Ultrasound Microbubble Contrast Agent Carrying Anti-cancer Drug Paclitaxel To Endometrial Carcinoma Rl-95-2 Cell Proliferation And Apoptosis And Its Mechanism Of Action

ObjectivesTo investigate the effect of ultrasound microbubble contrast agent with paclitaxel on the proliferation and apoptosis of human endometrial cancer RL-95-2 cells and its possible mechanism.MethodsCultured RL-95-2 cells at logarithmic growth phase were treated with or without ultrasound irradiation, ultrasound microbubbles contrast agent with paclitaxel alone or in combination. The growth and cellular morphology were observed under an inverted microscope. The proliferation inhibition of RL-95-2 cells was evaluated by clonal growth assay and MTT assay. Transmit electron microscope and flow cytometry (FCM) were used to examine apoptosis and the change of cell cycle, respectively. The expression of proliferating cell nuclear antigen (PCNA) and cysteine-requiring aspartate protease-3 (Caspase-3) was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting analysisResults(1) The number of cells was reduced, and the cellular morphology was found irregular after treatment with ultrasound microbubble with paclitaxel plus ultrasound wave irradiation as compared with control. (2) Clonal growth assay and MTT analysis showed that ultrasound microbubble with paclitaxel in combination with ultrasound irradiation significantly inhibited the growth of RL-95-2 cells in vitro. (3) Transmit electron microscope examination revealed that ultrasound microbubble with paclitaxel in combination with ultrasound irradiation significantly induced apoptosis. The inhibitory effect was accompanied by a significant increase in the percentage of cells in G₀/G₁-phase, and with a concurrent decrease in the proportion of S- and G₂/M-phase cells and the proliferative index. (4) The expression of PCNA and Caspase-3 was markedly decreased in both mRNA and protein levels in cells treated ultrasound microbubble contrast agents with paclitaxel plus ultrasound irradiation as compared with control.ConclusionsUltrasound microbubble with paclitaxel in combination with ultrasound irradiation can effectively inhibit proliferation and induce apoptosis of human endometrial cancer RL-95-2 cells in vitro through, at least in part, down-regulation of PCNA and up-regulation of Caspase-3.