Amal Al-Hazzani

Differential Expression Profile and Genetic Variants of MicroRNAs Sequences in Breast Cancer Patients

The technology available for cancer diagnosis and prognosis is not yet satisfactory at the molecular level, and requires further improvements. Micro RNAs (miRNAs) have been recently reported as useful biomarkers in diseases including cancer. We performed a miRNA expression profiling study using peripheral blood from breast cancer patients to detect and identify characteristic patterns. A total of 100 breast cancer patients and 89 healthy patients were recruited for miRNA genotyping and expression profiling. We found that hs-miR-196a2 in premenopausal patients, and hs-miR-499, hs-miR-146a and hs-miR-196a2 in postmenopausal patients, may discriminate breast cancer patients from healthy individuals. In addition, we found a significant association between two microRNA polymorphisms (hs-miR-196a2 and hs-miR-499) and breast cancer risk. However, no significant association between the hs-miR-146a gene and breast cancer risk was found. In summary, the study demonstrates that peripheral blood miRNAs and their expression and genotypic profiles can be developed as biomarkers for early diagnosis and prognosis of breast cancer.

Catechin hydrate inhibits proliferation and mediates apoptosis of SiHa human cervical cancer cells.

Catechin hydrate (CH), one of the chemical compounds in green tea, has been shown to inhibit tumor growth. Green tea possesses anticancer potential and is one of the most commonly used herbal medicines worldwide. In this study, we sought to characterize the DNA damage and downstream genes targeted by CH extracts using SiHa human cervical cancer cells. The efficacy of CH in killing cervical cancer cells in vitro was investigated in this study to determine whether CH possesses anticancer potential and could be developed as a therapeutic agent for cervical cancer upon further investigation. To scientifically validate the anticancer activities of CH on cervical cancer, CH was tested for its cytotoxic and growth-inhibition properties, specifically the induction of apoptosis in SiHa cervical cancer cells. CH showed a 50% inhibition of SiHa human cervical cancer cells at a concentration of 196.07 μg/mL at 24h. CH induced the several folds increase of caspase-3, -8, and -9 after 24h and 48 h; the increase of these genes may be involved in the induction of apoptosis. The analysis of apoptosis by DeadEnd terminal transferase-mediated dUTP-digoxigenin-end labeling (TUNEL) assay was used to further confirm that CH induced apoptosis. The results suggested that CH has the potential to benefit cervical cancer prevention. This is the first report that shows the possible mechanism of the anti-proliferative effects of CH in the prevention of cervical cancer in cell culture models. CH, either in its original form or in combination with other anticancer drugs, could potentially be an alternative medicine for cervical cancer. Further study may increase our understanding of the mechanism by which CH has an effect on cervical cancer therapy.

Novel Marine Compounds: Anticancer or Genotoxic?

In the past several decades, marine organisms have generously gifted to the pharmaceutical industries numerous naturally bioactive compounds with antiviral, antibacterial, antimalarial, anti-inflammatory, antioxidant, and anticancer potentials. But till date only few anticancer drugs (cytarabine, vidarabine) have been commercially developed from marine compounds while several others are currently in different clinical trials. Majority of these compounds were tested in the tumor xenograft models, however, lack of anticancer potential data in the chemical- and/or oncogene-induced pre-initiation animal carcinogenesis models might have cost some of the marine anticancer compounds an early exit from the clinical trials. This review critically discusses importance of preclinical evaluation, failure of human clinical trials with certain potential anticancer agents, the screening tests used, and choice of biomarkers.

Interleukin-10-1082 promoter polymorphism and ischemic stroke risk in a South Indian population.

Within the past few years there has been increasing evidence that the genetic variation in the genes coding pro- and anti-inflammatory markers may play an important role in the pathogenesis of various human diseases, including stroke. The aim of the study was to evaluate the association of Interleukin-10 (IL-10)-1082 G/A, promoter polymorphism (rs1800896) with ischemic stroke in a South Indian population from Andhra Pradesh. In this study 480 ischemic stroke patients and 470 age and sex matched healthy controls were included. The ischemic stroke patients were classified according to TOAST classification. The region of interest in the IL-10 gene was amplified by polymerase chain reaction with the use of allele specific oligonucleotide primers flanking the polymorphic region. Association between genotypes and stroke was examined by Odds Ratio (OR) with 95% confidence interval (CI) and Chi-square analysis. Significant difference was observed between the patients and healthy controls, in genotypic distribution as well as allelic frequency (p<0.05). Multiple logistic regression analysis with forward stepwise selection using the potential confounders (sex, age, diabetes, hypertension, smoking and alcoholism) and IL-10 gene variant revealed that -1082 G/A polymorphism in the promoter region of IL-10 gene is significantly [adjusted OR=2.26; 95% C.I. (1.24-4.15), p<0.001] associated with ischemic stroke in the South Indian population from Andhra Pradesh. We found significant association of this polymorphism with stroke of undetermined etiology (p<0.001). Moreover, hypertensive and diabetic individuals bearing A allele of IL-10 gene in high frequency were found to be more predisposed to stroke.

Association of genetic variants of fibrinolytic system with stroke and stroke subtypes.

Genetic variants of tPA (PLAT) and PAI-1 genes have been suggested to be the risk factors for stroke. In the present case-control study we investigated the association of -7351C/T polymorphism (rs2020918) and I/D polymorphism of tPA gene and Insertion/deletion polymorphism (4G/5G) of PAI-1 gene with genetic predisposition to ischemic stroke. 516 stroke patients and 513, sex and age matched healthy controls were involved in the study. We did not find a significant association of tPA -7351C/T polymorphism and PAI-1 4G/5G polymorphism with stroke. However, in case of I/D polymorphism significant difference was observed in the genotypic distribution and allelic frequency between the stroke patients and healthy controls. DD genotype and D allele associated significantly with stroke (p=0.002 and <0.001 respectively). We also found significant association of I/D polymorphism with intracranial large artery atherosclerosis and stroke of undetermined etiology. Exploring the association between gene-gene interaction (26 combinations including the three variants) and stroke, we found that individuals with CC+4G4G+DD, CC+5G5G+ID, CT+4G5G+ID, CT+5G5G+II, CT+5G5G+ID and TT+4G5G+II had a significantly higher risk of stroke. The results of this study suggest that -7351C/T polymorphism of tPA and 4G/5G polymorphism of PAI-1 are not associated with stroke, while as DD genotype and D allele of tPA gene are important risk factors for ischemic stroke. Further we found that the subjects with different tPA and PAI genotype combinations displayed a significantly high risk for overall ischemic stroke suggesting that gene-gene interaction involving more variants may change the susceptibility of particular subjects to the disease.

Association of tumor necrosis factor‐α and matrix metalloproteinase‐3 gene variants with stroke

Background and purpose:  There is increasing evidence that the genetic variation in the genes coding for pro‐inflammatory markers and matrix metalloproteinase may play an important role in the pathogenesis of various human diseases including stroke. The aim of this study was to evaluate the association of genetic variants within the genes encoding tumor necrosis factor‐α (TNF‐α) and matrix metalloproteinase‐3 (MMP‐3), with stroke.

A single‐nucleotide polymorphism in the TP53 and MDM‐2 gene modifies breast cancer risk in an ethnic Arab population

Breast cancer is the most common oncological disease in women worldwide. Genetic predisposition to breast cancer can be associated with single‐nucleotide polymorphisms (SNPs), which are observed in many women. Such gene polymorphisms, in combination with nutritional and environmental factors, can affect breast cancer development. The tumor suppressor TP53 and its negative regulator MDM2 play crucial roles in carcinogenesis. Previous case–control studies have revealed that TP53 72Arg > Pro and MDM2 309T > G polymorphisms contribute to the risk of common cancers. However, the relationship between these two functional polymorphisms and breast cancer susceptibility in the Saudi population has not been explored. In this study, we performed a case–control study of patients with breast cancer and healthy controls in a Saudi population using TaqMan‐based real‐time PCR. We found an increased breast cancer risk associated with the MDM2 GG [odds ratio (OR) = 2.79, 95% confidence interval (CI) = 2.04–3.92] and TG [OR = 1.43, 95% CI = 1.12–2.02] genotypes. An increased risk was also associated with the TP53 Pro/Pro genotype (OR = 2.19, 95% CI = 1.54–3.06) compared with the Arg/Arg genotype. The gene–gene interaction of MDM2 and TP53 polymorphisms increased breast cancer risk in a multiplicative manner (OR for the presence of both MDM2 GG and TP53 Pro/Pro genotypes = 7.71, 95% CI = 3.49–17.54). These findings suggest that polymorphisms of MDM2 and TP53 genes may be a genetic modifier for developing breast cancer in this ethnic population in the Arab world.

Estrogen receptor α genetic variants and the risk of stroke in a South Indian population from Andhra Pradesh

BACKGROUND Stroke is a complex disease caused by combination of multiple risk factors. Recent findings have suggested that stroke has a strong genetic component. Evidence suggests that variations in the estrogen receptor α (ESR1) gene may influence stroke risk. AIMS The present study was carried out to investigate the role of ESR1 gene polymorphisms [PvuII (rs 2234693) and XbaI (rs 9340799)] with stroke in a South Indian population from Andhra Pradesh. The relationship between ESR1 genotypes with estradiol levels was also investigated in pre- and postmenopausal women. METHODS Four hundred patients with ischemic stroke and three hundred and eighty subjects were enrolled in this case-control study. Ischemic stroke subtypes were classified according to TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. The ESR1 PvuII and XbaI genotypes were determined by PCR-RFLP method. Serum estradiol was measured by ELISA. RESULTS In case of PvuII polymorphism statistically significant difference was observed in the genotypic and allelic frequencies between patients and controls (joint analysis of men and women) (p=0.003 and 0.004 respectively). However, the XbaI genotypes and alleles did not show an association with stroke in the study population. When the analysis was carried out separately for men and women, the PvuII polymorphism did not show significant association with stroke in men; women showed a significant association. Further when women were grouped in to premenopausal and postmenopausal, the premenopausal group did not show a significant association with the polymorphism but significant association with stroke was found in postmenopausal women. A stepwise multiple logistic regression analysis confirmed these findings. Women with pp genotype had low estradiol levels in comparison with PP genotypic individuals (p<0.05). Further evaluating the association of this polymorphism with stroke subtypes, we found significant association of PvuII polymorphism with extracranial atherosclerosis, lacunar and cardioembolic stroke. CONCLUSION In conclusion our results suggest the PvuII gene polymorphism is significantly associated with stroke in postmenopausal women in a South Indian population from Andhra Pradesh. The pp genotypes have average 17β estradiol levels which are significantly low in comparison with PP genotypes. Therefore postmenopausal women with a high frequency of pp genotype are more predisposed to ischemic stroke. However, this is a preliminary study and the results need to be confirmed in a larger cohort.

Adsorptive removal of cadmium ions by Spirulina platensis dry biomass

Cadmium is one of the most toxic substances found in aquatic ecosystems. This metal tends to accumulate in photosynthetic plants and fish and is transferred to humans causing many diseases. It has to be removed from our environment to reduce any health risks. Dry biomass of the microalga (cyanobacterium) Spirulina platensis was used as biosorbent for the removal of cadmium ions (Cd2+) from aqueous solutions. The effects of different levels of pH (3–9), biomass concentration (0.25–2 g), temperature (18–46 °C), metal concentration (40–200 mg/l) and contact time (30–120 min) were tested. Batch cultures were carried out in triplicate in an orbital shaker at 150 rpm. After centrifuging the biomass, the remaining levels of cadmium ions were measured in the supernatant by Atomic Absorption Spectrometer. Very high levels of removal, reaching up to 87.69% were obtained. The highest percentage of removal was reached at pH 8, 2 g of biosorbent, 26 °C, and 60 mg/l of cadmium concentration after 90 min of contact time. Langmuir and Freundlich isotherm models were applied to describe the adsorption isotherm of the metal ions by S. platensis. Langmuir model was found to be in better correlation with experimental data (R2 = 0.92). Results of this study indicated that S. platensis is a very good candidate for the removal of heavy metals from aquatic environments. The process is feasible, reliable and eco-friendly.

Association of C3435T multi drug resistance gene-1 polymorphism with aspirin resistance in ischemic stroke and its subtypes

Aspirin is the most commonly used antiplatelet drug for treatment of a serious vascular event, most notably myocardial infarction and stroke. Significant fraction of aspirin treated patients is resistant to the antiplatelet effects of the drugs. Previous studies have suggested that a genetic basis for aspirin resistance exists. Therefore the present study was taken up to investigate the role of C3435T polymorphism (rs 1045642) of multiple drug resistance-1 (MDR-1) gene with aspirin resistance in stroke patients. Five hundred and sixty ischemic stroke patients and 560 age and sex matched healthy controls were involved in the study. Baseline clinical data were collected and follow-up telephone interviews were conducted with patients at 3, 6 and 12 months post event to determine stroke outcome. Blood samples were collected and genotypes determined. Significant difference was observed in the genotype distribution and allele frequency between patients and controls. The results were confirmed by a step wise multiple logistic regression analysis controlling all other confounding risk factors [adjusted Odds ratio=3.132 (95% CI; 2.043-4.800; p<0.001)]. There was a significant difference in genotype distribution between drug responders and non-responders. The risk of aspirin resistance was significantly high in patients with TT genotype in comparison to those with CC genotype [(TT vs. CC, χ(2)=6.268; p=0.012, Odds ratio=1.85) (95% CI; 1.142-3.017) (adjusted Odds ratio=2.465; 95% CI; 1.895-4.625 and p<0.001)]. As far as the stroke subtypes are concerned TT genotype associated significantly with aspirin resistance in intracranial large artery atherosclerosis. Our results indicate that the risk of aspirin resistance is more in patients with 3435TT genotype than in those with CC genotype. However, this is a preliminary study and a large study of replication is needed to confirm our results.