Biomedical subjects

Matthew Freedman

Publications and source records attributed to Matthew Freedman.

18 recordsLinked to original sources

PubMed2006

A comprehensive analysis of the androgen receptor gene and risk of breast cancer: results from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3).

INTRODUCTION: Androgens have been hypothesised to influence risk of breast cancer through several possible mechanisms, including their conversion to estradiol or their binding to the oestrogen receptor and/or androgen receptor (AR) in the breast. Here, we report on the results of a large and comprehensive study of the association between genetic variation in the AR gene and risk of breast cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3). METHODS: The underlying genetic variation was determined by first sequencing the coding regions of the AR gene in a panel of 95 advanced breast cancer cases. Second, a dense set of markers from the public database was genotyped in a panel of 349 healthy women. The linkage disequilibrium relationships (blocks) across the gene were then identified, and haplotype-tagging single nucleotide polymorphisms (htSNPs) were selected to capture the common genetic variation across the locus. The htSNPs were then genotyped in the nested breast cancer cases and controls from the Cancer Prevention Study II, European Prospective Investigation into Cancer and Nutrition, Multiethnic Cohort, Nurses' Health Study, and Women's Health Study cohorts (5,603 breast cancer cases and 7,480 controls). RESULTS: We found no association between any genetic variation (SNP, haplotype, or the exon 1 CAG repeat) in the AR gene and risk of breast cancer, nor were any statistical interactions with known breast cancer risk factors observed. CONCLUSION: Among postmenopausal Caucasian women, common variants of the AR gene are not associated with risk of breast cancer.

Aged↗

PubMed2006

Abnormalities on chest radiograph reported in subjects in a cancer screening trial.

BACKGROUND: Chest radiographs (CXRs) are commonly performed for diagnostic and other purposes. There is little literature either on the prevalence in the general population of various abnormalities seen on CXRs or on the risks associated with these abnormalities. METHODS: We followed up > 70,000 men and women who were enrolled in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Subjects received four annual posteroanterior CXRs for the early detection of lung cancer. Radiologists noted the presence of non-cancer-related abnormalities as well as nodules/masses that were suspicious for lung cancer. Subjects were followed up for mortality and cancer incidence. RESULTS: Abnormalities that were not suspicious for lung cancer were observed on 35% of examinations, compared to 8% of examinations with findings that were suspicious for cancer. The most commonly reported noncancer abnormalities were granuloma (10.7% of examinations), scarring/pulmonary fibrosis (8.2% of examinations), bone/soft tissue lesions (5.5% of examinations), cardiac abnormalities (4.4% of examinations), pleural fibrosis (3.6% of examinations), and COPD/emphysema (2.5% of examinations). Most noncancer abnormalities were more prevalent in men, older subjects, and smokers. Controlling for age, smoking, and other factors, scarring/pulmonary fibrosis was significantly associated with an increased risk of lung cancer with a hazard ratio (HR) of 2.0, while cardiac abnormalities (HR, 2.1), scarring/pulmonary fibrosis (HR, 1.4), COPD (HR, 1.7), and pleural fluid (HR, 2.3) were significantly associated with increased overall (ie, non-lung cancer) mortality. CONCLUSION: Abnormalities that are not suspicious for lung cancer are common in a population undergoing screening. Some of these abnormalities are associated with an increased risk for lung cancer incidence and/or overall mortality.

Age Factors↗

PubMed2005

A zebrafish bmyb mutation causes genome instability and increased cancer susceptibility.

A major goal of cancer research has been to identify genes that contribute to cancer formation. The similar pathology between zebrafish and human tumors, as well as the past success of large-scale genetic screens in uncovering human disease genes, makes zebrafish an ideal system in which to find such new genes. Here, we show that a zebrafish forward genetic screen uncovered multiple cell proliferation mutants including one mutant, crash&burn (crb), that represents a loss-of-function mutation in bmyb, a transcriptional regulator and member of a putative proto-oncogene family. crb mutant embryos have defects in mitotic progression and spindle formation, and exhibit genome instability. Regulation of cyclin B levels by bmyb appears to be the mechanism of mitotic accumulation in crb. Carcinogenesis studies reveal increased cancer susceptibility in adult crb heterozygotes. Gene-expression signatures associated with loss of bmyb in zebrafish are also correlated with conserved signatures in human tumor samples, and down-regulation of the B-myb signature genes is associated with retention of p53 function. Our findings show that zebrafish screens can uncover cancer pathways, and demonstrate that loss of function of bmyb is associated with cancer.

Animals↗

PubMed2005

Diagnostic procedures after a positive spiral computed tomography lung carcinoma screen.

BACKGROUND: Low-radiation dose spiral computed tomography (LDCT) currently is being evaluated as a screening modality for lung carcinoma in a randomized trial. Although several diagnostic algorithms for the workup of positive LDCT screens have been proposed, to the authors' knowledge there is no widely accepted standard to date and there are few nationwide data concerning how such diagnostic workups are actually being performed outside a research protocol setting. METHODS: The Lung Screening Study (LSS) was a multicenter feasibility trial that randomized 1660 subjects to undergo LDCT and an equivalent number to undergo chest X-ray. Subjects with positive screens were referred to their own health care providers for diagnostic follow-up; LSS did not specify a diagnostic algorithm. LSS collected and abstracted medical records regarding procedures employed in the diagnostic workup of positive screens. RESULTS: Of the 522 subjects with a positive LDCT screen at baseline or at Year One, 12% underwent biopsy. Biopsy was less likely to be performed in subjects with 4-9-mm nodules (5%) than in subjects with nodules measuring 10+ mm (25%) or in subjects with no nodules but other suspicious findings (15%). Among 63% of the subjects who underwent chest CT on follow-up, the median time between screening and first follow-up chest CT was 82 days. Only a minority of subjects received diagnostic workups that were consistent with published algorithms. CONCLUSIONS: The data from the current study represent the experience of subjects followed by their health care providers in five different U.S. metropolitan areas and one rural area. As such, they provide some indication of practices in the U.S. with regard to the diagnostic workup of patients with positive spiral CT screens.

Algorithms↗

PubMed2005

Final results of the Lung Screening Study, a randomized feasibility study of spiral CT versus chest X-ray screening for lung cancer.

The Lung Screening Study (LSS) was a pilot study designed to assess the feasibility of conducting a large scale randomized controlled trial (RCT) of low radiation dose spiral computed tomography (LDCT) versus chest X-ray (CXR) for lung cancer screening. Baseline results of LSS have been previously reported. Here, we report on the findings at the year one screen and on the final results of the LSS study. A total of 1660 subjects were randomized to the LDCT arm and 1658 to the CXR arm. Compliance with screening declined from 96% at baseline to 86% at year one in the LDCT arm and declined from 93% at baseline to 80% at year one in the CXR arm. Positivity rates for the year one screen were 25.8% for LDCT and 8.7% for CXR. Cancer yield was significantly less at year one for LDCT, 0.57%, than at baseline, 1.9%; cancer yield for CXR increased from 0.45% at baseline to 0.68% at year one. Forty lung cancers in the LDCT arm and 20 in the CXR arm were diagnosed over the study period. Stage I cancers comprised 48% of cases in the LDCT arm and 40% in the CXR arm. A total of 16 stage III-IV cancers were observed in the LDCT arm versus nine in the CXR arm. The LSS has established the feasibility of a RCT comparing annual spiral CT to chest X-ray for lung cancer screening.

Aged↗

PubMed2005

Long-term transfusion of polymerized bovine hemoglobin in a Jehovah's Witness following chemotherapy for myeloid leukemia: a case report.

A 52-year-old female Jehovah's Witness presented with relapsed secondary acute myeloid leukemia. Because of chemotherapy-induced anemia, she was infused with the bovine hemoglobin (Hb)-based oxygen carrier HBOC-201 (Biopure) as the sole means of transfusion support. HBOC-201 has only been used for management of acute hemorrhage, and its utility in providing longer term transfusion support is unknown. Over a period of 18 days, a total dose of 1230 g of HBOC-201 was delivered. Although the patient succumbed to the disease after 18 days of treatment, this case documents our experience with the highest dose and duration of HBOC-201 ever used. Although possible renal toxicity could not be definitively excluded, the homogeneous extraction of oxygen by the brain in the presence of and perhaps from HBOC-201 was demonstrated.

Animals↗

PubMed2005

Como international conference position statement: lung cancer screening for early diagnosis 5 years after the 1998 Varese conference.

BACKGROUND: Lung cancer is the most common cause of cancer death in the world. Nonetheless, public policy organizations have consistently recommended against screening for lung cancer, with the result that screening is not widely practiced. The Como Conference was undertaken to consider the need for a change in the existing recommendations against screening. PURPOSES: The primary objective of the Como Conference was to consider whether there is sufficient scientific evidence to advise screening for lung cancer among asymptomatic individuals outside the context of a clinical trial. Methodological issues that are relevant to the proper interpretation of early detection trials were carefully considered. Advantages and problems associated with technological advances in CT scans and digital chest radiographs (CXRs) were fully explored. Economic issues relevant to screening were also considered. RECOMMENDATIONS: It is recommended that physicians assume responsibility for informing high-risk individuals regarding options for screening for lung cancer. Targeted high-risk individuals include middle-aged or elderly men and women who are current or former cigarette smokers of > 20 to 30 pack-years without serious medical comorbidities. It is recommended that such persons be informed that symptomatic lung cancer is usually advanced and incurable, while surgery for early lung cancer offers a far better chance of cure. They should also be informed about advances in imaging technology, as they relate to CT scans and CXRs. CONCLUSIONS: Whenever possible, high-risk individuals should be encouraged to enroll in ongoing trials. For subjects who, though eligible, do not have access to such trials, a process of shared decision-making between physicians and at-risk individuals is strongly recommended. After discussion of the existing state of knowledge, high-risk individuals should be made aware that it is reasonable for them to choose to undergo testing for lung cancer.

Congresses as Topic↗

PubMed2004

A pilot study to establish a clinical model to perform phase II studies of breast cancer chemopreventive agents in women at high risk with biomarkers as surrogate endpoints for activity.

PURPOSE: Use of surrogate end point biomarkers in phase II trials may help select agents that appear to have activity and might be evaluated in future phase III definitive trials of breast cancer prevention. We performed a pilot clinical trial to establish the logistics for a clinical model to perform phase II studies of breast cancer chemopreventive agents in women at high risk with novel imaging techniques and candidate surrogate end point biomarkers for activity. We chose tamoxifen to establish proof of principal with a known effective agent. EXPERIMENTAL DESIGN: Women at a high risk of developing a new breast cancer and for whom tamoxifen was recommended were eligible. The women underwent baseline and 3 and 6 months mammogram and magnetic resonance imaging (MRI) of one breast to identify areas of water-like intensity (epithelial) and to determine the changes over time and MRI-directed core breast biopsies of these areas for surrogate end point biomarkers analysis. RESULTS: From August 1999 to March 2001, 26 women underwent baseline imaging and core biopsies. Sixteen women took tamoxifen and 10 chose not to. Overall, 79% of the samples contained glandular tissue evaluable for histology, but only 66% of the samples were evaluable for marker analysis. Only 12 patients had specimens with glandular tissue sufficient for marker analysis both at baseline and in at least one follow-up. Because of the small number of women with matched samples, marker analysis was not informative. CONCLUSIONS: This study shows the feasibility of obtaining serial core breast biopsies from women at a high risk of developing a new breast cancer. Patient participation in this model is satisfactory, and such a model may provide indication of drug activity. MRI-directed biopsy did not provide a high yield of evaluable samples, and additional work on adequate collection of epithelial tissue for surrogate end point biomarker analysis is thus necessary.

Adult↗

PubMed2004

Sensitivity of noncommercial computer-aided detection system for mammographic breast cancer detection: pilot clinical trial.

PURPOSE: To evaluate a noncommercial computer-aided detection (CAD) program for breast cancer detection with screening mammography. MATERIALS AND METHODS: A CAD program was developed for mammographic breast cancer detection. The program was applied to 2,389 patients' screening mammograms at two geographically remote academic institutions (institutions A and B). Thirteen radiologists who specialized in breast imaging participated in this pilot study. For each case, the individual radiologist performed a prospective Breast Imaging Reporting and Data System (BI-RADS) assessment after viewing of the screening mammogram. Subsequently, the radiologist was shown CAD results and rendered a second BI-RADS assessment by using knowledge of both mammographic appearance and CAD results. Outcome analysis of results of examination in patients recalled for a repeat examination, of biopsy, and of 1-year follow-up examination was recorded. Correct detection with CAD included a computer-generated mark indicating a possible malignancy on craniocaudal or mediolateral oblique views or both. RESULTS: Eleven (0.46%) of 2,389 patients had mammographically detected nonpalpable breast cancers. Ten (91%) of 11 (95% CI: 74%, 100%) cancers were correctly identified with CAD. Radiologist sensitivity without CAD was 91% (10 of 11; 95% CI: 74%, 100%). In 1,077 patients, follow-up findings were documented at 1 year. Five (0.46%) patients developed cancers, which were found on subsequent screening mammograms. The area where the cancers developed in two (40%) of these five patients was marked (true-positive finding) by the computer in the preceding year. Because of CAD results, a 9.7% increase in recall rate from 14.4% (344 of 2,389) to 15.8% (378 of 2,389) occurred. Radiologists' recall rate of study patients prior to use of CAD was 31% higher than the average rate for nonstudy cases (10.3%) during the same time period at institution A. CONCLUSION: Performance of the CAD program had a very high sensitivity of 91% (95% CI: 74%, 100%).

Adult↗

PubMed2004

State-of-the-art screening for lung cancer (part 1): the chest radiograph.

The chest radiographic methods used in prior studies of lung cancer screening and in current prospective clinical trials of lung cancer screening do not incorporate, as part of their prospective design, the newer methods available for the detection of lung nodules. DR, image processing, ES, and CAD have been shown to enhance lung nodule detection. TS is a promising method but with less supporting data currently available. These techniques, alone or in combination, do not equal the nodule detection capability of lung CT, but they are likely to benefit patients having CXRs for other clinically indicated purposes and when the detection of a nodule is incidental to the clinical indication for the radiographic study.

Female↗

PubMed2004

Detection of LOH and mitochondrial DNA alterations in ductal lavage and nipple aspirate fluids from hngh-risk patients.

We describe a method for the isolation of free DNA from ductal lavage (DL) and nipple aspirate fluid (NAF), and its evaluation for the presence of LOH at the BRCA1 and FHIT genes and for mitochondrial DNA (mtDNA) mutations at the D310 marker, to improve early detection of breast cancer. We evaluated 26 DL and six NAF samples from 14 women of known BRCA1 status, who have no clinical evidence of breast tumors: nine mutation carriers and five non-carriers. LOH studies at the BRCA1 locus were possible in 19/26 DL samples, and at the FHIT locus in 16/26 samples. In 4/9 mutation carriers we found LOH at the BRCA1 allele, and in two of these we also found LOH at the FHIT allele. In one of the mutation carriers with BRCA1 LOH, invasive breast cancer was subsequently detected, and the tumor showed the same LOH as the DL. In one of the true negatives, BRCA1 and FHIT LOH were detected. The mitochondrial studies were possible in all 26 DL samples and a somatic mutation was found in 3/9 carriers, two of whom also had LOH at the BRCA1 locus, and in none of the non-carriers. mtDNA mutation evaluation was possible in 4/6 NAF samples. The NAF and DL results were concordant. One NAF sample from a BRCA1 patient showed a mtDNA mutation. Our data demonstrates the feasibility of performing molecular studies using the free DNA present in the ductal fluid, while the intact cells can be used for cytologic studies.

Acid Anhydride Hydrolases↗

PubMed2004

Improved small volume lung cancer detection with computer-aided detection: database characteristics and imaging of response to breast cancer risk reduction strategies.

Computer-aided detection (CAD) and diagnosis (CADx) of in vivo imaging studies are important tools based on bioinformatics. Currently, there are two diseases for which the United States Food and Drug Administration (FDA) has given premarket approval (PMA): the detection of signs consistent with lung cancer on chest radiographs and breast cancer on mammograms. There are systems for other diseases and other types of images under development; however, this process depends on the availability of an accurate database. The author helped in the development of the databases for such systems and management of the clinical trial that resulted in the FDA-PMA of the system that detects findings consistent with lung cancer. The characteristics of the database used will be described. Further, a woman's risk of developing breast cancer differs from those of other women. Risk can be high, average, or low. There are now pharmaceuticals that decrease the risk that women, as a group, will develop breast cancer and it has been suggested that dietary changes could have similar effects. The pharmaceutical agents, though, have some associated side effects, and it is clinically important to determine whether these agents have decreased an individual woman's risk of breast cancer. In vivo imaging biomarkers of risk and successful risk reduction are therefore sought, but the information on possible in vivo imaging biomarkers is less mature than activities in CAD. Bioinformatics will be an important contributor to this in vivo imaging biomarker development.

Breast Neoplasms↗

PubMed2003

Acceptability of diagnostic tests for breast cancer.

PURPOSE: To assess the acceptability of new non-invasive breast cancer diagnostic tests intended to triage women in need of biopsy. METHODS: Women who had abnormal screening tests and had been recommended to have a biopsy were invited to receive digital mammography, magnetic resonance imaging (MRI), and nuclear medicine evaluation (Tc-99m-sestamibi scanning) before biopsy. Participants completed a questionnaire about satisfaction and acceptability of the procedures. Satisfaction measured women's overall and test-specific satisfaction. Acceptability was measured by self-reported discomfort, embarrassment and women's preference in terms of willingness to pay to avoid a biopsy. RESULTS: Women were satisfied with all of the potential diagnostic triage procedures. Most found the tests more comfortable than a routine mammogram (47, 50, and 66% undergoing MRI, digital mammography, and sestamibi scanning, respectively). Women who provided a response to willingness to pay questions (N = 43) were willing to pay an average of 611 dollars to have a test instead of a biopsy, if the test was as accurate as biopsy. The willingness to pay significantly decreased to 308 dollars if the test only had 95% accuracy. Those who had prior benign breast disease were less willing to pay for a test with 95% accuracy than those without this history. CONCLUSION: Instead of immediate biopsy after an abnormal screening, these results suggest that women would find non-invasive triage tests acceptable, or preferable to biopsy if they were equally accurate or nearly equally accurate as a biopsy. New technologies to diagnose breast cancer should focus on decreasing discomfort as well as increasing test accuracy.

Adult↗

PubMed2003

Modeling and E-M estimation of haplotype-specific relative risks from genotype data for a case-control study of unrelated individuals.

The US National Cancer Institute has recently sponsored the formation of a Cohort Consortium (http://2002.cancer.gov/scpgenes.htm) to facilitate the pooling of data on very large numbers of people, concerning the effects of genes and environment on cancer incidence. One likely goal of these efforts will be generate a large population-based case-control series for which a number of candidate genes will be investigated using SNP haplotype as well as genotype analysis. The goal of this paper is to outline the issues involved in choosing a method of estimating haplotype-specific risk estimates for such data that is technically appropriate and yet attractive to epidemiologists who are already comfortable with odds ratios and logistic regression. Our interest is to develop and evaluate extensions of methods, based on haplotype imputation, that have been recently described (Schaid et al., Am J Hum Genet, 2002, and Zaykin et al., Hum Hered, 2002) as providing score tests of the null hypothesis of no effect of SNP haplotypes upon risk, which may be used for more complex tasks, such as providing confidence intervals, and tests of equivalence of haplotype-specific risks in two or more separate populations. In order to do so we (1) develop a cohort approach towards odds ratio analysis by expanding the E-M algorithm to provide maximum likelihood estimates of haplotype-specific odds ratios as well as genotype frequencies; (2) show how to correct the cohort approach, to give essentially unbiased estimates for population-based or nested case-control studies by incorporating the probability of selection as a case or control into the likelihood, based on a simplified model of case and control selection, and (3) finally, in an example data set (CYP17 and breast cancer, from the Multiethnic Cohort Study) we compare likelihood-based confidence interval estimates from the two methods with each other, and with the use of the single-imputation approach of Zaykin et al. applied under both null and alternative hypotheses. We conclude that so long as haplotypes are well predicted by SNP genotypes (we use the Rh2 criteria of Stram et al. [1]) the differences between the three methods are very small and in particular that the single imputation method may be expected to work extremely well.

Algorithms↗

PubMed2002

Independent versus sequential reading in ROC studies of computer-assist modalities: analysis of components of variance.

RATIONALE AND OBJECTIVES: The authors analyzed two methods for arranging the temporal sequencing of unaided versus computer-assisted reading in multiple-reader, multiple-case receiver operating characteristic studies of detection of solitary pulmonary nodules on chest radiographs. In the "independent" mode the readings are separated by about I month; in the "sequential" mode, the computer-assisted reading immediately follows the unassisted reading. MATERIALS AND METHODS: The authors used the method of Beiden, Wagner, and Campbell (BWC) to decompose the components of variance of receiver operating characteristic accuracy measures into those that are correlated and those that are uncorrelated across reading conditions. Only the latter contribute to uncertainty in estimates of the difference in accuracy measures across reading conditions (unaided vs aided). This method was used to analyze data from two independent studies of the detection of solitary pulmonary nodules on chest radiographs. RESULTS: In the sequential reading mode the components that were correlated across reading conditions increased compared to the independent reading mode, as might be expected. What was not anticipated was the fact that the total reader variance was approximately the same for the two reading modes. The results were remarkably similar across the two independent studies analyzed. CONCLUSION: The sequential reading mode may thus be the more sensitive probe of the difference between unassisted and computer-assisted reading, if the mean effect is unperturbed (as here). It is also the least demanding on the logistics and investment of reader time.

Analysis of Variance↗

PubMed2002

Technology improvements for image-guided and minimally invasive spine procedures.

This paper reports on technology developments aimed at improving the state of the art for image-guided minimally invasive spine procedures. Back pain is a major health problem with serious economic consequences. Minimally invasive procedures to treat back pain are rapidly growing in popularity due to improvements in technique and the substantially reduced trauma to the patient versus open spinal surgery. Image guidance is an enabling technology for minimally invasive procedures, but technical problems remain that may limit the wider applicability of these techniques. The paper begins with a discussion of low back pain and the potential shortcomings of open back surgery. The advantages of minimally invasive procedures are enumerated, followed by a list of technical problems that must be overcome to enable the more widespread dissemination of these techniques. The technical problems include improved intraoperative imaging, fusion of images from multiple modalities, the visualization of oblique paths, percutaneous spine tracking, mechanical instrument guidance, and software architectures for technology integration. Technical developments to address some of these problems are discussed next. The discussion includes intraoperative computerized tomography (CT) imaging, magnetic resonance imaging (MRI)/CT image registration, three-dimensional (3-D) visualization, optical localization, and robotics for percutaneous instrument placement. Finally, the paper concludes by presenting several representative clinical applications: biopsy, vertebroplasty, nerve and facet blocks, and shunt placement. The program presented here is a first step to developing the physician-assist systems of the future, which will incorporate visualization, tracking, and robotics to enable the precision placement and manipulation of instruments with minimal trauma to the patient.

Back Pain↗

PubMedDate not supplied

Reflectance confocal microscopy for characterization of mammary ductal structures and development of neoplasia in genetically engineered mouse models of breast cancer.

The earliest steps of breast cancer begin with aberrations in mammary ductal structure. Techniques that enable an investigator to image in situ and then analyze the same tissue using biochemical tools facilitates identification of genetic networks and signaling pathways active in the imaged structure. Cellular confocal microscopy (VivaCell-TiBa, Rochester, New York) is used to image mammary ductal structures and surrounding vasculature in situ in intact wild-type and genetically engineered mice that develop ER alpha-initiated ductal carcinoma in situ (DCIS) and ER alpha-driven invasive mammary cancer. In wild-type mice, normal mammary ductal structures that appear from puberty through lactation are visualized and serially sectioned optically, and a developmental atlas is created. Altering tissue preparation enabled visualization of the vasculature surrounding the ductal structures. In the genetically engineered mice, aberrant mammary ductal structures and cancers are imaged and compared to corresponding normal structures. Different preparation techniques are able to preserve tissue for routine histological analyses and RNA isolation. Comparative studies demonstrate that reflectance confocal imaging provides more cellular detail than carmine-alum-stained mammary gland whole mounts and equivalent detail with hematoxylin and eosin stained tissue sections. In summary, reflectance confocal microscopy is a tool that can be used to rapidly and accurately analyze mammary gland structure.

Adenocarcinoma↗

PubMedDate not supplied

A tumor-targeted nanodelivery system to improve early MRI detection of cancer.

The development of improvements in magnetic resonance imaging (MRI) that would enhance sensitivity, leading to earlier detection of cancer and visualization of metastatic disease, is an area of intense exploration. We have devised a tumor-targeting, liposomal nanodelivery platform for use in gene medicine. This systemically administered nanocomplex has been shown to specifically and efficiently deliver both genes and oligonucleotides to primary and metastatic tumor cells, resulting in significant tumor growth inhibition and even tumor regression. Here we examine the effect on MRI of incorporating conventional MRI contrast agent Magnevist into our anti-transferrin receptor single-chain antibody (TfRscFv) liposomal complex. Both in vitro and in an in vivo orthotopic mouse model of pancreatic cancer, we show increased resolution and image intensity with the complexed Magnevist. Using advanced microscopy techniques (scanning electron microscopy and scanning probe microscopy), we also established that the Magnevist is in fact encapsulated by the liposome in the complex and that the complex still retains its nanodimensional size. These results demonstrate that this TfRscFv-liposome-Magnevist nanocomplex has the potential to become a useful tool in early cancer detection.

Animals↗