Author of

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  P2.05 - Poster Session 2 - Preclinical Models of Therapeutics/Imaging (ID 158)

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

  • 11516

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    P2.05-001 - Recombinant human Apo2L/TRAIL (Dulanermin) in combination with carboplatin/pemetrexed in Malignant Pleural Mesothelioma (MPM): anticancer effects in vitro and in vivo. (ID 136)

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

    Background
    Malignant pleural mesothelioma (MPM) is an aggressive tumour linked to chronic inhalation of asbestos fibers, with poor prognosis and increasing incidence in industrialized countries. Currently available chemotherapeutic regimens achieve a median progression free and overall survival of 6 and 12 months respectively. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family, which induces cancer cell death through extrinsic apoptotic pathway, while sparing normal cells. The aim of this study was to investigate the antitumor activity of recombinant human Apo2L/TRAIL (Dulanermin, Amgen;Genentech) in combination with antifolate-based chemotherapy in MPM cell lines and in vivo preclinical mouse model.

    Methods
    In vitro apoptosis assay was performed using Annexin-V-Fluos staining kit (Roche) according to the manufacturer’s instructions. Epithelioid (ZL55) and sarcomatoid (ZL34) cell lines were treated with carboplatin plus pemetrexed (CP), dulanermin (D) or CPD and then Annexin V positive cells were detected by flow cytometry using a FACSCalibur apparatus and CellQuest software (BD Biosciences). p53 protein expression level was detected by western blot analysis using a specific antibody. TRAIL death receptors (DR4 and DR5) and decoy receptors (DcR1 and DcR2) expression levels were assessed by flow cytometric analysis. In vivo experiments were performed in 30 SCID male mice, implanted subcutaneously in the right flank with 2x10[6 ]ZL55 cells suspended in 0.1 ml volume of RPMI, aged 6 weeks. When tumor volume reached 50-150 mm[3], the mice were randomized in 4 treatment groups: 1) not treated (NT); 2) C (75 mg/Kg day 1) plus P(100 mg/Kg day 1); 3) D (60 mg/Kg days 1 to 3); 4) CPD. Tumor volumes were recorded every second day, and mice suppressed at the 21[th] day or when tumor volume reached 500 mm[3].

    Results
    We observed a significant increase of specific cell death in epithelioid and sarcomatoid cell lines treated with CPD compared to those receiving CP or D as single agent (p<0.001). We then observed p53 activation in both cell lines after chemotherapy, and a subsequent significant increase of DR4/5 expression levels (p<0.005) without upregulation of decoy receptors. We finally assessed antitumor activity of CP and/or D in a ZL55 mouse model. We observed a statistically significant reduction of tumor volume at every time point in the three treatment groups compared to not treated; moreover, tumor volume was significantly reduced in mice treated with CPD (mean volume 58 mm[3]) compared to CP (mean volume 175 mm[3]) or D (mean volume 109 mm[3]) as single agent at the 21th day (p= 0.005). Finally, no difference in tumor growth was observed between mice treated with D compared to CP.

    Conclusion
    CP sensitizes MPM cell lines to TRAIL-dependent apoptosis in vitro, probably through p53 activation and subsequent upregulation of death receptors. CPD significantly reduces tumor volume in epithelioid mesothelioma mouse model compared to chemotherapy alone or dulanermin as a single agent; furthermore antitumor activity of dulanermin was comparable to that reported with chemotherapy. In vivo experiments in a sarcomatoid mouse model are currently ongoing.