Chemoradiotherapy-Induced CD4+ and CD8+ T-Cell Alterations to Predict Patient Outcomes in Esophageal Squamous Cell Carcinoma

Purpose and Objectives: Chemoradiotherapy (CRT) is an important component of treatment for patients with locally advanced esophageal squamous cell carcinoma (ESCC). Recent research findings support the role of CRT in activating an anti-tumor immune response. However, predictors of CRT efficacy are not fully understood. The aim of this study was to measure CRT-induced changes to lymphocyte subpopulations and to evaluate the prognostic value of lymphocyte alterations for patients with ESCC.Materials and Methods: In total, this pilot study enrolled 64 patients with ESCC who received neo-adjuvant CRT or definitive CRT. Peripheral blood samples were collected before and during treatment and were analyzed by flow cytometry for CD19, CD3, CD4, CD8, CD56, and CD16. Relationships between lymphocyte subset alterations and overall survival (OS) and progression-free survival (PFS) were evaluated using the log-rank test and a Cox regression model.Results: The median follow-up period was 11.8 months (range, 4.0–20.2 months). Compared to pre-treatment specimens, post-treatment blood samples had decreased proportions of CD19+ B-cells and increased proportions of CD3+ and CD8+ T-cells (all P < 0.05). Univariate and multivariate analysis showed that increased CD4+ T-cell ratios after CRT independently predicted superior PFS (hazard ratio [HR] = 0.383; 95% confidence interval [CI] = 0.173–0.848, P = 0.017) and that increased CD8+ T-cell ratios predicted improved OS (HR = 0.258; 95% CI = 0.083–0.802, P = 0.019). Patients with both increased CD4+ and CD8+ ratios had a superior PFS and OS, compared to patients with an increased CD4+ ratio only or CD8+ ratio only or neither (1-year PFS rate 63 vs. 25%, 1-year OS rate 80 vs. 62%, P = 0.005 and 0.025, respectively).Conclusions: CRT-induced increases in CD4+ and CD8+ T-cell ratios are reliable biomarker predictors of survival in patients with ESCC

NS1-binding protein radiosensitizes esophageal squamous cell carcinoma by transcriptionally suppressing c-Myc

Abstract Background Cisplatin-based chemotherapy with concurrent radiotherapy is a standard treatment for advanced esophageal squamous cell carcinoma (ESCC). NS1-binding protein (NS1-BP), a member of the BTB-kelch protein family, has been shown to inhibit the proliferation of Hela cells by suppressing c-Myc. In the present study, we examined the potential function role of NS1-BP expression in ESCC, and particularly, the sensitivity of ESCC to radiotherapy. Methods NS1-BP expression was examined using immunohistochemistry in two cohorts (n = 98 for the training cohort; n = 46 for independent validation cohort) of ESCC patients receiving cisplatin-based chemotherapy and concurrent radiotherapy. Normal esophageal mucosal tissue blocks were used as a control. We also conducted a series of in vitro and in vivo experiments to examine the potential effects of over-expressing NS1-BP on ESCC cells, and particularly their sensitivity to ionizing irradiation. Results In the training cohort, NS1-BP downregulation was observed in 59% (85/144) of the ESCC specimens. NS1-BP downregulation was associated with chemoradiotherapeutic resistance and shorter disease-specific survival (DSS) in both the training and validation cohorts. Over-expressing NS1-BP in cultured ESCC cells substantially increased the cellular response to irradiation both in vitro and in vivo. NS1-BP also significantly enhanced IR-induced apoptosis, and abrogated IR-induced G2/M cell-cycle arrest and ATM/Chk1 phosphorylation. Immunoprecipitation assays indicated that NS1-BP could interact with c-Myc promoter regions to inhibit its transcription. In ESCC tissues, c-Myc expression was inversely correlated with NS1-BP levels, and was associated with a shorter DSS. Conclusions Our findings highlight the role and importance of NS1-BP in radiosensitivity of ESCC. Targeting the NS1-BP/c-Myc pathway may provide a novel therapeutic strategy for ESCC