Loss of N-Myc interactor promotes epithelial-mesenchymal transition by activation of TGF-ß/SMAD signaling.

Epithelial-mesenchymal transition is one of the critical cellular programs that facilitate the progression of breast cancer to an invasive disease. We have observed that the expression of N-myc interactor (NMI) decreases significantly during progression of breast cancer, specifically in invasive and metastatic stages. Recapitulation of this loss in breast cell lines with epithelial morphology (MCF10A (non-tumorigenic) and T47D (tumorigenic)) by silencing NMI expression causes mesenchymal-like morphological changes in 3D growth, accompanied by upregulation of SLUG and ZEB2 and increased invasive properties. Conversely, we found that restoring NMI expression attenuated the mesenchymal attributes of metastatic breast cancer cells, accompanied by distinctly circumscribed 3D growth with basement membrane deposition and decreased invasion. Further investigations into the downstream signaling modulated by NMI revealed that NMI expression negatively regulates SMAD signaling, which is a key regulator of cellular plasticity. We demonstrate that NMI blocks TGF-ß/SMAD signaling via upregulation of SMAD7, a negative feedback regulator of the pathway. We also provide evidence that NMI activates STAT signaling, which negatively modulates TGF-ß/SMAD signaling. Taken together, our findings suggest that loss of NMI during breast cancer progression could be one of the driving factors that enhance the invasive ability of breast cancer by aberrant activation of TGF-ß/SMAD signaling.

Central incisor width as a predictor of appropriate curette size in adenoidectomy.

As inadvertent eustachian tube injury during adenoidectomy can have serious short- and long-term implications, a simple anatomic correlate that could predict the optimal curette choice for adenoidectomy, especially in severely hypertrophic cases, is beneficial. This study evaluates the correlation of the distance between the lateral borders of the upper central incisors and the distance between the tori tubarius in the nasopharynx. One hundred one consecutive patients undergoing adenoidectomy at a pediatric tertiary care hospital were enrolled in this study. The patients ranged in age from 7 months to 15 years. No complications were noted in any of the procedures. During the operation, the distance between the central upper incisors was measured in millimeters, as was the inter-tubarius width (ITW). A multiple regression analysis was completed to assess the correlation between central incisor width and ITW. Age and inter-incisor width were positively correlated with ITW in a statistically significant manner (p = .007 and p = .006, respectively). The distance between the lateral borders of the upper central incisors predicts the distance between the tori tubarius in the nasopharynx. Therefore, an adenoid curette the window of which does not overlap the lateral aspects of the central upper incisors can be used relatively safely, even in fields with poor visualization.

Biliary cystadenoma: rare variant of intrahepatic cystic disease.

Intrahepatic nonparasitic cystic disease is rare and may be of congenital or neoplastic origin. The most frequent symptoms and signs are nonspecific and include pain, nausea, fullness, increased girth, and palpable mass. Interventional therapy is reserved for symptomatic patients, which usually corresponds to cysts >5 cm in diameter. Retrospective analysis revealed 26 cases of intrahepatic cystic disease over 15 years at our institution. We discuss the case of a patient who had bilobular biliary cystadenomatous disease, a rare, benign variant of intrahepatic nonparasitic cystic disease.

Glomerulopathies with fibrillary deposits.

Renal diseases involving glomerular deposits of fibrillary material are an important diagnostic challenge for the ultrastructural pathologist. Two primary disorders of this type, termed "fibrillary glomerulonephritis" (characterized by fibrils measuring approximately 20 nm in diameter) and "immunotactoid glomerulopathy" (characterized by larger, microtubular deposits), have been described. The possible relatedness of these two disorders and their potential association with other systemic illnesses are subjects of current debate. Other multisystemic diseases, including amyloidosis and various forms of cryoglobulinemia, can also present with fibrillary or microtubular deposits in the kidney. Five cases are presented in which fibrillar or microtubular structures were identified in renal biopsies by ultrastructural examination. The distinction between fibrillary glomerulonephritis, immunotactoid glomerulopathy, and other processes that have similar ultrastructural features are discussed.

The continuing value of electron microscopy in surgical pathology.

For decades, transmission electron microscopy has played a valuable diagnostic role in surgical pathology. The continuing importance of electron microscopy, however, can be debated, given the major advances that have occurred in immunohistochemistry and other techniques. Electron microscopy retains excellent educational potential and broad research applicability, and it continues to be a necessity for the evaluation of a small subset of surgical pathology cases, such as renal biopsies and cilia specimens. The real controversy, then, centers on the contribution of electron microscopy in the evaluation of neoplasms. The opinion of many experts indicates that electron microscopy is still vital in the diagnostic assessment of some neoplasms, and that both electron microscopy and immunohistochemistry are more powerful when viewed as complementary rather than competitive techniques. For electron microscopy to be used to its potential, however, electron microscopists must function effectively as consultants. When optimally applied, electron microscopy remains an essential diagnostic tool.

Biatrial myxoma resembling an interatrial clot in transit on echocardiogram.

A 47-year-old man had an embolic stroke. Transesophageal echocardiography showed biatrial, elongated, mobile masses that appeared interconnected via a patent foramen ovale. Echocardiography did not distinguish between an interatrial clot in transit and an atypical biatrial myxoma. Surgical resection and subsequent histopathologic examination identified the mass as a biatrial myxoma. This case identifies a limitation of echocardiography in the diagnosis of cardiac myxoma.

Human breast carcinoma patients develop clonable oncofetal antigen-specific effector and regulatory T lymphocytes.

Oncofetal Ag (OFA) is a 44-kDa glycoprotein expressed during early to mid-gestation fetal development and re-expressed as a surface Ag by tumor cells soon after transformation. The Ag is detectable on all types of human and rodent tumors tested, but is undetectable on normal cells. In experimental animals it is autoimmunogenic and induces potentially protective T cell responses both after experimental immunization and during tumor development subsequent to carcinogenic insult. To determine whether this tumor-associated Ag is also immunogenic for human T lymphocytes, breast carcinoma patients' peripheral blood mononuclear leucocytes were stimulated in vitro with autologous tumor cells in the presence of IL-2, gamma-IFN, and IL-6 for 2 wk. The tumor-reactive cells were then restimulated and cloned by limiting dilution, and the clones were analyzed. We established 24, 19, 11, and 16 tumor-reactive clones from the four respective patients. Of those, 4, 6, 4, and 7, respectively, proliferated specifically to purified OFA. Both CD4 and CD8 OFA-specific clones were established, which responded equally well to purified OFA or 32- to 44-kDa immature laminin receptor protein. All were CD3+, TCR-alpha beta+. All CD4 clones secreted gamma-IFN, but neither secreted IL-4 nor IL-10. Both IFN-gamma-secreting cytotoxic CD8 clones and IL-10-secreting inhibitory CD8 clones were established. Thus, during human cancer development, the same types of OFA-specific effector and regulatory T cells are induced as during murine T lymphomagenesis.

Evaluation of membranous staining of mesothelioma.

Panels of immunohistochemical markers are often used to aid in categorizing malignant neoplasms involving the pleura. While epithelial membrane antigen (EMA) and human milk fat globule-2 (HMFG-2) are each reported to stain the majority of cases of adenocarcinoma and mesothelioma, authors have reported that the pattern of staining for these two antibodies can be a useful discriminant. Both are described as revealing a membranous pattern of staining for mesothelioma and a cytoplasmic staining pattern in adenocarcinoma. Immunostains were performed on 23 cases of malignant mesothelioma and 22 cases of adenocarcinoma. For EMA, 78% of mesotheliomas and 86% of adenocarcinomas stained positively, and 65% of mesotheliomas vs. 14% of adenocarcinomas exhibited a membranous staining pattern. For HMFG-2, 9% of mesotheliomas and 50% of adenocarcinomas stained positively, and 4% of mesotheliomas vs. 9% of adenocarcinomas exhibited a membranous staining pattern. Membranous staining for HMFG-2 was not a useful criterion. In this series, a membranous pattern of staining for EMA had a sensitivity of 65% and a specificity of 86% for the identification of malignant mesothelioma.

Dynamic magnetic resonance imaging in evaluating suspicious breast lesions: correlation with pathologic findings.

BACKGROUND: We used dynamic magnetic resonance imaging (MRI) to study breast lesions in 13 women. METHODS: We observed differences in contrast uptake between benignancy and malignancy in 14 suspicious breast lesions. Three-dimensional (3D) gradient echo sequences were obtained before and after administration of gadolinium-based contrast medium (0.16 mmol/kg). The percentage of signal increase in lesions was measured in a series of five 90-second sequences, and time-enhancement patterns were correlated with pathologic diagnoses. RESULTS: Seven benign lesions and three breast cancer recurrences showed less than 185% signal increase at 90 seconds after contrast administration. Three new breast cancers and one recently biopsied benign lesion showed more than 185% signal increase at 90 seconds. CONCLUSION: Using this MRI technique, we can discriminate between new breast cancers (more than 185% early signal increase) and breast cancer recurrence and/or benign lesions (less than 185% early signal increase) but cannot distinguish recurrent from benign lesions.

Anaplastic large-cell lymphoma (Ki-1 lymphoma) and diffuse large-cell immunoblastic lymphoma: two diagnostic problem cases.

Electron microscopy can be used to establish diagnoses in some otherwise difficult cases of neoplasia, but it is not generally regarded as important in the diagnosis of lymphoma. However, in some cases of anaplastic tumors not initially recognized as lymphomas, electron microscopy can prove quite valuable. Two cases are reported in which lymphoma was not suspected on the basis of the histologic findings, but was diagnosed by electron microscopy. Case 1 involved a 60-year-old woman who presented with a retroperitoneal mass that was located primarily in the body of the psoas muscle. Nuclear pockets were seen with electron microscopy. Ultimately she was diagnosed with anaplastic large-cell lymphoma (Ki-1 lymphoma). Case 2 involved a 43-year-old male with retroperitoneal lymphadenopathy, renal failure, polyclonal gammopathy, and a febrile illness. Signet-ring cells without junctions were identified with electron microscopy. Immunoperoxidase stains confirmed diffuse large-cell immunoblastic lymphoma.

Glucocorticoid-resistant B-lymphoblast cell line derived from the Bolivian squirrel monkey (Saimiri boliviensis boliviensis).

The goal of the study reported here was to develop a continuous cell line from the squirrel monkey that expresses the species-specific phenotype of impaired sensitivity to glucocorticoids. Thirty milliliters of blood from a male Bolivian squirrel monkey (Saimiri boliviensis boliviensis) was fractionated, and the buffy coat was obtained and incubated in the presence of B95-8 cell-conditioned medium, an abundant source of Epstein-Barr virus (EBV), and 2 micrograms of cyclosporin A/ml. Cell growth was detected within 8 weeks, after which the cells were cloned by use of the limiting dilution method. One clone (4D8) was characterized in detail. The chromosomal count and G-banding pattern confirmed that the cells were of Bolivian squirrel monkey origin. The B-cell origin of these cells was indicated by electron microscopic analysis and was confirmed by expression of CD20. The cells stained strongly for LMP1, a marker of latent EBV infection, and occasionally for the lytic infection marker ZEBRA (BZLF1). The responsiveness of clone 4D8 cells to glucocorticoids was determined by comparing the effects of dexamethasone on cell growth and the induction of a glucocorticoid-inducible mRNA in 4D8 cells with the effects on a human EBV-transformed B-lymphoblast cell line (HL). Dexamethasone inhibited the growth of HL cells, with IC50 of approximately 9 nM, but had no effect on the growth of 4D8 cells. The induction of FK506-binding protein FKBP51 mRNA by dexamethasone was also significantly blunted in 4D8 cells. Thus, we have developed and characterized a squirrel monkey lymphoblastic cell line derived by transformation of B-lymphocytes with EBV; the cell line has diminished growth and transcriptional responses to glucocorticoids.

Mesothelioma: a study of 22 gases.

Mesothelioma is a rare, asbestos-associated tumor that infrequently metastasizes. We reviewed 22 autopsies (from February 1989 through July 1994) showing mesothelioma. We determined distribution of metastases and staining characteristics of primary mesotheliomas compared to tissue involved by metastases and/or direct extension. Mean patient age was 68 years (range, 38 to 88 years); black:white patient ratio, 4:18; and male:female patient ratio, 2:1. All patients had a history of asbestos exposure. Fifteen autopsies were complete and 7 were limited to the thoracic cavity. Multiple sites were involved by direct extension. Metastases were in multiple sites, including omentum, stomach, intestine, mesentery, adrenal glands, ovary, pancreas, kidneys, liver, spleen, and vertebrae. Results of immunohistochemical staining of primary mesotheliomas and metastases were similar; both were positive for low-molecular-weight keratin and negative for carcinoembryonic antigen, Leu-M1, Ber-EP4, and periodic acid-Schiff reagent with diastase. Results of testing for high-molecular-weight keratin were variable.

Loss of heterozygosity on chromosome 17q11-21 in cancers of women who have both breast and ovarian cancer.

OBJECTIVE: Our purpose was to determine the frequency of allele loss in the region of the BRCA1 gene in cancers of women who have both breast and ovarian cancer. STUDY DESIGN: Four polymorphic microsatellite markers on chromosome 17q11-21 were examined by the polymerase chain reaction in deoxyribonucleic acid from paraffin blocks of normal tissues, breast cancers, and ovarian cancers in 24 women who had primary cancers in both sites. RESULTS: Loss of heterozygosity was seen in one or more markers on chromosome 17q11-21 in 46% of breast cancers and 78% of ovarian cancers. In 38% of cases allele loss was seen in both cancers, and in all these cases the same allele was lost in both cancers. Significantly younger ages at diagnosis of both breast and ovarian cancer were noted among cases with allele loss in both cancers compared with cases in which allele loss was found only in the ovarian cancer (p < 0.05). CONCLUSIONS: Because cases in which 17q11-21 allele loss was seen in both cancers had a young age of onset and the same allele was always deleted in both cancers, hereditary alterations in BRCA1 may play a role in this subset. The older age of onset in cases in which allele loss was seen only in the ovarian cancer suggests that the development of these cancers is not related to an inherited defect in BRCA1.

Fertility after cryptorchidism: a comparative analysis of early orchidopexy with and without concomitant hormonal therapy in the young male rat.

Infertility is common in patients with a history of bilateral cryptorchidism, even after successful prepubertal orchidopexy. Recent data suggest that this defect may be partially due to the existence of hormonal abnormalities in some forms of cryptorchidism. To analyze any potential benefit of hormonal therapy, we have evaluated the immediate and long-term effects of chronic hormonal therapy administered following surgical correction of cryptorchidism. First, using young male rats, we examined the effects of chronic human chorionic gonadotropin (HCG) and a luteinizing hormone-releasing hormone agonist (LHRH-A), alone or combined, on acute pituitary-gonadal axis responsiveness to LHRH administration. High doses of HCG and/or LHRH-A induced deleterious effects on the pituitary-testicular axis in terms of suppression of response to LHRH. Therefore, treatment with a low dose of HCG (50 U/kg/day) for 14 days was used, since it produced a significant increase in intratesticular testosterone (ITT). Second, we tested this hormonal regimen in a cryptorchid rat model. Bilateral cryptorchidism was produced by gubernaculum resection at 14 days of age. Early orchidopexy was performed at age 30 days, and HCG therapy was given from 31 to 44 days of age. Follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) levels were determined before and immediately after hormonal therapy, and at sacrifice. Animals were sacrificed at 61 days of age for determination of serum and testicular hormone levels, accessory sex organ weights and testis histology. Five or six animals from each group were retained for breeding studies at the age of 90 days. Hormonal alterations noted immediately following treatment of cryptorchid animals with HCG are not lasting. The data reveal that the fertility defect in bilateral cryptorchidism is partially prevented by early orchidopexy and that adjunctive hormonal therapy is probably of little additional benefit.

Filamentous inclusions in acinar cell carcinoma of the pancreas.

Acinar cell carcinoma of the pancreas exhibits a spectrum of histologic appearances. Some tumors can be readily identified by light microscopy, but others resemble endocrine/neuroendocrine neoplasms. Ultrastructurally, though large zymogen granules of acinar cells are usually distinctive, the zymogen granules of neoplastic acinar cells are sometimes abnormally small, overlapping in size with the granules of endocrine/neuroendocrine neoplasms. Six cases of acinar cell carcinoma, two with a typical histologic appearance and four that resembled endocrine/neuroendocrine tumors, were studied ultrastructurally. In addition to zymogen granules and abundant rough endoplasmic reticulum, all cases of acinar cell carcinoma exhibited pleomorphic, membrane bound inclusions that contained filaments. Similar inclusions were not identified in islet cell or carcinoid tumors, and several findings indicate that the inclusions represent deranged zymogen granules. In the ultrastructural study of a pancreatic neoplasm with granules, these inclusions may provide a clue for the diagnosis of acinar cell carcinoma.

Therapy monitoring in human and canine soft tissue sarcomas using magnetic resonance imaging and spectroscopy.

PURPOSE: The goals of this study were to determine whether magnetic resonance parameters (a) can identify early during therapy those patients most likely to respond to hyperthermia and radiotherapy, (b) can provide prior to or early during therapy information about the temperature distributions which can be obtained in patients receiving hyperthermia, and (c) can provide an understanding of the effects of hyperthermia on tumor metabolic status. METHODS AND MATERIALS: Twenty-one human patients and 10 canine patients with soft tissue sarcomas treated with preoperative hyperthermia and radiation had a series of magnetic resonance imaging and phosphorous spectroscopy studies done. To address the goals for both the human and canine populations, changes in mean T2 relaxation times, pH, and various phosphometabolite ratios from the pretreatment (Study 1) to the post first hyperthermia study (Study 2) were correlated with treatment outcome; pretreatment magnetic resonance parameters and changes in magnetic resonance parameters (Study 2-Study 1) were compared with various cumulative thermal descriptors; and thermal descriptors of the first hyperthermia were compared with changes in magnetic resonance phosphometabolite ratios. RESULTS: A decrease in adenosine triphosphate/phosphomonoester from study 1 to study 2 is associated with a greater chance of > or = 95% necrosis in surgical resected tumors from human patients, but no significant relationships were observed between changes in tumor pH or phosphometabolite ratios and time to local failure in dogs. Pretreatment magnetic resonance parameters correlated with various thermal dose descriptors in canines but not in humans. Change in adenosine triphosphate/inorganic phosphate and phosphomonoester signal to noise ratio correlated with cumulative thermal descriptors in dogs and humans, respectively. In dogs only, increases in thermal dose resulted in decreases in high energy phosphometabolites. CONCLUSION: Changes in magnetic resonance parameters early during therapy may be predictive of treatment outcome. Pretreatment and changes in magnetic resonance parameters appear to predict how well a tumor will be heated during hyperthermia. Magnetic resonance spectroscopy also appears to be a useful tool to study the effects of various thermal doses on tumor metabolic status.

MR imaging and spectroscopy for prognostic evaluation in soft-tissue sarcomas.

PURPOSE: To enable prediction of tumor response to a particular treatment. MATERIALS AND METHODS: The authors studied the value of hydrogen-1 T2 and phosphorus-31 magnetic resonance (MR) spectroscopic metabolic determinations as indicators of prognosis in 20 humans and 10 dogs with soft-tissue sarcomas. All patients underwent combined fractionated radiation therapy and hyperthermia. Surgical resection of the entire tumor in humans allowed comparison of pretherapy T2 and MR spectroscopic parameters with subsequent histologic findings. Long-term clinical follow-up (no surgical intervention) was available with the dogs and allowed comparison of pretherapy pH with the duration of local relapse-free survival. RESULTS: A relationship exists between pretherapy pH and T2 and ultimate tumor necrosis in humans and pretherapy pH and time elapsed until local failure in dogs. CONCLUSION: MR imaging and spectroscopy could be useful in the prognosis of patients with soft-tissue sarcomas before therapy is initiated.