Mihoko Nonaka

Hypoxia-inducible factor 1 alpha in oral squamous cell carcinoma and its relation to prognosis

The aim of this study was to investigate the correlation between the expression of hypoxia-inducible factor 1 alpha (HIF-1 alpha) and proliferative activity in tumor cells, lymph node metastasis, as well as prognosis in patients with oral squamous cell carcinoma (OSCC). Fifty-seven biopsy specimens of OSCC were investigated for the expression of HIF-1 alpha and proliferating cell nuclear antigen (PCNA) by immunohistochemistry. None of the patients had received any prior treatments. The percentage of HIF-1 alpha immunopositive area (PHIA) was calculated using computer-assisted image analysis for quantitative assessment of HIF-1 alpha expression. The PCNA labeling index (LI) was evaluated as a proliferation marker. We found that the mean PHIA in all stages was 12.1% in the poor prognosis patients, and it was 6.4% in the good prognosis patients. There was a significant difference of PHIA between poor prognosis and good prognosis patients (P=0.0065). Furthermore, the mean PHIA in the patients who had no metastatic lymph nodes was 7.5%, while it was 11.7% in the patients who had metastatic lymph nodes. There was also a significant difference of PHIA between patients who had no metastatic lymph nodes and those who had metastatic lymph nodes (P=0.0487). On the other hand, significant correlation between PHIA and PCNA LI was not observed. These results provide the clinical data indicating that HIF-1 alpha may play an important role in lymph node metastasis and prognosis in patients with OSCC.

Inhibitory Effect of Heat Shock Protein 70 on Apoptosis Induced by Photodynamic Therapy In Vitro

We examined the apoptotic effects of photodynamic therapy (PDT) in leukemia cells (HL60) and lymphoma cells (Raji). Moreover, we also investigated the relationship of apoptosis induced by PDT to heat shock protein (HSP) expression. To induce 80% of cell death by PDT, HL60 cells required 6 μg/mL and Raji cells required 9 μg/mL of Photofrin®. PDT induced apoptosis in 77.2% of HL60 and in 0.4% of Raji at lethal dose (LD80) conditions. The cell line in which apoptosis is predisposed may be more susceptible to PDT compared with the cell line in which necrosis is predisposed. Furthermore, HSP‐70 was expressed constitutively in Raji cells but not in HL60 cells. Heat treatment of HL60 cells induced expression of HSP‐70 and resulted in significant reduction of PDT‐mediated apoptosis. From the results of this experiment, it is suggestive that HSP‐70 contributes to inhibition of apoptosis mediated by PDT.

Effect of combined photodynamic and chemotherapeutic treatment on lymphoma cells in vitro

We investigated the cytotoxic and apoptotic effects of a combination of photodynamic therapy (PDT) and cisplatin (CDDP) on L5178Y (LY) cells. Treatment with PDT by photofrin((R)) (5 microg/ml) alone or with CDDP (20 microg/ml) alone killed 41.5+/-8.5% or 42.9+/-6.5% of LY cells, respectively, while a combination of these two treatments killed 99.7+/-0.6%. Apoptotic cell death after combination treatment was also revealed to be 49.6+/-7.8% compared to 12.4+/-3.4% after PDT alone, and 18.8+/-2.6% after CDDP. This study demonstrated that combined treatment of PDT and CDDP results in enhanced apoptotic cell death as well as a cytotoxic effect on LY cells.

Predictive factor for photodynamic therapy effects on oral squamous cell carcinoma and oral epithelial dysplasia.

OBJECTIVE The aim of this study was to investigate the correlation between the immunohistochemical expression of proliferating cell nuclear antigen (PCNA), factor VIII, and CD34 (markers of endothelial cells), and vascular endothelial growth factor (VEGF) and the recurrence of oral squamous cell carcinoma (OSCC) and oral epithelial dysplasia (OED) subjected to photodynamic therapy (PDT). DESIGN Twenty-one biopsy specimens (14 cases of OSCC and 7 cases of OED) before PDT were immunohistochemically investigated in terms of their expressions of PCNA, factor VIII, CD34 and VEGF. The percentages of the total sample area that were immunopositive for factor VIII (percentage factor VIII immunopositive area: PFIA) CD34 (PCIA) and VEGF (PVIA) were calculated using computer-assisted image analysis for quantitative assessment of endothelial cells or VEGF expression in the lesions. The PCNA labelling index (LI) was evaluated as a proliferation marker. RESULTS Five cases of OSCC and one case of OED recurred 4 to 30 months after PDT. We found that the average PVIA was 14.5% in the no-recurrence group and 1.7% in the recurrence group. The difference between these values was statistically significant (P=0.0483). On the other hand, the average PCNA LI was 30.3% in the no-recurrence group and 24.3% in the recurrence group; the average PFIA was 3.7% in the no-recurrence group and 1.6% in the recurrence group; and the average PCIA was 2.0% in the no-recurrence group and 1.4% in the recurrence group. There were no significant differences between the two groups for any of these markers (P=0.3379, P=0.1195, P=0.4835, respectively). CONCLUSIONS These results provide clinical data indicating that VEGF expression may be a useful predictive marker for the effects of PDT in OSCC and OED.

Antitumor effects on primary tumor and metastatic lymph nodes by superselective intra-arterial concurrent chemoradiotherapy for oral cancer

OBJECTIVE Superselective intra-arterial infusion of anticancer agents with concurrent delivery of external beam radiotherapy was applied to 13 previously untreated cases of oral cancer for the purpose of avoiding surgical resection of the primary tumor. STUDY DESIGN The catheter tips were placed in the tumor feeder arteries via the superficial temporal artery and/or occipital artery. The catheters were retained for 6 weeks to infuse anticancer agents daily with concurrent radiotherapy for 6 weeks. The total radiation doses to the primary tumor and neck were 60.0 Gy and 40.0 Gy, respectively. RESULTS Complete response of the primary tumor was achieved in all 13 patients; complete response of neck node metastasis was achieved in 5 out of 6 patients. CONCLUSION This strategy is quite effective for oral cancer at both the primary site and metastatic lymph nodes, and it has the potential to be curative in advanced cases that are inoperable.

Histopathological Change of Oral Malignant Tumour and Epithelial Dysplasia Subjected to Photodynamic Therapy

ABSTRACT Objectives The purpose of this study is to analyze the morphological change of cell nuclei and the change of proliferating activity of oral malignancy and epithelial dysplasia between before and after photodynamic therapy in order to predict recurrence. Material and methods We experienced 14 cases of oral squamous cell carcinoma, one case of verrucous carcinoma and seven cases of epithelial dysplasia treated by photodynamic therapy (PDT). The mean nuclear area (NA) and coefficient of variation of the nuclear area (NACV) of 100 nuclei per slide were calculated using computer-assisted image analysis in hematoxylin and eosin stained biopsy specimens before and after PDT. Additionally, proliferating cell nuclear antigen (PCNA) immunohistochemistry was carried out in each specimen. Results The mean NA after PDT was significantly lower than that before PDT in the nonrecurrent group. However, there was no significant difference in mean NA before and after PDT in the recurrent group. There were no significance differences in NACV before and after PDT in either the nonrecurrent or recurrent group. Furthermore, the PCNA labelling indices of the specimens after PDT was significantly lower than that before PDT in both the nonrecurrent and the recurrent group. Conclusions Mean nuclear area in the biopsy specimen after photodynamic therapy is likely to be a predictive marker for the recurrence of oral squamous cell carcinoma or epithelial dysplasia subjected to photodynamic therapy, while coefficient of variation of the nuclear area and proliferating cell nuclear antigen labelling indices are less helpful in predicting the recurrence of such lesions.

Myodermal Flap for Reconstruction of Oral Mucosa

Purpose Myocutaneous flaps were commonly used to repair the mucosal defect that results from ablative tumor surgery. However, skin is not a perfect substitute for the oral mucosa because it can lead to poor hygiene due to hair growth and desquamation. The myodermal flaps used for the reconstruction of mucosa in oncologic surgery of the oral cavity. Material and method Pectoralis major and platysma myodermal flaps were applied in 8 patients for the purpose of intraoral reconstruction in cancer surgery. The skin paddle of the flaps denuded by shaving the epithelial layer was transferred into the oral cavity to cover the mucosal defect. Result The flaps epithelialized secondarily without severe contraction. Conclusion The myodermal flap is a promising option for reconstruction of the oral mucosa.

Desmoplastic Fibroma Arising in the Maxilla

Abstract Desmoplastic fibroma is a rare benign osseous tumour, arising in the femur, mandible, pelvis, and humerus. It occurs rarely in the maxilla, and only 12 such patients have been reported. The lesion requires intensive care as it is clinically aggressive and destructive, often invading surrounding tissues. This report is of a 15-year-old girl with desmoplastic fibroma arising in the maxilla. The tumour had lumen and an invasive character. The tumour was curetted and the wound was packed open. Although recurrence was expected after surgery, no recurrence has been observed after 5 years of follow-up.

Photodynamic therapy for newly established human squamous cell carcinoma cell line and its cisplatin-resistant subline

Photodynamic therapy (PDT) is a modality for the treatment of various tumors. Although PDT has been proposed as an alternative in overcoming multi-drug resistance, the impact of Photofrin-mediated PDT on cisplatin-resistant cells has not been addressed thus far. We established two new human primary squamous cell carcinoma derived cell lines and its cisplatin-resistant subline to investigate resistance mechanisms. We investigated the efficacy of Photofrin-mediated PDT on cells which were cisplatin-sensitive and -resistant phenotype. The 50% inhibitory concentration (IC50) showed no statistically significant difference between both parent cell and its resistant subline. Twenty-four hours after PDT, both parent and cisplatin-resistant sublines showed the same DNA content pattern. The data reported in this study show that Photofrin-mediated PDT revealed equal photo-cytotoxicity in both sensitive and cisplatin-resistant cells.