RNAseq transcriptome of draining lymph node (LN) and tumor of MC38 murine tumors treated with cryoablation and chitosan/IL-12

Focal ablation technologies are routinely used in the clinical management of inoperable solid tumors but often result in incomplete ablations leading to high recurrence rates. Adjuvant therapies capable of safely eliminating residual tumor cells are therefore of great clinical interest. Interleukin 12 (IL-12) is a potent antitumor cytokine that can be localized intratumorally through coformulation with viscous biopolymers including chitosan (CS) solutions. The objective of this research was to determine if localized immunotherapy with CS/IL-12 could prevent tumor recurrence after cryoablation (CA). Tumor recurrence, overall survival, and protective immunity were assessed. Systemic immunity was evaluated in spontaneously metastatic and bilateral tumor models. Temporal bulk RNA sequencing was performed on tumor and draining lymph node samples. In multiple murine tumor models, the addition of CS/IL-12 to CA reduced recurrence rates by 30–55%. Altogether, this cryo-immunotherapy induced com..., MC38 tumors were implanted subcutaneously in the right flanks of female C57BL/6 mice as described above. When tumor volumes measured between 200–500 mm3, CA was performed and CS/IL-12 was intratumorally injected within an hour after CA. Mice were euthanized 3 days and 7 days post-ablation to harvest tumor tissues and tumor-draining inguinal lymph nodes (dLNs). To obtain cell suspensions, dLNs were homogenized through 40 µm mesh strainers with complete T cell media. Tumor tissues were first minced into approximately 0.5 cm squares before treatment with 5X Triple Enzyme Solution (collagenase type IV 10 mg/ml, hyaluronidase 1 mg/ml, and DNase 20,000 units final concentration in Hank’s Buffered Saline Solution) for 30 minutes at 37°C with magnetic bar stirring. The resulting homogenate was filtered through a 70 µm mesh strainer into a clean tube to achieve the final cell suspension.
Total RNA was extracted from the cell suspension using the GeneJET RNA Purification Kit (ThermoFisher cat #K0..., Excel file format, or .csv reader