Organotypic culture of normal, dysplastic and squamous cell carcinoma-derived oral cell lines reveals loss of spatial regulation of CD44 and p75 NTR in malignancy.
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.
UQ Centre for Clinical Research, The University of Queensland, Herston, Qld, Australia.
Andrew J
AJ
Dalley
Ahmad A
AA
AbdulMajeed
Zee
Z
Upton
Camile S
CS
Farah
D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D051927:CD24 Antigen / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D018929:Cell Culture Techniques; D002460:Cell Line; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D005434:Flow Cytometry; D051541:Hepatocyte Nuclear Factor 3-alpha / Q000378:metabolism; D051542:Hepatocyte Nuclear Factor 3-beta / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D053535:Keratin-13 / Q000378:metabolism; D053539:Keratin-19 / Q000378:metabolism; D009061:Mouth Mucosa / Q000378:metabolism / Q000473:pathology; D009062:Mouth Neoplasms / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011230:Precancerous Conditions / Q000378:metabolism*; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*
D051927:CD24 Antigen; C497483:CD44 protein, human; C496499:FOXA1 protein, human; C496502:FOXA2 protein, human; D051541:Hepatocyte Nuclear Factor 3-alpha; D018960:Hyaluronan Receptors; D053535:Keratin-13; D053539:Keratin-19; C484065:NGFR protein, human; D009419:Nerve Tissue Proteins; D017475:Receptors, Nerve Growth Factor; D051542:Hepatocyte Nuclear Factor 3-beta; D000444:Aldehyde Dehydrogenase