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Purpose: Glycine N-methyltransferase (GNMT) affects genetic stability by regulating DNA methylation and interacting with environmental carcinogens. In a previous study, we showed that GNMT acts as a susceptibility gene for hepatocellular carcinoma. Here, we report on our efforts to characterize the haplotypes, loss of heterozygosity (LOH), and expression levels of the GNMT in prostate cancer. Experimental Design: Peripheral blood mononuclear cell DNA collected from 326 prostate cancer patients and 327 age-matched controls was used to determine GNMT haplotypes. Luciferase reporter constructs were used to compare the promoter activity of different GNMT haplotypes. GNMT LOH rates in tumorous specimens were investigated via a comparison with peripheral blood mononuclear cell genotypes. Immunohistochemical staining was used to analyze GNMT expression in tissue specimens collected from 5 normal individuals, 33 benign prostatic hyperplasia patients, and 45 prostate cancer patients. Results: Three major GNMT haplotypes were identified in 92% of the participants: A, 16GAs/ DEL/C (58%); B, 10GAs/INS/C (19.9%); and C, 10GAs/INS/T (14.5%). Haplotype C carriers had significantly lower risk for prostate cancer compared with individuals with haplotype A (odds ratio, 0.68; 95% confidence interval, 0.48-0.95). Results from a phenotypic analysis showed that haplotype C exhibited the highest promoter activity (P < 0.05, ANOVA test). In addition, 36.4% (8 of 22) of the prostatic tumor tissues had LOH of the GNMT gene. Immunohistochemical staining results showed abundant GNMTexpression in normal prostatic and benign prostatic hyperplasia tissues, whereas it was diminished in 82.2% (37 of 45) of the prostate cancer tissues. Conclusions: Our findings suggest that GNMT is a tumor susceptibility gene for prostate cancer.

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Both groups benefited from macular hole surgery, with significant visual improvement. However, complete closure of the macular hole and visual outcomes after internal limiting membrane removal were less successful in highly myopic eyes.

MicroRNAs (miRNAs) are small non-coding RNAs that have crucial regulatory functions in carcinogenesis. miR-324-5p and miR-324-3p are generated from the same hairpin RNA structure, however, both are diverse in their direct target genes and expression levels. We report that expression of miR-324-5p and -3p was frequently observed to be either up-regulated or down-regulated, and the selection preference of miR-324 for 5p and 3p arms significantly varied in various types or human cancer. Overexpression of miR-324-5p or -3p suppressed growth and invasion of breast cancer cells. Overexpression of miR-324-5p reduced the growth and invasive abilities of colorectal cancer cells, whereas miR-324-3p suppressed colorectal cancer cell invasion but did not influence cell growth. We conclude that miR-324-5p and miR-324-3p might have distinct biological functions, further complicating the regulatory network in human cancer. Therefore, the arm selection preference of miR-324 may be a method for modulating its function.

Prostate cancer is a complex disease that can be relatively harmless or extremely aggressive. Although androgen-deprivation therapy is a commonly used treatment for men with prostate cancer, the adverse effects can be detrimental to patient health and quality of life. Therefore, identifying new target genes for tumor growth will enable the development of novel therapeutic intervention. TPX2 plays a critical role in chromosome segregation machinery during mitosis. Low rates of chromosome missegregation can promote tumor development, whereas higher levels might promote cell death and suppress tumorigenesis. Hence, the strategy of promoting cell death by inducing massive chromosome missegregation has been a therapeutic application for selectively eliminating highly proliferating tumor cells. RNAi was used for TPX2 protein expression knockdown, and a clonogenic assay, immunostaining, double thymidine block, image-cytometry analysis, and tumor spheroid assay were used to analyze the role of TPX2 in tumor cell growth, cell cycle progression, multinuclearity, ploidy, and tumorigenicity, respectively; finally, Western blotting was used to analyze anticancer mechanisms in TPX2 targeting. We demonstrated that targeting TPX2 reduced cell cycle regulators and chromosome segregation genes, resulting in increased cell micronucleation. Moreover, TPX2 depletion led to prostate cancer cell growth inhibition, increased apoptosis, and reduced tumorigenesis. These results confirmed the therapeutic potential of targeting TPX2 in prostate cancer treatment. Moreover, we found that TPX2 silencing led to deregulation of CDK1, cyclin B, securin, separase, and aurora A proteins; by contrast, p21 mRNA was upregulated. We also determined the molecular mechanisms for TPX2 targeting in prostate cancer cells. In conclusion, our study illustrates the power of TPX2 as a potential novel target gene for prostate cancer treatment.

BackgroundStudies on the association between prostate cancer and cadmium exposure have yielded conflicting results. This study explored cadmium burden on the risk and phenotype of prostate cancer in men with no evident environmental exposure.MethodsHospital-based 261 prostate cancer cases and 267 controls with benign diseases were recruited from four hospitals in Taiwan. Demographic, dietary and lifestyle data were collected by standardized questionnaires. Blood cadmium (BCd) and creatinine-adjusted urine cadmium (CAUCd) levels were measured for each participant. Statistical analyses measured the prostate cancer risk associated with BCd and CAUCd separately, controlling for age, smoking and institution. BCd and CAUCd levels within cases were compared in relation to the disease stage and the Gleason score.ResultsHigh family income, low beef intake, low dairy product consumption and positive family history were independently associated with the prostate carcinogenesis. There was no difference in BCd levels between cases and controls (median, 0.88 versus 0.87 μg/l, p = 0.45). Cases had lower CAUCd levels than controls (median, 0.94 versus 1.40 μg/g creatinine, p = 0.001). However, cases with higher BCd and CAUCd levels tended to be at more advanced stages and to have higher Gleason scores. The prostate cancer cases with Gleason scores of ≥ 8 had an odds ratio of 2.89 (95% confidence interval 1.25-6.70), compared with patients with scores of 2-6.ConclusionHigher CAUCd and BCd levels may be associated with advanced cancer phenotypes, but there was only a tenuous association between cadmium and prostate cancer.

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