High levels of leptin and non-high molecular weight-adiponectin in patients with colorectal cancer: Association with chemotherapy and common genetic polymorphisms

Abstract

Colorectal cancer (CRC) is the third most frequently diagnosed cancer worldwide. Leptin and adiponectin are hormones produced by adipose tissues, which exhibit opposing effects on tumor growth. Leptin promotes tumor development and metastasis, whereas adiponectin attenuates this. The aim of the present study was to assess the possible association between leptin and adiponectin [both high molecular weight (HMW) and non-HMW factions] levels with CRC, CRC response to chemotherapy, and to study the relationship between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270), and ADIPO (rs822369) polymorphisms and CRC. A total of 32 blood samples collected from CRC patients were analyzed to identify the serum levels of leptin and adiponectin, and the presence of CRC related polymorphisms. A total of 25 healthy subjects were recruited in the control group. Serum levels of leptin and adiponectin were detected using ELISA whereas DNA from patients and controls was amplified and analyzed using PCR-restriction fragment length polymorphism assay. The results showed that the levels of leptin and non-HMW adiponectin were significantly higher in CRC patients compared with the controls (P<0.05). In addition, HMW adiponectin was significantly higher in patients receiving chemotherapy. The association between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270) and ADIPO (rs822369) polymorphisms and CRC was not significant (P>0.05). In conclusion, higher leptin and non-HMW adiponectin levels may be associated with increased CRC. Chemotherapy may positively influence the levels of HMW adiponectin. No association between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270) and ADIPO (rs822369) polymorphisms with CRC was found.