DIFFERENCES IN STROMAL FEATURES AND CYTOKINE PRODUCTION IN HPV+ AND HPV− OPSCCS ARE ASSOCIATED WITH CLINICAL OUTCOME

Background Tumor cells communicate with many other cells in their microenvironment, aiding progression and spread of the tumors. Cytokines play an important role in the tumor-microenvironment communication, enhancing cancer cell invasion and metastasis. In the oropharynx, human papilloma virus–positive (HPV+) and human papilloma virus–negative (HPV−) carcinomas have a very different clinical course and prognosis. Objective To investigate whether differences in cytokines involved in tumor cell-fibroblast communication could explain the differences in oropharyngeal squamous cell carcinoma (OPSCC) subtypes and to assess the influence of such stromal and cytokine biomarkers on patient survival in OPSCC tumor microarrays. Results A cytokine multiplex array system was utilized to measure the production of 87 cytokines by normal tonsillar fibroblasts and cancer-associated fibroblasts after stimulation with HPV+ or HPV− OPSCC media for 24 hours. A subset of the cytokine profile including IL-6, IL‐8, CCL2, OPN, and KLK6 was significantly upregulated in the fibroblasts during or after HPV− media incubation compared to HPV+ media. Interactive co-culture of HPV+ or HPV− cancer cells with normal tonsillar fibroblasts or cancer-associated fibroblasts validate these results: CCL2, IL-6, and OPN enzyme-linked immunosorbent assay levels were significantly higher in the HPV− co-cultures than in the HPV+ co-cultures. To identify the source of OPN in the co-culture system, we have shown that OPN upregulation is primarily in OPSCC cells, not fibroblasts. In the OPSCC tumor microarrays, high SMA expression in HPV+ OPSCC correlated with overall survival (P Conclusions We have demonstrated reciprocal crosstalk between OPSCC and fibroblasts involving a subset of cytokines, with stroma effects on clinical outcome.