In-vitro study of Hep-G2 and THLE-3 liver cell lines with 1.0 MHz low-intensity pulsed ultrasound

• Main Author: Galban, Nescy Leann F.
• Format: text
• Language: English
• Published: Animo Repository 2022
• Subjects: Liver cells; Cancer cells; Cell lines; Physics
• Online Access: https://animorepository.dlsu.edu.ph/etdm_physics/5; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=1004&context=etdm_physics
• Institution: De La Salle University

Parametric in-vitro study was carried out using low-intensity pulsed ultrasound (LIPUS) to selectively target human-derived liver cell lines (i.e., HepG2 – cancer cell line and THLE-3 – normal liver cell line) by varying the intensity in W/m2 via voltage level control of the built LIPUS. The study aims to analyze the effect of 1.0 MHz LIPUS on human liver malignant cells with a MOSFET switcher that can regulate and generate square pulsed voltage signal at 0.14, 0.58, 1.30 and 2.31 W/cm2 intensity levels. In-vitro culture samples of HepG2 (American Type Culture Collection, Manassas, VA, USA) and THLE-3 (Invitrogen, USA) cells were grown in a humidified incubator at 37°C with 5% CO2. Cell culture medium was replaced every two days or until 90% confluence was achieved. These cells are then harvested and tested for cell viability using trypan blue fluorescent dye. From this batch, three replicates (wells) were respectively prepared to cluster the following groups: LIPUS-treated with sub-groups for different energy density level parametric values and untreated control (no LIPUS). In-vitro samples were then treated with LIPUS for 3-minutes to determine its cytotoxic index, genotoxic level thru comet score and molecular gene expression of cfos and cjun. Results showed that the LIPUS treatment at 2.31 W/cm2 had significantly reduced (p < 0.05) the viability of HepG2 cells compared to the THLE-3 cells at 1.30 and 2.31 W/cm2 intensity level, indicating cytotoxic effect of LIPUS on HepG2 at 2.31 W/cm2 and no significant damage on THLE-3 cells at the same voltage level. For genotoxic effect, the comet assay image showed that the LIPUS-treated HepG2 cells and THLE-3 cells have significant effect (p < 0.001) based on the CometScore (a computer-assisted measurements) of the tail length (TL), DNA tail % (TD), and tail moment (TM). In the same cell batch, the reverse transcription-quantitative polymerase chain reaction technique demonstrated that induced apoptosis due to the LIPUS treatment at 2.31 W/cm2 on HepG2 cells and THLE-3 cells from the elevated proapoptotic gene expression values of cfos and cjun. In summary, in-vitro study has showed that at 2.31 W/cm2 intensity level the LIPUS had caused significant cytotoxic, genotoxic and possible apoptotic effect on the malignant (HepG2) cells. While for the normal (THLE-3) hepatic cells, LIPUS have significant genotoxic and possible apoptotic effect. Thus, LIPUS can be a feasible treatment protocol in selectively discriminating the cytotoxic effect between the HepG2 malignant cells and normal THLE-3 hepatic cells beyond the 2.31 W/cm2 intensity level mark.