구강편평상피세포암에서의 치성요인

남웅,차인호,Nam, Woong,Cha, In-Ho 대한구강악안면외과학회 2001 대한구강악안면외과학회지 Vol.27 No.6

The oral cavity has frequent contacts with many carcinogenic compounds and its soft tissue is continuously stimulated by numerous dental factors. We have examined the detailed dental factors and its correlation with oral squamous cell carcinoma, and denture-wearing effects to analyze the effect of the dental factors on the genesis of oral squamous cell carcinoma. We have studied clinical contributing factors and the dental factors in the genesis of oral squamous cell carcinoma when the effects of smoking and drinking are controlled. The study cases are 100 patients(75 males and 25 females) who were diagnosed histo-pathologically as squamous cell carcinoma at the Yonsei Medical Center. The control group was 154 patients who have no systemic malignant tumors. The effects of 6 dental factors were analyzed in this study. They were divided into the smoking group, the non smoking group, the drinking group, and the non-smoking group. The effects of dental factors were analyzed in each group. In this study, we have drawn some conclusions on the relationship between the dental factors and oral squamous cell carcinoma using $x^2$-test. 1. The repaired teeth have statistical significance on the genesis of squamous cell carcinoma. This is probably due to the combining effects of past poor oral hygiene and continuous stimulation due to poor prosthesis. 2. There is statistical significance of the lost teeth in the smoking group, and the repaired teeth and the degree of alveolar bone resorption had statistical significance in the non-smoking group. 3. Smoking and drinking by-itself have no statistical significance in the genesis of oral squamous cell carcinoma. However, in combination, they have statistical significance. In this study, dental factors had a synergistic effect with smoking and drinking. Together with avoidance of smoking and drinking, appropriate restoration and oral hygiene control are most important factors in the preventive aspects of the oral squamous cell carcinoma.

구강편평세포암에서 telomerase 활성도의 임상적 연관성에 관한 연구

심유진,김명진,남동석,이종호,Shim, Yu-Jin,Kim, Myung-Jin,Nahm, Dong-Seok,Lee, Jong-Ho 대한구강악안면외과학회 2001 대한구강악안면외과학회지 Vol.27 No.4

Telomerase is a ribonucleoprotein that synthesizes telomere repeats. It has been reported that activation of telomerase was associtated with immortalization, proliferative activity and carcinogenesis. Recently, telomerase activity has been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In neuroblastoma, breast carcinoma, gastric carcinoma, non-small cell lung carcinoma, close relationship has been reported between high telomerase activity and lymph node metastasis, tumor aggressiveness and poor prognosis. The purpose of this study is to investigate the clinical implication of telomerase activity assay as an adjunctive factor in decision-making on neck node management, speedy pre-operative judging on histologic malignancy grading. Thus we performed semi-quantitative assay of telomerase activity using Telomerase PCR ELISA $kit^{(R)}$(Boeringer Manheim, Germany) and evaluated correlation between telomerase activity and tumor size, neck node metastasis, Anneroth malignancy score and influence of pre-operative chemotherapy on its activity in 27 cases of oral squamous cell carcinomas and 18 cases of normal oral epithelium. Also, correlation between telomerase activities and PCNA indices was evaluated. The results were obtained as follows: 1. The telomerase activities were detected in 24 specimens out of 27 oral squamous cell carcinoma specimens (88.9%) and in 5 specimens out of 18 normal oral epithelium specimens (27.8%). The mean value of telomerase activities was $0.9793{\pm}0.3428$ in 24 oral squamous cell carcinoma specimens and $0.4855{\pm}0.1117$ in 5 normal oral epithelium specimens. The positivity rate and mean value of telomerase activities in oral squamous cell carcinoma specimens were significantly higher than those of normal oral epithelium specimens (p<0.05). 2. There was no significant correlation between total Anneroth malignancy score and telomerase activity (p>0.05), but points of mitosis index and depth of invasion were significantly correlated with telomerase activities (p<0.05). 3. The positive immunohistochemical staining for PCNA(proliferating cell nuclear antigen) was observed in 26 specimens out of 27 oral squamous cell carcinoma specimens and mean value of PCNA indices of 26 specimens was $53.67{\pm}26.46$. PCNA indices were significantly correlated with telomerase activities (p<0.05). 4. The mean value of telomerase activities was significantly higher in pathologic T3/T4 group than in T1/T2 group (p<0.01). There was no significant difference of mean value of telomerase activities between pathologic neck node positive group and negative group (p> 0.05). Pre-operative chemotherapy significantly lowered the telomerase activities (p<0.05). The above results suggested telomerase activity could be used as diagnostic marker and adjunctive parameter for judging on histologic malignancy in oral squamous cell carcinoma.

구강 편평세포암종에서 Taxol과 Cyclosporin A의 세포사멸 상승 작용 효과

서민정,한세진,이재훈,Suh, Min-Jung,Han, Se-Jin,Lee, Jae-Hoon 대한악안면성형재건외과학회 2007 Maxillofacial Plastic Reconstructive Surgery Vol.29 No.5

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.

구강편평세포암에서 telomerase 활성도의 임상적 연관성에 관한 연구

심유진,김명진,남동석,이종호 大韓口腔外科學會 2003 大韓口腔外科學會誌 Vol.27 No.4

원발성 및 전이성 구강편평세포암종 세포주에서 p21 및 p73 mRNA발현에 관한 연구

강정훈,김경욱,이재훈,Kang, Jeong-Hoon,Kim, Kyung-Wook,Lee, Jae-Hoon 대한구강악안면외과학회 2001 대한구강악안면외과학회지 Vol.27 No.6

There were many controversies in the cause and progress of tumorigenesis. Recently, studies on the mutation of genes related to the tumor have extensively been performed due to development of molecular biology. Structural and morphological changes of chromosomes, which are related to the abnormal activation of oncogenes or inactivation of tumor suppression genes, transform the normal cells into the tumor cells. p53 and Rb are well known tumor suppressor genes, while oncogenes include c-myc, bcl-2 and ras, etc. When exposed to cell damaging agents, p53 inhibits cell growth by inducing transcription of p21. Especially p73, which is homo-logy of p53, frequently deleted in melanoma, neuroblastoma, colon cancer, and breast cancer, when over produced, p73 activates the transcription of p21, bax-1 and inhibits cell growth by inducing apoptosis. For study on mRNA expression of p21 and p73, normal oral keratinocytes, and cell lines of primary and metastatic oral squamous cell carcinoma were cultured and then electrophoresis and RT-PCR(reverse transcription-polymerase chain reaction) were performed. 1. The mRNA of p21 and p73 in normal oral keratinocyte expressed lower than that of primary squamous cell carcinoma. 2. The mRNA of p21 in metastatic oral squamous carcinoma cell lines was expressed as various patterns compared with that of normal oral keratinocyte. 3. In the metastatic oral squamous cell lines, the mRNA of HN8 expressed higher than that of HN12 or HN19. 4. The mRNA of p73 in primary oral squamous cell lines expressed 4-5 times higher than that of normal keratinocyte. 5. In metastatic oral squamous cell lines, there was no significant expression of p73 mRNA compared with that of normal oral keratinocyte. From the results obtained in this study, mRNA expression of p73 in primary oral squamous cell lines was remarkable, while mRNA expression of p21 and p73 in metastatic oral squamous cell lines were statistically insignificant.

분화도 좋은 구강 편평상피세포암종에서 Dominant Negative p63 isoform의 발현

김인수(In-Su Kim),김철환(Chul-Hwan Kim),김경욱(Kyung-Wook Kim) 대한구강악안면외과학회 2007 대한구강악안면외과학회지 Vol.33 No.3

The p53 which is well known as tumor suppressor gene is located at 17p13. p53 is a sequence-specific DNA binding transcription factor that responds to certain cytotoxic stresses, such as DNA damage, by enhancing the transcription of genes that regulate cell-cycle progression as well as programmed cell death. The p63 gene that is located at 3q27-29, is recognized members of the p53 family, and responsible for the transcription of 6 isoforms. Three isoforms (TAp63α, TAp63β, TAp63γ) contain an N-terminal transactivation (TA) domain and can induce apoptosis. The other 3 isoforms(ΔNp63α, ΔNp63β, ΔNp63γ) lack the TA domain and may function in a dominant-negative fashion by inhibiting the transactivation functions of p53 and TAp63 proteins, and thus act as oncoproteins. A number of studies have investigated the role of p63 in human squamous cell carcinomas from different organs. Only a few studies have examined ΔNp63 isoform in oral squamous cell carcinoma including normal epithelium. This study aimed to evaluate expression of ΔNp63 isoform in human oral squamous cell carcinoma tissue and normal mucosa. The 3 cases of well differenciated oral squamous cell carcinoma specimen including adjacent normal mucosa were examined, and immunohistochemical study with monoclonal antibody(4A4) and tumor cell apoptosis analysis with Transmission Electon Microscopy were studied. And, RT-PCR analysis was done for expression of ΔNp63 isoform. The results were as followed. 1. Normal gingiva showed the restricted p63 expression in basal cell layer. 2. Well differentiated squamous cell carcinoma showed mainly p63 expression in overall area of malignancy, especially in basal cell layer to adjacent stromal tissue. 3. Tumor cells around keratinized area with no p63 expression disclosed less micro-organelle in decreased size cytoplasm and severe chromatin margination with nuclear destruction that means apoptosis. 4. Comparison of mRNA expression of ΔNp63 isoform by RT-PCR showed variable expression of ΔNp63 isoform, but ΔNp63αwas most highly expressed in all 3 tumor specimen. From theses results, it should be suggested that ΔNp63 isoform expression in well differentiated squamous cell carcinoma was closely related to tumor oncogenesis, expecially overexpression of ΔNp63αis a most important factor in tumor genesis of oral squamous cell carcinoma.

COX 억제제에 의해 유도되는 구강편평세포암종 세포주의 성장 억제 효과

박광진,한세진,이재훈,Park, Gwang-Jin,Han, Se-Jin,Lee, Jae-Hoon 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.4

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.

Anti-proliferative and Asnti-telomerase Activity of Curcuma Rhizome Extract on Oral Squamous Cell Carcinoma and Osteosarcoma Cells

Kim, Kyung Jin,Kim, Hee Jeong 대한구강생물학회 2007 International Journal of Oral Biology Vol.32 No.4

Anti-proliferation of methanol extract of Curcuma rhizomeon oral squamous cell carcinoma (KB) and osteosarcoma(HOS) cells were investigated. In order to elucidate theinvolvement of telomerase inhibitory activity as a part ofanti-proliferative effect of Curcuma rhizome on cancer cells,we measured telomerase activity in Curcuma rhizomeextract-treated cancer cells. The concentration inhibitedcell proliferation to 50% (IC50) of the methanol extract ofCurcuma rhizome against oral squamous cell carcinoma(KB) cells and osteosarcoma (HOS) cells were 21.30µg/mland 39.3µg/ml, respectively. The methanol extract ofCurcuma rhizome showed inhibitory telomerase inhibitoryeffect which is required for cancer cell immortality.Therefore, it seems that the anticancer effect of methanolextract of Curcuma rhizome is at least partially due totelomerase inhibitory effect. Five fraction samples wereprepared according to its polarity differences and analyzedanti-proliferative effects of each fraction samples on oralsquamous cell carcinoma and osteosarcoma cells. Anticancereffect was observed in dichloromethane, and ethylacetatefractions. The highest anticancer effect was found indichloromethane fraction which had IC50 value of 23.3µg/ml and 10.5µg/ml against oral squamous cell carcinoma(KB) cells and osteosarcoma (HOS) cells, respectively.

구강편평상피암종에서 DCC 유전자의 역할

고성규(Seong-Kyu Ko),한세진(Se-Jin Han),김경욱(Kyung-Wook Kim) 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.5

Chromosome 18q alteration plays a key role in colorectal tumorigenesis, and loss of heterozygosity at 18q is associated with a poor prognosis in colon cancer. DCC(Deleted in Colorectal Cancer) is a putative tumor- suppressor gene at 18q21 that encodes a transmembrane protein with structural similarity to neural cell adhesion molecule that is involved in both epithelial and neuronal cell differentiation. DCC is implicated in regulation of cell growth, survival and proliferation. Thus, tumor progression in squamous cell carcinoma, stomach cancer, colorectal cancer correlates with downregulation of DCC expression. The mechanism for DCC suppression is associated with hypermethylation of the DCC gene promoter region. Hence, the goal of this study is to identify the promoter methylation responsible for the down-regulation of DCC expression in oral squamous cell carcinoma. 12 of tissue specimens for the study are excised and gathered from 12 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find expression of DCC in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1. In the DCC gene RT-PCR analysis, 5(41.6%) of 12 specimens of oral squamous cell carcinoma did not expressed DCC gene. 2. In the promoter methylation specific PCR analysis, 5(41.6%) of 12 specimens showed promoter methylation of DCC gene. 3. In the immunohistochemical staining of poor differentiated and invasive oral squamous cell carcinoma, loss of DCC expression was observed. These findings suggest that methylation of the DCC gene may play a role in loss of gene expression in invasive oral squamous cell carcinoma.

선택적 COX-2 저해를 통한 구강암세포주 KB의 침습성 변화에 관한 예비연구

이은진(Eun-Jin Lee),김명진(Myung-Jin Kim),명훈(Hoon Myoung) 대한구강악안면외과학회 2007 대한구강악안면외과학회지 Vol.33 No.2

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.