Influence of single nucleotide polymorphisms in pri-miR-124-1 and STAT3 genes on gastric cancer susceptibility

INTRODUCTION

MicroRNAs (miRNAs) are small ribonucleic acids that modulate the expression of downstream target genes. There is considerable evidence of their involvement in many malignancies, such as oesophageal and gastric. We hypothesised altered expressions of pri-miR-124-1 rs531564 and STAT3 rs1053023 polymorphisms in gastric cancer.

MATERIALS AND METHODS

Genomic DNA was extracted from peripheral blood of 250 patients with gastric cancer and 310 healthy individuals. The RFLP method was applied for determination of pri-miR-124 polymorphism and the AS-PCR method for STAT3 polymorphism.

RESULTS

The distribution of rs531564 genotypes in cases and controls was different: the G allele carriers had a reduced gastric cancer risk (OR = 0.62; 95%CI = 0.49-0.80, P = 0.0002). Presence of the minor allele of STAT3 (rs1053023) was linked with higher risk of gastric cancer (OR = 2.29; 95% CI = 1.79-2.93, P < 0.0001). Compared with the most frequent haplotype C-G [the SNP order was pri-miR-124-1 (rs531564) and STAT3 (rs1053023)] in controls, C-A haplotype was associated with a significantly increased risk of gastric cancer (OR = 2.28; 95%CI = 1.64-3.09, P < 0.0001).

CONCLUSION

There is a strong link between pri-miR-124-1 rs531564 and STAT3 rs1053023 and gastric cancer that may be pathogenic, and so worthy of further investigation.

OX40L gene polymorphism and breast cancer in Iranian population

BACKGROUND AND AIM

The immune system plays an important role in the breast cancer development. OX40L (also known as TNFSF4), a membrane protein, which is a member of the tumor necrosis factor super family binds to its receptor OX40 and this co-stimulation has a crucial role in T cell proliferation, survival and cytokine release. Previous studies have shown that OX40L is associated with cancer. Due to the importance of the T cells in antitumor activities of OX40L we studied the association of rs3850641 (A→G) polymorphism of OX40L gene with the breast cancer.

MATERIALS AND METHODS

The study included 123 women with breast cancer and 126 healthy volunteers with no signs of cancer. Genomic DNA was extracted from blood leucocytes. Genotype and allele frequencies were determined in patients and control cases with the method of polymerase chain reaction-restriction fragment length polymorphism and the statistical analysis was performed by Med Calc.

RESULTS

The prevalence of genotype frequencies of AA/AG/GG were 60.9%, 30.08% and 8.9% in patients with breast cancer cases and 74.6%, 18.25% and 7.14% in healthy volunteers while the A and G allelic frequency was 76.01 and 23.98% in patients and 83.73 and 16.26% in healthy controls, respectively. Statistical analysis has shown significant difference from the comparison of genotype (p = 0.03).

CONCLUSION

It is concluded that the rs3850641 SNP is significantly associated with the breast cancer susceptibility in Iranian population. However, further studies in larger populations including other genetic and environmental factors are required to achieve conclusion.

Novel calcified gum Arabic porous nano-composite scaffold for bone tissue regeneration

The aim of this study was to investigate the biomechanical and biological properties of a nanocomposite scaffold containing both mineral and polysaccharide constituents. Hydroxyapatite nanoparticles (n-HA) was synthesized from dead abra ovata shells using wet chemical methods and was used in different ratios in concert with gum Arabic, a branched plant polysaccharide. N-HA/gum nanocomposite was fabricated with freeze-drying process and characterized by FTIR and SEM for chemical structure and morphology. Porosity was estimated using liquid substitution method. The scaffold mechanical properties were evaluated by compressive test measurement. Osteogenic differentiation was assessed using alkaline phosphatase production and biomineralization was evaluated using Alizarin red assay. Results demonstrated that the hydroxyapatite/gum Arabic nanocomposite had favorable biocompatibility and a similar structure to natural bone matrix. Porous nanocomposite possessed macropore networks with a porosity 87-93% and mean pore size ranging between 164 and 230 μm. The gum/HA with a ratio of 50% w/w HA had the highest compressive modulus of ∼75.3 MPa Pa (MPa) and the ultimate compressive stress of ∼16.6 MPa. C2C12 cells cultured on a scaffold with higher percentage (40 and 50 w/w) of HA demonstrated increased ALP levels and calcium deposition. The data from the present study demonstrated significant changes to the biomechanical properties and osteoconductivity of the nanocomposite scaffold by modulating its mineral content. Nanocomposite scaffolds containing gum and n-HA of 40-50% exhibited highest mechanical properties, as well as supported increased biomineralization.

[Mitochondrial DNA deletion Δ4977 in peptic ulcer disease]

Reactive oxygen species (ROS) play a critical role in peptic ulcer disease (PUD). Due to the high rate of ROS production and limited capacity for DNA repair within mitochondria, mtDNA is susceptible to oxidative damage and mutations. mtDNA deletion Δ4977 is one of the most common deletion events identified in mitochondria. We examined the association of 4977-bp mtDNA deletion with PUD. Genotypes were determined in bioptic samples of 150 PUD patients and 190 controls. The 4977-bp mtDNA deletion was found more frequently among patients with PUD (52%) than among controls (22.63%). The strong association between the mtDNA 4977-bp deletion and PUD was confirmed (OR = 3.7; 95% CI, 2.32-5.91; P = 0.0001). The 4977-bp deletion in mitochondrial DNA may be a risk factor for PUD, or may reflect an increase in oxidative stress that commonly accompanies underlying PUD disease. Larger population-based studies are needed to uncover the possible causal relationship between this deletion and peptic ulcer disease.

[Evaluation of GPx1 Pro198Leu Polymorphism in Idiopathic Male Infertility]

Infertility is defined as failure to conceive a child after 1 year of unprotected regular sexual intercourse. Approximately half of all cases of infertility are caused by factors related to the male. In nearly 50% of infertile men it is not possible to determine the cause of infertility and this situation has been defined as unexplained or idiopathic. Oxidative stress plays an important role in the pathophysiology of male infertility. Oxidative stress results from an imbalance in free radicals and antioxidant defense mechanisms of the body. Genetic variations in the antioxidant gene coding for GPx enzyme may lead to decreased or impaired regulation of its enzymatic activity and alter reactive oxygen species (ROS) detoxification. We have investigated the possible association between polymorphism GPx1 Pro198Leu and idiopathic male infertility. One hundred patients with idiopathic male infertility and one hundred fifty healthy volunteers were enrolled. Genomic DNA was extracted from blood samples. Genotyping for the GPx1 Pro198Leu polymorphism was done by PCR-restriction fragment length polymorphism (RFLP) using ApaI. The genotype frequencies were 11% (Leu/Leu), 76% (Pro/Leu) and 13% (Pro/Pro) in the patient group and 8.7% (Leu/Leu), 67.3% (Pro/Leu) and 24% (Pro/Pro) in the control group. The genotype and allele frequencies of GPx1 Pro198Leu did not differ between the patient group and the control group (P = 0.09 and P = 0.1, respectively). In conclusion, there is no correlation between idiopathic male infertility and the GPx1 codon Pro198Leu polymorphism. Further studies are needed to investigate other genetic factors that influence the development of idiopathic male infertility.

The E-selectin S149R polymorphisms in breast cancer in a northern Iran population

Breast cancer is a complex polygenic disorder that genetic factors play an important role in disease etiology. E-selectin mediates the adhesion of tumor cells to endothelial cells. This interaction is associated with metastatic dissemination. Expression of E-selectin on the endothelium is a hallmark of inflammation. This study was performed to evaluate the association of E-selectin S149R polymorphisms and the risk of breast cancer. A total of 100 patients with breast cancer and 120 healthy sample donors (controls) were recruited in this study. Genomic DNA was extracted from fresh blood samples and genotyping of the E-selectin genes was performed using PCR-restriction fragment length polymorphism (PCR-RFLP). The frequencies of the CC, AC and AA genotypes were 2%, 84%, and 14% in patients and 2%, 12%, and 86% in controls, respectively, while the A and C allelic frequency was 56%, 44% in patients and 92%, 8% in controls, respectively. Statistical analysis showed that there is a significant difference between two groups (P<0.0001). It is concluded that the E-selectin S149R polymorphisms is associated with the oncogenesis of breast cancer in a population in northern Iran.

The association of ApE1 -656T>G and 1349T>G polymorphisms with breast cancer susceptibility in northern Iran

Breast cancer is the most common cancer and one of the main causes of cancer-related death in the world and has become a major public health concern. Many genes have been shown to be involved in the progress of the breast cancer. Human apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional protein that has an important role in the base excision repair (BER) pathway. The aim of this study was to evaluate the association between ApE1 -656T>G and 1349T>G polymorphisms and the susceptibility to breast cancer in northern Iran population. Samples were obtained from 150 patients diagnosed with breast cancer and 150 control subjects and genotyped by tetra - primer amplification refractory mutation system PCR (T-ARMS-PCR). We observed a significant difference in genotype distributions of -656T>G polymorphism between patients and controls (P= 0.03). Findings indicated that individuals with the variant TG genotypes had a significant decreased risk of breast cancer (OR= 0.55, 95% CI= 0.33 - 0.91, P= 0.019). However, the significant association between 1349T>G polymorphism and breast cancer risk was not observed (P = 0.89). Larger studies are needed to confirm our results.

The association of PON1 192 Q/R polymorphism and the risk of female infertility

Infertility is a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months of regular unprotected sexual intercourse. Both environmental and genetic factors are involved in female infertility. Paraoxonase (PON) is an oxidant enzyme which plays an important role in various diseases and is associated with inflammation, oxidative stress and lipid metabolism. The present study was aimed to evaluate the PON1 192 Q/R gene polymorphism in female infertility. Samples were obtained from 150 patients diagnosed with female infertility and 150 controls subjects and genotyped by Polymerase Chain Reaction&mdash;Restriction Fragment Length Polymorphism (PCR&mdash;RFLP). The PON genotype frequencies amongst the 70 cases were C/C=40%, C/T=52.8% and T/T=7.2%; the C and T allele frequencies were 66% and 34%, respectively. The PON genotype frequencies amongst the 73 controls were C/C=45.20%, C/T=50.70% and T/T=4.1%; the C and T allele frequencies were 70% and 30%, respectively. We observed a significant difference in the genotype distributions of PON1 192 Q/R polymorphism between patients and controls (P= 0.03). Our findings revealed that individuals with the variant QR had a significant decrease risk of female infertility (OR= 0.55, 95% CI= 0.33 - 0.91, P= 0.019). The data from this study indicates that the PON1 192 Q/R polymorphism may be associated with decreased risk of female infertility. Although more studies should be considered with larger number of patients and control subjects to confirm our results.

The relationship between MMP-9 promoterpolymorphism and IVF outcome

Angiogenesis, invasion and decidualization play an important role in implantation and embryo development. Matrix metalloproteinases (MMPs) are crucial for the degradation/remodeling of the extracellular matrix, and are involved in spiral artery formation and invasion of endometrium during implantation. A functional single&mdash;nucleotide polymorphism (SNP) in the MMP9 promoter, &mdash;1562C/T, is known to influence gene expression in allele&mdash;specific manner. The present study evaluated the association between maternal genotype of SNP &mdash;1562C/T of MMP9 and in vitro fertilization and embryo transfer (IVF&mdash;ET) outcome in infertile women. This case-control study was comprised of infertile patients (n= 123) and women having one healthy child as controls (n= 147). Genotyping for SNP&mdash;1562C/T was performed by PCR/RFLP. Allele and genotype distribution did not differ significantly between patients and controls (P>0.05). The MMP9 genotype frequencies amongst the 123 cases were C/C=73.17%, C/T=24.40% and T/T=2.43%; the C and T allele frequencies were 85.36% and 14.63%, respectively. The MMP9 genotype frequencies amongst the 147 controls were C/C=73.46%, C/T=20.40% and T/T=6.12%; the C and T allele frequencies were 83.67% and 16.32%, respectively. In conclusion, the results of this study indicate that SNP &mdash;1562C/T of MMP9 may not be associated with IVF&mdash;ET outcome in this population.

A single-nucleotide polymorphism in TP53 may be a genetic risk factor for Iranian patients with idiopathic male infertility

Male infertility is a heterogeneous disorder that contributes to the impairment of spermatogenesis. The purpose of this study was to assess whether tumour suppressor p53 gene (Tp53) polymorphism is associated with idiopathic male infertility in the Iranian population. The prevalence of G → C substitution at codon 72 in exon 4 was determined in 110 idiopathic infertile azoo-/oligospermic patients and 180 fertile healthy control men. PCR-restriction fragment polymorphism analysis was employed to determine the genotypes. PCR amplicons were subjected to restriction digestion with Bstu1 and separated by gel electrophoresis. The Arg/Arg genotype was found more frequently among men with idiopathic infertility (32.7%) than among controls (17.7%). No significant difference was observed between Pro/Pro genotype and Arg/Arg + Arg/Pro genotypes among men with idiopathic infertility and controls (P = 0.11; OR: 0.36; 95% CI: 0.36-1.10). In contrast, a significant difference was observed in the comparison of the Arg/Arg genotype and Arg/Pro + Pro/Pro genotypes among patients and controls (P = 0.004; OR: 2.25; 95% CI: 1.29-3.90). Allele frequency evaluation suggested a significantly higher incidence of the Arg allele among infertile men compared with controls (56% versus 44%; OR: 1.6; 95% CI: 0.92-2.80). In conclusion, arginine allele appears to be at greater risk of developing idiopathic infertility in Iranian men.

Significance of eIF4E expression in skin squamous cell carcinoma

Cutaneous squamous cell carcinoma (SCC) is a malignant tumour of keratinising epidermal cells. This type of skin cancer is the second leading cause of death after melanoma, and it is the second most common type of non-melanoma skin cancer after basal cell carcinoma. The cellular and molecular events involved in the progression of skin cancers are largely unknown. Increased protein synthesis is necessary for the transition of cells from quiescence to proliferation. Translational control is critical for the proper regulation of the cell cycle, tissue induction and growth. Eukaryotic initiation factor eIF4E, an important regulator of translation, plays critical roles in neo-plastic transformation and cancer progression. We investigated eIF4E expression in 49 skin samples (six normal tissues, eight Bowen diseases, seven stage I, 10 stage II, 13 stage III and five stage IV SCCs). Results obtained demonstrated that all SCC samples, evaluated by SDS-PAGE, Western blotting and cap-affinity chromatography using m7GTP-sepharose, presented eIF4E expression (13.6+/-1.2), whereas, starting from stage 0 (4.1+/-0.9) to stage I (7.4+/-1.4), stage II (12.1+/-2.4), stage III (18.1+/-3.0) and stage IV (26.2+/-3.8) SCCs, a constant and significant increase of protein over expression (P<0.001) was observed. A high expression of eIF4E is correlated with advanced stages. The results presented in this study demonstrate a possible role of eIF4E in SCC.

Infusion of anti-nerve growth factor into the cisternum magnum of chick embryo leads to decrease cell production in the cerebral cortical germinal epithelium

There has been considerable recent progress in understanding the processes involved in cerebral cortical development. Several mitogenic and trophic factors have been implicated in the processes of cortical cell proliferation and differentiation. Anti-nerve growth factor (NGF) antibody was administered to 15 days chick foetuses through the cisternum magnum. Control group received phosphate buffered saline (PBS). To identify cells born in the cerebral cortex at the time of antibody or PBS injection, 5'-bromo-2'- deoxyuridine was administered to the foetuses by intravenous injection into an outlying vein using micromanipulation. After injection, the foetuses were re-incubated for another 3 days. All the foetuses were collected on day 18, the brains fixed in paraformaldehyde, cut with a microtome and stained with methyl green pyronin and anti-NGF antibody. Quantitative measurements showed that the thickness of the germinal epithelium (GE) and cerebral cortex in the anti-NGF antibody injected foetuses was decreased when compared with normal control embryos. The number of cells produced in the GE of antibody injected foetuses was decreased when compared with normal control embryos. The results from this study using neutralizing antibody suggests that NGF is an important factor in cerebral cortical development, stimulating neuronal precursor proliferation.

The role of cerebrospinal fluid on neural cell survival in the developing chick cerebral cortex: an in vivo study

Cerebrospinal fluid (CSF) is secreted by the choroid plexuses located in the lateral, third and fourth ventricles. The fluid flows through the ventricular system, passing over all the regions of germinal activity. CSF contains growth factors and other neurotrophic factors, which are important for cell survival and proliferation. It has been shown that nerve growth factor deprivation induces apoptosis in the developing cerebral cortex. In this study, disruption of normal CSF flow on neural cell survival in the developing cortex has been investigated. Draining CSF from the ventricles of the brain during development increases the number of neural cell deaths and thinning of the cerebral cortex compared with normal ones. These data from our study indicate that normal CSF circulation is important for the survival of cells in the developing cerebral cortex and thus of CSF in the normal chick cerebral cortex development.

The importance of cerebrospinal fluid on neural cell proliferation in developing chick cerebral cortex

Cerebrospinal fluid (CSF) is mainly produced by the choroid plexuses within the ventricles of the brain. The CSF circulates in a regular manner after the ventricular system and the choroids plexuses have developed, and the foramina in the fourth ventricle have opened to enable it to carry chemical information. CSF flows through the ventricular system passing over all regions of germinal activity. In this study, chick embryos were used to show the importance of CSF on neural cell proliferation in the developing cerebral cortex. The chick embryos were cannulated in situ with a fine capillary tube to drain CSF out of the ventricular system. At the same time, BrdU was administered to the embryos. After surgery the embryos were incubated for another 3 days. Quantitative measurements showed that the thicknesses of the germinal epithelium and cerebral cortex in CSF-drained embryos were less than those in the control group at the same age. The number of cells produced in the germinal epithelium of CSF-drained embryos was decreased when compared with the normal group. This study provides confirmatory evidence that CSF is important for neural cell proliferation and therefore normal development of the cerebral cortex. It is proposed that CSF is vital in controlling development of the cerebral cortex.

Expression of nerve growth factor in cerebrospinal fluid of congenital hydrocephalic and normal children

Cerebrospinal fluid (CSF) is secreted by the choroids plexuses and has the potential to act as a signaling pathway for physiological control as it has been demonstrated to contain molecules such as interleukins, leukoterins, neuropeptides, growth transforming factor-beta (TGF-beta) and nerve growth factor (NGF), which are present at specific times during development. In this study, CSF from hydrocephalic and normal children were analysed using SDS-PAGE followed by silver staining. In order to obtain semi-quantitative estimates of the relative amounts of 26 kDa protein, an image analyzer was used to determine the intensities of the band in the respective lanes in silver-stained gels. Quantification of the silver-stained gels from repeated experiments showed that the amount of 26 kDa protein was clearly increases in the hydrocephalic CSF when compared with the normal CSF. A Western blot analysis using anti-NGF antibody as a probe confirmed the presence of NGF. Using enzyme-linked immunosorbent assay (ELISA), it was shown that the level of NGF in the hydrocephalic CSF is higher than in normal CSF. It is concluded that NGF is not only a constant component of human CSF but could also be significantly involved in the pathophysiology of hydrocephalus.

Changes in the CSF fluid pathways in the developing rat fetus with early onset hydrocephalus

Interest in the factors involved in the abnormal cortical development of the HTx rat fetus have led us to re-examine the structural and morphological changes in the CSF pathways preceding constriction and blockage of the cerebral aqueduct. Histological analysis was carried out on coronal and sagittal sections from HTx and Wistar fetuses. The aqueduct is found to be a broad channel extending from the posterior end of the third ventricle that ends in a blind pouch above the developing cerebellum. The aqueduct drains into the fourth ventricle via a vertically orientated, narrow channel lying between the posterior aspect of the pontine flexure and the anterior surface of the cerebellum. On Day E18 the connecting channel between the aqueduct and the fourth ventricle is blocked by apposition of its walls. 24 hours later the lateral ventricles begin to dilate and the anterior end of the aqueduct is blocked and the connecting channel between the aqueduct and the fourth ventricle reopens. The cause of these sequential changes in the CSF fluid pathways remains speculative.