Association between RASSF1A promoter methylation and renal cell cancer susceptibility: a meta-analysis.

Epigenetic inactivation of Ras-associated domain family 1A (RASSF1A) by hyper-methylation of its promoter region has been identified in various cancers. However, the role of RASSF1A in renal cancer has neither been thoroughly investigated nor reviewed. In this study, we reviewed and performed a meta-analysis of 13 published studies reporting correlations between methylation frequency of the RASSF1A promoter region and renal cancer risk. The odds ratios (ORs) of eligible studies and their corresponding 95% confidence intervals (95%CIs) were used to correlate RASSF1A promoter methylation with renal cell cancer risk and clinical or pathological variables, respectively. RASSF1A promoter methylation was significantly associated with the risk of renal cell cancer (OR = 19.35, 95%CI = 9.57-39.13). RASSF1A promoter methylation was significantly associated with pathological tumor grade (OR = 3.32, 95%CI = 1.55-7.12), and a possible positive correlation between RASSF1A promoter methylation status and tumor stage was noted (OR = 1.89, 95%CI = 1.00-3.56, P = 0.051). Overall, this meta-analysis demonstrated that RASSF1A promoter methylation is significantly associated with increased risk of renal cell cancer. RASSF1A promoter methylation frequency was positively correlated with pathological tumor grade, but not the clinical stage. This study showed that RASSF1A promoter methylation could be utilized to predict renal cell cancer prognosis.

Effect of overexpression of PTEN on apoptosis of liver cancer cells.

Liver cancer is a common malignant tumor associated with a short-survival period and high-mortality rate, and its prevalence in China is particularly high. This study aimed to investigate the effect of overexpressing the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene on liver cancer cell apoptosis and provide new insight into the treatment of this disease. The experimental design included four treatment groups, consisting of HHCC and H22 cells transfected with PTEN recombinant plasmids (HHCC+PTEN, H22+PTEN), and those transfected with control plasmids (HHCC+NC, H22+NC). The expression of PTEN mRNA was determined by quantitative polymerase chain reaction, and protein levels were examined by western blot. Cell apoptosis was measured using flow cytometry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. PTEN mRNA expression in cells transfected with pcDNA3.1-PTEN was significantly increased compared to the control groups (P < 0.05). In addition, western blotting revealed PTEN protein expression in the treatment groups to be significantly elevated in comparison to control cells (P < 0.05). Flow cytometry showed that apoptosis rates of both HHCC+PTEN (approximately 21.9%) and H22+PTEN (approximately 41.0%) cells were significantly higher than those of the control groups (P < 0.05). Moreover, the difference in apoptosis rate between experimental and control groups was significant (P < 0.05). In this study, HHCC and H22 cells were successfully transfected with pcDNA3.1-PTEN in vitro. We conclude that overexpression of PTEN can effectively inhibit proliferation of these cells and promote their apoptosis.

Genome-wide analysis of single nucleotide polymorphisms in patients with atrophic age-related macular degeneration in oldest old Han Chinese.

The aim of this study was to identify disease-associated loci in oldest old Han Chinese with atrophic age-related macular degeneration (AMD). This genome-wide association study (GWAS) only included oldest old (≥95 years old) subjects in Rugao County, China. Thirty atrophic AMD patients and 47 age-matched non-AMD controls were enrolled. The study subjects underwent a complete ophthalmic examination. Genomic DNA was extracted from peripheral blood samples. Single nucleotide polymorphisms (SNPs) were scanned by Genome-Wide Human Mapping SNP 6.0 Arrays and GeneChip Scanner 3000 7G. The results were read and analyzed by the Affymetrix Genotyping Console software. We filtered out the SNPs with a no-call rate ≥10%, MAF P < 0.05, and HWE P < 0.001. The remaining 561,277 SNPs were included in the association analysis. We found that the following 2 SNPs had the highest association with atrophic AMD: rs7624556 (located on 3q24) and rs13119914 (located on 4q34.3). In conclusion, we identified two atrophic AMD-associated SNPs (rs7624556 and rs13119914) in an oldest old Han Chinese population. This finding may lead to new strategies for screening of atrophic AMD for Han Chinese.

Germline mutation analysis in the CYLD gene in Chinese patients with multiple trichoepitheliomas.

Trichoepithelioma is a benign neoplasm that primarily shows follicular germinative differentiation. Classic trichoepithelioma typically presents as a skin-colored papule or nodule on the face or upper trunk; lesions have a predilection for the nose. Trichoepithelioma can be sporadic or familial and solitary or multiple. Most previously reported multiple trichoepithelioma cases are familial, and germline CYLD mutations could be detected in some patients. We performed mutational analysis of the germline CYLD gene in 8 Chinese multiple trichoepitheliomas patients, 6 of which were sporadic cases. A heterozygous missense mutation (c.1112C>A) in the 9th exon of the CYLD gene was detected in some mother-daughter patients. However, the germline CYLD mutation could not be detected in the 6 non-familial cases. The results suggest that the pathogenesis of sporadic multiple trichoepitheliomas may differ from that of familial cases. Our findings also further confirmed the genetic heterogeneity of multiple trichoepitheliomas.

Production and genetic characterization of interspecific hybrids among Crambe abyssinica, Crambe hispanica and Crambe kralikii.

In this paper, interspecific crosses among Crambe abyssinica, Crambe hispanica, and Crambe kralikii were reported. In the C. hispanica x C. abyssinica (H x A) cross, 118 F1 hybrids were produced without embryo rescue, while 5 F1 hybrids were obtained with embryo rescue, when C. hispanica was used as the female parent. In the reciprocal cross (A x H), 232 hybrids were obtained without embryo rescue. From more than 1000 C. kralikii flowers pollinated with pollen grains of C. abyssinica (K x A), only 2 F1 hybrids were obtained with embryo rescue, whereas the reciprocal cross produced no hybrids, even with embryo rescue. The hybrids were confirmed at the morphological, cytological, and molecular levels. In the combinations of A x H and H x A, many BC1 hybrids were obtained without embryo rescue. In contrast, in the K x A cross, only 7 BC1 plants were obtained with embryo rescue, while no seed set was achieved under self-pollination or in backcrosses without embryo rescue. In the H x A F1 hybrids, the pollen stainability was 65.4-86.0%, with an average of 76.9%. In comparison, the pollen viability of hybrids in the reciprocal cross (A x H) ranged from 66.2 to 81.1%, with an average of 75.4%. Fertile pollen grains were not found in the K x A F1 hybrids. All F1 hybrids of the 3 crosses (H x A, A x H, and K x A) had the expected 2n = 75 chromosomes. AFLP analyses indicated that all F1 hybrids and their progenies had typical bands of the parents. These hybrids and progenies are anticipated to be valuable for future C. abyssinica improvement in breeding programs.

Ovine prion protein genotype frequencies in northwestern China.

Anti-scrapie breeding programs have been initiated to screen for scrapie-resistant sheep based on ovine prion protein gene (PRNP) genotypes at codons 136, 154 and 171 in many countries, especially European Union member states. However, investigation of sheep PRNP genotypes is limited in China, despite the large number of sheep breeds. We analyzed 432 sheep of five different breeds from farms in northwestern China, using PCR-single-strand conformational polymorphism analysis (PCR-SSCP); the corresponding haplotypes of different PRNP alleles were cloned. PRNP allele genotyping was done by amplification refractory mutation system-PCR (ARMS-PCR), according to the haplotype clones of each PRNP allele. The validity of ARMS-PCR was checked by PCR-SSCP. Another 325 unknown PRNP genotypes of other sheep breeds were analyzed according to the established ARMS-PCR. Genotype frequencies of 757 sheep were analyzed with these two methods to evaluate susceptibility to scrapie in northwestern China. Relevant mutations were also detected at other sites. Both methods were effective for ovine PRNP allele genotyping, and the results of the analysis completely coincided. Scrapie-resistant genotypes were found to be uncommon, indicating a high risk for ovine scrapie in northwest China. In addition to codons 136, 154 and 171, we found numerous new mutations; nearly half of them were previously unreported. These sheep populations have a high degree of polymorphism at the PRNP locus.