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  P3.02 - Poster Session 3 - Novel Cancer Genes and Pathways (ID 149)

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

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    P3.02-010 - A PCR-based test detecting ectopic expressions of placenta/germline genes can predict aggressive lung tumours (ID 1648)

    09:30 - 09:30  |  Author(s): A. De Bernardi
    • Abstract

    Background
    Cell transformation and tumour progression are associated with severe alterations of the epigenetic control of gene expression. Although the abnormal repression of tumour suppressor genes has been thoroughly investigated, the concept of tissue-specific gene aberrant reactivations in cancer is only starting to emerge. The extent of this process has not been reported yet, mainly because of the difficulties in detecting these expressions by the currently used transcriptomic analyses

    Methods
    We have developed a simple approach, exploiting genome wide expression data, which has enabled us to demonstrate that these "off-context" gene activations occur in any cancer, providing a universal source of cancer biomarkers. By applying this analysis to our series of lung cancer patients (n=297) with the corresponding precise clinical annotations and 5 to 10 years patient follow-up, we found that hundreds of germline-specific genes are ectopically expressed in the tumours and that a subset of 26 genes are specifically activated in a subgroup of highly aggressive metastatic-prone tumours, even at an early stage of the disease. This approach has enabled us to define and isolate a homogeneous group of very aggressive tumours called P3 with at least 3 genes ectopically expressed, independently of other prognosis parameters (histo-pathological or stage) (Rousseaux et al. Sci Transl Med 2013, 5 (186): 186ra66).

    Results
    Based on these data we setup a PCR based test to directly rank lung tumours by detection of the prognosis associated gene activations. This test was first validated on a series of 60 tumour samples from the same cohort (also analyzed by an affymetrix transcriptomic approach), which revealed the remarkable robustness of the PCR approach and showed a higher sensitivity of the PCR-based detections in tumour ranking. We then extended these PCR-based analyses to include additional patients with precise clinical and pathological annotations and 10 years follow-up but for whom transcriptomic data were not available. Here again we could show that our test successfully ranked the patients into groups with significantly different survival probabilities. we show here the intermediate analysis on a first group of 88 patients without lymph node metastasis treated by surgeryFigure 1

    Conclusion
    In conclusion we are ready to launch a prospective study based on this PCR test to evaluate its ability to predict tailored follow up of patients after surgery and also tumour sensitivity to design specific targeted therapies including immunotherapy since this ectopic activation may lead to very innovative treatment .