Identification of a targetable JAK-STAT enriched androgen receptor and androgen receptor splice variant positive triple-negative breast cancer subtype

Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (∼80%) but also expresses AR splice variants (AR-SVs) (∼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.

NCCN Guidelines® Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2024

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic/likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer, including BRCA1, BRCA2, CDH1, PALB2, PTEN, and TP53, and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants. These NCCN Guidelines Insights summarize important updates regarding: (1) a new section for transgender, nonbinary and gender diverse people who have a hereditary predisposition to cancer focused on risk reduction strategies for ovarian cancer, uterine cancer, prostate cancer, and breast cancer; and (2) testing criteria and management associated with TP53 P/LP variants and Li-Fraumeni syndrome.

Early-stage breast cancer treatment disparities in the Midsouth: Has anything changed?

BACKGROUND

We sought to determine if racial disparities in treatment and survival persist among patients with breast cancer in the Midsouth.

METHODS

Patients with early-stage breast cancer were identified in the tumor registry of a large healthcare system in the Midsouth. Regression analyses were performed to determine how race was associated with receipt of treatment and mortality.

RESULTS

Among 4605 patients, 38.8% were Black. Black patients were less likely to undergo surgery (OR = 0.71; 95%CI 0.53-0.97) and receive hormone therapy (OR = 0.81; 95%CI 0.69-0.95) than White patients, but more likely to receive radiation (OR = 1.20; 95%CI 1.08-1.40) and chemotherapy (OR = 1.36; 95%CI 1.16-1.61). Among Black patients, the risk of mortality was lower among those who underwent partial (OR = 0.25; 95%CI 0.12-0.51) or total (OR = 0.35; 95%CI 0.16-0.76) mastectomy and among those who received hormone therapy (OR = 0.62; 95%CI 0.40-0.97).

CONCLUSION

There remains room for improvement in providing treatments that optimize survival among this patient population.

P-196 Assessing human embryo implantation competence through analysis of extracellular vesicles and their contents

Study question

Could extracellular vesicles (EVs) derived from spent media serve as a non-invasive quality marker for embryo implantation and pregnancy?

Summary answer

EVs isolated from spent media derived from human blastocysts that either did or didn’t establish a pregnancy after transfer differ in size, concentration, miRNA expression.

What is known already

EVs are important for communication from one cell to another, influencing the translation of genes to proteins. They play a regulating role during biological processes, including pregnancy. We hypothesized that EVs released by a high-quality human embryo, which has the potential to create a pregnancy after the transfer, differ from EVs released by poor quality non-implanting embryos.

Study design, size, duration

Patients scheduled for a fresh single blastoycst transfer in IVF/ICSI cycles using own gametes consented to sampling of spent culture media (n = 102). Spent media from the transferred blastocyst (25 μl) were collected from implanted (hCG+/ET) (n = 45) and non-implanted (hCG-/ET) (n = 51). Spent media from degenerated embryos (n = 21) were collected from 6 patients. Media samples were pooled randomly into three replicates for each group (implanted (I), non-implanted (NI), degenerated (DG)).

Participants/materials, setting, methods

Extracellular vesicles were isolated by qEV single size exclusion column(SEC):a maximum of 200 µl of implanted or non-implanted or degenerated spent media was loaded onto the qEV SEC. Identification and characterization of EVs was performed by nanoparticle tracking analysis, transmission electron microscopy, and western blotting (CD9, CD63). Next, EV-RNA isolation was performed on these three groups (three replicates from each group) by Norgen Biotek Exosomal RNA Purification Kit, followed by RT-qPCR, and further data analysis.

Main results and the role of chance

Extracellular vesicles isolated from the SEC column are referred to as I-EVs, NI –EVs, and DG-EVs (implanted, non-implanted, and degenerated, respectively). Western blot confirmed the presence of EV-specific markers (CD63, CD9) in all EV samples (I-EVs, NI-EVs, and DG-EVs). By NTA, a higher particle concentration was observed in I-EVs (2.69±1.9 × 1010 particles/mL) compared to NI-EVs (6.13±0.2 × 1010 particles/mL) (p < 0.05), whereas DG-EVs particle concentration (4.97±0. 2 × 109 particles/mL) was significantly (P < 0.01). I-EVs were also characterized by a larger particle size with an average mean diameter of 180.3±5.4 nm, whereas NI-EVs displayed a smaller particle size with a mean diameter of 141.5±2.5 nm (p < 0.05). TEM confirmed the presence of larger-sized vesicles in I-EVs (≥ 200 nm) compared with NI and DG samples. During earlier work in EVs from bovine blastocysts we found miR-378a-3p to be typically present in blastocyst EVs, with a prominent role in the hatching process of the blastocyst. Here, we compared miR-378a-3p expression levels by RT-qPCR in I-EVs vs. NI-EVs vs DG-EVs. Higher expression of miR-378a-3p was identified in NI-EVs and I-EVs, compared to DG-EVs (log2fc= 30.10, log2fc = 8.94 p < 0.001 respectively), but was not correlated with implantation rate.

Limitations, reasons for caution

Currently, the methodology is unable to study EVs from a single droplet of spent media, hence pooling of the samples is necessary. As a consequence, data on EV-miRNA from individual blastocyst is lost.

Wider implications of the findings

Our data demonstrated that EVs and their cargo (miRNAs) have potential to be used as a non-invasive method to predict embryo implantation:miR-378a-3p has been associated with hatching in bovine embryos, but was not related with human implantion. Other embryo-derived miRNAs may be tested as a possible biomarker for human pregnancy.

Trial registration number

EC 2018/0266 – B670201835577

67 Optimizing a protocol for isolating extracellular vesicles from medium conditioned by bovine embryos in vitro

In the absence of the maternal tract, pre-implantation bovine embryos cultured in group are able to promote their own development in vitro by releasing autocrine embryotropins. Recently we have identified extracellular vesicles (EV) among these embryotropins as one of the communication mechanisms among embryos. Extracellular vesicles are nano-sized (25-250nm), with a lipid bilayer, and are functionally active, since they contain proteins, lipids, and nucleic acids, including RNA and miRNA. However, one of the major challenges in isolating EV is an inadequate volume of medium conditioned by bovine embryo. As it requires larger volumes of conditioned medium to isolate EV, our study mainly focused on isolating high yields of functional EV from a minimal volume. There are 3 known isolation methods for EV: differential ultracentrifugation (DU), OptiPrep™ density gradient ultracentrifugation (ODGU), and size-exclusion chromatography (SEC). We have used these 3 protocols to determine the method that yielded the highest number of EV. We used routine in vitro maturation and fertilization methods, but for in vitro culture presumed zygotes were cultured until 8 days post-insemination (dpi) in medium (synthetic oviducal fluid supplemented with insulin, transferrin, selenium, and bovine serum albumin) that was ultracentrifuged to remove any possible contaminating EV. In vitro embryo culture took place in groups of 25 presumed zygotes in 50-mL drops, covered with mineral oil and incubated at 38°C in 5% CO2, 5% O2, and 90% N2. On 8 dpi, medium conditioned by bovine embryo was collected and pooled until 3mL. For each isolation method, 1mL of conditioned medium was used, and next, EV isolated from each isolation method were analysed with nanoparticle tracking, electron microscopy, and Western blot (CD9, Flotillin 1, and AGO 2). We observed higher concentrations (1.03×109 particles mL−1) of EV were isolated from the SEC compared with the other 2 methods (301.5×108 particles mL−1 and 64.5×108 particles mL−1 for DU and ODGU, respectively; P<0.05), whereas smaller size EV (20-50nm) were lost during the ultracentrifugation methods. Besides, it takes only 2h of time to perform size-exclusion chromatography for isolating EV, whereas it takes more than 1 day to perform ultracentrifugation methods. Therefore, we propose to use SEC for further downstream processing and sequencing of miRNA in isolated EV. We are currently focusing on optimizing an EV isolation protocol to extract EV from very low volumes of conditioned medium (less than 500 µL).

Prediction of Cancer Prevention: From Mammogram Screening to Identification of BRCA1/2 Mutation Carriers in Underserved Populations

BACKGROUND

The US Preventative Service Task Force recommends that physicians perform a genetic risk assessment to identify women at risk for BRCA1/2 mutations associated with hereditary breast and ovarian cancer (HBOC) syndrome. However, outcomes data after a diagnosis of HBOC syndrome especially in diverse populations, are minimal. Here we asked if genetic screening of high-risk underserved women identified in the mammogram population reduces cancer incidence.

METHODS

We evaluated 61,924 underserved women at screening mammography for family histories suggestive of HBOC syndrome over the course of 21 months. Data were collected retrospectively from patients at two safety net hospitals through chart review. A computer model was used to calculate the long-term effect of this screening on cancer incidence by assessing both the mutation detection rate and the completion of prophylactic surgeries in BRCA1/2 mutation carriers.

FINDINGS

We identified 20 of the 85 (23.5%) expected BRCA1/2 mutation carriers in the underserved population. The frequencies of prophylactic mastectomies and oophorectomies in the mutation carriers were 25% and 40%, respectively. Using these data, our model predicted only an 8.8% reduction in both breast and ovarian cancer in the underserved patients. This contrasts with a 57% reduction in breast cancer and 51% reduction in ovarian cancer in an insured reference population. Our data indicate that underserved patients with HBOC syndrome are difficult to identify and when identified are limited in their ability to adhere to NCCN guidelines for cancer prevention.

INTERPRETATION

Screening for women at risk for HBOC syndrome in mammogram populations will only prevent cancers if we can increase compliance with management guidelines. This study provides prototypic baseline data for step-wise analysis of the efficacy of the use of family history analysis in the mammography setting for detection and management of HBOC syndrome.

P1-03-08: Adipose Tissue in Breast Cancer: Not an Idle Bystander but an Active Participant in Breast Cancer Progression

Background: Adipose tissue is a dynamic organ that secretes a plethora of molecules called adipokines. In breast cancer we find a unique situation were genetically changed cells (the cancer cells) are in close contact with adipocytes. Moreover, obesity is a known negative prognostic marker for postmenopausal breast cancer patients. We hypothesize that adipocyte-derived factors influence breast cancer progression.

Materials and methods: Adipose tissue was collected from breast cancer patients undergoing a mastectomy. After macroscopic removal of blood vessels and connective tissue, the adipose tissue was carefully cut into 2–3mm3 pieces and were incubated in specific adipose-tissue culture medium. After 24h, the medium was collected and the quality was checked by determining the concentration of total proteins, leptin, adiponectin, TNFalpha and triglycerides. This conditioned medium of adipose tissue (CM AT) was used for in vitro experimentation with MCF-7 breast cancer cells.

Results: Effect of AT on morphology and aggregation: when MCF-7 cells are grown in a culture flask, they tend to form round compact islands. Under influence of CM AT, the islands form sharp edges, the cells in an island can be counted individually and they show scattering. Importantly, despite the major changes in cellular morphology, CM AT removal rescued the compact island formation of MCF-7 cells. In the slow aggregation assay, cells treated with CM AT (and a subtherapeutic concentration of a neutralizing E-cadherin antibody) lost the ability to form compact aggregates. Furthermore, MCF-7 spheroids placed inside adipose tissue showed massive reorganization into an irregularly shaped mass.

Effect of AT on proliferation: starting from an equal number of cells and counting them every 2 days, it became clear that MCF-7 cells with CM AT had a higher rate of proliferation than MCF-7 cells in control medium. This stimulation of proliferation was confirmed by cell cycle analysis which revealed a doubling of cells in the G2/M phase, and western blot which showed an upregulation of cyclin A and cyclin E, both positive regulators of the cell cycle. Effect of AT on invasion: a 24h collagen type I invasion assay revealed invasive characteristics of MCF-7 cells treated with CM AT while MCF-7 cells in control conditions are round and non-invasive. In contrast, a transwell collagen test over 14 days was not able to show MCF-7 cells invading the collagen gel under influence of CM AT. However, the growth pattern of MCF-7 cells on the collagen gel was clearly disorganised when compared with the control situation.

Conclusion: These findings suggest that adipose tissue-derived factors exert a dramatic selective force on patterning, invasion and growth of MCF-7 breast cancer cells. Unraveling the mechanism behind these observations may provide vital information regarding the link between obesity and poor prognosis in postmenopausal breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-03-08.

Regional differences in incidence of sudden cardiac death in the young

BACKGROUND

Observational data on sudden cardiac death (SCD) in the young are scarce, but the SCD incidence of this study is to examine regional differences in SCD incidence within a population among young individuals (<40 years) and to assess whether regional incidences are associated with socio-economic status (SES ).

METHODS

SCD cases aged <40 years were identified in 12 provinces of the Netherlands by using death certificates recorded by Statistics Netherlands during 1996-2006. Regional incidence estimates were standardised for age to the Dutch population and assessed for two age categories; 1-29 years and 30-39 years. Regional SCD incidence was related to regional SES with a Spearman correlation coefficient.

RESULTS

The nationwide incidence of SCD at ages 1 to 40 years was 1.6 (95% CI 1.5 to 1.7) per 100,000 person-years and the incidence increased substantially after 30 years of age. Significant differences in regional incidences were assessed for both age categories (1-29 and 30-39 years). Although in the population aged 1-29 years significant differences were found in the SCD incidence between regions, no relation could be found with SES . In men aged 30-39 years, the incidence of SCD was inversely related to SES ; a low socio-economic status was associated with a relatively high incidence of SCD.

CONCLUSION

Between regions, statistically significant differences in SCD incidence exist in young individuals. The nationwide incidence of SCD increased substantially after 30 years of age and was inversely related to SES in men aged 30-39 years.

Rationale and design of the CAREFUL study : The yield of CARdiogenetic scrEening in First degree relatives of sudden cardiac and UnexpLained death victims <45 years

Background. Sudden cardiac death (SCD) in the young (1-45 years) is a strong risk factor for the presence of inherited cardiac diseases in surviving first-degree relatives. Postmortem investigation of the victim and cardiogenetic evaluation of the first-degree relatives is indicated to detect inherited cardiac diseases and treat relatives at an early stage to prevent SCD. In the Netherlands, postmortem investigation is often not performed and relatives of SCD and sudden unexplained death (SUD) victims are rarely evaluated for inherited cardiac diseases.Methods. A prospective population-based follow-up study carried out in two intervention regions and two control regions. In the intervention regions a comprehensive intervention (stimulate autopsy and storage of victims DNA and the referral of first-degree relatives for cardiogenetic evaluation) is applied in a 'top down' and 'bottom up' mode. In each region, young sudden death victims are registered and for all cases performance of autopsy and evaluation of relatives in a cardiogenetics outpatient clinic will be determined.Expected results. The study will provide information on the incidence of sudden death in the young and the proportion of diagnosed inherited cardiac diseases. Moreover, the additional value of the introduction of two different preventive strategies directed at early detection of inherited cardiac diseases in first-degree relatives to usual care will be evaluated. Conclusion. The CAREFUL study will help to set a new standard of care in the evaluation of young sudden death victims and their relatives to identify the presence of inherited cardiac diseases, in order to prevent sudden death. (Neth Heart J 2010;18:286-90.).

Cellular and molecular mechanisms of cancer cell invasion

Cancer malignancy is characterized by cancer cell invasion within local and distant ecosystems. Data from our laboratory are reviewed with a focus on cross-signaling between cancer cells and host cells such as myofibroblasts, mesenchymal stem cells and adipocytes. Invasion-associated cellular activities, namely epithelial to mesenchymal transition, homotypic and heterotypic cell-cell adhesion, cell-matrix adhesion, migration, proteolysis and vesicle exocytosis, depend on branching networks of signal transduction pathways including activation of trimeric G proteins, phosphoinositide 3-kinase, src, signal transducer and activator of transcription and the Rab, Rac and Rho family of small GTPases. The role of proteolysis in invasion is not limited to breakdown of extracellular matrix but also causes cleavage of pro-angiogenic fragments from cell surface glycoproteins. Some cell types or molecules implicated in invasion-associated activities may serve as prognostic biomarker or as target for patient-tailored therapy.

The Secretory Small GTPase Rab27B Regulates Invasive Tumor Growth and Metastasis through Extracellular Heat Shock Protein 90α

Background: Vesicle exocytosis, controlled by secretory GTPases such as Rab27B, delivers critical pro-invasive factors into the tumor microenvironment. The biological role and expression status of Rab27B in breast cancer was unknown.Methods: Rab27B was studied in human breast cancer cells (MCF-7, T47D, ZR75.1) using GFP-fusion constructs, including Rab27A and Rab27B point mutants defective in GTP-binding or geranylgeranylation. In cell culture, cell-cycle progression was evaluated by flow cytometry and Western blotting, invasion was assessed using Matrigel and collagen type I substrates. Orthotopic tumor growth, local invasion and metastasis were analyzed in mouse xenograft models. Mass spectrometry was performed to identify Rab27B-secreted pro-invasive factors. Rab27B levels in clinical breast cancer were analyzed by quantitative reverse transcription-polymerase chain reaction (n=20) and immunohistochemistry (n=60). Statistical tests were two-sided.Results: Rab27B-upregulation promoted G1/S phase cell cycle transition, F-actin reorganization and invasion in cell culture, and invasive tumor growth and peritoneal metastasis in a xenograft mouse model (at 10 weeks, survival of MCF-7 GFP vs GFP-Rab27B injected mice was 100% vs 62.5%, P=0.0307). Proteomic analysis of purified Rab27B-secretory vesicles and the secretome of Rab27B-expressing breast cancer cells identified heat shock protein (HSP)90α as key pro-invasive factor. HSP90α secretion occurred in a Rab27B-dependent manner and was required for matrix metalloproteinase-2 activation. All Rab27B-mediated functional responses were GTP- and geranylgeranyl-dependent. In clinical samples, upregulation of endogenous Rab27B mRNA and protein correlated with lymph node metastasis (P=0.0002) and differentiation grade (P=0.0014) in estrogen receptor (ER)-positive human breast tumors.Conclusions: Rab27B, a new prognostic marker for ER-positive breast cancer, regulates invasive growth and metastasis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6144.

Enceladus' Water Vapor Plume

The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005. Cassini's UltraViolet Imaging Spectrograph observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Enceladus. This plume provides an adequate amount of water to resupply losses from Saturn's E ring and to be the dominant source of the neutral OH and atomic oxygen that fill the Saturnian system.

Characteristics and attitudes of parents of children born with the use of assisted reproductive technology

OBJECTIVE

To explore the medical issues, attitudes, concerns, and choices that parents have about their children born with the use of assisted reproductive technology (ART).

DESIGN

Retrospective and prospective survey.

SETTING

An academic medical center and a private practice.

PATIENT(S)

Participants who conceived and were delivered of infants in two ART programs.

INTERVENTION(S)

A total of 373 patients were mailed an anonymous survey, a consent form, and the Parent Child Relationship Inventory. The rate of response was approximately 49% for clinic A and 33% for clinic B.

MAIN OUTCOME MEASURE(S)

Pregnancy outcomes and attitudes about parenting.

RESULT(S)

Respondents' major concerns during pregnancy revolved around miscarriage and the infant's health; complications occurred in 38.9% of first pregnancies. Parents believed that their children were more appreciated, that their children were not emotionally different, that ART did not create ongoing medical or emotional problems, and they were not overprotective as parents. Gender differences were statistically significant on attitudinal variables.

CONCLUSION(S)

Parents had concerns about pregnancy. Overall, men and women felt positive about ART and their parenting. The ART experience is associated with complex choices, attitudes, and emotions.