Associations between polymorphisms in leptin and leptin receptor genes and colorectal cancer survival

Abstract

Objective: Leptin (LEP) is an obesity-associated adipokine associated with tumor cell growth. We examined the relevance of genetic variants of LEP and leptin receptor (LEPR) to colorectal cancer (CRC) survival by using data from the Newfoundland Familial Colorectal Cancer Study. Methods: A total of 532 patients newly diagnosed with CRC between 1997 and 2003 were followed up until April 2010. Data on their demographics and lifestyles were collected via questionnaires. Genotyping of blood samples was performed with the Illumina Human Omni-Quad Bead chip. Multivariable Cox models were used to assess the relationships of 35 tag single-nucleotide polymorphisms (SNPs) in LEP and LEPR with overall survival (OS), disease-free survival (DFS), and CRC-specific survival. Results: At the gene level, LEP was associated with DFS (P = 0.017), and LEPR was associated with both DFS (P = 0.021) and CRC-specific survival (P = 0.013) in patients with CRC. In single-SNP analysis, LEP rs11763517, LEPR rs9436301, and LEPR rs7602 were associated with DFS after adjustment for multiple testing. The LEPR haplotypes G-C-T (rs7534511-rs9436301-rs1887285) and A-A-G (rs7602-rs970467-rs9436748) were associated with prolonged OS among patients with CRC overall (G-C-T: HR, 0.63; 95% CI, 0.43–0.93; A-A-G: HR, 0.59; 95% CI, 0.38–0.91) and those diagnosed with colon cancer (G-C-T: HR, 0.54; 95% CI, 0.34–0.86; A-A-G: HR, 0.49; 95% CI, 0.29–0.83). Similar results were observed for DFS. Moreover, significant interactions were found among LEPR rs7602 (A vs. G), LEPR rs1171278 (T vs. C), red meat intake, and BMI status: the associations between these variants and prolonged DFS were limited to patients with below-median red meat consumption and body mass index (BMI) < 25 kg/m2. Conclusions: Polymorphic variations in the LEP and LEPR genes were associated with survival of patients after CRC diagnosis. The LEP/LEPR-CRC survival association was modified by participants’ red meat intake and BMI.

Identification of extracellular matrix-related biomarkers in colon adenocarcinoma by bioinformatics and experimental validation

“…LEP plays an important role in regulating cellular metabolism. LEP stimulates tumor cell proliferation, inhibits cell apoptosis and promotes angiogenesis by binding to its receptor LEPR ( 19 , 36 ). Epidemiological studies support that LEP is associated with poor prognosis of COAD patients ( 19 ).…”

Progress in clinical diagnosis and treatment of colorectal cancer with rare genetic variants

“…However, not every rare genetic variation in CRC is a known risk factor or is correlated with poor prognosis. For example, in LEP and LEPR, some mutated haplotypes present at relatively low frequencies have been associated with prolonged OS and DFS among patients with CRC 85 .…”