与 HPV 阴性的头颈部鳞状细胞癌相比，体外实验中 5-FU 和多西紫杉醇导致 p16 阳性的鳞状细胞癌细胞中β-连环蛋白和 c-KIT 的表达出现意外改变。

Unexpected alteration of β-catenin and c-KIT expression by 5-FU and docetaxel in p16-positive squamous cell carcinoma compared to HPV-negative HNSCC cells in vitro.

机构信息

Department of Otorhinolaryngology, Head and Neck Surgery, Medical Faculty of Mannheim, University of Heidelberg, Mannheim, Germany.

出版信息

Anticancer Res. 2013 Jun;33(6):2457-65.

PMID:23749896

Abstract

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common type of cancer worldwide. In several tumour entities, the tyrosine kinase receptor c-KIT is associated with tumour transformation in the epithelial tissue in cases of aberrant expression. Furthermore, tumour development and dissemination are a result of dysregulated cellular pathways such as the WNT/β-catenin pathway. β-Catenin is a multifunctional protein within the canonical WNT signalling pathway and a pivotal factor for the stabilization of cell-cell interactions. In malignant tissues, β-catenin triggers tumour proliferation and progression. The aim of this study is to investigate the expression patterns of c-KIT and β-catenin in human papillomavirus-negative and p16-positive SCC and to evaluate the chemosensitivity of the tumour cells to the chemotherapeutical agents docetaxel and 5-fluorouracil (5-FU).

MATERIALS AND METHODS

We incubated the tumour cell lines with docetaxel (5 μmol/ml) and 5-FU (1 μmol/ml) and detected β-catenin and c-KIT by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) after 48, 72, 120, 192 and 240 h.

RESULTS

We found a reliable trend towards decreased β-catenin expression levels in p16-positive and p16-negative tumour cell lines when incubated with docetaxel, in addition to induced apoptotic effect. At best, 5-FU had a slight influence on the alteration of the expression of β-catenin. Dose escalation of docetaxel and 5-FU had no statistically significant effect on the expression of β-catenin or c-KIT. In HPV-negative HNSCC, a reduced expression level of β-catenin and c-KIT was detected in an incubation period-dependent manner. p16-transformed SCC (CERV196) cells were characterized by a reduced susceptibility to docetaxel induced alteration of β-catenin expression.

CONCLUSION

We were unable to confirm the clinically-substantiated increased chemosensitivity of p16-positive tumour cells in vitro. Extended studies and clinical trials are needed to investigate these findings further in HPV-associated HNSCC.

摘要

背景

头颈部鳞状细胞癌（HNSCC）是全球第六大常见癌症。在几种肿瘤实体中，酪氨酸激酶受体 c-KIT 在上皮组织中异常表达时与肿瘤转化有关。此外，肿瘤的发生和转移是细胞通路失调的结果，如 WNT/β-catenin 通路。β-catenin 是经典 WNT 信号通路中的一种多功能蛋白，是稳定细胞间相互作用的关键因素。在恶性组织中，β-catenin 触发肿瘤增殖和进展。本研究旨在探讨 c-KIT 和β-catenin 在人乳头瘤病毒阴性和 p16 阳性 SCC 中的表达模式，并评估肿瘤细胞对化疗药物多西紫杉醇和 5-氟尿嘧啶（5-FU）的化疗敏感性。

材料和方法

我们用多西紫杉醇（5μmol/ml）和 5-FU（1μmol/ml）孵育肿瘤细胞系，并在 48、72、120、192 和 240 h 后通过免疫组化和酶联免疫吸附试验（ELISA）检测β-catenin 和 c-KIT。

结果

我们发现，在用多西紫杉醇孵育时，p16 阳性和 p16 阴性肿瘤细胞系的β-catenin 表达水平呈可靠下降趋势，此外还具有诱导凋亡作用。5-FU 对β-catenin 表达的改变影响最小。多西紫杉醇和 5-FU 的剂量递增对β-catenin 或 c-KIT 的表达没有统计学意义。在 HPV 阴性的 HNSCC 中，β-catenin 和 c-KIT 的表达水平呈孵育时间依赖性降低。p16 转化的 SCC（CERV196）细胞对多西紫杉醇诱导的β-catenin 表达改变的敏感性降低。