ISSN: 1574-888X (Print)Volume 9, 6 Issues, 2014
Characterization of Stem-Like Cells Directly Isolated from Freshly Resected Laryngeal Squamous Cell Carcinoma Specimens
Author(s): Ilknur Suer, Omer Faruk Karatas, Betul Yuceturk, Mehmet Yilmaz, Gulgun Guven, Buge Oz, Harun Cansiz and Mustafa Ozen
Affiliation: Istanbul University, Cerrahpasa Medical School, Department of Medical Genetics, Fatih, Istanbul, Turkey.
Larynx cancer (LCa) is an aggressive malignancy, which is the second most common malignant neoplasm of head and neck squamous cell carcinoma. Its incidences have been reported to increase and therapeutic options mostly fail to give positive clinical response especially for the advanced LCa cases. In this study we aimed to isolate stem-like cells from freshly resected LCa tumor specimens and characterize them by quantitative real time PCR (qRT-PCR) for expression of cancer stem cell markers including SOX2, OCT4, KLF4, ABCG2, CXCR4 and CD44. Our results showed that CD133(high) cells directly isolated from freshly resected tumor specimens exhibit elevated levels of SOX2, OCT4 and KLF4, and have increased expression levels of ABCG2 and CXCR4, which were associated with resistance of tumors to regular chemotherapeutic reagents. In conclusion, this study offers a useful approach utilizing CD133 to isolate stem cells directly from fresh tissues, which gives the opportunity to develop novel therapeutic tools specifically targeting these cells through their further characterization.
Spleen Stroma Maintains Progenitors and Supports Long-Term Hematopoiesis
Author(s): Helen C. O’Neill, Kristin L. Griffiths, Pravin Periasamy, Rebecca A. Hinton, Sawang Petvises, Ying-ying Hey and Jonathan K.H. Tan
Affiliation: Stem Cell & Immunology Lab, Research School of Biology, Bldg. 134, Australian National University, Canberra, ACT 0200, Australia.
Hematopoietic stem/progenitor cells (HSPC) differentiate in the context of stromal niches producing cells of multiple lineages. Limited success has been achieved in the past with induction of hematopoiesis in vitro. Previously, spleen long-term stromal cultures (LTC) were shown to continuously support restricted hematopoiesis for production of novel dendritic-like cells (LTC-DC). An in vivo equivalent dendritic cell type was then described which is specific for spleen. The in vivo counterpart cell was termed ‘L-DC’ and represents a dendritic-like CD11cloCD11bhiCD8α-MHC-II- cell which differs phenotypically and functionally from monocytes/macrophages and conventional and plasmacytoid DC. Splenic stroma is now shown to maintain HSPC and to support their restricted in vitro differentiation to give this ‘L-DC’ subset. In order to characterise progenitors of this distinct cell type, LTC were analysed for cell subsets produced, and these subsets sorted and assessed for hematopoietic potential in subsequent co-cultures over STX3 stroma. Progenitors were defined as a lineage (Lin)–ckitlo subset reflecting HSPC. Furthermore, when Lin–ckithiSca1+Flt3– HSPC were sorted from bone marrow, they colonised splenic stroma with long-term production of L-DC. The maintenance of HSPC by splenic stroma was confirmed when non-adherent cells collected from LTC showed oligopotent reconstitution of the hematopoietic compartment of lethally irradiated mice. All data support a model whereby spleen houses a niche for HSPC in the resting state, with production of progenitors, and their differentiation to give tissue-specific antigen presenting cells.