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Updated: Aug 20, 2026
Colorectal Cancer Cell Surface Protein Profiling Using an Antibody Microarray and Fluorescence Multiplexing
Published on: September 25, 2011
Proteogenomic profiling identifies FGFR2b as a prevalent cell-surface target in intrahepatic cholangiocarcinoma
Nakul M Shah1, Beatriz Alvarado-Hernandez1, Xinyue Chen1
1The University of Texas MD Anderson Cancer Center Houston, Texas United States.
Purpose:
Intrahepatic cholangiocarcinoma (iCCA) is rising in incidence and is associated with limited treatment options and poor prognosis, particularly in advanced disease. Recently, biologic strategies such as antibody-drug conjugates (ADCs) have expanded therapeutic opportunities across many tumor types, including HER2/neu-altered iCCA. However, validated and prevalent cell surface targets suitable for biologic therapies remain uncommon in iCCA, representing a critical bottleneck to the development of novel targeted treatments. In particular, gene-level analyses overlook tumor-enriched protein isoforms produced through alternative splicing.
Experimental Design:
To address this gap, we applied a novel isoform-resolved proteogenomic approach comprising transcriptomics, in silico translation, and cell surfaceomics to identify prevalent cell surface targets in iCCA, and further assessed their specificity through analysis of expression data from the TCGA and GTEx datasets.
Results:
This approach identified a unique peptide corresponding to FGFR2b, a splicing isoform of FGFR2, that demonstrated markedly higher tumor enrichment than the alternative FGFR2 isoform, FGFR2c. FGFR2b was the predominant FGFR2 isoform in BTC, including iCCA, in both our institutional cohort (88.6%) and TCGA (88.2%). FGFR2 fusions, in particular, were associated with high FGFR2b expression. High FGFR2b expression was associated with improved surgical outcomes, epithelial differentiation, and reduced CD8+ T-cell infiltration. Orthogonal validation using immunohistochemistry in a subset of 20 patients with available tissue samples confirmed membrane-bound FGFR2b expression in 31.6% of iCCA cases, including all patients with FGFR2 fusions.
Conclusions:
Our findings identify FGFR2b as a prevalent and compelling therapeutic target in iCCA and provide strong rationale for ongoing and future FGFR2b-targeted clinical trials.
Insights
Researchers identified FGFR2b as a promising therapeutic target for intrahepatic cholangiocarcinoma (iCCA). This cell surface protein isoform is highly expressed in iCCA tumors, offering new avenues for targeted therapies and clinical trials.
Area of Science:
- Oncology
- Molecular Biology
- Proteogenomics
Background:
- Intrahepatic cholangiocarcinoma (iCCA) incidence is increasing, with limited treatment options for advanced stages.
- Targeted therapies for iCCA are hindered by a lack of validated cell surface targets, especially those arising from alternative splicing.
- Current gene-level analyses often miss tumor-specific protein isoforms crucial for targeted treatment development.
Purpose of the Study:
- To identify prevalent cell surface targets in iCCA using a novel isoform-resolved proteogenomic approach.
- To assess the specificity and tumor enrichment of identified targets.
- To provide a rationale for developing new targeted therapies for iCCA.
Main Methods:
- Applied transcriptomics, in silico translation, and cell surfaceomics to identify iCCA cell surface targets.
- Utilized TCGA and GTEx datasets to analyze target expression specificity.
- Employed orthogonal validation with immunohistochemistry on patient tissue samples.
Main Results:
- Identified FGFR2b, a splicing isoform of FGFR2, as a highly tumor-enriched target in iCCA.
- FGFR2b was the predominant FGFR2 isoform in both institutional and TCGA iCCA cohorts (88.6% and 88.2%, respectively).
- High FGFR2b expression correlated with improved surgical outcomes, differentiation, and reduced CD8+ T-cell infiltration; validated in 31.6% of iCCA cases.
Conclusions:
- FGFR2b is a prevalent and promising therapeutic target for intrahepatic cholangiocarcinoma.
- The findings support ongoing and future clinical trials targeting FGFR2b in iCCA.
- This study highlights the utility of isoform-resolved proteogenomics in identifying novel cancer targets.
