CD68+ Macrophage Infiltration Associates With Poor Outcome of HPV Negative Oral Squamous Carcinoma Patients Receiving Radiation: Poly(I:C) Enhances Radiosensitivity of CAL-27 Cells but Promotes Macrophage Recruitment Through HMGB1.

Dan Ai,Zhaodi Nan,Yu Dou,Chao Ma,Huayang Wang,Ketao Wang,Wanye Tan,Lin Zhang,Wenjuan Gao,Shaohua Liu,Jintang Sun,Xun Qu,Zuoqing Dong,Lei Zhao,Bingfeng Song,Jia Liu,Qianqian Shao

doi:10.3389/fonc.2021.740622

Abstract

Patients with human papillomavirus (HPV) negative oral squamous cell carcinoma (OSCC) generally have poor clinical outcomes and worse responses to radiotherapy. It is urgent to explore the underlining mechanisms of the distinct prognoses between HPV negative and HPV positive OSCC and to develop effective therapy strategy to increase the survival rate of HPV negative OSCC patients. We conducted a retrospective cohort of 99 resected OSCC patients to evaluate the prognosis of HPV negative and HPV positive OSCC patients receiving radiation or not. We further addressed the association of CD68+ macrophage infiltration with HPV status and the effects on survival of OSCC patients. We also used the TCGA-OSCC cohort for further verification. Based on the cohort study, we applied a synthetic dsRNA polymer, polyriboinosinic-polyribocytidylic acid (poly(I:C)), on CAL-27 (HPV negative OSCC cells). We co-cultured its condition medium with THP-1 derived macrophage and examined the cytokines and macrophage migration. We found that high CD68+ macrophage infiltration associated with poor overall survival in HPV negative OSCC patients receiving radiation. In vitro, poly(I:C) could induce apoptosis and enhance the radiosensitivity, but increase macrophage recruitment. Targeting HMGB1 could inhibit IL-6 induction and macrophage recruitment. Our findings indicated that CD68+ macrophage might play an important role in the outcomes of HPV negative OSCC patients receiving radiation. Our findings also suggested that radiation combined poly(I:C) might be a potential therapy strategy to increase the radiation response and prognosis of HPV negative OSCC. Notably, HMGB1 should be targeted to inhibit macrophage recruitment and enhance overall therapy effects.

Highlights

Oral cancer, the most common head and neck cancer (HNC), accounts for more than 300,000 new cases of and 170,000 deaths occur worldwide per year [1]
Infiltration deconvolved using CIBERSOFT or EPIC and prognosis was observed in all Oral squamous cell carcinoma (OSCC) patients (Supplementary Figures S5, S6 and Supplementary Tables S13–S16), human papillomavirus (HPV) negative OSCC subgroup (Supplementary Figures S7, S8 and Supplementary Tables S17–S20), or HPV positive OSCC subgroup. These results suggested that CD68+ macrophage might play an important role in the distinct prognoses of HPV negative and positive OSCC patients receiving radiation or not
Neutralizing High Mobility Group Box 1 (HMGB1) significantly inhibited the recruitment of THP-1-derived macrophages by in response to CAL-27 conditioned medium (CM) (Figures 7F, G). These results suggested that poly(I:C) and radiation stimulated CAL-27 CM promoted macrophage recruitment could be inhibited by targeting HMGB1

Summary

Introduction

The most common head and neck cancer (HNC), accounts for more than 300,000 new cases of and 170,000 deaths occur worldwide per year [1]. Patients with human papillomavirus (HPV) negative OSCC generally have a poor prognosis and worse response to radiotherapy or chemoradiotherapy [3,4,5]. Macrophage polarization has been reported to increase radiosensitivity in HPV positive HNC [14]. It is not clear whether macrophage infiltration associates with response to radiotherapy and survival of HPV negative and HPV positive OSCC. Hanoteau et al reported that immune modulation of tumor microenvironment enhanced response to chemoradiotherapy of HNC [15]. We hypothesized that TLR agonists might modulate tumor microenvironment and enhance the radiosensitivity of HPV negative OSCC, the majority population of OSCC

Methods

Results

Conclusion