Showing papers in "International Journal of Cancer in 1981"

Monoclonal antibodies to epithelium-specific components of the human milk fat globule membrane: production and reaction with cells in culture.

Abstract: Three hybridomas producing monoclonal antibodies (IgG), reacting with components of the human mammary milk fat globule have been isolated. When tested for binding to a wide range of human cell lines and strains, all three antibodies show negative reactions with fibroblasts, lymphoblastoid cells, and a large number of epithelial cell lines of non-breast origin. Two of the antibodies (1.10.F3 and 3.14.A3) reacted with seven out of eight breast cancer lines tested, and with epithelial cells cultured from human milk. The other antibody (3.15.C3) reacted with only two of the breast cancer cell lines.

Lung cancer and passive smoking.

Abstract: Fifty-one women with lung cancer and 163 other hospital patients were interviewed regarding the smoking habits of themselves and their husbands. Forty of the lung cancer cases and 149 of the other patients were non-smokers. Among the non-smoking women there was a statistically significant difference between the cancer cases and the other patients with respect to their husbands' smoking habits. Estimates of the relative risk of lung cancer associated with having a husband who smokes were 2.4 for a smoker of less than one pack and 3.4 for women whose husbands smoked more than one pack of cigarettes per day. The limitations of the data are examined; it is evident that further investigation of this issue is warranted.

Differentiation antigens expressed by epithelial cells in the lactating breast are also detectable in breast cancers

Abstract: Two monoclonal antibodies, 3.14.A3 and 1.10.F3, raised against a delipidated preparation of the human milk fat globule and characterized as epithelium-specific (Taylor-papadimitriou et al., 1981) were assayed histologically, by an indirect immunoperoxidase technique, against formalin-fixed, paraffin-embedded, normal and tumour tissue sections, in order to establish their in vivo specificity. Both antibodies bound to less than 10% of the alveoli and ducts in the resting breast, but bound to all areas of alveoli, ducts and secretion in the lactating breast. Binding was to the luminal surface of the alveolar and ductal epithelium. Antibody 3.14.A3 showed positive reactions with each of 20 primary breast carcinomas tested, and with metastatic lesions in lymph nodes from six of these. Antibody 1.10.F3 also reacted with most of the primary carcinomas but not with those of the mucoid type nor with metastatic lesions in lymph nodes. When tested against a variety of normal tissues, 1.10.F3 bound only to the luminal epithelial surface of classically defined exocrine glands, to their associated ducts and to the collecting tubules of kidney and bronchioles of the lung. 3.14.A3 showed a similar pattern of binding to 1.10.F3 but also bound to sweat glands, the alveolar epithelium of lung and the luminal epithelium of the ductuli efferentes of the epididymis. The only tumours, other than breast, showing a positive reaction with the antibodies were adenocarcinomas of the lung, uterus and ovary.

Distribution and molecular characterization of a cell-surface and a cytoplasmic antigen detectable in human melanoma cells with monoclonal antibodies

Abstract: The monoclonal antibodies 225.28S and 465.12 to human melanoma-associated antigens have been tested with a large variety of surgically removed skin lesions and malignant tumors as well as with a panel of cultured cell lines in serological and immunochemical assays. The antibody 225.28S reacts with a plasma membrane antigen while the antibody 465.12 detects a cytoplasmic antigen. Both antibodies fail to react with melanocytes from normal skin as well as benign skin lesions but react with nevi, melanoma cells and some skin carcinomas. Analysis with surgically removed tumors and cultured human cell lines indicated that the plasma membrane antigen is restricted to skin lesions whereas the cytoplasmic antigen is synthesized by tumor cells of various histological origins. The plasma membrane antigen is composed of two glyco-polypeptides of 280,000 and greater than 440,000 daltons, while the cytoplasmic antigen consists of 4 glycopolypeptides of 94,000, 75,000, 70,000 and 25,000 daltons. None of these components are bridged by disulfide bonds. The cytoplasmic antigen was readily detected in the spent culture medium of melanoma cell lines in the form of a major 94,000 dalton and a minor 72,000 dalton structure, while the plasma membrane antigen was detectable only after vastly increasing the sensitivity of the assay system.

Animal Species in which N-nitroso compounds induce cancer.

Abstract: In reviews on the carcinogenicity of N-nitroso compounds (NC) the number of animal species in which these compounds induce cancer is understated. In recent years additional species have been used in experiments. Tumours have been induced by NC in 39 species which belong to 36 genera, 25 families, 17 orders and five class of animals. The names of these taxa are presented in Latin and the common names of species are given in English, French and German. The carcinogenic action of eight NC in various species is tabulated.

Phenotypic changes of human neuroblastoma cells in culture induced by 12‐O‐tetradecanoyl‐phorbol‐13‐acetate

Abstract: SK-N-SH and SH-SY5Y human neuroblastoma cells treated by 12-)-tetradecanoyl-phorbol-13-acetate(TPA) express morphological and biochemical changes, which indicate that differentiation towards more mature cells has occurred. The most prominent morphological changes were the development in 40-60% of the cells of cell-surface projections longer than 50 micrometers and cytoplasmic neurosecretory granules demonstrated by electron microscopy. At the biochemical level, TPA induced a two-fold increase in the relative activity of neuron-specific enolase and 30- to 40-fold increase in noradrenaline and adrenaline concentrations. A decrease in proliferation rate of TPA-treated cells was observed. The biological effects of TPA were slightly potentiated by nerve growth factor.

Dietary factors and breast cancer risk

Abstract: As part of a case-control study in northern Alberta, Canada, 577 women aged 30-80 with breast cancer diagnosed during 1976-77 and a population-based age-stratified random sample of 826 disease-free female controls were questioned about certain aspects of their diet. Computing relative risks (RRs) by tertiles, significant increasing trends were found with more frequent consumption of beef (RRs of 1.0, 2.3, 1.5; test for trends, p less than 0.001), pork (RRs of 1.0, 1.6, 2.2; test for trend, p less than 0.001), and sweet desserts (RRs of 1.0, 1.3, 1.5; test for trend, p = 0.01). Elevated risks were also noted for use of butter at the table and for frying with butter or margarine, as opposed to vegetable oils. The association of total beef and pork consumption with breast cancer was not materially affected by controlling for age at first birth, family history of breast cancer, previous benign breast biopsy or socioeconomic status. Nor was the association reduced by controlling for ages of menarche and menopause, even though within the control series the intake of beef and pork reported in adult life was higher among those with a lower age at menarche or a older age at natural menopause.

Demonstration of the transferrin receptor in human breast cancer tissue. Potential marker for identifying dividing cells.

Abstract: A transferrin receptor was demonstrated in tumor tissue from 10 patients with breast carcinoma and one patient with breast sarcoma. Binding studies were conducted by measuring the amont of 1251-transferrin binding to microsomal preparations of the tumor tissue. Elevated levels of specific transferrin binding were found in the tumors with a range of 11-35% of bound transferrin, whereas microsomes prepared from non-neoplastic breast tissue samples bound only 2.3% and 2.4% of the transferrin. Scatchard analysis of binding studies conducted with tissues from a breast cancer and from a breast sarcoma indicate that the receptor has a Ka = 9.0 x 10(8)M. The binding site is specific for transferrin, as studies show that non-radioactive transferrin displaced labelled transferrin, while human IgG and human albumin did not. The receptor-transferrin complex was precipitated from a detergent extract of the breast sarcoma with antiserum to human transferrin. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of the immunoprecipitate gave a polypeptide of M 90,000 daltons, which is of similar molecular weight found for the putative transferrin receptor in all of a series of human cultured cell lines previously examined.

Deficiency of natural killer cell activity in patients with chronic lymphocytic leukemia

Abstract: Natural killer (NK)6 cell activity of peripheral blood lymphocytes against human leukemia cell lines was measured in patients with chronic B-cell lymphocytic leukemia (CLL) and age- and sex-matched controls. In order to remove the leukemia cells that interfere with the in vitro assay we (1) isolated lymphocytes that form rosettes with sheep red blood cells (SRBC) or (2) lysed the CLL cells with a monoclonal anti-B cell antibody and complement. NK activity in either lymphocyte preparation from nine of 10 patients with advanced disease was not detectable and, when calculated in terms of lytic units per ml of blood, was at least seven times lower than in controls; only one of these patients exhibited activity within the control range. Two patients with early disease had measurable, but low, NK-cell activity. Prolongation of the NK cell assay from 6 to 18h gave rise to significant killing in the CLL patients lacking NK cell activity in the 6-h assay; however, the activity still was six times lower than in controls. Treatment of leukemia cell-depleted lymphocytes from CLL patients with human fibroblast interferon or the interferon inducer poly I:C enhanced NK-cell activity in the two early stage patients but this treatment was ineffective in three later stage patients. The percentage of cells with characteristics of NK cells, i.e. those with receptors for SRBC and Fc-portion of IgG, was four times higher in CLL patients and the percentage of lymphocytes binding to NK-sensitive target cells was equal to that in controls despite the fact that, in the majority of patients, lysis of the target cells by the lymphocytes does not ensue. The NK deficiency may be responsible for the increased incidence of secondary malignancies in CLL patients.

Kaposi's sarcoma. IV. Detection of CMV DNA, CMV RNA and CMNA in tumor biopsies.

Abstract: In order to determine whether human cytomegalovirus- (CMV) DNA homologous sequences as well as CMV-specific RNA(s) and antigen(s) exist in tumor biopsies of Kaposi's sarcoma (KS) DNA-DNA reassociation, RNA-DNA in situ cytohybridization and anticomplement immunofluorescence test (ACIF) tests were applied. Three of 10 DNAs extracted from Kaposi sarcoma biopsies contained DNA sequences homologous to radioactively labelled human CMV DNA probe. The amount of CMV DNA in these sarcoma tissues was calculated to range from 0.7 to 1 genome equivalent per diploid cell. The presence of virus-specific RNA was also demonstrated in sections from five of 10 tumor biopsies. CMV-determined nuclear antigen(s) (CMNA) present in variable degrees were also demonstrated. In contrast, we could not detect any herpes simple virus type II (HSV-2) or Epstein-Barr virus (EBV) DNA sequences in DNA of these tumor biopsies. Furthermore, there were no detectable HSV-2 or EBV-specific RNA or virus-specific antigens in sections of these biopsies. These results provide new lines of evidence for the relationship between CMV and Kaposi's sarcoma.

Rat mammary carcinoma cells secrete active collagenase and activate latent enzyme in the stroma via plasminogen activator.

Abstract: A spontaneous mammary adenocarcinoma (AC) from an inbred female rat was investigated with regard to secretion of neutral proteases. Cultures of neoplastic epithelial cells derived from the tumour secreted an enzyme that fulfilled the criteria for a specific collagenase. In contrast to cultures of non-neoplastic cells, tumour collagenase was present as an active enzyme, since treatment with trypsin or p-aminophenylmercuric acetate (APMA) did not increase activity. The neoplastic cells were also prolific producers of plasminogen activator (PA). Dexamethasone (Dex) (10(-6)M) markedly reduced the levels of both enzymes. Addition of tranexamic acid (TA), an inhibitor of plasmin and of plasminogen activation, did not affect collagenase activity, even at 10(-1)M TA, nor did latent collagenase accumulate. Latent collagenase was secreted in culture by normal fibroblasts from neonatal rat lungs. This latent enzyme was activated by the addition of tumour cell medium plus plasminogen, but this effect was inhibited by the addition of TA. These results demonstrate that the neoplastic cells themselves secrete collagenase as an active enzyme. PA is also secreted, is not involved with tumour collagenase, but is capable, in the presence of plasminogen, of activating latent collagenase produced by the non-neoplastic cells within the tumour or in the surrounding tissue. This tumour possesses potent collagenolytic ability in vitro which may be partly responsible for its rapid invasion in vivo.

Phenotypic drift of metastatic and cell‐surface properties of mammary adenocarcinoma cell clones during growth in vitro

Abstract: We have examined cell clones obtained from a 13762 mammary adenocarcinoma tumor and its spontaneous lung metastasis for phenotypic stability during serial culture passage in vitro. Two clones that varied markedly in their metastatic properties were chosen for further examination. One of these clones (MTC) obtained from the parental transplanted tumor initially failed to metastasize within 23 days post-injection s.c. but gained the ability to form spontaneous pulmonary metastases after several serial passages in vitro. Another clone (MTLn3) derived from a spontaneous lung metastasis was initially highly metastatic after short-term culture, but lost the potential to form large numbers of spontaneous lung metastases with long-term culture. In contrast to MTA, clone MTLn3 displayed lymph-node metastasis, and the frequency of lymph-node involvement increased when late-passage cultures of MTLn3 cells were assayed in vivo. Both clones from late-passage cultures produced larger tumor sizes at the primary (mammary fat pad) injection sites compared to early passage cells. The morphologies of MTC cells changed with serial tissue culture passage, while the morphologies of MTLn3 cells did not change. The display of fibronectin on MTC cells by immunofluorescence did not change with culture passage; fibronectin was not detected in cultures of clone MTLn3. Fibronectin was also found on MTC cells by cell surface labelling using lactoperoxidase-catalyzed iodination-sodium dodecylsulfate polyacrylamide gel electrophoresis-autoradio-graphy. lodination of fibronectin on MTC cells did not vary with culture passage, and as in immunofluorescence experiments it was not detected on MTLn3 cells. There was a decrease in exposure of certain cell surface proteins on MTC cells with culture passage, but we did not detect modifications with this procedure that correlated with culture passage of MTLn3 cells. We conclude that prolonged culture in vitro can result in modifications of metastatic and cell-surface properties of tumor cell clones.

Cholesterol metabolism in cancer cells in monolayer culture. III. Low-density lipoprotein metabolism.

Abstract: The metabolism of low-density lipoprotein (LDL) was studied in neoplastic and non-neoplastic cells of human gynecological origin, in monolayer cultures. The neoplastic cells were derived from epidermoid vaginal carcinoma, epidermoid cervical carcinoma and endometrial adenocarcinoma, in various degrees of differentiation. The non-neoplastic cells were cervical fibroblasts and epithelial cells from proliferative endometrial glands. Both neoplastic and non-neoplastic cells assimilated and degraded LDL in a similar fashion to other human cells (e.g. skin fibroblasts). However, the neoplastic cells metabolized LDL at a higher rate than the non-neoplastic cell (e.g. epidermoid cervical cancer cells metabolized LDL at a 20 times higher rate than did cervical fibroblasts). Such a high rate of LDL metabolism probably enables continuously replicating cancer cells to obtain the large amounts of cholesterol required for cell membrane synthesis. If a high rate of LDL metabolism proves to be a general property of cancer cells, such a property could prove useful for tumor chemotherapy, providing cytotoxic chemicals could be incorporated within the LDL molecule.

Fibronectin in human solid tumors.

Abstract: Fibronectin in human solid tumors was studied by indirect immunofluorescence staining of biopsy material. Altogether 73 tumors were examined, comprising 12 sarcomas, 3 melanomas 1 reticulum cell sarcoma, 39 carcinomas, 6 benign soft-tissue tumors and 12 benign epithelial tumors. In all sarcomas the individual tumor cells were surrounded by a network of fibronectin which was continuous with the stroma. The distribution of fibronectin was similar in the benign soft-tissue tumors. In contrast, no fibronectin was detected in the individual carcinoma cells or in their periphery. However, the reactive connective tissue stroma of carcinomas was strongly connective tissue stroma of carcinomas was strongly positive for fibronectin. This was true also for the stroma of benign epithelial tumors. These results show that, contrary to the situation in cell culture, in vivo sarcoma cells and benign soft-tissue tumor cells contain fibronectin in their pericellular matrix. On the other hand, fibronectin can be used to distinguish carcinomas from sarcomas in vivo.

Chromosomal banding patterns in human large bowel cancer.

Abstract: Cytogenetic banding studies were performed on direct preparations from 31 large bowel tumors. Twenty-eight of these were from primary sites and three from metastases. Some distinctive patterns were observed. The 31 tumors were separable into four groups: (1) Tumors with normal karyotypes (three cases); (2) tumors with simple gains of chromosomes (three cases); (3) tumors with gains, losses and structural aberrations (ten cases). Groups 1, 2 and 3 were all in the diploid range; and (4) tumors with hypotriploid-hypotetraploid karyotypes (15 cases). Non-random gains of several chromosomes, especially No. 8 and non-random losses of No. 17 were seen in this series. Thirteen cases had sex chromosome abnormalities. The most prominent structural abnormalities involved chromosomes No. 1 and No. 5. Marker chromosomes were sometimes absent, but when present ranged from simple translocations to the most complex rearrangements. Doubling of chromosome and/or marker chromosomes were prominent in Group 4. Double minutes were seen in all three metastatic tumors and three primary cancers. Premature chromosome condensation was observed in three cases in the hypotriploid-hypotetraploid group.

Incidence of ovarian cancer in relation to the use of oral contraceptives

Abstract: Female residents of six counties in Washington and Utah in whom a diagnosis of ovarian cancer was made during 1975-79 were interviewed concerning prior use of oral contraceptives. Interviews with a random sample of women drawn from these same counties were obtained for comparison. A smaller proportion of women with epithelial ovarian tumors had taken oral contraceptives than had controls: the estimated risk of ovarian cancer in uses relative to that in non-users was 0.57 (p = 0.04). The magnitude of the decreased risk depended on the duration over which oral contraceptives had been taken, as the negative association was present only after 4 or more years of use. In many ways, the use of oral contraceptives mimics the physiologic effects of pregnancy. The results of the present investigation, when interpreted together with those from other epidemiologic studies and from experiments in animals, suggest that, like pregnancy, the use of oral contraceptives has a protective effect against the development of ovarian cancer.

Activation of the epstein-barr virus genome by 5-aza-cytidine in latently infected human lymphoid lines

Abstract: Recent studies indicate that gene expression in higher eukaryotes is accompanied by a decrease in the frequency of 5-methyl cytosine residues around the activated site (Razin and Riggs, 1980). 5-aza-cytidine (5-aza-C) is an analogue that reduces cytidine methylation in DNA (Jones and Taylor, 1980) and has been reported to change the differentiation pattern of cultured mouse embryo cells (Taylor and Jones, 1979). We have tested its ability to activate the Epstein-Barr virus cycle in latently EBV-infected human lymphoid lines. After an incubation period of 6 to 8 h with the drug, early antigens (EA) were induced in a substantial fraction of the cells in all six lines tested that had a low rate of spontaneous viral antigen production. Optimal conditions for EA induction were defined. The efficiency of 5-aza-C was comparable to the inducing effect of iododeoxyuridine. EBV-DNA and EBNA positive virus-non-producer lines did not respond to 5-aza-C treatment. The findings are discussed in relation to the possibility that changes in EBV-gene expression may be related to the state of DNA methylation.

In vivo inhibition of the development of myeloid leukemia by injection of macrophage- and granulocyte-inducing protein.

Abstract: It is shown that injection of macrophage- and granulocyte-inducing protein (MGI) can inhibit the development of myeloid leukemia in vivo and stimulate normal myelopoiesis. The MGI injected contained MGI-1 activity that induces colony formation with normal myeloblasts, and MGI-2 activity that induces differentiation of normal and MGI+D+ leukemic myeloblasts to mature macrophages or granulocytes. The MGI preparations injected did not contain interferon and it was shown that the results obtained were not due to minute amounts of contaminating lipopolysaccharide (LPS). Intraperitoneal injection of MGI stimulated myelopoisesis in normal adult mice. Markedly higher levels of serum MGI activity could be obtained by injecting MGI than by injecting LPS, a compound that stimulates the in vivo production of MGI. Injection of MGI into mice that had been inoculated intravenously with MGI+D+ or MGI+D− myeloid leukemic cells showed that, 3 weeks after the beginning of treatment, there was a 3- to 5-fold decrease in the number of leukemic colony-forming cells and an increase in mature granulocytes in the bone marrow, together with a 2- to 5-fold decrease in the percentage of morphologically identified myeloid blast cells in the bone marrow and peripheral blood. The remaining leukemic colony-forming cells in the MGI-treated mice inoculated with MGI+D+ cells were not resistant to the induction of differentiation by MGI-2. Injection of LPS to mice inoculated with LPS-resistant MGI+D− leukemic cells also inhibited the development of leukemia, but this inhibition was less effective than with MGI and was presumably indirect. Injection of MGI reduced the tumor volume in mice subcutaneously inoculated with leukemic cells at least 50-fold. The median survival time of MGI-treated mice inoculated intravenously with MGI+D+ cells or subcutaneously with MGI+D− cells was increased by about 40%, and 50% of the MGI-treated mice inoculated subcutaneously with MGI+D+ cells did not develop tumors. MGI also increased the anti-tumor effect of cyclophosphamide. The leukemia-inhibiting activity in the injected MGI preparations was associated with the peak of MGI activity separated on a hydroxylapatite column and was destroyed by treatment at the temperature which destroys MGI-2 activity. This indicates that the inhibition of leukemia development was mediated by MGI-2. It is suggested that improved schedules of MGI treatment, with or without compounds used in the cytotoxic types of therapy, should be able to give an even better inhibition of leukemia development and that these results should also be applicable to the therapy of human myeloid leukemia.

Binding of 125I-labelled human alpha interferon to human lymphoid cells.

Abstract: To investigate the binding of interferon to human lymphoid cells, we purified human alpha interferon and radio-labelled it with iodine-125. Binding at 4 degrees C could be saturated and was inhibited by unlabelled interferon; it was specific for cells of human origin. Dissociation constants for the complex of interferon and receptor site were of the order 10(-9)-10(-11) M. All human cells tested showed such binding. Occupation of these high-affinity sites, at 37 degrees C, was compared with the inhibition of cellular growth due to interferon. The most sensitive cell line (Daudi) gave a complete biological response with only a fraction of its sites occupied. Evidence of two sites was found for a line (P3HRI) showing intermediate sensitivity. A relatively insensitive line (Raji) showed no response when all its high-affinity sites were occupied.

Carcinogenicity of analgesics: long-term treatment of Sprague-Dawley rats with phenacetin, phenazone, caffeine and paracetamol (acetamidophen).

Abstract: Six groups of male Sprague-Dawley rats were treated with phenacetin, phenazone or caffeine in the diet or with combinations of these chemicals. Another group received paracetamol in the diet and a further group received only the control diet. The rats were treated for up to 117 weeks. Renal pelvic tumors were only seen in rats treated with phenacetin or phenazone alone or in combination with caffeine, phenazone having slightly greater activity toward the urinary tract than phenacetin. Phenacetin, however, had a greater overall carcinogenic effect, inducing 31 malignant tumors. The urinary tract and the kidneys had the highest incidence of tumor followed by squamous-cell carcinomas of the head and neck. Half of the rats treated with phenacetin, phenazone and caffeine in combination developed hepatomas. The explanation may be that the addition of phenazone and caffeine altered the metabolism of phenacetin, increasing the production of N-hydroxy-phenacetin, a known liver carcinogen. The justification of using phenacetin as a human analgesic must be seriously questioned, and further studies with phenazone are required.

Spontaneous cytogenetic abnormalities in lymphocytes from thirteen patients with ataxia telangiectasia.

Abstract: Ataxia telangiectasia (AT) is a human autosomal recessive disorder in which patients show a marked predisposition to malignant disease and cytogenetic abnormalities. We report here the levels of spontaneously occurring chromosome aberrations and particularly the presence of cytogenetically marked clones of cells in peripheral lymphocytes of 13 patients. There is a variation between the patients with respect to frequency of different aberration types, and clones are present in 5/13 patients. Several of these patients appear to have more than a single clone, possible clones or subclones. There is no evidence for any malignant disease in any of these patients. A description is given from one of these patients, of the most complex clone so far reported in an AT patient without malignant disease. The development of such a complex clone might be important as a step in malignant change. Similarities between this clone and one reported in an AT patient with T-cell chronic lymphocytic leukaemia are discussed.

Induction of cytotoxic activity in human lymphocytes against autologous and allogeneic melanoma cells in vitro by culture with interleukin 2

Abstract: The influence of interleukin 2 (IL2) on the cytotoxic activity of lymphocytes from patients with melanoma against autologous and a variety of allogeneic melanoma cells was studied. IL2 was produced from blood lymphocytes cultured for 24 h with phytohaemagglutinin (PHA) and purified by membrane chromatography to exclude PHA. Lymphocytes from 13 patients with melanoma at various clinical stages were cultured for 6 days with IL2 (2 U/ml) and then tested for cytotoxic activity against autologous melanoma cells, three allogeneic melanoma and three non-melanoma cells. Autologous cytotoxicity was generated by culture with IL2 alone and was not increased by culture with both IL2 and autologous tumour cells. Marked increases in cytotoxic activity were also generated against the allogeneic target cells and were maximal against the NK-insensitive Chang target cells. Similar degrees of cytotoxicity were induced by IL2 stimulation of lymphocytes from melanoma patients, patients with non-melanoma carcinoma and normal subjects against the allogeneic target cells. Cold target inhibition studies were carried out against IL2 induced autologous cytotoxicity in five patients. In four of five studies the autologous target cells inhibited more than the allogeneic target cells. There was no significant difference between the inhibition produced by allogeneic melanoma cells and that produced by non-melanoma cells. Similarly, in studies against allogeneic target cells, there was no significant difference in the inhibition produced by allogeneic melanoma compared to non-melanoma target cells. This applied irrespective of whether effector cells were from melanoma or non-melanoma subjects. These results suggest that lymphocytes from patients with melanoma are primed against autologous antigens in vivo and that provision of a second signal, IL2, in vitro can induce cytotoxicity against the autologous tumour. The cytotoxicity generated against the allogeneic target cells did not appear to have specificity to melanoma. Several results, such as the pattern of cytotoxicity against the target cells and changes in cell surface markers on the lymphocytes during culture, suggested that cytotoxicity was mediated by activated T cells rather than by natural killer cells. These findings appear to have important implications both in the understanding of tumour host relationships and for the use of IL2 in therapy.

Extracellular matrix proteins characterize human tumor cell lines

Abstract: Extracellular matrix proteins synthesized and secreted by adherent human tumor cell lines were analyzed using metabolic labelling with glycine and proline in the presence of ascorbate, polypeptide analysis and polyacrylamide gel electrophoresis, affinity chromatography, collagenase digestion, and immunofluorescence staining. The results showed a characteristic pattern of matrix proteins for each tumor cell type. Tumor cell lines of mesenchymal origin produced mostly interstitial types (I and II) of collagen and fibronectin. Carcinoma cell lines secreted only basement membrane proteins, type IV collagen, laminin and fibronectin, but not interstitial collagen. A melanoma and a rhabdomyosarcoma cell line produced type V of procollagen that has not previously been described in cell culture. Neuroblastoma cells were shown to be phenotypically heterogeneous also with respect to matrix protein production. We propose that the analysis of extracellular matrix proteins may serve as an adjunct in the classification of human tumors.

Characterization of a human papillomavirus from epidermodysplasia verruciformis lesions of a patient from upper‐volta

Abstract: A case of epidermodysplasia verruciformis in a patient from Upper-Volta is described. Slightly elevated, flat warts were observed on hands, feet, arms and legs, and pityriasis versicolor-like lesions were found mainly on the trunk. The patient showed no malignant tumors. Histological examination revealed hyperkeratosis, granulosis and moderate acanthosis with large, foamy, basophilic keratinocytes in stratum granulosum and stratum spinosum. Papillomavirus particles could be prepared from these lesions and were differentiated from known papillomavirus types by immune electron microscopy with monospecific antisera and by DNA-DNA hybridization. The viral DNA was characterized by cleavage with several restriction endonucleases and a physical map of the resulting fragments was established. The virus is designated as HPV 8. Preliminary seroepidemiologic studies with human sera indicate a rather wide distribution of HPV 8. Blot hybridization of DNA from human carcinomas with 32P-labelled virus DNA detected no HPV 8-specific sequences.

Correlation of glycosphingolipids and sialic acid in YAC‐1 lymphoma variants with their sensitivity to natural killer‐cell‐mediated lysis

Abstract: Sialoglycoconjugates and glycosphingolipids were quantitated in a series of variants derived from the YAC-1 lymphoma, known to be highly sensitive to natural killer (NK)-cell-mediated lysis. The variants, which had widely diverging sensitivities to NK cells, were obtained by a number of methods, including selection in the presence of NK cells, antibody to H-2, or antibody to the murine leukemia-virus-induced antigen, and by fusion of sensitive cells with an NK-resistant cell line, A9HT. The sensitivities of these cells to NK-cell-mediated lysis did not correlate with their sensitivities to anti-H-2a cytotoxic T cells. While no correlation could be made between the NK-sensitivity of these variants and their total cellular sialic acid, a statistically significant inverse correlation was observed between the levels of percentage neuraminidase releasable surface sialic acid of total labelled sialyl components and sensitivity to NK cells. This correlation with cell surface sialic acid was observed with either endogenous or lymphocytic choriomeningitis virus-induced activated NK cells as effectors. Neuraminidase treatment of insensitive target cells caused a moderate increase in sensitivity but failed to render the resistant targets as sensitive as YAC-1. Analysis of glycosphingolipids among the variants revealed a strong positive correlation between the total cell neutral glycolipid with chromatographic migration of asialo-GM2 and sensitivity to endogenous or activated NK-cell-mediated lysis. Significant correlations were not found with any other neutral glycolipids. However, ganglioside homologues with chromatographic mobility of GM1, GD1a, GD1b, and GT also showed a positive correlation with both endogenous and activated NK-cell-mediated lysis. The ratio of asialo-GM2 to GM2 had a highly significant positive correlation with sensitivity. These correlative results suggest that asialo-GM2 and certain gangliosides could be involved in binding or lytic events in NK cell:target cell interactions, and that high levels of sialic acid and sialylation on the cell surface may inhibit and/or modify such interactions. Further studies with these YAC variants should be useful for examining the biochemical bases of target cell-effector cell interactions in the NK-system.

Extravascular natural cytotoxicity in man: Anti-K562 activity of lymph-node and tumour-infiltrating lymphocytes

Abstract: A major distinction is reported between the cytolytic activity of peripheral blood lymphocytes (PBL) and that of lymph-node and tumour-infiltrating lymphocytes (TIL) against targets of the NK-sensitive K562 cell line in short-term 51Cr release assays. In the PBL of normal donors and lung cancer patients in whom disease was advanced anti-K562 reactivity, though variable, was consistently detectable and this activity could be augmented to a similar extent in patients and controls by treatment of effectors with exogenous interferon (IF). By contrast anti-K562 activity in lymph-node cells (LNC) and TIL was virtually absent and significant levels could not be induced by exposure to IF. This activity was not attributable to coexistent suppressor cells for NK function since admixture of LNC and TIL with normal PBL failed to modulate K562 killing by the latter. The results imply that K562-reactive NK cells and their precursors may frequently be present at sub-threshold levels in the lymph nodes of tumour-bearing patients and a similar explanation could account for the inactivity of TIL. However, in the latter situation, actively-induced NK dysfunction in situ incapable of regeneration by IF, and attributable to as yet undefined tumour-associated factors, may also be involved.

Block of glioma cell line in S by interferon.

Abstract: The human glioma cell line U-251 MG, with a well-characterized defect in growth control, was sensitive to the antiproliferative effects of human (fibroblast) interferon (IFN). IFN inhibited exponentially growing cells by increasing the number of cells in the S stage of the cell cycle. At the same time the number of cells in Go/G1 diminished. The rate of thymidine incorporation was decreased during the first cell cycle, with no prolongation of S. However, in synchronized cultures, the wave of cells with a S-phase content did not decrease over a time period several hours longer than the length of S measured by pulse labelling. Thus we conclude that, at a sufficient dose, the cells were unable to accomplish cell division as they prematurely stopped synthesizing DNA.

Synergistic action of two polyamine antimetabolites leads to a rapid therapeutic response in childhood leukemia.

Abstract: Sequential administration of alpha-difluoromethyl ornithine and methylglyoxal bis(guanylhydrazone), two differently acting inhibitors of the biosynthesis of natural polyamines, produced a rapid and distinct therapeutic response in four children with advanced lymphoblastic and in one with myeloblastic leukemia. The synergism between the action of the two compounds was based upon a unique drug interaction; a preceding treatment with difluoromethyl ornithine greatly increased the uptake of subsequently administered methylglyoxal bis(guanylhydrazone) as verified by the actual determinations of the latter drug in the circulating leukemia cells. The side-effects associated with the combined drug regiment were either absent or mild.

Plasminogen activator content of neoplastic and benign human prostate tissues; fibrin augmentation of an activator activity.

Abstract: The plasminogen activator content of the extracts of excise prostate cancers (25 specimens) was determined with an azocasein assay and found to be on the average 1.7 times higher than that of extracts of excised prostate benign hyperplasias (29 specimens). Both groups contained the same average percentage of human urokinase type activator (approximately 45%) as determined by the inhibition of activity when anti-human urokinase antibody was included in the assay system. The two types of activators were partially purified and found to have distinctly different properties. The most striking difference was the large augmentation of activity o the non-urokinase enzyme in fibrinolysis. The implications of an enhanced fibrinolysis relative to azocaseinolysis (or other) is discussed, particularly with respect to its importance in the quantitation and characterization of activators by different investigators. Highly purified urokinase-like activator was found to be similar to commercial urokinase preparation with respect to molecular weight, isoelectric point, inhibition by the antibody, and inhibition by placenta inhibitor.

Analysis of normal neoplastic human tissues for the tumor-associated protein p97.

Abstract: We have used immunoprecipitation to test tumor biopsies and normal adult and fetal human tissues for p97, a tumor-associated protein. Five of nine melanoma biopsies contained p97 in low to very high levels. Three of seven non-melanoma tumors contained p97, but in smaller amounts. No p97 was detected in any of the normal adult tissues examined. The protein was, however, observed in samples of fetal colon and umbilical cord, and in one sample of fetal lung. One of two benign nevi contained high levels of p97, while one benign angiofibroma was negative. We conclude that the presence of p97, in levels detectable by our method, appears to be characteristic of certain neoplastic and fetal tissues.