PDT is an established cancer treatment modality. This can be attributed to the attractive basic concept of PDT; Combination of two therapeutic agents, a photosensitizing drug and light, which are relatively harmless by themselves but when combined, cause more or less selective tumor destruction. Hematoporphyrin-derived photosensitizers are known to be stable and highly efficient. In this study, we conducted a series of experiments to develop light-induced anticancer drugs against oral cancer cells. We tested the cytotoxicity of photodin by MTT assay and observed cell death pattern (apoptosis or necrosis) by hoechst 33342 and propidium iodide staining methods after PDT. IC50 value of photodin was 0.65 ug/ml. At higher doses of photodin ( > 7.8 ug/ml), cancer cells died exclusively from necrosis after PDT. By contrast, at IC50 value, photodin induced cancer cell to undergo apoptotic cell death. The induction begins approximately 6 hours after PDT. We investigated intracellular localization of photodin by oral cancer cell via confocal laser scanning microscopy. Oral cancer cells dual-stained with photodin and organelle-specific fluorescence probes (Mitotracker, Lysotracker, ER-Tracker) revealed that an intracellular fluorescence distribution was restricted to cytoplasmic compartments with no detectable fluorescence in the nucleus. Confocal images of cells containing photodin were overlapped with the mitochondria-specific fluorescence probe images of the same cells. These results demonstrated that photodin may play the role of a photosensitizer for oral squamous cancer cells without swelling and inflammation. Therefore, photodin-based PDT is a suitable treatment for oral cavity carcinoma patients.
Mucous retention cyst (MRC) is not uncommon in the pathology of maxillary sinus, which should be differentially diagnosed from chronic maxillary sinusitis. The main stream of diagnosis usually depends on the clinical symptoms and radiological findings. Thus it was sometimes puzzling to confirm the histological features of mucous retention phenomenon in the antral mucosa, when the specimen was from a limited portion or much degenerated by inflammatory reaction. This study aims to define the histopathological features of MRC through reevaluation of MRCs (n=19) and maxillary sinusitis (n=65) diagnosed previously. The present study classified three types of MRC, i.e., an extravasation type, a luminal retention type, and a mixed type of MRC. The extravasation type MRC showed clear pseudocyst cavity under sinus mucosa with infiltration of foamy macrophage, and the luminal retention type MRC showed mucous retention in the luminal cavity of maxillary sinus accompanied with inflammatory reaction, and the mixed type MRC showed the both features of extravasation and luminal retention type MRCs. Resultantly, among nineteen cases of MRC only three cases belonged to the extravasation type MRC, eleven cases belonged to luminal retention type MRC, and three cases belonged to mixed type MRC, while two cases were turned out to be postoperative residual cysts of maxillary sinus. The MRCs examined in this study showed different pathological features from ordinary maxillary sinusitis, exhibiting the typical mucin retention phenomenon of extravasation type or luminal retention type with relatively mild inflammatory reaction with infiltration of mucin-pooled macrophages. However, the luminal retention type MRC was predominant among the MRCs (11/17, 64.7%) and each of the extravasation and mixed type MRCs was only three cases out of 17 MRCs (17.6%). The extravasation type MRC characteristically produces a pseudocyst by the overexpressions of matrix metalloprotease-3 (MMP-3) and connective tissue growth factor (CTGF). Because not only the pathogenetic mechanism but also the prognosis of MRC is different from chronic maxillary sinusitis, we suggest that the MRC of maxillary sinus should be classified into extravasation, luminal retention, and mixed types in the histological observations in addition to the clinical and radiological informations.
Desmoplastic ameloblastoma (DA) and Ameloblastic fibroma (AF) show common histopathologic features such as enamel organ like epithelial islands or cords on the background of abundant fibrous stroma. Despite their similar histopathologic features, it was reported that they have different pathogenesis and clinical behavior. The purpose of this study was to rev iew clinicopathologic features of DA and AF among Korean subjects. 7 cases of DA and 4 cases of AF were retrieved from the files of Seoul National University Dental Hospital (SNUDH), and their clinical features, radiographic findings, and histopathologic features were reviewed and compared. DA occurred in 3 males and 4 females. They occurred from 24 to 62 years of age, showing the mean age of 42.7 years. 5 of the 7 tumors occurred in the maxilla, and all of them in the anterior region, showing predilection for the maxillary anterior regions. There was no recurrence. Radiographically, they showed well demarcated unilocular or multilocular radiolucency. AF occurred in 5 males and 2 female. They occurred from 6 to 29 years of age, showing the mean age of 14 years. All tumors occurred in the mandibular molar area. Recurrence was recognized in 1 case. Although DA and AF showed similar histopathologic features, they showed different clinical behaviors. While DA showed predilection for the anterior maxilla, AF did for posterior mandible. While DA occurred mainly in adults, AF did in adolescents. Recurrence was recognized not in DA but in AF. Therefore, DA and AF should be differentiated from each other in spite of similar histopathologic findings
Human papillomavirus (HPV) has been classified as one of the causing factors of head and neck squamous cell carcinoma (HNSCC). However, little is known about HPV-related carcinogenesis in HNSCC. The purpose o f this s tudy i s to characterize immortalized human oral keratinocyte (IHOK) transfected by HPV16 E6/E7, IHOK/hcdk4 (IHOK transfected by pLXRN-hcdk4) and IHOK/hcdk4/hTERT (IHOK transfected by pLPC-hTERT-hcdk4) to reconstitute HNSCC in vitro. Conclusively, we established a new immortalized cell lines, IHOK/hcdk4 and IHOK/hcdk4/hTERT, to understand multistep carcinogenic process of oncogenic HPV16 E6/E7 in HNSCC.
The eukaryotic translation initiation factor 5A (eIF5A) is a ubiquitous protein of eukaryotic and archaeal organisms which undergoes hypusination, and known to play pivotal functions for the synthesis of proteins involved in cell proliferation and cell cycle control. Its nuclear localization has an important implication for the eIF5A functions in nucleus, but the evidence of the nuclear translocation is still in controversy. This study is aimed to elucidate the nuclear localization of eIF5A in the epithelial cells of oral leukoplakia by the immunohistochemistry using trypsin digestion to remove their cytoplasms. The keratinocytes of the acanthotic and basal cell layers in oral leukoplakia showed the complete removal of their cytoplasmic components, but the nuclei of those cell layers were remained on the microsection. The immunostainings using both polyclonal and monoclonal antibody against eIF5A showed the strong positive reaction in the nuclei remained after trypsin digestion. And the immunostaining was more intensely expressed in the nuclei of the basal and suprabasal keratinocytes than in the nuclei of the upper spinous keratinocytes. These data directly indicate the post-translationally modified eIF5A is abundantly localized in the nuclear matrix components including nucleoli, which are resistant to the trypsin digestion. It is also presumed that the nuclear eIF5A localized at the trypsin resistant nuclear matrix, i.e., histone and r ibosomal proteins, may be closely relevant to the control of mRNA production or to the nuclear-cytoplamic trafficking for mRNA transportation.
Plasma cell myeloma is malignant disease of plasma cell in the bone marrow. Myeloma accounts for about 1% of all cancers. The solitary plasma cellmyeloma is rare tumors and account for less than 10% of plasma cell neoplasm. It is often progress to multiple myeloma at 30~40% despite successful local treatment with surgery and radiation therapy. We are reporting a case of solitary plasma cell myeloma on anterior Maxillary region that developed after kidney transplantation and immunosuppressive therapy.