RESUMEN
OBJECTIVES: The primary objective of this research targeted the biochemical effects of SDT on human cervix carcinoma (HeLa) and mouse Lewis lung carcinoma (LLC) cells grown in 2D monolayer and 3D spheroid cell culture. METHODS: HeLa and LLC monolayers and spheroids were treated with a 20 µM C60-Ber for 24 h, followed by irradiation with 1 MHz, 1 W/cm2 US. To evaluate the efficacy of the proposed treatment on cancer cells, assessments of cell viability, caspase 3/7 activity, ATP levels, and ROS levels were conducted. RESULTS: Our results revealed that US irradiation alone had negligible effects on LLC and HeLa cancer cells. However, both monolayers and spheroids irradiated with US in the presence of the C60-Ber exhibited a significant decrease in viability (32% and 37%) and ATP levels (42% and 64%), along with a notable increase in ROS levels (398% and 396%) and caspase 3/7 activity (437% and 246%), for HeLa monolayers and spheroids, respectively. Similar tendencies were observed with LLC cells. In addition, the anticancer effects of C60-Ber surpassed those of C60, Ber, or their mixture (C60 + Ber) in both cell lines. CONCLUSIONS: The detected intensified ROS generation and ATP level drop point to mitochondria dysfunction, while increased caspase 3/7 activity points on the apoptotic pathway induction. The combination of 1 W/cm2 US with C60-Ber showcased a promising platform for synergistic sonodynamic chemotherapy for cancer treatment.
RESUMEN
Cancer sonodynamic therapy (SDT) is the therapeutic strategy of a high-frequency ultrasound (US) combined with a special sonosensitizer that becomes cytotoxic upon US exposure. The growing number of newly discovered sonosensitizers and custom US in vitro treatment solutions push the SDT field into a need for systemic studies and reproducible in vitro experimental set-ups. In the current research, we aimed to compare two of the most used and suitable SDT in vitro set-ups-"sealed well" and "transducer in well"-in one systematic study. We assessed US pressure, intensity, and temperature distribution in wells under US irradiation. Treatment efficacy was evaluated for both set-ups towards cancer cell lines of different origins, treated with two promising sonosensitizer candidates-carbon nanoparticle C60 fullerene (C60) and herbal alkaloid berberine. C60 was found to exhibit higher sonotoxicity toward cancer cells than berberine. The higher efficacy of sonodynamic treatment with a "transducer in well" set-up than a "sealed well" set-up underlined its promising application for SDT in vitro studies. The "transducer in well" set-up is recommended for in vitro US treatment investigations based on its US-field homogeneity and pronounced cellular effects. Moreover, SDT with C60 and berberine could be exploited as a promising combinative approach for cancer treatment.
RESUMEN
The acoustic pressure waves of ultrasound (US) not only penetrate biological tissues deeper than light, but they also generate light emission, termed sonoluminescence. This promoted the idea of its use as an alternative energy source for photosensitizer excitation. Pristine C60 fullerene (C60), an excellent photosensitizer, was explored in the frame of cancer sonodynamic therapy (SDT). For that purpose, we analyzed C60 effects on human cervix carcinoma HeLa cells in combination with a low-intensity US treatment. The time-dependent accumulation of C60 in HeLa cells reached its maximum at 24 h (800 ± 66 ng/106 cells). Half of extranuclear C60 is localized within mitochondria. The efficiency of the C60 nanostructure's sonoexcitation with 1 MHz US was tested with cell-based assays. A significant proapoptotic sonotoxic effect of C60 was found for HeLa cells. C60's ability to induce apoptosis of carcinoma cells after sonoexcitation with US provides a promising novel approach for cancer treatment.