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Biomedical subjects

M P DiGiovanna

Publications and source records attributed to M P DiGiovanna.

13 recordsLinked to original sources
PubMed2001

Adenoid cystic carcinoma: a retrospective clinical review.

Adenoid cystic carcinoma (ACC) are uncommon tumors, representing about 10% to 15% of head and neck tumors. We compare the survival and control rates at our institution with those reported in the literature, and examine putative predictors of outcome. All patients registered with the tumor registry as having had ACC were identified. Demographic and survival variables were retrieved from the database. Additionally, a chart review of all patients was done to obtain specific information. Minor gland tumors were staged using the American Joint Committee on Cancer's criteria for squamous cell carcinomas in identical sites. Histopathologic variables retrieved included grade of the tumor, margins, and perineural invasion. Treatment modalities, field sizes, and radiation doses were recorded in applicable cases. An effort to retrieve archival tumor specimens for immunohistochemical analysis was undertaken. A total of 69 patients were treated for ACC from 1955 to 1999. One patient, who presented with fatal brain metastasis, was excluded from further analysis. Of the remaining 68 patients, 30 were men and 38 were women. The average age at diagnosis was 52 years, and mean follow-up was 13.2 years. Mean survival was 7.7 years. Overall survival (OS) rates at 5, 10, and 15 years were 72%, 44%, and 34%, and cause-specific survival was 83%, 71%, and 55%, respectively. Recurrence-free survival rates were 65%, 52%, and 30% at 5, 10, and 15 years, with a total of 29 of 68 (43%) eventually suffering a recurrence. Overall survival was adversely affected by advancing T and AJCC stage. Higher tumor grades were also associated with decreased OS, although the numbers compared were small. Primaries of the nasosinal region fared poorly when compared with other locations. Total recurrence-free survival, local and distant recurrence rates were distinctly better in primaries of the oral cavity/oropharynx when compared with those in other locations. Reduced distant recurrence-free survival was significantly associated with increasing stage. No other variables were predictive for recurrence. Additionally, we found that nasosinal tumors were more likely to display higher stage at presentation, and were more often associated with perineural invasion. Also of interest was the association of perineural invasion with margin status, with 15 of 20 patients with positive margins displaying perineural invasion, while only 5 of 17 with negative margins showed nerve invasion (P = 0.02). On immunohistochemistry, 2 cases of the 29 (7%) tumor specimens found displayed HER-2/neu positivity. No correlation between clinical behavior and positive staining could be demonstrated. Our data concur with previous reports on ACC in terms of survival and recurrence statistics. Stage and site of primary were important determinants of outcome. Grade may still serve a role in decision making. We could not demonstrate any differences attributable to primary modality of therapy, perhaps due to the nonrandomization of patients into the various treatment tracks and the inclusion of palliative cases. Similarly, perineural invasion, radiation dose and field size, and HER-2/neu positivity did not prove to be important factors in our experience.

Carcinoma, Adenoid Cystic↗
PubMed2001

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors.

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.

Breast Neoplasms↗
PubMed2001

Molecular marker expression in oral and oropharyngeal squamous cell carcinoma.

OBJECTIVE: To determine the relative prognostic value of p53, cyclin D1, epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF) expression in patients with oral and oropharyngeal squamous cell carcinoma. DESIGN: Retrospective cohort study. PATIENTS: Fifty-six patients with oral and oropharyngeal squamous cell carcinoma referred to the Department of Therapeutic Radiology at Yale-New Haven Hospital (Conn) between 1981 and 1992 who were treated with gross total surgical resection and postoperative external beam radiotherapy. RESULTS: Archival tumor tissue was stained with monoclonal antibodies directed against these 4 oncoproteins and scored for staining intensity and percent distribution by a pathologist blinded to the patients' clinical outcomes. Frequency of marker expression was 48% for p53, 20% for cyclin D1, 64% for EGFR, and 41% for VEGF. In multivariate analysis, EGFR positivity was protective against locoregional relapse (relative risk [RR], 0.27; 95% confidence interval [CI], 0.11-0.66; P =.002). In contrast, advanced N stage predicted poor locoregional relapse-free survival (RR, 1.94; 95% CI, 1.03-3.66; P =.04). Predictors of poor overall survival in multivariate analysis included VEGF positivity (RR, 3.53; 95% CI, 1.75-7.13; P<.001) and black race (RR, 2.48; 95% CI, 1.05-5.85; P =.04). Cyclin D1 and p53 expression were not significantly associated with prognosis in this cohort. CONCLUSIONS: In oral and oropharyngeal squamous cell carcinoma treated with surgery and postoperative radiotherapy, VEGF and EGFR expression may influence clinical outcome. If confirmed, these results have potential implications for the determination of patient prognosis and the development of biologically based pharmacotherapies.

Adult↗
PubMed2000

Activation (tyrosine phosphorylation) of ErbB-2 (HER-2/neu): a study of incidence and correlation with outcome in breast cancer.

PURPOSE: We hypothesize that phosphorylated ErbB-2 (P-ErbB-2, identified by a novel antibody PN2A) may provide either more significant or additional prognostic marker data for breast cancer patients. This study was designed to compare the incidence and prognostic value of ErbB-2 (HER-2/neu) and P-ErbB-2 immunoexpression in archival breast cancer samples. MATERIALS AND METHODS: Eight hundred sixteen invasive breast cancers with a median of 16.3 years of follow-up were immunostained for ErbB-2 (using antibody CB11) and P-ErbB-2 (using antibody PN2A). ErbB-2 and P-ErbB-2 data were compared with clinical, histologic, immunohistochemical, and outcome variables. RESULTS: Of 816 primary breast cancers, 307 (38%) were positive for ErbB-2 and 37 (12% of ErbB-2 positive and 5% of the study population) expressed P-ErbB-2. P-ErbB-2 was not detected in ErbB-2-negative cases (n = 509). ErbB-2 immunohistochemical data were bimodal; patients with > or = 80% cellular expression had the shortest disease-free and disease-specific survival. P-ErbB-2 was associated with a higher percentage of ErbB-2-positive cells, a higher number of positive lymph nodes, and cellular proliferation. ErbB-2 and P-ErbB-2 were indicators of poor prognosis in node-positive patients in both univariate and multivariate analyses. We found that either P-ErbB-2 expression or high (> or = 80%) ErbB-2 expression provided the most significant prognostic value in node-positive cases by multivariate analyses. There were too few P-ErbB-2-positive cases and events in the node-negative patient group to allow statistical analysis of P-ErbB-2 in that subgroup. CONCLUSION: PN2A immunostaining identified a subset (approximately 12% of ErbB-2-positive breast cancers) with activation (phosphorylation) of the receptor ErbB-2. P-ErbB-2 expression was strongly associated with higher levels of ErbB-2 expression (> or = 80%), although it was not a surrogate. Identification of cases with a high percentage of invasive breast cancer cells expressing ErbB-2 or determination of receptor activation via P-ErbB-2 may provide additional prognostic value in node-positive breast cancers.

Adult↗
PubMed1998

Active signaling by Neu in transgenic mice.

Transgenic mice engineered to overexpress the HER-2/neu/erbB-2 protooncogene under the control of a mammary-specific promoter develop mammary tumors and are a model for human breast cancer. Signal transduction by Neu was examined in situ in the tumors of these transgenic mice. This was accomplished using the PN2A monoclonal antibody, which recognizes Neu only in the phosphorylated, and therefore actively signaling, state. Immunohistochemistry using PN2A demonstrated that Neu actively signals in the tumors of Neu transgenic mice. Expression of Neu was always accompanied by co-overexpression of the endogenous epidermal growth factor receptor. Qualitatively similar results were found in mammary tumors from mice bitransgenic for the neu and transforming growth factor-alpha genes (both driven by the mouse mammary tumor virus promoter). Early mammary lesions demonstrated distinctive patterns of Neu activation relative to expression levels. Overexpression and activation were separable both temporally and spatially. These results refine the multi-step model for the role of Neu in mammary neoplasia and establish phosphorylation-state specific antibodies as a powerful tool for investigating tumor progression.

Animals↗
PubMed1996

Functional assay for HER-2/neu demonstrates active signalling in a minority of HER-2/neu-overexpressing invasive human breast tumours.

Overexpression of HER-2/neu in human breast carcinomas correlates with poor prognosis, although its strength as a prognostic indicator varies widely in different reports. Variability may be due to active signalling by HER-2/neu in a subset of the tumours in which it is overexpressed. To study this hypothesis, we have developed an activation state-specific anti-HER-2/neu monoclonal antibody. In this report, we use this antibody to analyse the signalling status of HER-2/neu in a large series of invasive breast carcinomas. Overexpression of HER-2/neu was detected in 9% of 223 cases. Of the cases demonstrating overexpression, active signalling by HER-2/neu was detected in only 35%. The clinicopathological characteristics of these cases are described. This functional assay is predicted to improve the utility of HER-2/ neu as a prognostic indicator.

Antibodies, Monoclonal↗
PubMed1995

Activation state-specific monoclonal antibody detects tyrosine phosphorylated p185neu/erbB-2 in a subset of human breast tumors overexpressing this receptor.

Amplification of the neu/erbB-2/HER-2 gene and/or overexpression of its receptor tyrosine kinase product, p185neu/erbB-2 (p185), occurs in 15-40% of primary human breast tumors and is variably correlated with poor patient prognosis. Variability in predictive accuracy likely results from activation of p185 by agonist(s) in only a subset of tumors in which it is overexpressed, which may greatly affect outcomes. As a first step toward evaluating this hypothesis, we previously produced a polyclonal antibody that specifically recognizes the activated, tyrosine-phosphorylated forms of p185 and the closely related epidermal growth factor receptor (L. Bangalore et al., Proc. Natl. Acad. Sci. USA, 89: 11637-11641, 1992). We now describe the production of a mAb, PN2A, that specifically recognizes tyrosine-phosphorylated p185 and bears no cross-reactivity with closely related receptors. Furthermore, we demonstrate its reactivity in immunohistochemical staining of paraffin-embedded, formalin-fixed tumor samples. In a series of five p185-overexpressing human tumors examined thus far, PN2A reactivity was detected in two, indicating that p185 is phosphorylated and hence actively signaling in a subset. This reagent will facilitate both clinical and research analyses of p185 activity. Furthermore, this work serves as a prototype for similar analyses of other tyrosine phosphoproteins.

Amino Acid Sequence↗
PubMed1992

Differentiation stage specificity of tyrosine phosphorylation in response to granulocyte macrophage colony stimulating factor (GM-CSF).

We have previously described differentiation associated tyrosine protein kinase activity in WEHI-3B monomyelocytic leukemia cells and have presented evidence which suggests that this activity may not be involved in the initiation of the differentiation process, but more likely has a functional role in the mature myeloid cell. The present study was undertaken in an attempt to identify the protein(s) responsible for the tyrosine protein kinase activity and to seek a potential role for this activity in the mature cell. We and others have detected the p92c-fes tyrosine protein kinase in WEHI-3B cells. This protein has been implicated in myeloid differentiation, as well as in the transduction of signals in response to granulocyte macrophage colony stimulating factor (GM-CSF). Thus, it was of interest to determine whether tyrosine phosphorylation may be involved in the response of WEHI-3B cells to GM-CSF. Treatment of differentiated WEHI-3B D+ cells with GM-CSF was found to result in the tyrosine phosphorylation of a number of endogenous cellular proteins in a concentration-dependent, rapid and transient manner. In contrast, the cytokine did not elicit such a response in undifferentiated cells, despite the fact that undifferentiated cells have been reported to possess GM-CSF receptors. These findings are consistent with the concept that the effects of GM-CSF on differentiated myeloid cells are mediated through tyrosine phosphorylation, that only differentiated cells are competent to accomplish this event, and that this response constitutes at least one functional role for the myeloid differentiation associated tyrosine protein kinase activity.

Animals↗
PubMed1991

Cytotoxicity and DNA crosslinks produced by mitomycin analogs in aerobic and hypoxic EMT6 cells.

Several mitomycin antibiotics were evaluated for their capacities to kill EMT6 tumor cells and to produce DNA crosslinks under conditions of oxygenation and hypoxia. The agents examined included mitomycin C, porfiromycin, and the 7-aminomethyl dithioacetal derivative of mitomycin C (BMY-43324), all of which caused greater kill of hypoxic cells than of their oxygenated counterparts; the N,N'-dimethylaminomethylene derivative of mitomycin C (BMY-25282), which was considerably more cytotoxic under oxygenated conditions than in hypoxia; and the N,N'-dimethylaminomethylene derivative of porfiromycin (BL-6783), which was equal in its toxicity to hypoxic and oxygenated cells. All of these agents produced DNA crosslinks in EMT6 cells, as measured by alkaline elution. The number of crosslinks required to produce a given amount of cell kill was similar, regardless of the mitomycin employed or the degree of oxygenation, suggesting that the crosslinking of DNA was a major lesion in the cytodestructive action of the mitomycins.

Aerobiosis↗
PubMed1991

Myeloid differentiation associated tyrosine protein kinase activity in WEHI-3B murine monomyelocytic leukemia cells.

Tyrosine protein kinase activity was examined during the induction of granulocytic differentiation of WEHI-3B murine monomyelocytic leukemia cells by retinoic acid and aclacinomycin A. Tyrosine kinase activity was found to increase throughout the period of induced maturation. The specificity of this increase in enzymatic activity for the differentiated state was demonstrated by the findings that (a) it was independent of the inducer used, and (b) the treatment of a differentiation-resistant subline of this murine leukemia with an inducer did not produce a significant elevation of tyrosine kinase activity. To determine whether tyrosine protein kinase activity was involved in the differentiation process itself or whether it was a product of the mature state, a series of experimental approaches was employed. Kinetic analyses showed that tyrosine protein kinase activity continued to increase beyond the peak in the level of differentiation. In addition, the total cellular protein phosphotyrosine content, measured by immunoblotting and flow cytometric analysis with anti-phosphotyrosine antibodies, did not increase in accord with the elevation of tyrosine kinase activity. Increases in protein phosphotyrosine content, which were dependent upon the length of exposure to the inducing agent, were observed when cultured cells were treated with the phosphotyrosine phosphatase inhibitor, sodium orthovanadate. Thus, the effect of the increasing tyrosine kinase activity in maturing cells appeared to be negated by competing protein phosphotyrosine phosphatase activity. Finally, the inhibitors of tyrosine kinase activity, genistein and PKI-23, did not interfere with the induction of differentiation by retinoic acid. These findings support the concept that myeloid differentiation associated tyrosine protein kinase activity may not be involved in the initiation of the differentiation process itself. This conclusion deviates from previous assumptions, based on earlier work in this laboratory as well as in that of others, that the differentiation associated kinase activity has an essential role in the initiation of the maturation process. An attractive alternative speculation is that this activity may have a functional role in the mature myeloid cell.

Animals↗
PubMed1991

Effects of recombinant murine granulocyte-macrophage colony-stimulating factor in cyclophosphamide-treated mice.

To evaluate the efficacy of recombinant murine granulocyte-macrophage colony-stimulating factor (rGM-CSF) in attenuating the myelosuppression associated with chemotherapy, the effects of 100 and 300 ng rGM-CSF, administered twice daily by intraperitoneal injection for 6 consecutive days to mice 24 hours after a dose of 200 mg/kg cyclophosphamide, were measured. Six days after the initial injection of rGM-CSF, a significant increase occurred in the absolute myeloid count compared to that of vehicle-treated animals. The difference was most pronounced on day 7, attaining levels of 327% and 428% of the control; these increases slowly declined to that of the control level by day 19. No significant effect was produced by rGM-CSF on the packed red cell volume or on the platelet count. Furthermore, the administration of rGM-CSF did not alter bone marrow cellularity or increase the number of marrow-derived hematopoietic stem cells. In contrast, a significant splenomegaly occurred, starting on day 6 and continuing until day 17. This was characterized by a pronounced increase in splenic-derived granulocyte (CFU-G), granulocyte-macrophage (CFU-GM), macrophage (CFU-M), megakaryocyte (CFU-MK), and erythroid (BFU-E, CFU-E) stem cells. The increases occurred between days 6 and 9 following the initial administration of rGM-CSF. These findings indicated that the administration of rGM-CSF to cyclophosphamide-treated animals causes an absolute increase in circulating myeloid cells and that these increases are derived from the spleen. The use of recombinant hematopoietic growth factors may permit the administration of more intensive chemotherapy through amelioration of chemically induced leukopenia.

Animals↗