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Biomedical subjects

M Loda

Publications and source records attributed to M Loda.

At least 19 recordsLinked to original sources

Multiclass cancer diagnosis using tumor gene expression signatures.

The optimal treatment of patients with cancer depends on establishing accurate diagnoses by using a complex combination of clinical and histopathological data. In some instances, this task is difficult or impossible because of atypical clinical presentation or histopathology. To determine whether the diagnosis of multiple common adult malignancies could be achieved purely by molecular classification, we subjected 218 tumor samples, spanning 14 common tumor types, and 90 normal tissue samples to oligonucleotide microarray gene expression analysis. The expression levels of 16,063 genes and expressed sequence tags were used to evaluate the accuracy of a multiclass classifier based on a support vector machine algorithm. Overall classification accuracy was 78%, far exceeding the accuracy of random classification (9%). Poorly differentiated cancers resulted in low-confidence predictions and could not be accurately classified according to their tissue of origin, indicating that they are molecularly distinct entities with dramatically different gene expression patterns compared with their well differentiated counterparts. Taken together, these results demonstrate the feasibility of accurate, multiclass molecular cancer classification and suggest a strategy for future clinical implementation of molecular cancer diagnostics.

Biomarkers, Tumor↗

Classification of human lung carcinomas by mRNA expression profiling reveals distinct adenocarcinoma subclasses.

We have generated a molecular taxonomy of lung carcinoma, the leading cause of cancer death in the United States and worldwide. Using oligonucleotide microarrays, we analyzed mRNA expression levels corresponding to 12,600 transcript sequences in 186 lung tumor samples, including 139 adenocarcinomas resected from the lung. Hierarchical and probabilistic clustering of expression data defined distinct subclasses of lung adenocarcinoma. Among these were tumors with high relative expression of neuroendocrine genes and of type II pneumocyte genes, respectively. Retrospective analysis revealed a less favorable outcome for the adenocarcinomas with neuroendocrine gene expression. The diagnostic potential of expression profiling is emphasized by its ability to discriminate primary lung adenocarcinomas from metastases of extra-pulmonary origin. These results suggest that integration of expression profile data with clinical parameters could aid in diagnosis of lung cancer patients.

Adenocarcinoma↗

The de-ubiquitinating enzyme Unp interacts with the retinoblastoma protein.

The ubiquitin pathway is involved in the proteolytic turnover of many short-lived cellular regulatory proteins. Since selective degradation of substrates of this system requires the covalent attachment of a polyubiquitin chain to the substrates, degradation could be counteracted by de-ubiquitinating enzymes (or isopeptidases) which selectively remove the polyubiquitin chain. Unp is a human isopeptidase with still poorly understood biological functions. Here, we show that cellular Unp specifically interacts with the retinoblastoma gene product (pRb).

Amino Acid Motifs↗

Microsatellite instability and hMLH1/hMSH2 expression in Barrett esophagus-associated adenocarcinoma.

BACKGROUND: Microsatellite instability (MSI) has been documented in malignancies associated with hereditary nonpolyposis colon carcinoma and in sporadic malignancies of the colon, stomach, and endometrium. In these malignancies, MSI is associated with defects in the DNA mismatch repair enzymes hMSH2 and hMLH1. Defects in these enzymes result in a phenotype characterized by instability of multiple microsatellite repeat sequences throughout the genome. This study sought to determine the prevalence of MSI in 80 primary Barrett esophagus-associated adenocarcinomas (BEAd) and to examine the relation of MSI with the clinical and pathologic features of the tumors. METHODS: Eighty BEAd were evaluated for the presence of MSI by using the microsatellite markers BAT25, BAT26, D10S219, D10S541, and D10S551. These tumors also were evaluated for immunohistochemical expression of hMSH2 and hMLH1. RESULTS: High levels of MSI were not found in any of the tumors examined. Furthermore, immunohistochemical expression of hMSH2 and hMLH1 was retained in all cases evaluated. Evidence of low level MSI was found in 16% of tumors. In none of these tumors, however, was MSI present in more than two of five loci. The presence of MSI did not correlate with patient age, tumor stage, degree of differentiation, or with patient survival. CONCLUSIONS: High level MSI and loss of hMLH1/hMSH2 expression is uncommon in BEAd. A subset of BEAd demonstrate low level MSI. The presence of low level MSI was not associated with the clinicopathologic features of the tumors examined.

Adaptor Proteins, Signal Transducing↗

Allelic loss of 10q23, the PTEN tumour suppressor gene locus, in Barrett's oesophagus-associated adenocarcinoma.

PTEN is a putative tumour suppressor gene located on chromosome band 10q23. Mutations in PTEN have been identified in numerous human malignancies, including cancers of the brain, endometrium, ovary, and prostate. In this study, we screened 80 Barrett's oesophagus-associated adenocarcinomas (BOAd) for loss of heterozygosity (LOH) at 10q23, using the microsatellite markers D10S541, D10S219, and D10S551. Tumours demonstrating LOH were then screened for the presence or absence of PTEN mutations. LOH at one or more loci was identified in 17/80 (21%) cases. In none of these cases did we detect mutations in PTEN. The presence of LOH did not correlate with patient age, tumour stage, degree of differentiation, presence of perineural or vascular invasion, or overall survival. We conclude that LOH at chromosome 10q23 is uncommon in BOAd, is not associated with mutations in the PTEN tumour suppressor gene, and does not correlate with the clinical or pathologic features of these tumours. It is possible that PTEN is inactivated through other mechanisms in BOAd.

Adenocarcinoma↗

Loss of CDX2 expression and microsatellite instability are prominent features of large cell minimally differentiated carcinomas of the colon.

Most large bowel cancers are moderately to well-differentiated adenocarcinomas comprised chiefly or entirely of glands lined by tall columnar cells. We have identified a subset of poorly differentiated colon carcinomas with a distinctive histopathological appearance that we term large cell minimally differentiated carcinomas (LCMDCs). These tumors likely include a group of poorly differentiated carcinomas previously described by others as medullary adenocarcinomas. To better understand the pathogenesis of these uncommon neoplasms, we compared molecular features of 15 LCMDCs to those present in 25 differentiated adenocarcinomas (DACs) of the colon. Tumors were examined for alterations commonly seen in typical colorectal carcinomas, including increased p53 and beta-catenin immunoreactivity, K-ras gene mutations, microsatellite instability, and loss of heterozygosity of markers on chromosomes 5q, 17p, and 18q. In addition, tumors were evaluated by immunohistochemistry for CDX2, a homeobox protein whose expression in normal adult tissues is restricted to intestinal and colonic epithelium. Markedly reduced or absent CDX2 expression was noted in 13 of 15 (87%) LCMDCs, whereas only 1 of the 25 (4%) DACs showed reduced CDX2 expression (P < 0.001). Nine of 15 (60%) LCMDCs had the high-frequency microsatellite instability phenotype, but only 2 of 25 (8%) DACs had the high-frequency microsatellite instability phenotype (P = 0.002). Our findings provide support for the hypothesis that the molecular pathogenesis of LCMDCs is distinct from that of most DACs. CDX2 alterations and DNA mismatch repair defects have particularly prominent roles in the development of LCMDCs.

Adaptor Proteins, Signal Transducing↗

Transition from in situ to invasive testicular germ cell neoplasia is associated with the loss of p21 and gain of mdm-2 expression.

INTRODUCTION: The tumor suppressor gene p53 has been shown to transcriptionally regulate expression of the cell cycle dependent kinase inhibitor p21. p53 is in turn regulated by the ubiquitin ligase mouse double minute-2 (mdm-2). We have set out to examine p21 expression in testicular germ cell tumors and its relationship with p53 and mdm-2 expression. METHODS: Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded tissue for p53, p21, and mdm-2 in 31 testicular germ cell tumors, which included 17 pure seminomas and 14 mixed germ cell tumors composed predominantly of embryonal carcinoma. Twenty-seven cases contained adjacent areas of intratubular germ cell neoplasia (ITGCN). RESULTS: 17 out of 17 seminomas and 14 out of 14 embryonal carcinomas expressed p53 in both ITGCN and the invasive tumor. In contrast, none of the 17 seminomas and only 2 of 14 embryonal carcinomas revealed positive staining for p21 protein. p21 expression was noted in 18 of 27 cases (67%) of ITGCN, and in 16 of these cases (89%) the corresponding invasive tumor had lost p21 expression. In nine additional cases p21 expression was absent in both the invasive and intratubular tumor. mdm-2 expression was present in 8 out of 17 (47%) seminomas and 13 out of 14 (93%) embryonal carcinomas but was present in only 2 out of 27 (7%) cases of ITGCN. Statistically significant associations for loss of p21 and gain of mdm-2 expression in invasive tumors were present (P < .0001). CONCLUSIONS: The co-expression of p53 and p21 in ITGCN is consistent with preservation of p53-directed induction of p21. The loss of p21 expression in invasive tumors suggests a disruption of the p53 regulatory pathway. The inverse correlation of p21 and mdm-2 expression in both ITGCN and invasive tumors could indicate that loss of the functional p53 regulatory pathway may be correlated with the onset of mdm-2 expression. These results raise the possibility that the loss of p21 expression may be associated with the development of invasive germ cell tumors from ITGCN. Persistent p53 expression in the presence of mdm-2 suggests that in testicular germ cell tumors, while mdm-2 can block the transactivation potential of p53, it can no longer target p53 for degradation.

Adult↗

Malignant transformation of the esophageal mucosa is enhanced in p27 knockout mice.

OBJECTIVE: In a previous study, we showed that experimentally induced gastroduodenal-esophageal reflux in mice treated with a carcinogen can result in Barrett esophagus and Barrett-associated adenocarcinoma. Since we have shown that most Barrett-associated adenocarcinomas in human beings have lost the tumor suppressor gene p27, we sought to determine whether cancer would be more likely to develop in p27 knockout mice than in p27 heterozygous or p27 wild type mice. METHODS: Three groups of mice were treated by esophagojejunostomy resulting in gastroduodenal-esophageal reflux and by a carcinogen (N -methyl-N -benzylnitrosamine): group I (50 wild type), group II (45 p27 heterozygous), and group III (50 p27 knockout). The mice were killed 18 to 20 weeks after operation and studied macroscopically and histopathologically. RESULTS: Barrett esophagus developed in 7 (14%) mice in group I, 4 (8.9%) mice in group II, and 13 (26%) mice in group III. Cancers developed in 30 (60%) mice in group I, 31 (68%) mice in group II, and 43 (86%) mice in group III. Ten percent of the cancers in group I were adenocarcinomas, as were 16.1% in group II, and 23.3% in group III. The difference between rates of Barrett esophagus in groups I and II compared with group III was statistically significant (P =.035), as was true of the cancer rates (P =.006). The percentage of cancers that were adenocarcinomas was highest in group III, but not significantly different from groups I and II. CONCLUSIONS: This experimental mouse model of Barrett esophagus and Barrett- associated adenocarcinoma is similar to what occurs in human beings and may be useful in developing methods to inhibit malignant transformation of Barrett esophagus.

Animals↗

Expression of Periostin, homologous with an insect cell adhesion molecule, as a prognostic marker in non-small cell lung cancers.

We used our palindromic polymerase chain reaction (PCR)-driven cDNA differential display technique to identify and isolate a gene, designated periostin, from cancer tissues and found it to be overexpressed in several human tumors. We attempted to determine the influence of periostin expression on clinical outcome in patients with non-small cell lung cancer (NSCLC) by reverse transcriptase (RT)-PCR analysis. Periostin gene was highly expressed at the tumor periphery of lung cancer tissue but not within the tumor by in situ RNA hybridization, suggesting that expression of periostin may be involved in the process of tumor invasion. Periostin transcripts were detected in 50 (49.0%) of the tumor samples, although some paired normal lung samples showed weak expression. There was no relationship between periostin gene expression and gender, N- or T-status. The NSCLC patients with periostin expression had significantly poorer survival than the patients without periostin expression (P = 0.0338).

Adenocarcinoma↗

Androgen-driven prostate epithelial cell proliferation and differentiation in vivo involve the regulation of p27.

Androgens control both growth and differentiation of the normal prostate gland. However, the mechanisms by which androgens act upon the cell cycle machinery to regulate these two fundamental processes are largely unknown. The cyclin-dependent kinase (cdk) inhibitor p27 is a negative cell cycle regulator involved in differentiation-associated growth arrest. Here, we investigate the role and regulation of p27 in the testosterone proprionate (TP)-stimulated regeneration of the ventral prostate (VP) of castrated rats. Continuous TP administration to castrated rats triggered epithelial cell proliferation, which peaked at 72 h, and then declined despite further treatment. Castration-induced atrophy of the VP was associated with a significant increase in p27 expression as compared with the VP of intact animals. Twelve hours after the initiation of androgen treatment, total p27 levels as well as its fraction bound to cdk2, its main target, significantly dropped in the VP of castrated rats. Thereafter, concomitantly to the induction of epithelial cell proliferation, the glandular morphology of VP was progressively restored at 48-96 h of TP treatment. During this period of the regenerative process, whereas both proliferating basal and secretory epithelial cells did not express p27, the protein was selectively up-regulated in the nonproliferating secretory epithelial compartment. This up-regulation of p27 expression was coincident with an increase in its association with, and presumably inhibition of, cdk2. At each time point of TP treatment, p27 abundance in the VP was inversely correlated with the level of its proteasome-dependent degradation activity measured in vitro in VP lysates, whereas only slight changes in the amount of p27 transcripts were detected. In addition, the antiandrogen flutamide blocked maximal TP-induced p27 degradation completely. Finally, the expression of skp2, the ubiquitin ligase that targets p27 for degradation, was seen to increase with androgen administration, preceding maximal proliferation and concomitantly to augmented p27 degradation activity. Taken together, our data indicate that androgens mediate both proliferation and differentiation signals in normal prostate epithelial cells in vivo, through regulation of p27.

Androgen Antagonists↗

Decrease in calcitonin and parathyroid hormone mRNA levels and hormone secretion under long-term hypervitaminosis D3 in rats.

In calcium homeostasis, vitamin D3 is a potent serum calcium-raising agent which in vivo regulates both calcitonin (CT) and parathyroid hormone (PTH) gene expression. Serum calcium is the major secretagogue for CT, a hormone product whose biosynthesis is the main biological activity of thyroid C-cells. Taking advantage of this regulatory mechanism, long-term vitamin D3-induced hypercalcemia has been extensively used as a model to produce hyperactivation, hyperplasia and even proliferative lesions of C-cells, supposedly to reduce the sustained high calcium serum concentrations. We have recently demonstrated that CT serum levels did not rise after long-term hypervitaminosis D3. Moreover, C-cells did not have a proliferative response, rather a decrease in CT-producing C-cell number was observed. In order to confirm the inhibitory effect of vitamin D3 on C-cells, Wistar rats were administered vitamin D3 chronically (25,000 IU/d) with or without calcium chloride (CaCl2). Under these long-term vitamin D3-hypercalcemic conditions, calcium, active metabolites of vitamin D3, CT and PTH serum concentrations were determined by RIA; CT and PTH mRNA levels were analysed by Northern blot and in situ hybridization; and, finally, the ultrastructure of calciotrophic hormone-producing cells was analysed by electron microscopy. Our results show, that, in rats, long term administration of vitamin D3 results in a decrease in hormone biosynthetic activities of both PTH and CT-producing cells, albeit at different magnitudes. Based upon these results, we conclude that hypervitaminosis D3-based methods do not stimulate C-cell activity and can not be used to induce proliferative lesions of calcitonin-producing cells.

Administration, Oral↗

BCR/ABL regulates expression of the cyclin-dependent kinase inhibitor p27Kip1 through the phosphatidylinositol 3-Kinase/AKT pathway.

Deregulation of cell cycle checkpoints is an almost universal abnormality in human cancers and is most often due to loss-of-function mutations of tumor suppressor genes such as Rb, p53, or p16(INK4a). In this study, we demonstrate that BCR/ABL inhibits the expression of a key cell cycle inhibitor, p27(Kip1), by signaling through a pathway involving phosphatidylinositol 3-kinase (PI3K). p27(Kip1) is a widely expressed inhibitor of cdk2, an essential cell cycle kinase regulating entry into S phase. We demonstrate that the decrease of p27(Kip1) is directly due to BCR/ABL in hematopoietic cells by two different approaches. First, induction of BCR/ABL by a tetracycline-regulated promoter is associated with a reversible down-regulation of p27(Kip1). Second, inhibition of BCR/ABL kinase activity with the Abl tyrosine kinase inhibitor STI571 rapidly increases p27(Kip1) levels. The PI3K inhibitor LY-294002 blocks the ability of BCR/ABL to induce p27(Kip1) down-regulation and inhibits BCR/ABL-induced entry into S phase. The serine/threonine kinase AKT/protein kinase B is a known downstream target of PI3K. Transient expression of an activated mutant of AKT was found to decrease expression of p27(Kip1), even when PI3K was inhibited by LY-294002. The mechanism of p27(Kip1) regulation is primarily related to protein stability, since inhibition of proteasome activity increased p27(Kip1) levels in BCR/ABL-transformed cells, whereas very little change in p27 transcription was found. Overall, these data are consistent with a model in which BCR/ABL suppresses p27(Kip1) protein levels through PI3K/AKT, leading to accelerated entry into S phase. This activity is likely to explain in part previous studies showing that activation of PI3K was required for optimum transformation of hematopoietic cells by BCR/ABL in vitro and in vivo.

Animals↗

Her-2-neu expression and progression toward androgen independence in human prostate cancer.

BACKGROUND: Human prostate cancers are initially androgen dependent but ultimately become androgen independent. Overexpression of the Her-2-neu receptor tyrosine kinase has been associated with the progression to androgen independence in prostate cancer cells. We examined the expression of Her-2-neu in normal and cancerous prostate tissues to assess its role in the progression to androgen independence. METHODS: Prostate cancer tissue sections were obtained from 67 patients treated by surgery alone (UNT tumors), 34 patients treated with total androgen ablation therapy before surgery (TAA tumors), and 18 patients in whom total androgen ablation therapy failed and who developed bone metastases (androgen-independent [AI] disease). The sections were immunostained for Her-2-neu, androgen receptor (AR), prostate-specific antigen (PSA), and Ki-67 (a marker of cell proliferation) protein expression. Messenger RNA (mRNA) levels and gene amplification of Her-2-neu were examined by RNA in situ hybridization and fluorescent in situ hybridization(FISH), respectively, in a subset of 27 tumors (nine UNT, 11 TAA, and seven AI). All statistical tests were two-sided. RESULTS: Her-2-neu protein expression was statistically significantly higher in TAA tumors than in UNT tumors with the use of two different scoring methods (P =.008 and P =.002). The proportion of Her-2-neu-positive tumors increased from the UNT group (17 of 67) to the TAA group (20 of 34) to the AI group (14 of 18) (P<.001). When compared with UNT tumors, tumor cell proliferation was higher in AI tumors (P =.014) and lower in TAA tumors (P<.001). All tumors expressed AR and PSA proteins. Although Her-2-neu mRNA expression was high in TAA and AI tumors, no Her-2-neu gene amplification was detected by FISH in any of the tumor types. CONCLUSIONS: Her-2-neu expression appears to increase with progression to androgen independence. Thus, therapeutic targeting of this tyrosine kinase in prostate cancer may be warranted.

Androgens↗

Control of TH2 polarization by the chemokine monocyte chemoattractant protein-1.

Activated T lymphocytes differentiate into effector cells tailored to meet disparate challenges to host integrity. For example, type 1 and type 2 helper (T(H)1 and T(H)2) cells secrete cytokines that enhance cell-mediated and humoral immunity, respectively. The chemokine monocyte chemoattractant protein-1 (MCP-1) can stimulate interleukin-4 production and its overexpression is associated with defects in cell-mediated immunity, indicating that it might be involved in T(H)2 polarization. Here we show that MCP-1-deficient mice are unable to mount T(H)2 responses. Lymph node cells from immunized MCP-1(-/-) mice synthesize extremely low levels of interleukin-4, interleukin-5 and interleukin-10, but normal amounts of interferon-gamma and interleukin-2. Consequently, these mice do not accomplish the immunoglobulin subclass switch that is characteristic of T(H)2 responses and are resistant to Leishmania major. These effects are direct rather than due to abnormal cell migration, because the trafficking of naive T cells is undisturbed in MCP-1(-/-) mice despite the presence of MCP-1-expressing cells in secondary lymphoid organs of wild-type mice. Thus, MCP-1 influences both innate immunity, through effects on monocytes, and adaptive immunity, through control of T helper cell polarization.

Animals↗

Prostate stem cell antigen (PSCA) expression increases with high gleason score, advanced stage and bone metastasis in prostate cancer.

Prostate stem cell antigen (PSCA) is a recently defined homologue of the Thy-1/Ly-6 family of glycosylphosphatidylinositol (GPI)-anchored cell surface antigens. PSCA mRNA is expressed in the basal cells of normal prostate and in more than 80% of prostate cancers. The purpose of the present study was to examine PSCA protein expression in clinical specimens of human prostate cancer. Five monoclonal antibodies were raised against a PSCA-GST fusion protein and screened for their ability to recognize PSCA on the cell surface of human prostate cancer cells. Immunohistochemical analysis of PSCA expression was performed on paraffin-embedded sections from 25 normal tissues, 112 primary prostate cancers and nine prostate cancers metastatic to bone. The level of PSCA expression in prostate tumors was quantified and compared with expression in adjacent normal glands. The antibodies detect PSCA expression on the cell surface of normal and malignant prostate cells and distinguish three extracellular epitopes on PSCA. Prostate and transitional epithelium reacted strongly with PSCA. PSCA staining was also seen in placental trophoblasts, renal collecting ducts and neuroendocrine cells in the stomach and colon. All other normal tissues tested were negative. PSCA protein expression was identified in 105/112 (94%) primary prostate tumors and 9/9 (100%) bone metastases. The level of PSCA expression increased with higher Gleason score (P=0.016), higher tumor stage (P=0.010) and progression to androgen-independence (P=0. 021). Intense, homogeneous staining was seen in all nine bone metastases. PSCA is a cell surface protein with limited expression in extraprostatic normal tissues. PSCA expression correlates with tumor stage, grade and androgen independence and may have prognostic utility. Because expression on the surface of prostate cancer cells increases with tumor progression, PSCA may be a useful molecular target in advanced prostate cancer.

Antibodies, Monoclonal↗

Coamplification of prostate stem cell antigen (PSCA) and MYC in locally advanced prostate cancer.

Gain of sequences on chromosome arm 8q is a common feature of prostate cancer that may correlate with metastatic and androgen-independent progression. The target gene(s) for this gain is not known, although MYC is amplified in a subset of advanced tumors and is one potential candidate. Prostate stem cell antigen (PSCA) is a prostate-specific cell surface protein that maps to chromosome region 8q24.2 and is overexpressed in prostate cancer. Our aim in this study was to test the hypothesis that PSCA overexpression may result from overrepresentation of chromosome arm 8q. Twenty locally advanced prostate cancers were analyzed by dual-probe fluorescence in situ hybridization (FISH) for alterations of MYC and PSCA. Extra copies of MYC were found in 12/20 (60%) tumors, including 5 (25%) with simple gain (no increase in MYC copy number relative to the chromosome 8 centromere) and 7 (35%) with an additional increase (AI or overrepresentation) in MYC copy number relative to the centromere. In the five cases with simple gain of MYC, there was a concomitant gain of PSCA. PSCA was overrepresented in 5/7 (71%) cases with AI of MYC. Immunohistochemical staining of the 20 tumors with monoclonal antibodies specific for PSCA showed a high degree of correlation between PSCA gene overrepresentation and protein overexpression. Four of 5 tumors with AI of PSCA overexpressed PSCA protein, compared with only 2/15 tumors with a normal PSCA copy number or simple gain of PSCA (P = 0.014). These results demonstrate that PSCA is co-overrepresented with MYC in a majority of cases, but may not be a necessary part of the 8q amplicon. PSCA protein overexpression can result from AI of PSCA and might be useful as a cell surface marker on prostate cancer cells with 8q overrepresentation. Genes Chromosomes Cancer 27:95-103, 2000.

Antigens, Neoplasm↗

Barrett's esophagus and associated adenocarcinoma in a mouse surgical model.

BACKGROUND: The development of Barrett's esophagus (BE) and Barrett's associated adenocarcinoma (BAA) in the rat after experimental inducement of esophageal reflux of gastric, bile, and pancreatic juice has been reported by others. The purpose of this study was to determine whether similar results could be demonstrated in the mouse model. MATERIALS AND METHODS: One hundred eight Swiss-Webster mice were used in this study and were divided into three groups: Group I, 37 mice with esophagojejunostomy; Group II, 39 mice with esophagojejunostomy and the carcinogen N-methyl-N-benzylnitrosamine (MBN); and Group III, 32 mice with MBN alone. The animals were sacrificed after 19 weeks. Macroscopic and histopathologic examinations were performed. RESULTS: One hundred mice survived and were available for pathologic study. Macroscopic evidence suggested esophagitis in 60.6% of mice in Group I, 62.8% of mice in Group II, and 9% of mice in Group III and suggested tumor in 3% of mice in Group I, 51.4% of mice in Group II, and 53.1% of mice in Group III. Histopathologic analysis disclosed BE in 42.4% of mice in Group I, 20% of mice in Group II, and 12.5% of mice in Group III. Cancer was present in 12.2% of mice in Group I, 54.3% of mice in Group II, and 46.9% of mice in Group III. Adenocarcinoma with or without squamous cell carcinoma was present in 6.1% of mice in Group I, 37.1% of mice in Group II, and 12.5% of mice in Group III. CONCLUSIONS: Esophagojejunostomy plus MBN in the mouse results in BE, BAA, or both in 57.1% of animals, consistent with findings in the rat model after similar interventions.

Adenocarcinoma↗