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B. Stanfill



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    P2.01 - Poster Session with Presenters Present (ID 461)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P2.01-031 - CCL Chemokines May Play an Important Role in Cisplatin Resistance (ID 4861)

      14:30 - 14:30  |  Author(s): B. Stanfill

      • Abstract

      Background:
      In the absence of a targetable mutation, cisplatin based chemotherapy is the backbone of NSCLC treatment. However, a diverse patient population combined with complex tumour heterogeneity is hampering its’ clinical utility. Although intrinsic and acquired resistance to cisplatin is common, the mechanisms have not yet been fully elucidated. However, some studies have suggested that inflammatory pathways may play a key role in chemo-resistance. The aim of this project is to increase our understanding of inflammatory mediated cisplatin resistance in NSCLC.

      Methods:
      A number of isogenic cell line models of NSCLC (adenocarcinoma, squamous cell carcinoma, large cell carcinoma) cisplatin resistance were utilised to assess the role of inflammation in chemo-resistance. These included a sensitive parental cell line (PT) and a matched resistant subtype (CisR). The cell lines were screened for NFKB and a number of inflammatory mediators including chemokines and TLRs at the mRNA (RT-PCR/qPCR) and protein level (Western Blot/ELISA). A specific NFKB inhibitor, DHMEQ, and recombinant chemokines were employed to further characterise inflammatory pathways in PT and CisR cells in terms of cisplatin sensitivity, proliferation (BrdU ELISA), cellular viability (Cytell Cell Imaging System) and DNA damage response (Comet). An in vivo study was also completed using DHMEQ alone and in combination with cisplatin.

      Results:
      A number of NFKB targets and responsive pathways are deregulated in CisR cells compared with their matched sensitive PT cell line. Amongst others, CCL2 and CCL5 were altered across all NSCLC subtypes. Preliminary data suggests that DHMEQ enhances cisplatin sensitivity in both PT and CisR cells, conversely recombinant chemokines elicit a protective effect. Additionally, DHMEQ treatment resulted in opposite affects on CCL2 and CCL5 mRNA levels in the PT and CisR cell lines. This may reflect an alternative pathway hierarchy within the cells. Further characterisation is ongoing assessing chemokine specific inhibitors. Although, in vivo data suggests a trend of decreased tumour growth in the DHMEQ cohorts compared with vehicle control, the data was not significant. However, tumour samples appeared more necrotic with DHMEQ and are currently being characterised using IHC for necrosis and proliferation.

      Conclusion:
      Targeting chemokines downstream of NFKB may provide a means to overcome inflammatory mediated acquired and intrinsic NSCLC chemo-resistance. Given the increased significance of immuno-oncology agents to harness the body’s own immune system in the fight against cancer, these agents may also prove fruitful in re-sensitising patients to chemotherapy.

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    P3.03 - Poster Session with Presenters Present (ID 473)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Mesothelioma/Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies
    • Presentations: 1
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      P3.03-021 - When RON MET TAM in Mesothelioma: All Druggable for One, and One Drug for All? (ID 5025)

      14:30 - 14:30  |  Author(s): B. Stanfill

      • Abstract

      Background:
      Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer associated with exposure to asbestos. Untreated, MPM has a median survival time of 6 months, and most patients die within 24 months of diagnosis. Therefore an urgent need exists to identify new therapies for treating MPM patients. The potential for therapeutically targeting receptor tyrosine kinase (RTK) signalling networks is emerging as a critical mechanism in ‘oncogene addicted’ cancer, with RTK inhibitors evolving as areas of considerable importance in cancer therapy. Furthermore, RTK hetero-dimerization has emerged as a key element in the development of resistance to cancer therapy. As such TKIs which target several RTKs may have superior efficacy compared with TKIs targeting individual RTKs. We and others have identified c-MET, RON, Axl and Tyro3 as RTKs frequently overexpressed and activated in MPM, making these attractive candidate therapeutic targets. A number of orally bioavailable small molecule inhibitors have been developed which can target these receptors. LCRF0004 specifically targets RON, whereas ASLAN002 (BMS-777607) or Merestinib (LY2801653) are orally bioavailable small molecule inhibitors which inhibit c-MET, RON, Axl and Tyro3 at nanomolar concentrations. These drugs may therefore have applicability in the treatment/management of MPM.

      Methods:
      A panel of MPM and normal pleural cell lines were screened for expression of Tyro3, c-MET, RON and Axl by RT-PCR, and subsequently examined in a cohort of patient samples comprising benign, epithelial, biphasic, and sarcomatoid histologies by qPCR. The effects of two small molecule inhibitors LCRF0004, ASLAN002 on MPM cellular health were assessed in vitro. The effects of LCRF0004 and ASLAN002 were subsequently examined in an in vivo SQ xenograft tumour model.

      Results:
      Expression of various RON isoforms, c-MET, Tyro3 and Axl were observed in all cell lines. Significantly higher expression of all genes were found in the malignant tumour material versus benign pleura and this was validated in other datasets. Both LCRF0004 and ASLAN002 demonstrated significant anti-tumour efficacy in vitro. In xenograft models ASLAN002 was far superior to LCRF0004.

      Conclusion:
      Our results suggest that a multi-TKI, targeting the RON/MET/TAM signalling pathways, may be a more effective therapeutic strategy for the treatment of MPM as opposed to targeting RON alone.