Characterization of oral mucosa lesions and prevalence of yeasts in diabetic patients: A comparative study.

BACKGROUND: There is no data available on the prevalence of oral mucosal lesion and candida infection among DM patients which necessitate conducting a local or nation-wide study to assess the oral mucosa lesions and candida prevalent in diabetic patients in Riyadh, Saudi Arabia. OBJECTIVES: The objective of the present study was to characterize oral mucosa lesions, and the prevalence of yeasts in diabetic patients and their association with the risk factors in comparison with a group of non-diabetic controls. METHODS: Study design: A cross-sectional comparative study was conducted assuming 50% of the diabetic patients have oral lesions compared to nondiabetic patients and a power of 80% with 5% level of significance, the minimum required sample size was estimated to be 115 in each group. The buccal swabs were collected to isolate Candida species from the individual patient with a current and former history of diabetes. The laboratory findings were collected and the clinical examination of the oral mucosa was processed at the department of microbiology. RESULTS: The results inferred a significant presence of oral mucosa alterations in the diabetic group. A majority of the patients were suffering from type 2 diabetes for the past 10 years. C. albicans was the predominant yeast, followed by. C. tropicalis and C. krusei nonalbicans species that were most frequently isolated. Diabetes and smoking habit were the two risk factors for oral mucosa alterations. CONCLUSIONS: The study found a significant presence of oral mucosa alterations in the diabetic group and the fungal infection tended to be more in the diabetic group with a high incidence of C. albicans. The presence of diabetes and smoking habit were two risk factors identified as significant for oral mucosa alterations. The significant variation in education level in groups indicates that education would help to enhance the prognosis in diabetic patients and healthcare behavior.

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.

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.

Human beta-defensin-1 rs2738047 polymorphism is associated with shisha smoking risk among Saudi population.

Human ß-defensin (HBD), a member of the antimicrobial peptides, is essential for respiratory epithelial cells' microbial defense, and is affected by cigarette smoking (CS). Its expression is upregulated by stimulation from microbes or inflammation. Genetic polymorphisms in the HBD-1 gene have been implicated in the development of various smoking-related diseases, including chronic obstructive pulmonary disease and asthma. Thus, we sought to analyze possible associations between HBD-1 single-nucleotide polymorphism (SNP) in HBD-1 gene and CS in ethnic Saudi Arabian subjects. Variants rs1047031 (C/T), rs1799946 (C/T), rs2738047 (C/T), and rs11362 (C/T) were investigated by genotyping 575 blood specimens from males and females, smokers/non-smokers: 288/287. The CT and CT+TT genotypes of rs1799946 presented an ~5-fold increased correlation with CS among the female smokers, compared with the female controls (OR = 5.473, P = 0.02003; and OR = 5.211, P = 0.02028, respectively), an observation similar to rs11362 SNP in female smokers, but with protective effects in TT genotype, compared with the CC reference allele (OR = 0.143, P = 0.04368). In shisha smokers, the heterozygous CT and the CT/TT genotype of rs2738047 polymorphism showed the same results with ~3-fold increased correlation with CS (OR = 2.788; P = 0.03448), compared with the cigarette smokers category. No significant association was shown in genotypic distributions and allelic frequencies of rs1047031. Further investigations, including large study samples, are required to investigate the effects of shisha on human beta-defensin expression and protein levels.

The protective effects of the methylenetetrahydrofolate reductase rs1801131 variant among Saudi smokers.

Methylenetetrahydrofolate reductase (MTHFR) polymorphism plays a fundamental role in susceptibility to various diseases, including cancers and autoimmune diseases. In the current study, we aimed to compare genotype and allele frequency variations of rs1801131, one of the most common variants found in the MTHFR gene, among Saudi smokers and non-smokers. We hypothesized that genetic variations of this gene are responsible for many diseases, particularly those caused by cigarette smoking (CS) such as pulmonary diseases, oral cancer and lung cancer. We performed a case-control study on a sample of 235 healthy smokers and 239 healthy non-smokers in Saudi Arabia. The rs1801131 SNP genotypes were determined using a genotyping assay and multiple in silico algorithmic software programs were used to identify the effects and structural functions of the rs1801131 (Glu429Ala) mutation. Using chi-squared tests, we found that, among smokers, TG and GG genotype carriers had 0.209-fold (OR = 0.209, P < 0.005) and 0.427-fold (OR = 0.427, P = 0.003) lower risks of CS-related disease compared to TT reference genotypes. In addition, this protective effect was observed in Saudi smokers independent of age, gender, types of smoking, duration, and average daily smoking consumption. Filling a research gap by exploring this topic in the Saudi population, the current findings indicate that genotype and allele distributions of MTHFR rs1801131 polymorphism present fundamental protective effects against the risk of CS-related disease. These findings should be verified in future studies with larger sample sizes, different ethnicities, and patients suffering from CS-related diseases, such as oral cancer and lung cancer.

A novel biocompatible formate bridged 1D-Cu(ii) coordination polymer induces apoptosis selectively in human lung adenocarcinoma (A549) cells.

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)2]n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-ß and MMP-2.

Human papillomavirus, gene mutation and estrogen and progesterone receptors in breast cancer: a cross-sectional study.

INTRODUCTION: recent studies show a good relationship between breast cancer (BC) and human papillomaviruses (HPV) wich is responsible for about 18% of BC cases. This study aimed to assess the relationship between different genotypes of HPV and the expression of P53 and retinoblastoma (RB) genes and estrogen and progesterone receptors in BC among Sudanese women. METHODS: one hundred and fifty tissue blocks were obtained from females diagnosed with BC. Positive samples were used to determine genotypes with an applied biosystem (ABI 3730XL) genetic analyzer for sequencing and immunohistochemistry. RESULTS: 13/150 samples showed HPV DNA. High-risk HPV-16 was detected in 5 cases, high-risk-HPV-58 was found in four cases, and HPV-18 was detected in three cases. Low-risk-HPV-11 was detected in a single invasive lobular carcinoma (ILC) case. P53 and RB gene mutations were detected in 35 and 30 BC cases, respectively. P53 gene mutation was frequently identified in grade (III) BC while RB gene mutation was positive in grade (II). Grade (II) BC had a higher incidence of HPV-16 and 58. On the other hand, HPV-18 had a higher incidence in grade (III). Estrogen and progesterone receptors were expressed in 94 and 79 HPV cases among the study group, respectively. CONCLUSION: this study elucidates the associations between HPV genotypes and BC. A statistically significant association was observed among p53 and RB gene mutations and different BC histological types. On the other hand, there was a statistically insignificant association between HPV genotyping and different BC gradings, BC histological types, P53 and RB genes mutations, and estrogen and progesterone receptor expression. Also, there was a statistically insignificant association among estrogen and progesterone receptors expression and BC grading. RB gene mutation was significantly associated with different BC grades. On the other hand, there was a statistically insignificant association between progesterone receptor expression and BC.

NOTCH Single Nucleotide Polymorphisms in the Predisposition of Breast and Colorectal Cancers in Saudi Patients.

Breast cancer (BC) is a heterogeneous disease and is one of the most common malignancy affecting women worldwide while colorectal cancer (CRC) is estimated to be the third common cancer and second leading cause of cancer related death globally. Both BC and CRC involve multiple genetic and epigenetic alterations in genes belonging to various signaling pathways including NOTCH that has been implicated in the development of these cancers. We investigated four single nucleotide polymorphisms, each in genes encoding NOTCH1-4 receptors for their role in susceptibility to breast and colorectal cancers in Saudi population. In this case-control study, TaqMan genotypic analysis of rs3124591 in NOTCH1 and rs3820041 in NOTCH4 did not exhibit association with breast as well as colorectal cancers. However, a strong association of rs11249433 which is in close proximity to NOTCH2 was observed with breast cancer susceptibility especially with those having an early onset of the disease. Interestingly, the rs1043994 located in NOTCH3 showed gender preference and was found to be significantly associated with colorectal cancers in males. Validation of these findings in bigger populations of different ethnicities may prove beneficial in identifying rs11249433 and rs1043994 as genetic screening markers for early detection of breast and colorectal carcinomas, respectively.

Association of HER1 and HER2 Gene Variants in the Predisposition of Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is a major health concern worldwide. A series of sequential accumulation of genetic and epigenetic changes are responsible for the initiation and progression of diseases via the normal > adenoma > carcinoma sequence. Genetic variants in crucial cancer-causing genes are known to mediate the risk of cancer. OBJECTIVE: In this case-control study, we examined single nucleotide polymorphism (SNP) in HER1 (rs763317 and rs3752651) and HER2 (rs1136201 and rs1058808) genes to assess their role in the susceptibility of CRC in a Saudi population. METHODS: TaqMan allelic discrimination assay was utilized to identify the genotypes in 163 normal and 143 CRC patients. RESULTS: In the overall analysis, the rs3752651 and rs1136201 were significantly associated with the risk of CRC. Although none of the examined SNPs had any impact on the age at which CRC was diagnosed, interestingly, three SNPs showed a significant association based on gender. The rs3752651 conferred significant protection only in men, whereas rs1136201 diminished the risk and rs1058808 considerably increased the susceptibility of CRC only in women. CONCLUSIONS: Our result suggests that these SNPs in HER1 and HER2 after validation in larger cohorts of different ethnicities may be utilized as genetic screening markers for predicting colorectal cancer predisposition.

Targeted sequencing of crucial cancer causing genes of breast cancer in Saudi patients.

Breast cancer is the most common cancer among women worldwide, causing 15% of cancer-related deaths among women. Breast cancer incidence rate is increasing in most countries. In Saudi Arabia, breast cancer constitutes nearly 22% of the newly diagnosed cancer cases in women. Breast cancer incidence in the women population of Saudi Arabia is 25.9%, with 18.2% mortality. In this study, targeted sequencing of 164 selected genes was performed on germline and somatic DNA derived from the blood and tissue samples of 50 breast cancer patients using customized panel on Ion torrent platform. This study focused on the identification of genetic variations of different cancer-causing genes, raising the hope for identification of personalized prognosis. After final filtration and validation, we found protein-truncating, non-synonymous missense, and splice site mutations in the known susceptibility genes for breast cancer. We identified a total of 14 point mutations and one deletion in BRCA1, BRCA2, and RAD50 genes from the BRCA panel analysis of breast cancer samples. In the customized panel analysis, we identified 37 potential mutations in 25 breast cancer risk associated genes. Out of these, most mutations were observed in TP53. After filtration, we observed 7 mutations in TP53 genes (n = 7:- one stop gain (p.R81X), four non-synonymous (p.R81X, p.Y88C, p.R141H, and p.V25D), and two deletions (c.59delC and c.327delC)). Among the mutations detected in our study, TP53 (p.R81X), VHL (p.E52X), and BRCA2 (p.K3326X) mutations, which lead to an aberrant transcript with a premature stop codon, were reported for the first time in breast cancer patients from Saudi Arabia. Our study will help in identifying the damaging mutations and predisposing genes in Saudi breast cancer patients.

Frequent Activation of Notch Signaling Pathway in Colorectal Cancers and Its Implication in Patient Survival Outcome.

Colorectal cancer is a major health concern as it ranks third in incidence and second major cause of cancer-related deaths worldwide. A leading cause of treatment failure has been attributed to cancer stem cells that can invariably resist existing chemotherapeutic regimens. Notch signaling pathway has been involved in the maintenance of stem cells besides being crucial in cell fate decision and embryonic development. This pathway has also been implicated in several human malignancies including colorectal cancer. We investigated mRNA expression of four Notch receptors (Notch1-4), five ligands (Jag1, Jag2, Dll1, Dll3, and Dll4), and four target genes (Hes1, Hes5, Hey1, and Hey2) using highly specific TaqMan gene expression assays in colorectal adenomas and cancers. Upregulated expression of Notch receptors ranged between 29 and 73% in colorectal cancers and between 11 and 56% in adenomas. Expression of Notch3 and Notch4 receptors was significantly higher in colorectal cancers compared to normal and adenoma tissues. The Jagged and Delta-like ligands were overexpressed between 25 and 52% in colorectal cancers, while in adenomas, it ranged between 0 and 33%. Combining the data for upregulation of receptors and ligands suggests that 86% colorectal cancers and 56% adenomas exhibited overexpression of Notch pathway genes in our cohort. Notch target genes were upregulated between 24 and 33% in colorectal cancers and between 11 and 22% in adenomas. Collating upregulation of Notch receptors and ligands with the target genes showed concordance in 58% colorectal tumors. Additionally, we evaluated expression of Notch receptors, ligands, and target genes with prognosis using the TCGA mRNA expression dataset. Patients overexpressing Notch3, Notch4, and Hey1 had significantly poorer overall survival relative to those having lower levels of these genes. Taken together, Notch signaling components are aberrantly overexpressed in colorectal tumors, and development of therapeutics targeting the Notch pathway may prove to be beneficial in the management of colorectal cancers.

MEG3: an Oncogenic Long Non-coding RNA in Different Cancers.

Long noncoding RNAs (lncRNAs) have recently considered as central regulators in diverse biological processes and emerged as vital players controlling tumorigenesis. Several lncRNAs can be classified into oncogenes and tumor suppressor genes depending on their function in cancer. A maternally expressed gene 3 (MEG3) gene transcripts a 1.6 kb lncRNA whose act as an antitumor component in different cancer cells, such as breast, liver, glioma, colorectal, cervical, gastric, lung, ovarian and osteosarcoma cancer cells. The present review highlights biological function of MEG3 to repress tumor through regulating the major tumor suppressor genes p53 and Rb, inhibiting angiogenesis-related factor, or controlling miRNAs. On the other hand, previous studies have also suggested that MEG3 mediates epithelial-mesenchymal transition (EMT). However, deregulation of MEG3 is associated with the  development and progression of cancer, suggesting that MEG3 may function as a potential biomarker and therapeutic target for human cancers.

Genetic variants in the WNT signaling pathway are protectively associated with colorectal cancer in a Saudi population.

The Wnt/ß-catenin signaling pathway has been etiologically implicated in the development and progression of colorectal cancer. We studied thirteen single nucleotide polymorphisms (SNPs) located in SFRP3 (rs7775), CTNNB1 (ß-catenin) [rs4135385, rs13072632], APC (rs454886, rs459552), LRP6 (rs2075241, rs2284396), DKK4 (rs3763511), DKK3 (rs6485350), TCF4 (rs12255372) and AXIN2 (rs3923086, rs3923087, rs4791171) in patients with colorectal cancer (n = 122) and controls (n = 110). Evaluation of WNT pathway SNPs showed protective association for rs4135385, located in ß-catenin. Additionally, variants in SFRP3 (rs7775) and LRP6 (rs2284396) which did not show any association in the overall analysis were significantly associated with female and old aged colorectal cancer patients, respectively.

Association between polymorphisms in PRNCR1 and risk of colorectal cancer in the Saudi population.

LncRNA Prostate cancer non-coding RNA (PRNCR1) is downregulated in many types of cancer. The current case-control study was performed on 144 patients with colorectal cancer and 130 matching controls. Genotyping was performed using TaqMan assays for four Single Nucleotide Polymorphisms (SNPs) in PRNCR1. RNAsnp Web Server was used to detect variations in the secondary structure for each SNP. The genotyping analysis for SNP rs1456315 showed increased association with colorectal cancer with the homozygous CC variant allele (OR: 2.09; χ2 = 4.95; CI: 1.08-4.02; p = 0.02), the minor allele frequency, and additive genotype, respectively (OR: 1.55; χ2 = 6.24; CI: 1.09-2.19; p = 0.01) & (OR: 1.64; χ2 = 4.04; CI: 1.01-2.67; p = 0.04). A risk association was also observed among younger age patients (≤57) and in female patients as well as in patients with tumors of the colon. For the other SNPs tested (rs16901946, rs13252298, rs1016343), no significant association was observed. The secondary structure of the rs1456315 mutant is different from that of the wild-type. Our findings suggest that the upregulation of PRNCR1 and its variants is associated with increased risk of colorectal cancer in Saudi patients, indicating that PRNCR1 might be a unique and valuable signature for predicting the risk of colorectal cancer in a Saudi population.

Novel Associations between BRCA1 Variants C.181 T>G (Rs28897672) and Ovarian Crisk in Saudi Females.

BACKGROUND: Mutations in BRCA1 gene have been implicated in ovarian cancers, and BRCA testing may be conducted in high-risk women. This study was designed to determine the frequency of three single nucleotide polymorphisms (SNPs) variants in BRCA1 gene and BRCA1 expression in Saudi females with ovarian cancer. METHODS: Expression levels of mRNA of BRCA1 gene were studied in 10 ovarian cancer and 10 normal ovarian tissues, by quantitative real time polymerase chain reaction (qPCR). The study also included 28 females who had suffered from ovarian cancer and had been successfully operated upon and 90 healthy females with no history of cancer. Blood was drawn in EDTA tubes and used for extraction of DNA. The genotyping was carried out using Taqman® SNP Genotyping kit by RT-PCR. The variants investigated included c.871 T>C (rs799917), c.1040 G>A (rs4986852), c.181 T>G (rs28897672) in BRCA1 gene. RESULTS: The c.181 T>G (rs28897672) showed significantly different genotype and allele frequencies between the patients and the control subjects (p value = 0.002 and 0.02, respectively). The genotype TG was significantly protective (OR = 0.36, p value = 0.024). The mRNA expression of BRCA1 gene was found to be low in the ovarian cancer tissues. CONCLUSIONS: This study showed that c.181 T>G in BRCA1 genes is associated with the development of ovarian cancer in Saudis. More studies are needed to unveil other SNPs that may be associated with ovarian cancer and to understand the mechanism(s) involved in reducing the expression of BRCA1 gene in ovarian cancer tissues.

Toll-like receptor 6 expression, sequence variants, and their association with colorectal cancer risk.

This is the first study to examine the potential correlation of the rs3796508 and rs5743810 SNPs of the TLR6 gene in patients with colorectal cancer (CRC) in a subset of the Saudi population. TLR6 gene expression was studied by real-time PCR assaysin 10 matching normal and cancer colon tissues. TLR6 expression at the protein level was determined by immunohistochemistry. A case-control search was conductedon 115 case patients and 102 controls. All samples were genotyped with the TaqMan assay for the TLR6 gene. Odds ratios and 95% confidence interval were computed from logistic regression models after adjusting for age, sex, and tumor localization. Our findings showed a decrease in TLR6 expression (p <0.001) in colon cancer tissues when compared to normal colon tissues. Global analysis revealed no significant association between the TLR6 rs3796508 and rs5743810 and CRC in this population. However, the Val/Met genotype of rs3796508 had a significantly higher frequency in the control group than in the cases for the male group (OR= 0.095, and p= 0.03385) or the volunteers aged more than 57 years OR= 0.152; and p= 0.04069, respectively). Two non-synonymous single nucleotide polymorphisms (SNP; S249P and V327M) were common in a few patients and were predicted as damaging by SIFT and Polyphen and were further analyzed for their protein stability and function using advanced bioinformatics tools. The results suggest that TLR6 rs3796508 has a crucial role as a protective factor against colorectal cancer in the older Saudi male population.

Potential of diatom consortium developed by nutrient enrichment for biodiesel production and simultaneous nutrient removal from waste water.

Because of the decreasing fossil fuel supply and increasing greenhouse gas (GHG) emissions, microalgae have been identified as a viable and sustainable feedstock for biofuel production. The major effect of the release of wastewater rich in organic compounds has led to the eutrophication of freshwater ecosystems. A combined approach of freshwater diatom cultivation with urban sewage water treatment is a promising solution for nutrient removal and biofuel production. In this study, urban wastewater from eutrophic Hussain Sagar Lake was used to cultivate a diatom algae consortium, and the effects of silica and trace metal enrichment on growth, nutrient removal, and lipid production were evaluated. The nano-silica-based micronutrient mixture Nualgi containing Si, Fe, and metal ions was used to optimize diatom growth. Respectively, N and P reductions of 95.1% and 88.9%, COD and BOD reductions of 91% and 51% with a biomass yield of 122.5 mg L-1 day-1 and lipid productivity of 37 mg L-1 day-1 were observed for cultures grown in waste water using Nualgi. Fatty acid profiles revealed 13 different fatty acids with slight differences in their percentage of dry cell weight (DCW) depending on enrichment level. These results demonstrate the potential of diatom algae grown in wastewater to produce feedstock for renewable biodiesel production. Enhanced carbon and excess nutrient utilization makes diatoms ideal candidates for co-processes such as CO2 sequestration, biodiesel production, and wastewater phycoremediation.

The heterotrophic eubacterial and archaeal co-inhabitants of the halophilic Dunaliella salina in solar salterns fed by Bay of Bengal along south eastern coast of India.

Halophilic microbes are studied to understand the metabolic pathways adopted by organisms in such extreme environment and for their biotechnological exploitation. In thallosohaline environments worldwide, the autotrophic alga Dunaliella salina Teodoresco is omnipresent, but it is being recently realised that the heterotrophic components vary in different regions. The unexplored eastern coastline of India abutted by Bay of Bengal was investigated for the heterotrophic halophilic microbes in this region. The waters in the salterns - replicas of natural hyper-saline water bodies of that region, were collected at four sites along 650 km of the coastal belt. In cultures set up from these waters, green and pink colonies were observed. The green colonies were found to be those of D. salina while the pink colonies were of heterotrophs. To identify the heterotrophic microbes, light microscopy, 16S rRNA typing and pigment profiling through spectrophotometry and HPLC were done. The cells in pink colonies were rod shaped. 16S rRNA typing of cells in these colonies detected the presence of Halomonas sp. - a eubacterium. The pigment profile of cells in pink cultures matched that of the archaea - Halobacterium; bacterioruberin derivatives were found. Thus, it was concluded that Halomonas and Halobacterium spp. are among the co-inhabitant heterotrophs of D. salina. Cultures of D. salina established from these salterns showed the typical three colours seen in the ponds of different sub-plots of salterns. They were green until 30 days, turning dark orange by 60 days and pink when 90 day old. In the 90 day old cultures, innumerable rod shaped cells were found. These cells were similar to the cells of the waters from the ponds of pink sub-plots of salterns and the pink colonies established from saltern waters in the laboratory. In the old (90 days) laboratory cultures of D. salina, the glycerol and proteins released from degenerating cells and the increase in salt concentration to super saturation levels due to evaporation of water in the medium led to the gregarious appearance of the heterotrophs - the co-inhabitants in natural environment.

Potential role of Toll-like receptor 2 expression and polymorphisms in colon cancer susceptibility in the Saudi Arabian population.

BACKGROUND: Inflammation is a fundamental factor that contributes to the development and progression of several types of cancer including colon cancer. Toll-like receptors (TLRs) and their signaling pathways have been reported to be associated with chronic inflammation and thereby induced cancer. Our aim was to investigate the expression and polymorphisms of TLR2 and their association with colon cancer. METHODS: Real-time PCR and immunohistochemistry were used to investigate TLR2 gene expression and to evaluate the potential risk of predisposition to colon cancer caused by three tagging single-nucleotide polymorphisms (SNPs) on TLR2, including rs3804100, rs4696480, and rs3804099. TaqMan assay was conducted on samples from 115 patients with colon cancer and 102 age- and sex-matched normal individuals. RESULTS: We found that, TLR2 was highly expressed in epithelial colon cancer cells and both TLR2 mRNA and protein levels, and significantly decreased in tumor tissues compared to normal tissues. Two of three TLR2 SNPs increased the risk of colon cancer. However, TLR2 rs3804099 increased the risk of colon cancer development by more than 3.8- and 5-fold in female patients and patients aged less than 57 years, respectively. The T allele of TLR2 rs3804100 showed a significant association with patients less than 57 years. In silico analysis of the TLR2 nucleotide substitution in SNP rs3804100 and rs3804099 determined that 67% and 70% probability of these single nucleotide variants alter splicing phenotypes, rs3804100 more specifically result on activating an additional splice site. Genotype and allele frequencies of rs4696480 were similar between the overall study populations. Thus, TLR2 rs4696480 appear to be not involved in colon cancer in our study population. CONCLUSIONS: There was a significant link between innate immunity deregulation through disruption of the TLRs and potential development of colon cancer. These SNPs can be used as screening markers for predicting colon cancer risk earlier in life to implement necessary prevention.

The expression of telomere-related proteins and DNA damage response and their association with telomere length in colorectal cancer in Saudi patients.

BACKGROUND: Colorectal cancer is the leading cause of cancer-related deaths in Saudi Arabia. Cancer has a multifactorial nature and can be described as a disease of altered gene expression. The profiling of gene expression has been used to identify cancer subtypes and to predict patients' responsiveness. Telomere-associated proteins that regulate telomere biology are essential molecules in cancer development. Thus, the present study examined their contributions to colorectal cancer progression in Saudi patients. METHODS: The expression of hTERT, TRF1, TRF2, POT1, ATR, ATM, Chk1 and Chk2 were measured via real-time PCR in matched cancerous and adjacent tissues of CRC patients. The protein level of hTERT, TRF1, TRF2, ATR, ATM, Chk1 and Chk2 were measured using immunohistochemistry. A region of hTERT core promoter was sequenced via Sanger sequencing. Methylation of CTCF binding site was examined via methylation-specific PCR. Finally, the length of telomere was estimated using q-PCR. RESULTS: Our results showed that POT1, ATR, Chk1 and Chk2 show increased expression in CRC relative to the adjacent mucosa. The expression levels of each gene were associated with clinicopathological characteristics of patients with CRC. There was a positive correlation between the age of the patients and hTERT expression. Regarding tumor site, telomere length, ATR, ATM and Chk1 were shown to be altered. No somatic mutation was detected in hTERT core promoter, and no differences in methylation patterns at CTCF binding site in the promoter between normal and cancer tissues. CONCLUSION: Analysis of targeted genes expression in colorectal cancer based on the clinical variables revealed that tumor location and age could have a role in gene expression and telomere length variations and this could be taken under consideration during CRC diagnosis and therapy. Other epigenetic mechanisms could influence hTERT expression in cancers. Our findings warrant further validation through experiments involving a larger number of patients.