Showing papers in "International Journal of Cancer in 1980"

Establishment and characterization of a human acute monocytic leukemia cell line (THP‐1)

Abstract: A human leukemic cell line (THP-1) cultured from the blood of a boy with acute monocytic leukemia is described. This cell line had Fc and C3b receptors, but no surface or cytoplasmic immunoglobulins. HLA haplotypes of THP-1 were HLA-A2, -A9, -B5, -DRW1 and -DRW2. The monocytic nature of the cell line was characterized by: (1) the presence of alpha-naphthyl butyrate esterase activities which could be inhibited by NaF; (2) lysozyme production; (3) the phagocytosis of latex particles and sensitized sheep erythrocytes; and (4) the ability to restore T-lymphocyte response to Con A. The cells did not possess Epstein-Barr virus-associated nuclear antigen. These results indicate that THP-1 is a leukemia cell line with distinct monocytic markers. During culture, THP-1 maintained these monocytic characteristics for over 14 months.

Induction of morphological and functional differentiation of human promyelocytic leukemia cells (HL-60) by componuds which induce differentiation of murine leukemia cells.

Abstract: Various compounds active in promoting in vitro differentiation of certain murine leukemia cell lines (Friend erythroleukemia cells and mouse myeloid leukemia cells) were tested for their capacity to induce differentiation of HL-60 cells, a human promyelocytic leukemia cell line capable of terminally differentiating in vitro to functionally mature granulocytes. Polar planar compounds including hexamethylene bisacetamide (HMBA), certain purines (particularly hypoxanthine), and actinomycin-D induced morphological and functional (as assessed by the capacity to reduce NBT dye) differentiation of HL-60. In contrast, hemin, ouabain, prostaglandin E1, X-irradiation, dexamethasone and some other anti-leukemic chemotherapeutic agents induced little if any significant differentiation of HL-60 cells. These results, together with previous observations with murine leukemia cells, suggest that the human HL-60 cells share common cellular target sites for the inducing action of polar planar compounds, hypoxanthine and actinomycin-D with some murine leukemic cells. In contrast, hemin, ouabain and prostaglandin E1 may be specific for mouse erythroleukemia cells, while X-irradiation and chemotherapeutic agents induce differentiation of both types (erythroid and myeloid) of mouse leukemic cells, but have little effect on HL-60 cells.

A case-control study of diet and colo-rectal cancer.

Abstract: A case-control study of cancer of the colon and rectum has been conducted in Calgary, Alberta and Toronto, Ontario, Canada. A total of 348 cases of cancer of the colon and 194 cases of cancer of the rectum were individually matched by age, sex and neighbourhood of residence to 542 population controls and frequency matched to 535 hospital controls who had undergone an abdominal operation. Each subject received a personal medical history questionnaire and a quantitative diet history questionnaire. Data on a number of potential non-nutrient risk factors for bowel cancer and on the consumption of 9 nutrients in the 2-month period up to 6 months before interview were analysed. The dietary data thus refer to recent diet consumed in a period antedating the diagnosis of, and in most cases symptoms from, large-bowel cancer in the cases, and a corresponding time period in the controls. The major findings were an elevated risk for those with a history of bowel polyps, and for those with an elevated intake of calories, total fat, total protein, saturated fat, oleic acid and cholesterol. No association was seen with an elevated intake of crude fibre, Vitamin C and linoleic acid. The nutrients for which an increased risk was demonstrated were highly correlated, though multivariate analysis using logistic regression indicated highest risk for saturated fat, with evidence of a dose-response relationship. The findings in both cancer sites, both sexes and with both sets of controls were quantitatively very similar. The population-attributable risk for colon and rectal cancer combined was estimated from the neighbourhood controls to be 41% for males and 44% for females for saturated fat intake and 9.8% and 6.4% respectively for any history of polyps.

Partial characterization of viral DNA from human genital warts (condylomata acuminata)

Abstract: By centrifuging total cellular DNA derived from human genital warts (condylomata acuminata) in CsCl-ethidium bromide gradients, supercoiled DNA was isolated. The molecular weight of this DNA was determined by agarose gel electrophoresis and amounted to 5.1 X 10(4). This DNA isolated from an individual genital wart was annealed to fractions of aqueous supernatants of the same wart after prior centrifugation of this material in CsCl density gradients. Annealing was observed at a density of approximately 1.32 g/ml corresponding to the expected density of papilloma virus particles. Since such particles were also observed in the same preparation by electron microscopy, it was concluded that the supercoiled DNA molecules were derived from papilloma virus nucleocapsids. Positive hybridization was found with six additional preparations from individual genital warts. Therefore, it seems that the isolated DNA prevails in condylomata acuminata. The DNA is different from the other five types of human papilloma viruses described thus far in regard to its restriction endonuclease cleavage patterns. The virus analyzed is tentatively designated as human papilloma virus type 6 (HPV 6).

Patterns of gastro‐intestinal cancer in european migrants to Australia: The role of dietary change

Abstract: Cancers of the stomach, pancreas, colon and rectum are increasingly regarded as being diet-influenced. Migrants to Australia from England, Scotland, Ireland, Poland, Yugoslavia, Greece, and Italy have come from countries with varied dietary backgrounds and gastrointestinal cancer risks. Age-standardized cancer death rates in migrrants, by country of origin, sex, age, and duration of residence in Australia (less than or equal to 16 years and greater than 16 years), have been calculated for 1962-76, and compared with those of the Australian-born population. All seven migrant source countries, in 1970, had higher rates of stomach cancer than Australia, and the corresponding migrants groups, which initially reflected those higher rates, experienced an approximately 25% risk reduction with increased duration of residence. For cancer of the pancreas, migrants initially had rates well above their "native" rates; with longer stay, the risks generally converged upon that of the Australian-born population. The four "continental" (European) migrant groups, whose native risk of colon cancer is about half that of the Australian population, showed an increased risk with increasing duration of stay. The increase was greater in men than in women, perhaps reflecting their greater dietary acculturation. By contrast, Scottish migrants, with an initially high risk of cigrants showed even larger increases than colon cancer, while in British migrants there was a marked decline towards the "Australian-borne" risk. These various changes in cancer risk are discussed with reference to inter-country dietary differences.

Kaposi's sarcoma and its relationship to cytomegalovirus (CMNV). III. CMV DNA and CMV early antigens in Kaposi's sarcoma.

Abstract: DNA-DNA reassociation kinetics, anti-complement immunofluorescence (ACIF) and ACIF-blocking tests were used to search for cytomegalovirus (CMV) gene products in Kaposi's sarcoma (DS) biopsies and early cell cultures deriving from them. Three of eight tumor biopsies were positive for CMV DNA; two of them at 0.35 genome/cell and one at one copy 25% genome/cell. CMV-related antigens, mainly localized in the nucleus, were found in cryostat sections of seven of 31 tumor biopsies and four of 12 KS cell lines at early passage level. It appears that the antigen is present in a high number of tumor cells, like the Epstein-Barr virus nuclear antigen (EBNA) in EBV-transformed cells. Inevitably, the increasing data concerning the oncogenic potential of CMV lead on to consideration of the increasing evidence of its association with Kaposi's sarcoma, a multiple hemorrhagic sarcoma with an epidemiologic distribution in Africa similar to that of Burkitt's lymphoma.

Metastatic tumor cells adhere preferentially to the extracellular matrix underlying vascular endothelial cells

Abstract: Two metastatic cell lines, mouse B16-Fl melanoma and human Hs939 melanoma, were examined for their abilities to adhere to confluent vascular endothelial cell monolayers and to the underlying endothelial extracellular matrix. Tumor cells attached slowly to the endothelial cell monolayers while they adhered rapidly to isolated extracellular matrix. When analyzed by poly-acrylamide gel electrophoresis in sodium dodecylsulfate solutions, the extracellular matrix was shown to be primarily composed of a protein of identical migration and molecular weight to fibronectin. Tumor-cell adhesion to fibronectin-coated polyvinyl surfaces mimicked the rapid rate of attachment of tumor cells to extracellular matrix, and tumor cells adherent to either extracellular matrix or fibronectin-coated polyvinyl dishes adopted an unusual, highly spread and flattened morphology with numerous small projections. These results suggest that fibronectin associated with the endothelial basement membrane may be, in part, responsible for establishing an adhesive gradient that could be important in malignant cell extravasation.

Establishment of a cell line (NPC/HK1) from a differentiated squamous carcinoma of the nasopharynx.

Abstract: A long-term cell culture epithelioid cell line was established from a recurrent squamous carcinoma of the nasopharynx of a Chinese male 17 1/2 years after radiation therapy. The cell line, designated NPC/HK1, has been passed 72 times over a period 1 year. The cells have been shown by light and electron microscopies to be of the squamous epithelial type. When they were transplanted subcutaneously into the back of athymic nude BALB/c (nu/nu) mice, tumors developed at the sites of inoculation, which on histological examination were shown to be well-differentiated squamous carcinomas, similar in morphology to the recurrent human tumor from which they were derived. Karyotypic analysis of cells from the cell line demonstrates an aneuploid human type with a modal chromosome number of 74 with both numerical and structural aberrations. Viral particles or Epstein-Barr viral nuclear antigen (EBNA) has not been demonstrated in the cells from the primary culture or several of the subcultures tested. The presence of EBNA in touch smears prepared from the biopsy tissue was inconclusive. Infection of the subcultured cells with EBV from P3HR1 and B95-8 cells was unsuccessful.

A comparative study of eight cell lines derived from human testicular teratocarcinoma

Abstract: Eight independent cell lines, derived from human testicular germ-cell tumors, were examined for the expression of various markers. These included major histocompatibility and embryonic antigens, chorionic gonadotropin, alpha fetoprotein, alkaline phosphatase, plasminogen activator, and infectivity by SV40. No line consisted primarily of choriocarcinoma or yolk sac cells, but several contained cells resembling murine embryonal carcinoma; some of these lines formed tumors with the distinctive features of embryonal carcinoma when injected into immunosuppressed animals. It is proposed that human embryonal carcinoma cells, unlike those of the mouse, correspond to a preblastocyst stage of development.

Expression of metastatic potential of tumor cells in young nude mice is correlated with low levels of natural killer cell-mediated cytotoxicity.

Abstract: Of 6- and 3-week-old nude mice given intravenous injections of murine tumor cells with well-defined metastatic properties, only the 3-week-old mice developed lung tumor colonies in significant numbers. The quantitative differences in metastatic potential among tumor cell lines injected into syngeneic recipients were also maintained following intravenous injection into young nude mice. Successful metastasis in 3-week-old nude mice is correlated with the low levels of natural killer cell activity detected in these young recipients. Boosting of the natural killer cell activity of 3-week-old nude mice by the administration of bacterial adjuvants and interferon inducers significantly inhibited metastasis formation. The differences in metastasis development could not be attributed to differences in the initial arrest of tumor cells in the pulmonary vascular bed, but rather to a better survival of the arrested cells in the lungs of 3-weeks-old nude mice as compared with 6-week-old counterparts. We concluded that low levels of NK cell activity are associated with increased incidence of experimental metastasis.

In vivo natural reactivity of mice against tumor cells.

Abstract: A rapid in vivo clearance of tumor cells was found in normal mice following intravenous inoculation of [125l]dUrd-labelled YAC-1 and RBL-5 cultured cell lines derived from lymphomas. The ability of mice to eliminate tumor cells from spleen, liver and lungs during the first 4 h, as evaluated by the recovery of radioactivity in these organs, was found to correlate with the level of natural killer (NK) cell reactivity in their spleen and lungs, as measured simultaneously in vitro in a shortterm 51Cr release assay (CRA). Lower recovery of radioactivity was found in mouse strains with high spontaneous levels of NK activity. The degree of clearance was also found to be age-dependent and older mice of several strains, whose NK activity had declined to low levels, were less effective in eliminating tumor cells. In vivo treatment with interferon and interferon inducers (poly I:C, pyran copolymer, Corynebacterium parvum, murine sarcoma virus) increased the levels of NK activity in the spleen and lungs and also augmented the in vivo clearance of tumor cells from the lungs and liver. Immunopharmacological treatments with antimacrophage agents (silica, iota-carrageenan, Seakem-carrageenan), antineoplastic drugs (dexamethasone, cyclophosphamide, 5-(3,-3′dimethyl-I-triazeno)-imidazole-4-carboxamide, 4-amino-L-D-arabinofuranosyl-2-(IH)-pyrimidone, adriamycin) or irradiation (850 R γ-ray) had comparable effects on both in vitro cytolytic activity and in vivo clearance of tumor cells. When the susceptibility to in vitro and in vivocytotoxicity by several other tumors was examined, the lines with detectable sensitivity to lysis by NK cells were found to be cleared in vivo to a greater degree in a high NK strain (CBA) than in a low NK strain (SJL). In contrast, NK-resistant lines were cleared at approximately the same rate in both strains. However, the actual levels of in vivo clearance and the degree of difference between the strains for the various NK-sensitive lines did not correlate well with their relative sensitivities to lysis in vitro. In the various situations in which the in vivo recovery of a particular NK-sensitive line was studied relative to the levels of NK reactivity in the recipients, the best correlations were seen with clearance from the lungs. In several instances, clearance from the spleen did not correlate well with splenic NK activity. These data indicate that rapid in vivo clearance of radiolabelled NK-sensitive tumor cell lines is appreciably influenced by levels of NK reactivity, but that other factors are probably also involved.

Characterization of a serum factor stimulating the differentiation of myelomonocytic leukemic cells.

Abstract: Culture of WEHI-3B myelomonocytic leukemic cells in semi-solid agar medium containing serum from mice injected with endotoxin serum (ES) led to the development of maturing granulocytes and macrophages in most leukemic colonies. ES contains high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), a regulator known to stimulate differentiation of these leukemic cells, but an antiserum which neutralized greater than 85% of the GM-CSF in ES did not suppress the differentiation-inducing activity of ES on WEHI-3B cells. The active factor in endotoxin serum stimulating differentiation in WEHI-3B leukemic cells (GM-DF) was separated from most of the GM-CSF by gel filtration using Ultrogel AcA44. The residual CSF associated with the GM-DF appeared to stimulate selectively granulocytic colonies. Disproportionation of GM-DF and GM-CSF was observed in ES fractions obtained using concanavalin-A/Sepharose chromatography: none of the GM-DF bound to this matrix, whereas 40% of the GM-CSF bound and was eluted with competing alpha methylglucopyranoside. Although no separation of GM-CSF and GM-DF was obtained using DEAE-Sepharose, non-isoelectric focusing in amphoteric buffers indicated charge differences between the differentiation factor and several sub-species of GM-CSF. Sequential purification of GM-DF from ES using 40 - 70% ammonium sulfate precipitation gel filtration and phenyl-Sepharose chromatography resulted in a 25-fold purification. In all fractionation procedures used, a sub-species of GM-CSF, stimulating granulocyte colony formation, was consistently associated with partially purified GM-DF, but some subspecies of GM-CSF clearly lacked any capacity to induce differentiation in the leukemic cells. The observations suggest that the factor in post-endotoxin serum most efficient in enforcing differentiation in myelomonocytic leukemic cells may be a subset of GM-CSF molecules with a selective capacity to stimulate granulocyte colony formation by normal cells.

Characterization of a human ovarian teratocarcinoma‐derived cell line

Abstract: A cell line (PA I), derived from human ovarian teratocarcinoma cells, was obtained by culturing ascitic fluid cells from a patient with recurrence of malignant ovarian teratoma. During early passages the cultured cells showed a variable morphology, a long doubling time, and a low plating efficiency (2%). After about 50 passages in vitro, a cell population which was more homogeneous and resembled embryonal carcinoma cells were obtained. These cells had a shorter doubling time (26 h), and increased plating efficiency (77%). The early-passage cells were aneuploid (P 24) whereas the late-passage cells had a normal diploid karyotype with one balanced translocation between chromosomes No. 15 and No. 20 (P 224). Details of the karyotype suggest that the cells are heterozygous, i.e. derived from a stage before the first meiotic division. One of the two X chromosomes were inactive, and the cells expressed HLA antigens (A28 and B12), and beta 2-microglobulin. Expression of F9 antigen, characteristic of two-cell and later preimplantation embryos, was absent, while expression of PCC4 antigen, expressed also by blastocysts, was present. This finding suggests that the line might express some embryonic characteristics. The PA I cell line maintained in monolayer cultures showed several characteristics of malignant cells. The proportion of malignant cells increased with successive passages in vitro. The late-passage cells represented a fairly homogenous population of malignant cells similar to embryonal carcinoma cells. Late-passage PA I cells, when seeded under conditions that prevented attachment of cells to the substratum, formed embryoid bodies consisting of an inner core of cells similar to embryonal carcinoma cells, surrounded by a rind of endoderm-like cells. These two cell layers were separated by a basement membrane-like structure containing fibronectin. The core embryonal carcinoma cells expressed high alkaline phosphatase activity whereas the endoderm-like cells had low alkaline phosphatase activity. Embryoid bodies seeded on an adhesive substratum formed polycystic structures divided by layers of epithelial-like cells and containing extracellular fibrils similar to collagen type I or III. In these cultures, further limited differentiation into endoderm-like, epithelial-like cells and pigmented cells was observed. Morphological differenciation of undifferentiated PA I cells into endoderm-like cells in monolayer cultures could be obtained by treatment with BrdUrd or by plating in low serum concentration and at low density. Cells with characteristic fibrillar distribution of fibronectin and actin microfilament bundles were then observed, indicating formation of cells lacking properties of malignant cells. As indicated by these results, the PA I cell line, in spite of a limited capacity to differentiate in vitro, shares some of the properties of mouse teratocarcinoma cell lines and might therefore serve as a useful model for studies on some developmental mechanisms in human cells.

Human cell line (COLO 357) of metastatic pancreatic adenocarcinoma

Abstract: A continuous human cell line, COLO 357, with exceptional characteristics was derived from a metastasis of a pancreatic adenocarcinoma. COLO 357 grew as an adhering monolayer with a cell doubling time of 21 h and grew with 10% clonal efficiency in soft agar. COLO 357 cells had numerous lamellar inclusions. The cells elaborated the pancreatic enzymes trypsin, elastase and chymotrypsin. COLO 357 also secreted appreciable amounts of carcinoembryonic antigen and human chorionic gonadotropin. COLO 357 had a chromosome mode of 53 with 20 identifiable Giemsa-banded marker chromosomes. Nine nucleolar organizing regions were found by silver-stained metaphase preparations. COLO 357 has been "fingerprinted" for seven allelic isozymes. This cell line has been maintained in active culture for over 2 years, is preserved in a cell bank, and is available to other investigators.

Epidemiology of pre-invasive and invasive malignant melanoma in Western Australia.

Abstract: The annual incidence rates of melanoma in Western Australia in 1975 and 1976 were estimated, by reference to hospital and pathology records. They were 4.4/ 100,000 in males and 6.2/100,000 in females for pre-invasive lesions and 18.6/100,000 and 18.8/100,000 for invasive lesions. Rates specific to particular body sites showed two distinct patterns of change with age - a progressive rise beginning about age 40 years (shown by Hutchinson's melanotic freckle and invasive melanoma of the head and neck) and an early rise beginning about age 20 years with a peak in middle-life and subsequent stabilization or decline (shown by superficial spreading melanoma, non-invasive and invasive melanoma of the lower limbs and, less typically, trunk and upper limbs). Incidence rates were highest in native-born Australians and higher in immigrants of British origin than in other immigrants. The rates in British immigrants were more than double those in the British Isles. The incidence was highest in residents of high social class areas, and in in-door rather than outdoor workers. Rates were also highest in the capital city, Perth, and the south-west corner of the State, rather than in the north where exposure of the population to ultra-violet light might be expected to be highest. In most of these respects the patterns for pre-invasive and invasive lesions were similar. Aspects of these data are inconsistent with the solar hypothesis of melanoma aetiology. It is suggested, however, that some of these inconsistencies may be explained if intermittent, intense exposure to the sun were more relevant to the aetiology of melanoma than continuous exposure.

Two neoplastic cell lines with unique features derived from Hodgkin's disease.

Abstract: Two in vitro cell lines (L428, L439) were established from pleural effusions of two patients with Hodgkin's disease. The histological diagnosis was ascertained in both cases by two independent pathologists. The neoplastic nature of the culture cells is indicated by the demonstration of several structural and numerical chromosome abnormalities associated with a monoclonal pattern of marker chromosomes. Heterotransplantation in nude mice was achieved by intracranial inoculation and by subcutaneous transplantation of cultured cells embedded in a plasma clot. EBV-specific antigens (EBNA, VCA) were not detectable in either cell line. la-like antigens, receptors for T cells, acid phosphatase and acid esterase were shown to be present in the cultured cells. The L428 and L439 cell line lacked surface- or cytoplasmic 1g, HTLA, receptors for C3b, C3d, 1gG-Fc, mouse E or sheep E, and were devoid of lysozyme, peroxidase and chloracetate esterase. These features do not correspond to those of B cells, T cells, myeloid cells, monocytes or macrophages; the morphology and the marker pattern of the culture cells, however, is identical with that of freshly obtained Hodgkin (H)- and Sternberg-reed (SR)- cells, except for the lack of C1g in the in vitro cells, which is explained by the culture conditions. These findings suggest that the L428 and L439 cell lines are indeed derived from H- and Sr-cells and offer the possibility of gaining new information upon the nature of Hodgkin's disease.

A prospective study on the development of hepatocellular carcinoma from liver cirrhosis with persistent hepatitis B virus infection.

Abstract: We made a prospective study on the development of hepatocellular carcinoma (HCC) in patients with liver cirrhosis with hepatitis B virus infection from April, 1973 to December, 1977. Seven out of 30 patients (23%) with hepatitis B surface antigen (HBsAg)-positive cirrhosis developed HCC. On the other hand, only 5.9% of the patients with HBsAg-negative liver cirrhosis developed HCC. These patients were classified into three groups according to their anti-HB core (anti-HBc) titers. When the anti-HBc titer, expressed as a dilution of serum, was 2(10) or more (Group I), 20-24% of the liver cirrhosis patients developed HCC either with or without a detectable amount of HBs Ag present in the sera. When the anti-HBc titer was 2(9) or less (Group II), only 0-5.7% developed HCC. There was no significant difference between this and the anti-HBc and HBsAg-negative group (Group III), which was 4.4%. In five individual cases from group I, HBsAg was detected in serum, and in biopsies of liver cells, before HCC could be detected by angiography and/or rising levels of alphafetoprotein (AFP). In all of these cases, the anti-HBc titer was higher than 2(10) throughout the observation period, even before the development of HCC. These findings indicate that active virus proliferation in chronic hepatitis B virus infection precedes the development of HCC as indicated by a higher anti-HBc titer. Therefore we have prepared these studies to show the pathogenic role of hepatitis B virus in the development of hepatocellular carcinoma.

Cervical carcinoma: detection of herpes simplex virus RNA in cells undergoing neoplastic change.

Abstract: 3H-HSV-2 DNA has been hybridized in situ to frozen sectioned tissue from human cervical biopsies. RNA complementary to the virus-specific probe was detected in cells undergoing pre-malignant changes, but not in the cells of the fully developed squamous-cell cancer.

Cancer cell traffic from the lungs to the liver: an example of metastatic inefficiency.

Abstract: It is probable that metastasis is an inefficient process in terms of cancer cells. One cause of this inefficiency may be that cancer cells temporarily arrested in one organ are «processed» by it, so that they die before or shortly after arrival in another organ. In the present experiments, the lung-to-liver traffic of [125I]dUrd-labelled W-256 cancer cells is examined over the course of 27 h in tumor-bearing and non-tumor-bearing rats, following injection into, and sampling from, various points in the cardiovascular system. Following tail-vein injections, W-256 are temporarily arrested in the lungs and slowly released; some of the released cells are then temporarily arrested in the liver. Two percent of the cells detected in the lungs are non-viable compared with approximately half of those in the liver; these measurements of viability correlate with a higher (10:I) incidence of lung transplants over liver transplants, and with the observation that extrapulmonary metastases are uncommon with this tumor. Direct injections of cancer cells into the liver indicate that the reduced viability of cancer cells at this site is not due to an inherently hostile hepatic environment. Injections into and sampling from, other sites indicate that only small proportions of cells were killed on their way to the lungs, during their arrest in the pulmonary capillaries and arterioles, or between the left ventricle, aorta, hepatic artery and liver. Pretreatment of W-256 cells with neuraminidase, which is expected to make them more deformable, did not affect the viability of cells in the liver, thereby arguing against «processing» occurring during transit in the pulmonary circulation distal to the initial arrest sites. By a process of elimination it is concluded that a significant amount of trauma resulting in cancer cell death occurs during the events culminating in their release from temporary arrest sites at the pulmonary vascular endothelium. As the lungs are commonly the first organ encountered by circulating tumor cells, it is suggested that the low viability of cells released from the lungs contributes to metatastic inefficiency.

Separation of different molecular forms of macrophage- and granulocyte-inducing proteins for normal and leukemic myeloid cells.

Abstract: It is shown that serum of mice treated with endotoxin (ES) contains three separable and functionally distinct forms of macrophage- and granulocyte-inducing (MGI) proteins. One form (MGI-1M) induced the formation of macrophage colonies from normal bone-marrow cells and showed on gel filtration an apparent molecular weight of 300,000; a second form (MGI-1G) induced the formation of granulocyte colonies from normal bone-marrow cells and had an apparent molecular weight of 45-100,000; and the third form (MGI-2) induced the normal differentiation of MGI+D+ myeloid leukemic cells to macrophages and granulocytes and had an apparent molecular weight of 28,000. Studies on the time course of the decrease of these three activities in ES have indicated that MGI-2 was more readily inactivated in vivo than MGI-1M and MGI-1G. The MGI-1M in ES isolated after gel filtration was completely neutralized by an antiserum to MGI-1 from mouse L-cells, whereas the isolated MGI-1G and MGI-2 were not affected by this antiserum. Gel filtration under dissociating conditions (6 M guanidinium chloride) resulted in a reduction of the apparent molecular weights of MGI-1M from 300,000 to 42,000, and of MGI-1G from 45-100,000 to 28,000, while it produced no change in the 28,000 apparent molecular weight of MGI-2. Similar studies with conditioned medium produced in vitro from mouse lung and peritoneal macrophages showed that in these conditioned media, MGI-1 (both G and M) in the native form had an apparent molecular weight of 41,000 and MGI-2 of 24,000, and that both MGI-1 and 2 had an apparent molecular weight of 24,000 under dissociating conditions. The results indicate that MGI-1 exists in serum in vivo and in these conditioned media as aggregated proteins, whereas MGI-2 does not, and that macrophages and lung tissue are not the only source of the MGI proteins found in ES. It is suggested that all three forms of MGI activity are derived from one precursor protein; that only the MGI-2 form assayed on leukemic cells should be used for treatment based on the induction of normal cell differentiation in myeloid leukemia; and that MGI-2 may serve as a survey mechanism for inducing differentiation in myeloid leukemic cells that have lost their responsiveness to the MGI-1 molecules that control the viability, proliferation and differentiation of normal myeloblasts.

A possible correlation between the degree of karyotype aberrations and the rate of sister chromatid exchanges in lymphoma lines.

Abstract: The sister chromatid exchange (SCE) frequencies of six freshly established and two old cell lines derived from patients with lymphatic tumors or leukemia were compared to the SCE rates of lymphoblastoid cell lines of normal controls. All cell lines from malignant tumors displayed significantly higher SCE values than the control lines. In general, the SCE rates seem to be correlated to the number of chromosomal markers and the degree of karyotypic instability of each line.

Prognosis of stage I melanoma of the skin. Who collaborating centres for evaluation of methods of diagnosis and treatment of melanoma

Abstract: Prognosis of stage I melanoma of the skin was evaluated in 747 previously untreated patients observed by the WHO Collaborating Centres for Evaluation of Methods of Diagnosis and Treatment of Melanoma from September 1967 to September 1975. The mean follow-up period of these patients was 8.9 years. Sex, maximum diameter of melanoma, elevation on skin surface, histologic type, levels of invasion and maximum tumor thickness were found to be significantly related to survival when considered one by one. However, multifactorial analysis showed that sex and maximum thickness only had a significant impact on survival of stage I melanoma patients. The effect of sex was not evident in patients with maximum tumor thickness not exceeding 2 mm (81 % 5-year survival for males and 87% for females and a p value >0.05), while females did significantly better (p <10−4) when maximum thickness of primary was over 2 mm.

Metabolism of benzo[a]pyrene by cultured tracheobronchial tissues from mice, rats, hamsters, bovines and humans.

Abstract: The metabolism of benzo[a]pyrene (BP)4by cultured tracheobronchial tissues from different species - human, bovine, hamster, rat and mouse - has been investigated. The total metabolism, as measured by both organic solvent-extractable and water-soluble metabolites of BP, was substantial in the respiratory tract from humans and from animal species susceptible to the carcinogenic action of BP. The ratio of organic-extractable metabolites to water-soluble metabolites was greater than one in hamster, human and C57BI/6N mouse, but less than one in rat, bovine and DBA/2N mouse, suggesting that determination of both activation and deactivation pathways are important in assessing carcinogenic risk of a chemical. Sulphate esters and glutathione conjugates were the major water-soluble metabolites in all animal species; tetrols and diols were the major organic extractable metabolites. The level of trans-7,8-dihydro-7,8-dihydroxybenzo[a]pyrene, the proximate carcinogenic form of BP, was three times higher in C57BI/6N than in DBA/2N mouse trachea. Trans-9,10-dihydro-9,10-dihydroxybenzo[a]pyrene was the major metabolite formed by cultured hamster trachea. The binding levels of BP to cellular DNA were quite similar in all tissues, although slightly higher binding was observed in hamster trachea. Wide inter-individual variation in the binding of BP to DNA was seen in tissues from outbred species. The major BP-DNA adducts in all animal species were formed by interaction of benzo[a]pyrene diol-epoxide with the 2-amino group of deoxyguanosine. Both stereoisomeric forms of (±)-(7β,8α)-dihydroxy-(9α, 10α)-epoxy-7,8,9,10-tetrahydro-benzo[a]pyrene (BPDE I) reacted with deoxyguanosine, the (7R)-form being the most reactive. No difference in the relative distribution of the various adducts was seen between the species except in the CD rat, where BPDE-deoxyadenosine adducts accounted for 20% of the total modification. In cultured hamster trachea the persistence of the different adducts was similar. In conclusion, the metabolism of BP is qualitatively similar in tracheobronchial tissues from both humans and animal species in which BP has been experimentally shown to be carcinogenic.

Potential pre-screening for therapeutic agents that induce differentiation in human myeloid leukemia cells.

Abstract: A cultured line of human myeloid leukemic cells has been used, to test for the ability of compounds used in chemotherapy to induce partial or complete differentiation of these leukemic cells. The compounds differed in their ability to induce specific differentiation-associated properties. Effectiveness of induction of Fc and C3 rosettes was of the order actinomycin C greater than cytosine arabinoside greater than mitomycin-C greater than adriamycin greater than bromodeoxyuridine greater than hydroxyurea. Induction of rosettes by actinomycin-D required a 8212-fold lower concentration than induction by hydroxyurea. All these compounds, except bromodeoxyuridine, induced the synthesis and secretion of lysozyme with the same order of effectiveness as for rosettes, but only actinomycin-D and to a lesser extent bromodeoxyuridine induced the formation of mature granulocytes. Vincristine induced only a small increase in lysozyme. The results indicate that actinomycin-D was the most potent inducer of differentiation in these human myeloid leukemic cells. It is suggested that pre-screening of individual patients for the most effective compounds that can induce differentiation of their myeloid leukemic cells in culture, may prove beneficial for treatment in a form of chemotherapy based on the induction of normal differentiation in leukemic cells.

Clonal extinction of myelomonocytic leukemic cells by serum from mice injected with endotoxin.

Abstract: Culture of WEHI-3B myelomonocytic leukemic cells in semi-solid agar medium containing post-endotoxin serum led to the development of maturing granulocytes and macrophages in most leukemic colonies. Colony size was consistently increased but the colony content of colony-forming cells (stem-cell self-replication) was markedly reduced. Serial recloning of WEHI-3B colony cells in the continuous presence of post-endotoxin serum led to clonal extinction of the leukemic cells in five of seven experiments. These effects of post-endotoxin serum on WEHI-3B cells were not seen in clonal cultures of 10 other tumor lines. Serum with the capacity to induce differentiation in WEHI-3B cells could be induced by the injection of as little as 0.1 microgram endotoxin and by purified bacterial cell-wall preparations. Serum activity reached peak levels 3 - 6 h after endotoxin injection and returned to preinjection levels within 48 h.

Natural killer activity of lymphoid cells isolated from human ascitic ovarian tumors.

Abstract: Lymphocytes and tumor cells were isolated from the carcinomatous ascites of 24 patients with epithelial ovarian tumors by stepwise application of density and velocity sedimentation on discontinuous Ficoll-Isopaque gradients and fetal bovine serum. Tumor-associated lymphocytes showed a lower percentage of cells with receptors for sheep erythrocytes (E) or for complement than did peripheral blood lymphocytes from the same patients. NK activity was measured, 51Cr-labelled K562 cells being used as targets in a 20-h assay. Tumor-associated lymphocytes showed significant NK activity. Cytotoxicity levels were lower than for peripheral blood effector cells from the same patients, and these in turn showed significantly lower cytotoxic capacity than peripheral blood lymphocytes from 64 control subjects. Similar results were obtained when lysis was measured after 4 h of incubation. Tumor-associated lymphocytes forming E rosettes were at least as effective as the unseparated population. When tumor-associated lymphocytes were mixed with normal effector cells, in three of six preparations with low NK activity tested, significant inhibition of normal lymphocyte NK activity was observed. Adherent macrophages from carcinomatous ascites, which contained lymphocytes that had suppressive activity, showed no inhibitory activity. Interferon (IF) boosted the NK activity against K562 of tumor-associated lymphocytes. Purified ovarian carcinoma cells were relatively resistant to lysis by normal lymphocytes. However, they inhibited lysis of K562 cells in cold target competition assays, though less efficiently than K 562 itself, and were consistently lysed when effector cells were stimulated with IF. It is therefore suggested that ovarian carcinoma cells express NK-relevant recognition structures, but are relatively resistant to cytolysis by unstimulated effector cells.

A fine fibrous silica contaminant of flour in the high oesophageal cancer area of north-east Iran.

Abstract: We report here the discovery and characterization of a fibrous mineral contaminant of the diet in that area of north-east Iran where oesophageal cancer has a very high incidence. This contaminant has a smoothly tapering shape and is between 50 and 150 micrometers long. The greatest diameter is between 1 and 10 micrometers and this decreases to a sharply pointed tip with a radius of curvature of between 0.25 and 0.60 micrometers. Electron microscope X-ray analysis shows that this fibre consists almost entirely of silica. It is free from alkali metals, aluminium and iron, and therefore differs from other known natural or manmade mineral fibres. Examination of the seeds of more than sixty different species of weed know to contaminate the wheat in this area of the Middle East shows that the fibre originates from the seeds of the common Mediterranean grass Phalaris minor. This seed bears fibres of the same dimensions, composition and birefringence, borne upon the inflorescence bracts which envelop the pericarp of the seeds of this and other members of the phalaris genus. They are broken off from the seed when the wheat is milled but persist in the flour, where up to 3,000 are found in each gram. Similar fibres can be isolated in quantity from the seeds of related species which are grown commercially, and they have a similar size and composition. When cells of the 3T3 mouse fibroblast line are exposed to these fibres in semi-solid suspension culture, their proliferation is stimulated more than 100-fold. We present an hypothesis for the involvement of these plant mineral fibres in the aetiology of oesophageal cancer in Iran and in other areas of high incidence.

Malignant melanoma in Connecticut and Denmark

Abstract: The rising incidence of malignant melanoma of the skin was reviewed using data from the Connecticut Tumor Registry (1935–1974) (Eisenberg et al., 1967) and the Danish Cancer Registry (1943–1972) (Clemmesen, 1965, 1974, 1977). A total of 7,530 cases were analyzed according to age, sex and anatomic site. The total age-adjusted incidence rates were similar for these two countries, despite geographic and demographic differences. However, the most rapid changes in melanoma incidence were observed in females from Denmark and males from Connecticut. In addition, the largest increases occurred for lower-extremity lesions in Danish middle-aged women and trunk-neck melanomas in Connecticut middle-aged men. Melanoma of the face was resistant to changing incidence and occurred in an older age group than melanoma of other skin sites. In general, birth cohort analysis confirmed that changing incidence began for persons born around 1900, but the rising incidence for lower-extremity melanomas in women and trunk-neck melanomas in males began earlier. In comparing incidence for anatomic sites by correcting for surface area and melanocyte density, higher than expected rates were seen for melanoma of the face in both sexes and trunk-neck melanomas in males. The data presented support the concept that a cumulative exposure to solar radiation may be important in the etiology of melanoma of the face, but short, intense sun exposure is probably related to melanoma in other sun-exposed areas, and that melanoma in areas other than the face is responsible for the rising incidence of this disease.

Long-term experience with Burkitt's lymphoma in Uganda.

Abstract: The cumulative results and long-term follow-up of all patients with Burkitt's lymphoma treated at the Uganda cancer Institute Kampala are reported. The annual admission rate is 29. The tumor patients commonly present with jaw swelling (72%), abdominal swelling (56%) and central nervous system involvement (30%). Complete response rate is achieved in a high proportion of patients (81 %). About 50% of these relapse, equal numbers relapsing before and after 3 months. The most important factor influencing remission duration and survival is disease stage. Other important factors are treatment protocols and, to a lesser extent, the type of relapse. Central nervous system relapse does not necessarily augur poor prognosis as second remissions and long-term survival can be achieved with appropriate therapy. Presently 25% of all treated patients have survived free of disease well beyond 5 years.

Regulation of natural killer activity in vivo. II. The effect of alcohol consumption on human peripheral blood natural killer activity

Abstract: Natural killer (NK) activity of human peripheral blood lymphocytes (HPBL) was studied in 32 alcoholics and 15 control subjects in a 4-h chromium release assay using K562 tumor target cells. The natural killer activity of human peripheral blood lymphocytes in alcoholics was significantly higher than the level found in the control group. NK activity of PBL from alcoholics was still higher than that of similarly treated PBL from control subjects after carbonyl iron and magnet treatment, or after passage through a nylon wool column or after removal of cells rosetting with sheep erythrocytes. Changes in T cell, B cell or macrophage populations, therefore, are not the mechanism for increased NK activity in alcoholics.