Abstract 4264: Lysosome inhibition sensitizes pancreatic cancer to replication stress by aspartate depletion

Objective: Functional lysosomes are required for autophagy and macropinocytosis, the intra- and extracellular scavenging pathways cancer cells engage for nutrient acquisition. Pancreatic ductal adenocarcinoma (PDAC) tumors exhibit high basal lysosomal activity, and genetic or pharmacologic inhibition of lysosome function suppresses PDAC cell proliferation and tumor growth. However, the codependencies induced by lysosomal inhibition in PDAC have not been systematically explored. We hypothesized that identification and targeting the lysosomal inhibition-induced codependencies in PDAC cells would be an effective therapeutic strategy.

Methods: A comprehensive pharmacological inhibition screen of the protein kinome was performed to identified lysosomal inhibition-induced codependency. LC-MS/MS-MRM and LC-MS methods were used to examine nucleotide biosynthesis and amino acid levels, respectively, to understand the mechanism of the identified codependency. A broad panel of PDAC cell lines, primary PDAC culture models, two- and three-dimentional culture models, a PDAC cell/stroma spheroid coculture model, and xenograft and syngeneic PDAC animal models were used to evaluate the treatment efficacy.

Results: We found that replication stress response (RSR) inhibitors were synthetically lethal with chloroquine (CQ) and other lysosomal inhibitors in PDAC cells. CQ treatment reduced de novo nucleotide biosynthesis and induced replication stress. We found that CQ treatment caused mitochondrial dysfunction and depletion of aspartate, an essential precursor for de novo nucleotide synthesis, as an underlying mechanism. Supplementation with aspartate in PDAC cell culture and overexpression of the aspartate transporter SLC1A3 in xenograft PDAC tumors partially rescued the phenotypes induced by CQ. The synergy of CQ and the RSR inhibitor VE-822 was comprehensively validated in a broad panel of PDAC cell lines and primary PDAC cultures, in two- and three-dimentional PDAC cultures, in heterotypic spheroid culture with cancer-associated fibroblasts, and in in vivo xenograft and syngeneic PDAC mouse models.

Conclusion: We discovered a codependency on functional lysosomes and an intact RSR pathway in PDAC, and developed the combination of CQ and RSR inhibitors as a translational therapeutic approach for PDAC.

Citation Format: Shili Xu, Irmina A. Elliott, Amanda M. Dann, Stephanie S. Kim, Evan R. Abe, Woosuk Kim, Soumya Poddar, Alexandra Moore, Lei Zhou, Jennifer L. Williams, Joseph R. Capri, Razmik Ghukasyan, Cynthia Matsumura, D. Andrew Tucker, Wesley R. Armstrong, Anthony E. Cabebe, Nanping Wu, Luyi Li, Thuc M. Le, Caius G. Radu, Timothy R. Donahue. Lysosome inhibition sensitizes pancreatic cancer to replication stress by aspartate depletion [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 4264.

High-profile studies frequently and repetitively present data on the same patients, particularly in immunotherapy studies

Background

Traditionally, study results have been presented as abstracts at major scientific meetings at the conclusion of the analysis. Recently, presentations of studies in progress and updates to previously presented data have been allowed at major meetings. The frequency and implications of a single study being presented multiple times, particularly in high profile oral presentations, have not been fully evaluated.

Methods

To identify studies presented multiple times, abstracts from an approximately 1-year period from international conferences for three major societies devoted largely or in part to lung cancer research were assessed (ASCO 2015, World Lung 2015, ESMO 2015 and ASCO 2016). Abstracts were selected in a two-step process. The first step was for subject matter based on keywords: non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC) or immunotherapy. Searches differed slightly based on individual website functionality, with ASCO searched by track, World Lung by session and ESMO by individual abstract. In a second step, abstracts for which clinical outcome data was presented from a trial with an identifiable National Clinical Trial (NCT) number were selected. Immunotherapy abstracts that did not include the treatment of NSCLC or SCLC were excluded in the second step.

Results

A total of 851 abstracts were identified that were related to NSCLC, SCLC or immunotherapy. Of these, 357 referred to a clinical trial. In total, 110 of 357 (31%) described clinical trials that were presented multiple times (mean 2.75, range 2-7), and in 44 (12%), this occurred at the same conference. Of the 113 oral presentations, 75 (66%) presented data from clinical trials, either as posters or oral presentations. Further, 35 of the 113 (31%) oral presentations presented data from clinical trials that had generated other oral presentations. Of the 16 unique clinical trials leading to multiple oral presentations, a variety of issues led to the duplicate presentations, including different cohorts of the same trial, biomarker analysis, analysis by one study variable, or simply updated data. Moreover, 107 of the 357 (30%) clinical trial abstracts pertained to immunotherapy, including 4 of the 16 clinical trials generating multiple oral presentations. Of the 16 trials generating multiple oral presentations, 11 (69%) lead to a full-length publication by July 2017, including all of those pertaining to immunotherapy.

Conclusions

There is a pattern of multiple presentations of clinical trials, particularly in oral presentations, at major meetings. In most cases, data presented in subsequent oral presentations related entirely to patients whose data was presented in the previous oral presentation.

Treatment-Related Adverse Events Predict Improved Clinical Outcome in NSCLC Patients on KEYNOTE-001 at a Single Center

We retrospectively analyzed non-small cell lung cancer (NSCLC) patients from a single center treated with pembrolizumab on the KEYNOTE-001 trial and evaluated the association between treatment-related adverse events (trAEs) and clinical outcomes. Investigators reported AEs on trial and graded them according to Common Terminology Criteria for Adverse Events v4.0, labeling them as unlikely, possibly, or probably treatment-related. AEs labeled as possibly/probably related were considered trAEs for this analysis. The relationship between the incidence of a trAE and clinical outcomes was evaluated. Ninety-seven NSCLC patients treated on KEYNOTE-001 at the University of California, Los Angeles were evaluated. Ten percent (85/826) of AEs were trAEs, occurring in 40% (39/97) of patients. The most frequent trAEs were rash (21% patients), fatigue (6% patients), and hypothyroidism (6% patients). The 39 patients that experienced a trAE had increased objective response rate (ORR, 38.5%), progression-free survival (PFS: median, 248 days), and overall survival (OS: median, 493 days), compared with the 58 patients that did not (ORR: 8.9%, PFS: median 60 days, OS: median 144.5 days). The observed association between trAEs and improved clinical outcome persisted when using Cox proportional hazards regression models to assess the confounding effect of covariates and mitigate guarantee-time bias. The association also remained when data were substratified by grade, degree of association, and treatment-related select AE designation. This single-center analysis revealed that trAEs predicted for improved clinical outcome with pembrolizumab, and when controlling for guarantee-time bias and plausible confounders, this association remained. This observed relationship adds to our understanding of anti-PD-1 therapy and could aid clinicians in identifying patients most likely to benefit from therapy. Cancer Immunol Res; 6(3); 288-94. ©2018 AACR.

Non-small cell lung cancer clinical trials requiring biopsies with biomarker-specific results for enrollment provide unique challenges

BACKGROUND

Clinical trials in lung cancer increasingly require patients to provide fresh tumor tissue as a prerequisite to enrollment. The effects of this requirement on enrollment rates, enrollment durations, and patient selection have not been fully elucidated.

METHODS

The authors retrospectively reviewed data generated by patients who consented to 1 or more interventional lung cancer clinical trials at the University of California-Los Angeles Jonsson Comprehensive Cancer Center between January 2013 and December 2014. Trials were considered to require a biopsy when enrollment was conditional on the procurement of tissue without intervening therapy between procurement and enrollment.

RESULTS

In total, 311 patients underwent 368 screening incidents for 1 or more of 19 trials. Trials that required a new biopsy had a longer median screening duration (34 vs 14 days) than trials that did not require a biopsy (P < .001). Trials that required a biopsy had a greater screen failure rate (49.1% vs 26.5%; P < .001), which was largely driven by patients who did not undergo the required biopsy or lacked the required biomarker. Worsening performance status led to the majority of screen failures (56.5%) among biomarker-eligible patients.

CONCLUSIONS

Although the scientific benefits of obtaining a new biopsy and requiring specific results for trial enrollment are clear, these requirements lead to a lengthening of the screening period, which, in some patients, is associated with clinical decline before enrollment. Implications for the interpretation of data from studies of this design should be explored. Cancer 2017;123:4800-7. © 2017 American Cancer Society.

Abstract B98: Serial evaluation of PD-L1 expression on circulating tumor cells (CTCs)

BACKGROUND: Metastatic non-small cell lung cancer (NSCLC) tumors have adopted methods to evade immune detection and/or clearance. This can occur via overexpression of programmed cell death ligand 1 (PD-L1). Response rate, progression free survival and overall survival with PD-1 inhibitors are greater in tumors with high tumor PD-L1 expression (Garon et al, NEJM 2015, Paz-Ares et al, ASCO 2015). There has been interest in using PD-L1 tumor expression as a treatment selection criterion. Currently available methods of screening involve invasive tumor biopsy followed by histological grading of PD-L1 levels. Biopsies allow sampling from limited sections of the tumor, which may miss heterogeneity. CTC PD-L1 levels could aid in screening patients, and could supplement tissue PD-L1 biopsy results by evaluating a representative sampling from multiple tumor sites which shed cells into the blood. Additionally, following PD-L1 levels on CTCs serially over time may potentially yield information about modulation of tumor PD-L1 expression in the presence of PD-1 or PD-L1 antibodies or other anti-cancer agents.

METHODS: We have developed a microfluidic device for rapid, size-based capture of CTCs from blood called Vortex HT chip. The Vortex HT chip utilizes inertial microfluidic flows to isolate CTCs with capture efficiency up to 40% and high purity (&gt;80%). We used the Vortex HT device to capture CTCs from NSCLC patients undergoing PD-1 immunotherapies, both prior to initiating treatment and during treatment. PD-L1 expression was evaluated on CTCs using immunofluorescence staining. CTC number and PD-L1 expression were correlated with treatment response as evaluated by immune related response criteria (irRC) on serial CT scans. We also measured cell size and intensity levels of cytokeratin (CK) and CD45 on the collected cells. We developed a semi-automated algorithm to quantify fluorescence for these different markers on DAPI positive cells collected from each patient sample. We compared these results to PD-L1 expression on the initial tumor biopsy sections, as assayed by immunohistochemical staining and expression quantified with HALO software (Indica Labs).

RESULTS: In patients receiving anti-PD-1 antibodies, PD-L1 expression on CTCs could be quantified and compared to a pre-treatment tumor biopsy, as well as to radiographic treatment response. Evaluating patient CTC count and PD-L1 expression at baseline and over time may lead to simple and non-invasive methods to predict response to immunotherapies. As an assay amenable to repeat testing, CTC PD-L1 levels may also be an important pharmacodynamics marker to assess the synergistic potential of combination immunotherapies. Further work is continuing to better understand this predictive biomarker. At the meeting, we will present correlation data between CTC and tumor biopsy PD-L1 expression assays and between the CTC assay and radiographic response to treatment.

Citation Format: Jonathan W. Goldman, Manjima Dhar, James Che, Edward B. Garon, Siwen Hu-Lieskovan, Melissa Matsumoto, Brian R. Wolf, James M. Carroll, Matthew J. Crabtree, D. Andrew Tucker, Jennifer Strunck, Elodie Sollier, Rajan Kulkarni, Dino Di Carlo. Serial evaluation of PD-L1 expression on circulating tumor cells (CTCs). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B98.

Effect of stimulus intensity level on auditory middle latency response brain maps in human adults

Auditory middle latency response (AMLR) brain maps were obtained in 11 young adults with normal hearing. AMLR waveforms were elicited with monaural clicks presented at three stimulus intensity levels (50, 70, and 90 dB nHL). Recordings were made for right and left ear stimulus presentations. All recordings were obtained in an eyes open/awake status for each subject. Peak-to-peak amplitudes and absolute latencies of the AMLR Pa and Pb waveforms were measured at the Cz electrode site. Pa and Pb waveforms were present 100 percent of the time in response to the 90 dB nHL presentation. The prevalence of Pa and Pb to the 70 dB nHL presentation varied from 86 to 95 percent. The prevalence of Pa and Pb to the 50 dB nHL stimulus never reached 100 percent, ranging in prevalence from 77 to 68 percent. No significant ear effect was seen for amplitude or latency measures of Pa or Pb. AMLR brain maps of the voltage field distributions of Pa and Pb waveforms showed different topographic features. Scalp topography of the Pa waveform was altered by a reduction in stimulus intensity level. At 90 dB nHL, the Pa brain map showed a large positivity midline over the frontal and central scalp areas. At lower stimulus intensity levels, frontal positivity was reduced, and scalp negativity over occipital regions was increased. Pb scalp topography was also altered by a reduction in stimulus intensity level. Varying the stimulus intensity significantly altered Pa and Pb distributions of amplitude and latency measures. Pa and Pb distributions were skewed regardless of stimulus intensity.

Chest pain. How serious is it?

The very thought of chest pain often brings terror to patients and health care providers. Chest pain typically invokes a "worst case" scenario of massive myocardial infarction (MI) resulting from cardiovascular disease (CD) and requiring immediate medical attention. However, chest pain is a common complaint suffered by most people at some time in their lives. People complaining of chest pain may be young, middle-aged, or elderly, and they may or may not be under a health care provider's care. Chest pain may be a symptom of a variety of disorders other than CD. Therefore it is helpful to differentiate quickly between the types of chest pain to determine whether immediate assistance is necessary.

Health care providers riding the information superhighway

Telehealth is the practice of providing health care services to people who are distant from the provider by the use of telecommunications and information technology. These services include client care, consultations, education, and research. Concerns include financial cost, reimbursement, liability, licensure, and confidentiality. Research to document treatment cost-effectiveness and efficacy is ongoing.

Strategies for getting students on the information superhighway

Many nurses indicate that they lack the formal education needed to use resources such as the Internet and computer technology related to healthcare. The results of a survey at a baccalaureate school of nursing revealed that although nearly 100% of those surveyed used computers, very few effectively used available Internet resources. In response, the authors implemented strategies to make available Internet resources "user-friendly" for communication and information gathering.

Effects of age, signal level, and signal rate on the auditory middle latency response

The effects of age, signal rate, and signal level on the maturing auditory middle latency response (AMLR) were evaluated in 50 normal-hearing subjects ranging in age from 2 days to 35 years. Ipsilateral and contralateral AMLR waveforms were recorded in newborns (n = 10), children (n = 10), preteens (n = 10), teens (n = 10), and adults (n = 10). The AMLR Pa waveform was obtained in 70 to 100 percent of all subjects. The variables of age, signal level, and site of recording significantly affected Pa peak amplitude and absolute latency. However, stimulus rate did not significantly affect the response.

The student process for success: the nursing care plan

Written nursing care plans are designed to focus students on individualizing nursing care, which promotes critical thinking and decision making. In actual practice, emphasis has shifted from care plans toward standards of care. The authors discuss a concise, simplified care plan format that includes both standards of care and collaborative problems. This plan of care is compatible with healthcare regulations and requires less time to produce and evaluate.

Basal forebrain neurons and memory: a biochemical, histological, and behavioral study of differential vulnerability to ibotenate and quisqualate

The differential vulnerability of basal forebrain cells to ibotenate (IBO) or quisqualate (QUIS) was investigated in rats. IBO was also coinjected with cystine (CYS) or zinc (Zn). Cortical choline acetyltransferase (ChAT) and glutamate decarboxylase (GAD) activity, neurotensin receptors, and high-affinity choline uptake sites were quantified in conjunction with radioimmunoassays for neurotensin, substance P, and somatostatin; immunocytochemistry for neurotensin-, somatostatin-, Leu-enkephalin-, and ChAT-positive cells; and in situ hybridization histochemistry of somatostatin, substance P, and enkephalin mRNAs. Compared with the performance of controls, continuous alternation performance in a T maze of IBO+Zn or IBO+CYS rats was better than that of IBO rats, whereas the performance of QUIS rats was unimpaired. Of those neurotransmitter systems examined, only ChAT-immunoreactive cells were vulnerable to IBO or QUIS. However, cholinergic cell loss did not correlate with impaired performance.

Working with the patient designated "Do not resuscitate"--how the nurse copes

In conclusion, this study describes coping mechanisms used by the nurse when caring for DNA patients. These coping mechanisms are of two types: caring for the patient and caring for the family. Coping mechanisms used when caring for the patient include spending minimal time, avoidance, depersonalization, being present at death, and grooming the patient. Coping mechanisms used when caring for the family include personalization of care and giving information to the family. An understanding of coping strategies used by nurses in caring for DNA patients may assist staff in recognizing and dealing with feelings associated with this stressful phenomenon.

Basal forebrain neurons and memory: A biochemical, histological, and behavioral study of differential vulnerability to ibotenate and quisqualate

The differential vulnerability of basal forebrain cells to ibotenate (IBO) or quisqualate (QUIS) was investigated in rats. IBO was also coinjected with cystine (CYS) or zinc (Zn). Cortical choline acetyltransferase (ChAT) and glutamate decarboxylase (GAD) activity, neurotensin receptors, and high-affinity choline uptake sites were quantified in conjunction with radioimmunoassays for neurotensin, substance P, and somatostatin; immunocytochemistry for neurotensin-, somatostatin-, Leu-enkephalin-, and ChAT-positive cells; and in situ hybridization histochemistry of somatostatin, substance P, and enkephalin mRNAs. Compared with the performance of controls, continuous alternation performance in a T maze of IBO+Zn or IBO+CYS rats was better than that of IBO rats, whereas the performance of QUIS rats was unimpaired. Of those neurotransmitter systems examined, only ChAT-immunoreactive cells were vulnerable to IBO or QUIS. However, cholinergic cell loss did not correlate with impaired performance.

Sensory evoked responses in the intensive care unit

Within the past decade, sensory evoked responses (SERs) have been increasingly applied in acute brain injury. In this paper, we present the rationale for this clinical application and discuss principles and practices that are important for successful measurement and interpretation of sensory evoked responses (SERs) in the intensive care unit. Fundamentals of pathophysiology and management of acute brain injury are reviewed. Varied uses of SERs in brain-injured children and adults are illustrated with case reports. Our experience suggests that SER measurement in acute brain injury is clinically challenging yet rewarding. We conclude that, with sufficient preparation, the audiologist can assume an important position on the intensive care unit team in acute management of brain injury.