Functional variants in the low-density lipoprotein receptor gene are associated with clear cell renal cell carcinoma susceptibility.

Recent studies indicate that abnormal levels of low-density lipoprotein (LDL), which is an important component of dyslipidaemia, are associated with alterations to cancer risk, including that of renal cell carcinoma (RCC). Single nucleotide polymorphisms at microRNA-binding sites contribute to cancer susceptibility and progression by affecting the messenger RNA (mRNA) function of target genes. In this case-control study, we examined the frequency of six potentially functional single nucleotide polymorphisms in the LDL receptor gene (LDLR) in 1004 clear cell RCC (ccRCC) patients and 1065 cancer-free subjects. Logistic regression analyses estimated odds ratios (ORs) and 95% confidence intervals (CIs). The association between genetic variants and levels of LDLR mRNA and protein was also evaluated. Compared with the CC genotype, multivariate logistic regression analysis showed that the LDLR rs2738464 variant GG genotype was associated with a significantly decreased ccRCC risk (P = 0.002, OR: 0.605, 95% CI: 0.439-0.833). Further functional experiments showed that the rs2738464 variant G allele affected miR-330 regulation of the LDLR 3'-untranslated region (UTR), increasing LDLR mRNA levels in patient kidney tissues. These findings suggest that LDLR rs2738464 may affect the affinity of miR-330 binding to the LDLR 3'-UTR, thus regulating LDLR expression and contributing to ccRCC risk.

Genetic variations in the mTOR gene contribute toward gastric adenocarcinoma susceptibility in an Eastern Chinese population.

BACKGROUND AND AIM: Genetic variants in the mammalian target of rapamycin (mTOR) gene have become an interesting topic for the study of genetic susceptibility to cancer, but their associations with the risk of gastric cancer have not been fully investigated. MATERIALS AND METHODS: In a hospital-based case-control study of 1002 gastric cancer patients and 1003 cancer-free controls, we genotyped four potentially functional single nucleotide polymorphisms (SNPs) (rs1034528G>C, rs17036508T>C, rs3806317A>G, and rs2295080T>G) of mTOR and assessed their associations with the risk of gastric cancer using univariate and multivariate logistic regression analyses. We also used the multifactorial dimension reduction analysis to explore possible interactions and the false-positive report probabilities to assess significant findings. RESULTS: We found that rs1034528 CG/CC and rs3806317 GA/GG variant genotypes were associated with an increased risk of gastric cancer under a dominant model (adjusted odds ratio=1.27 and 1.22, respectively). In the combined analysis of all four SNPs under investigation, patients with 3-4 risk genotypes of mTOR had a significantly increased risk of gastric cancer (adjusted odds ratio=1.46, 95% confidence interval=1.19-1.79) compared with those with 0-2 risk genotypes. Stratified analysis indicated that this risk was more pronounced in subgroups of men, never-smokers, never-drinkers, and clinical stages III+IV. The multifactorial dimension reduction analysis suggested some evidence of interactions between the combined genotypes and other risk factors for gastric cancer. CONCLUSION: These findings suggest that potentially functional SNPs of mTOR may individually or collectively contribute to the risk of gastric cancer. Larger studies with diverse ethnic populations are warranted to validate our findings.

Access to Piperazine-Fused Pyrrolocarbazoles Enabled by Acid-Catalyzed Stereoselective Hydroarylation of Ynamide-Indoles and Subsequent Diels-Alder Reactions/Aromatizations.

Pyrrolocarbazole skeletons are well known to possess a variety of biological activities that might be therapeutically useful in the treatment of cancers. Herein, an acid-catalyzed stereoselective hydroarylation/Diels-Alder cycloaddition/aromatization of ynamide-indoles is described. We newly designed and synthesized a variety of piperazine-fused pyrrolocarbazole derivatives that could be further applied to the synthesis of potent Wee1 inhibitors.

Rhodium(III)-Catalyzed Intramolecular Cyclization and Sequential Aromatization of Ynamides with Propargyl Esters: Access to 2,5-Dihydropyrroles and Pyrroles.

Disclosed herein is a rhodium(III)-catalyzed intramolecular cyclization of ynamides with propargyl esters. A variety of highly functionalized 2,5-dihydropyrroles were obtained in moderate to good yields with high E/Z selectivities. Subsequent oxidation of the products gave valuable pyrrole derivatives. Additionally, scale-up reactions and late-stage derivatizations highlight the potential synthetic utility of this methodology.

Associations of Lys939Gln and Ala499Val polymorphisms of the XPC gene with cancer susceptibility: a meta-analysis.

XPC polymorphisms may alter DNA repair capacity, thus leading to genetic instability and carcinogenesis. Numerous studies have investigated the associations of XPC Lys939Gln (rs2228001) and Ala499Val (rs2228000) polymorphisms with cancer susceptibility; however, the findings are inconclusive. We searched literature from MEDLINE and EMBASE for eligible publications that assessed the associations between these two polymorphisms and cancer risk. We also assessed genotype-mRNA expression correlation data from HapMap for rs2228001 and rs2228000 in normal cell lines derived from 270 subjects with different ethnicities. The final analysis included 62 published studies of 25,708 cases and 30,432 controls for the Lys939Gln and 34 studies with 14,877 cases and 17,888 controls for the Ala499Val. Overall, Lys939Gln was significantly associated with an increased overall cancer risk (Gln/Gln vs. Lys/Lys: OR = 1.16, 95% CI = 1.07 - 1.25, p < 0.001; recessive model: OR = 1.14, 95% CI = 1.06 - 1.22, p < 0.001; dominant model: OR = 1.06, 95% CI = 1.01 - 1.11, p = 0.015 and Gln vs. Lys: OR = 1.07, 95% CI = 1.03 - 1.10, p < 0.001) and further stratifications showed an increased risk for bladder, lung and colorectal cancer, Asian populations and population-based studies. Likewise, Ala499Val was also significantly associated with an increased overall cancer risk (Val/Val vs. Ala/Ala: OR = 1.21, 95% CI = 1.07 - 1.36, p = 0.003 and recessive model: OR = 1.20, 95% CI = 1.08 - 1.34, p = 0.001) and further stratification showed an increased risk for breast and bladder cancer, particularly in Asian populations. Interestingly, significantly correlation between XPC genotypes and mRNA expression was found only for Asian populations as well. Despite some limitations, this meta-analysis established some solid statistical evidence for an association between XPC polymorphisms and cancer risk, which warrants further validation in single large studies.

Genetic variations of mTORC1 genes and risk of gastric cancer in an Eastern Chinese population.

Mammalian target of rapamycin complex 1 (mTORC1) plays an important role in maintaining proper cellular functions, and genetic variations in this complex may affect cancer risk. In this study, we examined the associations between eight potential functional single nucleotide polymorphisms in the mTORC1 genes (rs2536T>C and rs1883965G>A for mTOR, rs3160T>C, and rs26865A>G for mLST8, rs3751934C>A, rs1062935T>C, rs3751932T>C, and rs12602885G>A for Raptor, not included in published gastric cancer genome-wide association studies) and gastric cancer risk in 1125 gastric cancer cases and 1196 cancer-free controls. We performed conditional logistic regression and multifactor dimensionality reduction (MDR) analyses to assess their associations with gastric cancer risk. We also used false-positive report probabilities (FPRP) for assessing significant findings. We found that only the rs1883965A variant genotypes were associated with an increased risk of gastric cancer (AG vs. GG: adjusted odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.00-1.59; AA vs. GG: adjusted OR = 1.85, 95% CI = 0.67-5.16 and dominant model: adjusted OR = 1.28, 95% CI = 1.03-1.61). Patients with ≥1 risk genotypes of mTOR had significant increased risk (adjusted OR = 1.25, 95% CI = 1.04-1.49), compared with those having zero risk genotypes. In the stratified analysis, the risk effect of the rs1883965 AG/AA genotypes was evident in subgroups of ever-smokers, non-gastric cardia adenocarcinoma and clinical stage I + II, which were noteworthy findings as evaluated by FPRP. The MDR analysis identified smoking status and rs1883965 as the strongest two-factors for gastric cancer risk. These data support the hypothesis that functional polymorphisms of mTOR may contribute to gastric cancer risk. Clearly, our results require validation in larger studies with different ethnic populations.

Rhodium(III)-catalyzed intermolecular [3+3] annulation of benzoxazines with quinone compounds: access to spiro-heterocyclic scaffolds.

A rhodium(III)-catalyzed redox-neutral spiroannulation approach to access the spiro[benzo[b][1,4]oxazine-benzo[c]chromene skeleton is described in this contribution. A variety of spiro[5.5]-heterocyclic scaffolds were obtained in moderate to excellent yields under mild conditions. Key features of this protocol are good substrate scope, silver-free conditions, low catalyst loadings, easy handling under air and 100% atom economy. Furthermore, scale-up reactions and late-stage derivatizations highlight the potential synthetic utility of this methodology.

Polymorphisms in the XPG gene and risk of gastric cancer in Chinese populations.

DNA repair genes play an important role in maintaining stability and integrity of genomic DNA. Polymorphisms in nucleotide excision repair genes may cause variations in DNA repair capacity phenotype and thus contribute to cancer risk. In this case-control study of 1,125 gastric cancer cases and 1,196 cancer-free controls, we investigated the association between three functional single nucleotide polymorphisms (SNPs, rs2296147T > C, rs2094258C > T and rs873601G > A) in the xeroderma pigmentosum group G (XPG) gene and gastric cancer risk. We used the Taqman assays to genotype these three SNPs and logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that only the rs873601A variant genotypes were associated with a significant higher risk for gastric adenocarcinoma (adjusted OR = 1.30, 95% CI = 1.03-1.64 for AA vs. GG and adjusted OR = 1.23, 95% CI = 1.01-1.49 for AA vs. GG/AG). Stratification analysis indicated that this risk was more pronounced in subgroups of older age (>59 years), males, ever-smokers, and patients with NGCA. All these were not found for the other two SNPs (rs2296147T > C and rs2094258C > T). We then performed expression analysis using gastric cancer adjacent normal tissues from 141 patients and found that the A variant allele was associated with non-significantly reduced expression of XPG mRNA (P(trend) = 0.107). Further analysis using mRNA expression data from the HapMap suggested that the A allele was associated with significantly reduced expression of XPG mRNA in normal cell lines for 45 Chinese (P(trend) = 0.003) as well as for 261 subjects with different ethnicities (P(trend) = 0.001). These support the hypothesis that functional XPG variants may contribute to the risk of gastric cancer. Larger studies with different ethnic populations are warranted to validate our findings.

[Human chromosome 8p11 (CHRNB3-CHRNA6) region gene polymorphisms and susceptibility to lung cancer in Chinese Han population].

To investigate the association between chromosome 8p11 (CHRNB3-CHRNA6) polymorphisms and lung cancer susceptibility in Chinese Han population, we genotyped 6 tag SNPs variants of this region among 784 patients with lung cancer and 782 age- and sex-matched cancer-free control participants to screen for any risk-associated SNPs. The results revealed that rs16891561 TT genotype had a protective effect against lung cancer in people over 60 years old (adjusted OR=0.42, 95% CI=0.20-0.88; P=0.022), female groups (adjusted OR=0.34, 95% CI=0.13-0.87; P=0.025), and non-smoking people (adjusted OR=0.32, 95% CI=0.13-079; P=0.013). Additionally, rs4236926 TT genotype had a protective effect against lung cancer in people over 60 years old (adjusted OR=0.48, 95% CI=0.23-0.99; P=0.048) and non-smoking people (adjusted OR=0.32, 95% CI=0.13-0.80; P=0.014). According to pathological type of lung cancer, these two SNPs were associated with adenocarcinomas susceptibility. As to cumulative effect of rs4236926 and rs16891561, in non-smokers strata, lung cancer risk was significantly reduced in those who had 3-4 mutant alleles (adjusted OR=0.29, 95% CI=0.11-0.71; P=0.007). Furthermore, people containing 3-4 mutant alleles had lower level of smoking doses (mean pack-year=13.2) compared with others. In conclusion, 8p11 (CHRNB3-CHRNA6) polymorphisms are related to smoking behavior and lung cancer susceptibility in Chinese Han population.

Association between two functional polymorphisms of insulin-like growth factor binding protein 3 and colorectal cancer risk in a Chinese population.

Circulating levels of insulin-like growth factor binding protein 3 (IGFBP3) are modulated by functional variants of IGFBP3 and therefore may be associated with higher risk of colorectal cancer development. However, few studies have investigated the role of IGFBP3 polymorphisms in colorectal cancer in Chinese individuals. In this study, two common polymorphisms of IGFBP3 were determined by the Taqman genotyping platform in 202 Chinese colorectal cancer cases diagnosed between 2006 and 2008 and 212 cancer-free population controls. Data showed that the genotype distribution of G2133C (rs2864746), but not A-202C (rs2864744), was significantly different between cancer cases and controls. Unconditional logistic regression analyses revealed that participants carrying the G2133C GC heterozygote or CC homozygote had a significant 1.55-fold increased risk of colorectal cancer development in an allele dose-responsive manner. However, there was no evidence of a dose-effect relationship between number of variants and risk for CRC occurrence. Data suggest that the exon 1 G2133C missense variant of IGFBP3 may be a susceptibility factor for colorectal cancer in Chinese subjects. Larger studies are warranted to validate our findings in a Chinese population.

Inhibition of lipid peroxidation and protein oxidation in rat liver mitochondria by curcumin and its analogues.

Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, 1) is a yellow ingredient isolated from turmeric (curcumin longa). It has been shown to exhibit a variety of biological activities including antioxidative activity. In order to find more active antioxidants with 1 as the lead compound we synthesized curcumin analogues, i.e., 1-(3,4-dihydroxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (2), 1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione (3), 1,7-bis-(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione (4), 1-(3,4-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (5), 1,7-bis(3,4-dimethoxyphenyl)-1,6-heptadiene-3,5-dione (6), and 1,7-diphenyl-1,6-heptadiene-3,5-dione (7), and evaluated their antioxidative activity. The in vitro oxidative damage to both lipids and proteins in rat liver mitochondria was used as a model to study the free radical-induced oxidative damage of biological lipids as well as proteins and the protective effects of these curcumin analogues. It was found that these compounds, except 6 and 7, could effectively inhibit the free radical induced lipid peroxidation and protein oxidative damage of rat liver mitochondria by H-atom abstraction from the phenolic groups. Compound 2 which bear ortho-diphenoxyl functionality exhibited remarkably higher antioxidative activity for lipids and proteins than curcumin and other analogues, and the 4-hydroxy-3-methoxyphenyl group also play an important role in the antioxidative activity.

Association between delta-aminolevulinic acid dehydratase (ALAD) polymorphism and blood lead levels: a meta-regression analysis.

A meta-regression analysis was undertaken to evaluate the association between delta-aminolevulinic acid dehydratase (ALAD) genotypes and blood lead levels obtained from data published in various journals. In total, 15 studies were included in the final analysis. Both fixed effects and random effects models were used to undertake the pooled analysis. Using a fixed effects model, pooled estimates of mean differences of various ALAD genotypes was significant at 0.61 microg/dl. Using a random effects model, the pooled estimate was also significant at 1.51 microg/dl. Data indicated that certain ALAD genotypes may affect the susceptibility of humans to lead.

Functional polymorphisms of JWA gene are associated with risk of bladder cancer.

The JWA gene is a novel cell differentiation-related gene thought to be a responsive gene in response to DNA damage and repair induced by environmental stressors. Recently, a novel single nucleotide polymorphism (SNP) was identified in the promoter of the JWA gene (-76GC) that may alter the transcription activity and thus play a role in increased risk of bladder cancer. Further, studies were conducted to screen for more novel variants in the JWA exons by using PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) followed by PCR-RFLP (PCR restriction fragment length polymorphism) methods. Finally, the functional relevance of the newly identified genetic variants in a hospital-based case-control study of 215 bladder cancer patients and 250 cancer-free controls was evaluated. In addition to the -76GC polymorphism, another novel SNP (454CA in exon2 and 723TG in exon 3) of JWA was identified. The -76GC allele and genotype frequencies were found to vary in different ethnic groups. The -76C allele and 454A allele were both associated with significantly increased risk of bladder cancer. In contrast, the 723GG genotype was associated with a decreased risk of bladder cancer. Furthermore, -76C and 454A together increased the risk of bladder caner using haplotype and stratification analysis. In conclusion, the three novel functional genetic polymorphisms of JWA gene, -76GC, 454CA, and 723TG, appear to contribute to the etiology of bladder cancer.

Identification and functional characterization of JWA polymorphisms and their association with risk of gastric cancer and esophageal squamous cell carcinoma in a Chinese population.

Recently, a novel single nucleotide polymorphism (SNP) in the promoter of the JWA gene (-76G --> C) was identified that may alter the transcription activity and thus play a role in increased risk of bladder cancer. In this study, a screen for more novel variants in the JWA exons was undertaken by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) followed by a PCR-restriction fragment length polymorphism (PCR-RFLP) method and evaluating the functions of newl identified JWA -76G --> C using the reporter gene assay. In addition to the -76G --> C polymorphism, another novel SNP (723T --> G) in exon 3 of JWA was identified. In a case-control study of these two SNPs in 413 gastric cancer and 250 esophageal squamous-cell carcinoma (ESCC) patients and 814 cancer-free controls in a Chinese population, data showed that both SNPs were associated with enhanced risk of these cancers. The reporter gene assay showed that the -76C variant allele lost its response to benzo[a]pyrene (BaP) exposure, compared to the -76G allele. In addition, the JWA -76C allele was found to be associated with increased gastric and esophageal cancer risks in this study population. Further studies are needed to substantiate the biological significance and related mechanisms underlying the associations.

HLA-DM polymorphism and risk of trichloroethylene induced medicamentosa-like dermatitis.

OBJECTIVE: To establish the association between genetic polymorphisms of HLA-DMA and HLA-DMB and risk of developing trichloroethylene-induced medicamentosa-like dermatitis (TIMLD). METHODS: Sixty-one cases were medically confirmed to have been affected with TIMLD and 60 controls were selected from exposed workers who were free from TIMLD. The TIMLD cases and controls were similar in terms of age, sex, and duration of exposure. DNA was extracted both from the TIMLD cases and controls, HLA-DMA and HLA-DMB loci were amplified by using Touchdown PCR, and the alleles and genotypes were confirmed by restriction fragment length polymorphism (RFLP) and direct sequencing. Finally, the frequencies of HLA-DMA and HLA-DMB variants were compared between the two groups. RESULTS: The results showed that the frequency of HLA-DMA*0101 and HLA-DMB*0103 alleles was significantly increased in TIMLD patients than in controls (71.3% vs. 55.0% for HLA-DMA*0101; P<0.05) (11.5% vs. 3.3% for HLA-DMB*0103; P<0.05). In addition, the frequency of HLA-DMA*0102-*0102 homozygous genotype was also significantly higher in the controls than in the patients (25.0% vs. 8.2%, P<0.05), whereas the frequency of heterozygous HLA-DMB *0101-*0102 genotype was lower in the patients in comparison with the controls. Conclusion The polymorphisms of HLA-DM may be associated with the susceptibility to TIMLD.

Is there a dose-dependent effect of genetic susceptibility loci for gastric cancer on prognosis of the patients?

Literature suggests that genetic variants associated with increased susceptibility to gastric cancer (GCa) are mostly located in genes involved in carcinogenesis and possibly tumor progression. Therefore, we hypothesize that high genetic susceptibility is also associated with prognosis of the patients. To test this hypothesis, we selected a total of 42 common genetic variants that were reportedly associated with GCa risk with a high level of evidence obtained from either genome-wide association studies (GWASs) or meta-analyses and performed survival analysis of patients used in a case-control analysis. We first used 1115 GCa cases and 1172 cancer-free controls of ethnic Han Chinese to construct a weighted genetic risk score (GRS). Then, we included 633 GCa cases with available clinical information, fit GRS in a fractional polynomial Cox proportional hazards regression model to investigate whether there is a dose-dependent effect of GRS on risk of death in survival analysis. Dynamic predictive value of genetic risk for prognosis was also calculated. The results showed that the increase of GRS had no effect on risk of death in these GCa patients. Compared with GCa patients with the medium GRS, there was no significant difference in survival in patients with either a low (P = 0.349) or a high (P = 0.847) GRS. The results unchanged when data were stratified by tumor stage and Lauren's classification. Time-dependent predictive value for prognosis in considering both clinical factors and GRS was comparable with that in considering clinical factors alone, for either all patients (P = 0.986) or stage- and Laruen type-based subgroups (P > 0.05 for all). In conclusion, higher polygenic susceptibility loci for GCa may not indicate worse prognosis of Chinese patients. Additional variants of relevant genes modulating GCa patients' survival need to be further identified.

MDM4 genetic variants and risk of gastric cancer in an Eastern Chinese population.

MDM4 is a p53-interacting protein and plays an important role in carcinogenesis. In this study of 1,077 gastric cancer (GCa) cases and 1,173 matched cancer-free controls, we investigated associations between three tagging single nucleotide polymorphisms (SNPs) (rs11801299 G>A, rs1380576 C>G and rs10900598 G>T) in MDM4 and gastric cancer risk in an Eastern Chinese Population. In logistic regression analysis, a significantly decreased GCa risk was associated with the rs1380576 GG variant genotype (adjusted odds ratio [OR] =0.74, 95% confidence interval [CI] =0.56-0.98) under a recessive model, which remained significant after correction by the false-positive reporting probability. This risk was more evident in subgroups of older subjects, males, never smokers, never drinkers and cancers of non-cardia. We then performed SNP-mRNA expression correlation analysis and found that the GG variant genotype was associated with significantly decreased expression of MDM4 mRNA in normal cell lines for 44 Chinese (P=0.032 for GG vs. CC) as well as for 269 multi-ethnic subjects (P<0.0001 for GG vs. CC). Our results suggest that the MDM4 rs1380576 G variant may be markers for GCa susceptibility. Larger, independent studies are warranted to validate our findings.

DNA damage induced by resveratrol and its synthetic analogues in the presence of Cu (II) ions: mechanism and structure-activity relationship.

The prooxidant effect of resveratrol (3,5,4'-trihydroxy-trans-stibene) and its synthetic analogues (ArOH), that is, 3,4,4'-trihydroxy-trans-stibene (3,4,4'-THS), 3,4,5-trihydroxy-trans-stibene (3,4,5-THS), 3,4-dihydroxy-trans-stibene (3,4-DHS), 4,4'-dihydroxy-trans-stibene (4,4'-DHS), 2,4-dihydroxy-trans-stilbene (2,4-DHS), 3,5-dihydroxy-trans-stilbene (3,5-DHS) and 3,5,4'-trimethoxy-trans-stibene (3,5,4'-TMS), on supercoiled pBR322 plasmid DNA strand breakage and calf thymus DNA damage in the presence of Cu (II) ions has been studied. It was found that the compounds bearing ortho-dihydroxyl groups (3,4-DHS, 3,4,4'-THS, and 3,4,5-THS) or bearing 4-hydroxyl groups (2,4-DHS, 4,4'-DHS, and resveratrol) exhibit remarkably higher activity in the DNA damage than the ones bearing no such functionalities. Kinetic analysis by UV-visible spectra demonstrates that the formation of ArOH-Cu (II) complexes, the stabilization of oxidative intermediate derived from ArOH and Cu (II)/Cu (I) redox cycles, might be responsible for the DNA damage. This study also reveals a good correlation between antioxidant and prooxidant activity, as well as cytotoxicity against human leukemia (HL-60 and Jurkat) cell lines. The mechanisms and implications of these observations are discussed.

Characterization of 67 kD laminin receptor, a protein whose gene is overexpressed on treatment of cells with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide.

The molecular mechanisms potentially related to tumorigenesis induced by anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) were investigated by suppression subtractive hybridization of the human bronchial epithelial cells (16HBE) carcinoma induced by BPDE-transformed 16HBE cells (16HBE-C). The 67 kD laminin receptor gene (67LR1) is one of the screened overexpressed genes in 16HBE-C cells when compared with 16HBE. In order to understand the main functions of 67LR1 gene, we amplified the full length of 67LR1 gene using reverse transcription-polymerase chain reaction (RT-PCR) method. The amplified gene products were inserted into pcDNA 3.1 Directional TOPO expression vector. We then transfected 16HBE cells with this vector and derived stable transfected 16HBE cell lines containing the 67LR1 gene by using lipofectin and G418 selection protocols. The expression products of transfected genes were analyzed by semiquantitative RT-PCR. Soft agar growth assay was carried out to identify the malignant features of 67LR1 gene. The stable transfected cell lines can form colonies in soft agar. Further, the transfected cells showed morphological changes compared to the control cells, such as the obvious pseudopods. These data suggest that the 67LR1 gene may be related to malignant transformation induced by the anti-BPDE. The 67LR1 protein may be related to the directionality of cell movement.

Effects of Brn-3a protein and RNA expression in rat brain following low-level lead exposure during development on spatial learning and memory.

The developing nervous system is preferentially vulnerable to lead exposure with alterations in neuronal and glial cells of the brain. Chronic exposure to lead (Pb2+) causes deficits of learning and memory in children and spatial learning deficits in developing rats. Brn-3a is a member of the Pit-Oct-Unc (POU) family of transcription factors that is expressed predominantly in neuronal cells. It exists in two forms, with the long form containing 84 amino acids at the N-terminus that are lacking in the short form. The N-terminal domain unique to the long form induces expression of the Bcl-2 gene and protects neuronal cells against apoptosis whereas the C-terminal POU domain common to both forms is sufficient for activating a number of other neuronally expressed genes and stimulating neuronal process outgrowth. We examined Brn-3a protein and RNA expression in rat brain following low-level lead exposure during development and subsequent effects on spatial learning and memory. Two groups of rats were investigated: a control group and a lead-exposed group (0.2% lead acetate in the drinking water of the dam from gestational day 15 to postnatal day 21). Levels of Brn-3a were measured in rat cortex, hippocampus and cerebellum by immunohistochemistry and in situ hybridization, both protein and mRNA levels were reduced in lead-exposed group (p < 0.05). In Morris water maze, we found spatial learning deficits in rats of lead-exposed group (p < 0.05). These data suggest that the alteration of Brn-3a may play a key role in the mechanisms underlying lead neurotoxicity.