Predicting Radiation Esophagitis using 18F-FAPI-04 PET/CT in Patients with LA-ESCC Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This prospective study examined whether 18F-FAPI-04 PET/CT can predict the development and severity of radiation esophagitis (RE) in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC) treated with concurrent chemoradiotherapy.

MATERIALS/METHODS

From June 2021 to March 2022, images were prospectively collected from LA-ESCC patients who underwent 18F-FAPI-04 PET/CT examinations before and during radiotherapy. The development of RE was evaluated weekly according to Radiation Therapy Oncology Group criterion. The target-to-background ratio in blood (TBRblood) was analyzed at each time point and correlated with the onset and severity of RE. Factors that predicted RE were identified by multivariate logistic analyses.

RESULTS

Thirty patients (median age, 66.5 years [interquartile range: 56¨C71 years]; 22 men) were evaluated. Significantly higher TBRblood (during radiotherapy, mean: 3.06 vs 7.11, P = 0.003) and change in TBRblood compared with pre-RT (ΔTBRblood, mean: 0.67 vs 4.81, P = 0.002) were observed in patients with RE than patients without RE. Those with grade 3 RE had a significantly higher TBRblood (during radiotherapy, mean: 4.55 vs 9.66, P = 0.003) and ΔTBRblood (mean: 2.16 vs 7.50, P = 0.003) compared with those with RE

CONCLUSION

The ΔTBRblood on 18F-FAPI-04 PET/CT may be effective at identifying patients at risk for the development of RE, especially grade 3 RE.

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Isotopic Control of the Boron-Vacancy Spin Defect in Hexagonal Boron Nitride

We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V_{B}^{-}) centers hosted in isotopically engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with ^{15}N yields a simplified and well-resolved hyperfine structure of V_{B}^{-} centers, while purification with ^{10}B leads to narrower ESR linewidths. These results establish isotopically purified h^{10}B^{15}N crystals as the optimal host material for future use of V_{B}^{-} spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically induced polarization of ^{15}N nuclei in h^{10}B^{15}N, whose mechanism relies on electron-nuclear spin mixing in the V_{B}^{-} ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.

Chinese patients with type 2 diabetes mellitus and nonalcoholic fatty liver disease have lower serum osteocalcin levels compared to individuals with type 2 diabetes mellitus and no liver disease: a single-center cross-sectional study

PURPOSE

Osteocalcin may benefit nonalcoholic fatty liver disease (NAFLD). The present study aimed to explore the levels of serum osteocalcin in NAFLD in patients with type 2 diabetes mellitus (T2DM).

METHODS

In total, 1026 inpatients diagnosed with T2DM were enrolled in the study. NAFLD was defined according to the working definition of the revised guidelines for the management of NAFLD published by the Chinese Liver Disease Association, and confirmed by abdominal ultrasonography.

RESULTS

The current study found a NAFLD prevalence of 54% in the T2DM population. Subjects with NAFLD had lower concentrations of osteocalcin (8.28-13.99 ng/mL vs. 8.80-16.25 ng/mL, P = 0.001) but similar vitamin D, parathyroid hormone, beta-C-terminal telopeptide of type I collagen and procollagen type 1 N-peptide levels. Osteocalcin levels (OR: 0.956; 95% CI 0.926-0.987) were significantly associated with NAFLD. When all significant clinical indicators were analyzed together, increased BMI (OR: 1.120; 95% CI 1.065-1.178), fasting C-peptide (OR: 1.270; 95% CI 1.089-1.481) and triglycerides (OR: 1.661; 95% CI 1.284-2.148) were associated with a greater risk of NAFLD, while older age (OR: 0.967; 95% CI 0.948-0.986) and high osteocalcin levels (OR: 0.935; 95% CI 0.902-0.969) were related with a decreased risk of NAFLD. For every additional unit of osteocalcin, the patients received 7% deduced odds of NAFLD.

CONCLUSION

Low osteocalcin levels were associated with an increased risk for NAFLD in patients with T2DM.

Phenotypic analysis of atopic dermatitis in children aged 1-12 months: elaboration of novel diagnostic criteria for infants in China and estimation of prevalence

BACKGROUND

Atopic dermatitis (AD) is the most common skin disorder in infancy. However, the diagnosis and definite significance of infantile AD remains a debated issue.

OBJECTIVE

To analyse the phenotypes of AD in infancy, to establish diagnostic criteria and to estimate the prevalence of this condition in China.

METHODS

This is a multicentric study, in which 12 locations were chosen from different metropolitan areas of China. Following careful and complete history-taking and skin examination, the definite diagnosis of AD was made and the severity based on the SCORAD index was determined by local experienced dermatologists. Based on the detailed phenotyping, the major and representative clinical features of infantile AD were selected to establish the diagnostic criteria and evaluate their diagnostic efficacy.

RESULTS

A total of 5967 infants were included in this study. The overall point prevalence of AD was 30.48%. The infantile AD developed as early as at the second month of life, and its incidence peaked in the third month of life at 40.81%. The proportion of mild, moderate and severe AD was 67.40%, 30.57% and 2.03%, respectively. The most commonly seen manifestations in the infantile AD were facial dermatitis (72.07%), xerosis (42.72%) and scalp dermatitis (27.93%). We established the novel diagnostic criteria of infants, which included: (i) onset after 2 weeks of birth; (ii) pruritus and/or irritability and sleeplessness comparable with lesions; and (iii) all two items above with one of the following items can reach a diagnosis of AD: (i) eczematous lesions distributed on cheeks and/or scalp and/or extensor limbs, and (ii) eczematous lesions on any other parts of body accompanied by xerosis.

CONCLUSIONS

In China, the prevalence of AD in infancy is 30.48% according to clinical diagnosis of dermatologists. The novel Chinese diagnostic criteria for AD in infants show a higher sensitivity and comparable specificity.

Bioinformatics Analysis on Molecular Mechanism of Green Tea Compound Epigallocatechin-3-Gallate Against Ovarian Cancer

Epigallocatechin‐3‐gallate (EGCG) is the most abundant and biologically active catechin in green tea, and it exerts multiple effects in humans through mechanisms that remain to be clarified. The present study used bioinformatics to identify possible mechanisms by which EGCG reduces the risk of ovarian cancer. Possible human protein targets of EGCG were identified in the PubChem database, possible human gene targets were identified in the National Center for Biotechnology Information database, and then both sets of targets were analyzed using Ingenuity Pathway Analysis (IPA). The results suggest that signaling proteins affected by EGCG in ovarian cancer, which include JUN, FADD, NFKB1, Bcl‐2, HIF1α, and MMP, are involved primarily in cell cycle, cellular assembly and organization, DNA replication, etc. These results identify several specific proteins and pathways that may be affected by EGCG in ovarian cancer, and they illustrate the power of integrative informatics and chemical fragment analysis for focusing mechanistic studies.

Evaluation of monocytic myeloid-derived suppressor cell (M-MDSC) frequency in patients with metastatic urothelial carcinoma (mUC)

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Background: M-MDSCs promote tumor progression through complex mechanisms, including immunosuppression and the production of mediators of angiogenesis and invasion. M-MDSCs are associated with poor outcomes in a number of malignancies. We conducted an exploratory analysis enumerating M-MDSCs (Lin-CD14+/HLA-DRlow/-) in the blood of pts with mUC and assessed for assay variability and correlation with clinical outcomes. Methods: Whole blood was collected at a single time point for each pt and stabilized in Cyto-Chex tubes. M-MDSC% was calculated by flow cytometric analysis of HLA-DR expression on CD14+ monocytes using an MSKCC developed computational algorithm-based approach (Kitano et al. 2014). Individual samples were run in quadruplicate at MSKCC. The mean MDSC% was used in subsequent analyses and the replicate standard deviation (SD) was considered a reflection of intra-assay variability. Clinical variables were collected and pts followed for OS, which was calculated from time of sample collection. Results: 21 pts with mUC who progressed after prior chemotherapy were included. At the time of collection, pts were on clinical trials with immune checkpoint blockade (n=13) or targeted therapy (n=1), receiving salvage chemotherapy (n=2), or awaiting treatment on clinical trials with immune checkpoint blockade (n=4) or targeted therapy (n=1). The median follow up from the time of collection in surviving patients (n=15) was 11.1 months (range: 10.5-11.5). Median OS was not reached. Mean (SD) M-MDSC% was 29.2 (4.92). The range of replicate SD was 0.13-1.05. M-MDSC% was not higher in pts with visceral mets (p=0.109). Pts with above median M-MDSC% had worse OS (p=0.01; 6 patients died during follow up, all with above median M-MDSC%). Conclusions: In a heterogeneous cohort of pts with mUC, the enumeration of M-MDSCs in stabilized whole blood was feasible and demonstrated marked inter-patient but not intra-assay variability. Pts with higher M-MDSC% values had worse OS. Additional characterization of M-MDSCs in larger cohorts and in pts receiving immunotherapy is ongoing and may have important prognostic and therapeutic implications in mUC.

Abstract P1-01-05: Prognostic values of circulating tumor cells (CTC) and cancer associated macrophage-like cells (CAML) enumerations in metastatic breast cancer: The role for innate immunity in the metastatic process

Background: The enumeration of circulating tumor cells (CTCs) using the CellSearch assay is a well-established prognostic and predictive marker for metastatic breast cancer (MBC). However, additional prognostic markers are lacking in patients with ≥ 5 CTCs in 7.5 ml of blood. Tumor-associated macrophages (TAMs) are derived from circulating monocytes or tissue-resident macrophages. TAMs have a controversial role in metastasis and anti-tumor processes. Recent studies showed that circulating cancer associated macrophage-like cells (CAMLs) are specialized phagocytic myeloid cells and found in the peripheral blood of patients with solid tumors including breast cancer, but not in healthy individuals. The presence of CAMLs may indicate the activation of innate immunity in cancer patients. The function and prognostic value of CAMLs in MBC is unknown. In the current study, we measured CTCs and CAMLs on the CellSearch™ platform and investigated their prognostic values in MBC.

Methods: Peripheral blood samples from 127 stages IV breast cancer patients were collected at baseline before starting first-line therapy. The detection and enumeration of CTCs and CAMLs in 7.5 ml blood sample were performed on the CellSearch™ system. CTCs were identified by cytokeratins (CK-8, 18, and 19) positive and CD45 negative staining. CAMLs were defined by positive staining for cytokeratins and CD45 (Adams et al, PNAS, 111(9):3514-9, 2014). CTCs and CAMLs enumeration in associations with the progression-free survival (PFS) and overall survival (OS) of patients were evaluated using Kaplan Meier curves and Cox proportional hazards modeling.

Results: The image review of CAMLs by using CellSearch analysis showed heterogeneous morphological phenotypes. CAMLs are large cells presenting enlarged nuclei or multiple individual nuclei, and both cytokeratin and CD45 positive with diffused cytoplasmic staining. Among the 127 MBC patients, 38 (29.9%) had elevated CTCs (≥5 CTCs), and 21 (16.5%) had at least one CAML detected. Patients with CAMLs had a significantly increased PFS (p=0.0374) and OS (p=0.0042), compared to patients without CAMLs at baseline. Patients with elevated baseline CTCs and CAMLs had worse PFS with a hazard ratio (HR) of 4.04 (95% CI 2.16 -7.56, P<0.0001), compared to patients with < 5 CTCs and without CAMLs. The combined analysis of baseline CTCs enumeration and CAMLs showed similar effect on patient OS. Compared to patients with < 5 CTCs and without CAMLs, patients with < 5 CTCs and with CAMLs, patients with ≥ 5 CTCs and without CAMLs, and patients with ≥ 5 CTCs and with CAMLs, had an increasing trend of death risk, with an HR of 2.66 (95% CI 0.53-13.21), 6.14 (2.10-17.92), and 9.13 (3.05-27.37), respectively (p for trend<0.0001).

Conclusion: Baseline enumerations of both individual CTCs and CAMLs are feasible and increase our ability to accurately predict outcome in MBC patients. Evaluation of CAMLs in peripheral blood may be a marker of innate immunity and provide additional prognostic values for MBC.

Citation Format: Mu Z, Wang C, Ye Z, Rossi G, Austin L, Yang H, Cristofanilli M. Prognostic values of circulating tumor cells (CTC) and cancer associated macrophage-like cells (CAML) enumerations in metastatic breast cancer: The role for innate immunity in the metastatic process [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-05.

[The study of atmospheric particulate matters and IFN-γDNA methylation in CD4⁺ T cells from patients with AR children]

Objective:To investigate the possible effects of meteorological and environmental factors on AR of children and IFN-γgene specific DNA methylation levels in CD4⁺ T cells of patients with AR. Method:Undergoing follow-up on 35 pediatric AR patients (6-12 years). Data on daily sulfur dioxide (SO₂), nitrogen dioxide (NO₂), particulate matter of diameter smaller than 10 micrometer (PM-10) and particulate matter of diameter smaller than 2.5 micrometer (PM2.5), the average of ozone (O₃) per 8 hours was available as average values derived from the data of 6 state controlled monitoring stations distributed across Pudong district, Shanghai. We quantified IFN-γ (interferon-γ) gene specific DNA methylation levels in CD4⁺ T cells from 35 patients with AR and 30 healthy controls. mRNA levels of IFN-γ gene were measured by real-time reverse transcriptase-PCR. Methods of personal exposure assessment of PM2.5 and PM10 were measured. Result:Compared with control, IFN-γ promoter region was hypermethylated in AR CD4⁺ T cells (P<0.05). Of all observed CpG sites in IFN-γ promoter region, there were significant differences in CpG⁻²⁹⁹, CpG⁺¹¹⁹, CpG⁺¹⁶⁸ (P=0.004, P=0.029, P=0.035). IFN-γ mRNA expression was significantly increase in CD4⁺ T cells (P<0.05). The level of IFN-γ mRNA expression was negatively correlated to mean level of methylation in IFN-γ promoter region. After adjusting, level of long exposure PM2.5 was positively correlated with level of methylation in IFN-γ promoter region. Conclusion:Level of methylation in IFN-γ promoter region may be affected by long exposure PM2.5.

Abstract P6-18-01: Novel genetic susceptibility loci for inflammatory breast cancer identified by whole exome sequencing

Background: Inflammatory breast cancer (IBC) is an extremely aggressive form of locally advanced breast cancer that affects approximately 5% of breast cancer patients. The prognosis of IBC patients is remarkably poor, with a three-year survival rate of approximately 30% compared to 60% for non-IBC breast cancer patients. The etiology of IBC is largely unknown. A few risk factors have been reported such as body mass index (BMI) and educational level. Prior evidence has also implicated genetic components in IBC etiology. For instance, the reported familial cases and racial incidence disparity of IBC patients, as well as the fact IBC patients typically have a younger age onset than non-IBC patients, all indicated the possible involvement of genetic factors. Nevertheless, as yet no genetic epidemiological study has been reported to evaluate IBC genetic predisposition.

Methods: To test the hypothesis that genetic variants and mutations may affect IBC susceptibility, we performed whole exome sequencing in a pilot case-control study that contained 70 IBC cases and 119 unrelated cancer-free controls. Sequencing data were de-multiplexed, filtered, assessed for various quality control metrics, mapped to reference genome and annotated. Comprehensive single variant-based, gene-centered, and pathway-based analyses were conducted to identify variants, genes, and pathways that may be involved in IBC predisposition.

Results: We obtained &gt; 50x on-target sequencing coverage of the whole exome in &gt; 90% of the patients. In single variant analysis, we identified six variants reaching genome-wide significance. Four variants were encoded by genes that have been implicated in breast cancer development including MALAT1, MAP3K9, POLR3B, and FIP1L1. Two variants were encoded by novel genes that have not been related to breast cancer, including CCDC30 and LINC01565. Two types of analyses based on a gene-centered strategy identified top genes such as SLC39A4, CDHR1, AP5Z1, GNB3, ITGA10, etc. However, possibly due to the limited sample size, none of these genes reached genome-wide significance. Ingenuity Pathway Analysis (IPA), using the complete list of significant genes identified by each of these analyses all reported "cancer" as the highest possible disorder associated with these genes, demonstrating the biological plausibility of our findings. Moreover, canonical pathways such as IL4 signaling, glycogen degradation, epithelial adherence junction signaling, and CCR3 signaling in eosinophils were among the top pathways that were found involved in IBC predisposition.

Conclusion: Overall, we provided novel preliminary evidence that genetic variants are potentially associated with the risk of developing IBC. We are currently conducting validation studies with larger sample sizes are warranted to confirm these findings and identify additional genetic susceptibility loci.

Citation Format: Ye Z, Li B, Wang C, Zhong X, Wei Q, Mu Z, Austin L, Jaslow R, Avery T, Palazzo J, Biederman L, Yang H, Cristofanilli M, IBC Inflammatory Breast Cancer International Consortium. Novel genetic susceptibility loci for inflammatory breast cancer identified by whole exome sequencing. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-18-01.

Abstract P2-08-09: Prognostic values of circulating tumor cell (CTC) enumeration and their clusters in advanced breast cancer

Background The enumeration of circulating tumor cells (CTCs) has been proven to have prognostic values in several solid tumors including breast cancer. It has been established that a cut-off of 5 CTCs in 7.5 ml of blood may significantly differentiate breast cancer patients with favorable and unfavorable survival. However, CTC enumeration has not been shown to further predict the prognosis in those patients with more than 5 CTCs in 7.5 ml of blood. There are several recent in vitro and in vivo studies suggesting that clusters of CTC can be identified in blood and those clusters may play an important role in tumor progression and metastasis. Few clinical studies have been reported to enumerate CTC clusters and evaluate their prognostic values. In the current study, we hypothesize that the enumeration of CTC clusters play an important role in the prognostication of advanced breast cancer patients by providing additional predictive performance independent of CTC enumeration.

Methods In an ongoing study of blood-based breast cancer biomarkers, we enrolled 114 patients with stages III and IV breast cancer. Among them, 68 patients had inflammatory breast cancer (IBC), an extremely aggressive form of breast cancer with a much lower survival rate than non-IBC breast cancer patients. The number of single CTCs and CTC clusters (two or more CTCs bound together) in 7.5 ml blood sample were counted using the CellSearch™ system (Janssen Diagnostic) at baseline study entry, and their associations with the progression-free survival (PFS) of patients were evaluated using Kaplan Meier curves and Cox proportional hazards modeling.

Results Baseline CTCs were detected in 67 (58.77%) patients. Thirty-five (30.70%) and 19 patients (16.67%) had elevated CTCs (≥5 CTCs/7.5 mL) and clusters, respectively. IBC patients had a slightly higher percentage of cluster (17.65%) compared to non-IBC patients (15.22%). Patients with elevated baseline CTC and cluster had worse PFS (log rank P, 0.0009 and 0.0035, respectively). Compared to patients with &lt; 5 CTC and without cluster, those patients with elevated CTC without cluster, and those with elevated CTC with cluster had an increasingly higher risk of disease progression with an hazard ratio [HR] of 1.93 (95% confidence interval [CI] 1.01-3.67) and 2.91 (1.54-5.50), respectively (P for trend = 0.001). Moreover, the combined analysis of baseline CTC and cluster enumerations showed similar effect when the analysis was restricted to IBC patients (HR 3.03, 95% CI 1.34-6.86).

Conclusion Baseline enumerations of both individual CTCs and CTC clusters predict PFS in advanced stage breast cancer patients. CTC clusters provide further prognostic value in patients with elevated CTC and their molecular characterizations may provide novel insights into the metastasis process.

Citation Format: Ye Z, Mu Z, Wang C, Palazzo JP, Biederman L, Li B, Jaslow R, Avery T, Austin L, Yang H, Cristofanilli M. Prognostic values of circulating tumor cell (CTC) enumeration and their clusters in advanced breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-09.

Abstract P2-02-14: Detection and characterization of CTCs isolated by ScreenCell®-Filtration in metastatic breast cancer

Background: Circulating Tumor cells (CTCs) detection has prognostic and predictive implications in patients with metastatic breast cancer (MBC). Genomic and phenotypic analysis of CTCs hold enormous promise as blood-based molecular characterization and monitoring disease progression and treatment benefit with a strong potential to be translated into more individualized targeted treatments. FDA-approved CellSearch™ detection allows only enumeration of CTCs expressing EpCAM without molecular characterization. CTCs represent very heterogeneous populations of tumorigenic cancer cells and some subpopulations have undergone epithelial-Mesenchymal transition (EMT), which is associated metastasis process and an unfavourable outcome. EpCAM-based enrichment technique has failed to detect EMT subpopulations due to the decreased expression or loss of epithelial markers. Non-EpCAM-based approaches are needed for identifying EMT CTCs. The ScreenCell® devices are single-use and low-cost innovative devices that use a filter for enrichment-free isolation of CTCs by a two-steps combining size-based separation and staining using different markers. The DEPArray™ system is the ideal downstream isolation system to collect single or pooled CTCs for molecular and genetic analysis. In this study, we evaluated the feasibility of achieving CTCs detection/enumeration using ScreenCell® filtration followed by single cell isolation with the DEPArray™ in MBC patients.

Methods: The first part of the study consisted in evaluating CTCs detection/enumeration in 30 patients with stage III and stage IV breast cancer. 3 mL of whole blood in an EDTA or Transfix tubes was collected and processed on the ScreenCell® Cyto device following the instructions of the supplier. CTCs were stained with cytokeratin (CK-8, 18, and 19), leukocyte antigen (CD45), and a nuclear dye (DAPI) and counted under fluorescence microscope. CTCs were identified as positive staining for CK and DAPI and negative staining for CD45 (CK+/DAPI+CD45-). In the second part, After enrichment, CTCs were stained with CK, CD45, and DAPI and sorted with DEPArray™ Platform (Silicon Biosystems, Inc). Single CTCs were collected and the DNA of each single CTCs was amplified with Ampli1™ WGA kit, and the genome integrity index (GII) was assessed by Ampli1™ QC kit (Silicon Biosystems, Inc). Library was constructed and whole exome sequencing (WES) of DNA mutations was conducted.

Results: Twenty patient samples had CTCs detected (66.7%), the number of CTCs was 1 to 347 per 3.0 ml of whole blood. CTC-clusters were detected in 7 patient samples (23.3%). Single CTCs were collected on DEPArray™ platform after enrichment with ScreenCell filtration. GII was confirmed with the presence of short, medium, and long DNA fragments (3 to 4 PCR bands) in the WGA library by PCR-based assay. All collected CTCs showed high GII as measured by Ampli1™ QC kit (GII ≥ 3) for WES of DNA mutations. The data analysis of WES results is under processing.

Conclusions: ScreenCell® filtration is simple and effective devices to isolate CTCs and identify CTC-clusters. Isolation of single cells for molecular analysis using the combination of ScreenCell® filtration and DEPArray™ Platform is feasible for genetic characterization of CTCs.

Citation Format: Mu Z, Benali-Furet N, Uzan G, Ye Z, Austin L, Wang C, Nguyen1 T, Avery T, Jaslow R, Yang H, Cristofanilli M. Detection and characterization of CTCs isolated by ScreenCell®-Filtration in metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-14.

Abstract P2-02-11: Detection of activating estrogen receptor 1 (ESR1) mutation on single circulating tumor cells from metastatic breast cancer patients

Background: 65% of primary breast cancers express the estrogen receptor α (ERα) and the mainstay of treatment are therapies that result in selective estrogen receptor modulation (SERM) of estrogen deprivation (aromatase inhibitors, AIs). Even thought endocrine therapy resulted in reduced recurrence and mortality, a significant portion of patients relapse with a metastatic disease and subsequently progress while of therapy for advanced disease (endocrine resistance). Recent evidence showed that activating hot spot mutation in the ligand binding domain of the ERα are acquired on treatment (frequency of 20%) and can drive resistance to endocrine therapy. Circulating tumor cells (CTCs) provide a non-invasive accessible source of tumor material and the molecular profiling of these rare cells might lead to insight on disease progression and therapeutic strategies. These features suggest that the detection of ESR1 mutation on single CTC may be a useful biomarker for therapy guidance.

Purpose: Investigate the incidence and heterogeneity of ESR1 mutational status within single CTCs isolated from individual metastatic breast cancer patients (mBCs), combining the FDA approved CellSearch® system for enumeration of CTCs with the DEPArrayTM technologies.

Methods: CTCs were enriched and enumerate by CellSearch® in 7.5 ml blood samples collected from 21 mBCs according to standard protocol. Each CTC-enriched sample with at least 20 CTCs was recovered from Veridex cartridge and loaded into the DEPArrayTM A300K chip, since the DEPArrayTM analyzed only the 66% of the sample volume loaded, according to the manufacturer's instructions. The chip scanning was performed by automated fluorescence microscope. The loaded cells were recovered as single cell and subdivided in tree different group: Cytokeratin (CK) positive ( Dapi+, CK+, ER-, CD45-); ER positive (Dapi+, ER+, CK+, CD45-); White Blood cells (WBCs) (Dapi+, CD45+, CK-, ER-). Single CTCs and WBCs were then submitted to whole genome amplification (WGA) using the Single Cell WGA kit (Yikon Genomics) according the manufacturer's instructions. Detection of target 14 ESR1 hot spot mutations was performed on ABI PRISM® 3700 genetic analyzer by target Sanger sequencing.

Results: 3 out of 21 mBCs with ≥20 CTCs were sorted and a total of 65 cells were recovered. WGA and ESR1 mutational status were performed on a total of 25 cells (respectively 11 ER+, 6 CK+ and 8 WBCs). In 1 of the 3 patients, that failed 2 lines of chemotherapy and previous single agent endocrine therapy, molecular heterogeneity was detected among its ER+ cells. 4 of 5 ER+ cells were heterozygote for the Y537S while one cell was homozygous, maybe due to a loss of heterozygosity. Y537S is one of the most common mutations that leads to a ligand independent ER transcriptional activity that does not respond to endocrine manipulation. No mutations were reported in all the CK+ and WBC cells analyzed.

Conclusions: This study demonstrates the feasibility of a non-invasive approach based on liquid biopsy in mBCs. Evaluation of ER status and early identification of ESR1 mutation in ER+ CTCs might allow to predict effect of the endocrine therapies and switching to other treatments before the emergence of metastatic disease.

Citation Format: Paolillo C, Mu Z, Austin L, Nguyen T, Capoluongo E, Fortina P, Cristofanilli M. Detection of activating estrogen receptor 1 (ESR1) mutation on single circulating tumor cells from metastatic breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-11.

Enhancement of tumor-reactive cytotoxic CD4+ T cell responses after ipilimumab treatment in four advanced melanoma patients

CD4(+) T cells provide help to enhance and sustain cytotoxic CD8(+) T cell responses. A direct lytic role for this cell population in mouse models further supports the use of tumor-reactive CD4(+) T cells for cancer immunotherapy. CTLA-4 blockade has been shown to expand antigen-specific cytotoxic CD4(+) T cells in mouse models. We took advantage of spontaneous immunity to the NY-ESO-1 cancer-testis antigen to investigate quantitative and qualitative changes in antigen-specific CD4(+) T cell responses after ipilimumab (anti-CTLA-4 monoclonal antibody) treatment in advanced melanoma patients. Four NY-ESO-1 seropositive melanoma patients were chosen upon the availability of suitable blood specimens for characterizing the functions of NY-ESO-1 antigen-specific CD4(+) T cell response by enzyme-linked immunospot (ELISPOT), intracellular cytokine staining (ICS) and cytotoxicity assays. Multiple NY-ESO-1 antigen-specific CD4(+) T cell responses with Th1 dominance were induced or enhanced after ipilimumab treatment in peripheral blood in all four patients. NY-ESO-1 antigen-specific CD4(+) T cell lines established from all 4 patients after ipilimumab treatment recognized naturally processed NY-ESO-1 protein in antigen-presenting cells, expressed master transcription factor Eomesodermin (Eomes) and secreted perforin and Granzyme B. Finally, we demonstrated that these NY-ESO-1 antigen-specific CD4(+) T cell lines directly lysed autologous melanoma cell lines expressing NY-ESO-1 in an MHC class II restricted manner. Our results show that antigen specific cytotoxic CD4(+) T cell responses are induced after ipilimumab therapy in human cancer patients. Ipilimumab may induce the expression of lytic granules on antigen specific cytotoxic CD4(+) T cells via Eomes, revealing a novel consequence of immunologic checkpoint blockade.

Abstract P2-15-01: Integrated immunologic assessment of tumor infiltrating lymphocytes (TILs) and peripheral blood to assess synergy of cryoablation (cryo) plus ipilimumab (ipi) in early stage breast cancer (ESBC) patients (pts)

Background: In pts with ESBC, cryo combined with cytotoxic T-lymphocyte antigen 4 blockade was well tolerated and did not delay standard-of-care mastectomy. As observed in mice, cryo+ipi may liberate tumor-associated antigens, synergistically activate tumor-reactive T-cells, and confer long-term anti-tumor immunity. Because singular biomarkers of response to immunotherapy have not been well defined, we conducted an integrated immunologic assessment to explore potential predictors of immune activation and response.

Methods: Serial blood and pre-/post-treatment tumor tissue were collected from 18 pts treated with cryo (6 pts), single-dose ipi at 10mg/kg (6 pts), or cryo + ipi (6 pts). A Meso Scale Discovery platform was used to measure plasma cytokine interferon gamma (IFNγ). Multiparameter flow cytometry was used to evaluate peripheral and intratumoral T-cell and myeloid cell quantity, T-cell phenotype (effector versus regulatory), proliferation state (Ki67), and activation state (inducible costimulator [ICOS] expression). Finally, a DNA deep sequencing platform was used to conduct T-cell repertoire analysis of peripheral T-cells and TILs.

Results: Sustained &gt;2-fold elevations (1 month post-treatment) in plasma IFNγ were observed in the majority (4/6) of pts receiving cryo/ipi (median 6-fold increase), but in the minority of pts receiving cryo (0/6, median 0-fold) or ipi (2/6, median 0-fold). Similarly, sustained &gt;2 fold elevations in ICOS expression in peripheral CD3+CD4+ T-cells, a known pharmacodynamic marker of ipi, were observed in the majority (5/6) of pts receiving cryo/ipi (median 4-fold increase), but in the minority of pts receiving cryo (0/6, median 0-fold) or ipi (2/6 ipi; median 1-fold). No trends were observed in peripheral myeloid derived suppressor cells. Analysis of TILs by flow cytometry identified increased numbers of proliferating CD8+ T-cells (CD8+Ki67+) in ipi and cryo/ipi groups relative to cryo alone; furthermore, the ratio of proliferating (CD8+Ki67+) to regulatory (CD4+CD25+FoxP3+) cells was enhanced in the cryo/ipi group. Finally, analysis of T-cell repertoire in TILs demonstrated that cryo/ipi generated an influx of novel T-cell clones, with select clones surging dramatically in predominance and circulating within the periphery.

Conclusions: Utilizing an integrated assessment, we identified evidence of immunologic synergy with combination cryo/ipi versus either therapy alone. Of the tested parameters, peripheral CD4+ ICOS expression, plasma IFNγ, Ki67-gated TIL effector/regulatory ratios, and clonal repertoire analysis were identified as promising biomarkers of immune activation. These findings will inform a prospective assessment of potential immunologic biomarkers of immune response and clinical benefit in a phase 2 study of cryo-immunotherapy in ESBC.

Citation Format: David Page, Jianda Yuan, Adi Diab, Zhiwan Dong, Arielle Ginsberg, Phillip Wong, Ryan Emerson, David Redmond, Brian Blum, Zhenyu Mu, Chunjun Zhao, Christopher Comstock, Elizabeth Morris, Elizabeth Comen, Alan Kotin, Janice Sung, Edi Brogi, Monica Morrow, Stephen Solomon, Virgilio Sacchini, Majid Maybody, Deirdre Neville, Harlan Robins, Sujata Patil, Jedd Wolchok, Clifford Hudis, Larry Norton, James Allison, Padmanee Sharma, Heather McArthur. Integrated immunologic assessment of tumor infiltrating lymphocytes (TILs) and peripheral blood to assess synergy of cryoablation (cryo) plus ipilimumab (ipi) in early stage breast cancer (ESBC) patients (pts) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-15-01.

Presence of myeloid-derived suppressor cells (MDSC) in patients with metastatic castration-sensitive and castration-resistant prostate cancer

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Background: MDSC contribute to an immune suppressive environment and have been implicated in cancer progression. Measurement (identification and enumeration) is challenged by the lack of analytically valid assays limiting data interpretation between groups. This impacts our understanding of rationale immune targets and design of clinical trials. We employed a novel biomarker based assay in whole blood to enumerate MDSC from patients with metastatic castration sensitive (CSPC) and castration resistant prostate cancer (CRPC). Methods: Whole blood was collected in Cyto-Chex (Streck) tubes. A published computational algorithm-based approach (developed by Memorial Sloan Kettering Cancer Center and commercialized by Serametrix) was employed to determine the %MDSC-monocytic and coefficient of variance (CV=ratio of SD and geometric mean fluorescence intensity) to assess HLA-DR spread on CD14+CD11b cells. Samples were performed in duplicate. Clinical variables including clinical state, past and current treatment, metastatic sites, PSA, and standard prognostic markers were collected. Results: 36 pts with metastatic prostate cancer (29 CRPC; 7 CSPC) were included. Median (SD) %MDSC in 29 CRPC pts was 21.15 (5.33) and median (SD) CV was1.29 (0.25); 7 CSPC demonstrated a median (SD) %MDSC 19.15 (4.86) and median (SD) CV 1.22 (0.25). MDSC did not differ between chemotherapy exposed (n=13) and chemotherapy naive (n=16) CRPC (23.3 vs 19.5, p=ns). MDSC were not significantly higher in those with visceral mets, though a trend existed (20.3 vs 24.0, p=0.076). PSA did not appear to correlate with MDSC or CV. Conclusions: Understanding the distribution and characterization of MDSC in various clinical states in prostate cancer is relevant to the development of immune targets in this disease. MDSC were quantifiable in both CSPC and CRPC. There was a trend for higher MDSC values in patients with visceral metastases, which historically are associated with worse prognoses. Presence of MDSC in metastatic CSPC and CRPC has important therapeutic and trial implications. Further discovery in larger cohorts and earlier disease states is underway.

Effects of tetra-arsenic tetra-sulfide on BXSB lupus-prone mice: a pilot study

Systemic lupus erythematosus (SLE) is an autoimmune disease of uncertain etiology that affects multiple tissues and organs. Arsenic trioxide (ATO) has been used in lupus-prone mice with a regulatory effect on immune abnormality. Tetra-arsenic tetra-sulfide (As4S4), a traditional Chinese medicine, is effective on acute promyelocytic leukemia with mild side effects than ATO. In this study, a pilot study was performed to investigate the effects and the mechanism of As4S4 on the lupus-prone BXSB mice. Improvement of monocytosis (p<0.05) in spleen and decreased serum interleukin-6 (IL-6) (p=0.0277) were observed with As4S4 treatment. As4S4-treated mice exhibited amelioration of skin, liver and renal disease with mild side effects. Histological analysis revealed that As4S4 suppressed immune complex deposition, mesangial proliferation and inflammatory cell infiltration in kidney and liver. Our study support that As4S4 selectively suppresses cutaneous lupus and nephritis in BXSB mice and might be a potential treatment for SLE.

Abstract P3-01-05: Metabolomic analysis of breast cancer cell lines: Clues to the metabolic fingerprint of inflammatory breast cancer

BACKGROUND: Inflammatory breast cancer (IBC) is an aggressive type of advanced breast cancer with a poor prognosis and lower survival rate. IBC is characterized by peculiar clinical and biological features and resistance to standard treatments. IBC has shown the capacity to spread early through lymphatic channels and blood vessels causing the specific inflammatory signs. Currently, there are no specific therapeutic options for IBC patients because of very few molecular alterations associated with IBC. Thus, there is an unmet need to identify distinguished features of IBC that differentiate the disease from non-inflammatory breast cancer (nIBC). Metabolomic analysis of cancer cells holds the promise to identify unique chemical fingerprints of important cellular processes. In this study we investigated the global biochemical profiles of IBC and nIBC cells.

METHODS: Three IBC cell lines, SUM190, SUM149, FC-IBC-02, and three nIBC cell lines, MCF-7, MDA-MB-231, MDA-MB-468, with five replicates for each cell line, were analyzed in this study. Metabolomic profiling analysis was performed by Metabolon, Inc (Durham, NC) on the gas chromatography/mass spectroscopy and ultrahigh performance liquid chromatography/mass spectroscopy platforms as previously described (Proc. Natl. Acad. Sci. U. S. A. 108, 3270-3275, 2011). A total of 347 metabolites were detected. Welch's two-sample t-test was used to identify biochemicals that differed significantly between experimental groups (p≤0.001), as well as those approaching significance (0.001&lt;p&lt;0.05).

RESULTS: Comparison of global biochemical profiles for IBC and nIBC cell lines revealed numerous statistically changed metabolites at a p-value threshold of p&lt;0.001. Statistical comparisons also revealed a clear metabolic separation of samples due to cell line differences. Several biochemical pathways emerged as being commonly altered across all IBC cell lines compared to all nIBC cell lines. Notable observations include alterations in inflammatory signaling, energy metabolism, and cell proliferation. Signatures of inflammation were elevated and inflammatory signaling pathways showed activation in IBC cell lines. In energy metabolism, the cellular energy for IBC cells appeared to be derived from amino acid catabolism to a greater extent than in nIBC cells. Furthermore, fatty acids was significantly elevated in IBC cell lines, that may indicate a reduced cellular proliferation and increased glycogen storage in IBC cells. Moreover, an altered methylation and glutathione metabolism were shown in IBC cell lines.

CONCLUSIONS: Our study is the first to demonstrate difference of metabolic profiles between IBC and nIBC cells. Future studies comparing global biochemical profiles in tissue biopsy and blood from IBC and nIBC patients may help to confirm the relevance of these findings in cell lines. Metabolic targets may provide more effective and specific therapeutic strategy for the treatment of IBC patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-01-05.

Immunologic responses to xenogeneic tyrosinase DNA vaccine administered by electroporation in patients with malignant melanoma

Background

Prior studies show that intramuscular injection and particle-mediated epidermal delivery of xenogeneic melanosomal antigens (tyrosinase or Tyr, gp100) induce CD8⁺ T cell responses to the syngeneic protein. To further define the optimal vaccination strategy, we conducted a phase I study of in vivo electroporation (EP) of a murine Tyr DNA vaccine (pINGmuTyr) in malignant melanoma patients.

Methods

Human leukocyte antigen (HLA)-A1, A2, A24 or B35 stage IIb-IV melanoma patients received up to five doses of the mouse tyrosinase DNA vaccine by EP every three weeks at dose levels of 0.2 mg, 0.5 mg, or 1.5 mg per injection. Peripheral blood mononuclear cells (PBMC) were collected, cultured with a peptide pool containing eight HLA class I-restricted Tyr-specific T-cell epitopes, and analyzed by HLA-A*0101-restricted tetramers and intracellular cytokine staining (ICS).

Results

Twenty-four patients received ≥1 dose of the pINGmuTyr vaccine; PBMCs from 21 patients who completed all five doses were available for Tyr immune assays. The only common toxicity was grade 1 injection site reaction. Six of 15 patients (40%) in the 1.5 mg dose cohort developed Tyr-reactive CD8⁺ T cell responses following stimulation, defined as a ≥3 standard deviation increase in baseline reactivity by tetramer or ICS assays. No Tyr-reactive CD8⁺ T cell response was detected in the 0.2 mg and 0.5 mg dose cohort patients. Epitope spreading of CD8⁺ T cell response to NY-ESO-1 was observed in one patient with vitiligo. One patient subsequently received ipilimumab and developed an enhanced Tyr-reactive response with polyfunctional cytokine profile. After a median follow-up of 40.9 months, median survival has not been reached.

Conclusions

A regimen of five immunizations with pINGmuTyr administered by EP was found to be safe and resulted in Tyr-reactive immune responses in six of 15 patients at 1.5 mg dose cohort.

Trial registration

ClinicalTrials.gov NCT00471133

Immunological insights from patients undergoing surgery on ipilimumab for metastatic melanoma

BACKGROUND

The tumor microenvironment after treatment with ipilimumab is not well described. Furthermore, the safety of surgery for patients being treated with ipilimumab for metastatic melanoma has not been well reported. This study analyzed the safety of surgery and the immune phenotype of tumors resected while on ipilimumab.

METHODS

From our prospective melanoma database, we identified patients undergoing surgery for any indication within 30 days of receiving a dose of induction ipilimumab or while on maintenance ipilimumab therapy. Surgical toxicity was graded 1-5 by the Clavien classification. Tumor-infiltrating lymphocytes were classified by flow cytometry and compared with peripheral blood.

RESULTS

23 patients were identified who underwent 34 operations a median of 27 weeks after initiation of ipilimumab (1-123 weeks). Subcutaneous resections were the most frequent, followed by intra-abdominal and nodal procedures. Grade 1 or 2 wound complications were seen in 22% of patients. No Grade 3-5 complications were seen. Analysis of the T cell infiltrate and matched peripheral blood from ten patients showed an elevated % of CD4+FOXP3+ T-regulatory cells and a 2.8-fold lower ratio of CD8+/CD4+FOXP3+ in the tumor compared with blood (p=0.02). In addition, all CD8+ T cells had a higher expression of PD-1 in the tumor, compared with peripheral blood.

CONCLUSIONS

Surgery for patients on ipilimumab is safe. This study highlights the immunosuppressive phenotype in tumors not responding to immunotherapy. The high percentage of T-regulatory cells and low T-effector cells in progressive tumors suggests a possible mechanism of immune escape.

Abstract P6-02-05: A novel culturing 3-D model to evaluate the role of tumor microenvironment in IBC

Introduction: Inflammatory breast cancer (IBC) is a highly aggressive form of breast cancer associated with extremely poor outcomes. The clinical and pathological characteristics of the disease are the peculiar invasion of the dermal lymphatics as tumor emboli and the development of early recurrences. We aimed to establish a 3D model to evaluate the role of tumor microenvironment.

Methods: We used human tumor-associated fibroblasts (or fibroblasts derived from metastatic skin) from IBC patients to build a multilayer extracellular matrix structure which effectively mimics aspects of the mesenchymal microenvironment of IBCs. Using this in vivo-like microenvironment we proceeded to test both matrix effects upon IBC's phenotypes and IBC modifications upon the cell-derived 3D matrices.

We seeded the IBC cells into the matrix and cultured for 3 days, then tested the characterization markers cancer cells and ECM e.g. Phalloidin, E-cadherin, Ki67, α5β1 integrin and fibronectin by immunofluorescence and the expression of E-cadherin and vimentin as marker of epithelial-mesenchymal transition (EMT) by western blot.

Results: We divided six IBC cell lines into 2 groups depending on the phenotypes acquired when cultured in the IBC fibroblast-derived ECM. SUM149 (EGF receptor positive and aggressive phenotype), BR016 and LG018 (harvested from patient's pleural effusions) presented a single cell organization with a spindle-like or mesenchymal type (as opposed to cluster) morphology. In comparison, SUM190 (HER2 positive and non aggressive tumorigenesis), MDA-IBC-3 and FC-IBC-02 (abstracted from patient's pleural effusion) presented a phenotype resembling mammospheres or in vivo emboli. Moreover, this last group of cells showed a peculiar capability for ECM modifications which greatly differed from the ECM modifications that were apparent following 3 day culturing of the above mentioned group represented by SUM149. In addition, proliferation measurements by Ki67 expression demonstrated a significant increased in 3D culture for SUM149, BR016 and LG018 compared with that in 2D culture, while no differences in proliferation were observed in the other three cell lines. Moreover, the expression of E-cadherin known to be upregulated in IBC tumors was increased in all cancer cells when seeded into the human fibroblast-derived 3D matrix indicating a potential role of the microenvironment in promoting proliferation, growth and invasion.

Conclusion: The present study demonstrated the establishment of a novel IBC stromal 3D model using extracellular matrix produced from human fibroblasts of patients with advanced IBC. We showed a dynamic interaction between cancer cells and the microenvironment and potential sorting of IBC cells into two discrete groups which also correlate with their aggressive behaviors in vivo. We believe that these system may serve to predict levels of IBC tumorigenesis. We will proceed to further study the two identified responsive phenotypes with the goal of uncovering mechanisms of IBC tumor-stromal interactions and better understand ECM influences upon IBC development and progression. The ultimate goal will be to use the system to study IBC biology and better design drugs that will specifically affect the newly identified phenotypes.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-02-05.

Surgery for patients receiving ipilimumab: Safety profile and immunological insights

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Background: Ipilimumab (ipi), a monoclonal antibody blocking CTLA-4, demonstrated survival benefit in metastatic melanoma in two randomized controlled trials. With its approval by the FDA, the use of this immunotherapy is increasing. The surgical safety of ipi has not been reported. Methods: From our prospective database, we identified patients undergoing surgery within 30 days of receiving a dose of ipi or on maintenance ipi between October 2007 and August 2011. Surgical toxicity was graded 1-5 by the Clavien classification. In 10 patients matched blood and tumor infiltrating lymphocytes were harvested. Phenotype of T cell subsets were analyzed by flow cytometry. Results: 23 patients were identified who underwent 34 operations a median of 27 weeks after initiation of ipi (1-123 weeks). Indications for surgery were symptomatic, progressive, or isolated persistent disease in 52%, 39% and 9% respectively. Subcutaneous resections were the most frequent, followed by intra-abdominal and nodal procedures (Table). Grade 1 wound complications were seen in 17% of patients. One patient had a Grade 2 wound complication. No Grade 3-5 complications were seen. With a median follow up from starting ipi of 86 weeks, 3 patients have no evidence of disease, 10 are alive with disease and 10 have died of disease. Analysis of the T cell infiltrate and peripheral blood from 10 patients with progressive or symptomatic disease shows an elevated % of CD4+FOXP3+ T regulatory cells and a 2.8 fold reduction in CD8+/ CD4+FOXP3+ T regulatory ratio in the tumor compared to blood (p=0.02). Conclusions: Results from this single-center experience suggest that surgery is safe in patients receiving ipi. Immune modulation caused by CTLA-4 blockade does not appear to impact wound healing, even in the bowel. In carefully selected patients metastectomy may be appropriate for breakthrough metastases. The high percentage of T regulatory cells and low T effector cells in the progressive tumors suggests a mechanism of immune escape. [Table: see text]

Immunologic correlates of the abscopal effect in a patient with melanoma

The abscopal effect is a phenomenon in which local radiotherapy is associated with the regression of metastatic cancer at a distance from the irradiated site. The abscopal effect may be mediated by activation of the immune system. Ipilimumab is a monoclonal antibody that inhibits an immunologic checkpoint on T cells, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4). We report a case of the abscopal effect in a patient with melanoma treated with ipilimumab and radiotherapy. Temporal associations were noted: tumor shrinkage with antibody responses to the cancer-testis antigen NY-ESO-1, changes in peripheral-blood immune cells, and increases in antibody responses to other antigens after radiotherapy. (Funded by the National Institutes of Health and others.).

P4-03-06: Development and Comparative Characterization of Metastasis in Newly Developed Pre-Clinical Models of Inflammatory Breast Cancer

Background: Inflammatory breast cancer (IBC) is the most metastatic variant of breast cancer. It is associated with a poor survival rate (40% 5-year survival) despite appropriate multidisciplinary care. For such an aggressive type of cancer, IBC has been understudied, in part due to the lack of adequate numbers of cell lines and mouse models that recapitulate the human disease. To expand our understanding of IBC, we have obtained all of the previously developed and characterized IBC cell lines and models including Mary-X, SUM149, SUM190, KPL-4, MDA-IBC-3 and have developed two new IBC models, designated as FC-IBC01 and FC-IBC02, using tumor cells derived from pleural effusion of IBC patients.

Materials and Methods: Each of these IBC cell lines has been luciferase (LUC)-tagged, allowing the growth of orthotopic injection or subcutaneous implantation to be evaluated by bioluminescent imaging (BLI). Alternatively, the LUC-tagged IBC cells can by injected via either intra-cardiac or intravenous route of delivery, which promotes rapid tumor colonization, resulting in both visceral and skeletal metastasis. Growth of IBC tumors can then be monitored immediately using BLI, thus eliminating the lag time needed for the physical detection of palpable tumors. BLI imaging also allows for monitoring of the kinetics and location of development of metastatic lesions. Whole transcriptome analysis was performed on IBC cell lines and xenograft tissues to define the heterogeneity of IBC as a distinct variant of breast cancer

Results: These models have allowed us to identify micro-metastatic foci in multiple sites distant from the IBC primary tumor in each of these models of IBC and allow the quantitation of anti-tumor and anti-metastatic effects of targeted therapeutics as single agents as well as the potential synergy of combinations of agents. As an example, injection of LUC-tagged IBC cell lines such as SUM149-Luc, into the left ventricle of NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice allows the metastatic tumor burden to be monitored longitudinally by whole animal BLI, which can be validated at necropsy and by immunohistochemical analysis. Whole transcriptome analysis of pre-clinical models of IBC reflect the molecular subtypes observed in IBC patients, with the majority of IBC models being of the basal like, luminal B and Her2 amplified. Discussion: First time analysis of known and newly developed pre-clinical models of IBC allows a more complete analysis of IBC as a distinct variant of breast cancer. Furthermore, these approaches allow rapid evaluation of the promising targeted therapeutics identified based on whole transcriptome analysis of both IBC patient tumors and pre-clinical models developed from IBC patients. We believe that this extensive collection of LUC-tagged IBC cell lines is an invaluable tool for IBC research since the cell lines encompass the broad spectrum of IBC heterogeneity.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-03-06.

P2-05-04: Mapping the Specific Gene Families Activated in the Lymphangiogenesis and Vasculogenic Mimicry Exhibited by Inflammatory Breast Cancer

Background: Inflammatory breast cancer (IBC) is the most metastatic variant of locally advanced breast cancer. Although IBC is diagnosed less commonly than other types of breast cancer, it is extremely aggressive, and accounts for a disproportionate number of breast cancer related deaths annually. IBC exhibits very specific patterns of lymphangiogenesis and vasculogenic mimicry, however detailed studies of the genes and proteins involved in these angiogenic processes are lacking. This study performed whole unbiased gene transcription studies with validation by protein arrays using all available pre-clinical cell lines and in vivo xenograft models of IBC, including a new model of IBC, FC-IBC01, which exhibits lymphovascular invasion, to identify the specific pathways involved in the distinctive angiogenesis observed in IBC.

Materials and Methods: Real-time quantitative RT-PCR, cDNA microarray gene profiling, immunofluorescence with confocal imaging and protein arrays were used to examine differential expression of specific angiogenic gene families including VEGFA,B,C,D, VEGF Receptor genes, and ANG/TIE genes linked to angiogenesis and lymphangiogenesis.

Results: Activity of the matrix metalloproteinase, MMP-2, is required for IBC tumor cells to undergo vasculogenic mimicry (VM), which is associated with a loss of TIMP-2, a well known inhibitor of angiogenesis. Therapeutics that target MMP activity can successfully inhibit this VM. Furthermore, pre-clinical models of IBC that form IBC tumor emboli exhibit lymphovascular invasion that is associated with distinct patterns of expression of genes that encode for distinct receptor tyrosine kinases that may represent important therapeutic targets for IBC.

Discussion: Identification of the distinct angiogenic pathways that are activated in IBC provides insight into the therapeutic targets that may abrogate the distinct lymphovascular invasion and vasculogenic mimicry that are linked to the aggressive metastasis of IBC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-05-04.

Immunologic response to xenogeneic gp100 DNA in melanoma patients: comparison of particle-mediated epidermal delivery with intramuscular injection

PURPOSE

Prior studies show that i.m. injection of xenogeneic orthologues of melanosomal antigens (tyrosinase, gp100) induces CD8(+) T-cell responses to the syngeneic protein. To further define the optimal vaccination strategy, we conducted a pilot clinical trial comparing i.m. injection with particle-mediated epidermal delivery (PMED).

EXPERIMENTAL DESIGN

Human leukocyte antigen (HLA)-A*0201(+) disease-free melanoma patients were randomized to the PMED or i.m. arm, receiving eight vaccinations over 4 months. Patients received 4 microg or 2,000 microg per injection, respectively, of mouse gp100 DNA. Peripheral blood mononuclear cells were collected, cultured with gp100 peptides, and analyzed by tetramer and intracellular cytokine staining for responses to HLA-A*0201-restricted gp100 epitopes [gp100(209-217) (ITDQVPFSV) and gp100(280-288) (YLEPGPVTA)].

RESULTS

Twenty-seven patients with stage IIB-IV melanoma were analyzable for immune response. The only common toxicity was grade 1 injection site reaction in nine patients with no intergroup difference, and one dose-limiting toxicity of acute hypersensitivity occurred in a PMED patient with undiagnosed gold allergy. Four of 27 patients produced gp100 tetramer(+)CD8(+) T cells, all carrying the CCR7(lo)CD45RA(lo) effector-memory phenotype. Five of 27 patients generated IFN-gamma(+)CD8(+) T cells, one who was also tetramer-positive. Overall, vaccination induced a response in 30% of patients, which was not significantly associated with study arm or clinical outcome. However, the PMED group showed a trend toward increased IFN-gamma(+)CD8(+) T-cell generation (P = 0.07).

CONCLUSION

A comparable efficacy and safety profile was shown between the i.m. and PMED arms, despite a significantly decreased dose of DNA used for PMED injection.

Correlation of clinical and immunological data in a metastatic melanoma patient with heterogeneous tumor responses to ipilimumab therapy

Melanoma patients treated with anti-CTLA-4 have shown a range of anti-tumor responses. In this report, we describe the response of a single patient to anti-CTLA-4, with individual lesions disappearing, others stabilizing, and others progressing. These responses can be viewed as a clear manifestation of cancer immunoediting and its three phases of elimination, equilibrium and escape, with each tumor in this patient being at a discrete stage in the process. The patient's course and associated immunological monitoring and other laboratory data are presented in an immunogram, a way to visualize temporal associations between the multiple clinical and laboratory parameters.

Safety and immunogenicity of a human and mouse gp100 DNA vaccine in a phase I trial of patients with melanoma

A differentiation antigen commonly expressed on melanoma cells, gp100 is the target of infiltrating T cells. We conducted a phase I randomized cross-over trial of melanoma patients with either xenogeneic (mouse) or human gp100 plasmid DNA injected intramuscularly at three dosages (100, 500 or 1,500 microg) every three weeks for three doses. After the first three injections, patients were then immunized three times with gp100 from the other species. Peripheral blood samples were analyzed at various time points following 10-day culture with gp100 peptides using multi-parametric flow cytometry. A total of 19 patients were enrolled, with 18 assessable for immune function and survival. 14 (74%) were male, with a median age of 56 years (range, 20-82). All patients had no evidence of disease; 10 (53%) had stage III disease, 3 each (16%) had stage IIB and IV disease, 2 (11%) had choroidal and 1 (5%) had anal mucosal involvement. With a median follow-up of 30 months, median progression-free survival (PFS) is 44 months. Median survival is not reached. There was no grade 3/4 toxicity; the most common grade 1/2 toxicity was an injection site reaction in 12 patients (63%, all grade 1). Five patients developed CD8+ cells binding gp100(280-288) HLA-A2-restricted tetramer. One patient had an increase in CD8+ IFN-gamma+ cells. This xenogeneic immunization strategy was safe and associated with minimal toxicity. There was also evidence of immune response.

Mice that lack activity of alphavbeta6- and alphavbeta8-integrins reproduce the abnormalities of Tgfb1- and Tgfb3-null mice

The arginine-glycine-aspartate (RGD)-binding integrins alphavbeta6 and alphavbeta8 activate latent TGFbeta1 and TGFbeta3 in vivo, but it is uncertain whether other RGD-binding integrins such as integrins alphavbeta5 and alphavbeta3 activate these TGFbeta isoforms. To define the combined role of alphavbeta6- and alphavbeta8-integrin in TGFbeta activation, we analyzed mice lacking function of both integrins by means of gene deletion and/or pharmacologic inhibition. Most Itgb6-/-;Itgb8-/- embryos die at mid-gestation; those that survive develop cleft palate-as observed in Tgfb3-/- mice. Itgb8-/- mice treated with an anti-alphavbeta6-integrin antibody develop severe autoimmunity and lack Langerhans cells-similar to Tgfb1-null mice. These results support a model in which TGFbeta3-mediated palate fusion and TGFbeta1-mediated suppression of autoimmunity and generation of Langerhans cells require integrins alphavbeta6 and alphavbeta8 but not other RGD-binding integrins as TGFbeta activators.

Absence of integrin-mediated TGFbeta1 activation in vivo recapitulates the phenotype of TGFbeta1-null mice

The multifunctional cytokine transforming growth factor (TGF) β1 is secreted in a latent complex with its processed propeptide (latency-associated peptide [LAP]). TGFβ1 must be functionally released from this complex before it can engage TGFβ receptors. One mechanism of latent TGFβ1 activation involves interaction of the integrins αvβ6 and αvβ8 with an RGD sequence in LAP; other putative latent TGFβ1 activators include thrombospondin-1, oxidants, and various proteases. To assess the contribution of RGD-binding integrins to TGFβ1 activation in vivo, we created a mutation in Tgfb1 encoding a nonfunctional variant of the RGD sequence (RGE). Mice with this mutation (Tgfb1^RGE/RGE) display the major features of Tgfb1^−/− mice (vasculogenesis defects, multiorgan inflammation, and lack of Langerhans cells) despite production of normal levels of latent TGFβ1. These findings indicate that RGD-binding integrins are requisite latent TGFβ1 activators during development and in the immune system.