Detection of Cervical Cancer Biomarker Patterns in Blood Plasma and Urine by Differential Scanning Calorimetry and Mass Spectrometry

Nichola C Garbett,C William Helm,Jon B Klein,Michael L Merchant,Jonathan B Chaires,Alfred B Jenson,Jose M Sanchez-Ruiz

doi:10.1371/journal.pone.0084710

Abstract

Improved methods for the accurate identification of both the presence and severity of cervical intraepithelial neoplasia (CIN) and extent of spread of invasive carcinomas of the cervix (IC) are needed. Differential scanning calorimetry (DSC) has recently been shown to detect specific changes in the thermal behavior of blood plasma proteins in several diseases. This methodology is being explored to provide a complementary approach for screening of cervical disease. The present study evaluated the utility of DSC in differentiating between healthy controls, increasing severity of CIN and early and advanced IC. Significant discrimination was apparent relative to the extent of disease with no clear effect of demographic factors such as age, ethnicity, smoking status and parity. Of most clinical relevance, there was strong differentiation of CIN from healthy controls and IC, and amongst patients with IC between FIGO Stage I and advanced cancer. The observed disease-specific changes in DSC profiles (thermograms) were hypothesized to reflect differential expression of disease biomarkers that subsequently bound to and affected the thermal behavior of the most abundant plasma proteins. The effect of interacting biomarkers can be inferred from the modulation of thermograms but cannot be directly identified by DSC. To investigate the nature of the proposed interactions, mass spectrometry (MS) analyses were employed. Quantitative assessment of the low molecular weight protein fragments of plasma and urine samples revealed a small list of peptides whose abundance was correlated with the extent of cervical disease, with the most striking plasma peptidome data supporting the interactome theory of peptide portioning to abundant plasma proteins. The combined DSC and MS approach in this study was successful in identifying unique biomarker signatures for cervical cancer and demonstrated the utility of DSC plasma profiles as a complementary diagnostic tool to evaluate cervical cancer health.

Highlights

Invasive carcinoma of the uterine cervix (IC) is the third most common cancer affecting women with an estimated 529,000 cases diagnosed worldwide in 2008 and 274,000 deaths [1]
Once IC is detected the principal need is to determine whether there is early stage disease (FIGO stage IC (Stage I)) which is confined to the cervix or if there is more advanced metastatic disease
Using Differential scanning calorimetry (DSC) methodology we have demonstrated distinct thermogram profiles that differentiated healthy control subjects from precancerous cervical intraepithelial neoplasia (CIN) and IC and showed a clear distinction between high-grade squamous intraepithelial lesion (HSIL) from both controls and IC and FIGO Stage I IC from more advanced IC (Stage II–IV)

Summary

Introduction

Invasive carcinoma of the uterine cervix (IC) is the third most common cancer affecting women with an estimated 529,000 cases diagnosed worldwide in 2008 and 274,000 deaths [1]. In recent decades routine screening has helped to significantly reduce both the incidence and deaths from IC in the USA but, an estimated 12,340 new cases will be diagnosed with 4,030 deaths in 2013 [2]. Invasive cervical cancer is preceded by a precancerous condition, cervical intraepithelial neoplasia (CIN), in which abnormal cell growth occurs in the epithelial lining of the cervix. CIN is divided into grades (1 = mild, 2 = moderate, 3 = severe) based on histologic features including nuclear changes and the extent of involvement of the epithelium. CIN can be treated to greatly reduce the chance of IC developing. Disease confined to the cervix and of sufficiently small size is considered treatable with surgery

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Conclusion