Featherston Therese, Marsh Reginald Walter, van Schaijik Bede, Brasch Helen D, Tan Swee T, Itinteang Tinte
Gillies McIndoe Research Institute, Wellington, New Zealand.
University of Auckland, Auckland, New Zealand.
Front Med (Lausanne). 2017 Jul 20;4:100. doi: 10.3389/fmed.2017.00100. eCollection 2017.
We have previously demonstrated the putative presence of two cancer stem cell (CSC) subpopulations within moderately differentiated oral tongue squamous cell carcinoma (MDOTSCC), which express components of the renin-angiotensin system (RAS). In this study, we investigated the expression and localization of cathepsins B, D, and G in relation to these CSC subpopulations within MDOTSCC.
3,3-Diaminobenzidine (DAB) and immunofluorescent (IF) immunohistochemical (IHC) staining was performed on MDOTSCC samples to determine the expression and localization of cathepsins B, D, and G in relation to the CSC subpopulations. NanoString mRNA analysis and colorimetric hybridization (CISH) were used to study their transcripts expression. Enzyme activity assays were performed to determine the activity of these cathepsins in MDOTSCC.
IHC staining demonstrated expression of cathepsins B, D, and G in MDOTSCC. Cathepsins B and D were localized to CSCs within the tumor nests, while cathepsin B was localized to the CSCs within the peri-tumoral stroma, and cathepsin G was localized to the tryptase phenotypic mast cells within the peri-tumoral stroma. NanoString and CISH mRNA analyses confirmed transcription activation of cathepsins B, D, and G. Enzyme activity assays confirmed active cathepsins B and D, but not cathepsin G.
The presence of cathepsins B and D on the CSCs and cathspsin G on the phenotypic mast cells suggest the presence of bypass loops for the RAS which may be a potential novel therapeutic target for MDOTSCC.
我们之前已证实在中度分化的口腔舌鳞状细胞癌（MDOTSCC）中可能存在两个癌症干细胞（CSC）亚群，它们表达肾素 - 血管紧张素系统（RAS）的成分。在本研究中，我们调查了组织蛋白酶B、D和G在MDOTSCC中与这些CSC亚群相关的表达和定位。
对MDOTSCC样本进行3,3 - 二氨基联苯胺（DAB）和免疫荧光（IF）免疫组织化学（IHC）染色，以确定组织蛋白酶B、D和G与CSC亚群相关的表达和定位。使用NanoString mRNA分析和比色原位杂交（CISH）来研究它们的转录本表达。进行酶活性测定以确定这些组织蛋白酶在MDOTSCC中的活性。
免疫组织化学染色显示MDOTSCC中存在组织蛋白酶B、D和G。组织蛋白酶B和D定位于肿瘤巢内的CSC，而组织蛋白酶B定位于肿瘤周围基质内的CSC，组织蛋白酶G定位于肿瘤周围基质内的类胰蛋白酶表型肥大细胞。NanoString和CISH mRNA分析证实了组织蛋白酶B、D和G的转录激活。酶活性测定证实了组织蛋白酶B和D具有活性，但组织蛋白酶G没有活性。
CSC上存在组织蛋白酶B和D以及表型肥大细胞上存在组织蛋白酶G表明RAS存在旁路环，这可能是MDOTSCC潜在的新型治疗靶点。
