Molecular Therapy: Nucleic Acids (Dec 2021)

A transcriptional signature detects homologous recombination deficiency in pancreatic cancer at the individual level

  • Shuping Zhuang,
  • Tingting Chen,
  • Yawei Li,
  • Yuquan Wang,
  • Liqiang Ai,
  • Yiding Geng,
  • Min Zou,
  • Kaidong Liu,
  • Huanhuan Xu,
  • Linzhu Wang,
  • Zhangxiang Zhao,
  • Zhiqiang Chang,
  • Yunyan Gu

Journal volume & issue
Vol. 26
pp. 1014 – 1026

Abstract

Read online

Pancreatic cancer (PC) with homologous recombination deficiency (HRD) has been reported to benefit from poly ADP-ribose polymerase (PARP) inhibitors. However, accurate identification of HRD status for PC patients from the transcriptional level is still a great challenge. Here, based on a relative expression ordering (REO)-based algorithm, we developed an HRD signature including 24 gene pairs (24-GPS) using PC transcriptional profiles from The Cancer Genome Atlas (TCGA). HRD samples classified by 24-GPS showed worse overall survival (p = 4.4E-3 for TCGA; p = 1.2E-3 for International Cancer Genome Consortium-Australia cohort; p = 6.4E-2 for GSE17891; p = 7.5E-2 for GSE57495) and higher HRD scores than non-HRD samples (p = 1.4E-4). HRD samples showed highly unstable genomic characteristics and also displayed HRD-related alterations at the epigenomic and proteomic levels. Moreover, HRD cell lines identified by 24-GPS tended to be sensitive to PARP inhibitors (p = 6.6E-2 for olaparib; p = 2.6E-3 for niraparib). Compared with the non-HRD group, the HRD group presented lower immune scores and CD4/CD8 T cell infiltration proportion. Interestingly, PC tumor cells with co-inhibition of PARP-related genes and ATR showed reduced survival ability. In conclusion, 24-GPS can robustly identify PC patients with HRD status at the individualized level.

Keywords