The 471delAAAG mutation and C353T polymorphism in the RNASEL gene in sporadic and inherited cancer in Israel

[RNASEL study of genetics of prostate cancer and its relation to clinical staging]

OBJECTIVES

This study has aimed to find a possible genetic relationship between sporadic prostate cancers. An attempt is made to establish population subgroups in patients based on the genotype found and the aggressiveness of the cancer.

MATERIAL AND METHODS

A total of 231 patients with sporadic prostate cancer and 68 controls were selected. The subjects were selected by an urologist using clinical parameters such as PSA level and Gleason score. Both groups (patients and controls) were genotyped in RNASEL gene by sequencing the exons 1 and 3.

RESULTS

Statistically significant differences were found between controls and patients in some of the genotyped regions of the RNASEL gene (I97L, D541E and R462Q).

CONCLUSIONS

Thanks to the genetic profile in some regions of the genoma, such as the RNASEL gene, together with the combination of the clinical and environmental parameters, we can suggest a care and more personalized follow-up of each patient.

Predictive value in the analysis of RNASEL genotypes in relation to prostate cancer

BACKGROUND

We would like to compare the different RNASEL genotypes with the stage of the cancer using parameters such as PSA levels, Gleason score and T-stage, and to develop a clinical protocol for the monitoring of the disease for trying a better evolution of the patient.

METHODS

A total of 231 patients with sporadic prostate cancer and 100 of controls were genotyped in RNASEL gene by sequencing the exons 1 and 3. A survey of clinical information was collected by a specialist following the Helsinki protocol. All patients and controls were interviewed by a researcher and signed their informed consent to participation in the study, which was approved by Ethics Committee of the hospital. The genetic information was processed and collected with an ABI PRISM Genetic Analyser 3130 using SeqScape software v.2.6. All the patients were analysed by comparing the genetic and clinical data. χ(2)-tests, Monte Carlo, Fisher tests and contigency tables were performed using SPSS v.15.0 and ARLEQUIN v.3.5 software on patient population.

RESULTS

Significant differences were found only between patients and controls in D541E, R461Q and I97L genotypes, the remainder of the variants did not seem relevant to our population in contrast to other populations, such as north-Caucasians, Afro Americans and Ashkenazi Jews. The genotypes associated with the worst prognoses are G/G in D541E, A/A in R462Q and A/G in I97L. The controls were included in our study to determine an approximation of the genotype in our population compared with the patients, but they did not account for the statistical process.

CONCLUSIONS

The genetic profile of patients with this cancer combined with other parameters could be used as a prognosis factor in deciding to give more radical and frequent treatments, depending on personal genotype.

Contribution of HPC1 (RNASEL) and HPCX variants to prostate cancer in a founder population

BACKGROUND

Prostate cancer is a genetically complex disease with locus and disease heterogeneity. The RNASEL gene and HPCX locus have been implicated in hereditary prostate cancer; however, their contributions to sporadic forms of this malignancy remain uncertain.

METHODS

Associations of prostate cancer with two variants in the RNASEL gene (a founder mutation, 471delAAAG, and a non-synonymous SNP, rs486907), and with five microsatellite markers in the HPCX locus, were examined in 979 cases and 1,251 controls of Ashkenazi Jewish descent. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

There was an inverse association between RNASEL rs486907 and prostate cancer in younger men (<65 years) and those with a first-degree relative with prostate cancer; men with AA genotype had ORs of 0.64 and 0.47 (both P < 0.05), respectively, in comparison to men with GG genotype. Within the HPCX region, there were positive associations for allele 135 of bG82i1.1 marker (OR = 1.77, P = 0.01) and allele 188 of DXS1205 (OR = 1.65, P = 0.02). In addition, allele 248 of marker D33 was inversely associated (OR = 0.65, P = 0.05) with Gleason score ≥7 tumors.

CONCLUSIONS

Results suggest that variants in RNASEL contribute to susceptibility to early onset and familial forms of prostate cancer, whereas HPCX variants are associated with prostate cancer risk and tumor aggressiveness. The observation that a mutation predicted to completely inactivate RNASEL protein was not associated with prostate cancer, but that a missense variant was associated, suggests that the effect is due to either partial inactivation of the protein, and/or acquisition of a new protein activity.

Diagnostic accuracy of methods for the detection of BRCA1 and BRCA2 mutations: a systematic review

As sequence analysis for BRCA1 and BRCA2 mutations is both time- and cost-intensive, current strategies often include scanning techniques to identify fragments containing genetic sequence alterations. However, a systematic assessment of the diagnostic accuracy has been lacking so far. Here, we report on a systematic review to assess the internal and external validity of current scanning techniques. Inclusion criteria were: controlled design, investigators blinded, and tests suitable as a scanning tool for the whole genes BRCA1 and BRCA2. Outcome parameters were sensitivity, specificity, and positive and negative predictive values compared to direct sequencing. Out of 3816 publications, 10 studies reporting on 12 methods met our inclusion criteria. The internal and external validity of most of these studies was limited. Sensitivities were reported to be 100% for enzymatic mutation detection (EMD), multiple-dye cleavase fragment length polymorphism (MD-CFLP), fluorescence-based conformation-sensitive gel electrophoresis (F-CSGE), RNA-based sequencing, restriction endonuclease fingerprinting-single strand conformation polymorphism (REF-SSCP), stop codon (SC) assay, and denaturing high-performance liquid chromatography (DHPLC). Sensitivity was 50-96% for SSCP, 88-91% for two-dimensional gene scanning (TDGS), 76% for conformation-sensitive gel electrophoresis (CSGE), 75% for protein truncation test (PTT), and 58% for micronucleus test (MNT). Specificities close to 100% were reported, except for MNT. PTT and SC assay are only able to detect truncating mutations. Most studies were designed to introduce new experimental approaches or modifications of established methods and require further evaluation. F-CSGE, REF-SSCP, RNA-based sequencing, EMD, and MD-CFLP will need further evaluation before their use in a routine setting can be considered. SSCP, MNT, PTT, CSGE, and TDGS cannot be recommended because of their low sensitivity. DHPLC outperforms all other methods studied. However, none of the four studies evaluating DHPLC was performed on BRCA2.