The utility of hyperthermia for local recurrence of breast cancer

Self-inhibition of HER2 and HER3 at fever temperatures may prevent their hetero-dimerization

HER2 and HER3 receptors dimerize into potent pro-oncogenic complexes involved in various aggressive and recurrent tumors. The role of febrile temperatures on the formation of HER2:HER3 complexes is unknown. To this end, molecular dynamics simulations of HER2 and HER3 were performed in the 37 °C-40 °C range. HER2 and ligand-free HER32 display inactive conformers that cannot form complexes at 40 °C, while maintaining their extended conformations able to dimerize in the 37 °C-39 °C range. Thermal therapy at particular fever points may complement existing therapy options for HER2-relevant cancers.Communicated by Ramaswamy H. Sarma.

Clinical evaluations of diaphysis malignant tumors of femur and tibia treated with microwave ablation in situ

Background

This study was designed to evaluate the clinical outcomes of patients with diaphysis malignant tumors of femur and tibia treated with microwave ablation (MWA) in situ.

Methods

Retrospective study of 32 patients with diaphysis malignant bone tumors of femur or tibia have been treated by microwave ablation. Instead of en bloc resection, hyperthermia ablation in situ was carried out followed by strengthen procedure. The patients were followed up for a period ranging from 36 to 180 months.

Results

Twenty-five patients survived over 3 years and all of the patients alive have a satisfactory functional and cosmetic limb. The postoperative survival rate of MWA group was significantly higher than the amputation group in consecutive inclusions.

Conclusions

MWA is a feasible and effective surgical method for limb salvage operation and it might offer an innovative and distinctive therapeutic alternative for diaphysis malignant bone tumors, which avoiding osteotomy or prosthesis replacement.

Level of evidence

Level IV, clinical cohort study

Association between integrin-linked kinase and hyperthermia in oral squamous cell carcinoma

The present study aimed to observe the effect of the biological functions of integrin-linked kinase (ILK) silencing combined with hyperthermia on Tca8113 cells. Lentivirus-mediated short hairpin RNA (shRNA)-targeting ILK was transfected into oral squamous cell carcinoma (OSCC) Tca8113 cells and, combined with hyperthermia, several experimental methods were used to detect their biological behavior in vitro. On the basis of in vitro experiments, Tca8113 cells were transplanted into nude mice models, and ILK-shRNA-lentivirus was injected into the nude mice transplanted tumor and combined with hyperthermia. Tumor morphology and the associated protein expression changes were determined. Subsequent to ILK silencing combined with hyperthermia, the growth, migration and proliferation of Tca8113 cells were significantly inhibited. Flow cytometry revealed that the cells were blocked in the S phase, and western blot analysis demonstrated that ILK, phosphorylated (p)-RAC-alpha serine/threonine-protein kinase (Akt), p-glycogen synthase kinase-3β and p-heat shock factor 1 protein expression levels were significantly decreased, while apoptosis-associated protein B-cell lymphoma-2-associated X protein expression and the efficacy of hypothermia were significantly increased. By ILK silencing combined with hyperthermia, a significant therapeutic effect on transplanted tumors was observed in nude mice. Immunohistochemistry revealed the same results as the in vitro experiments. ILK silencing combined with hyperthermia can inhibit the growth, proliferation and migration of Tca8113 cells, promote Tca8113 cell apoptosis, inhibit the phosphatidylinositol-3-kinase/Akt signaling pathway and increase hyperthermia sensitivity; the combination therapy exhibits a synergistic sensitizing effect. Therefore, ILK silencing combined with hypothermia may serve as a novel combination therapy strategy against OSCC.

Treatment of osteosarcoma with microwave thermal ablation to induce immunogenic cell death

Microwave ablation (MWA) has been used as a classical hyperthermic ablation method for decades with the intention to induce direct killing of tumor cells or modulation of tumor architecture. The purpose of this study was to explore whether MWA induced tumor cell death could generate an immunogenic source of tumor antigens and elicit tumor-specific immune responses, taking an alternative antitumor effects. Three kinds of osteosarcoma cell lines, respectively derived from mice, rats and human, were selected as ablation models. In vitro and in situ tumor ablation were both performed to detect the “damage-associated molecular patterns” (DAMPs) exposure level. Active ablated products vaccination resulted in complete protection in both mouse and rat tumor-bearing models, which was mediated primarily by vaccine-elicited CD8⁺ T cells. These effector cells functioned by releasing IFN-γ and TNF-α in the presence of target cells, which may trigger FasL-directed cell apoptosis. These data suggest that MWA-processed osteosarcoma cells could be applied to generate specific antitumor effects, especially for in situ ablation. Hence, MWA could be used in combination with immunotherapy, especially for patients who have failed chemotherapy or who have limited treatment options.

Role of Hyperthermia in Breast Cancer Locoregional Recurrence: A Review

In patients with locoregional recurrences of breast cancer not suitable for resection, subsequent local control is difficult to maintain in previously irradiated areas when reirradiation alone or reirradiation with chemotherapy is used. Due to the limited number of treatment options there is a high risk of subsequent failure and uncontrollable local disease. In this group of patients, local hyperthermia combined with radiotherapy increases the clinical response and local control, adding limited acute and late toxicity, as has been shown in randomized trials. Hyperthermia is an artificial elevation of tissue temperature (range 40-44°C for 30-60 min). If hyperthermia is applied shortly before or after radiation, the effect of radiation is enhanced by influencing intratumoral hypoxia and by inhibiting sublethal damage repair in the tumor. Moreover, hyperthermia combined with radiation reduces the total dose of radiation needed compared to radiation alone, of which a higher dose is needed to obtain the same effect. Few data are available on the combination of radiotherapy and hyperthermia with chemotherapy, although the results of trimodality treatment consisting of reirradiation and hyperthermia together with liposomal doxorubicin are promising. Therefore, this literature review was performed to provide more comprehensive data on the mechanism and use of hyperthermia in locoregional recurrence of breast cancer.

Molecular Imaging-Guided Interventional Hyperthermia in Treatment of Breast Cancer

Breast cancer is the most frequent malignancy in women worldwide. Although it is commonly treated via chemotherapy, responses vary among its subtypes, some of which are relatively insensitive to chemotherapeutic drugs. Recent studies have shown that hyperthermia can enhance the effects of chemotherapy in patients with refractory breast cancer or without surgical indications. Recent advances in molecular imaging may not only improve early diagnosis but may also facilitate the development and response assessment of targeted therapies. Combining advanced techniques such as molecular imaging and hyperthermia-integrated chemotherapy should open new avenues for effective management of breast cancer.

Hyperthermia Is Now Included in the NCCN Clinical Practice Guidelines for Breast Cancer Recurrences: An Analysis of Existing Data

BACKGROUND

Hyperthermia has been included in the 2013 National Comprehensive Cancer Network (NCCN) guidelines as an option for the treatment of breast recurrences. The purpose of this article is to demonstrate the important role of hyperthermia as a therapeutic modality by presenting clinical trials on this subject carried out in the last decades.

MATERIALS AND METHODS

All relevant trials published since 1987 were retrieved from Medline and reviewed.

RESULTS

Results show that the addition of hyperthermia to radiotherapy and/or chemotherapy for the treatment of breast cancer enhances treatment response and can increase local control.

CONCLUSION

Further studies are required to evaluate potential benefits of hyperthermia in the treatment of other kinds of superficial tumors.

Perspectives of breast cancer thermotherapies

In this article, the use of different types of thermotherapies to treat breast cancer is reviewed. While hyperthermia is most commonly used as an adjuvant in combination with radiotherapy, chemotherapy, targeted therapy or cryotherapy to enhance the therapeutic effect of these therapies, thermoablation is usually carried out alone to eradicate small breast tumors. A recently developed thermotherapy, called magnetic hyperthermia, which involves localized heating of nanoparticles under the application of an alternating magnetic field, is also presented. The advantages and drawbacks of these different thermotherapies are highlighted.

FOLIC ACID-FUNCTIONALIZED GOLD AND SILVER NANOPARTICLES: THEIR CYTOTOXIC EFFECT ON CANCEROUS MYELOID CELLS WITH MICROWAVE IRRADIATION

Introduction: Metal nanoparticles such as gold and silver nanoparticles have attracted much interest during the last decades for their special chemical and physical properties. Gold and silver nanoparticles can be functionalized with active biologic moieties like antibodies, drugs and chemicals, enabling them to react with specific cells. Furthermore, penetration and cytotoxic effects of nanoparticles can be increased by electromagnetic waves such as infrared, ultraviolet, radiofrequency and microwave. Aim: The aim of this study was to evaluate the rate of cell cytotoxicity induced by folic acid-functionalized gold and silver nanoparticles with and without microwave irradiation on cancer cells from patients with acute myeloid leukemia (AML). Method: Patients with known AML (M1, M2, M3 and M4), all recently diagnosed by histopathology, special stains and immunohistochemistry, and 4 normal persons were enrolled in the study. The blood mononuclear cell fraction was separated, so that the final concentration of neoplastic myeloid cells and normal mononuclear cells in each tube was adjusted to about 400 cells/μL. For preparation of folate-functionalized gold and silver nanoparticles, folic acid was dissolved in deionized water, added to 1 mM HAuCl4 and 1 mM AgNO3 solution, and incubated at 50°C for 8 h. Scanning electron micrographs, ultraviolet-visible spectrophotometer and Fourier transform infrared (FTIR) were used for confirmation of the synthesis of functionalized nanoparticles. After preparation, nanoparticles were added to cancerous and normal cell suspensions, and then incubated at 37°C for 1 h. Another experiment was carried out in the same way but with exposure to microwave irradiation for 10 s so that its temperature reached at 50°C, and then incubated at 37°C for 1 h, after which cell cytotoxicity was evaluated with MTT test. All of the tests were duplicated, and paired t-test was used to compare the mean absorbance read-out in each of the above-mentioned groups of wells. Results: The sizes of functionalized gold and silver nanoparticles were approximately 25 nm to 32 nm. After synthesis of functionalized nanoparticles, the tubes containing HAuCl4 turned to red color, and the peak absorbance for gold nanoparticles was at 520 nm. For AgNo3 , it turned to yellow color with a peak absorbance at 420 nm. FTIR test showed connection of folic acid moieties to gold and silver surfaces. This study showed that functionalized gold nanoparticles were more toxic than functionalized silver nanoparticles on cancer and normal cells. Also, microwave irradiation was more synergic with functionalized gold nanoparticles. Furthermore, the most effectiveness score was 2.87 for functionalized silver nanoparticles without microwave irradiation and the minimum effectiveness score was 2.20 for functionalized silver nanoparticles with microwave. Conclusion: This study clearly demonstrated that although functionalized gold nanoparticles have high toxicity to cells, but silver nanoparticles without microwave irradiation are more effective because of less cytotoxic effect on normal cells.