Effects of p53 gene therapy in radiotherapy or thermotherapy of human head and neck squamous cell carcinoma cell lines.

We report herein the effects of p53 gene therapy in the radiotherapy or thermotherapy of eight human head and neck squamous cell carcinoma (SCC) cell lines. The discrepancy between radiosensitivity combined with p53 gene therapy than that without p53 gene therapy increased among the eight SCC cell lines. The discrepancy increased in the thermosensitivity at 43 degrees C and decreased in that at 44 degrees C among the eight SCC cell lines. Thus, the p53 gene therapy did not always improve the discrepancy between radiosensitivity and thermosensitivity in the eight SCC cell lines. In the radiotherapy combined with adenoviral p53 gene therapy, the survival rates of three of eight SCC cell lines decreased, and that of only one cell line increased compared with radiotherapy alone. In thermotherapy combined with p53 gene therapy, the survival rates of three at 44 degrees C and five at 43 degrees C of the eight SCC cell lines decreased, although only one cell line at 43 degrees C increased its survival rate compared with thermotherapy alone. The p53 gene therapy decreased the survival rates of both radiotherapy and thermotherapy in three of eight SCC cell lines. Further, the distribution of plots on the basis of the time for 10% survival of radiotherapy and the dose for 10% survival of thermotherapy with p53 gene therapy shifted to the lower left side of the plots compared with those without p53 gene therapy. These findings indicated that p53 gene therapy improves the effects of both radiotherapy and thermotherapy.

Thermoradiotherapy combined with adenoviral p53 gene therapy in head and neck squamous cell carcinoma cell lines.

We examined effects of recombinant p53-expressing adenovirus combined with thermoradiotherapy in 8 head and neck squamous cell carcinoma (SCC) cell lines to improve the outcomes of the treatment of advanced head and neck cancer. The p53 gene therapy did not improve the discrepancy between thermoradiosensitivities among the 8 SCC cell lines. However, p53 gene therapy improved the effects of thermoradiotherapy in all 8 cell lines, and there were significant differences in four situations of the HSC4 44 degrees C (p=0.032), SAS at 44 degrees C (p=0.029), the KB at 43 degrees C (p=0.025), and the Ca9-22 43 degrees C (p=0.020). In comparing the survival rates of thermoradiotherapy with those of thermotherapy and radiotherapy, thermoradiotherapy demonstrated actual survival rates less than theoretical survival rates based on the survival rates of thermotherapy multiplied by the survival rates of radiotherapy in almost all treatments of thermoradio-gene therapy of the 8 SCC cell lines. These results demonstrate that thermoradiotherapy combined with p53 gene therapy may be a useful tool in treating SCC cells.

Thermoradiotherapy combined with p53 gene therapy of human salivary gland adenocarcinoma cell line.

We report on thermoradiotherapy combined with p53 gene therapy in the human salivary gland adenocarcinoma cell line HSG. HSG cells were successfully infected at a rate of 62.3% with MOIs of 20 of either AxCAip53 or AxCAiLacZ. The AxCAiLacZ did not inhibit the survival of the HSG cells. The survival fractions of AxCAip53-infected HSG cells were lower than those of the AxCAiLacZ-infected HSG cells, but there was no significant difference (p=0.30). AxCAip53 decreased the survival rates of thermotherapy (43 degrees C; p=0.084 and 44 degrees C; p=0.18), radiotherapy (6 Gy; p=0.20) and thermoradiotherapy (6 Gy plus 43 degrees C; p=0.24 and 6 Gy plus 44 degrees C; p=0.96), but there were no significant differences. In comparing the survival rates of thermoradiotherapy with those of thermotherapy and radiotherapy, thermoradiotherapy, regardless of the combination with p53 gene therapy, demonstrated actual survival rates lower than theoretical survival rates based on survival rates of thermotherapy multiplied by survival rates of radiotherapy. This result indicates that thermoradiotherapy is effective in the treatment of HSG cells. Thermoradiotherapy combined with p53 gene therapy was the most effective therapy among the combinations of therapies demonstrating that thermoradiotherapy combined with p53 gene therapy may be a useful tool in the treatment of HSG cells.

Adenoviral p53 gene therapy in head and neck squamous cell carcinoma cell lines.

We reconstructed the recombinant p53-expressing adenovirus and examined its infections and effects in head and neck squamous cell carcinoma cell lines. Eight human head and neck squamous cell carcinoma cell lines were infected by the recombinant adenovirus harboring the lacZ gene (AxCAiLacZ) or the wild-type p53 gene (AxCAip53), and the effects were investigated. The eight cell lines were successfully infected by AxCAiLacZ at a level of more than 50%. The survival of all 8 squamous cell lines were inhibited in the range from 8 to 26.7% by only one treatment of the AxCAip53 infection. This result suggested that p53 gene therapy might become a useful tool in head and neck squamous cell carcinoma treatment.

Application of dynamic CT for various diseases in the oral and maxillofacial region.

OBJECTIVE: To investigate whether dynamic CT enables quantitative differentiation between inflammation, benign tumors, and malignant tumors in oral and maxillofacial regions. METHODS: Sixteen malignant tumors (14 squamous cell Ca, one adenoid cystic Ca, one mucoepidermoid Ca), six benign tumors (one Warthin tumor, two pleomorphic adenomas, one lipoma, one Schwanoma, one hemangioma), and seven inflammation cases (three submandibular adenitis, two osteomyelitis, two perimandibular inflammations) were examined. Contrast agent (0.8 ml/kg) was injected intravenously at 5 ml/s. CT (Toshiba TCT 900S) scanning was performed at the time of the beginning of contrast medium injection. Parameters from the time-density curve were investigated: peak height (PH), relative CT value from the base CT value when the curve reached peak point; peak time (PT), the time when the curve reaches the peak point from contrast medium infusion; transit time (TT), time between two transit points on the time-density curve; and peak time ratio (PR), the ratio of peak time from the lesion to the artery and peak time from the vein to the artery. RESULTS: PH was highest in inflammation, followed by malignant tumors and benign tumors. TT was significantly longer in benign tumor cases compared with malignant tumor and inflammation cases. PR for malignant tumor and inflammation were between the artery and vein phase, and that for benign tumor was beyond the vein phase. CONCLUSION: Parametrical analysis of a contrast enhanced dynamic CT study may serve to differentiate the lesions in the oral and maxillofacial region.

Thermoradiotherapy in human head and neck squamous cell carcinoma cell lines.

Thermoradiosensitivity of 8 cell lines of head and neck squamous cell carcinoma (HO-1-u-1, HSC2, HSC3, HSC4, SAS, KB, Hep2, and Ca9-22) was investigated. The differences of radiosensitivity between the cell line with the highest radiosensitivity and the cell line with the lowest radiosensitivity were 1.7-, 7.7-, and 41-fold at 2, 6 and 8 Gy, respectively. The differences between the cell line with the highest thermosensitivity and the cell line with the lowest thermosensitivity were 2.4-, 6.2- and 34.4-fold at 43 degrees C for 40, 60 and 100 min, and 2.6-, 4.9- and 127-fold at 44 degrees C for 20, 30 and 50 min, respectively. These findings indicated that there were large differences in both radiosensitivity and thermosensitivity among the 8 cell lines. There was a negative relationship between radiosensitivity and thermosensitivity (43 degrees C: r=-0.600, 44 degrees C: r=-0.848) in 7 of 8 cell lines, the exception being the HSC4 cell line, which was resistant to both therapies. Four of the 8 cell lines at 43 degrees C and 5 at 44 degrees C in the radiotherapy combined with thermotherapy showed actual survival rates smaller than the theoretical survival rates. Thus, thermoradiotherapy was deemed effective in the head and neck carcinoma cell lines, although 1 of 8 cell lines was resistant to both radiotherapy and thermotherapy.

Thermochemotherapy of a human salivary adenocarcinoma cell line.

We report on thermochemotherapy in a human salivary gland adenocarcinoma cell line. Hyperthermia reduced the survival rate to 50 and 20% by heating at 43 degrees C for 40 and 60 min, respectively, and is by itself useful in human salivary gland carcinoma treatment. Adriamycin, cisplatin, and mitomycin C can possible be used clinically, while bleomycin and 5-fluorouracil cannot, to treat this carcinoma. The optimal temperature was considered to be 41 degrees C in adriamycin, 42 degrees C in cisplatin, 37 degrees C in mitomycin C, and 42 degrees C in bleomycin in the thermochemotherapy. Thermochemotherapy is a useful tool in the treatment of human salivary gland carcinoma cells, but it is necessary to select the best anticancer drugs and the optimal temperature for optimal success using this treatment.