UQ Centre for Clinical Research, The University of Queensland, Herston, Qld, Australia.
J Oral Pathol Med. 2013 Jan;42(1):37-46. doi: 10.1111/j.1600-0714.2012.01170.x. Epub 2012 May 29.
Oral squamous cell carcinomas (OSCC) often arise from dysplastic lesions. The role of cancer stem cells in tumour initiation is widely accepted, yet the potential existence of pre-cancerous stem cells in dysplastic tissue has received little attention. Cell lines from oral diseases ranging in severity from dysplasia to malignancy provide opportunity to investigate the involvement of stem cells in malignant progression from dysplasia. Stem cells are functionally defined by their ability to generate hierarchical tissue structures in consortium with spatial regulation. Organotypic cultures readily display tissue hierarchy in vitro; hence, in this study, we compared hierarchical expression of stem cell-associated markers in dermis-based organotypic cultures of oral epithelial cells from normal tissue (OKF6-TERT2), mild dysplasia (DOK), severe dysplasia (POE-9n) and OSCC (PE/CA P J15). Expression of CD44, p75(NTR), CD24 and ALDH was studied in monolayers by flow cytometry and in organotypic cultures by immunohistochemistry. Spatial regulation of CD44 and p75(NTR) was evident for organotypic cultures of normal (OKF6-TERT2) and dysplasia (DOK and POE-9n) but was lacking for OSCC (PE/CA PJ15)-derived cells. Spatial regulation of CD24 was not evident. All monolayer cultures exhibited CD44, p75(NTR), CD24 antigens and ALDH activity (ALDEFLUOR(®) assay), with a trend towards loss of population heterogeneity that mirrored disease severity. In monolayer, increased FOXA1 and decreased FOXA2 expression correlated with disease severity, but OCT3/4, Sox2 and NANOG did not. We conclude that dermis-based organotypic cultures give opportunity to investigate the mechanisms that underlie loss of spatial regulation of stem cell markers seen with OSCC-derived cells.
口腔鳞状细胞癌(OSCC)通常起源于发育不良病变。癌症干细胞在肿瘤起始中的作用已被广泛接受,但在发育不良组织中存在癌前干细胞的潜在可能性尚未得到关注。从发育不良到恶性的严重程度不同的口腔疾病的细胞系为研究干细胞在从发育不良到恶性进展中的作用提供了机会。干细胞的功能定义是它们与空间调节一起产生分层组织结构的能力。器官型培养物在体外很容易显示组织层次结构;因此,在这项研究中,我们比较了正常组织(OKF6-TERT2)、轻度发育不良(DOK)、重度发育不良(POE-9n)和 OSCC(PE/CA P J15)口腔上皮细胞真皮基器官型培养物中与干细胞相关的标记物的分层表达。通过流式细胞术在单层和免疫组织化学在器官型培养物中研究 CD44、p75(NTR)、CD24 和 ALDH 的表达。正常(OKF6-TERT2)和发育不良(DOK 和 POE-9n)器官型培养物中可见 CD44 和 p75(NTR)的空间调节,但 OSCC(PE/CA PJ15)衍生细胞中则缺乏。CD24 的空间调节不明显。所有单层培养物均表现出 CD44、p75(NTR)、CD24 抗原和 ALDH 活性(ALDEFLUOR®assay),并且随着疾病严重程度的增加,细胞群体异质性呈下降趋势。在单层培养物中,FOXA1 的表达增加和 FOXA2 的表达减少与疾病严重程度相关,但 OCT3/4、Sox2 和 NANOG 则没有。我们得出的结论是,真皮基器官型培养物为研究与 OSCC 衍生细胞中观察到的干细胞标记物空间调节丧失相关的机制提供了机会。