Ischemia and loss of ATP in tumours following treatment with focused high energy shock waves

[Shock wave therapy in oncology: in vitro, in vivo, rehabilitation]

Extracorporeal shock wave therapy (ESWT) is a relatively new branch of physiotherapy.

PURPOSE OF THE STUDY

Conduct an analytical review of the available literature data on the use of ESWT in oncology.

MATERIAL AND METHODS

A review was conducted, including data from electronic databases: Scopus, Web of Science, MedLine, World Health Organization, The Cochrane Central Register of Controlled Trials, ScienceDirect, US National Library of Medicine National Institutes of Health, PubMed, Google Scholar, elibrary, CyberLeninka, disserCat.

RESULTS AND CONCLUSION

The study of ESWT in oncology is carried out in two directions: 1) impact on the tumor with the aim of its disintegration, inhibition of growth, enhancement of the action of radiation and/or chemotherapy; 2) rehabilitation of cancer patients. Shock waves in vitro and in vivo significantly reduce the viability and activate apoptosis of cell lines of osteosarcoma, cancer of the stomach, colon, rectum, bladder, breast, urothelial cancer of the upper urinary tract, adenocarcinoma of the cervix, Burkitt's lymphoma, sarcoma, anaplastic thyroid cancer glands, glioblastoma multiforme. Shock waves also sensitize tumor cells for adjuvant chemotherapy and increase its antitumor activity. The lack of a stimulating effect on a number of malignant tumors in this physical factor makes it possible to conduct ESWT studies in the rehabilitation of cancer patients. The data obtained by a number of authors indicate the clinical efficacy of ESWT in the rehabilitation of patients with erectile dysfunction after radical prostatectomy, with postmastectomy lymphedema of the upper limb, with myofascial pain syndrome after cervical lymph node dissection due to malignant neoplasms of the head and neck, with peripheral polyneuropathy induced by cytostatics. However, in order to develop indications and contraindications for the appointment of ESWT in the rehabilitation of cancer patients, it is not enough just to evaluate its clinical effectiveness; currently absent scientific studies with long-term follow-up of patients who received this method of physiotherapy are needed.

Shock wave therapy (Orthotripsy) in musculoskeletal disorders

Extracorporeal shock wave therapy, which now is used routinely for urolithiasis, has gained increasing acceptance in Europe for some musculoskeletal problems and has led to the inception of clinical studies in the United States. The authors have reviewed the available literature to assess the biologic effects of shock waves on human musculoskeletal tissues, the credibility of published studies on therapeutic applications, and the potential for more widespread application of this modality to various skeletal and near-skeletal disorders. The primary advantage of extracorporeal shock wave therapy is its noninvasive nature and seemingly minimal complications when applied to musculoskeletal tissues.

Metabolic imaging in multicellular spheroids of oncogene-transfected fibroblasts

Four rat embryo fibroblast (REF) cell lines with defined oncogenic transformation were used to study the relationship between tumorigenic conversion, metabolism, and development of cell death in a 3D spheroid system. Rat1 (spontaneously immortalized) and M1 (myc-transfected) fibroblasts represent early nontumorigenic transformation stages, whereas Rat1-T1 (T24Ha-ras-transfected Rat1) and MR1 (myc/T24Ha-ras-co-transfected REF) cells express a highly tumorigenic phenotype. Localized ATP, glucose, and lactate concentrations in spheroid median sections were determined by imaging bioluminescence. ATP concentrations were low in the nonproliferating Rat1 aggregates despite sufficient oxygen and glucose availability and lack of lactate accumulation. In MR1 spheroids, a 50% decrease in central ATP preceded the development of central necrosis at a spheroid diameter of around 800 micrometer. In contrast, the histomorphological emergence of cell death at a diameter of around 500 micrometer in Rat1-T1 spheroids coincided with an initial steep drop in ATP. Concomitantly, reduction in central glucose and increase in lactate before cell death were recorded in MR1 but not in Rat1-T1 spheroids. As shown earlier, myc transfection confers a considerable resistance to hypoxia of MR1 cells in the center of spheroids, which is reflected by their capability to maintain cell integrity and ATP content in a hypoxic environment. The data obtained suggest that small alterations in the genotype of tumor cell lines, such as differences in the immortalization process, lead to substantial differences in morphological structure, metabolism, occurrence of cell death, and tolerance to hypoxia in spheroid culture.

Flow cytometric analysis of cell suspensions exposed to shock waves in the presence of the radical sensitive dye hydroethidine

The occurrence of intracellularly and extracellularly generated free radicals during shock wave exposure on an experimental Siemens lithotripter was tested with the radical sensitive dyes hydroethidine and dichlorofluorescin (DCFH). DCFH, a nonfluorescent compound, is oxidised to dichlorfluorescein (DCF) by hydrogen peroxide in the presence of peroxidase. DCF green fluorescence intensity was used for fluorescence spectrometric measurement of hydrogen peroxide generated during shock-wave treatment of cell-free dye solutions. The fluorescence intensity of ethidium, the oxidised form of hydroethidine, was used for the flow-cytometric measurement of intracellular oxidising reagents present in RT4 tumour cells during shock-wave exposure. Changes in membrane permeability, which influence the intracellular content of ethidium, were controlled by counterstaining the cells with propidium iodide, an indicator for membrane integrity. We observed no increase in intracellular ethidium fluorescence intensity after shock-wave treatment of single cell suspensions and therefore no indication for shock-wave-induced intracellular free radicals.