• Journal of Oral Medicine and Pain
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• v.24 no.2
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• pp.145-161
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• 1999

The proto-oncogene bcl-2 confers a survival advantage to cells by blocking programmed cell death (apoptosis). Overexpression of bcl-2 probably plays a role in tumorigenesis, and the expression of the bcl-2 protein has been investigated in many kinds of tumors. An increased expression of nitric oxide synthetase(NOS) has been observed in human colon cancer cell lines as well as in human gynecological, breast, and CNS tumors. However there have been only a few reports on the expression of bcl-2 and $NOS_2$ in oral white lesions and cancer. The aim of this study was to investigate the relationship between the expression of Bcl-2 and $NOS_2$ and several pathological parameters such as histological types and layers. We reported desregulation of bcl-2 and $NOS_2$ expression during progression from oral white lesion, lichen planus and leukoplakia to squamous cell carcinoma. The obtained results were as follows: 1. Immunohistochemical analysis with monoclonal antibodies to bcl-2 oncoprotein and $NOS_2$ in formalin-fixed paraffin-embedded tissue sections revealed that bcl-2 expression is restricted to the basal cell layer and $NOS_2$ was mild expressed only in subepithelial inflammatory cells in normal human mucosa. There wasn't specific finding of those in lichen planus and leukoplakia. 2. Bcl-2 immunoreactivity in severe epithelial dysplasia or CIS occurs throughout the epithelium, $NOS_2$ reactivity in most superficial layer were noted. 3. In well-differentiated squamous cell carcinomas, mostly bcl-2 was overexpressed. In moderated and poor squamous cell carcinomas, the expression of $NOS_2$ was increased and that of bcl-2 was decreased. 4. The immunoreactivity of bcl-2 was 12.5% of normal mucosa, 30% of leukoplakia, 44% of lichen planus and 67% of carcinoma in situ. In carcinoma, those were 43%, 50% and 67% according to differentiation, respectively. 5. The immunoreactivity of $NOS_2$ was 25% of normal mucosa, 70% of leukoplakia, 78% of lichen planus and 100% of carcinoma in situ and epithelial dysplasia. In carcinoma, those were higher in moderated(100%) and poor(83%) squamous cell carcinomas than in well differentiated type(71%). 6. The expression of bcl-2 and $NOS_2$ by Western blot was increased highly in lichen planus and leukoplakia. Therefore, the expression of bcl-2 was increased in the white and precancerous lesions and that was decreased by differentiation of carcinoma. However, $NOS_2$ immunoreactivity in carcinoma in situ was lower than those in moderated and poor squamous cell. These findings suggest that the interaction of bcl-2 and $NOS_2$ may be roled importantly in growth and development of carcinoma.

• International Journal of Oral Biology
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• v.46 no.4
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• pp.176-183
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• 2021

Oral squamous cell carcinoma (OSCC) metastasis is characterized by distant metastasis and local recurrence. Combined chemotherapy with cisplatin and 5-fluorouracil is routinely used to treat patients with OSCC, and the combined use of gefitinib with cytotoxic drugs has been reported to enhance the sensitivity of cancer cells in vitro. However, the development of drug resistance because of prolonged chemotherapy is inevitable, leading to a poor prognosis. Therefore, understanding alterations in signaling pathways and gene expression is crucial for overcoming the development of drug resistance. However, the altered characterization of Ca²⁺ signaling in drug-resistant OSCC cells remains unclear. In this study, we investigated alterations in intracellular Ca²⁺ ([Ca²⁺]_i) mobilization upon the development of gefitinib resistance in human tongue squamous carcinoma cell line (HSC)-3 and HSC-4 using ratiometric analysis. This study demonstrated the presence of altered epidermal growth factor- and purinergic agonist-mediated [Ca²⁺]_i mobilization in gefitinib-resistant OSCC cells. Moreover, Ca²⁺ content in the endoplasmic reticulum, store-operated calcium entry, and lysosomal Ca²⁺ release through the transient receptor potential mucolipin 1, were confirmed to be significantly reduced upon the development of apoptosis resistance. Consistent with [Ca²⁺]_i mobilization, we identified modified expression levels of Ca²⁺ signaling-related genes in gefitinib-resistant cells. Taken together, we propose that the regulation of [Ca²⁺]_i mobilization and related gene expression can be a new strategy to overcome drug resistance in patients with cancer.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.251-261
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• 2007

Bile acids and synthetic its derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. Previous studies have been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis inducing activity on various cancer cells in vitro. It wasn't discovered those materials have apoptosis induced effects on YD9 human oral squamous carcinoma cells. The present study was done to examine the synthetic bile acid derivatives(HS-1199, HS-1200) induced apoptosis on YD9 cells and such these apoptosis events. We administered them in culture to YD9 cells. Tested YD9 cells showed several lines of apoptotic manifestation such as activation of caspase-3, degradation of DFF, production of poly (ADP-ribose) polymerase(PARP) cleavage(HS-1200 only), DNA degradation(HS-1200 only), nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential(HS-1200 only) and the release of cytochrome c and AIF to cytosol. Between two synthetic CDCA derivatives, HS-1200 showed stronger apoptosis-inducing effect than HS-1199. Therefore HS-1200 was demonstrated to have the most efficient antitumor effect. Taken collectively, we demonstrated that a synthetic CDCA derivative HS-1200 induced caspases-dependent apoptosis via mitochondrial pathway in human oral sqauamous carcinoma cells in vitro. Our data therefore provide the possibility that HS-1200 could be considered as a novel therapeutic strategy for human orall squamous carcinoma from its poweful apoptosis-inducing activity.

• Journal of dental hygiene science
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• v.23 no.3
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• pp.216-224
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• 2023

Background: Smilax glabra has various pharmacological activities and is widely used as a herbal medicine. Although the incidence of oral cancer is low, the recurrence rate is high, and the 5-year survival rate is poor. It is necessary to search for anticancer drugs that increase the effect of cancer chemotherapy on heterogeneous oral tissues and reduce the side effects on normal cells. This study aimed to investigate the effects and mechanism of ethanol extract of Smilax glabra (EESG) as an anticancer drug for oral cancer. Methods: Smilax glabra root components extracted with 70% ethanol were used to analyze their effects on cancer cells. A 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay was performed for cytotoxicity analysis. Flow cytometry was performed to determine the cell cycle phase distribution. To observe apoptotic cells, terminal deoxynucleotidyl transferase dUTP nick end labeling and γH2AX were detected by fluorescence microscope. The protein levels of cleaved PARP and caspase were analyzed using western blotting. The activation of procaspase-3 was confirmed by measuring caspase-3 activity. Results: EESG was no cytotoxic to normal gingival fibroblast but was high in YD10B oral squamous cell carcinoma (OSCC) cells. EESG treatment increased the subdiploid DNA content of YD10B cells by assessing DNA content distribution. Chromatin condensation and DNA strand breaks increased in YD10B cells treated with EESG. EESG-treated YD10B cells had high Annexin V and low propidium iodide levels, confirming that early apoptosis was induced. In addition, increased levels of γH2AX foci, a marker of DNA damage, were observed in the nuclei of EESG-treated YD10B cells. The EESG-treated YD10B cells also exhibited decreased procaspase-3 and procaspase-9 levels, increased PARP cleavage and caspase-3 activity. Conclusion: These results indicate that EESG inhibited cancer cell proliferation by inducing apoptosis in YD10B OSCC cells.

• International Journal of Oral Biology
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• v.49 no.1
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• pp.1-9
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• 2024

Oral bacterial infections substantially affect the development of various periodontal diseases and oral cancers. However, the molecular mechanisms underlying the association between Fusobacterium nucleatum (F. nucleatum ), a major periodontitis (PT)-associated pathogen, and these diseases require extensive research. Previously, our RNA-sequencing analysis identified a few hundred differentially expressed genes in patients with PT and peri-implantitis (PI) than in healthy controls. Thus, in the present study using oral squamous cell carcinoma (OSCC) cells, we aimed to evaluate the effect of F. nucleatum infection on genes that are differentially regulated in patients with PT and PI. Human oral squamous cell carcinoma cell lines OSC-2O, HSC-4, and HN22 were used. These cells were infected with F. nucleatum at a multiplicity of infection of 100 for 3 hours at 37℃ in 5% CO₂. Gene expression was then measured using reverse-transcription polymerase chain reaction. Among 18 genes tested, the expression of CSF3, an inflammation-related cytokine, was increased by F. nucleatum infection. Additionally, F. nucleatum infection increased the phosphorylation of AKT, p38 MAPK, and JNK in OSC-20 cells. Treatment with p38 MAPK (SB202190) and JNK (SP600125) inhibitors reduced the enhanced CSF3 expression induced by F. nucleatum infection. Overall, this study demonstrated that F. nucleatum promotes CSF3 expression in OSCC cells through p38 MAPK and JNK signaling pathways, suggesting that p38 MAPK and JNK inhibitors may help treat F. nucleatum-related periodontal diseases by suppressing CSF3 expression.

• Environmental Mutagens and Carcinogens
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• v.18 no.1
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• pp.37-42
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• 1998

In the present study, we have evaluated cytotoxic effects of the chloroform soluble fraction of the methanolic extract of Perilla frutescens in human oral epitheloid carcinoma cells. The light microscopic study showed morphological changes of the treated cells. Cell membrane damaging activity was measured by the lactate dehydrogenase (LDH) assay and disruptions in cell organelles were determined by 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of colorimetric assay. These results suggest that Perilla frutescens retains a potential antitumor activity.

• International Journal of Oral Biology
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• v.48 no.1
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• pp.1-7
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• 2023

Oral squamous cell carcinoma (OSCC), which accounts for approximately 90% of oral cancers, has a high rate of local recurrence and a poor prognosis despite improvements in treatment. Exosomes released from OSCC cells promote cell proliferation and metastasis. Although it is clear that the biogenesis of exosomes is mediated by the endosomal sorting complex required for transport (ESCRT) machinery, the gene expression pattern of ESCRT, depending on the cell type, remains elusive. The exosomal release from the human OSCC cell lines, HSC-3 and HSC-4, and their corresponding gefitinib-resistant sub-cell lines, HSC-3/GR and HSC-4/GR, was assessed by western blot and flow cytometry. The levels of ESCRT machinery proteins, including Hrs, Tsg101, and Alix, and whole-cell ubiquitination were evaluated by western blot. We observed that the basal level of exosomal release was higher in HSC-3/GR and HSC-4/GR cells than in HSC-3 and HSC-4 cells, respectively. Long-term gefitinib exposure of each cell line and its corresponding gefitinib-resistant sub-cell line differentially induced the expression of the ESCRT machinery. Furthermore, whole-cell ubiquitination and autophagic flux were shown to be increased in gefitinib-treated HSC-3 and HSC-4 cells. Our data indicate that the expression patterns of the ESCRT machinery genes are differentially regulated by the characteristics of cells, such as intracellular energy metabolism. Therefore, the expression patterns of the ESCRT machinery should be considered as a key factor to improve the treatment strategy for OSCC.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.132-136
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• 2000

The cell surface glycoprotein CD44 is a kind of adhesion molecule, which binds hyaluronic acid, type I collagen and fibronectin. Although there have been numerous reports on the expression and the function of CD44 in lymphocytes and macrophages, very little is known about its distribution and definite role in epithelial tissue, especially in oral epithelial one. The present study was performed to investigate the distribution and expression of the CD44 in human gingiva and squamous cell carcinoma(SCC) arising in human gingiva. And the authors compared CD44 expression with histopathologic grade of SCC. The results were as follows: 1. The CD44 was strongly expressed in granular, spinous and basal layers of normal marginal and attached gingiva, in spinous and basal layers of normal sulcular gingiva, and in all epithelial layers of normal junctional gingiva. 2. In SCC of gingiva, the CD44 was expressed in all but one case. In most of the cases the CD44 was expressed at cell membrane and the degree of expression was relatively strong. 3. In low-grade SCC of gingiva, the CD44 was strongly expressed, especially at the basal and spinous layers of abundantly keratinized cancer nests. In high-grade SCC of gingiva, the CD44 expression tended to be weak but was strong at cells showing individual keratinization. This study suggest that the CD44 expression of normal and cancerous gingival epithelium is associated with the degree of proliferation and differentiation of epithelial cells.

• 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 dental hygiene science
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• v.21 no.4
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• pp.227-232
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• 2021

Background: Cancer-associated fibroblasts (CAFs) are abundant in tumor microenvironments and interact with cancer cells to promote tumor proliferation in oral squamous cell carcinoma (OSCC). Cathepsin D (CTSD) is a soluble lysosomal aspartic endopeptidase involved in tumor proliferation and angiogenesis. In this preliminary study, we observed CTSD expression in OSCC and CAFs, postulating that CTSD might act as a bridge between OSCC and CAFs. Methods: Human epidermal keratinocytes (HEKs), OSCC, and immortalized human normal oral fibroblasts (hTERT-hNOFs) were used in this study. Additionally, we used hTERT-hNOFs transfected with an empty vector, WT (wild-type)-YAP (Yes-associated protein), and YAPS127A (YAP serine 127 to alanine). YAP127A hTERT-hNOFs activated fibroblasts similar to CAFs. To identify CTSD expression between OSCC and CAFs, conditioned medium (CM) was collected from each cell. Protein expression of CTSD was identified by western blotting. Results: To identify the expression of CTSD in fibroblasts stimulated by OSCC, we treated fibroblasts with CM from HEK and OSCC. Results indicated that hTERT-hNOFs with OSCC CM showed a weakly increased expression of CTSD compared to stimulation by HEK CM. This indicates that CAFs, YAPS127 hTRET-hNOFs, overexpress CTSD protein. HEK cells showed no CTSD expression, regardless of treatment with fibroblast CM, whereas OSCC highly expressed CTSD proteins compared with the CTSD expression in HEK cells. We also found that CTSD expression was unaffected by changes in transforming growth factor-β levels. Conclusion: This study proposes that CTSD might have potential as an interacting executor between OSCC and CAFs. Further studies are needed to investigate the role of CTSD in tumor and stromal cells.