P53 Codon 72 (Arg72Pro) Polymorphism and Prostate Cancer Risk: Association between Disease Onset and Proline Genotype

The tumor suppressor gene p53 plays an important role in the stress response of the cell and is mutated in 50% of all human tumors. The p53 Arg72Pro single-nucleotide polymorphism (SNP) was found to be associated with an increased risk of various malignancies. Biochemical and biological differences between the 2 polymorphic variants of wild-type P53 might lead to distinct susceptibility to HPV- and non-HPV-induced tumors. For prostate cancer, only limited data are available, especially in the Caucasian pop-ulation. Therefore, we determined the distribution of the Arg72Pro SNP in a Caucasian case-control study including 118 prostate cancer patients and 194 male controls without any malignancy using restriction fragment length polymorphism analysis. A subset of 33 tumors was tested for HPV infection, and no HPV DNA was found. Cases and controls showed similar distributions of alleles in the SNP (p = 0.720). Regarding the onset of the disease, patients diagnosed at ≤60 years of age and older patients (>60 years of age) showed a significant difference in genotype distribution (p = 0.035); there was also an increased occurrence of risk allele Pro72 in cases aged ≤60 years (p = 0.045). A subset of 64 prostate tumors was stained immunohistochemically for P53. 5 of 64 prostate tumors (7.8%) were positive for P53 expression, indicating integrity of the protein in the majority of cases. Genotype distribution showed no association with the Gleason score or additional histopathological characteristics. This study shows that the overall risk of prostate cancer was not associated with Arg72Pro SNP and HPV infection in our cohort. However, disease onset might be modulated by the p53 Pro72 allele, suggesting an important role of apoptosis regulation in prostate carcinogenesis

Cytogenetic analysis of HER1/EGFR, HER2, HER3 and HER4 in 278 breast cancer patients

INTRODUCTION: The HER (human EGFR related) family of receptor tyrosine kinases (HER1/EGFR (epidermal growth factor receptor)/c-erbB1, HER2/c-erbB2, HER3/c-erbB3 and HER4/c-erbB4) shares a high degree of structural and functional homology. It constitutes a complex network, coupling various extracellular ligands to intracellular signal transduction pathways resulting in receptor interaction and cross-activation. The most famous family member is HER2, which is a target in Herceptin therapy in metastatic status and also in adjuvant therapy of breast cancer in the event of dysregulation as a result of gene amplification and resulting protein overexpression. The HER2-related HER receptors have been shown to interact directly with HER2 receptors and thereby mutually affect their activity and subsequent malignant growth potential. However, the clinical outcome with regard to total HER receptor state remains largely unknown. METHODS: We investigated HER1-HER4, at both the DNA and the protein level, using fluorescence in situ hybridisation (FISH) probes targeted to all four receptor loci and also immunohistochemistry in tissue microarrays derived from 278 breast cancer patients. RESULTS: We retrospectively found HER3 gene amplification with a univariate negative impact on disease-free survival (hazard ratio 2.35, 95% confidence interval 1.08 to 5.11, p = 0.031), whereas HER4 amplification showed a positive trend in overall and disease-free survival. Protein expression revealed no additional information. CONCLUSION: Overall, the simultaneous quantification of HER3 and HER4 receptor genes by means of FISH might enable the rendering of a more precise stratification of breast cancer patients by providing additional prognostic information. The continuation of explorative and prospective studies on all HER receptors will be required for an evaluation of their potential use for specific therapeutic targeting with respect to individualised therapy

Immunohistochemical and molecular characterizations in urothelial carcinoma of bladder in patients less than 45 years

Bladder tumours in early-onset patients are rare and seem to exhibit unique clinicopathological features. Only few studies have investigated somatic alterations in this specific age of onset group and evidence is accumulating of a distinct molecular behaviour of early-onset bladder tumours. We collected the largest cohort of early-onset tumours of patients 45 years old or younger and aimed to test genomic alterations typically found in bladder cancer. Tumours of 118 early-onset patients were compared with a consecutive group of 113 cases. Immunohistochemistry of TP53, CK20 and Ki-67 was carried out. Molecular analysis was conducted to test for loss of heterozygosity of chromosome 9 and 17, as well as TP53 and FGFR3 mutations. Fisheŕs exact and chi-squared test were appropriately used. No differences in grade/stage characteristics were observed. Overexpressed TP53 was differentially distributed between the two groups. TP53 nuclear accumulation was significantly more frequent in early-onset papillomas, PUNLMPs and pTa low-grade tumours compared to the consecutive cohort (p=0.005). Moreover, chromosome 9 deletions (29.5% vs. 44.6%) and FGFR3 mutations (34.5% vs. 63.7%) were less often detected in early-onset patients (p=0.05 and p<0.0001). By comparing the largest cohort of early-onset bladder cancer patients with an unselected group, we demonstrated that the typical molecular features are not independent of age at diagnosis. Our study supports the hypothesis of a distinct biological behaviour in early-onset tumours

Extraction of cells from paraffin-embedded tissue sections for single-cell DNA cytophotometry.

A simple technique is presented for the isolation of cells from paraffin-embedded tissues for Feulgen DNA cytophotometric investigations. Tissue fragments from paraffin blocks were deparaffinized in xylene, rehydrated and refixed in a formalin solution and incubated in a solution of 0.5 pepsin in 0.25% hydrochloric acid. After filtration through a 70 micron mesh and centrifugation, the cells were smeared upon a glass slide. Comparison between the results obtained with freshly prepared imprints and with pepsin-extracted cells of the same tumor showed that the extraction technique does not influence the Feulgen reaction or the DNA distribution pattern. Investigations carried out on bladder and embryonal carcinomas have demonstrated that the method permits an analysis of histologically or histochemically identified tumor cells within individual tissue areas

Ultrastructural telepathology - remote EM-diagnostic via Internet

New collaboratory opportunities in ultrastructural research and diagnostics are now available on the Internet through the combination of digital image acquisition, remote operation of modern digitally controlled and automated electron microscopes, and the development of software specifically tailored for collaboratory needs. Remote experts can examine samples directly, and unique instruments can be utilized from anywhere. In the case of diagnostic dilemmas, the second-opinion expert is no longer constrained by problems inherent in the interpretation of preselected images. The remote examiner can independently choose the area of interest on the sample as well as select the appropriate magnification for an accurate diagnosis. With these capabilities and together with teleconferencing tools and securely accessible databases on-line, telepathology can provide increased effectiveness and support for diagnostics, research, and teaching in many areas. The authors report their experience with remote electron microscope diagnoses of pathological samples using two different dynamic imaging systems and discuss the main technical issues encountered. It appears that only minor technical issues need to be resolved before ultrastructural telepathology can be promoted for routine use in areas with high-speed Internet access