Cecilia Gunnarsson

17β-hydroxysteroid dehydrogenases involved in local oestrogen synthesis have prognostic significance in breast cancer

The 17β-hydroxysteroid dehydrogenase (17HSD) enzymes are involved in the local regulation of sex steroids. The 17HSD type 1 enzyme catalyses the interconversion of the weak oestrone (E1) to the more potent oestradiol (E2), whereas 17HSD type 2 catalyses the oxidation of E2 to E1. The aim of this study was to correlate the expression of these enzymes in the tumour with the recurrence-free survival of tamoxifen-treated breast cancer patients. We used real-time reverse transcriptase PCR to investigate the mRNA expression of 17HSD types 1 and 2 in tumour samples from 230 postmenopausal patients. For the patients with oestrogen receptor (ER)-positive breast cancer, we found a statistically significant positive correlation between recurrence-free survival and expression of 17HSD type 2 (P=0.026). We examined the ratio of 17HSD types 2 and 1, and ER-positive patients with low ratios showed a significantly higher rate of recurrence than those with higher ratios (P=0.0047). ER positive patients with high expression levels of 17HSD type 1 had a significantly higher risk for late relapse (P=0.0051). The expression of 17HSD types 1 and 2 in breast cancer differs from the expression of these enzymes in normal mammary gland, and this study indicates that the expression has prognostic significance in breast cancer.

Amplification of HSD17B1 and ERBB2 in primary breast cancer.

Estrogens play a crucial role in the development of breast cancer. Estradiol can be produced in the breast tissue in situ, and one of the enzymes involved in this process is 17β-hydroxysteriod dehydrogenase (17β-HSD) type 1 that catalyzes the interconversion of estrone (E1) to the biologically more potent estradiol (E2). The gene coding for 17β-HSD type 1 (HSD17B1) is located at 17q12–21, close to the more studied ERBB2 and BRCA1. The aim of this study was to investigate if HSD17B1 shows an altered gene copy number in breast cancer. We used real-time PCR and examined 221 postmenopausal breast tumors for amplification of HSD17B1 and ERBB2. In all, 32 tumors (14.5%) showed amplification of HSD17B1 and 21% were amplified for ERBB2. Amplification of the two genes was correlated (P=0.00078) and in 14 tumors (44%) with amplification of HSD17B1, ERBB2 was co amplified. The patients with amplification in at least one of the genes had a significantly worse outcome than patients without (P=0.0059). For estrogen receptor (ER)-positive patients who received adjuvant tamoxifen, amplification of HSD17B1 was related to decreased breast cancer survival (P=0.017), whereas amplification of ERRB2 was not. Amplification of HSD17B1 might be an indicator of adverse prognosis among ER-positive patients, and possibly a mechanism for decreased benefit from tamoxifen treatment.

17β-Hydroxysteroid Dehydrogenase 14 Affects Estradiol Levels in Breast Cancer Cells and Is a Prognostic Marker in Estrogen Receptor–Positive Breast Cancer

Estrogens have an important role in the progression of breast cancer. The 17β-hydroxysteroid dehydrogenase (17HSD) family has been identified to be of significance in hormone-dependent tissues. 17HSD1 and 17HSD2 are the main 17HSD enzymes involved in breast cancer investigated this far, but it is possible that other hormone-regulating enzymes have a similar role. 17HSD5 and 17HSD12 are associated with sex steroid metabolism, and 17HSD14 is a newly discovered enzyme that may be involved in the estrogen balance. The mRNA expression of 17HSD5, 17HSD12, and 17HSD14 were analyzed in 131 breast cancer specimens by semiquantitative real-time PCR. The results were compared with recurrence-free survival and breast cancer-specific survival of the patients. The breast cancer cell lines MCF7, SKBR3, and ZR75-1 were transiently transfected with 17HSD14 to investigate any possible effect on estradiol levels. We found that high 17HSD5 was related to significantly higher risk of late relapse in estrogen receptor (ER)–positive patients remaining recurrence-free later than 5 years after diagnosis ( P = 0.02). No relation to 17HSD12 expression was found, indicating that 17HSD12 is of minor importance in breast cancer. Patients with ER-positive tumors with high expression levels of 17HSD14 showed a significantly better prognosis about recurrence-free survival ( P = 0.008) as well as breast cancer-specific survival ( P = 0.01), confirmed by multivariate analysis ( P = 0.04). Transfection of 17HSD14 in the human breast cancer cells MCF7 and SKBR3 significantly decreased the levels of estradiol, presenting an effect of high expression levels of the enzyme. (Cancer Res 2006; 66(23): 11471-7)

Molecular characterization and clinical features of a patient with an interstitial deletion of 3p25.3‐p26.1

Distal chromosome 3p deletions (3p‐ syndrome) are associated with various developmental defects. The majority of cases have a terminal deletion of the short arm of chromosome 3 with loss of either the maternal or the paternal copy. A girl with an interstitial molecularly characterized 1.6 Mb deletion in cytoband 3p25.3‐26.1 of the paternal chromosome 3 is presented. To our knowledge, she possesses the smallest deletion that has ever been reported for a patient with a clinical phenotype in accordance with the 3p‐ syndrome. The boundaries of the deletion lies within nearly all previously reported terminal deletions causing this syndrome. Selected genes that are present in the hemizygous state and which might be important for the phenotype of this patient as regards the congenital heart defect, autistic behavior and mental retardation (CAV3, OXTR, and SRGAP3/MEGAP, respectively) are discussed in context of the clinical features.

Activating mutations affecting the Dbl homology domain of SOS2 cause Noonan syndrome

The RASopathies constitute a family of autosomal‐dominant disorders whose major features include facial dysmorphism, cardiac defects, reduced postnatal growth, variable cognitive deficits, ectodermal and skeletal anomalies, and susceptibility to certain malignancies. Noonan syndrome (NS), the commonest RASopathy, is genetically heterogeneous and caused by functional dysregulation of signal transducers and regulatory proteins with roles in the RAS/extracellular signal‐regulated kinase (ERK) signal transduction pathway. Mutations in known disease genes account for approximately 80% of affected individuals. Here, we report that missense mutations altering Son of Sevenless, Drosophila, homolog 2 (SOS2), which encodes a RAS guanine nucleotide exchange factor, occur in a small percentage of subjects with NS. Four missense mutations were identified in five unrelated sporadic cases and families transmitting NS. Disease‐causing mutations affected three conserved residues located in the Dbl homology (DH) domain, of which two are directly involved in the intramolecular binding network maintaining SOS2 in its autoinhibited conformation. All mutations were found to promote enhanced signaling from RAS to ERK. Similar to NS‐causing SOS1 mutations, the phenotype associated with SOS2 defects is characterized by normal development and growth, as well as marked ectodermal involvement. Unlike SOS1 mutations, however, those in SOS2 are restricted to the DH domain.

Ratio of 17HSD1 to 17HSD2 Protein Expression Predicts the Outcome of Tamoxifen Treatment in Postmenopausal Breast Cancer Patients

Purpose: Estrogens have great significance in the development of breast cancer. After menopause, most estrogen biosynthesis is done in peripheral tissue, and the main enzymes involved in balancing the amount of estrone against estradiol are 17β-hydroxysteroid dehydrogenases (17HSD). The aim of this study was to investigate the prognostic and tamoxifen predictive values of 17HSD1 and 17HSD2 expression. Experimental Design: Tumors from low-risk breast cancer patients randomized to adjuvant tamoxifen therapy or no adjuvant treatment were analyzed with immunohistochemistry to investigate protein expression of 17HSD1 and 17HSD2 in 912 cases. All patients had lymph node-negative breast cancer and were postmenopausal at the time of diagnosis. Results: Low 17HSD1 expression was associated with significant benefit from tamoxifen treatment among patients with estrogen receptor (ER)-positive tumors (P < 0.001). For patients with a 17HSD1 score not exceeding that of 17HSD2, tamoxifen increased the rate of distant recurrence-free survival (hazard ratio, 0.37; 95% confidence interval, 0.23-0.60) and breast cancer-specific survival (hazard ratio, 0.30; 95% confidence interval, 0.16-0.54), whereas no apparent effect was observed when the 17HSD1 score was higher than that of 17HSD2. The interaction was significant for both distant recurrence-free survival (P = 0.036) and breast cancer-specific survival (P = 0.014). In the cohort of systemically untreated patients, no prognostic importance was observed. Conclusions: This is the first report that clearly distinguishes between the prognostic and predictive importance of 17HSD1 and 17HSD2 in ER-positive breast cancer treated with or without tamoxifen. Our data suggest that the 17HSD1/17HSD2 ratio might be useful as a predictive factor for tamoxifen treatment in ER-positive breast cancer patients.

Pregnant women are satisfied with the information they receive about prenatal diagnosis, but are their decisions well informed?

Objective. To survey the information about prenatal diagnosis that midwives give to pregnant women and to find out how the women experience the information. Furthermore, to evaluate the midwives’ opinion about their knowledge and personal need for education. Design. Descriptive cross‐sectional study. Setting. The southeast healthcare region of Sweden. Methods. One hundred and fifty‐seven midwives and 150 pregnant women were invited to reply to a confidential questionnaire in 2008. Results. The reply rate was 78% for the midwives and 53% for the women. Ninety‐six percentage of the midwives used ≤10 minutes to inform women about prenatal diagnosis. Seventy‐two percentage always informed about the advantages and 41% about the choice to continue or terminate the pregnancy if a serious abnormality was detected. In addition, 41% considered that they had sufficient knowledge to inform about prenatal diagnosis, while 84% wanted additional education. Seventy‐six percentage of the women took the decision to have prenatal diagnosis as soon as they found out that they were pregnant. A majority considered that they had been given enough time for questions and reflections. Conclusions. There was discrepancy between the amount of information, which midwives gave to pregnant women about prenatal diagnosis compared to what would be needed for a complete understanding of the relevant medical facts and the risks involved, but even so the women were satisfied with the information.

A new polymorphism in the coding region of exon four in HSD17B2 in relation to risk of sporadic and hereditary breast cancer

In situ synthesis of oestrogens is of great importance in the development and progression of breast cancer. 17β-hydroxysteroid dehydrogenase (17HSD) type 2 catalyses oxidation from oestradiol to oestrone, and thereby protects the breast epithelial cells from oestradiol. Low expression of 17HSD type 2 has been associated with decreased survival in breast cancer, but no studies have investigated the mechanism behind the low expression. The 17HSD type 2 gene (HSD17B2) was screened for mutations with Single Stranded Conformation Polymorphism (SSCP)-DNA sequencing in 59 sporadic breast cancer cases, 19 hereditary breast cancer cases and seven breast cancer cell lines. DNA samples from 226 healthy individuals were used to identify if changes were previously unknown polymorphisms. No mutation was detected and therefore mutations in HSD17B2 do not explain why some breast tumours exhibit low 17HSD type 2 expression. However, a previously unknown polymorphism was found in exon four (Met226Val). Using molecular modelling, we found that the substituted residue is located at the outer part of the steroid binding site, probably causing minor alterations in the substrate binding. We further studied if the polymorphism contributes to breast cancer susceptibility in a larger material, but did not find an increased risk in the group of 317 sporadic breast cancer patients, 188 breast cancer patients with two close relatives with breast cancer or 122 hereditary breast cancer patients, compared to the healthy control group. We suggest that the detected polymorphism does not contribute to a higher risk of developing breast cancer.

Assessment of HaloPlex Amplification for Sequence Capture and Massively Parallel Sequencing of Arrhythmogenic Right Ventricular Cardiomyopathy–Associated Genes

The genetic basis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is complex. Mutations in genes encoding components of the cardiac desmosomes have been implicated as being causally related to ARVC. Next-generation sequencing allows parallel sequencing and duplication/deletion analysis of many genes simultaneously, which is appropriate for screening of mutations in disorders with heterogeneous genetic backgrounds. We designed and validated a next-generation sequencing test panel for ARVC using HaloPlex. We used SureDesign to prepare a HaloPlex enrichment system for sequencing of DES, DSC2, DSG2, DSP, JUP, PKP2, RYR2, TGFB3, TMEM43, and TTN from patients with ARVC using a MiSeq instrument. Performance characteristics were determined by comparison with Sanger, as the gold standard, and TruSeq Custom Amplicon sequencing of DSC2, DSG2, DSP, JUP, and PKP2. All the samples were successfully sequenced after HaloPlex capture, with >99% of targeted nucleotides covered by >20×. The sequences were of high quality, although one problematic area due to a presumptive context-specific sequencing error-causing motif located in exon 1 of the DSP gene was detected. The mutations found by Sanger sequencing were also found using the HaloPlex technique. Depending on the bioinformatics pipeline, sensitivity varied from 99.3% to 100%, and specificity varied from 99.9% to 100%. Three variant positions found by Sanger and HaloPlex sequencing were missed by TruSeq Custom Amplicon owing to loss of coverage.

Hypersecretion of ovarian androgens may be gonadotrophin dependent many years after menopause

BACKGROUND In fertile women both adrenals and ovaries contribute to androgen production, whereas after the menopause the ovarian contribution normally decreases. OBJECTIVE The objective of this case study was to assess whether ovarian androgen secretion was responsive to decreased gonadotrophin stimulation and whether gonadotrophins were sensitive to negative feedback from sex steroids many years after the menopause. METHODS In this uncontrolled case study a 72 years old slightly overweight woman with noninsulin-dependent diabetes mellitus presented with hirsuitism and elevated serum testosterone concentrations. The woman was reluctant to have an oophorectomy, and received an oral estradiol/progestagene preparation. Serum testosterone and gonadotrophin concentrations were measured before and after steroid hormone therapy. RESULTS Serum gonadotrophin concentrations decreased and testosterone levels returned to normal during therapy. When the hormone therapy was stopped for 1 month the high testosterone concentrations returned, but were again normalized when the hormone therapy was reinitiated. CONCLUSION The ovaries of this woman were apparently still responsive to pituitary stimulation and her hypothalamic pituitary ovarian feed-back system still seemed to be working after 70 years of age.