Genomic hypomethylation in cell-free DNA predicts responses to checkpoint blockade in lung and breast cancer

Genomic hypomethylation has recently been identified as a determinant of therapeutic responses to immune checkpoint blockade (ICB). However, it remains unclear whether this approach can be applied to cell-free DNA (cfDNA) and whether it can address the issue of low tumor purity encountered in tissue-based methylation profiling. In this study, we developed an assay named iMethyl, designed to estimate the genomic hypomethylation status from cfDNA. This was achieved through deep targeted sequencing of young LINE-1 elements with > 400,000 reads per sample. iMethyl was applied to a total of 653 ICB samples encompassing lung cancer (cfDNA n = 167; tissue n = 137; cfDNA early during treatment n = 40), breast cancer (cfDNA n = 91; tissue n = 50; PBMC n = 50; cfDNA at progression n = 44), and ovarian cancer (tissue n = 74). iMethyl-liquid predicted ICB responses accurately regardless of the tumor purity of tissue samples. iMethyl-liquid was also able to monitor therapeutic responses early during treatment (3 or 6 weeks after initiation of ICB) and detect progressive hypomethylation accompanying tumor progression. iMethyl-tissue had better predictive power than tumor mutation burden and PD-L1 expression. In conclusion, our iMethyl-liquid method allows for reliable noninvasive prediction, early evaluation, and monitoring of clinical responses to ICB therapy.

Comparative RNA-Seq Analysis Revealed Tissue-Specific Splicing Variations during the Generation of the PDX Model

Tissue-specific gene expression generates fundamental differences in the function of each tissue and affects the characteristics of the tumors that are created as a result. However, it is unclear how much the tissue specificity is conserved during grafting of the primary tumor into an immune-compromised mouse model. Here, we performed a comparative RNA-seq analysis of four different primary-patient derived xenograft (PDX) tumors. The analysis revealed a conserved RNA biotype distribution of primary-PDX pairs, as revealed by previous works. Interestingly, we detected significant changes in the splicing pattern of PDX, which was mainly comprised of skipped exons. This was confirmed by splicing variant-specific RT-PCR analysis. On the other hand, the correlation analysis for the tissue-specific genes indicated overall strong positive correlations between the primary and PDX tumor pairs, with the exception of gastric cancer cases, which showed an inverse correlation. These data propose a tissue-specific change in splicing events during PDX formation as a variable factor that affects primary-PDX integrity.

Study on Rolling Defects of Al-Mg Alloys with High Mg Content in Normal Rolling and Cross-Rolling Processes

This study investigated defect formation and strain distribution in high-Mg-content Al-Mg alloys during normal rolling and cross-rolling processes. The finite element analysis (FEA) revealed the presence of wave defects and strain localization-induced zipper cracks in normal cold rolling, which were confirmed by the experimental results. The concentration of shear strain played a significant role in crack formation and propagation. However, the influence of wave defects was minimal in the cross-rolling process, which exhibited a relatively uniform strain distribution. Nonetheless, strain concentration at the edge and center regions led to the formation of zipper cracks and edge cracks, with more pronounced propagation observed in the experiments compared to FEA predictions. Furthermore, texture evolution was found to be a crucial factor affecting crack propagation, particularly with the development of the Goss texture component, which was observed via electron backscattered diffraction analysis at bending points. The Goss texture hindered crack propagation, while the Brass texture allowed cracks to pass through. This phenomenon was consistent with both FEA and experimental observations. To mitigate edge crack formation and propagation, potential strategies involve promoting the formation of the Goss texture at the edge through alloy and process conditions, as well as implementing intermediate annealing to alleviate stress accumulation. These measures can enhance the overall quality and reliability of Al-Mg alloys during cross-rolling processes. In summary, understanding the mechanisms of defect formation and strain distribution in Al-Mg alloys during rolling processes is crucial for optimizing their mechanical properties. The findings of this study provide insights into the challenges associated with wave defects, strain localization, and crack propagation. Future research and optimization efforts should focus on implementing strategies to minimize defects and improve the overall quality of Al-Mg alloys in industrial applications.

MHC II immunogenicity shapes the neoepitope landscape in human tumors

Despite advances in predicting physical peptide-major histocompatibility complex I (pMHC I) binding, it remains challenging to identify functionally immunogenic neoepitopes, especially for MHC II. By using the results of >36,000 immunogenicity assay, we developed a method to identify pMHC whose structural alignment facilitates T cell reaction. Our method predicted neoepitopes for MHC II and MHC I that were responsive to checkpoint blockade when applied to >1,200 samples of various tumor types. To investigate selection by spontaneous immunity at the single epitope level, we analyzed the frequency spectrum of >25 million mutations in >9,000 treatment-naive tumors with >100 immune phenotypes. MHC II immunogenicity specifically lowered variant frequencies in tumors under high immune pressure, particularly with high TCR clonality and MHC II expression. A similar trend was shown for MHC I neoepitopes, but only in particular tissue types. In summary, we report immune selection imposed by MHC II-restricted natural or therapeutic T cell reactivity.

Predictors of the Effects of Flow Diversion in Very Large and Giant Aneurysms

BACKGROUND AND PURPOSE

The treatment paradigm for very large and giant aneurysms has recently changed to flow diversion, in light of the results of the Pipeline for Uncoilable or Failed Aneurysms trial. However, the effects of flow diversion were definitely unknown. We explored this topic and identified the predictors of such effects.

MATERIALS AND METHODS

We retrospectively reviewed 51 patients with unruptured aneurysms admitted to our institution for flow diversion between February 2014 and August 2019. Patients were categorized into an effect group (no filling or remnant entry) and a no-effect group (subtotal or total filling). We evaluated the aneurysm size and shape, incorporation vessel, parent artery stenosis and curvature, stagnation of contrast medium within the aneurysm, use of balloon angioplasty, and intra-aneurysm thrombus as potential predictors of the effects of flow diversion.

RESULTS

The effect group comprised 34 patients (66.7%, 34/51; no filling, 35.3%, 18/51; and remnant entry, 31.4%, 16/51). The no-effect group comprised 17 patients (33.3%, 17/51; subtotal filling, 29.4%, 15/51; and total filling, 3.9%, 2/51). An incorporation vessel and balloon angioplasty were independent risk factors for the no-effect group in multivariate logistic regression analyses (OR = 0.13 and 0.05; 95% confidence intervals, 0.02-0.62 and 0.00-0.32; P values, .021 and .004, respectively).

CONCLUSIONS

Flow diversion is effective for very large and giant aneurysms, but the outcomes require further improvement. The results of this study show that an incorporated vessel and excessive balloon angioplasty might compromise flow diversion. This finding can help improve the outcomes of flow diversion.

Intraprocedural Flat Panel Detector Rotational Angiography and an Image Fusion Technique for Delivery of a Microcatheter into the Targeted Shunt Pouch of a Dural Arteriovenous Fistula

The accurate and safe delivery of a microcatheter to a targeted shunt pouch is essential for successful transvenous embolization of intracranial dural arteriovenous fistulas. However, complex anatomy and variations in head and neck veins and occluded sinuses can hinder intraprocedural microcatheter delivery. In this study, we introduce an intraprocedural flat panel detector rotational angiography and image fusion technique to aid precise navigation inside the veins and proper placement of the microcatheter in the targeted shunt pouch.

Prospective clinical evaluation of Momguard non-invasive prenatal test in 1011 Korean high-risk pregnant women

Clinical performance of the Momguard non-invasive prenatal test (NIPT) was evaluated in a cohort of Korean pregnant women. The foetal trisomies 21, 18 and 13 (T21, T18 and T13) were screened by low-coverage massive parallel sequencing in the maternal blood. Among the 1011 confirmed samples, 32 cases (3.2%) had positive NIPT results. Of these positive cases, 20 cases of T21, all cases of T18 and two cases of T13 had concordant karyotype findings. Only one case out of the remaining 979 negative NIPT samples showed a false negative result. The overall sensitivity and specificity of Momguard to detect the three chromosomal aneuploidies were 96.8% and 99.8%, respectively. Momguard is a clinically useful tool for the detection of T21, T18 and T13 in singleton pregnancy. However, as other NIPT tests, it carries the risk of false positive and false negative results. Hence, the genetic counsellors should provide these limitations to the examinees.Impact StatementWhat is already known on this subject? The NIPT approach using massive parallel sequencing (MPS) showed high sensitivity and specificity in various clinical studies. These results are based on analysis systems using their own bioinformatics algorithms.What the results of this study add? When this NIPT technology was introduced in Korea, the first biological specimens collected in Korea were transported overseas for processing in overseas laboratories and analysed by other country's analysis methods. We needed our own NIPT algorithm and developed Momguard NIPT for the first time in Korea. This study attempted to evaluate this Momguard NIPT protocol prospectively in a large number of samples obtained from three Korean hospitals.What the implications are of these findings for clinical practice and/or further research? The overall sensitivity and specificity to identify T13, T18 and T21 were 96.8% and 99.8%, respectively. These accuracy values were comparable to that of other studies. From this study, we found that Momguard is a clinically useful tool for the detection of three chromosomal aneuploidies. However, as other NIPT tests, it carries the risk of false positive and false negative results. Hence, the genetic counsellors should provide these limitations to the examinees.

The Fate of Unruptured Intracranial Vertebrobasilar Dissecting Aneurysm with Brain Stem Compression According to Different Treatment Modalities

BACKGROUND AND PURPOSE

Unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression are difficult to treat. In the present study, the clinical and radiologic outcomes of unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression based on different treatment modalities were evaluated.

MATERIALS AND METHODS

This study included 28 patients with unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression treated from January 2009 to December 2017. Treatment methods were observation (n = 6), stent-assisted coil embolization (n = 9), parent artery occlusion (n = 6), and flow diversion (n = 7). The data of baseline characteristics, change of aneurysm size, retreatment rate, stroke occurrence, and alteration of the mRS score were obtained from retrospective chart review.

RESULTS

The initial size of dissecting aneurysms was largest in the flow diversion group (22.5 ± 7.7 mm), followed by parent artery occlusion (20.3 ± 8.4 mm), stent-assisted coil embolization (11.7 ± 2.2 mm), and observation (17.8 ± 5.5 mm; P = .01) groups. The reduction rate of aneurysm size was highest in the parent artery occlusion group (26.7 ± 32.1%), followed by flow diversion (14.1% ± 28.7%), stent-assisted coil embolization (-17.9 ± 30.3%), and observation (-31.5 ± 30.8%; P = .007) groups. Additional treatment was needed in the observation (4/6, 66.7%) and stent-assisted coil embolization (3/9, 33.3%; P = .017) groups. Improvement of the mRS score on follow-up was observed in the flow diversion (6/7, 85.7%) and parent artery occlusion (4/6, 66.7%) groups but not in the stent-assisted coil embolization and observation groups. A worsened mRS score was most common in the observation group (4/6, 66.7%), followed by stent-assisted coil embolization (3/9, 33.3%), parent artery occlusion (2/6, 33.3%), and flow diversion (0/7, 0%) groups.

CONCLUSIONS

When treating intracranial vertebrobasilar dissecting aneurysms with brain stem compression, parent artery occlusion and flow diversion should be considered to reduce aneurysm size and improve the mRS score.

Exercise improves the effects of testosterone replacement therapy and the durability of response after cessation of treatment: a pilot randomized controlled trial

The effects of the combination of exercise and TRT on symptoms of late-onset hypogonadism (LOH) and the durability of response after cessation of TRT were investigated. A total of fifty patients with erectile dysfunction (ED) who had a sedentary lifestyle and low serum total testosterone (T) levels were enrolled and followed for 20 weeks. Patients were randomly divided into two groups; all of them received T gel for 12 weeks and it was discontinued for 8 weeks. Patients assigned to Group II were offered a supervised exercise program for 20 weeks. Measurement of serological testing was performed and self-assessment questionnaires and Global Assessment Question (GAQ) were asked. Baseline characteristics and the initial symptom scores showed no significant difference between the two groups. Serum total T levels and the symptom scores were increased at 12 weeks in both groups, and Group II showed better results with statistical significance. There was a decrease in T levels and worsening of symptom scores at week 20 compared to week 12 in both groups, and Group II showed better results with statistical significance. On the GAQ, Group II showed higher ratio of “yes” at week 12 and the same tendency was sustained at week 20 with significant difference between two groups. The combination of exercise and TRT showed significant improvements in serum T levels and LOH symptoms compared to TRT alone. In addition, these improvements were maintained in the combination group with continuous exercise, even after cessation of TRT.

Frequency of hereditary neuropathy with liability to pressure palsies (HNPP) due to 17p11.2 deletion in a Korean newborn population

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder mainly due to a deletion of chromosome 17p11.2 including PMP22 (PMP22 Del HNPP). The prevalence of HNPP is estimated to be 0.84 to 16 per 100,000, but could be underestimated because of the mild symptoms of HNPP. In this study, we estimated the prevalence of PMP22 Del HNPP in a Korean newborn population who underwent next-generation sequencing (NGS)-based copy number variation (CNV) analysis. Of the 11,885 newborns tested by NGS-based CNV analysis, 17p11.2 deletions were found in seven samples. The prevalence of PMP22 Del HNPP was estimated to be 58.9 per 100,000 (95% confidence interval (CI), 25.8–116.5) or 1 in 1698 (95% CI, 1/909–1/5000). Our data suggest that PMP22 Del HNPP might not be uncommon at least in the Korean population.

Universally applicable, quantitative PCR method utilizing fluorescent nucleobase analogs

We herein describe a novel quantitative PCR (qPCR) method, which operates in both signal-off and on manners, by utilizing a unique property of fluorescent nucleobase analogs. The first, signal-off method is developed by designing the primers to contain pyrrolo-dC (PdC), one of the most common fluorescent nucleobase analogs. The specially designed single-stranded primer is extended to form double-stranded DNA during PCR and the fluorescence signal from the PdCs incorporated in the primer is accordingly reduced due to its conformation-dependent fluorescence properties. In addition, the second, signal-on method is devised by designing the primers to contain 5′-overhang sequences complementary to the PdC-incorporated DNA probes. At the initial phase, the PdC-incorporated DNA probes are hybridized to the 5′-overhang sequences of the primer, exhibiting the significantly quenched fluorescence signal, but are detached by either hydrolysis or strand displacement reaction during PCR, leading to the highly enhanced fluorescence signal. This method is more advanced than the first one since it produces signal-on fluorescence response and permits the use of a single PdC-incorporated DNA probe for the detection of multiple target nucleic acids, remarkably decreasing the assay cost. With these novel qPCR methods, we successfully quantified target nucleic acids derived from sexually transmitted disease (STD) pathogens with high accuracy. Importantly, the proposed strategies overcome the major drawbacks in the current SYBR Green and TaqMan probe-based qPCR methods such as low specificity and high assay cost.

A novel quantitative PCR (qPCR) method was developed by utilizing a unique property of fluorescent nucleobase analogs (PdCs).

Frequency of pathogenic germline mutation in CHEK2, PALB2, MRE11, and RAD50 in patients at high risk for hereditary breast cancer

PURPOSE

This study was performed to evaluate the frequency of mutations in CHEK2, PALB2, MRE11, and RAD50 among Korean patients at high risk for hereditary breast cancer.

METHODS

A total of 235 Korean patients with hereditary breast cancer who tested negative for BRCA1/2 mutation were enrolled to this study. Entire coding regions of CHEK2, PALB2, MRE11, and RAD50 were analyzed using massively parallel sequencing (MPS). Sequence variants detected by MPS were confirmed by Sanger sequencing.

RESULTS

Six patients (2.5 %) were found to have pathogenic variants in CHEK2 (n = 1), PALB2 (n = 2), MRE11 (n = 1), and RAD50 (n = 2). Among the pathogenic variants, PALB2 c.2257C>T was previously reported in other studies, while CHEK2 c.1245dupC, PALB2 c.1048C>T, MRE11 c.1773_1774delAA, RAD50 c.1276C>T, and RAD50 c.3811_3813delGAA were newly identified in this study. A total of 15 missense variants were found in the four genes among 26 patients; 7 patients had a variant in CHEK2, 11 in PALB2, 2 in MRE11, and 6 in RAD50. When in silico analyses were performed to the 15 missense variants, six variants (CHEK2 c.686A>G, PALB2 c.1492G>T, PALB2 c.3054G>C, MRE11 c.140C>T, RAD50 c.1456C>T, and RAD50 c.3790C>T) were predicted to be deleterious.

CONCLUSIONS

Pathogenic variants in CHEK2, PALB2, MRE11, and RAD50 were detected in a small proportion of Korean patients with features of hereditary breast cancer.

Heterozygous germline mutations in NBS1 among Korean patients with high-risk breast cancer negative for BRCA1/2 mutation

The purpose of the present study was to analyze genetic variations in the NBS1 gene and to evaluate the contribution of heterozygous NBS1 mutation to the risk of breast cancer among Korean patients with high-risk breast cancer negative for BRCA1/2 mutation. We screened 235 non-BRCA1/2 Korean patients with high-risk breast cancer for NBS1 mutations. The entire NBS1 gene was sequenced using fluorescent conformation-sensitive capillary electrophoresis. In silico analysis of the NBS1 variants was performed using PolyPhen-2 and SIFT. The frequency of variants predicted to be deleterious by in silico analysis was compared between breast cancer patients and controls. Twenty-eight sequence variants in the NBS1 gene were identified: 9 exonic variants, including 5 missense mutations (p.R169C, p.I171V, p.E185Q, p.E564K, and p.F603L) and 4 silent mutations, and 19 variants within introns. Among the five missense variants, p.I171V (c.511A > G) was the only variant predicted to be deleterious by in silico analysis. Heterozygosity for p.I171V was found in 4/235 patients with breast cancer and 3/281 individuals in the control group. The frequency of p.I171V was not significantly different between the patient and control groups (1.7 vs. 1.06%, p = 0.7). Heterozygosity of p.I171V in the NBS1 gene was found in a small proportion of Korean patients with high-risk breast cancer. The contribution of the p.I171V variant to the development of breast cancer among Korean patients was not significant.

Analysis of BRIP1 Variants among Korean Patients with BRCA1/2 Mutation-Negative High-Risk Breast Cancer

Purpose

The aim of the current study is to assess the spectrum of genetic variation in the BRIP1 gene among Korean high-risk breast cancer patients who tested negative for the BRCA1/2 mutation.

Materials and Methods

Overall, 235 Korean patientswith BRCA1/2 mutation–negative high-risk breast cancerwere screened for BRIP1 mutations. The entire BRIP1 gene was analyzed using fluorescent-conformation sensitive gel electrophoresis. In silico analysis of BRIP1 variants was performed using PolyPhen-2 and SIFT.

Results

A total of 20 sequence alterations including 12 exonic and eight intronic variantswere found. Among the 12 exonic variants, 10 were missense and two were silent mutations. No protein-truncating mutation was found among the tested patients. Among the 10 missense variants, four (p.L263F, p.L340F, p.L474P, and p.R848H) were predicted to be pathogenic by both PolyPhen-2 and SIFT, and these variants were found in five patients. Of the four missense variants, p.L263F, p.L474P, and p.R848H localize to regions between the helicase motifs, while p.L340F resides in an iron-sulfur domain of BRIP1.

Conclusion

No protein-truncating mutation in BRIP1 was found among the tested patients. The contribution of BRIP1 variants is thought to be minor in Korean non-BRCA1/2 high-risk breast cancer.

Large genomic rearrangement of BRCA1 and BRCA2 genes in familial breast cancer patients in Korea

We screened large genomic rearrangements of the BRCA1 and BRCA2 genes in Korean, familial breast cancer patients. Multiplex ligation-dependent probe amplification assay was used to identify BRCA1 and BRCA2 genomic rearrangements in 226 Korean familial breast cancer patients with risk factors for BRCA1 and BRCA2 mutations, who previously tested negative for point mutations in the two genes. We identified only one large deletion (c.4186-1593_4676-1465del) in BRCA1. No large rearrangements were found in BRCA2. Our result indicates that large genomic rearrangement in the BRCA1 and BRCA2 genes does not seem like a major determinant of breast cancer susceptibility in the Korean population. A large-scale study needs to validate our result in Korea.

The efficacy of combination treatment with injectable testosterone undecanoate and daily tadalafil for erectile dysfunction with testosterone deficiency syndrome

INTRODUCTION

Both testosterone therapy and chronic treatment with phosphodiesterase type 5 inhibitors (PDE5Is) have positive effects on the histology of penile corpora and erectile function. However, few clinical studies have evaluated the efficacy of combination therapy with both testosterone replacement and chronic PDE5Is.

AIM

This study was designed to evaluate the efficacy and safety of combination treatment with long-acting injectable testosterone undecanoate (TU) and a once-daily tadalafil 5 mg for erectile dysfunction with testosterone deficiency syndrome.

METHODS

Sixty patients were consecutively enrolled and followed for 36 weeks. Thirty patients were randomly assigned to group I and received 1,000 mg of parenteral TU on day 1, followed by additional injections at weeks 6 and 18 with on-demand tadalafil 10-20 mg during the 30 weeks of treatment. The remaining 30 patients received the same dose and schedule of TU as group I, and were prescribed once-daily tadalafil 5 mg during 30 weeks.

MAIN OUTCOME MEASURES

Serological tests were performed, and the International Index of Erectile Function (IIEF), Aging Males' Symptoms (AMS) questionnaires, and Global Assessment Question (GAQ) were administered to the patients.

RESULTS

Total IIEF and AMS scores were significantly improved during the 30 weeks of treatment in both groups. When IIEF scores were compared between the two groups, group II showed better symptom scores than group I at weeks 6 and 30. A similar pattern was observed when comparing AMS scores between the groups. At week 36, changes in IIEF and AMS scores that indicated worsened symptoms compared with week 30 were observed in both groups; group II showed better symptom scores than group I. On the GAQ, the ratio of patients reporting improvement in erectile function was significantly higher in group II than group I.

CONCLUSIONS

The combination of long-acting injectable TU and once-daily tadalafil 5 mg produced a significant improvement in erectile function. Moreover, the improvement in erectile function was well maintained, even after the cessation of treatment.

Antioxidant Effect and Functional Properties of Hydrolysates Derived from Egg-White Protein

This study utilized commercially available proteolytic enzymes to prepare egg-white protein hydrolysates (EPHs) with different degrees of hydrolysis. The antioxidant effect and functionalities of the resultant products were then investigated. Treatment with Neutrase yielded the most α-amino groups (6.52 mg/mL). Alcalase, Flavourzyme, Protamex, and Ficin showed similar degrees of α-amino group liberation (3.19-3.62 mg/mL). Neutrase treatment also resulted in the highest degree of hydrolysis (23.4%). Alcalase and Ficin treatment resulted in similar degrees of hydrolysis. All hydrolysates, except for the Flavourzyme hydrolysate, had greater radical scavenging activity than the control. The Neutrase hydrolysate showed the highest 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity (IC50=3.6mg/mL). Therefore, Neutrase was identified as the optimal enzyme for hydrolyzing egg-white protein to yield antioxidant peptides. During Neutrase hydrolysis, the reaction rate was rapid over the first 4 h, and then subsequently declined. The IC50 value was lowest after the first hour (2.99 mg/mL). The emulsifying activity index (EAI) of EPH treated with Neutrase decreased, as the pH decreased. The EPH foaming capacity was maximal at pH 3.6, and decreased at an alkaline pH. Digestion resulted in significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activity. The active peptides released from egg-white protein showed antioxidative activities on ABTS and DHHP radical. Thus, this approach may be useful for the preparation of potent antioxidant products.

Association between the GRM7 rs3792452 polymorphism and attention deficit hyperacitiveity disorder in a Korean sample

Background

The purpose of this study was to investigate the association between the ionotropic and glutamate receptors, N-methyl D-asparate 2A (GRIN2A) and 2B (GRIN2B), and the metabotropic glutamate receptor mGluR7 (GRM7) gene polymorphisms and attention-deficit hyperactivity disorder (ADHD) in Korean population.

Methods

We conducted a case–control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test (TDT) on 149 trios, and compared scores from the continuous performance test (CPT), the Children’s Depression Inventory (CDI), and the State-Trait Anxiety Inventory for Children (STAIC) according to the genotype of the glutamate receptor genes.

Results

There were no significant differences in the genotype or allele frequencies of the GRIN2A rs8049651, GRIN2B rs2284411, or GRM7 rs37952452 polymorphisms between the ADHD and control groups. For 148 ADHD trios, the TDT analysis also showed no preferential transmission of the GRIN2A rs8049651 or GRIN2B rs2284411 polymorphisms. However, the TDT analysis of the GRM7 rs3792452 polymorphism showed biased transmission of the G allele (χ2 = 4.67, p = 0.031). In the ADHD probands, the subjects with GG genotype in the GRM7 rs37952452 polymorphism had higher mean T-scores for omission errors on the CPT than did those with the GA or AA genotype (t = 3.38, p = 0.001). In addition, the ADHD subjects who were homozygous for the G allele in the GRM7 rs37952452 polymorphism had higher STAIC-T (t = 5.52, p < 0.001) and STAIC-S (t = 2.74, p = 0.007) scores than did those with the GA or AA genotype.

Conclusions

These results provide preliminary evidence of an association between the GRM7 rs37952452 polymorphism and selective attention deficit and anxiety found within the Korean ADHD population.

Serotonin 2A Receptor Gene Polymorphism in Korean Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

The purpose of this study was to investigate the association between the T102C polymorphism in the serotonin 2A receptor gene and attention-deficit/hyperactivity disorder (ADHD) in Korean patients.

METHODS

A total of 189 Korean children with ADHD as well as both parents of the ADHD children and 150 normal children participated in this study. DNA was extracted from blood samples from all of the subjects, and genotyping was conducted. Based on the allele and genotype information obtained, case-control analyses were performed to compare the ADHD and normal children, and Transmission disequilibrium tests (TDTs) were used for family-based association testing (number of trios=113). Finally, according to the significant finding which was showed in the case-control analyses, the results of behavioral characterastics and neuropsychological test were compared between ADHD children with and without the C allele.

RESULTS

In the case-control analyses, statistically significant differences were detected in the frequencies of genotypes containing the C allele (χ(2)=4.73, p=0.030). In the family-based association study, TDTs failed to detect linkage disequilibrium of the T102C polymorphism associated with ADHD children. In the ADHD children, both the mean reaction time and the standard deviation of the reaction time in the auditory continuous performance test were longer in the group with the C allele compared to the group without the C allele.

CONCLUSION

The results of this study suggest that there is a significant genetic association between the T102C polymorphism in the serotonin 2A receptor gene and ADHD in Korean children.

A one-step electrochemical method for DNA detection that utilizes a peroxidase-mimicking DNAzyme amplified through PCR of target DNA

A novel one-step electrochemical method for DNA detection is described. The procedure utilizes a reaction catalyzed by a peroxidase-mimicking DNAzyme to produce a product, which forms an insoluble precipitation layer on the surface of an electrode. A rationally designed forward primer, conjugated with a peroxidase DNAzyme complementary sequence at its 5'-end, is used for PCR amplification of target DNA. As a result, the DNAzyme sequence is produced by amplification only when the target DNA is present in the sample. The PCR product is then subjected to the precipitation reaction on the electrode surface using an electrolyte assay buffer containing 4-chloronaphthol, hydrogen peroxide, ferrocenemethanol, hemin, and 5'-lambdaexonuclease. Finally, analysis is carried out using Faradaic impedance spectroscopy. The impedance value was found to greatly increase when target DNA is present owing to the formation of a precipitation layer on the electrode surface caused by the catalytic action of the DNAzyme. In contrast, no impedance increase is observed when a control sample not containing target DNA is utilized. By employing this strategy, target DNA from Chlamydia trachomatis was reliably detected within a 10 min period following precipitation without the need for complicated secondary procedures. This effort has led to the development of a highly convenient electrochemical one-step method for DNA detection that utilizes a peroxidase-mimicking DNAzyme, which is specifically designed to undergo amplification during PCR of target DNA.

Genetic Polymorphism of FLG in Korean Ichthyosis Vulgaris Patients

BACKGROUND

Filaggrin is a key protein that facilitates the formation of skin barrier by forming a stratum corneum. Mutations in the gene encoding filaggrin (FLG) have recently been reported in patients with ichthyosis vulgaris (IV). Interestingly, there are ethnic differences between FLG mutations identified in Asians and Europeans, and few FLG mutations are overlapping between Chinese and Japanese IV patients.

OBJECTIVE

The aim of this study was to investigative the genetic polymorphism of FLG in Korean IV patients.

METHODS

Genomic DNA was extracted from whole venous blood specimen of Korean patients with IV and a control group, and the full sequence of FLG was determined via overlapping long-range polymerase chain reaction method.

RESULTS

Analysis of base sequence previously unreported reveal new nonsense mutation p.Y1767X in a Korean IV patient, and additional new single nucleotide polymorphisms.

CONCLUSION

On the basis of this study, it is anticipated that analysis of FLG gene sequence be extended to other dermatoses associated with FLG, such as atopic dermatitis.

Initial biopsy outcome prediction in Korean patients-comparison of a noble web-based Korean prostate cancer risk calculator versus prostate-specific antigen testing

We developed and validated a novel Korean prostate cancer risk calculator (KPCRC) for predicting the probability of a positive initial prostate biopsy in a Korean population. Data were collected from 602 Koreans who underwent initial prostate biopsies due to an increased level of prostate-specific antigen (PSA), a palpable nodule upon digital rectal examination (DRE), or a hypoechoic lesion upon transrectal ultrasound (TRUS). The clinical and laboratory variables were analyzed by simple and multiple logistic regression analysis. The area under the receiver operating characteristic curve (AUC) was computed to compare its performance to PSA testing alone. Prostate cancer was detected in 172 (28.6%) men. Independent predictors included age, DRE findings, PSA level, and prostate transitional zone volume. We developed the KPCRC using these variables. The AUC for the selected model was 0.91, and that of PSA testing alone was 0.83 (P < 0.001). The AUC for the selected model with an additional dataset was 0.79, and that of PSA testing alone was 0.73 (P = 0.004). The calculator is available on the website: http://pcrc.korea.ac.kr. The KPCRC improved the performance of PSA testing alone in predicting the risk of prostate cancer in a Korean population. This calculator would be a practical tool for physicians and patients.

Gender-specific association of the brain-derived neurotrophic factor gene with attention-deficit/hyperactivity disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder with a strong genetic component. Brain-derived neurotrophic factor (BDNF), which participates in the differentiation and survival of dopaminergic and noradrenergic neurons, could play a role in ADHD development. We aimed to explore the relationships between ADHD and BDNF gene polymorphism.

METHODS

We conducted a case-control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test on 151 trios, and compared the results of a continuous performance test (CPT) according to the genotype of the three single nucleotide polymorphisms (rs11030101, rs6265, rs16917204) in the BDNF gene.

RESULTS

In the case-control analysis, the AA genotype of the BDNF rs11030101 polymorphism was significantly associated with ADHD only in girls (p=0.024, odds ratio=3.00). The T-G-G haplotype was significantly less frequent (p=0.005) and A-G-G was more frequent (p=0.048) in girls with ADHD than in control girls (global p=0.027). A multivariate analysis of variance for commission errors on the CPT showed a significant main effect for the rs11030101 genotype (p=0.026) and an interaction effect of the rs11030101 genotype and gender (p=0.032) in ADHD probands.

CONCLUSION

These results provide preliminary evidence for a gender-specific association between BDNF and ADHD in the Korean population.

Neurotrophin-3 gene, intelligence, and selective attention deficit in a Korean sample with attention-deficit/hyperactivity disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder with a strong genetic component. Neurotrophin-3 (NTF3), which participates in the differentiation and survival of dopaminergic and noradrenergic neurons, has been identified as a factor in the development of ADHD. We investigated the relationships between ADHD and NTF3 gene polymorphism.

METHODS

We conducted a case-control analysis of 202 ADHD subjects and 159 controls, performed a transmission disequilibrium test (TDT) on 151 trios, and compared the intelligence quotient (IQ) and a continuous performance test (CPT) according to the genotype of two single-nucleotide polymorphisms (SNPs) (rs6332 and rs6489630) in the NTF3 gene.

RESULTS

In the case-control and family-based analyses, NTF3 was not significantly associated with ADHD. However, in the ADHD probands, the subjects with AA genotype in the rs6332 SNP had significantly higher mean T-scores for commission errors on the CPT than did those with the AG genotypes (p=0.045). The mean IQ of the ADHD probands who had the CC genotype of the rs6489630 SNP were higher compared with those who had the CT or TT genotype (p=0.035). The mean T-score for response time on the CPT was higher in the subjects with TT genotype in the rs6489630 SNP compared to those with the CC or CT genotype, even after adjusting for the effect of IQ (p=0.021).

CONCLUSIONS

These results provide preliminary evidence of an association between NTF3 and the intelligence and selective attention deficit in the Korean population.

The effects of intravesical chemoimmunotherapy with gemcitabine and Bacillus Calmette-Guérin in superficial bladder cancer: a preliminary study

This prospective study investigated the long-term effects of intravesical chemoimmunotherapy with gemcitabine (GEM) and bacillus Calmette-Guérin (BCG; n = 36) versus BCG alone (n = 51) for the treatment of superficial bladder cancer. For the chemoimmunotherapy (GEM + BCG) group, GEM (1000 mg) was instilled immediately after transurethral resection of bladder tumour (TURBT) and again (2000 mg) 1 week later. From 2 to 7 weeks after TURBT, BCG was instilled into the bladder of all patients once weekly. The recurrence-free period of the GEM + BCG group (24.13 months) was significantly longer than that of the BCG monotherapy group (19.81 months). The overall recurrence rate was similar between the groups, although at 6 and 9 months post-TURBT, GEM + BCG produced a significantly lower rate of recurrence compared with BCG alone. This study suggests that intravesical chemoimmunotherapy with GEM + BCG is effective in reducing early tumour recurrence and in prolonging the recurrence-free period of superficial bladder cancer.

Association between homozygosity of a G allele of the alpha-2a-adrenergic receptor gene and methylphenidate response in Korean children and adolescents with attention-deficit/hyperactivity disorder

BACKGROUND

Methylphenidate (MPH) blocks the norepinephrine transporter as well as the dopamine transporter. The alpha-2a-adrenergic receptor is a key component of the noradrenergic system. The aim of this study was to evaluate the association between the ADRA2A -1291 C>G polymorphism and the response to MPH treatment in Korean subjects with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This study enrolled 114 ADHD children (mean age = 9.08 +/- 1.94 years) from a child psychiatric clinic in South Korea. Subjects who had an improvement of >/= 50% compared with the baseline ADHD rating scale (ARS) score or who had a Clinical Global Impression-improvement score of 1 or 2 points after treatment were defined as the "good response". We examined the relationship of the ADRA2A to MPH response.

RESULTS

We found that a good response to MPH treatment, measured by the ARS as assessed by the parents, was observed for 76.9% of the subjects carrying the G/G genotype but for only 46.0% and 41.7% of those with the C/G and C/C genotypes, respectively [chi(2)(2) = 11.929, p = .003]. We also found a significant difference in the change in total ARS scores between subjects with and without the G/G genotype [t(1) = 2.21, p = .029].

CONCLUSIONS

Our findings provide evidence of an association between the ADRA2A -1291 C>G genotype and response to MPH treatment in Korean subjects with ADHD. Nonetheless, the methodological limitation of not being a randomized placebo-controlled trial and primarily basing results on parent report to clinicians suggest that these results should be viewed as more preliminary.

Association between the alpha-2C-adrenergic receptor gene and attention deficit hyperactivity disorder in a Korean sample

Findings from preclinical and clinical research support the involvement of central noradrenergic dysregulation in the etiology of attention deficit hyperactivity disorder (ADHD). Previous studies have suggested that the alpha-2C-adrenergic receptor gene (ADRA2C) is associated with ADHD. The aims of this study were to examine the association between the ADRA2C (GT)n repeat polymorphism (STR marker adra2c1) and ADHD in a Korean sample. In this case-control and family-based association study, we assessed 184 ADHD probands, 150 normal controls, and 98 trios. There were no significant differences in the allele frequencies of the ADRA2C polymorphism between the ADHD and control groups (p > 0.05). The overall allele-wise transmission disequilibrium test (TDT) analysis showed statistical significance (chi2 = 19.07, p = 0.025). We found a trend for preferential transmission of the 183-bp allele (chi2 = 3.72, p = 0.054), and a significantly lower-than-expected rate of transmission of the 187-bp allele (chi2 = 6.26, p = 0.012). With regard to the temperament profiles of the Junior Temperament and Character Inventory (JTCI), the ADHD subjects with the 183/183 genotype at the ADRA2C polymorphism showed a trend toward a lower score in the Novelty Seeking (p = 0.020) profile than did those with the other genotypes. Our findings provide important evidence that the ADRA2C polymorphism is involved in the etiology of ADHD in Korean subjects. In addition, our results provide evidence that the temperament of Novelty Seeking and ADHD might share molecular genetic characteristics related to the noradrenergic system.

A polydiacetylene microchip based on a biotin-streptavidin interaction for the diagnosis of pathogen infections

A micropatterned polydiacetylene (PDA) chip, utilizing the unique fluorogenic property of PDA and a specific biotin-streptavidin (STA) interaction, is constructed to detect pathogen infections. To construct the PDA chip, biotin-modified diacetylene liposomes are immobilized on aldehyde glass and conjugated with STA, followed by UV irradiation to polymerize the STA-functionalized diacetylene liposomes. Genomic DNA of a model pathogen, Chlamydia trachomatis, is isolated from human samples and biotin-labeled target DNA is obtained through PCR amplification using biotin-11-dUTP. Owing to the stimulus caused by the biotin-STA interaction, the biotinylated DNA induces an intense fluorescence signal on the immobilized PDA. By using this strategy, it is possible to diagnose Chlamydia infections by applying DNA samples from several nonhealthy humans to a single PDA chip. The results of this study serve as the basis for a new strategy for fluorogenic PDA microarray-based diagnosis of pathogen infections.

No evidence of an association between norepinephrine transporter gene polymorphisms and attention deficit hyperactivity disorder: a family-based and case-control association study in a Korean sample

Neurobiological and pharmacological research has suggested that dysregulation of the central noradrenergic systems might be involved in the pathophysiology of attention deficit hyperactivity disorder (ADHD). Previous studies have demonstrated that the norepinephrine transporter gene (SLC6A2) is associated with ADHD. The aims of this study were to examine the association of the SLC6A2 G1287A and -3081(A/T) polymorphisms with ADHD in Korean children and adolescents, and to determine the relationships of the genotypes of these two polymorphisms with continuous performance test results and the Junior Temperament and Character Inventory profiles of ADHD. In a case-control study, we assessed 186 ADHD probands and 150 normal controls; 109 trios were studied in a family-based association analysis. There were no significant differences in the genotype or allele frequencies of the SLC6A2 G1287A and -3081(A/T) polymorphisms between the ADHD and control groups (p > 0.05). In the transmission disequilibrium test analyses, there was no evidence for biased transmission of any of the alleles of the SLC6A2 G1287A and -3081(A/T) polymorphisms. In the haplotype analyses of these two polymorphisms, the global and individual chi(2) tests showed no significant associations between any of the haplotypes and ADHD. There were no significant differences with respect to the continuous performance test results and the Junior Temperament and Character Inventory profiles in the ADHD probands according to the genotypes of the SLC6A2 G1287A and -3081(A/T) polymorphisms. Our findings do not support SLC6A2 as a major genetic susceptibility factor in ADHD.

Possible association of the alpha-2A-adrenergic receptor gene with response time variability in attention deficit hyperactivity disorder

Previous studies have demonstrated that the MspI and DraI polymorphisms at the alpha-2A-adrenergic receptor gene (ADRA2A) are associated with ADHD. However, few studies have been designed to ascertain the association between the ADRA2A genotypes and the performance on neurocognitive measures in ADHD. The aims of this study were to examine the association of the ADRA2A MspI and DraI polymorphisms with ADHD in Korean subjects, and to determine the relationship between the genotypes of these two polymorphisms and the candidate endophenotypes, as measured by the continuous performance test (CPT). In a case-control study, we assessed 186 ADHD probands and 150 normal controls. One hundred eight trios were studied in a family based association analysis. The transmission disequilibrium test (TDT) analysis showed preferential transmission of the C allele of the DraI polymorphism (chi(2) = 5.88, P = 0.015). In the haplotype analyses, a trend of over-transmission of haplotype C/C was observed (chi(2) = 3.80, P = 0.051). The homozygous subjects for the C allele (C/C genotype) at the DraI polymorphism showed a trend toward a higher mean T-score with respect to the response time variability profiles of the CPT than did those with the other genotypes (C/T + T/T genotypes; P = 0.042). The homozygous subjects for the G allele (G/G genotype) at the MspI polymorphism showed a tendency to have a lower mean T-score with respect to the response time variability profiles of the CPT (P = 0.068). The results of this study provide important evidence for the involvement of the ADRA2A MspI and DraI polymorphisms in the etiology of ADHD in Korean subjects. In addition, our results provide evidence for the possible role of these two polymorphisms in ADHD symptom expression, such as increased response time variability.

PHEX gene mutations and genotype-phenotype analysis of Korean patients with hypophosphatemic rickets

X-linked hypophosphatemic rickets (XLH) results from mutations in the PHEX gene. Mutational analysis of the PHEX gene in 15 unrelated Korean patients with hypophosphatemic rickets revealed eight mutations, including five novel mutations, in nine patients: two nonsense mutations, two missense mutations, one insertion, and three splicing acceptor/donor site mutations. Of these, c.64G>T, c.1699C>T, c.466_467 insAC, c.1174-1G>A, and c.1768+5G>A were novel mutations. To analyze the correlation between genotype and phenotype, phenotypes were compared between groups with and without a mutation, in terms of mutation location, mutation type, and sex. Skeletal disease tended to be more severe in the group with a mutation in the C-terminal half of the PHEX gene, but no genotype-phenotype correlation was detected in other comparisons. Further extensive studies of the PHEX gene mutations and analyses of the genotype-phenotype relationships are required to understand PHEX function and the pathogenesis of XLH.

Tryptophan hydroxylase and serotonin transporter gene polymorphism does not affect the diagnosis, clinical features and treatment outcome of panic disorder in the Korean population

Panic disorder may be associated with defective serotonin (5-HT) neurotransmission. This study was to investigate the association between the tryptophan hydroxylase (TPH) gene and a serotonin transporter gene promoter polymorphism (5-HTTLPR), with panic disorder in a Korean population. 244 Korean patients with panic disorder and the 227 controls were genotyped by a polymerase chain reaction-based method. The severity of panic disorders was assessed by number of panic attacks during the previous 1 month, as well as scores for anticipatory anxiety, panic distress, and agoraphobic distress, as determined by a visual analogue scale (VAS). All the subjects completed the assessment measures including Spielberger State-Trait Anxiety Inventory-State (STAI-S), Spielberger State-Trait Anxiety Inventory-Trait (STAI-T), Beck Depression Inventory (BDI), Symptom Checklist-90-Revised (SCL-90-R), Revised Anxiety Sensitivity Index (ASI-R), Clinical Global Impression Scale--Severity of Illness (CGI-S), Panic Disorder Severity Scale (PDSS), and the Hamilton Depression Rating Scale (HAMD). Responder analyses were conducted based on changes in CGI-I scores after 10 weeks of treatment. We found no significant differences in the genotype and allele frequencies in TPH A218C and 5-HTTLPR polymorphisms between the panic patients and the control group. Subgroup analyses in terms of comorbidities, response, and other primary clinical variables, indicated no differences in these polymorphisms. Our findings suggest that the TPH A218C polymorphism and 5-HTTLPR play no significant roles in the pathogenesis and clinical symptomatologies, at least in a Korean population.

BRCA1 and BRCA2 germline mutations in Korean breast cancer patients at high risk of carrying mutations

We analyzed the mutation spectrum of BRCA1 and BRCA2 genes in 354 Korean breast cancer patients. Overall, 40 patients carried 25 distinct BRCA1/2 mutations including 12 novel mutations. Seven district mutations were found in multiple unrelated patients, with the BRCA2 c.7480C>T mutation detected in eight unrelated patients, accounting for 50% of the mutations detected in BRCA2. The large number (25/40, 62.5%) of recurrent mutations suggests the possibility of developing a simple screening test for these mutations. The frequency of mutations was related to the number and kinds of risk factors, varying from 10.4 to 25% in the five major risk factor groups. The frequency of BRCA mutations in patients with two or more risk factors was markedly higher than that in patients with one risk factor.

Array-based mutation detection of BRCA1 using direct probe/target hybridization

We describe here an efficient microarray-based multiplex assay to detect Korean-specific mutations in breast cancer susceptibility gene BRCA1 using direct probe/target hybridization. Allele-specific oligonucleotides were covalently immobilized on an aldehyde-activated glass slide to prepare an oligonucleotide chip. From a wild-type sample, a two-step method was used to generate labeled multiplex polymerase chain reaction (PCR) amplification products of genomic regions containing the mutation sites. Amino allyl-dUTP, an amine-modified nucleotide, was incorporated during multiplex PCR amplifications and a monofunctional form of cyanine 3 dye was subsequently attached to the reactive amine group of the PCR products. Hybridization of the labeled PCR products to the oligonucleotide chip successfully identified all of the genotypes for the selected mutation sites. This work demonstrates that oligonucleotides chip-based analysis is a good candidate for efficient clinical testing for BRCA1 mutations when combined with the indirect strategy to prepare labeled target samples.

Thiopurine S-methyltransferase polymorphisms and the relationship between the mutant alleles and the adverse effects in systemic lupus erythematosus patients taking azathioprine

OBJECTIVE

The present study sought to elucidate the genetic basis of thiopurine methyltransferase (TPMT) polymorphism and subsequently to investigate the relationship between mutant TPMT and an adverse response observed in Korean patients with systemic lupus erythematosus (SLE) taking azathioprine (AZA).

METHODS

The TPMT genotype of 342 patients with SLE was determined by MALDI-TOF mass spectrometry and correlated with the effects of clinical exposure to AZA.

RESULTS

TPMT polymorphism was detected in 17 of the 342 study subjects (5.0%), 12 heterozygous for the TPMT*3C allele and 5 heterozygous for the TPMT*6 allele. Numerous patients taking AZA demonstrated adverse drug responses. Severe nausea occurred in 4 patients with the TPMT*3C allele, while 1 patient with the TPMT*6 allele suffered severe bone marrow toxicity. Leucopenia (n = 17), nausea (n = 4), and abnormal liver function (n = 1) were suspected in 23 of the 94 lupus patients taking AZA. AZA was relatively well tolerated by the remainder of the patients. The heterozygous genotype for the TPMT*3C and *6 alleles was frequently detected in Korean SLE patients.

CONCLUSION

Contrary to previous hypotheses, this study identified no statistical correlation between TPMT genotype and AZA toxicity. We thus conclude that TMPT genotyping cannot replace regular blood monitoring in SLE patients receiving AZA treatment.

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

Drought-inducible-but ABA-independent-thaumatin-like protein from carrot (Daucus carota L.)

Drought treatment induces the accumulation of dcTLP, which is similar in structure to the thaumatin-like proteins (TLPs) found in the embryogenic calli, seedlings, and mature plants of carrot (Daucus carota). We isolated a full-length dcTLP cDNA clone from carrot and characterized the 5' upstream sequences. The coding region of dcTLP consisted of 645 nucleotides; the theoretical pI value was 4.9, and its molecular weight was approximately 22 kDa. The production of dcTLP transcripts in the seedlings increased dramatically with dehydration treatment but was not affected by abscisic acid (ABA), salicylic acid, or jasmonic acid. The expression patterns of dcTLP mRNA at different developmental stages and in response to a variety of signal molecules was analyzed using reverse transcriptase-PCR and promoter analysis with fused genes of 0.5-kb 5' upstream sequences in which beta-glucuronidase (GUS) reporter genes (gus) were established. The induction of dcTLP was found to be highly specific to drought stress in the embryogenic calli, seedlings, and mature plants. Our results suggest that this new isoform of TLP that has been isolated from carrot is a drought-specific, ABA-independent, non-organ-specific, and non-developmental-stage-specific protein.

Genetic Polymorphisms of Selected DNA Repair Genes, Estrogen and Progesterone Receptor Status, and Breast Cancer Risk

PURPOSE

Genetic polymorphisms of DNA repair genes seem to determine the DNA repair capacity, which in turn may affect the risk of breast cancer. To evaluate the role of genetic polymorphisms of DNA repair genes in breast cancer, we conducted a hospital-based case-control study of Korean women.

EXPERIMENTAL DESIGN

We included 872 incident breast cancer cases and 671 controls recruited from several teaching hospitals in Seoul from 1995 to 2002. Twelve loci of selected DNA repair genes were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (XRCC2 Arg188His, XRCC4 921G > T, XRCC6 1796G > T, LIG4 1977T/C, RAD51 135G > C, 172G > T, RAD52 2259C > T, LIG1 551A > C, ERCC1 8092A > C, 354C > T, hMLH1 -93G > A, and Ile219Val).

RESULTS

We found that the RAD52 2259 CT or TT, hMLH1 -93 GG, and ERCC1 8092 AA genotypes were associated with breast cancer risk after adjustment for known risk factors [odds ratio (OR), 1.33; 95% confidence interval (95% CI), 1.02-1.75; OR, 1.31; 95% CI, 0.99-1.74; and OR, 0.58; 95% CI, 0.38-0.89, respectively]. When Bonferroni's method was used to correct for multiple comparisons for nine polymorphisms with P = 0.005, all of these associations were not significant. However, the effects of RAD52 2259 CT or TT and ERCC1 354 CT or TT genotypes were more evident for the estrogen/progesterone receptor-negative cases (OR, 2.03; 95% CI, 1.24-3.34 and OR, 1.99; 95% CI, 1.35-2.94, respectively).

CONCLUSION

Our findings suggest that genetic polymorphisms of RAD52, ERCC1, and hMLH1 may be associated with breast cancer risk in Korean women.