Vaccination With Mitoxantrone-Treated Primary Colon Cancer Cells Enhances Tumor-Infiltrating Lymphocytes and Clinical Responses in Colorectal Liver Metastases

摘要

BackgroundColorectal cancer remains a leading cause of cancer-related mortality worldwide. Metastases to the liver are often present at initial presentation and will form in most patients during their course of disease. We have previously demonstrated that enhanced trafficking and activation of tumor-infiltrating lymphocytes in colorectal liver metastases (CRLM) may improve antitumor immune responses. Thus, development of novel mechanisms to increase lymphocyte infiltration and activation are needed to improve patient outcomes. MethodsCT26 murine colorectal cancer cells were treated with physiologic levels of the potent inducer of immunogenic cell death mitoxantrone (MTX). Anin situvaccine was created with treated cells in an established model of CRLM. Cells were evaluated by flow cytometry for cell cycle evaluation and calreticulin expression. Splenic and tumor-infiltrating lymphocytes were isolated for phenotypic studies. ResultsMTX-treatment of colon cancer cells resulted in a sub-G1 peak, inhibition of G1 cell cycle progression, and increased G2/M cell fractions while simultaneously increasing dynamic exposure of calreticulin on the cell surface (P?