Featherston Therese, Yu Helen H, Dunne Jonathan C, Chibnall Alice M, Brasch Helen D, Davis Paul F, Tan Swee T, Itinteang Tinte
Gillies McIndoe Research Institute , Wellington , New Zealand.
Gillies McIndoe Research Institute, Wellington, New Zealand; Wellington Regional Plastic, Maxillofacial and Burns Unit, Wellington, New Zealand.
Front Surg. 2016 Sep 27;3:52. doi: 10.3389/fsurg.2016.00052. eCollection 2016.
We have recently identified and characterized cancer stem cell (CSC) subpopulations within moderately differentiated buccal mucosal squamous cell carcinoma (MDBMSCC). We hypothesized that these CSCs express components of the renin-angiotensin system (RAS).
3,3'-Diaminobenzidine (DAB) immunohistochemical (IHC) staining was performed on formalin-fixed paraffin-embedded MDBMSCC samples to investigate the expression of the components of the RAS: (pro)renin receptor (PRR), angiotensin converting enzyme (ACE), angiotensin II receptor 1 (ATIIR1), and angiotensin II receptor 2 (ATIIR2). NanoString mRNA gene expression analysis and Western Blotting (WB) were performed on snap-frozen MDBMSCC samples to confirm gene expression and translation of these transcripts, respectively. Double immunofluorescent (IF) IHC staining of these components of the RAS with the embryonic stem cell markers OCT4 or SALL4 was performed to demonstrate their localization in relation to the CSC subpopulations within MDBMSCC.
DAB IHC staining demonstrated expression of PRR, ACE, ATIIR1, and ATIIR2 in MDBMSCC. IF IHC staining showed that PRR was expressed by the CSC subpopulations within the tumor nests, the peri-tumoral stroma, and the endothelium of the microvessels within the peri-tumoral stroma. ATIIR1 and ATIIR2 were localized to the CSC subpopulations within the tumor nests and the peri-tumoral stroma, while ACE was localized to the endothelium of the microvessels within the peri-tumoral stroma. WB and NanoString analyses confirmed protein expression and transcription activation of PRR, ACE, and ATIIR1, but not of ATIIR2, respectively.
Our novel findings of the presence and localization of PRR, ACE, ATIIR1, and potentially ATIIR2 to the CSC subpopulations within MDBMSCC suggest CSC as a therapeutic target by modulation of the RAS.
我们最近在中度分化的颊黏膜鳞状细胞癌（MDBMSCC）中鉴定并表征了癌症干细胞（CSC）亚群。我们推测这些癌症干细胞表达肾素 - 血管紧张素系统（RAS）的成分。
对福尔马林固定石蜡包埋的MDBMSCC样本进行3,3'-二氨基联苯胺（DAB）免疫组织化学（IHC）染色，以研究RAS成分的表达：（前）肾素受体（PRR）、血管紧张素转换酶（ACE）、血管紧张素II受体1（ATIIR1）和血管紧张素II受体2（ATIIR2）。对速冻的MDBMSCC样本进行NanoString mRNA基因表达分析和蛋白质印迹（WB），分别以确认这些转录本的基因表达和翻译情况。对RAS的这些成分与胚胎干细胞标志物OCT4或SALL4进行双重免疫荧光（IF）IHC染色，以证明它们在MDBMSCC内与CSC亚群的定位关系。
DAB IHC染色显示MDBMSCC中存在PRR、ACE、ATIIR1和ATIIR2的表达。IF IHC染色表明，PRR在肿瘤巢内、肿瘤周围基质以及肿瘤周围基质内微血管的内皮中的CSC亚群中表达。ATIIR1和ATIIR2定位于肿瘤巢内和肿瘤周围基质中的CSC亚群，而ACE定位于肿瘤周围基质内微血管的内皮。WB和NanoString分析分别证实了PRR、ACE和ATIIR1的蛋白质表达和转录激活，但未证实ATIIR2的情况。
我们关于PRR、ACE、ATIIR1以及可能的ATIIR2在MDBMSCC内CSC亚群中的存在和定位的新发现表明，CSC可作为通过调节RAS进行治疗的靶点。
