RNAseq of murine MB49 tumors - WT and gal-9-KO - grown on C57BL/6 syngenic mice through serial transplantations
A number of studies have reported evidence of positive or negative contributions of galectin-9 (gal-9) to human and experimental malignancies. Some clinical observations and in vitro experiments suggest that cell-associated gal-9 has anti-metastatic effects. On the other hand, extra-cellular gal-9 consistently enhances tumor immune escape. So far, all animal studies on this subject have been focused on gal-9 released by infiltrating cells, without paying attention to gal-9 released by malignant cells. To address this issue, we derived by gene editing, isogenic clones - either positive or negative for gal-9 - from the MB49 murine bladder carcinoma cell line. A progressive reduction of tumor growth was observed when gal-9-KO cells were subjected to serial transplantations into syngenic mice but not into nude mice thus accounting the tumor growth reduction in syngenic mice to a better immune response. Tumor fragments were collected from WT and KO tumors at different steps of the experiment : 2nd growth cycle (WT = 5 samples ; KO = 6 samples ) ; 3rd growth cycle (WT = 5 samples ; KO = 7 samples) ; 4th growth cycle (WT = 4 samples ; KO = 3 samples), in order to study the differences between WT and KO tumors through the serial transplantations, by RNAseq analysis.