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With the recent advances in the immunological surveillance system, an understanding of the role of host immunity has become essential to the management of carcinogenesis, tumor proliferation, recurrence and metastasis. Although it is important to continue chemical and surgical treatment of cancer, support of the anti-tumor immune system of the host should also be considered. Long term remission has been reported in leukemia by treating with BCG after chemotherapy whereas surgical treatment is usually more effective in preventing cancer recurrence in digestive organ cancer. The first step is extirpating the tumor as thoroughly as possible and the second step is chemo-immunotherapy. Cancer immunity, however weak, constitutes the basis for other treatments in selectively attacking cancer cells remaining after surgery, chemotherapy or irradiation. Immunotherapy should thus not replace chemotherapy or radiotherapy, but these methods should be employed in combination to attain more favorable results.

Human KC cell monolayer inoculated with concentraten Mason-Pfizer monkey virus (MPMV) showed syncytia formation within an hour. The cell fusion was blocked by the treatment of the MPMV with neutralizing antiserum. Treatment of the MPVM with beta-propiolactone resulted in the loss of infectivity although KC cell fusion ability of the virus still remained. KC cells inoculated with unconcentrated MPMV showed no cell fusion even after several transfers, although a chronic MPMV infection was established. The virus-producing KC cells were refractory to fusion by MPMV. Human embryonic lung cells (HEL) were infected by serially diluted MPMV harvested from virus-producing culture, transferred twice, then cultivated together with KC cells for syncytia formation to examine the end point dilution titer of the virus. HEL infected by 10(-4)-diluted MPMV still induced syncytia formation by cocultivation with KC cells.

The chemotactic activity of granulocytes obtained by the Terumo Filtration Leucapheresis System (F.L.) was examined by the method of Boyden's chamber. The number of cells migrating through the Millipore filter was expressed as the chemotactic activity. The mean values were 117 for the F.L. and 122 in a control, in which cells were collected from the same donor blood using dextran sedimentation. The results suggested that the in vitro chemotactic function of granulocytes obtained by F.L. was within normal limits.

To investigate the role of folic acid deficiency in the pathogenesis of anemia in the elderly, hematological examinationa and assays of serum iron, vitamin B12 and folate were carried out on the 86 elderly patients admitted to a home for the aged. Means of red blood cell counts, hemoglobin levels and hematocrit were 385.3 x 10(4)/mm3, 12g/dl and 36%, respectively. These levels were lower than any other report in Japan. Anemia was detected in 23 out of 86 patients. Judging from mean corposcular volume and mean corposcular hemoglobin, most of them were normocytic and normochromic. Although low serum levels of iron and folate were rather frequently observed, the results on hematological examinations suggest that deficiency of these factors alone is not the cause of the anemia in the elderly patients. Rapid clearance of 5-methyl-tetrahydrofolic acid and increased excretion of formiminoglutamic acid after histidine loading were revealed in some of those who had subnormal serum folate levels. Therefore, supplementation of folic acid is recommended to those who had poor dietary intake.

 To determine whether the predominant infiltration with memory CD4⁺T cells in joints is specific to the local immune and inflammatory response in rheumatoid arthritis (RA), the proportions of CD45RA⁺ or CD45RO⁺ cells in the CD4⁺T cell populations in three different compartments (i.e., peripheral blood, synovial fluid, and synovial tissue) from patients with RA and osteoarthritis (OA) were compared by two-color flow-cytometric analysis. In the CD4⁺T cell population of peripheral blood, the number of CD45RO⁺ cells was relatively higher than CD45RA⁺ cells in both RA and OA patients, but their percentages did not differ from those found in healthy individuals. However, the great majority of CD4⁺T cells present in synovial fluid and synovial tissue were CD45RO-positive and CD45RA-negative in both patient groups; although CD4⁺T cells infiltrating both the disease compartments were markedly greater in RA joints, their mean percentages of CD45RO⁺ cells were not significantly different from those in OA joints. These data indicate that an accumulation of CD45RO⁺ memory CD4+T cells is a generalized phenomenon during local inflammatory responses in both RA and OA joints, and may be due mainly to the propensity of these cells to preferentially transmigrate into the inflamed joint via adhesion molecules as compared with CD45RA⁺ naive CD4⁺T cells.

 This study was conducted to evaluate the frequency of DNA transfection into human cells following X-ray irradiation. We transfected plasmid DNA (pSV2neo) into human cells, HeLa and PA-1, by either calcium phosphate precipitation or the lipofection method immediately after irradiating the cells with various doses of X-rays. The transfection frequency was evaluated by counting the number of G418-resistant colonies. When circular plasmid DNA was used, irradiation up to a dose of 2 Gy dose-dependently increased the transfection frequency, which reached a maximum of 5 to 10-fold that of the control unirradiated cells. When linear plasmid DNA was used, the transfection frequency was 2 times higher than that of circular DNA. All five of the clones that were randomly chosen expressed the transfected neo gene. In addition, the pSV2neo gene was randomly integrated into the genomic DNA of each clone. These findings indicate that X-ray treatment can facilitate foreign DNA transfer into human cells and that radiation-induced DNA breaks may promote the insertion of foreign DNA into host DNA. The enhancement of DNA transfection with X-rays may be instrumental in practicing gene therapy.

Malignant lymphoma was induced in Japanese (JWY), New Zealand (NZY) and Dutch (DUY) white rabbits by oral spray of cell-free pellets of culture fluid (crude virus fraction) of Ts-B6 cells (cynomolgus monkey B-lymphoblastoid cells harboring Epstein Barr virus-related simian herpesvirus or Cyno-EBV). Nine of 11 inoculated rabbits developed malignant lymphomas within 42-160 days after oral inoculation (JWY, 2/3; NZY, 5/6; DUY, 2/2). In contrast, none of the control rabbits inoculated in the same fashion with B95-8 (EBV-producing marmoset cell line) cell-free pellets developed malignant lymphoma. Most rabbits showed increased anti-VCA IgG and anti-EA-DR IgG antibody titers after inoculation by oral spray of Ts-B6 cell-free pellets. EBV-encoded RNA-1 was revealed in the tumor cells by in situ hybridization. EBV DNA was detected in the rabbit peripheral blood leukocytes (PBL) by polymerase chain reaction; the earliest positive result was obtained only two days after oral inoculation. These data suggest that orally administered Cyno-EBV in Ts-B6 cells infects PBL and then induces malignant lymphoma in rabbits. The availability of this animal model promises to clarify the role of EBV in human lymphoma and provides a means for studying prophylactic and therapeutic regimens.

Physiological strain plays an important role in maintaining the normal function and metabolism of bone cells. It is well known that the mineral content of astronauts' bones decreases during spaceflight. Thus, gravity is one of the important factors in the muscloskeletal system. The vector-free horizontal clinostat has been used to simulate conditions of microgravity for examining such effects on cells in culture. We analyzed the effects of simulated microgravity using a horizontal clinostat on cultured osteoblast-like cells (HuO9 cell line). Total cellular protein, which was measured as an indication of cell proliferation, was not significantly inhibited under simulated microgravity conditions. No morphological changes were detected under microgravity conditions by phase-contrast microscopy. However, the alkaline phosphatase (ALP) activity and osteocalcin production of the HuO9 cells decreased significantly under microgravity conditions. Our data indicate that simulated microgravity directly inhibits some differentiation phenotypes and some functions of osteoblasts. On the other hand, the addition of 1,25-dihydroxy-vitamin D₃ (1,25-(OH)₂-D₃) increased ALP activity under simulated microgravity conditions, although the total activity of ALP in the cells treated with 1,25-(OH)₂-D₃ was still lower under simulated microgravity conditions than that in the control cells. However, the cells under simulated microgravity conditions showed a greater enhancement of ALP activity by treatment with 1,25-(OH)₂-D₃.

We have established an Adriamycin (ADM) -resistant small cell lung cancer (SCLC) cell line, SBC-3/ADM100, which shows multifactorial mechanisms of resistance to ADM, such as overexpression of P-glycoprotein, an enhanced detoxifying system and a decrease in topoisomerase II activity. In the present study, we confirmed that SBC-3/ADM 100 showed collateral sensitivity to methotrexate and TNP-351, a new antifolate, though this cell line showed a typical multidrug resistance (MDR) pattern. We also demonstrated a faster uptake and higher accumulation (1.3-fold) of TNP-351 in the SBC-3/ADM100 cells than those in the parent SBC-3 cells. These results explain one of the mechanisms for collateral sensitivity in the resistant cells. Furthermore, this cell line was found to have no cross-resistance to edatrexate and minimal cross-resistance to trimetrexate, 254-S (cisplatin analog), 5-fluorouracil and 4-hydroperoxyifosfamide. These drugs will have clinical importance in patients with SCLC who were previously treated with an ADM-containing regimen. Thus, antifolates, especially TNP-351 and edatrexate, can be expected to eradicate residual multidrug resistant SCLC cells selected by ADM.

We compared the transfection efficiency of four types of positively charged liposomes composed of (i) N-(α-trimethylammonioacetyl)-didodecyl-D-glutamate chloride (TMAG), dilauroylphosphatidylcholine (DLPC), and dioleoylphosphatidylethanolamine (DOPE) (1:2:2 molar ratio); (ii) 3β [N-(N′, N′-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and DOPE (3:2 molar ratio); (iii) dimethyldioctadecylammonium bromide (DDAB) and DOPE (1:2.2 molar ratio); (iv) N-[1-(2,3-dioleyloxy) propyl] -N,N,N-trimethylammonium chloride (DOTMA) and DOPE (1:1, w/w; lipofectin). Luciferase gene was used as a reporter gene. Among the cationic liposomes used, the liposomes composed of TMAG, DOPE and DLPC showed a much higher efficiency of plasmid DNA entrapment than the other cationic liposomes tested. In the absence of serum, the cationic multilamellar vesicles (MLV) and small unilamellar vesicles (SUV) composed of TMAG, DOPE and DLPC gave highly efficient transfection. On the other hand, MLV, dehydration-rehydration vesicles (DRV), and SUV liposomes prepared with the mixtures of DC-Chol and DOPE showed similar levels of transfection efficiency. However, the cationic liposomes composed of DDAB and DOPE showed inferior efficiency, whether in the form of DRV, SUV or MLV. The transfection efficiency of lipofectin was also low. In the presence of serum, on the other hand, a considerable (about 30-50%) amount of transfection activity was still observed at 10% fetal calf serum in the cationic MLV and SUV composed of TMAG, DOPE and DLPC. Cationic MLV, composed of TMAG, DOPE and DLPC, can transfect plasmid DNA, not only in the adherent cell lines but also in the suspension cell lines. These findings indicate that the transfection efficiency of cationic liposomes is affected by the lipid composition, the type of liposome, or the presence or absence of serum. They also indicate that the cationic liposomes containing TMAG, DOPE and DLPC are efficient vectors for gene transfer into cells.

Accurate assessment of elbow function is important to determine the total ability of the arm. The purpose of this study was to clarify the relationship between isometric muscle strength of the elbows of patients with rheumatoid arthritis (RA) and Larsen's X-ray evaluation. Fifty-six elbows of 45 RA patients aged 47 to 77 years (mean age, 63 years) were tested. Muscle strength was measured with an isometric torque-cell dynamometer. Test-retest reliability of the dynamometer was proven by measuring 12 elbows of 6 healthy young men. In RA patients, elbow flexion and extension strength decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 4. However, Grade 5 elbows had greater muscle strength than those in Grade 4. Forearm pronation and supination strength also decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 5. This quantitative study made it clear that the muscle strength of RA patients' elbows almost completely correlates to X-ray finding according to the grade of Larsen's evaluation based on X-rays. With regard to muscle strength of postoperative elbows, both flexion strength and supination strength after total elbow replacement (TER) were about two times greater than before TER, and after synovectomy it was as great as those in non-operative RA patients of Grade 2.

The expression of osteonectin (ON) in osteoarthritic articular cartilage was investigated by enzyme immunohistochemistry and colloidal gold immunoelectron microscopy. A total of 96 specimens from 9 knees of 8 patients with osteoarthritis (OA) were examined. In OA cartilage, ON-positive cells varied in distribution and were not seen in all the specimens obtained from the same patient. However, in over half of the specimens (56 of 96), especially in the specimens of Mankin's grades from 4 to 9, which corresponds to relatively early stages of OA, ON was expressed in the cartilage above the calcified layer. On the other hand, ON was detected only in the calcified layer below the tidemark in normal articular cartilage. In addition, colloidal gold immunoelectron microscopy revealed ON in chondrocytes and matrix vesicles (MVs). These findings suggest that ON acts through MVs in the early stages of OA as a significant pathogenetic factor involved in intracartilage calcification, which is known to have a close relationship to the progression of OA.

We used a yeast functional assay (functional analysis of separated alleles in yeast: FASAY) to determine the p53 gene status of human cell lines maintained in our laboratory. This assay enables the researcher to score wild-type p53 expression on the basis of the ability of expressed p53 to transactivate the reporter gene HIS 3 via the p53-responsive GAL 1 promoter in Saccharomyces cerevisiae. The cell lines examined were ten hepatoma, two hepatoblastoma, three in vitro immortalized fibroblast, two osteosarcoma, a chondrosarcoma, an ovarian teratocarcinoma and a colon cancer cell line. Out of 20 cell lines, 11 cell lines had mutations in both alleles of the p53 gene, and another 8 cell lines had no mutation in the p53 gene. Thus, 55% of the cell lines examined had mutations in the p53. Interestingly, PA-1 cells had both the normal and the mutant p53 alleles, showing that FASAY is a useful method for detecting the wild-type and mutated p53 genes simultaneously. As for the three liver cell lines harboring HBsAg, there was no relationship between their p53 gene status and the presence of HBsAg. Two cell lines were normal for p53 status, while the other had a mutation of the p53 gene.

Retinal cells from chick embryos aged 7.5 days of gestation were cultured for two months in a non-adherent suspension culture dish to study the effects of growth factors and co-culture with retinal pigment epithelial cells on their differentiation. Dissociated retinal cells became cellular aggregates (multicellular spheroids) within a day, and rosettes were formed in the spheroids after 2 days. Ultrastructurally, neurons of the rosettes developed connecting cilia, ellipsoids (accumulation of mitochondria), and external limiting membrane, indicative of their differentiation into photoreceptor cells. Epidermal growth factor enhanced the expression of rhodopsin by rosette-forming neurons, while basic fibroblast growth factor induced the growth of Mueller cells at 4 weeks, and their transdifferentiation into lens-epithelial-like cells at 8 weeks. Co-culture of retinal cells with retinal pigment epithelial cells enhanced the formation of rosettes in spheroids. Multicellular spheroids formed in a dish for suspension culture would provide a convenient in vitro system to examine differentiation and transdifferentiation of the retina.

A novel endonuclease of 55-kDa was found in rat liver mitochondria by a zymographic assay, in addition to the 29 kDa enzyme that is well-known as endonuclease G (Endo G). Subcellular localization of these enzymes in rat liver cells was examined by biochemical fractionation. Endo G was located in both nuclei and mitochondria as has been previously reported, while the 55-kDa enzyme was only detected in the mitochondrial fraction. The levels of the endonucleases in the mitochondria varied greatly among the rat organs, and the activity in the heart was about 30 times higher than that in the liver. The 55-kDa enzyme and Endo G were extracted from bovine heart mitochondria with 0.4 M NaCl. During purification the 55-kDa enzyme and Endo G were copurified because of their similar chromatographic behavior, so they were separated by gel filtration or electrophoresis in the presence of SDS and the proteins were then renatured. The nucleolytic properties of the 55-kDa enzyme resembled those of Endo G and other known mitochondrial nucleases. The enzyme degraded single-stranded DNA more rapidly than duplex DNA at a weak alkaline pH, requiring Mg²⁺ or Mn²⁺ but not Ca²⁺ or Zn²⁺. Nicks generated by the enzyme had 5′-P and 3′-OH ends. The 55-kDa enzyme, like Endo G, displayed an unusually strong preference to nick within a (dG)_n · (dC)_n tract.

Sections of the visual cortex of newborn (1-4 weeks after birth) and adult cats were stained with cationic iron colloid, aldehyde fuchsin or lectins (lectin Vicia villosa, soybean and Wisteria floribunda agglutinins). Many neurons in the adult cat visual cortex contained perineuronal sulfated proteoglycans detectable with cationic iron colloid and aldehyde fuchsin, or cell surface glycoproteins reactive to lectins. Double staining indicated that some of the lectin-labeled neurons were not stained with cationic iron colloid, and also that some of the cationic iron colloid-stained neurons were not labeled with lectins. The perineuronal sulfated proteoglycans and cell surface glycoproteins developed 3 weeks after birth. In the newborn cats 1-2 weeks after birth, no neurons were reactive to cationic iron colloid, aldehyde fuchsin or lectins. In the newborn cats 34 weeks after birth, it was clearly observed that the cytoplasm of the glial cells closely associated with the neurons containing the perineuronal sulfated proteoglycans showed an intense reaction to cationic iron colloid and aldehyde fuchsin, and that the Golgi complexes of the neurons with cell surface glycoproteins were intensely labeled with lectins. These findings suggest that the perineuronal sulfated proteoglycans are derived from the associated glial cells, and that the cell surface glycoproteins are produced by the associated nerve cells.

Characteristics of human hepatoma cell lines with the wild-type p53 were compared with those of human hepatoma cell lines with the mutant-type p53. The p21 protein located downstream of p53 was expressed in cell lines with the wild-type p53 but was not expressed in cell lines with the mutant-type p53. As to other tumor suppressor genes such as p16 and p27, there was no difference in their expression between both types of cell lines. In addition, no marked difference was observed in the activities of CDK2 and CDK4 between cell lines with the wild-type and the mutant-type p53. Phosphorylated Rb protein was detected in all cell lines except the HLE line, indicating that this cell line may have a deletion of and/or a mutation of the Rb gene. These results indicate that abnormalities of tumor suppressor genes other than p53, p16, p27, and Rb may be involved in hepatocarcinogenesis. The population doubling time of the wild-type p53 cells was significantly longer than that of the mutant p53 cells. Neither type of cell line showed a specific chromosome distribution which would indicate karyotype instability. The cell lines expressing the wild-type p53 produced tumors at lower frequency than those with the mutant p53 gene. Although there was no significant difference in effects of TGF-β1, EGF, cholera toxin, and db-cAMP on cell growth between the two types of cells, all three cell lines with the wild-type p53 were resistant to cytotoxicity of TNF-α, while two of the three with the mutant p53 were very sensitive to its cytotoxic effects.

To understand the development of the trabecular meshwork of the eye, floating cellular aggregates (multicellular spheroids) were formed from human trabecular cells in a non-adherent environment of culture and incubated for up to one month. Dissociated trabecular cells formed multicellular spheroids within one day in the non-adherent environment, and apoptosis continued to occur in the spheroids which had been initially filled with cells. The final structure after one month appeared as a meshwork of cells with large extracellular spaces. Epidermal and basic fibroblast growth factor (EGF and bFGF) protected trabecular cells in the spheroids from apoptosis and, as a result, kept the spheroids filled with cells even after one month. In the absence of excess EGF or bFGF, the multicellular spheroids grown in vitro from human trabecular cells mimicked the mesh-like structure of normal trabecular tissue. In constrast, under an excess of these growth factors, spheroids of high cellularity, resembling the abnormal trabecular tissues of patients with congenital glaucoma, were formed.

A simian cell line, Si-IIA, harboring Epstein-Barr-virus (EBV) -related herpesvirus (Si-IIA-EBV), produces malignant lymphoma in rabbits when administered by intravenous inoculation. In this study, we analyzed the Si-IIA-EBV genome and compared it with human EBV and herpesvirus macaca fascicularis 1 (HVMF 1 ), which is associated with B-cell lymphoma developing in SIV-infected immunosuppressed monkeys. DNA from Si-IIA-EBV was amplified by the polymerase chain reaction using three different primer pairs complementary to human EBV (B95-8) DNA; two of the primer pairs covered part of the long internal repeat 1 region (IR 1) and the third covered part of the BRRF 1 region. Direct sequencing of the three PCR products revealed that Si-IIA-EBV DNA had about 82% nucleotide homology to the human EBV DNA in all three regions and 92.4% homology to HVMF1 in the IR1 region. The blotting pattern by Southern blot analysis was different between Si-IIA-EBV and human EBV.

We purified a 44-kDa nuclear protein from salt-extract of permeable mouse ascites sarcoma cells in an effort to isolate factors involved in the repair of acid-depurinated DNA. It was copurified with a major AP endonuclease (APEX nuclease) by sequential column chromatography then further purified by sodium dodecyl sulphate-poly-acrylamide gel electrophoresis as a possible DNA repair support factor. Its partial amino acid sequences were determined, and a cDNA clone for the protein was isolated from a mouse T-cell cDNA library using long degenerate oligonucleotide probes deduced from the amino acid sequence. The complete nucleotide sequence of the cDNA (1.7 kilobases) was determined. Northern hybridization using this cDNA detected two transcripts: 1.8kb being the major one and 2.6 kb being the minor one. The complete amino acid sequence for the protein predicted from the nucleotide sequence of the cDNA indicates that the 44-kDa protein consists of 394 amino acids with a calculated molecular weight of 43,698. In tests performed thus far, the recombinant 44-kDa protein expressed in Escherichia coli has not expressed any repair-support activity. It remains to be analyzed whether the protein attains this activity after appropriate posttranslational modifications. Most parts of the 44-kDa protein cDNA and the deduced amino acid sequence were found to be identical to those of the protein p38 -2G4, recently reported as a cell cycle-specifically modulated nuclear protein of 38kDa. The p38-2G4 may be a truncated form of the present 44-kDa protein.