Genome expression analysis by suppression subtractive hybridization identified overexpression of Humanin, a target gene in gastric cancer chemoresistance

Background

In cancer cells, apoptosis is an important mechanism that influences the outcome of chemotherapy and the development of chemoresistance. To find the genes involved in chemoresistance and the development of gastric cancer, we used the suppression subtractive hybridization method to identify the genes that are overexpressed in gastric cancer tissues compared to normal gastric tissues.

Results

In the suppression subtractive hybridization library we constructed, the most highly overexpressed genes were humanin isoforms. Humanin is a recently identified endogenous peptide that has anti-apoptotic activity and has been selected for further study due to its potential role in the chemoresistance of gastric cancer. Upregulation of humanin isoforms was also observed in clinical samples by using quantitative real-time PCR. Among the studied isoforms, humanin isoform 3, with an expression level of 4.166 ± 1.44 fold, was the most overexpressed isoform in GC.

Conclusions

The overexpression of humanin in gastric cancer suggests a role for chemoresistance and provides new insight into the biology of gastric cancer. We propose that humanin isoforms are novel targets for combating chemoresistance in gastric cancer.     

Significance of mast cells in spermatogenesis,implantation, pregnancy,and abortion: Cross talk and molecular mechanisms

Both subsets of MCs including MC_TC (tryptase‐positive, chymase‐positive) and MC_T (tryptase‐positive, chymase‐negative) are present in the testis and epididymis. Increased number of MCs, higher levels of MC‐released tryptase in testis and seminal plasma of males with fertility problems, and promoting sperm motility in individuals with oligozoospermia after using MC blockers provide evidence that MCs may play a role in male infertility/subfertility disturbances. MC‐released tryptase and histamine contribute to the fibrosis and may disrupt spermatogenesis. MCs not only influence the process of spermatogenesis but also have effects on the function of other testis‐residing cells. MC‐derived histamine may influence the steroidogenesis of Leydig cells by acting through H1R and H2R receptors. Additionally, the interaction between MC‐released ATP and P2X receptors expressed on the peritubular cells may induce the production of the pro‐inflammatory mediators by peritubular cells. Further investigations showed that MCs may be involved in the pathology of female infertility during implantation, pregnancy, and abortion. In the uterus, MC_T subtype is abundant in myometrium and adjacent basal layer while MC_TC subtype is distributed in all layers. MCs in response to hormones mainly estradiol and progesterone become activated and release a wide range of mediators including histamine, VEGF, proteases, and metalloproteinases (MMPs) that have a role in different stages of pregnancy. An increasing influx of MCs to the cervix during the pregnancy occurs that helps to the physiologic cervical ripening. While MMPs degrade the extracellular matrix (ECM), VEGF modulates neovascularization and histamine influences the embryo implantation. MC‐derived histamine may have a positive effect during implantation due to its participation in tissue remodeling. MC proteases including tryptase and chymase activate the precursors of MMP2 and MMP9 to mediate ECM degradation during the physiologic menstrual cycle. There is a line of evidence that MCs have a role in abortion by releasing TNF‐α.     

Longitudinal Tissue Velocity and Deformation Imaging in Inferobasal Left Ventricular Aneurysm

Background: Longitudinal myocardial tissue velocity imaging (TVI) and strain rate imaging (SRI) quantify regional myocardial function. We aimed to measure TVI and SRI indices for inferobasal aneurysmal segments by echocardiography at rest. Method: Sixteen patients with inferobasal left ventricular (LV) aneurysm, LV ejection fraction (EF) ≤50%, and 14 normal coronaries with normal echocardiography (control group) were studied. In SRI, peak systolic strain (ST), strain rate (SR), and pattern of strain curves and in TVI, peak systolic inward motion (Sm) were evaluated all at rest. Ascending curve means systolic expansion and descending means shortening. Results: LVEF was significantly lower in the patient group. Mean ST, SR, and Sm of inferobasal segment showed significant difference between patient and control groups; for ST: 1.45 ± 7.18% versus ?17.64 ± 7.45%, P < 0.0001; SR: ?0.25 ± 0.26 versus ?1.44 ± 0.64 sec^?1, P < 0.0001; and Sm: 3.85 ± 1.26 versus 5.56 ± 1.28 cm/sec, P = 0.006, respectively. All inferobasal aneurysmal segments had ascending curve while normal segments showed a descending curve. In patient group, aneurysmal segments had significantly reduced ST and SR compared to normal segments. Normal functioning segments of patients showed significant reduction of ST and SR compared to normal LV segments in control subjects. The range of SR and ST for inferobasal aneurysmal segments did not overlap with that of the normal segments (?0.60, 0.19 and ?3.00, ?0.80 sec^?1 for SR, and ?8.30, 23.30 and ?35.30, ?10.00% for ST, respectively). Conclusion: SRI indices were significantly reduced in inferobasal aneurysmal segment in comparison with either the same segment in normal subjects or normal functioning segments in the same patients. SR and ST may be superior to Sm in the evaluation of inferobasal aneurysmal segments. (Echocardiography 2010;27:803‐808)     

l-Arginine supplementation enhances eNOS expression in experimental model of hypercholesterolemic rabbits aorta

Introduction: Diminished bioavailability of nitric oxide is crucial in endothelial dysfunction and the development of atherosclerosis. Several studies have found that l-arginine as a nitric oxide (NO) donor has beneficial effect in prevention of atherosclerosis, but the mechanism is not completely known. We hypothesized that increased endothelial nitric oxide synthase (eNOS) and/or decreased inducible NOS (iNOS) expressions might be involved in the preventive effects of l-arginine in hypercholesterolemic rabbits. Methods: Seventeen male rabbits were divided randomly in two groups. They received rabbits chow supplemented with 1% cholesterol (group 1, n = 8) and the other group received also l-arginine (3% in drinking water) (group 2, n = 9) for 1 month. Blood samples were obtained before and after the experiment. At the end of experiment, the aortas were harvested. The serum levels of cholesterol and low-density lipoproteins (LDL) were measured. The intima/media thickness (IMT) ratio was measured and the determination of fatty streak formation was done with the aid of light microscopy. eNOS and iNOS expression in aorta were studied with immuohistochemistery. Results: The IMT ratio in first group having fatty streaks was 0.287 ± 0.15. No fatty streak lesion was detected in l-arginine-treated group. The results also indicated that eNOS expression (intensity) in aortas was significantly higher in l-arginine-treated group (group 1: 13.62 ± 2.7 and group 2: 21.77 ± 2.8; p < 0.05), but no significant difference was observed for iNOS expression between the groups. Conclusion: The expression of eNOS plays an important role in the protection of the vessel wall from atherosclerosis. l-Arginine in drinking water has a beneficial effect in the enhancement of eNOS protein expression.     

A therapeutic splint for hypertonic flexed elbow in upper motor neuron diseased patients

Change in muscle tonus is characteristic of upper motor neuron disease. Upper limb hypertonus is mostly experienced in the flexor muscles group, causing abnormal fixed flexion of the elbow. This in turn leads to functional impairments in daily life (especially in stability while standing and walking, and in activities such as dressing), often accompanied by chronic pain. Extension of the spastic elbow is therefore a significant target goal of the rehabilitation process of these patients. This study presents the development of a simple, cheap and easy-to-use splint aimed at keeping the elbow extended. The splint is made out of cloth and plastic strips with longitudinal pockets sown into a double layer cloth surface. The splint is then wrapped and tightened around the extended elbow. The splint was applied to 30 patients with hypertonic flexed elbow. Patients were asked to keep the splint wrapped around their elbows between one to five hours a day, for a period of three weeks. They were instructed to shorten the time of use whenever they felt pain, discomfort or extended pressure on the arm. Most of the patients completed the trial as instructed and expressed their wish to carry on using it. The reported "side effects" included discomfort, feeling of pressure at the critical points and difficult self-application of the splint. The final splint model was developed based on this feedback. Its efficacy in keeping the elbow in an extended position, its low cost price and easy use makes this splint a viable and simple tool for the rehabilitation process of upper motor neuron disease patients.     

Hepatitis B virus (HBV) genotype and YMDD motif mutation profile among patients infected with HBV and untreated with lamivudine.

OBJECTIVES: A few reports exist on hepatitis B virus (HBV) genotype distribution in Iran; however the sample sizes of these studies are insufficient. The first objective of this study was to determine the HBV genotype distribution with a large sample size (147 specimens). The second objective was to determine the incidence of the lamivudine-resistant YMDD mutant profile among HBV-infected patients not treated with lamivudine; some studies have reported that YMDD mutants are detectable even before antiviral treatment. METHODS: We used two cost-effective PCR-based methods that have been developed in-house: gap-PCR and artificially created restriction site-PCR (ACRS-PCR). Also, 11 samples were randomly selected and bi-directionally sequenced and subjected to phylogenetic analysis. RESULTS: Gap-PCR results revealed genotype D of HBV in all patients, and ACRS-PCR results disclosed the absence of mutation within the YMDD motif before antiviral therapy in the study population. Phylogenetic analysis supported the former genotyping results with the segregation of all Iranian HBV isolates in the genotype D branch with a high bootstrap value (99%, 1000 replicates). CONCLUSIONS: The present study using two cost-effective methods showed that genotype D of HBV is dominant among Iranian HBV-infected subjects, and HBV lamivudine-resistant strains do not exist naturally among Iranian patients not treated with lamivudine.     

Esophageal pH exposure and epithelial cell differentiation

It is proposed that epithelial changes induced by gastroesophageal reflux disease are related to the pH environment of the esophageal lumen. We hypothesized that the various types of esophageal epithelium are associated with specific pH environments that induce their formation. The aim of this study was to compare the luminal pH environment to the histology of the distal esophageal epithelium in patients with gastroesophageal reflux disease. A total of 197 symptomatic patients with increased esophageal acid exposure on 24-hour pH monitoring were grouped according to the histology based on biopsies from the distal esophagus: 17 with squamous epithelium, 126 with cardiac epithelium (CE), and 54 with Barrett's epithelium (BE). All were free of Helicobacter pylori infection and monitored off acid suppression therapy. Acid exposure was expressed as the percent of time the luminal pH was at intervals of 0–1, 1–2, 2–3, 3–4, 4–5, 5–6, and 6–7 over a 24-hour period. Patients with BE spent significantly more time at pH intervals 2–3, 3–4, and 4–5 than those with CE. This pattern switched at pH interval 5–6, where patients with cardiac mucosa spent more time than those with BE. Patients with squamous and CE had similar pH exposure at all intervals. Patients with BE have significantly longer exposure time at the pH interval of 2 to 5 compared to those with cardiac and squamous epithelium. This suggests that the exposure of stem cells to a luminal pH between 2 and 5 may trigger the differentiation of CE into intestinalized CE.