E-cadherin promoter polymorphisms are not associated with the aggressiveness of prostate cancer in Caucasian patients

Regulatory Variants and Disease: The E-Cadherin -160C/A SNP as an Example

Single nucleotide polymorphisms (SNPs) occurring in noncoding sequences have largely been ignored in genome-wide association studies (GWAS). Yet, amounting evidence suggests that many noncoding SNPs especially those that are in the vicinity of protein coding genes play important roles in shaping chromatin structure and regulate gene expression and, as such, are implicated in a wide variety of diseases. One of such regulatory SNPs (rSNPs) is the E-cadherin (CDH1) promoter -160C/A SNP (rs16260) which is known to affect E-cadherin promoter transcription by displacing transcription factor binding and has been extensively scrutinized for its association with several diseases especially malignancies. Findings from studying this SNP highlight important clinical relevance of rSNPs and justify their inclusion in future GWAS to identify novel disease causing SNPs.

The matrix metalloproteinase-7 polymorphism rs10895304 is associated with increased recurrence risk in patients with clinically localized prostate cancer

PURPOSE

To evaluate whether selected high-risk matrix metalloproteinase-7 single nucleotide polymorphisms influence clinicopathologic outcomes in patients with early-stage prostate cancer.

METHODS AND MATERIALS

Two hundred twelve prostate cancer patients treated with radical prostatectomy were evaluated with a median follow-up of 9.8 years. Genotyping was performed using hybridization with custom-designed allele-specific probes. Three single nucleotide polymorphisms within the matrix metalloproteinase-7 gene were assessed with respect to age at diagnosis, margin status, extracapsular extension, lymph node involvement, recurrence-free survival, and overall survival in paraffin-embedded prostate tissue specimens from patients with early-stage prostate cancer who underwent radical prostatectomy.

RESULTS

Rs10895304 was the sole significant polymorphism. The A/G genotype of rs10895304 had a statistically significant association with recurrence-free survival in postprostatectomy patients (p = 0.0061, log-rank test). The frequency of the risk-reducing genotype (A/A) was 74%, whereas that of the risk-enhancing genotypes (A/G and G/G) were 20% and 6%, respectively. Multivariable Cox regression analyses detected a significant association between rs10895304 and recurrences after adjustment for known prognostic factors. The G allele of this polymorphism was associated with increased risk of prostate cancer recurrence (adjusted hazards ratio, 3.375; 95% confidence interval 1.567-7.269; p < 0.001). The other assayed polymorphisms were not significant, and no correlations were made to other clinical variables.

CONCLUSIONS

The A/G genotype of rs10895304 is predictive of decreased recurrence-free survival in patients with clinically localized prostate cancer. Our data suggest that for this subset of patients, prostatectomy alone may not be adequate for local control. This is a novel and relevant marker that should be evaluated for improved risk stratification of patients who may be candidates for adjuvant radiation therapy to improve local control.

New experimental markers for early detection of high-risk prostate cancer: role of cell-cell adhesion and cell migration

Today's treatment and diagnosis of prostate cancer still exhibit major limitations. The search for new and additional prognostic markers is therefore still an actual field of interest. Potential markers involved in numerous biological processes in the tumor cell have been investigated intensively. For therapeutic interventions it is important to distinguish between harmless and aggressive disease in an early stage. Therefore the subject of this review is limited to markers associated with those functional processes, which discriminate early stage aggressive, metastatic cancer from harmless disease. Important processes in this respect are: altered cell adhesion and cellular migration. E-cadherin, N-cadherin, beta-catenin, integrins, focal adhesion kinase, connexins and matrix metalloproteinases all appear promising biological markers associated with the early stage metastatic process in prostate cancer. Here we discuss their potential to become valid biological markers based on literature data. Thus far, none of these markers proved to be a valid individual marker by itself due to prostate cancer heterogeneity and transient expression. Analyzing a combination of the potential markers discussed in this review is expected to be a better approach toward discriminating high- from low-risk tumors in an early stage of prostate cancer.