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  P3.01 - Poster Session 3 - Cancer Biology (ID 147)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 2
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

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    P3.01-017 - Nitric Oxide Adapted Lung Tumor Cells Express Tumor Stem Cell-Like Markers (ID 2367)

    09:30 - 09:30  |  Author(s): M. Aqil
    • Abstract

    Background
    Recent studies in our laboratory show that tumor cells exposed to progressively higher concentrations of DETA-NONOate grow more aggressively than the parent cells. The currently accepted tumor stem cell model proposes that rare tumor stem cells produce both tumor cells (TCs) and rare tumor stem cells (TSCs). A number of TSC markers have been proposed, including CD antigens expression, Hoerscht 33342 exclusion, ALDH1/2 expression, and ALDH1/2 activity. In this study, we compare the TSC-like properties of parent and HNO cells. We hypothesized that human lung tumor cells adapted to high nitric oxide (HNO) levels will exhibit enhanced tumor stem cell-like properties relative to analogous cells not adapted to NO (“parent” cells).

    Methods
    The human lung adenocarcinoma cell line A549-Parent and the previously reported A549-HNO adapted cell lines were used in these studies. Immunohistochemistry was used to measure the expression of ALDH1/2 and six different CD antigens. Gene expression was measured using chip microarray analysis. FACS analysis was used to measure the population of H33342-positive and H33342-negative cells. ALDH activity was assessed using the ALDEfluor assay.

    Results
    The ALDEFLUOR assay demonstrated that ALDH activity of A549-HNO has increased compared to that of A549-parental. Relative to the A549-parental cells, A549-HNO cells showed markedly higher H33342-exclusion in the FACS analysis and greater ALDH1/2 expression in the immunostaining studies. Shocking these cells with 700 mM NO donor prior to treatment produced even more pronounced stem cell-like properties, suggesting that NO might be able to influence TCs into becoming more TSC-like. Gene chip results show that CD44, ALDH1A1, and ALDH2 are more highly expressed in A549-HNO cells than in A549-Parent cells. Cytospin results showed that ALDH1/2, CD44, and CD133 were more highly expressed in the A549-HNO cells, relative to A549-Parent cells.

    Conclusion
    The TSC markers tested in this study are consistent with the A549-HNO cells being more TSC-like than the A549-Parent cells. Having a large population of TSC-like cells would allow for improved drug screening of therapeutic candidates specifically designed to target TSCs.

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    P3.01-018 - Supporting Evidence For A New Tumor Stem Cell Plasticity Model Based On Adaption To Nirtic Oxide (ID 1932)

    09:30 - 09:30  |  Author(s): M. Aqil
    • Abstract

    Background
    Hypothesis: Tumor stem cells (TSCs) are not rare cells and tumor cells TCs) have the plasticity to become TSCs. Objectives: Currently the rate limiting step in these efforts is the use of fluorescence-activated cell sorting (FACS) instrumentation to physically sort TSCs from TCs. We have shown that tumor cell lines could be adapted to comparatively high Nitric Oxide (NO) levels and that these cells had properties similar to TSCs. These cells were tested for various TSC properties using cellular, immunological, and molecular biology methods which included ALDH expression, ALDH activity, CD antigen expression, and H33342 dye exclusion. Proving that these are in fact TSCs would mean that we can produce large quantities of these cells to study. In a similar fashion, proving that TCs can become TSCs, would be very important.

    Methods
    We used the A549 and several Head & Neck SCC cell line in this study. They were FACS sorted five to seven times consecutively using H33342, to remove any chance of TSCs being present. The resulting TCs were cultured, and retested using H33342 at various times (several days to several weeks), for the presence of TSCs. The cells were cultured with or without NO.

    Results
    The FACS-sorted “pure” TCs, after being cultured, resulted in a TSC population re-immerging within days.

    Conclusion
    Collectively, these data support the idea that TSCs are not rare cells and that NO can drive TC populations to express properties of TSCs. This plasticity means that any TC can become a TSC.