Colorectal cancer susceptibility: apparent gender-related modulation by ABCB1 gene polymorphisms

Background: The ATP-binding cassette transporter B1 (ABCB1) gene codes for a membrane efflux pump localized in epithelial cells. Together with other Permeability-glycoproteins in the small and large intestine, its product represents a barrier against xenobiotics, bacterial toxins, drugs and other substances introduced with diet, including carcinogens. The aim of this investigation was to verify the possible contribution of ABCB1 single nucleotide polymorphisms (SNPs) to the genetic risk of colorectal cancer (CRC). Results: DNA obtained from the peripheral blood of 98 CRC patients and 100 healthy controls was genotyped for the three selected SNPs: 1236C > T (rs1128503), 2677G > T/A (rs2032582), and 3435C > T (rs1045642). Molecular data were analyzed to asses allele and haplotype association with CRC. No evidence of an association between ABCB1 alleles and CRC occurrence as a whole was found. However, ABCB1 showed either association with carcinoma of the sigmoid colon, and appeared able to influence the sex ratio among CRC patients. These two effects seemed to act independently based on multivariate analysis. We showed that ABCB1 polymorphisms were able to influence CRC susceptibility related to tumor localization and patient gender. Conclusions: We suggest that sensitivity to undetermined risk factors could depend on the genetic background of ABCB1 locus, with a mechanism that also depends on patient gender

Transportin 3 (TNPO3) and related proteins in limb girdle muscle dystrophy D2 muscle biopsies: a morphological confocal microscopy study and pathogenetic hypothesis

LGMD D2 is a disease caused by TNPO3 mutation. We describe the expression of TNPO3 and selected proteins, likely modified by TNPO3 mutation, in muscle biopsies of affected patients. We also aim to find other genes involved in pathways correlated to TNPO3. Our morphological study on LGMD D2 muscle described the expression of TNPO3 and SRSF1, a splicing factor transported by TNPO3. Moreover, we investigated some sarcomeric and nuclear proteins, likely altered by TNPO3 mutation. Through an in silico approach we tried to identify genes involved in pathways that include, besides TNPO3 and SRSF1, p62 and Murf-1, altered in LGMD D2. In patients\u2019 muscles TNPO3 appeared weaker and randomly organized, with sporadic cytoplasmic aggregates positive for TNPO3; both SRSF1 and sarcomeric alpha actinin showed a different expression, while there were no alterations in the expression of the nuclear proteins. The in silico study lead to identify five genes, all coding for proteins responsible for muscle contraction. Our data suggest a possible interference in the morphology and function of myofibrillar network by mutated TNPO3; these findings are supported by the in silico identification of genes involved in muscle contraction that could help to explain the pathogenic mechanisms of LGMD D2