Tissue engineered cancer metastases as cancer vaccine to improve cancer immunotherapy

Radiotherapy is often used to improve cancer immunotherapy outcomes. While there are both pre-clinical and clinical data supporting this approach, there are also significant challenges. One key challenge is that not all patients have tumors that can be easily treated with radiotherapy due to potential normal tissue toxicity and prior treatment. In addition, it is difficult to control the tumor microenvironment to promote the immune response after radiosurgery. To overcome these challenges, we hypothesize that we can engineer cancer metastasis and utilize irradiated engineered tumor cells as a personalized cancer vaccine to improve cancer immunotherapy. Herein, we report the development of engineered lung metastasis using decellularized rat lung tissue. Using the B16F10 melanoma tumor model, we showed that radiotherapy-treated engineered metastases are highly effective in improving cancer immunotherapy responses and more effective than in vivo metastasis. Our work has demonstrated the potential of applying tissue engineering to cancer immunotherapy. Statement of significance: Combination of radiation and immunotherapy are an effective way to treat metastasis. Despite their success, long term response still remains low. Tumor microenvironment evading the immune response, normal tissue toxicity to radiation and inaccessibility to radiosurgery are some of the limitations. To overcome these challenges, in this paper we present with data supporting the use of high dose radiation treated ex vivo engineered B16F10 metastasis model using decellularized lung scaffolds. These engineered metastases closely mimic the in vivo tumors and when given into tumor bearing mice along with check point inhibitors are highly effective in improving the cancer immunotherapy response.