Immunodetection of cells with a CD44+/CD24- phenotype in canine mammary neoplasms

Abstract

BackgroundCancer stem cells (CSCs) are able to self-renew and to form metastases. Using flow cytometry, CSCs were detected in canine mammary tumors as cells CD44+ and CD24-. The aim of this study was to detect these CSCs by immunohistochemistry and correlate their frequency with canine mammary neoplasm grade and histopathological type.130 mammary neoplasm samples were selected from tissue blocks at the Department of Pathology at UNESP and classified according to (BJVP 4:153-180, [2011]). These samples were composed by adenomas, lymph node metastases, solid carcinomas grades II and III, tubular, papillary and carcinomas in mixed tumor grades I, II and III. Immunohistochemistry was performed with antibodies against CD44 and CD24. Linear regression was performed using Pearson’s correlation test.ResultsThe value at CD44 was positive and CD24 becomes zero was 46.75%. Cells with a CD44+/CD24- phenotype were detected in 40 out of 130 samples with an advantage of high grade tumors (II and III) and metastases among tubular, papillary and carcinomas in mixed tumors. In these samples, percentages of cells stained by CD44 and CD24 antibodies were 62.2% and 0%, respectively. Published reports usually correlate grade III tumors with the expression of CD44 but not with CD24 expression. Studies using flow cytometry have found CSC frequencies similar to those found in our study.ConclusionsImmunohistochemistry was found to be a reliable technique for the detection of CSCs in canine mammary neoplasms, and the frequency of these cells positively correlates with grades II and III tumors (poor prognosis).

CD44+/CD24– Cancer Stem Cells Are Associated With Higher Grade of Canine Mammary Carcinomas

“…The significance of CD44 as an individual marker has been examined previously in canine mammary tumors; its expression was associated with benign biological behavior and a noninfiltrative subtype in some studies, while others showed that CD44 expression correlated with aggressive histological features and tumor progression. [9][10][11] These discrepancies might be due to the different sample cohorts studied, as well as to the usage of different immunohistochemical scoring methods; thus, large sample sizes must be reanalyzed to draw firm conclusions. A recent in vitro study using cultured canine MC cells indicated that CD44 is related more to proliferation rather than as a CSC marker per se.…”

“…Specifically, spheroids derived from canine MC cell lines in an in vitro CSC model have high CD44 expression but are negative or low for CD24 expression. 3 A previous study reported that the CD44þ/CD24-phenotype was detectable in archival tissues; 10 however, the molecular and histopathological features associated with those markers remain to be elucidated. It is suggested that hormone receptor (HR) status (specifically, the estrogen receptor [ER] and/or progesterone receptor [PR]) and the triple-negative (TN) subtype (ER, PR, and human epidermal growth factor receptor 2 [HER2] negative) are associated with aggressive tumor types in canine MCs.…”

Salinomycin inhibits canine mammary carcinoma in vitro by targeting cancer stem cells

“…In canines, mammary CSCs are associated with a higher grade of carcinoma and poor prognosis (7,8). In addition, canine mammary CSCs are typically resistant to common cancer therapies (9,15).…”

“…Increasing evidence supports the presence of CSCs in canine mammary tumors (7)(8)(9)(10). Human breast CSCs are primarily characterized by cluster of differentiation (CD)44 + /CD24 -/low cells, sphere formation and active aldehyde dehydrogenase (11).…”

“…-/low phenotype is also a specific maker of CSCs in canine mammary carcinoma (8,9,12). Another feature of CSCs is overexpression of stem cell-associated genes, including octamer-binding transcription factor 4 (Oct-4) and sex determining region Y-box 2 (Sox-2) (10).…”