Biological and molecular basis of human breast cancer

Human breast cancer remains the most common malignancy in the American women. The ultimate cure of this disease relies on a better understanding of the mechanisms underlying the initiation and progression of this disease. The neoplastic transformation of HBEC in vitro represents a successful model for obtaining knowledge on the molecular and biological alterations that may contribute to the tumorigenic mechanisms. We have presented here a current understanding of chemically transformed HBEC in the following aspects: 1. Factors affecting the transformation of HBEC such as genetic predisposition and differentiation status and prior immortalization; 2. New targets for studying the mechanism of cell immortalization such as alterations in telomerase activity and differential expression of cell cycle dependent genes as well as others recently isolated through differential cloning such as H-ferritin, and a calcium binding protein; 3. Epigenetic and genetic mechanisms underlying cell transformation; 4. The association of microsatellite instability in specific loci on chromosomes 11, 13, and 16 with the progression of cell transformation; and 5. The application of microcell mediated chromosome transfer technique as an approach to testing the functional role of specific genes whose dysregulation or loss of function may contribute to the ultimate cell transformation. Further efforts in this cell system will be directed to determine the roles of identified molecular changes as well as the mapping/cloning of tumor suppressor or senescence genes such as those that may reside on chromosomes 11 or 17.

Identification of new genes differentially expressed in breast carcinoma cells treated with human chorionic gonadotropin

Human chorionic gonadotropin (hCG) inhibits the growth of human breast epithelial cells MCF-7. Differential display was utilized for analyzing RNA of hCG-treated MCF-7 cells in order to determine whether this effect was mediated by specific gene activation or repression. Three cDNA clones, 19, 29 and 44, were differentially expressed in treated cells. Clone 44, whose sequence matched a gene expressed in dexamethasone-treated T-cell hybridoma, was increased by approximately 4-fold, while clones 19 and 29 were markedly reduced by hCG treatment. These latter ones were considered to be novel genes, since no homology was found in the gene-bank. Our results indicate that hCG influences gene expression in mammary epithelial cells, supporting its potential role in breast cancer prevention and therapy.

Longitudinal changes associated with improvement in chronic fatigue patients

Tertiary care patients with chronic fatigue were followed for 2.5 years to determine if changes in physical and psychological status were associated with improvements in chronic fatigue, physical functioning, and return to work. Results indicated that improvement in psychological symptoms, DSM-III-R disorders, physical examination signs, and changes in whether the patient continued to meet criteria for chronic fatigue syndrome (CFS) were associated with recovery from fatigue, improved functioning, and return to work. Patients who never met CFS criteria or only met criteria at the initial assessment, reported improved physical functioning. Patients whose psychiatric disorders and physical examination signs were still present at a mean follow-up time of 2.5 years were more likely to have persistent fatigue and work disability. Loss of physical examination signs was a significant independent predictor of improved functioning and return to work. These results suggest that psychiatric status, as well as physical status, are associated with recovery from chronic fatigue.

Self-efficacy and self-reported functional status in coronary heart disease: a six-month prospective study

OBJECTIVE

We examine prospectively the role of specific forms of self-efficacy in the physical and role function for patients with coronary heart disease after controlling for the effects of anxiety and depression.

METHODS

A 6-month prospective cohort study was conducted after cardiac catheterization of 198 HMO members, demonstrating clinically significant coronary disease. Coronary disease severity was assessed through cardiac catheterization; physical function, role function, anxiety, depression, and self-efficacy were assessed through questionnaires.

RESULTS

The Cardiac Self-Efficacy Scale had two factors (maintain function and control symptoms) with high internal consistency and good convergent and discriminant validity. In multiple regression models, the self-efficacy scales significantly predicted physical function, social function, and family function after controlling for baseline function, baseline anxiety, and other significant correlates.

CONCLUSIONS

Self-efficacy to maintain function and to control symptoms helps predict the physical function and role function, after accounting for coronary disease severity, anxiety, and depression in patients with clinically significant coronary disease. Interventions to improve self-efficacy may have a broader applicability in the heart disease population than previously appreciated.

Correlation between cell cycle regulators and the immortalization and transformation of human breast epithelial cell lines

Cellular proliferation, essential for normal development, may result in neoplastic growth when the cell cycle clock is disrupted. In order to determine whether the protein expression of cell cycle regulators differs among normal, immortalized non-tumorigenic and malignant human breast epithelial cells (HBECs), we analyzed the protein expression of cyclins D1, D3, A and E, cyclin-dependent kinase (cdk) 4 and c-fos in exponentially growing MCF-10M, MCF-10F, and MCF-7 cells. The tumorigenicity of HBECs in vivo correlated with both cell cycle regulators and early-gene protein expression in vitro. The differential expression of cyclin E- and cyclin A-related proteins and their putative relevance in the tumorigenic properties of HBECs are also discussed.

Neoplastic progression of breast epithelial cells--a molecular analysis

Molecular changes associated with breast cancer progression were characterized using the MCF-10F cell series. MCF-10F was established from fibrous mastectomy tissue of a patient without detectable cancer. In vitro treatment of MCF-10F cells with benzo(a)pyrene resulted in a transformed subclone MCF-10F-BP1 (BP1). Transfection of clone BP1 with T24-Hras resulted in the tumorigenic line MCF-10F-BP1-Tras (BP1-Tras). Using flow cytometry, the expression of HLA I, ERBB-2 and MUC-1 was found to be comparable in 'normal' MCF-10F, transformed BP1 and tumorigenic BP1-Tras cells. Glycosylated mucin is elevated in BP1 but reduced in BP1-Tras cells. Using mRNA differential display analysis, cDNA profiles of the 'normal', transformed and tumorigenic cell lines were strikingly similar, yet distinct and elevated expression of several common cDNA fragments was detected in BP1 and BP1-Tras when compared with MCF-10F cells. These fragments were cloned and sequenced. The sequences of clones T1-360 and C4-310 are homologous to two reported EST cDNA clones from human fetal tissue and were further characterized. Elevated expression of the genes corresponding to clones T1-360 and C4-310 was verified using Northern blotting. High-level expression of these genes was also detected in the breast cancer cell line MCF-7 that was derived from the pleural effusion of a patient with advanced breast cancer. Therefore, specific molecular changes associated with breast cancer development were identified and may be indicators of neoplastic progression.

Increased expression of estrogen receptor beta in chemically transformed human breast epithelial cells

Recent molecular cloning of estrogen receptor beta (ERbeta) suggests alternative pathways of estrogen signaling, but little is known concerning the role of ERbeta in the development of human breast cancer. In the present study, expression of ERalpha and ERbeta mRNA was determined in a series of chemically transformed human breast epithelial cells as well as various normal and malignant breast cancer cell lines. We observed a very low level of ERbeta expression in the mortal S130 and the spontaneously immortalized MCF10-F human breast epithelial cell lines. As MCF-10F cells were treated with environmental chemical carcinogens, an elevated level of ERbeta expression was observed in the resultant transformed BP1, D3 and BP1-ras cells. An even higher level of ERbeta expression was detected in the more transformed BP1-E, D3-1 and D3-1-ras cell lines. Therefore, results from our study indicate that expression of ERbeta can be induced in chemical carcinogen-transformed human breast epithelial cells, and the more transformed cells showed higher levels of ERbeta expression, regardless of which chemical carcinogens were initially used for cell transformation. These results suggest that expression of ERbeta may contribute to the initiation and progression of chemical carcinogen-induced neoplastic transformation.

Differentiation and breast cancer

The mammary gland is an organ whose size, shape and function undergo fundamental changes during the various phases of a woman's growth. Although the development of the mammary gland begins during infancy, the most dramatic changes occur with the initiation of puberty. Pregnancy and lactation complete the functional development of the organ, which regresses during menopause. Epidemiological and experimental studies have demonstrated that certain hormonal influences, especially those related to reproduction, modify the risk of developing breast cancer. Thus, a full term pregnancy completed before the age of 24 years significantly reduces the lifetime incidence of breast cancer. Although the mechanism through which pregnancy protects the breast from breast cancer has not been clearly established, experimental models of mammary carcinogenesis have allowed researchers to determine that pregnancy inhibits the initiation of the neoplastic process through the induction of a complete differentiation of the mammary gland. This process activates specific genes, which in turn modify the response of the organ to ulterior hormonal changes. It is postulated that the same mechanism might be responsible for the protective effect of a woman's early first full term pregnancy. The greater incidence of breast cancer observed in nulliparous women correlates well with the greater susceptibility of the virgin rat to develop mammary carcinomas when exposed to chemical carcinogens. The successful induction of malignant transformation in the virgin animal mammary epithelium is due to the presence of undifferentiated structures with a high rate of cell proliferation. These structures are eliminated by pregnancy. The breast of nulliparous women retains those undifferentiated structures, which increase the predisposition of the organ to undergo malignant transformation, which will manifest itself clinically several years after its initiation. The correlation of human epidemiological, clinical and experimental data with those data obtained in rodent experimental models lends support to this hypothesis.

The MOS 36-Item Short Form Health Survey: reliability, validity, and preliminary findings in schizophrenic outpatients

OBJECTIVES

The authors test the reliability and validity of the Medical Outcomes Study Short Form 36-Item Health Survey (SF-36) as a written, self-administered survey in outpatients with chronic schizophrenia.

METHODS

Thirty-six schizophrenic outpatients completed a written and oral form of the SF-36. A psychiatrist rated the patients using the Brief Psychiatric Rating Scale to determine severity of psychopathology. Cognitive functioning and academic achievement were also assessed. Internal consistency, test-retest reliability, concurrent and discriminative validity of the oral and written versions were determined.

RESULTS

The SF-36 in both forms was shown to have good internal consistency, stability, and concurrent validity. The mental health SF-36 subscales had poor discriminant validity, compared with the physical functioning scale that demonstrated good discriminant validity.

CONCLUSIONS

The validity of using the written form of the SF-36 on a sample of patients with chronic mental illness was demonstrated. The SF-36 appears to be an appropriate outcome measure for changes in physical and role functioning in consumers of outpatient mental health programs.

Impact of improved depression treatment in primary care on daily functioning and disability

BACKGROUND

Few data are available regarding the impact of improved depression treatment on daily functioning and disability.

METHODS

In two studies of more intensive depression treatment in primary care, patients initiating antidepressant treatment were randomly assigned to either usual care or to a collaborative management programme including patient education, on-site mental health treatment, adjustment of antidepressant medication, behavioural activation and monitoring of medication adherence. Assessments at baseline as well as 4 and 7 months included several measures of impairment, daily functioning and disability: self-rated overall health, number of bodily pains, number of somatization symptoms, changes in work due to health, reduction in leisure activities due to health, number of disability days and number of restricted activity days.

RESULTS

Average data from the 4- and 7-month assessments in both studies, intervention patients reported fewer somatic symptoms (OR 0.68, 95% CI 0.46, 0.99) and more favourable overall health (OR 0.50, 95% CI 0.28, 0.91). While intervention patients fared better on other measures of functional impairment and disability, none of these differences reached statistical significance.

CONCLUSIONS

More effective acute-phase depression treatment reduced somatic distress and improved self-rated overall health. The absence of a significant intervention effect on other disability measures may reflect the brief treatment and follow-up period and the influence of other individual and environmental factors on disability.

Antiproliferative effect of synthetic resveratrol on human breast epithelial cells

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phytoalexin, is a constituent of the human diet that has been shown to inhibit cellular processes associated with tumor initiation, promotion and progression. In this study, we examined the effect of synthetic resveratrol on the proliferative capacity of immortal and neoplastic human breast epithelial cells in culture. MCF-7, an estrogen receptor-positive breast cancer cell line, MCF-10F, an immortal estrogen receptor-negative breast epithelial cell line, and MDA-MB-231, a malignant estrogen receptor-negative breast epithelial cell line, were treated with 5, 10, 20 or 40 microg/ml resveratrol, and their proliferative activities were determined with the WST-1 colorimetric assay after periods of time ranging from 24 to 144 h of treatment. Our results showed that this phytoalexin inhibited the proliferation of human breast epithelial cells in a dose- and time-dependent manner. Treatment of cells with resveratrol reduced the number of viable cells and prevented the exponential growth of the three cell lines examined. These observations indicate that resveratrol has a direct antiproliferative effect on human breast epithelial cells that is independent of the estrogen receptor status of the cells. Thus, this dietary compound is a potential chemopreventive agent for both hormone responsive and non-responsive breast cancers.

Roscovitine inhibits the proliferative activity of immortal and neoplastic human breast epithelial cells

[2-(R)-(1-Ethyl-2-hydroxyethylamino)-6-benzylamino-9-isopropylp urine] (roscovitine) is a potent and selective inhibitor of cyclin-dependent kinases cdc2 and cdk2. In this study, we evaluated the potential involvement of this novel cyclin-dependent kinase inhibitor in the proliferative activity of malignant and non-malignant human breast epithelial cells in vitro. Estrogen receptor-positive MCF-7 breast carcinoma cells, immortalized estrogen receptor-negative breast epithelial cells and highly malignant estrogen receptor-negative MDA-MB-231 breast epithelial cells, were incubated with different concentrations of roscovitine ranging from 1 to 40 micrograms/ml, and cell numbers were measured with the WST-1 colorimetric assay after 24, 48, 72, 96, 120, and 144 hours of treatment. Our results demonstrated that roscovitine inhibited the proliferation of human breast epithelial cells in a dose- and time-dependent manner. Roscovitine treatment decreased the number of viable cells and prevented the exponential growth of all the cell lines examined. The antiproliferative effect of this potent cdk inhibitor was independent of the estrogen receptor status of the cells. These data suggest that roscovitine is a potential antiproliferative drug for the treatment and/or prevention of both estrogen responsive and non-responsive breast cancers.

Randomized, placebo-controlled trial of paroxetine versus imipramine in depressed HIV-positive outpatients

OBJECTIVE

This study examined whether a selective serotonin reuptake inhibitor (paroxetine) had comparable efficacy but greater tolerability than a tricyclic antidepressant (imipramine) in depressed patients with HIV infection.

METHOD

Seventy-five HIV-positive patients (45% of whom had AIDS) were blindly and randomly assigned to receive paroxetine (N = 25), imipramine (N = 25), or placebo (N = 25) in a 12-week trial. The Hamilton Anxiety Rating Scale, the Hamilton Depression Rating Scale, the Clinical Global Impression scale, and the SAFETEE general inquiry (for safety and tolerability) were administered at weeks 2, 4, 6, 8, and 12.

RESULTS

Fifty-six (75%) of the 75 patients completed 6 weeks and 34 (45%) completed 12 weeks of the trial. The mean daily doses of both paroxetine (33.9 mg) and imipramine (162.5 mg) were significantly more effective than placebo; they were comparably effective at weeks 6, 8, and 12 according to the intent-to-treat analysis and at week 8 according to the analysis for the subjects who completed the trial (for them, only imipramine was superior to placebo at week 12). There were significantly more dropouts due to side effects from imipramine (48%) than from both paroxetine (20%) and placebo (24%).

CONCLUSIONS

Depressed patients with HIV infection responded to imipramine or paroxetine at a higher rate than to placebo irrespective of severity of immunosuppression. Because paroxetine was much better tolerated than imipramine, its overall effectiveness may be greater. However, because of the small study group and the high attrition rate, these findings cannot be generalized and may need replication in a larger study group.

Nuclear and nucleolar image analysis of human breast epithelial cells transformed by benzo[a]pyrene and transfected with the c-Ha-ras oncogene

Changes in nuclear and nucleolar morphometric parameters were investigated by image analysis procedures in human breast MCF-10F epithelial cells expressing different stages of the tumourigenic progression after benzo[a]pyrene (BP) transformation (BP1, BP1-E, and BP1-E1 cell lines), and additionally transfected with the c-Ha-ras oncogene (BP1-Tras cell line). Nuclear pleomorphism was evident in all the transformed cells. The analysis of different morphometric parameters did not show a clear relationship between specific nuclear and nucleolar changes and the expression of the different stages of the tumourigenesis, with the exception of the nucleolar size, which could be associated to the expression of the tumourigenic phenotype, and a nucleolar area/nuclear area ratio, which discriminated the immortalized, the transformed, and the tumourigenic phenotypes from one another. The nuclear morphometric data established for the BP-transformed cells and for the cells additionally transfected with the c-Ha-ras oncogene were suggestive of complex and distinct morphofunctional mechanisms involving the in vitro transformation of the MCF-10F cells. The nuclear changes found in the BP1-Tras cell line were assumed to be related to the additional effects and/or enhanced genomic instability induced by transfection with the ras oncogene.

Role of hormones in mammary cancer initiation and progression

Breast cancer, the most frequent spontaneous malignancy diagnosed in women in the Western world, is a classical model of hormone dependent malignancy. There is substantial evidence that breast cancer risk is associated with prolonged exposure to female hormones, since early onset of menarche, late menopause, hormone replacement therapy and postmenopausal obesity are associated with greater cancer incidence. Among these hormonal influences a leading role is attributed to estrogens, either of ovarian or extra-ovarian origin, as supported by the observations that breast cancer does not develop in the absence of ovaries, ovariectomy causes regression of established malignancies, and in experimental animal models estrogens can induce mammary cancer. Estrogens induce in rodents a low incidence of mammary tumors after a long latency period, and only in the presence of an intact pituitary axis, with induction of pituitary hyperplasia or adenomas and hyperprolactinemia. Chemicals, radiation, viruses and genomic alterations have all been demonstrated to have a greater tumorigenic potential in rodents. Chemical carcinogens are used to generate the most widely studied rat models; in these models hormones act as promoters or inhibitors of the neoplastic process. The incidence and type of tumors elicited, however, are strongly influenced by host factors. The tumorigenic response is maximal when the carcinogen is administered to young and virgin intact animals in which the mammary gland is undifferentiated and highly proliferating. The atrophic mammary gland of hormonally-deprived ovariectomized or hypophysectomized animals does not respond to the carcinogenic stimulus. Administration of carcinogen to pregnant, parous or hormonally treated virgin rats, on the other hand, fails to elicit a tumorigenic response, a phenomenon attributed to the higher degree of differentiation of the mammary gland induced by the hormonal stimulation of pregnancy. In women a majority of breast cancers that are initially hormone dependent are manifested during the postmenopausal period. Estradiol plays a crucial role in their development and evolution. However, it is still unclear whether estrogens are carcinogenic to the human breast. The apparent carcinogenicity of estrogens is attributed to receptor-mediated stimulation of cellular proliferation. Increased proliferation could result in turn in accumulation of genetic damage and stimulation of the synthesis of growth factors that act on the mammary epithelial cells via an autocrine or paracrine loop. Alternatively estrogens may induce cell proliferation through negative feedback by removing the effect of one or several inhibitory factors present in the serum. Multidisciplinary studies are required for the elucidation of the mechanisms responsible for the initiation of breast cancer. Understanding of such mechanisms is indispensable for developing a rational basis for its prevention and control.

Differential expression of human ferritin H chain gene in immortal human breast epithelial MCF-10F cells

Subtractive hybridization was used to isolate genes expressed uniquely in the immortalized human breast epithelial cell (HBEC) line MCF-10F and not in the mortal HBEC line S-130, from which MCF-10F cells were derived. We identified a 233-bp cDNA that was expressed in MCF-10F cells and not in their mortal counterpart S-130 cells. Sequence comparison with the GenBank database revealed that the cDNA was identical to the gene encoding human ferritin heavy H chain. Northern blot analysis using the isolated cDNA as a probe showed a differentially expressed 1.1-kb transcript of ferritin H in total RNA from the immortal MCF-10F cells, MCF-10F cells treated with the chemical carcinogens 7,12-dimethylbenz[a]anthracene and benzo[a]pyrene, and the breast cancer cell lines MCF-7, HBL-100, T-47D, and BT-20. No ferritin H transcript was detected in the mortal line S-130 or in other primary HBEC cultures. Increased levels of mRNA transcript signals were also detected in total RNA from breast cancer tissue samples. Tissue with ductal hyperplasia had higher expression levels than normal adjacent mammary tissue. In situ hybridization showed high levels of ferritin H transcript in mammary tissue areas with ductal hyperplasia, carcinoma in situ, and infiltrating ductal carcinoma. This is the first report of the differential expression and upregulation of human ferritin H chain gene in immortal HBECs. It may be an important factor in the process of immortalization, possibly an early stage of malignant transformation of HBECs, providing cells with iron necessary for growth and clonal expansion. Also, ferritin iron, once released, may increase the level of reactive iron, leading to an increase in oxygen free-radical generation, oxidative DNA damage, and mutation.

Psychiatric status, quality of life, and level of care as predictors of outcomes of acute inpatient treatment

OBJECTIVE

The study examined the role of five types of variables--demographic characteristics, psychiatric status, functional quality of life, satisfaction with quality of life, and level of care--in predicting key outcomes of inpatient treatment.

METHODS

Multivariate canonical regression and univariate multiple regression models were constructed using data from 1,053 inpatients at a public hospital in Washington State. The models were used to predict length of stay, change in symptom severity during hospitalization, psychiatrists' ratings of patients' insight into their illness at discharge, patients' global satisfaction with life, and rehospitalization within 18 months. Hierarchical stepwise procedures were used to select variables that were significant predictors of outcomes.

RESULTS

All five classes of predictors were related to the outcomes. The roles of demographic characteristics and diagnoses were minimal. Previous hospitalization and severity of symptoms at admission were strong predictors of psychiatric status. Indicators of functional quality of life and satisfaction with quality of life explained significant variance in all models after accounting for the other classes of predictors. Frequency of family visits was the strongest functional quality-of-life predictor, relating to positive outcomes. Pretreatment satisfaction with life was a significant predictor of most outcomes, and increased satisfaction was associated with positive outcomes.

CONCLUSIONS

Patients' quality of life before psychiatric inpatient treatment predicted treatment outcomes independently of psychiatric status, demographic characteristics, and level-of-care variables. Prospective studies are needed to predict outcomes using multidimensional constructs.

Periodontal laser surgery

A gingivectomy performed with a laser is a short, easy procedure that produces an immediately dramatic effect. Compared to a scalpel gingivectomy, there is excellent hemostasis, which improves visualization, requires less need for periodontal packing, and results in minimal postoperative discomfort. Tissue rebound also is minimal. Use of lasers requires specific training. The only approved function in periodontics at this time according to the American Academy of Periodontology is soft tissue surgery. Some periodontal applications include frenectomy, soft tissue crown lengthening, distal wedge procedures, soft tissue tuberosity reductions, gingivectomy, gingivoplasty, stage II of implants, operculectomies, biopsies, coagulation of graft donor sites, hemorrhage disorder patients, and stripping procedures for various leukoplakias.

Chorionic gonadotropin inhibits rat mammary carcinogenesis through activation of programmed cell death

Human chorionic gonadotropin (hCG) inhibits the progression of 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinomas. In order to determine whether this phenomenon was mediated by induction of programmed cell death or apoptosis, 45-day-old virgin Sprague-Dawley rats received 8 mg DMBA/100 g body weight; 20 days later they were injected daily with 100 IU hCG for 40 days (DMBA + hCG group). Age-matched untreated, hCG- and DMBA + saline treated rats were used as controls. Tissues were collected at the time of DMBA administration and at 5, 10, 20 and 40 days of hCG injection. RNA from mammary glands, adenocarcinomas and ovaries was probed for transforming growth factors (TGF) alpha and beta, and the apoptotic genes TRPM2, ICE, bcl2, bcl-XL, bcl-XS, p53 and c-myc. The mammary glands of hCG-treated animals with or without DMBA exhibited elevated expression of TRPM2, ICE, bcl-XS, c-myc and p53; and elevation in the apoptotic index. Mammary adenocarcinomas developed in those animals treated with hCG showed an elevation in the expression of p53, c-myc and ICE genes in comparison with the levels detected in the adenocarcinomas developed by the animals treated with DMBA alone. No significant alterations in the expression of any of the genes tested was observed in ovarian RNAs. These results led us to conclude that hCG induces programmed cell death in the mammary gland initiated in the carcinogenic process, that this process is p53 dependent, and is modulated by c-myc expression. Our data also indicate the possibility that a cell death program dependent on the bcl2 family exists, because of the potential involvement of p53, bcl-XS and Bax in apoptosis. This additional mechanism of tumor inhibition makes hCG treatment a useful approach for the prevention and therapy of breast cancer.

Microsatellite instability of D17S513 on chromosome 17 is associated with progression of breast cancer

Genetic abnormalities of chromosome 17 are frequently found in human breast cancer. Recently, loss of heterozygosity (LOH) and microsatellite instability (MSI) studies have shown evidence for the presence of at least several unknown tumor suppressor genes (TSG) on chromosome 17, in addition to the well known TP53 and the breast cancer susceptibility gene BRCA1. We have previously reported the establishment of a transformed human breast epithelial cell (HBEC) system induced by benzo(a)pyrene in vitro that is tumorigenic in an exogenous host. This has allowed us to develop a cell line designated BP1E-Tp cells. Further studies have shown that various regions of chromosome 17 in these cells expressed genomic changes in the forms of LOH and/or MSI, indicating that putative TSGs anchoring in these regions might have been the targets for the carcinogenic induction. In the present work, we report that normal chromosome 17, upon introduced into the BP1E-Tp cells, was able to partially reverse the transformed phenotypes in vitro as well as the tumorigenic phenotypes in vivo, providing direct functional evidence that chromosome 17 does harbor unknown TSGs. Moreover, we discovered that the MSI of D17S513 (located distal to TP53 at 17p13.1), pre-existing in BP1E-Tp? cells and derived tumors, was abrogated in the BP1E-Tp cell-chromosome 17 microcell hybrids, or BPIE-Tp-17neo cells, and the derived tumors. The reversion of this MSI was in association with the phenotypic reversion observed in these cells, thus suggesting that MSI of D17S513 might represent an important event in the progression of breast carcinogenesis. We further confirmed this by analyzing two groups of primary human breast cancers, one group consisted of tumors less than 2 cm in diameter with negative lymph node, and another group of tumors larger than 5 cm in diameter with positive lymph nodes. We found that MSI of D17S513 occurred significantly more frequently in the second group of breast cancers (80%) than in the first group (18%). These results led us to conclude that chromosome 17 harbors putative TSGs, whose inactivation partially accounted for the expression of neoplastic phenotypes of the BP1E-Tp cells, and that MSI of D17S513 represents a genomic change occurring at the late stage of the neoplastic transformation of HBECs as well as during the progression of breast cancers.

Neuroticism and extraversion as predictors of health outcomes in depressed primary care patients

Depressed primary care patients (N = 217) were assessed to determine if certain personality characteristics predict health domains independent of chronic disease, demographics, depression, and psychiatric diagnoses. Eleven health variables were used to create three outcome factor scores: disability (e.g., days missed work); somatization (e.g., medically unexplained symptoms); and subjective pain (severity, interference). Neuroticism explained significant variance in all health outcomes independent of the other predictors. Depression and neuroticism interacted in the disability and pain models. Depression was related to health in neurotic patients, while in the absence of neuroticism, little relation between depression and health was observed. Neuroticism may explain why persons with similar health problems have differing levels of disability, pain, and somatization.

Cloning and gene mapping of the chromosome 13q14 region deleted in chronic lymphocytic leukemia

Frequent deletions and loss of heterozygosity in a segment of chromosome 13 (13q14) in cases of B-cell chronic lymphocytic leukemia (CLL) have suggested that this malignancy is caused by inactivation of an unknown tumor suppressor gene located in this region. Toward the identification of the putative CLL tumor suppressor, we have constructed a high-resolution physical map of YAC, PAC, and cosmid contigs covering 600 kb of the 13q14 genomic region. In addition to densely positioned genetic markers and STSs, this map was further annotated by localization of 32 transcribed sequences (ESTs) using a combination of exon trapping, direct cDNA selection, sample sequencing of cosmids and PACs, and homology searches. On the basis of these mapping data, allelic loss analyses at 13q14 using CLL tumor samples allowed narrowing of the genomic segment encompassing the putative CLL gene to <300 kb. Twenty-three ESTs located within this minimally deleted region are candidate exons for the CLL-associated tumor suppressor gene.