Biomedical subjects

R C Rees

Publications and source records attributed to R C Rees.

At least 73 records · Page 4Linked to original sources

PubMed1994

Matrix metalloproteinase 9 expression in primary human prostatic adenocarcinoma and benign prostatic hyperplasia.

Matrix metalloproteinase (MMP) expression was investigated in patients with prostatic adenocarcinoma and benign prostatic hyperplasia (BPH). Forty-one men were studied: 26 had histologically proven prostate cancer, with 14 (54%) showing metastatic disease; 15 patients had BPH. Prostatic tissue was obtained from transurethral resection and needle core biopsies; gelatinolytic activity was determined by zymography. Seven gelatinolytic bands were detected, with molecular weights ranging from > 100 kilodalton (kDa) to 29 kDa. Nine of 14 patients (64%) with skeletal metastases had 92 kDa activity, present in only two of 12 patients (17%) with a negative bone scan, and absent in BPH. The 92 kDa gelatinolytic activity was expressed in 73% of aneuploid tumours compared with 20% of diploid tumours. A 97 kDa gelatinase was expressed in 80% of BPH samples and 23% of carcinoma patients. Enzyme bands of 72, 66 and 45 kDa were equally expressed in malignant tissue, irrespective of metastatic status, but were expressed in fewer BPH patients. The 97, 92, 66 and 45 kDa enzymes were identified as being pro-MMP-9 sequences by Western blotting, using a specific antibody directed against the pro sequence of the mature protein. MMP activity appeared to be increased in malignant prostatic tissue compared with BPH. Pro-MMP-9, in its 92 kDa form, was shown to be exclusively expressed by malignant prostatic tissue, and in particular by tumours that exhibited the aggressive and metastatic phenotype.

Adenocarcinoma↗

PubMed1994

Changes in the phenotypic characteristics of eosinophils from patients receiving recombinant human interleukin-2 (rhIL-2) therapy.

We have studied the properties of eosinophils from 26 patients with malignant melanoma and 16 patients with renal cell carcinoma (RCC) who were entered into a phase II clinical trial using various schedules of low-dose rhIL-2 immunotherapy. Eosinophilia was observed in 65% of melanoma patients and 100% of renal patients when receiving rhIL-2 therapy. The eosinophil count increased up to 20-fold approximately 5 d after the appearance of lymphocyte activation markers. This would be consistent with eosinophil kinetics and the release of soluble mediators, for example IL-5, from lymphocytes. Eosinophils from eosinophilic patients became hypodense compared to their pre-treatment levels as demonstrated by sedimentation through a discontinuous metrizamide density gradient; they also showed an increased expression of CD4, CD25 and CD11b cell surface activation markers. Eosinophil count could not be correlated to either patient survival or response to therapy in melanoma patients; however, patients with renal cell carcinoma demonstrated a significant correlation (P < or = 0.05) between eosinophil count and survival but not with clinical response. Therefore the maximum eosinophil count achieved during rhIL-2 therapy is of prognostic significance in patients with renal cell carcinoma.

Antigens, Surface↗

PubMed1994

Nm23 protein expression in thyroid neoplasms.

The nm23 gene production has been heralded as a suppressor of metastasis in many human tumours but it is not clear at which stage in the metastatic process nm23 protein exerts its effect. The aim of this study was to test whether nm23 protein is associated with occurrence or category of angioinvasion. We have made use of the well documented fact that follicular carcinoma of the thyroid may show vascular invasion whereas papillary carcinomas may metastasis via the lymphatics. 65 thyroid tumours (20 follicular adenomas, 22 papillary carcinomas, 23 follicular carcinomas) were stained for nm23 protein using an immunopurified polyclonal antibody. Nm23 protein status showed no correlation with category of thyroid tumour. This is indirect evidence that nm23 does not suppress metastasis by influencing vascular invasion in this tumour type.

Adenocarcinoma, Follicular↗

PubMed1994

Transfection of tissue transglutaminase into a highly malignant hamster fibrosarcoma leads to a reduced incidence of primary tumour growth.

Reduced expression of the tissue transglutaminase in both murine and human tumours has been consistently associated with tumour growth and progression. To investigate the functional effects of transglutaminase expression we have transfected a constitutive human tissue transglutaminase expression construct into a highly malignant hamster fibrosarcoma cell line Met B. Met B clones expressing the exogenous tissue transglutaminase exhibited a reduced incidence of primary tumour formation and an increased adherence to tissue culture plastic and fibronectin coated surfaces when compared to transfected and non transfected control cells. Transglutaminase transfected clones exhibited no significant differences in their growth rates measured in vitro, cell morphology or levels of spontaneous apoptosis measured by the determination of detergent insoluble apoptotic envelopes. The data demonstrates a suppressive effect of tissue transglutaminase on tumour growth and confirms its importance in the phenotypic changes associated with the cancer process.

Animals↗

PubMed1993

Interleukin-6 and tumour necrosis factor alpha synergistically block S-phase cell cycle and upregulate intercellular adhesion molecule-1 expression on MCF7 breast carcinoma cells.

The effect of IL-6 and TNF alpha were studied on human MCF7 breast cancer cells. Synergistic interaction between IL-6 and TNF alpha, on the growth inhibition (50% reduction in the percentage of S-phase cells) and the upregulation of ICAM-1 expression (4 to 11-fold increase) was shown using flow cytometric methods. IL-6 and TNF alpha alone had negligible effect on the cell cycle. The individual effect of IL-6 resulted in down-regulation of ICAM-1 expression (30-35%), while TNF alpha always upregulated ICAM-1 (1.5 to 4-fold increase). The combined effect of IL-6 and TNF alpha consistently caused an increased expression of ICAM-1, which was greater than the sum of each one alone and also sustained for 72 h following cytokine withdrawal.

Breast Neoplasms↗

PubMed1993

Nm23 protein expression in ductal in situ and invasive human breast carcinoma.

BACKGROUND: Mortality associated with human breast carcinoma is almost entirely due to subsequent metastatic disease, but the molecular basis of this metastasis is not understood. Elucidation of the genetic control of metastatic propensity of a tumor is important in determining prognosis and choice of therapy. Expression of nm23, a putative metastasis suppressor gene, has been detected in human breast cancers, but studies have not consistently shown high levels of the Nm23 messenger RNA or protein to be associated with better histological differentiation. This inconsistency suggests that Nm23 protein may act independently as a metastasis suppressor. PURPOSE: The purpose of this retrospective study was to investigate the relationship of Nm23 protein expression with 1) histology in ductal breast carcinoma in situ and 2) the variables considered to be the major prognostic indicators in invasive breast carcinoma. METHODS: We obtained formalin-fixed biopsy specimens of breast tissue excised from 128 patients with breast lesions detected by mammography. Of these patients, 35 had been diagnosed with benign breast disease, 26 with ductal carcinoma in situ (DCIS), and 67 with invasive carcinoma. Tissue sections were embedded in paraffin blocks, and immunohistochemical staining was used to determine Nm23 expression. Specimens were rated positive if all lesional epithelium was stained and negative if any lesional epithelium was unstained. Statistical analysis was performed by multiple regression analysis because of nonorthogonality of the data. RESULTS: All 35 examples of benign breast disease showed uniform epithelial cell staining. The seven cases of comedo DCIS were negative for Nm23 protein; all 18 noncomedo types were positive. Nm23 negativity was significantly associated with worsening invasive ductal carcinoma grade and advancing lymph node stage but not with tumor diameter or vascular invasion. Despite the putative antimetastatic role of the nm23 gene, no statistically significant association was found between Nm23 protein expression and vascular invasion. CONCLUSIONS: The precise role of the nm23 gene remains to be established, but our simplified immunohistochemical rating system shows an association between Nm23 protein expression and the two most significant prognostic factors relating to histologic grade and stage. Nm23 negativity distinguished comedo ductal carcinoma in situ from the other histological types, a finding consistent with the fact that comedo histology is known to have a higher likelihood of becoming invasive and of having higher cell proliferation rates and higher expression of growth factor (c-erb B2) receptor.

Breast Diseases↗

PubMed1993

Phenotypic and cell cycle analysis of human peripheral blood mononuclear cells activated with interleukin-2 and/or OKT3.

The poor clinical response rates of cancer patients following immunotherapy with interleukin-2 (IL-2) and other cytokines has prompted attempts to enhance the response rate by using combinations of biological response modifiers. Peripheral blood mononuclear cells (PBMC) respond to interleukin-2 and mediate non-MHC-restricted cytotoxicity and cell proliferation. The addition of anti-human CD3 monoclonal antibody OKT3 has been reported to increase cytotoxicity by increasing the number of cells generated in response to the two stimuli; however, our results could not confirm this finding. In the present study we have investigated the proliferative capacity of individual populations of PBMC responding to IL-2 and OKT3 compared to either stimulus alone, in order to identify possible reasons for the failure of OKT3 to generate enhanced cytotoxic responses. PBMC were stained with monoclonal antibodies to surface antigens and propidium iodide in order to determine the phenotype of populations of PBMC progressing through the cell cycle. OKT3 alone caused an increase in PBMC progressing through the cell cycle, and addition of recombinant human IL-2 (rhIL-2) sustained this response. A higher percentage of CD56- or CD16-positive cells responded to the rhIL-2 alone, but the addition of OKT3 lowered the percentage of this phenotype and increased the number of CD3-positive T cells, which additionally demonstrated an increased CD25 expression. Comparison of the phenotypes progressing through the cell cycle in response to OKT3 plus rhIL-2 or rhIL-2 alone showed that a higher percentage of all populations responded to OKT3 plus rhIL-2, compared to IL-2 alone. Using flow cytometric cell sorting, those populations of cells with cytolytic activity were identified. Using flow cytometry, it was also possible to show minority cell populations (i.e., those representing less than 5% of the total number of cells) responding to individual stimuli and entering the cell cycle. This technique therefore offers distinct advantages over conventional proliferation assays.

Antigens, CD↗

PubMed1993

TNF alpha protects SW742 human colon carcinoma cells against non-MHC-restricted cytolysis.

The ability of interferons (IFN alpha and IFN gamma) to protect human tumour cells from non-MHC-restricted cytotoxicity is well established. We show that in addition to rhIFN gamma, rhTNF alpha is also able to decrease the susceptibility of the human colon carcinoma cell line SW742 to non-MHC-restricted lysis by fresh and IFN alpha activated peripheral blood mononuclear cells. The observed decrease in lysis was not the result of a decrease in the rate of killing. rhTNF alpha and rhIFN gamma were unable to alter MHC class 1 expression, indicating that the protection induced was not the result of increased class 1 antigen expression; however, both cytokines enhanced ICAM-1 expression on the tumour cells. rhTNF alpha and rhIFN gamma did not alter the proliferation or cell-cycle profile of SW742 cells, indicating that the protection was not cell-cycle phase dependent and was not secondary to suppression of cell growth.

Cell Adhesion Molecules↗

PubMed1993

Loss of heterozygosity of the thyroid hormone receptor B in posterior uveal melanoma.

Cytogenetic investigations of posterior uveal melanomas have identified non-random changes of chromosomes 3, 6, and 8. Monosomy of chromosome 3 with additional copies of 8q occur principally in the subgroup of uveal melanomas arising from the ciliary body. To determine whether ciliary body and choroidal melanomas maintain submicroscopic differences in their genetic aetiology, studies of the loss of heterozygosity (LOH) of THRB (ERBA beta) on 3p were undertaken. DNA from the blood and tumours of 19 patients with uveal melanoma were analysed for LOH of two restriction fragment length polymorphisms (RFLP). Approximately 60% of the uveal melanomas demonstrated allelic loss of THRB. Although the majority of tumours with allelic loss originated wholly, or in part, from the ciliary body, choroidal melanomas also demonstrated allelic loss of THRB. These results suggest that deletions of chromosome 3 occur in the absence of visible cytogenetic changes and may imply that alterations of chromosome 3 are integral to the tumourigenesis of both sets of uveal melanomas.

Choroid Neoplasms↗

PubMed1993

'Anti-metastatic' nm23 gene product expression in keratoacanthoma and squamous cell carcinoma.

An inverse correlation has been demonstrated between nm23 gene expression and metastasis. The gene is located on chromosome 17q (q1.1-q2.1), a region distinct from tumour suppressor gene p53. We have previously reported expression of mutant products of p53 gene to be significantly associated with worsening degrees of differentiation in squamous cell carcinoma. nm23 gene product, which shows complete identity to human erythrocyte nucleoside diphosphate kinase, was used to raise an affinity-purified polyclonal antibody Ab-11 which is applicable to formalin-fixed and paraffin-embedded tissues. Keratoacanthomas and squamous cell carcinomas of the epidermis form a fascinating human tumour model in which to test the hypothesis that the nm23 gene confers 'anti-metastatic' properties, since the former never metastasise while the latter have this potential. Two observers rated immunohistochemistry for the nm23 gene product as the proportion of tumour positive from grades 1-4 (corresponding to 25, 50, 75 and 100% of tumour cells stained). Nineteen typical keratoacanthomas, 20 well, 21 moderately and 8 poorly differentiated epidermal squamous cell carcinomas were studied. The Jonckheere-Terpstra test statistic of association between staining grade and lesion type was 762.5, p = 0.189 (2 tails), p = 0.0945 (1 tail). There was no statistically significant trend in tumour staining from keratoacanthoma through decreasing grades of differentiation of squamous cell carcinoma. nm23 product expression does not appear to correlate with differentiation, itself an indicator of metastatic potential, in this system of human squamous cell neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗

PubMed1993

Interleukin-2-activated human effector lymphocytes mediate cytotoxicity by inducing apoptosis in human leukaemia and solid tumour target cells.

The mode of cytotoxic action employed by cytolytic lymphocytes remains unclear, with the possibility of several mechanisms being utilized dependent upon the activation state of the effector cell. In this work, the induction of apoptosis in target cells by 'killer' lymphocytes at differing states of activation has been studied. Although the cytotoxicity of natural killer (NK) cells and recombinant human interleukin-2 (rhIL-2) or interferon-alpha (IFN-alpha)-activated effector cells, against NK-sensitive target cells, was high, their cytotoxic action appeared to be mediated via differing pathways. Effector cells activated short term (4 hr) with rhIL-2 and those mediating rhIL-2 lymphokine-activated killer (LAK) activity after long-term (4 day) activation were found to induce the formation of sodium dodecyl sulphate (SDS)-insoluble apoptotic bodies in NK-sensitive target cells, as well as increasing the level of activity of the apoptosis related enzyme tissue transglutaminase, thus suggesting the induction of the apoptotic pathway as a means of effecting target cell death. Non-activated and short-term (4 hr) IFN-alpha-activated effector cells did not appear to utilize this pathway in the target cell as their means of cytotoxicity. Effector cells showing LAK activity were also cytotoxic towards NK-insensitive cells, and this cytotoxicity again appeared to be mediated via the apoptotic pathway.

Apoptosis↗

PubMed1993

Identification of the 72-kDa (MMP-2) and 92-kDa (MMP-9) gelatinase/type IV collagenase in preparations of laminin and Matrigel.

EDTA inhibitable type IV collagenolytic activity copurified with laminin preparations from the Engelbreth-Holm-Swarm (EHS) tumor. Several gelatinolytic and type IV collagenolytic matrix metalloproteinase (MMP) species were visualized in EHS laminin from three different sources by gelatin and type IV collagen substrate gel electrophoresis. Incubation with 4-aminophenylmercuric acetate and trypsin suggested that laminin contained both active and latent MMPs. EHS-derived reconstituted basement membrane, Matrigel, was found to possess an MMP profile identical to that of laminin. The presence of 72-kDa (MMP-2) and 92-kDa (MMP-9) gelatinases/type IV collagenases was demonstrated in laminin and Matrigel preparations by Western blot analysis. A rough quantitation of MMP-2 and MMP-9 in 30 micrograms of laminin and 100 micrograms of Matrigel was between 0.3 and 0.6 ng. The presence of these contaminants must be considered in experiments addressing the effects of EHS laminin or Matrigel on cell behavior and, in particular, stimulation of cellular proteolytic activity.

Animals↗

PubMed1993

Anti-tumor effect of human lymphocytes and interleukin-2.

We studied the anti-tumor effect of control human lymphocytes and interleukin-2 (IL-2) activated lymphocytes (lymphokine activated killer cells, LAK-cells), on two different cell lines: SW742 human colon adenocarcinoma and K562 human myeloid leukaemia cell line. Our results indicate that IL-2 augment the anti-tumor activity of human lymphocytes and these LAK-cells lyse the tumor cells very efficiently. Furthermore, we treated the target cells (SW742 and K562) with different cytokines in order to establish whether these cytokines have any effect on susceptibility to lysis by LAK-cells. Anti-tumor activity of human lymphocytes and IL-2 is discussed in this study.

Adenocarcinoma↗

PubMed1992

Variable expression of the interleukin-2 receptor alpha chain and MYC genes in lymphocytes from renal cell carcinoma patients treated with interleukin-2.

We have studied the expression of the interleukin-2 receptor alpha chain, c-MYC and L-MYC genes in lymphocytes obtained from four renal cell carcinoma patients undergoing an interleukin-2 clinical trial. Two of these patients exhibited stable disease after the interleukin-2 therapy and two exhibited progressive disease. Analysis of mRNA levels by dot blot hybridization indicated that changes in the expression of both the interleukin-2 receptor alpha chain and c-MYC genes were erratic and varied widely between patients. L-MYC expression was not observed in any sample. There appeared to be little correlation between the changes in gene expression and parameters such as thymidine incorporation, the proportion of CD25 positive cells present or cytotoxic activity. The situation in vivo therefore appears to be more complex than would be predicted from in vitro studies.

Antigens, CD↗

PubMed1992

Non-random abnormalities of chromosomes 3, 6, and 8 associated with posterior uveal melanoma.

We present ten cases of posterior uveal melanoma which were karyotyped after short-term culture. One tumour had a normal chromosome complement. The remaining nine tumours were cytogenetically abnormal, with chromosomes 3, 6, 8, 11, and 13 most frequently involved. Abnormalities of chromosome 13 were seen in two cases, chromosome 11 in three cases, and chromosomes 3, 6, and 8 in five cases. Four tumours, all derived from the ciliary body, demonstrated monosomy 3 and i(8q), confirming the involvement of these aberrations with a subgroup of uveal melanomas arising from the ciliary body.

Aged↗

PubMed1992

The expression of class I major histocompatibility antigens by human retinal pigment epithelium in vitro.

Since the expression of class I major histocompatibility antigens by the retinal pigment epithelium (RPE) may be important with regard to ocular immune responses, we investigated this using flow cytometry and compared the RPE cells with the colon carcinoma cell line SW742. Six cultured RPE cell lines were examined. All showed strong basal expression of class I antigen. However, this expression was not maximal, and all the RPE lines tested showed a marked capacity for up-regulation of expression by culture in the presence of interferon-alpha, interferon-gamma, or tumour necrosis factor alpha, cytokines involved in immunological responses.

Antibodies, Monoclonal↗

PubMed1992

Differential effects of human blood monocytes on the growth of human tumour cell lines in vitro.

Monocytes and macrophages have been shown to be cytotoxic towards tumour cells in vitro. However, although tumour-associated monocytes and macrophages are now widely accepted to contribute a relatively high proportion of the cellular infiltrate of experimental and human solid carcinomas, a cytotoxic/cytostatic effector function for these cells in vitro or in vivo has yet to be conclusively demonstrated. In the present study, we show that non-activated peripheral blood monocytes co-cultured with tumour cells across a semi-permeable membrane release soluble factors that modulate the growth of tumour cells in contrasting ways. After Nycoprep 1.068 separation, non-activated peripheral blood monocytes enhanced the in vitro proliferation of HT29 colon adenocarcinoma cells but inhibited T47D breast carcinoma cell replication; peripheral blood lymphocytes were incapable of mediating these effects. In contrast, peripheral blood monocytes activated by interferon gamma caused a pronounced inhibition of both HT29 and T47D cell proliferation.

Adenocarcinoma↗

PubMed1992

The augmentation of lymphokine-activated killer activity following pulsing of human peripheral blood mononuclear cells with recombinant human interleukin-2.

The short-term exposure of peripheral blood mononuclear cells (PBMC) to recombinant human interleukin-2 (rhIL-2) at 37 degrees C leads to the generation of lymphokine-activated killer (LAK) activity similar in magnitude to that obtained by the exposure of PBMC to rhIL-2 continuously for 3-5 days. In order to investigate whether the required signal for LAK induction occurred during the short exposure to rhIL-2 or at a later point in the induction phase, PBMC were exposed to rhIL-2 for 1 h at 4 degrees C and then exposed to a low-pH wash to remove bound IL-2 from its receptor. PBMC treated in such a way showed increased LAK activity and proliferation compared to cells exposed to rhIL-2 alone. Expression of the p55 (alpha) subunit of the IL-2 receptor was also increased. In order to cause the augmentation, a lowering of the pH below 4.0 was necessary, and exposure of PBMC to low pH alone (in the absence of rhIL-2) failed to cause activation. Another relevant feature was a transient increase in the expression of the p75 subunit of the IL-2 receptor (beta chain) immediately following the exposure to low pH and the release of interferon gamma, tumour necrosis factor alpha and IL-6; activation was blocked by the inclusion of neutralising antisera raised against rhIL-2 and interferon gamma, thus demonstrating that the endogenous release of these cytokines is important for activation.

Cytokines↗