Expression of CYP and GST in human normal and colon tumor tissues.

We investigated the immunohistochemical staining characteristics of cytochrome P450 1A1 (CYP1A1), CYPB1, CYP2E1, and glutathione S-transferase P1 (GSTP1), GSTT1, GSTO1, GSTK1 in colon tumor and surrounding normal colon tissues. Tissues were obtained from 47 patients with colon adenocarcinoma and the staining intensity of tumor and control tissues was compared. CYP1A1, CYP1B1, CYP2E1, GSTP1, GSTT1, GSTO1 and GSTK1 expressions in colon cancer cells were significantly greater than those in normal colon epithelial cells. No significant relation was found between the isoenzyme expressions and age, gender, smoking status, tumor grade and tumor stage. The higher expressions of CYP1A1, CYP1B1, CYP2E1, GSTP1, GSTO1, GSTT1 and GSTK1 in tumor than in normal colon tissues may be important for colon cancer progression and development.

Relationship between perilipin genes polymorphisms and growth, carcass and meat quality traits in pigs.

The perilipins (PLIN) belong to a family of structural proteins that play a role regulating intracellular lipid storage and mobilization. Here, PLIN1 and PLIN2 have been evaluated as candidate genes for growth, carcass and meat quality traits in pigs. A sample of 607 Duroc pigs were genotyped for two single-nucleotide polymorphisms, one in intron 2 of the PLIN1 gene (JN860199:g.173G>A) and the other at the 3' untranslated region of the PLIN2 gene (GU461317:g.98G>A). Using a Bayesian approach, we have been able to find evidence of additive, dominant and epistatic associations of the PLIN1 and PLIN2 polymorphisms with early growth rate and carcass length. However, the major effects were produced by the dominant A allele at the PLIN2 polymorphism, which also affected the carcass lean weight. Thus, pigs carrying an additional copy of the A allele at the g.98G>A PLIN2 polymorphism had a probability of at least 98% of producing carcasses with heavier lean weight (+0.41 kg) and ham weight (+0.10 kg). The results obtained indicate that the PLIN2 polymorphism could be a useful marker for lean growth. In particular, it may help to reduce the undesired negative correlated response in lean weight to selection for increased intramuscular fat content, a common scenario in some Duroc lines involved in the production of high quality pork products.

Expression profiling of the GBP1 gene as a candidate gene for porcine reproductive and respiratory syndrome resistance.

A genomic region in pig chromosome 4 has been previously associated with higher viraemia levels and lower weight gain following porcine reproduction and respiratory syndrome virus (PRRSV) infection. The region includes the marker WUR1000125, a G>A polymorphism next to a putative polyadenylation site in the 3'-untranslated region (3'-UTR) of the guanylate-binding protein 1, interferon-induced (GBP1) gene. The protein encoded by GBP1 is a negative regulator of T-cell responses. We show here that GBP1 expression is lower in liver and tonsils of pigs carrying the WUR1000125-G allele due to differential allele expression (allele A expression is 1.9-fold higher than for allele G). We also show that the GBP1 gene has two active polyadenylation signals 421 bp apart and that polyadenylation usage is dependent on the WUR1000125 genotype. The distal site is the most prevalently used in all samples, but the presence of the A allele favours the generation of shorter transcripts from the proximal site. This is confirmed by a differential allele expression study in AG genotype liver and tonsil samples. The interaction between WUR1000125 and other mutations identified in the 5'- and 3'-UTR regions of this gene needs to be studied. In conclusion, our study indicates that the WUR1000125 mutation is associated with changes in the expression of the negative T-cell regulator GBP1 gene. However, the chromosome 4 locus for PRRSV viraemia levels and weight gain contains a cluster of four other GBP genes that remain to be studied as candidate genes for this QTL.