Metastatic Potential Of Primary Tumor Research Articles

Volumetric Evaluation of Staging 18F-FDG PET/CT Images in Patients with Esophageal Cancer.

Objectives:The aim of this study was to evaluate the metastatic potential of primary tumor and survival in esophageal cancer (EC) patients by using metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from the staging 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images. Another aim is to determine a tumor volume-based cut-off value to predict long-term survival.Methods:Medical records of EC patients were retrospectively evaluated. Sixty-two patients with staging 18F-FDG PET/CT and at least five years of follow-up were included in the study. The region of interest to the primary tumor and all metastatic sites was created and MTV and TLG values of the primary tumor (MTVp, TLGp) and total tumor volume (MTVt and TLGt) values were obtained. The relationship between the obtained MTV and TLG values and short-time (one-year) and long time (five-year) survival was investigated.Results:Significant factors on survival were determined as lymph node or distant metastasis (p=0.024, 0.008, respectively) at the staging PET/CT. A significant relationship between volumetric parameters of the primary tumor and total tumor burden (MTVp, TLGp, MTVwb and TLGwb) between survivors and non-survivors for one-year and five-year was detected. In receiver operating characteristics analysis, the most significant volumetric parameter was MTVwb, with area under curve 0.771 in estimated five-year survival. The best cut-off value was detected as 36.1 mL with 78% sensitivity and 75% specificity for MTVwb in determining long-term survivors.Conclusion:Tumor burden in 18F-FDG PET/CT images at the time of staging of patients with EC will contribute to the prediction of long-term survivors.

Metastatic Esophageal Carcinoma Cells Exhibit Reduced Adhesion Strength and Enhanced Thermogenesis.

Despite continuous improvements in multimodal therapeutic strategies, esophageal carcinoma maintains a high mortality rate. Metastases are a major life-limiting component; however, very little is known about why some tumors have high metastatic potential and others not. In this study, we investigated thermogenic activity and adhesion strength of primary tumor cells and corresponding metastatic cell lines derived from two patients with metastatic adenocarcinoma of the esophagus. We hypothesized that the increased metastatic potential of the metastatic cell lines correlates with higher thermogenic activity and decreased adhesion strength. Our data show that patient-derived metastatic esophageal tumor cells have a higher thermogenic profile as well as a decreased adhesion strength compared to their corresponding primary tumor cells. Using two paired esophageal carcinoma cell lines of primary tumor and lymph nodes makes the data unique. Both higher specific thermogenesis profile and decreased adhesion strength are associated with a higher metastatic potential. They are in congruence with the clinical patient presentation. Understanding these functional, biophysical properties of patient derived esophageal carcinoma cell lines will enable us to gain further insight into the mechanisms of metastatic potential of primary tumors and metastases. Microcalorimetric evaluation will furthermore allow for rapid assessment of new treatment options for primary tumor and metastases aimed at decreasing the metastatic potential.

The Role of Multiparametric Magnetic Resonance Imaging in the Study of Primary Tumor and Pelvic Lymph Node Metastasis in Stage IB1-IIA1 Cervical Cancer.

The aim of this study was to investigate the value of multiparametric magnetic resonance imaging (MRI) in demonstrating the metastatic potential of primary tumor and differentiating metastatic lymph nodes (MLNs) from nonmetastatic lymph nodes (non-MLNs) in stage IB1-IIA1 cervical cancer. Fifty-seven stage IB1-IIA1 subjects were included. The apparent diffusion coefficient (ADC) values and dynamic contrast-enhanced MRI (DCE-MRI) parameters of primary tumors and lymph nodes and the conventional imaging features of the lymph nodes were measured and analyzed. Mann-Whitney test and χ test were used to analyze statistically significant parameters, logistic regression was used for multivariate analysis, and receiver operating characteristic analysis was used to compare the diagnostic performance of the MLNs. Nineteen subjects had lymph node metastasis. A total of 94 lymph nodes were evaluated, including 30 MLNs and 64 non-MLNs. There were no significant difference in ADC and DCE-MRI parameters between metastatic and nonmetastatic primary tumors. The heterogeneous signal was more commonly seen in MLNs than in non-MLNs (P = 0.001). The values of ADCmean, ADCmin, and ADCmax of MLNs were lower than those of non-MLNs (P < 0.001). The values of short-axis diameter, K, Kep, and Ve of MLNs were higher than those of non-MLNs (P < 0.05). Compared with individual MRI parameters, the combined evaluation of short-axis diameter, ADCmean, and K showed the highest area under the curve of 0.930. Diffusion-weighted imaging and DCE-MRI could not demonstrate the metastatic potential of primary tumor in stage IB1-IIA1 cervical cancer. Compared with individual MRI parameters, the combination of multiparametric MRI could improve the diagnostic performance of lymph node metastasis.

Lithocholic acid, a bacterial metabolite reduces breast cancer cell proliferation and aggressiveness

Our study aimed at finding a mechanistic relationship between the gut microbiome and breast cancer. Breast cancer cells are not in direct contact with these microbes, but disease could be influenced by bacterial metabolites including secondary bile acids that are exclusively synthesized by the microbiome and known to enter the human circulation. In murine and bench experiments, a secondary bile acid, lithocholic acid (LCA) in concentrations corresponding to its tissue reference concentrations (< 1 μM), reduced cancer cell proliferation (by 10–20%) and VEGF production (by 37%), aggressiveness and metastatic potential of primary tumors through inducing mesenchymal-to-epithelial transition, increased antitumor immune response, OXPHOS and the TCA cycle. Part of these effects was due to activation of TGR5 by LCA. Early stage breast cancer patients, versus control women, had reduced serum LCA levels, reduced chenodeoxycholic acid to LCA ratio, and reduced abundance of the baiH (7α/β-hydroxysteroid dehydroxylase, the key enzyme in LCA generation) gene in fecal DNA, all suggesting reduced microbial generation of LCA in early breast cancer.

Abstract 1977: Tracking cancer colonization in xenografts using ultrasensitive accelerator mass spectrometry methods

Abstract Background: The inability to effectively treat metastases is the main reason for the limited progress in reducing the rates of cancer morbidity and mortality. One major drawback is the lack of quantitative assays for assessing the size and tissue prevalence of tumors in newly diagnosed individuals. Current methods for quantifying tumor burden are mainly qualitative and include measuring the gross weight of the affected organ, counting tumors on the surface of the organ, or evaluating a small sample of the organ using histologic sections. These methods are crude measures of tumor burden and size distribution, and in the case of histology, they are time consuming, difficult to process an adequate sample size and non-quantitative. Methods: Animal models of metastasis have been useful in identifying genes that regulate susceptibility to the development and progression of metastasis and have helped to highlight potential novel targets for drug development. In particular several small animal imaging technologies including magnetic resonance imaging, high frequency ultrasound, and optical imaging have been recently applied to this task. Each of these methods may be useful for specific research projects, based on their unique combination of resolution, image acquisition time, animal throughput, and cost-effectiveness, yet none of these modalities adequately address the need for rapid quantification of tumors across the entire organism, nor do they assess therapeutic effectiveness in eradicating cancer in xenograft models. We have developed an Accelerator Mass Spectrometry (AMS)-based high precision quantitative method for assessing the metastatic potential of primary tumors isolated from newly diagnosed patients. Results: Our AMS-based methodology to study metastasis uses xenograft cancer cells labeled with 14C-labeled thymidine that are delivered intravenously into NSG mice and allowed to develop metastatic cancer over the course of up to 10 weeks. At the end of the experiment, all vital organs are collected; the DNA is isolated and is examined by AMS for the presence of 14C-signal. The labeling was optimized to achieve sufficient signal such that a tumor derived from a single cell could be detected by AMS, in secondary tumors, in vivo, independent of histological data. Conclusions: Using this approach we have determined that tissue colonization by tumor cells is a very rare event, where most metastatic tumors are initiated by less than 10 cells delivered into NSG mice. Further optimization of these techniques will allow us to explore the metastatic potential of primary tumors, isolated from biopsies and expanded in Avatar mice. This study was supported in part by NIH P41MI03483 and was conducted under the auspices of the USDOE by LLNL (DE-AC52-07NA27344). IM number: LLNL-678306 Citation Format: Nicholas R. Hum, Kelly A. Martin, Michael Malfatti, Kurt Haack, Bruce A. Buchholz, Gabriela G. Loots. Tracking cancer colonization in xenografts using ultrasensitive accelerator mass spectrometry methods [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1977. doi:10.1158/1538-7445.AM2017-1977

Abstract 3891: Development of quantitative methods for assessing metastatic potential of human primary tumors

Abstract Background: The inability to effectively treat metastases is the main reason for the limited progress in reducing the rates of cancer morbidity and mortality. One major drawback is the lack of quantitative assays for assessing the size and tissue prevalence of tumors in newly diagnosed individuals. Current methods for quantifying tumor burden are mainly qualitative and include measuring the gross weight of the affected organ, counting tumors on the surface of the organ, or evaluating a small sample of the organ using histologic sections. These methods are crude measures of tumor burden and size distribution, and in the case of histology, they are time consuming, difficult to process an adequate sample size and non-quantitative. Methods: Animal models of metastasis have been useful in identifying genes that regulate susceptibility to the development and progression of metastasis and helped highlight potential novel targets for drug development. In particular several small animal imaging technologies including magnetic resonance imaging, high frequency ultrasound, and optical imaging have been recently applied to this task. Each of these methods may be useful for specific research projects, based on their unique combination of resolution, image acquisition time, animal throughput, and cost-effectiveness, yet none of these modalities adequately address the need for rapid quantification of tumors across the entire organism, nor do they assess therapeutic effectiveness in eradicating cancer in xenograft models. We have developed an Accelerator Mass Spectrometry (AMS)-based high precision quantitative method for assessing the metastatic potential of primary tumors isolated from newly diagnosed patients. Results: Our Accelerator Mass Spectrometry-based methodology to study metastasis uses xenograft cancer cells labeled with 14C-labeled thymidine that are delivered intravenously into NSG mice and allowed to develop metastatic cancer over the course of up to 10 weeks. At the end of the experiment, all vital organs are collected; the DNA is isolated and is examined by AMS for the presence of 14C-signal. The labeling was optimized to achieve sufficient signal such that a tumor derived from a single cell could be detected by AMS, in secondary tumors, in vivo, independent of histological data. Conclusions: Using this novel approach we have evaluated the metastatic potential of several prostate cancer cell lines, characterized stem-cell like sublines derived from prostate cancer cell lines [PC3] and examined tissue tropism of cancer sublines derived from kidney and liver metastatic tumors. Further optimization of these techniques will allow us to explore the metastatic potential of primary tumors, isolated from biopsies and expanded in Avatar mice. Citation Format: Kelly A. Martin, Nicholas Hum, Kurt W. Haack, Bruce A. Buchholz, Gabriela G. Loots. Development of quantitative methods for assessing metastatic potential of human primary tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3891.

Bridged cyclams as imaging agents for chemokine receptor 4 (CXCR4).

Over-expression of chemokine receptor 4 (CXCR4) is present in a majority of cancers, has been linked to an aggressive phenotype, and may indicate the metastatic potential of primary tumor. Several CXCR4 targeted therapeutics are in clinical trials and the development of the corresponding imaging agents is an area of active interest. Previously, (64)Cu-labeled imaging agents for CXCR4 have provided clear images of CXCR4-bearing tissues in relevant experimental models but demonstrated fast washout from tissues harboring receptor. Addition of stabilizing bridges is known to provide more robust chelator-Cu(II) complexes. In addition, bridged cyclam-based CXCR4 binding agents demonstrated increased receptor residence times relative to existing agents. Based on that knowledge we synthesized several bridged cyclam analogs of AMD3465, a monocyclam-based CXCR4 imaging agent, to increase the retention time of the tracer bound to the receptor to allow for protracted imaging and improved target-to-non-target ratios. Specific accumulation of two radiolabeled, cross-bridged analogs ([(64)Cu] RAD1-24 and [(64)Cu]RAD1-52) was observed in U87-stb-CXCR4 tumors in both PET/CT imaging and biodistribution studies. At 90min post-injection of radiotracer, tumor-to-muscle and tumor-to-blood ratios reached 106.05±17.19 and 28.08±4.78, respectively, for cross-bridged pyrimidine analog [(64)Cu]RAD1-52. Receptor blockade performed in vivo denoted target binding specificity. The biodistribution and PET/CT imaging studies with the radiolabeled bridged cyclams demonstrated longer tumor retention and comparable uptake to [(64)Cu]AMD3465, though [(64)Cu]AMD3465 demonstrated superior overall pharmacokinetics.

Expression of epithelial to mesenchymal transition-related markers in lymph node metastases as a surrogate for primary tumor metastatic potential in breast cancer

BackgroundBreast cancers are phenotypically and genotypically heterogeneous tumors containing multiple cancer cell populations with various metastatic potential. Aggressive tumor cell subpopulations might more easily be captured in lymph nodes metastases (LNM) than in primary tumors (PT). We evaluated mRNA and protein levels of master EMT regulators: TWIST1, SNAIL and SLUG, protein levels of EMT-related markers: E-cadherin, vimentin, and expression of classical breast cancer receptors: HER2, ER and PgR in PT and corresponding LNM. The results were correlated with clinicopathological data and patients outcomes.MethodsFormalin-fixed paraffin-embedded samples from PT and matched LNM from 42 stage II-III breast cancer patients were examined. Expression of TWIST1, SNAIL and SLUG was measured by reverse-transcription quantitative PCR. Protein expression was examined by immunohistochemistry on tissue microarrays. Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were compared using F-Cox test. Hazard ratios (HRs) with 95% confidence intervals (95% CI) were computed using Cox regression analysis.ResultsOn average, mRNA expression of TWIST1, SNAIL and SLUG was significantly higher in LNM compared to PT (P < 0.00001 for all). Gene and protein levels of TWIST1, SNAIL and SLUG were highly discordant between PT and matched LNM. Increased mRNA expression of TWIST1 and SNAIL in LNM was associated with shorter OS (P = 0.04 and P = 0.02, respectively) and DFS (P = 0.02 and P = 0.01, respectively), whereas their expression in PT had no prognostic impact. Negative-to-positive switch of SNAIL protein correlated with decreased OS and DFS (HR = 4.6; 1.1-18.7; P = 0.03 and HR = 3.8; 1.0-48.7; P = 0.05, respectively).ConclusionsLNM are enriched in cells with more aggressive phenotype, marked by elevated levels of EMT regulators. High expression of TWIST1 and SNAIL in LNM, as well as negative-to-positive conversion of SNAIL confer worse prognosis, confirming the correlation of EMT with aggressive disease behavior. Thus, molecular profiling of LNM may be used as surrogate marker for aggressiveness and metastatic potential of PT.

Abstract 2385: A highly sensitive detection system of genetic alterations in circulating tumor cells using a telomerase-specific replication-competent adenovirus

Abstract Background: Malignant tumor cells often develop metastatic nodules at distant organs through circulation in blood flow and result in poor prognosis. Detection of circulating tumor cells (CTCs) is clinically an important issue to evaluate the metastatic potential of primary tumors in cancer patients. Furthermore, confirmation of genetic alterations in CTCs provides us the critical information to clarify the molecular mechanism in the acquisition of metastatic capability of tumor cells and to treat tumor metastasis by molecular targeted therapy. We recently developed a telomerase-specific replication-selective adenovirus (OBP-401; TelomeScan) expressing the green fluorescence protein (GFP). OBP-401-mediated GFP induction method was a simple and highly sensitive imaging system to detect a small population of viable CTCs in the peripheral blood. In this study, we assessed the potential of OBP-401-mediated CTC detection system to analyze the genetic alterations in CTCs. Methods: We used two types of human colon cancer cell lines SW480 and HCT116 that have the mutations in codon 12 and 13, respectively, of the K-ras gene. The detection method involved a 4-step procedure, including the lysis of red blood cells, the subsequent addition of OBP-401 to the cell pellets, the isolation of GFP-positive tumor cells using a fluorescence-activated cell sorting (FACS), and a confirmation of genetic mutations by direct sequencing. DNA was extracted from the captured cells using FACS and we investigated the mutation status in the K-ras gene by direct sequencing. Results: When only 10 cells of SW480 or HCT116 cells were added in a 5 ml of blood obtained from healthy volunteer, a total of 2-12 GFP-positive cells were captured from OBP-401-infected blood samples using FACS Aria. We confirmed the mutations in codon 12 and 13 of the K-ras gene in the FACS-captured cells from blood samples containing SW480 and HCT116 cells, respectively, by direct sequencing. Conclusion: These results suggest that OBP-401-mediated GFP induction and FACS-based capture system are useful methods to isolate small population of CTCs from peripheral blood samples and to evaluate the genetic alterations in CTCs. The combination method using OBP-401 and FACS would be a reliable strategy for the surveillance of genetic alterations in CTCs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2385. doi:1538-7445.AM2012-2385

Intratumoral Epiregulin Is a Marker of Advanced Disease in Non–Small Cell Lung Cancer Patients and Confers Invasive Properties onEGFR-Mutant Cells

Non-small cell lung cancer (NSCLC) cells with activating epidermal growth factor receptor (EGFR) somatic mutations have unique biological properties, including high expression of the ErbB ligand epiregulin; however, the biological role of epiregulin in these cells has not been elucidated. To examine its role, we used an immunohistochemical approach to detect epiregulin expression in NSCLC biopsy samples and pharmacologic and genetic approaches to inhibit epiregulin in cultured NSCLC cells. In NSCLC biopsy samples, epiregulin was detected in 237 of 366 (64.7%) tumors, which correlated with nodal metastasis and a shorter duration of survival. In EGFR-mutant NSCLC cell lines, treatment with a small-molecule EGFR tyrosine kinase inhibitor diminished mRNA levels of the gene encoding epiregulin (EREG). The ability of EGFR-mutant NSCLC cells to invade through Matrigel in vitro was inhibited by treatment with an anti-epiregulin neutralizing antibody or by transfection with an EREG short hairpin RNA. Collectively, these findings show that epiregulin expression correlated with advanced disease, was EGFR dependent, and conferred invasive properties on NSCLC cells. Additional studies are warranted in NSCLC patients to evaluate whether epiregulin expression predicts the metastatic potential of primary tumors and whether anti-epiregulin treatment strategies are efficacious in the prevention of metastasis.

Effects of threshold choice on biological conclusions reached during analysis of gene expression by DNA microarrays

Global analysis of gene expression by using DNA microarrays is employed increasingly to search for differences in biological properties between normal and diseased tissue. In such studies, expression that deviates from defined thresholds commonly is used for creating genetic signatures that characterize disease vs. normality. Although it is axiomatic that the threshold parameters applied to microarray analysis will alter the contents of such genetic signatures, the extent to which threshold choice can affect the fundamental conclusions made from microarray-based studies has not been elucidated. We used GABRIEL (Genetic Analysis By Rules Incorporating Expert Logic), a platform of knowledge-based algorithms for the global analysis of gene expression, together with conventional statistical approaches, to examine the sensitivity of conclusions to threshold choice in recently published microarray-based studies. An analysis of the effects of threshold decisions in one of these studies [Ramaswamy, S., Ross, K. N., Lander, E. S. & Golub, T. R. (2003) Nat. Genet. 33, 49-54], which arrived at the important conclusion that the metastatic potential of primary tumors is encoded by the bulk of cells in the tumor, is the focus of this article. We discovered that support for this conclusion highly depends on the threshold used to create gene expression signatures. We also found that threshold choice dramatically affected the gene function categories represented nonrandomly in signatures. Our results suggest that the robustness of biological conclusions made by using microarray analysis should be routinely assessed by examining the validity of the conclusions by using a range of threshold parameters.

Immunostained cathepsins B and L correlate with depth of invasion and different metastatic pathways in early stage gastric carcinoma

With the recent development of minimal treatment for early stage gastric carcinoma, identifying specific indicators of the metastatic potential of primary tumors has become more important. Cathepsin B and cathepsin L, both lysosomal cysteine proteases, degrade the extracellular matrix during tumor progression. Although many studies have shown their relation to human cancer progression, little is known about their roles in the early stage. The clinicopathologic significance of cathepsins was therefore studied in early stage gastric carcinoma. Expression of both cathepsins was studied immunohistochemically in 51 tissue specimens from gastric carcinomas that invaded the submucosal layer or muscularis propria. The relation between their expression and clinicopathologic factors was analyzed. Both cathepsins were expressed at higher levels in tumors that invaded the muscularis propria than in those within the submucosa (P < 0.05). In addition, tumors with lymphatic invasion showed higher cathepsin B expression than those without it (P < 0.05), whereas tumors with venous invasion showed higher cathepsin L expression than those without it (P < 0.05). No other clinicopathologic factors correlated with expression of either cathepsin. Tumors with overexpression of cathepsins have powerful potential for invasiveness in the early stage of gastric carcinoma. Moreover, the authors hypothesize that cathepsins may be one of the determinants of the metastatic route. To the authors' knowledge, this is the first report on specific proteases concerning the mode of metastasis, and the results of this study suggest that therapeutic strategies for early stage gastric carcinoma might need to be changed according to the status of cathepsins.

Highly metastatic hepatocellular carcinomas induced in male F344 rats treated with N-nitrosomorpholine in combination with other hepatocarcinogens show a high incidence of p53 gene mutations along with altered mRNA expression of tumor-related genes

The carcinogenic and metastatic processes are thought to consist of a sequence of steps, and animal models featuring highly metastatic lesions are clearly necessary to allow analysis of the whole process of transformation from preneoplastic changes to high grade metastatic tumors, and to access effectiveness of therapeutic treatments of advanced cancers in vivo. The purpose of the present study was to establish a model and to screen for reported genetic alterations in induced lesions. In the present study, it was confirmed that lung metastasis of hepatocellular carcinomas (HCCs) induced in male F344 rats by N-nitrosomorpholine (NNM), given in the drinking water at a dose of 120 ppm for 24 weeks, was significantly enhanced by additional carcinogenic pretreatments and that a single i.p. injection of 100 mg/kg body weight N-diethylnitrosamine (DEN) alone was sufficient for that purpose. Molecular biological analyses of the induced lesions revealed point mutations in the p53 gene in 60.9% of HCCs, and elevated expression of mRNAs for p53, c-myc, c-fos, TGF-α, TGF-β1, α-fetoprotein, GST-P, and GGT, and decreased mRNA expression of EGF and EGFR in HCCs when compared to controls. No obvious association of gene alterations with metastatic potential of primary tumors was found except for an increase in the incidence of p53 mutations. Since the process of metastasis is thought to be sequential and selective, further comparative analysis of metastatic and primary lesions should clarify the mechanisms involved in the multi-step process of metastasis.

Synthesis and Intracellular Trafficking of Muc-1 and Mucins by Polarized Mouse Uterine Epithelial Cells

Mucins function as a protective layer rendering the apical surface of epithelial cells nonadhesive to a variety of microorganisms and macromolecules. Muc-1 is a transmembrane mucin expressed at the apical cell surface of mouse uterine epithelial cells (UEC) that disappears as UEC become receptive for embryo implantation (Surveyor, G. A., Gendler, S. J., Pemberton, L., Das, S. K., Chakraborty, I., Julian, J., Pimental, R. A., Wegner, C. W., Dey, S. K., and Carson, D. D. (1995) Endocrinology 136, 3639-3647). In the present study, the kinetics of Muc-1 assembly, cell surface expression, release, and degradation were examined in polarized mouse UEC in vitro. Mucins were identified as the predominant glycoconjugates synthesized, apically expressed, and vectorially released in both wild-type and Muc-1 null mice. When mucins were released, greater than 95% were directed to the apical compartment. Approximately half of the cell-associated mucins lost during a 24-h period were found in the apical compartment. Vectorial biotinylation detected apically disposed, cell-surface mucin and indicated that at least 34% of these mucins are released apically within 24 h. This suggests that release of mucin ectodomains is part of the mechanism of mucin removal from the apical cell surface of UEC. The half-lives of total cell-associated mucins and Muc-1 were 19.5 +/- 1 and 16.5 +/- 0.8 h, respectively. Muc-1 represented approximately 10% of the [3H]glucosamine-labeled, cell-associated mucins. Studies of the kinetics of intracellular transport of Muc-1 indicated transit times of 21 +/- 15 min from the rough endoplasmic reticulum to Golgi apparatus and 111 +/- 28 min from the Golgi apparatus to the cell surface. Collectively, these studies provide the first comprehensive description of Muc-1 and mucin maturation, metabolism, and release by polarized cells, as well as defining a major metabolic fate for mucins expressed by UEC. Normal metabolic processing appears to be sufficient to account for the removal of Muc-1 protein during the transition of UEC to a receptive state.

ALLELIC DELETIONS ON CHROMOSOME-17 AND MUTATIONS IN THE P53 GENE IN TUMORS METASTATIC TO BRAIN

Metastasis associated with tumor progression denotes more aggressive tumor behavior, more malignant histology, and worsening patient prognosis. Brain is one of the common sites to which solid tumors metastasize. Since mutations in the tumor suppressor gene p53 are associated with tumor progression to malignancy in various cancers, we examined the molecular genetic profile of the p53 gene and also analyzed allelic losses of various genes on the short arm of chromosome 17 (17p) in 10 metastatic brain tumors (4 breast, 3 renal, 1 lung, 1 esophageal, and 1 squamous cell carcinoma) and in two of the primary tumors (I breast, 1 renal) corresponding to two of the 10 metastases. Six of the 10 metastatic tumors (4/4 breast, 1/1 esophageal and 1/1 squamous cell carcinoma) contained allelic loss and/or mutations of the p53 gene. The p53 gene profile was identical in both of the primary tumors and their corresponding metastases that were examined. If borne out by a larger series of analysis on tumors, especially from breast, as well as from other organs, detection of chromosome 17/p53 alterations may be of substantial clinical significance in predicting the metastatic potential of primary tumors.

High-resolution proton nuclear magnetic resonance analysis of metastatic cancer cells.

High-resolution proton nuclear magnetic resonance (NMR) studies of intact cancer cells revealed differences between cells with the capacity to metastasize and those that produce locally invasive tumors. The NMR resonances that characterize the metastatic cells were associated with an increased ratio of cholesterol to phospholipid and an increased amount of plasma membrane-bound cholesterol ester. High-resolution NMR spectroscopy could therefore be used to assess the metastatic potential of primary tumors.