Adrenocortical carcinoma (ACC) is an aggressive tumor showing frequent metastatic spread and poor survival. Although recent genome-wide studies of ACC have contributed to our understanding of the disease, major challenges remain for both diagnostic and prognostic assessments. The aim of this study was to identify specific microRNAs (miRNAs) associated with malignancy and survival of ACC patients. miRNA expression profiles were determined in a series of ACC, adenoma, and normal cortices using microarray. A subset of miRNAs showed distinct expression patterns in the ACC compared with adrenal cortices and adenomas. Among others, miR-483-3p, miR-483-5p, miR-210, and miR-21 were found overexpressed, while miR-195, miR-497, and miR-1974 were underexpressed in ACC. Inhibition of miR-483-3p or miR-483-5p and overexpression of miR-195 or miR-497 reduced cell proliferation in human NCI-H295R ACC cells. In addition, downregulation of miR-483-3p, but not miR-483-5p, and increased expression of miR-195 or miR-497 led to significant induction of cell death. Protein expression of p53 upregulated modulator of apoptosis (PUMA), a potential target of miR-483-3p, was significantly decreased in ACC, and inversely correlated with miR-483-3p expression. In addition, high expression of miR-503, miR-1202, and miR-1275 were found significantly associated with shorter overall survival among patients with ACC (P values: 0.006, 0.005, and 0.042 respectively). In summary, we identified additional miRNAs associated with ACC, elucidated the functional role of four miRNAs in the pathogenesis of ACC cells, demonstrated the potential involvement of the pro-apoptotic factor PUMA (a miR-483-3p target) in adrenocortical tumors, and found novel miRNAs associated with survival in ACC.
Deniz M Özata, Stefano Caramuta, David Velázquez-Fernández, Pinar Akçakaya, Hong Xie, Anders Höög, Jan Zedenius, Martin Bäckdahl, Catharina Larsson, and Weng-Onn Lui
Dong Wang, Jia-Fu Feng, Ping Zeng, Yun-Hong Yang, Jun Luo, and Yu-Wei Yang
Oxidative stress is considered to be involved in the pathophysiology of all cancers. In order to evaluate the total oxidant/antioxidant status in patients with thyroid cancer and to investigate the relationship between oxidative stress parameters and serum thyroid profiles among thyroid cancer patients and various controls, we determined oxidative status including total antioxidant status (TAS) and total oxidant status (TOS) and calculation of oxidative stress index (OSI) in sera in 82 thyroid cancer patients, 56 benign thyroid disease patients, and 50 healthy controls. It was found that serum TAS levels were significantly lower in patients with thyroid cancer than in controls (P<0.001), while serum TOS levels and OSI values were significantly higher (both P<0.001) in the cancer patients. No significant correlations were observed between various oxidative stress markers and thyroid profiles in either the thyroid cancer patients or the controls. Receiver operating characteristic curve analysis demonstrated that OSI was the best indicator for distinguishing cancer patients from benign thyroid diseased or healthy controls, followed by TOS and TAS. Risk estimate statistics also indicated that TOS and/or OSI were good risk factors to discriminate patients with thyroid cancer from two controls. These findings suggested that oxidants are increased and antioxidants are decreased in patients with thyroid cancer. OSI may be a more useful oxidative stress biomarker than TAS and TOS for monitoring the clinical status of thyroid cancer patients.
Christine M Friedenreich, Heather K Neilson, Christy G Woolcott, Anne McTiernan, Qinggang Wang, Rachel Ballard-Barbash, Charlotte A Jones, Frank Z Stanczyk, Rollin F Brant, Yutaka Yasui, Melinda L Irwin, Kristin L Campbell, Margaret L McNeely, Kristina H Karvinen, and Kerry S Courneya
Physical activity is a known modifiable lifestyle means for reducing postmenopausal breast cancer risk, but the biologic mechanisms are not well understood. Metabolic factors may be involved. In this study, we aimed to determine the effects of exercise on insulin resistance (IR) indicators, IGF1, and adipokines in postmenopausal women. The Alberta Physical Activity and Breast Cancer Prevention Trial was a two-armed randomized controlled trial in postmenopausal, inactive, cancer-free women. A year-long aerobic exercise intervention of 225 min/week (n=160) was compared with a control group asked to maintain usual activity levels (n=160). Baseline, 6- and 12-month serum levels of insulin, glucose, IGF1, IGF-binding protein 3 (IGFBP3), adiponectin, and leptin were assayed, and after data collection, homeostasis model assessment of IR (HOMA-IR) scores were calculated. Intention-to-treat analyses were performed using linear mixed models. The treatment effect ratio (TER) of exercisers to controls was calculated. Data were available on 308 (96.3%) women at 6 months and 310 (96.9%) women at 12 months. Across the study period, statistically significant reductions in insulin (TER=0.87, 95% confidence interval (95% CI)=0.81–0.93), HOMA-IR (TER=0.86, 95% CI=0.80–0.93), and leptin (TER=0.82, 95% CI=0.78–0.87), and an increase in the adiponectin/leptin ratio (TER=1.21, 95% CI=1.13–1.28) were observed in the exercise group compared with the control group. No significant differences were observed for glucose, IGF1, IGFBP3, adiponectin or the IGF1/IGFBP3 ratio. Previously inactive postmenopausal women who engaged in a moderate-to-vigorous intensity exercise program experienced changes in insulin, HOMA-IR, leptin, and adiponectin/leptin that might decrease the risk for postmenopausal breast cancer.
Alicia A Tone, Carl Virtanen, Patricia A Shaw, and Theodore J Brown
We previously reported that BRCA1/2-mutated fallopian tube epithelium (FTE) collected during the luteal phase exhibits gene expression profiles more closely resembling that of high-grade serous carcinoma (HGSC) specimens than FTE collected during the follicular phase or from control patients. Since the luteal phase is characterised by high levels of progesterone, we determined whether the expression of progesterone receptor (PR) and PR-responsive genes was altered in FTE obtained from BRCA mutation carriers during the luteal phase of the menstrual cycle. RT-qPCR confirmed a decreased expression of PR mRNA in FTE during the luteal phase relative to follicular phase, in both BRCA1/2 mutation carriers and control patients. Immunohistochemistry using isoform-specific antibodies confirmed a low level of both PR-A and PR-B in HGSC and a lower level of staining in FTE samples obtained during the luteal phase compared with the follicular phase. No significant difference in PR-A or PR-B staining was found based on patient BRCA mutation status. Analysis of our previously reported gene expression profiles based upon known PR-A- and PR-B-specific target genes did not partition samples by BRCA mutation status, indicating that overall FTE PR response is not altered in BRCA mutation carriers. HGSC samples grouped separately from other samples, consistent with the observed loss of PR expression. These findings indicate no overall difference in PR signalling in FTE as a function of BRCA mutation status. Thus, the molecular similarity of BRCA1/2-mutated luteal phase FTE and HGSC likely results from an altered response to luteal phase factors other than progesterone.
Catherine Ory, Nicolas Ugolin, Céline Levalois, Ludovic Lacroix, Bernard Caillou, Jean-Michel Bidart, Martin Schlumberger, Ibrahima Diallo, Florent de Vathaire, Paul Hofman, José Santini, Bernard Malfoy, and Sylvie Chevillard
Both external and internal exposure to ionizing radiation are strong risk factors for the development of thyroid tumors. Until now, the diagnosis of radiation-induced thyroid tumors has been deduced from a network of arguments taken together with the individual history of radiation exposure. Neither the histological features nor the genetic alterations observed in these tumors have been shown to be specific fingerprints of an exposure to radiation. The aim of our work is to define ionizing radiation-related molecular specificities in a series of secondary thyroid tumors developed in the radiation field of patients treated by radiotherapy. To identify molecular markers that could represent a radiation-induction signature, we compared 25K microarray transcriptome profiles of a learning set of 28 thyroid tumors, which comprised 14 follicular thyroid adenomas (FTA) and 14 papillary thyroid carcinomas (PTC), either sporadic or consecutive to external radiotherapy in childhood. We identified a signature composed of 322 genes which discriminates radiation-induced tumors (FTA and PTC) from their sporadic counterparts. The robustness of this signature was further confirmed by blind case-by-case classification of an independent set of 29 tumors (16 FTA and 13 PTC). After the histology code break by the clinicians, 26/29 tumors were well classified regarding tumor etiology, 1 was undetermined, and 2 were misclassified. Our results help shed light on radiation-induced thyroid carcinogenesis, since specific molecular pathways are deregulated in radiation-induced tumors.
Dewi Astuti, Christopher J Ricketts, Rasheduzzaman Chowdhury, Michael A McDonough, Dean Gentle, Gail Kirby, Susanne Schlisio, Rajappa S Kenchappa, Bruce D Carter, William G Kaelin Jr, Peter J Ratcliffe, Christopher J Schofield, Farida Latif, and Eamonn R Maher
Germline mutations in the von Hippel–Lindau disease (VHL) and succinate dehydrogenase subunit B (SDHB) genes can cause inherited phaeochromocytoma and/or renal cell carcinoma (RCC). Dysregulation of the hypoxia-inducible factor (HIF) transcription factors has been linked to VHL and SDHB-related RCC; both HIF dysregulation and disordered function of a prolyl hydroxylase domain isoform 3 (PHD3/EGLN3)-related pathway of neuronal apoptosis have been linked to the development of phaeochromocytoma. The 2-oxoglutarate-dependent prolyl hydroxylase enzymes PHD1 (EGLN2), PHD2 (EGLN1) and PHD3 (EGLN3) have a key role in regulating the stability of HIF-α subunits (and hence expression of the HIF-α transcription factors). A germline PHD2 mutation has been reported in association with congenital erythrocytosis and recurrent extra-adrenal phaeochromocytoma. We undertook mutation analysis of PHD1, PHD2 and PHD3 in two cohorts of patients with features of inherited phaeochromocytoma (n=82) and inherited RCC (n=64) and no evidence of germline mutations in known susceptibility genes. No confirmed pathogenic mutations were detected suggesting that mutations in these genes are not a frequent cause of inherited phaeochromocytoma or RCC.
Laure Dossus, Sabina Rinaldi, Susen Becker, Annekatrin Lukanova, Anne Tjonneland, Anja Olsen, Jakob Stegger, Kim Overvad, Nathalie Chabbert-Buffet, Aida Jimenez-Corona, Francoise Clavel-Chapelon, Sabine Rohrmann, Birgit Teucher, Heiner Boeing, Madlen Schütze, Antonia Trichopoulou, Vassiliki Benetou, Pagona Lagiou, Domenico Palli, Franco Berrino, Salvatore Panico, Rosario Tumino, Carlotta Sacerdote, Maria-Luisa Redondo, Noémie Travier, Maria-Jose Sanchez, Jone M Altzibar, Maria-Dolores Chirlaque, Eva Ardanaz, H Bas Bueno-de-Mesquita, Fränzel J B van Duijnhoven, N Charlotte Onland-Moret, Petra H M Peeters, Goran Hallmans, Eva Lundin, Kay-Tee Khaw, Nicholas Wareham, Naomi Allen, Tim J Key, Nadia Slimani, Pierre Hainaut, Dora Romaguera, Teresa Norat, Elio Riboli, and Rudolf Kaaks
Obesity, a major risk factor for endometrial cancer, is a low-grade inflammatory state characterized by elevated concentrations of cytokines and acute phase reactants. The current study had two aims: first to investigate the associations of C-reactive protein (CRP), interleukin 6 (IL6), and IL1 receptor antagonist (IL1Ra) with endometrial cancer risk and second to examine to which extent these markers can influence the association between obesity and endometrial cancer. We conducted a case–control study, nested within the European Prospective Investigation into Cancer and Nutrition, which comprised 305 incident cases of endometrial cancer and 574 matched controls. CRP, IL6, and IL1Ra were measured in prospectively collected blood specimens by immunoassays. Data were analyzed using conditional logistic regression. All statistical tests were two-sided, and P values <0.05 were considered statistically significant. We observed a significant increase in risk of endometrial cancer with elevated levels of CRP (odds ratio (OR) for top versus bottom quartile: 1.58, 95% confidence interval (CI): 1.03–2.41, P trend=0.02), IL6 (OR for top versus bottom quartile: 1.66, 95% CI: 1.08–2.54, P trend=0.008), and IL1Ra (OR for top versus bottom quartile: 1.82, 95% CI: 1.22–2.73, P trend=0.004). After adjustment for body mass index (BMI), the estimates were strongly reduced and became non-significant. The association between BMI and endometrial cancer was also substantially attenuated (∼10–20%) after adjustment for inflammatory markers, even when the effects of C-peptide or estrone had already been taken into account. We provided epidemiological evidence that chronic inflammation might mediate the association between obesity and endometrial cancer and that endometrial carcinogenesis could be promoted by an inflammatory milieu.
Petteri Ahtiainen, Victoria Sharp, Susana B Rulli, Adolfo Rivero-Müller, Veronika Mamaeva, Matias Röyttä, and Ilpo Huhtaniemi
The etiology of pituitary adenomas remains largely unknown, with the exception of involvement of estrogens in the formation of prolactinomas. We have examined the molecular pathogenesis of prolactin-producing pituitary adenomas in transgenic female mice expressing the human choriongonadotropin (hCG) β-subunit. The LH/CG bioactivity is elevated in the mice, with consequent highly stimulated ovarian progesterone (P4) production, in the face of normal estrogen secretion. Curiously, despite normal estrogen levels, large prolactinomas developed in these mice, and we provide here several lines of evidence that the elevated P4 levels are involved in the growth of these estrogen-dependent tumors. The antiprogestin mifepristone inhibited tumor growth, and combined postgonadectomy estradiol/P4 treatment was more effective than estrogen alone in inducing tumor growth. Evidence for direct growth-promoting effect of P4 was obtained from cultures of primary mouse pituitary cells and rat somatomammotroph GH3 cells. The mouse tumors and cultured cells revealed stimulation of the cyclin D1/cyclin-dependent kinase 4/retinoblastoma protein/transcription factor E2F1 pathway in the growth response to P4. If extrapolated to humans, and given the importance of endogenous P4 and synthetic progestins in female reproductive functions and their pharmacotherapy, it is relevant to revisit the potential role of these hormones in the origin and growth of prolactinomas.
Yuet-Kin Leung, Hung-Ming Lam, Shulin Wu, Dan Song, Linda Levin, Liang Cheng, Chin-Lee Wu, and Shuk-Mei Ho
Estrogens play a pivotal role in the development and progression of prostate cancer (PCa). Their actions are mediated by estrogen receptors (ERs), particularly ERβ in the prostate epithelium. With the discovery of ERβ isoforms, data from previous studies that focused principally on the wild-type ERβ (ERβ1) may not be adequate in explaining the still controversial role of ERβ(s) in prostate carcinogenesis. In this study, using newly generated isoform-specific antibodies, immunohistochemistry (IHC) was performed on a tumor microarray comprised of 144 specimens. IHC results were correlated with pathological and clinical follow-up data to delineate the distinct roles of ERβ1, ERβ2, and ERβ5 in PCa. ERβ2 was commonly found in the cytoplasm and was the most abundant isoform followed by ERβ1 localized predominantly in the nucleus, and ERβ5 was primarily located in the cytoplasm. Logistic regression analyses demonstrated that nuclear ERβ2 (nERβ2) is an independent prognostic marker for prostate specific antigen (PSA) failure and postoperative metastasis (POM). In a Kaplan–Meier analysis, the combined expression of both nERβ2 and cytoplasmic ERβ5 identified a group of patients with the shortest POM-free survival. Cox proportional hazard models revealed that nERβ2 predicted shorter time to POM. In concordance with IHC data, stable, ectopic expression of ERβ2 or ERβ5 enhanced PCa cell invasiveness but only PCa cells expressing ERβ5 exhibited augmented cell migration. This is the first study to uncover a metastasis-promoting role of ERβ2 and ERβ5 in PCa, and show that the two isoforms, singularly and conjointly, have prognostic values for PCa progression. These findings may aid future clinical management of PCa.
N Burrows, J Resch, R L Cowen, R von Wasielewski, C Hoang-Vu, C M West, K J Williams, and G Brabant
Hypoxia-inducible factor 1α (HIF-1α) is upregulated by hypoxia and oncogenic signalling in many solid tumours. Its regulation and function in thyroid carcinomas are unknown. We evaluated the regulation of HIF-1α and target gene expression in primary thyroid carcinomas and thyroid carcinoma cell lines (BcPAP, WRO, FTC-133 and 8505c). HIF-1α was not detectable in normal tissue but was expressed in thyroid carcinomas. Dedifferentiated anaplastic tumours (ATCs) exhibited high levels of nuclear HIF-1α staining. The HIF-1 target glucose transporter 1 was expressed to a similar level in all tumour types, whereas carbonic anhydrase-9 was significantly elevated in ATCs. In vitro studies revealed a functionally active HIF-1α pathway in thyroid cells with transcriptional activation observed after graded hypoxia (1% O2, anoxia) or treatment with a hypoxia mimetic cobalt chloride. High basal and hypoxia-induced expression of HIF-1α in FTC-133 cells that harbour a phosphatase and tensin homologue (PTEN) mutation was reduced by introduction of wild-type PTEN. Similarly, pharmacological inhibition of the phosphoinositide 3-kinase (PI3K) pathway using LY294002 inhibited HIF-1α and HIF-1α targets in all cell lines, including those with B-RAF mutations (BcPAP and 8505c). In contrast, the effects of inhibition of the RAF/MEK/extracellular signal-regulated kinase pathway were restricted by environmental condition and B-RAF mutation status. HIF-1 is functionally expressed in thyroid carcinomas and is regulated not only by hypoxia but also via growth factor signalling pathways and, in particular, the PI3K pathway. Given the strong association of HIF-1α with an aggressive disease phenotype and therapeutic resistance, this pathway may be an attractive target for improved therapy in thyroid carcinomas.