Development and Application of a Microfluidics-Based Panel in the Basal/Luminal Transcriptional Characterization of Archival Bladder Cancers

PLoS One. 2016 Nov 15;11(11):e0165856. doi: 10.1371/journal.pone.0165856. eCollection 2016.

Abstract

In the age of personalized medicine stratifying tumors into molecularly defined subtypes associated with distinctive clinical behaviors and predictable responses to therapies holds tremendous value. Towards this end, we developed a custom microfluidics-based bladder cancer gene expression panel for characterization of archival clinical samples. In silico analysis indicated that the content of our panel was capable of accurately segregating bladder cancers from several public datasets into the clinically relevant basal and luminal subtypes. On a technical level, our bladder cancer panel yielded robust and reproducible results when analyzing formalin-fixed, paraffin-embedded (FFPE) tissues. We applied our panel in the analysis of a novel set of 204 FFPE samples that included non-muscle invasive bladder cancers (NMIBCs), muscle invasive disease (MIBCs), and bladder cancer metastases (METs). We found NMIBCs to be mostly luminal-like, MIBCs to include both luminal- and basal-like types, and METs to be predominantly of a basal-like transcriptional profile. Mutational analysis confirmed the expected enrichment of FGFR3 mutations in luminal samples, and, consistently, FGFR3 IHC showed high protein expression levels of the receptor in these tumors. Our bladder cancer panel enables basal/luminal characterization of FFPE tissues and with further development could be used for stratification of bladder cancer samples in the clinic.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biological Specimen Banks*
  • Cohort Studies
  • Computer Simulation
  • Female
  • Formaldehyde
  • Gene Expression Regulation, Neoplastic*
  • Genes, Neoplasm
  • Humans
  • Male
  • Microfluidics / methods*
  • Middle Aged
  • Paraffin Embedding
  • Reproducibility of Results
  • Tissue Fixation
  • Transcription, Genetic*
  • Urinary Bladder Neoplasms / genetics*
  • Urinary Bladder Neoplasms / pathology

Substances

  • Formaldehyde

Grants and funding

DK, YC, OF, RNT, RP, EBS, MM, DF, CVW, EP, LM, RR, LCA, GMH, MRL, and OK are current or former employees of Genentech, Inc. Genentech, Inc. provided support in the form of salaries for these authors but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. JI is an employee of Alternative Allele Consulting. Alternative Allele Consulting provided support in the form of salary for this author but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section.