ABSTRACT
BACKGROUND: Background parenchymal enhancement (BPE) is an established breast cancer risk factor. However, the relationship between BPE levels and breast cancer risk stratification remains unclear. PURPOSE: To evaluate the clinical relationship between BPE levels and breast cancer risk with covariate adjustments for age, ethnicity, and hormonal status. STUDY TYPE: Retrospective. POPULATION: 954 screening breast MRI datasets representing 721 women divided into four cohorts: women with pathogenic germline breast cancer (BRCA) mutations (Group 1, N = 211), women with non-BRCA germline mutations (Group 2, N = 60), women without high-risk germline mutations but with a lifetime breast cancer risk of ≥20% using the Tyrer-Cuzick model (Group 3, N = 362), and women with <20% lifetime risk (Group 4, N = 88). FIELD STRENGTH/SEQUENCE: 3 T/axial non-fat-saturated T1, short tau inversion recovery, fat-saturated pre-contrast, and post-contrast T1-weighted images. ASSESSMENT: Data on age, body mass index, ethnicity, menopausal status, genetic predisposition, and hormonal therapy use were collected. BPE levels were evaluated by two breast fellowship-trained radiologists independently in accordance with BI-RADS, with a third breast fellowship-trained radiologist resolving any discordance. STATISTICAL TESTS: Propensity score matching (PSM) was utilized to adjust covariates, including age, ethnicity, menopausal status, hormonal treatments, and prior bilateral oophorectomy. The Mann-Whitney U test, chi-squared test, and univariate and multiple logistic regression analysis were performed, with an odds ratio (OR) and corresponding 95% confidence interval. Weighted Kappa statistic was used to assess inter-reader variation. A P value <0.05 indicated a significant result. RESULTS: In the assessment of BPE, there was substantial agreement between the two interpreting radiologists (κ = 0.74). Patient demographics were not significantly different between patient groups after PSM. The BPE of Group 1 was significantly lower than that of Group 4 and Group 3 among premenopausal women. In estimating the BPE level, the OR of gene mutations was 0.35. DATA CONCLUSION: Adjusting for potential confounders, the BPE level of premenopausal women with BRCA mutations was significantly lower than that of non-high-risk women. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.
Subject(s)
Breast Neoplasms , Female , Humans , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Retrospective Studies , Clinical Relevance , Breast/diagnostic imaging , Breast/pathology , Magnetic Resonance Imaging/methods , Risk AssessmentABSTRACT
PURPOSE OF REVIEW: Breast cancer (BC) is the most common cancer among women in the United States and the second leading cause of cancer death. BC research, diagnostics, drug development, and expansion of therapies for novel indications advances so rapidly that BC treatment standards change month-by-month. Herein we discuss notable advancements in the past year for hormone receptor positive (HR+) HER2 negative (HER2-) BC. RECENT FINDINGS: Radiolabeled estradiol imaging and circulating tumor DNA (ctDNA) have changed our approach to metastatic BC (mBC) detection. Amongst an abundance of therapy options, treatment de-escalation to avoid toxicities is a priority. Promising results with CDK4/6 inhibitors in the curative setting have been demonstrated even as we await final data for use in the metastatic setting. Several novel endocrine therapies are expected to gain FDA-approval in the near future. Antibody-drug conjugates have expanded from other mBC types to HR+HER2- mBC. The PROMISE trial helped define disease recurrence outcomes for premenopausal women seeking pregnancy. SUMMARY: The diagnostic and treatment landscape for HR+HER2- BC continues to rapidly evolve on multiple fronts.
Subject(s)
Breast Neoplasms , Female , Humans , United States , Breast Neoplasms/pathology , Receptor, ErbB-2 , Neoplasm Recurrence, Local , EstradiolABSTRACT
PURPOSE OF REVIEW: Triple negative breast cancer (TNBC) is defined by a lack of targets, namely hormone receptor (HR) expression and human epidermal growth factor receptor 2 amplification. Cytotoxic chemotherapy remains the mainstay of treatment. Though TNBC constitutes approximately 10-15% of breast cancer, it is disproportionally lethal, but it is hoped that outcomes will improve as targetable oncogenic drivers are identified. RECENT FINDINGS: Translational work in TNBC has focused on subsets defined by defects in homologous recombination repair, immune cell infiltration, or programmed death ligand receptor 1 expression, an over-active phosphoinositide-3 kinase pathway, or expression of androgen receptors. Though not specific to TNBC, the novel cell surface antigen trophoblast antigen 2 has also been identified and successfully targeted. This work has led to Food and Drug Administration approvals for small molecule poly-ADP-ribosyl polymerase inhibitors in patients with deleterious germline mutations in BRCA1 or BRCA2, the combination of nab-paclitaxel with immune checkpoint inhibitor antibodies in the first-line metastatic setting for programmed death ligand receptor 1+ TNBC, and use of the antibody-drug conjugate sacituzumab govitecan in the later-line metastatic setting. SUMMARY: Identification of targetable oncogenic drivers in TNBC is an area of intense cancer biology research, hopefully translating to new therapies and improved outcomes.
Subject(s)
Antineoplastic Agents/therapeutic use , Molecular Targeted Therapy/trends , Triple Negative Breast Neoplasms/drug therapy , HumansABSTRACT
Poly-ADP-ribosyl polymerase (PARP) enzymes PARP-1 and PARP-2 recognize DNA damage and set off a cascade of cellular mechanisms required for multiple types of DNA damage repair. PARP inhibitors are small molecule mimetics of nicotinamide which bind to PARP's catalytic domain to inhibit poly-ADP-ribosylation (PARylation) of target proteins, including PARP-1 itself. PARP inhibitors olaparib, veliparib, talazoparib, niraparib and rucaparib have predominantly been studied in women with breast or ovarian cancers associated with deleterious germline mutations in BRCA1 and BRCA2 (gBRCA1/2+). The BRCA1 and BRCA2 proteins are involved in DNA repair by homologous recombination. This review will focus on talazoparib, a PARP inhibitor approved by the US FDA for the treatment of metastatic gBRCA1/2+ breast cancers in October 2018.
Subject(s)
BRCA1 Protein/metabolism , BRCA2 Protein/metabolism , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Phthalazines/therapeutic use , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor , Breast Neoplasms/diagnosis , Breast Neoplasms/mortality , Clinical Trials as Topic , Drug Approval , Female , Humans , Molecular Targeted Therapy , Phthalazines/administration & dosage , Phthalazines/adverse effects , Poly(ADP-ribose) Polymerase Inhibitors/administration & dosage , Poly(ADP-ribose) Polymerase Inhibitors/adverse effects , Treatment OutcomeABSTRACT
PURPOSE OF REVIEW: Poly-ADP-ribosyl-polymerase (PARP) inhibitors are an increasingly-utilized therapy in women with high-grade serous ovarian carcinoma, but tumor resistance to PARP inhibitor monotherapy is inevitable. RECENT FINDINGS: PARP inhibitors have been most studied in patients with breast and ovarian cancers associated with deleterious germline BRCA1 or BRCA2 mutations, though their role has expanded to include use as maintenance therapy in women with platinum-sensitive high-grade serous ovarian cancer due to the high propensity of such cancers to have defects in DNA repair by homologous recombination. As mechanisms of PARP inhibitor resistance are elucidated, rationale combination strategies can be devised to extend therapeutic benefits and to abrogate resistance. SUMMARY: Mechanisms of resistance include restoration of homologous recombination repair proficiency, loss of cancer cell reliance on PARP, and increased intracellular signaling through cell growth pathways.
Subject(s)
Drug Resistance, Neoplasm/drug effects , Ovarian Neoplasms/drug therapy , Phthalazines/therapeutic use , Piperazines/therapeutic use , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , BRCA1 Protein/drug effects , BRCA2 Protein/drug effects , Clinical Trials as Topic , Female , Humans , Ovarian Neoplasms/pathology , Phthalazines/pharmacology , Piperazines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/pharmacologyABSTRACT
PURPOSE OF REVIEW: The recent United States Food and Drug Administration approvals of niraparib and olaparib as maintenance monotherapy for platinum-sensitive, high-grade ovarian cancers independent of BRCA status reflect a willingness to seek indications for poly-ADP-ribose polymerase (PARP) inhibitors beyond cancers with deleterious breast cancer 1 and breast cancer 2 mutations. In this review, I describe the rationale behind current PARP combination clinical trials with chemotherapies, angiogenesis inhibitors, cell cycle checkpoint inhibitors, and inhibitors of the phosphoinositide 3-kinase/AK thymoma/mechanistic target of rapamycin pathway. RECENT FINDINGS: PARP inhibitors have primarily been studied as monotherapy in cancers with homologous recombination repair defects based on an early understanding of PARP-1 as a base excision repair enzyme and the idea that abrogation of two DNA repair pathways cripples rapidly dividing cancer cells. It is now known that PARP-1 is a DNA damage sensor with much wider reaching roles in DNA repair processes and normal cellular functions, opening possibilities for PARP inhibitor use in other clinical contexts. SUMMARY: PARP inhibitor combination clinical trials are in the early stages, but will deepen our understanding of DNA repair mechanisms, cancer biology, and targeted therapies, thus contributing to the next iteration of therapeutic options for our patients.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Ovarian Neoplasms/drug therapy , Ovary/drug effects , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Drug Approval , Female , Humans , Neoplasm Proteins/antagonists & inhibitors , Neoplasm Proteins/metabolism , Ovarian Neoplasms/enzymology , Ovarian Neoplasms/metabolism , Ovary/enzymology , Ovary/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/adverse effects , Poly(ADP-ribose) Polymerases/chemistry , Poly(ADP-ribose) Polymerases/metabolism , United States , United States Food and Drug AdministrationABSTRACT
Use of gonadotropin-releasing hormone (GnRH) agonists has been widely adopted to provide reversible ovarian function suppression for pre-menopausal breast cancer patients who are also receiving aromatase inhibitor or tamoxifen therapy based on results of 25 randomized trials representing almost 15,000 women demonstrating a survival benefit with this approach. Past clinical trials designed to establish the efficacy of GnRH agonists have monitored testosterone in the prostate cancer setting and estradiol in the breast cancer setting. We explore the merits of various biomarkers including estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) and their utility for informing GnRH agonist treatment decisions in breast cancer. Estradiol remains our biomarker of choice in ensuring adequate ovarian function suppression with GnRH agonist therapy among pre-menopausal women with breast cancer. We recommend future trials to continue to focus on estradiol levels as the primary endpoint, as they have in the past.
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BACKGROUND: Recruiting to multi-site trials is challenging, particularly when striving to ensure the randomized sample is demographically representative of the larger disease-suffering population. While previous studies have reported disparities by race and ethnicity in enrollment and randomization, they have not typically investigated whether disparities exist in the recruitment process prior to consent. To identify participants most likely to be eligible for a trial, study sites frequently include a prescreening process, generally conducted by telephone, to conserve resources. Collection and analysis of such prescreening data across sites could provide valuable information to improve understanding of recruitment intervention effectiveness, including whether traditionally underrepresented participants are lost prior to screening. METHODS: We developed an infrastructure within the National Institute on Aging (NIA) Alzheimer's Clinical Trials Consortium (ACTC) to centrally collect a subset of prescreening variables. Prior to study-wide implementation in the AHEAD 3-45 study (NCT NCT04468659), an ongoing ACTC trial recruiting older cognitively unimpaired participants, we completed a vanguard phase with seven study sites. Variables collected included age, self-reported sex, self-reported race, self-reported ethnicity, self-reported education, self-reported occupation, zip code, recruitment source, prescreening eligibility status, reason for prescreen ineligibility, and the AHEAD 3-45 participant ID for those who continued to an in-person screening visit after study enrollment. RESULTS: Each of the sites was able to submit prescreening data. Vanguard sites provided prescreening data on a total of 1029 participants. The total number of prescreened participants varied widely among sites (range 3-611), with the differences driven mainly by the time to receive site approval for the main study. Key learnings instructed design/informatic/procedural changes prior to study-wide launch. CONCLUSION: Centralized capture of prescreening data in multi-site clinical trials is feasible. Identifying and quantifying the impact of central and site recruitment activities, prior to participants signing consent, has the potential to identify and address selection bias, instruct resource use, contribute to effective trial design, and accelerate trial enrollment timelines.
Subject(s)
Research Design , Humans , Data Collection , Educational StatusABSTRACT
PURPOSE: On the basis of preclinical data, we hypothesized that low doses of chemotherapy (10% of therapeutic doses) with full dose of a PARP inhibitor could have improved efficacy and tolerability. PATIENTS AND METHODS: In this phase I dose-escalation study, patients with BRCA-normal advanced malignancies were assigned to either talazoparib/temozolomide or talazoparib/irinotecan. Talazoparib was dose-escalated from 500 mcg to 1 mg daily before dose escalation of temozolomide/irinotecan. The starting dose of temozolomide was 25 mg/m2/day orally on days 1 to 5 and irinotecan was 25 mg/m2/day intravenously on days 1 and 15. The primary objectives of this trial were safety and tolerability, dose-limiting toxicities (DLT), and maximum tolerated dose (MTD). RESULTS: Of 40 patients enrolled, 18 (mean: 7 prior therapies) were enrolled in talazoparib + temozolomide and 22 in talazoparib + irinotecan. DLTs were hematologic in both arms, but all hematologic adverse events resolved with either treatment interruption and/or dose reductions of talazoparib. The MTDs were talazoparib 1 mg + temozolomide 37.5 mg/m2 and talazoparib 1 mg + irinotecan 37.5 mg/m2. There were four partial responses in the talazoparib + temozolomide arm and five in the talazoparib + irinotecan arm for a response rate of 23% (9/40). The pharmacokinetic profiles of talazoparib + temozolomide/irinotecan were similar to that of talazoparib monotherapy. Responses were seen independent of homologous recombination (HR) status and HR deficiency score. CONCLUSIONS: These results show that talazoparib with low-dose temozolomide or irinotecan is reasonably well tolerated and demonstrates clinical activity in a wide range of cancers. Randomized trials of talazoparib with or without low-dose chemotherapy are ongoing in small cell lung cancer and ovarian cancer.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Neoplasms , Female , Humans , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Irinotecan/administration & dosage , Neoplasms/drug therapy , Temozolomide/administration & dosageABSTRACT
INTRODUCTION: HER2-positive metastatic breast cancer (mBC) is an incurable disease associated with years of chronic therapy and excess cost. HER2-targeted therapies have shown survival benefit for early-stage and mBC; however, the economic impact of these therapies has not been fully assessed. We evaluated health care resource use (HCRU) and costs of mBC patients treated with HER2-targeted therapy. METHODS: This was a retrospective cohort study using the IQVIA Real-World Data Adjudicated Claims Database (July 1, 2014 to July 31, 2019). Female patients aged ≥18 years with mBC who initiated HER2-targeted therapy in the prior year were identified. The index date was the initiation date of the HER2-targeted agent, after which patients were required to have ≥12 months of follow-up. Annual and cumulative all-cause and BC-related costs (2019 USD) and annual BC-related HCRU were computed in years 1, 2, and 3 following the index date. RESULTS: Following the initiation of HER2-targeted therapy, the mean annual total all-cause costs per patient in years 1 (n = 423), 2 (n = 357), and 3 (n = 166) were $320,892 (SD: $224,343), $235,159 (SD: $185,287), and $226,254 (SD: $197,901), respectively. The mean annual total BC-related costs were $240,048 (SD: $151,230), $175,631 (SD: $148,058), and $165,506 (SD: $159,374) in years 1, 2, and 3, respectively. A major portion of BC-related costs were costs associated with HER2-targeted treatment. The 3-year cumulative all-cause and BC-related total costs were $769,573 (SD: $456,920) and $624,455 (SD: $401,319), respectively. CONCLUSION: Treatment of HER2-positive mBC is a substantial economic burden. A potential approach to minimizing cost and HCRU is to prevent recurrence.
Subject(s)
Antineoplastic Agents , Breast Neoplasms , Adolescent , Adult , Antineoplastic Agents/therapeutic use , Breast Neoplasms/pathology , Female , Humans , Patient Acceptance of Health Care , Receptor, ErbB-2/metabolism , Retrospective StudiesABSTRACT
OBJECTIVE: To assess whether changes in quantitative parameters on breast MRI better predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) in breast cancer than change in volume. METHODS: This IRB-approved retrospective study included women with newly diagnosed breast cancer who underwent 3T MRI before and during NAC from January 2013 to December 2019 and underwent surgery at our institution. Clinical data such as age, histologic diagnosis and grade, biomarker status, clinical stage, maximum index cancer dimension and volume, and surgical pathology (presence or absence of in-breast pCR) were collected. Quantitative parameters were calculated using software. Correlations between clinical features and MRI quantitative measures in pCR and non-pCR groups were assessed using univariate and multivariate logistic regression. RESULTS: A total of 182 women with a mean age of 52 years (range, 26-79 years) and 187 cancers were included. Approximately 45% (85/182) of women had pCR at surgery. Stepwise multivariate regression analysis showed statistical significance for changes in quantitative parameters (increase in time to peak and decreases in peak enhancement, wash out, and Kep [efflux rate constant]) for predicting pCR. These variables in combination predicted pCR with 81.2% accuracy and an area under the curve (AUC) of 0.878. The AUCs of change in index cancer volume and maximum dimension were 0.767 and 0.613, respectively. CONCLUSION: Absolute changes in quantitative MRI parameters between pre-NAC MRI and intra-NAC MRI could help predict pCR with excellent accuracy, which was greater than changes in index cancer volume and maximum dimension.
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BACKGROUND: Expert knowledge is often shared among multidisciplinary academic teams at tumor boards (TBs) across the country, but these conversations exist in silos and do not reach the wider oncology community. OBJECTIVE: Using an oncologist-only question and answer (Q&A) website, we sought to document expert insights from TBs at National Cancer Institute-designated Comprehensive Cancer Centers (NCI-CCCs) to provide educational benefits to the oncology community. METHODS: We designed a process with the NCI-CCCs to document and share discussions from the TBs focused on areas of practice variation on theMednet, an interactive Q&A website of over 13,000 US oncologists. The faculty translated the TB discussions into concise, non-case-based Q&As on theMednet. Answers were peer reviewed and disseminated in email newsletters to registered oncologists. Reach and engagement were measured. Following each Q&A, a survey question asked how the TB Q&As impacted the readers' practice. RESULTS: A total of 23 breast, thoracic, gastrointestinal, and genitourinary programs from 16 NCI-CCC sites participated. Between December 2016 and July 2021, the faculty highlighted 368 questions from their TBs. Q&As were viewed 147,661 times by 7381 oncologists at 3515 institutions from all 50 states. A total of 277 (75%) Q&As were viewed every month. Of the 1063 responses to a survey question on how the Q&A affected clinicians' practices, 646 (61%) reported that it confirmed their current practice, 163 (20%) indicated that a Q&A would change their future practice, and 214 (15%) reported learning something new. CONCLUSIONS: Through an online Q&A platform, academics at the NCI-CCCs share knowledge outside the walls of academia with oncologists across the United States. Access to up-to-date expert knowledge can reassure clinicians' practices, significantly impact patient care in community practices, and be a source of new knowledge and education.
ABSTRACT
Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptor and progesterone receptor and human epidermal growth factor receptor 2 (HER2) overexpression. This malignancy, representing 15-20% of breast cancers, is a clinical challenge due to the lack of targeted treatments, higher intrinsic aggressiveness, and worse outcomes than other breast cancer subtypes. Immune checkpoint inhibitors have shown promising efficacy for early-stage and advanced TNBC, but this seems limited to a subgroup of patients. Understanding the underlying mechanisms that determine immunotherapy efficiency is essential to identifying which TNBC patients will respond to immunotherapy-based treatments and help to develop new therapeutic strategies. Emerging evidence supports that epigenetic alterations, including aberrant chromatin architecture conformation and the modulation of gene regulatory elements, are critical mechanisms for immune escape. These alterations are particularly interesting since they can be reverted through the inhibition of epigenetic regulators. For that reason, several recent studies suggest that the combination of epigenetic drugs and immunotherapeutic agents can boost anticancer immune responses. In this review, we focused on the contribution of epigenetics to the crosstalk between immune and cancer cells, its relevance on immunotherapy response in TNBC, and the potential benefits of combined treatments.
ABSTRACT
OBJECTIVES: Although death is not uncommon for hospitalised patients with cancer, there are few interventions in oncology that are designed to create a dignified, compassionate end-of-life (EOL) experience for patients and families. The 3 Wishes Project (3WP), a programme in which clinicians elicit and implement final wishes for dying patients, has been shown effective in intensive care units (ICUs) at improving the EOL experience. The objective was to initiate 3WP on an oncology ward and evaluate its effect on family member experiences of their loved one's EOL. We hypothesised that the 3WP can be implemented in the non-ICU setting and help oncological patients and their families with transition to the EOL. METHODS: When the patient's probability of dying is greater than 95%, patients and families were invited to participate in the 3WP. Wishes were elicited, implemented and categorised. Audiorecorded, semistructured interviews were conducted with family members, transcribed and analysed using content analysis. RESULTS: 175 wishes were implemented for 52 patients with cancer (average cost of US$34). The most common wish (66%) was to personalise the environment. Qualitative analysis of 11 family member interviews revealed that the 3WP facilitates three transitions at the EOL: (1) the transition from multiple admissions to the final admission, (2) the transition of a predominantly caregiver role to a family member role and (3) the transition from a focus on the present to a focus on legacy. CONCLUSION: The 3WP can be implemented on the oncology ward and enhance the EOL experience for hospitalised patients with cancer.
ABSTRACT
The concept that disease rooted principally in chronic aberrant constitutive and reactive activation of mast cells (MCs), without the gross MC neoplasia in mastocytosis, first emerged in the 1980s, but only in the last decade has recognition of "mast cell activation syndrome" (MCAS) grown significantly. Two principal proposals for diagnostic criteria have emerged. One, originally published in 2012, is labeled by its authors as a "consensus" (re-termed here as "consensus-1"). Another sizable contingent of investigators and practitioners favor a different approach (originally published in 2011, newly termed here as "consensus-2"), resembling "consensus-1" in some respects but differing in others, leading to substantial differences between these proposals in the numbers of patients qualifying for diagnosis (and thus treatment). Overdiagnosis by "consensus-2" criteria has potential to be problematic, but underdiagnosis by "consensus-1" criteria seems the far larger problem given (1) increasing appreciation that MCAS is prevalent (up to 17% of the general population), and (2) most MCAS patients, regardless of illness duration prior to diagnosis, can eventually identify treatment yielding sustained improvement. We analyze these proposals (and others) and suggest that, until careful research provides more definitive answers, diagnosis by either proposal is valid, reasonable, and helpful.
Subject(s)
Mastocytosis , Consensus , Humans , Mast Cells , Mastocytosis/diagnosisABSTRACT
Bone morphogenetic proteins (BMPs) have multiple roles during embryogenesis. Current data indicate that the dosage of BMPs is tightly regulated for normal development in mice. Since Bmp2 or Bmp4 homozygous mutant mice show early embryonic lethality, we generated compound heterozygous mice for Bmp2 and Bmp4 to explore the impact of lowered dosage of these BMP ligands. Genotyping pups bred between Bmp2 and Bmp4 heterozygous mice revealed that the ratio of adult compound heterozygous mice for Bmp2 and Bmp4 is much lower than expected. During embryogenesis, the compound heterozygous embryos showed several abnormalities, including defects in eye formation, body wall closure defects, and ventricular septal defects (VSD) in the heart. However, the ratio of the compound heterozygous embryos was the same as expected. Caesarean sections at E18.5 revealed that half of the compound heterozygotes died soon after birth, and the majority of the dead individuals exhibited VSD. Survivors were able to grow to adults, but their body weight was significantly lower than control littermates. They demonstrated progressive abnormalities in the heart, eventually showing a branched leaflet in atrioventricular valves. These results suggest that the dosage of both BMP2 and 4 is critical for functional heart formation during embryogenesis and after birth.
Subject(s)
Bone Morphogenetic Protein 2/genetics , Bone Morphogenetic Protein 4/genetics , Embryo, Mammalian/metabolism , Myocardium/metabolism , Animals , Animals, Newborn , Bone Morphogenetic Protein 2/metabolism , Bone Morphogenetic Protein 4/metabolism , Embryo, Mammalian/abnormalities , Embryo, Mammalian/embryology , Embryonic Development/genetics , Eye Abnormalities/embryology , Eye Abnormalities/genetics , Female , Genotype , Heart/embryology , Heart Septal Defects/genetics , Heart Septal Defects/metabolism , Histocytochemistry , Male , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Mice, Mutant Strains , Myocardium/pathology , Time FactorsABSTRACT
BMPRIA and its high-affinity ligand BMP4 have recently been shown to be expressed in the beta-cells of the pancreas. Here, we report the abnormalities of heterozygous mice for Bmpr1a in glucose metabolism during the course of intraperitoneal glucose tolerance test. The heterozygous mice had increased blood glucose levels throughout the first 2.5 h after the administration of glucose. Analysis of glucose-stimulated insulin secretion (GSIS) indicates that insulin secretion in the heterozygous mice is compromised, and induction of secreted insulin by stimulation is substantially lower compared with the wild-type controls. No apparent abnormalities in pancreas, thyroid, and liver were seen upon histological examination. Real-time PCR results of selected genes showed an increase in the mRNA level of Ins1 and Ins2 in the heterozygous group. These results indicate that the glucose-sensing pathway in these heterozygous mice is altered because of the heterozygosity in Bmpr1a. Together, our data suggest that BMP signaling through BMPRIA plays an important role in glucose metabolism and possibly working through the GSIS pathway.
Subject(s)
Blood Glucose/metabolism , Bone Morphogenetic Protein Receptors, Type I/metabolism , Bone Morphogenetic Proteins/metabolism , Signal Transduction , Animals , Bone Morphogenetic Protein Receptors, Type I/genetics , Female , Gene Expression , Glucose/metabolism , Glucose Tolerance Test/statistics & numerical data , Heterozygote , Insulin/blood , Insulin/genetics , Insulin/metabolism , Insulin Secretion , Male , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Mice, Mutant Strains , Proinsulin/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Double-stranded RNA (dsRNA) is a potent signal to the host immune system for the presence of an ongoing viral infection. The presence of dsRNA, intracellularly or extracellularly, leads to the induction of innate inflammatory cytokines in many cell types including epithelial cells. However, the cell surface receptor for recognition of extracellular dsRNA is not yet determined. Here, we report that extracellular dsRNA is recognized and internalized by scavenger receptor class-A (SR-A). Treatment of human epithelial cells with specific antagonists of SR-A or with an anti-SR-A antibody significantly inhibited dsRNA induction of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8, and regulated on activation normal T-cell expressed and secreted (RANTES). Furthermore, intranasal dsRNA treatment of SR-A-deficient (SR-A(-/-)) mice showed a significant decrease in the expression of inflammatory cytokines and a corresponding decrease in the accumulation of polymorphonuclear leukocytes (PMNs) in lungs. These data provide direct evidence that SR-A is a novel cell surface receptor for dsRNA, and therefore, SR-A may play a role in antiviral immune responses.
Subject(s)
RNA, Double-Stranded/metabolism , Receptors, Scavenger/metabolism , Animals , Base Sequence , Bronchi/cytology , Bronchi/metabolism , Cell Line , Cytokines/antagonists & inhibitors , Cytokines/biosynthesis , DNA Primers , Epithelial Cells/metabolism , Humans , Inflammation Mediators/antagonists & inhibitors , Inflammation Mediators/metabolism , Male , Mice , Mice, Knockout , Microscopy, Confocal , Radioligand Assay , Receptors, Scavenger/antagonists & inhibitors , Reverse Transcriptase Polymerase Chain Reaction , Signal TransductionABSTRACT
While the outcomes for patients diagnosed with hormone receptor positive (HR+) and/or human epidermal growth factor receptor 2-positive (HER2+) breast cancers have continued to improve with the development of targeted therapies, the same cannot be said yet for those affected with triple-negative breast cancer (TNBC). Currently, the mainstay of treatment for the 10-15% of patients diagnosed with TNBC remains cytotoxic chemotherapy, but it is hoped that through an enhanced characterization of TNBC biology, this disease will be molecularly delineated into subgroups with targetable oncogenic drivers. This review will focus on recent therapeutic innovations for TNBC, including poly-ADP-ribosyl polymerase (PARP) inhibitors, phosphoinositide 3-kinase (PI3K) pathway inhibitors, immune checkpoint inhibitors, and cyclin-dependent kinase (CDK) inhibitors.
Subject(s)
Antineoplastic Agents/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Triple Negative Breast Neoplasms/drug therapy , Cyclin-Dependent Kinases/metabolism , Female , Humans , Molecular Targeted Therapy/methods , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Poly(ADP-ribose) Polymerases/metabolism , Programmed Cell Death 1 Receptor/metabolism , Receptor, ErbB-2/metabolism , Triple Negative Breast Neoplasms/metabolismABSTRACT
A genome-wide screen in Saccharomyces cerevisiae identified LSM1 as a new gene affecting sensitivity to ultraviolet (UV) radiation. Lsmlp is a member of a cytoplasmic complex composed of Lsmlp-7p that interacts with the yeast mRNA degradation machinery. To investigate the potential role of Lsmlp in response to UV radiation, we constructed double mutant strains in which LSM1 was deleted in combination with a representative gene from each of three known yeast DNA repair pathways. Our results show that lsm1delta increases the UV-radiation sensitivity of the rad1delta and rad51delta mutants, but not the radl8delta mutant, placing LSM1 within the post-replication repair/damage tolerance pathway (PRR). When combined with other deletions affecting PRR, lsm1delta increases the UV-radiation sensitivity of the rev3delta, rad30delta and pol30-K164R mutants but not rad5delta. Furthermore, the UV-radiation sensitivity phenotype of lsmldelta is partially rescued by mutations in genes involved in 3' to 5' mRNA degradation, and mutations predicted to function in RNA interactions confer the most UV-radiation sensitivity. Together, these results suggest that Lsmlp may confer protection against UV-radiation damage by protecting the 3' ends of mRNAs from exosome-dependent 3' to 5' degradation as part of a novel RAD5-mediated, PCNA-K164 ubiquitylation-independent subpathway of PRR.