Abstract 5606: Characterization of temporal proteomic dynamics of murine breast and melanoma tumor microenvironments without and with pulsed focused ultrasound
Authors: Cohen Gadi , Chandran Parwathay , Tomlinson Lauren E. , Sundby Maggie E. , Lorsung Rebecca M. , Burks Scott R. , Frank Joseph A. 
Published: September 2020

Abstract
Focused ultrasound (FUS) ablation has been successfully used for thermal ablation of solid malignancies. However, non-ablative pulsed-FUS (pFUS) has received less attention but could be less destructive anti-tumor therapy by stimulating a pro-inflammatory immune response within the tumor microenvironment (TME). Clinically, such an approach could be useful to treat peripheral disease (e.g. micro-metastases) in otherwise normal-appearing tissues. Here, we explored the alterations of cytokines, chemokines and trophic factors (CCTF) and cell adhesion molecules (CAM) in the TME of mouse flank tumor models following pFUS treatment at different time points of tumor progression. Mice were bilaterally inoculated with subcutaneous B16 melanoma or 4T1 breast tumors into the hind limbs and allowed to reach diameters of ~5 mm (n=6/group/timepoint) before performing experiments (Day 1). Separate groups of mice were subjected to pFUS (1 MHz; Peak negative pressure = 6 MPa; Duty cycle = 10%, 100 pulses per site) at Days 1, 5, or 10 and euthanized 24 hr post-pFUS for proteomic analyses. Separate groups of time-matched tumor-bearing mice that did not receive pFUS were also euthanized at the same time points both to assess relative changes due to pFUS at each time point and provide information regarding the natural history of TME progression in each tumor type. Proteomic analyses in untreated control tumors revealed an overall shift toward immunosuppressive (pro-tumor) TME over the 10 days. When comparing proteomic effects of pFUS treatment in compared to untreated time-matched controls, tumors treated on Day 1 exhibited greater upregulation of pro-inflammatory (anti-tumor) CCTF and CAM and pFUS had less pronounced effects on the TME when administered in groups of mice treated at Days 5 or 10. To further examine the acute effects of pFUS at on CCTF and CAM over 72hr. pFUS treatment in elicited unique CCTF and CAM profiles for the two tumor types, but both could be considered shifted towards anti-tumoral TME, especially within the first 24 hrs. These data suggest that pFUS can potentially modulate TME in a therapeutically beneficial way. However, they reveal two important caveats that require substantial investigation: 1) Different tumor types have unique molecular responses and imply pFUS may be more suitable for certain tumor types; 2) Natural histories encompass dynamic TME changes as part of disease progression and appropriate timing of pFUS in each tumor type will be necessary to maximizing the potential therapeutic benefits of pFUS.
Citation Format: Gadi Cohen, Parwathay Chandran, Lauren E. Tomlinson, Maggie E. Sundby, Rebecca M. Lorsung, Scott R. Burks, Joseph A. Frank. Characterization of temporal proteomic dynamics of murine breast and melanoma tumor microenvironments without and with pulsed focused ultrasound [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5606.