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Cepharanthine (Ce) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. In our previous study, Ce significantly enhanced thermosensitivity and thereby reduced thermotolerance in vitro, and intra-peritoneal injection of Ce slightly enhanced thermosensitivity in vivo. In the present study, we investigated Ce's effect in vitro on the pattern of cell death after heating and the effect of intra-tumoral injection of Ce on in vivo thermosensitivity using a mouse fibrosarcoma, FSa-II, and C3H/He mice. Ce significantly enhanced the in vitro thermosensitivity of FSa-II cells with heating at 44 degrees C, with increased Ce concentration. Time-lapse microscopic observation of individual cells confirmed that Ce treatment hastened both apoptosis (specifically, apoptotic budding) and necrosis (as indicated by staining with propidium iodide). Staining with annexin V-enhanced green fluorescent protein indicated that Ce used concomitantly with heating significantly increased the proportion of cells in the early stage of apoptosis. Ce combined with heating also significantly increased the proportion of cells with high intracellular caspase-3 activity, as detected by a substrate of caspase-3, PhiPhiLux-G1D2. The intra-tumoral injection of Ce, followed by heating at 44 degrees C, significantly delayed in vivo tumor growth, and this delay increased in a Ce concentration-dependent manner. Ce injected 30 min before heating delayed tumor growth more than Ce injected immediately before heating. These findings suggest the potential of Ce as a thermosensitizer to increase apoptosis of tumor cells.

It has been shown that hyperthermia can enhance the cytotoxicity of some chemotherapeutics. However, the most effective agent(s) at elevated temperatures have yet to be determined. A previous study suggests that the drug of choice at elevated temperatures may be different from that at the physiological temperature, and that the alkylating agents may be most effective at elevated temperatures. To further investigate these possibilities, the effect of chemotherapeutic agents were compared. These agents were cyclophosphamide, ifosfamide, melphalan, cis-diamminedichloroplatinum (II), 5-fluorouracil, mitomycin C and bleomycin. Three tumours (mammary carcinoma, osteosarcoma and squamous cell carcinoma) were used. They were transplanted into the feet of C3H/He mice. When tumours reached 65 mm(3), a test agent was injected intraperitoneally. Tumours were immediately heated at 41.5 degrees C for 30 min, and the tumour growth (TG) time was studied for each tumour. Using the TG times, the TG-50 (the time required for one-half of the total number of the treated tumours to reach the volume of 800 mm(3) from 65 mm(3)) was calculated. Subsequently, the tumour growth delay time (GDT) and the thermal enhancement ratio (TER) were obtained. The GDT was the difference between the TG-50 of treated tumours and that of non-treated control tumours. The TER was the ratio of the GDT of a group treated with an agent at 41.5 degrees C to that of a group treated with the agent at room temperature. Results showed that the top three effective agents tested at 41.5 degrees C were solely alkylating agents--CY, IFO and L-PAM--for each kind of tumour. A GDT of cisplatin was smaller than those of the alkylating agents. The smallest TER, 1.1, was observed for 5-fluorouracil, which was given for mammary carcinoma, and for mitomycin C, which was given for squamous cell carcinoma. It could be concluded that the alkylating agents at elevated temperatures might be the drugs of choice for many types of tumours. The possible mechanisms of thermal enhancement associated with these agents are discussed.

Cepharanthin (Ce) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. The results of our previous in vitro study indicated that Ce reduces thermotolerance by enhancing thermosensitivity. In the present study, we investigated the in vitro and in vivo effects of Ce on thermosensitivity and thermotolerance using a murine mammary carcinoma, MCa, and C3H/HeN mice. Ce enhanced the thermosensitivity of MCa cells for heating at 44 degrees C not only in vitro but also in vivo. The in vivo enhancement ratio +/- SD of Ce at 100 mg/kg for heating at 44 degrees C was 1.3+/-0.3. The fractionated heat treatments at 44 degrees C for 30 and 60 min with an interval time of 0-6 days resulted in the development of remarkable thermotolerance and the expression of heat shock protein 70 in MCa tumors after the first heating. Ce at 100 mg/kg given immediately after the first heating increased the expression of heat shock protein 70 in MCa tumors, and did not reduce the development of thermotolerance. Ce given immediately before the first or second heating also did not inhibit the thermotolerance. The results of this study suggest that Ce enhances the thermosensitivity of MCa tumors as a thermosensitizer, but that this mild thermosensitizing property of Ce might be insufficient to conquer the remarkable thermotolerance in MCa tumors that develops after the first heating.

We report the results of phase I/II studies of preoperative multidisciplinary treatment of 14 patients with soft tissue sarcoma using hyperthermia from November 1990 to April 1995. The preoperative treatment was conducted with thermo-radio-chemotherapy in 11 cases of stage III, and with thermo-radiotherapy as well as thermo-chemotherapy in three cases of stages I and II. Hyperthermia was carried out twice a week with totals ranging from 4 to 14 times (average: 8.4 times); each session lasted 60 min. Radiotherapy was administered four or five times per week, and the dose was 1.8 2Gy/fraction, with a total of 30-40 Gy in a four week period. Chemotherapy was mainly in the form of MAID regimen (2-mercaptoethanesulphonic acid (mesna), adriamycin, ifosfamide and dacarbazine). The tumors were surgically resected in all patients after completing the preoperative treatment. The efficacy rate, as expressed by the percentage of either tumors in which reduction rate was 50% or more, or tumors for which post-treatment contrast enhanced CT image revealed low density volumes occupying 50% or more of the total mass, was 71% (ten of the 14 tumors). The mean tumor necrosis rate in the resected specimens was 78%. The tumor necrosis rate was significantly high (P < 0.05) in patients whose Time > or = 42 degrees C was of long duration. Postoperative complications were observed in six patients; among these, two patients developed wound infection that required surgical treatment as a complication of surgery performed in the early stage following the preoperative treatment. After a mean postoperative follow-up of 27 months, distant metastasis occurred in four patients resulting in three fatalities. The three-year cumulative survival rate was 64.3%. No local recurrence was observed in any patient during the follow-up, thus confirming our hypothesis that preoperative multidisciplinary treatment has an excellent local efficacy. We think that it would be valuable to conduct, at many facilities, phase III studies on the treatment of soft tissue sarcoma by a combination of surgery and preoperative multidisciplinary treatment using hyperthermia, paying close attention to the interval between these two modalities.

We performed a long-term follow-up of 4 patients with penile cancer who underwent hyperthermotherapy from August 1985 until August 1992. Hyperthermia was applied using a frequency of 350 MHz with a waveguide applicator twice a week for 60 min each for an average of 9.5 times (varying from 6 to 13 times). The total heating time that the temperature of urethra could be kept above 42 degrees C, was 166 min on the average (ranging from 0 to 463 min). Two patients classified as stage I according to the Jackson classification and 1 patient classified as stage IV underwent combined radiotherapy and received an average radiation dose of 53 Gy (range, 40-70 Gy). Among these patients 2 underwent combined chemotherapy with bleomycin or peplomycin. Malignant cells disappeared posttherapeutically and in August 1992, after an average of 5 years and 9 months (varying from 4 years 6 months to 6 years 10 months), the patients were free of recurrences. The one patient on stage IV had extensive invasion of the abdominal wall, but still recovered completely. One patient on stage III underwent combined chemotherapy and hyperthermotherapy, but heating had obviously been insufficient. There was a residue of malignant cells after the treatment and we performed a penectomy. Regarding functional preservation of the penis a multidisciplinary therapy incorporating hyperthermotherapy can be expected to increase the curativity. This indicates that it could induce in an advanced case, where an operation would be difficult, complete remission.