Relationship between Energy Dosage and Apoptotic Cell Death by Modulated Electro-Hyperthermia.

Modulated electro-hyperthermia (mEHT) is a form of mild hyperthermia (HT) used for cancer treatment. The principle utility of HT is the ability not only to increase cell temperature, but also to increase blood flow and associated pO2 to the microenvironment. While investigational evidence has shown the unique ability of mEHT to elicit apoptosis in cancer cells, in vivo and in vitro, the same trait has not been observed with conventional HT. There is dissension as to what allows mEHT to elicit apoptosis despite heating to only mild temperatures, with the predominant opinion in favor of increased temperature at a cellular level as the driving force. For this study, we hypothesized that in addition to temperature, the amount of electrical energy delivered is a major factor in induction of apoptosis by mEHT. To evaluate the impact of electrical energy on apoptosis, we divided generally practiced mEHT treatment into 3 phases: Phase I (treatment start to 10 min. mark): escalation from 25 °C to 37 °C Phase II (10 min. mark to 15 min. mark): escalation from 37 °C to 42 °C Phase III (15 min. mark to 45 min. mark): maintenance at 42 °C Combinations of mEHT at 18 W power, mEHT at 7.5 W power, water bath, and incubator were applied to each of the three phases. Power output was recorded per second and calculated as average power per second. Total number of corresponding Joules emitted per each experiment was also recorded. The biological effect of apoptotic cell death was assayed by annexin-V assay. In group where mEHT was applied for all three phases, apoptosis rate was measured at 31.18 ± 1.47%. In group where mEHT was only applied in Phases II and III, apoptosis rate dropped to 20.2 ± 2.1%. Where mEHT was only applied in Phase III, apoptosis was 6.4 ± 1.7%. Interestingly, when mEHT was applied in Phases I and II, whether Phase III was conducted in either water bath at 42 °C or incubator at 37 °C, resulted in nearly identical apoptosis rates, 26 ± 4.4% and 25.9 ± 3.1%, respectively. These results showed that accumulation of mEHT at high-powered setting (18 W/sec) during temperature escalation (Phase I and Phase II), significantly increased apoptosis of tested cancer cells. The data also showed that whereas apoptosis rate was significantly increased during temperature escalation by higher power (18 W/sec), apoptosis was limited during temperature maintenance with lower power (7.5 W/sec). This presents that neither maintenance of 42 °C nor accumulation of Joules by mEHT has immediate correlating effect on apoptosis rate. These findings may offer a basis for direction of clinical application of mEHT treatment.

Modulated electro-hyperthermia-enhanced liposomal drug uptake by cancer cells.

PURPOSE: Modulated electro-hyperthermia (mEHT) stands to be a significant technological advancement in the hyperthermia field, utilizing autofocusing electromagnetic power on the cell membrane to create massive apoptosis. Since mEHT possesses the unique ability to excite cell membranes, we hypothesized that mEHT could enhance the uptake of liposomal drugs by enhancing phagocytic activity. MATERIALS AND METHODS: Water bath control and mEHT were used to compare the enhancement of liposome-encapsulated doxorubicin (Lipodox®) uptake by cancer cells. Cancer cells were made visible by doxorubicin fluorescence to investigate drug uptake. Viable cell yield was determined via the Trypan Blue exclusion method. Various substrates were used to investigate the mechanism of drug-uptake enhancement. The murine colon carcinoma model, CT26, was used to confirm the tissue infiltration of Lipodox® and its therapeutic effect. RESULTS: mEHT treatment showed a significant enhancement of Lipodox® uptake of doxorubicin fluorescence compared with 37°C or 42°C water bath treatment. Tumor tissue sections also confirmed that mEHT treatment achieved the highest doxorubicin concentration in vivo (1.44±0.32 µg/g in mEHT group and 0.79±0.32 µg/g in 42°C water bath). Wortmannin was used to inhibit the macropinocytosis effect and 70 kDa dextran-FITC served as uptake substance. The uptake of dextran-FITC by cancer cells significantly increased after mEHT treatment whereas such enhancement was significantly inhibited by wortmannin. CONCLUSION: The result showed mEHT-induced particle-uptake through macropinocytosis. mEHT-enhanced uptake of Lipodox® may amplify the therapeutic effect of liposomal drugs. This novel finding warrants further clinical investigation.

Comparing the Effectiveness of Combined External Beam Radiation and Hyperthermia Versus External Beam Radiation Alone in Treating Patients With Painful Bony Metastases: A Phase 3 Prospective, Randomized, Controlled Trial.

PURPOSE: To compare the response, duration of pain relief, and time to achieve complete pain relief after radiation therapy (RT) with or without hyperthermia (HT) in patients with painful bony metastases. METHODS AND MATERIALS: Cancer patients with bony metastases and pain score ≥4 on the Brief Pain Inventory (BPI) were randomized to RT of 30 Gy in 10 fractions combined with HT (RT + HT) versus RT alone. Hyperthermia was performed by the Thermotron RF-8, with maintenance of the target temperature for 40 minutes per treatment within 2 hours after RT, twice weekly for 2 weeks. Patients were stratified by lesion number (solitary or multiple), BPI score (4-6 vs 7-10), and primary site. The primary endpoint was complete response (CR) (BPI = 0 with no increase of analgesics) within 3 months after treatment. This study was registered with ClinicalTrials.gov. RESULTS: The study was terminated early after an interim analysis of 57 patients, 3 years after the first enrollment (November 2013 to November 2016): 29 patients in the RT + HT group and 28 patients in the RT-alone group. The CR rate at 3 months after treatment was 37.9% in the RT + HT group versus 7.1% in the RT-alone group (P=.006). The accumulated CR rate within 3 months after treatment was 58.6% in the RT + HT group versus 32.1% in the RT-alone group (P=.045). Median time to pain progression was 55 days in patients with CR (n=9) in the RT-alone group, whereas the endpoint was not reached during the 24-week follow-up in the RT + HT group (P<.01). CONCLUSIONS: The addition of HT to RT significantly increases the pain control rate and extends response duration compared with RT alone for painful bony metastases.

In vitro comparison of conventional hyperthermia and modulated electro-hyperthermia.

Radiofrequency-induced hyperthermia (HT) treatments for cancer include conventional capacitive coupling hyperthermia (cCHT) and modulated electro-hyperthermia (mEHT). In this study, we directly compared these methods with regard to in vitro cytotoxicity and mechanisms of action under isothermal conditions. Hepatoma (HepG2) cells were exposed to HT treatment (42°C for 30 min) using mEHT, cCHT or a water bath. mEHT produced a much higher apoptosis rate (43.1% ± 5.8%) than cCHT (10.0% ± 0.6%), the water bath (8.4% ± 1.7%) or a 37°C control (6.6% ± 1.1%). The apoptosis-inducing effect of mEHT at 42°C was similar to that achieved with a water bath at 46°C. mEHT also increased expression of caspase-3, 8 and 9. All three hyperthermia methods increased intracellular heat shock protein 70 (Hsp70) levels, but only mEHT greatly increased the release of Hsp70 from cells. Calreticulin and E-cadherin levels in the cell membrane also increased after mEHT treatment, but not after cCHT or water bath. These results suggest that mEHT selectively deposits energy on the cell membrane and may be a useful treatment modality that targets cancer cell membranes.

Improving immunological tumor microenvironment using electro-hyperthermia followed by dendritic cell immunotherapy.

BACKGROUND: The treatment of intratumoral dentritic cells (DCs) commonly fails because it cannot evoke immunity in a poor tumor microenvironment (TME). Modulated electro-hyperthermia (mEHT, trade-name: oncothermia) represents a significant technological advancement in the hyperthermia field, allowing the autofocusing of electromagnetic power on a cell membrane to generate massive apoptosis. This approach turns local immunogenic cancer cell death (apoptosis) into a systemic anti-tumor immune response and may be implemented by treatment with intratumoral DCs. METHODS: The CT26 murine colorectal cancer model was used in this investigation. The inhibition of growth of the tumor and the systemic anti-tumor immune response were measured. The tumor was heated to a core temperature of 42 °C for 30 min. The matured synergetic DCs were intratumorally injected 24 h following mEHT was applied. RESULTS: mEHT induced significant apoptosis and enhanced the release of heat shock protein70 (Hsp70) in CT26 tumors. Treatment with mEHT-DCs significantly inhibited CT26 tumor growth, relative to DCs alone or mEHT alone. The secondary tumor protection effect upon rechallenging was observed in mice that were treated with mEHT-DCs. Immunohistochemical staining of CD45 and F4/80 revealed that mEHT-DC treatment increased the number of leukocytes and macrophages. Most interestingly, mEHT also induced infiltrations of eosinophil, which has recently been reported to be an orchestrator of a specific T cell response. Cytotoxic T cell assay and ELISpot assay revealed a tumor-specific T cell activity. CONCLUSIONS: This study demonstrated that mEHT induces tumor cell apoptosis and enhances the release of Hsp70 from heated tumor cells, unlike conventional hyperthermia. mEHT can create a favorable tumor microenvironment for an immunological chain reaction that improves the success rate of intratumoral DC immunotherapy.

MS-20, a chemotherapeutical adjuvant, reduces chemo-associated fatigue and appetite loss in cancer patients.

A small pilot study of the fermented soybean extract MicrSoy-20(MS-20) demonstrated its ability to restore chemotherapy-induced immunosuppression and improve quality of life (QoL). This randomized, cross-over, comparative trial was conducted to confirm the effects of MS-20 on QoL and to understand its underlying mechanism when used in conjunction with chemotherapy. One hundred forty-three patients undergoing cancer chemotherapy were randomly assigned to 2 groups. Group 1 was administered MS-20 for 1 wk followed by 3 wk of concomitant MS-20 plus chemotherapy. Group 2 was administered chemotherapy for 3 wk. QoL was assessed by the EORTC/QLQ-C30 questionnaire and visual analogue scales (VAS). Changes in immunological parameters and antioxidant profiles were also examined. Significant increases were observed in EORTC/QLQ-C30 scores for physical (4.45, P = 0.023) and social (3.99, P = 0.023) functioning in Group 1 patients compared to Group 2 patients. VAS scores for fatigue and appetite loss significantly improved with MS-20 treatment (P < 0.001). Group 1 patients exhibited smaller decreases in peripheral blood mononuclear cells compared to Group 2 patients (P = 0.026). Other immunological parameters, antioxidant, and safety profiles were not significantly different between treatment groups. Addition of MS-20 as an adjuvant to chemotherapy can be effective in improving QoL for cancer patients.

Evaluation of EGFR-targeted radioimmuno-gold-nanoparticles as a theranostic agent in a tumor animal model.

This study evaluated the tumor targeting and therapeutic efficacy of a novel theranostic agent (131)I-labeled immuno-gold-nanoparticle ((131)I-C225-AuNPs-PEG) for high epidermal growth factor receptor (EGFR)-expressed A549 human lung cancer. Confocal microscopy demonstrated the specific uptake of C225-AuNPs-PEG in A549 cells. (131)I-C225-AuNPs-PEG induced a significant reduction in cell viability, which was not observed when incubated with AuNPs-PEG and C225-AuNPs-PEG. MicroSPECT/CT imaging of tumor-bearing mice after intravenous injection of (123)I-C225-AuNPs-PEG revealed significant radioactivity retention in tumor suggested that (131)I-labeled C225-conjugated radioimmuno-gold-nanoparticles may provide a new approach of targeted imaging and therapy towards high EGFR-expressed cancers.

Antisense thymidylate synthase electrogene transfer to increase uptake of radiolabeled iododeoxyuridine in a murine model.

UNLABELLED: In vitro and in vivo experiments from our laboratory and others have suggested that the combination of thymidylate synthase (TS) inhibitor and radiolabeled iododeoxyuridine (IdUrd) is synergistic. Efficacy is limited by drug resistance, which is often mediated by TS overexpression. We designed an in vivo electrogene transfer (EGT) model for delivering antisense TS plasmid (ATS) into tumor to increase the subsequent efficacy of (131)I-IdUrd therapy. METHODS: Plasmid complementary to nucleotide 531-710 in the coding region of the mouse TS (mTS) mRNA was constructed. TS activity and (131)I-IdUrd DNA incorporation were determined 48 h after in vitro EGT of ATS to CT26 cells. In vivo therapeutic effect and radioactivity retained in tumor after various combinations of EGT ATS, 5-fluorouracil (5-FU), and continuous infusion of (131)I-IdUrd by osmotic minipump were determined. RESULTS: A reduction of TS activity was achieved after in vitro EGT ATS. Flow cytometry analysis indicated that ATS-treated cells were arrested at S phase. In the in vivo tumor model, the combination of EGT ATS and 5-FU was able to partially overcome 5-FU drug resistance. Sixty percent of tumors can be eradicated by the combination of EGT ATS, 5-FU, and infusion of (131)I-IdUrd. The tumors treated by EGT ATS had higher radioactivity retained 1 wk after (131)I-IdUrd therapy than after EGT of control plasmid. CONCLUSION: In situ EGT ATS can downregulate TS and increase the therapeutic effect of radiolabeled IdUrd therapy. The combination of EGT ATS, 5-FU, and (131)I-IdUrd may result in tumor eradication.

A phase III study of adjuvant chemotherapy in advanced nasopharyngeal carcinoma patients.

PURPOSE: To evaluate the role of adjuvant chemotherapy in locally advanced nasopharyngeal carcinoma (NPC) patients, we conducted a randomized Phase III trial comparing radiotherapy (RT) followed by adjuvant chemotherapy to RT alone in patients with advanced NPC. METHODS AND MATERIALS: Between November 1994 and March 1999, 157 patients with Stage IV, M(0) (UICC/AJCC, 1992) advanced NPC disease were randomized to receive standard radiotherapy, as follows: 35-40 fractions, 1.8-2.0 Gy/fraction/day, 5 days/week, to a total dose 70-72 Gy with or without 9 weekly cycles of 24-h infusional chemotherapy (20 mg/m(2) cisplatin, 2,200 mg/m(2) 5-fluorouracil, and 120 mg/m(2) leucovorin) after RT. Of 157 patients enrolled, 154 (77 radiotherapy, 77 combined therapy) were evaluable for survival and toxicity analysis. RESULTS: With a median follow-up of 49.5 months, the 5-year overall survival and relapse-free survival rates were 60.5% vs. 54.5% (p = 0.5) and 49.5% vs. 54.4% (p = 0.38) for the radiotherapy-alone group and the combined radiotherapy and adjuvant chemotherapy group, respectively. The Cox regression showed that the hazard rates ratio of combined treatment to RT alone was 0.673 (p value = 0.232); the 95% confidence interval was 0.352 and 1.288, respectively. Patients who received combined treatment had a lower systemic relapse rate than radiotherapy-alone patients, according to relapse pattern analysis. The incidence of leukopenia (>or= Grade 3) occurred in 17 out of 819 (2.1%) cycles of weekly chemotherapy. No patient developed moderate to severe mucositis (>or= Grade 3). CONCLUSIONS: We conclude that adjuvant chemotherapy after RT for patients with advanced NPC has no benefit for overall survival or relapse-free survival.