Challenges in αCD38-chimeric antigen receptor (CAR)-expressing natural killer (NK) cell-based immunotherapy in multiple myeloma: Harnessing the CD38dim phenotype of cytokine-stimulated NK cells as a strategy to prevent fratricide.

BACKGROUND AIMS: Adoptive cell therapy with chimeric antigen receptor (CAR)-expressing natural killer (NK) cells is an emerging approach that holds promise in multiple myeloma (MM). However, the generation of CAR-NK cells targeting CD38 is met with obstacles due to the expression of CD38 on NK cells. Knock-out of CD38 is currently explored as a strategy, although the consequences of the lack of CD38 expression with regards to engraftment and activity in the bone marrow microenvironment are not fully elucidated. Here, we present an alternative approach by harnessing the CD38dim phenotype occurring during long-term cytokine stimulation of primary NK cells. METHODS: Primary NK cells were expanded from peripheral blood mononuclear cells by long-term IL-2 stimulation. During expansion, the CD38 expression was monitored in order to identify a time point when introduction of a novel affinity-optimized αCD38-CAR confered optimal viability, i.e. prevented fratricide. CD38dim NK cells were trasduced with retroviral vectors encoding for the CAR trasngene and their functionality was assessed in in vitro activation and cytotoxicity assays. RESULTS: We verified the functionality of the αCD38-CAR-NK cells against CD38+ cell lines and primary MM cells. Importantly, we demonstrated that αCD38-CAR-NK cells derived from patients with MM have increased activity against autologous MM samples ex vivo. CONCLUSIONS: Overall, our results highlight that incorporation of a functional αCD38-CAR construct into a suitable NK-cell expansion and activation protocol results in a potent and feasible immunotherapeutic strategy for the treatment of patients with MM.

Systematic development and feasibility testing of a multibehavioural digital prehabilitation intervention for patients approaching major surgery (iPREPWELL): A study protocol.

Improving outcomes for people undergoing major surgery, specifically reducing perioperative morbidity and mortality remains a global health challenge. Prehabilitation involves the active preparation of patients prior to surgery, including support to tackle risk behaviours that mediate and undermine physical and mental health and wellbeing. The majority of prehabilitation interventions are delivered in person, however many patients express a preference for remotely-delivered interventions that provide them with tailored support and the flexibility. Digital prehabilitation interventions offer scalability and have the potential to benefit perioperative healthcare systems, however there is a lack of robustly developed and evaluated digital programmes for use in routine clinical care. We aim to systematically develop and test the feasibility of an evidence and theory-informed multibehavioural digital prehabilitation intervention 'iPREPWELL' designed to prepare patients for major surgery. The intervention will be developed with reference to the Behaviour Change Wheel, COM-B model, and the Theoretical Domains Framework. Codesign methodology will be used to develop a patient intervention and accompanying training intervention for healthcare professionals. Training will be designed to enable healthcare professionals to promote, support and facilitate delivery of the intervention as part of routine clinical care. Patients preparing for major surgery and healthcare professionals involved with their clinical care from two UK National Health Service centres will be recruited to stage 1 (systematic development) and stage 2 (feasibility testing of the intervention). Participants recruited at stage 1 will be asked to complete a COM-B questionnaire and to take part in a qualitative interview study and co-design workshops. Participants recruited at stage 2 (up to twenty healthcare professionals and forty participants) will be asked to take part in a single group intervention study where the primary outcomes will include feasibility, acceptability, and fidelity of intervention delivery, receipt, and enactment. Healthcare professionals will be trained to promote and support use of the intervention by patients, and the training intervention will be evaluated qualitatively and quantitatively. The multifaceted and systematically developed intervention will be the first of its kind and will provide a foundation for further refinement prior to formal efficacy testing.

Co-designed weight management intervention for women recovering from oestrogen-receptor positive breast cancer.

BACKGROUND: Weight gain is commonly observed during and after breast cancer treatment and is associated with poorer survival outcomes, particularly in women with oestrogen receptor-positive (ER +) disease. The aim of this study was to co-design (with patients) a programme of tailored, personalised support (intervention), including high-quality support materials, to help female breast cancer patients (BCPs) with ER + disease to develop the skills and confidence needed for sustainable weight loss.  METHODS: ER + BCPs were recruited from two UK National Health Service (NHS) Trusts. The selection criteria included (i) recent experience of breast cancer treatment (within 36 months of completing primary treatment); (ii) participation in a recent focus group study investigating weight management perceptions and experiences; (iii) willingness to share experiences and contribute to discussions on the support structures needed for sustainable dietary and physical activity behaviour change. Co-design workshops included presentations and interactive activities and were facilitated by an experienced co-design researcher (HH), assisted by other members of the research team (KP, SW and JS). RESULTS: Two groups of BCPs from the North of England (N = 4) and South Yorkshire (N = 5) participated in a two-stage co-design process. The stage 1 and stage 2 co-design workshops were held two weeks apart and took place between Jan-March 2019, with each workshop being approximately 2 h in duration. Guided by the Behaviour Change Wheel, a theoretically-informed weight management intervention was developed on the basis of co-designed strategies to overcome physical and emotional barriers to dietary and physical activity behaviour change. BCPs were instrumental in designing all key features of the intervention, in terms of Capability (e.g., evidence-based information, peer-support and shared experiences), Opportunity (e.g., flexible approach to weight management based on core principles) and Motivation (e.g., appropriate use of goal-setting and high-quality resources, including motivational factsheets) for behaviour change. CONCLUSION: This co-design approach enabled the development of a theoretically-informed intervention with a content, structure and delivery model that has the potential to address the weight management challenges faced by BCPs diagnosed with ER + disease. Future research is required to evaluate the effectiveness of the intervention for eliciting clinically-important and sustainable weight loss in this population.

A Novel Affinity Engineered Anti-CD47 Antibody With Improved Therapeutic Index That Preserves Erythrocytes and Normal Immune Cells.

Therapeutic blockade of the CD47/SIRPα axis by small molecules or monoclonal antibodies (mAbs) is a proven strategy to enhance macrophages-mediated anti-tumor activity. However, this strategy has been hampered by elevated on-target toxicities and rapid clearance due to the extensive CD47 expression on normal cells ("antigen sink") such as red blood cells (RBCs). To address these hurdles, we report on the development of STI-6643, an affinity-engineered fully human anti-CD47 IgG4 antibody with negligible binding to normal cells. STI-6643 exhibited no hemagglutination activity on human RBCs at concentrations up to 300 µg/mL yet specifically blocked the CD47/SIPRα interaction. Of particular interest, STI-6643 preserved T cell functionality in vitro and showed significantly lower immune cell depletion in vivo in contrast to three previously published competitor reference anti-CD47 clones Hu5F9, AO-176 and 13H3. In cynomolgus monkeys, STI-6643 was well-tolerated at the highest dose tested (300 mg/kg/week) and provided favorable clinical safety margins. Finally, STI-6643 displayed comparable anti-tumor activity to the high-affinity reference clone Hu5F9 in a RAJI-Fluc xenograft tumor model as monotherapy or in combination with anti-CD20 (rituximab) or anti-CD38 (daratumumab) mAbs. These data suggest that STI-6643 possesses the characteristics of an effective therapeutic candidate given its potent anti-tumor activity and low toxicity profile.

Sacituzumab govitecan, a Trop-2-directed antibody-drug conjugate, for patients with epithelial cancer: final safety and efficacy results from the phase I/II IMMU-132-01 basket trial.

BACKGROUND: Sacituzumab govitecan (SG), a trophoblast cell surface antigen-2 (Trop-2)-directed antibody-drug conjugate, has demonstrated antitumor efficacy and acceptable tolerability in a phase I/II multicenter trial (NCT01631552) in patients with advanced epithelial cancers. This report summarizes the safety data from the overall safety population (OSP) and efficacy data, including additional disease cohorts not published previously. PATIENTS AND METHODS: Patients with refractory metastatic epithelial cancers received intravenous SG (8, 10, 12, or 18 mg/kg) on days 1 and 8 of 21-day cycles until disease progression or unacceptable toxicity. Endpoints for the OSP included safety and pharmacokinetic parameters with investigator-evaluated objective response rate (ORR per RECIST 1.1), duration of response, clinical benefit rate, progression-free survival, and overall survival evaluated for cohorts (n > 10 patients) of small-cell lung, colorectal, esophageal, endometrial, pancreatic ductal adenocarcinoma, and castrate-resistant prostate cancer. RESULTS: In the OSP (n = 495, median age 61 years, 68% female; UGT1A1∗28 homozygous, n = 46; 9.3%), 41 (8.3%) permanently discontinued treatment due to adverse events (AEs). Most common treatment-related AEs were nausea (62.6%), diarrhea (56.2%), fatigue (48.3%), alopecia (40.4%), and neutropenia (57.8%). Most common treatment-related serious AEs (n = 75; 15.2%) were febrile neutropenia (4.0%) and diarrhea (2.8%). Grade ≥3 neutropenia and febrile neutropenia occurred in 42.4% and 5.3% of patients, respectively. Neutropenia (all grades) was numerically more frequent in UGT1A1∗28 homozygotes (28/46; 60.9%) than heterozygotes (69/180; 38.3%) or UGT1A1∗1 wild type (59/177; 33.3%). There was one treatment-related death due to an AE of aspiration pneumonia. Partial responses were seen in endometrial cancer (4/18, 22.2% ORR) and small-cell lung cancer (11/62, 17.7% ORR), and one castrate-resistant prostate cancer patient had a complete response (n = 1/11; 9.1% ORR). CONCLUSIONS: SG demonstrated a toxicity profile consistent with previous published reports. Efficacy was seen in several cancer cohorts, which validates Trop-2 as a broad target in solid tumors.

Hemocytic sarcoma of the body wall in a California king crab Paralithodes californiensis.

Neoplasia is rarely reported in decapod crustaceans, and sarcoma has not been previously reported in any crab species. A California king crab Paralithodes californiensis with a recent history of autotomy (4 legs lost) and anorexia was found dead. Grossly, the crab had a pigmented ulcer on the right cheliped merus. Necropsy tissue samples were placed in 10% neutral buffered formalin and processed routinely for histology. Both histochemical (i.e. Brown and Brenn Gram, Fite-Faraco acid fast, Fontana-Masson, Giemsa, hematoxylin and eosin, Masson's trichrome, periodic acid-Schiff [PAS], phosphotungstic acid-hematoxylin, and von Kossa) and immunohistochemical (i.e. cytokeratin, vimentin, and lysozyme) stains were performed. The body wall (presumably of the right cheliped merus) was ulcerated and subtended by a densely cellular, unencapsulated, invasive neoplasm composed of spindle cells arranged in intersecting streams and bundles embedded in a small to moderate amount of fibromatous stroma. Neoplastic cells were oval to elongate with fibrillar, pale eosinophilic cytoplasm that occasionally contained moderate numbers of small, spherical, brightly eosinophilic granules that were highlighted with PAS and Giemsa stains. Neoplastic cells had mild atypia and no evident mitoses. Immunohistochemical stains were noncontributory. This neoplasm is consistent with hemocytic sarcoma of semi-granulocytic origin. Decapod crustaceans have 3 types of hemocytes: hyalinocytes, granulocytes, and semi-granulocytes. Neoplastic cells had PAS- and Giemsa-positive granules, which are present in both semi-granulocytes and granulocytes. Semi-granulocytes can elongate and are associated with deposition of extracellular matrix during some immune responses. Neoplastic cells were elongate and associated with deposition of matrix. These findings suggest neoplastic cells were of semi-granulocytic origin.

The 1960s cervical screening incident at National Women's Hospital, Auckland, New Zealand: insights for screening research, policy making, and practice.

BACKGROUND AND OBJECTIVES: This article examines a cervical screening incident from the 1960s and draws lessons for screening policy. STUDY DESIGN AND SETTING: Concern about harmful overtreatment of symptomless lesions prompted university gynecologist Herbert Green to study, between 1965 and 1970, a 'special series' of 33 women with carcinoma in situ (CIS) who were managed with only limited punch or wedge biopsy. These women were carefully followed up but not treated unless they showed evidence of progression to invasive cancer. This paper examines source documents and subsequent publications in order to ascertain lessons from this incident. RESULTS: In keeping with the 1964 Helsinki Declaration, written consent was not sought. Green published the outcomes for his patients with CIS including the 'special series.' A Judicial inquiry (the Cartwright Inquiry) in 1987 concluded that some women had suffered harm and some had died, but numbers and evidence were not clearly stated. Medical case review for the Inquiry identified 25 women with only punch or wedge biopsy; in 21 of these, there were reasons why no further treatment was given; two had developed cervical cancer, and none were recorded as having died. The case review found eight patients, not necessarily in the 'special series,' who 'in retrospect and by 1987 standards' might have benefited from earlier conisation or hysterectomy. CONCLUSION: Subsequent claims relating to Green's practice have wrongly stated that as many as one hundred women or more had treatment withheld and over 30 died as a result. These claims are inaccurate.

Reducing Implant Infection in Orthopaedics (RIIiO): Results of a pilot study comparing the influence of forced air and resistive fabric warming technologies on postoperative infections following orthopaedic implant surgery.

BACKGROUND: Active warming during surgery prevents perioperative hypothermia but the effectiveness and postoperative infection rates may differ between warming technologies. AIM: To establish the recruitment and data management strategies needed for a full trial comparing postoperative infection rates associated with forced air warming (FAW) versus resistive fabric warming (RFW) in patients aged >65 years undergoing hemiarthroplasty following fractured neck of femur. METHODS: Participants were randomized 1:1 in permuted blocks to FAW or RFW. Hypothermia was defined as a temperature of <36°C at the end of surgery. Primary outcomes were the number of participants recruited and the number with definitive deep surgical site infections. FINDINGS: A total of 515 participants were randomized at six sites over a period of 18 months. Follow-up was completed for 70.1%. Thirty-seven participants were hypothermic (7.5% in the FAW group; 9.7% in the RFW group). The mean temperatures before anaesthesia and at the end of surgery were similar. For the primary clinical outcome, there were four deep surgical site infections in the FAW group and three in the RFW group. All participants who developed a postoperative infection had antibiotic prophylaxis, a cemented prosthesis, and were operated under laminar airflow; none was hypothermic. There were no serious adverse events related to warming. CONCLUSION: Surgical site infections were identified in both groups. Progression from the pilot to the full trial is possible but will need to take account of the high attrition rate.

Patient preferences of chemotherapy treatment options and tolerance of chemotherapy side effects in advanced stage lung cancer.

BACKGROUND: In the U.S., lung cancer accounts for 14% of cancer diagnoses and 28% of cancer deaths annually. Since no cure exists for advanced lung cancer, the main treatment goal is to prolong survival. Chemotherapy regimens produce side effects with different profiles. Coupling this with individual patient's preferred side effects could result in patient-centered choices leading to better treatment outcomes. There are apparently no previous studies of or tools for assessing and utilizing patient chemotherapy preferences in clinical settings. The long-term goal of the study was to facilitate patients' treatment choices for advanced-stage lung cancer. A primary aim was to determine how preferences for chemotherapy side effects relate to chemotherapy choices. METHODS: An observational, longitudinal, open cohort study of patients with advanced-stage non-small cell lung cancer (NSCLC) was conducted. Data sources included patient medical records and from one to three interviews per subject. Data were analyzed using Chi-square, Fisher's Exact and McNamara's test, and logistic regression. RESULTS: Patients identified the top three chemotherapy side effects that they would most like to avoid: shortness of breath, bleeding, and fatigue. These side effects were similar between first and last interviews, although the rank order changed after patients experienced chemotherapy. CONCLUSIONS: Patients ranked drug side effects that they would most like to avoid. Patient-centered clinical care and patient-centered outcomes research are feasible and may be enhanced by stakeholder commitment. The study results are limited to patients with advanced NSCLC. Most of the subjects were White, since patients were drawn from the U.S. Midwest, a predominantly White population.

Improving medication safety for home nursing clients: A prospective observational study of a novel clinical pharmacy service-The Visiting Pharmacist (ViP) study.

WHAT IS KNOWN AND OBJECTIVE: Polypharmacy, medication errors and adverse events are common in older people receiving home nursing medication management support. Access to clinical pharmacists is limited. In Australia, few home nursing clients receive a general practitioner (GP)-initiated pharmacist-led Home Medicines Review, despite their eligibility and community nurses' (CN) efforts to facilitate this. An integrated home nursing clinical pharmacy service, in which CNs directly referred clients to a pharmacist, was therefore developed and piloted. The aim was to explore the number and type of medication-related problems (MRPs) and medication treatment authorization (medication order) discrepancies identified and addressed by clinical pharmacists. METHODS: Two part-time clinical pharmacists were employed. They reviewed and reconciled clients' medications, educated clients/carers about their medicines, provided advice and support to CNs and worked with clients' GPs and other prescribers to optimize medication regimens and revise/update nurses' medication treatment authorizations. Evaluation involved review of clients' medicines data, including treatment authorizations and pharmacist medication review reports. RESULTS AND DISCUSSION: Eighty-four clients (median 86 years, 6 health conditions, 13 medications) were reviewed. The pharmacists identified 334 MRPs (median 4 per client) and 307 medication discrepancies in treatment authorizations (median 2 per client). The pharmacists made 282 recommendations to prescribers to address MRPs; 148 (52.5%) recommendations were acted on, resulting in 190 medication changes for 60 (71.4%) clients (median 2 per client). The pharmacists prepared, or assisted GPs to update, treatment authorizations for 68 (81%) clients. WHAT IS NEW AND CONCLUSION: Integrating pharmacists into a home nursing service identified and addressed MRPs and medication treatment authorization discrepancies, hence contributing to enhanced medication safety.

Osteonecrosis following treatment for childhood acute lymphoblastic leukaemia: The Southampton Children's Hospital experience.

Purpose: To determine the prevalence of osteonecrosis (ON) in children following treatment of acute lymphoblastic leukaemia (ALL), characterise these cases and review treatment methods. Methods: All children diagnosed and treated for ALL between 01 January 2003 and 31 December 2013 at our centre were retrospectively reviewed. Logistic regression was used to investigate risk factors for ON occurrence. Results: Of 235 children treated for ALL, 48/235 (20.4%) children suffered musculoskeletal symptoms necessitating radiological investigation. A total of 13 (5.5%) had MRI-diagnosed ON, with a median diagnosis time of 12 months (interquartile range 10 to 14) following initiation of chemotherapy.ON affected 40 joints in 13 children. The most commonly involved joints were hips (14 joints in eight patients) and knees (12 joints in seven patients).Older age at ALL diagnosis was associated with significantly increased risk of development of ON per year (odds ratio 1.35, 95% confidence interval 1.17 to 1.57, p < 0.001).Eight children underwent at least one surgical intervention. Joint arthroplasty was undertaken in nine joints of four children at a mean age of 18.3 years. All patients who underwent hip arthroplasty had previously received core decompression, with a mean time of 27.8 months (18 to 33) between treatments. Conclusions: ON is a significant complication of ALL treatment. Our results suggest risk stratification for development of ON by age, and targeted monitoring of high-risk joints is possible. ON treatment is varied with little evidence base.

Randomized feasibility trial of high-intensity interval training before elective abdominal aortic aneurysm repair.

BACKGROUND: This study assessed the feasibility of a preoperative high-intensity interval training (HIT) programme in patients awaiting elective abdominal aortic aneurysm repair. METHODS: In this feasibility trial, participants were allocated by minimization to preoperative HIT or usual care. Patients in the HIT group were offered three exercise sessions per week for 4 weeks, and weekly maintenance sessions if surgery was delayed. Feasibility and acceptability outcomes were: rates of screening, eligibility, recruitment, retention, outcome completion, adverse events and adherence to exercise. Data on exercise enjoyment (Physical Activity Enjoyment Scale, PACES), cardiorespiratory fitness (anaerobic threshold and peak oxygen uptake), quality of life, postoperative morbidity and mortality, duration of hospital stay and healthcare utilization were also collected. RESULTS: Twenty-seven patients were allocated to HIT and 26 to usual care (controls). Screening, eligibility, recruitment, retention and outcome completion rates were 100 per cent (556 of 556), 43·2 per cent (240 of 556), 22·1 per cent (53 of 240), 91 per cent (48 of 53) and 79-92 per cent respectively. The overall exercise session attendance rate was 75·8 per cent (276 of 364), and the mean(s.d.) PACES score after the programme was 98(19) ('enjoyable'); however, the intensity of exercise was generally lower than intended. The mean anaerobic threshold after exercise training (adjusted for baseline score and minimization variables) was 11·7 ml per kg per min in the exercise group and 11·4 ml per kg per min in controls (difference 0·3 (95 per cent c.i. -0·4 to 1·1) ml per kg per min). There were trivial-to-small differences in postoperative clinical and patient-reported outcomes between the exercise and control groups. CONCLUSION: Despite the intensity of exercise being generally lower than intended, the findings support the feasibility and acceptability of both preoperative HIT and the trial procedures. A definitive trial is warranted. Registration number: ISRCTN09433624 ( https://www.isrctn.com/).

Multi-centre field evaluation of the performance of the Trinity Biotech Uni-Gold HIV 1/2 rapid test as a first-line screening assay for gay and bisexual men compared with 4th generation laboratory immunoassays.

BACKGROUND: The Trinity Biotech Uni-Gold HIV test (Uni-Gold) is often used as a supplementary rapid test in testing algorithms. OBJECTIVE: To evaluate the operational performance of the Uni-Gold as a first-line screening test among gay and bisexual men (GBM) in a setting where 4th generation HIV laboratory assays are routinely used. STUDY DESIGN: We compared the performance of Uni-Gold with conventional HIV serology conducted in parallel among GBM attending 22 testing sites. Sensitivity was calculated separately for acute and established infection, defined using 4th generation screening Ag/Ab immunoassay (EIA) and Western blot results. Previous HIV testing history and results of supplementary 3rd generation HIV Ab EIA, and p24 antigen EIA were used to further characterise cases of acute infection. RESULTS: Of 10,793 specimens tested with Uni-Gold and conventional serology, 94 (0.90%, 95%CI:0.70-1.07) were confirmed as HIV-positive by conventional serology, and 37 (39.4%) were classified as acute infection. Uni-Gold sensitivity was 81.9% overall (77/94, 95%CI:72.6-89.1); 56.8% for acute infection (21/37, 95%CI:39.5-72.9) and 98.2% for established infection (56/57, 95%CI:90.6-100.0). Of 17 false non-reactive Uni-Gold results, 16 were acute infections, and of these seven were p24 antigen reactive but antibody negative. Uni-Gold specificity was 99.9% (10,692/10,699, 95%CI:99.9-100.0), PPV was 91.7% (95%CI:83.6-96.6) and NPV was 99.8% (95%CI:99.7-99.9), respectively. CONCLUSIONS: In this population, Uni-Gold had good specificity and sensitivity was high for established infections when compared to 4th generation laboratory assays, however sensitivity was lower in acute infections. Where rapid tests are used in populations with a high proportion of acute infections, additional testing strategies are needed to detect acute infections.

Fifteen-minute consultation: the agar plates your microbiology colleagues want you to be scared about.

The WHO has recognised antibiotic resistance as one of the greatest threats to human health. As a microbiologist, antibiotic resistance is a problem that keeps me awake at night and inevitably the impact of antibiotic resistance on paediatricians is a matter of when, and not if. I fear for the future of paediatric services such as neonatology, oncology and elective surgery. A recent US study found that 26.8% of post chemotherapy infections and 38.7-50.9% of post-operative infections were caused by bacteria resistant to standard antibiotic prophylaxis. The authors predicted that this will lead to an additional 6300 infection-related deaths in the USA each year. Closer to home, David Cameron commissioned a review into antimicrobial resistance in 2014 and the findings were extremely worrying. The report predicted that by 2050, 10 million annual worldwide deaths will be attributable to antimicrobial resistance. More than annual predicted cancer-associated and diabetes-associated mortality combined. The golden antibiotic era is certainly over. Selecting the most appropriate antibiotic to treat an infection depends on many factors, including route of administration, penetration to site of infection and pathogen susceptibility. Most clinicians do not need an in-depth understanding of bacterial resistance mechanisms as local microbiologists can provide expertise and advice. However, in an era of increasing antibiotic resistance, an insight into the organism factors that affect antibiotic selection can prove useful.

The ErbB2ΔEx16 splice variant is a major oncogenic driver in breast cancer that promotes a pro-metastatic tumor microenvironment.

Amplification and overexpression of erbB2/neu proto-oncogene is observed in 20-30% human breast cancer and is inversely correlated with the survival of the patient. Despite this, somatic activating mutations within erbB2 in human breast cancers are rare. However, we have previously reported that a splice isoform of erbB2, containing an in-frame deletion of exon 16 (herein referred to as ErbB2ΔEx16), results in oncogenic activation of erbB2 because of constitutive dimerization of the ErbB2 receptor. Here, we demonstrate that the ErbB2ΔEx16 is a major oncogenic driver in breast cancer that constitutively signals from the cell surface. We further show that inducible expression of the ErbB2ΔEx16 variant in mammary gland of transgenic mice results in the rapid development of metastatic multifocal mammary tumors. Genetic and biochemical characterization of the ErbB2ΔEx16-derived mammary tumors exhibit several unique features that distinguish this model from the conventional ErbB2 ones expressing the erbB2 proto-oncogene in mammary epithelium. Unlike the wild-type ErbB2-derived tumors that express luminal keratins, ErbB2ΔEx16-derived tumors exhibit high degree of intratumoral heterogeneity co-expressing both basal and luminal keratins. Consistent with these distinct pathological features, the ErbB2ΔEx16 tumors exhibit distinct signaling and gene expression profiles that correlate with activation of number of key transcription factors implicated in breast cancer metastasis and cancer stem cell renewal.

Functional proteomics identifies miRNAs to target a p27/Myc/phospho-Rb signature in breast and ovarian cancer.

The myc oncogene is overexpressed in almost half of all breast and ovarian cancers, but attempts at therapeutic interventions against myc have proven to be challenging. Myc regulates multiple biological processes, including the cell cycle, and as such is associated with cell proliferation and tumor progression. We identified a protein signature of high myc, low p27 and high phospho-Rb significantly correlated with poor patient survival in breast and ovarian cancers. Screening of a miRNA library by functional proteomics in multiple cell lines and integration of data from patient tumors revealed a panel of five microRNAs (miRNAs) (miR-124, miR-365, miR-34b*, miR-18a and miR-506) as potential tumor suppressors capable of reversing the p27/myc/phospho-Rb protein signature. Mechanistic studies revealed an RNA-activation function of miR-124 resulting in direct induction of p27 protein levels by binding to and inducing transcription on the p27 promoter region leading to a subsequent G1 arrest. Additionally, in vivo studies utilizing a xenograft model demonstrated that nanoparticle-mediated delivery of miR-124 could reduce tumor growth and sensitize cells to etoposide, suggesting a clinical application of miRNAs as therapeutics to target the functional effect of myc on tumor growth.