Naoko Okayama

Association of functional polymorphisms of matrix metalloproteinase (MMP)-1 and MMP-3 genes with colorectal cancer

Matrix metalloproteinase (MMP)‐1 and MMP‐3 genes are associated with tumor cell invasion and metastasis with their promoter polymorphisms influencing the level of transcription. Our study explored the association of these polymorphisms with colorectal cancer risk in a Japanese population. DNA was extracted from peripheral blood of 101 patients with colorectal cancer and 127 age‐ and gender‐matched healthy volunteers. Genotyping was carried out using PCR‐RFLP and direct sequencing. In the MMP‐1 gene polymorphism, the frequency of the 2G/2G genotype that is associated with higher enzyme activity was significantly increased in colorectal cancer patients when compared to controls (p = 0.0067; OR = 2.077; 95% CI = 1.221–3.534). With regard to the MMP‐3 polymorphism, unexpectedly, the frequency of the 6A/6A genotype causing lower enzyme activity was significantly increased in patients (p = 0.0129; OR = 2.110; 95% CI = 1.165–3.822). Because the loci for the 2 MMP genes are closely linked, we examined linkage disequilibrium between the 2 loci using expectation‐maximization algorithm. We found that the 2 loci were in linkage disequilibrium and that 2G‐6A haplotype was significantly increased in patients compared to controls (p = 0.0010; OR = 1.949; 95% CI = 1.305–2.911). Our present data suggest that the MMP‐1 and MMP‐3 promoter polymorphisms may be associated with a colorectal cancer susceptibility in Japanese.

Association of the -173G/C polymorphism of the macrophage migration inhibitory factor gene with ulcerative colitis

BackgroundMacrophage migration inhibitory factor (MIF) is a proinflammatory cytokine and has been shown to be involved in the development of chronic murine colitis. In the +173 G/C polymorphism of the MIF gene, the presence of C creates the binding motif of activator protein 4. This study explored the association of this polymorphism with ulcerative colitis (UC).MethodsGenotyping was carried out, with a tetra-primer polymerase chain reaction (PCR) method, for 659 DNA specimens from 438 healthy volunteers and 221 patients with UC. Genotype distribution between cases and controls and the association of patients’ genotypes with clinical parameters were statistically evaluated.ResultsNo significant difference in genotype distribution was found between UC patients and healthy controls. However, when the relation of the C/C genotype to clinical parameters in UC patients was evaluated by Fisher’s exact test, it was found that the frequency of the C/C genotype was higher in patients with pancolitis type than in those with other types restricted to the distal or left-sided colon (odds ratio [OR], 10.781; 95% confidence interval [CI], 1.342–86.619; P = 0.0074).ConclusionsThese data suggest that the MIF −173 G/C polymorphism may be related to the extent of disease in UC in a Japanese population.

Aneuploidy Predicts Outcome in Patients with Endometrial Carcinoma and Is Related to Lack of CDH13 Hypermethylation

Purpose: Many investigators have reported that aneuploidy detected by flow cytometry is a useful prognostic marker in patients with endometrial cancer. Laser scanning cytometry (LSC) is a technology similar to flow cytometry but is more feasible for clinical laboratory use. We evaluated the usefulness of DNA ploidy detected by LSC as a prognostic marker in patients with endometrial cancer and investigated genetic and epigenetic factors related to aneuploidy. Experimental Design: Endometrial cancer specimens from 106 patients were evaluated. The methylation status of CDH13, Rassf1, SFRP1, SFRP2, SFRP4, SFRP5, p16, hMLH1, MGMT, APC, ATM, and WIF1 and mutations in the p53 and CDC4 genes were investigated. LSC was carried out to determine DNA ploidy. Fluorescence in situ hybridization was done with chromosome-specific centromeric probes to assess chromosomal instability. Results: Univariate and multivariate analyses revealed that p53 mutation and lack of CDH13 hypermethylation associated positively with aneuploidy. Univariate analysis showed that aneuploidy, chromosomal instability, and lack of CDH13 hypermethylation as well as surgical stage were significantly predictive of death from endometrial cancer. Furthermore, multivariate analysis revealed that stage in combination with either DNA aneuploidy or lack of CDH13 hypermethylation was an independent prognostic factor. Conclusion: These results suggest that analysis of DNA ploidy and methylation status of CDH13 may help predict clinical outcome in patients with endometrial cancer. Prospective randomized trials are needed to confirm the validity of an individualized approach, including determination of tumor ploidy and methylation status of CDH13, to management of endometrial cancer patients.

Association of the BCRP C421A polymorphism with nonpapillary renal cell carcinoma

Breast cancer resistance protein (BCRP), the second member of the ATP‐binding cassette membrane transporter family, has a single nucleotide polymorphism, C421A (resulting in Q141K), that is of functional importance. Our aim was to explore the relationship between this polymorphism of the BCRP gene and the risk of renal cell carcinoma (RCC) development. For a case‐control study, DNA samples from 200 nonpapillary RCC patients and 200 healthy control subjects were analyzed using the TaqMan technique. The genotypic frequencies of the BCRP C421A polymorphism were compared between RCC patients and control subjects. The frequency of the C/C genotype was significantly higher in RCC patients than in control subjects (age‐ and gender‐adjusted OR = 1.96, 95% CI 1.32–2.93). No associations were observed between the BCRP C421A polymorphism and clinicopathologic or epidemiologic factors, including age, gender, tumor grade, stage, cigarette smoking, family history of cancer and body mass index. Carriers with the C/C genotype of the BCRP C421A polymorphism are at risk of developing nonpapillary RCC. These data suggest that BCRP is a candidate RCC susceptibility gene.

TWIST1 hypermethylation is observed frequently in colorectal tumors and its overexpression is associated with unfavorable outcomes in patients with colorectal cancer

Although growing evidence demonstrates that TWIST1 is an interesting tumor biomarker, little is known about the clinical significance of TWIST1 expression and TWIST1 methylation in human primary colorectal cancer. In this study, we examined the association of TWIST1 expression and TWIST1 methylation with clinicopathologic features in human primary colorectal tumors. Primary colorectal cancer (CRC) specimens from 319 patients, corresponding normal colorectal nontumorous mucosa from 251 patients with cancer, and colorectal adenomas from 189 patients were used. Methylation and expression levels of TWIST1 were compared with clinicopathologic features. The TWIST1 methylation level was higher in colorectal adenoma and cancer than in normal colorectal mucosa. Elevated TWIST1 mRNA expression in normal colorectal mucosa in patients with CRC as well as in primary CRC specimens was associated with unfavorable outcomes. There was no correlation between TWIST1 methylation and TWIST1 expression. Our results suggest that TWIST1 methylation may be a useful biomarker for screening colorectal tumors. In addition, TWIST1 mRNA expression is a possible molecular marker for predicting the outcome in patients with CRC. Confirmatory studies using independent data sets are needed to confirm our findings.

Catechol-O-methyltransferase Gene Polymorphisms in Benign Prostatic Hyperplasia and Sporadic Prostate Cancer

Various carcinogenic metabolites, including catechol estrogens, play a role in malignant transformation. An enzyme that is capable of neutralizing the genotoxic effects of these compounds is catechol-O-methyltransferase (COMT). A variant form of this enzyme has been shown to reduce its activity by up to 4-fold; thus, we hypothesize that single nucleotide polymorphisms of the COMT gene can be a risk factor for benign prostatic hyperplasia (BPH) and prostate cancer. To test this hypothesis, the genetic distribution of three different COMT polymorphisms at codon 62 (C→T), codon 72 (G→T), and codon 158 (G→A) were analyzed in 131 normal healthy subjects, 134 BPH, and 178 sporadic prostate cancer samples from a Japanese population. Results of these experiments show that the variant genotype at codon 62 (P = 0.060) and codon 158 (P = 0.047) are risk factors for prostate cancer but not BPH when compared with normal controls. Odds ratio (OR) and 95% confidence interval (95% CI) for cancer were 3.24 and 1.38 to 7.61, respectively, for codon 62 T/T genotype when compared with wild type. At codon 158, the A/A variant for cancer had an OR of 3.00 with a 95% CI of 1.38 to 6.54 compared with wild type. Codons 62 and 158 were in linkage disequilibrium (LD), and when compared with the C-G haplotype, other types (C-A, T-G, T-A) were observed to be associated with prostate cancer (P = 0.040) but not BPH. Codon 72 on the other hand, was not in LD with either codon 62 or 158. The homozygous variant on codon 72 was rare in this Japanese population, and the heterozygous G/T at this codon was not associated with either prostate cancer or BPH. When evaluating the risk of COMT polymorphisms with stage or grade of cancer, no associations were observed for any of the genotypes with the exception of a tendency (P = 0.096) for the variant A allele on codon 158 to be correlated with higher stages (≥T3) of cancer. This is the first report that shows the polymorphisms of COMT to be associated with sporadic prostatic carcinogenesis. These results are important in understanding the role of COMT polymorphisms in the pathogenesis of prostate cancer. (Cancer Epidemiol Biomarkers Prev 2006;15(2):238–44)

Evaluation of a new efficient procedure for single-nucleotide polymorphism genotyping: tetra-primer amplification refractory mutation system-polymerase chain reaction.

Abstract Tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) is a new efficient method for single-nucleotide polymorphism (SNP) genotyping. To determine the optimal conditions for ARMS-PCR we attempted to genotype ten SNPs. DNA was extracted from the peripheral blood of 168 unrelated healthy Japanese volunteers. Two problems inhibited uniform efficiency of the amplification of three bands. The first problem was the lower amplification efficiency of the shorter and allele-specific products compared with the largest product. This phenomenon was overcome by increasing the relative concentration of the inner primers. The second problem was non-specific amplification of the shorter products. To reduce the amplification of these nonspecific bands, adjusting any one of the following PCR conditions was effective: i) reducing the ratio of the inner primer concentration relative to that of the outer primers; ii) increasing the annealing temperature for the initial 5–10 cycles; iii) hot start PCR. With these procedures all ten of the SNPs were successfully genotyped. Our present data may be useful in the further application of tetra-primer ARMS-PCR to SNP genotyping.

Phase I study of irinotecan and doxifluridine for metastatic colorectal cancer focusing on the UGT1A1*28 polymorphism

(Cancer Sci 2010; 101: 722–727)

Mismatch Repair Gene MSH3 Polymorphism is Associated With the Risk of Sporadic Prostate Cancer

PURPOSE The mismatch repair system is a DNA repair mechanism that corrects mispaired bases during DNA replication errors. Cancer cells deficient in MMR proteins have a 10(2) to 10(3)-fold increase in the mutation rate. Single nucleotide polymorphisms of mismatch repair genes have been shown to cause a decrease in DNA repair activity. We hypothesized that mismatch repair gene polymorphism could be a risk factor for prostate cancer and p53 Pro/Pro genotype carriers could influence MSH3 and MSH6 polymorphisms. MATERIALS AND METHODS DNA samples from 110 patients with prostate cancer and 110 healthy controls were analyzed by single strand conformational polymorphism and polymerase chain reaction-restriction fragment length polymorphism to determine the genotypic frequency of 5 polymorphic loci on 2 MMR genes (MSH3 and MSH6) and p53 codon72. The chi-square test was applied to compare genotype frequency between patients and controls. RESULTS A significant increase in the G/A+A/A genotype of MSH3 Pro222Pro was observed in patients compared to controls (OR 1.87, 95% CI 1.0-3.5). The frequency of A/G + G/G genotypes of MSH3 exon23 Thr1036Ala also tended to increase in patients (OR 1.57, 95% CI 0.92-2.72). In p53 codon72 Arg/Pro + Pro/Pro carriers the frequency of the AG + GG genotype of MSH3 exon23 was significantly increased in patients compared to controls (OR 2.1, 95% CI 1.05-4.34). CONCLUSIONS To our knowledge this is the first report of the association of MSH3 gene polymorphisms in prostate cancer. These results suggest that the MSH3 polymorphism may be a risk factor for prostate cancer.

COMT polymorphisms affecting protein expression are risk factors for endometrial cancer.

In estrogen metabolic pathways, the COMT enzyme is related to detoxification. COMT gene polymorphisms have been shown to effect enzyme function. We hypothesized that these polymorphisms may be risk factors for endometrial cancer (EC). DNA samples from 150 cases of EC and healthy controls (n = 165) were analyzed by PCR‐RFLP to determine the genotypic frequency of four different polymorphic loci on COMT [codon 62 (rs4633), 102 (rs5031015), 136 (rs4818), 158 (rs4680)]. Genotyping was confirmed by direct DNA sequencing. We also conducted haplotype analysis of COMT and investigated the relationship between COMT expression and COMT SNPs in EC tissues by immunohistochemistry. A significant increase in the T/T genotype of codon 62 (C/T) was observed in patients compared to controls (OR = 2.39, 95% CI: 1.31–4.37, P = 0.004). The frequency of the C–G haplotype of codon 62 C/T and codon 158 G/A was significantly higher in controls (P < 0.0001) than in patients. The expression level of COMT protein in EC tissues was significantly lower in COMT codon 62 variant TT and codon 158 variant AA genotype carriers. Therefore, the EC samples with polymorphic variants of COMT lead to lower expression of COMT protein whereas EC samples with wild‐type codon 62 C/C and codon 158 G/G have higher expression of COMT protein. This is the first study demonstrating that polymorphisms in COMT codon 62 and codon 158 altered protein expression levels in EC, suggesting that they may be risk factors for EC in Caucasians.