ml), for 6-24 hours. We measured the effects of CRE on the changes of cell viability and cell membrane, TUNEL assay of CRE-treated YD-10B cell. Results : In this study, CRE caused a decrease of viability in YD-10B cells, human oral squamous carcinoma cell line. When YD-10B cells were treated with CRE, cells showed dose-dependent manner apoptotic cell death. Conclusions : These results suggest that CRE may be potential therapeutic approach in the clinical management of oral squamous cell carcinoma.

• International Journal of Oral Biology
• /
• v.35 no.2
• /
• pp.51-60
• /
• 2010

Few studies have evaluated the apoptosis-inducing efficacy of NaF on cancer cells in vitro but there has been no previous investigation of the apoptotic effects of NaF on human oral squamous cell carcinoma cells. In this study, we have investigated the mechanisms underlying the apoptotic response to NaF treatment in the YD9 human squamous cell carcinoma cell line. The viability of YD9 cells and their growth inhibition were assessed by MTT and clonogenic assays, respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to detect apoptosis. YD9 cells were treated with NaF, and western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, and MMP and proteasome activity assays were performed sequentially. The NaF treatment resulted in a time- and dose-dependent decrease in YD9 cell viability, a dose-dependent inhibition of cell growth, and the induction of apoptotic cell death. The apoptotic response of these cells was manifested by nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, a significant shift of the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF treatment resulted in the downregulation of G1 cell cyclerelated proteins, and upregulation of p53 and the Cdk inhibitor $p27^{KIP1}$. Taken collectively, our present findings demonstrate that NaF strongly inhibits YD9 cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via mitochondrial and caspase pathways.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.30 no.6
• /
• pp.474-481
• /
• 2004

Squamous cell carcinoma is the most prevalent oral cancer, which is characterized by its low survival rate, high malignancy, mortality with facial defects, and poor prognosis. Exact cause and pathogenesis of the squamous cell carcinoma is still unknown. Various routes including smoking, radiation, and viral infections predispose its genesis, and recent studies revealed that genetic defects which fail to prevent cancer proliferation play a role. Generally, a cancer develops from the decreased rate of apoptosis which is an active and voluntary cell death, and from the altered cell cycles. Anticancer effect can be obtained by recovering the apoptotic process, and by suppressing the cell cycles. Among the apoptosis related factors, bcl-2, caspase-9, and VDAC (voltage-dependent anion channel)are produced in mitochondria of the cell. Cyclosporin-A is known to induce apoptosis through its activation with VDAC. This study was to reveal the anticancer effect of Cyclosporin A to the oral squamous cell carcinoma. The inverted microscope was used to find alterations in the tissue, and sensitivity test to the anticancer cells was performed with MTT (Tetrazolium-based colorimetric) assay. Following cell line culture of primary and metastastic oral squamous cell carcinoma, electrophoresis was performed with extracted total RNA. Finally, semi-quantitative study was carried out through RT-PCR (Reverse Transcription-Polymerase Chain Reaction). The results of this study are as follows: 1. The inverted microscopic observation revealed a poorly defined cytoplasm at $2000ng{\sim}3000ng/ml$, indistinct nucleus, and apoptosis. 2. The Growth of cancer cells was decreased at 1000ng/ml of cyclosporin-A. No cancer cell growth was observed at over 2000ng/ml concentration of cyclosporin-A, and at one week, growth of cancer cells was ceased. 3. The MTT assays were decreased as cyclosporin-A concentration was increased. This means that the activation of succinyl dehydrogenase in mitochondria was decreased following administration of cyclosporin A. 4. A result of RT-PCR showed that amount of mRNA of VDAC-2 was decreased half times at a cyclosporine-A concentration of 2000ng/ml. In bcl-2, amount of mRNA was significantly decreased 1/5 times at 2000ng/ml. caspase-9, however, showed slight increase compared to the control group. From the results obtained in this study, administration of cyclosporin-A to the cell lines of oral squamous cell carcinoma induced alterations in morphology and growth of the cells as its concentration increased. Since apoptosis related factors such as VDAS-2, bcl-2, and caspase-9 also showed distinct alterations on their mRNAs, further research on cyclosporin A as an anti-cancer agent will be feasible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.6
• /
• pp.535-542
• /
• 2001

The purpose of this study was to examine the mRNA levels of TNF-${\alpha}$ and IL-6 in the cell lines of normal oral keratocyte and oral squamous cell carcinoma. Total RNA was extracted from these cell lines, observed under UV light, developed by radiographic films of PCR products via reverse transcriptase polymerase chain reaction(RT-PCR) amplication, and measured with densitometer. Each mRNA level of these cell lines divided by ${\beta}$-actin mRNA level was compared to that of normal control group. The results were as follows: 1. Higher mRNA expression of TNF-${\alpha}$ than IL-6 in the normal oral epithelial cell line. 2. In general, expression of mRNA of IL-6 appeared 3-4 times more in tumor cell lines than in control group. 3. mRNA expression of TNF-${\alpha}$ showed variable expression in tumor cell lines, unlike normal cell line. 4. There are no special connections between differentiation of oral cancer cell lines and mRNA expression of TNF-${\alpha}$ and IL-6. From the above results, expression of mRNA of IL-6 in the cell lines of squamous cell carcinoma used in this study has higher than the normal oral epithelial cell line, but there are no relationship between the differentiation of oral cancer cell lines and the expression of mRNA of TNF-${\alpha}$ and IL-6.