Deletion and Down-Regulation of HRH4 Gene in Gastric Carcinomas: A Potential Correlation with Tumor Progression

Background: Histamine is an established growth factor for gastrointestinal malignancies. The effect of histamine is largely determined locally by the histamine receptor expression pattern. Histamine receptor H4 (HRH4), the newest member of the histamine receptor family, is positively expressed on the epithelium of the gastrointestinal tract, and its function remains to be elucidated. Previously, we reported the decreased expression of HRH4 in colorectal cancers and revealed its correlation with tumor proliferation. In the current study, we aimed to investigate the abnormalities of HRH4 gene in gastric carcinomas (GCs). Methodology/Principal Findings: We analyzed H4R expression in collected GC samples by quantitative PCR, Western blot analysis, and immunostaining. Our results showed that the protein and mRNA levels of HRH4 were reduced in some GC samples, especially in advanced GC samples. Copy number decrease of HRH4 gene was observed (17.6%, 23 out of 131), which was closely correlated with the attenuated expression of H4R. In vitro studies, using gastric cancer cell lines, showed that the alteration of HRH4 expression on gastric cancer cells influences tumor growth upon exposure to histamine. Conclusions/Significance: We show for the first time that deletion of HRH4 gene is present in GC cases and is closely correlated with attenuated gene expression. Down-regulation of HRH4 in gastric carcinomas plays a role in histaminemediate

Effect of Oxadiazolyl 3(2H)-Pyridazinone on the Larval Growth and Digestive Physiology of the Armyworm, Pseudaletia separata

The effect of oxadiazolyl 3(2H)-pyridazinone (ODP), a new insect growth regulator, on growth of larvae of the armyworm, Pseudaletia separata Walker (Lepidoptera: Noctuidae) was evaluated in comparison to the insecticide, toosendanin, a tetranortriterpenoid extracted from the bark of Melia toosendan that has multiple effects on insects. The digestive physiological properties of these compounds on insects were investigated by feeding them maize leaves dipped in these compounds. The results showed that ODP inhibited the growth of P. separata significantly, causing a slowed development and a prolonged larval period, smaller body size and sluggish behavior, delayed pupation and a reduced eclosion rate of pupae and adults. Moreover, ODP strongly inhibited the activities of weak alkaline trypsine-like enzyme, chymotrypsin-like enzyme and alpha amylase in the midguts of fifth instar P. separata larvae, in vivo, and inhibited the activity of alpha amylase, in vitro. These data suggest that ODP has severe consequences on the larval carbohydrate assimilation and/or nutrient intake and thereby causes inhibition of larval growth. The regulatory action of ODP on larval growth development was similar to that of toosendanin; both could be used to decrease the growth of insect populations

Coexistence of copy number increases of ZNF217 and CYP24A1 in colorectal cancers in a Chinese population

Evidence suggests that the amplification of chromosome 20q13 is common in colorectal cancers (CRCs). Certain candidate oncogenes located in this region are reported to be associated with tumorigenesis of the gastrointestinal tract. The functional impact of such regions should be extensively investigated in a large number of clinical samples. In this study, 145 CRC samples with matched adjacent normal tissues were collected from a Chinese population for copy number variation (CNV) analysis. Our results showed that both the copy numbers of 25-hydroxy vitamin D3 24-hydroxylase (CYP24A1) and zinc-finger protein 217 (ZNF217) were amplified in a relatively high percentage of CRC samples (51.1 and 60%, respectively). The mRNA expression levels of both CYP24A1 and ZNF217 were found to have increased in the collected CRC samples as compared to the matched adjacent normal tissues. ZNF217, but not CYP24A1, showed a positive correlation between copy number increases and mRNA overexpression. These findings suggest the potential role of CNVs of certain oncogenes in CRCs

Detection of APC Gene Deletions in Colorectal Malignancies Using Quantitative PCR in a Chinese Population

The adenomatous polyposis coli (APC) gene has been shown to be involved in genetic instability and to be downregluated in several human carcinomas. The chromosome locus of APC, 5q21-22, is frequently deleted in colorectal cancers (CRCs). The functional impact of such regions needs to be extensively investigated in large amount of clinical samples. Case-matched tissues of CRC and adjacent normal epithelium (n = 134) were included in this study. Quantitative PCR was carried out to examine the copy number as well as mRNA expression of APC gene in colorectal malignancies. Our results showed that copy number deletions of APC were present in a relatively high percentage of colorectal cancer samples (26.1%, 35 out of 134). There was a positive correlation between copy number decrease of APC and tumor progression in CRCs. Furthermore, copy number loss of APC was correlated with decreased mRNA expression. However, mRNA levels of APC were also impaired in CRC samples with unaltered copy numbers, indicating that sporadic CRCs exhibit different mechanisms of APC regulation

Copy number increase of aurora kinase A in colorectal cancers: a correlation with tumor progression

The centrosome-associated kinase aurora A (AURKA) is involved in genetic instability and is over-expressed in several human carcinomas including colorectal cancer (CRC). The choromosome locus of AURKA, 20q13, is frequently amplified in CRC, and the functional impact of such regions needs to be extensively investigated in large amount of clinical samples. Case-matched tissues of colorectal adenocarcinomas and adjacent normal epithelium (n= 134) were included in this study. Quantitative PCR was carried out to examine the copy number and mRNA level of AURKA in CRC. Our results showed that copy number gains of AUKRA were detected in a relative high percentage of CRC samples (32.4%, 43 of 134). There was a positive correlation between copy number increase of AURKA and tumor progression. And copy number gains of AURKA also showed a positive correlation with mRNA over-expression in CRC. However, the expression level of AURKA mRNA was also enhanced in the group of CRC samples with unaltered copy numbers. These findings indicated that sporadic colorectal cancers exhibit different mechanisms of aurora A regulation and this may impact the efficacy of aurora-targeted therapies

Diazoxide Attenuates Postresuscitation Brain Injury in a Rat Model of Asphyxial Cardiac Arrest by Opening Mitochondrial ATP-Sensitive Potassium Channels

Objective. We investigated whether and how diazoxide can attenuate brain injury after cardiopulmonary resuscitation (CPR) by selective opening of mitochondrial ATP-sensitive potassium (mitoKATP) channels. Methods. Adult male Sprague-Dawley rats with induced cerebral ischemia (n=10 per group) received an intraperitoneal injection of 0.1% dimethyl sulfoxide (1 mL; vehicle group), diazoxide (10 mg/kg; DZ group), or diazoxide (10 mg/kg) plus 5-hydroxydecanoate (5 mg/kg; DZ + 5-HD group) 30 min after CPR. The control group (sham group, n=5) underwent sham operation, without cardiac arrest. Mitochondrial respiratory control rate (RCR) was determined. Brain cell apoptosis was assessed using TUNEL staining. Expression of Bcl-2, Bax, and protein kinase C epsilon (PKCε) in the cerebral cortex was determined by Western blotting and immunohistochemistry. Results. The neurological deficit scores (NDS) in the vehicle group decreased significantly at 24 h and 48 h after CPR. Diazoxide significantly improved NDS and mitochondrial RCR after CPR at both time points; 5-HD cotreatment abolished these effects. Diazoxide decreased TUNEL-positive cells following CPR, upregulated Bcl-2 and PKCε, downregulated Bax, and increased the Bcl-2/Bax ratio; 5-HD cotreatment reversed these effects. Conclusions. Diazoxide attenuates postresuscitation brain injury, protects mitochondrial function, inhibits brain cell apoptosis, and activates the PKC pathway by opening mitoKATP channels

A clinically relevant CTLA4-Ig-based regimen induces chimerism and tolerance to heart grafts

Background. We determined whether a nontoxic CTLA4-Ig-based conditioning regimen effected mixed chimerism and donor-specific tolerance when heart and bone marrow were transplanted simultaneously. Methods. Fully mismatched rat strain combinations were used. Recipients received total-body irradiation (300 centigrays), bone marrow (10 8 cells), and cardiac transplants from the donor on day 0. Subsequently, recipient animals received CTLA4-Ig (2 mg/kg, every other day, × 5 doses), tacrolimus (1 mg/kg/day; days 0 to 9), and one dose (10 mg) of antilymphocyte serum on day 10. Results. All bone marrow recipients (n = 7) developed mixed chimerism (mean = 25% ± 9% at 1 year) and accepted cardiac allografts permanently (> 375 ± 32 days). Recipients that received conditioning regimen but no bone marrow (n = 5) rejected donor hearts within 51 ± 13 days ( p 180 days) donor-specific skin grafts, but rapidly rejected (< 10 days) third-party skin grafts. Conclusions. A nontoxic CTLA4-Ig-based conditioning regimen effects mixed chimerism and donor-specific tolerance when heart and bone marrow are transplanted simultaneously. This regimen may have clinical application

Combined host-conditioning with CTLA4-Ig, tacrolimus, anti-lymphocyte serum, and low-dose radiation leads to stable mixed hematopoietic chimerism

The toxic dose of irradiation required to achieve stable mixed hematopoietic chimerism is the major limitation to its clinical application in transplantation and other nonmalignant conditions such as hemoglobinopathies. This study examines the additive effect of costimulatory blockage, to our previously described tacrolimus-based conditioning regimen, in further reducing the dose of total-body irradiation to achieve stable mixed chimerism in rats. Fully mismatched, 4- to 6-week-old ACI and Wistar Furth rats were used as donors and recipients, respectively. Recipients were administered CTLA4-Ig 2mg/kg/day (alternate days) in combination with tacrolimus 1 mg/kg/day (daily) from day 0 through day +10, anti-lymphocyte serum 10 mg at day +10 (single dose), and total-body irradiation ranging from 100–600 cGy, prior to bone marrow transplantation (day 0) with 100 × 10 6 of T-cell-depleted bone marrow cells. Levels of donor chimerism were determined over a period of 12 months. The short course of CTLA4-Ig, tacrolimus, and ALS led to dramatic engraftments at reduced doses of irradiation: 100% (5/5) and 93% (13/14) of the animals developed mixed chimerism at 400 cGy and 300 cGy, respectively. At 300 cGy, recipients exhibited durable, multilineage mixed chimerism at 365 days with donor cells ranging from 19–42% (mean 23.4%) with no evidence of graft-vs-host disease. These mixed chimeras exhibited in vitro (mixed lymphocyte reaction) and in vivo (skin grafts) donor-specific tolerance. This study suggests that addition of costimulatory blockade to a tacrolimus-based conditioning regimen reduces the dose of irradiation required to achieve stable multilineage chimerism in rats

Copy-number increase of AURKA in gastric cancers in a Chinese population: a correlation with tumor progression

The centrosome-associated kinase aurora A (AURKA) has been shown to be involved in genetic instability and to be over-expressed in several human carcinomas including gastric cancers (GCs). The chromosome locus of AURKA, 20q13, is frequently amplified in GCs, and the functional impact of such regions needs to be extensively investigated in large amount of clinical samples. Case-matched tissues of gastric carcinomas and adjacent normal epithelium (n = 141) were included in this study. Quantitative PCR was carried out to examine the copy number and mRNA expression of AURKA in GCs. Our results showed copy-number gains of AUKRA were detected in a relative high percentage of GC samples (30.5%, 43 out of 141). There was a positive correlation between copy-number increase of AURKA and tumor progression. And copy-number gains of AURKA also showed a positive correlation with mRNA over-expression in GCs. However, expression level of AURKA mRNA was also enhanced in the group of GC samples with unaltered copy numbers. These findings indicated that sporadic gastric cancers exhibit different mechanisms of AURKA regulation and that this may impact the efficacy of aurora-targeted therapies