Search PubMed⌕ Search

Biomedical subjects

R K Oldham

Publications and source records attributed to R K Oldham.

At least 73 records · Page 4Linked to original sources
PubMed1990

Binding and functional properties of a mouse-human chimeric monoclonal antibody of the human IgG1 subclass with specificity for human carcinomas.

Recombinant DNA techniques were utilized successfully to join the coding regions for the variable region of a mouse anti-tumor antibody (BA-Br-1) and the human IgG1 constant region for both the light and heavy chains. After insertion into a mouse myeloma host cell line, the chimeric genes were expressed successfully and the resulting antibody (ING-1) was purified. In this study, we describe biochemical, serological, immunohistochemical, and functional properties of the chimeric ING-1 antibody. Analysis of the synthesized antibody revealed that while it was similar in size to the mouse antibody, it had a different pI as determined by isoelectrofocusing. The flow cytometric binding profiles of the new molecule were found to be essentially identical to the parental mouse immunoglobulin. The specificity of the chimeric ING-1 and mouse BA-Br-1 antibodies were compared by extensive immunohistochemical analysis on human normal and tumor tissues. The chimeric antibody retained the same broad carcinoma binding activity, showing strong reactivity with greater than 90% of epithelial tumor tissues, as was previously observed for the mouse BA-Br-1 antibody. The chimeric and mouse antibodies also recognized the same selected normal tissues: primarily glandular epithelia, gastrointestinal mucosa, bile ducts, and thyroid follicles. Analysis of the biological function of the chimeric antibody revealed that it possessed ADCC activity against antigen-bearing tumor targets in vitro which was absent from the mouse form of the antibody. Competent effector cells could be either PBMCs from normal healthy donors, PBMCs from cancer patients receiving LAK/IL-2 therapy, or LAK cells prepared from cancer patients. Enhanced cytotoxicity even in the presence of LAK cell killing was noted with effector cells from the latter two sources. This contrasts sharply with the absence of activity in the same systems when the native murine antibody was used. The in vitro activation of cell-dependent cytolysis observed with the chimeric antibodies when effector cells from both normal and tumor-bearing donors were used strongly suggests that comparable activity would be observed in vivo. These results, along with the broad carcinoma binding activity and minimal normal tissue reactivity, suggest that the ING-1 chimeric antibody may be useful in cancer therapy. The application of the ING-1 chimeric antibody for treatment of tumors thus offers a promising avenue for future research.

Animals↗
PubMed1989

Activation and expansion of tumor-derived activated cells for therapeutic use.

We obtained tumor specimens from patients with cancer in an effort to activate and expand the tumor-infiltrating lymphocytes for therapeutic use. With the use of finely minced tumor preparations from eight different tumor types, recombinant interleukin-2, and lymphokine-activated killer cell-conditioned medium, lymphocytes were expanded in vitro. After 4 weeks, the tumor cells were virtually absent from the cultures. At this point, the lymphocytes were termed "tumor-derived activated cells" (TDACs). Over 90% of the TDACs from each of the different tumor types were T lymphocytes, and the percentage of cells expressing either CD4 or CD8 varied considerably from population to population. The lymphocytes showed specific cytolytic activity in melanoma and colon and renal cell carcinomas. Continued expansion and long-term growth of the TDACs, as well as maintenance of the cytolytic activity, were achieved by periodic stimulation of the TDACs with irradiated autologous tumor cells. In a clinical study of 28 patients with cancer, we generated a mean number of 1.2 X 10(11) TDACs in an average time in culture of 69 days. These TDACs were subsequently infused into the patients with cancer. TDACs appear to represent an important resource for biotherapy of patients with cancer.

Antigens, Neoplasm↗
PubMed1989

Cancer biotherapy.

Explore the source record for details and available documents.

Book Reviews as Topic↗
PubMed1989

Tumor acquisition, propagation, and preservation. The culture of human colorectal cancer.

Fourteen new colorectal cancer cell lines were developed as part of a tumor acquisition, propagation, and preservation program for biotherapy. Fifty-six specimens were received. Nine cell lines were generated from biopsies; seven of these cell lines were from metastatic lesions. Five additional cell lines were developed from xenografts grown in nude mice. Biopsies that produced three of these xenografts gave rise to parallel culture cell lines. Biopsy-derived and xenograft-derived cell lines from the same tumor behaved similarly in culture and exhibited similar markers when assessed immunohistochemically. Collagen substrate was beneficial in the primary culture of 50% of the specimens tested. Collagen was required for the successful propagation of two cell lines.

Animals↗
PubMed1989

Immunohistochemical phenotyping of human solid tumors with monoclonal antibodies in devising biotherapeutic strategies.

A panel of 14 monoclonal antibodies (MoAbs) (4 raised against breast cancer, 6 against colon cancer and 4 against melanoma) were used to phenotype frozen sections of tumor biopsies obtained from 110 patients, by avidin-biotin-peroxidase complex techniques. We observed heterogeneity of antigen expression among the multiple metastatic lesions of single patients, as well as among tumor lesions from different patients with similar tumor histotypes. A wide range of cross-reactivity of anti-(breast-carcinoma) and anti-(colon-carcinoma) MoAbs with other carcinoma histotypes and limited reactivity with melanoma and sarcoma was detected. Some of our anti-melanoma MoAbs were also found to cross-react with selected carcinomas. Nine of the 14 MoAbs most reactive with carcinomas of diverse histotypes have been identified. A mixture or 'cocktail' of different MoAbs could be selected for each individual patient in order to achieve binding of MoAbs with most, if not 100% of tumor cells. This study illustrates the approach that we have taken to individualize the cocktail of MoAbs for the development of patient-specific therapeutic immunoconjugates.

Adult↗
PubMed1989

IL-2: a review of current knowledge.

A limiting factor in the use of T-cell therapy for cancer has always been the ability to expand T-cells, whether derived from the peripheral blood, spleen or tumor. The availability of r-IL-2 has confirmed the feasibility of expanding T-cells and LAK cells for clinical trials after confirmation of their anti-tumor activity in murine models. While the most promising results using IL-2/LAK cells have been in patients with melanomas and renal cancer, anti-tumor effects have been seen in patients with a wide variety of cancers, even those with bulky tumors. This form of adoptive cellular biotherapy has confirmed that an expanded and activated cell population using the cancer research laboratory can provide a method by which clinicians can effectively treat advanced cancer. In tumor biopsies, the infiltrating lymphocytes have been recognised and are known to be cytolytically active for many years. Using IL-2 stimulation of growth and an ongoing antigen stimulation (tumor cells), we have maintained selective killing of tumor cells. Accessing cells and various factors in the medium which support and enhance T-cell growth and activation are being defined. The role of antigen stimulation is also basic to further progress with this technology. Tumor cell chunks and cultures, nude mouse xenografts, or purified antigen all represent potential sources of repeated antigen stimulation. Thus, the components are now available to develop a broad attack on advanced cancer using this laboratory-based technology of tumor-derived activated cell (TDAC) stimulation, expansion and therapy. These approaches and preliminary results point to the dramatic change in technology which has allowed the cancer research laboratory to be a substantial component in new clinical approaches to cancer treatment. Laboratory scientists have become a major component in the design and conduct of clinical trials using adoptive biotherapy. These techniques are laboratory based and it is only with close and effective communication between the laboratory scientists and the clinician that rapid and effective translation of these technologies to the patient will occur (20).

Epitopes↗
PubMed1989

Immunoconjugates of doxorubicin and murine antihuman breast carcinoma monoclonal antibodies prepared via an N-hydroxysuccinimide active ester intermediate of cis-aconityl-doxorubicin: preparation and in vitro cytotoxicity.

Doxorubicin (DXR) conjugated to murine monoclonal antibodies (MoAb) raised against human breast tumor cells demonstrated a MoAb-specific, molar ratio-dependent in vitro cytotoxicity. These conjugates were prepared on a scale sufficient to allow for subsequent clinical trials (1 to 3 g of MoAb per conjugation reaction). The conjugation reaction proceeded via an N-hydroxysuccinimide (NHS) active ester intermediate of cis-aconityl-DXR (CA-DXR), resulting in a cis-aconitate acid-sensitive linker between the DXR and MoAb. Molar ratios of DXR to MoAb ranged from 40 to 45. The immunoreactivity of conjugated MoAb was only slightly decreased from naked MoAb. When immunoconjugates were incubated with MoAb-reactive tumor cells for 3 hours, specific cell-killing was observed. If the exposure time was lengthened to 18 hours, however, nonspecific killing resulted. Incubation of the immunoconjugate with the nonspecific adsorbant Amberlite XAD-2 caused an average 30% decrease in the DXR-to-MoAb molar ratio, suggesting a population of drug that is tightly but noncovalently associated with MoAb.

Adsorption↗
PubMed1989

Establishment and characterization of a malignant lymphoid cell line from a chronic lymphocytic leukemia patient.

A long-term culture Epstein-Barr virus (EBV)-negative malignant lymphoid cell line (NAK) was established from a lymph node biopsy of a chronic lymphocytic leukemia patient. This cell line is of particular interest because it grows as an adherent cell line and depends on the presence of autologous conditioned medium for growth. After 6 months of growth in vitro, doubling time and cell cycle parameters were derived. Doubling time was 48 hours with over 45% cycling cells. Cell viability was over 90%. Expression of B-cell markers (CD19 and CD20) and surface immunoglobulin of the original tumor cell biopsy were roughly the same as in passage 14 (3 months in culture), including the expression of the original patient idiotype and IgM-lambda. Furthermore, binding of antiidiotypic antibodies was only slightly decreased at passage 14. Cytogenetic studies of chromosomal abnormalities in the primary tumor tissue and in later passages indicated similar abnormalities, with no translocations t(8;14), t(14;22), or t(2;8). However, frequent trisomies, deletions, and t(1;4) translocations were observed. Negative results for EBV nuclear antigen indicate that this cell line is an EBV-negative cell line.

Antigens, Differentiation, B-Lymphocyte↗