A genome wide association study for backfat thickness in Italian Large White pigs highlights new regions affecting fat deposition including neuronal genes.

BACKGROUND: Carcass fatness is an important trait in most pig breeding programs. Following market requests, breeding plans for fresh pork consumption are usually designed to reduce carcass fat content and increase lean meat deposition. However, the Italian pig industry is mainly devoted to the production of Protected Designation of Origin dry cured hams: pigs are slaughtered at around 160 kg of live weight and the breeding goal aims at maintaining fat coverage, measured as backfat thickness to avoid excessive desiccation of the hams. This objective has shaped the genetic pool of Italian heavy pig breeds for a few decades. In this study we applied a selective genotyping approach within a population of ~ 12,000 performance tested Italian Large White pigs. Within this population, we selectively genotyped 304 pigs with extreme and divergent backfat thickness estimated breeding value by the Illumina PorcineSNP60 BeadChip and performed a genome wide association study to identify loci associated to this trait. RESULTS: We identified 4 single nucleotide polymorphisms with P≤5.0E-07 and additional 119 ones with 5.0E-07

Gene expression profiling in glioblastoma and immunohistochemical evaluation of IGFBP-2 and CDC20.

Thirty-nine glial tumours (28 glioblastomas (GB) and 11 low-grade gliomas) were investigated with DNA microarrays to reveal a possible specific gene expression profile. Unsupervised classification through hierarchical cluster analysis identified two groups of tumours, the first composed of low-grade gliomas and the second mainly composed of GB. Nine genes were identified as most informative: seven were over-expressed in low-grade gliomas and under-expressed in GB; on the contrary, two genes, insulin-like growth factor binding protein 2 (IGFBP-2) and cell division cycle 20 homologue (CDC20), were over-expressed in GB and under-expressed in low-grade tumours. This same genetic profile was confirmed by reverse transcriptase polymerase chain reaction. Immunohistochemistry for IGFBP-2 was positive in 88.8% of the cases of GB and in only one low-grade glioma, whilst CDC20 immunostained 74.1% of the cases of GB and none low-grade glioma. This was confirmed in an additional series of cases studied with immunohistochemistry only. In conclusion, over-expression of mRNA levels of IGFBP-2 and CDC20 is highly related to GB, IGFBP-2 and CDC-20 gene and protein expressions are strongly correlated, and IGFBP-2 and CDC20 immunopositivity can be useful for the identification of GB in small biopsies.

The impact of large sections on the study of in situ and invasive duct carcinoma of the breast.

Large histologic sections (LHSs) are increasingly used in the study of normal and neoplastic breast tissue. LHSs allow the direct visualization of a large part of the breast glandular tree. Accordingly, LHSs have shown that in situ and invasive lobular carcinoma is a multilobar (and hence multifocal) neoplastic lesion in more than 50% of the cases, and that poorly differentiated duct carcinoma in situ (DCIS grade 3) is frequently unifocal, whereas it is often multifocal when the in situ lesion is a well-differentiated type (DCIS grade 1). Forty-five mastectomies were studied with large sections. Mastectomies were performed when quadrantectomy did not guarantee radical excision of the tumor with adequate cosmesis because of the large size of the lesion or because the neoplastic lesion was located below the nipple. Excluded were cases of lobular neoplasia or invasive lobular carcinoma, because they were reported separately, and cases of mastectomies performed for sarcoma or recurrent phyllodes tumor. All cases had undergone a preoperative diagnostic procedure (fine needle aspiration), and the relative positive material was reviewed. All 45 cases showed in situ duct carcinoma and 37 showed evidence of invasive duct carcinoma. Forty-two cases of DCIS were multifocal, whereas only 4 invasive duct carcinoma were shown as multifocal. When DCIS lesions were subdivided into 3 grades, no statistical significance was seen among the 3 groups of DCIS in regard to multifocality. Nevertheless, DCIS grade 1 was a widespread condition involving more than one lobe and quadrant, whereas DCIS grades 2 and 3 appeared more localized. DCIS grade 1 was more similar to that previously observed in lobular in situ neoplasia/lobular in situ carcinoma. In 66.6% of the cases, DCIS foci were found within the invasive areas, indicating a more than fortuitous occurrence (2-sided P=.0357).