Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adoptive immunotherapy is a novel approach to treating patients with cancer, utilizing as therapy a patient's own peripheral blood lymphocytes that have been activated by incubation with interleukin-2 (IL-2). These cells develop the ability to mediate tumor regression in vivo and are referred to as lymphokine-activated killer (LAK) cells. The production of LAK cells is a complex and labor-intensive process. Lymphocytes are collected by continuous-flow centrifugation, purified on Ficoll-Hypaque (FH) density gradients, incubated in vitro with IL-2, and then harvested for infusion into the patient. An automated approach to LAK cell generation has been developed using the Fenwal CS-3000 cell separator and polyolefin PL-732 blood storage bags. Lymphocyte concentrates (LC) containing 6.5 x 10(9) mononuclear cells per pack were obtained using standard leukapheresis techniques. Disposable apheresis kits were then modified to allow the LC to be pumped into the separation chamber along with a counter-centrifugal flow of saline, removing the platelets and plasma by elutriation. The remaining cells were underlaid with FH, displacing the lymphocytes into a collection bag, where they were washed and concentrated. Mean leukocyte recovery was 59.2% (99.9% lymphocytes, n = 14). The final product contained 6.7% of the initial platelets and had a hematocrit of less than 1%.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Technical aspects of lymphokine-activated killer cell production. 339 72

Immunotherapy utilizing the adoptive transfer of lymphokine activated killer (LAK) cells in conjunction with recombinant interleukin 2 (RIL-2) is capable of reducing established metastatic cancer in a variety of animal tumor models. A major difficulty in the application of these efforts to the treatment of human cancer has been the activation in vitro of up to 2 X 10(11) human peripheral blood lymphocytes obtained by repeated leukaphereses. We have thus developed optimal and simplified techniques for the generation of human LAK cells for use in clinical trials. We have found that 1.5 X 10(9) lymphocytes separated on Ficoll-Hypaque gradients and incubated in 1000 ml of culture medium in a 2.3 liter roller bottle with 1000-1500 U of RIL-2 per ml, generated LAK cells capable of killing fresh human tumor cells in a 4 h chromium release assay. The culture medium used was RPMI 1640 with 2 mM glutamine, 2% heat-inactivated human AB serum, 50 micrograms/ml streptomycin and gentamicin and 50 U/ml penicillin. This technique allows activation of sufficient numbers of cells in a research laboratory setting to conduct human clinical trials. The administration of LAK cells generated in this fashion can mediate the regression of human tumors when administered in conjunction with IL-2.
 ...
PMID:Large scale production of human lymphokine activated killer cells for use in adoptive immunotherapy. 348 92

The Dunning R3327 tumor represents a system for studying prostate cancer in Copenhagen X Fischer rats. Animals bearing variant sublines (H, G, and MAT-LyLu) differing in growth rate, differentiation, hormone responsiveness, and metastatic ability were assayed for three immunological markers. Spleens were passed through a tissue sieve, and mononuclear cells were obtained by Ficoll-Hypaque centrifugation. These were assayed for leukocytic subsets using monoclonal antibodies. An adherent population was isolated and evaluated using thin-layer chromatography for conversion of radiolabeled arachidonic acid to E series prostaglandins. Finally, sera from these animals were assayed for levels of circulating immune complexes using polyethylene glycol precipitation. Data from 52 rats bearing the various tumors were obtained, correlated with subline aggressiveness, and compared to 15 controls. Each tumor group demonstrated significantly lower helper/suppressor T-cell ratios than controls, probably due to general tumor presence. In addition, the most aggressive R3327 MAT-LyLu variant had significantly increased prostaglandin E synthesis by adherent spleen cells compared to the H or G sublines and significantly increased levels of circulating immune complexes relative to the H subline. G subline values for both prostaglandin E and circulating immune complexes levels were intermediate, suggesting that these markers correlate better with tumor aggressiveness than helper/suppressor T-cell ratios.
 ...
PMID:Immunoregulatory markers in rats carrying Dunning R3327 H, G, or MAT-LyLu prostatic adenocarcinoma variants. 349 74

Primary breast adenocarcinomas obtained from ten patients were enzymatically digested using collagenase (1 mg/ml), hyaluronidase (1 mg/ml), elastase (0.1 mg/ml) and DNAse (0.2 mg/ml). The tumor cells were labeled with 3H-thymidine and, in some cases, with 3H-estradiol. The isolated cells were submitted successively to a Ficoll-Hypaque and a bovine serum albumin gradient, from which 12 fractions were obtained. In each fraction, several characteristics were determined: carcinoembryonic antigen (CEA), thymidine (dThd) incorporation, and estrogen receptors (ER). Three main cellular subpopulations were characterized: An intermediate density subpopulation (1.046-1.054 g/ml), in which the proliferating cells are concentrated. In this subpopulation a small number of CEA-positive cells are present, but ER containing cells are virtually absent. A high-density, small cell subpopulation that concentrates most of the ER-containing cells. This subpopulation lacks proliferating cells, but CEA-containing cells are abundant. A low-density subpopulation, lacking proliferating cells and with scarce ER-positive cells, although CEA-positive cells are frequent. These findings strongly suggest that proliferating cells lack ER.
 ...
PMID:Determination of DNA synthesis, estrogen receptors, and carcinoembryonic antigen in isolated cellular subpopulations of human breast cancer. 352 93

In an effort to make interleukin-2/lymphokine-activated killer cell (IL-2/LAK) therapy safer for cancer patients, we examined the efficacy of using Fenwal PL732 bags as tissue culture flasks. These bags can be sterilly connected using tubing kits thus reducing the risk of contamination to the cells. Peripheral blood mononuclear cells were obtained from normal donors or cancer patients undergoing IL-2/LAK cell therapy. Following Ficoll-Hypaque purification, these cells were incubated in the presence of IL-2 in either PL732 plastic bags or standard tissue culture flasks. Our results showed that LAK cells could be generated from either normal donors or cancer patients in the bags as well as in the flasks. Comparisons were made of the LAK cell populations obtained from the two sources and showed that each was similar in terms of morphology as determined by Wright stain differentials. The populations of cells were also similar in regard to cell surface phenotype as determined by flow cytometric analysis. In addition, recoveries from either tissue culture vessel as well as cell viability of the LAK cells were comparable. Finally, the LAK cells obtained from both sources were assessed for cytolytic activity against the tumor cell lines K562 and Daudi. These results showed that the cytolytic activity of the LAK cells against these target cells was the same whether the cells were obtained from the flasks or the bags.
 ...
PMID:An improved method for the generation of human lymphokine activated killer cells. 359 94

Immunotherapy utilizing the adoptive transfer of lymphokine-activated killer (LAK) cells in conjunction with recombinant interleukin-2 (IL-2) can mediate tumor regression in some patients with advanced cancer. The activation of large numbers of LAK cells was performed in roller bottles in a research laboratory setting and required meticulous aseptic technique, at least one skilled technician per patient and one laminar flow hood per patient. To reduce the complexity and expense of LAK cell generation for human immunotherapy trials we have developed a closed-system automated procedure using a continuous flow blood cell separator. PBL were obtained by standard apheresis techniques. Platelets and plasma were elutriated using countercentrifugal flow of saline in the cell separator machine. The washed PBL were underlaid with Ficoll-Hypaque (FH) in the original separation bag. Lymphocytes were then flushed into a collection bag where they were concentrated and washed with 2 liters of saline. Mean recovery from the automated FH technique was 54.6 +/- 4.3% compared to 62.3 +/- 4.0% using manual methods in 50 ml tubes (P greater than 0.05). Cells were diluted in the collection bag with RPMI 1640 +/- 2% human AB serum and could be dispensed in an automated fashion to polyolefin bags via a sample port with 1000-1500 U/ml IL-2. After 3-4 days of culture in 5% CO2 at 37 degrees C, activated cells from the bags were harvested and washed in a closed system using the continuous flow cell separator. Cell yield from the harvest was 79.2 +/- 5.4% in the automated system compared to 64.9 +/- 5.0% in the standard procedure using manual harvest of roller bottles (P less than 0.01). Lytic capacity of the cells against fresh human tumor in a 4 h 51Cr release assay was equivalent in cells processed either by the automated or the conventional manual method. The advantages of a closed system include decreased potential for microbial contamination and reduced labor and capital equipment costs. This technique may be easily adapted for use with other cell collection and culture systems.
 ...
PMID:Development of an automated closed system for generation of human lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy. 361 95

Thirty-one bone marrow aspirations were performed on patients with prostatic carcinoma metastatic to bone. After separation over a Ficoll-Hypaque gradient viable nucleated cells were cultured in semisolid agar. Colony formation occurred in 14 of 27 (52%) nonbacterially contaminated cultures. Characterization of cells from the colonies showed them to be consistent with malignant prostate cells. After staining, these cells were periodic acid-Schiff positive, prostatic acid phosphatase positive, and prostatic specific antigen positive. Other studies demonstrated the cells to be karyotypically abnormal, ultrastructurally similar to epithelial cells, and capable of secondary colony formation. Three bone marrow aspirate specimens did not have metastatic prostatic carcinoma detected by standard methods but did demonstrate colony formation. However, colony formation was most frequently seen when a radionuclide scan was positive at the aspiration site and when tumor cells were microscopically detectable by Wright staining of a smeared aspirate. The potential utility of colony forming cultures in prostate cancer is discussed. In working with bone marrow aspirates, additional cell separation procedures may be required to calculate and maximize plating efficiencies.
 ...
PMID:Growth in semisolid agar of prostate cancer cells obtained from bone marrow aspirates. 370 87

A study was done to investigate the tumoricidal activity of peripheral blood lymphocytes (PBL) and tumor-associated lymphoid cells (TAL) against freshly isolated tumor cells in human ovarian carcinoma. TAL and carcinoma cells were purified by density and velocity sedimentation on discontinuous Ficoll-Hypaque gradients and fetal bovine serum. Purified carcinoma cells from 23 ascitic and 3 solid tumors were used as targets in a 4- or a 20-hour 51Cr release assay. K562 cells were used to measure natural killer (NK) activity. Freshly purified ovarian carcinoma cells were relatively resistant to lysis by normal unstimulated PBL. Cytolytic activity of ovarian cancer PBL and TAL did not exceed that of control PBL: Only one PBL preparation had high levels of cytotoxicity (36.2 and 42.9% specific lysis after 4 and 20 hr at an effector-to-target cell ratio of 50:1) against autologous cancer cells but not against allogeneic targets (less than 5% specific lysis). TAL and, to a lesser extent, ovarian cancer PBL showed impaired NK activity against K562 compared to the activity seen in controls. In vitro exposure to partially purified human fibroblast interferon (IFN) (1,000 U/ml for 1-18 hr) augmented NK activity against K562 of PBL and TAL. When ovarian carcinoma cells were used as targets, IFN enhanced the cytotoxicity of normal PBL in a 4- and 20-hour assay; stimulation by IFN was less frequently observed with ovarian cancer PBL and TAL in a 4-hour assay, but after 20 hours effector cells from tumor-bearing subjects showed IFN-boosted cytotoxicity against carcinoma cells similar to the degree of cytotoxicity seen in controls. IFN enhanced the cytotoxicity of PBL and TAL against both autologous and allogeneic carcinoma cells. Thus PBL and TAL are rarely cytotoxic against 51Cr-labeled fresh autologous carcinoma cells, but in vitro exposure to IFN induced low levels of killing of ovarian tumor cells.
 ...
PMID:Interferon effect on cytotoxicity of peripheral blood and tumor-associated lymphocytes against human ovarian carcinoma cells. 617 86

The potential for the establishment of predictive assays for cancer chemotherapy was generated recently by the development of a soft agar clonogenic assay for human tumor cells. Though the assay technique is promising, certain technical problems remain. One is the difficulty of preparing viable cell suspensions from solid human tumors. A method of separating viable and nonviable cells by Ficoll-Hypaque centrifugation was used. When this method was used to plate isolated viable single cells, an improvement in cloning was observed when compared with a nonseparated mixture of viable and nonviable cells.
 ...
PMID:Improved clonal growth of human solid tumors by isolation of viable cells. 654 70

When plated in agar, PHA-stimulated Ficoll-Hypaque separated human mononuclear cells readily form discrete T lymphocyte colonies. Separation of these mononuclear cells on Sephadex G-10 columns yields enriched populations of T lymphocytes (greater than 95% E rosette-positive); these purified cells do not respond to this nonspecific mitogen by undergoing clonal expansion. Colony growth, however, can be restored by the addition of irradiated adherent cells. T cell responses can also be reconstituted by incubating the Sephadex-nonadherent fraction with irradiated cultured human tumor cells of monocytic (U937 and HL60) and B lymphocytic (Raji and Daudi cells) lines, but not from a T cell clone (MOLT-4) or erythroleukemic (K562) cells. Growth can also be induced in cultures containing T cells by adding cells from patients with either acute myeloblastic or B cell chronic lymphocytic leukemia or by the addition of B cell-enriched, monocyte-depleted normal mononuclear cells. Soluble factors prepared from Sephadex-adherent cells or active tumor cell lines are effective in promoting T cell colony formation. These results indicate that accessory cells are required for PHA responses of cloned human T cells. This function can be supplied by both monocytic and B lymphocytic tumor cell lines and is due to the release of soluble factors that act, in conjunction with the mitogen, to activate responsive lymphocytes.
 ...
PMID:Dependency of human T lymphocyte colony formation on soluble factors produced by accessory or tumor cells. 660 78


<< Previous 1 2 3 4 5 6 7 Next >>