Author of

• 30943

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  P2.04 - Immuno-oncology (ID 167)

  • Event: WCLC 2019
  • Type: Poster Viewing in the Exhibit Hall
  • Track: Immuno-oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall

  • 30993

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    P2.04-43 - High Occurrence of LINE-1 Retrotransposition Is Correlated with Smoking History, Local Immunosuppression and Poor Prognosis in LUSC (ID 773)

    10:15 - 18:15  |  Author(s): Xiao Zhang
    • Abstract

    Background
    

    Somatic Long Interspersed element-1 (LINE-1) retrotransposition (RT) is a genomic process that relates to gene disruption and tumor occurrence. However, the expression and function of LINE-1 RT in lung squamous cell carcinoma (LUSC) remains unclear.

    Method
    

    We analyzed the transcriptomes of paired LUSC samples in The Cancer Genome Atlas (TCGA), to characterize the most common somatic LINE-1 RTs in LUSC, followed by validation in an independent Chinese LUSC cohort and several cancer cell lines. We also analyzed the association between these LINE-1 RTs and clinico-pathology features, as well as the immunocyte content in local LUSC tumor tissues.

    Result
    

    We observed LINE-1 RT occurred within 90% of tumor samples in TCGA, among which thirteen LINE-1 RTs were filtered for high occurrence in LUSC. In Chinese cohort, the expression of 13 LINE-1 RTs in LUSC tissues was significantly higher than those in matched adjacent normal tissues. Furthermore, 11 of 13 LINE-1 RTs were exclusively detected in LUSC cell lines rather than normal lung epithelial cells. Further analysis showed 3 LINE-1 RTs, including L1-FGGY, L1-ATP8B1 and L1-SVEP1 were correlated with smoking history, large tumor size, central tumor location, and poorer prognosis. The immunohistochemical staining (IHC) analysis showed that less CD3⁺ T cells, more CD68⁺ macrophages and CD33⁺ myeloid-derived suppressive cells (MDSCs) were detected in LINE-1 RT positive tissues which implied that LINE-1 RT might induce significant immunosuppression in situ.

    Conclusion
    

    In conclusion, LINE-1 RT is a frequent genomic event that correlates with smoking-related LUSC development and LUSC immune evasion which might be a promising predictive biomarker of poor prognosis in LUSC.