The Use of Human Serum Samples to Study Malignant Transformation: A Pilot Study.

Andreana N Holowatyj,Tengda Lin,Biljana Gigic,Petra Schrotz-King,Christy A Warby,Jamie J Bernard,Cornelia M Ulrich,Jennifer Ose

doi:10.3390/cells10102670

Abstract

Obesity and excess adiposity account for approximately 20% of all cancer cases; however, biomarkers of risk remain to be elucidated. While fibroblast growth factor-2 (FGF2) is emerging as an attractive candidate biomarker for visceral adipose tissue mass, the role of circulating FGF2 in malignant transformation remains unknown. Moreover, functional assays for biomarker discovery are limited. We sought to determine if human serum could stimulate the 3D growth of a non-tumorigenic cell line. This type of anchorage-independent 3D growth in soft agar is a surrogate marker for acquired tumorigenicity of cell lines. We found that human serum from cancer-free men and women has the potential to stimulate growth in soft agar of non-tumorigenic epithelial JB6 P+ cells. We examined circulating levels of FGF2 in humans in malignant transformation in vitro in a pilot study of n = 33 men and women. Serum FGF2 levels were not associated with colony formation in epithelial cells (r = 0.05, p = 0.80); however, a fibroblast growth factor receptor-1 (FGFR1) selective inhibitor significantly blocked serum-stimulated transformation, suggesting that FGF2 activation of FGFR1 may be necessary, but not sufficient for the transforming effects of human serum. This pilot study indicates that the FGF2/FGFR1 axis plays a role in JB6 P+ malignant transformation and describes an assay to determine critical serum factors that have the potential to promote tumorigenesis.

Highlights

Epidemiologic and experimental studies have linked obesity, abdominal obesity, as a critical risk factor to thirteen different cancer types [1]
JB6 P+ cells cultured with human serum demonstrated a significantly higher percentage of cells growing in soft agar compared with the untreated control cells
To determine if the stimulatory effect of serum was due to fibroblast growth factor receptor-1 (FGFR1) signaling, JB6 P+ cells treated treated withwere serum were cultured in the presence of a selective

Summary

Introduction

Epidemiologic and experimental studies have linked obesity, abdominal obesity, as a critical risk factor to thirteen different cancer types [1]. Haffa et al have further shed light that BMI poorly reflects fat mass-associated changes in visceral adipose tissue (VAT) [5]. Our prior studies suggest that VAT secretion of fibroblast growth factor-2 (FGF2) is associated with malignant transformation [9,10]. It is unknown if human serum-derived FGF2 stimulate malignant transformation in vitro. We found that human serum from cancer-free men and women has the potential to stimulate growth in soft agar and this assay can be used to determine critical serum factors that may promote tumorigenesis

Methods

Results

Conclusion