100133941

CD24

The epithelial-mesenchymal transition (EMT) has been linked to induction of a stem-cell like phenotype, characterized by altered cell surface marker expression and increased tumor formation. The aim of this study was to investigate whether EMT correlates with CD24+CD44+ and CD133+ cells in pancreatic cancer. The morphology of untreated and gemcitabine-treated SW1990 gemcitabine-resistant cells and normal SW1990 cells were compared. NF-kappaB p65 expression was knocked down using siRNA. Vimentin and E-cadherin expression were analyzed using western blotting, and CD24+CD44+, CD133+ cells were quantified by FACS. Additionally, immunohistochemistry of EMT-associated markers and stem cell-associated markers were performed in 41 cases of human pancreatic ductal adenocarcinoma. In SW1990 gemcitabine-resistant cells, gemcitabine induced a mesenchymal cell phenotype, expression of EMT-related molecular markers and increased CD24+CD44+ and CD133+ cells compared to untreated SW1990 gemcitabine-resistant and SW1990 cells. Knockdown of NF-kappaB p65 inhibited the ability of gemcitabine to increase the proportion of CD24+CD44+ or CD133+ cells and expression of EMT-related molecular markers. In human pancreatic ductal adenocarcinoma, significant correlations were observed between expression of the EMT-associated markers vimentin and E-cadherin, and stem cell-associated markers CD24, CD133 and CD44. This study demonstrated that EMT correlated with CD24+CD44+ and CD133+ cells in pancreatic cancer. This study also suggests that EMT may induce cancer stem-like cells in pancreatic cancer, with different degrees of EMT probability inducing different proportions of CD24+CD44+ and CD133+ cells.

We report here that CD24 knockdown resulted in decreased expression of Notch1 in MCF-7 cells. CD24-downstream p38MAPK was shown to regulate Notch1 at the level of mRNA stability. We also found that CD24-mediated cell migration, invasion, mammosphere formation, and drug resistance was regulated by its downstream target Notch1. Together, our results indicate that CD24 may regulate the epithelial to mesenchymal transition and stemness through Notch1 signaling in breast cancer cells.CI - Copyright (c) 2014 Elsevier Inc. All rights reserved.

Cell surface proteins such as CD44 and CD24 are used to distinguish cancer stem cells (CSCs) from the bulk-tumor population. However, the molecular functionalities of CD24 and CD44, and how these two molecules coordinate in CSCs remain poorly understood. We found that nasopharyngeal carcinoma (NPC) cells with high expression of CD44 and CD24 proteins presented with pronounced CSC properties. Accordingly, a subpopulation of NPC cells with co-expression of CD44 and CD24 were specially enriched in high-stage clinical samples. Furthermore, ectopically expressing the epithelial-mesenchymal transition (EMT) regulator Twist was able to upregulate the stemness factors, and vice versa. This indicates a reciprocal regulation of stemness and EMT. Intriguingly, we found that this reciprocal regulation was differentially orchestrated by CD44 and CD24, and only simultaneous silencing the expression of CD44 and CD24 led to a broad-spectrum suppression of CSC properties. Oppositely, overexpression of CD44 and CD24 induced the reprogramming of parental NPC cells into CSCs through STAT3 activation, which could be blunted by STAT3 inhibition, indicating that CD44 and CD24 collaboratively drive the reprogramming of NPC cells through STAT3-mediated stemness and EMT activation. Consequently, targeting of the CD44/CD24/STAT3 axis may provide a potential therapeutic paradigm for the treatment of NPC through repressing CSC activities.

The degree of peritoneal dissemination and chemotherapy-resistant tumors is related to the prognosis in patients with advanced-stage ovarian cancer. The epithelial-mesenchymal-transition (EMT) is a multifaceted pathological program that endows cancer cells with the ability to invade and disseminate. CD24 is frequently overexpressed in various human cancers and is correlated with a poor prognosis. We herein examined the functions of CD24 in human ovarian cancer cell lines and evaluated how it contributes to the molecular mechanism underlying the regeneration of cancer stem-like cells (CSCs) through the EMT mechanism in ovarian carcinoma. We demonstrated that CD24 was expressed in 70.1% of primary ovarian carcinoma tissues, which were obtained from 174 patients, and that the expression of CD24 was an independent predictor of survival in patients with ovarian cancer. The expression of CD24 has been found to be correlated with the FIGO stage, presence of peritoneal and lymph node metastasis. CD24 induces the EMT phenomenon, which is involved in cell invasion, the highly proliferative phenotype, colony formation and which is associated with cisplatin resistance and the properties of CSCs, via the activation of PI3K/Akt, NF-kappaB and ERK in Caov-3 cisplatin-resistant cell lines. CD24-positive ovarian carcinomas have been shown to have a greater potential for intra-abdominal tumor cell dissemination in in vivo models. Our findings suggest that CD24 induced the EMT phenomenon in ovarian cancer, and that CD24 amplified cell growth-related intracellular signaling via the PI3K/Akt and MAPK pathways by affecting the EMT signal pathways. We believe that CD24 is a key molecule of metastatic progression in the EMT phenomenon and a promising therapeutic target for advanced ovarian cancer.