Search PubMed⌕ Search

Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

414 records · Page 23Linked to original sources
PubMedDate not supplied

Anti-BLA.36 monoclonal antibody shows reactivity with Hodgkin's cells and B lymphocytes in frozen and paraffin-embedded tissues.

A newly developed monoclonal antibody, anti-BLA.36, raised against a Hodgkin cell line, was shown to have reactivity with Reed-Sternberg cells and activated B lymphocytes and appears to be distinct from other antibodies which identify antigens of hematopoietic cells. Anti-BLA.36 was evaluated in B5-fixed paraffin-embedded tissue from 16 cases of Hodgkin's disease of various types and 35 cases of non-Hodgkin's lymphomas representative of the different major subtypes. The specificity of anti-BLA.36 was compared with other antibodies that have been used to mark Hodgkin's cells and B lymphocytes: namely, L26, LN-1, Leu-M1 and Ber-H2, as well as UCHL-1, a pan-T lymphocyte marker. In addition, a subset of the cases was evaluated using frozen tissue in order to validate the staining characteristics of anti-BLA.36 as observed in fixed paraffin sections. Anti-BLA.36 was found to react with Hodgkin's cells more consistently than the other antibodies used in this panel. The antibody reacted with an antigen on Reed-Sternberg cells and their variants (Hodgkin's cells) in all four subtypes of Hodgkin's disease, and with a subset of reactive and malignant B lymphocytes, but not with T lymphocytes. It may, therefore, be useful in the evaluation of non-Hodgkin's lymphomas. Finally, this is the first antibody raised to a Hodgkin's cell line which also consistently marks reactive and malignant B cells, but not T cells. The implications of this observation are discussed in relation to the cellular origin of the Reed-Sternberg cell and the overall nature of Hodgkin's disease.

Antibodies, Monoclonal↗
PubMedDate not supplied

Energetic cost of carrying loads: have African women discovered an economic way?

When travelling in East Africa one is often surprised at the prodigious loads carried by the women of the area. It is not uncommon to see women of the Luo tribe carrying loads equivalent to 70% of their body mass balanced on the top of their heads (Fig. 1). Women of the Kikuyu tribe carry equally large loads supported by a strap across their foreheads; this frequently results in a permanently grooved skull. Recent experiments on running horses, humans, dogs and rats showed that the energy expended in carrying a load increased in direct proportion to the weight of the load for each animal at each speed, that is, carrying a load equal to 20% of body weight increased the rate of energy consumption by 20% (ref. 1). The purpose of the present study was to determine whether these African women use specialized mechanisms for carrying very large loads cheaply. We found that both the Luo and Kikuyu women could carry loads of up to 20% of their body weight without increasing their rate of energy consumption. For heavier loads there was a proportional increase in energy consumption, that is, a 30% load increased energy consumption by 10%, a 40% load by 20% and so on. We suggest that some element of training and/or anatomical change since childhood may allow these women to carry heavy loads economically.

Back↗
PubMedDate not supplied

Standardization in immunohistochemistry: the role of antigen retrieval in molecular morphology.

Molecular morphology seeks to integrate the traditional morphologic criteria of surgical pathology with immunohistochemical and in situ hybridization techniques that allow demonstration of a variety of molecules, proteins, RNA and DNA in a tissue section. While immunohistochemistry has proven to be successful for demonstrating lineage related biomarkers of value for diagnosis and classification of tumors, concerns have been raised periodically about validation of reagents, overall reproducibility of the staining method, and interpretation of results. These concerns have been heightened by the burgeoning interest in prognostic markers, where the question extends beyond a relatively simple positive or negative result to an absolute need for quantification of the staining result; not only is it positive, but how much is there? In this presentation at the Annual Meeting of the Biological Stain Commission in June, 2005, I advocate a total test approach that requires systematic attention to pre-analytic, analytic, and post-analytic issues. The approach encompasses all aspects of test performance from specimen acquisition, through fixation, antigen retrieval, processing, staining, interpretation, and reporting of results. A similar systematic approach also may be adopted for in situ hybridization methods, which have performance requirements that in many ways parallel immunohistochemistry.

Antigens↗
PubMedDate not supplied

Controlled drug trials in photodermatoses.

While clinical drug trials in photodermatoses may be complex because of the fickleness of these disorders in their reproducibility following ultraviolet exposure, such investigations require the same general principles of careful design as those in any other disciplines. The ideal clinical trial in photodermatology is both randomized and double-blind. Precise diagnostic terminology and monitoring of sun exposure must be employed. Polysulphone film badges are the most suitable personal dosimeters to date for these studies. Assessment of itching and discomfort may be reliably performed by the use of a visual analogue scale. Symptoms may also be assessed, but less precisely, by means of a diary record. Only by the use of controlled trials, however, will anecdotal dogma be prevented from inappropriately entering the therapeutic armamentarium of the dermatologist who manages such light sensitive conditions.

Controlled Clinical Trials as Topic↗
PubMedDate not supplied

Total body heliotherapy.

Sunlight has long been known to be beneficial for a variety of skin diseases. Patients with psoriasis and eczema frequently employ ambient heliotherapy to control their conditions. However, social norms do not permit a person to expose the entire body in public, thus placing severe restrictions on the utility of this modality for the treatment of generalized psoriasis, for example. Tan-Thru bathing suits, designed to attract those who wish to tan without an accentuated "tan line", are reported to absorb ultraviolet (UV) rays up to a maximum equivalent of a sun protection factor (SPF) 10 sunblock, thus offering approximately 89% protection while in use, according to their manufacturer. If so, this bathing suit may allow patients with UV-responsive skin dermatoses to achieve full body exposure in a socially acceptable manner. The objective of this study was to verify the SPF and to determine the actual transmittance to skin covered by a Tan-Thru bathing suit. Ten healthy adult subjects were recruited for this investigation. UVB minimal erythema dose (MED) was determined on unaffected gluteal or lower back skin, once with and once without the swimsuit on. Our results showed that the mean SPF afforded by the bathing suit was in fact 4.9 (range 4.5-5.6). In conclusion, theoretically, the Tan-Thru bathing suits could allow enough UVB penetration under ambient conditions to be beneficial for patients with UVB responsive conditions.

Adult↗
PubMedDate not supplied

Purification and characterization of a Hodgkin's and B cell-associated glycoprotein.

A glycoprotein (BLA.36), expressed on the plasma membrane of Hodgkin's cells and also on normal and malignant B lymphocytes and histiocytes, was identified by reaction with a monoclonal antibody. BLA.36 was not detectable on other hematopoietic, carcinoma or melanoma cell lines. BLA.36 was purified to homogeneity by extracting proteins from a Hodgkin's cell line (HDLM-3), followed by immunoaffinity chromatography, utilizing immobilized anti-BLA.36 antibody, and gel filtration on Sephacryl S-100 in the presence of protein dissociating agents. The purified component yielded a single band on sodium dodecyl sulphate/polyacrylamide gel electrophoresis under both non-reducing and reducing conditions, and closely related three isotypes of similar molecular weight and with the apparent isoelectric points that ranged from 5.0 to 5.2 on two-dimensional gel electrophoresis. The purified BLA.36 reacted with the original specific antibody, on both one- or two-dimensional gel electrophoresis, suggesting that antigenic determinant was not adversely affected during purification procedure. Competitive immunoprecipitation analyses and the determination of N-terminus sequence of the first 13 amino acid residues suggest that BLA.36 is unrelated to other known Hodgkin's or hematopoietic cell antigens. Finally, significance of BLA.36 expression on the growth of BLA.36-positive cell lines was studied. Blocking of BLA.36 with anti-BLA.36 antibody led to the in vitro growth-inhibition of BLA.36-positive cell lines. The antibody pre-absorbed with the purified BLA.36 was unable to exert growth-inhibition, demonstrating the specificity of reaction. In addition, the treatment of the BLA.36-positive cell lines with differentiation-inducing agent, alpha-interferon (alpha-IFN), down-regulated BLA.36 expression and also showed in vitro growth-inhibition of BLA.36-positive cell lines. Taken together, these results suggest a growth-related function of BLA.36.

Amino Acid Sequence↗
PubMedDate not supplied

LEA.135 expression: its comparison with other prognostic biomarkers for patients with primary breast carcinoma.

The purpose of this retrospective study was to examine the prognostic value of expression of luminal epithelial antigen (LEA.135) for recurrence and overall survival of patients with primary invasive breast carcinoma by both univariate and multivariate analyses. The possible prognostic value of LEA.135 was also compared with some widely utilized prognostic biomarkers such as c-erbB 2, topoisomerase II.alpha (TPII.alpha), MIB 1, estrogen receptor (ER) and progesterone receptor (PR), as well as age of the patients and clinicopathologic parameters. The study was carried out by immunohistochemical methods on formalin-fixed/paraffin-embedded tissue sections in a series of 225 patients with median follow-up of 8.5 years. Prognostic significance of the biomarkers was determined by two-sided p value. In this series of patients, among the age and clinicopathologic parameters, only age, was significantly associated with a decreased overall survival (logrank p = 0.027). Among the prognostic biomarkers, TPII a expression at high (> 50% positive cells) or moderate (6-50% positive cells) level was associated with an increased rate of recurrence (logrank p < 0.001). However, the association of TPII.alpha expression with a decreased overall survival failed to reach a statistically significance. Expression of c-erbB 2 showed a trend of being associated with an increased probability of recurrence, but the association did not reach statistical significance. The remaining biomarkers were not associated with either the probability of recurrence or overall survival. LEA.135 expression was observed in 163 (72.4%) of the 225 patients. The patients with high (> 50% positive cells) or moderate (6-50% positive cells) level of LEA.135-positive cancer cells showed a significantly decreased probability of recurrence (logrank p < 0.001) and an increased overall survival (logrank p < 0.001) compared with those with LEA.135-negative cancer cells. The association remained significant by multivariate analysis for recurrence (likelihood ratio test p < 0.001) and overall survival (likelihood ratio test p < 0.001) when assessed with other prognostic parameters. Furthermore, the combination of LEA.135 with other prognostic biomarkers stratified four subgroups of patients with distinct clinical outcome. The subgroup of patients who were LEA.135+/TPII.alpha- showed the lowest probability of recurrence and the longest overall survival compared with those who were LEA.135-/TPII.alpha+ (logrank p < 0.001). Interestingly, the patients whose cancer cells were LEA.135+/TPII.alpha+, LEA.135+ MIB.1+ or LEA.135+/c-erbB 2+ experienced a decreased probability of recurrence and an increased overall survival compared with those with LEA.135-/TPII.alpha+, LEA.135- MIB.1+ or LEA.135-/c-erbB 2+ (logrank p < 0.001). The results demonstrated that LEA.135 is an independent and favorable prognostic biomarker for patients with primary invasive breast carcinoma, that the loss of LEA.135 expression is associated with aggressive phenotype of cancer cells during the breast cancer progression, and that its continued expression seems to override the adverse effects of expression of an oncogene or cell proliferation-associated molecules.

Age Factors↗
PubMedDate not supplied

BLA.36: a glycoprotein specifically expressed on the surface of Hodgkin's and B cells.

Anti-BLA.36 is an antibody that recognizes a glycoprotein with an apparent molecular weight of 36 kilodaltons, termed B lymphocyte antigen (BLA.36). By using an immunochemical staining technique, BLA.36 was found to be specifically expressed on Hodgkin's and human B cell lines including early B progenitor cells. Other cell lines representing T cell lymphomas, non-B large cell lymphomas, melanomas and carcinomas were consistently negative. BLA.36 is distinct from the previously identified antigens of hematopoietic cell lineage. The specificity of expression of BLA.36 in tissue sections mirrored that of cell lines. In normal tissues, BLA.36 was detectable predominantly on cells in the germinal center and mantle zone of reactive follicles in lymph nodes and spleens. In hematopoietic malignancy, the antigen was expressed on the surface of Reed-Sternberg cells, mononuclear Hodgkin's cells and also on malignant cells of B cell lineage. BLA.36 was also observed on lymphoid cells of 10 to 24 week fetal liver: a double-antibody-staining method revealed that these BLA.36-positive cells also contained immunoglobulin mu heavy chain consistent with identification as early B cells. Under these conditions, T lymphocytes, histiocytes, granulocytes, macrophages, stromal cells in lymphoid tissue, and both normal and neoplastic epithelial cells were consistently negative for the expression of the antigen, with the single exception of a variable proportion of Kupffer cells in normal liver. The antibody has already established its usefulness for the identification of Reed-Sternberg and Hodgkin's cells, and also normal and malignant B lymphocytes in frozen as well as formalin-fixed tissue sections. Furthermore, binding of F(ab)2 fragments of anti-BLA.36 to antigen-positive cell lines specifically inhibited the proliferation of cells. Such an effect was eliminated by the removal of the antibody from the culture-medium, suggesting a possible growth-related function of the antigen in Hodgkin's and B cells.

Animals↗
PubMedDate not supplied

A history of the Reed-Sternberg cell.

The diagnosis of Hodgkin's disease continues to depend upon the finding of Reed-Sternberg cells in an appropriate histological setting. The cellular origin of the Reed-Sternberg cell is, however, controversial, and the relationship of Hodgkin's disease to the "non-Hodgkin" lymphomas remains uncertain. In the last decade techniques derived from basic immunology have added a new dimension to our understanding of the cellular origin of the "non-Hodgkin" lymphomas. Our concepts of Hodgkin's disease may require modification along similar principles.

Diagnosis, Differential↗
PubMedDate not supplied

Development of tumorigenicity and rearrangement of chromosome 1 correlates with down-regulation of cell-surface glycoproteins in human mammary carcinoma cell line.

In the current study, attempts were made to identify any products of normal breast cell genes, that may become inactivated in the malignant counterparts. Using an immune-tolerization/immunization procedure of generating antibody, two different cell-surface glycoproteins termed luminal epithelial antigen, LEA.92 and LEA.135 were identified. LEA.92 and LEA.135 expressions on MEC in a culture model-system, that reflect various steps of neoplastic transformation were detected on normal or immortalized MEC lines that were non-tumorigenic in nude mice. Furthermore, no rearrangement of chromosome 1 was observed in those cells. In contrast, both glycoproteins were undetectable on oncogenically transformed or established lines of mammary carcinoma cells that were tumorigenic. LEA.92 or LEA.135 negative cell lines exhibited a partial deletion of their chromosome 1. In tissue sections, LEA.92 expression was detected on the apical plasma membrane of normal and hyperplastic but not on the malignant mammary or extramammary epithelial cells (MEC). However, unlike LEA.92, LEA.135 was detected on certain cases of primary breast carcinoma cells, irrespective of morphological differentiation, in tissue sections.

Antibodies, Monoclonal↗
PubMedDate not supplied

Comparison of two microwave based antigen-retrieval solutions in unmasking epitopes in formalin-fixed tissue for immunostaining.

The present study compared two microwave based antigen-retrieval solutions in their ability to unmask antigenic determinants in formalin-fixed and paraffin-embedded tissues for Immunostaining. In this regard, two widely used antigen-retrieval solutions, namely 0.05 M glycine-HCl buffer, pH 3.6, containing 0.01% (w/v) (EDTA) and 0.1 M sodium citrate buffer, pH 6.0, were evaluated for (1) their effectiveness in unmasking a wide range of antigenic determinants (2) their ability to yield reproducible results (3) the lack of deleterious effects in any antibody antigen systems of interest. Both of these antigen-retrieval solutions resulted in greatly improved immunostaining following microwave-heating of dewaxed tissue sections for 2 x 5 min. Glycine-HCl buffer solution resulted in stronger immunostaining with antibodies to nuclear antigens [androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), p53, proliferating cell nuclear antigen (PCNA), Ki-67 and MIB-1], cytoplasmic antigens (actin and factor-VIII) and cell-surface antigens [Cu-18, epithelial membrane antigen (EMA) and MT-1 (CD43)], whereas sodium citrate buffer yielded superior immunostaining with antibodies to vimentin, and some cell-surface antigens [common leukocyte antigen (CLA) (CD45) and UCHL-1 (CD45RO)]. The effect of unmasking the epitopes recognized by antibody to PCNA was equally effective with either of the antigen-retrieval solutions. Antibodies to pan-keratin, prostatic acid phosphatase (PAP), B lymphocyte antigen (BLA.36, CD20CY) and L26 (CD20) exhibited no enhancement in the intensity of staining with either of the antigen-retrieval solutions.

Antigens↗
PubMedDate not supplied

Immunocytochemical observation of multidrug resistance (MDR) p170 glycoprotein expression in human osteosarcoma cells. The clinical significance of MDR protein overexpression.

Resistance to several cytotoxic agents (MultiDrug Resistance MDR), including anthracyclines, vinca alkaloids and epipodophylline derivatives can occur in human osteosarcoma (OS) cells, detected by the overexpression of a 170 kD glycoprotein (p170), as a result of increased expression of the MDR gene (mdr1). The p170 glycoprotein in normal cells is a membrane transport system protein and its quantitative increase results in increased drug efflux and decreased intracellular drug concentration. Normal renal epithelial cells express p170 as a function of their secretory duties therefore this human tissue was used as a positive tissue control in our immunocytochemical study. This partially retrospective immunocytochemical study was carried out on routine, 10% neutral formalin fixed, decalcified, paraffin embedded, tissue sections of 43 OSs, treated between 1981 and 1993 at the Orthopaedic Hospital of Los Angeles. The immunoperoxidase antigen detection protocol, submitted by Hsu et al (1981) was employed. The search for p170 was carried out with three newly developed monoclonal antibodies (MoABs) (JSB-I, C-219 and C-494, from Signet Laboratories, Dedham, MA 02026). The initial expression of MDR was not detectable in seven OSs. 36/43 OSs expressed p170 on/in their cells. Heterogenous cellular microenvironment and various grades of differentiation features were also determined in the examined OSs. In 17/43 OS cases presence of intensive staining (probably overexpression) of p170 protein was registered. The 43 OSs exhibited different staining patterns with each MoAB. MoAB JSB-I reacted with a transmembranic antigen epitope. The long incubation time with C-219 resulted in heterogeneous cytoplasmic staining. MoAB C-494 also produced an intensive staining mainly localized on the cell membrane of the OS cells. These statistically significant immunocytochemical results suggest a direct correlation between the quantitative presence of p170 glycoprotein in human OS cells and the efficacy of the employed chemotherapy. Future observations employing the in situ hybridization technique will allow the quantitative measurement of the primary or secondary presence of MDR glycoprotein in human OS cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Evidence for the release of autocrine growth factor(s) by Hodgkin's cell lines.

A cell surface glycoprotein (BLA.36) expressed on Hodgkin's cell and also on normal and malignant B lymphocytes, was identified by reaction with a monoclonal antibody. Expression of BLA.36 was detected on Hodgkin's cell lines, as well as B or pre-B cell lines, but was not detectable on other hematopoietic, carcinoma or melanoma cell lines, both by immunoprecipitation of intrinsically labeled cell lines and by immunocytochemical staining methods. Hodgkin's cell lines which were positive for BLA.36 expression were also responsive to a partially purified Hodgkin's cell growth factor(s) (HCGFs). HCGFs was partially purified by concentrating conditioned medium from a Hodgkin's cell line (HDLM-3), followed by ion-exchange chromatography (DE52) and gel filtration on Sephadex G-50. The active fractions yielded protein bands with apparent molecular weights ranging from 16 to 21 kilodaltons on sodium dodecyl sulphate-polyacrylamide gel electrophoresis under both non-reducing or reducing conditions. Hodgkin's cell lines treated with antiBLA.36 antibody were not growth responsive to exogenously added HCGFs. Addition of alpha-interferon (alpha-IFN) to BLA.36-positive Hodgkin's cell lines resulted in down-regulation of BLA.36, accompanied by inhibition of growth. Cell lines treated in this way failed to respond to exogenously added HCGFs, suggesting a requirement for BLA.36 expression in order for HCGFs to exercise its growth-stimulatory effect.

Antibodies, Monoclonal↗
PubMedDate not supplied

A sialoglycoprotein (LEA.135) associated with favourable prognosis of patients with lymph node-negative primary breast carcinoma.

A cell-surface sialoglycoprotein (LEA.135) was identified using a monoclonal antibody that was generated by immunization of Balb/c mice with extracts of normal breast tissue following prior immune-tolerization with mammary carcinoma cell lines. LEA.135 is distinct from other known epithelial cell-associated antigens, including the family of mucins or keratins and epidermal growth factor receptor. Using immunohistochemical staining methods, LEA.135 expression was detected predominantly on the apical plasma membrane of normal and neoplastic mammary and extramammary epithelial cells in freshly frozen or formalin-fixed paraffin-embedded tissue sections. A retrospective study of 111 cases of lymph node-negative patients (TanyN0M0) with primary infiltrating ductal breast carcinoma, with a median follow-up of 7.9 years, was conducted. A comparison of overall survival (O.S.) was made of patients whose tumor cells exhibited reactivity with anti-LEA.135 antibody (O.S. 92.9 +/- 3.3% at 8 years), compared with those whose specimens showed the absence of LEA.135 expression (O.S. 68.3 +/- 10.8% at 8 years). A statistically significant univariant association between LEA.135 expression and O.S. was observed (logrank p < 0.001). In addition, in a subgroup of patients with histologically moderately differentiated tumors (N = 71), LEA.135-positive cases showed an improved O.S. (90.8 +/- 4.6% at 8 years; p < 0.001) compared with those who were LEA.135-negative (O.S. 55.6 +/- 13.6% at 8 years). The association remained statistically significant in a multivariable analysis after adjusting for histological grade, tumor size and age (p < 0.02). Thus, in this series of patients with lymph node-negative primary breast carcinoma, LEA.135 expression was associated with a significant decrease in the rate of recurrence and with an increase in overall survival, independent of tumor size, histologic grade, and patient's age. In contrast to the majority of other prognostic markers which predicts a worse biology, LEA.135 is a unique class of antigen whose expression indicates a lower aggressiveness of the tumor cells.

Aged↗
PubMedDate not supplied

Immunocytochemical detection of the p170 multidrug resistance (MDR) and the p53 tumor suppressor gene proteins in human breast cancer cells: clinical and therapeutical significance.

The phenomenon of multidrug resistance (MDR) is characterized by resistance to several unrelated cytotoxic agents, such as anthracyclines, vinca alkaloids and epipodophylline derivatives. MDR has been described frequently in human breast carcinoma (BC), as has the alteration of the p53 gene, responsible for ensuring the integrity of the genome. The most well known type of MDR is associated with the overexpression of a 170kD glycoprotein (p170). This mechanism of MDR is the result of increased transcription of the mdr 1 gene. The p170 glycoprotein in normal cells with excretory functions is a permanent component of a membrane transport system and an increase in its expression, such as that which occurs in neoplastically transformed cells, results in increased drug efflux and decreased intracellular drug concentration. The present immunocytochemical study was carried out on routine, formalin fixed, paraffin-wax embedded, 3-4 microns thick tissue sections of 15 breast carcinomas, treated at the University of Southern California. The immunoperoxidase antigen detection protocol, developed by Hsu et al (1981) was employed using three anti-p170 monoclonal antibodies (MoABs), JSB-1, C-219 and C-494 (Signet Laboratories, Dedham, MA, USA), and the anti-p53 MoAB PAb1801 (NeaMarkers, Inc., Fremont, CA, USA). 14/15 BCs contained large proportions of cells which displayed the characteristic transmembrane localized expression of p170. All 15 BCs were comprised of distinct groups of cells which accumulated p53 in their nucleus and occasionally in their cytoplasm. A distinct, heterogeneous immunophenotype (IP) of the cells comprising the tumor microenvironment and different grades of neoplastic differentiation was also observed. In 5/15 BC cases intense immunoreactivity, correlating with p170 overexpression, was detected. The 15 BCs exhibited different staining patterns typical for each anti-p170 MoAB. MoAB JSB-1 reacted strongly with the transmembranic antigen epitope, as did MoAB C-494, the long incubation time employed with MoAB C-219, on the other hand, resulted in inhomogeneous cytoplasmic staining. Previous reports suggest a direct correlation between the presence of the p170 glycoprotein in human cancer cells and the poor response to chemotherapy. Furthermore, the genetic instability, which is the consequence of the loss of wild-type p53 function, may be the underlying property which allows highly malignant cells to amplify the mdr 1 gene and thus become resistant to a wide spectrum of cytotoxic drugs.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Clinical and prognostic significance of the expression of the c-erbB-2 and c-erbB-3 oncoproteins in primary and metastatic malignant melanomas and breast carcinomas.

Several growth factors and proto-oncogenes play a leading regulatory role during human carcinogenesis. In this systematic immunocytochemical study we observed the expression (overexpression) of the c-erbB-2 and c-erbB-3 oncoproteins in 30 primary cutaneous malignant melanomas (CMMs), 10 already metastasized malignant melanomas (MMMs) and 15 lymph-node negative breast carcinomas (BCs). Both oncoproteins were expressed as a result of either oncogene amplification or post-translational stabilization c-erbB-2 alone is unable to bind neuregulins, but it is able to act as a pan c-erbB receptor subunit. Heterodimerization between cerbB-2 and c-erbB-3 is required to initiate neuregulin directed signal transduction. We employed an indirect, four step streptavidinbiotin conjugated immunocytochemical technique for antigen detection. The visualization of the primary antigen-antibody reaction was carried out with alkaline phosphatase or immunoperoxidase labeling and the use of the appropriate enzymatic substrates. The presence of c-erbB-2 oncoprotein was detected in 12/30 CMMs, 8/10 MMMs and 6/15 BCs, while c-erbB-3 was identified in 14/30 CMMs, 7/10 MMMs and 6/15 BCs. The intensity of the cell membrane localized immunoreactivity was observed to be greater when the c-erbB-2 oncoprotein was targeted (A, AB and B). The c-erbB-3 oncoprotein was also detected in the cytoplasm with medium intensity (B, BC and C). Unfortunately, little is known concerning the range of oncoprotein overexpression after formalin fixation and paraffin embedding. We demonstrated overexpression localized to several cell clones within the oncoprotein positive population of malignant cells. The immunocytochemically defined extent of expression of both oncoproteins was between 10-40% (+ to +2) of the total cell population in the malignant melanomas and 20-35% (+2) of the total cell population in the BCs. In conclusion a) the results of the present study demonstrate the presence of c-erbB-2 and c-erbB-3 oncoprotein expression (overexpression) in melanoma and breast carcinoma, and b) oncogene receptor directed immunotherapy, as part of a more individualized anti-cancer treatment, represents a potentially valuable targeted treatment for the future.

Breast Neoplasms↗
PubMedDate not supplied

Systematic determination of telomerase activity and telomerase length during the progression of human breast cancer in cell culture models.

The purpose of the study was to determine systematically the expression of telomerase activity and the length of telomere repeat arrays by utilizing two different cell culture models that derive from normal individual donors, and probably represent various stages of human breast oncogenesis in cell culture. The models consist of mortal, non-tumorigenic immortal and tumorigenic immortal human mammary epithelial cell (MEC) lines. Using a recently developed polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay, telomerase activity was undetectable in mortal MEC cells. In contrast, the immortal MEC that were nontumorigenic or tumorigenic in immunosuppressed athymic mice, showed telomerase activity. The absence of telomerase activity in mortal and its presence in both non-tumorigenic and tumorigenic immortal cell lines did not reflect their proliferative rate, as demonstrated by the similar pattern and intensity of reactivity of these cell lines with anti-Ki 67 antibody which recognizes a human nuclear cell proliferation--associated antigen. Southern blot analyses of Hinf I-digested genomic DNA hybridized with a (TTAGGG)4 probe revealed arrays of telomeric repeat lengths ranging from 3 to 5, 3.5 to 9, 3.2 to 9 or 3 to 15 kilobase pair (kbp) for mortal, nontumorigenic immortal, and tumorigenic immortal or established MEC lines respectively. These results suggest that telomerase activity and stable telomeric repeat lengths may be a molecular phenotype of the early stages in the progression of breast cancer.

Animals↗