Feasibility study of the multishot gradient-echo planar imaging sequence in non-enhanced and free-breathing whole-heart magnetic resonance coronary angiography

AIM

To investigate the feasibility of non-enhanced and free-breathing whole-heart magnetic resonance coronary angiography (MRCA) using multishot gradient-echo planar imaging (MSG-EPI).

MATERIALS AND METHODS

In total, 29 healthy volunteers were recruited for free-breathing whole-heart MRCA acquisition using the MSG-EPI sequence and fast gradient echo (GRE) sequence. After the examination, the actual scanning times, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the left main (LM) coronary artery, subjective quality scores for each segment, and evaluable length of the coronary artery were recorded and statistically analysed.

RESULTS

There was no significant difference between the SNRLM of the MSG-EPI sequence and fast GRE sequence (p=0.130), but the CNRLM of the MSG-EPI sequence was higher (p=0.001). The subjective quality score of the mid- and distal left anterior descending branch as well as the distal circumflex branch of the coronary artery in the MSG-EPI sequence was higher than that in the fast GRE sequence (p=0.003, 0.001, and 0.003, respectively). The evaluable length of the left anterior descending branch and the circumflex branch was better using the MSG-EPI sequence than that of the fast GRE sequence (p=0.015 and < 0.001, respectively). Moreover, the scanning time of the MSG-EPI sequence was 54.5% less than that of the fast GRE sequence (p<0.001).

CONCLUSION

The MSG-EPI sequence improves the subjective and objective image quality of MRCA as well as reduces the scanning time.

An Analysis of Patients Treated with Stereotactic Body Radiotherapy for Metastatic Urinary Tract Tumors to Identify Predictors of Response

PURPOSE/OBJECTIVE(S)

To identify selection criteria linked to outcomes in patients treated with stereotactic body radiotherapy (SBRT) for metastatic tumors of the urinary tract (UT).

MATERIALS/METHODS

Single institution retrospective analysis of SBRT treated patients for oligometastatic/progressive UT tumors from 2006-2022. Charts were queried for M1 status at diagnosis or during disease course, treatment details (surgery, SBRT, systemic therapy), metabolic status (diabetes [DM], BMI) and outcomes. A linear quadratic formula was used to calculate the biologically effective dose (BED) using an α/β of 10 for tumor. Descriptive statistics portrayed the cohort, and analyses were done at patient and site level. Time-to-event analyses, including overall survival (OS) and progression-free survival (PFS) from SBRT, were assessed by the Kaplan-Meier method. Cox regression was used for univariable (UVA) and multivariable analyses (MVA) to identify predictors of outcomes.

RESULTS

A total of 35 patients were treated at 44 metastatic sites, including: bone (25%), node (36.4%), lung (20.5%), soft tissue (13.6%) and liver (4.5%). Most were male (74.3%) with a median age of 70 (range: 51-89), without DM (60%) having a median BMI of 29.8, and ECOG <2 (97.1%) at time of SBRT. Six (17.1%) patients were M1 at diagnosis. Of the 29 non-M1 patients, 86.2% received definitive local therapy (LT), 58.6% had at least T3/N+ disease, 75.8% received systemic therapy with a median of 2 agents (range: 1-6) prior to SBRT. Sixteen (45.7%) received immunotherapy (IO) with most receiving this before (75%) and after (56.2%) SBRT. Six patients had positive PD-L1 status (n = 10). The median RT dose, fractionation and BED was 40 Gy (range: 14-46), 5 fractions, and 72 (range: 28-132), respectively. At a median follow-up of 34.8, the median OS was 18.4 m (range: 9.3-27.4) with a 2-year OS of 35.9%. At patient level, 62.8% recurred after SBRT. The median PFS after SBRT was 5.3 m (range: 1.8-8.7) with a 2-yr PFS of 29.3%. Patient-level PFS was improved with LT (6.7 vs 1.4 m; p = 0.001) and DM (NR vs 2.9 m; p = 0.015), whereas improved OS was related with LT (18.9 vs 6.6 m; p = 0.03), DM (p = 0.04), ECOG (p = 0.004), and no relapse after SBRT (NR vs 9.8 m; p <0.001). Exposure to < 3 systemic agents prior to SBRT portended better PFS (6.7 vs 2.6 m; p = 0.04) without any impact by IO. At site level, 20.4% of sites had local relapse with 4 being the first event. Site was related with PFS (p = 0.009) with order of increased relapse risk being liver > bone > soft tissue > node > lung. No dosimetric feature was related with recurrence risk. On MVA, both DM (p = 0.02) and LT (p = 0.002) were predictive for PFS. Only recurrence after SBRT predicted for OS on MVA (HR: 6.7, 95% CI: 1.4-31; p = 0.014). In the IO subset, median PFS was 5.3 m and OS was 9.4 m, with no difference seen with IO-SBRT sequence or PDL1 status.

CONCLUSION

Optimized selection criteria for metastasis-directed therapy in patients with UT tumors is unclear, notably with IO. Future studies may benefit by assessing circulating tumor markers prior to SBRT.

High-Dose Rate Brachytherapy Alone for Treatment of Unfavorable Intermediate Risk Prostate Cancer: A Propensity-Score Matched Analysis

PURPOSE/OBJECTIVE(S)

To demonstrate the feasibility of high-dose rate brachytherapy (HDR BT) as monotherapy for unfavorable intermediate risk (UIR) prostate cancer by comparing survival outcomes of HDR BT alone against external beam radiation therapy (EBRT) + HDR BT boost, +/- androgen deprivation therapy (ADT) using propensity-score matched (PSM) data.

MATERIALS/METHODS

This retrospective study queried two data registries collecting patient data from 1991 to present. 633 patients with UIR prostate cancer treated with HDR BT alone, HDR BT+EBRT or HDR+EBRT+ADT were included. HDR BT patients received 42-45Gy/6 fractions (fx) or 27 Gy/2 fx. For HDR BT+EBRT, the HDR dose was 20-24 Gy/2 fx, 24 Gy/4 fx, or 15 Gy/1 fx. EBRT patients received 45 Gy/25 fx to the prostate +/- pelvic nodes. GU/GI toxicities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Time-to-event analyses were carried out to evaluate the relationship between treatments and five primary endpoints of interest: freedom from biochemical recurrence (FFBC), freedom from distant metastasis (FFDM), freedom from local failure (FFLF), cancer specific survival (CSS), and overall survival (OS) at 5 years. PSM was performed with one-to-n matching. Logistic regression was used to estimate the respective propensity scores. The five potential confounders identified were T-stage, Gleason score, pre-treatment PSA, age, and percent positive cores. Balance was checked using the standardized mean difference of covariates. Univariate and multivariate analyses were conducted on the matched data. Toxicity analysis was performed via association between a change in pre- and post-treatment GU/GI toxicity status and the treatment group, as well as incidence of post-treatment severe GI/GU toxicity (grade 3 or higher) and the treatment group.

RESULTS

Univariate analysis with Kaplan-Meier method and log rank test comparison between the three cohorts demonstrated no significant difference in all survival outcomes FFBC, FFDM, FFLF, CSS, OS (p = 0.15, 0.19, 0.29, 0.57, 0.28, respectively). Multivariate analysis with Cox proportional hazard regression showed no differences in HR for FFBC and OS (p = 0.95, 0.11) with addition of EBRT, or with EBRT+ADT (p = 0.17, 0.24); no fit was obtainable for FFDM, CSS, FFLF. Toxicities between the three cohorts were not significantly different when comparing post-treatment and baseline GI/GU symptoms (p = 0.53/1). No Grade 2 or 3 GI toxicities were identified, while 8%/1% HDR patients, 10%/1% HDR+EBRT patients, and 12%/2% HDR+EBRT+ADT patients experienced Grade 2/3 GU toxicities. The incidence of grade 3 or higher GU toxicities between the three groups was not significantly different (p = 0.91).

CONCLUSION

This propensity-score matched study demonstrates the feasibility of HDR BT alone for effective treatment of UIR prostate cancer when compared to HDR+EBRT or HDR+EBRT+ADT, while potentially minimizing the added toxicities of EBRT and the undesirable side effect profile of ADT.

Activation of neural lineage networks and ARHGEF2 in enzalutamide-resistant and neuroendocrine prostate cancer and association with patient outcomes

Background

Treatment-emergent neuroendocrine prostate cancer (NEPC) after androgen receptor (AR) targeted therapies is an aggressive variant of prostate cancer with an unfavorable prognosis. The underlying mechanisms for early neuroendocrine differentiation are poorly defined and diagnostic and prognostic biomarkers are needed.

Methods

We performed transcriptomic analysis on the enzalutamide-resistant prostate cancer cell line C4-2B MDVR and NEPC patient databases to identify neural lineage signature (NLS) genes. Correlation of NLS genes with clinicopathologic features was determined. Cell viability was determined in C4-2B MDVR and H660 cells after knocking down ARHGEF2 using siRNA. Organoid viability of patient-derived xenografts was measured after knocking down ARHGEF2.

Results

We identify a 95-gene NLS representing the molecular landscape of neural precursor cell proliferation, embryonic stem cell pluripotency, and neural stem cell differentiation, which may indicate an early or intermediate stage of neuroendocrine differentiation. These NLS genes positively correlate with conventional neuroendocrine markers such as chromogranin and synaptophysin, and negatively correlate with AR and AR target genes in advanced prostate cancer. Differentially expressed NLS genes stratify small-cell NEPC from prostate adenocarcinoma, which are closely associated with clinicopathologic features such as Gleason Score and metastasis status. Higher ARGHEF2, LHX2, and EPHB2 levels among the 95 NLS genes correlate with a shortened survival time in NEPC patients. Furthermore, downregulation of ARHGEF2 gene expression suppresses cell viability and markers of neuroendocrine differentiation in enzalutamide-resistant and neuroendocrine cells.

Conclusions

The 95 neural lineage gene signatures capture an early molecular shift toward neuroendocrine differentiation, which could stratify advanced prostate cancer patients to optimize clinical treatment and serve as a source of potential therapeutic targets in advanced prostate cancer.

The petrosal artery and its variations: a comprehensive review and anatomical study with application to skull base surgery and neurointerventional procedures

BACKGROUND

The petrosal artery supplies several structures at the skull base and is often the focus of various neurointerventional procedures. Therefore, knowledge of its anatomy and variations is important to surgeons and interventionalists.

MATERIALS AND METHODS

Twenty latex injected cadaveric heads (40 sides) underwent microsurgical dissection of the petrosal artery. Documentation of the course of the artery and its branches were made. Measurements of the petrosal artery's length and diameter were performed using microcallipers.

RESULTS

A petrosal artery was identified on all sides. The mean length and diameter of the artery within the middle cranial fossa was 2.4 cm and 0.38 mm, respectively. Branches included the following: dural, ganglionic, V3 branches, branches extending through the foramen ovale, branches directly to the greater petrosal and lesser petrosal nerves, branches to the floor of the hiatus of the greater and lesser petrosal nerves, branch to the arcuate eminence, and superior tympanic artery. No statistically significant differences were noted between male and female specimens, but right-sided petrosal arteries were in general, larger in diameter than left sides.

CONCLUSIONS

A thorough anatomical knowledge of the petrosal artery and to its relationship to the facial nerve and other neurovascular structures is necessary to facilitate effective endovascular treatment and to preclude facial nerve complications.

Quantifying Contact Patterns: Development and Characteristics of the British Columbia COVID-19 Population Mixing Patterns Survey

Purpose

Several non-pharmaceutical interventions such as physical distancing, self-isolation, a stay-at-home order, hand washing, and schools and businesses closures were implemented in British Columbia (BC) following the first lab-tested case of COVID-19 on January 26, 2020. These interventions were aimed at minimizing in-person contacts that could potentially lead to new COVID-19 infections. The BC COVID-19 Population Mixing Patterns survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. We describe the BC-Mix survey design and the demographic characteristics of respondents.

Methods & Materials

The ongoing repeated online survey was launched in September 2020. Participants are recruited through a variety of social media platforms including Instagram, Facebook, YouTube, and community group mailing lists. A follow up survey is sent to participants two to four weeks after completing the first iteration. Survey responses are weighted to BC's population by age, sex, geography, and ethnicity to obtain generalizable estimates. A survey completion rate of at least 33% AND a valid response for the sex questionnaire item AND a valid response for age questionnaire item were required for inclusion in weighting and further analysis. Additional indices such as material and social deprivation index, and residential instability are generated using census and location data.

Results

As of June 14, 2021, over 58,000 residents of BC had participated in the survey of which 31,007 survey responses were eligible for analysis. Of the eligible participants, about 60% provided consent for monthly follow up and about 26% provided their personal health numbers for linkage with other healthcare utilization databases. Approximately 51% were females 39% were 55 years or older, 63% identified as white or not a visible minority and 48% had at least a university degree.

Conclusion

The pandemic response is best informed by surveillance systems capable of timely assessment of behaviour patterns. BC-Mix survey respondents represented a large cohort of British Columbians providing near real-time information on behavioural and contact patterns in BC. Data from the BC-Mix survey continues to inform provincial COVID-19-related control measures.

Substantial oxygen consumption by aerobic nitrite oxidation in oceanic oxygen minimum zones

Oceanic oxygen minimum zones (OMZs) are globally significant sites of biogeochemical cycling where microorganisms deplete dissolved oxygen (DO) to concentrations <20 µM. Amid intense competition for DO in these metabolically challenging environments, aerobic nitrite oxidation may consume significant amounts of DO and help maintain low DO concentrations, but this remains unquantified. Using parallel measurements of oxygen consumption rates and ¹⁵N-nitrite oxidation rates applied to both water column profiles and oxygen manipulation experiments, we show that the contribution of nitrite oxidation to overall DO consumption systematically increases as DO declines below 2 µM. Nitrite oxidation can account for all DO consumption only under DO concentrations <393 nM found in and below the secondary chlorophyll maximum. These patterns are consistent across sampling stations and experiments, reflecting coupling between nitrate reduction and nitrite-oxidizing Nitrospina with high oxygen affinity (based on isotopic and omic data). Collectively our results demonstrate that nitrite oxidation plays a pivotal role in the maintenance and biogeochemical dynamics of OMZs.

ARVib suppresses growth of advanced prostate cancer via inhibition of androgen receptor signaling

Targeting androgen signaling with the second-generation anti-androgen drugs, such as enzalutamide (Enza), abiraterone (Abi), apalutamide (Apal), and darolutamide (Daro), is the mainstay for the treatment of castration-resistant prostate cancer (CRPC). While these treatments are effective initially, resistance occurs frequently. Continued expression of androgen receptor (AR) and its variants such as AR-V7 despite AR-targeted therapy contributes to treatment resistance and cancer progression in advanced CRPC patients. This highlights the need for new strategies blocking continued AR signaling. Here, we identify a novel AR/AR-V7 degrader (ARVib) and found that ARVib effectively degrades AR/AR-V7 protein and attenuates AR/AR-V7 downstream target gene expression in prostate cancer cells. Mechanistically, ARVib degrades AR/AR-V7 protein through the ubiquitin-proteasome pathway mediated by HSP70/STUB1 machinery modulation. ARVib suppresses HSP70 expression and promotes STUB1 nuclear translocation, where STUB1 binds to AR/AR-V7 and promotes its ubiquitination and degradation. ARVib significantly inhibits resistant prostate tumor growth and improves enzalutamide treatment in vitro and in vivo. These data suggest that ARVib has potential for development as an AR/AR-V7 degrader to treat resistant CRPC.

Delivery of the Dementia Friends programme on the MPharm degree course: a qualitative exploration of pharmacy students’ perspectives

Introduction

A person-centred approach to dementia care has been advocated1, but limited literature exists on integration of this into pharmacist undergraduate education. The Alzheimer’s Society Dementia Friends programme was developed to change peoples’ perceptions and promote understanding of living with dementia. In 2019, the School piloted provision of Dementia Friends training; Level 3 MPharm students (n=102) were invited by email to participate as an optional part of a Clinical Therapeutics module. Sixty-three students (61.8%) attended the workshop, which combined Dementia Friends training with an interactive session facilitated by a person living with dementia (PLWD).

Aim

To explore undergraduate pharmacy students’ views and experiences of the Dementia Friends pilot.

Methods

All students who had attended the workshop were invited by email to participate in a focus group during February 2020. Participants provided written informed consent. The topic guide focused on students’ views of workshop delivery, improvements that could be made, their understanding of person-centred care, and the impact of the workshop on their clinical practice. The focus group was audio-recorded, transcribed verbatim, and analysed using thematic analysis.

Results

One focus group was conducted with eight students. Three overarching themes were identified: learning from an expert patient; importance of person-centred care; and dementia education during MPharm degree. Students valued the opportunity to learn from a PLWD and felt it allowed them to relate the condition to a real person: “it felt more personal so you could really connect with them [PLWD] and understand their experience”. Hearing about the ‘lived experience’ helped to contextualise learning from other methods of delivery, e.g. lectures: “you don’t know what’s going on in someone else’s life, and sometimes we’re all a bit quick to judge, I think [the workshop] put that into perspective”. Students described having greater understanding of person-centred care and taking a holistic approach to pharmaceutical care provision for PLWD: “it’s very important to take into account their quality of life…we can focus on the clinical but looking at the person as a whole actually helps their treatment” and “one of the things I found most interesting was that they might not remember the interaction but they will [retain] the feeling or emotion”. Students reported feeling more confident in engaging with PLWD following the workshop, which is something they would not have had the opportunity to learn from lectures alone: “If we hadn’t had that dementia training, I feel like I would still have no confidence chatting to dementia patients”. Students suggested that future Dementia Friends training should be delivered earlier in the MPharm degree course.

Conclusion

This study has shown that Dementia Friends training complemented students’ existing knowledge of dementia and increased their confidence to communicate with PLWD. The use of an expert patient was an effective way of supporting MPharm students to develop a person-centred approach to their professional practice. The study was limited to one university so findings may not be generalisable. However, these data provide a good basis for future development and evaluation of Dementia Friends training provision to MPharm students.

References

1. Kitwood, T. M. Dementia reconsidered: the person comes first. 1997. Buckingham [England], Open University Press

Phase I/II Study of Capmatinib Plus Erlotinib in Patients With MET-Positive Non-Small-Cell Lung Cancer

PURPOSE

MET dysregulation is an oncogenic driver in non-small-cell lung cancer (NSCLC), as well as a mechanism of TKI (tyrosine kinase inhibitor) resistance in patients with epidermal growth factor receptor (EGFR)-mutated disease. This study was conducted to determine safety and preliminary efficacy of the combination EGFR and MET inhibitors as a strategy to overcome and/or delay EGFR-TKI resistance.

METHODS

A standard 3 + 3 dose-escalation trial of capmatinib in combination with erlotinib in patients with MET-positive NSCLC was used. Eighteen patients in the dose-escalation cohort received 100-600 mg twice daily of capmatinib with 100-150 mg daily of erlotinib. There were two dose-expansion cohorts. Cohort A included 12 patients with EGFR-mutant tumors resistant to TKIs. Cohort B included five patients with EGFR wild-type tumors. The primary outcome was to assess safety and determine the recommended phase II dose (RP2D) of the combination.

RESULTS

The most common adverse events of any grade were rash (62.9%), fatigue (51%), and nausea (45.7%). Capmatinib exhibited nonlinear pharmacokinetics combined with erlotinib, while showing no significant drug interactions. The RP2D was 400 mg twice daily capmatinib tablets with 150 mg daily erlotinib. The overall response rate (ORR) and DCR in dose-expansion cohort A was 50% and 50%, respectively. In cohort B, the ORR and disease control rate were 75% and 75%.

CONCLUSION

Capmatinib in combination with erlotinib demonstrated safety profiles consistent with prior studies. We observed efficacy in specific patient populations. Continued evaluation of capmatinib plus EGFR-TKIs is warranted in patients with EGFR activating mutations.

Phase I study of the combination of alisertib (MLN8237) and gemcitabine in advanced solid tumors

3589

Background: Aurora Kinase A (AKA) is a key mitotic regulator overexpressed in multiple solid tumors. This open-label dose escalation and expansion phase I study evaluated the safety and tolerability of alisertib (MLN8237), an oral AKA inhibitor, in combination with gemcitabine. Methods: In dose escalation, patients (pts) > 18y with refractory solid tumors received 28-day cycles of gemcitabine on days 1, 8, 15 and alisertib twice daily on days 1-3, 8-10, and 15-17. Gemcitabine was given at 1000mg/m2. Four dose levels (DL) of alisertib (20-50mg) were given per 3+3 design to investigate dose limiting toxicities (DLT) in cycle 1, to determine maximum tolerated dose (MTD) and recommended phase II dose (RP2D). In dose expansion, advanced pancreatic adenocarcinoma pts received the MTD dose twice daily on a modified dosing schedule to allow for pharmacokinetic (PK) evaluation. Anti-tumor activity was assessed by response rate (RECIST 1.1) and progression-free survival (PFS). PK evaluation of plasma gemcitabine and alisertib was performed on all pts enrolled in the dose expansion. PK sampling was performed before treatment, immediately after gemcitabine infusion, and at other pre-specified post-infusion timepoints. Results: Twenty-six pts were treated in total: 21 pts in dose escalation and 5 pts in dose expansion. Overall, median age was 57y [42-82]; 50% male; 62% PS 1 (16 pts); 2 [0-7] median prior therapies. In the dose escalation phase, 9 tumor types were included and NSCLC was most common (7 pts). Maximum administered dose (DL4) achieved 900 mg alisertib per cycle and was tolerated (1 DLT in 6 pts). The dose expansion phase enrolled 5 pts with advanced pancreatic adenocarcinoma; median age 63y [48-82]; 60% male; 60% PS 1 (3 pts); 2 [1-2] median prior therapies. Grade ≥3 TRAEs were observed in 73% of all pts and were predominantly hematologic, including neutropenia (54%), leukopenia (50%), and lymphopenia (31%). Similar TRAEs were seen at DL4; all 14 pts experienced neutropenia with 64% experiencing grade ≥3 neutropenia. Fourteen of 23 evaluable pts (61%) had stable disease and 2 pts (9%) had partial response (PR) as best overall response. Median PFS was 2.9 months (95% CI 2.0-4.2). Analysis of PK data is ongoing and will be reported. Conclusions: Alisertib can be safely administered with gemcitabine. RP2D for alisertib is 50 mg PO BID in combination with full dose gemcitabine. Best response was at least stable disease in a majority of pts with PR observed in 9% of this heavily pretreated group of patients. Most grade ≥3 TRAEs were hematologic. Results of PK studies will also be reported. Clinical trial information: NCT01924260 .

Carnitine palmitoyltransferase 1C contributes to progressive cellular senescence

Stable transfection manipulation with antibiotic selection and passaging induces progressive cellular senescence phenotypes. However, the underlying mechanisms remain poorly understood. This study demonstrated that stable transfection of the empty vector induced PANC-1 cells into cellular senescence. Metabolomics revealed several acylcarnitines and their upstream regulatory gene, carnitine palmitoyltransferase 1C (CPT1C) involved in fatty acid β-oxidation in mitochondria, were strikingly decreased in senescent PANC-1 cells. Low CPT1C expression triggered mitochondrial dysfunction, inhibited telomere elongation, impaired cell survival under metabolic stress, and hindered the malignance and tumorigenesis of senescent cells. On the contrary, mitochondrial activity was restored by CPT1C gain-of-function in senescent vector PANC-1 cells. PPARα and TP53/CDKN1A, crucial signaling components in cellular senescence, were downregulated in senescent PANC-1 cells. This study identifies CPT1C as a key regulator of stable transfection-induced progressive PANC-1 cell senescence that inhibits mitochondrial function-associated metabolic reprogramming. These findings confirm the need to identify cell culture alterations after stable transfection, particularly when cells are used for metabolomics and mitochondria-associated studies, and suggest inhibition of CPT1C could be a promising target to intervene pancreatic tumorigenesis.

Oxaliplatin-DNA Adducts as Predictive Biomarkers of FOLFOX Response in Colorectal Cancer: A Potential Treatment Optimization Strategy

FOLFOX is one of the most effective treatments for advanced colorectal cancer. However, cumulative oxaliplatin neurotoxicity often results in halting the therapy. Oxaliplatin functions predominantly via the formation of toxic covalent drug-DNA adducts. We hypothesize that oxaliplatin-DNA adduct levels formed in vivo in peripheral blood mononuclear cells (PBMC) are proportional to tumor shrinkage caused by FOLFOX therapy. We further hypothesize that adducts induced by subtherapeutic "diagnostic microdoses" are proportional to those induced by therapeutic doses and are also predictive of response to FOLFOX therapy. These hypotheses were tested in colorectal cancer cell lines and a pilot clinical study. Four colorectal cancer cell lines were cultured with therapeutically relevant (100 μmol/L) or diagnostic microdose (1 μmol/L) concentrations of [14C]oxaliplatin. The C-14 label enabled quantification of oxaliplatin-DNA adduct level with accelerator mass spectrometry (AMS). Oxaliplatin-DNA adduct formation was correlated with oxaliplatin cytotoxicity for each cell line as measured by the MTT viability assay. Six colorectal cancer patients received by intravenous route a diagnostic microdose containing [14C]oxaliplatin prior to treatment, as well as a second [14C]oxaliplatin dose during FOLFOX chemotherapy, termed a "therapeutic dose." Oxaliplatin-DNA adduct levels from PBMC correlated significantly to mean tumor volume change of evaluable target lesions (5 of the 6 patients had measurable disease). Oxaliplatin-DNA adduct levels were linearly proportional between microdose and therapeutically relevant concentrations in cell culture experiments and patient samples, as was plasma pharmacokinetics, indicating potential utility of diagnostic microdosing.

A Novel Bioengineered miR-127 Prodrug Suppresses the Growth and Metastatic Potential of Triple-Negative Breast Cancer Cells

miR-127 is downregulated in breast cancer, where it has been shown to suppress the proliferation, migration, and invasion of breast cancer cells. In triple-negative breast cancer (TNBC), miR-127 downregulation correlates with decreased disease-free and overall patient survival. Tumor suppressor miRNAs may hold therapeutic promise but progress has been limited by several factors, including the lability and high cost of miRNA mimics. Here, we take a novel approach to produce a miR-127 prodrug (miR-127^PD), which we demonstrate is processed to mature, functional miR-127-3p in TNBC tumor cells. miR-127^PD decreased the viability and motility of TNBC cells, sensitized TNBC cells to chemotherapy, and restricted the TNBC stem cell population. Furthermore, systemic delivery of miR-127^PD suppressed tumor growth of MDA-MB-231 and MDA-MB-468 TNBC cells and spontaneous metastasis of MDA-MB-231 cells. In addition, CERK, NANOS1, FOXO6, SOX11, SOX12, FASN, and SUSD2 were identified as novel, functionally important targets of miR-127. In conclusion, our study demonstrates that miR-127 functions as a tumor and metastasis suppressor in TNBC and that delivery of miR-127 may hold promise as a novel therapy. SIGNIFICANCE: Exogenous administration of miR-127, which is functionally activated in target cells, inhibits growth and spontaneous metastasis of triple-negative breast cancer.

Deceptive but not open label placebos attenuate motion-induced nausea

OBJECTIVE

Nausea is a common complaint, known to respond to the placebo effect. Existing research has employed deception when administering placebos for nausea, limiting therapeutic translation on ethical grounds. We therefore examined the potential of non-deceptive open-label placebos (OLPs) to reduce nausea.

METHODS

Galvanic Vestibular Stimulation (GVS) and Virtual Reality (VR) were employed to model nausea in healthy volunteers across two experiments. In both experiments nausea was elicited with and without sham treatment (peppermint vapor and brain stimulation, respectively). In Exp. 1, participants (n = 61) were randomized to deceptive placebo, semi-open placebo, fully-open placebo, or control. In Exp. 2, participants (n = 93) were randomized to deceptive placebo, semi-open placebo, or control.

RESULTS

Exp. 1 found limited evidence for a placebo effect (F(1, 56) = 1.15, p = .29, η_p² =0.02), even following deceptive treatment (F(1, 56) = 1.92, p = .17, η_p²=0.03). In Exp. 2, deceptive placebo reduced nausea relative to control (F(1, 89) = 6.91, p = .010, η_p²=0.07) and OLP (F(1, 89) = 5.47, p = .022, η_p²=0.06). Pooled Bayesian analysis across experiments provided strong evidence that deceptive placebos reduce nausea relative to control (BF₁₀ = 30.91) and anecdotal evidence for the benefit of deceptive treatment over non-deceptive (BF₁₀ = 2.46) and no benefit of OLP over control (BF₁₀ = 0.63).

CONCLUSIONS

No positive evidence for OLP effects in nausea were observed. However, a deceptive effect in VR was observed. These findings raise questions regarding the efficacy of open-label intervention in nausea.

Erythrocyte membrane affinity chromatography, solid-phase extraction and UPLC-QTOF-MS/MS to screen active ingredients of Buyang Huanwu decoction

Buyang Huanwu decoction (BHD) is a well-known traditional Chinese medicine that has long been used to treat ischemic brain damage which is associated with hemorheology. To screen active ingredients in BHD responsible for reducing blood viscosity by reducing red blood cell (RBC) lesions to treat ischemic stroke, a method involving RBC membrane binding and solid-phase extraction (SPE) was developed in this study. The components of BHD interacting with RBC were analyzed by mass spectrometry and four compounds, calycosin, paeoniflorin, 6-hydroxy behenol-3,6-di-O-glucoside and calycosin-7-O-β-d-glucoside, showed binding affinity to RBCs. An erythrocyte activity assay revealed that the identified ingredients promoted the activities of Na+-K+-ATPase, sialic acid and superoxide dismutase and reduced the content of cholesterol on the RBC membrane, suggesting a mechanism underlying their anti-erythrocyte aggregation activity. Based on these results, the RBC membrane binding assay combined with SPE and mass spectrometry is a novel and effective approach for screening potentially anti-erythrocyte lesion constituents in traditional Chinese medicines.

Abstract CT055: Microdose induced oxaliplatin-DNA adducts as a predictive biomarker of response in colorectal cancer

Background

Combination 5-FU and oxaliplatin (FOLFOX) is standard therapy for colorectal cancer (CRC) in neoadjuvant, adjuvant, and metastatic settings. However, oxaliplatin neuropathy is the main dose-limiting toxicity that often necessitates dose reduction or discontinuation before progression. Prediction of oxaliplatin sensitivity in tumor cells would be valuable for dose optimization to maximize anti-tumorigenic effect and limit sensory neuropathy. Oxaliplatin functions via the formation of covalent drug-DNA adducts which ultimately inhibit cell replication and promote apoptosis. Detection of these drug-DNA adducts could serve as a biomarker of oxaliplatin efficacy. We therefore hypothesized that drug-DNA adduct levels induced by sub-therapeutic "diagnostic microdoses" are proportional to those induced by therapeutic doses and are predictive of tumor responses.

Methods

The feasibility of this predictive diagnostic microdosing approach was assessed in CRC cell culture and a pilot clinical trial of six CRC patients. Four CRC cell lines were cultured with therapeutically relevant (100 µM) or diagnostic microdose (1 µM) concentrations of [14C]oxaliplatin. The C-14 label enabled quantification of oxaliplatin-DNA adduct levels with accelerator mass spectrometry, an ultrasensitive isotope analysis technique. Adduct formation was correlated with oxaliplatin cytotoxicity as measured by the MTT viability assay. In a pilot clinical trial (NCT02569723), six CRC patients received an intravenous diagnostic microdose containing [14C]oxaliplatin prior to treatment and a second [14C]oxaliplatin dose during FOLFOX chemotherapy. Adduct levels from peripheral blood mononuclear cells (PBMC), used as surrogates for tumor cells, were correlated to mean tumor volume change of evaluable target lesions.

Results

Drug-DNA adduct levels were linearly proportional between microdoses and therapeutically relevant concentrations in cell culture (R2 = 0.91, p &lt; 0.0001) and patient samples (R2 = 0.63, p &lt; 0.0001). Plasma pharmacokinetics of microdoses were consistent with those of therapeutic dosing. No microdose-associated toxicity was observed in this patient population. PBMC adduct levels significantly correlated with tumor shrinkage (microdose: R2 = 0.82, p = 0.033; therapeutic dose: R2=0.65, p = 0.099).

Conclusion

Diagnostic microdosing with oxaliplatin is feasible and is predictive of oxaliplatin sensitivity in CRC patients.

Citation Format: Justin Chen, May Cho, Maike Zimmermann, Thomas Semrad, Chun-Yi Wu, Aiming Yu, Chong-Xian Pan, Paul T. Henderson, Edward J. Kim. Microdose induced oxaliplatin-DNA adducts as a predictive biomarker of response in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT055.

The relationship between self-reported sensory impairments and psychosocial health in older adults: a 4-year follow-up study using the English Longitudinal Study of Ageing

OBJECTIVES

To explore cross-sectional and longitudinal relationships between self-reported hearing and vision impairments and self-rated health, quality of life (QoL) and depressive symptoms at 4-year follow-up.

STUDY DESIGN

The study involved cross-sectional and longitudinal analyses with 4-year follow-up using data from the English Longitudinal Study of Ageing.

METHODS

Community-dwelling adults (n = 3931) aged ≥50 years from the English Longitudinal Study of Ageing participated in this study. Self-reported hearing and vision were defined as good or poor. Self-rated health was treated as a dichotomous variable (good and poor health). QoL was based on the 19-item Critical Appraisal Skills Programme and treated as a continuous variable (score 0-57). Depressive symptoms were assessed using the eight-item Center for Epidemiologic Studies Depression Scale (CES-D8) and defined as CES-D≥3. Relationships between sensory impairments and self-rated health and depressive symptoms were analysed using logistic regression. Linear regression was used to assess the relationships between sensory impairments and QoL.

RESULTS

In cross-sectional analyses, both self-reported hearing and vision impairment were positively associated with all outcomes assessed. In longitudinal analyses, self-reported poor hearing and vision were associated with increased risks of poor self-rated health (hearing: odds ratio [OR] 1.65, 95% confidence interval [CI] 1.32, 2.05; vision: OR 1.57, 95% CI 1.16, 2.12) and depressive symptoms (hearing: OR 1.35, 95% CI 1.07, 1.71; vision: OR 1.44, 95% CI 1.09, 1.90) after adjustment for sociodemographic and lifestyle factors, chronic illness, mobility limitations and cognition. Poor hearing and poor vision were not associated with reduced QoL after adjustment for covariates.

CONCLUSIONS

The findings stress the importance of identifying and addressing sensory impairments in older adults to improve their health and well-being.

Local Hemodynamic Conditions Associated with Focal Changes in the Intracranial Aneurysm Wall

BACKGROUND AND PURPOSE

Aneurysm hemodynamics has been associated with wall histology and inflammation. We investigated associations between local hemodynamics and focal wall changes visible intraoperatively.

MATERIALS AND METHODS

Computational fluid dynamics models were constructed from 3D images of 65 aneurysms treated surgically. Aneurysm regions with different visual appearances were identified in intraoperative videos: 1) "atherosclerotic" (yellow), 2) "hyperplastic" (white), 3) "thin" (red), 4) rupture site, and 5) "normal" (similar to parent artery), They were marked on 3D reconstructions. Regional hemodynamics was characterized by the following: wall shear stress, oscillatory shear index, relative residence time, wall shear stress gradient and divergence, gradient oscillatory number, and dynamic pressure; these were compared using the Mann-Whitney test.

RESULTS

Hyperplastic regions had lower average wall shear stress (P = .005) and pressure (P = .009) than normal regions. Flow conditions in atherosclerotic and hyperplastic regions were similar but had higher average relative residence time (P = .03) and oscillatory shear index (P = .04) than thin regions. Hyperplastic regions also had a higher average gradient oscillatory number (P = .002) than thin regions. Thin regions had lower average relative residence time (P < .001), oscillatory shear index (P = .006), and gradient oscillatory number (P < .001) than normal regions, and higher average wall shear stress (P = .006) and pressure (P = .009) than hyperplastic regions. Thin regions tended to be aligned with the flow stream, while atherosclerotic and hyperplastic regions tended to be aligned with recirculation zones.

CONCLUSIONS

Local hemodynamics is associated with visible focal wall changes. Slow swirling flow with low and oscillatory wall shear stress was associated with atherosclerotic and hyperplastic changes. High flow conditions prevalent in regions near the flow impingement site characterized by higher and less oscillatory wall shear stress were associated with local "thinning" of the wall.

Case study on the effects of fit and material of sports gloves on hand performance

Active and sports fashion in the high-end market focuses on fit, superior comfort and functional performance for various end-uses. However, the engineering design of sports gloves in relation to hand anthropometry measurements remains unclear. In this study, two types of ready-to-wear sport gloves, namely, war-gaming glove and hiking glove were purchased from the market. The glove dimensions, fabrication properties and the effect of glove fit on hand and finger dexterity were investigated. Thirty female individuals (20-29 years old) participated a series of hand performance tests and subjective perception rating assessments towards the gloves. Results indicated that the active range of motion of fingers, finger tactile sensitivity, gripping strength and ability to handle pegs and marbles decreased with the use of gloves compared with bare hands. The perceptions of comfort and ease of hand motions decreased with the increased of wear time. The glove fit in terms of finger length dimensions was significantly correlated with hand grip force. The glove fit in hand, wrist and finger circumference dimensions had significant impact on the ability to handle small objects. It is suggested that hand length, hand circumference, finger circumference and the ratio of finger length to palm length should be considered in the design and development of gloves to improve hand performance and comfort.

Pulmonary hemorrhage in neonatal respiratory distress syndrome: Radiographic evolution, course, complications and long-term clinical outcomes

BACKGROUND

Pulmonary hemorrhage (PH) is occasionally seen in premature infants after surfactant treatment for respiratory distress syndrome (RDS). These infants receive frequent chest radiographs (CXR) during and after hospitalization enabling long-term radiographic-clinical correlation.

OBJECTIVE

To chart the natural evolution of CXR findings of PH in RDS and correlate radiographic patterns to supplemental oxygen requirement.

MATERIALS AND METHODS

Retrospective review of clinical notes for gestational age (GA), birth weight (BW), intraventricular hemorrhage (IVH) and oxygen requirement were performed. CXRs were reviewed at 4 time-points; during PH, 28 days postnatal age, 36 weeks and at farthest available clinical follow-up.

RESULTS

18 infants born (2003-2016), GA (24-30 weeks); BW (482-1590 grams) were included. Mean onset of PH was 1.94 (0-5) days. 9/18 (50%) had IVH. 3 died during PH; all had IVH. During PH, CXR showed whiteout 9/18 (50%); patchy opacities 5/18 (27%); diffuse haziness 1/18 (6%) and no change 3/18 (17%). At 28 days postnatal age, CXR showed fine-interstitial (FI) markings 14/15 (93%) and whiteout 1/15 (7%). At 36 weeks,12/14 (85%) had FI and 2/14 (15%) developed cystic-interstitial changes. At farthest follow-up, FI 3/13 (23%); coarse-interstitial 4/13 (30%); peri-bronchial cuffing 5/13 (38%); normal 1/13 (9%) and the majority had hyperinflation 9/13 (69%). At discharge, 9/14 (64%) required home-oxygen and 5/14 (36%) were on room-air. At farthest follow-up, 6/14 (42%) required home-oxygen and 8/14 (58%) were on room-air.

CONCLUSION

Premature infants that survive PH may later develop chronic lung disease of prematurity with an evolving interstitial pattern on CXR that clears overtime as they outgrow the need for supplemental oxygen.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Recurrent attacks of acute hepatic porphyria: major role of the chronic inflammatory response in the liver

BACKGROUND

Acute intermittent porphyria (AIP) is an inherited disorder of haem metabolism characterized by life-threatening acute neurovisceral attacks due to the induction of hepatic δ-aminolevulinic acid synthase 1 (ALAS1) associated with hydroxymethylbilane synthase (HMBS) deficiency. So far, the treatment of choice is hemin which represses ALAS1. The main issue in the medical care of AIP patients is the occurrence of debilitating recurrent attacks.

OBJECTIVE

The aim of this study was to determine whether chronic hemin administration contributes to the recurrence of acute attacks.

METHODS

A follow-up study was conducted between 1974 and 2015 and included 602 French AIP patients, of whom 46 had recurrent AIP. Moreover, we studied the hepatic transcriptome, serum proteome, liver macrophage polarization and oxidative and inflammatory profiles of Hmbs^-/- mice chronically treated by hemin and extended the investigations to five explanted livers from recurrent AIP patients.

RESULTS

The introduction of hemin into the pharmacopeia has coincided with a 4.4-fold increase in the prevalence of chronic patients. Moreover, we showed that both in animal model and in human liver, frequent hemin infusions generate a chronic inflammatory hepatic disease which induces HO1 remotely to hemin treatment and maintains a high ALAS1 level responsible for recurrence.

CONCLUSION

Altogether, this study has important impacts on AIP care underlying that hemin needs to be restricted to severe neurovisceral crisis and suggests that alternative treatment targeting the liver such as ALAS1 and HO1 inhibitors, and anti-inflammatory therapies should be considered in patients with recurrent AIP.

Abstract P6-12-17: Identifying risk factors and effect modifiers of trastuzumab-induced cardiotoxicity among multi-ethnic women with early-stage HER2-positive breast cancer

Introduction: Trastuzumab-based adjuvant therapy is the current standard of care for early-stage HER2-positive breast cancer. However, trastuzumab has also been associated with an increased risk of cardiotoxicity, especially when given following an anthracycline. Trastuzumab-induced cardiotoxicity (TIC) can present as asymptomatic left ventricular ejection fraction (LVEF) decline or symptomatic heart failure. Our objective was to identify predictors of TIC among multi-ethnic patients with early-stage HER2-positive breast cancer. Unlike prior observational studies, our study included a high representation of racial/ethnic minorities, who are at increased risk of cardiovascular disease (CVD) compared to non-Hispanic whites.

Methods: We conducted a retrospective cohort study in patients with stage I-III HER2-positive breast cancer, diagnosed from 2007 to 2015 at Columbia University Medical Center (CUMC) in New York, NY, who had received adjuvant trastuzumab therapy. Participants had at least two serial echocardiograms or MUGA scans to assess TIC, which was defined as at least a 10% decrease in LVEF from baseline or LVEF &lt;50%. LVEF recovery was defined as at least a 10% increase in LVEF or LVEF &gt;50%. We conducted descriptive statistics and univariate and multivariable logistic regression to estimate the associations between socio-demographic factors, breast tumor and treatment characteristics, and CVD risk factors (including smoking status, body mass index [BMI], hypertension, diabetes, hyperlipidemia, coronary artery disease) and TIC. Interactions between race/ethnicity and CVD risk factors were assessed using a logistic regression model.

Results: In our study population (N=279), the mean age was 52.7 years (standard deviation, 12.1) with 36.6% non-Hispanic white, 18.3% non-Hispanic black, 34.8% Hispanic, and 10.4% Asian patients. There were no differences by race/ethnicity in tumor and treatment characteristics (over half had prior anthracyclines), but racial/ethnic minorities had higher BMI and were more likely to have hypertension compared to non-Hispanic whites. About a third of patients developed TIC and 14.7% had an LVEF decline to &lt;50%, of which 15 (16.1%) experienced LVEF recovery. In multivariable analysis, prior anthracycline use and hypertension were significantly associated with increased odds of developing TIC (odds ratio [OR]: 2.25, 95% confidence interval [CI]: 1.25, 4.06; OR: 2.13, 95% CI: 1.15, 3.93, respectively). There was a significant interaction (p=0.027) between race/ethnicity and hypertension on odds of developing TIC with hypertensive non-Hispanic white patients experiencing 6.05 (95% CI: 2.19, 16.75) times the odds of developing TIC compared to non-hypertensive non-Hispanic whites.

Discussion: We observed a higher incidence of TIC and lower incidence of LVEF recovery compared to previous clinical trials. Given patient selection for clinical trials, our results may be more representative of clinical practice settings. We found a particularly high risk among non-Hispanic white patients with hypertension. Patients with hypertension may require closer blood pressure monitoring and treatment with anti-hypertensives in order to reduce risk of developing cardiotoxicity.

Citation Format: Yuan A, Topkara V, Hershman DL, Kalinsky K, Accordino MK, Trivedi MS, Yu A, Genkinger JM, Crew KD. Identifying risk factors and effect modifiers of trastuzumab-induced cardiotoxicity among multi-ethnic women with early-stage HER2-positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-17.

Abstract PD2-15: Effect of mammography screening frequency on false-positive biopsy rates and detection of local recurrence among breast cancer survivors

Introduction: Current guidelines are for yearly mammograms in women with early-stage breast cancer. Among breast cancer survivors treated with lumpectomy, semi-annual compared to annual screening mammography of the ipsilateral breast has been associated with early detection of local recurrence. However, a potential harm of more frequent screening is false-positive breast biopsies that may lead to negative psychosocial effects and increased costs. Our objective was to investigate how frequency of screening mammograms affects rates of false-positive biopsy results and local recurrences among breast cancer survivors.

Methods: We conducted a retrospective cohort study at Columbia University Medical Center (CUMC) in New York, NY of women diagnosed with stage 0-III breast cancer between 2007 and 2015, who were treated with lumpectomy and had at least 2 screening mammograms at CUMC within the first 3 years after diagnosis. Demographic and clinical information, including tumor characteristics and breast cancer treatments, were collected from the electronic health record. Frequency of mammography screening was defined as the median interval between 2 consecutive mammograms (every 6 months vs. yearly). Both false-positive biopsy results and local recurrences were identified by review of breast pathology reports. A false-positive biopsy was defined as a diagnostic breast biopsy without evidence of invasive or non-invasive cancer. Descriptive statistics and logistic regression models were conducted to examine relationships between covariates and either false-positive biopsy or local recurrence.

Results: In our sample (n=1257), the median age at breast cancer diagnosis was 60 years (range, 24-93), including 47% non-Hispanic white, 14% non-Hispanic black, 31% Hispanic, and 7% Asian. Nearly 80% of women had semi-annual screening mammography of the ipsilateral breast during the first 3 years after breast cancer diagnosis. In univariate analysis, higher body mass index, more advanced stage disease, higher tumor grade, and receipt of chemotherapy, hormonal therapy, and radiation therapy were associated with more frequent screening. Comparing women who screened every 6 months vs. yearly, there was no difference in local recurrence rates (4.1% vs. 3.9%), including screen-detected or invasive/non-invasive breast cancer recurrences. In multivariable analysis, women who screened every 6 months compared to yearly had a greater than 2-fold increased risk of having a false-positive biopsy (OR: 2.40; 95% CI: 1.50-3.86). Also, younger age at diagnosis, higher tumor grade, and receipt of chemotherapy were associated with higher false positive rates, adjusting for covariates.

Conclusions: We observed that women with early-stage breast cancer treated with lumpectomy who underwent semi-annual vs. annual screening mammography had more false-positive breast biopsies, but no difference in local recurrence rates. To date, there is no evidence that more frequent screening in breast cancer patients is associated with improved survival. Future studies are needed to determine optimal screening strategies for breast cancer survivors, including frequency of screening and use of supplemental breast imaging with ultrasound, MRI, or tomosynthesis.

Citation Format: Yuan S, Manley HJ, Ha R, Yu A, Genkinger JM, Crew KD. Effect of mammography screening frequency on false-positive biopsy rates and detection of local recurrence among breast cancer survivors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-15.

MicroRNA-1291 effects on pancreatic cancer (PC) cells sensitivity to arginine deprivation and chemotherapy through modulation of ASS1 and GLUT1

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Background: Cancer cells are reprogrammed to become addicted to a continuous supply of nutritional glucose and semi-essential amino acids like arginine, to drive synthesis of critical macromolecules for proliferation, tumorigenesis and metastasis. This dependence on nutritional supply makes cancer cells potentially vulnerable to deprivation by agents like pegylated arginine deiminase (ADI-PEG) which converts arginine back to citrulline. However, this vulnerability depends on limited ability of cancer cells to make arginine. PC cells that express high levels of argininosuccinate synthase 1 (ASS1), the rate limiting enzyme in cellular arginine synthesis, appear to be resistant to ADI-PEG. Our recent study showed that miR-1291 modulates factors in nutrient metabolism including ASS1 and GLUT1. We have developed a novel method to bioengineer miR-1291 agents for treatment. The aim of the current study was to evaluate if miR-1291 could enhance efficacy of metabolism-targeting drugs in PC. Methods: Cell proliferation was measured by CellTiter-Glo assay. Mature miR-1291 levels were determined by stem-loop reverse transcription real-time PCR assay. GLUT1 and ASS1 protein levels in miR-1291-treated pancreatic cancer cell lines were assessed by Western blot. Glucose uptake in AsPC-1 and PANC-1 cell lines was determined with a fluorescent probe, 2-NBDG. Results: A bioengineered pre-miR-1291 was processed to high levels of mature miR-1291 in PC cells. L3.3 and PANC-1 cells endogenously express high levels of ASS-1 and are resistant to arginine deprivation by ADI-PEG. ASS1 protein was downregulated by miR-1291 in L3.3 and PANC-1 cells and sensitized pancreatic cancer cells to ADI-PEG. In addition, miR-1291 significantly downregulated the protein levels of GLUT1 in AsPC-1 cells, leading to a lower glucose uptake capacity and a greater sensitivity to chemotherapy. Conclusions: Our results demonstrate that miR-1291 sensitizes PC cells to arginine deprivation and chemotherapy through downregulation of ASS1 and GLUT1. These results provide new insight into the mechanistic actions of miR-1291 and provide a new strategy for treatment of pancreatic cancer.

Bioengineered microRNA-1291 effects on pancreatic cancer cell proliferation and xenograft tumor growth

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Background: MicroRNAs (miR) have proved to be vital regulators in the control of tumor progression. Our recent studies have revealed miR-1291 is downregulated in patient pancreatic cancer (PC) specimens and re-introduction of miR-1291 suppresses tumorigenesis of PC cells. We have developed a novel ncRNA bioengineering technology to produce a miR-1291 prodrug. In this study, we aimed to assess the effectiveness of this miR-1291 prodrug as a monotherapy, as well as in combination with chemotherapy, for treatment of PC. Methods: Sensitivity of PC cells to miR-1291 prodrug alone, gemcitabine plus nab-paclitaxel (Gem-nP) alone, and their combination was evaluated by CellTiter-Glo assay. Mature miR-1291 and ARID3B mRNA levels were determined by quantitative real-time PCR (q-PCR) assay. A luciferase reporter gene assay was used to validate interaction between miR-1291 and ARID3B 3’UTR. Target protein expression was examined by Western blot and immunofluorescence analyses. PANC-1 and PC patient-derived xenograft (PDX) mouse models were established and used to assess anti-tumor effects of miR-1291 monotherapy and combination therapy with Gem-nP. Results: Cytotoxicity assays showed that miR-1291 prodrug enhanced the sensitivity of PANC-1 and AsPC-1 cells to Gem-nP. Luciferase assays confirmed ARID3B as a target for miR-1291 as predicted by computational analysis. qPCR analysis demonstrated that miR-1291 prodrug was readily processed to mature miR-1291 and subsequently upregulated ARID3B mRNA levels. miR-1291 prodrug also elevated the protein levels of ARID3B. Co-administration of miR-1291 prodrug and Gem-nP increased caspase-3/7 and γH2AX levels in PC cells, compared to miR-1291 or Gem-nP treatment alone. In addition, systemic administration of in vivo-jet PEI formulated miR-1291 prodrug suppressed tumor growth in both a PANC-1 xenograft model and three PDX models, and largely enhanced the efficacy of Gem-nP. All treatments were well tolerated in mice in vivo. Conclusions: Our bioengineered miR-1291 prodrug has therapeutic potential as a monotherapy but also can act as a sensitizing agent to chemotherapy. This novel treatment approach should be further explored for PC.

Novel therapeutic strategy to inhibit growth of pancreatic cancer organoids using a rational combination of drugs to induce mitotic arrest and apoptosis

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Background: The ability of cancer cells to suppress apoptosis is critical for carcinogenesis. The Bcl-2-family of regulator proteins, including the anti-apoptotic members Bcl-2, Bcl-xL and Mcl-1, contributes to a complex network in control of apoptosis. BH3-mimetics (e.g. ABT-263) can inhibit anti-apoptotic Bcl-2 proteins and therefore have been developed as potential cancer therapeutics. Aurora Kinase A (AKA) is over-expressed in pancreatic cancer (PC) and is expressed to regulate G2-M transition during mitosis, making it an attractive target for PC. In this study we hypothesized that a combination of mitotic arrest using an AKA inhibitor (e.g. MLN8237) would sensitize PC to induction of apoptosis by a BH3-mimetic. Methods: Pancreatic cell lines (AsPC-1, PANC-1, MIA PaCa-2, HPAF-II) and patient-derived pancreatic cancer organoids (PDO) were treated with a BH3-mimetic (ABT-263) alone, an AKA inhibitor (MLN8237) alone, or the combination in comparison to untreated controls. Cell viability was measured using the CellTiter-Fluor (Promega) assay. Apoptosis was evaluated by Western blot (WB) for cleaved PARP, caspase 3 or caspase 7, and flow cytometry. Nude mice were implanted with pancreatic cancer cells to generate PC xenografts which were then treated with the same 4 treatment groups as in the in vitro studies. Results: ABT-263 combined with MLN8237 showed greater potency than either single drug alone, demonstrating synergy in inhibiting the growth of PC cells and PDOs. Combined treatment with MLN8237 and ABT-263 in PDOs suppressed organoid formation and proliferation by inducing apoptosis. Mechanistically, MLN8237 enhanced the activity of ABT-263 through reduction of Bcl-xL and Mcl-1 in pancreatic cancer cell lines and PDOs. The combination therapy also showed greater suppression of the growth of xenograft tumors, as compared with control treatments with single drug alone or vehicle. Conclusions: The combination of ABT-263 and MLN8237 appears to synergistically induce apoptosis via reduction of Bcl-2 family proteins in PC and should be further explored.