Showing papers in "International Journal of Cancer in 1973"

Cellular localization of an Epstein-Barr virus (EBV)-associated complement-fixing antigen in producer and non-producer lymphoblastoid cell lines.

Abstract: Anti-complement immunofluorescence (ACIF) was used to study the complementfixing antigens of human lymphoblastoid cell lines. These cell lines carry the Epstein-Barr virus (EBV) genome although only producer cultures synthetize EBV-specific antigens (virus capsid antigen, VCA and early antigen, EA) detectable by direct and indirect immunofluorescence, usually in less than 5% of the cells. The ACIF test revealed an antigen localized in the nucleus of the lymphoblastoid cells. In contrast to EA and VCA, this antigen was present in over 90% of the cells of both producer and non-producer cultures. The antigen was shown to be specific for EBV by comparing the reactions of 52 sera in the ACIF test. Sera giving the nuclear reaction contained antibodies to VCA, EA or antigens detectable by complement fixation tests on cell extracts, but sera without EBV antibodies failed to give the reaction. Weak, equivocal or discordant reactions occurred with six sera with low titres in VCA, EA or complement fixation tests. Cell lines derived by transformation of human and primate lymphocytes by EBV gave the nuclear reaction. Control cells with no known association with EBV were non-reactive. These included foetal lymphocytes transformed by phytohaemagglutinin, cell lines derived from breast cancer, glioma, normal glia, pleuritis maligna and myeloma, and two marmoset lymphoid lines carrying Herpesvirus saimiri (HVS). In preliminary experiments, the ACIF test was used as a tool to trace the EBV genome at the cellular level. Cells from two Burkitt lymphoma biopsies, one tested after biopsy and one after passaging in nude mice, contained an EBV-specific antigen. Three clones of cells derived from hybrids of mouse somatic cells and a human lymphoblastoid cell line also contained such an antigen, but the number of reactive cells varied from clone to clone. A fourth clone was non-reactive.

Established cell line of urinary bladder carcinoma (T24) containing tumour-specific antigen.

Abstract: A cell line derived from human urinary bladder carcinoma, designated T24, was established in vitro. The growth of T24 cells in tissue culture was characterized by a disorderly pattern of growth in one or more layers and by mixed epithelioid-fibroblastoid morphology. The generation time of T24 cells was 19 h. The cells had a hypotetraploid stemline with marker chromosomes. The malignant character of the line was verified by inoculation of cell suspension into hamster cheek pouch. The presence of tumour-specific antigen (TSA) in T24 cells was demonstrated by a micromodification of the cytotoxicity test with autochthonous leukocytes and serum from the donor of the tumour. The TSA was also well detectable by the reaction with allogeneic leukocytes from tumour-bearing patients and persisted during a 30-month culture period. The permanent presence of TSA in this carcinoma cell line suggests that the TSA is a genetically determined characteristic of T24 cells.

Platelet—tumor-cell interactions in mice. The role of platelets in the spread of malignant disease

Abstract: Thrombocytopenia reduces the number of metastases produced by a wide variety of murine tumors. Studies aimed at investigating interactions between tumors and platelets reveal that many tumors aggregated platelets in vitro and/or produced thrombocytopenia in vivo. In some instances, tumor-cell-induced thrombocytopenia in vivo was accompanied by accumulation of platelets in the lung. Thrombocytopenia was most active against metastases produced by tumors with the capacity to aggregate platelets in vitro and/or in vivo but it was also effective against metastases produced by tumors lacking such a capacity. Further studies, aimed at increasing platelet aggregation in vivo, as when fibroblasts were added to the tumor inoculum, or decreasing the platelet response to aggregating agents, as when aspirin was administered to mice, strongly support the role of platelet aggregation and the platelet release reaction in metastasis. As expected, fibroblasts enhanced while aspirin decreased tumor spread, the latter being equally effective against both artificially induced and spontaneously-occurring metastases. Formation of platelet aggregates not only enhances but also seems to change the distribution of metastases. Tumors with platelet aggregating capacities usually give lung metastases while those devoid of such a capacity may show metastases of widespread distribution. Research with 125IUDR-labelled B16 melanoma cells indicates that thrombocytopenia does not affect the initial vascular arrest of tumor cells but seems to influence their subsequent retention by the lung.

A quantitative system for assay of malignant transformation by chemical carcinogens using a clone derived from BALB-3T3.

Abstract: A31–714, a subclone isolated from clone A31 of the BALB/3T3 line showed a high degree of contact inhibition and an extremely low incidence of spontaneous transformation. Treatment of this subclone with 4-nitroquinoline-1-oxide, 3-methylcholanthrene, benzo(a)pyrene or N-methyl-N'-nitro-N-nitrosoguanidine produced foci of multilayered growth on the background of contact-inhibited monolayer within 2 to 4 weeks. In this system the transformation frequency can be determined quantitatively on either an inoculated cell basis or a surviving cell basis. The transformation frequency increased with the concentration of carcinogens within a certain range, and was affected by the duration of treatment and the cell density at the time of treatment. Treatment with DMSO alone or with the non-carcinogenic substances, 4-nitroquinoline, 4-aminoquinoline-1-oxide, phenanthrene and pyrene, did not cause any transformation. The cytotoxic effects of carcinogens were not directly correlated with the transformation frequencies. All transformed cell lines derived from each focus showed characteristics known as the indices of malignant transformation, such as a criss-cross pattern or piling up of cells, a high saturation density and the ability to grow progressively in soft agar. When the transformed cells were injected into the skin of the back of newborn or adult mice at a dose of 106 cells, fibrosarcomas were produced at the site of injection after 3–6 weeks. Neither untreated A31–714 cells nor morphologically untransformed cells in cultures with foci produced tumors on injection at a dose of 107 cells. In general, transformed cells had a reduced cloning efficiency, and almost the same susceptibility to the cytotoxic effects of carcinogens as untransformed cells, though these properties varied in different lines.

Cancer of respiratory organs among workers at a nickel refinery in Norway.

Abstract: In a previous report (Pedersen et al., 1973) an excess risk of respiratory cancer among Norwegian nickel workers was demonstrated. The number of cancer cases was relatively small for the study of temporal changes in exposure. In this report the number of cancer cases increased by 70% through an extended follow-up to 1979, and the results published previously were confirmed. Data on smoking habits of the employees at the nickel refinery have now become available. The interaction between smoking and occupational nickel exposure is assessed by comparing the excess risk of lung cancer caused by smoking in the study group and in a sample of the general population. It is shown that the interaction is closer to being additive than multiplicative. This observation has methodological implications for studying temporal changes in occupational exposure. These implications are discussed. No substantial reduction in occupational exposure at the nickel refinery can be observed as far as lung cancer is concerned. For nasal cancer, however, the risk is much smaller among those employed around 1960 than among those employed around 1930. The difference in trend of occupational risk for the two types of cancer cannot be explained by the data presented.

Primary immunodeficiency diseases and cancer: the immunodeficiency-cancer registry.

Abstract: Data from the newly established Immunodeficiency-Cancer Registry show 151 tumors in 145 patients with primary immunodeficiency syndromes, including: sex-linked (Bruton's) agammaglobulinemia, 6 patients; severe combined system immunodeficiency, 9 patients; Wiskott-Aldrich syndrome, 24 patients; ataxia-telangiectasia, 52 patients; common variable (late onset) immunodeficiency, 41 patients; isolated IgA deficiency, 7 patients; and isolated IgM deficiency, 6 patients. The risk of development of malignancy is from 2–10%, indicating that these individuals have a far greater than chance risk of developing malignancies, in spite of their short life-spans. Tumors are divided into major histologic types: lymphoreticular, 58% of total; leukemias, 17% of total; epithelial. 18% of total; mesenchymal, 3% of total; and nervous system, 4% of total. Data are reported on 14 families in which 12 siblings had the same tumors and identical primary immunodeficiency diseases. The majority of tumors are lymphoreticular or leukemias: these findings are consistent with the hypothesis that individuals with primary immunodeficiency syndromes have intrinsic abnormalities of the lymphoid system which result in increased frequency of malignant transformation and inability to eliminate transformed cells. Further reporting of tumors is urged.

Inhibition of hepatoma-immune lymph-node cell cytotoxicity by tumour-bearer serum, and solubilized hepatoma antigen

Abstract: Sera from rats bearing transplanted aminoazo-dye-induced hepatomas inhibited the cytotoxicity of lymph-node cells from tumour-immune rats for plated hepatoma cells, when the sera were incubated with the effector cells, rather than target cells. In contrast, sera from hepatoma-immune rats, which have previously been shown to block lymphocyte cytotoxicity at the level of the target cell, failed to inhibit lymph-node cell cytotoxicity when pre-incubated with the effector cells. The possibility that antigenic determinants could be responsible for lymphocyte inhibition is supported by the demonstration that papain-solubilized hepatoma-specific antigen preparations inhibited lymph-node cell cytotoxicity. The role of specific antibody, antigen and immune complexes in the interaction between cellular immunity and humoral factors during tumour growth is discussed.

Sequential studies on cell-mediated tumor immunity and blocking serum activity in ten patients with malignant melanoma.

Abstract: Ten human patients with malignant melanoma were followed with respect to two in vitro parameters of tumor immunity, the ability of the patients' blood lymphocytes to destroy cultivated melanoma cells, and the ability of the patients' sera to block such destruction, and with respect to changes in the clinical status, such as increases or decreases in detectable tumor mass. Allogeneic and (to a much lesser extent) autochthonous melanoma cells were used as targets. The degree of lymphocyte-mediated tumor immunity was higher in patients with little or no residual tumor than in patients with large tumor loads, although the latter patients were also found to be reactive. Sera from patients with clinically detectable melanoma could block the cytotoxic lymphocyte effect, as could sera from patients who developed melanoma shortly after the serum harvest. Disappearance of blocking serum activity was seen to accompany clinical improvement. Sera from some patients without clinically detectable tumor could potentiate the cytotoxic effect of lymphocytes from melanoma patients. The findings support the view that cell-mediated tumor immunity and blocking serum activity, as studied in vitro, are important correlates of the patients' immunological defense against their tumors in vivo, and they suggest that monitoring of these parameters may be prognostically useful. They also suggest that procedures capable of improving cell-mediated tumor immunity without increasing blocking serum activity may be therapeutically beneficial.

Relationship between the sensitivity of EBV‐carrying lymphoblastoid lines to superinfection and the inducibility of the resident viral genome

Abstract: Human, EBV-carrying lymphoblastoid lines show wide differences in their sensitivity to superinfection with EBV concentrates and also in their sensitivity to the activation of the resident viral genome by BUDR and IUDR. A significant correlation was found between sensitivity to superinfection and activation in 23 virus-receptor-positive lines. In 10 receptor-negative lines, there was no such correlation: they were resistant to superinfection since they could not adsorb the virus, but differed widely in their activatability. The findings suggest that the intracellular restrictive mechanism that limits superinfection in the receptor-positive, resistant lines, can also restrict the function of the activated genome, derived from within. Since some of the lines that were resistant to both superinfection and activation were spontaneous producers, however, it appears that the same mechanism does not necessarily affect the “spontaneous” function of the resident genome.

Pilot experiments with EB virus in owl monkeys (aotus trivirgatus). I. Reticuloproliferative disease in an inoculated animal

Abstract: A pilot experiment is described in which EB virus-containing cultured lymphoblasts were inoculated into a group of three adult owl monkeys. Virion-free cells were inoculated into three other monkeys, and four further animals were kept as uninoculated controls. One of the animals receiving the virus died after 14 weeks with a striking reticulopro-liferative disease very compatible with certain forms of malignant lymphoma. The findings are described and their significance considered in relation to a possible onocgenic capacity for EB virus.

Carcinoembryonic antigenic activity of tissue extracts: a quantitative study of malignant and benign neoplasms, cirrhotic liver, normal adult and fetal organs.

Abstract: A quantitative study of carcinoembryonic antigenic activity (CEA) in extracts of 44 tumors, 42 fetal and 36 non-malignant adult tissues from various organs was made and the CEA content detected by microradioimmunoassay was related to the wet tissue weight. A variety of malignant neoplasms, including carcinomas, sarcoma and Hodgkin's disease, contained CEA (range 17 to 2727 ng); apart from gastrointestinal carcinomas which had the highest content of CEA (230–2727 ng/g) only carcinomas of the lung contained moderate amounts of CEA (63–950 ng/g). The amount of CEA in extracts of fetal and normal adult organs was mostly low or not detectable except in the gastrointestinal tract and pancreas where it ranged from 65 to 200 ng/g in the fetus, and 28 to 86 ng/g in the adult. Differences in mean content of CEA between normal and cirrhotic livers were not significant. Although our results indicated that CEA was present in varying amounts in a variety of tumors the identification of these reactive substances will require more precise physico-chemical and antigenic characterization.

Growth and antigenic properties of a biopsy-derived Burkitt's lymphoma in thymus-less (nude) mice.

Abstract: A Burkitt's lymphoma was transferred to the congenitally athymic mouse mutant nude with biopsy material from a 7-year-old Kenyan girl. The tumor grows locally at the site of inoculation with no distant metastases. The established tumor has been maintained for six passages so far with preservation of histological and cytological appearance. The mouse-passaged tumor has a normal human diploid female chromosome complement. Isozyme studies have shown tumor to be of the same glucose-6-phosphatedehydrogenase (G-6-PD) and phosphoglucomutase1 phenotype (B and 2-1 respectively) as tumor biopsy from the patient. The mouse-passaged line maintained surface IgM, similarly to the original tumor and the derived tissue culture line, but lost the IgG coating characteristic for the original tumor but absent from two subsequent biopsies and from the derived tissue culture line. This is in line with previous observations indicating that surface-associated IgG on Burkitt biopsies is due to coating from the outside, whereas surface-associated IgM is a cell marker. Whereas the biopsy cells of the patient were positive for EBV-associated membrane antigen (MA), but not for early antigen (EA) and viral capsid antigen (VCA), the mouse-passaged line was positive for all three. This suggests that the restrictive influence of the human host on the production of EA and VCA in the Burkitt tumor is raised in the mouse host. The serum of the tumor-bearing nude mice contained anti-human antibodies, but no detectable EBV (anti-MA, EA and VCA)-antibodies.

Cytogenetic analysis of human acute and chronic myeloid leukemic cells cloned in agar culture

Abstract: Karyotypic analysis was performed on agar cultures of blood or bone marrow from 12 patients with acute or chronic myeloid or myelomonocytic leukemia in whom karyotypic markers were present. The granulocytic colonies and clusters which developed on culture were shown to be derived from representative cells of the leukemic population. In two patients with acute leukemia in remission, normal colonies with a normal karyotype were grown from marrow cells but in two patients with chronic myeloid leukemia in remission the Ph1 abnormality persisted in colony cells. The agar culture technique appears to be ideal for following the emergence and disappearance of leukemic and normal granulopoietic populations in patients with these types of leukemia.

The deficient density-dependent growth control of human malignant glioma cells and virus-transformed glia-like cells in culture.

Abstract: The density-dependent growth control of eight established human glioma lines and virus-transformed human glia-like cells has been investigated. All neoplastic lines reached higher terminal cell densities than the corresponding normal glia-like cells. A marked decrease in proliferation rate occurred at high cell densities which could not be explained by medium depletion or accumulation of toxic substances. An absolute resting phase was not reached by the neoplastic cells; a considerable residual DNA synthesis continued even at the highest cell density levels which could be reached. The intervals of the cell cycle were determined on one glioma line. Cells inhibited in crowded cultures were arrested in G1. The results imply that at least a proportion of neoplastic human glia lines retain a degree of topoinhibition, i.e. are still sensitive to growth restraint induced by increased cell density. However, topoinhibition was never as complete as among normal cells, since possibly cell density-independent (“autonomous”) multiplication was maintained at a fairly high rate even at the abnormally high cell densities which all neoplastic lines attained.

Cell-mediated immune reaction against tumors induced by oncornaviruses. II. Nature of the effector cells in tumor-cell cytolysis.

Abstract: The nature of the effector cells detected by the chromium release test (CRT) has been studied in BALB/c and C57Bl/6 mice bearing murine sarcoma virus (MSV)-induced tumors. Anti-θ-C3H immune sera completely inhibited the cytotoxic activity of lymphoid cells in the presence of complement; anti-immunoglobulin sera failed to decrease this activity. No activation of normal non-sensitized lymphoid cells in the presence of heat-decomplemented sera from mice bearing MSV-induced sarcomas could be obtained. Identical results have been found in allogeneic systems with major H-2 histocompatibility antigens. It can be concluded that a thymus-processed lymphoid cell sub-population sharing the θ antigen is exclusively or very predominantly responsible for the immune cytolysis both in syngeneic tumor systems and in allogeneic transplantation systems.

The effects of neonatal thymectomy on the antitumour activity of lentinan, carboxymethylpachymaran and zymosan, and their effects on various immune responses.

Abstract: The mechanism of antitumour action of the polysaccharides, lentinan and carboxymethylpachymaran, was examined and compared with that of zymosan. It was revealed that (1) these polysaccharides did not show any direct cytocidal effect on tumour cells; (2) these polysaccharides had no antitumour action at all in neonatally thymectomized mice, indicating the important role of the thymus gland in tumour regression; and (3) in spite of these facts, these polysaccharides, contrary to zymosan, did not accelerate various conventional immune responses such as phagocytic activity, antibody production against heterologous antigen, increased number of peripheral lymphocytes, skin homograft rejection, and delayed hypersensitivity. This evidence suggests the presence of a complex and unknown mechanism for regression of transplanted tumour in the action of lentinan and carboxymethylpachymaran.

Cell‐mediated and serum blocking reactivity to tumor antigens in patients with malignant melanoma

Abstract: The reactivity of human lymphocytes, separated from peripheral blood by procedures involving sedimentation through plasmagel and settling on a glass surface, on survival or growth of melanoma tumor cells is reported Assay of reactivity was by either a colony inhibition in dilute agar (GEL) technique or a microcytotoxicity assay (MC) In 54 experiments with lymphocytes from normal donors, inhibition of melanoma cell viability, as compared to growth in medium alone, was seen 25 (463%) times, stimulation was observed seven (129%) times and no effect 22 (407%) times These results were not influenced by matching of the lymphocyte and tumor-cell donor for ABO blood group Inhibition was seen less often, however, in tests with the GEL method than in those with the MC assay Eighty-two experiments assessed the effect of lymphocytes from melanoma patients on melanoma cell viability Inhibition to an extent greater than that of normal lymphocytes tested at the same time was seen 65 (793%) times There was no difference in the frequency of detection of inhibition with lymphocytes from patients with local, regional, or widespread disease, although the percentage inhibition was less in the latter group No differences were seen between patients with clinically active versus inactive disease Only one of five patients who were within a week of death was reactive Reactivity was detected as frequently with allogeneic as with autochthonous melanoma target cells Serum blocking factor (SBF), capable of inhibiting in vitro cell-mediated reactivity to melanoma tumor cells, was assayed in serum from melanoma patients at various stages of disease SBF was detected at some time in 30% of patients with local, 889% with regional, and 800% with widespread disease It was found in 429% of those with clinically inactive and 706% with active melanoma However, detection of SBF was found to fluctuate from sample to sample taken at different times during the course of disease in individual patients regardless of clinical status The importance of sequential determinations of SBF activity for patient assessment is stressed

The predictive value of mouse liver tumour induction in carcinogenicity testing--a literature survey.

Abstract: A survey of the available data in the literature was carried out in an attempt to verify the possible correlation between the capacity of a number of chemicals to induce parenchymal liver tumours in the mouse and their capacity to induce tumours in the liver and/or other organs in the rat and hamster. Data on 58 chemicals were collected. A positive correlation appears to exist between the capacity of a chemical to induce liver tumours in the mouse and its capacity to induce tumours at any site in the rat or the hamster. The strongest correlation is found when the chemical, given to adult mice, induces tumours of the liver and other sites in both sexes. The induction of liver tumours in the mouse by a chemical does not signify that the liver would be the target organ in the rat or the hamster. Among the 58 chemicals considered, seven are recognized or suspected human carcinogens. All were hepatocarcinogenic in the mouse and six were carcinogenic in the liver and/or other organs in the rat. Four were tested in the hamster and found to be carcinogenic.

Cellular and humoral immunity to rat hepatoma-specific antigens correlated with tumour status.

Abstract: Lymphocytes from rats bearing primary or transplanted aminoazo-dye-induced hepatomas were specifically cytotoxic for cells of the same tumour. Cytotoxic antibody was not present in the serum of these animals, although humoral factors capable of abrogating lymph-node cell-mediated cytotoxicity in vitro were detected. Following excision of transplanted hepatomas, cytotoxic lymph-node cells were still demonstrable, with slightly increased reactivities comparable to those detected in a previous study of repeatedly immunized rats. Cytotoxic antibody was present in serum after tumour excision, and this correlates with the loss of serum blocking activity for lymph-node cell-mediated cytotoxic effects. In comparison, serum from rats repeatedly immunized to hepatomas, where high levels of cytotoxic antibody are also present, blocks lymph-node cell-mediated reactions in vitro, despite the immune status of the donor. These considerations suggest qualitative differences between the blocking factors in the serum of tumour-bearer and tumour-immune hosts, the former being antigen-antibody complexes, and the latter free antibody.

Inhibition of lymphocyte cytotoxicity for human colon carcinoma by treatment with solubilized tumour membrane fractions.

Abstract: The in vitro cytotoxic action of patients' lymphocytes against colon carcinoma cells was evaluated following incubation of the lymphocytes with papain-solubilized tumour-membrane preparations. Soluble extracts of pooled colon carcinomas inhibited cytotoxicity by sensitized lymphocytes, but similar extracts of normal colon or melanoma had no inhibitory effect. The results suggest that soluble tumour antigen may play a role in abolishing lymphocyte reactivity, and this is interpreted as supporting the concept that cellular immunity against tumours in vivo may be inhibited by circulating antigen.

Cell-mediated and humoral immune reactions to human tumours.

Abstract: Peripheral lymphocytes from cancer patients were tested for immune reactivity against cultured target cells derived from carcinomas of colon, rectum, breast, kidney and lung, and a melanoma by microcytotoxicity in plastic plates. Lymphocytes from colon or rectum carcinoma patients were cytotoxic for allogeneic colon or rectum carcinoma cells in 61% of tests, and no difference in reactivity could be detected between pre- or post-operative patients. Breast carcinoma patients' lymphocytes were cytotoxic for breast carcinoma cells in 50% of cases tested. Autochthonous lymphocytes were reactive against melanoma cells, but no lymphocyte cytotoxicity could be demonstrated on cells of a renal carcinoma or a lung carcinoma. None of the lymphocyte preparations tested reacted positively against cells of a tumour different from that of the lymphocyte donor, and none reacted against cells from normal colon. Complement-dependent cytotoxic humoral antibody was regularly detected against breast carcinomas, but only one sample of colon carcinoma serum, from a post-operative patient, was reactive against colon carcinoma cells. Sera from melanoma patients likewise were only reactive against melanoma cells in two post-operative cases.

Possible role of 6-hydroxymethylbenzo[a]pyrene as a proximate carcinogen of benzo[a]pyrene and 6-methylbenzo[a]pyrene†

Abstract: Benzo[a]pyrene (B[a]P) and 6-methylbenzo[a]pyrene ( 6-MeB[a]P) are metabolized by fortified rat-liver homogenates to a number of metabolites including one which is indistinguishable from 6-hydroxymethylbenzo[a]pyrene (6–OHMeB[a]P) by either thin-layer chromatography or ultra-violet absorption spectra. This compound is a potent carcinogen when administered by subcutaneous injection to rats. These observations are in accord with the hypothesis that methylation or hydroxymethylation is one of the first steps in metabolic activation of carcinogenic polycyclic hydrocarbons.

Metabolism of the carcinogenic hydrocarbon benzo(a)pyrene in human fibroblast and epithelial cells.

Abstract: Metabolism of the carcinogenic hydrocarbon benzo(a)pyrene (BP) to water and alkali-soluble products was measured in cultured fibroblast and epithelial cells from human embryos. The alkali-soluble products represented only a small fraction of BP metabolism. Fibroblasts from different organs from the same embryo metabolized similar amounts of BP, while those derived from different embryos can metabolize different amounts. The fibroblasts were divided into three groups which metabolized an average of 350, 850 and 3,400 μμmoles of water soluble products/106cells/3 days. No significant differences were found in relationship to the age of the embryos from 2.5 to 5 months. Fibroblasts from the endometrium of adult women metabolized less than embryonic fibroblasts. Cultures which contained more than 20% epithelial cells metabolized 3–25 times more BP than fibroblast cultures from the same embryo. Epithelial cells from different embryos also varied in the degree of BP metabolism and low epithelial activity was not necessarily associated with low fibroblast activity in the same embryo. It is suggested that there is a genetic heterogeneity in BP metabolism in fibroblast and epithelial cells, and that the higher activity of epithelial cells might be related to the higher incidence of carcinomas rather than sarcomas in humans.

Some international differences in histology and survival in breast cancer.

Abstract: Survival rates for patients with breast cancer have been reported to be higher in Japan than in the United States. It has also been reported that histologic features associated with more favorable survival are more frequent in Tokyo than in the United States. In this report data are presented on the question of whether differences in breast cancer histology could account for the differences in survival rate between Tokyo and two western areas–Boston, USA, and Glamorgan, Wales. Intraductal carcinoma was found to be most frequent in Tokyo and least frequent in Boston, but survival differences between the two cities were found when non-invasive cases were excluded. Low (relatively malignant) nuclear grade was observed most often in Glamorgan; there was little difference in frequency of this characteristic between Boston and Tokyo. Since nuclear-grade specific survival ratios were highest in Tokyo, this histologic feature also does not account for the better survival experience of Japanese patients. Tumors of medullary histologic type and those with high degrees of lymphoid infiltration were most frequent in Japan and least frequent in Boston. However, the relationships of histologic type and lymphoid infiltrate to survival were not consistent in the three areas, and the higher survival ratio of the Japanese patients could not be related to these characteristics.

Increase of lymphocyte-mediated tumor-cell destruction by certain patient sera.

Abstract: Sera from one patient with an ovarian carcinoma, one with sarcoma, one with a breast carcinoma, and four patients with melanoma were found to “potentiate” (i.e. increase) the cytotoxic effect of blood lymphocytes reactive to the respective type of tumor target cells. This effect was specific. Furthermore, sera from the breast cancer and sarcoma patients and from one of the melanoma patients “armed” (i.e. made cytotoxic) lymphocytes from non-reactive donors, not having (had) the respective tumor studied. The possible relevance, in vivo, of these findings, and the frequency with which they occur, need further clarification.

Cell locomotion and contact inhibition of normal and neoplastic rat cells.

Abstract: The morphology, locomotion and contact inhibition of locomotion of normal and neoplastic rat cells were studied in relation to oncogenicity Embryonic fibroblasts (LWF) and a spontaneously neoplastic variant (LW13) were both fibroblastic in appearance, with a monolayered arrangement of cells at moderate densities A variant transformed by Rous sarcoma virus (RsK4) was epithelioid and was also well monolayered Scanning electron microscopy revealed a smooth dorsal surface on LWF cells, microvilli on the dorsal surface of LW13 cells and numerous microvilli, blebs and ruffles over the entire surface of RsK4 cells LWF cells and LW13 cells moved with broad fan-shaped lamellae on which lamellipodia (ruffles) arose at the leading edge These cells showed polarized locomotion and migrated rapidly into wounds made in confluent cultures RsK4 cells neither possessed large, fan-shaped lamellae nor showed polarized movement They did not invade wounds efficiently After treatment with colcemid LWF and LW13 cells resembled RsK4 cells more closely and lost polarity of movement On analysis of cell collisions by time-lapse cinemicrography, the three cell types showed pronounced homotypic contact inhibition of cell locomotion, as judged by cessation of forward displacement LWF and LW13 cells exhibited paralysis of ruffling, contraction of the leading edge, cell to cell adhesion and inhibition of pinocytosis typical of contact inhibition between fibroblasts Paralysis and contraction were not evident in RsK4 cell collisions Colcemid treatment did not prevent the initiation of contact inhibition but reduced the lasting paralysis of LWF and LW13 cells In collisions between tumour cells and normal cells, cell locomotion and membrane ruffling were inhibited in the normal cells but not in the tumour cells Such non-reciprocal contact inhibition resulted in apparent monolayering in mixed cultures The loss of contact inhibitory responses of neoplastic cells to normal cells appears to be more closely related to oncogenicity than are homotypic contact inhibition and cellular morphology The contact inhibitory stimuli of certain neoplastic cells differ from those of normal fibroblasts, and may be preserved by fixation with glutaraldehyde

Influence of cultivation, trypsinization and aggregation on the transplantability of melanoma B16 cells.

Abstract: To elucidate the usefulness of tumour cells grown in vitro for transplantation studies, Melanoma B16 was grown in monolayer culture. Three types of suspensions were prepared from the cell cultures: two virtually monocellular suspensions, one produced by mechanical procedures and Versene (CV), the other with the addition of trypsinization (CTV); a third suspension containing cell aggregates (CVA) was produced by centrifuging a CV suspension. For comparison, a well-dissociated suspension of solid tumor origin was prepared by a trypsin-Versene procedure (STV). All suspensions were characterized with regard to dissociation grade, cell volumes and cellular electrophoretic mobility and were transplanted in graded cell doses subcutaneously, intraperitoneally and intravenously. While inoculum-doses needed for progressive growth were lower IP than SC, the transplantabilities were similar in these sites for all suspensions, indicating similar viabilities and absence of major dilution errors. The growth patterns for IV infused cells exhibited significant differences between the suspensions. CV cells gave rise to lung tumours almost exclusively, while CVA animals, in addition to a large total lung tumour volume, had some extrapulmonary takes. CTV had the greatest number of extrapulmonary tumours, but in combination with small lung tumours, STV cell recipients were intermediate with respect to pulmonary as well as extrapulmonary tumours. These observations were collated with data regarding aggregation, cell volumes and electrophoretic mobility. It was concluded that (1) cultivated tumour cells can have similar transplantation characteristics to the tumour of origin; (2) such cells may be useful in tumour dissemination studies; (3) trypsinization as well as the presence of cell aggregates affects the growth pattern of IV infused tumour cells by yielding an increased extrapulmonary tumour crop.

BCG immunotherapy of local subcutaneous growths and post-surgical pulmonary metastases of a transplanted rat epithelioma of spontaneous origin

Abstract: The potential value of BCG immunotherapy in the treatment of pulmonary metastases had been evaluated using a weakly immunogenic transplanted rat epithelioma. Subcutaneous injection of tumour cells in admixture with viable BCG retarded tumour development at this site and reduced the development of pulmonary metastases. Partial control of metastatic disease following surgical removal of subcutaneous tumour was obtained by intravenous injection of BCG, the main response being an increase in survival and reduction in the number of pulmonary metastases. Treatment was not rendered more effective by concomitant immunostimulation with irradiated tumour cells in admixture with BCG. These studies illustrate the potential of BCG adjuvant therapy, but support the concept that localization of BCG at the tumour site is a necessary requirement for effective tumour suppression.

Effects of BCG on various facets of the immune response against polyoma tumors in rats.

Abstract: Administration of BCG at the time of rat polyoma tumor isografting or 2 weeks previously, inhibited tumor growth and induced an increased level of lymphocyte cytotoxicity and an increase in the number of circulating lymphocytes, i.e. it resulted in an increased level of cell-mediated immunity. A similar inoculation of BCG at the time when the tumor isograft had already grown out to a palpable nodule did not inhibit tumor growth, but rather caused an enhanced growth. It did not increase the level of cell-mediated immunity under these conditions and did not decrease the blocking activity in serum, but rather increased it. Furthermore, it did not induce any production of cytotoxic antibodies detectable with rat complement. BCG treatment of rats which had the same day undergone incomplete tumor excision increased the growth of remaining tumor and increased the blocking activity in serum. On the other hand, BCG treatment of analogous rats which had received “unblocking treatment” in the form of splenectomy and inoculation of unblocking serum caused tumor regression in some animals and increased the cell-mediated immunity in all animals tested.

Histologic characteristics of breast cancer in Boston and Tokyo.

Abstract: Histologic slides from representative series of breast cancer patients in Boston, where the incidence rate of breast cancer is high, and in Tokyo, where the incidence rate is low, were reviewed by pathologists who did not know the city of origin of the material. Intraductal, medullary and colloid histologic types were relatively more frequent in Tokyo. Also more frequent in Tokyo were tumors with circumscribed margins and a high degree of cellular reaction. Tumors of small-cell or invasive ductal histologic type and tumors with a high degree of fibrosis were more frequent in Boston than in Tokyo.