Low-penetrance susceptibility variants and postmenopausal oestrogen receptor positive breast cancer
JOURNAL OF GENETICS
Authors: Ozgoz, Asuman; Mutlu Icduygu, FadIme; Yukselturk, Aysegul; Samli, Hale; HekImler ozturk, Kuyas; Baskan, Zuhal
Abstract
The risk of breast cancer (BC) in women is high and many factors including genetic factors increase the risk for the disease. It is revealed that the variations of low-penetrance susceptibility genes are important for carcinogenesis as they interact with the environmental and hereditary factors. Recently, the list of BC-associated common single nucleotide polymorphisms (SNPs) and chromosomal loci in low-penetrance susceptibility genes have been expanded in genomewide association studies. FGFR2, LSP1, MAP3K1, TGFB1, TOX3, 2q35 and 8q loci variations are some examples for these common SNPs. These SNPs and their association with BC risk was investigated in many different populations. Therefore in this study, we aimed to evaluate low-penetrance susceptibility SNPs; namely FGFR2 rs1219648, rs2981579, rs2981582; MAP3K1 rs889312; TOX3 rs3803662; LSP1 rs909116, rs3817198 and SLC4A7 rs4973768 together, for the first time in Turkish postmenopausal oestrogen receptor positive BC cases. Following the DNA isolation, multiplex PCR and matrix-assisted laser desorption/ionization mass spectrometry with time of flight measurement (MALDI-TOF) based SNP analysis were performed. MAP3K1 rs889312 SNP demonstrated the strongest association with BC risk among the other low penetrant SNPs, it was also associated with BC risk in a dominant model. Only in a ressesive model, TOX3 rs3803662 was associated with BC risk. In addition, rs4973768 CC and rs909116 CC genotypes are correlated with higher tumour size which is not reported in the literature as yet; on the other hand there are no associations between any of the other SNP genotypes and clinopathological parameters. In our opinion, MAP3K1 rs889312 may be a good BC susceptibility biomarker candidate for Turkish population.
S-Adenosylmethionine Treatment of Colorectal Cancer Cell Lines Alters DNA Methylation, DNA Repair and Tumor Progression-Related Gene Expression
CELLS
Authors: Zsigrai, Sara; Kalmar, Alexandra; Nagy, Zsofia B.; Bartak, Barbara K.; Valcz, Gabor; Szigeti, Krisztina A.; Galamb, Orsolya; Danko, Titanilla; Sebestyen, Anna; Barna, Gabor; Szabo, Vanessza; Pipek, Orsolya; Medgyes-Horvath, Anna; Csabai, Istvan; Tulassay, Zsolt; Igaz, Peter; Takacs, Istvan; Molnar, Bela
Abstract
Global DNA hypomethylation is a characteristic feature of colorectal carcinoma (CRC). The tumor inhibitory effect of S-adenosylmethionine (SAM) methyl donor has been described in certain cancers including CRC. However, the molecular impact of SAM treatment on CRC cell lines with distinct genetic features has not been evaluated comprehensively. HT-29 and SW480 cells were treated with 0.5 and 1 mmol/L SAM for 48 h followed by cell proliferation measurements, whole-genome transcriptome and methylome analyses, DNA stability assessments and exome sequencing. SAM reduced cell number and increased senescence by causing S phase arrest, besides, multiple EMT-related genes (e.g.,TGFB1) were downregulated in both cell lines. Alteration in the global DNA methylation level was not observed, but certain methylation changes in gene promoters were detected. SAM-induced gamma-H2AX elevation could be associated with activated DNA repair pathway showing upregulated gene expression (e.g.,HUS1). Remarkable genomic stability elevation, namely, decreased micronucleus number and comet tail length was observed only in SW480 after treatment. SAM has the potential to induce senescence, DNA repair, genome stability and to reduce CRC progression. However, the different therapeutic responses of HT-29 and SW480 to SAM emphasize the importance of the molecular characterization of CRC cases prior to methyl donor supplementation.