Browsing by Subject "Breast cancer"

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  • Aho, Niina (Helsingin yliopisto, 2022)
    Breast cancer is the most prevalent cancer in women worldwide and in 2020 it was the fifth deadliest. In Finland 2019 more than 5000 breast cancer cases were diagnosed, 94% in women and 6% in men. Until now, the high-risk breast cancer susceptibility genes have been identified including BRCA1, BRCA2 and TP53 as well as many of the moderate risk genes. Still, together all the identified genes explain only approximately half of the familial breast cancer cases. Furthermore, all the known breast cancer susceptibility genes are linked to the DNA repair mechanism. Serpina3 stands out as a non-DNA repair gene but as a gene that encodes a protease inhibitor which belongs to the serpin superfamily. Serpina3 has been associated with various diseases before and especially changes in its expression levels are linked to the tumor prognosis in many cancers including breast cancer. However, a previous study proposed that Serpina3 c.918-1G>C is a susceptibility variant for breast cancer in the Northern Finland population. This thesis a case-control study to investigate whether Serpina3 c.918-1G>C variant is associated with breast cancer in the Southern Finland population. In addition, the tumor histology and cellular markers of Serpina3 c.918-1G>C carriers were examined. This study utilized DNA collected from breast cancer patients as well as DNA from blood donors and healthy biobank controls. Breast cancer patients included both familial and unselected cases. The prevalence of Serpina3 c.918- 1G<C variant was studied by genotyping the cases and controls. Genotyping was done by TaqMan real-time PCR and carriers were further confirmed by Sanger sequencing. Moreover, statistical tests were used in the data analyses. The studied Serpina3 c.918-1G>C variant was not found to be significantly (p>0.05) enriched in the breast cancer cases. The variant was found in 0.23 % of familial and 0.36 % of unselected cases, altogether in 0.28 % of all studied breast cancer cases, the frequency in controls was 0.27 %. The tumor histology was found to be ductal in 73 % of the Serpina3 c.918- 1G>C variant carriers and only 9 % had lobular tumor. In other words, the tumor histology followed the usual distribution. All the carriers had a HER2 negative tumor and all except one case were both ER and PR positive. About half of the carriers expressed the cellular proliferation marker Ki67. As a conclusion, the results from this study do not suggest Serpina3 c.918-1G>C as a breast cancer risk variant at least in the Southern Finland population.
  • Tuohinen, Suvi Sirkku; Aula, Hanna; Skyttä, Tanja; Huhtala, Heini; Keski-Pukkila, Konsta; Nikus, Kjell; Virtanen, Vesa; Kellokumpu-Lehtinen, Pirkko-Liisa; Raatikainen, Pekka (2022)
    Background/Aim: Radiotherapy (RT) induces late changes in all cardiac structures. Most studies of early changes focus on individual parameters. Patients and Methods: Data from eighty early-stage breast cancer patients at baseline, post-RT and three-year follow-up visit were assessed prospectively. Changes in ten cardiac parameters were collected including electrocardiogram (ECG), echocardiography, and biomarkers. A percentage of abnormal changes was calculated. Results: The mean heart radiation dose (Dmean) was independently associated with the increased incidence of changes post-RT (?? =0.403, p
  • Breast Canc Assoc Consortium; Beeghly-Fadiel, Alicia; Khankari, Nikhil K.; Delahanty, Ryan J.; Zheng, Wei; Blomqvist, Carl; Nevanlinna, Heli (2020)
    Background: Conventional epidemiologic studies have evaluated associations between circulating lipid levels and breast cancer risk, but results have been inconsistent. As Mendelian randomization analyses may provide evidence for causal inference, we sought to evaluate potentially unbiased associations between breast cancer risk and four genetically predicted lipid traits. Methods: Previous genome-wide association studies (GWAS) have identified 164 discrete variants associated with high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), triglycerides and total cholesterol. We used 162 of these unique variants to construct weighted genetic scores (wGSs) for a total of 101 424 breast cancer cases and 80 253 controls of European ancestry from the Breast Cancer Association Consortium (BCAC). Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between per standard deviation increase in genetically predicted lipid traits and breast cancer risk. Additional Mendelian randomization analysis approaches and sensitivity analyses were conducted to assess pleiotropy and instrument validity. Results: Corresponding to approximately 15 mg/dL, one standard deviation increase in genetically predicted HDL-C was associated with a 12% increased breast cancer risk (OR: 1.12, 95% CI: 1.08-1.16). Findings were consistent after adjustment for breast cancer risk factors and were robust in several sensitivity analyses. Associations with genetically predicted triglycerides and total cholesterol were inconsistent, and no association for genetically predicted LDL-C was observed. Conclusions: This study provides strong evidence that circulating HDL-C may be associated with an increased risk of breast cancer, whereas LDL-C may not be related to breast cancer risk.
  • Ojala, K.; Meretoja, T. J.; Leidenius, M. H. K. (2017)
    Background: Recent studies implicate that oncoplastic breast cancer surgery provides better aesthetic outcome than conventional resection. Several factors have been associated with poor aesthetic outcome. This study aims to compare patient-reported aesthetic and functional outcome after conventional and oncoplastic resection and to evaluate prognostic factors for poor aesthetic outcome in a population based setting. Methods: 637 patients having breast conserving treatment (BCT) due to unilateral primary breast cancer at a single hospital district during 2010 were included. Aesthetic and functional outcome were evaluated using two questionnaires three years after surgery. Results: Questionnaires were returned by 379 (59%) patients; 293 (77%) of these had conventional and 86 (23%) oncoplastic resection. Patients in oncoplastic resection group had larger tumour diameter (p <0.001), larger resection specimens (p <0.001), and more often multifocal tumours-(p = 0.032), node positive cancer (p = 0.029) and lower quadrant tumour localization (p = 0.007). Aesthetic outcome according to BCTOS questionnaire was good in 284 (75%) patients; 52 (61%) patients in the oncoplastic group and 230 patients (81%) in the conventional resection group, p <0.001. Larger tumour diameter (p = 0.033), multifocality (p = 0.022), weight of resection specimen ( Conclusions: Patient satisfaction to aesthetic outcome after BCT is high. Conventional resection provides good aesthetic outcome in appropriately selected patients. Oncoplastic resection enables BCT in patients with larger and multifocal tumours with favourable aesthetic outcome. (C) 2016 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.
  • Varga, Zsuzsanna; Lebeau, Annette; Bu, Hong; Hartmann, Arndt; Penault-Llorca, Frederique; Guerini-Rocco, Elena; Schraml, Peter; Symmans, Fraser; Stoehr, Robert; Teng, Xiaodong; Turzynski, Andreas; von Wasielewski, Reinhard; Guertler, Claudia; Laible, Mark; Schlombs, Kornelia; Joensuu, Heikki; Keller, Thomas; Sinn, Peter; Sahin, Ugur; Bartlett, John; Viale, Giuseppe (2017)
    Background: Accurate determination of the predictive markers human epidermal growth factor receptor 2 (HER2/ERBB2), estrogen receptor (ER/ESR1), progesterone receptor (PgR/PGR), and marker of proliferation Ki67 (MKI67) is indispensable for therapeutic decision making in early breast cancer. In this multicenter prospective study, we addressed the issue of inter- and intrasite reproducibility using the recently developed reverse transcription-quantitative real-time polymerase chain reaction-based MammaTyper (R) test. Methods: Ten international pathology institutions participated in this study and determined messenger RNA expression levels of ERBB2, ESR1, PGR, and MKI67 in both centrally and locally extracted RNA from formalin-fixed, paraffin-embedded breast cancer specimens with the MammaTyper (R) test. Samples were measured repeatedly on different days within the local laboratories, and reproducibility was assessed by means of variance component analysis, Fleiss' kappa statistics, and interclass correlation coefficients (ICCs). Results: Total variations in measurements of centrally and locally prepared RNA extracts were comparable; therefore, statistical analyses were performed on the complete dataset. Intersite reproducibility showed total SDs between 0.21 and 0.44 for the quantitative single-marker assessments, resulting in ICC values of 0.980-0.998, demonstrating excellent agreement of quantitative measurements. Also, the reproducibility of binary single-marker results (positive/negative), as well as the molecular subtype agreement, was almost perfect with kappa values ranging from 0.90 to 1.00. Conclusions: On the basis of these data, the MammaTyper (R) has the potential to substantially improve the current standards of breast cancer diagnostics by providing a highly precise and reproducible quantitative assessment of the established breast cancer biomarkers and molecular subtypes in a decentralized workup.
  • Sobral-Leite, Marcelo; Wesseling, Jelle; Smit, Vincent T. H. B. M.; Nevanlinna, Heli; van Miltenburg, Martine H.; Sanders, Joyce; Hofland, Ingrid; Blows, Fiona M.; Coulson, Penny; Patrycja, Gazinska; Schellens, Jan H. M.; Fagerholm, Rainer; Heikkila, Paivi; Aittomaki, Kristiina; Blomqvist, Carl; Provenzano, Elena; Ali, Hamid Raza; Figueroa, Jonine; Sherman, Mark; Lissowska, Jolanta; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Phillips, Kelly-Anne; Couch, Fergus J.; Olson, Janet E.; Vachon, Celine; Visscher, Daniel; Brenner, Hermann; Butterbach, Katja; Arndt, Volker; Holleczek, Bernd; Hooning, Maartje J.; Hollestelle, Antoinette; Martens, John W. M.; van Deurzen, Carolien H. M.; van de Water, Bob; Broeks, Annegien; Chang-Claude, Jenny; Chenevix-Trench, Georgia; Easton, Douglas F.; Pharoah, Paul D. P.; Garcia-Closas, Montserrat; de Graauw, Marjo; Schmidt, Marjanka K.; kConFab-AOCS Investigators (2015)
    Background: Annexin A1 (ANXA1) is a protein related with the carcinogenesis process and metastasis formation in many tumors. However, little is known about the prognostic value of ANXA1 in breast cancer. The purpose of this study is to evaluate the association between ANXA1 expression, BRCA1/2 germline carriership, specific tumor subtypes and survival in breast cancer patients. Methods: Clinical-pathological information and follow-up data were collected from nine breast cancer studies from the Breast Cancer Association Consortium (BCAC) (n = 5,752) and from one study of familial breast cancer patients with BRCA1/2 mutations (n = 107). ANXA1 expression was scored based on the percentage of immunohistochemical staining in tumor cells. Survival analyses were performed using a multivariable Cox model. Results: The frequency of ANXA1 positive tumors was higher in familial breast cancer patients with BRCA1/2 mutations than in BCAC patients, with 48.6 % versus 12.4 %, respectively; P <0.0001. ANXA1 was also highly expressed in BCAC tumors that were poorly differentiated, triple negative, EGFR-CK5/6 positive or had developed in patients at a young age. In the first 5 years of follow-up, patients with ANXA1 positive tumors had a worse breast cancer-specific survival (BCSS) than ANXA1 negative (HRadj = 1.35; 95 % CI = 1.05-1.73), but the association weakened after 10 years (HRadj = 1.13; 95 % CI = 0.91-1.40). ANXA1 was a significant independent predictor of survival in HER2+ patients (10-years BCSS: HRadj = 1.70; 95 % CI = 1.17-2.45). Conclusions: ANXA1 is overexpressed in familial breast cancer patients with BRCA1/2 mutations and correlated with poor prognosis features: triple negative and poorly differentiated tumors. ANXA1 might be a biomarker candidate for breast cancer survival prediction in high risk groups such as HER2+ cases.
  • Hamdi, Yosr; Soucy, Penny; Kuchenbaeker, Karoline B.; Pastinen, Tomi; Droit, Arnaud; Lemacon, Audrey; Adlard, Julian; Aittomäki, Kristiina; Andrulis, Irene L.; Arason, Adalgeir; Arnold, Norbert; Arun, Banu K.; Azzollini, Jacopo; Bane, Anita; Barjhoux, Laure; Barrowdale, Daniel; Benitez, Javier; Berthet, Pascaline; Blok, Marinus J.; Bobolis, Kristie; Bonadona, Valerie; Bonanni, Bernardo; Bradbury, Angela R.; Brewer, Carole; Buecher, Bruno; Buys, Saundra S.; Caligo, Maria A.; Chiquette, Jocelyne; Chung, Wendy K.; Claes, Kathleen B. M.; Daly, Mary B.; Damiola, Francesca; Davidson, Rosemarie; De la Hoya, Miguel; De Leeneer, Kim; Diez, Orland; Ding, Yuan Chun; Dolcetti, Riccardo; Domchek, Susan M.; Dorfling, Cecilia M.; Eccles, Diana; Eeles, Ros; Einbeigi, Zakaria; Ejlertsen, Bent; Engel, Christoph; Evans, D. Gareth; Feliubadalo, Lidia; Foretova, Lenka; Fostira, Florentia; Nevanlinna, Heli; EMBRACE; GEMO Study Collaborators; HEBON; kConFab Investigators (2017)
    Cis-acting regulatory SNPs resulting in differential allelic expression (DAE) may, in part, explain the underlying phenotypic variation associated with many complex diseases. To investigate whether common variants associated with DAE were involved in breast cancer susceptibility among BRCA1 and BRCA2 mutation carriers, a list of 175 genes was developed based of their involvement in cancer-related pathways. Using data from a genome-wide map of SNPs associated with allelic expression, we assessed the association of similar to 320 SNPs located in the vicinity of these genes with breast and ovarian cancer risks in 15,252 BRCA1 and 8211 BRCA2 mutation carriers ascertained from 54 studies participating in the Consortium of Investigators of Modifiers of BRCA1/2. We identified a region on 11q22.3 that is significantly associated with breast cancer risk in BRCA1 mutation carriers (most significant SNP rs228595 p = 7 x 10(-6)). This association was absent in BRCA2 carriers (p = 0.57). The 11q22.3 region notably encompasses genes such as ACAT1, NPAT, and ATM. Expression quantitative trait loci associations were observed in both normal breast and tumors across this region, namely for ACAT1, ATM, and other genes. In silico analysis revealed some overlap between top risk-associated SNPs and relevant biological features in mammary cell data, which suggests potential functional significance. We identified 11q22.3 as a new modifier locus in BRCA1 carriers. Replication in larger studies using estrogen receptor (ER)-negative or triple-negative (i.e., ER-, progesterone receptor-, and HER2-negative) cases could therefore be helpful to confirm the association of this locus with breast cancer risk.
  • Hultsch, Susanne; Kankainen, Matti; Paavolainen, Lassi; Kovanen, Ruusu-Maaria; Ikonen, Elina; Kangaspeska, Sara; Pietiäinen, Vilja; Kallioniemi, Olli (2018)
    Background: Tamoxifen treatment of estrogen receptor (ER)-positive breast cancer reduces mortality by 31%. However, over half of advanced ER-positive breast cancers are intrinsically resistant to tamoxifen and about 40% will acquire the resistance during the treatment. Methods: In order to explore mechanisms underlying endocrine therapy resistance in breast cancer and to identify new therapeutic opportunities, we created tamoxifen-resistant breast cancer cell lines that represent the luminal A or the luminal B. Gene expression patterns revealed by RNA-sequencing in seven tamoxifen-resistant variants were compared with their isogenic parental cells. We further examined those transcriptomic alterations in a publicly available patient cohort Results: We show that tamoxifen resistance cannot simply be explained by altered expression of individual genes, common mechanism across all resistant variants, or the appearance of new fusion genes. Instead, the resistant cell lines shared altered gene expression patterns associated with cell cycle, protein modification and metabolism, especially with the cholesterol pathway. In the tamoxifen-resistant T-47D cell variants we observed a striking increase of neutral lipids in lipid droplets as well as an accumulation of free cholesterol in the lysosomes. Tamoxifen-resistant cells were also less prone to lysosomal membrane permeabilization (LMP) and not vulnerable to compounds targeting the lipid metabolism. However, the cells were sensitive to disulfiram, LCS-1, and dasatinib. Conclusion: Altogether, our findings highlight a major role of LMP prevention in tamoxifen resistance, and suggest novel drug vulnerabilities associated with this phenotype.
  • Hultsch, Susanne; Kankainen, Matti; Paavolainen, Lassi; Kovanen, Ruusu-Maaria; Ikonen, Elina; Kangaspeska, Sara; Pietiäinen, Vilja; Kallioniemi, Olli (BioMed Central, 2018)
    Abstract Background Tamoxifen treatment of estrogen receptor (ER)-positive breast cancer reduces mortality by 31%. However, over half of advanced ER-positive breast cancers are intrinsically resistant to tamoxifen and about 40% will acquire the resistance during the treatment. Methods In order to explore mechanisms underlying endocrine therapy resistance in breast cancer and to identify new therapeutic opportunities, we created tamoxifen-resistant breast cancer cell lines that represent the luminal A or the luminal B. Gene expression patterns revealed by RNA-sequencing in seven tamoxifen-resistant variants were compared with their isogenic parental cells. We further examined those transcriptomic alterations in a publicly available patient cohort. Results We show that tamoxifen resistance cannot simply be explained by altered expression of individual genes, common mechanism across all resistant variants, or the appearance of new fusion genes. Instead, the resistant cell lines shared altered gene expression patterns associated with cell cycle, protein modification and metabolism, especially with the cholesterol pathway. In the tamoxifen-resistant T-47D cell variants we observed a striking increase of neutral lipids in lipid droplets as well as an accumulation of free cholesterol in the lysosomes. Tamoxifen-resistant cells were also less prone to lysosomal membrane permeabilization (LMP) and not vulnerable to compounds targeting the lipid metabolism. However, the cells were sensitive to disulfiram, LCS-1, and dasatinib. Conclusion Altogether, our findings highlight a major role of LMP prevention in tamoxifen resistance, and suggest novel drug vulnerabilities associated with this phenotype.
  • Wirtz, Ralph M.; Sihto, Harri; Isola, Jorma; Heikkila, Paivi; Kellokumpu-Lehtinen, Pirkko-Liisa; Auvinen, Paivi; Turpeenniemi-Hujanen, Taina; Jyrkkio, Sirkku; Lakis, Sotiris; Schlombs, Kornelia; Laible, Mark; Weber, Stefan; Eidt, Sebastian; Sahin, Ugur; Joensuu, Heikki (2016)
    The biological subtype of breast cancer influences the selection of systemic therapy. Distinction between luminal A and B cancers depends on consistent assessment of Ki-67, but substantial intra-observer and inter-observer variability exists when immunohistochemistry (IHC) is used. We compared RT-qPCR with IHC in the assessment of Ki-67 and other standard factors used in breast cancer subtyping. RNA was extracted from archival breast tumour tissue of 769 women randomly assigned to the FinHer trial. Cancer ESR1, PGR, ERBB2 and MKI67 mRNA content was quantitated with an RT-qPCR assay. Local pathologists assessed ER, PgR and Ki-67 expression using IHC. HER2 amplification was identified with chromogenic in situ hybridization (CISH) centrally. The results were correlated with distant disease-free survival (DDFS) and overall survival (OS). qPCR-based and IHC-based assessments of ER and PgR showed good concordance. Both low tumour MKI67 mRNA (RT-qPCR) and Ki-67 protein (IHC) levels were prognostic for favourable DDFS [hazard ratio (HR) 0.42, 95 % CI 0.25-0.71, P = 0.001; and HR 0.56, 0.37-0.84, P = 0.005, respectively] and OS. In multivariable analyses, cancer MKI67 mRNA content had independent influence on DDFS (adjusted HR 0.51, 95 % CI 0.29-0.89, P = 0.019) while Ki-67 protein expression had not any influence (P = 0.266) whereas both assessments influenced independently OS. Luminal B patients treated with docetaxel-FEC had more favourable DDFS and OS than those treated with vinorelbine-FEC when the subtype was defined by RT-qPCR (for DDFS, HR 0.52, 95 % CI 0.29-0.94, P = 0.031), but not when defined using IHC. Breast cancer subtypes approximated with RT-qPCR and IHC show good concordance, but cancer MKI67 mRNA content correlated slightly better with DDFS than Ki-67 expression. The findings based on MKI67 mRNA content suggest that patients with luminal B cancer benefit more from docetaxel-FEC than from vinorelbine-FEC.
  • Turkki, Riku; Byckhov, Dmitrii; Lundin, Mikael; Isola, Jorma; Nordling, Stig; Kovanen, Panu E.; Verrill, Clare; von Smitten, Karl; Joensuu, Heikki; Lundin, Johan; Linder, Nina (2019)
    PurposeRecent advances in machine learning have enabled better understanding of large and complex visual data. Here, we aim to investigate patient outcome prediction with a machine learning method using only an image of tumour sample as an input.MethodsUtilising tissue microarray (TMA) samples obtained from the primary tumour of patients (N=1299) within a nationwide breast cancer series with long-term-follow-up, we train and validate a machine learning method for patient outcome prediction. The prediction is performed by classifying samples into low or high digital risk score (DRS) groups. The outcome classifier is trained using sample images of 868 patients and evaluated and compared with human expert classification in a test set of 431 patients.ResultsIn univariate survival analysis, the DRS classification resulted in a hazard ratio of 2.10 (95% CI 1.33-3.32, p=0.001) for breast cancer-specific survival. The DRS classification remained as an independent predictor of breast cancer-specific survival in a multivariate Cox model with a hazard ratio of 2.04 (95% CI 1.20-3.44, p=0.007). The accuracy (C-index) of the DRS grouping was 0.60 (95% CI 0.55-0.65), as compared to 0.58 (95% CI 0.53-0.63) for human expert predictions based on the same TMA samples.ConclusionsOur findings demonstrate the feasibility of learning prognostic signals in tumour tissue images without domain knowledge. Although further validation is needed, our study suggests that machine learning algorithms can extract prognostically relevant information from tumour histology complementing the currently used prognostic factors in breast cancer.
  • NBCS Collaborators; kConFab Investigators; SGBCC Investigators; Dorling, Leila; Carvalho, Sara; Allen, Jamie; Nevanlinna, Heli; Suvanto, Maija (2022)
    Background Protein truncating variants in ATM, BRCA1, BRCA2, CHEK2, and PALB2 are associated with increased breast cancer risk, but risks associated with missense variants in these genes are uncertain. Methods We analyzed data on 59,639 breast cancer cases and 53,165 controls from studies participating in the Breast Cancer Association Consortium BRIDGES project. We sampled training (80%) and validation (20%) sets to analyze rare missense variants in ATM (1146 training variants), BRCA1 (644), BRCA2 (1425), CHEK2 (325), and PALB2 (472). We evaluated breast cancer risks according to five in silico prediction-of-deleteriousness algorithms, functional protein domain, and frequency, using logistic regression models and also mixture models in which a subset of variants was assumed to be risk-associated. Results The most predictive in silico algorithms were Helix (BRCA1, BRCA2 and CHEK2) and CADD (ATM). Increased risks appeared restricted to functional protein domains for ATM (FAT and PIK domains) and BRCA1 (RING and BRCT domains). For ATM, BRCA1, and BRCA2, data were compatible with small subsets (approximately 7%, 2%, and 0.6%, respectively) of rare missense variants giving similar risk to those of protein truncating variants in the same gene. For CHEK2, data were more consistent with a large fraction (approximately 60%) of rare missense variants giving a lower risk (OR 1.75, 95% CI (1.47-2.08)) than CHEK2 protein truncating variants. There was little evidence for an association with risk for missense variants in PALB2. The best fitting models were well calibrated in the validation set. Conclusions These results will inform risk prediction models and the selection of candidate variants for functional assays and could contribute to the clinical reporting of gene panel testing for breast cancer susceptibility.
  • Barok, Mark; Puhka, Maija; Vereb, Gyorgy; Szollosi, Janos; Isola, Jorma; Joensuu, Heikki (2018)
    Background: Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate that carries a cytotoxic drug (DM1) to HER2-positive cancer. The target of T-DM1 (HER2) is present also on cancer-derived exosomes. We hypothesized that exosome-bound T-DM1 may contribute to the activity of T-DM1. Methods: Exosomes were isolated from the cell culture medium of HER2-positive SKBR-3 and EFM-192A breast cancer cells, HER2-positive SNU-216 gastric cancer cells, and HER2-negative MCF-7 breast cancer cells by serial centrifugations including two ultracentrifugations, and treated with T-DM1. T-DM1 not bound to exosomes was removed using HER2-coated magnetic beads. Exosome samples were analyzed by electron microscopy, flow cytometry and Western blotting. Binding of T-DM1-containing exosomes to cancer cells and T-DM1 internalization were investigated with confocal microscopy. Effects of T-DM1-containg exosomes on cancer cells were investigated with the AlamarBlue cell proliferation assay and the Caspase-Glo 3/7 caspase activation assay. Results: T-DM1 binds to exosomes derived from HER2-positive cancer cells, but not to exosomes derived from HER2-negative MCF-7 cells. HER2-positive SKBR-3 cells accumulated T-DM1 after being treated with T-DM1-containg exosomes, and treatment of SKBR-3 and EFM-192A cells with T-DM1-containing exosomes resulted in growth inhibition and activation of caspases 3 and/or 7. Conclusion: T-DM1 binds to exosomes derived from HER2-positive cancer cells, and T-DM1 may be carried to other cancer cells via exosomes leading to reduced viability of the recipient cells. The results suggest a new mechanism of action for T-DM1, mediated by exosomes derived from HER2-positive cancer.
  • Barok, Mark; Puhka, Maija; Vereb, Gyorgy; Szollosi, Janos; Isola, Jorma; Joensuu, Heikki (BioMed Central, 2018)
    Abstract Background Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate that carries a cytotoxic drug (DM1) to HER2-positive cancer. The target of T-DM1 (HER2) is present also on cancer-derived exosomes. We hypothesized that exosome-bound T-DM1 may contribute to the activity of T-DM1. Methods Exosomes were isolated from the cell culture medium of HER2-positive SKBR-3 and EFM-192A breast cancer cells, HER2-positive SNU-216 gastric cancer cells, and HER2-negative MCF-7 breast cancer cells by serial centrifugations including two ultracentrifugations, and treated with T-DM1. T-DM1 not bound to exosomes was removed using HER2-coated magnetic beads. Exosome samples were analyzed by electron microscopy, flow cytometry and Western blotting. Binding of T-DM1-containing exosomes to cancer cells and T-DM1 internalization were investigated with confocal microscopy. Effects of T-DM1-containg exosomes on cancer cells were investigated with the AlamarBlue cell proliferation assay and the Caspase-Glo 3/7 caspase activation assay. Results T-DM1 binds to exosomes derived from HER2-positive cancer cells, but not to exosomes derived from HER2-negative MCF-7 cells. HER2-positive SKBR-3 cells accumulated T-DM1 after being treated with T-DM1-containg exosomes, and treatment of SKBR-3 and EFM-192A cells with T-DM1-containing exosomes resulted in growth inhibition and activation of caspases 3 and/or 7. Conclusion T-DM1 binds to exosomes derived from HER2-positive cancer cells, and T-DM1 may be carried to other cancer cells via exosomes leading to reduced viability of the recipient cells. The results suggest a new mechanism of action for T-DM1, mediated by exosomes derived from HER2-positive cancer.
  • Mutka, Minna; Virtakoivu, Reetta; Joensuu, Kristiina; Hollmen, Maija; Heikkilä, Päivi (2022)
    Purpose Common Lymphatic Endothelial and Vascular Endothelial Receptor 1 (Clever-1) is expressed by a subset of immunosuppressive macrophages and targeting the receptor with therapeutic antibodies has been shown to activate T-cell-mediated anti-cancer immunity. The aim of this research was to study Clever-1 expression in breast cancer. Specifically, how Clever-1 + macrophages correlate with clinicopathologic factors, Tumor Infiltrating Lymphocytes (TILs) and prognosis. Methods Tissue microarray blocks were made from 373 primary breast cancer operation specimens. Hematoxylin and Eosin (H&E-staining) and immunohistochemical staining with Clever-1, CD3, CD4 and CD8 antibodies were performed. Differences in quantities of Clever-1 + macrophages and TILs were analyzed. Clever-1 + cell numbers were correlated with 25-year follow-up survival data and with breast cancer clinicopathologic parameters. Results Low numbers of intratumoral Clever-1 + cells were found to be an independent adverse prognostic sign. Increased numbers of Clever-1 + cells were found in high grade tumors and hormone receptor negative tumors. Tumors that had higher amounts of Clever-1 + cells also tended to have higher amounts of TILs. Conclusion The association of intratumoral Clever-1 + macrophages with better prognosis might stem from the function of Clever as a scavenger receptor that modulates tumor stroma. The association of Clever-1 + macrophages with high number of TILs and better prognosis indicates that immunosuppression by M2 macrophages is not necessarily dampening adaptive immune responses but instead keeping them in control to avoid excess inflammation.
  • Liesto, Sanna; Sipilä, Reetta; Hietanen, Marja; Kalso, Eija (2022)
    Many patients return to cognitively demanding work after breast cancer treatments. This makes treatment-related cognitive decline an important research topic. Psychological resilience, cognitive reserve and better perceived general health may work as protective factors against cognitive decline. The aim of this study was to analyse whether these factors are associated with cognitive function among such women. Data from 384 breast cancer survivors who underwent neuropsychological examination at follow-up 4-9 years after surgery were used. The neurocognitive domain variable Learning and Memory was computed from Wechsler Memory Scale-III subtests Learning and Delayed Recall. Another variable, Attention, Processing speed and Executive function, was computed from semantic and verbal fluency tests, Trail Making Test A and B, and Wechsler Adult Intelligence Test-IV subtest Coding. Psychological resilience was measured with Resilience Scale-14, and perceived general health with RAND-36 subitem General Health. Results: showed that levels of cognitive performance and general health were statistically higher than population average. Resilience and general health in separate models were associated with Attention, Processing speed and Executive function (beta = 0.14, p = 0.01; beta = 0.13, p = 0.03, respectively). When added simultaneously in the same model, resilience was significant (beta = 0.13, p = 0.04), but general health was not. These associations were nonsignificant after controlling for confounding factors. Learning and Memory was not associated with resilience or general health. Future research should focus on longitudinal studies identifying patients at a high risk of developing cognitive decline after breast cancer treatments and on preventive and therapeutic approaches.
  • NBCS Collaborators; ABCTB Investigators; kConFab-AOCS Investigators; Ahearn, Thomas U.; Zhang, Haoyu; Michailidou, Kyriaki; Blomqvist, Carl; Nevanlinna, Heli (2022)
    Background Genome-wide association studies (GWAS) have identified multiple common breast cancer susceptibility variants. Many of these variants have differential associations by estrogen receptor (ER) status, but how these variants relate with other tumor features and intrinsic molecular subtypes is unclear. Methods Among 106,571 invasive breast cancer cases and 95,762 controls of European ancestry with data on 173 breast cancer variants identified in previous GWAS, we used novel two-stage polytomous logistic regression models to evaluate variants in relation to multiple tumor features (ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and grade) adjusting for each other, and to intrinsic-like subtypes. Results Eighty-five of 173 variants were associated with at least one tumor feature (false discovery rate < 5%), most commonly ER and grade, followed by PR and HER2. Models for intrinsic-like subtypes found nearly all of these variants (83 of 85) associated at p < 0.05 with risk for at least one luminal-like subtype, and approximately half (41 of 85) of the variants were associated with risk of at least one non-luminal subtype, including 32 variants associated with triple-negative (TN) disease. Ten variants were associated with risk of all subtypes in different magnitude. Five variants were associated with risk of luminal A-like and TN subtypes in opposite directions. Conclusion This report demonstrates a high level of complexity in the etiology heterogeneity of breast cancer susceptibility variants and can inform investigations of subtype-specific risk prediction.
  • Alhopuro, Pia; Vainionpää, Reetta; Anttonen, Anna-Kaisa; Aittomäki, Kristiina; Nevanlinna, Heli; Pöyhönen, Minna (2020)
    Germline mutations in theBRCA1andBRCA2genes cause hereditary breast and ovarian cancer syndrome (HBOC). Mutations in these genes are usually inherited, and reports ofde novo BRCA1/2mutations are rare. To date, only one patient with low-levelBRCA1mutation mosaicism has been published. We report on a breast cancer patient with constitutional somatic mosaicism of aBRCA2mutation.BRCA2mutation c.9294C>G, p.(Tyr3098Ter) was detected in 20% of reads in DNA extracted from peripheral blood using next-generation sequencing (NGS). TheBRCA2mutation was subsequently observed at similar levels in normal breast tissue, adipose tissue, normal right fallopian tube tissue and ovaries of the patient, suggesting that this mutation occurred early in embryonic development. This is the first case to report constitutional mosaicism for aBRCA2mutation and shows thatBRCA2mosaicism can underlie early-onset breast cancer. NGS forBRCA1/2should be considered for patients whose tumors harbor aBRCA1/2mutation and for individuals suggestive of genetic predisposition but without a family history of HBO.
  • Sonnenblick, Amir; Brohee, Sylvain; Fumagalli, Debora; Vincent, Delphine; Venet, David; Ignatiadis, Michail; Salgado, Roberto; Van den Eynden, Gert; Rothe, Francoise; Desmedt, Christine; Neven, Patrick; Loibl, Sibylle; Denkert, Carsten; Joensuu, Heikki; Loi, Sherene; Sirtaine, Nicolas; Kellokumpu-Lehtinen, Pirkko-Liisa; Piccart, Martine; Sotiriou, Christos (2015)
    Background: The likelihood of recurrence in patients with breast cancer who have HER2-positive tumors is relatively high, although trastuzumab is a remarkably effective drug in this setting. Signal transducer and activator of transcription 3 protein (STAT3), a transcription factor that is persistently tyrosine-705 phosphorylated (pSTAT3) in response to numerous oncogenic signaling pathways, activates downstream proliferative and anti-apoptotic pathways. We hypothesized that pSTAT3 expression in HER2-positive breast cancer will confer trastuzumab resistance. Methods: We integrated reverse phase protein array (RPPA) and gene expression data from patients with HER2-positive breast cancer treated with trastuzumab in the adjuvant setting. Results: We show that a pSTAT3-associated gene signature (pSTAT3-GS) is able to predict pSTAT3 status in an independent dataset (TCGA; AUC = 0.77, P = 0.02). This suggests that STAT3 induces a characteristic set of gene expression changes in HER2-positive cancers. Tumors characterized as high pSTAT3-GS were associated with trastuzumab resistance (log rank P = 0.049). These results were confirmed using data from the prospective, randomized controlled FinHer study, where the effect was especially prominent in HER2-positive estrogen receptor (ER)-negative tumors (interaction test P = 0.02). Of interest, constitutively activated pSTAT3 tumors were associated with loss of PTEN, elevated IL6, and stromal reactivation. Conclusions: This study provides compelling evidence for a link between pSTAT3 and trastuzumab resistance in HER2-positive primary breast cancers. Our results suggest that it may be valuable to add agents targeting the STAT3 pathway to trastuzumab for treatment of HER2-positive breast cancer.