Cell State and Cell Type: Deconvoluting Circulating Tumor Cell Populations in Liquid Biopsies by Multi-Omics

Bi-directional crosstalk between the tumor and the tumor microenvironment (TME) has been shown to increase the rate of tumor evolution and to play a key role in neoplastic progression, therapeutic resistance, and a patient's overall survival. Here, we set out to use a comprehensive liquid-biopsy analysis to study cancer and specific TME cells in circulation and their association with disease status. Cytokeratin+, CD45- circulating rare cells (CRCs) from nine breast and four prostate cancer patients were characterized through morphometrics, single-cell copy number analysis, and targeted multiplexed proteomics to delineate cancer cell lineage from other rare cells originating in the TME. We show that we can detect epithelial circulating tumor cells (EPI.CTC), CTCs undergoing epithelial-to-mesenchymal transition (EMT.CTC) and circulating endothelial cells (CECs) using a universal rare event detection platform (HDSCA). Longitudinal analysis of an index patient finds that CTCs are present at the time of disease progression, while CECs are predominately present at the time of stable disease. In a small cohort of prostate and breast cancer patients, we find high inter-patient and temporal intra-patient variability in the expression of tissue specific markers such as ER, HER2, AR, PSA and PSMA and EpCAM. Our study stresses the importance of the multi-omic characterization of circulating rare cells in patients with breast and prostate carcinomas, specifically highlighting overlapping and cell type defining proteo-genomic characteristics of CTCs and CECs.

Disease characterization in liquid biopsy from HER2-mutated, non-amplified metastatic breast cancer patients treated with neratinib

Metastatic breast cancer (mBC) patients have a high risk of progression and face poor prognosis overall, with about one third (34%) surviving five years or more. In rare instances (2-4% of cases) patients with mBC have ERBB2 (HER2) activating mutations but are ERBB2 non-amplified. Neratinib is a potent, irreversible inhibitor that binds HER2 and inhibits downstream signaling. We used the previously validated high-definition single cell assay (HDSCA) workflow to investigate the clinical significance of the liquid biopsy in ERBB2 mutant, non-amplified, post-menopausal mBC patients starting neratinib and fulvestrant combination therapy. Characterization with a comprehensive liquid biopsy methodology (HDSCA) included genomic analysis of both the cell-free DNA (cfDNA) and single circulating tumor cells (CTCs) to monitor tumor evolution and identify potential mutational variants unique to the patient's clinical response. A limited series of five sequentially enrolled patients presented here were from the MutHER ( https://www.clinicaltrials.gov , NCT01670877) or SUMMIT ( https://www.clinicaltrials.gov , NCT01953926) trials. Patients had an average of 5.4 lines of therapy before enrollment, variable hormone receptor status, and ERBB2 mutations at diagnosis and during treatment. CTC enumeration alone was not sufficient to predict clinical response. Treatment pressure was shown to lead to an observable change in CTC morphology and genomic instability (GI), suggesting these parameters may inform prognosis. Single cell copy number alteration (CNA) analysis indicated that the persistence or development of a clonal population of CTCs during treatment was associated with a worse response. Hierarchical clustering analysis of the single cells across all patients and timepoints identified distinct aberrant regions shared among patients, comprised of 26 genes that are similarly affected and may be related to drug resistance. Additionally, the genomic analysis of the cfDNA, identified new mutations in ERBB2, PIK3CA, and TP53 that arose likely due to treatment pressure in a patient with poor response, further providing insights on the dynamics of the cancer genome over the course of therapy. The data presented in this small cohort study demonstrates the feasibility of real-time molecular profiling of the cellular and acellular fractions of the liquid biopsy using the HDSCA methodology. Additional studies are necessary to determine the potential use of morphometric and genomic analysis as a prognostic tool to advance personalized oncology.

A Randomized Trial of Fulvestrant, Everolimus, and Anastrozole for the Front-line Treatment of Patients with Advanced Hormone Receptor-positive Breast Cancer, SWOG S1222

PURPOSE

Metastatic hormone receptor (HR)-positive, HER2-negative breast cancer is an important cause of cancer mortality. Endocrine treatment with or without additional targeted therapies has been the mainstay of treatment. This trial was designed to evaluate the combination of fulvestrant plus everolimus versus fulvestrant, everolimus, and anastrozole compared with fulvestrant alone in the first-line treatment of advanced HR-positive, HER2-negative breast cancer.

PATIENTS AND METHODS

This randomized placebo-controlled trial included postmenopausal women with HR-positive, HER2-negative advanced breast cancer who had received no prior systemic therapy for metastatic disease. Participants were randomized to one of three treatment arms and the primary outcome was progression-free survival (PFS), comparing combinations of fulvestrant and everolimus with or without anastrozole with fulvestrant alone. Circulating tumor cells (CTC), as measured with two different methods, and circulating tumor DNA (ctDNA) were evaluated serially prior to treatment and the beginning of the second cycle of therapy.

RESULTS

Due in part to changes in clinical practice, the study was closed after accruing only 37 participants. There was no evidence that everolimus-containing combination treatment improved PFS or overall survival relative to fulvestrant alone. When modeled continuously, an association was observed of baseline CTC and ctDNA with poorer survival.

CONCLUSIONS

Although power of the study was limited, the findings were unable to support the routine use of everolimus combination endocrine therapy in the first-line treatment of advanced hormone-sensitive breast cancer. Prognostic impact of baseline ctDNA and copy-number variations in CTC was demonstrated.

Treatment response and tumor evolution: lessons from an extended series of multianalyte liquid biopsies in a metastatic breast cancer patient

Currently, clinical characterization of metastatic breast cancer is based on tissue samples taken at time of diagnosis. However, tissue biopsies are invasive and tumors are continuously evolving, which indicates the need for minimally invasive longitudinal assessment of the tumor. Blood-based liquid biopsies provide minimal invasive means for serial sampling over the course of treatment and the opportunity to adjust therapies based on molecular markers. Here, we aim to identify cellular changes that occur in breast cancer over the lifespan of an affected patient through single-cell proteomic and genomic analysis of longitudinally sampled solid and liquid biopsies. Three solid and 17 liquid biopsies from peripheral blood of an ER⁺/HER2⁻ metastatic breast cancer patient collected over 4 years and eight treatment regimens were analyzed for morphology, protein expression, copy-number alterations, and single-nucleotide variations. Analysis of 563 single morphometrically similar circulating tumor cells (CTCs) and 13 cell-free DNA (cfDNA) samples along with biopsies of the primary and metastatic tumor revealed progressive genomic evolution away from the primary tumor profiles, along with changes in ER expression and the appearance of resistance mutations. Both the abundance and the genomic alterations of CTCs and cfDNA were highly correlated and consistent with genomic alterations in the tissue samples. We demonstrate that genomic evolution and acquisition of drug resistance can be detected in real time and at single-cell resolution through liquid biopsy analytes and highlight the utility of liquid biopsies to guide treatment decisions.

Preanalytical Variables for the Genomic Assessment of the Cellular and Acellular Fractions of the Liquid Biopsy in a Cohort of Breast Cancer Patients

Liquid biopsy allows assessment of multiple analytes, providing temporal information with potential for improving understanding of cancer evolution and clinical management of patients. Although liquid biopsies are intensely investigated for prediction and response monitoring, preanalytic variables are of primary concern for clinical implementation, including categories of collection method and sample storage. Herein, an integrated high-density single-cell assay workflow for morphometric and genomic analysis of the liquid biopsy is used to characterize the effects of preanalytical variation and reproducibility of data from a breast cancer cohort. Following prior work quantifying performance of commonly used blood collection tubes, this study completes the analysis of four time points to assay (24, 48, 72, and 96 hours), demonstrating precision up to 48 hours after collection for assay sensitivity, highly reproducible rare cell enumeration, morphometric characterization, and high efficiency and capacity for single-cell genomic analysis. For the cell-free analysis, both freezing and use of fresh plasma produced similar quality and quantity of cell-free DNA for sequencing. The genomic analysis (copy number variation and single-nucleotide variation) described herein is broadly applicable to liquid biopsy platforms capable of isolating cell-free and cell-based DNA. Morphometric parameters and genomic signatures of individual circulating tumor cells were evaluated in relation to patient clinical response, providing preliminary evidence of clinical validity as a potential biomarker aiding clinical diagnostics or monitoring progression.

Abstract 2877: Genomic cfDNA analysis of aqueous humor in retinoblastoma (RB) predicts eye salvage

Background: Retinoblastoma (RB) was one of the first tumors to demonstrate a genetic basis to the development of cancer. However, unlike other cancers, RB cannot be directly biopsied due to the high risk of extraocular cancer spread. Therefore, unless the eye is enucleated, tumor tissue is not evaluated for genetic and genomic changes and these alterations are not used to inform diagnosis or prognosis for this disease. However, in a 2017 publication in JAMA Ophthalmology, we demonstrated that tumor-derived cell-free DNA can be extracted from the aqueous humor (AH) of RB eyes, which is safe to remove even with active intraocular disease. The purpose of this current study (Berry JL, Xu L et al. Molec Canc Res 2018) was to identify somatic chromosomal copy number alterations (SCNA) in tumor-derived cell-free DNA in the AH of RB eyes and to correlate with clinical outcomes particularly tumor relapse requiring enucleation.

Methods: AH was extracted via paracentesis from RB eyes during intravitreal injection of chemotherapy or post enucleation. Shallow whole genome sequencing was performed to assess for cell-free tumor DNA fractions and highly-recurrent SCNAs in RB which include gain of 1q, 2p, 6p and loss of 13q and 16q. Globe salvage was recorded.

Results: 26 patients were included; 3 patients had both eyes included for 29 eyes. From these, 63 samples of AH were analyzed; 5 post-enucleations and 58 during intravitreal chemotherapy injection. Ultimately 13 eyes required enucleation and 16 eyes were salvaged. Follow-up ranged from 8-43 months (median 17 months).

The presence of any detectable SCNA was 92% in enucleated eyes versus 38% in salvaged eyes (p=0.006). 6p gain was the most common SCNA found in 77% of enucleated eyes versus 25% of salvaged eyes (p=0.0092). 6p gain was associated with a ten-fold increased odds of enucleation (OR=10, 95% CI:1.8-55.6). The mean amplitude of 6p gain was 1.47 in enucleated eyes versus 1.07 in salvaged eyes (p=0.001). The probability of ocular survival was higher in eyes without detectable SCNAs in the AH (p=0.0028).

Serum testing was positive for a germline mutation in 17 eyes of 14 patients with the following incidence of RB SCNAs 1q (35%); 2p (18%); 6p (47%); 13q (18%) and 16q (35%) versus 12 eyes of 12 patients without germline disease with 1q (33%); 2p (8%); 6p (50%); 13q (17%) and 16q (33%) (p=0.71).

Conclusions: This is the first study to show that clinical outcomes correlate with highly-recurrent SCNAs in the AH from RB eyes. This study suggests that the AH can reliably serve as a surrogate to tumor biopsy and improves upon current clinical staging to predict tumor response to therapy and the ability to salvage the eye. Unlike previous studies that suggest a greater incidence of RB SCNAs in patients with non-germline disease, this was not seen in this evaluation which may be because all previous work was done on tumor from enucleated eyes instead of salvaged eyes.

Citation Format: Liya Xu, Jesse L. Berry, Irsan Kooi, A Linn Murphree, Rishvanth K. Prabakar, Mark W. Reid, Kevin Stachelek, Bao Han A. Le, Lisa Welter, Rima Jubran, Thomas C. Lee, Jonathan W. Kim, Peter Kuhn, David Cobrinik, James B. Hicks. Genomic cfDNA analysis of aqueous humor in retinoblastoma (RB) predicts eye salvage [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 2877.

A new anion exchange purification method for Cu stable isotopes in blood samples

The isotopic composition of iron, zinc, copper, and cadmium (δ⁵⁶Fe, δ⁶⁶Zn, δ⁶⁵Cu, and δ¹¹⁴Cd) are novel and promising tools to study the metabolism and homeostasis of trace metals in the human body. Serum δ⁶⁵Cu has been proposed as a potential tool for diagnosis of cancer in liquid biopsy, and other metals may have similar utility. However, accurate analysis of trace metal isotopes is challenging because of the difficulties in purifying the metals from biological samples. Here we developed a simple and rapid method for sequential purification of Cu, Fe, Zn, and Cd from a single blood plasma sample. By using a combination of 11 M acetic acid and 4 M HCl in the first steps of column chemistry on AG-MP1 resin, we dramatically improve the separation of Cu from matrix elements compared to previous methods which use concentrated HCl alone. Our new method achieves full recovery of Cu, Fe, Zn, and Cd to prevent column-induced isotope fractionation effects, and effectively separates analytes from the matrix in order to reduce polyatomic interferences during isotope analysis. Our methods were verified by the analysis of isotope standards, a whole blood reference material, and a preliminary sample set including five plasma samples from healthy individuals and five plasma samples from cancer patients. This new method simplifies preparation of blood samples for metal isotope analysis, accelerating multi-isotope approaches to medical studies and contributing to our understanding of the cycling of Fe, Zn, Cu, and Cd in the human body. Graphical abstract ᅟ.

Genomic cfDNA Analysis of Aqueous Humor in Retinoblastoma Predicts Eye Salvage: The Surrogate Tumor Biopsy for Retinoblastoma

Tumor-derived cell-free DNA (cfDNA) has biomarker potential; therefore, this study aimed to identify cfDNA in the aqueous humor (AH) of retinoblastoma eyes and correlate somatic chromosomal copy-number alterations (SCNA) with clinical outcomes, specifically eye salvage. AH was extracted via paracentesis during intravitreal injection of chemotherapy or enucleation. Shallow whole-genome sequencing was performed using isolated cfDNA to assess for highly recurrent SCNAs in retinoblastoma including gain of 1q, 2p, 6p, loss of 13q, 16q, and focal MYCN amplification. Sixty-three clinical specimens of AH from 29 eyes of 26 patients were evaluated; 13 eyes were enucleated and 16 were salvaged (e.g., saved). The presence of detectable SCNAs was 92% in enucleated eyes versus 38% in salvaged eyes (P = 0.006). Gain of chromosome 6p was the most common SCNA found in 77% of enucleated eyes, compared with 25% of salvaged eyes (P = 0.0092), and associated with a 10-fold increased odds of enucleation (OR, 10; 95% CI, 1.8-55.6). The median amplitude of 6p gain was 1.47 in enucleated versus 1.07 in salvaged eyes (P = 0.001). The presence of AH SCNAs was correlated retrospectively with eye salvage. The probability of ocular salvage was higher in eyes without detectable SCNAs in the AH (P = 0.0028), specifically 6p gain. This is the first study to correlate clinical outcomes with SCNAs in the AH from retinoblastoma eyes, as such these findings indicate that 6p gain in the aqueous humor is a potential prognostic biomarker for poor clinical response to therapy.Implications: The correlation of clinical outcomes and SCNAs in the AH identified in the current study requires prospective studies to validate these finding before SCNAs, like 6p gain, can be used to predict clinical outcomes at diagnosis. Mol Cancer Res; 16(11); 1701-12. ©2018 AACR.

Abstract 2963: Characterization of disease evolution in sequential sampled metastatic breast cancer using liquid biopsy

Background: It is established that tumors evolve over time due to treatment pressure or physiological constraints. Tissue biopsies give a one-time window into the characteristics of a primary tumor or metastatic nodule. Their main pitfall is procedure risk, pain, and cost, which is why they are rarely repeated. Liquid biopsies, however, are performed with minimal discomfort and risk, providing an easier way to monitor disease. Circulating tumor cells (CTCs) and cell-free DNA (cfDNA) have proven to be of high prognostic and diagnostic value. Here we evaluate 17 longitudinal blood draws collected from a metastatic breast cancer patient over 4 years and assess the power of single-cell analysis relative to analysis of tissue biopsies and cfDNA.

Methods: CTCs were enumerated using the high-definition single-cell assay (HD-SCA) and single CTCs were isolated by micromanipulation. DNA of single cells underwent whole genome amplification and Illumina library construction for copy number variation (CNV) analysis. Genomic DNA from microdissected FFPE tissue and cfDNA extracted from plasma were converted into Illumina sequencing libraries for CNV analysis. CA27.29 levels were reported by the clinic.

Results: Levels of CTCs and circulating tumor DNA (ctDNA) fractions were positively correlated with CA27.29. CNV analysis of single tumor cells at time of enrollment revealed 3 morphometrically indistinguishable clones that persisted during the 4-year follow-up. Genomic analysis of primary breast tissue and bone metastasis detected at time of diagnosis matched CNV data of the evolutionary first clone, while a later liver metastasis was comprised solely of clone 2. Remarkably, CTCs in clone 2 were identified years before discovery of the liver metastasis. To date, we have not detected a metastatic site harboring clone 3. We found that CNV profiles from cfDNA represented the aggregate of CTC clones.

Conclusion: Longitudinal blood sampling enabled tracing of tumor evolution robustly and less invasively than solid tumor biopsies. Metastasis associated clones were identified years before measureable disease, providing an opportunity for earlier interventions. While plasma-based assays detected the presence of tumor-derived DNA, the single-cell high-content resolution of the HD-SCA workflow was required to deconvolute 3 genomically distinct clones present in this patient. We propose that enumeration of CTCs and analysis of ctDNA could be used as additional clinical markers to monitor disease recurrence, adding valuable morphogenomic information about the primary tumor and metastatic sites.

Additionally, we are currently analyzing the results of single nucleotide variation analysis of single CTCs, cfDNA and FFPE tissue from this patient.

Citation Format: Lisa Welter, Liya Xu, Dillon McKinley, Sara Restrepo-Vassalli, Angel Dago, Mariam Rodriguez Lee, Anand Kolatkar, James Hicks, Jorge Nieva, Peter Kuhn. Characterization of disease evolution in sequential sampled metastatic breast cancer using liquid biopsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2963.

Abstract 1576: Clonal diversity revealed by morphoproteomic and copy number profiles of single prostate cancer cells at diagnosis

Tumor heterogeneity is prevalent in both treatment-naïve and end-stage metastatic castration-resistant prostate cancer (PCa), and may contribute to the broad range of clinical presentation, treatment response, and disease progression. To characterize molecular heterogeneity associated with de novo metastatic PCa, multiplatform single cell profiling was performed using High Definition Single Cell Analysis (HD-SCA). HD-SCA enabled morphoproteomic and morphogenomic profiling of single cells from touch preparations of tissue cores (prostate and bone marrow biopsies) as well as liquid samples (peripheral blood and bone marrow aspirate). Morphology, nuclear features, copy number alterations, and protein expression were analyzed. Tumor cells isolated from prostate tissue touch preparation (PTTP) and bone marrow touch preparation (BMTP) as well as metastatic tumor cells (MTCs) isolated from bone marrow aspirate were characterized by morphology and cytokeratin expression. Although peripheral blood was examined, circulating tumor cells were not definitively observed. Targeted proteomics of PTTP, BMTP, and MTCs revealed cell lineage and luminal prostate epithelial differentiation associated with PCa, including co-expression of EpCAM, PSA, and PSMA. Androgen receptor expression was highest in MTCs. Hallmark PCa copy number alterations, including PTEN and ETV6 deletions and NCOA2 amplification, were observed in cells within the primary tumor and bone marrow biopsy samples. Genomic landscape of MTCs revealed to be a mix of both primary and bone metastatic tissue. This multiplatform analysis of single cells reveals several clonal origins of metastatic PCa in a newly diagnosed, untreated patient with polymetastatic disease. This case demonstrates that real-time molecular profiling of cells collected through prostate and bone marrow biopsies is feasible and has the potential to elucidate the origin and evolution of metastatic tumor cells. Altogether, biological and genomic data obtained through longitudinal biopsies can be used to reveal the properties of PCa and can impact clinical management.

Citation Format: Paymaneh D. Malihi, Michael Morikado, Lisa Welter, Anders Carlsson, Carmen Ruiz Velasco, Anand Kolatkar, Mariam Rodriguez-Lee, James Hicks, Peter Kuhn, Sandy T. Liu, Eric T. Miller, Radu M. Cadaneanu, Beatrice S. Knudsen, Michael S. Lewis, Isla P. Garraway. Clonal diversity revealed by morphoproteomic and copy number profiles of single prostate cancer cells at diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1576.

Abstract 4591: Integration of genomic analysis and assessment of pre-analytic variables in the HD-SCA workflow: A technical validation study

The liquid biopsy allows assessment of multiple biological analytes over time to provide dynamic temporal information with the potential for improving clinical management and guiding treatment decisions. While the promise of liquid biopsies for prediction and response monitoring are intensely investigated, the pre-analytic variables are of primary concern for its implementation in diagnostic clinical medicine, including such categories as collection method, shipping conditions, and sample storage. Here we utilize an integrated high-definition single cell analysis (HD-SCA) workflow for genomic analysis of rare cells and cfDNA from the liquid biopsy to characterize the effects of pre-analytical variation and reproducibility of data analysis from the same cohort of patients. The results presented here confirm consistent rare cell enumeration and morphometric characterization between 24h and 48h time to assay (TTA), with a high efficiency and capacity for both copy number variation (CNV) and single nucleotide variation (SNV) analysis at the single cell level. Additionally, the freezing process neither diminishes or increases the DNA quantity, nor does it affect the DNA quality for CNV or SNV analysis. The integration of genomic information is imperative to reveal essential disease-implicated mutational profiles, but effective molecular diagnostic tests require reproducible coverage over a broad dynamic range. The performance of the HD-SCA platform quantified here may be utilized as a guide for implementation into patient care and/or research biorepository processes.

Citation Format: Stephanie Nicole Shishido, Mariam Rodriguez_Lee, Anand Kolatkar, Liya Xu, Sara Restrepo-Vassalli, Lisa Welter, Anders Carlsson, Emily Greenspan, Shelley Hwang, Kathryn Waitman, Jorge Nieva, Kelley Bethel, James Hicks, Peter Kuhn. Integration of genomic analysis and assessment of pre-analytic variables in the HD-SCA workflow: A technical validation study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4591.

Clonal diversity revealed by morphoproteomic and copy number profiles of single prostate cancer cells at diagnosis

Tumor heterogeneity is prevalent in both treatment-naïve and end-stage metastatic castration-resistant prostate cancer (PCa), and may contribute to the broad range of clinical presentation, treatment response, and disease progression. To characterize molecular heterogeneity associated with de novo metastatic PCa, multiplatform single cell profiling was performed using high definition single cell analysis (HD-SCA). HD-SCA enabled morphoproteomic and morphogenomic profiling of single cells from touch preparations of tissue cores (prostate and bone marrow biopsies) as well as liquid samples (peripheral blood and bone marrow aspirate). Morphology, nuclear features, copy number alterations, and protein expression were analyzed. Tumor cells isolated from prostate tissue touch preparation (PTTP) and bone marrow touch preparation (BMTP) as well as metastatic tumor cells (MTCs) isolated from bone marrow aspirate were characterized by morphology and cytokeratin expression. Although peripheral blood was examined, circulating tumor cells were not definitively observed. Targeted proteomics of PTTP, BMTP, and MTCs revealed cell lineage and luminal prostate epithelial differentiation associated with PCa, including co-expression of EpCAM, PSA, and PSMA. Androgen receptor expression was highest in MTCs. Hallmark PCa copy number alterations, including PTEN and ETV6 deletions and NCOA2 amplification, were observed in cells within the primary tumor and bone marrow biopsy samples. Genomic landscape of MTCs revealed to be a mix of both primary and bone metastatic tissue. This multiplatform analysis of single cells reveals several clonal origins of metastatic PCa in a newly diagnosed, untreated patient with polymetastatic disease. This case demonstrates that real-time molecular profiling of cells collected through prostate and bone marrow biopsies is feasible and has the potential to elucidate the origin and evolution of metastatic tumor cells. Altogether, biological and genomic data obtained through longitudinal biopsies can be used to reveal the properties of PCa and can impact clinical management.

Serum phosphatidylcholine is lower among breast cancer patients on systemic chemotherapy

e12571

Background: Chemotherapy-induced cognitive impairment, also known as 'chemobrain', is widely recognized as a frequent adverse effect of chemotherapy, occurs in 10-40% of all cancer patients. Those cancer survivors suffer from poor concentration, memory, abstract reasoning, and motor dysfunction. The etiology is unclear. In our study, we analyzed the metabolite panels in breast cancer patients with vs. without chemotherapy trying to identify metabolic mediators of neurologic injury. Methods: We obtained plasma sample from 18 breast cancer patients, 9 received chemotherapy prior to blood drawn; while the other 9 had no systemic therapy. The plasma samples were sent for mass spectroscopy. Each metabolites level was normalized, and the two groups were compared in each metabolite by t-test with statistical significance corrected for multiple comparisons using the Holm-Sidak method. Results: We identified 57 amines and their metabolites; 106 carbohydrate related metabolites, and 228 lipid molecules. While amino acid, and carbohydrate did not show significant difference, phosphatidylcholine level in the chemotherapy treated group demonstrated lower level in the patients received chemotherapy. Among 59 phosphatidylcholine identified, 6 variants were significantly lower in the chemo group compare with non chemo group. Additionally the sum of all phosphatidylcholine variants was diminished in the chemotherapy treated patients compared with untreated controls. No other differences in plasma lipid levels were identified. Conclusions: Phosphatidylcholine is a major component of cell membranes and lipid rafts which are critical elements in nerve conduction. It also plays a role as the precursor to the neurotransmitter acetylcholine. The finding that phosphatidylcholine is significantly different between chemotherapy treated vs. the no chemotherapy group raises the possibility that lipid metabolism contributes to chemotherapy-induced cognitive impairment and further experiments are planned to explore this hypothesis.

Circulating tumor cells and genomic profiling of patients with ERBB2 mutant, HER2 non-amplified metastatic breast cancer treated with neratinib

e12554

Background: ERBB2 mutations in the absence of gene amplification are rare, with an incidence of 2-4%. Neratinib is a HER2/EGFR tyrosine kinase inhibitor being evaluated for use in ERBB2 mutated breast cancer. Neratinib has been found to have clinical activity on heavily pre-treated ERBB2 mutant breast cancer patients. We are evaluating the response and genomic profiles of 3 postmenopausal patients with metastatic ERBB2 mutant/non-amplified breast cancer receiving neratinib and fulvestrant NCT01953926, NCT01670877. Methods: Samples were collected at different points during treatment and CTCs were identified. Other representative cells were tracked but not classified as CTCs. CD45-CK+ cells with cytoplasmic and/or nuclear apoptosis were defined as CTC-Apoptotic. CD45- cells expressing little to no CK but otherwise meeting morphological criteria for CTCs are CTC-LowCK. CD45-CK+ cells with small nuclear size are CTC-SmallCK. Single CTCs will be analyzed using whole genome copy number variation to determine chromosomal alterations. Results: The patients had an average of 4.7 lines of therapy for metastatic disease before neratinib. Two had stable disease and one had progression. The patient who progressed had a rise in the number of CTCs from 37 to 52 cells/ml and drop in apoptotic cells from 5 to 0 cells/ml. Conclusions: The high CTC count of the patient who progressed may suggest more aggressive disease. The drop in the apoptotic cell count may correlate with a failure to respond to therapy. Samples have been sent for copy number variation profiling. The goal is to identify any genomic amplifications or deletions associated with clinical response and progression after targeted therapy. We hope to demonstrate the timeframe of tumor evolution in response to therapy and provide a framework for the use of fluid biopsies to monitor disease progression. [Table: see text]

Tissue-infiltrating neutrophils constitute the major in vivo source of angiogenesis-inducing MMP-9 in the tumor microenvironment

According to established notion, one of the major angiogenesis-inducing factors, pro-matrix metalloproteinase-9 (proMMP-9), is supplied to the tumor microenvironment by tumor-associated macrophages (TAMs). Accumulated evidence, however, indicates that tumor-associated neutrophils (TANs) are also critically important for proMMP-9 delivery, especially at early stages of tumor development. To clarify how much angiogenic proMMP-9 is actually contributed by TAMs and TANs, we quantitatively evaluated TAMs and TANs from different tumor types, including human xenografts and syngeneic murine tumors grown in wild-type and Mmp9-knockout mice. Whereas host MMP-9 competence was required for full angiogenic potential of both normal and tumor-associated leukocytes, direct comparisons of neutrophils versus macrophages and TANs versus TAMs demonstrated that macrophages and TAMs secrete 40- to 50-fold less proMMP-9 than the same numbers of neutrophils or TANs. Correspondingly, the levels of MMP-9–mediated in vivo angiogenesis induced by neutrophils and TANs substantially exceeded those induced by macrophages and TAMs. MMP-9–delivering TANs were also required for development of metastasis-supporting intratumoral vasculature, characterized by ≥ 11-μm size lumens and partial coverage with stabilizing pericytes. Importantly, MMP-9–producing TAMs exhibit M2-skewed phenotype but do not express tissue inhibitor of metalloproteinases-1 (TIMP-1), a novel characteristic allowing them to secrete TIMP-1–free, neutrophil-like MMP-9 zymogen unencumbered by its natural inhibitor. Together, our findings support the notion whereby TANs, capable of immediate release of their pre-stored cargo, are the major contributors of highly angiogenic MMP-9, whereas tumor-influxing precursors of macrophages require time to differentiate, polarize into M2-skewed TAMs, shut down their TIMP-1 expression, and only then, initiate relatively low-level production of TIMP-free MMP-9 zymogen.