Location
Moultrie, GA
Start Date
9-5-2023 1:00 PM
End Date
9-5-2023 4:00 PM
Description
Advanced cancers are typically resistant to treatment, which leads to most experimental cancer immunotherapy approaches being tested against smaller tumors. In this study, we show that even late-stage, weakly immunogenic mouse B78 melanomas, with tumor volumes of 1500-2000 mm3, can be eradicated by a combined radio-immunotherapy regimen (CRIR) which includes local radiotherapy, intratumoral interleukin 12, slow-release systemic interleukin 2 and checkpoint blockade with anti-CTLA-4 antibody. Flow analysis of the tumors revealed a reduction in T regulatory (Treg) cells and an increase in CD8/Treg ratios following CRIR. T cell depletion did not prevent the rapid shrinkage of treated tumors, but suppressed regression of distant tumors. Cured mice developed immunological memory. These findings highlight the largely underappreciated efficacy of certain cancer immunotherapy regimens against large, late-stage tumors.
Embargo Period
1-11-2024
A combined radio-immunotherapy regimen eradicates late-stage melanoma in mice.
Moultrie, GA
Advanced cancers are typically resistant to treatment, which leads to most experimental cancer immunotherapy approaches being tested against smaller tumors. In this study, we show that even late-stage, weakly immunogenic mouse B78 melanomas, with tumor volumes of 1500-2000 mm3, can be eradicated by a combined radio-immunotherapy regimen (CRIR) which includes local radiotherapy, intratumoral interleukin 12, slow-release systemic interleukin 2 and checkpoint blockade with anti-CTLA-4 antibody. Flow analysis of the tumors revealed a reduction in T regulatory (Treg) cells and an increase in CD8/Treg ratios following CRIR. T cell depletion did not prevent the rapid shrinkage of treated tumors, but suppressed regression of distant tumors. Cured mice developed immunological memory. These findings highlight the largely underappreciated efficacy of certain cancer immunotherapy regimens against large, late-stage tumors.
Comments
Awarded PCOM South Georgia Research Day 2023 Best in Show.