Narasimha Reddy Parine

Association of Single Nucleotide Polymorphisms in Wnt Signaling Pathway Genes with Breast Cancer in Saudi Patients

Breast cancer is a complex heterogeneous disease involving genetic and epigenetic alterations in genes encoding proteins that are components of various signaling pathways. Candidate gene approach have identified association of genetic variants in the Wnt signaling pathway genes and increased susceptibility to several diseases including breast cancer. Due to the rarity of somatic mutations in key genes of Wnt pathway, we investigated the association of genetic variants in these genes with predisposition to breast cancers. We performed a case-control study to identify risk variants by examining 15 SNPs located in 8 genes associated with Wnt signaling. Genotypic analysis of individual locus showed statistically significant association of five SNPs located in β-catenin, AXIN2, DKK3, SFRP3 and TCF7L2 with breast cancers. Increased risk was observed only with the SNP in β-catenin while the other four SNPs conferred protection against breast cancers. Majority of these associations persisted after stratification of the cases based on estrogen receptor status and age of on-set of breast cancer. The rs7775 SNP in exon 6 of SFRP3 gene that codes for either arginine or glycine exhibited very strong association with breast cancer, even after Bonferronis correction. Apart from these five variants, rs3923086 in AXIN2 and rs3763511 in DKK4 that did not show any association in the overall population were significantly associated with early on-set and estrogen receptor negative breast cancers, respectively. This is the first study to utilize pathway based approach to identify association of risk variants in the Wnt signaling pathway genes with breast cancers. Confirmation of our findings in larger populations of different ethnicities would provide evidence for the role of Wnt pathway as well as screening markers for early detection of breast carcinomas.

Association between PARP-1 V762A Polymorphism and Breast Cancer Susceptibility in Saudi Population

Genetic aberrations of DNA repair enzymes are known to be common events and to be associated with different cancer entities. Aim of the following study was to analyze the genetic association of rs1136410 (Val762Ala) in PARP1 gene with the risk of breast cancer using genotypic assays and insilico structural predictions. Genotypic analysis of individual locus showed statistically significant association of Val762Ala with increased susceptibility to breast cancer. Protein structural analysis was performed with Val762Ala variant allele and compared with the predicted native protein structure. Protein prediction analysis showed that this nsSNP may cause changes in the protein structure and it is associated with the disease. In addition to the native and mutant 3D structures of PARP1 were also analyzed using solvent accessibility models for further protein stability confirmation. Taken together, this the first study that confirmed Val762Ala variant has functional effect and structural impact on the PARP1 and may play an important role in breast cancer progression in Saudi population.

Intracellular biosynthesis of Au and Ag nanoparticles using ethanolic extract of Brassica oleracea L. and studies on their physicochemical and biological properties

In this present study, we reported broccoli (Brassica oleracea L.) as a potential candidate for the synthesis of gold and silver nanoparticles (NPs) in green chemistry method. The synthesized metal nanoparticles are evaluated their antimicrobial efficacy against different human pathogenic organisms. The physico-chemical properties of gold nanoparticles were analyzed using different analytical techniques such as a UV-Vis spectrophotometer, Field Emission Scanning Electron Microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and a Fourier Transform Infrared spectrophotometer. In addition, gold and silver NP antimicrobial efficacy was checked by disc diffusion assay. UV-Vis color intensity of the nanoparticles was shown at 540 and 450 nm for gold and silver nanoparticles respectively. Higher magnification of the Field Emission Scanning Electron Microscopy image shows the variable morphology of the gold nanoparticles such as spherical, rod and triangular shapes and silver nanoparticles were seen in spherical shapes. The average spherical size of the particles was observed in 24-38 nm for gold and 30-45 nm for silver NPs. X-ray diffraction pattern confirmed the presence of gold nanoparticles and silver nanoparticles which were crystalline in nature. Additionally, the functional metabolites were identified by the Fourier Transform Infrared spectroscopy. IR spectra revealed phenols, alcohols, aldehydes (sugar moieties), vitamins and proteins are present in the broccoli extract which are accountable to synthesize the nanoparticles. The synthesized gold and silver NPs inhibited the growth of the tested bacterial and fungal pathogens at the concentration of 50 μg/mL respectively. In addition, broccoli mediated gold and silver nanoparticles have shown potent antimicrobial activity against human pathogens.

Evaluation of in-vitro antioxidant and antibacterial properties of Commelina nudiflora L. extracts prepared by different polar solvents.

The study explored on the commonly available weed plant Commelina nudiflora which has potential in-vitro antioxidant and antimicrobial activity. The different polar solvents such as ethanol, chloroform, dichloromethane, hexane and aqueous were used for the soxhlet extraction. The extracts were identified pharmacologically as important bioactive compounds and their potential free radical scavenging activities, and antimicrobial properties were studied. C. nudiflora extracts were monitored on their in-vitro antioxidant ability by DPPH and ABTS radical scavenging assay. Aqueous extract shows significant free radical scavenging activity of 63.4 mg/GAE and 49.10 mg/g in DPPH and ABTS respectively. Furthermore, the aqueous crude extract was used in antibacterial studies, which shows the highest inhibitory activity against Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Among all the extracts, aqueous extract of C. nudiflora has significant control over free radical scavenging activity and inhibition of the growth of food pathogenic bacteria. Also, the aqueous extract contains abundance of phenolics and flavonoids higher than other extracts. This study explored weed plant C. nudiflora as a potential source of antioxidant and antibacterial efficacy and identified various therapeutic value bioactive compounds from GC–MS analysis.

Association of XRCC1 Gene Polymorphisms with Breast Cancer Susceptibility in Saudi Patients

BACKGROUND X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. XRCC1 is reported to be a candidate influence on cancer risk. The aim of our present study was to assess the association of rs1799782 (Arg194Trp) and rs25487 (Arg399Gln) XRCC1 gene polymorphisms with breast cancer in the Saudi population. MATERIALS AND METHODS The two SNPs were analyzed in breast cancer patients and healthy control subjects. Genotypes were determined by TaqMan SNP genotype analysis technique and data were analyzed using Chi- square or t test and logistic regression analysis by SPSS16.0 software. RESULTS AND CONCLUSIONS Results showed that rs1799782 significantly increased susceptibility to breast cancer with Arg/Trp, Arg/Trp+Trp/Trp genotypes and at Trp allele overall study. It also increased risk of breast cancer in older age patients (above 48) and with the ER positive category. XRCC1rs25487 (Arg399Gln) did not showed any significant association. In conclusion the XRCC1rs1799782 polymorphism may be involved in the etiology of breast cancer in the Saudi population. Confirmation of our findings in larger populations of different ethnicities is warranted.

Matrix Metalloproteinase-2 (-1306 C>T) Promoter Polymorphism and Risk of Colorectal Cancer in the Saudi Population

BACKGROUND Matrix metalloproteinase-2 (MMP-2) is an enzyme with proteolytic activity against matrix proteins, particularly basement membrane constituents. A single nucleotide polymorphism (SNP) at -1306, which disrupts a Sp1-type promoter site (CCACC box), results in strikingly lower promoter activity with the T allele. In the present study, we investigated whether this MMP-2 genetic polymorphism might be associated with susceptibility to colorectal cancer (CRC) in the Saudi population. We also analyzed MMP-2 gene expression level sin CRC patients and 4 different cancer cell lines. MATERIALS AND METHODS TaqMan allele discrimination assays and DNA sequencing techniques were used to investigate the C-1306T SNP in the MMP-2 gene of Saudi colorectal cancer patients and controls. The MMP-2 gene expression level was also determined in 12 colon cancer tissue samples collected from unrelated patients and histologically normal tissues distant from tumor margins. RESULTS AND CONCLUSIONS The MMP-2 C-1306T SNP in the promoter region was associated with CRC in our Saudi population and the MMP-2 gene expression level was found to be 10 times higher in CRC patients. The MMP-2 C-1306T SNP is significantly associated with CRC in the Saudi population and this finding suggested that MMP-2 variants might help predict CRC progression risk among Saudis. We propose that analysis of this gene polymorphism could assist in identification of patient subgroups at risk of a poor disease outcome.

Association between FTO, MC4R, SLC30A8, and KCNQ1 gene variants and type 2 diabetes in Saudi population

Recent genome wide association studies identified many loci in several genes that have been consistently associated with type 2 diabetes mellitus in various ethnic populations. Among the genes that were most strongly associated with diabetes were fat mass- and obesity-associated, melanocortin 4 receptor, solute carrier family 30 member 8 (SLC30A8), and a member of the potassium voltage-gated channels. In the present study, we examined the association between variants in fat mass- and obesity-associated [rs9939609 (A/T)], melanocortin 4 receptor [rs17782313 (C/T), and rs12970134 (A/G)], SLC30A8 [rs13266634 (C/T)], and a member of the potassium voltage-gated channels [rs2237892(C/T)] genes in diabetes patients from Saudi Arabia. Genotypes were determined using the TaqMan single-nucleotide polymorphism genotype analysis technique. Minor allele frequency of the 4 variants tested was comparable between type 2 diabetes cases and controls. We observed an association between allele variants of SLC30A8 [rs13266634 (C/T)] and type 2-diabetes (P = 0.04). The other single-nucleotide polymorphisms examined in this study showed moderate or no correlation with diabetes in Saudis. Our data indicate that the SLC30A8 polymorphisms are associated with type 2 diabetes in the Saudi population. There is no evidence supporting an association between variants in the fat mass- and obesity-associated and melanocortin 4 receptor, and a member of the potassium voltage-gated channels genes and type 2 diabetes in the Saudi population.

DNA Repair Genes XRCC1, XRCC3, XPD, and OGG1 Polymorphisms among the Central Region Population of Saudi Arabia

DNA repair is one of the central defense mechanisms against mutagenic exposures. Inherited SNPs of DNA repair genes may contribute to variations in DNA repair capacity and susceptibility to cancer. Due to the presence of these variants, inter-individual and ethnic differences in DNA repair capacity have been established in various populations. Saudi Arabia harbors enormous genetic and cultural diversity. In the present study we aimed to determine the genotype and allele frequencies of XRCC1 Arg399Gln (rs25487), XRCC3 Thr241Met (rs861539), XPD Lys751Gln (rs13181), and OGG1 Ser326Cys (rs1052133) gene polymorphisms in 386 healthy individuals residing in the central region of Saudi Arabia and compare them with HapMap and other populations. The genotype and allele frequencies of the four DNA repair gene loci in central Saudi population showed a distinctive pattern. Furthermore, comparison of polymorphisms in these genes with other populations also showed a unique pattern for the central Saudi population. To the best of our knowledge, this is the first report that deals with these DNA repair gene polymorphisms among the central Saudi population.

Cytochrome P450 1A1, 2E1 and GSTM1 Gene Polymorphisms and Susceptibility to Colorectal Cancer in the Saudi Population

BACKGROUND The Saudi population has experienced a sharp increase in colorectal and gastric cancer incidences within the last few years. The relationship between gene polymorphisms of xenobiotic metabolizing enzymes and colorectal cancer (CRC) incidence has not previously investigated among the Saudi population. The aim of the present study was to investigate contributions of CYP1A1, CYP2E1, and GSTM1 gene polymorphisms. MATERIALS AND METHODS Blood samples were collected from CRC patients and healthy controls and genotypes were determined by polymerase chain reaction restriction fragment length polymorphism and sequencing. RESULTS AND CONCLUSIONS CYP2E1*6 was not significantly associated with CRC development (odd ratio=1.29; confidence interval 0.68-2.45). A remarkable and statistically significant association was observed among patients with CYP1Awt/*2A (odd ratio=3.65; 95% confidence interval 1.39-9.57). The GSTM1*0/*0 genotype was found in 2% of CRC patients under investigation. The levels of CYP1A1, CYP2E1 and GSTM1 mRNA gene expression were found to be 4, 4.2 and 4.8 fold, respectively, by quantitative real time PCR. The results of the present case-control study show that the studied Saudi population resembles Caucasians with respect to the considered polymorphisms. Investigation of genetic risk factors and susceptibility gene polymorphisms in our Saudi population should be helpful for better understanding of CRC etiology.

Association of DNA Repair Gene APE1 Asp148Glu Polymorphism with Breast Cancer Risk

Objective. The aim of this study was to investigate the role of APE1 Asp148Glu polymorphism in breast cancer progression in Saudi population. Methods. We examined the genetic variations (rs1130409) in the DNA base excision repair gene APE1 at codon 148 (Asp148Glu) and its association with breast cancer risk using genotypic assays and in silico structural as well as functional predictions. In silico structural analysis was performed with Asp148Glu allele and compared with the predicted native protein structure. The wild and mutant 3D structures of APE1 were compared and analyzed using solvent accessibility models for protein stability confirmation. Results. Genotypic analysis of APE1 (rs1130409) showed statistically significant association of Asp148Glu with elevated susceptibility to breast cancer. The in silico analysis results indicated that the nsSNP Asp148Glu may cause changes in the protein structure and is associated with breast cancer risk. Conclusion. Taken together, this is the first report that established that Asp148Glu variant has structural and functional effect on the APE1 and may play an important role in breast cancer progression in Saudi population.