Population pharmacokinetics (PK) of tremelimumab in patients (pts) with melanoma

3048

Background: Tremelimumab is a fully human monoclonal antibody targeted against CTLA4, a protein on T cells critical for regulating T-cell activities, which is under development for treatment of various cancers, including melanoma. Population PK analysis was conducted using concentration-time data from 450 pts, most with melanoma or solid tumors, enrolled in four phase I or II studies that evaluated PK, tolerability, and efficacy of single-agent tremelimumab. Methods: Tremelimumab was administered intravenously either as single dose or multiple doses every 4 or 12 weeks; doses varied between 0.01 and 15 mg/kg. PK was determined using nonlinear mixed-effect modeling implemented in NONMEM VI. Baseline characteristics, including body weight, ECOG score, age, sex, serum creatinine, AST, ALT, and bilirubin, and formulation effects were investigated as potential factors affecting PK. Tremelimumab plasma concentrations were determined using a sensitive, specific, validated ELISA assay. Results: A two-compartment linear model adequately described tremelimumab concentration-time data; an additive residual error model was employed on log-transformed data. Initial and terminal half-lives were 2.5 days and 22 days, respectively. Estimated parameter values were: 0.0109 L/hr for CL (clearance), 3.72 L for V1 (central volume of distribution), 0.0172 L/hr for Q (intercompartment clearance), and 3.31 L for V2 (peripheral volume of distribution). Females had 29.6% smaller V2 compared with males. Both CL and central V1 increased with weight. An ECOG score of ≥1 showed 20.2% increase in CL compared with a score of 0. New commercial formulation decreased CL by 18.5%. The model-predicted area under concentration-time curve value in females was 13.3% greater than males (p=0.5). None of the other covariates tested significantly affected PK. Furthermore, tremelimumab was tolerated in most pts at all doses tested. Conclusions: PK of tremelimumab were shown to be affected by weight, baseline ECOG score, and formulation. However, no effects other than weight were considered clinically significant enough to warrant treatment regimen change. Further investigation of PK-response relationships is warranted.

[Table: see text]

Relationship between pharmacokinetics and safety of tremelimumab in patients with melanoma

3049

Background: Tremelimumab is a fully human anti-CTLA4 monoclonal antibody that has antitumor activity in some patients with advanced melanoma. The most common adverse event associated with tremelimumab is diarrhea/colitis. This analysis investigated the relationship between pharmacokinetics (PK) and diarrhea or colitis in 450 patients enrolled in four phase I or II clinical studies. Methods: PK parameters including AUC during the first 90 days (AUC90), Cmax, concentration at day 29 (C29), and AUC of concentration >30 μg/mL (AUCG30) of tremelimumab were determined using nonlinear mixed-effect modeling. Severity and frequency of diarrhea and colitis during the 90 days after the first dose were considered in relation to each individual PK parameter. Frequency of diarrhea was further analyzed by logistic regression analysis. Frequencies of diarrhea and colitis were combined for logistic analysis. Results: The PK/safety analysis included 450 patients (445 with advanced melanoma). In this analysis, the severity of diarrhea and colitis appeared to be independent of PK (AUC90, Cmax, C29, and AUCG30) of tremelimumab. Although frequency of diarrhea was positively related to AUC (AUC or AUCG30), Cmax, and C29, AUC appeared to be best correlated to frequency of diarrhea. Logistic regression analysis of change in AUC on probability of having diarrhea indicated that the frequency of diarrhea increased initially with increasing AUC, but reached a plateau quickly at approximately AUC value of 50,000 μg × hr/mL (20th percentile). Results of the combined diarrhea and colitis analysis were similar to those of diarrhea alone. Conclusions: Severity of diarrhea and colitis is independent of AUC in patients with melanoma treated with tremelimumab. Frequency of diarrhea and colitis initially increases with increasing AUC, but plateaus quickly.

[Table: see text]

Intraoperative sentinel lymph node identification using novel receptor binding agent (technetium-99m neomannosyl human serum albumin, 99mTc-MSA) in stage I non-small cell lung cancer

7588

Background: In order to simplify synthesis and labelling procedures and to improve the biological properties, we developed a novel mannose receptor-binding agent, Technetium-99m neomannosyl human serum albumin (99mTc-MSA). This study was designed to test the reliability and feasibility of sentinel nodes identification using this new radioactive agent in stage I non-small cell lung cancer. Methods: A total dose of 1mCi of 99mTc- MSA in 0.2ml was administered in one shot at the peri-tumoral region under the chest CT or bronchoscope guidance 3 hours before surgery in the CT room. Dynamic whole-body SPECT lymphoscintigraphic image was obtained at 30 min after injection and static thoracic SPECT lymphoscintigraphy images were acquired at 1 and 2 hour after injection. During operation, the radioactivity of the lymph nodes was counted with a handheld gamma probe before (in vivo) and after (ex vivo) dissection. Lymph nodes with an ex vivo radioactive count more than 5 times the radioactivity count of the resected lung tissue were identified as sentinel nodes. The correlation between the in vivo and ex vivo results was examined. All harvested lymph nodes were examined histologically. Results: Thirty patients (20 men, 10 women; mean age, 62.6±9.40 years) who were candidates for lobectomy with mediastinal lymph node dissection for stage I non-small cell lung cancer were enrolled consecutively. Sentinel nodes could be detected from 30 minutes to 5 hours after the injection of 99mTc-MSA on lymphoscintigraphy. The mean number of dissected lymph nodes per patients was 20.7±1.30 (8∼41). Among 30 patients, sentinel lymph nodes could be identified in all patients (100%). The mean number of sentinel lymph nodes identified was 2.4±1.04 stations (range, 1∼5) per patient. No false-negative sentinel lymph nodes were detected in any of the 8 patients with N1 or N2 disease (0%). The relationship between in vivo and ex vivo results for mediastinal sentinel lymph nodes showed concurrence in 25 of 30 patients (83.3%). Conclusions: The results of this clinical trial showed that 99mTc-MSA had promising properties for sentinel nodes identification in non-small cell lung cancer.

No significant financial relationships to disclose.

A soft preparative method for membrane proteome analysis using frit inlet asymmetrical flow field-flow fractionation: application in a prostatic cancer cell line

Membrane proteins participate in a number of important biological functions such as signal transduction, molecular transport, and cell-cell interactions. However, due to the nature of membrane proteins, the development of a preparative method that produces a sufficient yield of purified membrane proteins from the cell remains a challenge. In the present study, frit inlet asymmetrical flow field-flow fractionation (FI-AFlFFF) was employed to fractionate membrane fragments containing membrane proteins from free cytoplasmic proteins of prostatic cancer cell (DU145 cell) lysates. The isolated membrane proteins were then digested and analyzed by nanoflow liquid chromatography/tandem mass spectrometry (nLC-ESI-MS-MS). Since fractionation of the cell lysate mixtures containing membrane fragments and cytoplasmic proteins could be achieved based on the differences of their sizes in FI-AFlFFF, membrane fragments were partially isolated from the cytoplasmic proteins and collected. The performance of FI-AFlFFF for prefractionation of the membrane proteome was examined by comparing the number of membrane proteins that were identified with the number identified using an ultracentrifugation method. The application of FI-AFlFFF to membrane proteomics produced an increased yield of purified membrane proteins with fewer cytoplasmic proteins compared to a conventional ultracentrifugation method.

On the dynamics of piezoactuated positioning systems

Piezoelectric actuators (PEAs) are commercially available for producing extremely small displacements. If a PEA is used to drive a positioning mechanism, the combined dynamics is approximated empirically by that of a second-order system. However, the rationale for such an approximation is lacking in the literature, thus leaving some issues unaddressed, such as the scope of and the error associated with the approximation. This paper presents such a rationale for the second-order approximation and a method to quantify the error associated with the approximation, by employing the assumed mode method to solve the governing equation. For the experimental verification, step voltages of 48.2, 64.2, and 75.4 V were used to excite a prototype of the positioning system with a mass ratio of 24.7, 47.7, 87.5, 115.8, and 138.8, respectively; and the measured system step responses were compared to the ones simulated by using the second-order approximation. Also, it is illustrated that the error associated with the approximation can be well characterized and quantified by using the developed method.

Proteomic analysis of exosomes from human neural stem cells by flow field-flow fractionation and nanoflow liquid chromatography-tandem mass spectrometry

Exosomes, small membrane vesicles secreted by a multitude of cell types, are involved in a wide range of physiological roles such as intercellular communication, membrane exchange between cells, and degradation as an alternative to lysosomes. Because of the small size of exosomes (30-100 nm) and the limitations of common separation procedures including ultracentrifugation and flow cytometry, size-based fractionation of exosomes has been challenging. In this study, we used flow field-flow fractionation (FlFFF) to fractionate exosomes according to differences in hydrodynamic diameter. The exosome fractions collected from FlFFF runs were examined by transmission electron microscopy (TEM) to morphologically confirm their identification as exosomes. Exosomal lysates of each fraction were digested and analyzed using nanoflow LC-ESI-MS-MS for protein identification. FIFFF, coupled with mass spectrometry, allows nanoscale size-based fractionation of exosomes and is more applicable to primary cells and stem cells since it requires much less starting material than conventional gel-based separation, in-gel digestion and the MS-MS method.

Molecular mass sorting of proteome using hollow fiber flow field-flow fractionation for proteomics

Hollow fiber flow field-flow fractionation (HF FlFFF) has been demonstrated as a tool for pre-fractionating proteomes by differences in molecular mass (Mr), where the resulting protein fractions are subsequently digested and analyzed by shotgun proteomics using two-dimensional liquid chromatography-electrospray ionization-tandem mass spectrometry (2D-LC-ESI-MS/MS). HF FlFFF is a separation device capable of fractionating proteins or cells by hydrodynamic radius, and protein fraction can be readily collected as intact conditions in aqueous buffer solutions. In this study, HF FlFFF was applied to fractionate the proteome of Corynebacterium glutamicum, a well known soil bacterium that has been widely used in bioindustry due to its remarkable ability to secrete high amounts of glutamic acid. The collected HF FlFFF fractions of different MW intervals were enzymatically digested for protein identification by 2D-LC-ESI-MS/MS. Experiments showed improvements in protein identification when HF FlFFF pre-fractionation was applied, due to decreases in the ionization suppression effect and the MS exclusion effect by spectral congestion. Pre-fractionation of C. glutamicum proteome allowed us to find 90 additional proteins by 2D-LC-ESI-MS/MS that were not found by a direct shotgun analysis without pre-fractionation. A total of 415 proteins were found overall with 203 proteins commonly found from experiments with and without pre-fractionation.

A novel function for HSF1-induced mitotic exit failure and genomic instability through direct interaction between HSF1 and Cdc20

Although heat-shock factor (HSF) 1 is a known transcriptional factor of heat-shock proteins, other pathways like production of aneuploidy and increased protein stability of cyclin B1 have been proposed. In the present study, the regulatory domain of HSF1 (amino-acid sequence 212-380) was found to interact directly with the amino-acid sequence 106-171 of Cdc20. The association between HSF1 and Cdc20 inhibited the interaction between Cdc27 and Cdc20, the phosphorylation of Cdc27 and the ubiquitination activity of anaphase-promoting complex (APC). The overexpression of HSF1 inhibited mitotic exit and the degradations of cyclin B1 and securin, which resulted in production of aneuploidy and multinucleated cells, but regulatory domain-deficient HSF1 did not. Moreover, HSF1-overexpressing cells showed elevated levels of micronuclei and genomic alteration. The depletion of HSF1 from cells highly expressing HSF1 reduced nocodazole-mediated aneuploidy in cells. These findings suggest a novel function of HSF1 frequently overexpressed in cancer cells, to inhibit APC/C activity by interacting with Cdc20, and to result in aneuploidy development and genomic instability.

Distribution and determinants of maximal physical work capacity of Korean male metal workers

The distribution of maximal physical work capacity (MPWC) can be used to establish an upper limit for energy expenditure during work (EEwork). If physically demanding work has wearing effects, there will be a negative relationship between MPWC and workload. This study was conducted to investigate the distribution of MPWC among Korean metal workers and to examine the relationship between workload and MPWC. MPWC was estimated with a bicycle ergometer using a submaximal test. Energy expenditure was estimated by measuring heart rates during work. The study subjects were 507 male employees from several metal industries in Korea. They had a lower absolute VO2max than the Caucasian populations described in previous studies. The older workers had a lower physical capacity and a greater overload at work. A negative relationship was found between MPWC and workload across all age groups. Upper limits for EEwork for all age groups and for older age groups are recommended based on the 5th percentile value of MPWC.

Genetic diversity of the natural populations of Arabidopsis thaliana in China

Although extensive studies have been conducted on the genetic structure of Arabidopsis thaliana (A. thaliana) populations worldwide, the populations from China have never been studied. In this study, we collected 560 individuals from 19 natural populations of A. thaliana distributed in East China along the lower reaches of the Yangtze River, and two populations from northwest China (Xinjiang Province). We adopted two kinds of molecular marker, inter-simple sequence repeats (ISSRs) and random amplified polymorphic DNA (RAPDs) to investigate the genetic diversity within and among populations, and the correlation between the genetic and geographic distances. Thirteen ISSR primers produced 165 polymorphic bands (PPB) (96%) and 11 RAPD primers produced 162 polymorphic bands (98%) in about 560 individuals. The two marker systems generated similar patterns of genetic diversity in these natural populations. The AMOVA analysis indicated about 42-45% of the total genetic variation existed within populations, and found possible geographic structure. The Mantel test revealed a significant correlation between the geographic distance and the genetic distance of these populations in general. A close genetic relationship was found among four populations in the Jiangxi Province, and these always appeared clustered together as a monophyletic group in unweighted pair-group method with arithmetic averages dendrograms based on both ISSR and RAPD data sets. Based on the observation of recolonization and extinction of naturally distributed populations of A. thaliana, and the pattern of their genetic differentiation, the distribution of this species in China might be a result of natural dispersal under the strong influence of human activity.

Miniaturized asymmetrical flow field-flow fractionation: Application to biological vesicles

Asymmetrical flow field-flow fractionation (AFlFFF) has been carried out in a miniaturized channel by reducing the channel dimensions. Performance of the miniaturized AFlFFF (mAFlFFF) channel was evaluated with standard proteins and polystyrene latex spheres from nanometer to micrometer size. By reducing the channel dimension, proteins or particulate materials can be separated within a few minutes without a significant loss in resolution. The mAFlFFF channel was applied for the separation of exosomes harvested from immortalized human mesenchymal stem cell line. It shows a potential to fractionate exosome vesicles according to sizes which can be useful for proteomic studies in relation to immunotherapeutic applications.

Benign prostatic hyperplasia and subsequent risk of bladder cancer

We evaluated the risk of bladder cancer in a cohort of 79,280 Swedish men hospitalised for benign prostatic hyperplasia (BPH), identified in the Swedish Inpatient Register between 1964 and 1983 and followed until 1989 via multiple record linkages with nationwide data on cancer registry, death and emigration. Standardised incidence ratios (SIRs), the ratios of the observed to the expected numbers of incident bladder cancers, were used to calculate the risk associated with BPH. The expected number was calculated by multiplying the number of person-years by the age-specific cancer incidence rates in Sweden for each 5-year age group and calendar year of observation. Analyses were stratified by BPH treatment, latency, calendar year and presence of genitourinary (GU) comorbid conditions. After excluding the first 3 years of follow-up after the index hospitalisation, we observed 506 incident bladder cancer cases during follow-up in the cohort. No overall increased risk of bladder cancer was apparent in our main analysis involving the entire BPH cohort. However, among BPH patients with transurethral resection of the prostate (TURP), there was an increased risk in all follow-up periods; SIRs of bladder cancer during years 4-6 of follow-up was 1.22 (95% confidence interval=1.02-1.46), 1.32 for 7-9 years of follow-up, and 1.47 for 10-26 years of follow-up. SIRs of bladder cancer among TURP-treated BPH patients were particularly elevated among those with comorbid conditions of the GU tract (e.g., stone, infection, etc.); 1.72, 1.74 and 2.01 for 4-6, 7-9, 10-26 years of follow-up, respectively, and also for those whose diagnoses occurred before 1975, when TURP was more likely to be performed by a urologist than a general practitioner: 1.87, 1.90 and 1.74, respectively. These findings suggest that BPH overall is not associated with bladder cancer risk. However, among men treated with TURP, particularly those with other comorbid GU tract conditions, risk of bladder cancer was elevated.

Development of non-gel-based two-dimensional separation of intact proteins by an on-line hyphenation of capillary isoelectric focusing and hollow fiber flow field-flow fractionation

A rapid, non-gel-based, on-line, two-dimensional separation method is introduced for proteome analysis. Protein fractionation was carried out by first exploiting the differences in their respective isoelectric points (pI) in a Teflon capillary using isoelectric focusing (IEF), followed by a molecular weight (MW)-based separation in a hollow fiber by flow field-flow fractionation (FlFFF). The method developed here (CIEF-HFFlFFF) may be a powerful alternative to two-dimensional polyacrylamide gel electrophoresis, which is currently used for the separation and purification of proteins. In CIEF-HFFlFFF, proteins can be collected as a fraction of a certain pI and MW interval without being denatured. Additionally, the ampholyte solution is simultaneously removed during separation in the hollow fiber, and the overall process time is significantly reduced. This method was applied to a human urinary proteome sample, leading to the identification of 114 proteins with the subsequent off-line use of nanoflow liquid chromatography-tandem mass spectrometry after the tryptic digestion of each collected protein fraction.

269 EXPRESSION OF TANDEM-PORE DOMAIN K+ CHANNELS IN BOVINE OOCYTES AND PRE-IMPLANTATION EMBRYOS

Tandem-pore domain K+ (K2P) channels that contribute to setting the resting membrane potential of excitable and nonexcitable cells are expressed in many kinds of cells and tissues. Recent studies have shown that TASK [TWIK (Tandem of P domains in Weak Inward rectifying K+ channels)-related acid-sensitive K+ channels] and TREK (TWIK-Related K+ channels), members of K2P channel family that are involved in a variety of cellular functions, are expressed in human myometrium, placenta, and cytotrophoblast cells. However, their expression in bovine oocytes and embryos has not yet been reported. In this study, we examined whether TASK and TREK channels are expressed in bovine immature (germinal vesicle-stage) and mature (metaphase II-stage) oocytes and in pre-implantation (2-cell- and 16-cell-stage) embryos using RT-PCR and immunocytochemistry. RT-PCR data showed that TASK-1, TASK-3, TREK-1, TREK-2, and TRAAK channels were expressed in bovine immature and mature oocytes. Interestingly, the expression levels of TREK channels were 2-fold higher than those of TASK channels as judged by semiquantitative RT-PCR and real-time PCR with cDNA synthesized from 50 individual immature and mature oocytes (P < 0.05, n = 4). Intensity of genes was normalized with respect to that of GAPDH. Consistent with RT-PCR data, immunocytochemical data showed that TASK-1, TASK-3, TREK-1, TREK-2, and TRAAK channels were expressed in bovine immature and mature oocytes. The fluorescence intensity of TREK channels was higher than that of TASK channels (P < 0.05, n = 5). TASK and TREK channels were also expressed in pre-implantation embryos. Of TREK channels, the TREK-2 channel was strongly expressed in immature and mature oocytes and in pre-implantation embryos (P < 0.05, n = 5). For statistics, Student's t-test was used, with P < 0.05 as the criterion for significance. Our results show that TASK-1, TASK-3, TREK-1, TREK-2, and TRAAK channels were expressed in bovine immature and mature oocytes and pre-implantation embryos. These results suggest that TASK and TREK channels could be involved in various physiological processes in mammalian oocytes and embryos.

237 POTASSIUM CONCENTRATION AND mRNA LEVELS OF POTASSIUM CHANNELS DECREASED IN CYSTIC OVARIAN FOLLICLE FLUID

Cystic ovarian follicle (COF) is one of the most frequently diagnosed ovarian diseases and a major cause of reproductive failure in cattle. Despite an abundance of reports on this subject, the exact pathogenesis of COF still remains unclear. It is generally accepted that disruption of the hypothalmo-pituitary-gonadal axis, by endogenous and/or exogenous factors, causes cystic formation. We here examined whether ion concentration and expression of ion channels are altered in the follicle fluid derived from a Korean native cow with COF. In an ovary with a cystic follicle, granulosa cell layers were exfoliated; the theca interna was thinner than that in an ovary without cystic follicle, based on histological examination. Concentrations of K+, Na+, and Cl- in COF fluid (COFF) were 10.4 � 3.5 mM, 138 � 12 mM, and 104.9 � 7.0 mM, respectively. In COFF, K+ concentration showed a significant difference from the value observed in normal follicle fluid (NFF) (P < 0.05; NFF: 10.4 � 3.5 mM vs. COFF: 6.2 � 0.8 mM). The total numbers of follicles observed (normal, 3–5 mm in diameter vs. COF, 20–30 mm in diameter) were 200 and 20 in normal and COF, respectively. To compare mRNA expression of K+ channels, we performed semiquantitative RT-PCR using follicle fluid and ovaries with or without cystic follicles. RT-PCR showed that mRNA levels of TASK channels (TASK-1, TASK-3, and TASK-5) decreased by 50% in COFF and an ovary with cystic follicles compared to NFF and a normal ovary. TASK channels are involved in apoptosis of mammalian cells. Our results suggest that potassium may play an important role in the pathogenesis of COF.

334 DNA SYNTHESIS DURING THE FIRST CELL CYCLE OF PORCINE OOCYTES FOLLOWING DIFFERENT ACTIVATION TREATMENTS

Inhibitors of protein synthesis and phosphorylation have been widely used for oocyte activation and have been reported to induce abnormalities in nuclear ploidy due to aberrant DNA synthesis (DNAS). The present experiment was designed to compare the DNAS during the first cell cycle of porcine parthenotes following different activation treatments. Cumulus–oocyte complexes were cultured in TCM-199 supplemented with 0.5 �g mL-1 LH and FSH, 10 ng mL-1 EGF, and 0.1% PVA for 22 h, and additionally cultured in media without LH and FSH for 22 h. MII oocytes were then electrically pulsed twice in 0.28 M mannitol containing 0.05 mM CaCl2 and 0.1 mM MgSO4 at 1.8 kV cm-1 for 30 �s (group 1), followed by 7.5 �g mL-1 cytochalasin B (CCB, group 2), 10 �g mL-1 cycloheximide (CHX, group 3), or 1.9 mM 6-dimethylaminopurine (6-DMAP, group 4) for 3 h. Eggs were incubated with 100 �M 5-bromo-222-deoxyuridine (BrdU) for 1 h at 0, 2, 4, 6, 8, 10, and 12 h after activation to evaluate DNAS (Adenot et al. 1997 Development 124, 4615–4625) by determining the BrdU signal under a fluorescence microscope. Experiments were replicated 4 times; results were expressed as mean � SD and analyzed using one-way ANOVA by SPSS 10.0. The percentage of DNAS was calculated by dividing the number of BrdU-positive eggs by the total number of eggs used. DNAS in groups 1, 3, and 4 initiated at 2–3 h post-activation (hpa) but at 4–5 hpa in group 2. In group 1, DNAS was faint until 3 hpa, gradually increasing thereafter until 11 hpa (20.7 � 19.6, 29.4 � 17.0, 41.3 � 16.7, and 64.4 � 6.2, at 4–5, 6–7, 8–9, and 10–11 hpa, respectively). There was a significant (P < 0.05) increase in DNAS at 10–11 h, but a significant (P < 0.05) decrease (34.3 � 6.4) at 12–13 hpa. In groups 2 and 3, after 4–5 hpa, DNAS gradually increased until 7 h (6.2 � 1.4 and 29.8 � 16.6 at 4–5 hpa, and 21.1 � 13.7 and 40.0 � 18.7 at 6–7 hpa, respectively), but a DNAS peak was observed at 8–9 h (44.6 � 9.0) in group 2 and at 10–11 h (40.5 � 22.1) in group 3. Interestingly, group 4 parthenotes showed a different DNAS pattern compared with other groups, as it started at 2–3 hpa (24.8 � 11.7), reached a significantly (P < 0.05) high level at 4–5 hpa (56.3 � 9.0), and gradually decreased at 6–7 hpa (42.7 � 10.3) until 12–13 hpa (29.5 � 14.9). In conclusion, CCB, CHX, and 6-DMAP used for oocyte activation exhibited different patterns of DNA synthesis during the first cell cycle of porcine parthenotes. Therefore, further experiments are required to evaluate the molecular signaling that regulates DNAS, embryonic developmental velocity, and ploidy of 2-cell parthenotes.

Meta- and pooled analysis of GSTT1 and lung cancer: a HuGE-GSEC review

Lung cancer is the most common malignancy in the Western world, and the main risk factor is tobacco smoking. Polymorphisms in metabolic genes may modulate the risk associated with environmental factors. The glutathione S-transferase theta 1 gene (GSTT1) is a particularly attractive candidate for lung cancer susceptibility because of its involvement in the metabolism of polycyclic aromatic hydrocarbons found in tobacco smoke and of other chemicals, pesticides, and industrial solvents. The frequency of the GSTT1 null genotype is lower among Caucasians (10-20%) than among Asians (50-60%). The authors present a meta- and a pooled analysis of case-control, genotype-based studies that examined the association between GSTT1 and lung cancer (34 studies, 7,629 cases and 10,087 controls for the meta-analysis; 34 studies, 7,044 cases and 10,000 controls for the pooled analysis). No association was observed between GSTT1 deletion and lung cancer for Caucasians (odds ratio (OR) = 0.99, 95% confidence interval (CI): 0.87, 1.12); for Asians, a positive association was found (OR = 1.28, 95% CI: 1.10, 1.49). In the pooled analysis, the odds ratios were not significant for either Asians (OR = 0.97, 95% CI: 0.83, 1.13) or Caucasians (OR = 1.09, 95% CI: 0.99, 1.21). No significant interaction was observed between GSTT1 and smoking on lung cancer, whereas GSTT1 appeared to modulate occupational-related lung cancer.

SULT1E1 genetic polymorphisms modified the association between phytoestrogen consumption and bone mineral density in healthy Korean women

Sulfotransferase 1E1 (SULT1E1) catalyze estrogen into sulfate conjugation and is involved in the metabolism of phytoestrogen. A community-based cross-sectional study was conducted on 397 Korean women, to evaluate the association between genetic polymorphisms of SULT1E1 and bone mineral density (BMD) and the combined effect of the genetic polymorphism and phytoestrogen intake for BMD in Korean women. BMDs of the distal radius and the calcaneus were measured by dual-energy X-ray absorptiometry. Genotypes of SULT1E1 IVS1-447 C>A, IVS4-1653 T>C, and *959 G>A were determined by the 5'-nuclease assay (TaqMan). Phytoestrogen intake was estimated by a food-frequency questionnaire validated against multiple 24-hour recalls. Women with the SULT1E1 *959 GG genotype had a 4.5% lower BMD at the distal radius (P (trend )= 0.05) and a 7.9% lower BMD at the calcaneus compared to those with AA genotype (P (trend) < 0.01), whereas the SULT1E1 IVS1-447 CC genotype and IVS4-1653 TT genotype were not associated with BMD. There was no significant trend of BMD with the numbers of CTG-containing haplotypes, but calcaneal BMDs significantly differed between SULT1E1 CTA-CTA haplotype and CTG-CCA haplotype (P < 0.05). When stratified by SULT1E1 genotype, the correlation between phytoestrogen consumption and BMD at the calcaneus was noteworthy in women with SULT1E1 *959 GG genotype (r = 0.25, P = 0.01) or SULT1E1 IVS 4-1653 TT genotype (r = 0.15, P = 0.02). This trend remained significant only in postmenopausal women (r = 0.36, P = 0.01) after multiple testing was corrected by the false discovery rate method. In conclusion, the genetic polymorphism of SULT1E1 *959 G > A was associated with BMD at the distal radius and calcaneus, and the association between phytoestrogen consumption and calcaneal BMD might be modified by this genetic polymorphism.

CagA-producing Helicobacter pylori and increased risk of gastric cancer: a nested case-control study in Korea

In a nested-case control study of 100 cases of gastric cancer and 400 matched controls in relation to virulence factors of Helicobacter pylori in a Korean cohort, CagA seropositivity was significantly associated with a higher risk of gastric cancer among H. pylori-infected subjects (OR=3.57, 95% CI 1.05–12.14).

Single-nucleotide polymorphisms and haplotypes of bone morphogenetic protein genes and peripheral bone mineral density in young Korean men and women

Bone morphogenetic proteins (BMPs) play critical roles in osteoblast differentiation. To investigate the association between common single-nucleotide polymorphisms (SNPs) of BMPs and bone mineral density (BMD), a cross-sectional study was conducted in healthy Korean men (n = 237) and women (n = 276) aged 20-39 years. Calcaneus and distal radius BMD were measured by dual energy X-ray absorptiometry. SNPs of BMP2 (-1103C > A, c.584G > A, IVS1-2744A > G, c.893T > A), BMP4 (c.712T > C, IVS1-160C > T), and BMP6 (c.1283C > G, IVS4-6838A > G, IVS5 + 24C > T) were determined using the 5'-nuclease assay. Significant associations were observed between BMP2 c.584G > A, c.893T > A genotypes and male calcaneus as well as female distal radius BMD. Men with the BMP2 c.893 AA genotype had a 16% higher BMD at the calcaneus (P for trend = 0.014), whereas women with this genotype had a 7% lower BMD at the distal radius than the other genotypes (P for trend = 0.010). A significant association was also observed between BMP4 IVS1-160C > T and male calcaneus BMD (P for trend = 0.024). When the association between haplotypes and BMD was investigated, the AAGA haplotype of BMP2 was significantly associated with low bone mass in female distal radius (P for trend = 0.013). These results suggested that one or more SNPs of BMP2 and BMP4 are associated with peripheral BMD in Korean men and women. However, this association is dependent on anatomical sites and gender. Thus, larger studies with complete coverage of SNPs are needed in the future.