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Biomedical subjects

R H Whitehead

Publications and source records attributed to R H Whitehead.

At least 73 records · Page 4Linked to original sources
PubMed1986

Lectin binding patterns and monoclonal antibodies to epidermal antigens in tumours of the skin.

Monoclonal antibodies to epidermal antigens and cell surface carbohydrate markers, as defined by lectin binding, were used to analyze the cells in squamous and basal cell carcinomas of the skin (SCC and BCC). The cells in BCC failed to stain with the lectin peanut agglutinin (PNA), which stains surface carbohydrates of cells in the stratum spinosum and stratum granulosum layers of normal epidermis, confirming histological observations that the cells in BCC are incapable of differentiation beyond the basal cell stage. Conversely, the central cells in SCC did react with PNA, suggesting that they can differentiate to a stage equivalent to the stratum spinosum of epidermis. The zone immediately surrounding BCC differed from that around SCC in lectin binding and staining with antisera to laminin and fibronectin, an observation which could be connected with the failure to metastasize. It was of interest that histologically normal skin immediately adjacent to and overlying these tumours showed marked changes in reaction with markers of normal epidermis. The outer layers of this epidermis showed aberrant retention of the lower molecular weight cytokeratins marked by the monoclonal antibodies LMM2 and LMM3, and occasional strong staining of individual cells by the stratum granulosum-reactive LMM1. These changes appear to be indicative of a 'premalignant' state in these cells and the monoclonal antibodies are thus potentially useful reagents for early detection of skin malignancies.

Antibodies, Monoclonal↗
PubMed1986

Production and characterization of monoclonal antibodies reactive with subsets of epidermal cells.

Monoclonal antibodies were raised against an extract of human callus to provide markers of cell differentiation. Three antibodies, LMM1, LMM2 and LMM3, have been isolated and react with different histological structures in skin. LMM1 reacts with two distinct proteins of 62-65 kD molecular weight and stains cells in the stratum spinosum and stratum granulosum of normal epidermis. This antibody stains a high proportion of cultured epidermal cells showing a diffuse cytoplasmic reactivity with nucleolar staining also being present in some cells. LMM2 reacts with several lower molecular weight proteins, the two major bands being 38 kD and 44 kD. It stains basal epidermal cells strongly and stratum spinosum cells less strongly. A population of cultured keratinocytes reacts with an intense fibre stain suggesting that this antibody is directed against an intermediate filament or intermediate filament-associated protein. LMM3 reacts with a 48 kD protein. Although it does not stain cells in normal epidermis its staining of a subpopulation of hair follicle cells is consistent with this protein being a cytokeratin. It also stains a population of cultured keratinocytes, the main reactivity being against mitotic cells. The anti-cytokeratin or anti-cytokeratin-associated reactivity of these three antibodies is supported by their altered reactivities against psoriasis epidermis, where modifications of cytokeratin biosynthesis are known to occur.

Animals↗
PubMed1986

Development of monoclonal antibodies to the human breast carcinoma cell line PMC42.

In an attempt to identify antigens expressed during breast differentiation, three murine monoclonal antibodies, CIBr2, CIBr7, and CIBr18, were produced against the human pleomorphic breast carcinoma cell line PMC42. All three monoclonal antibodies reacted with previously undescribed antigenic determinants on the PMC42 cell line. Antibody CIBr18 reacted only with the immunizing cell line PMC42, whereas antibodies CIBr2 and CIBr7 showed minimal reactivity toward a panel of 34 human leukemia- and solid tumor-derived cell lines. The antigenic determinants detected by the three antibodies were distinct, and each showed variable expression in PMC42 monolayer and organoid cultures. The heterogeneity of staining seen on PMC42 cultures may reflect the fact that this cell line contains up to eight morphologically distinct cell types. Antigen expression correlated with cell type in some instances, whereas in other instances phenotypic subdivision within a cell type was apparent. Antigens recognized by antibodies CIBr7 and CIBr18 were characterized biochemically. In Western blotting, antibody CIBr7 identified a single band of an apparent molecular weight of 38,000 within PMC42 cell lysates. Sodium dodecyl sulfate-polyacrylamide gel analysis of polypeptides immunoprecipitated by antibody CIBr18 from [35S]methionine-labeled PMC42 cell lysates identified two glycoproteins of apparent molecular weights of 115,000 and 120,000, respectively. No biochemical data for the CIBr2 antigen are yet available. All three antigens were detected in human mammary epithelium and some non-breast tissues. The expression of these antigens in normal and neoplastic mammary epithelia is discussed in terms of antigen heterogeneity and changes in antigen expression upon conversion to the malignant state.

Adult↗
PubMed1985

Organ specificity of epithelial cells grown in tissue culture from explants obtained from various levels of the rat gut.

Monolayer cultures of epithelial cells grown from explants of fetal rat small intestine can differentiate into columnar as well as goblet cells in tissue culture (Kondo et al., Exp cell res 153 (1984) 12) [9]. In this study we have cultured tissue from various levels of the fetal rat gastrointestinal tract in order to characterize those cell types that can be cultured from these tissues and to determine the growth potential of these cells using this culture system. Explants of esophagus and forestomach tissue yielded monolayer outgrowths of squamous epithelial cells which grew as closely apposed polygonal cells capable of developing cornified envelopes. Explants of the glandular portion of the stomach yielded outgrowths of densely packed cells which were more pleiomorphic and which did not desquamate or form cornified envelopes. Explants of small intestine and colon yielded outgrowths of epithelial cells, some of which differentiated into goblet cells, while others developed a 'columnar' cell morphology. The following differences between squamous- and non-squamous cultures were observed. Squamous epithelium showed self-sustained growth, while growth of non-squamous epithelial cells became self-limiting. Cytochalasin B (CB) (5 micrograms/ml for 1 h) induced contraction of the whole cell sheet of non-squamous cells, but of only individual squamous cells. Squamous cell outgrowth was observed from tissues derived from fetuses of all ages (13-day fetuses through to 3-week-old rats); whereas non-squamous epithelial outgrowth was poor when rats older than the 21st gestational day were studied. These results indicate that cultures established in this manner developed the general characteristics of the cells of the organ from which they were derived, even when undifferentiated fetal tissue was used. The growth conditions needed for columnar epithelium are more stringent than those needed for squamous tissues. This technique opens the way for further characterization of growth requirements of gastrointestinal columnar epithelium.

Animals↗
PubMed1985

A colon cancer cell line (LIM1215) derived from a patient with inherited nonpolyposis colorectal cancer.

A new human colon cancer cell line (LIM1215) has been derived from a tumor arising in a member of a family known to have a high incidence of colorectal cancer. The tumor cell line is comprised of small pleomorphic cells that clone in liquid medium and form tumors in immunosuppressed mice. Ultrastructurally, the cells are capable of differentiation, with cells with multiple microvilli and cells resembling goblet cells being present in the one culture. The cells are pseudodiploid and contain a 13p+ marker chromosome.

Adenocarcinoma↗
PubMed1985

An immunocytochemical and ultrastructural study of heterogeneity in the human breast carcinoma cell line PMC42.

A recently established human breast carcinoma cell line has been reported to exhibit a number of morphological cell types in monolayer cultures as defined by phase-contrast microscopy. The cell line also produces cords of viable cells floating within the culture medium. Cultures of this cell line, grown in monolayer, on collagen gels, and as floating cords of cells, were studied by transmission electron microscopy and immunocytochemistry. A detailed analysis of the staining pattern obtained with a series of monoclonal antibodies with well-defined human breast epithelial cell specificities and a polyclonal antikeratin antibody showed PMC42 to resemble cultures of both normal human breast and other human breast carcinoma cell lines. The pleomorphic nature of PMC42 cultures was confirmed at an ultrastructural level, and of the eight cell types observed by phase-contrast appearance, seven ultrastructural counterparts were observed. In addition, the presence of intracytoplasmic lumina and overt epithelial differentiation confirm a breast epithelial origin for this cell line.

Breast Neoplasms↗
PubMed1984

Growth and differentiation of fetal rat small intestinal epithelium in tissue culture. Relationship to fetal age.

Explants of small intestinal tissue have been cultured from fetal and young rats (from 13-day fetuses to 3-week-old rats). Growth of morphologically typical epithelial cells was obtained from explants of tissue from 14-20 day fetuses. Optimal growth was obtained using tissue from 17-day fetuses with outgrowth from the explant being observed 1-day after explant. Eighty per cent of explants developed epithelial growth by 11 days in culture. Initially, the epithelial outgrowth showed no morphological evidence of differentiation but after 5-10 days in culture differentiation into goblet or elongated cells with alkaline phosphatase activity occurred. Cells with brush borders and goblet cells were identified using electron microscopy. No differentiation occurred if the explant was removed even though growth continued. It was very difficult to culture tissue from fetuses older than 20 days' gestation, and when small intestine of 18-20-day fetuses was divided into two parts (proximal and distal) and cultured separately, growth of epithelial cells from explants of the proximal segment was less successful than that of the distal segment, indicating that the growth ability of these epithelial cells in vitro was closely related to tissue maturation in vivo. In contrast to the apparent relationship between fetal age and successful growth of intestinal epithelial cells, squamous epithelial cells of the esophagus could be grown from explants of 14-day fetus through newborn and 3-week-old rats.

Aging↗
PubMed1984

A new human breast carcinoma cell line (PMC42) with stem cell characteristics. III. Hormone receptor status and responsiveness.

PMC42 is a new human breast carcinoma cell line. In this report the content of estrogen, progesterone, and glucocorticoid receptors in PMC42 has been determined. The estrogen receptor content (1,750 cytoplasmic sites and 350 nuclear sites) was lower than that described for MCF7 and T47D. The cells would not proliferate in serum-free medium without the addition of beta-estradiol (optimum concentration 10(-8) M) or progesterone (5 X 10(-8) M). The addition of both hormones induced a more than additive increase in proliferation (P less than .005, n = 18). Similarly, addition of insulin or hydrocortisone induced proliferation; however, in this case, the effect of the hormones together was only additive. The addition of tamoxifen (10(-6) M) led to a significant decrease in cell numbers and inhibited the stimulatory effects of 10(-8) M beta-estradiol.

Breast Neoplasms↗
PubMed1983

E-rosette inhibition and tumour recurrence in early breast cancer.

The relationship of serum blocking activity and susceptibility to tumour recurrence using E-rosette inhibition by normal allogenic lymphocytes was evaluated before and after operation in 20 patients with early breast cancer. Preoperative serum inhibition levels did not predict recurrent tumour. The mean postoperative inhibition in patient with recurrence was significantly greater than in those without recurrence. Postoperative testing only in a group of 124 patients showed that the development of local tumour recurrence was preceded by significantly greater inhibition of E-rosetting than occurred in patients without recurrence. The application of a threshold level of serum inhibition of 15 per cent distinguishes patients who are unlikely to develop tumour recurrence over a 4-year follow-up period. Serial measurements of serum inhibition at 6-monthly intervals over 2 years did not add to the predictive value of this test.

Breast Neoplasms↗
PubMed1983

Immunity to melanoma associated antigens detected by both leukocyte adherence inhibition and antibody dependent cellular cytotoxicity assays.

Two different assays, leukocyte adherence inhibition (LAI) and antibody dependent cellular cytotoxicity (ADCC) have been used to measure the immune responses of 69 melanoma patients, 116 patients with other tumours and 64 normal controls to a number of melanoma and control antigens. Using the LAI test, melanoma patients were significantly more reactive (43-69% positive) than normal controls (7-32% positive) to membrane extracts from 3 to 6 melanoma cell lines, and 4 to 6 extracts of melanoma biopsy specimens. However, the proportion of patients with other tumours reacting with 3 of these extracts was similar to melanoma patients. Melanoma patients were more reactive to the melanoma extract than to extracts of normal skin, normal muscle and 2 breast cancer cell lines. ADCC tests were used to detect anti-melanoma antibodies in patient sera. Preferential reactivity by melanoma patients was detected towards only 2 of the 6 melanoma cell lines tested--53% of 55 melanoma sera reactive to LiBr compared with 28% of 79 sera from patients with other tumours and 17% of 29 normal sera (P less than 0.05); 42% of 31 melanoma sera reactive to MM127 compared with 18% of 22 sera from other tumour patients (n.s.) and 5% of 20 normal sera (P less than 0.005). Melanoma patients tested against a number of melanoma cell lines by ADCC or antigen extracts by LAI generally reacted with one or more, but not all of them. Thus, incomplete cross-reactivity between different melanomas was observed. There was no correlation between results of the same patient in the 2 tests.

Antibodies, Neoplasm↗
PubMed1983

A human breast tissue-associated antigen detected by a monoclonal antibody.

Two monoclonal antibodies were produced in mice immunized with the human breast carcinoma cell line MCF-7. One antibody (24-17.1) reacted with MCF-7 and other breast tumor cell lines and detected an antigen of Mr 95,000. This antigen was not breast-specific because other tumor cell lines were also reactive. The second antibody (24-17.2) detected an antigen of Mr 100,000 (initially appearing to be specific for breast tissue and possibly for breast carcinomas) which was present on 10 of 10 malignant breast lines and absent from 41 of 43 other cell lines of differing origins. The antigen could not be detected by absorption or a direct test on normal tissues (liver, kidney, heart, spleen) or on lymphocytes. In addition, the 24-17.2 antibody reacted absorptively with 12 of 13 fresh breast carcinoma samples but not with fresh colon carcinoma samples. The 100,000-Mr antigen detected by the 24-17.2 antibody appeared to be distinct from the other components of normal breast, such as casein, lactalbumin, or milk fat globulin protein. This evidence indicated that the 24-17.2 antibody detected a human breast carcinoma-associated antigen (HBCAA). However, further histologic studies were used to determine the cellular distribution of the HBCAA, which was found on malignant breast epithelium, the epithelium of gynecomastia, and in lesser amounts and differently distributed on normal breast epithelium. The antigen was also found in several other tissues; nonetheless, the anti-HBCAA could be detected in increased amounts in the sera of patients with breast cancer.

Antibodies, Monoclonal↗
PubMed1983

A new human breast carcinoma cell line (PMC42) with stem cell characteristics. I. Morphologic characterization.

A new human breast carcinoma cell line (PMC42) was established from a pleural effusion from a woman with metastatic breast cancer. The cells were significantly pleomorphic even after 3.5 years in continuous culture. Eight different cell types could be characterized morphologically in monolayer culture. Cells cloned in agar and replated in monolayer culture were equally heterogenous. Cells also grew in suspension in papillary clusters that structurally resembled glandular organoids. Electron microscopy confirmed the differentiated structure of these cells in which many of the features of lactating breast tissue were evident. It is proposed that this is a culture derived from a malignant breast stem that has retained its ability to differentiate in vitro.

Aged↗
PubMed1983

A new human breast carcinoma cell line (PMC42) with stem cell characteristics. II. Characterization of cells growing as organoids.

A new human breast carcinoma cell line (PMC42) has been further characterized. The cells can grow either as monolayers or as floating cords of cells. The cords grow in suspension for long periods but may spontaneously attach and grow out to form a typical PMC42 monolayer. Ultrastructurally, the cells resemble breast ductal cells in many respects. Both epidermal growth factor (EGF) and prolactin induce ultrastructural changes, and lipid production is stimulated markedly by both factors. EGF also promoted the attachment of the floating cords and the growth of cells from these cords as monolayer cultures. The karyotype of the cord cells is different from that previously described for the monolayer cultures. Cord cells are hypodiploid (mode 39), whereas the monolayer cultures are subtriploid (mode 66). Although the ploidy is different, the karyotypes are related with 9 marker chromosomes being common to both populations. In addition, cultures in which cords have attached and in which cells are growing out as monolayers are bimodal with 10-20% of the cells becoming pseudotetraploid with a mode of 77.

Breast Neoplasms↗
PubMed1982

Children's brain tumour cells produce RNA particles with incomplete retrovirus characteristics.

Short-term cultures of cells from human rain tumours have been reported to synthesise RNA particles of density in the range characteristic of C type RNA retroviruses, with associated DNA polymerase activity. Fresh tumour cells obtained from 6 children with astrocytoma and 7 children with medulloblastoma, together with one sample of normal brain tissue and normal leukocytes from brain tumour patients were assayed by several characteristics for the primate retrovirus. 1 or 6 (17%) astrocytomas and 4 of 7 (57%) medulloblastomas released RNA particles which banded in sucrose gradients at a density of 1.16-1.18 g/cm3 together with a short segment of DNA, which was eliminated by prior ribonuclease treatment and two proteins of 28k and 16k daltons. These findings were compatible with the presence of a primate retrovirus. Immune coprecipitation of 125I-labelled proteins from the 1.16-1.18 g/cm3 gradient region failed to show any reactivity with antisera to p28 core antigens or the p70 reverse transcriptase antigens of simian sarcoma virus, baboon endogenous virus or Mason Pfizer virus. Assays for DNA polymerase activity in culture supernatant fluid showed only a low amount of activity with template preferences not characteristic of the retroviral reverse transcriptase enzyme.

Animals↗
PubMed1981

A study of the growth requirements of human tumour cells in tissue culture.

The effect of potential growth enhancing substances and other environmental factors on the growth of human cells in culture were examined. For all the cell lines tested the optimum pH range was 7 . 45-7 . 55. Optimum osmolality varied with different cell lines, optimum values being 240 milliosmoles/kg for melanoma cell lines and foetal fibroblasts, 260 milliosmoles/kg for adult fibroblasts and 300 milliosmoles/kg for a breast cancer cell line. A number of hormones were found to affect the growth of the cell lines examined. Insulin and hydrocortisone enhanced the growth of all the tumour cells tested, whereas 17 beta-oestradiol enhanced the growth of breast cancer cells but inhibited the growth of melanoma cells and fibroblasts. Stilboestrol inhibited the growth of all the cell lines but prolactin enhanced the growth of melanoma cells and inhibited fibroblast cell growth. Addition of galactose to the medium stimulated the growth of all cell lines tested, whereas sucrose and fructose resulted in stimulation of tumour cell growth but had little effect on fibroblasts. alpha-thioglycerol and beta-mercaptoethanol enhanced the growth of the tumour cells but had little effect on the growth of fibroblasts. A modified medium has been formulated which enhanced the growth of all the cell lines used when compared with McCoy's 5A medium.

Breast Neoplasms↗
PubMed1981

Use of the antibody-dependent cellular cytotoxicity test to detect antibodies in sera of breast cancer patients.

Sera from 114 breast cancer patients, 53 patients with other tumors, and 29 healthy controls were tested for antibodies reactive in antibody-dependent cellular cytotoxicity tests against a new breast cancer cell line (PMC9), two well-documented cell lines (MCF-7 and BT-20), and two melanoma cell lines. Of the breast cancer sera, 47% reacted with PMC9, whereas 30% reacted with the melanoma cell lines (P less than 0.05). Only 22% of sera from other cancer patients and 21% of sera from healthy controls reacted with PMC9 (P less than 0.05). The reactivity of sera from breast cancer patients was related to clinical stage of disease. Absorption studies on sera showing reactivity to both PMC9 and melanoma cells showed that the antimelanoma reactivity could be removed leaving anti-PMC9 reactivity intact. This study demonstrated the presence of breast cancer-associated antibody to PMC9 but not MCF-7 or BT-20 in the sera of breast cancer patients.

Antibodies, Neoplasm↗