PubMed Health⌕ Search

Biomedical subjects

M Campiglio

Publications and source records attributed to M Campiglio.

24 records · Page 2Linked to original sources
PubMed1993

Overexpression of p185 is not related to erbB2 amplification in ovarian cancer.

BACKGROUND: While in breast cancer the amplification and overexpression of the erbB2 gene has been reported in numerous studies and found to be correlated to poor prognosis, information about this oncogene with respect to ovarian cancer is still limited. A recent study reported that approximately 30% of tumor biopsies from ovarian cancer patients exhibited erbB2 amplification and overexpression and suggested that the overexpression of this oncogene is an indicator of bad prognosis in ovarian cancer. The purpose of our studies was to investigate amplification of the erbB2 gene, the levels of erbB2 m-RNA and the erbB2 product (p185) in ovarian cancer, and the correlation between these findings and the pathological and clinical features. RESULTS: Amplification of the erbB2 gene was investigated by Southern blot analysis in 75 samples from 62 patients; mRNA levels were evaluated by Northern blot analysis in 58 samples from 48 patients; and p185 was determined by immunohistochemistry in 65 samples from 65 patients. The erbB2 gene was amplified in only one case (1.6%), and a marked increase in erbB2 mRNA was found only in the same case. Staining for p185 was positive in 12 cases (18.5%). The staining was always confined to the cytoplasm except in the case that showed amplification of erbB2 in which p185 was localized in the membrane. No correlation was found between p185 positivity and pathological and clinical features or response to chemotherapy. Western blot analysis showed that the molecular weight of p185 in positive ovarian cancer cells was approximately 10 KDa lower than in breast cancer. CONCLUSION: In contrast to breast cancer, in ovarian cancer the amplification of erbB2 appears infrequent. The levels of p185 detected by immunohistochemistry were not related to the amplification of the gene or to the increase in mRNA, suggesting the possibility of a longer half-life of the protein in the positive cases. The finding that erbB2 product in ovarian cancer is mostly localised in cytoplasm and not in the membrane as in breast cancer and that it has a lower molecular weight than the p185 in breast cancer suggest that this oncogene plays a different biological role in these two neoplasms.

ErbB Receptors↗
PubMed1991

Selection of monoclonal antibodies which induce internalization and phosphorylation of p185HER2 and growth inhibition of cells with HER2/NEU gene amplification.

In order to obtain further information on the biological role of the HER2/neu oncoprotein monoclonal antibodies (MAbs) were produced against the p185 extracellular domain. To immunize the mice and screen the hybridoma supernatants we selected a lung adenocarcinoma cell line (Calu-3), which demonstrated an over-expression of p185HER2 measured as the reactivity with polyclonal rabbit serum to the 14-amino-acid carboxy-terminal-HER2/neu. Two MAbs, designated MGR2 (IgG1) and MGR3 (IgG2), selected for reactivity on Calu-3 and negativity on A43I live cells, the reference target cell for EGF receptor expression, were found to immunoprecipitate a 185-kDa molecule. Immunodepletion experiments with the polyclonal antiserum and cross-competition experiments indicated that the 2 reagents recognized 2 different epitopes located on the p185HER2 molecule. One of the 2 MAbs, MGR3, was found to internalize, induce p185HER2 phosphorylation and inhibit tumor cell growth in vitro. These results indicate that MGR3 is directed against a determinant located in the p185HER2 ligand binding site and may compete with the p185HER2 ligand, but is incapable of inducing a complete mitotic signal.

Animals↗
PubMedDate not supplied

Two novel monoclonal antibodies against the MUC4 tandem repeat reacting with an antigen overexpressed by lung cancer.

In this study we investigated the immunochemical and cytochemical reactivity of two monoclonal antibodies against the 16-amino acid tandem repeat of MUC4 to demonstrate a possible variation of the mucin core peptide expression related to lung cancer. The immunocytochemical anti-MUC4 reactivity was analyzed in four lung cancer cell lines (Calu-1, Calu-3, H460, SKMES) and in other tumor cell lines, as well as in frozen materials from 21 lung adenocarcinomas (ACs), including five bronchioloalveolar carcinomas (BACs), and 11 squamous cell lung carcinomas (SqCCs). A weak fluorescence anti-MUC4 positivity (range: 10.3-16.2) was observed only in acetone-fixed lung cancer cell lines Calu-1, Calu-3 and H460. These three lung cancer cell lines also showed a cytoplasmic immunoperoxidase reactivity. The immunostaining in lung cancer tissues showed a granular cytoplasmic reactivity: 15/21 (71%) and 17/21 (80%) ACs were positive with BC-LuC18.2 and BC-LuCF12, respectively. All BACs were positive. Moderate to strong reactivity was present in well-differentiated ACs. In the normal lung parenchyma counterparts weak reactivity was found only in bronchiolar cells. All SqCCs were negative. Anti-MUC4 reactivity was also observed in the alveolar mucus. In conclusion, our anti-MUC4 MAbs detect a secretion product present in mucus and this product is elaborated by lung cancer cells and overexpressed in well-differentiated lung ACs.

Adenocarcinoma↗
PubMedDate not supplied

Production of a monoclonal antibody directed against the recombinant SEL1L protein.

SEL1L, highly similar to the C elegans sel-1 gene, is a recently cloned human gene whose function is under investigation. SEL1L is differentially expressed in tumors and normal tissues and seems to play a role in tumor growth and aggressiveness. We used the recombinant N-terminus of the SEL1L protein to immunize a Balb/c mouse and produce a monoclonal antibody. A hybridoma secreting an antibody specifically reacting on the SEL1L recombinant fragment was selected. This monoclonal antibody, named MSel1, recognizes the SEL1L protein by Western blotting, immunofluorescence and immunohistochemistry on normal and tumor cells. MSel1 is able to recognize SEL1L even on archival tumor specimens and is therefore particularly appropriate to study SEL1L involvement in tumor progression.

Animals↗
PubMedDate not supplied

Conventional antibodies: requirements and methods for their optimization.

Eighteen years after the discovery of monoclonal antibodies (MAbs), the debate as to whether these reagents have fulfilled their promise must now be addressed. When MAbs were studied as tools for diagnosis and therapy, problems arose regarding the reagents themselves and the recognized target antigens. Because most MAbs are of murine origin, they usually evoke an immune response in human patients, which reduces their effectiveness. Moreover, their bulky size and dispersal via the blood prevent most of the injected antibodies from substantially penetrating solid, poorly vascularized tumors. However, MAbs that are adequately selected and manipulated to circumvent these problems have been found to successfully image tumors and to be therapeutically active.

Antibodies, Monoclonal↗