title: IL-6 polymorphism in non-small cell lung cancer: a prognostic value?
abstract: Lung cancer was found to be the most commonly diagnosed cancer, as well as the primary cause of cancer-related mortality for males worldwide and the second leading cause of cancer-related deaths for women. Cytokines are fundamental for several biological processes-associated malignant tumors. The IL-6 is a cytokine involved in the regulation of cellular functions including processes associated with cancer, such as proliferation, apoptosis, angiogenesis, and differentiation. Furthermore, IL-6 is a potent pleiotropic inflammatory cytokine that is considered a key growth-promoting and antiapoptotic factor. The polymorphism-174G/C SNP is a G to C transition in the -174 position of the promoter region of the IL-6 gene. The aim of our study was to evaluate the influence of -174G/C polymorphism in clinical outcome of non-small cell cancer (NSCLC) patients. DNA was extracted from peripheral blood of 424 patients diagnosed with cytologically or histologically NSCLC. The characterization of IL-6 -174G/C genotypes was performed by PCR-RFLP (NlaIII). IL-6 polymorphism's genotypes were divided according to functional activity, so the G carriers (CG/GG) is the high-producer IL-6, and CC genotype is the low-producer IL-6. Regarding survival, we verify that patients with genotypes carrying the G allele (CG/GG) had a statistically significant diminished survival when compared with patients with CC genotype (62.79 and 42.31 months, respectively; P = 0.032). In the promoter region of the IL-6 gene, polymorphic variants were located and may be responsible for alterations in transcription that consequently affect serum levels of the cytokine. With our study, we demonstrated that genetic variant (-174G/G and G/C) can be responsible for changes in prognosis of NSCLC patients.
authors.affiliation: Molecular Oncology Group-CI, Portuguese Institute of Oncology, Porto, Portugal, monicagomes26@gmail.com.
authors.forename: Mónica
authors.initials: M
authors.lastname: Gomes
authors.forename: Ana
authors.initials: A
authors.lastname: Coelho
authors.forename: António
authors.initials: A
authors.lastname: Araújo
authors.forename: Andreia
authors.initials: A
authors.lastname: Azevedo
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Teixeira
authors.forename: Raquel
authors.initials: R
authors.lastname: Catarino
authors.forename: Rui
authors.initials: R
authors.lastname: Medeiros
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics*; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011379:Prognosis
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6