Aptamer-based analysis of plasma proteome of growing tumors


In most cases, detecting malignancies at an early-stage increases treatment options, minimizes the risk of metastases and dramatically improves long-term survival. Nevertheless, tumors are typically discovered at more advanced stages, either with onset of symptoms or as part of unrelated procedures. Non-invasive means of detecting tumors in systemic circulation has long held considerable appeal, but also enormous challenges. A major difficulty is related to the need to detect a small volume of a malignancy remotely, after massive dilution of tumor-associated analytes in the total circulating volume of blood. To date, such “liquid biopsies” have mainly focused on the identification of genetic material unique to transformed cells, typically derived from circulating tumor cells, or cell-free DNA. With proteins, the presence of a tumor is more often accompanied with changes in the levels of endogenous, unmutated proteins in circulation. In this context, knowing which proteins represent the earliest markers or tumor presence would be enormously useful. So what are the first tumor-associated proteins that can be detected in blood as the initial transformed cells establish residence in their tissues of origin?


To answer this question, we used aptamer-based SomaScan® assay to monitor the time course of changes in the plasma proteome of mice carrying transplanted human tumors.


Our study shows that tumor cells representing human lung, ovarian, breast and colon cancer produce both unique and common sentinel proteomic signatures in plasma that could be used to identify both the early presence as well as the identity of tumors growing remotely.


  • Mouse models of human tumor growth reveal the emergence of early protein markers of tumor presence in plasma
  • Unique and common markers exist for lung, colon, ovarian and breast cancer cell lines
  • Tests based on multiple protein analytes reveal tumors at an early stage
  • Protein-based tests can enhance the performance of liquid biopsies


Shashi Gupta1
Matthew Westacott1
Deborah G. Ayers1
Daniel J. Schneider1
Anis Karimpour-Fard2
Lawrence E. Hunter2
Daniel W. Drolet1
Nebojsa Janjic1

1. SomaLogic Operating Co., Inc., Boulder, CO, USA
2. University of Colorado School of Medicine, Aurora, CO, USA

Click below to download a version of this white paper

Download white paper

Share with colleagues

More posters

PosterQuantitative immunology protein panel built on the SomaScan Assay platform

The SomaScan® assay is a highly multiplexed proteomic assay that uses SOMAmer® reagents to detect proteins in various biological samples. The latest version of the SomaScan assay allows researchers to measure over 11,000 proteins in human blood. The SomaScan assay is designed to provide protein epitope abundance measurements by reporting relative SOMAmer reagent abundance quantified using DNA microarrays.

Learn more

PosterComparison of Proteomic CV Risk to Established ASCVD 10-Year Risk Decision Points

The ASCVD pooled cohort equation (PCE) is well-established for CV risk assessment. Decision points for determining treatment plans are low, intermediate and high risk over 10 years, however this approach over and underestimates risk in certain subgroups. The validated CV Risk SomaSignal® Test (SST) provides 4-year risk probability of MACE allowing for timely assessment of risk, but the shorter timescale makes comparison to 10-year PCE risk less intuitive.

Learn more

PosterStatin signature: using proteomics to detect pharmacological fingerprints

Using a previously described metacohort (n=5,575) of patients with increased CV risk, we hypothesized that PCE would stratify patients differently than the CV Risk SST, and that CV Risk score scaled to 10 years would yield an improved net reclassification index (NRI).

Learn more

Explore posters in our interactive viewer