Co-Expression and Combined Prognostic Value of CSPG4 and PDL1 in TP53-Aberrant Triple-Negative Breast Cancer

Zhe-Yu Hu1,2,3, Chanjuan Zheng4,5, Jianbo Yang1,6,7

  • 1Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya Medical School, Central South University, Changsha, China.

Frontiers in Oncology
|March 14, 2022
PubMed
Abstract

Insights

Chondroitin sulfate proteoglycan 4 (CSPG4) and PDL1 are highly expressed in triple-negative breast cancer (TNBC), especially with TP53 aberrations. CSPG4 expression is linked to poor survival and may offer new therapeutic targets in TNBC.

Area of Science:

  • Oncology
  • Immunotherapy
  • Molecular Biology

Background:

  • Immunotherapy targeting PDL1/PD1 is effective in less than 20% of triple-negative breast cancer (TNBC) patients.
  • Chondroitin sulfate proteoglycan 4 (CSPG4) is highly expressed with PDL1 in TNBC, particularly in tumors with TP53 aberrations.
  • The clinical significance of co-expressed CSPG4 and PDL1 in TNBC is not well understood.

Purpose of the Study:

  • To investigate the clinical implications of CSPG4 and PDL1 co-expression in advanced TNBC.
  • To analyze the association between CSPG4, PDL1, TP53 status, and patient survival.
  • To explore the potential molecular mechanisms involving CSPG4 in TNBC progression.

Main Methods:

  • Retrospective analysis of 85 advanced TNBC patients.
  • Immunohistochemistry (IHC) to assess CSPG4 and PDL1 expression in tumor tissues.
  • TCGA-BRCA RNA-seq data analysis for CSPG4 and PDL1 mRNA levels, especially in TP53-aberrant TNBCs.
  • Survival analysis using Cox proportional hazards models and Kaplan-Meier curves.
  • In vitro studies using TNBC cell lines to investigate molecular mechanisms.

Main Results:

  • TP53 aberrations were found in over 50% of metastatic TNBCs and correlated with higher tumor mutation burden.
  • High CSPG4 and PDL1 mRNA levels were observed in TNBCs, particularly those with TP53 aberrations.
  • IHC revealed CSPG4 positivity in nearly 60% and co-positivity for CSPG4 and PDL1 in about 25% of advanced TNBCs.
  • CSPG4 positivity was a significant risk factor for progression-free survival (HR=2.26, P=0.05) and high CSPG4 levels predicted poor overall survival (P=0.02).
  • EMT-related pathways were implicated in CSPG4-mediated invasion.

Conclusions:

  • CSPG4 expression is associated with PDL1 positivity and poor prognosis in TP53-aberrant TNBC.
  • Co-expressed CSPG4 and PDL1 hold prognostic value and represent potential therapeutic targets for TNBC.
  • CSPG4 may drive tumor invasion and PDL1 overexpression via EMT-related pathways.