Verification of ALDH Activity as a Biomarker in Colon Cancer Stem Cells-Derived HT-29 Cell Line

Abstract

Background:Recent evidence has suggested that epithelial cancers including colorectal cancer (CRC) have driven by a small population of self-renewing, multi-potent cells termed cancer stem cells (CSCs) which could be responsible for recurrence of cancer. Aldehyde dehydrogenase 1 (ALDH1) activity has used as a functional stem cell biomarker to isolate CSCs in different cancers such as colorectal cancer.Objectives:The main aim of this research was to determine the utility of ALDH1 activity along with CD44 and EPCAM in identifying stem cell-like cells in human HT-29 colonic adenocarcinoma cell line.Materials and Methods:In this experimental study, colon CSCs biomarkers including CD44, EPCAM and ALDH1 in colonospheres and parent cells have analyzed by flow cytometry. The expression levels of stemness genes in spheroid and parental cells have investigated using SYBR Green real-time PCR. In addition, in vivo xenografts assay has performed to determine tumorigenic potential of tumor spheroid cells in nude mice.Results:According to results, over 92% of spheroids were CD44+/EpCAM+, while parent cells only have expressed 38% of CD44/EpCAM biomarkers (P < 0.001). Controversially, ALDH activity was about 2-fold higher in the parent cells than spheroid cells (P < 0.05). In comparison with the parental cells, expression levels of ‘‘stemness’’ genes, like Sox2, Oct4, Nanog, C-myc, and Klf4 have significantly increased in colonosphere cells (P < 0.05). Further, administration of 2500 spheroids could be sufficient to initiate tumor growth in nude mice, while 1x106 of parental cells has needed to form tumor.Conclusions:For the first time, we have shown that colonospheres with low ALDH1 activity has indicated increased tumorigenic potential and stemness properties. So, it hasn’t seemed that ALDH1 could become a useful biomarker to identify CSCs population in HT-29 cell line.

Lgr5+CD44+EpCAM+ Strictly Defines Cancer Stem Cells in Human Colorectal Cancer

“…2A). Previous studies have demonstrated correlations between the maintenance of human CSC stemness and the expression of multipotency genes [48-50]. Saiki et al showed that Sox2 expression was highly associated with lymph node metastasis and Dukes stage in human colorectal cancer [50].…”

Evodiamine Eliminates Colon Cancer Stem Cells via Suppressing Notch and Wnt Signaling

“…In addition, the expression of known CSC markers also decreased. We tested ALDH1 activity, a widely used marker for cancer stem cells for many tissues; however, colon BCCs already harbor strong ALDH1 activity, so this marker cannot be used as a reliable stem cell marker in colon cancer cell lines [33].…”

Immunohistochemical Study of HER2/neu Expression in Colorectal Cancer and its Relation to other Clinicopathological Criteria and Prognostic Factors

“…Colorectal cancer (CRC) has been considered as one of the most common malignancies all over the world and its incidence is increasing slowly (1)(2)(3). Dietary, environmental factors and genetic susceptibility play substantial roles in the development of CRC (4,5).…”