Molecular screening of interleukin-6 gene promoter and influence of −174G/C polymorphism on breast cancer

• Published in: Cytokine (Philadelphia, Pa.) Pa.), 2009-09, Vol.47 (3), p.214-223
• Main Authors: Chérel, Michel, Campion, Loïc, Bézieau, Stéphane, Campone, Mario, Charrier, Josiane, Gaschet, Joëlle, Ricolleau, Gabriel, Gouraud, Wilfried, Charbonnel, Catherine, Jézéquel, Pascal
• Format: Article
• Language: English
• Subjects: Adult; Base Sequence; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - genetics; Breast Neoplasms - mortality; Disease-Free Survival; Female; Gene Frequency; Genetic Markers; Humans; Interleukin-6 - genetics; Interleukin-6 promoter; Middle Aged; Molecular Sequence Data; Polymorphism; Polymorphism, Single Nucleotide; Prognosis; Prognostic; Promoter Regions, Genetic; Sequence Analysis, DNA; Sequencing
• ISSN: 1043-4666; 1096-0023
• DOI: 10.1016/j.cyto.2009.06.011

Interleukin-6 (IL-6) is a cytokine involved in different physiologic and pathophysiologic processes including carcinogenesis. In 2003, a single nucleotide polymorphism (−174G/C) of the IL-6 gene promoter has been linked to breast cancer prognosis in node-positive (N+) breast cancer patients. Since, different studies have led to conflicting conclusions about its role as a prognostic and/or diagnostic marker. The primary aim of our study was to investigate the link between −174G/C polymorphism and breast cancer risk on the one hand, and −174G/C polymorphism and prognosis in different groups of patients: sporadic N+ breast cancers ( n = 138), sporadic N− breast cancers ( n = 95) and familial breast cancer ( n = 60) on the other hand. The variables of interest were disease-free survival and overall survival. The secondary aim of the study was to screen IL-6 gene promoter using direct sequencing to identify new polymorphisms in our French Caucasian breast cancer population. No association or trend of association between −174G/C polymorphism of IL-6 gene promoter gene and breast cancer diagnosis or prognosis was shown, even in meta-analyses. Furthermore, we have identified four novel polymorphic sites in the IL-6 gene promoter region: −764G → A, −757C → T, −233T → A, 15C → A.