Kathrin Riemann

The human X-ray repair cross-complementing group 1 (XRCC1) enzyme plays an important role in response to DNA damage. Two common polymorphisms in XRCC1, Arg194Trp and Arg399Gln, have been repeatedly associated with risk for and outcome of numerous types of cancer treated with radio- and chemotherapy. Recently, a Japanese study suggested these polymorphisms both as risk factors and outcome predictors in renal cell carcinoma (RCC). In the present study, 142 Caucasian patients suffering from RCC were genotyped and analyzed for tumor-related and overall survival and time to metastasis and progression. Analyses revealed absence of the pre-described risk haplotype (194Trp/399Gln) as well as a lack of a statistically significant difference between the different endpoints and genotypes and diplotypes, respectively. We conclude that in Caucasian patients, XRCC1 polymorphisms do not influence the outcome of RCC.

Polymorphisms in genes encoding subunits of heterotrimeric G proteins have been repeatedly associated with the course of cancer. As previously shown, intron 1 of GNB4 harbours distinct haplotype blocks and block 1 is associated with survival and disease progression in urothelial bladder cancer. This study investigated whether haplotype block 2 is associated with survival in colorectal cancer patients. The haplotype tagging polymorphism of GNB4 haplotype block 2 was genotyped in 136 colorectal cancer patients and associated with demographic and clinical data and survival. Haplotype block 2 is associated with survival in colorectal cancer patients. Patients with advanced tumour stages carrying the 2*1 haplotype revealed decreased survival (HR 2.04, 95% CI 0.91-3.69). In multivariate analysis, the diplotypes were independent prognostic factors. Intron-1 haplotypes of GNB4 might be predictive markers for survival of patients with advanced colorectal cancer, thus influencing the clinical management of these patients.

Purpose Polymorphisms in genes encoding subunits of heterotrimeric G proteins have been repeatedly associated with various cancers. As Gβγ signaling is presumed to be involved in proliferation and invasion processes, we analyzed genetic variations in regulatory regions of GNB4, which encodes the Gβ4 subunit, for their potential influence on cancer progression. Experimental Design We characterized the promoter of GNB4 and screened the promoter as well as exon 1 and intron 1 for single nucleotide polymorphisms by sequencing 100 healthy controls. Following a haplotype analysis, we determined the functional impact upon gene expression of the defined haplotypes by reporter assays, electrophoretic mobility shift assay and western blot. In addition, these haplotypes were tested for their relation to the disease course of urothelial bladder cancer. Results Whereas the promoter of GNB4 revealed no polymorphisms, 33 single nucleotide polymorphisms located in exon 1 and intron 1 were identified and together with a common exon-4 polymorphism implemented in haplotype analysis, which resulted in the determination of distinct haplotype blocks. Reporter activity was haplotype-dependently different (P=0.001). 1*1/1*1 showed increased Gβ4 protein (P=0.003), and bladder cancer patients carrying this diplotype displayed more progressive disease (P=0.046) and a significantly increased mortality (P=0.046). In multivariate analysis,the diplotypes were independent prognostic factors for survival and progression. Conclusion Intron-1 haplotypes of GNB4 may, thus, serve as predictive markers for progression and survival of patients suffering from bladder cancer.

Bladder cancer is a leading cause of morbidity and mortality. Despite intensive research efforts, histopathological diagnosis of grade and stage, the most important markers for predicting the outcome of the disease, is still necessary. Therefore, a new candidate gene was investigated with regard to its potential utility as a prognostic marker for the course of disease in bladder cancer. A functional insertion/deletion polymorphism has recently been identified in the promoter region of NFKB1 which regulates transcription of the transcription factor NF-kappaB. Several genes involved in oncogenic processes are controlled by NF-kappaB and might be influenced by alterations in its expression.

Nucleic acid extraction and purification from whole blood is a routine application in many laboratories. Automation of this procedure promises standardized sample treatment, a low error rate, and avoidance of contamination. The performance of the BioRobot M48 (Qiagen) and the manual QIAmp^® DNA Blood Mini Kit (Qiagen) was compared for the extraction of DNA from whole blood. The concentration and purity of the extracted DNAs were determined by spectrophotometry. Analytical sensitivity was assessed by common PCR and genotyping techniques. The quantity and quality of the generated DNAs were slightly higher using the manual extraction method. The results of downstream applications were comparable to each other. Amplification of high‐molecular‐weight PCR fragments, genotyping by restriction digest, and pyrosequencing were successful for all samples. No cross‐contamination could be detected. While automated DNA extraction requires significantly less hands‐on time, it is slightly more expensive than the manual extraction method. J. Clin. Lab. Anal. 21:244–248, 2007.