TAM Infiltration Differences in “Tumor-First” and “ZHENG-First” Models and the Underlying Inflammatory Molecular Mechanism in Pancreatic Cancer

Background: Syndrome (ZHENG in Chinese) in traditional Chinese medicine (TCM) refers to the intrinsic characteristics of a pathological process at a certain stage; these characteristics are influenced by internal and external environments and reveal the nature of a disease. Proper syndrome differentiation is the basic principle that guides clinical treatment. Objective: To have a good understanding of tumor progression and the different mechanisms related to ZHENG that have occurred before and after tumor development and to explore the valid evaluation criteria of different pancreatic cancer syndromes to improve the guiding role of TCM syndrome differentiation in pancreatic cancer treatment. Methods: In this study, we established mouse subcutaneous pancreatic cancer models, namely, Con (control), Pi-Xu (Spleen-Deficiency), Shi-Re (Dampness-Heat), and Xue-Yu (Blood-Stasis). Then, for the first time, we compared the different effects of “ZHENG-first” (referring to a different disease status that occurred before tumor occurrence) and “Tumor-first” (referring to the change in the tumor microenvironment and the resulting changes in the state of the body) conditions on tumor progression and evaluated the associated molecular mechanisms. Results: We found that tumor growth in the “ZHENG-first” and “Tumor-first” conditions was different. In the “Tumor-first” model, the tumor growth in the Pi-Xu group was faster than that in the other groups. However, in the “ZHENG-first” model, the tumor growth trend was most obvious in the Shi-Re group. There was a difference in tumor-associated macrophage infiltration between the 2 models. The expression levels of the inflammatory cytokines IL-6, IL-10, and P-STAT3 were also differentially altered. Conclusion: The emergence of ZHENG conditions before or after tumor occurrence had different impacts on pancreatic cancer development, and these impacts may be related to differences in tumor-associated macrophage infiltration and the involved inflammatory cytokines IL-6, IL-10, and P-STAT3. The study results uncovered the molecular basis of syndrome differentiation in pancreatic cancer progression, which might provide more specific guidance for TCM treatment of pancreatic cancer.