Performance of plasma-perfused, microencapsulated hepatocytes: prospects for extracorporeal liver support.

The growing success of liver transplantation and the shortage of donor livers has turned attention to the possibility of utilizing hepatocytes within artificial liver support systems to allow time for donor livers to become available and to improve the condition of patients with hepatic failure. This study evaluated encapsulated hepatocytes, a technology which might allow the possibility of using xenogenic or human hepatoma cells. Rabbit hepatocytes were encapsulated using the ionic polysaccharides carboxymethylcellulose, chondroitin sulfate A, chitosan, and polygalacturonic acid. Encapsulated cells were maintained in perfusion culture for at least 6 days in heparinized, normal human plasma or in a defined culture medium. Parallel cultures of plated hepatocytes were also conducted. The metabolic capability of the cells was evaluated by following the rates of urea, albumin, and transferrin synthesis and the transformation rate of the drug antipyrine. Protein synthesis and ureogenesis in plasma were depressed from the levels expressed in defined culture medium. Drug detoxification as measured by antipyrine metabolism appeared to be enhanced in plasma. We conclude that encapsulated rabbit hepatocytes retain significant levels of function for at least 6 days of perfusion with human plasma, suggesting the feasibility of this technology as a potential method of short-term liver support.

Complex coacervate microcapsules for mammalian cell culture and artificial organ development.

A number of combinations of anionic and cationic polymers, the majority being polysaccharides, were screened to determine their suitability for the development of alternative microcapsule formulations capable of supporting cells. The capsules were taken through a limited optimization and then evaluated on the bases of rupture strength, permeability to albumin, and ability of their components to promote the attachment, aggregation, and function of encapsulated rabbit hepatocytes. The widely used alginate-polylysine capsules were employed as a comparative standard in all tests. A number of the new formulations compared favorably with the standard, and some exhibited superior performance in specific areas. Hepatocyte function, as evaluated by the rate of urea synthesis, showed no significant differences between formulations over a 24-h test period. One formulation, composed of the polysaccharides (carboxymethyl)cellulose, chondroitin sulfate A, chitosan, and polygalacturonate, was found to be superior to alginate-polylysine capsules in the areas investigated and supported the long-term survival and growth of liver endothelial cells.

Microencapsulated hepatocytes. Prospects for extracorporeal liver support.

To assess the potential for encapsulated hepatocytes as a bioartificial liver support system, rabbit hepatocytes were encapsulated within multicomponent capsules using a complex coacervation technique, and cultured both on plates and in a perfusion reactor. The urea synthesis rate and antipyrine and diazepam degradation rates were evaluated in each system over a 10 day period, and compared with standard plate-cultured hepatocyte efficacy. Urea synthesis rates were significantly higher in the perfusion cultures than in either of the plate culture environments, whereas drug degradation rates were not significantly different in any of the systems.

Isolation and characterization of a spontaneously immortalized human breast epithelial cell line, MCF-10.

Two sublines of a breast epithelial cell culture, MCF-10, derived from human fibrocystic mammary tissue exhibit immortality after extended cultivation in low calcium concentrations (0.03-0.06 mM) and floating transfers in low calcium (MCF-10F), or by trypsin-Versene passages in the customary (normal) calcium levels, 1.05 mM (MCF-10A). Both sublines have been maintained as separate entities after 2.3 years (849 days) in vitro and at present have been in culture for longer than 4 years. MCF-10 has the characteristics of normal breast epithelium by the following criteria: (a) lack of tumorigenicity in nude mice; (b) three-dimensional growth in collagen; (c) growth in culture that is controlled by hormones and growth factors; (d) lack of anchorage-independent growth; and (e) dome formation in confluent cultures. Cytogenetic analysis prior to immortalization showed normal diploid cells; although later passages showed minimal rearrangement and near-diploidy, the immortal cells were not karyotypically normal. The emergence of an immortal culture in normal calcium media was not an inherent characteristic of the original tissue from which MCF-10 was derived since reactivated cryo-preserved cells from cultures grown for 0.3 and 1.2 years in low calcium were incapable of sustained growth in normal calcium.

The HuT series of 'carcinogen-transformed' human fibroblast cell lines are derived from the human fibrosarcoma cell line 8387.

In 1977 Kakunaga reported the carcinogen-induced transformation of the diploid human fibroblast cell line KD into focus-forming, morphologically altered cells. Cell lines were developed from 15 individual foci. These exhibited an infinite lifespan in culture and all those that were tested (7/7) formed malignant tumors (sarcomas) in athymic mice. The existing cell lines, designated HuT-11 to HuT-14, have been studied intensively during the past decade as examples of human fibroblasts malignantly transformed by treatment with a chemical carcinogen, 4-nitroquinoline-1-oxide. Recently, in comparing the HuT-11, HuT-12 and HuT-14 cell lines with KD cells, McCormick and Maher (Mutat. Res., 199, 273-291, 1988) found evidence that the malignant cells could not have been derived from the latter. But, this did not rule out the possibility that as the target cells for his original study of carcinogen-induced transformation, Kakunaga had inadvertently used cells from some other, unidentified normal individual. Since the donor of such cells would not be known and the original cell line was not available, it would be impossible to determine the degree of identity between such a target cell line and the HuT cell lines. However, in the course of examining methods for such testing, we recently became aware that the isozyme pattern of these HuT cell lines was identical to that of the human fibrosarcoma-derived cell line 8387 established in 1966. We here report that the HuT cell lines and the 8387 cell line also exhibit an identical series of HLA determinants and identical restriction fragment length polymorphisms (RFLPs). Assuming that each of these three assays measures independently inherited characteristics, the chance that an unrelated donor of the fibroblasts that gave rise to the HuT cell lines happened to possess characteristics identical to those of the patient whose fibrosarcoma gave rise to the 8387 cell line is 1 x 10(-8). Therefore, we conclude that 8387 cells are the source of the malignant cells designated HuT from Kakunaga's original transformation experiment. Additional RFLP analysis, using a probe made from M13 bacteriophage DNA which detects a hyperpolymorphic 'minisatellite' pattern in human DNA, also showed that DNA from HuT-14 cells and from 8387 cells exhibit identical banding patterns, indicating that the cell lines were taken from the same individual. The latter banding patterns differed from that observed with DNA from KD cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Enhanced G2 chromatid radiosensitivity, an early stage in the neoplastic transformation of human epidermal keratinocytes in culture.

A deficiency in DNA repair, manifest as enhanced chromatid radiosensitivity during the G2 phase of the cell cycle, together with a proliferative stimulus such as that provided by active oncogenes may be necessary and sufficient for the malignant neoplastic transformation of human keratinocytes in culture. Normal epidermal keratinocytes established as continuous cell lines by transfection with pSV3-neo or infection with adeno 12-SV40 hybrid virus developed enhanced G2 chromatid radiosensitivity after 18 passages in culture. In contrast to cells from primary or secondary culture, these cells could be transformed to malignant neoplastic cells by infection with Kirsten murine sarcoma virus containing the Ki-ras oncogene or in one line by the chemical carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine; both of these agents produced a marked proliferative response. Cytological heterogeneity and karyotypic instability characterized the cells during their progression to neoplasia. These results are interpreted in terms of a mechanism for neoplastic transformation.

Long-term proliferation of mouse thymic epithelial cells in culture.

Epithelial cells from the normal mouse thymus were successfully cultivated on tissue culture plastic when plated with lethally irradiated support cells of the LA7 rat mammary tumor line. As the irradiated LA7 cells slowly decreased in number the thymus cells proliferated concomitantly to form a confluent monolayer. The cells now in culture have been subcultured 8 times, have doubled in number at least 30 times, and are still proliferating vigorously. The culture technique also supported clonal growth from a single cell, and nine clones have been isolated. The colony-forming efficiency of thymic cells plated at low concentrations was about 8%. These cultures were never overgrown by fibroblasts. The thymus cells were characterized as epithelial by the presence of cytoplasmic keratin and numerous desmosomes and tonofilaments. They were shown to be mouse cells by immunocytochemistry with species specific antibodies, by isoenzyme analysis, and by karyology. The cells stained when reacted with antibodies to tubulin, vimentin, and actin, but not with antibodies to Thy-1.2, Lyt-1, Lyt-2, Ia, or H-2 proteins. More than 85% of the cells had a normal mouse diploid chromosome number of 40. This culture technique opens the way for future studies of T-cell education with homogeneous thymic epithelial cell populations both in vitro and after reimplantation into genetically defined strains of mice.

Development of a new human breast cancer cell line Ia-270.

A new human breast cancer cell line (Ia-270) has been isolated from a malignant pleural effusion from a woman with metastatic infiltrating ductal carcinoma of the breast. This cell line contains cytoplasmic estrogen (ER) and progesterone (PR) receptors. Following estradiol (E2) administration, PR synthesis is augmented and a higher level of saturation density is reached. In an athymic mouse, the cell line produced a tumor morphologically similar to the primary tumor. The results of isoenzyme and karyotype analyses demonstrate Ia-270 to be of human origin and free of HeLa cell contamination. The cell line has been maintained in continuous culture since April 1982 and may provide a useful in vitro system for studying the biology of human breast cancer.

Morphological, biological, and biochemical characteristics of human bladder transitional cell carcinomas grown in tissue culture and in nude mice.

The morphological, biological, biochemical, and karyotypic characteristics of four human bladder transitional cell carcinoma lines, SW-780, SW-800, SW-1738, and SW-1710, were investigated. In tissue culture, each cell line presented a distinct phenotypic expression. All but line SW-1710 grew when transplanted in the nude mouse. Light and electron microscopic studies showed morphological characteristics similar to the tumors of origin, being independent of the passages in tissue culture medium, tumor cell extracts, and the plasma of nude mouse-grown tumors, showing isoenzyme quantitative distribution typical for each cell line. In addition, each cell line exhibited a unique genetically determined enzyme phenotypic profile which, along with the karyotypic analysis, makes their identification feasible. These characteristics make the described tumor lines a valuable tool in studying various aspects of the biology of human bladder transitional cell carcinoma.

Establishment and characterization of four new human non-small cell lung cancer cell lines.

Four new human non-small cell lung cancer cell lines have been established in vitro. These cell lines have been characterized by (a) growth of a tumor in nude mice with histopathology similar to that of the primary, (b) isoenzyme patterns phenotypically human and distinct from each other, (c) distinguishing karyotypic findings, (d) growth rate determinations, and (e) presence of epidermal growth factor receptors. Each of the cell lines will form colonies when directly seeded into a flask without soft agar. The development and availability of the four cell lines may facilitate in vitro studies of the biology of this common cancer. Their clonogenic potential may be of value in the study of sensitivity to antineoplastic agents. Their low passage level may mean that their antigens still resemble those of the primary tumor.

Biological and biochemical characterization of an SV40-transformed xeroderma pigmentosum cell line.

We have isolated a subclone of the SV40-transformed xeroderma pigmentosum (XP) cell line SV40XP12RO. The cell line, designated M1, is highly sensitive to ultraviolet light and is deficient in unscheduled DNA synthesis. The isoenzyme, HLA profile and karyotype of the cell line is presented. The structure and function of the resident SV40 genome is analysed. The M1 clone contains a complete copy of the SV40 genome flanked by partial SV40-DNA copies in a head-to-tail arrangement. The large T-antigen is defective in the ability to induce SV40-DNA replication. The M1 subclone is an efficient recipient of DNA in transfection experiments. Transfection of these cells with the pSV2gpt plasmid shows that the M1 subclone is as efficient as the NIH 3T3 cell line in uptake and expression of foreign DNA. This cell line should be suitable for genetic analysis of the xeroderma pigmentosum defect. It should also be useful for the study of gene expression in human cells.

To grow mouse mammary epithelial cells in culture.

Normal mouse mammary epithelial cells from Balb/c mice were successfully cultivated on tissue culture plastic with lethally irradiated LA7 feeder cells. The feeder cells also promoted colony formation from single mouse mammary cells, and the fraction of cells that formed colonies was proportional to the density of feeder cells. The mouse mammary cells could be passaged at least 8-12 times as long as new feeder cells were added at each passage. The cells now in culture have doubled in number at least 30 times, but the in vitro lifespan is not yet known. The cultures of mouse cells maintained by this technique never became overgrown with fibroblasts and numerous domes formed in the cultures.

Cell characterization by use of multiple genetic markers.

The extensive use of cell cultures for diverse research purposes is one of the truly great international growth industries. With the proliferation of cells comes a responsibility for monitoring them for inter- and intraspecies characteristics. We use multiple genetic markers for cell identification, i.e. species specific antigens, isozymic phenotypes, chromosomal complement, and HL-A haplotypes. The methodologies employed are briefly described, and various examples cited to show how these markers can be utilized for cell line monitoring. Data are summarized from 275 cultures sent to our laboratory for analysis during the past eighteen months. The data show that, overall, 35% of the cultures received were contaminated. The majority of cell cultures submitted were human cell lines. We found that 36% of these cultures were cross contaminated; 25% by cells of another species and 11% by another human cell line. This high incidence of inter- and intraspecies contamination underscores the importance of frequent monitoring of cell cultures.

A phenotypically normal revertant of an adenosine deaminase-deficient lymphoblast cell line.

Two lymphoblast lines from a patient with partial adenosine deaminase deficiency have been obtained. The patient has a T cell deficiency, with normal B cell function, and has been successfully treated by multiple partial exchange transfusions with normal erythrocytes. The patient's lymphocytes have about 8% of normal adenosine deaminase activity. The derived lymphoblast line that initially had low adenosine deaminase activity has undergone spontaneous reversion to normal enzyme activity. The HL-A types remain the same as the patient's. Both cell lines have the same HL-A types, and eight isoenzymes are identical. In addition, the isoenzymes of a fibroblast line derived earlier, GM-2445, are identical with those in our lymphoblast lines. The following characteristics of the enzyme in the cell lines are normal: Km, Vmax, inhibitor sensitivity, heat sensitivity, and m.w. This suggests, but does not prove, that the low adenosine deaminase activity in this patient is caused by underproduction of a normal enzyme, and the observed reversion to normal activity in one line is a correction of this regulation defect.

Cell culture quality control by rapid isoenzymatic characterization.

Procedures that involve cell cultures require careful quality control to avoid inter- and intraspecies contamination. We have developed an electrophoresis technique that can be used routinely in cell culture laboratories to monitor cell line integrity. The method involves the isoenzymatic separation of nine polymorphic enzymes, three of which can be used for cell line species determinations and seven of which can be used for human cell line characterizations. Examples of how the system has been applied to both inter- and intraspecies identifications are described. The routine application of this protocol would be a valuable asset for laboratories concerned with establishing effective cell culture quality control.

In vitro microwave effects on human neutrophil precursor cells (CFU-C).

Human marrow cells were irradiated with 2450-MHz CW microwaves in a fluid-filled waveguide irradiation system. Cell exposure was conducted by placing a marrow cell suspension in 20-microliter glass microcapillary tubes were positioned in the exposure chamber, and irradiated at power densities from 31 to 1,000 mW/cm2 (with corresponding specific absorption rates of 62 to 2,000 mW/g) for 15 minutes. The temperature of the sample was maintained at a fixed point. Sham-irradiated (SI) and microwave-irradiated (MWI) cells were cultured in a methylcellulose culture system for neutrophil colony proliferation. There was no reduction in neutrophil colony number on days 6-7 or 12-14 in cells exposed at 31 or 62 mW/cm2, but as the power density was increased to 1,000 mW/cm2, there was a reduction in colony number of MWI cells compared with SI cells. The microwave interaction with the human neutrophil colony-forming cells was apparently not related to temperature rise, or to the state of cells cycle, and was irreversible.

Expression of human T lymphocyte antigens by killer cells.

K cells, the effectors of antibody-dependent cell-mediated cytotoxicity, were found to express human T but not B lymphocyte antigens detected by rabbit anti-HTLA and anti-HBLA. Pretreatment of effector cells with anti-HTLA+C inhibited ADCC by specifically lysing K cells: no inhibition of ADCC by anti-HTLA occurred when deltaC was substituted for C. By contrast, pretreatment of effector cells with anti-HBLA nonspecifically inhibited ADCC, probably for forming antigen-antibody complexes with HBLA+ cells in effector suspensions: a) treatment with anti-HBLA deltaC was more inhibitory of ADCC than treatment with anti-HBLA+C, and b) the inhibitory effect of anti-HBLA on ADCC was either eliminated or markedly reduced if effector suspensions were first passed through a nylon fiber column, a procedure that removed most HBLA+ cells without affecting K cell activity. HTLA antigens expressed by K cells and NK cells are the same as HTLA antigens expressed by thymocytes since thymocytes completely absorb the anti-K cell and NK cell reactivity of anti-HTLA.

Cytotoxicity of human peripheral lymphocytes in cell-mediated lympholysis; antibody-dependent cell-mediated lympholysis and natural cytotoxicity assays after mixed lymphocyte culture.

Lymphocytes that have been purified by Ficoll-Hypaque centrifugation lose antibody-dependent and natural cytotoxic activities upon culture in tissue culture medium supplemented with human plasma. However, stimulation of peripheral lymphocytes in the mixed leukocyte culture (MLC) appears to enhance killer (K) and natural killer (NK) activities in addition to generating cytotoxic T ymphocytes. Enhancement of NK and antibody dependent activities appears to correlate with cell division as measured by 3H-thymidine uptake. However, elimination of dividing cells in the MLC by addition of 5-bromodeoxyuridine has no effect on NK and K cells activities. Since this treatment abolishes cell-mediated lympholysis mediated by cytotoxic T lymphocytes, it is a useful probe for determining the relative activities of NK, K, and cytotoxic T lymphocyte effector cells after lymphocyte stimulation.