Cohort profile: The Clinical and Multi-omic (CAMO) cohort, part of the Norwegian Women and Cancer (NOWAC) study.

INTRODUCTION: Breast cancer is the most common cancer worldwide and the leading cause of cancer related deaths among women. The high incidence and mortality of breast cancer calls for improved prevention, diagnostics, and treatment, including identification of new prognostic and predictive biomarkers for use in precision medicine. MATERIAL AND METHODS: With the aim of compiling a cohort amenable to integrative study designs, we collected detailed epidemiological and clinical data, blood samples, and tumor tissue from a subset of participants from the prospective, population-based Norwegian Women and Cancer (NOWAC) study. These study participants were diagnosed with invasive breast cancer in North Norway before 2013 according to the Cancer Registry of Norway and constitute the Clinical and Multi-omic (CAMO) cohort. Prospectively collected questionnaire data on lifestyle and reproductive factors and blood samples were extracted from the NOWAC study, clinical and histopathological data were manually curated from medical records, and archived tumor tissue collected. RESULTS: The lifestyle and reproductive characteristics of the study participants in the CAMO cohort (n = 388) were largely similar to those of the breast cancer patients in NOWAC (n = 10 356). The majority of the cancers in the CAMO cohort were tumor grade 2 and of the luminal A subtype. Approx. 80% were estrogen receptor positive, 13% were HER2 positive, and 12% were triple negative breast cancers. Lymph node metastases were present in 31% at diagnosis. The epidemiological dataset in the CAMO cohort is complemented by mRNA, miRNA, and metabolomics analyses in plasma, as well as miRNA profiling in tumor tissue. Additionally, histological analyses at the level of proteins and miRNAs in tumor tissue are currently ongoing. CONCLUSION: The CAMO cohort provides data suitable for epidemiological, clinical, molecular, and multi-omics investigations, thereby enabling a systems epidemiology approach to translational breast cancer research.

Serglycin Is Involved in TGF-ß Induced Epithelial-Mesenchymal Transition and Is Highly Expressed by Immune Cells in Breast Cancer Tissue.

Serglycin is a proteoglycan highly expressed by immune cells, in which its functions are linked to storage, secretion, transport, and protection of chemokines, proteases, histamine, growth factors, and other bioactive molecules. In recent years, it has been demonstrated that serglycin is also expressed by several other cell types, such as endothelial cells, muscle cells, and multiple types of cancer cells. Here, we show that serglycin expression is upregulated in transforming growth factor beta (TGF-ß) induced epithelial-mesenchymal transition (EMT). Functional studies provide evidence that serglycin plays an important role in the regulation of the transition between the epithelial and mesenchymal phenotypes, and it is a significant EMT marker gene. We further find that serglycin is more expressed by breast cancer cell lines with a mesenchymal phenotype as well as the basal-like subtype of breast cancers. By examining immune staining and single cell sequencing data of breast cancer tissue, we show that serglycin is highly expressed by infiltrating immune cells in breast tumor tissue.

A man in his sixties with dyspnoea and oedema. / Mann i 60-årene med tungpustethet og ødemer.

BACKGROUND/CASE PRESENTATION: A man in his sixties with chronic obstructive pulmonary disease was hospitalised due to oedema and dyspnoea during the previous weeks. He was hypertensive, with 10 kg weight gain, generalised oedema, proximal myopathy and moon face. The assessment was consistent with ectopic ACTH-dependent Cushing's syndrome. A 15 mm lung tumour was detected on CT, with inconclusive cytological examination, and negative FDG/PET CT and octreotide scintigraphy. He developed necrotising pancreatitis and a duodenal perforation, which were surgically treated. His cortisol levels and Cushingoid appearance normalised after surgery, and it was concluded that his hypercortisolism was part of a physiological response. He remained clinically in habitual shape until two years later, when he again developed Cushingoid stigmata. A new octreotide scintigraphy was negative, but FDG/PET CT revealed increased FDG uptake in the lung lesion. Before a lung biopsy was performed, the patient developed necrotising pancreatitis. He was treated conservatively and died in respiratory failure. Autopsy revealed a NET in the lung and necrotising pancreatitis. INTERPRETATION: The case demonstrates diagnostic challenges in the assessment of ectopic ACTH-dependent cyclic Cushing's syndrome. Is also suggests that pancreatitis could be triggered by hypercortisolism.

Differential expression of the miR-17-92 cluster and miR-17 family in breast cancer according to tumor type; results from the Norwegian Women and Cancer (NOWAC) study.

BACKGROUND: MicroRNAs (miRNAs) are promising biomarkers due to their structural stability and distinct expression profile in various cancers. We wanted to explore the miRNA expression in benign breast tissue and breast cancer subgroups in the Norwegian Women and Cancer study. METHODS: Specimens and histopathological data from study participants in Northern Norway diagnosed with breast cancer, and benign tissue from breast reduction surgery were collected. Main molecular subtypes were based on surrogate markers; luminal A (ER+ and/or PR+, HER2- and Ki67 ≤ 30%), luminal B (ER+ and/or PR+, HER2- and Ki67 > 30% or ER+ and/or PR+ and HER2+), HER2 positive (ER- and PR- and HER2+) and triple-negative (ER-, PR- and HER2-). RNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue, and miRNAs were successfully analyzed in 102 cancers and 36 benign controls using the 7th generation miRCURY LNA microarray containing probes targeting all human miRNAs as annotated in miRBASE version 19.0. Validation with RT-qPCR was performed. RESULTS: On average, 450 miRNAs were detected in each sample, and 304 miRNAs were significantly different between malignant and benign tissue. Subgroup analyses of cancer cases revealed 23 miRNAs significantly different between ER+ and ER- tumors, and 47 miRNAs different between tumors stratified according to grade. Significantly higher levels were found in high grade tumors for miR-17-5p (p = 0.006), miR-20a-5p (p = 0.007), miR-106b-5p (p = 0.007), miR-93-5p (p = 0.007) and miR-25-3p (p = 0.015) from the paralogous clusters miR-17-92 and miR-106b-25. Expression of miR-17-5p (p = 0.0029), miR-20a-5p (p = 0.0021), miR-92a-3p (p = 0.011) and miR-106b-5p (p = 0.021) was significantly higher in triple-negative tumors compared to the rest, and miR-17-5p and miR-20a-5p were significantly lower in luminal A tumors. CONCLUSIONS: miRNA expression profiles were significantly different between malignant and benign tissue and between cancer subgroups according to ER- status, grade and molecular subtype. miRNAs in the miR-17-92 cluster and miR-17 family were overexpressed in high grade and triple-negative tumors associated with aggressive behavior. The expression and functional role of these miRNAs should be further studied in breast cancer to explore their potential as biomarkers in diagnostic pathology and clinical oncology.

Expression and function of the miR-143/145 cluster in vitro and in vivo in human breast cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that function as post-transcriptional regulators of gene expression and are dysregulated in cancer. Studies of miRNAs to explore their potential as diagnostic and prognostic markers are of great scientific interest. Here, we investigate the functional properties and expression of the miR-143/145 cluster in breast cancer (BC) in vitro and in vivo. The ER positive MCF7, the HER2 positive SK-BR-3, and the triple negative cell line MDA-MB-231 were used to assess cell proliferation and cell invasion. Expression of miRNA in 108 breast cancers in the Norwegian Women and Cancer Study and 44 benign tissue controls were analyzed by microarray and validated by RT-PCR. Further, in situ hybridization (ISH) was used to study the cellular and subcellular distribution of the miRNAs. In vitro, miR-143 promoted proliferation of MCF7 and MDA-MB-231 cells, whereas miR-145 and the cotransfection of both miRNAs inhibited proliferation in all three cell lines. The cells' invasive capacity was reduced after transfection and cotransfection of the miRNAs. In line with the tumor suppressive functions in vitro, the expression of miR-143 and miR-145 was lower in malignant compared to benign breast tissue, and lower in the more aggressive tumors with higher tumor grade, loss of ER and the basal-like phenotype. ISH revealed miR-143 to be cytoplasmatic and predominantly expressed in luminal cells in benign tissue, whilst miR-145 was nuclear and with strong staining in myoepithelial cells. Both miRNAs were present in malignant epithelial cells and stromal fibroblasts in BC. This study demonstrates that miR-143 and -145 have functional properties and expression patterns typical for tumor suppressors, but the function is influenced by cellular factors such as cell type and miRNA cotransfection. Further, the nuclear functions of miR-145 should be explored for a more complete understanding of the complexity of miRNA regulation and function in BC.

Plasma microRNAs as biomarkers of pancreatic cancer risk in a prospective cohort study.

Noninvasive biomarkers for early pancreatic ductal adenocarcinoma (PDAC) diagnosis and disease risk stratification are greatly needed. We conducted a nested case-control study within the Prospective Investigation into Cancer and Nutrition (EPIC) cohort to evaluate prediagnostic microRNAs (miRs) as biomarkers of subsequent PDAC risk. A panel of eight miRs (miR-10a, -10b, -21-3p, -21-5p, -30c, -106b, -155 and -212) based on previous evidence from our group was evaluated in 225 microscopically confirmed PDAC cases and 225 controls matched on center, sex, fasting status and age/date/time of blood collection. MiR levels in prediagnostic plasma samples were determined by quantitative RT-PCR. Logistic regression was used to model levels and PDAC risk, adjusting for covariates and to estimate area under the receiver operating characteristic curves (AUC). Plasma miR-10b, -21-5p, -30c and -106b levels were significantly higher in cases diagnosed within 2 years of blood collection compared to matched controls (all p-values <0.04). Based on adjusted logistic regression models, levels for six miRs (miR-10a, -10b, -21-5p, -30c, -155 and -212) overall, and for four miRs (-10a, -10b, -21-5p and -30c) at shorter follow-up time between blood collection and diagnosis (≤5 yr, ≤2 yr), were statistically significantly associated with risk. A score based on the panel showed a linear dose-response trend with risk (p-value = 0.0006). For shorter follow-up (≤5 yr), AUC for the score was 0.73, and for individual miRs ranged from 0.73 (miR-212) to 0.79 (miR-21-5p).

Fibroblast miR-210 overexpression is independently associated with clinical failure in Prostate Cancer - a multicenter (in situ hybridization) study.

There is a need for better prognostication in prostate cancer (PC). "The micromanager of hypoxia", microRNA-210 (miR-210) is directly linked to hypoxia, is overexpressed in PC and has been implied in tumor cell-fibroblast crosstalk. We investigated the prognostic impact of miR-210 in tumor cells and fibroblasts in PC. Tumor and stromal samples from a multicenter PC cohort of 535 prostatectomy patients were inserted into tissue microarrays. To investigate the expression of miR-210, we used in situ hybridization and two pathologists semiquantitatively scored its expression. Overexpression of miR-210 in tumor cells was not associated to biochemical failure-free survival (BFFS, p = 0.85) or clinical failure-free survival (CFFS, p = 0.09). However, overexpression of miR-210 in fibroblasts was significantly associated to a poor CFFS (p = 0.001), but not BFFS (p = 0.232). This feature was validated in both cohorts. Overexpression of miR-210 was independently associated with a reduced CFFS (HR = 2.76, CI 95% 1.25-6.09, p = 0.012). Overexpression of miR-210 in fibroblasts is independently associated with a poor CFFS. This highlights the importance of fibroblasts and cellular compartment crosstalk in PC. miR-210 is a candidate prognostic marker and potential therapeutic target in PC.

Organized metabolic crime in prostate cancer: The coexpression of MCT1 in tumor and MCT4 in stroma is an independent prognosticator for biochemical failure.

BACKGROUND: Lactate import or export over cell membranes is facilitated by monocarboxylate transporters (MCTs) 1 and 4. Expression profiles can be markers of an oxidative or glycolytic phenotype. Descriptive studies and functional studies in neoplastic cells and fibroblasts in prostate cancer (PC) have suggested a distinct phenotype. We aimed to explore expression of MCT1 and MCT4 in PC cells and surrounding stroma in a large cohort. Additionally, we wanted to find out if distinct expression profiles were associated with biochemical failure-free survival (BFFS). METHODS: Tissue microarrays were constructed from 535 patients with radical prostatectomies between January 1, 1995, and December 31, 2005. Immunohistochemistry was used to detect expression, and degrees of expression were evaluated semiquantitatively by 2 pathologists using light microscopy. RESULTS: For MCT1, there was only epithelial expression, whereas there was a low level of expression of MCT4 in tumor and stroma. A total of 172 patients had a low expression of MCT1 in tumor and MCT4 in stroma. There were 232 patients who had a high expression of MCT1 and a low expression of MCT4 in stroma. Only 11 patients had a low tumoral MCT1 expression and a high stromal MCT4 expression, and 26 patients (5%) had a high expression of both. Patients with a high-high combination had a significantly reduced BFFS (P = 0.011), and when adjusting for other factors, its effect was significant and independent (HR = 1.99, CI 95%: 1.09-3.62; P = 0.024). CONCLUSIONS: This study adds to the current understanding of the reversed Warburg effect to be a significant phenotype in PC. High coexpression of MCT1 in tumor and MCT4 in stroma is independently associated to a worse BFFS, and the strength of this association is as strong as having a Gleason score of ≥9.

Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer.

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.

Tissue distribution of 4-hydroxy-N-desmethyltamoxifen and tamoxifen-N-oxide.

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.

Effect of low-dose tamoxifen on steroid receptor coactivator 3/amplified in breast cancer 1 in normal and malignant human breast tissue.

PURPOSE: Nuclear receptor coactivator expression and activity may partly explain the complex agonist/antagonist effects of tamoxifen at clinical level. In a preoperative trial, dose reduction from 20 to 1 mg tamoxifen was associated with retained antiproliferative effect on breast cancer. Here, we assessed the gene expression of the steroid receptor coactivators SRC-1, SRC-2/transcription intermediary factor 2, and SRC-3/amplified in breast cancer 1 (AIB1) and the growth factor receptor HER-2/neu under three tamoxifen dose regimens. EXPERIMENTAL DESIGN: Surgical specimens from estrogen receptor-positive breast cancer and adjacent normal breast tissue from 64 patients treated 4 weeks preoperatively with 20, 5, or 1 mg/d tamoxifen and 28 nontreated breast cancer controls were analyzed for coactivator and HER-2/neu mRNA expression using real-time reverse transcription-PCR. The gene expression levels were related to immunohistochemical expression of Ki67, serum levels of insulin-like growth factor I and sex hormone binding globulin, other prognostic factors, and clinical outcome. RESULTS: The coactivators and HER-2/neu mRNA levels were higher in malignant compared with normal tissue (P < 0.001). Tamoxifen significantly increased the expression of coactivators in normal and malignant tissue irrespective of dose, especially for SRC-3/AIB1 (P < 0.001 tamoxifen-treated versus nontreated subjects). SRC-3/AIB1 and HER-2/neu mRNA levels were positively correlated (P = 0.016), but the coactivators could not explain the variability of Ki67, insulin-like growth factor I, and sex hormone binding. Although not significant, SRC-3/AIB1 tended to be higher in subjects with poor clinical outcome and unfavorable prognostic factors. CONCLUSIONS: Increased coactivator mRNA levels seem to be an early response to tamoxifen without dose-response relationship in the 1- to 20-mg range. Clinical and molecular effects of low-dose tamoxifen should be further explored.

A pan-PPAR ligand induces hepatic fatty acid oxidation in PPARalpha-/- mice possibly through PGC-1 mediated PPARdelta coactivation.

Tetradecylthioacetic acid (TTA) is a hypolipidemic modified fatty acid and a peroxisome proliferator-activated receptor (PPAR) ligand. The mechanisms of TTA-mediated effects seem to involve the PPARs, but the effects have not been assigned to any specific PPAR subtype. PPARalpha-/- mice were employed to study the role of PPARalpha after TTA treatment. We also performed in vitro transfection assays to obtain mechanistic knowledge of how TTA affected PPAR activation in the presence of PPARgamma coactivator (PGC)-1 and steroid receptor coactivators (SRC)-1 and SRC-2, which are associated with energy balance and mitochondrial biogenesis. We show that TTA increases hepatic fatty acid beta-oxidation in PPARalpha-/- mice. TTA acts as a pan-PPAR ligand in vitro, and PGC-1, SRC-1 and SRC-2 have cell type and PPAR-specific effects together with TTA. In the absence of exogenous ligands, SRC-1 did not induce PPAR activity, while PGC-1 was the most potent PPAR coactivator. When the coactivators were overexpressed, pronounced effects of TTA were observed especially for PPARdelta and PPARgamma. We conclude that PPARalpha is involved in, but not required for, the hypolipidemic mechanisms of TTA. It appears that the activity of PPARdelta, with substantial contribution of nuclear receptor coactivators, PGC-1 in special, is conducive to TTA's mechanism of action.

Induction of hepatic drug-metabolising enzymes and tamoxifen metabolite profile in relation to administration route during low-dose treatment in nude rats.

Tamoxifen is the most used anticancer drug and is approved for chemoprevention. Little is known about the enzyme inducing properties of low-dose regimens and the influence of route of administration. In this study, nude rats received 5 mg/kg/day of tamoxifen orally or a 50 mg continuous-release pellet subcutaneously. The mRNAs for cytochrome P450-enzymes (CYPs), flavin-containing monooxygenase 1 (FMO1) and phase II drug-metabolising enzymes were quantified by real-time RT-PCR. Tamoxifen and metabolite concentrations were measured using HPLC. We observed a significant increase in CYP3A18 and FMO1 mRNA expression levels in the orally treated animals, whereas the increase in CYP3A2 expression did not reach statistical significance (p=0.057). No significant induction of enzyme expression was observed in rats that received subcutaneous (S.c.) treatment. After 33 days the serum levels of 4-hydroxytamoxifen (4OHtam), tamoxifen and N-desmethyltamoxifen (NDtam) in orally treated animals were 1.8+/-0.7, 11.1+/-3.2 and 11.4+/-3.8 ng/ml, respectively. In subcutaneously treated animals, tamoxifen and N-desmethyltamoxifen were detected in tissues, but not in serum. These data demonstrate that in contrast to the subcutaneous administration, low-dose oral tamoxifen induced tamoxifen-metabolising enzymes. Furthermore, the different routes of administration resulted in different serum and tissue levels of tamoxifen and metabolites.