Cytocidal effect of high energy shock wave on tumour cells enhanced with larger dose and multiple exposures

Extracorporeal shock waves stimulate osteoblast activities

The extracorporeal shock wave therapy (ESWT) is an extensively applied treatment for musculoskeletal disorders because it promotes bone repair. The aim of this study was to evaluate the direct effect of ESWT on murine osteoblasts to clarify the cellular mechanism that leads to the induction of osteogenesis. Osteoblasts in culture flasks were treated with ESWT pulses (500 impulses of 0.05 mJ/mm(2)) generated by an electromagnetic device. Using western blot analysis 3h after ESWT, an increased expression of Bax was found, indicating a fast pro-apoptotic effect of treatment on some of the osteoblasts. Activation of the cyclin E2/CDK2 is the complex that regulates the G1-S transition and is essential for cell proliferation. It was evident 24 to 72h after treatment, indicating a proliferative stimulus. A decreased expression of osteoprotegerin (OPG) and receptor activator NF kappa B ligand (RANKL) 24 and 48h after ESW, followed by a later increase of OPG, paired with a much smaller increase of RANKL, was evident by real-time polymerase chain reaction (PCR). The decreased RANKL/OPG ratio suggests inhibition of osteoclastogenesis. We can conclude that ESWT induces bone repair through the proliferation and differentiation of osteoblasts and the reduction of their secretion of pro-osteoclastogenic factors.

High energy shock waves (HESW) increase paclitaxel efficacy in a syngeneic model of breast cancer

The combined effect of high energy shock waves (HESW), generated by a piezoelectric device, and paclitaxel on Mat B-III rat breast cancer cells in vitro and in an in vivo animal model is presented. A significant reduction of in vitro Mat B-III cell proliferation versus cells treated with paclitaxel alone was observed with the combined exposure to paclitaxel (0.1, 1, or 10 nM) and HESW (0.22 mJ/mm2, 1000 shots). Moreover earlier induction and enhanced apoptosis occurred in cells subjected to the combined treatment with paclitaxel and HESW at 1 and 10 nM versus paclitaxel alone (p<0.01 and p<0.001, respectively). The percentage of apoptotic cells along with BAD mRNA expression, confirm a significant enhancement of apoptosis in tumor tissues subjected to the combined treatment with paclitaxel (2.5 mg/kg on days 7 and 11) and HESW (0.50 mJ/mm2, 500 shots on day 11) in comparison with paclitaxel alone. In conclusion, these data suggest that HESW enhance paclitaxel cytotoxicity in the Mat B-III syngeneic model of breast cancer.

High energy shock waves activate 5'-aminolevulinic Acid and increase permeability to Paclitaxel: antitumor effects of a new combined treatment on anaplastic thyroid cancer cells

OBJECTIVE

Multimodal treatments do not meaningfully improve survival of anaplastic thyroid cancer. Consequently, new effective therapeutic modalities are needed. The use of paclitaxel is under clinical investigation; it shows about a 50% response rate, but it is not able to alter the fatal outcome for patients with anaplastic carcinoma. High energy shock waves (HESW) have been shown to cause a transient increase in the permeability of cell membranes thus allowing higher intracellular drug concentrations. 5-Aminolevulinic acid (ALA) is used in the photodynamic therapy (PDT) of cancer, and HESW are under evaluation for their use as an activator in ALA-PDT.

DESIGN

We investigated the effect of HESW produced by a piezoelectric generator on the sensitivity to paclitaxel and ALA treatments of two different anaplastic thyroid cancer cell lines (ARO and CAL-62). Cells, treated sequentially with ALA and paclitaxel were exposed to HESW; thereafter, cell viability and apoptosis induction were evaluated.

MAIN OUTCOME

Combined exposure to ALA, paclitaxel, and shock waves resulted in a significant enhancement of cytotoxicity and induction of apoptosis in thyroid cancer cells with respect to cells treated with paclitaxel alone.

CONCLUSIONS

These preliminary data suggest the possibility of using HESW and ALA in combination with paclitaxel as a promising new therapy in the treatment of anaplastic thyroid cancer.

High Energy Shock Waves (HESW) Enhance Paclitaxel Cytotoxicity in MCF-7 Cells

High energy shock waves (HESW) produced by a piezoelectric generator were studied for their effect on human breast cancer cell (MCF-7) viability and sensitivity to paclitaxel. A dose-dependent impairment of cell viability was observed after HESW treatment (250-2000 shock waves, rate = 4/s, energy flux density = 0.25 mJ/mm2). Single treatment with shock waves produced no significant growth inhibition. Combined exposure to paclitaxel (ranging 0.1 nM to 20 microM) and shock waves (100, 500 and 1000 shots, respectively) resulted in a significant reduction of MCF-7 cell proliferation at day 3 after treatment in respect with cells treated with paclitaxel alone. Notably, a cell viability reduction of about 50% was obtained after combined treatment with HESW and 10 nM paclitaxel, in front of a reduction of only 40% using 10 microM paclitaxel alone. Moreover, an earlier induction as well as an enhancement of apoptotis was observed in cells subjected to combined treatment with shock waves and paclitaxel (200 nM; 20 microM). In conclusion, HESW can enhance paclitaxel cytotoxicity in MCF-7 cells, thus allowing the treatment with lower doses of drug.