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Biomedical subjects

Y Tanio

Publications and source records attributed to Y Tanio.

At least 37 records · Page 2Linked to original sources

High sensitivity to peripheral blood lymphocytes and low HLA-class I antigen expression of small cell lung cancer cell lines with diverse chemo-radiosensitivity.

Three cell lines of small cell lung cancer (SCLC), which were established from specimens of untreated primary tumors biopsied by diagnostic bronchofiberscopy, were analyzed for immunological characteristics. These cell lines showed considerable heterogeneity in chemo-radiosensitivity, which was well correlated with clinical responses of the respective tumors, but their HLA-class I antigen expressions were equally depressed and they were susceptible to peripheral blood lymphocytes (PBL) and lymphokine-activated killer (LAK) cells, irrespective of their diverse chemo-radiosensitivity. Treatment of the cell lines with recombinant immune interferon (rIFN-gamma) increased their HLA-class I antigen expression and conversely depressed PBL sensitivity but not LAK sensitivity. This inverse relationship between HLA-class I expression and PBL susceptibility was also demonstrated using other pairs of autologous PBL and SCLC cell lines. rIFN-gamma changed neither HLA-class II antigen nor SCLC-specific antigen expression under the same experimental conditions. In vitro immunization of allogeneic peripheral blood lymphocytes with rIFN-gamma-treated SCLC cells induced allo-specific killer cells which lysed rIFN-gamma-treated more strongly than non-treated SCLC cells. These results suggest that reduced HLA-class I antigen expression of SCLC could protect the cancer from attack of killer T cells in spite of the higher sensitivity to PBL or LAK cells.

Antigens, Surface↗

[Relationship between drug resistance and oncogenes in lung cancer cell lines].

The 5-year survival of lung cancer patients is about 30% in Japan. One of the reasons for the poor prognosis seems to be drug resistance. It has been reported that certain types of oncogenes, such as ras, myc and fos, may play an important role in drug resistance. The myc protein forms a sequence-specific DNA-binding complex with Max and may act as a transcription factor; thus, it may be possible that myc family oncogenes are involved in DNA synthesis and repair processes mediating drug resistance. We report here that L-myc oncogene may be involved in the transition from drug-sensitive to drug-resistant phenotype of a certain small cell lung cancer cell line.

Animals↗

Two monoclonal antibodies against small-cell lung cancer show existence of synergism in binding.

Murine IgG1 monoclonal antibodies (mAbs), ITK-2 and ITK-3, were generated against a small-cell lung cancer (SCLC) cell line. Enzyme-linked immunosorbent assay using a variety of established cell lines as substrates, immunoperoxidase staining of freshly frozen tissue sections, and fluorescence-activated cell sorter analysis of peripheral blood leukocytes showed that these mAbs recognize a part of the SCLC-associated cluster 1 antigen. In immunoprecipitation studies, both ITK-2 and ITK-3 bound to a 145-kDa glycoprotein of SCLC cell membrane extracts, as did MOC-1 and NKH-1, which both recognize the cluster 1 antigen. However, because the binding of 125I-labeled ITK-2 to SCLC cells was not inhibited by MOC-1 or NKH-1, the binding site of ITK-2 on SCLC cells appeared to be different from that of either MOC-1 or NKH-1. Unexpectedly, binding of 125I-labeled ITK-2 to SCLC cells increased in the presence of ITK-3. This ITK-3-induced increase in ITK-2 binding was due partly to an increase in the number of binding sites for ITK-2 on SCLC cells. Addition of ITK-3 may, therefore, improve the effectiveness of ITK-2-based tumor detection or therapy.

Antibodies, Monoclonal↗

Characterization and purification of an immunosuppressive factor produced by a small cell lung cancer cell line.

The present study was undertaken to determine whether small cell lung cancer (SCLC) cell lines produce immunosuppressive factors and, if they do, to characterize the factors. The supernatants of SCLC cell lines, H69 and N857, inhibited not only the blastogenic response of human peripheral blood lymphocytes (PBL) to phytohemagglutinin or concanavalin A, but also the cytotoxic activity of lymphokine-activated killer cells. Neither was inhibited by supernatants from non-SCLC cell lines PC9, QG56, and A549. The immunosuppressive activity of H69 supernatant was stable upon heating to 56 degrees C for 60 min, but labile when heated to 70 degrees C for 10 min. The activity was abolished after dialysis at pH 2.0 or pH 11.0, but not at pH 4.5 or pH 9.0. Digestion with trypsin or proteinase eliminated the immunosuppressive activity, whereas treatment with neuraminidase, mixed glycosidase, DNase or RNase had no effect, suggesting that the immunosuppressive activity in H69 supernatant is due to a protein factor. This H69-derived immunosuppressive factor was isolated by ion exchange chromatography using a gradient of 0.04 to 0.08 M NaCl solution. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the factor to have molecular weights of 98 kD and 102 kD, respectively. These results suggest that SCLC cells produce a potent immunosuppressive factor which may account for the immune deficiency in SCLC patients.

Carcinoma, Small Cell↗

Chemo-radioresistance of small cell lung cancer cell lines derived from untreated primary tumors obtained by diagnostic bronchofiberscopy.

New cell lines of small cell lung cancer (SCLC) were established from specimens of untreated primary tumors biopsied by diagnostic bronchofiberscopy. The advantage of this method was ease of obtaining specimens from lung tumors. Establishment of cell lines was successful with 4 of 13 specimens (30%). Clinical responses of the tumors showed considerable variation, but were well correlated with the in vitro sensitivity of the respective cell lines to chemotherapeutic drugs and irradiation. One of the cell lines was resistant to all drugs tested and irradiation, while another was sensitive to all of them. Although the acquired resistance of SCLC is the biggest problem in treatment, the natural resistance to therapy is another significant problem. Either acquired or natural, resistance mechanisms of SCLC may be elucidated by the use of such cell lines derived from untreated tumors. This method and these SCLC cell lines are expected to be useful for the serial study of biologic and genetic changes of untreated and pre-treated tumors, or primary and secondary tumors.

Animals↗

Synergy of Nocardia rubra cell wall skeleton and interleukin 2 in the in vivo induction of murine lymphokine-activated killer cell activity.

Combination of an ip injection of Nocardia rubra cell wall skeleton (N-CWS) and 3 daily sc injections of human recombinant interleukin 2 (rIL 2) into C3H/HeN mice resulted not only in a significant increase in the number of peritoneal cells (PC) but also in a potent induction of their lymphokine-activated killer (LAK) activity, compared with results obtained with N-CWS or rIL 2 alone. The augmented LAK activity of PC was mediated by nonadherent, nonphagocytic, Thy-1.2+(-)- and asialo GM1+ cells. Nonadherent PC induced by an ip injection of N-CWS bound more 125I-labeled rIL 2 than did normal, nonadherent PC, and generated high LAK activity when cultured overnight with rIL 2. In contrast, normal, nonadherent PC responded only weakly to the overnight stimulation with rIL 2. The phenotype of N-CWS-induced PC with an elevated IL 2 responsiveness was Thy-1.2+(-)-, Lyt-1.1-, Lyt-2.1- and asialo GM1+, suggesting that the N-CWS-stimulated LAK precursors were derived mainly from the NK cell lineage. However, mature T cells may also be involved in this mechanism, because N-CWS failed to augment the IL 2 responsiveness of nonadherent PC in BALB/c nu/nu mice. Treatment of C57BL/6N mice bearing solid Lewis lung carcinoma (3LL) tumors with an intratumoral injection of N-CWS followed by 6 daily sc injections of rIL 2 resulted in the apparent suppression of tumor growth, while N-CWS or rIL 2 alone produced no such suppression. These results suggest that N-CWS augments the antitumor effect of rIL 2 by accumulating LAK precursors and elevating their responsiveness to rIL 2 at the injection site.

Adjuvants, Immunologic↗

Augmentation of murine lymphokine-activated killer cell induction by a factor produced by Nocardia rubra cell wall skeleton-stimulated T cells.

Four-hour exposure of C3H/HeN mouse spleen cells to Nocardia rubra cell wall skeleton (N-CWS) before 4-day culture with a suboptimal dose of human recombinant interleukin 2 (rIL 2) augmented the induction of lymphokine-activated killer (LAK) cell activity, whereas the treatment with N-CWS alone induced no cytotoxicity. In accordance with this, the IL 2 binding activity of spleen cells was augmented by combined stimulation with N-CWS and rIL 2. The augmented cytotoxicity was mediated by Thy-1.2+, Lyt-1.1-, Lyt-2.1- and asialo GM1+ cells. Cell cultures in diffusion chambers revealed that N-CWS-treated spleen cells produced a LAK cell induction-helper factor (LAK-helper factor, LHF) when cultured with rIL 2. The LHF production required Thy-1.2+, Lyt-1.1+, Lyt-2.1+ and asialo GM1- cells, and the coexistence of unstimulated accessory cells was also essential for the LHF production. Cells responding to both LHF and rIL 2 to generate LAK activity were Thy-1.2-, Lyt-1.1-, Lyt-2.1- and asialo GM1+. The culture fluid of spleen cells stimulated with both N-CWS and rIL 2 contained no tumor necrosis factor (TNF) activity, and the additional stimulation with N-CWS caused no production of either IL 2 or interferon (IFN). Murine recombinant interleukin 1 alpha (Mu-rIL 1 alpha) could not replace the augmentative effect of N-CWS on LAK cell induction. These results suggest that in the presence of rIL 2, N-CWS stimulates murine T cells to produce LHF that is probably distinct from IL 1, IL 2, TNF and IFN.

Adjuvants, Immunologic↗

Combined therapy of mice bearing a lymphokine-activated killer-resistant tumor with recombinant interleukin 2 and an antitumor monoclonal antibody capable of inducing antibody-dependent cellular cytotoxicity.

The ability of lymphokine-activated killer (LAK) cells to mediate antibody-dependent cellular cytotoxicity and its efficacy against a LAK-resistant tumor were investigated. Cells of the MH134 murine hepatoma line are scarcely lysed by LAK cells generated in vitro by incubation of C3H/HeN mouse spleen cells with human recombinant interleukin 2 (rIL 2). However, the splenic LAK cells potently lysed the LAK-resistant tumor cells in the presence of 11G2, a monoclonal antibody (MAb) of the IgG1 isotype reactive with a part of MM antigen. Peritoneal cells induced by daily i.p. injections of rIL 2 not only exhibited LAK activity but also mediated antibody-dependent cellular cytotoxicity against MH134 tumor cells in the presence of 11G2. The peritoneal cells exhibiting these cytotoxic activities were found to be nonadherent and nonphagocytic mononuclear cells possessing a similar cell surface phenotype as that of splenic LAK cells, that is Thy-1.2+ approximately -, Lyt-1.1-, Lyt-2.1-, and asialo GM1+. Treatment of spleen cells with antibodies and complement before culture with rIL 2 revealed that the phenotype of splenic LAK precursors is Thy-1.2- and asialo GM1+. The in vivo induction of peritoneal LAK cells in response to i.p. injections of rIL 2 was markedly depressed in C57BL/6 beige mice but was normally accomplished in BALB/c nude mice. Combined therapy of C3H/HeN mice bearing MH134 ascitic tumor with i.p. injection of rIL 2 and 11G2 brought about potent suppression of the tumor growth, resulting in the significant increase in the number of tumor-free mice, whereas neither rIL 2 nor the MAb could exhibit such a potent antitumor effect when used alone. Injection (i.v.) of anti-asialo GM1 antibody not only blocked the induction of peritoneal LAK cells by rIL 2 but also abrogated the development of the antitumor effect of the combined therapy. These results strongly suggest that combination of antitumor MAbs capable of inducing antibody-dependent cellular cytotoxicity with rIL 2 therapy could result in the generation of potent antitumor effects against LAK-resistant tumors and that asialo GM1-positive non-T-cell populations including cells of the natural killer cell lineage are essential, at least in part, for development of the antitumor effects of the combined therapy with rIL 2 and MAbs.

Animals↗

Tumor cells transfected with the neomycin resistance gene (neo) contain unique genetic markers useful for identification of tumor recurrence and metastasis.

Studies in tumor biology often require techniques to accurately identify tumors or tumor cell lines. Transfection of plasmid DNA into mammalian cells has been shown to introduce unique genetic markers into recipient cells. These unique genetic markers are detected by Southern transfer. To determine the usefulness of such markers for in vivo studies, a bacterial gene, neo, was transfected into mouse and guinea pig tumor cells. Inbred mice and guinea pigs were injected with syngeneic tumor lines marked with neo. DNA extracted from primary and recurrent tumors and metastases was tested for the presence of the characteristic markers. Integration of neo in cell lines was shown to be stable during tumor growth, recurrence and metastasis, and therefore to be useful for identification of tumors growing in vivo.

Animals↗

Host-clonal interactions in the generation of proviral gene deletion variants.

A nonproducer clone (clone A1) (from a retrovirus-infected guinea pig fibrosarcoma) has been described that under conditions of in vivo immunologic selection forms variants that lack the proviral gene. One trivial explanation for the apparent loss of the provirus from clone A1 is that clone A1 did not originate from a single cell. For evaluation of this possibility, subclones were derived from clone A1 and tested for tumor recurrence in nonimmune and virus-immune animals. Each of four subclones contained the A1 provirus and exhibited specific viral interference; tumor recurrences formed from each of these four subclones lacked the clone A1 provirus. Possible, when heterogeneous populations of retrovirus-infected cells are injected into nonimmune animals, some clones will elicit immunologic responses to retroviral antigens and subject other clones in the population to immunologic selective pressures. For testing this concept, clone A1 was injected in admixture with a producer clone (clone A4) into nonimmune Sewall Wright strain 2 guinea pigs. Tumors formed in nonimmune guinea pigs inoculated with clone A1 in admixture with clone A4 were shown to lack a detectable clone A1 provirus. The results supported the concept that a somatic mutational event (deletion of the proviral gene) occurs during growth of clone A1. When heterogeneous populations of retrovirus-infected cells are injected into animals, host-clonal interactions may occur leading to outgrowth of proviral gene deletion variants. These results supported the notion that interactions between tumor clones and the host can change the dominant clonal type of the tumor and provide a genetic basis for this change.

Animals↗

In vivo immunologic selection of proviral gene deletion variants from a nonproducer clone.

The mechanism by which tumors recur at sites of injection of retrovirus-infected fibrosarcoma cell lines was investigated. Previously, it was established that tumor recurrences reflect outgrowth of rare cells that lack viral antigens and are susceptible to superinfection with the homologous retrovirus. In the present study clones isolated from a retrovirus-infected cell line were evaluated as precursors for tumor recurrence. Under conditions of in vivo immunologic selection, a clone that contained a single abbreviated copy of the provirus formed variants that lacked the proviral gene. Tumor variants lacking the proviral gene grew progressively in both nonimmune and virus-immune male Sewall Wright strain 2 guinea pigs. Tumor recurrence could be prevented by superinfection of the virus-infected fibrosarcoma cell line or by superinfection of the precursor for tumor recurrence. Cell lines infected with retroviruses varied in frequency of tumor recurrence formation. This model may be useful in analyzing gene deletion as a mechanism of tumor escape from host immunologic attack.

Animals↗

Immunogenicity and immunosensitivity of a guinea pig B-cell leukemia subline lacking cell surface Ia antigens.

L2C is a transplantable B-cell leukemia of strain 2 guinea pigs. Transplantation protection experiments were performed with L2C sublines expressing or lacking cell surface antigens coded for by the I region of the major histocompatibility complex (Ia). A subline (BZ-L2C) that lacked cell surface Ia antigens was immunogenic but relatively resistant to immunological attack. The data suggest that rejection of this B-cell leukemia may be influenced by expression of cell surface Ia antigens.

Animals↗

A reliable method for reconstituting thymectomized, lethally irradiated guinea pigs with bone marrow cells.

We developed a reliable method for reconstituting thymectomized, lethally irradiated guinea pigs. Injection of 2.5-10 X 10(7) syngeneic bone marrow cells into adult thymectomized, lethally irradiated guinea pigs produced survival of 46-100% of treated animals. Gentamycin sulfate (5 mg/kg of body weight) for 10 days was required for optimal results. Acidified drinking water (pH 2.5) appeared to be required for optimal results. Thymectomized, lethally irradiated, bone marrow reconstituted ('B') guinea pigs had impaired ability to develop delayed cutaneous hypersensitivity to mycobacterial antigens and cutaneous basophil hypersensitivity to keyhole limpet hemocyanin; proliferative responses to phytohemagglutinin were impaired.

Aging↗

Selection and rejection of retrovirus-expressing tumor cells from a heterogeneous murine leukemia virus-infected cell population.

We studied the basis of tumor recurrence at sites of rejection of retrovirus-infected guinea pig fibrosarcoma cells. Tumor recurrences, in contrast to the parent tumor, lacked retroviral antigens and did not release infectious virus. When reinjected into syngeneic animals, cell lines derived from tumor recurrences grew progressively. Tumor recurrences could be infected with the homologous retrovirus. Tumor rejection and recurrence were modulated by host immunity. In guinea pigs immunized to virus-infected cells, tumor recurrences occurred earlier and in a higher proportion of animals than in nonimmune guinea pigs. In some immunosuppressed guinea pigs, retrovirus-infected tumor cells grew progressively. Progressively growing tumors of immunosuppressed guinea pigs contained large amounts of infectious virus and expressed viral antigens. To identify the source of tumor recurrences, the parent virus-infected tumor was cloned. Clones were heterogeneous in virus expression; some clones released large quantities of infectious virus; others did not. Two clones formed tumors in syngeneic animals. Injection of a virus producer clone into virus-immune animals was not followed by tumor recurrence. The data suggest that the reappearance of tumors at sites of injection of retrovirus-infected fibrosarcoma cells represents immune selection and rejection of retrovirus-expressing cells. Cells with the potential to form tumor recurrences existed in the parent virus-infected tumor population.

Animals↗

Antigenic variants isolated from a mutagen-treated guinea pig fibrosarcoma.

Antigenic variants were derived from a mutagen-treated, apparently nonimmunogenic fibrosarcoma of strain 2 guinea pigs. Fibrosarcoma line 107C3, originally induced by exposure of fetal cells to a chemical mutagen, was treated in vitro with the same mutagen. Cells that survived mutagen treatment were cloned, and the clones were tested for growth in soft agar, in conventional and immunosuppressed syngeneic guinea pigs, and in nude mice. At early passages after treatment, all clones tested in conventional syngeneic guinea pigs either failed to grow intradermally or grew temporarily and then regressed. At later passages after treatment, five of eight evaluable clones grew progressively; the characteristic of intradermal tumor growth followed by tumor regression (tum- or regressor) was a stable property of three of eight evaluable clones. The number of tumor cells required to produce progressively growing intradermal tumors in 50% of the animals (TD50) of the three tum- clones was at least 4 orders of magnitude greater than the TD50 of the parent fibrosarcoma. Tum- clones were not detected among 10 clones derived from the untreated parent tumor. Regressor clones formed colonies in soft agar and grew progressively in immunosuppressed syngeneic guinea pigs and nude mice. Regressor clones contained tumor transplantation antigens. Guinea pigs immunized with clones that grew and regressed rejected a challenge with the parent tumor when the dose of parent tumor cells was 1 to 3 times the TD50. Guinea pigs immunized by temporary growth of the parent tumor followed by excision of the local tumor and the regional lymph node did not reject a challenge with the parent tumor. These results confirm the results of experiments with murine tumors and extend the observations on tum- clones to the guinea pig. The results indicate that in guinea pigs it is possible by immunization with tumor cell variants derived from the mutagen-treated parent tumor to produce transplantation immunity to an apparently nonimmunogenic tumor.

Animals↗

Comparison of antimetastatic effect against Lewis lung carcinoma after intratumoral and intravenous injections of cell-wall skeleton of Propionibacterium acnes C7 in C57BL/6 mice.

Antimetastatic activity of cell-wall skeleton of Propionibacterium acnes C7 (P. acnes-CWS) in C57BL/6 mice varied depending on the injection route. The kinetics of antimetastatic effect against Lewis lung carcinoma (3LL) revealed that the sooner intratumoral (it) injection of P. acnes-CWS was carried out, the better the result. However, intravenous (iv) injection of P. acnes-CWS produced the best result if P. acnes-CWS was injected at about the time when metastases began to develop in the lungs. Pretreatment with intrafootpad (ifp) injection of P. acnes-CWS inhibited primary tumor growth and subsequent pulmonary metastases especially when given 7 days before tumor inoculation into the same footpad, but tended to enhance artificial pulmonary metastases when given 7 days before iv injection of tumor cells. In contrast, pretreatment with iv injection of P. acnes-CWS enhanced spontaneous pulmonary metastases especially when given 7 days before ifp inoculation of tumor cells, but inhibited artificial pulmonary metastases when given one day or 7 days before iv injection of tumor cells. These results suggest the difficulty of treatment of tumor metastases with immunological adjuvants. In T-cell-deprived mice, it injection of P. acnes-CWS showed no antimetastatic effect against 3LL, but iv injection was still effective. This indicates that T-cells are required for the antimetastatic effect of it injection of P. acnes-CWS, but iv injection of P. acnes-CWS is able to inhibit pulmonary metastases in T-cell-deprived mice.

Animals↗

Effect of quinonyl-N-acetyl muramyl dipeptide on immune responses in tumor-bearing mice.

The efficacy of 6-O-QS-10-N-acetyl muramyl-L-valyl-D-isoglutamine methyl ester (quinonyl-MDP-66) for restoring impaired immune status was examined in mice bearing Lewis lung carcinoma. Quinonyl-MDP-66 suspended in phosphate-buffered saline was shown to restore the depressed allogeneic cell-mediated cytotoxicity of spleen cells from mice with Lewis lung carcinoma when the chemical was injected twice intraperitoneally, intravenously, or intratumorally. However, primary tumor size and the numbers of lung metastases were not affected when quinonyl-MDP-66 was administered under the present experimental conditions. Intraperitoneal injection of quinonyl-MDP-66 in mice with Lewis lung carcinoma enhanced host resistance to Listeria monocytogenes infection.

Acetylmuramyl-Alanyl-Isoglutamine↗