Author of

• 11454

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  P2.01 - Poster Session 2 - Cancer Biology (ID 145)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11465

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    P2.01-011 - The IL-23 family may be a novel therapeutic target in non small cell lung cancer (ID 3304)

    09:30 - 09:30  |  Author(s): D. Doherty
    • Abstract

    Background
    IL-23A is a member of the IL-6 super-family and is composed of covalently bound IL-12p40 and IL-23p19 (IL-23A) subunits. The functional IL-23R is composed of the IL-23R and IL-12Rβ1 subunits and once activated can promote the STAT3 signalling pathway. IL-23A plays a key role in chronic inflammation through the promotion of IL-17 production by T helper 17 cells (Th 17). Stimulation of IL-23A associated pathways produces pro and anti oncogenic effects which are cell type dependant. We have previously identified IL-23A axis as deregulated in NSCLC and sought to examine the family in greater detail.

    Methods
    The expression of IL-23A/IL-23R was examined in a series of resected fresh frozen NSCLC tumours and in a panel of normal (HBEC) and NSCLC cell lines. Epigenetic regulation of IL-23A/IL-23R was determined in NSCLC cell lines using histone deacetylase (HDi) and DNA methyltransferase (DNMTi) inhibitors. A ChIP assay was performed to investigate the direct effect of Trichostatin A (TSA) on the IL-23A/IL-23R promoter regions. Additionally, the effect of Gemcitabine on IL-23A/IL-23R expression was examined. Finally, the effect of recombinant IL-23 treatment and Apilimod (STA 5326) (a small molecule which blocks the expression of IL-23 and IL-12) on NSCLC cell line proliferation was examined. IL-23 expression was also studied in a panel of NSCLC cisplatin sensitive and resistant cell lines. Furthermore due to its role in immune regulation, we are currently studying the effect of IL-23 on innate immune cell function.

    Results
    IL-23A expression was significantly elevated in a cohort of NSCLC patient tumour samples (p<0.05). Differential IL-23R expression was evident in a panel of NSCLC normal/tumour matched pairs (n=20), with no expression in 25%, reduced levels in 20% and increased levels in 55% of tumour samples compared with matched normal. In addition, IL-23A/IL-23R was found to be epigenetically regulated through histone post-translational modifications and DNA CpG residue methylation in the A549 cell line (p<0.05), with associated chromatin remodelling at both promoters. Gemcitabine, also induced IL-23A/IL-23R expression in this cell line (p<0.05). Furthermore, treatment with recombinant IL-23 resulted in increased cellular proliferation in the A549 cell line, while Apilimod reduced cellular proliferation. Preliminary results indicate that IL-23 can potentially affect the function of innate γδ T cells. In a panel of cisplatin resistant and sensitive cell lines, IL-23A was up-regulated in 3/5 resistant cell lines. Work is ongoing to assess the IL-23R expression in CisR and Parent cells lines and the effect of co-treating cells with HDi and Apilimod and to determine whether these compounds can re-sensitise cells to cisplatin therapy.

    Conclusion
    Based on our results the IL-23A/IL-23R axis is dysregulated in NSCLC. The IL-23 family is subject to epigenetic regulation through HDAC modifications and CpG island methylation. Gemcitabine treatment also affected the expression of this family. Recombinant IL-23 was pro-proliferative in NSCLC and blocking IL-23 with Apilimod reduced the proliferative capacity of the cells. Levels of IL-23A are differentially expressed between cisplatin sensitive and resistant cell lines. Apilimod may be a novel therapeutic drug in the treatment of NSCLC.