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Background: Breast cancer (BC) is currently regarded as a heterogeneous disease classified, through gene expression analysis, into various molecular subtypes with different biological characteristics and clinical behaviour. Using a few protein biomarkers as estrogen, progesterone and HER2 receptors, BC subtypes can be divided in four main groups: luminal A, luminal B, HER2 and triple negative (TN). Triple negative BC are a heterogeneous subset of tumors grouped together on the basis of their lack of hormone receptor and HER2 expression. Although they demonstrate similarities in terms of pathological and molecular characteristics, they do not represent a uniform clinical entity since the expression of the basal cytokeratin (CK5) and EGFR may identify a subgroup, called basal-like, of very aggressive tumors encompassing about 10% of BC that display a particularly poor prognosis. Recently, in vitro and in vivo studies reported that the length of a CA Simple Sequence Repeat 1 (CASSRI) dinucleotides in the intron 1 of egfr was associated with the expression of EGFR. In addition, the loss of heterozigosity (LOH) within this region would also lead to altered receptor expression. In this study we aimed to determine the association between LOH and overexpression of EGFR in a series of basal-like BC and their in autologous uninvolved peritumoral tissues (PTT) in comparison to normal tissues (NT). Material and Methods: 35 TN BC, the correspondent PTT and the autologous NT were analyzed for EGFR, CK5 expression by immunohistochemistry (IHC) and for LOH using a fragment separation performed by capillary electrophoresis (ABI 3130 Applied Biosystem). The assessment of LOH on the three tissue substrates were evaluated comparing the peak area of the two alleles using the following equation: LOH score=T1XN2/T2XN1, where T is BC or PTT, N is normal tissue, 1 is the area under the peak corresponding to the shorter allele, and 2 to the longer allele. The result was significantly different from the ratio of the normal allele peak areas when the LOH score was < 0.79 (loss of the longer allele) or >1.27 (loss of the shorter allele). Results: Of the 35 TN BC, 29 (83%) expressed EGFR and/or CK5 and were defined basal-like BC. The remaining 6 (17%) cases, negative both for EGFR and CK5, were excluded from the study. Of the 16 EGFR positive basal-like BC, 10 (63%) showed LOH whereas of the 13 EGFR negative basal-like BC, only 3 (23%) showed LOH (p=0.03). Although in the majority basal-like BC with LOH (8/10; 80%) PTT displayed a genetic profile similar to NT and did not show LOH, interestingly, in 2 cases (20%) PTT is different from NT presenting LOH and expressing EGFR as the autologous BC. Conclusions: Our data indicate that LOH of CASSRI in the intron 1 of egfr is related to EGFR expression in basal-like BC. In addition, the evidence of LOH in PTT, denoting the occurrence of early molecular alterations in histologically normal tissues, could represent a potential biomarker with diagnostic/prognostic implications. Supported by AIRC Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-10.

Puroindolines, the tryptophan-rich proteins controlling grain hardness in wheat, appeared as two pairs of 13 kDa polypeptides in the Acid-PAGE (A-PAGE) and two-dimensional A-PAGE×SDS-PAGE patterns of starch-granule proteins from wild allotetraploid wheat Aegilops ventricosa Tausch. (2n = 4x = 28, genomes DvDvNvNv). Puroindoline pair a1 + a2 reacted strongly with an antiserum specific for puroindoline-a from common wheat (Triticum aestivum L.), whereas puroindoline pair b1 + b2 exhibited A-PAGE relative mobilities similar to that of puroindoline-b in Aegilops tauschii (Coss.), the D-genome donor to both common wheat and Ae. ventricosa. Puroindolines a2 and b1 were found to be encoded by alleles Pina-D1a and Pinb-D1h on chromosome 5Dv, respectively, whereas puroindolines a1 and b2 were assumed to be under the genetic control of chromosome 5Nv. Puroindoline a1 encoded by the novel Pina-N1a allele exhibited a high level of amino acid variation with respect to puroindoline-a. On the other hand, the tryptophan-rich region of puroindoline b2 encoded by allele Pinb-N1a showed a sequence change from lysine-42 to arginine, with no effect on the amount of protein b2 accumulated on the starch granules. A partial duplication of the pin-B gene (Pinb-relic) was identified about 1100 bp downstream from Pinb-D1 on chromosome 5Dv. The present findings are the first evidence of a tetraploid wheat species in which four puroindoline genes are expressed. The potential of Ae. ventricosa as a source of genes that may be used to modulate endosperm texture and other valuable traits in cultivated wheat species is discussed.

TP53 is the most widely mutated gene across all cancer types. In head and neck cancer, approximately half of the tumors are found to contain TP53 mutations, which are correlated to an increased risk for locoregional recurrence and poor outcomes. In this study a mutational profiling of TP53 exons 5-8 was performed on tumor, peritumor and normal tissues from 57 HNSCC patients by direct sequencing of genomic DNA and cDNA. Cloning/sequencing in tumors carrying multiple TP53 mutations and semiquantitative SNaPShot mutation assay was performed in order to assess eventual allelic expression imbalances (AEI). We identified 24 out of 57 HNSCC patients (42%) carrying TP53 mutations and 5 patients carrying the R213R polymorphism. Cloning of the genomic DNA encompassing TP53 exons 5-8 from tumors with multiple TP53 mutations revealed that alleles carrying different types of TP53 mutations are present in these tumors. TP53 missense and nonsense mutations exhibit higher and lower TP53 transcript abundance compared to wild-type TP53 allele, respectively. Interestingly, three out of four patients with the R213R polymorphism analyzed were found positive for TP53 loss of heterozygosity (LOH) and also presented higher transcript abundance than the wild-type counterpart, specifically, in the tumor tissue and not in peritumor or normal tissues. HNSCC tumors present heterogenic cell populations carrying different TP53 mutations. All HNSCC samples analyzed show an alteration in the expression of mutated TP53 mRNA compared to the wild-type allele, most likely independently from the TP53 hemizygous status. The higher expression of R213R TP53 polymorphic allele in cancer tissue compared to normal tissue demonstrates a noninherited variation in allelic expression, independently from its mutation status for exons 5-8, suggesting a potential contribution to TP53 expression in HNSCC disease.

Background: The key role of egfr in thymoma pathogenesis has been questioned following the failure in identifying recurrent genetic alterations of egfr coding sequences and relevant egfr amplification rate. We investigated the role of the non-coding egfr CA simple sequence repeat 1 (CA-SSR-1) in a thymoma case series. Methods: We used sequencing and egfr-fluorescence in situ hybridization (FISH) to genotype 43 thymomas; (I) for polymorphisms and somatic loss of heterozygosity of the non-coding egfr CA-SSR-1 microsatellite and (II) for egfr gene copy number changes. Results: We found two prevalent CA-SSR-1 genotypes: A homozygous 16 CA repeat and a heterozygous genotype, bearing alleles with 16 and 20 CA repeats. The average combined allele length was correlated with tumor subtype: Shorter sequences were significantly associated with the more aggressive WHO thymoma subtype group including B2/B3, B3 and B3/C histotypes. Four out of 29 informative cases analysed for somatic CA-SSR-1 loss of heterozygosity showed allelic imbalance (AI), 3/4 with loss of the longer allele. By egfr-FISH analysis, 9 out of 33 cases were FISH positive. Moreover, the two integrated techniques demonstrated that 3 out of 4 CA-SSR-1-AI positive cases with short allele relative prevalence showed significantly low or high chromosome 7 "polysomy"/increased gene copy number by egfr-FISH. Conclusions: Our molecular and genetic and follow up data indicated that CA-SSR-1-allelic imbalance with short allele relative prevalence significantly correlated with EGFR 3+ immunohistochemical score, increased egfr Gene Copy Number, advanced stage and with relapsing/metastatic behaviour in thymomas. © Journal of Thoracic Disease.