No abstract

In summary, GSTM1 and GSTP1, but not GSTT1 genetic polymorphisms are associated with increased risk of breast cancer in our population.

The present study was aimed to investigate the possible association between 19-base pair (bp) deletion polymorphism of the DHFR gene (rs70991108), null genotype of UDP-glucuronosyltransferase 2B17 (UGT2B17) as well as the expression level of nasopharyngeal carcinoma-associated gene 6 (NGX6) with the risk of breast cancer. This case-control study was done on 236 patients with breast cancer and 203 cancer free women. Detection of 19-bp del of DHFR was done using bi-directional PCR allele-specific amplification and UGT2B17 genotyping was performed using multiplex PCR assay. NGX6 mRNA expression level was determined by quantitative reverse transcriptase PCR in 62 breast cancerous and 62 adjacent non-cancerous tissues. Our finding showed an association between null genotype of UGT2B17 and risk of breast cancer and the null genotype increased susceptibility to breast cancer (OR: 2.99; 95 % CI: 1.94-4.60; p < 0.0001). However, no statistically significant difference was found between breast cancer patients and cancer free normal women regarding 19-bp ins/del of DHFR (χ(2) = 0.91, p = 0.63). Real-time PCR data showed that the relative expression level of NGX6 mRNA was significantly lower in cancerous than that in non-cancerous breast tissue specimens (0.936 ± 0.042 and 1.042 ± 0.039, respectively). However, NGX6 mRNA expression was not correlated with tumors grade (p > 0.05). In conclusion, the null genotype of UGT2B17 revealed to be a risk factor for breast cancer in a sample of Iranian population. Furthermore, down-regulation of NGX6 mRNA expression in breast carcinoma confirms the growing proof regarding the tumor suppressor role of NGX6.

No abstract

The targeted genome modification using RNA-guided nucleases is associated with several advantages such as a rapid, easy, and efficient method that not only provides the manipulation and alteration of genes and functional studies for researchers, but also increases their awareness of the molecular basis of the disease and development of new and targeted therapeutic approaches. Different techniques have been emerged so far as the molecular scissors mediating targeted genome editing including zinc finger nuclease, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). CRISPR-Cas9 is a bacterial immune system against viruses in which the single-strand RNA-guided Cas9 nuclease is linked to the targeted complementary sequences to apply changes. The advances made in the transfer, modification, and emergence of specific solutions have led to the creation of different classes of CRISPR-Cas9. Since this robust tool is capable of direct correction of disease-causing mutations, its ability to treat genetic disorders has attracted the tremendous attention of researchers. Considering the reported cases of nonspecific targeting of Cas9 proteins, many studies focused on enhancing the Cas9 features. In this regard, significant advances have been made in choosing guide RNA, new enzymes and methods for identifying misplaced targeting. Here, we highlighted the history and various direct aspects of CRISPR-Cas9, such as precision in genomic targeting, system transfer and its control over correction events with its applications in future biological studies, and modern treatment of diseases.