Molecular Imaging in Precision-Cut Non-Small Cell Lung Cancer Slices

BACKGROUND

Small animal models remain invaluable for the preclinical study of emerging molecular imaging agents. However, the data obtained in this setting are generated in genetically homogenous animals that do not mimic human pathophysiology. The purpose of this study was to prospectively validate precision-cut lung slices (PCLSs) obtained from patients with lung cancer as a translational tool for the development of targeted fluorophores.

METHODS

The lung tissue was gently inflated with 2% Low-Melt Agarose (Fisher, 16520050) to avoid lung damage and minimize inflation pressure. The slices were then loaded into specialized cylindrical cartridges and inserted into a compressotome, and slices 150 to 350 μm thick were cut. Samples were incubated with fluorophore conjugates for ex vivo validation and immunohistochemical staining for receptor expression.

RESULTS

A total of 184 unique 3-dimensional, architecturally preserved normal lung and non-small cell lung cancer samples were obtained between 2020 and 2022. The median nodule size was 1.1 ± 0.21 cm for benign lesions and 2.1 ± 0.19 cm for malignant nodules. A total of 101 of 135 (74.8%) malignant lesions were adenocarcinoma spectrum lung cancers. The median viability was 9.78 ± 1.86 days, and 1 μM of FAPL-S0456 (high-affinity fibroblast activation protein [FAP] targeting ligand linked to the near-infrared fluorophore S0456, On Target Laboratories)-targeted near-infrared fluorochrome localization demonstrated correlative labeling of FAP-positive tumor areas with a correlation coefficient of +0.94 (P < .01). There was no FAP fluorochrome uptake in normal lungs (r = -1; P < .001).

CONCLUSIONS

PCLSs comprise a novel human tissue-based translational model that can be used to validate the efficacy of molecular imaging fluorochromes. PCLSs preserve the tumor microenvironment and parenchymal architecture that closely resemble the interactions of the immune and stromal components in humans.

Abstract A016: Selective delivery of fibroblast activation protein conjugated dual phosphoinositide 3-kinase–AKT Kinase-mTOR inhibitor associated with decreased tumor proliferation and on-target toxicity in high-grade soft-tissue sarcomas

Soft-tissue sarcomas (STS) are a group of lethal mesenchymal tumors that are a major cause of cancer related morbidity for those under the age of 20.PI3K inhibitors have been found to be effective against subset of STS but are associated with significant toxicities limiting their use.We have thought to test a selective fibroblast activation protein (FAP) targeted delivery of PI3K/AKT/mTOR inhibitor omipalisib to STS in pre-clinical setting as FAP is overwhelmingly expressed agressive soft tissue malignancies. Experimental Design: Patient derived fibrosarcomas (aSMA-,FAP+,pAKT+) were isolated by flow cytometry.FAP(-)HT1080 fibrosarcoma cell lines were used as a negative control whereas methylcoanthrene induced mouse fibrosarcoma transfected with human FAP cDNA were used as positive control.Cell expression of FAP,AKT,mTOR was compared using SDS Page,IHC,and flow cytometry.FAP ligand coupled to omipalisib(FAPL-PI3Ki)was then evaluated in-vitro and in small animal models. Results: Cell lines with known FAP expression demonstrated significant uptake of FAPL conjugated NIR fluorochrome.Wild type cells(hFAP-) showed no ligand binding both in flow cytometry and fluorescent microscopy(p&lt;0.05).Escalating doses of FAP-PI3Ki suppressed AKT/mTOR activity in HT-1080 hFAP cells with 10 nM being the smallest effective dose.In hFAP+cell lines 10 nM of FAP-PI3Ki inhibited the AKT/mTOR signaling but inhibition was not observed in hFAP- cell lines demonstrating the need for FAP presence for FAPL-PI3Ki activity(p&lt;0.05).Pan non-targeted PI3Ki inhibited the AKT/mTOR pathway in both hFAP+ and hFAP-cell lines.Densitometric analysis demonstrated that in hFAP+ cells,FAP-PI3Ki at above 10 nM suppresses the AKT/mTOR activity with ratio of pAKT/AKT and pmTOR/mTOR decreasing 11 and 4-fold respectively(p&lt;0.05).FAP-PI3Ki activity significantly reduced when hFAP+ cells were competitively inhibited with free FAPL(4.6x increase in AKT activity,p&lt;0.05).hFAP+ cells treated with FAP-PI3Ki had significant decrease in cell migration.In small animal models,SCID Mice injected with 25 umol/kg of either FAP-PI3Ki and non-targeted PI3Ki showed marked elevation of serum insulin levels in the non-targeted PI3Ki group (0.91 ng/mL vs 0.58 ng/mL,p&lt;0.05).Xenograft tumor digest demonstrated mice treated with FAP-PI3Ki had Akt/mTOR pathway downregulated only in hFAP+ cell lines and this was evident in mice which received 10 nM or higher dosing(pAkt/Akt ratio of 1.1 WT mice vs 0.55 in hFAP+ mice,p&lt;0.05).There was near complete suppression of the mTOR expression in the hFAP+ treatment group (pmTOR/mTOR 1.05 vs 0.087,p&lt;0.05).There was no treatment related mortality in FAPL-PI3Ki group as compared to non-targeted PI3Ki delivery (p&lt;0.05). Conclusion: Our study demonstrated that FAP conjugated modified omipalisib binds FAP expressing soft-tissue sarcomas both in-vitro and in xenograft models in concordance with FAP receptor density.FAP-PI3Ki induces PI3K/AkT/mTOR pathway inhibition similar to non-targeted PI3K inhibitors without significant systemic toxicities observed in pan nontargeted PI3K inhibitors.

Citation Format: Feredun Azari, Gregory T. Kennedy, Ashley Chang, Bilal Nadeem, Azra Din, Isvita Marfatia, Steven Albelda, Philip Low, Madduri Srinivasarao, Ramesh Mukkamala, Neil T. Sullivan, Evgeniy Eruslanov, Sunil Singhal. Selective delivery of fibroblast activation protein conjugated dual phosphoinositide 3-kinase–AKT Kinase-mTOR inhibitor associated with decreased tumor proliferation and on-target toxicity in high-grade soft-tissue sarcomas [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A016.

0787 Autonomic Dysfunction and Phenoconversion in Idiopathic/Isolated REM Sleep Behavior Disorder

Introduction

REM-sleep behavior disorder (RBD) is a common finding among patients with synucleinopathies. We aimed to determine the degree of autonomic dysfunction in patients presenting with idiopathic RBD (iRBD), and the predictive value of autonomic dysfunction for phenoconversion to a defined neurodegenerative disease.

Methods

We searched our electronic medical record for patients diagnosed with iRBD who also underwent standardized autonomic function testing within 6 months of iRBD diagnosis, and who had clinical follow-up of at least 3 years following iRBD diagnosis. Patients who received a diagnosis of phenoconversion within 3 months of autonomic testing were excluded. The composite autonomic severity score (CASS) was derived and compared between phenoconverters and non-converters using chi-square and Wilcoxon rank-sum tests.

Results

We identified 18 patients who fulfilled in- and exclusion criteria. Average age at autonomic testing was 67 ± 6.6 years. Twelve (67%) patients phenoconverted during the follow-up period; 6 developed PD, the other 6 DLB. Fifteen (83%) patients had at least mild autonomic dysfunction. There were no significant differences between overall converters and non-converters in total CASS or CASS subscores. However, iRBD patients who developed DLB had significantly higher total and cardiovagal CASS scores compared with those who developed PD (p &lt;0.05), and a trend for higher adrenergic CASS scores compared to those who developed PD and those who did not phenoconvert (p=0.08 for each).

Conclusion

Autonomic dysfunction was seen in 83% of iRBD patients, and more severe baseline cardiovagal and adrenergic autonomic dysfunction in iRBD was associated with phenoconversion to DLB but not PD. Prospective studies are needed to confirm the value of autonomic testing for predicting phenoconversion and disease phenotype in iRBD.

Support

 

Folate Receptor Near-Infrared Optical Imaging Provides Sensitive and Specific Intraoperative Visualization of Nonfunctional Pituitary Adenomas

BACKGROUND

Surgical resection is the primary treatment for nonfunctional (NF) pituitary adenomas, but gross-total resection is difficult to achieve in all cases. NF adenomas overexpress folate receptor alpha (FRα).

OBJECTIVE

To test the hypothesis that we could target FRα for highly sensitive and specific intraoperative detection of NF adenomas using near-infrared (NIR) imaging.

METHODS

Fourteen patients with NF pituitary adenoma were infused with the folate analog NIR dye OTL38 preoperatively. NIR fluorescence signal-to-background ratio (SBR) was recorded for each tumor during resection of the adenomas. Extent of surgery was not modified based on the presence or absence of fluorescence. Immunohistochemistry was performed to assess FRα expression in all specimens. Magnetic resonance imaging (MRI) was performed postoperatively to assess residual neoplasm.

RESULTS

Nine adenomas overexpressed FRα and fluoresced with a NIR SBR of 3.2 ± 0.52, whereas the 5 non-FRα-overexpressing adenomas fluoresced with an SBR of 1.5 ± 0.21. Linear regression demonstrated a significant correlation between intraoperative SBR and the FRα expression (P-value < .001). Analysis of 14 margin samples revealed that the surgeon's impression of the tissue had 83% sensitivity, 100% specificity, 100% positive predictive value, and 89% negative predictive value, while NIR fluorescence had 100% for all values. NIR fluorescence accurately predicted postoperative MRI results in 78% of FRα-overexpressing patients.

CONCLUSION

Preoperative injection of folate-tagged NIR dye provides strong signal and visualization of NF pituitary adenomas. It is 100% sensitive and specific for detecting margin neoplasm and can predict postoperative MRI findings. Our results suggest that NIR fluorescence may be superior to white-light visualization alone and may improve resection rates in NF pituitary adenomas.

Abstract 2316: Systemic Control of CAR T Cell Activity Using a Secret Passageway Fusion Receptor

Chimeric antigen receptor (CAR) T cells are modified T cells that have been genetically engineered to recognize and kill any cancer cell expressing a specific cell surface tumor antigen. Despite the remarkable success of CAR T cell technologies to date, adoption of the technologies has been limited by severe side-effects such as a potentially fatal cytokine release syndromes (CRS), neurologic toxicities, and on-target off-tumor toxicities, etc. Moreover, chronic exposure of CAR T cells to tumor antigen can lead to CAR T cell exhaustion, which results in inactivation of the CAR T cell therapy. Therefore, an ability to sensitively control CAR T cell fate in vivo, either to suppress its activity when confronted with a cytokine storm, or to rejuvenate its activity when encountering CAR T cell exhaustion, would be highly desirable.

We have developed a CAR T cell regulatory platform that enables delivery of any desired modulator selectively into an engineered CAR T cell without simultaneously permitting any modulator uptake by other cells. For this purpose, a fusion receptor that contains two subdomains, a ligand binding module and a membrane-anchoring/internalizing module, is co-expressed with the classical CAR construct in the desired T cell. In the embodiment described here, the ligand binding domain is comprised of human FK506 binding protein (FKBP), while the membrane-anchoring/internalizing domain is comprised of sequences from human folate receptor alpha (FRα). Because the fusion construct is human, it is not expected to be highly immunogenic. Moreover, because FRα is a GPI-anchored cell surface protein that constitutively internalizes, the fusion construct is predicted to constantly enter cells by endocytosis throughout the lifespan of the CAR T cell.

We show here that this fusion construct can be co-expressed with an anti-CD19 CAR in the same human T cell with a T2A linker in between in one lentiviral vector. We then demonstrate that any CAR T cell modulator can be selectively targeted to CAR T cells in vivo by linking the desired modulator to FK506; i.e. the ligand that binds FKBP. Upon binding FKBP, the FK506-modulator conjugate is shown to rapidly internalize into the targeted CAR T cell via standard FRα endocytosis. Furthermore, when the linker connecting FK506 to the desired modulator is designed to be cleaved within early endosomes, the modulator is demonstrated to be released following entry into the CAR T cell, where it becomes immediately available for modulation of CAR T cell properties. In the panels shown in this poster, examples of the use of this universal CAR T cell regulatory strategy to control the activities of CAR T cells following their infusion into animal models are provided.

Citation Format: Boning Zhang, John V Napoleon, Philip Low. Systemic Control of CAR T Cell Activity Using a Secret Passageway Fusion Receptor [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 2316.

Standardization and Optimization of Intraoperative Molecular Imaging for Identifying Primary Pulmonary Adenocarcinomas

PURPOSE

Intraoperative molecular imaging (IMI) is an emerging technology used to locate pulmonary adenocarcinomas and identify positive margins during surgery. Background noise and tissue autofluorescence have been major obstacles. The goal of this study is to optimize the image quality of folate receptor alpha (FRα) targeted IMI for pulmonary adenocarcinomas by modifying emission data.

PROCEDURES

A total of 15 lung cancer patients were enrolled in a pilot study. In the first cohort, FRα upregulation within pulmonary adenocarcinoma tumors was confirmed by analyzing specimens from five pulmonary adenocarcinoma patients with flow cytometry and immunohistochemistry. Next, in a cohort of five additional patients, autofluorescence of intrathoracic structures and tissues was quantified. Lastly, five patients with tumors at various depths from the pleural surface were enrolled and received the FRα-targeted optical contrast agent, EC17. In this final cohort, resected pulmonary adenocarcinomas were imaged at a wide range of fluorescence exposure times (0 to 200 ms), various laser powers, and with unique filter configurations. Tumor-to-noise ratio (TNR) for images was generated using region of interest software.

RESULTS

Pulmonary adenocarcinomas highly express FRα. Significant autofluorescence from native thoracic tissues was found with the highest fluorescent signals at the bronchial stump (547 ± 98, range 423-699), the pulmonary artery (267 ± 64, range 200-374), and cortical bone (266 ± 17, range 243-287). High levels of autofluorescence were appreciated after systemic administration of EC17; however, TNR was improved by altering exposure settings at the time of the imaging. Optimal fluorescent exposure time occurs at 40 ms (25 frames/s).

CONCLUSIONS

Exposure properties can be manipulated to maximize TNR thus allowing for successful intraoperative detection of pulmonary adenocarcinomas during surgery. Optimization of the conditions for intraoperative molecular imaging sets the stage for future clinical trials utilizing targeted IMI techniques which can aid the surgeon at the time of cancer resection.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Utilization of targeted near-infrared molecular imaging to improve pulmonary metastasectomy of osteosarcomas

Pulmonary metastasectomy for osteosarcoma provides a select group of patients an opportunity for long-term survival and possible cure. Unfortunately, a complete metastasectomy is challenging due an inability to accurately identify lesions that lay below the threshold of preoperative imaging or intraoperative visual and tactile inspection. Growing evidence suggests that osteosarcomas express a number of unique molecular markers, including the folate receptor alpha. In this case report, we describe the application of a folate receptor-targeted, near-infrared optical contrast agent (OTL38) to improve osteosarcoma localization during minimally invasive pulmonary resection. In addition to localizing preoperatively identified lesions, this technology helped identify additional disease that was undetected on preoperative imaging or with traditional intraoperative techniques. This report marks the first successful utilization of a molecular imaging probe useful for osteosarcomas. This technology may provide a unique approach to improve pulmonary metastasectomy of osteosarcomas.

Intraoperative Molecular Imaging of Lung Adenocarcinoma Can Identify Residual Tumor Cells at the Surgical Margins

PURPOSE

During lung surgery, identification of surgical margins is challenging. We hypothesized that molecular imaging with a fluorescent probe to pulmonary adenocarcinomas could enhance residual tumor during resection.

PROCEDURES

Mice with flank tumors received a contrast agent targeting folate receptor alpha. Optimal dose and time of injection was established. Margin detection was compared using traditional methods versus molecular imaging. A pilot study was then performed in three humans with lung adenocarcinoma.

RESULTS

The peak tumor-to-background ratio (TBR) of murine tumors was 3.9. Fluorescence peaked at 2 h and was not improved beyond 0.1 mg/kg. Traditional inspection identified 30% of mice with positive margins. Molecular imaging identified an additional 50% of residual tumor deposits (p < 0.05). The fluorescent probe visually enhanced all human tumors with a mean TBR of 3.5.

CONCLUSIONS

Molecular imaging is an important adjunct to traditional inspection to identify surgical margins after tumor resection.

Intraoperative Molecular Diagnostic Imaging Can Identify Renal Cell Carcinoma

PURPOSE

Margin status can often be difficult to assess intraoperatively, particularly during partial nephrectomy given the time constraints related to renal hilar clamping. We hypothesized that a targeted molecular imaging approach could be used during surgery to identify tumor margins and confirm disease clearance.

MATERIALS AND METHODS

EC17, a novel tracer targeting FRα, was used in murine models of renal cell carcinoma to identify positive margins after surgery. Positive margins were detected due to elevated tumor-to-background ratios of the tumor compared to surrounding normal tissues. We performed a pilot study in 4 patients using EC17 preoperatively with intraoperative imaging during the operation.

RESULTS

FRα was highly expressed in 65% of clear cell renal cell carcinomas harvested from the operating room. In the murine model intraoperative imaging of renal cell carcinoma revealed a mean ± SD tumor-to-background ratio of 8.2 ± 1.1 in the RCC10, 11.2 ± 1.1 in the 786-0 and 4.3 ± 1.1 in the UMRC2 cell line. Compared to visual inspection intraoperative imaging of the surgical resection bed identified residual disease in 24% more animals. In the human pilot study targeted molecular imaging identified 2 of 4 renal cell carcinomas and had no false-positive results. In these 2 cases the tumor-to-background ratio was 3.7 and 4.6, respectively. In each case we confirmed disease clearance and tumor fluorescence did not correlate with nodule size or tumor grade.

CONCLUSIONS

To our knowledge this is the first demonstration in humans of identifying renal cell carcinoma during surgery using a targeted molecular contrast agent. This approach may lead to a superior method of identifying malignancy and tumor borders in the intraoperative setting.

A Double-Blinded Randomized Trial to Compare the Effectiveness of Minimally Invasive Procedures Using Patient-Reported Outcomes

BACKGROUND

The Institute of Medicine has included the comparison of minimally invasive surgical techniques in its research agenda. This study seeks to evaluate a model for the comparison of minimally invasive procedures using patient-reported outcomes.

STUDY DESIGN

A double-blinded randomized controlled trial (NCT01489436) was conducted. Baseline data were obtained, standardized anesthesia was induced, and patients were randomized to single-port (SP) or 4-port (FP) laparoscopic cholecystectomy. Perioperative care was standardized. The outcomes were pain (Visual Analog Scale) on postoperative day 1 (primary) and quality of life (Patient-Reported Outcomes Measures Information System and Linear Analog Self-Assessment), serum cytokines, and heart rate variability (secondary). Analysis was intention to treat. Using identical occlusive dressings, patients and the outcomes assessor remained blinded until postoperative day 2.

RESULTS

Fifty-five patients were randomized to each arm. There was no difference in demographics. Visual Analog Scale pain score on postoperative day 1 was significantly different from baseline in each group (SP: 1.6 ± 1.9 to 4.2 ± 2.4 vs FP: 1.8 ± 2.3 to 4.2 ± 2.2), but not different from each other (p = 0.83). Patients in the FP arm reported significantly less fatigue on postoperative day 7 than patients in the SP group (3.1 ± 2.1 vs 4.2 ± 2.2; p = 0.009). Fewer patients in the FP group required postoperative oral narcotics before discharge (40% vs 60%; p = 0.056). Cytokines levels and heart rate variability were similar between arms. In patients followed for >1 year, no difference in umbilical hernia rates was noted.

CONCLUSIONS

Early postoperative quality of life data captured differences in fatigue, indicating improved recovery after FP within a controlled trial. Physiologic measures were similar, suggesting that the differences between SP and FP are minimal.

Management strategies for gastrointestinal, erectile, bladder, and sudomotor dysfunction in patients with diabetes

There are substantial advances in understanding disordered gastrointestinal autonomic dysfunction in diabetes. It occurs frequently. The underlying pathogenesis is complex involving defects in multiple interacting cell types of the myenteric plexus as well. These defects may be irreversible or reversible. Gastrointestinal symptoms represent a major and generally underestimated source of morbidity for escalating health care costs in diabetes. Acute changes in glycaemia are both determinants and consequences of altered gastrointestinal motility. 35-90% of diabetic men have moderate-to-severe erectile dysfunction (ED). ED shares common risk factors with CVD. Diagnosis is based on medical/sexual history, including validated questionnaires. Physical examination and laboratory testing must be tailored to patient's complaints and risk factors. Treatment is based on PDE5-inhibitors (PDE5-I). Other explorations may be useful in patients who do not respond to PDE5-I. Patients at high cardiovascular risk should be stabilized by their cardiologists before sexual activity is considered or ED treatment is recommended. Estimates on bladder dysfunction prevalence are 43-87% of type 1 and 25% of type 2 diabetic patients, respectively. Common symptoms include dysuria, frequency, urgency, nocturia and incomplete bladder emptying. Diagnosis should use validated questionnaire for lower urinary tract symptoms. The type of bladder dysfunction is readily characterized with complete urodynamic testing. Sudomotor dysfunction is a cause of dry skin and is associated with foot ulcerations. Sudomotor function can be assessed by thermoregulatory sweat testing, quantitative sudomotor axon reflex test, sympathetic skin response, quantitative direct/indirect axon reflex testing and the indicator plaster.

A comparison of depression, anxiety, and health status in patients with progressive supranuclear palsy and multiple system atrophy

The objective of this study was to compare subjective health status and its correlates in progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). One hundred eighty-eight patients with PSP and 286 patients with MSA completed EQ-5D and Hospital Depression and Anxiety Scale. The impact on mobility, usual activities, and self-care was similarly high in both groups after similar duration. Fifty-six percent of PSP and 43% of MSA had probable depression, and 37% of both groups had probable anxiety. Patients with PSP had significantly higher depression scores, but groups did not differ in anxiety scores. Patients with MSA had significantly greater pain/discomfort than patients with PSP. The most important association with subjective health status was with depressive symptoms, which accounted for 38% and 29% of EQ-5D variance in patients with PSP and MSA, followed by disease severity and anxiety scores. We conclude that depressive symptoms were common in both disorders, but more severe in PSP. Anxiety symptoms affected 37% of patients in both groups and contributed to impaired subjective health status. Pain was more problematic in MSA than PSP.

Abstract 3248: PSMA specific imaging of prostate cancer

A peptide derivative of a prostate specific membrane antigen (PSMA) targeting ligand [Glu-C(O)-Glu] was designed to efficiently coordinate 99mTc. This chelate, referred to as EC0652, was found to bind cultured PSMA-positive LNCaP tumor cells in a concentration-dependent manner with very high affinity (Kd ∼ 20 nM). Its binding was reduced &gt; 10 fold in the presence of the ligand competitor PMPA (a high affinity PSMA binder). In addition, this molecule did not bind to panel of PSMA negative cells (4T1, A549, IGR-OV1, J6456, KB, L1210 and M109), thereby demonstrating the agent's PSMA-specific binding property. Following intravenous injection into nu/nu mice, 99mTc-EC0652 was rapidly cleared from circulation (and non-targeted tissues), and only 1.3% of the injected dose remained in the blood after 1 hour. Data from quantitative biodistribution studies confirmed that 99mTc-EC0652 predominantly accumulates in PSMA-positive subcutaneous LNCaP tumor and kidney (PSMA/glutamate carboxypeptidase positive) tissues. Net uptake in the tumor and kidney remained steady throughout the 8 h experiment resulting in a continued increase in tumor to background tissue radioactivity with time. Radioactive uptake in both of these tissues was reduced &gt; 10 fold when this radiodiagnostic imaging agent was co-dosed with PMPA. The safety of decayed 99mTc-EC0652 was evaluated as a single intravenous dose in an acute toxicology study in male mice. All doses tested were well tolerated with no demonstrated toxicity. The study established a no observed adverse effect level (NOAEL) of 14.0 mg/kg, a dose which provides an appropriate safety margin relative to the FDA designated Phase 0 dose. Equipped with these encouraging results, preparations have begun for a Phase 0 clinical trial to evaluate 99mTc-EC0652 distribution in patients with metastatic prostate cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3248.

Measuring health-related quality of life in MSA: the MSA-QoL

The objective of this study was to develop a new patient-reported outcome measure for patients with multiple system atrophy (MSA) and to test its psychometric properties. There were three stages. First, a pool of potential scale items was generated from in-depth patient interviews. Second, these items were administered, in the form of a questionnaire, to a sample of people with MSA and traditional psychometric methods used to develop a rating scale satisfying standard criteria for reliability and validity. Third, the psychometric properties of the rating scale were examined in a second sample. In stage one, a pool of 105 items was generated from 20 patient interviews. In stage two, a scale with three subscales (motor, 14 items; nonmotor, 12 items; emotional/social functioning, 14 items), satisfying standard criteria for reliability and validity, was developed from the response data of 317 patients with MSA (response rate 71%). In stage three, the scale was examined in 286 people with MSA. Missing data were low, scores in both subscales were evenly distributed, and floor and ceiling effects were small. Reliability was high (Cronbach's alpha 0.83-0.93; test-retest ICC 0.88-0.92). Validity was supported by the interscale correlations (r = 0.47-0.59), known group differences, and the magnitude and pattern of correlations with four other rating scales, disease severity, and disease duration. In conclusion, the patient-rated MSA health-related Quality of life scale (MSA-QoL) may be a suitable patient-reported scale for use in clinical trials and studies in MSA.

A phase II study of FolateImmune (EC90 with GP1–0100 adjuvant followed by EC17) with low dose cytokines interleukin-2 (IL-2) and interferon-α (IFN-α) in patients with refractory or metastatic cancer

13516

Background: FolateImmune is a folate-receptor (FR)-targeted immunotherapy that induces an immune response against tumor cells by marking them with a folate-hapten conjugate. The conjugate is specifically designed to target FR, which is over-expressed in a variety of cancers. FolateImmune therapy is comprised of a vaccine fluorescein conjugate (EC90), an adjuvant (GP-0100), and a folate-hapten conjugate (EC17). Patients (pts) receive a series of subcutaneous (SQ) injections of EC90 vaccine to stimulate the production of antibodies to the fluorescein-hapten, followed by SQ injections of EC17, which forms a molecular bridge between the tumor cell and the endogenous circulating anti-fluorescein IgG antibody. This is thought to initiate an Fc-mediated immune response leading to antibody-dependent cellular cytotoxicity and/or phagocytosis. IL-2 and IFN are utilized at low doses (7 MIU and 3 MIU, respectively) to further promote an immune response. The Phase Ib objective is to determine the safety of EC90 vaccine/EC17 folate-targeted therapy in combination with IL-2 and IFN. The previous phase I trial explored the safety of FolateImmune without cytokines. Methods: This phase 1b safety study treated eligible patients with FolateImmune therapy at dose levels of 1.2 mg EC90 and EC17 of 0.3 mg/kg. Results: As of Jan 2, 2007, all patients have tolerated therapy without significant toxicity. Grade 1–2 toxicity included: chills, fever, and nausea. One patient has had a minor response and continues on study. Laboratory studies revealed decline in circulating FR+ cells. Of 6 pts enrolled, 5 had a pathologic classification of renal cell cancer (RCC). Conclusion: Preliminary data suggest that FolateImmune therapy, with the addition of low dose cytokines, may be administered in a safe and well-tolerated manner. Phase II trials are planned for RCC.

No significant financial relationships to disclose.

The North American Multiple System Atrophy Study Group

The North American Multiple System Atrophy Study Group involves investigators in 12 US medical centers funded by a grant from the National Institutes of Health. The objectives are to examine the environmental and genetic risk factors for MSA; elucidate pathogenic mechanisms underlying the disorder; and refine evaluations used for assessment. During its first year, the group enrolled 87 patients, implemented four cores, and initiated four scientific projects. Most patients among the 87 had parkinsonian features, which frequently began asymmetrically and remained asymmetrical; one-third responded to levodopa and many developed levodopa complications; almost two-thirds of the patients had cerebellar dysfunction, of these 90% had ataxia; urinary incontinence occurred commonly, and sleep disorders affected most. The investigators studied the effects of oxidative and nitrative stress upon the formation of alpha-synuclein inclusions; generated transgenic models of alpha-synuclein accumulation that recapitulate several behavioral and neuropathological features of MSA; and compared the severity of the autonomic features of MSA, Parkinson's disease and dementia with Lewy bodies.

The N-terminal 11 amino acids of human erythrocyte band 3 are critical for aldolase binding and protein phosphorylation: implications for band 3 function

The 911 amino acid band 3 (SLC4A1) is the major intrinsic membrane protein of red cells and is the principal Cl-/HCO3- exchanger. The N-terminal cytoplasmic domain of band 3 anchors the spectrin-based membrane skeleton to the lipid bilayer through its interaction with ankyrin and also binds glycolytic enzymes and hemoglobin. We identified a son of a consanguineous marriage with severe anemia in association with marked deficiency of band 3 (12% +/- 4% of normal). Direct nucleotide sequencing of SLC4A1 gene demonstrated a single base substitution (T --> C) at position + 2 in the donor splice site of intron 2, resulting in the generation of a novel mutant protein. Biochemical characterization of the mutant protein showed that it lacked the first 11 N-terminal amino acids (band 3 Neapolis). The expression of the mutant protein resulted in the complete absence of membrane-bound aldolase, and the mutant band 3 could not be tyrosine phosphorylated. The ability of the malarial parasite P falciparum to invade these red cells was significantly decreased. The identification of a novel band 3 mutant and its structural and functional characterization enabled us to identify pivotal roles for the 11 N-terminal amino acids in several protein functions and, in turn, in red-cell physiology.

Assay for Rab geranylgeranyltransferase using size exclusion chromatography

A simple chromatographic assay for Rab geranylgeranyltransferase (Rab GGTase) has been developed. The method involves separation of the reaction mixture on a Sephadex G-25 superfine minicolumn. Addition of 2-propanol to the assay results in substantial (approximately 90%) decline of formation of noncovalent lipid-protein complexes, increasing reproducibility and reliability of the method. The activity of Rab prenyltransferase was measured in crude and partially purified enzyme preparations from wheat seedlings; measurements for several other plants and rat brain cytosol fractions are also presented. This method can be routinely applied to evaluate the activity of different protein prenyltransferases.

Evidence-based design: the ACOEM Practice Guidelines Dissemination Project

A steering committee and investigators from the American College of Occupational and Environmental Medicine (ACOEM) designed and carried out the ACOEM Practice Guidelines Dissemination Project to encourage adoption of the ACOEM Occupational Medicine Practice Guidelines. The project also involved research on guideline acceptance as well as potential improvements and additions to the guidelines. To increase guideline adoption and use in improving the appropriateness and consistency of practice and case management, the design was based on existing research on guideline format, education, and adoption efforts. This article summarizes that information and the needs assessment done prior to case-based guidelines training. Other articles in this issue report on guideline adoption and use and the results of the market research on the ACOEM guidelines.

Acceptance and self-reported use of national occupational medicine practice guidelines

The authors conducted a survey to ascertain post-training attitudes and self-reported use of the American College of Occupational and Environmental Medicine occupational medicine practice guidelines. Trainees were surveyed 3 to 4 months after completing a case-based practice ACOEM occupational practice guidelines seminar. Of 96 physician respondents, 95% reported that the guidelines improved their practice in some manner. Fifty-two percent of physicians thought that guideline use decreased medical costs. Seventy-one percent reported that their care complied with the guidelines in 70% or more of their cases; however, "actually considering the guidelines in particular cases" was reported by only 47%. Discussion of cases was frequent (92%) and involved physicians, patients, and other health care providers. We concluded that physicians' attitudes toward the guidelines are positive and that reported compliance is high. Guidelines are discussed frequently.

Beliefs about and use of occupational medicine practice guidelines by case managers and insurance adjusters

Workers' compensation case managers and adjusters have increased their use of practice guidelines recently, partly in response to state regulations. However, informally reported rates of use are not as high as desired for the best managed care practices and the greatest reductions in lost work time. Although there are several studies of physicians' use of guidelines, there are few if any studies about case managers' and adjusters' beliefs about, and utilization of, either general medical or occupational medical practice guidelines. Information about attitudes, beliefs about practice guidelines, and actual use should help developers make the guidelines more usable and bring about more effective interaction among case managers, adjusters, treating physicians, and other health professionals. This article reports on pre- and post-training surveys of a cohort of case managers and adjusters who participated in a case-based guideline training course. It then compares their responses to those of the physicians whose cases they might manage.

Suggested improvements in practice guidelines: market research to support clinical quality improvement

The American College of Occupational and Environmental Medicine's Practice Guideline Dissemination Project included market research to better understand the wants and needs of physicians, case managers, and insurance adjusters who used the guidelines. We used structured and open-ended survey questions and focus groups administered to a cohort of physicians, adjusters, and case managers trained as part of the project. Respondents were generally satisfied with the format and contents of the guidelines. They requested additional material on case management and facilitation of effective treatment and return to work by other health professionals. They also suggested a variety of formats to improve the accessibility of the guidelines. The suggestions may be used in new product development or for guideline revisions.

[Consensus on the diagnosis of multi-system atrophy]

We report the results of a consensus conference on the diagnosis of multiple system atrophy. We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible multiple system atrophy requires one criterion plus two features from separate domains. The diagnosis of probable multiple system atrophy requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite multiple system atrophy requires pathological confirmation.

Consensus statement on the diagnosis of multiple system atrophy. American Autonomic Society and American Academy of Neurology

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Chronic hypoxia induces selective maldevelopment of peripheral myelin in rat

To determine the morphologic effect of chronic hypoxia on peripheral nerve development, four-week-old rats were placed in a 10% O2 environment for ten weeks and compared with controls. Light microscopic morphometric analysis of hind limb nerves of hypoxic as compared to control nerves showed at statistically significant levels, a) smaller total fascicular areas, b) smaller median diameters, c) fiber spectra with peaks at smaller diameters, d) fewer large myelinated fibers per nerve, e) larger fiber density, f) smaller myelin areas. On average myelin areas, relative to axon size, were smaller in oxygen-deprived than in control rats. Also myelin spiral length and the number of myelin lamellae relative to axon area were smaller. These findings suggest that hypoxia retards myelinated fiber diameter and especially myelin development.

Somatic and autonomic function in progressive autonomic failure and multiple system atrophy

We studied 62 consecutive patients with progressive autonomic failure (PAF) or multiple system atrophy (MSA) (26 PAF; 36 MSA). Patients were well matched in age (67 vs 66 years), duration (39 vs 36 months), and severity of autonomic failure (median values for PAF and MSA). Peripheral somatic neuropathy occurred in 2 patients with PAF and 7 patients with MSA. Postganglionic sudomotor and vasomotor functions were studied using the quantitative sudomotor axon reflex test and supine plasma norepinephrine. The extent and severity of autonomic failure were assessed by the thermoregulatory sweat test, by heart rate responses to deep breathing and the Valsalva maneuver, and by blood pressure recordings. Severe and widespread anhidrosis was found in both PAF and MSA patients. Postganglionic sudomotor failure occurred at the forearm in 50% each of PAF and MSA patients and at the foot in 69% and 66% of PAF and MSA patients, respectively. However, postganglionic sudomotor function was preserved in some patients with anhidrosis on thermoregulatory sweat test, indicating a preganglionic lesion. Vagal abnormalities were found in 77% and 81% of PAF and MSA patients. Supine plasma free norepinephrine values were significantly reduced in PAF (p less than 0.001), but not in MSA, patients. Standing plasma norepinephrine values were reduced in both PAF (p less than 0.001) and MSA (p less than 0.001) patients. We conclude the following: (1) PAF is characterized by combined postganglionic sudomotor and adrenergic failure. (2) MSA is associated with a similar frequency of postganglionic sudomotor failure, but postganglionic adrenergic denervation was uncommon. (3) Preganglionic neuron is also involved in both disorders, but more severely in MSA. (4) Somatic neuropathy may occur.

Slow axonal transport in experimental hypoxia and in neuropathy induced by p-bromophenylacetylurea

The slow axonal transport of proteins radiolabeled by incorporation of [35S]methionine was studied in motor nerves of rats subjected to chronic hypoxia. The conditions involved exposure to an atmosphere of 8-10% oxygen for periods of 3, 5, or 10 weeks. An experimentally verified computer model predicted a drop in mean endoneurial oxygen tension from 30.5 to 19 mm Hg, despite a measured increase in circulating hemoglobin from 16 to 22 g%. Nerve conduction velocity was unaffected during the early stages of hypoxia. After 10 weeks of hypoxia, conduction velocity still appeared normal in the sciatic nerve but was reduced in the caudal nerve by 2.5-4.5 m/s. At no time, however, was there evidence of impaired slow axonal transport, which proceeded with a mean velocity between 1 and 2 mm/day. Another set of experiments was performed to evaluate slow axonal transport in motor nerves of rats with peripheral neuropathy induced by the toxicant, p-bromophenylacetylurea. The results suggested a lower transport velocity in rats showing total hind-limb paralysis as compared with rats showing only mild to moderate motor dysfunction. The difference, however, could have reflected accelerated transport in mild neuropathy. In our view, the observations in experimental hypoxia- and toxicant-induced neuropathy are noteworthy for the resistance of slow transport to perturbation of the neuronal environment.

Combined azathioprine and prednisone in chronic inflammatory-demyelinating polyneuropathy

Twenty-seven patients with static or worsening chronic inflammatory-demyelinating polyradiculoneuropathy were randomly assigned to alternate day decremental prednisone therapy alone or with azathioprine (2 mg/kg) for 9 months. No statistically significant alterations were demonstrated between these treatment schedules.

Spatial pattern of nerve fiber abnormality indicative of pathologic mechanism

Estimates of the number, density, and size distribution of myelinated fibers at selected levels of roots, spinal tracts, and sampled levels of peripheral nerves may be used in the detection and characterization of alterations of motor, sensory, and autonomic neurons and their axons with development, aging and disease. Use of imaging techniques, now available, increases the reliability, versatility, and speed of such analysis. In this study, the authors evaluated the spatial pattern of fibers in sampled frames and contour areas of transverse sections of nerve fascicles, utilizing, the coefficient of variation and index of dispersion (ID), the latter extensively employed by plant ecologists. The ID was used for recognization of increased, normal, or decreased variability of density within fascicles, between fascicles, and between nerves in health and in various experimental neuropathies. In addition, various morphometric measurements were made in transverse sections at defined levels along the hind limb nerves of rats in acute and chronic ischemia, after rhizotomy and in galactose neuropathy. These stereomorphometric studies, emphasizing the number, size, shape, and spatial pattern of fibers, revealed differences among experimental neuropathies and may be found to be helpful in the characterization and prediction of pathologic mechanisms in neuropathies of unknown cause. Specifically, these approaches could be used for study of whether fiber loss in human diabetic neuropathy is multifocal and determination of the levels of such losses.