Gehrmann Mathias, Specht Hanno M, Bayer Christine, Brandstetter Markus, Chizzali Barbara, Duma Marciana, Breuninger Stephanie, Hube Kathrin, Lehnerer Sophie, van Phi Valerie, Sage Eva, Schmid Thomas E, Sedelmayr Michael, Schilling Daniela, Sievert Wolfgang, Stangl Stefan, Multhoff Gabriele
Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Radiat Oncol. 2014 Jun 9;9:131. doi: 10.1186/1748-717X-9-131.
Tumor but not normal cells frequently overexpress heat shock protein 70 (Hsp70) and present it on their cell surface (mHsp70) from where it can be actively released. Therefore, membrane (mHsp70) and soluble Hsp70 (sHsp70) were investigated as potential tumor biomarkers and for monitoring the outcome of radiation therapy.
Biopsies and blood were collected from patients with squamous cell carcinoma of the head and neck (SCCHN) at different time points (before, during therapy and in the follow-up period). Hsp70 membrane expression was determined on single cell suspensions of tumor biopsies and reference tissues by flow cytometry, sHsp70 protein and antibody levels were determined in the serum of patients and healthy donors by ELISA and NK cell markers that are related to the presence of sHsp70 were analyzed in the patient's peripheral blood lymphocytes (PBL).
Tumor biopsies exhibited significantly increased mHsp70 expression levels compared to the reference tissue. Soluble Hsp70 levels were significantly higher in SCCHN patients compared to healthy human volunteers and high mHsp70 expression levels on tumor cells were associated with high sHsp70 levels in the serum of patients. Following surgery and radiotherapy sHsp70 levels in patients dropped in patients without tumor relapse in the follow-up period. In contrast to sHsp70 protein, anti-Hsp70 antibody levels remained nearly unaltered in the serum of SCCHN patients before and after therapy. Furthermore, sHsp70 protein but not anti-Hsp70 antibody levels were found to be associated with the tumor volume in SCCHN patients before start of therapy. The expression densities of the activatory NK cell markers CD56, CD94, NKG2D, NKp30, Nkp44, and NKp46 differed in patients following therapeutic intervention. A significant increase in the density of NKG2D was observed in SCCHN patients in the follow-up period after surgery and radiotherapy.
We suggest sHsp70 as a potential biomarker for detecting tumors and for monitoring the clinical outcome of radiotherapy in SCCHN patients.
肿瘤细胞而非正常细胞常常过度表达热休克蛋白70（Hsp70），并将其呈递于细胞表面（mHsp70），且能从该部位主动释放。因此，对膜型（mHsp70）和可溶性Hsp70（sHsp70）作为潜在肿瘤生物标志物以及监测放射治疗效果进行了研究。
在不同时间点（治疗前、治疗期间及随访期）采集头颈部鳞状细胞癌（SCCHN）患者的活检组织和血液。通过流式细胞术测定肿瘤活检组织和对照组织单细胞悬液中Hsp70的膜表达，采用酶联免疫吸附测定法（ELISA）测定患者及健康供体血清中的sHsp70蛋白和抗体水平，并分析患者外周血淋巴细胞（PBL）中与sHsp70存在相关的自然杀伤（NK）细胞标志物。
与对照组织相比，肿瘤活检组织中mHsp70表达水平显著升高。与健康志愿者相比，SCCHN患者血清中可溶性Hsp70水平显著更高，且肿瘤细胞上高mHsp70表达水平与患者血清中高sHsp70水平相关。在随访期无肿瘤复发的患者中，手术和放疗后患者血清中sHsp70水平下降。与sHsp70蛋白不同，SCCHN患者治疗前后血清中抗Hsp70抗体水平几乎未改变。此外，在治疗开始前，SCCHN患者中sHsp70蛋白而非抗Hsp70抗体水平与肿瘤体积相关。治疗干预后患者中活化NK细胞标志物CD56、CD94、NKG2D、NKp30、Nkp44和NKp46的表达密度有所不同。在手术和放疗后的随访期，SCCHN患者中NKG2D密度显著增加。
我们建议将sHsp70作为检测肿瘤以及监测SCCHN患者放射治疗临床效果的潜在生物标志物。
