The DRD2 TaqI-B polymorphism and its relationship to smoking abstinence and withdrawal symptoms.

The dopamine receptor D2 (DRD2) gene has polymorphisms that have been linked to regulation of the dopamine system and to an increased prevalence of smoking. The present study examined the relationship of the DRD2 TaqI-A and -B polymorphisms with short-term clinical outcome (abstinence and withdrawal symptoms), collected from daily (14 pre-quit and 42 post-quit) diary data among smokers (n=116) treated with the nicotine patch plus either venlafaxine or placebo. The results showed that B1/B1 or B1/B2 smokers were slightly less likely to be abstinent on a given day than those homozygous for the TaqI-B2 allele. Significant DRD2 TaqI-B x time interactions were found for several of the withdrawal scales, indicating that those smokers with the B1/B1 or B1/B2 genotypes tended to report more symptoms over time compared to those with the B2/B2 genotype. No interactions or main effects were found for the DRD2 TaqI-A polymorphism. The findings demonstrate that smokers homozygous for the TaqI-B2 allele experience progressive improvement in self-reported withdrawal symptoms while smokers with the TaqI-B1 allele showing little change.

Gamma-radiation-induced G2 delay, apoptosis, and p53 response as potential susceptibility markers for lung cancer.

Gamma-radiation results in cell cycle arrest and apoptosis in a wide variety of cells. Cell cycle arrest provides time for the cell to repair damaged DNA before entering the next phase of the cycle. If the damage is severe and cannot be repaired, the cells undergo apoptosis. However, if the damaged cells continue to grow without repair or apoptosis, then carcinogenic transformation may occur. We hypothesized that individuals with inherited disruption in cell cycle control and/or apoptosis and/or DNA repair may be susceptible to lung cancer development. The cells from susceptible individuals would have a shorter G2 period and less apoptosis compared with cells from normal individuals upon exposure to gamma-radiation. To test this hypothesis, the following methods were used: (a) fluorescence-activated cell sorting method was used to measure apoptosis and G2 cell cycle delay; (b) the ELISA method was used to measure p53 protein expression levels in these cell lines; and (c) gamma-radiation-induced chromatid breaks were counted as a marker for DNA damage or repair. Next, gamma-radiation-induced G2 delay and apoptosis were tested in three lymphoblastoid cell lines to determine the dose response effect and optimal time points of gamma-radiation. Finally, these assays were tested in lymphoblastoid cell lines from 30 lung cancer patients and 22 healthy controls. We found a dose-response relationship for gamma-radiation-induced G2 delay and apoptosis. The optimal time points to detect differential G2 delay and apoptotic index were 10 h and 48 h after gamma-radiation, respectively. The mean G2 delay was 22.5% +/- 10.5% for the control cell lines and 14.71% +/- 8.8% for case cell lines (P < 0.01). The mean apoptotic index was 20.4% +/- 11.7% for the controls and 14.3% +/- 7.8% for the cases (P < 0.05). The controls had a significantly higher p53 response ratio and fewer chromatid breaks than the cases. We also found that a p53 increasing ratio was strongly related to cell cycle G2 delay (gamma = 0.413; P = 0.002) and chromatid breaks (gamma =0.384; P = 0.028). Therefore, we concluded that gamma-radiation-induced G2 delay, apoptosis, p53 increasing ratio, and chromatid breaks might potentially be used as susceptibility markers for lung cancer risk. A large epidemiology study is in progress to confirm these findings.

Germline BRCA1-2 mutations in non-Ashkenazi families with double primary breast and ovarian cancer.

OBJECTIVE: Ashkenazi women with double primary breast and ovarian cancer have a high prevalence (57%) of germline Jewish founder mutations in the BRCA1 (185delAG, 5382insC) and BRCA2 (6174delT) genes. The purpose of this study was to determine the frequency and type of BRCA1-2 mutations in non-Ashkenazi families with at least one member having double primary breast and ovarian cancer. METHODS: Women at increased risk for cancer based upon their family history were enrolled at the University of Texas Southwestern Familial Cancer Registry between 1992 and 2000. Blood samples from patients desiring genetic testing were sent for complete DNA sequencing of the BRCA1 and BRCA2 genes. Families with a member having both breast and ovarian cancer were identified and clinical data were obtained. RESULTS: Sixty-two (7%) of 900 enrolled families were non-Ashkenazi and had at least one member with double primary breast and ovarian cancer. Twenty-one families had members who underwent genetic testing; 41 did not. Thirteen (62%) families had a germline BRCA1 (n = 11) or BRCA2 (n = 2) mutation; only one Jewish founder mutation (185delAG) was detected. Eight (38%) families tested negative. Six (86%) of seven women undergoing genetic testing who themselves had double primary breast and ovarian cancer were BRCA1-2 mutation carriers. CONCLUSIONS: Germline BRCA1-2 mutations are common in non-Ashkenazi families with a member having double primary breast and ovarian cancer. These mutations occurred throughout both genes, emphasizing the need for comprehensive sequencing. One family had the BRCA2 6985delCT mutation, which lies beyond the "ovarian cancer cluster" region.

Searching for microsatellite mutations in coding regions in lung, breast, ovarian and colorectal cancers.

RepX represents a new informatics approach to probe the UniGene database for potentially polymorphic repeat sequences in the open reading frame (ORF) of genes, 56% of which were found to be actually polymorphic. We now have performed mutational analysis of 17 such sites in genes not found to be polymorphic (<0.03 frequency) in a large panel of human cancer genomic DNAs derived from 31 lung, 21 breast, seven ovarian, 21 (13 microsatellite instability (MSI)+ and eight MSI-) colorectal cancer cell lines. In the lung, breast and ovarian tumor DNAs we found no mutations (<0.03-0.04 rate of tumor associated open reading frame mutations) in these sequences. By contrast, 18 MSI+ colorectal cancers (13 cancer cell lines and five primary tumors) with mismatch repair defects exhibited six mutations in three of the 17 genes (SREBP-2, TAN-1, GR6) (P<0.000003 compared to all other cancers tested). We conclude that coding region microsatellite alterations are rare in lung, breast, ovarian carcinomas and MSI (-) colorectal cancers, but are relatively frequent in MSI (+) colorectal cancers with mismatch repair deficits.

Cardiovascular risk factors in young adult survivors of childhood acute lymphoblastic leukemia.

PURPOSE: To assess cardiovascular risk factors (CVRF) in young adult survivors of childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Twenty-six subjects (median age, 20.9 years; median interval since completion of therapy, 13.3 years) were evaluated. Ten participants had received cranial irradiation (CRT), whereas 16 had received only chemotherapy. Primary outcome measures included body mass index (BMI), blood pressure, fasting lipoprotein, glucose, and insulin levels. Secondary measures included insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 levels, physical activity index, a 7-day dietary recall, tobacco product use, and measurement of the intima-media thickness (IMT) of the common carotid artery. RESULTS: Sixty-two percent (16/26) of participants had at least one CVRF potentially related to their cancer treatment (obesity, dyslipidemia, increased blood pressure, or insulin resistance), with 30% (7/26) having more than two CVRF. Thirty-one percent (8/26) of subjects were obese (BMI > or = 30). Subjects who were treated with CRT (BMI, 30.4 +/- 6.7) had an increased BMI (P = 0.039) in comparison with those who received only chemotherapy (BMI, 25.4 +/- 5.1). Triglyceride and very low-density lipoprotein C levels were significantly higher in those treated with CRT (P = 0.027 and 0.022, respectively). The IGF-1 was inversely correlated with IMT (total group, -0.514, P = 0.009; females only, -0.729, P = 0.003). CONCLUSIONS: Young adult survivors of childhood ALL, especially those treated with CRT, are at risk for obesity and dyslipidemia, insulin resistance, hypertension, and cardiovascular disease. Further investigation of these risks is warranted.

Providing primary care for long-term survivors of childhood acute lymphoblastic leukemia.

Primary care physicians will be providing longitudinal health care for long-term survivors of childhood acute lymphoblastic leukemia (ALL) with increasing frequency. Late effects (sequelae) secondary to treatment with radiation or chemotherapeutic agents are frequent and may be serious. Depending on treatment exposures, this at-risk population may experience life-threatening late effects, such as cirrhosis secondary to hepatitis C or late-onset anthracycline-induced cardiomyopathy, or life-changing late effects, such as cognitive dysfunction. Many survivors of childhood ALL will develop problems such as obesity and osteopenia at a young age, which will significantly affect their risk for serious health outcomes as they grow older. The goal of our review is to assist primary care physicians in providing longitudinal health care for long-term survivors of childhood ALL. We also highlight areas needing further investigation, including the prevalence of different late effects, determination of risk factors associated with a late effect, a better understanding of the potential impact of late effects on the premature development of common adult health problems, and the value and timing of different tests for screening asymptomatic survivors.

Two identical triplet sisters carrying a germline BRCA1 gene mutation acquire very similar breast cancer somatic mutations at multiple other sites throughout the genome.

Monozygotic twins, each of whom has breast cancer, offer a natural study population for gene-environmental interactions as causation of cancer, because they are genetically identical. If heritable factors play a large role in the origin of a neoplasm, disease concordance should be significant in monozygotic twins. Two monozygotic triplet sisters carrying a germline BRCA1 gene mutation (5382insC) who both developed breast cancer at early ages were studied for loss of heterozygosity (LOH) in their microdissected, paraffin-embedded tumors along with control blood and stromal breast tissue at 19 chromosomal arms using 161 microsatellite markers. Microdissected areas of normal lobular and ductal epithelium and ductal in situ carcinoma were also studied for LOH using a subset of microsatellite markers. The mother's DNA (extracted from peripheral blood lymphocytes) was analyzed to determine the parental allele under LOH in each case. Both tumors demonstrated similar histologic features suggestive of a secretory variant of ductal carcinoma. The tumors from both sisters had similar overall LOH frequency expressed by the fractional allelic loss (FAL) indices (0.56 vs. 0.60) and demonstrated concordance for loss or retention at 82 of 97 informative markers (85% correlation). In addition, detailed mapping analysis of several chromosomal arms revealed that identical breakpoints were detected in both tumors at several chromosome regions. Finally, in both sisters' tumors, when a chromosome exhibited allelic loss, all of the markers exhibited LOH of the same parental allele even when there were intervening regions of retention of heterozygosity. In contrast, 17 archival sporadic breast carcinomas demonstrated a wide range of FAL indexes and highly individual patterns of LOH. Our findings support the hypothesis that inherited factors play a role in the development of the multiple somatic deletions occurring in breast carcinomas. Whether one of these factors is the mutant BRCA1 allele or some other gene(s) remains to be determined. Genes Chromosomes Cancer 28:359-369, 2000.

Grading of late effects in young adult survivors of childhood cancer followed in an ambulatory adult setting.

BACKGROUND: The objective of the current study was to describe a multidisciplinary transition program for following young adult survivors of childhood cancer in an adult-based ambulatory medical setting and to report the late effects with grades of toxicity diagnosed in all adult survivors followed in the program. METHODS: The study population was comprised of all young adult survivors (n = 96) of childhood cancer who were seen in the After the Cancer Experience (ACE) Young Adult Program prior to January 31, 1999. The median age of the survivors was 22.8 years (range, 17-34 years) and the median interval from the time of cancer diagnosis was 15.2 years (range, 6-25 years). Primary cancer groups included: leukemia, 33%; sarcoma, 24%; Hodgkin disease, 15%; non-Hodgkin lymphoma, 12%; Wilms' tumor, 9%; and other, 7%. Late effects were graded using the Common Toxicity Criteria, Version 2 (CTCv2), developed by the National Cancer Institute. RESULTS: Approximately 69% of the patients (66 of 96) had at least 1 late effect. Thirty-three percent of patients had a single late effect whereas 36% had >/= 2 late effects. Thirty percent of patients had a CTCv2 Grade 3 or 4 late effect. CONCLUSIONS: The current study represents an example of a successful multidisciplinary transition program in an ambulatory, adult setting for young adult survivors of childhood cancer. Late effects of cancer treatment are common in young adult survivors, with approximately 33% being moderate to severe. Further studies are needed to modify CTCv2 with the aim of developing a reliable and valid tool to assess late effects in long term survivors of childhood cancer.

BRCA2 is required for ionizing radiation-induced assembly of Rad51 complex in vivo.

Mutations in BRCA1 and BRCA2 account for the majority of familial breast cancers. Cells with mutated BRCA1 or BRCA2 are hypersensitive to ionizing radiation (IR) and exhibit defective DNA repair. Both BRCA1 and BRCA2 have been reported to bind Rad51, a protein essential for homologous recombination and the recombinational repair of DNA double-strand breaks. In normal cells, a redistribution of Rad51 protein, manifested as formation of Rad51 nuclear foci, is seen upon IR treatment. Here we demonstrate that IR-induced Rad51 foci formation is aberrant in BRCA2- but not BRCA1-deficient tumor cells. In Capan-1 cells, which do not express functional BRCA2, there was little Rad51 foci formation in response to a wide range of radiation dosages. Moreover, forced expression of a fusion protein containing green fluorescent protein and the first Rad51-binding BRC repeat of BRCA2 in cells with wild-type BRCA2 rendered them hypersensitive to IR and cisplatin and compromised IR-induced Rad51 foci formation. In HCC1937 cells, which harbor mutation of BRCA1, IR-induced Rad51 foci were readily detected. This study suggests a requirement of BRCA2 protein for the IR-induced assembly of Rad51 complex in vivo.

Programs for adult survivors of childhood cancer.

PURPOSE: The potential for late effects of treatment necessitates long-term monitoring of adult survivors of childhood cancer. The purpose of this study was to determine how institutions follow up young adult survivors of pediatric malignancy. Specifically, we were interested in the types of health care providers who follow up these patients, how the follow-up is administered, and what barriers to follow-up have been encountered. METHODS: A 16-item questionnaire was mailed to the 219 members of the Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG). The survey consisted of four categories of questions that asked for information regarding the existence of a program to follow up young adults, the setting of the program, routine activities of the program, and commonly encountered barriers to care. RESULTS: One hundred eighty-two members returned the survey (83% response rate). Fifty-three percent of the respondents have a long-term follow-up clinic at their institution. Whereas 44% have a mechanism for following up adult survivors, only 15% of the programs have established a formal database for adults. Nearly all the programs (93%) use a pediatric oncologist. Although an adult oncologist assists in 13% of the programs, primary care physicians are uncommonly (8%) involved. CONCLUSION: Few programs focus on the long-term health care needs of adult survivors of childhood cancer. The majority of existing programs are in pediatric institutions, without significant input from adult-oriented, generalist health care providers.

Characterization of a breast cancer cell line derived from a germ-line BRCA1 mutation carrier.

A tumor cell line, HCC1937, was established from a primary breast carcinoma from a 24-year-old patient with a germ-line BRCA1 mutation. A corresponding B-lymphoblastoid cell line was established from the patient's peripheral blood lymphocytes. BRCA1 analysis revealed that the tumor cell line is homozygous for the BRCA1 5382insC mutation, whereas the patient's lymphocyte DNA is heterozygous for the same mutation, as are at least two other family members' lymphocyte DNA. The tumor cell line is marked by multiple additional genetic changes including a high degree of aneuploidy, an acquired mutation of TP53 with wild-type allele loss, an acquired homozygous deletion of the PTEN gene, and loss of heterozygosity at multiple loci known to be involved in the pathogenesis of breast cancer. Comparison of the primary tumor with the cell line revealed the same BRCA1 mutation and an identical pattern of allele loss at multiple loci, indicating that the cell line had maintained many of the properties of the original tumor. This breast tumor-derived cell line may provide a useful model system for the study of familial breast cancer pathogenesis and for elucidating BRCA1 function and localization.

Benzo[a]pyrene diol epoxide-induced 3p21.3 aberrations and genetic predisposition to lung cancer.

3p deletion, a common chromosome defect in lung cancer, occurs more frequently in the lung tumor tissues of smoking patients than it does in those of nonsmoking patients. This pilot study evaluated whether 3p aberrations induced by 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 40 lung cancer patients than they were in those of 54 matched controls. Our hypothesis was that 3p sensitivity to BPDE reflects the susceptibility of a specific locus to damage from carcinogens in tobacco smoke. BPDE-induced chromosome 3p21.3 aberrations were significantly more frequent in cases (34.1 per 1000) than they were in controls (22.1 per 1000; P < 0.0001). However, no such difference was observed for 6q27, a control locus. Using the median value in the controls (20 per 1000) as a cutoff point to classify BPDE-induced sensitivity at 3p21.3 and after adjustment by age, sex, ethnicity, and smoking status, 3p BPDE sensitivity was associated with an elevated risk of 14.1 (95% confidence interval: 3.5, 56.2) for lung cancer. There was also a dose-response relationship between the degree of BPDE sensitivity at 3p21.3 and increased risk for lung cancer. Therefore, 3p may be a molecular target for BPDE damage in lung cancer cases.

Analysis of the FHIT gene and FRA3B region in sporadic breast cancer, preneoplastic lesions, and familial breast cancer probands.

The FHIT gene, which spans the FRA3B fragile site at chromosome 3p14.2, is a candidate tumor suppressor gene in breast and other cancers. We investigated FHIT and FRA3B for loss of heterozygosity (LOH); homozygous deletions; abnormal transcripts; and acquired/germ-line point mutations in breast cancer cell lines (n = 32), breast epithelial and stromal cell cultures (n = 18), microdissected invasive (n = 16) and ductal in situ carcinomas (n = 6), and their accompanying normal and abnormal epithelial foci (n = 14). LOH at 3p14.2, especially at FHIT intragenic marker D3S1300, was found in 6 of 16 microdissected invasive tumors and 3 of 6 ductal in situ carcinomas. In accompanying preneoplastic foci, LOH occurred in two of eight intraductal hyperplasias but not in histologically normal ductal epithelium (n = 6). Three of 32 (9%) breast cancer cell lines demonstrated homozygous deletions of FHIT exon 4 (two cases) and exon 5 (one case), which correlated with exon 4-deleted transcripts and loss of the cDNA transcript containing the coding exons 5-9, respectively. Normal mammary cultures and 31 of 32 tumor cell lines (97%) expressed wild-type coding transcripts as well as a minor exon 8-deleted message. Single-strand conformation polymorphism analysis of the coding exons in the 32 tumor and 18 normal breast cell lines and their sequencing revealed four silent polymorphisms and a germ-line histidine triad point mutation (651 G-->T) in a tumor arising in a 70-year-old woman. This mutation was also present in one of her two thus far unaffected daughters. Analysis of additional DNAs from 280 probands of high-risk breast cancer families for other FHIT exon 8 mutations detected an intronic point mutation 13 bases upstream of exon 8. Thus, we have demonstrated relatively early abnormalities of the FHIT/FRA3B region in breast cancer and discovered two rare FHIT germ-line mutations. The expression of a transcript containing the coding exons in nearly all cell lines, including those with germ-line mutations, suggests the possibility that another gene in the FRA3B region may be involved in the pathogenesis of breast cancer.

The first recurring chromosome translocation in hepatoblastoma: der(4)t(1;4)(q12;q34).

We report four cases of hepatoblastoma with a derivative chromosome 4 from an unbalanced translocation between the long arms of chromosomes 1 and 4, an aberration reported only rarely in isolated cases of other types of neoplasms. The abnormality in three hepatoblastomas was der(4)t(1;4)(q12;q34), whereas the fourth case appeared to have a der(4)t(q25;q32). All had hyperdiploid tumor karyotypes; however, in the case with t(q25;q32), the der(4) was the only abnormality in the stemline. We speculate that the oncogenetic event in our cases may be the loss of a gene on distal 4q or their alteration by juxtaposition to 1q12 heterochromatin.