Polymorphism of nucleotide excision repair genes as predictors for clinical outcome in advanced gastric cancer patients treated with oxaliplatin-based chemotherapy

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Background: The individual variations in treatment response and the toxicity of combination regimen of oxaliplatin and 5-fluorouracil with leucovorin (FOLFOX) for advanced gastric cancer patients have been reported. The aim of this study is to evaluate the influence of polymorphism of nucleotide excision repair genes that are involved in the metabolism of cisplatin on the clinical outcomes of gastric cancer patients treated with modified FOLFOX-6 chemotherapy. Methods: From March 2006 to December 2007, eighty-two patients with advanced gastric cancer were treated with modified FOLFOX-6 as the primary chemotherapy in our institution. Of these patients, 55 patients who were available for peripheral blood sampling before starting chemotherapy were enrolled in this study. Genomic DNA was extracted from mononuclear cells of patients’ blood. Four polymorphisms were investigated in three genes, ERCC, GSTP and XRCC. Results: The overall response rate (RR) was 40.0%. Median time to progression (TTP) and overall survival (OS) was 6 months (C.I.: 5.0 - 7.0 months) and 15.0 months (C.I.: 9.7 - 20.3 months). Grade 3 or 4 hematologic toxicities were presented in 17 patients (30.9%), gastrointestinal toxicities in 5 patients (9.1%), peripheral neuropathy in 5 patients (9.1%) and hepato-toxicity in 4 patients (7.3%). Most common types of polymorphism were G/G (67.3%) in XRCC1 Arg399Gln, A/A (74.5%) in GSTP1 Ile105Val, C/C (60.0%) in ERCC1 Asn118Asn and C/A (49.1%) in ERCC1 C8092A. The RR was significantly lower in patients with C/C type in ERCC1 C8092A gene than those with other type (25.0% vs 51.6%, p=0.046). However, there were no differences of TTP and OS among the polymorphisms in three genes. The rate of grade 3 or 4 hematologic toxicity was higher in patients with C/T or T/T in ERCC1 codon 118 gene than those with C/C type (45.5% vs 21.2%, p=0.057). Conclusions: We demonstrated that modified FOLFOX-6 chemotherapy was effective and tolerable. The polymorphism of C/C type in ERCC1 C8092A gene was found to be a predictive marker of the poor response and C/C type in ERCC1 Asn118Asn gene was to be a predictive marker of the hematologic toxicity.

No significant financial relationships to disclose.

Relationship and prognosis of hospho-Akt and CD44v6 in breast cancer

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Background: The purpose of this study was to investigate the relationship between pAkt and CD44v6 expression of breast cancer after surgery. We also evaluated the expression patterns and predictive value of pAKT and CD44v6 in breast cancer tissues. Methods: Expression of pAkt and CD44v6 protein was detected using immunohistochemistry in 98 patients. The correlation between the expression of pAkt, CD44v6, and other disease-related characteristics with treatment outcome was investigated. Kaplan-Meier survival analysis and Cox regression were used to observe the correlation between variables and the prognostic value. Results: Of all these 98 cases, 37 cases (37.8%) were observed as positive for pAkt expression, and there were 25 cases (51.0%) pAKT positive expression in the lymph node (+) and 15 (30.6%) in lymph node (-) of 49 cases. pAkt expression had no significant difference in node-positive group and node-negative group. We examined the relationship between pAKT and HER2 expression, pAkt expression was positively correlated with HER-2 expression (p = 0.009). A statistically significant difference in positive staining for pAkt was observed between CD44V6-positive and CD44V6-negative tumors (p = 0.016). CD44v6 positive tumors showed a statistically very highly significant association between node-positive and node-negative (p = 0.013). For prognosis value, a week relationship was observed between pAkt and OS, but DFS was inversely associated with pAkt staining intensity (p = 0.061, p = 0.004). There had a statistical correlation between CD44v6 overexpression and OS and DFS (p = 0.026 and 0.006 respectively). Univariate analysis revealed that lymph node status and CD44V6 were significantly associated with decreased OS and DFS, but there had no significant difference between variables and OS and DFS by multivariate analysis. Conclusions: Our data suggested that there had a intensive relationship between pAKT and CD44v6 expression in breast cancer tissues. We demonstrated that both pAkt and CD44v6 were significantly assiociated with a decreased OS and DFS in breast cancer patients. pAKT and CD44v6 overexpressed in cancer cells may be sensitive markers for predicting the treatment outcome in breast cancer patients.

No significant financial relationships to disclose.

Risk prediction of prevalent diabetes in a Swiss population using a weighted genetic score--the CoLaus Study

AIMS/HYPOTHESIS

Several susceptibility genes for type 2 diabetes have been discovered recently. Individually, these genes increase the disease risk only minimally. The goals of the present study were to determine, at the population level, the risk of diabetes in individuals who carry risk alleles within several susceptibility genes for the disease and the added value of this genetic information over the clinical predictors.

METHODS

We constructed an additive genetic score using the most replicated single-nucleotide polymorphisms (SNPs) within 15 type 2 diabetes-susceptibility genes, weighting each SNP with its reported effect. We tested this score in the extensively phenotyped population-based cross-sectional CoLaus Study in Lausanne, Switzerland (n = 5,360), involving 356 diabetic individuals.

RESULTS

The clinical predictors of prevalent diabetes were age, BMI, family history of diabetes, WHR, and triacylglycerol/HDL-cholesterol ratio. After adjustment for these variables, the risk of diabetes was 2.7 (95% CI 1.8-4.0, p = 0.000006) for individuals with a genetic score within the top quintile, compared with the bottom quintile. Adding the genetic score to the clinical covariates improved the area under the receiver operating characteristic curve slightly (from 0.86 to 0.87), yet significantly (p = 0.002). BMI was similar in these two extreme quintiles.

CONCLUSIONS/INTERPRETATION

In this population, a simple weighted 15 SNP-based genetic score provides additional information over clinical predictors of prevalent diabetes. At this stage, however, the clinical benefit of this genetic information is limited.

Autologous somatic cell nuclear transfer in pigs using recipient oocytes and donor cells from the same animal

The objective of the present study was to examine the feasibility of the production of autologous porcine somatic cell nuclear transfer (SCNT) blastocysts using oocytes and donor cells from slaughtered ovaries. Therefore, we attempted to optimize autologous SCNT by examining the effects of electrical fusion conditions and donor cell type on cell fusion and the development of SCNT embryos. Four types of donor cells were used: 1) denuded cumulus cells (DCCs) collected from in vitro-matured (IVM) oocytes; 2) cumulus cells collected from oocytes after 22 h of IVM and cultured for 18 h (CCCs); 3) follicular cells obtained from follicular contents and cultured for 40 h (CFCs); and 4) adult skin fibroblasts. The DCCs showed a significantly (p < 0.01) lower rate of fusion than the CCCs when two pulses of 170 V/mm DC were applied for 50 µsec (19 ± 2% vs. 77 ± 3%). The rate of DCC fusion with oocytes was increased by the application of two DC pulses of 190 V/mm for 30 µsec, although this was still lower than the rate of fusion in the CCCs (33 ± 1% vs. 80 ± 2%). The rates of cleavage (57 ± 5%) and blastocyst formation (1 ± 1%) in the DCC-derived embryos did not differ from those (55 ± 6% and 3 ± 1%, respectively) in the CCC-derived SCNT embryos. Autologous SCNT embryos derived from CFCs (5 ± 2%) showed higher levels of blastocyst formation (p < 0.01) than CCC-derived autologous SCNT embryos (1 ± 0%). In conclusion, the results of the present study show that culturing cumulus and follicular cells before SCNT enhances cell fusion with oocytes and that CFCs are superior to CCCs in the production of higher numbers of autologous SCNT blastocysts.

Alpha-5/alpha-3 nicotinic receptor subunit alleles increase risk for heavy smoking

Twin studies indicate that additive genetic effects explain most of the variance in nicotine dependence (ND), a construct emphasizing habitual heavy smoking despite adverse consequences, tolerance and withdrawal. To detect ND alleles, we assessed cigarettes per day (CPD) regularly smoked, in two European populations via whole genome association techniques. In these approximately 7500 persons, a common haplotype in the CHRNA3-CHRNA5 nicotinic receptor subunit gene cluster was associated with CPD (nominal P=6.9 x 10(-5)). In a third set of European populations (n= approximately 7500) which had been genotyped for approximately 6000 SNPs in approximately 2000 genes, an allele in the same haplotype was associated with CPD (nominal P=2.6 x 10(-6)). These results (in three independent populations of European origin, totaling approximately 15 000 individuals) suggest that a common haplotype in the CHRNA5/CHRNA3 gene cluster on chromosome 15 contains alleles, which predispose to ND.

Modification of maturation condition improves oocyte maturation and in vitro development of somatic cell nuclear transfer pig embryos

This study examined effects on the developmental competence of pig oocytes after somatic cell nuclear transfer (SCNT) or parthenogenetic activation (PA) of : 1) co-culturing of oocytes with follicular shell pieces (FSP) during in vitro maturation (IVM); 2) different durations of maturation; and 3) defined maturation medium supplemented with polyvinyl alcohol (PVA; control), pig follicular fluid (pFF), cysteamine (CYS), or beta-mercaptoethanol (beta-ME). The proportion of metaphase II oocytes was increased (p < 0.05) by co-culturing with FSP compared to control oocytes (98% vs. 94%). However, blastocyst formation after SCNT was not improved by FSP coculture (9% vs. 12%). Nuclear maturation of oocytes matured for 39 or 42 h was higher (p < 0.05) than that of oocytes matured for 36 h (95-96% vs. 79%). Cleavage (83%) and blastocyst formation (26%) were significantly higher (p < 0.05) in oocytes matured for 42 h than in other groups. Supplementation of a defined maturation medium with 100 microM CYS or 100 microM beta-ME showed no stimulatory effect on oocyte maturation, embryo cleavage, or blastocyst formation after PA. beta-ME treatment during IVM decreased embryo cleavage after SCNT compared to pFF or PVA treatments, but no significant difference was found in blastocyst formation (7-16%) among the four treatment groups. The results indicated that maturation of oocytes for 42 h was beneficial for the development of SCNT embryos. Furthermore, the defined maturation system used in this study could support in vitro development of PA or SCNT embryos.

100 EFFECT OF DIFFERENT POST-ACTIVATION TREATMENTS ON THE DEVELOPMENT OF SOMATIC CELL NUCLEAR TRANSFER PIG EMBRYOS

Activation treatment is one of the important factors that affect the development of somatic cell nuclear transfer (SCNT) embryos. We examined the effect of post-activation (PA) treatment on the change in donor nucleus and SCNT embryo development in pig. Cumulus–oocyte complexes (COCs) were matured in TCM-199 supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and in fresh hormone-free medium for 18 h. After 40 h of IVM, oocytes with a polar body were enucleated, injected with a donor cell (ear skin fibroblasts bearing the human decay accelerating factor gene), electrically fused, and activated 1 h after fusion. Then, SCNT embryos were cultured in a modified NCSU-23 medium (Park et al. 2005 Zygote 13, 269–275) containing no additives (control), 5 �g mL-1 cytochalasin B (CB), 0.4 �g mL-1 demecolcine (D), or CB+D for 4 h. CB and D were prepared from stock solutions of 5 mg mL-1 CB in DMSO and 10 �g mL-1 D in Hank&apos;s balanced salt solution (HBSS), respectively. After PA treatment, SCNT embryos were cultured in a modified NCSU-23 medium for 6 days. The embryos (n &equals; 188, 189, 187, and 186 for control, CB, D, and CB&plus;D, respectively) were examined for cleavage and blastocyst (BL) formation on Days 2 and 6, respectively (Day 0 &equals; the day of SCNT). Cell number of BL was examined by counting the number of nuclei stained with Hoechst 33342 under fluorescence. To assess the nuclear structure, some of the fused oocytes were fixed at 12 h after PA and stained with aceto-orcein (n &equals; 42, 44, 43, and 45 for control, CB, D, and CB&plus;D, respectively). Nuclear state was classified as 1 pseudopronucleus (PPN), multi-PPN, and others. Data were analyzed by ANOVA (GLM procedure) in SAS (SAS Institute, Inc., Cary, NC, USA). PA treatment with D and CB&plus;D significantly (P &lt; 0.05) increased 1 PPN formation (84 and 80&percnt;, respectively) compared to control and CB (62 and 64&percnt;, respectively). Conversely, a higher (P &lt; 0.001) rate of multi-PPN was observed in control and CB (31 and 36&percnt;, respectively) than in D and CB&plus;D (9 and 7&percnt;, respectively). This result was in contrast with the finding in mouse that nocodazole, another microtubule depolymerizing agent, induced multi-PPN in reconstructed zygotes. Pig meiotic spindles differ at their poles from those in mice by lacking &gamma;-tubulin. Absence of &gamma;-tubulin in pig oocytes would make spindle dynamics more sensitive to depolymerization, which might lead to a different result in this study. Embryo cleavage (77&ndash;85&percnt;) was not altered by PA treatments, but BL formation was significantly (P &lt; 0.05) increased by CB, D, or CB&plus;D (26, 28, and 28&percnt;, respectively) compared to control (16&percnt;). Total cell number of BL (36&ndash;40 cells/BL) was not different among groups. These results indicate that PA treatment with CB and/or D improved in vitro development of SCNT pig embryos and that D treatment effectively prevented the formation of multi-PPN. This work was supported by the Research Project on the Production of Bio-organs (No. 200506020601), Ministry of Agriculture and Forestry, Republic of Korea.

59 HIGHER BLASTOCYST FORMATION OF SOMATIC CELL NUCLEAR TRANSFER EMBRYOS DOES NOT GUARANTEE BETTER PREGNANCY IN PIG

Generally, blastocyst (BL) formation and embryo cell number are used as main parameters to evaluate the viability and quality of in vitro-produced somatic cell nuclear transfer (SCNT) embryos. We investigated whether in vitro development of SCNT pig embryos correlates with in vivo viability after transfer to surrogates. For SCNT, cumulus–oocyte complexes (COCs) were matured in TCM-199 supplemented with follicular fluid, hormones, EGF, cysteine, and insulin for the first 22 h and in a hormone-free medium for 18 h. Three sources of pig skin cells were used as nuclear donor: (1) skin fibroblasts of a cloned piglet that were produced by SCNT of fetal fibroblasts from a Landrace × Yorkshire × Duroc F1 hybrid (LYD), (2) skin fibroblasts of a miniature pig having the human decay accelerating factor gene (hDAF-MP), and (3) skin fibroblasts of a miniature pig with a different strain (MP). MII oocytes were enucleated, subjected to nuclear transfer from a donor cell, electrically fused, and activated 1 h after fusion. SCNT embryos were cultured in a modified NCSU-23 (Park Y et al. 2005 Zygote 13, 269–275) for 6 days or surgically transferred (110–150 fused embryos) into the oviduct of a surrogate that showed standing estrus on the same day as SCNT. Embryos were examined for cleavage and BL formation on Days 2 and 6, respectively (Day 0 = the day of SCNT). BLs were examined for their cell number after staining with Hoechst 33342. Pregnancy was diagnosed by ultrasound 30 and 60 days after embryo transfer. Embryo cleavage was not affected by donor cells (82, 81, and 72% for LYD, hDAF-MP, and MP, respectively), but BL formation was higher (P &lt; 0.05) in hDAF-MP (16%) than in LYD (9%) and MP (6%). MP showed higher (P &lt; 0.05) BL cell number (46 cells/BL) than hDAF-MP (34 cells) but did not show a difference from LYD (37 cells). LYD and MP showed higher pregnancy rates (Table 1) on Days 30 and 60, even though they showed lower BL formation in vitro. Due to a relatively small number of embryo transfers through a limited period, we could not exclude any possible effects by seasonal or operational differences. These results indicated that pregnancy did not correlate with in vitro BL formation of SCNT pig embryos but rather were affected by the source of donor cells. Table 1.In vivo development of somatic cell nuclear transfer pig embryos derived from different sources of donor cells This work was supported by the Research Project on the Production of Bio-organs (No. 200506020601), Ministry of Agriculture and Forestry, Republic of Korea.

356 IMPROVED ENUCLEATION EFFICIENCY FOR PIG SOMATIC CELL NUCLEAR TRANSFER BY DENUDING OOCYTES AT 30 HOURS OF IN VITRO MATURATION

Oocytes for somatic cell nuclear transfer (SCNT) have to be removed from their cumulus cells before enucleation. Denuding oocytes by vortexing or repeated pipetting makes the polar body (PB) deviate from the metaphase (MII) plate, which in turn makes it difficult to remove DNA materials completely during enucleation. We hypothesized that denuding oocytes at 30 h of IVM maintains the MII plate and PB in a closer position and therefore makes it easy to enucleate. To test this hypothesis, oocytes were matured in TCM-199 supplemented follicular fluid, hormones, EGF, cysteine, and insulin for first 22 h, and in a hormone-free medium for 18 h with three modifications: (1) cumulus cells were removed from oocytes just prior to enucleation at 40 h of IVM (control), (2) oocytes were denuded at 30 h of IVM and co-cultured with their detached cumulus cells for 10 h (D+), and (3) oocytes denuded at 30 h of IVM were cultured without cumulus cells (D-). After IVM, some oocytes were stained with Hoechst 33342 and photographed by a digital camera; the distance between the MII plate and the PB were measured using an image analysis program (ImageJ 1.36; http://rsb.info.nih.gov/ij). Also, the enucleation rate after blind enucleation and the in vitro development of SCNT embryos were determined. For SCNT, oocytes were enucleated, and nuclear material from donor cells (skin fibroblasts from a miniature pig) was inserted; oocytes were then electrically fused, and activated 1 h after fusion. SCNT embryos were cultured in a modified NCSU-23 (Park et al. 2005 Zygote 13, 269-275) for 6 days. Embryos were examined for their cleavage and blastocyst formation on Days 2 and 6, respectively (the day of SCNT was designated Day 0). Data were analyzed by the GLM procedure and the least significant difference test in SAS (SAS Institute, Cary, NC, USA). The distance between the MII plate and the PB was significantly (P &lt; 0.01) shorter in D+ and D- embryos (19.4 and 18.9 �m, respectively) than in the controls (25.5 �m). Enucleation rates after blind enucleation were significantly (P &lt; 0.01) higher in D+ and D- groups (77% and 72%, respectively) than in the controls (60%). Oocyte maturation (89–91%), SCNT embryo cleavage (71–77%), blastocyst formation (4–5%), and embryo cell number (39-45 cells/embryo) were not altered by different denuding methods. The perivitelline space (PVS) increases with time during maturation and denudation, after PB extrusion markedly enhances PB deviation. It is likely that increased PVS in control oocytes enhanced PB deviation during denudation and then resulted in lower enucleation rate. In conclusion, the results of this study indicated that denuding at 30 h of IVM maintained the MII plate and the PB in a closer position and improved enucleation efficiency without impairing developmental capacity of SCNT embryos. This work was supported by the Research Project on the Production of Bio-organs (No. 200506020601), Ministry of Agriculture and Forestry, Republic of Korea.

Cloning and sequence analysis of the estA gene encoding enzyme for producing (R)-beta-acetylmercaptoisobutyric acid from Pseudomonas aeruginosa 1001

The estA gene encoding the enzyme that catalyzes the production of (R)-beta-acetylmercaptoisobutyric acid from (R,S)-ester from Pseudomonas aeruginosa 1001, was cloned in Escherichia coli and its nucleotide sequence was determined, revealing the presumed open reading frame encoding a polypeptide of 316 amino acid residues (948 nucleotides). The overall A + T and C + G compositions were 32.59% and 67.41%, respectively. The amino acid sequence of the estA gene product showed a significant similarity with that of the triacylglycerol lipase from Psychrobacter immobilis (38% identity), triacylglycerol lipase from Moraxella sp. (36% identity), and two forms of carboxyl esterases from Acinetobacter calcoaceticus (17% and 17% identities). The deduced amino acid sequences have a pentapeptide consensus sequence, G-X-S-X-G, having an active serine residue, and another active site, dipeptides H-G, located at 70-100 amino acids upstream of the G-X-S-X-G consensus sequence.

Cotton liners to mediate glove comfort for greenhouse applicators

Greenhouse applicators' acceptance of cotton knit gloves worn as liners under nitrile chemical-resistant gloves (CRG) for pesticide application was investigated through a wear study in Iowa and New York. Comfort was assessed by questionnaires and interviews with 10 applicators. Contamination levels of four pesticides on CRG and liners at thumb, forefinger, palm, and cuff locations were determined by chemical analysis using high-performance liquid chromatography or gas chromatography. Applicators reported feeling more comfortable with cotton liners under their CRG than without and that cotton liners were easy to manage. Contamination was significantly greater on nitrile CRG than on cotton liners underneath, but a few liner specimens had measurable contamination. No significant contamination differences were found between right- and left-hand gloves. Contamination varied significantly by hand location, with cuffs least, and by pesticide, with chlorpyrifos most. These results support the Environmental Protection Agency's recommendation that liners should be disposable, but further work on liners and their laundering feasibility seems indicated.