The demonstration of alpha lactalbumin in human breast carcinomas

Transcriptional targeting modalities in breast cancer gene therapy using adenovirus vectors controlled by alpha-lactalbumin promoter

The breast-specific antigen alpha-lactalbumin is expressed in >60% of breast cancer tissues. To evaluate the effect of gene therapy for breast cancer by controlling adenovirus replication with human alpha-lactalbumin promoter, we investigated the activity of a 762-bp human alpha-lactalbumin promoter. Alpha-lactalbumin promoter showed significantly higher activity in MDA-MB-435S and T47D breast cancer cells than in normal breast cell lines or other tumor cell lines. We then developed two novel breast cancer-restricted replicative adenoviruses, AdALAE1a and AdE1aALAE1b. In AdALAE1a, expression of adenoviral E1a gene is under the control of alpha-lactalbumin promoter, and in AdE1aALAE1b, expression of both E1a and E1b genes is under the control of a single alpha-lactalbumin promoter. Both breast cancer-restricted replicative adenoviruses showed viral replication efficiency and tumor cell-killing capability similar to wild-type adenovirus in MDA-MB-435S and T47D cells. The replication efficiency and tumor cell-killing capability of both viruses were attenuated significantly in cells that did not support alpha-lactalbumin promoter. AdE1aALAE1b showed better breast cancer-restricted replication than AdALAE1a, suggesting that a transcriptional targeting modality with alpha-lactalbumin promoter controlling both E1a and E1b gene expression is superior to alpha-lactalbumin promoter controlling only E1a gene expression. Importantly, we found that AdE1aALAE1b could be used to target hormone-independent breast tumors in vivo by inhibiting the growth of MDA-MB-435S s.c. tumors. These data showed that alpha-lactalbumin promoter could regulate the replication of adenovirus to target hormone-independent breast cancers, suggesting that alpha-lactalbumin promoter can be used to develop a novel therapeutic modality for hormone-independent breast cancer.

Transcriptionally targeted gene therapy to detect and treat cancer

The greatest challenge in cancer treatment is to achieve the highest levels of specificity and efficacy. Cancer gene therapy could be designed specifically to express therapeutic genes to induce cancer cell destruction. Cancer-specific promoters are useful tools to accomplish targeted expression; however, high levels of gene expression are needed to achieve therapeutic efficacy. Incorporating an imaging reporter gene in tandem with the therapeutic gene will allow tangible proof of principle that gene expression occurs at the correct location and at a sufficient level. Gene-based imaging can advance cancer detection and diagnosis. By combining the cancer-targeted imaging and therapeutic strategies, the exciting prospect of a 'one-two punch' to find hidden, disseminated cancer cells and destroy them simultaneously can potentially be realized.

Adenovirus-mediated tissue-targeted expression of the HSVtk gene for the treatment of breast cancer

In an effort to develop a genetic therapy for the treatment of breast cancer, we constructed adenoviral vectors containing either the beta-galactosidase (beta-gal) reporter gene or the herpes simplex thymidine kinase (HSVtk) suicide gene driven by breast tissue-specific promoters. We utilized upstream regulatory sequences from either the human alpha-lactalbumin (hALA) gene, or the ovine beta-lactoglobulin (oBLG) gene in these vector constructs to target expression of heterologous genes transcriptionally to breast cancer cells both in vitro and in vivo. Data derived from breast tissue-specific reporter vectors in vitro demonstrate that expression from the hALA and oBLG promoters are indeed specific for breast cells (T47D, MCF-7, ZR75-1) when compared with non-breast cells (U2OS, HeLa). Moreover, these vectors displayed tumor cell specificity when compared with the normal MCF-10A breast cell line. These vectors also displayed breast tissue specificity when injected systemically (i.v.) into lactating Balb/c mice, which suggests that these promoters maintain their tissue-specific expression pattern within the context of the adenoviral genome in vivo. Tumors, derived from T47D human breast cancer cells, were established in nude mice and injected with either the tissue-specific reporter or suicide vectors. Results from tumors injected (i.t.) with reporter adenoviruses demonstrate that these promoters are active in T47D cells when grown as established tumors and we observed a marked regression of tumors injected with suicide vectors and treated systemically with gancyclovir (150 mg/kg/day) when compared with control animals. Moreover, mouse survival was prolonged after 35 days in mice undergoing therapy with the suicide vectors in conjunction with gancyclovir when compared with the control animals. These data suggest that the transcriptionally targeted hALA or oBLG driven expression of the HSVtk gene may be a feasible therapy for the treatment of human breast cancer.

Immunohistochemical profile of invasive lobular carcinoma of the breast: predominantly vimentin and p53 protein negative, cathepsin D and oestrogen receptor positive

Vimentin, p53 protein and cathepsin D positivity were assessed by immunohistochemistry, and oestrogen receptor (ER) by an enzyme immunoassay, in invasive lobular carcinomas (LC) of the breast. While vimentin was positive in only 5% (3/57) and p53 protein was positive only in 3% (2/63), cathepsin D was expressed in 86% (48/56) and ER in 78% (25/32). Classical LC were negative for p53 protein and all except one were cathepsin D positive. These results are in contrast to invasive ductal breast carcinomas (DC), where the reported average incidence of vimentin and p53 protein is much higher (19% and 33% respectively) and that of cathepsin D and ER lower (63% and 67% respectively). Thus lack of expression of vimentin and lack of p53 positivity together with high incidence of expression of cathepsin D and ER are more often associated with lobular than with ductal differentiation of invasive breast cancer. The results show that LC, distinguished morphologically, can further be defined by its immunohistochemical profile. This in turn may point to underlying biological differences between LC and DC.

Immunohistochemical markers in the identification of metastatic breast cancer

A panel of nine monoclonal and polyclonal antibodies were tested regarding specificity for metastatic breast cancer. A hundred metastatic tumors were stained, 50 of breast origin and 50 of other origins. Antibodies used were anti-alpha-lactalbumin, anti-lactoferrin, anti-casein, E29 (Dako-EMA), anti-secretory component, anti-gross cystic disease fluid protein (GCDFP15), BRST1, BRST2, and MC5. Analyses of the results were performed using chi-square and logistic regression. Positivity for MC5, BRST1, BRST2, lactoferrin, EMA, and GCDFP15 was significantly higher in tumors of breast origin than in others (p less than 0.05). Analyses of the whole panel indicated that GCDEP15 and MC5 were the best markers for identification of breast cancer metastases. When both were positive (58% of breast origin cases), the predicted probability of breast origin was 98%, compared to only 5% when both were negative. Comparison of anti-GCDFP15 with BRST2, a monoclonal antibody against the same protein, showed a slightly better sensitivity of the former, and a similar degree of specificity for breast tissue. In conclusion, a panel of antibodies can be used to securely differentiate metastatic breast cancer from other cancers in a large number of metastatic tumors of unknown origin.

Monoclonal antibodies for radioimmunoscintigraphy of breast cancer

Breast cancer is the leading cause of cancer deaths among females, and it is estimated that each year, one in ten American women will be newly diagnosed as having the disease. It is therefore not surprising, that a great deal of effort has been made to better understand the biology of breast cancer, and that investigators keep up the search for new tools to better characterize, diagnose and treat these tumours. In this regard, the introduction of the hybridoma technique in 1975 by Kohler and Milstein has lead to an extensive work in the characterization of monoclonal and polyclonal antibodies against breast cancers. A large number of antibodies has been raised to different epitopes present in normal and neoplastic breast tissue; but unfortunately we have yet to find a highly sensitive and specific monoclonal antibody for breast cancer that can successfully be used for scintigraphic detection of nodal metastases and for radioimmunotherapy treatment of this disease. As possible radioimmunodiagnostics, antibodies are known which react with the following antigens: (1) cytoskeletal proteins (2) breast cell products (3) steroid receptors (4) putative tumor-associated antigens (5) oncogene products (6) pregnancy-related products (7) basement membrane antigens (8) degradative enzymes (9) cell receptors for extracellular matrix molecules (10) multidrug resistance gene product (p-glycoprotein) (11) proliferative markers.

Correlation between laminin and type IV collagen distribution in breast carcinomas, and estrogen receptors expression, lymph node and vascular involvement

The laminin (Lam) and type IV collagen (Coll IV) and estrogen receptor (ER) immunodetections were assessed in a large series of 400 human breast carcinomas. In all the cases the patient's age, the tumor size, the histological type and grade, the presence or the absence of axillary lymph node metastasis and of vascular invasion in tumor borders, and ER tumor content were recorded. Monoclonal anti-Lam, anti-Coll IV were applied with the avidin-biotin-peroxidase complex and monoclonal anti ER with peroxidase anti-peroxidase complex, on frozen sections. A computerized system of image analysis referred to as SAMBA (TITN) with specific software for tissue sections analysis permitted a multiparametric quantitative analysis of immunostained surfaces. With this system, in each tumor, the cellularity, the percentage of Lam, Coll IV and receptor positive surfaces versus the total cell surface and versus the epithelial (keratin positive) surface, the integrated optical density IOD histograms were obtained and correlated to morphometrical and standard histological data. From this study, it was shown that: (1) Lam and Coll IV immunostained epithelial basement membranes in carcinomas were correlated to the presence of estrogen and progesterone receptor antigenic sites within the tumors, with a significant decrease of the positive staining in ER-ICA negative tumors in comparison to ER-ICA/PR-ICA positive tumors. (2) The combined densitometric and morphometric evaluation demonstrated a decrease of Lam and Coll IV immunostaining in malignant tumors, correlated to (i) the presence of peritumorous vascular invasion and (ii) keratin positive cells in bone marrow (iii) axillary lymph node involvement. It is concluded that the variations in Lam and Coll IV antigens distribution may be relevant indicators of tumor metastatic potential in breast carcinomas and that computerized image analysis enables the standardization of the evaluation antigens distribution.

Immunodetection in fine-needle aspirates and multiparametric (SAMBA) image analysis. Receptors (monoclonal antiestrogen and antiprogesterone) and growth fraction (monoclonal Ki67) evaluation in breast carcinomas

Immunocytochemical assays (ICA) using monoclonal antiestrogen receptors (ER ICA), antiprogesterone receptors (PR ICA), and monoclonal antibody Ki67 (Ki67 ICA) were performed in 127 breast carcinomas. The immunostaining procedures were applied on frozen tissue sections, tumour imprints, and fine-needle aspirates in order to compare the variations in the distribution of the antigens detected in the three different types of preparations. Positive reactions detected with peroxidase-antiperoxidase and avidinbiotin-peroxidase, and alkaline phosphatase-antialkaline phosphatase complexes were evaluated through a computerized system of image analysis referred to as SAMBA 200 (SAMBA TITN, Grenoble, France). Application programs specifically developed for the analysis of tissue sections and of cytologic preparations were applied. This system allowed a multiparametric, accurate, reliable, reproducible and automatized evaluation of the heterogeneity of the antigenic sites in tumors. For each markers positive cell surface (PS), and integrated and mean optical densities (IOD, MOD) and IOD histograms were compared. It was shown that (1) there was no significant variation in optical densities in cell imprints and aspirates whereas PS significantly (P less than 0.01) differed in both preparations; (2) there were significant differences of the optical densities between tissue sections and cytological preparations, either imprints or aspirates, likely due to randomly cut nuclei in tissue sections; and (3) there was a significant difference between the PS of tissue sections and aspirates but no significant difference between tissue sections and imprints. It is concluded that fine-needle aspiration constitutes a convenient method for cell sampling, reliable for the diagnosis of malignancies. However, it may not reflect the heterogeneity of cell subpopulations in tissue.

Gross cystic disease fluid protein-15 as a marker for breast cancer: immunohistochemical analysis of 690 human neoplasms and comparison with alpha-lactalbumin

The identification of metastatic carcinoma of the breast may be difficult in the absence of a previous history of breast cancer. Various immunophenotypic markers have been introduced to aid in this process. A monoclonal antibody directed at a 15-kilodalton (kd) gross cystic disease fluid protein (GCDFP-15) was applied immunohistochemically to paraffin sections of 105 breast cancers and 585 nonmammary malignancies in order to assess its value in this context. In addition, GCDFP-15 was compared with another putative mammary epithelial marker, alpha-lactalbumin (ALA), with respect to sensitivity and specificity for a diagnosis of breast carcinoma. Overall, the rates of specificity and sensitivity and the predictive value of a positive result for GCDFP-15 were 95%, 74%, and 74%, respectively. Corresponding statistical parameters for ALA were 50%, 50%, and 23%. A consistent congruency between the reactivity patterns of primary and metastatic breast cancers was noted for GCDFP-15 but not for ALA. Besides mammary carcinomas, the major tumor types that expressed GCDFP-15 were carcinomas of the salivary glands, sweat glands, and prostate. Since the latter three types of lesions are unlikely to be diagnosed as metastatic breast cancer, statistical indices were recalculated after exclusion of these three tumor types. Following this exclusion, the adjusted rate of specificity of GCDFP-15 and the predictive value of a positive result for a diagnosis of metastatic carcinoma of the breast were each 99%. In contrast, predictive parameters for ALA were not altered. These results show that GCDFP-15 is a specific marker for breast cancer and is superior to ALA in this respect.

Production and characterization of murine monoclonal antibody to human alpha-lactalbumin

Human alpha-lactalbumin (alpha-LA), a milk protein normally produced by, and restricted to, functionally differentiated breast epithelial cells has been shown immunohistochemically to be a good marker for breast cancer. Antibodies with specificity only for human alpha-LA have not previously been reported. The present study documents the production and characterization of an IgG1 murine monoclonal antibody with specificity restricted only to human alpha-LA. This monoclonal antibody, designated ET-1, was purified by affinity chromatography using human alpha-LA. Specificity of ET-1 for human alpha-LA was established by enzyme linked immunosorbent assay (ELISA), absorption studies, immunoprecipitation and by immunoblotting. ET-1 binds to human alpha-LA with a KD of 7.41 x 10(-8) mol/l and does not cross-react with bovine alpha-LA. This unique reactivity of ET-1, which is not inherently shared by polyclonal antisera, should enable the antibody to be used for the development of a sensitive immunoassay for circulating human alpha-LA.

Tumor-associated antigens in breast carcinomas. Prognostic significance

In an attempt to identify biologic markers that might predict prognosis in breast cancer patients, the presence or absence of seven tumor-associated antigens in 54 infiltrating breast carcinomas was correlated with tumor recurrence rates (minimum five-year follow-up), axillary lymph node metastases and tumor volume. Immunohistochemical kappa-casein was present in 30 (56%) tumors, alpha-lactalbumin in 39 (72%) tumors, secretory component of IgA in 26 (48%) tumors, carcinoembryonic antigen in 34 (63%) tumors, pregnancy-specific beta-1-glycoprotein in 7 (13%) tumors, beta subunit of human chorionic gonadotrophin in 1 (2%) tumor and human placental lactogen in 0 (0%) tumors. There was no significant correlation between the presence or absence in tumor of any of the antigens, and prognosis as assessed either by 5-year recurrence rates (P greater than 0.18) or by the presence of axillary lymph node metastases (P greater than 0.20). No significant difference was noted in mean tumor volume (cm3) +/- SEM, between tumors with or without antigen immunoreactivity (P greater than 0.05).

Glycogen-rich clear cell carcinoma of the breast: a solid variant with mucus. A light microscopic, immunohistochemical and ultrastructural study of a case

The light microscopic, immunohistochemical and ultrastructural features of a clear cell carcinoma of the breast have been studied. Both intraductal and invasive components were found. Histochemistry showed large amounts of intracytoplasmic glycogen and sparse neutral mucin in the tumour. The tumour cells were stained by antisera to carcinoembryonic antigen, keratin and epithelial membrane antigen, but not by antisera to alpha-lactalbumin, desmin or vimentin. Ultrastructurally, the epithelial derivation of the tumour was confirmed. Only a few intracytoplasmic lumina were demonstrated. The tumour was classified as a mucin-containing variant of glycogen-rich, clear cell carcinoma of the breast.

Invasive lobular carcinoma of the breast. An analysis of 29 cases

Twenty-nine cases of invasive lobular carcinoma were analyzed, based on three aspects of the histology: 1) cellular features such as a monotonous proliferation of uniform small cells, 2) a single file or targetoid arrangement, and 3) loss of cell cohesion or dissociation of tumor cells. Twenty-four tumors which fulfilled these three criteria were appraised as cases of conventional lobular carcinoma, in a classic sense, while five others were a variant of this tumor. Individual tumor cells of lobular carcinoma were estimated to be well differentiated, both morphologically and functionally, revealing well developed intracytoplasmic organelles and a high percentage of alpha-lactalbumin content in the cytoplasm. Nevertheless, the tumor itself was characterized by a lack of any particular structural differentiation in the arrangement of cells. Based on the observation of the histologic features, invasive lobular carcinoma was subclassified into three groups, in situ predominant, intermediate, and diffuse infiltrating and with a definite correlation to the age of the patient and to the prognosis. Validity of this classification indicates that lobular carcinoma progresses gradually, even in the invasive phase, and can be categorized as a slowly growing subset of mammary carcinoma.

Transferrin receptor (TrfR) expression in breast carcinoma and its possible relationship to prognosis. An immunohistochemical study

TrfR, a primitive membrane protein was demonstrated by immunohistochemistry in 87.6% of 105 cases of breast carcinoma, predominantly on the cell surface and in a strong and rather uniform pattern. Sporadic staining in a patchy fashion was observed. No difference between individual tumour types was seen, neither in cytomorphological staining pattern nor in staining intensity. Exceptionally, mucoid carcinomas showed weaker intensity for receptor expression. Because of the heterogenous expression of TrfR within most of the tumours the extent of staining reaction was determined by semiquantitative grading (low, moderate, high). These results were compared with grade of anaplasia, tumour staging and nodal status of the axilla. The extent of immunoreactivity revealed significant correlation with grade of anaplasia, whereas no correlation was found with staging and status of axillary lymph nodes. Tumours with higher degree of malignancy (GII-GIII) showed a higher extent of staining. The presence of TrfR in a high degree of expression thus implies some prognostic value. Its quantitative determination can provide kinetic data on the neoplasm.

Validation of radioimmunoassay for human lactalbumin in the serum by testing the endogenous antibodies interference

For re-establishing the value of human lactalbumin as a functional marker of normal and pathological activity of the breast a sensitive and specific radioimmunoassay was established with the prior important control of the interference of endogenous antibodies. The specificity of the assay was assessed by the absence of interference from other proteins in milk or in breast cyst fluid, various hormones and tumor markers. Bovine lactalbumin showed incomplete and weak cross-reactivity. By an enzymoimmunoassay method it was shown that all the 222 human sera studied contain IgG immunoglobulins which bind bovine and human lactalbumin with greater reactivity of children's serum and without relationship to the blood groups. The maximum affinity constant of these endogenous immunoglobulins determined by the radioimmunoassay method is 4.5 times greater for bovine (Kd = 18 X 4(-11) M) than for human (Kd = 4 X 10(-11) M) lactalbumin. These endogenous anti-lactalbumin immunoglobulins caused no interference in the radioimmunoassay as shown by the complete correlation between the concentrations of human lactalbumin previously incubated and added to sera containing high-affinity antibodies and those measured directly in the radioimmunoassay. This lack of interference was explained by the higher (22-fold) affinity constant of the rabbit antiserum against human lactalbumin (Kd = 9 X 10(-12) M). The study of endogenous antibodies by the two enzymes and radioimmunoassay methods is needed before assessing and using a radioimmunoassay of human lactalbumin in serum.

Kappa casein, lactalbumin and GCDFP 70 localization in human breast carcinomas: an immunohistochemical study using the avidin-biotin-peroxidase complex method

A retrospective study of 67 human breast carcinomas of various types and grades was conducted using the avidin-biotin-peroxidase complex (ABC) to localize casein, lactalbumin, and GCDFP 70 on paraffin sections. Estrogen and progesteron receptors also were evaluated. This study demonstrated the following: (1) Casein positive cells were present in all cases with a variable distribution and degree of staining, whereas lactalbumin and GCDFP 70 were seen in only 40 and 43% of the cases, respectively. (2) No significant relationship was observed between casein, lactalbumin, GCDFP 70 and the histologic types of tumors or the extent of stromal elastosis, with the exception GCDFP 70, which was observed more often in well-differentiated ductal carcinomas. (3) No significance was established in the relationship between antigens and steroid receptor content, with the exception of casein; strong casein immunostaining was significantly related to high progestin receptor levels. (4) Lactalbumin and GCDFP 70 were significantly associated with each other, but independently so of the histologic grades and types, the extent of stromal elastosis, and the steroid receptor content of the tumor cells.

Ultrastructural and immunohistochemical features of lobular carcinoma of the breast

Twenty cases of infiltrating lobular carcinoma (12 of classical type, five of trabecular type and three of alveolar type) and one case of lobular carcinoma in situ were studied by transmission electron microscopy. The in situ component in three of the infiltrating carcinomas was also studied. The ultrastructure of the tumour cells in the alveolar variant of infiltrating lobular carcinoma was the same as seen in the tumour cells of lobular carcinoma in situ. The tumour cells in infiltrating lobular carcinoma of the classical and trabecular types had more irregular nuclei and were more organelle- and filament-rich. Immunohistochemical staining for the presence of alpha-lactalbumin was proved in 19 per cent of the cases, casein 81 per cent, CEA in 65 per cent and prekeratin in 90 per cent. The light microscopic separation of some subgroups of infiltrating lobular carcinoma may be difficult, in particular the distinction between the classical and the trabecular variants. Unfortunately, our study shows that these distinctions cannot easily be made either by electron microscopy or by light microscopic immunohistochemistry with antibodies against prekeratin, CEA, casein and alpha-lactalbumin.

Production and characterization of monoclonal antibodies to human casein. A monoclonal antibody that cross-reacts with casein and alpha-lactalbumin

Four hybridomas have been produced that secrete monoclonal antibodies to human beta-casein, a protein synthesized by fully differentiated breast epithelial cells. The antibodies have been characterized on immunoblots and have been shown to react with methanol: acetone-fixed sections of human lactating mammary gland. Immunoblots show that three of these antibodies react with casein whereas one, F20.10, also recognizes an epitope present on human alpha-lactalbumin. Computer analysis of the amino acid sequences of these two milk proteins reveals very little sequence homology, leading to the conclusion that the three-dimensional shape, rather than the primary sequence, is important in this cross-reactivity.

Immunohistochemical detection of alphalactalbumin in breast lesions

Alphalactalbumin was investigated in breast cells using the immunoperoxidase technique with a specific anti-alphalactalbumin serum. In 50 benign tumors alphalactalbumin immunoreactivity was demonstrated in the epithelium of fibroadenomas and in fibrocystic disease showing apocrine metaplasia. Alphalactalbumin immunoreactivity, investigated in 124 breast cancers, was present in all cells of lobular tumors but in only 76% of other cancers where the pattern was heterogeneous. Perineoplastic mammary tissue of normal appearance was not labeled with the anti-alphalactalbumin antiserum except where lobular hyperplasia was present. The presence of alphalactalbumin-type immunoreactivity was not correlated with the histopathological staging of Bloom and Richardson, nor with menopausal status. The incidence of positivity was 90% when estrogen and progesterone receptors were present in the tumor. The demonstration of alphalactalbumin using immunoperoxidase could be used to complement the histological classification of breast cancers.

Biological markers in human breast carcinoma

An indirect immunoperoxidase method has been used to study a series of breast carcinomas for the presence of five potential biological markers (two appropriate to breast, two placental proteins and one oncofetal protein). One or more markers were detectable in 84 per cent. of tumours, two or more in 60 per cent. and three of more in 32 per cent. Similarity of staining patterns was noted for two placental proteins and for the oncofetal protein and one placental protein. Markers appropriate to breast tissue tended to be detected in separate areas. In certain instances more than one antigen could be detected within the same cell. The relationship of the number of markers present to histological differentiation was found to be complex, but carcinomas with three or more antigens demonstrated showed a tendency to be well or moderately differentiated. Tumours with no markers often had not metastasised to lymph nodes but conversely those with four and five markers had. A striking throughout the study was the heterogenous secretory nature of breast carcinomas.

An immunocytochemical study of alpha-lactalbumin in human breast tissue

The distribution of the milk protein, lactalbumin, has been studied in human breast tissue by the indirect immunoperoxidase technique on formalin fixed paraffin embedded sections. It was found in all lactating breasts examined and in all breasts from subjects who were more than 18 weeks pregnant. It was also seen in a small proportion of non-pregnant, non-lactating patients usually confined to small focal secretory lobular lesions known as lactational foci but also occasionally in morphologically normal lobules. Previous pregnancy does not appear to be a pre-requisite for lactalbumin secretion and our study suggests a possible relationship with usage of hormonal preparations. A wide variety of benign and malignant breast lesions were studied and none was found to contain the protein, except for fibroadenomas from patients who were pregnant or who harboured lactional foci. The absence of lactalbumin from all 44 breast carcinomas studied suggests that it has no role to play as a marker in the histopathological diagnosis or clinical monitoring of this disease.

Immunocytochemical detection of tumour markers in bone metastases from carcinoma of the breast

The value of immunocytochemical methods for detecting seven tumour-associated antigens was assessed in ten cases of bone metastases from carcinoma of the breast. In order to obtain the optimal preservation of both their structure and antigenicity, the biopsies were fixed-decalcified in Bouin's fluid by means of an apparatus based on ion-exchange resins recently developed in this laboratory. Of the different tumour markers, milk fat globule membrane antigen and carcino-embryonic antigen were found to be present in the majority of the cases of neoplastic cells. These two markers appear, therefore, to be the most useful for the immunocytochemical identification of metastatic neoplastic cells in the bone marrow originating from carcinoma of the breast.

Medullary carcinoma of breast: an immunohistochemical study of its lymphoid stroma

Immunoperoxidase staining for IgA, IgG, IgM, and secretory component (SC) was performed on ten cases each of medullary carcinoma and infiltrating duct carcinoma of breast. Plasma cell-rich stroma of medullary carcinoma was found to contain predominantly IgA plasma cells. Tumor cells also contained IgA and SC. In contrast, the few plasma cells of infiltrating duct carcinoma were found to be predominantly IgG type, and the tumor cells contained none or very small amounts of IgA and SC. Because the presence of IgA plasma cells and IgA and SC in lining epithelial cells are characteristic features of organs of the secretory Ig system, these findings in medullary carcinoma may suggest a good degree of functional differentiation of these tumor cells and correlate well with the well-known favorable prognosis associated with this tumor.

Differentiation of human breast carcinomas: an immunohistological study of appropriate and inappropriate protein production

Secretory piece of immunoglobulin A, a product of normal breast tissue, and beta 1 pregnancy-specific glycoprotein, a product of syncytiotrophoblast of placenta, have been demonstrated in breast carcinomas by an indirect immunoperoxidase method. A close relationship has been found between the site of staining within cells and tumour structure for both secretory piece, the appropriate protein, and beta 1 pregnancy-specific glycoprotein, the inappropriate protein. The reaction was at the periphery of cells in areas of tubular differentiation and was diffusely intracytoplasmic in solid groups of tumour cells. The poorly differentiated carcinomas have a low incidence of detection for both antigens but the tumours showing good histological differentiation appear to be functionally heterogeneous with some being negative for both proteins, some staining for the appropriate secretory piece of immunoglobulin A and the inappropriate beta 1 pregnancy-specific glycoprotein and only one out of 12 producing the appropriate protein alone.

Comparative functional histopathology of human breast carcinoma xenografts

A series of xenografts of human breast carcinomas has been established and serially transplanted in immune-suppressed mice. Certain structural and functional features of the original human tumours, including carcinoembryonic antigen and epithelial membrane antigen, continue to be expressed by the resulting xenografts. Stromal responses such as elastosis and oestrogen-receptor activity were lost by the xenografts. No metastases were detected in tumour-bearing mice. This study suggests that xenografts may have some value in experimental pathology as one type of model of human breast carcinoma.