Reduced FANCD2 influences spontaneous SCE and RAD51 foci formation in uveal melanoma and Fanconi anaemia.

Uveal melanoma (UM) is unique among cancers in displaying reduced endogenous levels of sister chromatid exchange (SCE). Here we demonstrate that FANCD2 expression is reduced in UM and that ectopic expression of FANCD2 increased SCE. Similarly, FANCD2-deficient fibroblasts (PD20) derived from Fanconi anaemia patients displayed reduced spontaneous SCE formation relative to their FANCD2-complemented counterparts, suggesting that this observation is not specific to UM. In addition, spontaneous RAD51 foci were reduced in UM and PD20 cells compared with FANCD2-proficient cells. This is consistent with a model where spontaneous SCEs are the end product of endogenous recombination events and implicates FANCD2 in the promotion of recombination-mediated repair of endogenous DNA damage and in SCE formation during normal DNA replication. In both UM and PD20 cells, low SCE was reversed by inhibiting DNA-PKcs (DNA-dependent protein kinase, catalytic subunit). Finally, we demonstrate that both PD20 and UM are sensitive to acetaldehyde, supporting a role for FANCD2 in repair of lesions induced by such endogenous metabolites. Together, these data suggest FANCD2 may promote spontaneous SCE by influencing which double-strand break repair pathway predominates during normal S-phase progression.

Prevalence of meeting physical activity guidelines for cancer prevention in Alberta.

INTRODUCTION: Guidelines for recommended physical activity (PA) levels have been developed by the Canadian Society for Exercise Physiology (CSEP) and the U.S. Department of Health and Human Services (USDHHS) for health benefits and by the American Cancer Society (ACS) and the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) for cancer prevention benefits. METHODS: We examined if these guidelines were met using a sample of 14 294 Albertan participants of the Tomorrow Project, aged 35 to 64 years, enrolled from 2001 to 2005. We used logistic regression to examine correlates of leisure PA behaviour. RESULTS: An estimated 55%, 42%, 26% and 23% of participants met CSEP, ACS, USDHHS, and WCRF/AICR guidelines, respectively. Women were less likely than men to meet ACS (Odds Ratio [OR] = 0.72, 95% confidence interval [CI]: 0.55-0.93), USDHHS (OR = 0.67, 95% CI: 0.50-0.89) and WCRF/AICR (OR = 0.63, 95% CI: 0.47-0.85) guidelines, and being obese was correlated with not meeting USDHHS (OR = 0.45, 95% CI: 0.32-0.65) and WCRF/AICR guidelines (OR = 0.79, 95% CI: 0.63-0.98). CONCLUSION: Albertans, particularly women and obese individuals, are not sufficiently active for cancer prevention benefits.

Pan-Canadian initiatives in colorectal cancer screening: adopting knowledge translation tools to accelerate uptake and impact.

BACKGROUND: Despite the positive conclusions of several randomized controlled trials and the publication of national recommendations on colorectal cancer (crc) screening, uptake remained low. The inauguration of the National Colorectal Cancer Screening Network in 2007, the same year that the first screening program was announced in Canada, provided an opportunity for integrated knowledge translation to accelerate the processes of program implementation and screening uptake. AIM: Two primary aims were identified. The first focused on means to monitor the effects of various implementation plans in delivering high-quality population-based crc screening. The second focused on identifying and addressing knowledge gaps that may impair screening participation. METHOD: The methods used are described in the context of the knowledge-to-action cycle and demonstrate that the initiative itself dictates the point in the cycle at which to start. RESULTS: The identified need to monitor various implementation plans resulted in the shared development of a quality determinants document. All programs committed to designing data collection so that core components could be measured and compared; 6 operating programs have conducted the first data collection, which will allow for monitoring and for new knowledge creation as the process develops further. The knowledge gap identification project started with new knowledge creation, which identified a higher-than-expected willingness of Canadians to discuss crc screening with physicians, but a low level of understanding of screening as a wellness-related behaviour. Knowledge translation interventions have been developed with the stakeholders to address those gaps, and ongoing surveys to be carried out later in 2011 will help to gauge progress in the understanding and acceptance of crc screening by the population. CONCLUSIONS: A national network that engaged all programs, policymakers, experts, and lay representatives successfully used knowledge translation principles to enhance the trajectory of crc screening in Canada.

Resistance of uveal melanoma to the interstrand cross-linking agent mitomycin C is associated with reduced expression of CYP450R.

BACKGROUND: Uveal melanoma (UM) is the most common primary intraocular tumour of adults, frequently metastasising to the liver. Hepatic metastases are difficult to treat and are mainly unresponsive to chemotherapy. To investigate why UM are so chemo-resistant we explored the effect of interstrand cross-linking agents mitomycin C (MMC) and cisplatin in comparison with hydroxyurea (HU). METHODS: Sensitivity to MMC, cisplatin and HU was tested in established UM cell lines using clonogenic assays. The response of UM to MMC was confirmed in MTT assays using short-term cultures of primary UM. The expression of cytochrome P450 reductase (CYP450R) was analysed by western blotting, and DNA cross-linking was assessed using COMET analysis supported by γ-H2AX foci formation. RESULTS: Both established cell lines and primary cultures of UM were resistant to the cross-linking agent MMC (in each case P<0.001 in Student's t-test compared with controls). In two established UM cell lines, DNA cross-link damage was not induced by MMC (in both cases P<0.05 in Students's t-test compared with damage induced in controls). In all, 6 out of 6 UMs tested displayed reduced expression of the metabolising enzyme CYP450R and transient expression of CYP450R increased MMC sensitivity of UM. CONCLUSION: We suggest that reduced expression of CYP450R is responsible for MMC resistance of UM, through a lack of bioactivation, which can be reversed by complementing UM cell lines with CYP450R.

Poly(ADP-ribose) polymerase inhibitors as potential chemotherapeutic agents.

PARP [poly(ADP-ribose) polymerase] activity is up-regulated by binding to DNA strand breaks and its association with DNA repair is well documented. Many anticancer therapies work by inducing breaks in DNA, if unrepaired these can lead to cell death. As PARP promotes DNA repair there is a strong rational to suggest that its inhibition may increase the efficiency of certain cytotoxic treatments. This review discusses the advances made in PARP inhibitor design and the mechanism by which they enhance anti-tumour therapies.

Influence of physical activity in different age and life periods on the risk of breast cancer.

We conducted a population-based case-control study of 1,237 incident breast cancer cases and 1,241 controls in Alberta between 1995 and 1997 to examine the effect of physical activity performed at different ages and life periods on breast cancer risk. In this study, we measured all types of physical activity done throughout life with a questionnaire developed and tested specifically for this study. We found that breast cancer risk was most associated with a risk reduction for activity done later in life, particularly between menopause and the reference year, for which we observed an odds ratio of 0.70 (95% confidence interval = 0.52-0.95). We also stratified the study participants into four categories according to their patterns of physical activity performed before and after menopause. For the women who sustained physical activity throughout life vs those who were never active, we found an odds ratio of 0.58 (95% confidence interval = 0.41-0.83). This study suggests that sustained activity throughout life and particularly activity done later in life may have the most benefit in reducing breast cancer risk.

Relation between intensity of physical activity and breast cancer risk reduction.

PURPOSE: To examine the influence of frequency, duration, and intensity of physical activity on risk of breast cancer and to compare breast cancer risks associated with self-reported versus assigned intensity levels of activity. METHODS: A population-based case-control study of 1233 incident breast cancer cases and 1241 controls was conducted in Alberta between 1995 and 1997. The frequency, duration and intensity of occupational, household, and recreational activities were measured throughout lifetime using the Lifetime Total Physical Activity Questionnaire and cognitive interviewing methods. Unconditional logistic regression analyses were used to estimate odds ratios and a full assessment of confounding and effect modification was undertaken. Odds ratios for self-reported and compendium-based assigned levels of activity were compared for lifetime total activity and by type of activity. RESULTS: Breast cancer risk reductions were comparable when self-reported and assigned intensity values were used, although the results and trends were more evident with the assigned intensity data. Moderate-intensity occupational and household activities decreased breast cancer risk, whereas recreational activity, at any intensity level, did not contribute to a breast cancer risk reduction. CONCLUSION: This study found that moderate-intensity activities were the major contributors to the decrease in breast cancer risk found in this study and that risk reductions were more evident when the frequency and duration of activity alone were modeled. Of the three types of activity considered, the greatest risk reductions observed were for occupational and household activities.

Case-control study of lifetime physical activity and breast cancer risk.

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.

Risk factors for benign breast biopsies: a nested case-control study in the Alberta breast screening program.

A nested case-control study was conducted to identify risk factors for benign breast biopsies in 382 cases (women with a benign biopsy result) and 399 controls (women who had not undergone a biopsy) who were sampled from the Alberta breast cancer screening program. The breast biopsy specimens of the cases were reviewed by a panel of pathologists, and percent fibroglandular tissue density was assessed. The multivariable odds ratios for the risk of open benign breast biopsy associated with current cigarette smoking was 2.04 (95% CI 1.32-3.13), for ever regular smoking was 1.61 (1.20-2.16), and for passive smoking was 1.41 (0.99-2.02). A risk reduction was found for ever alcohol consumption (0.61 [0.44-0.85]). Some risk reductions were found when the highest and the lowest quintiles of total aerobic recreational activity were compared (0.71 [0.42-1.20]), stair climbing (0.61 [0.37-1.01]) and walking pace (0.13 [0.02-0.741). Lifestyle risk factors may be implicated in the continuum between detection of an abnormality on a screening mammogram and a breast biopsy specimen. By considering these risk factors, breast screening programs may be better able to identify those women who require a breast biopsy and reduce the number of benign breast biopsies.

Herpes simplex virus IE63 (ICP27) protein interacts with spliceosome-associated protein 145 and inhibits splicing prior to the first catalytic step.

The multifunctional herpes simplex virus type 1 (HSV-1) protein IE63 (ICP27) interacts with the essential pre-mRNA splicing factor, spliceosome-associated protein 145 (SAP145), and in infected cells IE63 and SAP145 colocalize. This interaction was reduced or abrogated completely using extracts from cells infected with IE63 viral mutants, with mutations in IE63 KH and Sm homology domains, which do not exhibit host shutoff or inhibit splicing. In the presence of IE63, splicing in vitro was inhibited prior to the first catalytic step and the B/C complex formed during splicing was shifted up in mobility and reduced in intensity. With the use of splicing extracts, IE63 and SAP145 both comigrated with the B/C complex, suggesting that they interact within this complex to inhibit B/C complex formation or conversion. The inhibition of splicing may facilitate the export of viral or cellular transcripts, possibly via other protein partners of IE63. These data provide important new insights into how IE63 influences pre-mRNA processing during HSV-1 infection.

Interaction between herpes simplex virus type 1 IE63 protein and cellular protein p32.

The herpes simplex virus type 1 (HSV-1) immediate-early gene IE63 (ICP27), the only HSV-1 regulatory gene with a homologue in every mammalian and avian herpesvirus sequenced so far, is a multifunctional protein which regulates transcriptional and posttranscriptional processes. One of its posttranscriptional effects is the inhibition of splicing of viral and cellular transcripts. We previously identified heterogeneous nuclear ribonucleoprotein (hnRNP) K and casein kinase 2 (CK2) as two protein partners of IE63 (H. Bryant et al., J. Biol. Chem. 274:28991-28998, 1999). Here, using a yeast two-hybrid assay, we identify another partner of IE63, the cellular protein p32. Confirmation of this interaction was provided by coimmunoprecipitation from virus-infected cells and recombinant p32 binding assays. A p32-hnRNP K-CK2 complex, which required IE63 to form, was isolated from HSV-1-infected cells, and coimmunoprecipitating p32 was phosphorylated by CK2. Expression of IE63 altered the cytoplasmic distribution of p32, with some now colocalizing with IE63 in the nuclei of infected and transfected cells. As p32 copurifies with splicing factors and can inhibit splicing, we propose that IE63 together with p32, possibly with other IE63 partner proteins, acts to disrupt or regulate pre-mRNA splicing. As well as contributing to host cell shutoff, this effect could facilitate splicing-independent nuclear export of viral transcripts.

The lifetime total physical activity questionnaire: development and reliability.

OBJECTIVE: To develop and test the intra-rater reliability of an interview-administered questionnaire that assesses lifetime patterns of total physical activity including occupational, household, and exercise/sports activities. METHODS: The questionnaire was developed and pretested using cognitive interviewing techniques on a sample of women with and without previous breast cancer diagnoses. A pilot study was conducted with 115 women who were interviewed twice, 6 to 8 wk apart by interviewers trained in cognitive interviewing methods. Respondents used recall calendars to record their education, occupations, life events, and physical activity patterns before the interviews. Interviewers helped respondents recall their lifetime exposures, including their occupational, household, and exercise/sports activities, using these calendars and memory-probing strategies. Activity levels were estimated as the average number of hours of activity per week over different time periods. Means and correlation coefficients were estimated and compared for the two time periods. RESULTS: The questionnaire was found to be highly reliable. The test-retest correlations for hours per week spent in total lifetime physical activity was 0.74, for lifetime occupational activity was 0.87, for household activity was 0.77, and for exercise/sports activities was 0.72. CONCLUSIONS: This is the first questionnaire to measure lifetime physical activity by collecting data on each type of physical activity separately over lifetime and by measuring frequency, intensity, and duration of each activity. It is also the first physical activity questionnaire to be developed, refined, and administered using cognitive-based methods employed in survey research. Respondents were able to reliably recall their lifetime physical activity patterns. This instrument can be used for any disease outcome for which physical activity may be a risk factor.

The role of past mammography and future intentions in screening mammography usage.

Screening mammography is effective in the early detection of breast cancer among women aged 50 through 69, but under utilization by the target age group is common. The present study determined how past mammography behavior and intentions to have a mammogram were related to screening behaviors, attitudes, and beliefs. Participants were 1211 Alberta women aged 40 through 75 without breast cancer who were surveyed in a population-based random digit dial telephone interview. The response rate was 78%. Based on the stages of change and adoption models, women were grouped as Screeners (N = 363, 30%), who had had a "checkup" mammogram in the past 24 months and intended to have another in the next 24 months; Intenders (N = 355, 28%), who had not had a mammogram in the past 24 months but intended to have one in the next 24 months; and Nonparticipants (N = 513, 42%), who neither had had a mammogram in the past 24 months nor intended to have one in the next 24 months. Compared with Screeners, both Intenders and Nonparticipants were more likely to live in the rural areas and to have lower educational levels. Nonparticipants were also older, less likely to be married, of lower income, and less likely to be employed outside of the home. Separate logistic regression analyses showed that both Intenders and Nonparticipants were significantly less able to encourage a friend to have a mammogram (OR = 2.7 and 4.4, respectively), more likely to believe that most women were not getting screening mammograms (OR = 1.7 and 2.9, respectively), and less likely to believe symptoms were not needed for mammograms (OR = 0.3 and 0.1, respectively). In addition, Nonparticipants were also significantly more likely to believe that getting a mammogram would not reassure others (OR = 4.0) and less able to talk to a doctor about getting a mammogram (OR = 5.2). Adoption of screening can be seen as a continuum in which Screeners had the most positive and Nonparticipants the most negative breast cancer screening attitudes, beliefs, and early detection behaviors. The importance of physician referral and utilization of other information dissemination channels was highlighted.

Risks and probabilities of breast cancer: short-term versus lifetime probabilities.

OBJECTIVE: To calculate age-specific short-term and lifetime probabilities of breast cancer among a cohort of Canadian women. DESIGN: Double decrement life table. SETTING: Alberta. SUBJECTS: Women with first invasive breast cancers registered with the Alberta Cancer Registry between 1985 and 1987. MAIN OUTCOME MEASURES: Lifetime probability of breast cancer from birth and for women at various ages; short-term (up to 10 years) probability of breast cancer for women at various ages. RESULTS: The lifetime probability of breast cancer is 10.17% at birth and peaks at 10.34% at age 25 years, after which it decreases owing to a decline in the number of years over which breast cancer risk will be experienced. However, the probability of manifesting breast cancer in the next year increases steadily from the age of 30 onward, reaching 0.36% at 85 years. The probability of manifesting the disease within the next 10 years peaks at 2.97% at age 70 and decreases thereafter, again owing to declining probabilities of surviving the interval. CONCLUSIONS: Given that the incidence of breast cancer among Albertan women during the study period was similar to the national average, we conclude that currently more than 1 in 10 women in Canada can expect to have breast cancer at some point during their life. However, risk varies considerably over a woman's lifetime, with most risk concentrated after age 49. On the basis of the shorter-term age-specific risks that we present, the clinician can put breast cancer risk into perspective for younger women and heighten awareness among women aged 50 years or more.

Quality assurance and cancer detection rates in a provincial screening mammography program. Work in progress.

In 1990, a provincial screening program was inaugurated in Alberta, a Canadian province of 2.4 million people. The goal of the program is to decrease the number of deaths from breast cancer by 30% in women aged 50-69 years. In the first 18 months of program operations, efforts were concentrated on high levels of quality assurance in all areas of program activities. In particular, the abnormality referral rates, cancer detection rates, and size and stage of mammographically detected cancers were evaluated. Of the 9,553 women seen, 8,524 were between the ages of 50 and 69 years. Reported abnormality rates were initially more than 16%, but were brought down steadily to less than 5%. Cancer detection rates increased with age, ranging from 1.9 cancers detected per 1,000 women aged 40-49 years to 14.1 cancers per 1,000 women aged 70 years and older. Forty-one of the 61 cancers detected (67%) were less than 1.5 cm in diameter. Forty-three of the 52 cancers (83%) in which the nodal status was known were node negative. At the conclusion of the first 18 months of operation, interpretation parameters were within the target zones expected for a population-based screening program.

Evaluation of a Candida antigen detection method (Cand-Tec): Experience from a university teaching hospital.

The usefulness of a rapid latex agglutination method for the detection of Candida antigen (Cand-Tec; Ramco Laboratories. Texas) was retrospectively assessed in a university teaching hospital over a one year period. Patients were enrolled when the managing physician requested Cand-Tec testing for confirmation of possible invasive candidal infection. The majority of patients were critically ill; 56% were in the intensive care unit, and 30% subsequently died. Analyses were available from 79 patients and 125 samples. Thirty-three patients were diagnosed as having either definite invasive candidiasis or a high probability of infection based upon clinical, microbiological and tissue criteria. The sensitivity and specificity of Candida antigen detection was determined for doubling titres ≥1:4 to ≥1:16. If a titre of ≥1:4 was used as the diagnostic cut-off level for definite candidal infection, overall sensitivity and specificity were 77% and 69%, respectively, while the positive predictive value was 48%, and the negative predictive value 89%. When patients with a high probability of invasive candidal infection were included in analyses for a cut-off titre of ≥1:4, overall sensitivity and specificity were 70% and 69%, respectively, while the positive predictive value was 68%, and the negative predictive value 71%. The usefulness of the Cand-Tec test was not improved further for any subgroup of patients (including those in the intensive care unit), nor by following serial titres in individual patients. In this experience, the Cand-Tec test did not add enough information to include definitively or exclude invasive candidiasis in this high risk general patient population.

Frequency of hereditary nonpolyposis colorectal cancer in southern Alberta.

The frequency of hereditary nonpolyposis colorectal cancer was evaluated in a group of colorectal cancer patients under age 50 diagnosed in southern Alberta between 1973 and 1987. Families were identified as positive for this syndrome if three first-degree relatives in the kindred had colorectal cancer. Of the 390 patients with adenocarcinoma, 318 patients participated. The frequency of hereditary nonpolyposis colorectal cancer was 3.1% (12 families) in this group (Ci95 1.6-5.3%). Clinical characteristics reported on from the index patients include tumor location, Dukes stage at presentation, frequency of synchronous and metachronous tumors, frequency of second primaries, and survival. The 5- and 10-year actuarial survival was 86% and 69%, respectively.

Self-reported illness and risk behaviours amongst Canadian travellers while abroad.

403 travellers who attended The University of Calgary International Travel Clinic between August 1, 1987 and June 1, 1988, were asked to return a questionnaire detailing health, illness and risk factors while abroad. Of the 296 respondents, most travelled for fewer than 6 weeks time; destinations were primarily areas where chloroquine-resistant Plasmodium falciparum had been reported. Diarrhea was experienced by 57.3% of respondents; eating food purchased from street vendors was found to be a significant risk factor. Travellers who made trips exceeding 60 days' duration were significantly more likely to experience skin rashes, fevers or diarrhea, although it could not be determined whether this was due to their higher likelihood of undertaking high-risk behaviours, or to a higher number of person-days at risk. The findings of this high rate of illness while abroad underscores the need for specific advice on appropriate risk avoidance behaviours when pre-travel medical visits occur. Further prospective studies to determine effectiveness of such advice, and the patterns of illness based on person-days at risk, are required.

Gender, family status, and career patterns of graduates of the University of Calgary Faculty of Medicine.

In 1986 the authors sent a questionnaire to 745 physicians who had graduated between 1973 and 1985 from The University of Calgary Faculty of Medicine. The survey obtained information on the graduates' status as parents, the "breaks" they had taken from their practices, and the hours per week they devoted to direct patient care, in order to observe what relationship the graduates' gender and status as parents had on the other variables. The women were far more likely to have taken breaks for parental leave, but the differences in the frequencies of breaks taken by the men and the women for other reasons were less striking. The women were working fewer hours in direct patient-care settings, and those women who were parents and under 35 years old spent fewer hours on patient care than did the men (from all age groups) who were parents. The authors discuss their findings in terms of the impacts of age and cohort effects and the possible lessening of gender-based differences in present-day physicians' practices.