Differential Regulation of Circadian Clock Genes by UV-B Radiation and 1,25-Dihydroxyvitamin D: A Pilot Study during Different Stages of Skin Photocarcinogenesis

BACKGROUND

Increasing evidence points at an important physiological role of the timekeeping system, known as the circadian clock (CC), regulating not only our sleep-awake rhythm but additionally many other cellular processes in peripheral tissues. It was shown in various cell types that environmental stressors, including ultraviolet B radiation (UV-B), modulate the expression of genes that regulate the CC (CCGs) and that these CCGs modulate susceptibility for UV-B-induced cellular damage. It was the aim of this pilot study to gain further insights into the CCs' putative role for UV-B-induced photocarcinogenesis of skin cancer.

METHODS

Applying RT-PCR, we analyzed the expression of two core CCGs (brain and muscle ARNT-like 1 (Bmal1) and Period-2 (Per2)) over several time points (0-60 h) in HaCaT cells with and without 1,25-dihydroxyvitamin D (D3) and/or UV-B and conducted a cosinor analysis to evaluate the effects of those conditions on the circadian rhythm and an extended mixed-effects linear modeling to account for both fixed effects of experimental conditions and random inter-individual variability. Next, we investigated the expression of these two genes in keratinocytes representing different stages of skin photocarcinogenesis, comparing normal (Normal Human Epidermal Keratinocytes-NHEK; p53 wild type), precancerous (HaCaT keratinocytes; mutated p53 status), and malignant (Squamous Cell Carcinoma SCL-1; p53 null status) keratinocytes after 12 h under the same conditions.

RESULTS

We demonstrated that in HaCaT cells, Bmal1 showed a robust circadian rhythm, while the evidence for Per2 was limited. Overall expression of both genes, but especially for Bmal1, was increased following UV-B treatment, while Per2 showed a suppressed overall expression following D3. Both UVB and 1,25(OH)2D3 suggested a significant phase shift for Bmal1 (p < 0.05 for the acrophase), while no specific effect on the amplitude could be evidenced. Differential effects on the expression of BMAL1 and Per2 were found when we compared different treatment modalities (UV-B and/or D3) or cell types (NHEK, HaCaT, and SCL-1 cells).

CONCLUSIONS

Comparing epidermal keratinocytes representing different stages of skin photocarcinogenesis, we provide further evidence for an independently operating timekeeping system in human skin, which is regulated by UV-B and disturbed during skin photocarcinogenesis. Our finding that this pattern of circadian rhythm was differentially altered by treatment with UV-B, as compared with treatment with D3, does not support the hypothesis that the expression of these CCGs may be regulated via UV-B-induced synthesis of vitamin D but might be introducing a novel photoprotective property of vitamin D through the circadian clock.

Grief and loss in old age: Exploration of the association between grief and depression

BACKGROUND

The proportion of older adults is increasing due to demographic changes. Depression belongs to the most common mental disorders in late life. The loss of an emotionally significant person is a risk factor for the development of depression. The aim of this study is to analyze the association between depression and grief burden resulting from loss. Based on prior evidence, we examined loneliness as a possible mediator and social support as possible moderator of this association.

METHODS

The cross-sectional analyses are based on a sample (N = 863) of study participants aged 75+ (M = 81.4 years, SD = 4.4, 62.2% female) with loss experience deriving from the multicenter prospective German cohort study AgeMooDe. Regression analyses (moderated mediation) were performed.

RESULTS

With increasing age (β = 0.10, p = .005) and grief burden (β = 0.33, p <. 001) depression severity increased. There was an indirect mediating effect of loneliness on the correlation of grief burden and depression (b = 0.04, CI [0.03, 0.05]), but no moderating effect of social support on the correlation of grief burden and loneliness. People living alone had a significantly higher risk of depression, increased loneliness and lack of social support.

LIMITATIONS

Assessments were based on self-reporting and recorded dimensionally. The cross-sectional design limits conclusions about directions and causality of associations. Sampling bias cannot be completely excluded.

CONCLUSION

The study provides empirical evidence and a better understanding of the association between grief and depression among the very old and the mediating role of loneliness.

Postnatally acquired CMV meningitis diagnosed via BioFire FilmArray: A case report

Postnatally acquired cytomegalovirus (CMV) is commonly acquired via breast milk, with premature infants more frequently developing symptoms of CMV infection in comparison to term infants. Meningitis is a rare clinical manifestation of CMV infection. The diagnosis of meningitis is difficult to make in infants, particularly those who are preterm. Consequentially, broad-spectrum empiric antimicrobial coverage is often administered for several days while waiting for current gold standard CSF testing to result. The BioFire FilmArray (BFA) simultaneously tests for 14 different pathogens, including CMV, allowing for quicker diagnosis and shorter time to definitive treatment. Here, we report a very low birth weight infant with postnatally acquired CMV meningitis, the first to our knowledge to be diagnosed using the BioFire FilmArray.

Influences on students' empathy in medical education: an exploratory interview study with medical students in their third and last year

BACKGROUND

Empathy is beneficial for patients and physicians. It facilitates treatment and improves physical and psychosocial outcomes. The therapeutic relevance of empathy emphasizes the need to help medical students develop their empathic abilities. Our study aimed to identify factors which promote or hinder the development and expression of empathy in medical students during the course of their studies.

METHODS

We interviewed 24 medical students (six male and six female students in their 6th semester as well as six male and six female students in their final clinical year) using semi-structured interviews. The interviews were recorded, transcribed verbatim and analyzed using Braun & Clarke's thematic analysis.

RESULTS

We identified four main themes influencing the development and expression of empathy. 1) Course of studies: hands-on-experience, role models, science and theory, and emphasis on the importance of empathy; 2) students: insecurities and lack of routine, increasing professionalism, previous work experiences, professional distance, mood, maturity, and personal level of empathy; 3) patients: "easy" and "difficult" patients including their state of health; and 4) surrounding conditions: time pressure/stress, work environment, and job dissatisfaction.

CONCLUSIONS

The development and use of empathy could be promoted by increasing: hands-on-experiences, possibilities to experience the patient's point of view and offering patient contact early in the curriculum. Students need support in reflecting on their actions, behavior and experiences with patients. Instructors need time and opportunities to reflect on their own communication with and treatment of patients, on their teaching behavior, and on their function as role models for treating patients empathically and preventing stress. Practical experiences should be made less stressful for students. The current changes implemented in some medical school curriculums (e.g., in Germany) seem to go in the right direction by integrating patient contact early on in the curriculum and focusing more on teaching adequate communication and interaction behaviors.

Abstract P2-09-09: Polyligand profiling differentiates cancer patients according to their benefit of treatment

Introduction: Deconvolution of multi-nodal perturbations in cancer network architecture demands highly multiplexed profiling assays. We demonstrate the value of polyligand profiling of tumor systems states using libraries of single stranded oligodeoxynucleotides (ssODN) to distinguish between tumor tissue from breast cancer patients who did or did not derive benefit from treatment regimens containing trastuzumab.

Methods: This study included cases from women with invasive breast cancer who received chemotherapy+ trastuzumab (C+T) or trastuzumab monotherapy with available retrospective data on the time to next treatment (TTNT). A library of 2x1012 unique ssODN was exposed to FFPE tissues from patients who benefited (B) or not (NB) from trastuzumab-based regimens in several rounds of positive and negative selection. Two enriched libraries were screened on independent set of 42 B and 19 NB cases using a modified IHC protocol for detection of bound ssODNs. Poly-Ligand Profiles (PLP) were scored by a blinded pathologist. Two libraries, EL-NB and EL-B, showed significant p-values between groups of responders and non-responders. A Cox-PH model was fitted using either tumors' HER2 status or PLP test results as the independent variable. Median survival time was calculated from the Kaplan-Meier estimate. A separate group of 63 cases with TTNT data from chemotherapy without trastuzumab was used as a control to distinguish prognostic from predictive performance.

Results: The PLP scores of EL-NB and EL-B were assessed by receiver operating characteristic (ROC) curves and resulted in a combined AUC value of 0.81. EL-NB and EL-B were able to effectively classify B and NB patients with either HER2-negative/equivocal (AUC = 0.73) or HER2-positive cancers (AUC = 0.84). In contrast, HER2 status alone yielded an AUC value of 0.47. The combined PLP scores for the independent set of 63 patients treated with C excluding trastuzumab resulted in an AUC value of 0.53, indicating that the assay was predictive and not simply prognostic. Kaplan-Meier curves analysis shows that PLP+ cases have 429 days median TTNT, while PLP- cases have 129 days (HR = 0.38, log-rank p = 0.001). Analysis based on HER2 status showed no significant difference in TTNT between patients that were HER2+ (280 days) or HER2-negative/equivocal (336 days, HR = 1.27, log-rank p =0.45).

Summary: Performance of the PLP assay in differentiating patients who did or did not benefit from trastuzumab therapy outperforms the standard IHC assay for HER2 status. These results represent a promising step towards the development of a CDx to identify the 50-70% of HER2+ patients who will not benefit from trastuzumab. In addition, PLP also has the potential to identify the HER2-negative/equivocal patients who may benefit from trastuzumab-containing regimens.

Citation Format: Domenyuk V, Gatalica Z, Santhanam R, Wei X, Stark A, Kennedy P, Toussaint B, Levenberg S, Wang R, Xiao N, Greil R, Rinnerthaler G, Gampenrieder S, Heimberger AB, Berry DJ, Barker A, Demetri GD, Quackenbush J, Marshall JL, Poste G, Vacirca JL, Vidal GA, Schwartzberg LS, Halbert DD, Voss A, Miglarese MR, Famulok M, Mayer G, Spetzler D. Polyligand profiling differentiates cancer patients according to their benefit of treatment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-09.

Abstract P4-12-08: Use of an aptamer library based next generation omics platform for the development of a novel trastuzumab predictive assay

Introduction: Previous attempts to use individual aptamers as diagnostic reagents have failed to consistently achieve performance comparable to antibodies. Here we report a novel systems biology approach using poly-ligand aptamer libraries to identify responders and non-responders to traztuzumab-based regimens in metastatic breast cancer.

Methods: To overcome the fundamental limitation of the individual aptamer binding affinities, large libraries (106 species) were created so that potentially thousands of aptamers could bind to each of a multitude of targets related to the whole cellular changes in response to trastuzumab therapy. A set of breast cancer patients, which received trastuzumab mono- or combined therapy for at least 7 months were classified as “Responders” (R); cases with particular regimen discontinued in the period not exceeding 5 months were classified as “Non-Responders”(NR). A library of 2x1012 unique 90-mer ssDNA oligodeoxynucleotides (ssODN) was trained on FFPE tissue of both R and NR patients. Partitioning of aptamer libraries was done by microdissection of the tumor tissue, after incubation of aptamer library with the entire tissue section, to drive selection pressure toward cancer cells. A total of 10 cases of R and NR, 6 Her2+ cases each, were used to train separate aptamer libraries, with 1 positive and 2 counter selection cases per enrichment. Enriched libraries were screened on 20 R and 20 NR cases (11 Her2+ cases each) by adopting modified immunohistochemistry protocol. Each library was used as an independent reagent (similar to an antibody in IHC) across all 40 cases to evaluate the efficacy of the aptamer library to distinguish differences between the R and NR groups. Staining (DAB chromogen) profiles were scored from 0 to 3+ (nuclear and cytoplasmic staining) by a pathologist without any knowledge of the clinical outcomes. Initial validation was done by t-test using raw histological scores. Four libraries showed significant p-values between groups of responders and non-responders, a classification algorithm was constructed and evaluated using area under the receiver-operator characteristic curve (AUC). The datasets of two best-performing libraries were combined into one model using logistic regression to further improved the classifier performance.

Results: Of seventeen trained libraries, eight were evaluated and four showed significant correlation to clinical benefit with a minimum accuracy of 75% for each library when evaluated independently. Furthermore, two libraries showed exceptional performance (ROC curve AUC of 0.86 and 0.77). Combination of the profiling data from these two libraries using logistic regression resulted in an AUC of 0.985. A prospective validation of aptamer histochemical theranostic testing has been initiated.

Summary: Enriched aptamer libraries appear to distinguish trastuzumab responsiveness in metastatic breast cancer. This technology could be used as an additional technique beyond FISH testing to determine sensitivity to anti-HER2 agents. The demonstrated platform is applicable to virtually any disease where the safe and effective use of corresponding drug is yet to be improved.

Citation Format: Spetzler D, Domenyuk V, Santhanam R, Wei X, Stark A, Wang J, Gatalica Z, Miglarese M, Vidal G, Schwartzberg LS. Use of an aptamer library based next generation omics platform for the development of a novel trastuzumab predictive assay [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-08.

Abstract P6-12-14: Comparative analysis of breast cancer phenotypes in African American, White American, and African patients- Correlation between African ancestry and triple negative breast cancer

Introduction: Population-based incidence rates of triple negative breast cancer (TNBC) are higher for African American (AA) compared to White American (WA) women, but it is unclear whether TNBC risk is genetically associated with African ancestry because AA women represent an ancestrally admixed population. Higher frequencies of TNBC have also been observed in sub-Saharan African breast cancer (BC) patients, but comparative analyses of biomarker expression among datasets that include AA, WA, and African women are sparse. We report findings from an international registry that features specimens from a diverse patient population in Detroit, Michigan as well as a hospital in Kumasi, Ghana.

Methods: The study dataset included formalin-fixed, paraffin-embedded invasive BC tumors diagnosed between 1998 and 2014 at the Komfo Anokye Teaching Hospital in Ghana and the prospectively-maintained/annotated Henry Ford Health System cohort in Michigan. All Ghanaian tumors underwent pathology confirmation and immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR) and HER2/neu expression at the University of Michigan. Women were classified into five BC phenotypes and dichotomized into two age groups, &lt;50 and ≥50 years. Polychotomous multivariate GLM models were developed to estimate the risk for each BC phenotype. Statistical analyses were performed in SAS v. 9.0 (Carey, NC). This research was approved by the Institutional Review Boards of the participating institutions.

Results: A total of 234 Ghanaian cases with mean age 49 years (range 24-92); 271 AA with mean age 60 (range 27-87); and 321 WA with mean age 62 (range 31-91) (P=0.001) contributed to this study. Prevalence of histologic grade 3 was lowest in WA (n=107, 33.7%) which was statistically significant from the observed prevalence in AA (n=135, 50.4%) and Ghanaians (n=84, 53.8%) (P&lt;0.0001). ER-negative and TNBC were more common among Ghanaian and AA compared to WA cases (frequency ER-negativity 67.5%, 37.1%, and 19.8%, respectively, p&lt;0.0001; frequency TNBC 53.2%, 29.8%, and 15.5%, respectively, p&lt;0.0001). In the age group &lt;50 years, 82 women (42.5%) were diagnosed with ER+/PR+/HER2-, 65 (33.7%) with TNBC, 27 (14.0%) with ER+/PR+/HER2+, 14 (7.2%) with ER-/PR-/HER2+ and 5(2.6%) with ER-/PR+/HER2- phenotypes. In this young age group, prevalence of TNBC remained highest among Ghanaian women (50.8%), followed by AA (34.3%) and WA (15.9%); (P=.0006). In contrast, highest prevalence of ER+/PR+/HER2+ and ER+/PR+/HER2- phenotypes was observed in WA, followed by AA and Ghanaians. On multivariate analysis histologic grade 3 and racial heritage remained statistically significantly associated with the TNBC phenotype (OR for AA vs. WA with TNBC 1.87, 95% CI 1.15-3.04; OR for Ghanaian vs. WA with TNBC 10.63, 95% CI 5.32-21.25; OR for Grade 3 vs Grade 1 histology with TNBC 33.3, 95% CI 13.45-82.4).

Conclusions: This study confirms an association between the TNBC phenotype and African ancestry; furthermore, extent of African ancestry appears to be associated with an increased likelihood of having a TNBC tumor, since frequency of TNBC among AA patients was intermediate between WA and Ghanaian patients.

Citation Format: Newman LA, Jiagge E, Bensenhaver JM, Chitale D, Kleer C, Merajver S, Kyei I, Aitpillah F, Oppong J, Amankwaa-Frempong E, Adjei E, Wicha M, Awuah B, Stark A. Comparative analysis of breast cancer phenotypes in African American, White American, and African patients- Correlation between African ancestry and triple negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-14.

Abstract P2-01-08: Adaptive dynamic artificial poly-ligand targeting: Aptamer-based profiling of liquid biopsies to improve the accuracy of breast cancer diagnoses in women with dense breast tissue

Introduction:

Breast cancer screening relies upon mammography, but for women with dense breast tissue this method is often uninformative. Routine screening identifies suspicious breast lesions in some women, but the pain and risk associated with follow-up biopsies along with the poor accuracy of traditional histopathology urgently call for improved approaches to breast cancer screening. This is especially important for those high-risk patients for whom mammography is of limited value. We describe a non-invasive liquid biopsy method of profiling plasma exosome preps designed to improve the accuracy and safety of breast cancer screening for women with dense breast tissue.

Results:

We incubated plasma samples (300 microliters per sample) from breast cancer patients (n=60) and a control cohort (n=60) with a high-complexity DNA aptamer library using a modified SELEX scheme, termed “adaptive dynamic artificial poly-ligand targeting (ADAPTTM)”. Differentially bound (cancer vs. non-cancer) aptamers were recovered from precipitated exosomes and were identified by deep sequencing. Two thousand aptamer sequences were resynthesized and used to probe a larger set of 500 plasma samples from a patient cohort (n=206) and a control cohort comprised of self-reported healthy volunteers (n=117) and patients whose biopsies led to a diagnosis of non-cancer (n=177). We employed several statistical models to build a cancer/non-cancer predictor, including a Random Generalized Linear Model (RGLM) and a Random Forest Model (RFM). Both models yielded an equivalent classification performance with areas under the receiver-operator characteristic curve (ROC AUC) of 0.7. Testing the prediction performance by 100 Out-of-Bag permutations or by pre-filtered (read cutoff and estimated sample size) cross-validation (CV) resulted in ROC AUC values of 0.66 and 0.62, respectively. When samples were randomly assigned to groups, the aptamers were no longer able to distinguish the groups (ROC AUC = 0.54), indicating that the underlying information driving the model is truly specific to cancer. Importantly, incorporation of BIRAD results as a clinical covariate did not influence model performance, signifying that predictions by ADAPTTM were independent of breast tissue density.

Conclusions:

We have identified a set of 2000 DNA aptamers that distinguish women with breast cancer from women without breast cancer. Our liquid biopsy approach requires only 300 microliters of plasma and is amenable to high-throughput processing. By employing a number of statistical approaches including rigorous cross-validation, we consistently achieve cross validation ROC AUC values approaching 0.7. The performance of the predictor was not affected by BIRAD scores, supporting its potential utility in difficult cases where imaging is insufficient, such as in women with dense breast tissue. Further optimization of the aptamer library and testing on additional samples should improve performance. Upon complete validation, an ADAPTTM – derived breast cancer test may serve as a vital diagnostic adjunct that can be easily incorporated into standard clinical practice.

Citation Format: Domenyuk V, Zhong Z, Wang J, Stark A, Chen W, Xiao N, Miglarese MR, Famulok M, Mayer G, Spetzler DB. Adaptive dynamic artificial poly-ligand targeting: Aptamer-based profiling of liquid biopsies to improve the accuracy of breast cancer diagnoses in women with dense breast tissue. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-01-08.

In situ synchrotron radiation measurements of orthorhombic phase formation in an advanced TiAl alloy with modulated microstructure

New low aluminium high niobium TiAl alloys exhibit a nano scale modulated microstructure consisting of lamellae with a tweed substructure. These tweed like appearing lamellae are a modulated arrangement of at least two phases. One constituent of the crystallographic modulation in the lamellae is an orthorhombic phase, which is closely related to both the hexagonal α2-Ti3Al phase and the cubic B2 ordered βo-TiAl phase.

In this study the nature and formation of this orthorhombic phase has been investigated by high-energy X-ray diffraction.

Measurements have shown that the newly formed orthorhombic phase is structurally comparable to the O phase (Ti2AlNb). It forms in the temperature range of 550 °C to 670 °C from the α2 phase by small atomic displacements and chemical reordering. The in situ experiments yielded information about the thermal stability of the orthorhombic phase. After dissolving at temperatures above 700 °C the phase can be re-precipitated by annealing within the temperature range of formation.

Solid-ionic liquid interfaces: pore filling revisited

The properties of ionic liquids on ordered and non-ordered mesoporous silicas (silica gel, MCM-41, SBA-15) were studied by nitrogen sorption, mercury intrusion and thermogravimetric analyses, as well as (129)Xe-NMR spectroscopy. The ionic liquids investigated are based on the 1-hexyl-3-methylimidazolium cation, which was combined with anions of low (bis(trifluoromethanesulfonyl)imide; [NTf2](-)), medium (trifluoromethylsulfonate; [CF3SO3](-)) to high (acetate; [OAc](-)) basicity. The surface coverage depends on both the type of ionic liquid and support used. This results not only in layer or droplet formation, but also in different physico-chemical properties of the ionic liquid when compared to the bulk, depending mainly on the strength of interaction at the interface. Furthermore, the mercury intrusion analysis of mesopores is shown not to be suitable for supported ionic liquids.

Neutron and synchrotron probes in the development of Co–Re-based alloys for next generation gas turbines with an emphasis on the influence of boron additives

Nickel-based superalloys are the materials of choice in the hot section of current gas turbines, but they are reaching temperature limits constrained by their melting temperature range. Co–Re alloy development was prompted by a search for new materials for future gas turbines, where the temperature of application will be considerably higher. Addition of the very high melting point refractory metal Re to Co can increase the melting range of Co alloys to much higher temperatures than the commercial Co alloys in use today. The alloy development strategy is first discussed very briefly. In this program, model ternary and quaternary compositions were studied in order to develop a basic understanding of the alloy system.In situneutron and synchrotron measurements (small and wide angle) at high temperatures were extensively used for this purpose and some selected results from thein situmeasurements are presented. In particular, the effect of boron doping in Co–Re–Cr alloys and the stability of the TaC precipitates at high temperatures were investigated. A fine dispersion of TaC precipitates strengthens some Co–Re alloys, and their stability at the application temperature is critical for the long-term creep properties.

Colostrogenesis during an induced lactation in dairy cattle

Colostrum immunoglobulin G (IgG) is of major importance for the newborn calf because epitheliochorial placentae do not provide transport in utero. The formation of colostrum occurs in the later stages of pregnancy. Our objectives were to induce lactation in non-pregnant dairy cows and (i) to determine the changes of IgG in serum and mammary secretions during the induction process and (ii) to establish α-lactalbumin (αLA) and prolactin (Prl) alterations to monitor the changing mammary epithelial tight junction status and development pattern. Estradiol-17β (E2) and progesterone (P4) injections in a 1-7 days series were combined with a 3-day injection series (day 21-23) of dexamethasone (DEX). Blood and both front quarter secretion samples were collected daily. Milking started 24 days after the start of the experiment. Results show that the mammary secretory IgG1 was increased at >7 days after the start of steroid injections and depicted a bimodal pattern reaching a high of 16 mg/ml at 21 day compared with 3.2 mg/ml in the serum. There was a small increase in secretory IgG2 that did not correlate with tight junction status, but never reached the serum concentration. The injections of DEX resulted in constriction of tight junctions. Secretory αLA was immediately increased with steroid injections, dropped precipitously after 7 days and then began a steady increase until the start of milking. Changes in serum αLA are related to mammary tight junctions while serum Prl gradually increased from 30 to >60 ng/ml after the steroid injections stopped. These results provide insights into the mechanisms and timing of colostrogenesis during an induced lactation protocol.

Abstract P6-11-04: Profound prevention of experimental brain metastases of breast cancer by temozolomide in a MGMT-dependent manner

Purpose: Brain metastases of breast cancer cause neurocognitive damage and are incurable. We evaluated in experimental brain metastasis model a role of temozolomide, an oral brain permeable alkylating agent characterized by significant uptake in the central nervous system, in the prevention of brain metastases of breast cancer.

Material and methods: To assess preventive role of temozolomide, mice were inoculated with 175,000 triple-negative 231-BR-EGFP cells in 0.1 mL PBS in the left ventricle of the heart. Three days after tumor cell inoculation, mice were randomized to temozolomide at the dose of 50 mg/kg delivered by oral gavage in saline, 5 days a week for 4 weeks, or vehicle. Subsequent experiments used temozolomide doses of 25, 10, 5, 1 and 0.5 mg/kg. To evaluate the efficacy of temozolomide in treating established BM, mice received temozolomide (50 mg/kg) beginning on either day 18 or day 24 post-injection of 231-BR-EGFR cells, 5 days a week for two and one week, respectively. To investigate the impact of temozolomide on survival, mice injected with 231-BR-EGFP cells were randomized to vehicle, temozolomide on days 3-14, or temozolomide on days 17-28 post-injection, per the schedule described above. To determine the functional contribution of MGMT expression in the BM preventive model, similar experiments were performed using 231-BR-EGFP cells with induced MGMT expression, and MGMT-positive Jimt-1 cells. Metastases were counted in step sections of one hemisphere of each brain. Additionally, the percentage of MGMT-positive tumor cells in 62 patient-matched sets of breast cancer primary tumors and resected brain metastases was determined immunohistochemically.

Results: Temozolomide, when dosed at 50, 25, 10 or 5 mg/kg, 5 days/week, beginning 3 days after inoculation, completely prevented the formation of experimental brain metastases from MGMT-negative 231-BR-EGFP cell line. At a 1 mg/kg dose, temozolomide prevented 68% of large brain metastases, and was ineffective at a dose of 0.5 mg/kg. When the 50 mg/kg dose was administered beginning on days 18 or 24, temozolomide efficacy was reduced or absent. Both schedules of temozolomide (days 3-14 and days 17-28) significantly increased survival (P = .0003 by long-rank test). Earlier administration of temozolomide resulted in long term survival of 6 and 2 out of 10 mice, respectively; a significant difference compared to vehicle (P &lt; .0001 and .0003, respectively).Temozolomide was ineffective at preventing brain metastases in the MGMT-positive 231-BR-EGFP and Jimt-BR3 sublines. In 62 patient-matched sets of primary breast tumors and resected brain metastases 43.5% of the specimens had concordant low MGMT expression, while in another 14.5% sets high MGMT staining in the primary tumor corresponded with low staining in the brain metastasis.

Conclusions: Temozolomide profoundly prevents the outgrowth of experimental brain metastases of breast cancer in a MGMT-dependent manner. The majority of patients had low MGMT expressing brain metastases. These data provide a compelling rationale for investigating preventive efficacy of temozolomide in high-risk advanced breast cancer patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-04.

The influence of comorbidity scores on re-operations following primary total hip replacement: comparison and validation of three comorbidity measures

While an increasing amount of arthroplasty articles report comorbidity measures, none have been validated for outcomes. In this study, we compared commonly used International Classification of Diseases-based comorbidity measures with re-operation rates after total hip replacement (THR). Scores used included the Charlson, the Royal College of Surgeons Charlson, and the Elixhauser comorbidity score. We identified a nationwide cohort of 134 423 THRs from the Swedish Hip Arthroplasty Register. Re-operations were registered post-operatively for up to 12 years. The hazard ratio was estimated by Cox's proportional hazards regression, and we used C-statistics to assess each measure's ability to predict re-operation. Confounding variables were age, gender, type of implant fixation, hospital category, hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant relationship with increased risk of re-operation, with increased scores for both one to two and three or more comorbidities. However, the predictive C-statistic in this period for the Elixhauser score was poor (0.52). None of the measures proved to be of any value between two and 12 years. They might be of value in large cohort or registry studies, but not for the individual patient.

Dynamic Recovery and Recrystallization during Hot-Working in an Advanced TiAl Alloy

Intermetallic TiAl alloys are light-weight high-temperature materials and intended to partly replace Ni based alloys in jet engines. Due to difficult forming operations, component prices are high and limit the possible field of application. During hot-working, recovery and recrystallization effects determine the microstructural evolution and thereby the mechanical properties of the finished part as well as its behavior during deformation. To study the occurring phenomena, in-situ diffraction experiments with high-energy X-rays were conducted. By means of this method, the dominating processes were identified. The results were validated through electron back scatter diffraction experiments.

Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells

Bovine colostrogenesis is distinguished by the specific transfer of IgG1 from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E2 ) and progesterone (P4 ) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta-2-Microglobulin (β2M). We hypothesized that steroid hormone treatments (E2 and P4 ) of bovine mammary epithelial cells in vitro would induce up-regulation of IgG1 transcytosis candidate gene mRNA expression suggesting involvement in IgG1 transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up-regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG1 transcytosis in bovine mammary cells.

Abstract P4-13-12: Identifying women at increased risk for breast cancer using the electronic health record in an integrated health system

Women at increased risk for breast cancer (BC) are eligible to take selective estrogen receptor modulators (SERMs) to reduce their risk; Food and Drug Administration (FDA) approval of tamoxifen or raloxifene for BC risk reduction and American Society of Clinical Oncology (ASCO) guidelines for the use of SERMs recommend the two drugs for any woman over the age of 35 years with a 5-year risk of 1.67% or greater, but identifying those women can be both challenging and costly. We used an electronic database (Centricity RIS-IC) from the Geisinger Health System (GHS) Department of Radiology with 77,000 women ages 35–90 years to calculate 5-year and lifetime risks of developing invasive BC using National Cancer Institute's (NCI) Breast Cancer Risk Assessment Macro (BrCa RAM). BrCa RAM calculates risk based on patient age, number of biopsies, did a biopsy ever display atypical hyperplasia (Yes/No), age at menarche, age at first live birth, number of first degree relatives with breast cancer, and patient race. Demographic information (age, race, sex) was obtained from the electronic health record (EpicCare), pathology information (number of biopsies, atypical hyperplasia) was obtained from the pathology application (CoPath), and personal history (number of first degree relatives with breast cancer) were obtained from RIS. Age at menarche and age at first live birth could not be obtained, but makes a small relative contribution to the risk of BC. Sensitivity analysis explored implications of missing data; imputing ages for age at first live birth and age at menarche showed that the absence of this data did not overestimate the five-year and lifetime risks. There were 5,897 patients with calculated 5-year breast cancer risk 2; mean age was 65.8 years, mean 5-yr risk of BC = 3.05% (max 18.2%). The number of patients by 5-year risk score category were: risk 2–2.5% (n = 1728); 2.5%–3% (n = 3188); 3%+ (n = 981). There were 4,196 patients with a GHS primary care physician (PCP); 5,086 patients had seen any Geisinger physician within the past year; 4,113 women had seen their PCP in the past year. Only 239 patients ever received a prescription for tamoxifen or raloxifene, and some received raloxifene for prevention or treatment of osteoporosis and not for BC risk reduction. Only 40 were currently taking tamoxifen or raloxifene. These data from an integrated health system with an electronic health record validate the under-utilization of SERMs for primary BC risk reduction. Strategies are being designed to increase their use in GHS by using the risk score to identify the population and attempt to intervene using a risk modification clinical program.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-13-12.

Detection of differentially expressed genes in human bladder cancer cells using arbitrarily primed PCR of RNA

The aim of the present study was to detect differentially expressed genes in human bladder cancer cell lines using a non-radioactive RNA fingerprinting technique (arbitrarily primed polymerase chain reaction of RNA, RAP-PCR). The two clonal urothelial cancer cell lines, RT4 and J82, show different growth kinetics upon stimulation with EGF. By RAP-PCR we detected changes in band patterns for J82 cells treated with EGF but not for RT4 cells. Polymorphic fragments were further characterized and sequences from two of these gave a perfect match to the coding sequence of the human tropomyosin gene TM30(pl) and the human MAC30 gene, respectively. In accordance with the results of RAP-PCR downregulation in EGF-stimulated J82 cells could be demonstrated by reverse transcription PCR.

ORAI1 Ca(2+) channels control endothelin-1-induced mitogenesis and melanogenesis in primary human melanocytes

UV radiation of the skin triggers keratinocytes to secrete endothelin-1 (ET-1) that binds to endothelin receptors on neighboring melanocytes. Melanocytes respond with a prolonged increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), which is necessary for proliferation and melanogenesis. A major fraction of the Ca(2+) signal is caused by entry through Ca(2+)-permeable channels of unknown identity in the plasma membrane. ORAI Ca(2+) channels are molecular determinants of Ca(2+) release-activated Ca(2+) (CRAC) channels and are expressed in many tissues. Here, we show that ORAI1-3 and their activating partners stromal interaction molecules 1 and 2 (STIM1 and STIM2) are expressed in human melanocytes. Although ORAI1 is the predominant ORAI isoform, STIM2 mRNA expression exceeds STIM1. Inhibition of ORAI1 by 2-aminoethoxydiphenyl borate (2-APB) or downregulation of ORAI1 by small interfering RNA (siRNA) reduced Ca(2+) entry and CRAC current amplitudes in activated melanocytes. In addition, suppression of ORAI1 caused reduction in the ET-1-induced cellular viability, melanin synthesis, and tyrosinase activity. Our results imply a role for ORAI1 channels in skin pigmentation and their potential involvement in UV-induced stress responses of the human skin.

Ductal carcinoma in situ (DCIS) of the breast: Race- and treatment-adjusted specific disease-free probability

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Background: Findings of DCIS outcome between African-American (AA) and White-American (WA) women are inconclusive.

Methods: We conducted a retrospective longitudinal study with the objective of comparing the risk of any second breast cancer after the first primary DCIS, adjusting for pathologic prognostic indicators, treatment, age, and the established epidemiologic risk factors. Women were diagnosed and treated in one institution between 1990-1999. Diagnostic slides were reviewed and prognostic indicators documented; demographic, clinical and method of detection, screening mammography vs. palpation, were collected from medical records. We applied Accelerated Failure Time Modeling (AFTM) to determine the variables that were best associated with the risk of a second cancer.

Results: 335 women, 29.6% (n=100) AA with mean age of 60 (±13) and 70.4% (n=235) WA with mean age of 57 (±12.4), contributed to this study. Distributions of some of the prognostic indicators and final treatment are presented. (Table) During the 10 years of follow-up 12.0% (n=12) of AA and 3.0% (n=7) WA experienced second cancer in ipsilateral breasts; 5.0% (n=5) of AA and 3.8% (n=9) WA in their contralateral breasts and 2 women, 1 AA and 1 WA, in both breasts. Results from the AFTM yielded race as the only variable associated with the risk of a second cancer but only in ipsilateral breasts (HR= 4.11, 95% CI=1.6-10.5 p=0.003).

Conclusions: No difference in the risk of a second cancer in contralateral breast between AA and WA women support the notion of equal access and equal treatment in comparable treatment outcome. Reasons for increased risk of a second cancer in ipsilateral breast in AA women are being evaluated.

[Table: see text]

Plasticity in cortical motor upper-limb representation following stroke and rehabilitation: two longitudinal multi-joint FMRI case-studies

Motor dysfunction and recovery following stroke and rehabilitation are associated with primary motor cortex plasticity. To better track these effects we studied two patients with sub-acute sub-cortical stroke causing hemiparesis, who underwent an effective behavioral treatment termed Constraint Induced Movement Therapy (CIMT). The therapy involves 2 weeks of intensive motor training of the hemiparetic limb coupled with immobilization of the unaffected limb. The study included a longitudinal series of clinical evaluations and fMRI scans, before and after the treatment. The fMRI task included wrist, elbow, or ankle movements. Activity in the M1 upper-limb region of control subjects was stable, strictly contralateral, and similar in amplitude for elbow and wrist movements. These findings reflect the well-known contralateral motor control and support the idea of overlapping representations of adjacent joints in M1. In both patients, pre-CIMT activation patterns in M1 were tested twice and did not change significantly, were contralateral, and included elbow-wrist differences. Following CIMT, the clinical condition of both patients improved and three fMRI-explored prototypes were found: First, cluster position remained constant; Second, ipsilateral activity appeared in the unaffected hemispheres during hemiparetic movements; Third, patient-specific elbow-wrist inter and intra hemispheric differences were modified. All effects were long-lasting. We suggest that overlapping representations of adjacent joints contributed to the cortical plasticity observed following CIMT. Our findings should be confirmed by studying larger groups of homogeneous patients. Nevertheless, this study introduces multi-joint imaging studies and shows that it is both possible and valuable to carry it out in stroke patients.

Computed tomography analysis of radiostereometric data to determine flexion axes after total joint replacement: application to the elbow joint

Kinematic analysis for in vivo assessment of elbow endoprostheses requires knowledge of the exact positions of motion axes relative to bony landmarks or the prosthesis. A prosthesis-based reference system is required for comparison between individuals and studies. The primary aim of this study was to further develop an earlier described algorithm for fusion of radiostereometric analysis (RSA) data and data obtained in 3D computed tomography (CT) for application to the elbow after total joint replacement. The secondary aim was to propose a method for marking of prostheses in 3D CT, enabling definition of a prosthesis-based reference system. Six patients with elbow endoprostheses were investigated. The fusion of data made it possible to visualize the motion axes in relation to the prostheses in the 3D CT volume. The differences between two repeated positioning repetitions of the longitudinal prosthesis axis were less than 0.6 degrees in the frontal and sagittal planes. Corresponding values for the transverse axis were less than 0.6 degrees in the frontal and less than 1.4 degrees (in four out of six less than 0.6 degrees ) in the horizontal plane. This study shows that by fusion of CT and RSA data it is possible to determine the accurate position of the flexion axes of the elbow joint after total joint replacement in vivo. The proposed method for implant marking and registration of reference axes enables comparison of prosthesis function between patients and studies.

Body mass index at the time of diagnosis and the risk of advanced stages and poorly differentiated cancers of the breast: findings from a case-series study

INTRODUCTION

Obesity is a risk factor for postmenopausal breast cancer and is independently associated with shorter disease-free and overall survival. Currently, in clinical settings, the combination of stage and grade of cancer at the initial presentation of the disease is the best prognostic indicator.

OBJECTIVE

To evaluate the association between body mass index (BMI) and risk of advanced stages and poorly differentiated grade of breast cancer.

DESIGN

A case-series study of women diagnosed with their first primary invasive breast cancer. Patients include a total of 831 women aged >or=40 years with a mean BMI of 29.6(± 6.6)  kg m(-2). Pathological, clinical and demographic data were retrieved from electronic medical records. Multinomial logistic regression analysis was preformed to estimate the risk of more advanced stages and poorly differentiated grade of cancer, adjusting for covariates.

RESULTS

Obese compared with normal weight women had an 80% increased risk of cancer with more advanced stages (III/IV) and poorly differentiated grade (odds ratio = 1.80, 95% confidence interval 1.13-2.86, P = 0.014). No significant increase in risk was observed for overweight women.

CONCLUSION

Obesity at the time of diagnosis of breast cancer is associated with more advanced stages and poorly differentiated grade of cancers.

The disintegrin-metalloproteinases ADAM 10, 12 and 17 are upregulated in invading peripheral tumor cells of basal cell carcinomas

BACKGROUND

Members of the a disintegrin and metalloproteinase (ADAM) family are expressed in malignant tumors and participate in the pathogenesis of cancer. However, the presence of ADAM 10, 12, 17 and their role in basal cell carcinoma (BCC) have not been described. The purpose of this study was to investigate expression of ADAM 10, 12 and 17 in BCC.

METHODS

Expression of ADAM 10, 12 and 17 was analyzed by immunohistochemistry in skin tissues obtained from 25 patients with different types of BCC.

RESULTS

Immunoreactivity of ADAM 10, 12 and 17 was increased at the peripheral tumor margin compared with central areas of BCC tumor cell nests. Immunoreactivity of ADAM 10 and 12 was increased in the deep margin of invading tumor cell nests in mixed BCC. Focally increased expression of ADAM 12 was detected in squamous differentiated tumor cells of nodular BCC. In addition, immunoreactivity of ADAM 17 was increased in superficial BCC.

CONCLUSIONS

ADAM 10, 12 and 17 showed different expression pattern in BCC histologic subtypes, indicating their different role in the BCC pathogenesis. Overexpression of ADAM 10, 12 and 17 immunoreactivity in deep invasion area of BCC indicates that these three proteases may play an important role in the locally invasive and highly destructive growth behavior of BCC. Additionally, we suggest that ADAM 17 may play an important role in early development of BCC.

Intracranial trigeminal nerve metastasis of a desmoplastic neurotropic melanoma: case report

BACKGROUND

Desmoplastic neurotropic mela-noma is a rare and highly malignant variant of melanoma. Solitary nervus trigeminus and Gasserian ganglion metastasis of a neurotropic melanoma has not been previously described in the literature.

CASE DESCRIPTION

A 69-year-old man presented to our clinic with trigeminal neuralgia. 4 years previously he underwent tumor removal with an initial diagnosis of amelanotic malignant cutaneous melanoma; 1 year later, because of tumor recurrence, the patient underwent neck dissection, chemotherapy and radiation. Magnet resonance imaging (MRI) disclosed an enhancement of the Gasserian ganglion and tumor extension along the mandibular and maxillar nerves of the intracranial part of the trigeminal nerve suggestive of tumor. The intraoperative macroscopic appearance of the tumor was compatible with a neurinoma. Histopathological studies proved the tumor to be a desmoplastic neurotropic melanoma (DNM) that was related to the previously treated malignant melanoma.

CONCLUSION

A metastatic tumor arising solely in a trigeminal nerve from a cutaneous malignant melanoma is quite rare; to our knowledge this may be the first report of such a case in the literature.