ABSTRACT
High intensity focused ultrasound (HIFU) technology is becoming a potential noninvasive treatment for solid tumor. To explore whether HIFU can be applied to treat melanoma and its metastasis, we investigated the effect of HIFU on murine melanoma model. While there was little influence on cell survival, viability or apoptosis, HIFU exposure suppressed melanoma cell migration in vitro and metastasis in vivo. The expression of microRNA-21(miR-21) was down-regulated and PTEN expression was up-regulated in response to HIFU exposure, which was in concomitant with the reduction of AKT activity. Furthermore, ectopic miR-21 expression suppressed this effect of HIFU. These results demonstrate that HIFU exposure can inhibit AKT-mediated melanoma metastasis via miR-21 inhibition to restore PTEN expression. Therefore, targeting the miR-21/PTEN/AKT pathway might be a novel strategy of HIFU in treatment of melanoma.
Subject(s)
Melanoma, Experimental/metabolism , Melanoma, Experimental/therapy , MicroRNAs/metabolism , PTEN Phosphohydrolase/metabolism , Skin Neoplasms/metabolism , Skin Neoplasms/therapy , Ultrasonic Therapy/methods , Animals , Apoptosis , Cell Movement , Cell Survival , Down-Regulation , Female , Mice , Mice, Inbred C57BL , Neoplasm Metastasis , Neoplasm Transplantation , Up-RegulationABSTRACT
HIFU has been demonstrated to enhance anti-tumor immunity, however, the mechanism of which has not been well elucidated. Emerging evidence indicates that miRNAs play important roles in immune response. In this study, we used the B16F10 melanoma allograft mouse model to investigate the role of miRNAs in HIFU-enhanced anti-tumor immunity. We found that HIFU treatment decreased circulating B16F10 cells and pulmonary metastasis nodules while increased IFN-γ and TNF-α in the peripheral blood and cumulative mouse survival, which was associated with inhibition of miR-134 expression and activation of CD86 expression in tumor tissues. Further, we determined that miR-134 directly binds to the 3'UTR of CD86 mRNA to suppress its expression in B16F10 cells. When B16F10 cells transfected with miR-134 were co-cultured with normal splenic lymphocytes, the secretion of IFN-γ and TNF-α from lymphocytes was reduced and B16F10 cell survival was increased. HIFU exposure efficiently decreased miR-134 while increased CD86 expression in B16F10 cells in vitro. CD86 knockdown with siRNA markedly rescued the viability of HIFU-treated B16F10 cells that co-cultured with lymphocytes. Altogether, our results suggest that HIFU down-regulates miR-134 to release the inhibition of miR-134 on CD86 in melanoma cells, thereby enhancing anti-tumor immune response.
Subject(s)
B7-2 Antigen/antagonists & inhibitors , Lung Neoplasms/immunology , Melanoma, Experimental/immunology , MicroRNAs/genetics , Ultrasonic Therapy , Animals , Apoptosis/genetics , Apoptosis/radiation effects , B7-2 Antigen/genetics , B7-2 Antigen/metabolism , Blotting, Western , Cell Proliferation/genetics , Cell Proliferation/radiation effects , Female , Flow Cytometry , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/genetics , Lung Neoplasms/secondary , Melanoma, Experimental/diagnostic imaging , Melanoma, Experimental/genetics , Melanoma, Experimental/pathology , Mice , Mice, Inbred C57BL , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Ultrasonography , Xenograft Model Antitumor AssaysABSTRACT
OBJECTIVE: To observe the changes of blood pressure (BP), pulse rate (PR) and the microstructure of celiac ganglion (CG) in rabbits with damaged CGs induced by alcohol and high intensity focused ultrasound. METHODS: Fourteen rabbits were randomly divided into two groups. The CGs of the rabbits in group A and group B were damaged by alcohol and high intensity focused ultrasound respectively. The changes of BP and PR 0, 1, 3, 5, and 10 minutes after the damage were recorded and compared. The microstructure changes of the damaged CGs were examined under optics microscope and electron microscope. RESULTS: Ganglionic morphology changes were obvious in both groups, with moved and concentrated karyons. In the CGs damaged by alcohol, the nucleolus still existed; some organelles could be identified; the myelination nerve fibre lost its myelin sheath or delaminated while the unmyelination nerve fibre exhibited vacuole formation. In the CGs damaged by high intensity focused ultrasound, all nucleolus disappeared, vacuole formed, intracellular membrane disappeared, axone locally necrotized. The BPs of the rabbits started to decrease three minutes after the alcohol treatment (P < 0.01), one minute after the high intensity focused ultrasound (P < 0.01). Significant differences of BP decline were observed between the two groups one minute after the CG damages. (P < 0.01). The PRs of the rabbits increased 5 minutes and 10 minutes after the high intensity focused ultrasound (P < 0.05, P < 0.01). CONCLUSION: Using high intensity focused ultrasound to damage CGs has more significant impacts on BPs and PRs than alcohol.
