IntroductionBreast cancer is still the most common malignancy among women worldwide. The Prospective Breast Cancer Biobank (PBCB) collects blood and urine from patients with breast cancer every 6 or 12 months for 11 years from 2011 to 2030 at two university hospitals in Western Norway. The project aims to identify new biomarkers that enable detection of systemic recurrences at the molecular level. As blood represents the biological interface between the primary tumour, the microenvironment and distant metastases, liquid biopsies represent the ideal medium to monitor the patient‘s cancer biology for identification of patients at high risk of relapse and for early detection systemic relapse.Including patient-reported outcome measures (PROMs) allows for a vast number of possibilities to compare PROM data with biological information, enabling the study of fatigue and Quality of Life in patients with breast cancer.Methods and analysisA total of 1455 patients with early-stage breast cancer are enrolled in the PBCB study, which has a one-armed prospective observational design. Participants consent to contribute liquid biopsies (i.e., peripheral blood and urine samples) every 6 or 12 months for 11 years. The liquid biopsies are the basis for detection of circulating tumour cells, circulating tumour DNA (ctDNA), exosomal micro-RNA (miRNA), miRNA in Tumour Educated Platelet and metabolomic profiles. In addition, participants respond to 10 PROM questionnaires collected annually. Moreover, a control group comprising 200 women without cancer aged 25–70 years will provide the same data.Ethics and disseminationThe general research biobank PBCB was approved by the Ministry of Health and Care Services in 2007, by the Regional Ethics Committee (REK) in 2010 (#2010/1957). The PROM (#2011/2161) and the biomarker study PerMoBreCan (#2015/2010) were approved by REK in 2011 and 2015 respectively. Results will be published in international peer reviewed journals. Deidentified data will be accessible on request.Trial registration numberNCT04488614.

Background Breast cancer represents the most frequent neoplasm diagnosed in women of childbearing age. When the tumour is oestrogen receptor-positive, tamoxifen is among the recommended endocrine treatments. Lactating women are advised not to breastfeed while receiving tamoxifen. However, information about tamoxifen transfer into breast milk is lacking. Methods We measured the concentration of tamoxifen and its metabolites by liquid chromatography-tandem mass spectrometry in the milk of a nursing mother that was treated for pregnancy-associated breast cancer diagnosed a few months after delivery. She was advised not to breastfeed her child and she collected milk samples for 23 days while the baby was fed with formula. Results Tamoxifen concentrations in milk increased reaching a maximum of 214 nM. The two active metabolitesZ-4-hydroxy-tamoxifen and Z-endoxifen, could not be quantified in milk the first days after tamoxifen intake, but increased over time and reached clinically significant levels after day 18. Conclusion This study demonstrates for the first time in human that tamoxifen and its metabolites transfer into milk. Since tamoxifen has a complete oral bioavailability, a long half-life (>7 days) and may interfere with the normal development of the infant, mothers should not breastfeed during tamoxifen treatment.

Tamoxifen is an important targeted endocrine therapy in breast cancer. However, side effects and early discontinuation of tamoxifen remains a barrier for obtaining the improved outcome benefits of long-term tamoxifen treatment. Biomarkers predictive of tamoxifen side effects remain unidentified. The objective of this prospective population-based study was to investigate the value of tamoxifen metabolite concentrations as biomarkers for side effects. A second objective was to assess the validity of discontinuation rates obtained through pharmacy records with the use of tamoxifen drug monitoring. Longitudinal serum samples, patient-reported outcome measures and pharmacy records from 220 breast cancer patients were obtained over a 6-year period. Serum concentrations of tamoxifen metabolites were measured by LC–MS/MS. Associations between metabolite concentrations and side effects were analyzed by logistic regression and cross table analyses. To determine the validity of pharmacy records we compared longitudinal tamoxifen concentrations to discontinuation rates obtained through the Norwegian Prescription database (NorPD). Multivariable Cox regression models were performed to identify predictors of discontinuation. At the 2nd year of follow-up, a significant association between vaginal dryness and high concentrations of tamoxifen, Z-4′-OHtam and tam-NoX was identified. NorPD showed a tamoxifen-discontinuation rate of 17.9% at 5 years and drug monitoring demonstrated similar rates. Nausea, vaginal dryness and chemotherapy-naive status were significant risk factors for tamoxifen discontinuation. This real-world data study suggests that measurements of tamoxifen metabolite concentrations may be predictive of vaginal dryness in breast cancer patients and verifies NorPD as a reliable source of adherence data.

Controversies exist as to whether the genetic polymorphisms of the enzymes responsible for the metabolism of tamoxifen can predict breast cancer outcome in patients using adjuvant tamoxifen. Direct measurement of concentrations of active tamoxifen metabolites in serum may be a more biological plausible and robust approach. We have investigated the association between CYP2D6 genotypes, serum concentrations of active tamoxifen metabolites, and long-term outcome in tamoxifen treated breast cancer patients.

Decreased CYP2D6 activity is associated with lower levels of active tamoxifen metabolites. We examined the impact of CYP2D6 genotype on tamoxifen pharmacokinetics, biomarker activity, and efficacy in a pooled analysis of low-dose tamoxifen. Four randomized breast cancer prevention trials of very-low-dose (1 mg/day, n = 52 or 10 mg/week, n = 152) or low-dose tamoxifen (5 mg/day, n = 171) were pooled. DNA from 367 subjects was genotyped for CYP2D6 alleles associated with absent (PM allele: *3, *4, *5, *6, *7, *8, *12, and *14), reduced (IM allele: *9, *10, *17, *29, *41), normal (EM allele), or increased (UM: *XN) enzyme activity. Associations of tamoxifen, metabolites, activity biomarkers, and event-free survival with rapid (UM/EM, UM/IM, EM/EM, EM/IM, or EM/PM alleles) versus slow metabolizers (PM/IM or PM/PM) were investigated through random effects models, with ‘study’ as the random factor, and Cox regression models, adjusting for confounders. Rapid metabolizers had higher endoxifen levels than slow metabolizers: 15.3 versus 12.2 ng/mL (P = 0.018) with 5 mg/day, and 3.8 versus 2.8 ng/mL (P = 0.004) with 1 mg/day or 10 mg/week tamoxifen. The IGF-I decrease correlated with endoxifen (P = 0.002) and 4-hydroxytamoxifen levels, demonstrating steeper decreases at higher metabolite levels (P = 0.001). After a median follow-up of 12 years, rapid metabolizers with prior history of breast neoplasms allocated to tamoxifen 5 mg/day had a 60 % reduction of risk of recurrences (HR = 0.40, 95 % CI: 0.16–0.99) compared to slow metabolizers. CYP2D6 genotype may have an impact on tamoxifen efficacy at low doses. Trials investigating tamoxifen dose adjustments based on the woman’s hormonal context and CYP2D6 genotype are warranted.

INTRODUCTION:Tamoxifen is an anti-estrogen drug used in treatment of Estrogen Receptor (ER) positive breast cancer. Effects and side effects of tamoxifen is the sum of tamoxifen and all its metabolites. 4-Hydroxytamoxifen (4OHtam) and 4-hydroxy-N-demethyltamoxifen (4OHNDtam, endoxifen) both have ER affinity exceeding that of the parent drug tamoxifen. 4OHNDtam is considered the main active metabolite of tamoxifen. Ndesmethyltamoxifen (NDtam) is the major tamoxifen metabolite. It has low affinity to the ER and is not believed to influence tumor growth. However, NDtam might mediate adverse effects of tamoxifen treatment. In this study we investigated the gene regulatory effects of the three metabolites of tamoxifen in MCF-7 breast cancer cells. MATERIAL AND METHODS:Using concentrations that mimic the clinical situation we examined effects of 4OHtam, 4OHNDtam and NDtam on global gene expression in 17β-estradiol (E2) treated MCF-7 cells. Transcriptomic responses were assessed by correspondence analysis, differential expression, gene ontology analysis and quantitative real time PCR (Q-rt-PCR). E2 deprivation and knockdown of Steroid Receptor Coactivator-3 (SRC-3)/Amplified in Breast Cancer 1 (AIB1) mRNA in MCF-7 cells were performed to further characterize specific effects on gene expression. RESULTS:4OHNDtam and 4OHtam caused major changes in gene expression compared to treatment with E2 alone, with a stronger effect of 4OHNDtam. NDtam had nearly no effect on the global gene expression profile. Treatment of MCF-7 cells with 4OHNDtam led to a strong down-regulation of the CytoKeratin 6 isoforms (KRT6A, KRT6B and KRT6C). The CytoKeratin 6 mRNAs were also down-regulated in MCF-7 cells after E2 deprivation and after SRC-3/AIB1 knockdown. CONCLUSION:Using concentrations that mimic the clinical situation we report global gene expression changes that were most pronounced with 4OHNDtam and minimal with NDtam. Genes encoding CytoKeratin 6, were highly down-regulated by 4OHNDtam, as well as after E2 deprivation and knockdown of SRC-3/AIB1, indicating an estrogen receptor-dependent regulation.

Bone remodeling is a continuous process regulated by several hormones such as estrogens and parathyroid hormone (PTH). Here we investigated the influence of PTH on estrogen receptor alpha (ERα)-dependent transcriptional activity in MC3T3-E1 osteoblasts. Cells that were transfected with an ER-responsive reporter plasmid and treated with PTH showed increased luciferase activity. However, in the presence of 17β-estradiol, we observed that PTH inhibited ERα-mediated transcription. cAMP mimicked the effects by PTH, and the findings were confirmed in COS-1 cells transfected with expression vector encoding the catalytic subunit of cAMP-dependent protein kinase (PKA). Furthermore, PTH exhibited specific effects on the mRNA expression of the decoy receptor osteoprotegerin (OPG) and the receptor activator of NF kappa-B ligand (RANKL) in MC3T3-E1 osteoblasts. In the absence of 17β-estradiol, PTH and cAMP enhanced the OPG/RANKL ratio, whereas, OPG/RANKL was suppressed when estradiol was present. In conclusion, our results indicate that the presence of estradiol determines whether PTH and cAMP stimulates or inhibits ERα-dependent activity and the OPG/RANKL mRNA expression in an osteoblastic cell line.

Purpose Several studies have shown that uncertainty about disease and fear of disease progression affects psychosocial adjustment and quality of life. The purpose of this study was to validate a Norwegian short version of the “The Mishel Uncertainty in Illness Scale” (SF-MUIS) and to examine the impact of uncertainty in illness in breast cancer patients. Method and sample 209 patients in breast cancer treatment completed questionnaires for SF-MUIS, Hospital Anxiety and Depression Scale (HADS), the Functional Assessment of Cancer Therapy-Breast (FACT-ES), and eight questions concerning quality of the patient information provided (IQP). Relationship between scores on uncertainty in illness and anxiety, depression, social support, emotional well-being, the quality of patient information provided, and age were studied by multiple regression analyses. Results Ordinal coefficient alpha for the Norwegian version of SF-MUIS was 0.70. Scores on SF-MUIS correlated significantly with scores on HADS (P = 0.001), FACT-ES (P = 0.001), and IQP (P = 0.001) indicating good convergent validity. The patients reported a moderate degree of uncertainty in illness. However, those who had been diagnosed with breast cancer for a year, reported higher scores than those newly diagnosed (P = <0.0001). Information provided was the sole significant predictor of illness uncertainty (P = <0.0001). Conclusion The results of the present study confirm that the Norwegian version of the SF-MUIS is a suitable tool for assessment of uncertainty in breast cancer patients, who reported a moderate degree of uncertainty in illness.

Abstract Background: Vitamin D is mainly synthesized in the skin through UVB irradiation, while a minor intake comes from the diet. Vitamin D is converted in the liver to 25-hydroxyvitamin D-(25(OH)D) and circulating levels of this metabolite is an appropriate index of vitamin D status. A further hydroxylation occurs to produce the biologically active metabolite 1,25-dihydroxyvitamin D. Epidemiological studies have suggested a role for vitamin D in cancer prevention showing an inverse relationship between incidence of cancers and mortality and 25(OH)D plasma levels. Vitamin D exerts its activity through a nuclear receptor (VDR) that regulates the expression of multiple genes, including genes for cell cycle regulation, differentiation, and apoptosis Methods: We have collected plasma from pre and post menopausal healthy women (HW) and newly diagnosed patients with an intraepithelial neoplasia (IEN) or breast carcinoma (BC). We measured circulating levels of 25(OH)D3 using LC-MS/MS. The median values were then correlated with the disease status. In a subgroup, we performed a correlation with VDR polymorphisms (SNPs) and disease recurrences. BsmI, FokI, TaqI and ApaI SNPs were determined using the Applied Biosystems’ Taqman Allelic Discrimination Assay. Results: 25(OH)D3 was measured in 249 HW, 175 subjects with IEN and 168 BC patients undergoing surgery. Age and BMI were taken into account for adjustments the median age being 51, 46 and 59 years and median BMI being 24, 23 and 25.6 kg/m2 in the HW, IEN and BC categories, respectively. Median 25(OH)D3 were respectively: 37.2, (inter-quartile range, IQR 25.0-49.7) 43 (IQR 30.0-60.0) and 42 (IQR 30.0-60.0) nmol/L respectively. The LS means with BC + IEN combined versus HW were 43 (IQR 40.8-45.2) vs 46.4 (IQR 43.9-49.0) nmol/L. The levels of 25(OH)D3 are statistical different between healthy versus affected subjects (p = 0.05). We also conducted an exploratory analysis in a subgroup of 228 subjects to evaluate the correlation of VDR polymorphisms and the disease free survival (DFS for breast recurrence or new event). With a follow-up of 160 months and a total of 70 breast events, the homozygote and heterozygote subjects for VDR ApaI polymorphism had a worst DFS compared to the wild type ones (log rank test p= 0.04).Conclusions: our data confirm the possible role of the vitamin D and its receptor in the carcinogenesis process. It is not clear when 25(OH)D level starts to decline and thus may influence the disease progression. In accordance with other research groups the ApaI polymorphism may have, together with other VDR SNPs, an influence on BC incidence and recurrence. Further correlations and analysis of the VDR genotype are ongoing. A prospective study to clarify is recommended the issue of the timing of 25(OH)D levels measurement is warranted. Citation Format: Davide Serrano, Harriet Johansson, Debora Macis, Ernst Lien, Jennifer Gjerde, Antonella Puccio, Sara Gandini, Aliana Guerrieri-Gonzaga, Irene Feroce, Matteo Lazzeroni, Andrea Decensi, Bernardo Bonanni. A comparison of 25-OH-vitamin D levels and VDR polymorphisms in healthy and patients with breast intraepithelial neoplasia or cancer . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 167. doi:10.1158/1538-7445.AM2013-167

The glucocorticoid receptor interacting protein (GRIP1) belongs to the p160 steroid receptor coactivator family that plays essential roles in nuclear receptor-dependent transcriptional regulation. Previously, we reported that the cAMP-dependent protein kinase (PKA) induces ubiquitination leading to degradation of GRIP1. Here we show that the cAMP response element-binding protein (CREB) downregulates GRIP1 and is necessary for the PKA-stimulated degradation of GRIP1, which leads to changes in the expression of a subset of genes regulated by estrogen receptor-α in MCF-7 breast cancer cells. Our data of domain-mapping and ubiquitination analyses suggest that CREB promotes the proteasomal breakdown of ubiquitinated GRIP1 through 2 functionally independent protein domains containing amino acids 347 to 758 and 1121 to 1462. We provide evidence that CREB interacts directly with GRIP1 and that CREB Ser-133 phosphorylation or transcriptional activity is not required for GRIP1 interaction and degradation. The basic leucine zipper domain (bZIP) of CREB is important for the interaction with GRIP1, and deletion of this domain led to an inability to downregulate GRIP1. We propose that CREB mediates the PKA-stimulated degradation of GRIP1 through protein-protein interaction and stimulation of proteasomal degradation of ubiquitinated GRIP1.

Objective: Parathyroid hormone (PTH) and vitamin D are the most important hormones regulating calcium metabolism. In primary hyperparathyroidism (PHPT) excessive amounts of PTH are produced. Bone turnover is enhanced, leading to reduced bone mineral density and elevated levels of serum calcium. The aim of this study was to investigate relations between serum levels of 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and bone mineral density, as well as known genetic polymorphisms in the vitamin D receptor and enzymes metabolising vitamin D in patients with PHPT.Design/Subjects: We conducted a cross-sectional study of 52 patients with PHPT.Results: Mean level of 25(OH)D was 58.2 nmol/L and median 1,25(OH)(2)D level was 157 pmol/L. Among our patients with PHPT 36.5% had 25(OH)D levels below 50 nmol/L. Serum 1,25(OH)(2)D was inversely correlated to bone mineral density in distal radius (p = 0.002), but not to bone mineral density at lumbar spine or femoral neck. The vitamin D receptor polymorphism Apa1 (rs7975232) was associated with bone mineral density in the lumbar spine.Conclusions: The results suggest that PHPT patients with high blood concentrations of 1,25(OH)(2)D may have the most deleterious skeletal effects. Randomized, prospective studies are necessary to elucidate whether vitamin D supplementation additionally increases serum 1,25(OH)(2)D and possibly enhances the adverse effects on the skeleton in patients with PHPT.

It has been suggested that the concentrations of tamoxifen and its demethylated metabolites increase with age. We measured the serum concentrations of the active tamoxifen metabolites, 4OHtamoxifen (4OHtam), 4-hydroxy-N-desmethyltamoxifen (4OHNDtam, Endoxifen), tamoxifen and its demethylated metabolites. Their relations to age were examined. One hundred fifty-one estrogen receptor and/or progesterone receptor positive breast cancer patients were included. Their median (range) age was 57 (32–85) years. Due to the long half-life of tamoxifen, only patients treated with tamoxifen for at least 80 days were included in the study in order to insure that the patients had reached steady-state drug levels. Tamoxifen and its metabolites were measured by liquid chromatography-tandem mass spectrometry. Their serum concentrations were related to the age of the patients. To circumvent effects of cytochrome (CYP) 2D6 polymorphisms we also examined these correlations exclusively in homozygous extensive metabolizers. The concentrations of 4OHNDtam, tamoxifen, NDtam ( N -desmethyltamoxifen), and NDDtam ( N -desdimethyltamoxifen) were positively correlated to age ( n = 151, p = 0.017, 0.045, 0.011, and 0.001 respectively). When exclusively studying the CYP2D6 homozygous extensive metabolizers ( n = 86) the correlation between 4OHNDtam and age increased ( p = 0.008). Up to tenfold inter-patient variation in the serum concentrations was observed. The median (inter-patient range) concentration of 4OHNDtam in the age groups 30–49, 50–69, and >69 years were 65 (24–89), 116 (25–141), and 159 (26–185) ng/ml, respectively. We conclude that the serum concentrations of 4OHNDtam (endoxifen), tamoxifen, and its demethylated metabolites increase with age during steady-state tamoxifen treatment. This may represent an additional explanation why studies on the effects of CYP2D6 polymorphisms on outcome in tamoxifen-treated breast cancer patients have been inconsistent. The observed high inter-patient range in serum concentrations of tamoxifen and its metabolites, especially in the highest age group, suggest that use of therapeutic monitoring of tamoxifen and its metabolites is warranted.

INTRODUCTION:We previously demonstrated that 1 or 5 mg per day of tamoxifen (T) given for four weeks before surgery reduces Ki-67 in breast cancer (BC) patients to the same extent as the standard 20 mg/d. Given the long half-life of T, a weekly dose (10 mg per week (w)) may be worth testing. Also, raloxifene (R) has shown Ki-67 reduction in postmenopausal patients in a preoperative setting, but data in premenopausal women are limited. We conducted a randomized trial testing T 10 mg/w vs. R 60 mg/d vs. placebo in a presurgical model.METHODS:Out of 204 screened subjects, 57 were not eligible, 22 refused to participate and 125 were included in the study. The participants were all premenopausal women with estrogen receptor-positive BC. They were randomly assigned to either T 10mg/w or R 60 mg/d or placebo for six weeks before surgery. The primary endpoint was tissue change of Ki-67. Secondary endpoints were modulation of estrogen and progesterone receptors and several other circulating biomarkers.RESULTS:Ki-67 was not significantly modulated by either treatment. In contrast, both selective estrogen receptor modulators (SERMs) significantly modulated circulating IGF-I/IGFBP-3 ratio, cholesterol, fibrinogen and antithrombin III. Estradiol was increased with both SERMs. Within the tamoxifen arm, CYP2D6 polymorphism analysis showed a higher concentration of N-desTamoxifen, one of the tamoxifen metabolites, in subjects with reduced CYP2D6 activity. Moreover, a reduction of Ki-67 and a marked increase of sex hormone-binding globulin (SHBG) were observed in the active phenotype.CONCLUSIONS:A weekly dose of tamoxifen and a standard dose of raloxifene did not inhibit tumor cell proliferation, measured as Ki-67 expression, in premenopausal BC patients. However, in the tamoxifen arm women with an extensive phenotype for CYP2D6 reached a significant Ki-67 modulation.

1 Stavanger University Hospital, Department of Surgery, Section for Breast and Endocrine Surgery, Stavanger, Norway, 2 University of Bergen, Institute of Medicine, Bergen, Norway, 3 University of Bergen, Institute of Surgical Sciences, Bergen, Norway, 4 Haukeland University Hospital, Department of Breast and Endocrine Surgery, Bergen, Norway and 5 Haukeland University Hospital, Hormonlaboratoriet, Bergen, Norway

Abstract Background: To further investigate tamoxifen (T) minimal active dose, we conducted a window of opportunity study in estrogen receptor (ER) positive breast cancer (BC) patients. The study was a three arms randomized phase II double blind clinical trial. The participants were randomized to tamoxifen 10 mg a week vs. raloxifene 60 mg a day vs. placebo for 6 weeks, which was the average waiting list in our Institute at the time of this study was conducted. The primary endpoint was tissue change of Ki67LI. This result was previously reported and overall we did not observe any KI67LI modulation by treatment. The clinical relevance of CYP2D6 polymorphisms is controversial, and recently negative data have been published. Here we present a significant biomarkers modulation by low dose tamoxifen based on CYP2D6 subjects phenotype. Methods: DNA was extracted from whole blood by the use of QIAamp DNA blood kit. We employed the INFINITI analyzer for CYP2D6 genotyping, according to the protocol of the manufacturer. A total of 14 SNPs were analyzed. To determine the concentrations of tamoxifen and its metabolites, we used a high-pressure liquid chromatography-tandem mass spectrometry system. Expression of Ki-67, ER and PgR were determined by immunohistochemistry. Serum concentration of SHBG and estradiol were measured by chemiluminescent immunometric assay; IGF1 and IGFBP3 were determined by enzymatic colorimetric methods. Results: CYP2D6 was analyzed in the 50 women who took tamoxifen. We found 40% of EM (extensive metabolizer), 48% of IM (intermidiet metabolizer), 6% of PM (poor metabolizer) and 6% UM (ultra-rapid metabolizer). The phenotypes were grouped in two classes: active (EM + UM) and with a reduced activity (IM + PM). Among T metabolites a significant accumulation of N-desmethyl-Tamoxifen was present in the reduced activity group (mean plasma level 19.9 vs. 14.4 ng/ml reduced vs. active group p=.05). Endoxifen and 4-OH-Tamoxifen were not significantly different in the two phenotype groups. Then we correlated the phenotype with biomarkers modulations. The active phenotype showed a significant different modulation in Ki67 with a median chage of −2.5 in the active group and +3 in the reduced one. No differences on ER or PgR expression were determined by the phenotype. Among the circulating biomarkers, SHBG in the active group showed a significant difference compared to the reduced one (median change 8.35 and 2 p=0.05) whereas the estradiol and IGF1/BP3 did not show any difference between groups. Conclusions: CYP2D6 phenotypes interact with the biological activity of low dose T. A reduced activity of the enzyme induces an accumulation of N-desmethyl-Tamoxifen, whereas no significant differences for Endoxifen. In spite of a similar Endoxifen concentration, a reduced activity phenotype may influence T activity as demonstrated by the different modulation of Ki67 and SHBG biomarkers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2664. doi:1538-7445.AM2012-2664

Abstract Background Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Methods Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Results Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0.001). Conclusions The expression of SRCs and HER-2 and -3 is stimulated by tamoxifen treatment in DMBA-induced breast cancer. Stimulation and positive correlation of coactivators and HERs may represent an early response to endocrine treatment. The role of SRCs and HER-2 and -3 should be further studied in order to evaluate their effects on response to long-term tamoxifen treatment.

Tamoxifen dosage is based on the one-dose-fits-all approach. The anticancer effect of tamoxifen is believed to be due to the metabolites, 4-hydroxytamoxifen (4OHtam), and 4-hydroxy-N-desmethyltamoxifen (4OHNDtam/endoxifen). These demethylated metabolites of tamoxifen have been associated with its side effects, whereas the effect mediated by tamoxifen-N-oxide (tamNox) is still poorly understood. Our objective was to improve the therapeutic index of tamoxifen by personalizing its dosage and maintaining serum tamoxifen metabolite concentrations within a target range. We examined the levels of tamoxifen, 4OHtam, 4OHNDtam, N-desmethyltamoxifen (NDtam), N-desdimethyltamoxifen (NDDtam), and tamNox in serum and in breast tumors specimens of 115 patients treated with 1, 5 or 20 mg/day of tamoxifen for 4 weeks before surgery in a randomized trial. Furthermore, the metabolism of tamNox in MCF-7 breast cancer cells was also studied. The concentrations of tamoxifen and its metabolites in tumor tissues were significantly correlated to their serum levels. Tumor tissue levels were 5-10 times higher than those measured in serum, with the exception of tamNox. In MCF-7 cells, tamNox was converted back to tamoxifen. In contrast to the tissue distribution of tamNox, the concentrations of 4OHtam and 4OHNDtam in tumor tissues corresponded to their serum levels. The results suggest that implementation of therapeutic drug monitoring may improve the therapeutic index of tamoxifen. Furthermore, the tissue distribution of tamNox deviated from that of the other tamoxifen metabolites.

ObjectiveFailure to mirror the diurnal cortisol profile could contribute to the impaired subjective health status in Addison's disease (AD). Some patients report benefit from the use of various nutritional compounds. The objective of this study was to investigate the impact of licorice and grapefruit juice (GFJ) on the absorption and metabolism of cortisone acetate (CA).DesignPatients (n=17) with AD on stable CA replacement therapy were recruited from the outpatient clinic at Haukeland University Hospital, Norway. They were assessed on their ordinary CA medication and following two 3-day periods of co-administration of licorice or GFJ.MethodsTime series of glucocorticoids (GCs) in serum and saliva were obtained, and GCs in 24 h urine samples were determined. The main outcome measure was the area under the curve (AUC) for serum cortisol in the first 2.6 h after orally administered CA.ResultsCompared with the ordinary treatment, the median AUC for serum cortisol increased with licorice (53 783 vs 50 882, P<0.05) and GFJ (60 661 vs 50 882, P<0.05). Median cortisol levels in serum were also elevated 2.6 h after tablet ingestion (licorice 223 vs 186 nmol/l, P<0.05; GFJ 337 vs 186 nmol/l, P<0.01). Licorice increased the median urinary cortisol/cortisone ratio (0.43 vs 0.21, P<0.00001), whereas GFJ increased the (allo-tetrahydrocortisol+tetrahydrocortisol)/tetrahydrocortisone ratio (0.55 vs 0.43, P<0.05).ConclusionLicorice and in particular GFJ increased cortisol available to tissues in the hours following oral CA administration. Both patients and physicians should be aware of these interactions.

Background: Primary hyperparathyroidism (PHPT) is characterised by increased production of parathyroid hormone (PTH) resulting in elevated serum calcium levels. The influence on bone metabolism with altered bone resorption is the most studied clinical condition in PHPT. In addition to this, patients with PHPT are at increased risk of non-skeletal diseases, such as impaired insulin sensitivity, arterial hypertension and increased risk of death by cardiovascular diseases (CVD), possibly mediated by a chronic low-grade inflammation. The aim of this study was to investigate whether adipose tissue reflects the low-grade inflammation observed in PHPT patients.Methodology/Principal Findings: Subcutaneous fat tissue from the neck was sampled from 16 non-obese patients with PHPT and from 16 patients operated for benign thyroid diseases, serving as weight-matched controls. RNA was extracted and global gene expression was analysed with Illumina BeadArray Technology. We found 608 differentially expressed genes (q-value<0.05), of which 347 were up-regulated and 261 were down-regulated. Gene ontology analysis showed that PHPT patients expressed increased levels of genes involved in immunity and defense (e.g. matrix metallopeptidase 9, S100 calcium binding protein A8 and A9, CD14, folate receptor 2), and reduced levels of genes involved in metabolic processes. Analysis of transcription factor binding sites present in the differentially expressed genes corroborated the up-regulation of inflammatory processes.Conclusions/Significance: Our findings demonstrate that PHPT strongly influences gene regulation in fat tissue, which may result in altered adipose tissue function and release of pathogenic factors that increase the risk of CVD.