Yong Zhu

University of Texas MD Anderson Cancer Center, Houston, TX, USA

Are you Yong Zhu?

Claim your profile

Publications (14)85.94 Total impact

  • Article: Functional polymorphisms of circadian positive feedback regulation genes and clinical outcome of Chinese patients with resected colorectal cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Previous studies have demonstrated that circadian genes play a role in the development and progression of many cancers. This study aims to assess the effects of single nucleotide polymorphisms (SNPs) in circadian genes on recurrence and survival of colorectal cancer (CRC) patients. Nine functional SNPs in 3 genes (CLOCK, NPAS2, and BMAL1) on the circadian positive feedback loop were selected and genotyped using the Sequenom iPLEX genotyping system in a cohort of 411 resected Chinese CRC patients. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the prognosis analysis. The authors identified 2 SNPs in the CLOCK gene to be significantly associated with CRC overall survival. SNP rs3749474 exhibited a significant association with survival of CRC patients in the additive model (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.37-0.81; P = .003). In addition, patients carrying the heterozygous variant of rs1801260 had significantly increased overall survival compared with those carrying homozygous wild-type genotype (HR, 0.31; 95% CI, 0.11-0.88; P = .03). Findings from functional assay provided further biological support for these significant associations. Stratified analysis found no modifying effect of chemotherapy on the prognostic significance of both SNPs. Moreover, we observed cumulative effects of these 2 SNPs on CRC overall survival (P for trend = .01). Compared with patients carrying no unfavorable genotypes, those carrying 2 unfavorable genotypes had a 2.92-fold increased risk of death (P = .03). The results suggest for the first time that CLOCK gene polymorphisms may serve as an independent prognostic marker for CRC patients.
    Cancer 07/2011; 118(4):937-46. · 4.77 Impact Factor
  • Article: Evaluation of genetic variants in microRNA-related genes and risk of bladder cancer.
    [show abstract] [hide abstract]
    ABSTRACT: MicroRNAs (miRNA) are small noncoding RNA molecules involved in a diversity of cellular functions. Although it has been reported that global suppression of the miRNA biogenesis pathway leads to enhanced tumorigenesis, the effect of common genetic variants of miRNA-related genes on cancer predisposition is unclear. To better understand this effect, we genotyped 41 single-nucleotide polymorphisms (SNP) from 24 miRNA-related genes in a case-control study conducted in 746 Caucasian patients with bladder cancer and 746 matched controls. The homozygous variant genotype of a nonsynonymous SNP in the GEMIN3 gene (rs197414) was associated with a significantly increased bladder cancer risk [odds ratios (OR), 2.40; 95% confidence interval (95% CI), 1.04-5.56]. Several additional miRNA-related SNPs were also identified that showed a borderline significant association with bladder cancer risk. Haplotype analysis indicated that a common haplotype of the GEMIN4 gene was associated with a significantly increased bladder cancer risk with an OR of 1.25 (95% CI, 1.01-1.54). To assess the aggregate effects of the promising SNPs, we performed a combined unfavorable genotype analysis that included all SNPs showing at least a borderline statistical significance. We found that, compared with the low-risk reference group with less than two unfavorable genotypes, the medium-risk group with two unfavorable genotypes exhibited a 1.29-fold (0.92-1.81) increased risk whereas the high-risk group with more than two unfavorable genotypes exhibited a 1.92-fold (1.36-2.71) increased risk (P(trend) < 0.0001). Overall, this is the first epidemiologic study showing that miRNA-related genetic variants may affect bladder cancer risk individually and jointly.
    Cancer Research 05/2008; 68(7):2530-7. · 7.86 Impact Factor
  • Article: Differential induction in telomerase activity among bladder cancer patients and controls on gamma-radiation.
    [show abstract] [hide abstract]
    ABSTRACT: Expression of telomerase is one of the hallmarks of tumor cells and has been used as a diagnostic biomarker and a therapeutic target in cancer. Novel findings have shown that telomerase activation in normal human epithelial cells may affect expression of several cancer-related genes, such as growth-related genes and c-myc gene, suggesting a possible role of telomerase in tumor initiation. Therefore, we hypothesized that individuals who are sensitive to mutagen challenge in terms of induced telomerase activity might have increased cancer risk. We tested this hypothesis in a bladder cancer case-control study (51 cases and 51 matched controls) by measuring baseline and gamma-radiation-induced telomerase activities in peripheral blood lymphocytes. We found a significantly higher gamma-radiation-induced telomerase activity in bladder cancer cases compared with the controls (1.34 versus 1.23; P = 0.044). A similar finding was also observed using the normalized telomerase activity (ratio of gamma-radiation induced versus baseline; 1.49 versus 1.19; P < 0.001). In further categorizing the telomerase activity using 75% of the normalized value in the controls as a cutoff point, we found a significantly increased risk for bladder cancer associated with higher induced telomerase activity (adjusted odds ratio, 3.62; 95% confidence interval, 1.38-9.51). In quartile analysis, a dose-response association was noted between the induced telomerase activity and increased bladder cancer risk (P(trend) = 0.005). Our findings provide the first evidence linking the mutagen-induced telomerase activity in peripheral blood lymphocytes to the risk of bladder cancer, which warrants further investigation in large-sized studies and other cancer types.
    Cancer Epidemiology Biomarkers &amp Prevention 04/2007; 16(3):606-9. · 4.12 Impact Factor
  • Article: Nucleotide excision repair gene polymorphisms and recurrence after treatment for superficial bladder cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Interindividual differences in DNA repair capacity not only modify individual susceptibility to carcinogenesis, but also affect individual response to cancer treatment. Nucleotide excision repair (NER) is one of the major DNA repair pathways in mammalian cells involved in the removal of a wide variety of DNA lesions. Polymorphisms in NER genes may influence DNA repair capacity and affect clinical outcome of bladder cancer treatment. To test the influence of NER gene polymorphisms on superficial bladder cancer outcome (recurrence and progression), we conducted a follow-up study of 288 patients with superficial bladder cancer. Median follow-up among patients who were recurrence-free at the end of observation was 21.7 months from diagnosis. The specific polymorphic loci examined include XPA [A/G at 5' untranslated region (UTR)], XPC (poly AT, Ala(499)Val, Lys(939)Gln), XPD (Asp(312)Asn, Lys(751)Gln), XPG (His(1104)Asp), ERCC 1 (G/T at 3' UTR), and ERCC6 (Met(1097)Val, Arg(1230)Pro). The ERCC6 (Met(1097)Val) polymorphism had a significant impact on recurrence: carriers of at least one variant allele (Val) had a significantly higher recurrence risk than carriers of the wild-type allele (Met/Met; hazard ratio, 1.54; 95% confidence interval, 1.02-2.33). There were no overall statistically significant differences in the distributions of the other polymorphisms between patients with and without recurrence. However, when we combined these variant genotypes, there was a significant trend for an increased recurrence risk with an increasing number of putative high-risk alleles. Using individuals with five or fewer putative high-risk alleles as the reference group, individuals with six to seven risk alleles and individuals with eight or more risk alleles had higher recurrence risks, with hazard ratios of 0.92 (0.54-1.57) and 2.53 (1.48-4.30), respectively (P for trend < 0.001). There was also a significant trend for shorter recurrence-free survival time with increasing number of variant alleles (log rank test, P = 0.0007). When we stratified the patients according to intravesical Bacillus Calmette-Guerin treatment, we found a significant trend for shorter recurrence-free survival time in patients with variant alleles of XPA or ERCC6 polymorphisms who received Bacillus Calmette-Guerin treatment (log rank test, P = 0.078 and 0.022, respectively). There were no significant individual or joint associations between these polymorphisms and progression. These data suggest that interindividual differences in DNA repair capacity may have an important impact on superficial bladder cancer recurrence. A pathway-based approach is preferred to study the effects of individual polymorphism on clinical outcomes.
    Clinical Cancer Research 03/2005; 11(4):1408-15. · 7.74 Impact Factor
  • Article: Benzo[a]pyrene diol epoxide-induced 9p21 aberrations associated with genetic predisposition to bladder cancer.
    [show abstract] [hide abstract]
    ABSTRACT: CDKN2A, 9p21, encodes two alternatively spiked, functionally distinct, tumor-suppressor proteins, P16INK4A and P14ARF, which play active roles in the RB1 and TP53 pathways, respectively. Deletion of 9p is one of the most frequent genomic alterations in bladder cancer. In addition, alterations of 9p21 and P16 are frequently seen in the epithelial cells of chronic smokers. This pilot study evaluated whether 9p21 aberrations induced by exposure in vitro to benzo[a]pyrene diol epoxide (BPDE), the metabolic product of benzo[a]pyrene, a constituent of tobacco smoke, were more common in the peripheral blood lymphocytes of 61 bladder cancer patients compared to 64 matched controls. Our hypothesis was that 9p21 sensitivity to BPDE reflects the susceptibility of a specific locus to damage from carcinogens in tobacco smoke. We found that BPDE-induced chromosome band 9p21 aberrations were significantly higher in lymphocytes of bladder cancer cases (24.97 +/- 5.26 per 1,000) than in controls (20.72 +/- 4.51 per 1,000; P < 0.0001). However, no difference was observed for CEP9, a control locus. After adjustment for age, sex, ethnicity, and smoking status, 9p BPDE sensitivity had an odds ratio (OR) of 9.01 [95% confidence interval (95% CI) 3.75, 21.67] for bladder cancer. We further observed a gradient of elevated bladder cancer risk associated with increasing chromosomal damage. The adjusted ORs for subjects in the second, third, and highest quartiles of BPDE-induced 9p21 aberrations relative to the first quartile were 0.48 (0.04, 5.69), 5.14 (1.12, 23.59), and 21.51 (4.75, 97.34), respectively, providing increasing dose-response evidence of the locus-specific alterations. Thus, 9p21 may be a molecular target for BPDE-induced damage in bladder cancer cases.
    Genes Chromosomes and Cancer 12/2004; 41(4):330-8. · 3.31 Impact Factor
  • Article: Methyl-CpG-binding domain 2: a protective role in bladder carcinoma.
    [show abstract] [hide abstract]
    ABSTRACT: MBD2, a methyl-CpG-binding domain 2 protein, has attracted much attention because of its role in epigenetic regulation of gene expression. In addition to transcriptional repression, MBD2 has also been shown to catalyze demethylation by directly removing methyl groups from 5-methylcytosine residues in DNA. Although the demethylase activity of MBD2 remains controversial, reduction of MBD2 messenger RNA expression has been observed in various tumor tissue types. In the current case-control study, the authors investigated the association between MBD2 expression and bladder carcinoma risk. RNA was isolated from the peripheral blood lymphocytes of 98 bladder carcinoma case patients and 135 frequency-matched control patients. MBD2 expression was measured by real-time quantitative reverse transcription-polymerase chain reaction assays. Overall, there was a significantly reduced risk associated with high levels of MBD2 expression (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.21-0.90). This relation was maintained when the data were categorized according to quartile distribution for MBD2 expression (P for trend < 0.05). It is noteworthy that the protective effects were more apparent in women (OR, 0.25; 95% CI, 0.06-1.02) compared with men (OR, 0.58; 95%; CI, 0.24-1.42), in older individuals (OR, 0.12; 95% CI, 0.03-0.45) compared with younger individuals (OR, 1.16; 95% CI, 0.40-3.33), and in heavier smokers (OR, 0.40; 95% CI, 0.18-0.93) compared with lighter smokers (OR, 0.71; 95% CI, 0.18-2.86). Although the underlying molecular mechanisms remain unclear, the data obtained in the current study represent the first evidence demonstrating a protective role against bladder carcinoma risk for MBD2. MBD2 expression may prevent age-related, gender-related, and smoking-induced hypermethylation, which are predisposing factors for tumor development.
    Cancer 05/2004; 100(9):1853-8. · 4.77 Impact Factor
  • Source
    Article: An evolutionary perspective on single-nucleotide polymorphism screening in molecular cancer epidemiology.
    [show abstract] [hide abstract]
    ABSTRACT: Given that there are millions of single-nucleotide polymorphisms (SNPs) in the entire human genome, a major difficulty faced by scientists in planning costly population-based genotyping is to choose target SNPs that are most likely to affect phenotypic functions and ultimately contribute to disease development. Although it is widely accepted that sequences with important functionality tend to be less variable across species because of selective pressure, to what extent evolutionary conservation is mirrored by epidemiological outcome has never been demonstrated. In this study, we surveyed odds ratios detected for 46 SNPs in 39 different cancer-related genes from 166 molecular epidemiological studies. The conservation levels of amino acid that these SNPs affected were calculated as a tolerance index by comparing sequences from different species. Our results provide evidence of a significant relationship between the detected odds ratios associated with cancer risk and the conservation levels of the SNP-affected amino acids (P = 0.002; R(2) = 0.06). Tolerance indices were further calculated for 355 nonsynonymous SNPs identified in 90 human DNA repair genes, of which 103 caused amino acid changes in very conserved positions. Our findings support the concept that SNPs altering the conserved amino acids are more likely to be associated with cancer susceptibility. Using such a molecular evolutionary approach may hold great promise for prioritizing SNPs to be genotyped in future molecular epidemiological studies.
    Cancer Research 04/2004; 64(6):2251-7. · 7.86 Impact Factor
  • Article: From genotype to phenotype: correlating XRCC1 polymorphisms with mutagen sensitivity.
    [show abstract] [hide abstract]
    ABSTRACT: This study correlated the extent of induced in vitro chromosomal damage, assessed by the mutagen sensitivity assay, with genotypes of the X-ray repair cross complementing group 1 (XRCC1) gene, which encodes for a base excision repair protein. There are two common polymorphisms that cause amino acid substitutions in XRCC1, one at codon 194 in exon 6 and another at codon 399 in exon 10. We genotyped these two polymorphisms in 524 healthy subjects and performed mutagen sensitivity assays using both bleomycin and benzo[a]pyrene-diol-epoxide (BPDE) as challenge mutagens. Our results showed that individuals with the wildtype exon 6 Arg/Arg exhibited significantly higher values of chromosomal breaks per cell (b/c) than those with one or two variant Trp alleles (P=0.005 for bleomycin and P=0.05 for BPDE). For the exon 10 polymorphism, subjects who were Gln/Gln homozygotes had higher b/c than did those with other genotypes, with evidence of a gene dosage effect. When we combined the two polymorphic sites and used the exon 6 Arg/Trp and Trp/Trp and exon 10 Arg/Arg genotypes as the reference category, these differences were enhanced for bleomycin sensitivity (P for trend = 0.032), but not for BPDE sensitivity (P for trend = 0.821). These data are biologically plausible since codon 399 is located within the BRCA1 C-terminus functional domain and codon 194 is in the linker region of the XRCC1 N-terminal functional domain. To our knowledge, this is the largest study conducted evaluating the functional relevance of these polymorphisms.
    DNA Repair 09/2003; 2(8):901-8. · 4.14 Impact Factor
  • Article: Telomere dysfunction: a potential cancer predisposition factor.
    [show abstract] [hide abstract]
    ABSTRACT: Genetic instability associated with telomere dysfunction (i.e., short telomeres) is an early event in tumorigenesis. We investigated the association between telomere length and cancer risk in four ongoing case-control studies. All studies had equal numbers of case patients and matched control subjects (92 for head and neck cancer, 135 for bladder cancer, 54 for lung cancer, and 32 for renal cell carcinoma). Telomere length was measured in peripheral blood lymphocytes from study participants. Genetic instability was assessed with the comet assay. Patient and disease characteristics were collected and analyzed for associations with risk for these cancers. All statistical tests were two-sided. Telomeres were statistically significantly shorter in patients with head and neck cancer (6.5 kilobases [kb]) than in control subjects (7.4 kb) (difference = 0.9 kb, 95% confidence interval [CI] = 0.5 to 1.2 kb; P<.001). Nine percent of patients with head and neck cancer were in the longest quartile of telomere length, whereas 59% were in the shortest quartile. Similar patterns were observed for lung, renal cell, and bladder cancer. When subjects were categorized into telomere length quartiles defined by the distribution in control subjects, the following inverse relationship between telomere length and cancer risk was observed: adjusted odds ratios [ORs] for decreasing quartiles = 0.84 (95% CI = 0.36 to 1.97), 1.77 (95% CI = 0.72 to 4.36), and 5.11 (95% CI = 1.90 to 13.77). In stratified analysis, we found a suggestive greater-than-additive interaction between smoking status and telomere length: for ever smokers with short telomeres, OR = 25.05 (95% CI = 6.91 to 90.73); for never smokers with short telomeres, OR = 6.18 (95% CI = 1.72 to 22.13); and for ever smokers with long telomeres, OR = 6.49 (95% CI = 1.54 to 27.38). Telomere length was statistically significantly and inversely associated with baseline and mutagen-induced genetic instability. Short telomeres appear to be associated with increased risks for human bladder, head and neck, lung, and renal cell cancers.
    CancerSpectrum Knowledge Environment 08/2003; 95(16):1211-8. · 14.07 Impact Factor
  • Article: Death receptor 4 and bladder cancer risk.
    [show abstract] [hide abstract]
    ABSTRACT: Tumor necrosis factor-related apoptosis-inducing ligand stimulates the extrinsic apoptoticpathway by binding to death receptors 4 (DR4) and 5 (DR5). In DR4 exon 4, a C-->G polymorphism at amino acid 626 located immediately 3' to one of the main receptor ligand interface regions, results in a threonine-->arginine change. We found that the DR4 exon 4 G/G genotype was associated with an overall decreased risk of bladder cancer in Caucasians [odds ratio (OR) = 0.58; 95% confidence interval (CI), 0.38-0.88]. This protective effect was more apparent in younger individuals (OR = 0.42; 95% CI, 0.20-0.87) than in older individuals (OR = 0.60; 95% CI, 0.35-1.02) and in women (OR = 0.45; 95% CI, 0.20-0.99) than in men (OR = 0.60; 95% CI, 0.36-0.99). Moreover, the protective effect was greater for light smokers (OR = 0.19; 95% CI, 0.06-0.59) compared with heavy smokers (OR = 0.83; 95% CI, 0.41-1.69). These data provide the first large-scale molecular epidemiological evidence that the DR4 polymorphism is associated with environmental exposure and bladder cancer risk, possibly through modulating the capacity of the receptor ligand complex to engage the apoptotic pathway.
    Cancer Research 03/2003; 63(6):1157-9. · 7.86 Impact Factor
  • Article: A case-control analysis of lymphocytic chromosome 9 aberrations in lung cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Cytogenetic aberrations on chromosome 9 have been reported to be one of the most frequent genetic changes in lung tumorigenesis. Although many of these changes have been detected in lung carcinoma specimens, there is growing evidence showing the concordance between chromosomal alterations in primary lung tumors and peripheral blood lymphocytes (PBLs). We investigated whether spontaneous aberrations on chromosome 9 in PBLs are associated with the presence of lung cancer and with a family history of cancer. A personal interview, to construct a detailed epidemiologic profile including family history of cancer, was conducted on 174 lung cancer cases and 162 matched controls. One hundred metaphases from PBLs of each subject were analyzed for chromosome 9 aberrations using the whole chromosome painting technique. Overall, the mean proportion of individuals with chromosome 9 abnormalities in their PBLs was significantly higher in cases (96.0%) than in controls (60.5%) (p < 0.05). After adjustment by age, gender, ethnicity, family size, and pack-years, there was a 16.63-fold significantly elevated odds ratio (OR) for lung cancer associated with chromosome 9 aberrations. When subjects were categorized by frequencies of the chromosome 9 lesions, we observed significantly increased odds ratios of 11.13 (4.66, 26.58) and 27.45 (11.15, 67.54) for individuals with 1 chromosome 9 aberration and >/=2 chromosome 9 aberrations, respectively. By performing family history analyses, we further observed that control individuals with chromosome 9 aberrations were more likely to report a family history of any cancer (OR = 1.67 [0.84, 3.32]) and lung cancer (OR = 2.49 [0.81, 7.67]). Our findings suggest that chromosome 9 aberrations in PBLs might be considered a marker of lung cancer predisposition and may be associated with familial aggregation of cancer.
    International Journal of Cancer 12/2002; 102(5):536-40. · 5.44 Impact Factor
  • Article: BPDE-induced lymphocytic 3p21.3 aberrations may predict head and neck carcinoma risk.
    [show abstract] [hide abstract]
    ABSTRACT: Tobacco exposure is an established risk factor for head and neck squamous cell carcinoma (HNSCC). Benzo[alpha]pyrene diol expoxide (BPDE), a main metabolic product of the tobacco smoke constituent benzo[alpha]pyrene, induces chromosomal aberrations at specific loci. Chromosomal aberrations in peripheral blood lymphocytes (PBLs) induced by BPDE may reflect individuals' genetic susceptibility to tobacco carcinogens. This study was designed to detect BPDE-induced aberrations in PBLs at locus 3p21.3 in cultured lymphocytic cells. Our hypothesis is that the presence of BPDE-induced 3p21.3 aberrations is a biomarker of an individual's genetic susceptibility and that individuals with these aberrations are at an increased risk for HNSCC. PBL cultures from 52 cases and 54 controls were treated with 2 microM BPDE for 24 hours before the 3p21.3 aberrations were assessed by fluorescence in situ hybridization. One thousand lymphocyte interphases were scored for each sample. We found that BPDE-induced chromosome 3p21.3 aberrations occurred more frequently in cases (mean: 31.4 per 1000 cells) than in controls (mean: 22.1 per 1000 cells; P < 0.001). However, when 6q27 was selected as a control locus, no such difference was observed (P = 0.545). When the 75th percentile value of induced aberrations in the controls was used as a cutoff point to classify 3p21.3 BPDE-induced sensitivity, 30 of the 52 cases (57.69%) and only 14 of the 54 controls (25.93%) were sensitive to BPDE exposure. This approach resulted in an odds ratio of 4.8 (95% confidence interval: 1.87-12.28) for HNSCC risk associated with BPDE-induced 3p21.3 aberrations. There was also a dose-response relationship between the number of BPDE-induced aberrations at 3p21.3 and risk for HNSCC. The results from this study demonstrated that 3p21.3 may be a specific molecular target of tobacco carcinogens and that BPDE sensitivity at this locus may reflect an individual's genetic susceptibility to HNSCC.
    Cancer 09/2002; 95(3):563-8. · 4.77 Impact Factor
  • Article: Genetic instability of specific chromosomes associated with a family history of cancer.
    [show abstract] [hide abstract]
    ABSTRACT: This study evaluated the association between family history of cancer and bleomycin-induced mutagen breaks at specific chromosomes. The authors' hypothesis was that individuals exhibiting mutagen-induced specific chromatid breaks might have genetic instability and thus be more likely to report a family history of cancer. The study included 78 healthy individuals. All subjects completed a personal interview to collect epidemiologic information, including a detailed family history of cancer, and donated a 10-mL blood sample. Bleomycin-induced mutagen sensitivity on specific chromosomes was quantified by counting the bleomycin-induced specific chromosomal breaks with Q-banding techniques. We found that chromosome 4 breaks were significantly associated with a positive family history of cancer in first-degree relatives with an odds ratio of 3.18 and 95% confidence interval of 1.05-9.61. However, none of the other chromosomes showed significantly increased risk with family cancer history. In addition, the mutagen-induced chromosome 4 breaks were not associated with age, sex, ethnicity, or smoking status. These findings suggested that chromosome 4 mutagen sensitivity might be a predictor of familial susceptibility to cancer.
    Cancer Genetics and Cytogenetics 08/2002; 136(1):73-7. · 1.39 Impact Factor
  • Article: Chromosome instability in lymphocytes: a potential indicator of predisposition to oral premalignant lesions.
    [show abstract] [hide abstract]
    ABSTRACT: Oral premalignant lesions (OPLs) are related to tobacco use and mark individuals at high risk for oral cancer development. Increased mutagen sensitivity as measured by an in vitro mutagen challenge assay has been shown to be a risk factor for upper aerodigestive tract cancers. In this case control study, we used two assays with mutagens relevant to tobacco exposure (benzo[a]pyrene diol epoxide (BPDE) and bleomycin) to see whether sensitivity to these mutagens could be used as biomarkers for assessing risk of premalignant lesions. Furthermore, we evaluated whether 3p21.3 is a molecular target of BPDE damage in lymphocytes of patients with OPLs. There were 82 patients with OPLs and 89 healthy controls frequency matched to the cases on age, sex, ethnicity, and smoking status. These subjects' lymphocytes were treated in two separate experiments with either 2 microM BPDE for 24 h or 0.03 units/ml bleomycin for 5 h, and the frequency of induced chromatid breakage in Giemsa-stained preparations was determined. BPDE-induced 3p21.3 aberrations were scored by fluorescent in situ hybridization technique in 1000 interphases/sample. We found that the mean BPDE-induced chromatid breaks per cell were higher in cases than controls (1.05 +/- 0.40 and 0.55 +/- 0.27, respectively; P < 0.01). Similar results were evident with bleomycin-induced chromatid breaks per cell (0.78 +/- 0.37 and 0.57 +/- 0.31, respectively; P < 0.01). After adjusting for age, sex, ethnicity, and smoking status, significantly elevated odds ratios (95% confidence interval) for OPL risk were noted for BPDE sensitivity [12.96 (5.51, 30.46)] and bleomycin sensitivity [3.33 (1.64, 6.77)]. When subjects were categorized into quartiles of the number of breaks per cell, a dose response was observed for both assays. The adjusted odds ratios for subjects with increasing numbers of breaks per cell in quartiles were 2.34, 9.14, and 54.04 for BPDE sensitivity and 1.92, 3.33, and 7.15 for bleomycin sensitivity, respectively. Subjects sensitive to both mutagens had a 50-fold increased risk for OPLs. In addition, there were significantly more BPDE-induced chromosome aberrations at the 3p21.3 locus in cases (51.13/1000) than in controls (40.93/1000; P < 0.0001). However, no such difference was observed for 3q13, a control locus. BPDE-induced 3p21.3 aberrations were associated with an elevated risk for OPLs of 6.08 (2.57, 14.4). The degree of BPDE sensitivity at 3p21.3 and risk for OPLs increased in a dose-dependent manner. In summary, BDPE sensitivity and bleomycin sensitivity appear to be individually and jointly associated with elevated risk of OPLs. Furthermore, 3p21.3 may be a molecular target of BPDE in OPLs. This is the first study to examine mutagen sensitivity in a premalignant condition. The next step is to correlate these findings in surrogate (lymphocyte) tissue with molecular events in the target tissue.
    Cancer Research 05/2002; 62(10):2813-8. · 7.86 Impact Factor