Functional features of cancer stem cells in melanoma cell lines

Abstract

BackgroundRecent evidence suggests a subset of cells within a tumor with "stem-like" characteristics. These cells are able to transplant tumors in immunodeficient hosts. Distinct from non-malignant stem cells, cancer stem cells (CSC) show low proliferative rates, high self-renewing capacity, propensity to differentiate into actively proliferating tumor cells, and resistance to chemotherapy or radiation. They are often characterized by elevated expression of stem cell surface markers, in particular CD133, and sets of differentially expressed stem cell-associated genes. CSC are usually rare in clinical specimens and hardly amenable to functional studies and gene expression profiling. In this study, a panel of heterogenous melanoma cell lines was screened for typical CSC features.MethodsNine heterogeneous metastatic melanoma cell lines including D10 and WM115 were studied. Cell lines were phenotyped using flow cytometry and clonogenic assays were performed by limiting dilution analysis on magnetically sorted cells. Spheroidal growth was investigated in pretreated flasks. Gene expression profiles were assessed by using real-time rt-PCR and DNA microarrays. Magnetically sorted tumor cells were subcutaneously injected into the flanks of immunodeficient mice. Comparative immunohistochemistry was performed on xenografts and primary human melanoma sections.ResultsD10 cells expressed CD133 with a significantly higher clonogenic capacity as compared to CD133- cells. Na8, D10, and HBL cells formed spheroids on poly-HEMA-coated flasks. D10, Me39, RE, and WM115 cells expressed at least 2 of the 3 regulatory core transcription factors SOX2, NANOG, and OCT4 involved in the maintenance of stemness in mesenchymal stem cells. Gene expression profiling on CD133+ and CD133- D10 cells revealed 68 up- and 47 downregulated genes (+/-1.3 fold). Two genes, MGP and PROM1 (CD133), were outstandingly upregulated. CD133+ D10 cells formed tumors in NSG mice contrary to CD133- cells and CD133 expression was detected in xenografts and primary human melanoma sections using immunohistochemistry.ConclusionsEstablished melanoma cell lines exhibit, to variable extents, the typical features of CSCs. The tumorigenic cell line D10, expressing CD133 and growing in spheroids and might qualify as a potential model of melanoma CSCs.

STAT3/p53 pathway activation disrupts IFN-β–induced dormancy in tumor-repopulating cells

“…Dormancy is another type of G 0 /G 1 arrest state and is often related to undifferentiated stem cells with downregulated metabolic process and protein translation (22)(23)(24)(25). CD133 is commonly used to identify SCLCCs in tumors, including melanomas (26,27). Here, we sorted CD133 hi tumor cells from B16 melanoma.…”

Decrease of ZEB1 expression inhibits the B16F10 cancer stem-like properties

“…The capacity of cancer cells to undergo EMT is now considered a hallmark of tumor metastasis (11,31). For this purpose, we tested EMT related molecular expression in the tumor tissues.…”

“…More importantly, the knockdown of ZEB1 in B16F10 CD133 + CD44 + CSCs inhibited the tumorigenicity and distant lung metastasis potential. According to the CSC hypothesis, the tumorigenicity and metastasis potential represent mainly CSC-like properties in epithelial originated tumor cells (31,32). Consistent with the previously reported findings (2,5,6,17), our current study demonstrated that B16F10 CD133 + CD44 + CSCs had a multipotent, self-renewal capacity and strong tumorigenesis, while the decrease of ZEB1 expression in B16F10 CD133 + CD44 + CSCs caused reduction of CSC-like properties, which may be good evidence that ZEB1 serves as a crucial factor to maintain CSC-like properties.…”

Prognostic value of cancer stem cell marker CD133 expression in esophageal carcinoma: A meta-analysis

“…CD133 is currently identified as a cancer stem cell marker in various solid tumors, such as hepatocellular carcinoma (5), ovarian (6), colon (7) and esophageal carcinoma (8). Zimmerer et al (9) reported that as few as 500 CD133 + melanoma cells were able to form a tumor in NOD/SCID mice, whereas 100,000 CD133 -cells failed to do so; in addition, Taxol induced apoptosis in CD133 -cells, but not in CD133 + cells. These findings suggested that cancer stem cells have the ability to form the bulk of a tumor cell population and confer resistance to conventional therapy.…”