Transforming growth factor (TGF)-beta1 gene common polymorphisms and plasma TGF-beta1 levels in patients with lung cancer

摘要

Transforming growth factor (TGF)-b1 is known to regulate many cellularprocesses, including cell proliferation, differentiation, and apoptosis. PlasmaTGF-b1 levels has been shown to be elevated in patients with lung cancer.In this study, we test the association of the polymorphisms at 2 loci, i.e.nucleotide position -509 in the promoter region (C-509T), and nucleotideposition 869 relative to the transcription initiation site (T869C) of theTGF-b1 gene using polymerase chain reaction-restriction fragment lengthpolymorphism (PCR-RFLP) and measure the plasma TGF-b1 levels. TGF-b1genotype and allele frequencies were not significantly different for patientswith lung cancer (n = 102) and controls (nonsmokers, n = 140 or smokers,n = 116). The odds ratio of the TGF-b1 C allele at nucleotide position 869was 0.51 (95% confidence interval 0.25 to 1.06; P = 0.0827) for patients andnonsmoking controls and 0.49 (95% confidence interval 0.23 to 1.03; P =0.0702) for patients and smoking controls in a dominant model (TC + CCversus TT), close to reach significant level. The patients group showedsignificant higher plasma TGF-b1 levels across different genotypes (1852 ±123 pg/ml vs. 3422 ± 158 pg/ml for nonsmoking controls and patientsrespectively). There was no difference in plasma TGF-b1 levels betweensmoking controls and patients. Our results suggest that TGF-b1polymorphisms do not play a role in the pathogenesis of lung cancer, eventhough there remains the possibility of a lower incidence of lung cancer forpolymorphism at nucleotide position 869, which need further investigation.(Supported by a University of Hong Kong, URC/CRCG Research Grant.)