Low-pressure pulsed focused ultrasound with microbubbles promotes an anticancer immunological response. 


Author: Liu HL, Hsieh HY, Lu LA, Kang CW, Wu MF, Lin CY.


Conference/Journal: J Transl Med.
Date published: 2012 Nov 11
Other:
 Volume ID: 10   ,  Issue ID: 1   ,  Pages: 221   ,  Word Count: 180  
    ABSTRACT:

BACKGROUND: High-intensity focused-ultrasound (HIFU) has been successfully employed for thermal ablation of tumors in clinical settings. Continuous- or pulsed-mode HIFU may also induce a host antitumor immune response, mainly through expansion of antigen-presenting cells in response to increased cellular debris and through increased macrophage activation/infiltration. Here we demonstrated that another form of focused ultrasound delivery, using low-pressure, pulsed-mode exposure in the presence of microbubbles (MBs), may also trigger an antitumor immunological response and inhibit tumor growth.

METHODS:

A total of 280 tumor-bearing animals were subjected to sonographically-guided FUS. Implanted tumors were exposed to low-pressure FUS (0.6 to 1.4 MPa) with MBs to increase the permeability of tumor microvasculature.

RESULTS:

Tumor progression was suppressed by both 0.6 and 1.4-MPa MB-enhanced FUS exposures. We observed a transient increase in infiltration of non-T regulatory (non-Treg) tumor infiltrating lymphocytes (TILs) and continual infiltration of CD8+ cytotoxic T-lymphocytes (CTL). The ratio of CD8+/Treg increased significantly and tumor growth was inhibited.

CONCLUSIONS:

Our findings suggest that low-pressure FUS exposure with MBs may constitute a useful tool for triggering an anticancer immune response, for potential cancer immunotherapy.

PMID: 23140567