PubMed Health⌕ Search

Biomedical subjects

K Sangster

Publications and source records attributed to K Sangster.

At least 19 recordsLinked to original sources
PubMed2002

Cytokine regulation of constitutive production of interleukin-8 and -6 by human pancreatic cancer cell lines and serum cytokine concentrations in patients with pancreatic cancer.

Patients with pancreatic cancer frequently demonstrate symptoms such as weight-loss and muscle wasting and have clinical evidence of a systemic inflammatory response. Such effects may be mediated by pro-inflammatory cytokines derived from tumor cells. The production of interleukin-6 and -8 by pancreatic cancer cell lines and the influence of other cytokines on this production was studied. IL-8 was produced by all cell lines and production was increased following exposure to IL-1 and TNF. Cytokine-stimulated, but not basal IL-8 production was reduced by co-incubation with IL-4 in the MIA PaCa-2 and PANC-1 cell lines. The CFPAC cell line produced IL-6, but this production was not altered by IL-1, TNF or IL-4. In the PANC-1 cell line IL-8 and IL-8 receptors were only detected by PCR in cells which had been stimulated with TNF or IL-1. Serum concentrations of IL-6 and IL-8 were elevated in patients with pancreatic cancer compared with controls. In conclusion, human pancreatic cancer cell lines elaborate pro-inflammatory cytokines which have the potential to mediate elements of the systemic inflammatory response.

Aged↗
PubMed1998

Apoptotic death of pancreatic cancer cells induced by polyunsaturated fatty acids varies with double bond number and involves an oxidative mechanism.

Polyunsaturated fatty acids (PUFAs), reported to be cytotoxic at micromolar concentrations for cancer cells in vitro and in vivo, are currently being tested in clinical trials as anti-cancer agents. This study has shown that seven PUFAs all inhibited the growth in vitro of three pancreatic cancer cell lines and the HL-60 leukaemic cell line. Five PUFAs induced cell death within 20-30 h, but two less potent PUFAs induced death between 50 and 75 h. Apoptosis was demonstrated to be the mode of cell death by light, UV fluorescence, and electron microscopy, together with studies of DNA fragmentation. In a time-course study of PUFA-treated Mia-Pa-Ca-2 cells, apoptosis accounted for an average of 80 per cent of the loss of viability, with 'secondary necrosis', a feature of late apoptosis, apparently accounting for the remainder. Correlations were found between the number of fatty acid double bonds and the proportion of cells undergoing apoptosis induced in both Mia-Pa-Ca-2 cells (R = 0.88, P = 0.0001) and HL-60 cells (R = 0.85, P = 0.0001) and inversely with the micromolar concentrations of PUFAs required for 50 per cent inhibition of growth (IC50) of Mia-Pa-Ca-2 cells (R = -0.73, P = 0.05). Cell death was preceded by progressively increasing lipid peroxidation. The extent of PUFA-induced lipid peroxidation, measured as malondialdehyde (MDA), also correlated with the proportion of apoptosis induced in Mia-Pa-Ca-2 cells (R = 0.69, P = 0.025) or HL-60 cells (R = 0.64, P = 0.043), as well as with the number of fatty acid double bonds (R = 0.82, P = 0.0015). PUFA-induced apoptosis was oxidative, being blocked by both vitamin E acetate and sodium selenite, the latter in a critically time-dependent manner. The cytotoxic effects of exposure to a PUFA and to gamma-irradiation simultaneously with, or prior to, the addition of PUFA.

Animals↗
PubMed1992

Indications for primary tamoxifen therapy in elderly women with breast cancer.

A group of 66 elderly women with primary breast cancer were treated with tamoxifen and followed for a minimum of 2 years. Of these, 32 whose disease remained controlled for the 2-year period were considered to have had a 'worthwhile' response, 27 in whom disease progressed were considered to have had an unsatisfactory result and seven opted for alternative treatment. By Union Internacional Contra la Cancrum (UICC) criteria, 14 women had a complete response, 20 a partial response, in five disease remained static and in 20 it progressed without response. Prediction of outcome after assessment according to UICC criteria at 3 and 6 months was unsatisfactory (19 and 34 of 59 correctly predicted respectively). Analysis of multiple tumour measurements over 12 weeks was no better (33 of 59 correctly predicted). Immunocytochemical assay of fine-needle aspirates for oestrogen receptor (ER) provided a better predictor (38 of 47 correct) and the difference in survival between patients with and without ER activity was significant (P < 0.001). Conventional assessments of response at 3 and 6 months are unsatisfactory for judging the long-term benefit to the patient. ER status is the best predictor of response and outcome.

Aged↗
PubMed1992

Change in the oestrogen receptor status of breast cancer with age--comparison of two types of assay.

The oestrogen receptor (ER) is considered to be an essential component of the mechanism of response of a breast tumour to endocrine therapy, but ER measurements have proved to have only modest predictive value. In the present study, we have examined ER status by both immunocytochemical assay (ER-ICA) on a fine needle aspirate and by radioligand-binding assay (DCC) on an excised portion of tumour. There was a correlation between the ER level detected by the two assays (Spearman's r = 0.77 for DCC versus ER-ICA staining intensity, r = 0.70 for DCC versus ER-ICA percentage of cells stained, P < 0.0001, n = 137 in each case). Each assay showed an increasing proportion of ER+ve results with increasing patient age. In the case of ER+ve tissues only, while ER concentration by DCC assay increased steadily with age (r = 0.39, P < 0.0001, n = 108), the ER-ICA assay revealed that, staining intensity increased with age (r = 0.26, P = 0.001, n = 149) but the percentage of cells stained did not (r = 0.08, P = NS, n = 149). It is concluded that increasing endocrine responsiveness with advancing age could reflect the increasing proportion of ER+ve tumours with increased levels of ER per cell (as indicated by staining intensity) rather than increasing proportion of ER+ve cells.

Adult↗
PubMed1992

The differing predictive values of oestrogen receptor assays for large breast cancers.

Thirty elderly patients with T3 or T4 breast cancer underwent a wedge biopsy for radioligand-binding assay (RLA) of oestrogen receptor (ER) activity. A second, separate group of 21 elderly patients with T3 and T4 breast cancers underwent fine needle aspiration biopsy (FNA) for immunocytochemical assay of ER (ER-ICA). All the women received tamoxifen as primary treatment and response was assessed by UICC criteria. Tumour ER concentration by RLA was correlated with both response (Spearman's R = + 0.52) and time to progression (R = + 0.76). Nine patients with receptor-rich tumours (> 100 fmol/mg protein) failed to show a response. However, the percentage of cells staining for ER by ER-ICA assay was much more strongly related to the likelihood of response (R = + 0.89); no patient with < 20% cells staining responded. Wedge biopsy and the biochemical determination of ER activity is of limited value in predicting the likely response to tamoxifen; ER-ICA assays on such tumours may be more informative.

Aged↗
PubMed1988

Oestrogen receptors, lactate dehydrogenase and cellularity in human breast cancer.

Oestrogen receptor (ER) concentrations in breast tissues are almost universally expressed in relation to total soluble protein, though the latter does not fully correct for gross variations in receptor concentration due to variations in tissue cellularity. It was considered possible that the concentration of a specific glycolytic enzyme might be a better index and reflection of tumour cellularity. Measurements of the concentrations of lactate dehydrogenase (LDH), oestrogen receptor and total soluble protein and estimates of tumour cellularity were therefore performed on 98 breast tissues (80 breast cancers, 18 benign tissues). Cellularity and the concentrations of oestrogen receptor, lactate dehydrogenase and total soluble protein were significantly higher in breast cancers than in the benign tissues. The concentration of oestrogen receptors (positives only) was, as expected, related to tissue cellularity (correlation coefficient, r = 0.35). The concentrations of both LDH and total soluble protein were also both strongly related to tissue cellularity (correlation coefficients r = 0.67 and 0.75, respectively), and to each other (r = 0.78). These results suggest that (1) total soluble protein concentration is a good index of cellularity and (2) there is unlikely to be any additional value in expressing receptor concentrations relative to LDH since the latter appears to be a 'typical' soluble protein.

Biomarkers, Tumor↗
PubMed1988

The cytochemical detection of oestrogen receptors in fine needle aspirates of breast cancer; correlation with biochemical assay and prediction of response to endocrine therapy.

A total of 98 breast aspirates from patients with breast cancer have been fixed and stained for oestrogen receptors using the Abbott ERICA kit. In a preliminary series of 41 aspirates, cytochemical staining index (% cells staining x mean intensity) related to the receptor concentration determined biochemically on a subsequent biopsy with a correlation coefficient of +0.65. In a second series of 56 aspirates examined after lysis and cytocentrifugation, the correlation coefficient was +0.73. For 14 patients, the response of the primary tumour to endocrine therapy was assessed objectively by serial clinical and mammographic measurements (Forrest et al., 1986) and was found to relate strongly to the cytochemical staining of the initial aspirate. The potential and limitations of this technique are discussed.

Adult↗
PubMed1987

Histochemical studies of human breast cancer using a monoclonal antibody against an oestrogen receptor-related antigen.

The presence or absence of an oestrogen receptor-related antigen in breast tumours has been examined histochemically using a monoclonal antibody ('Ds' - Coffer & King, 1981). In frozen sections, fixed either by the method of Tamura et al. (1980) or in methanol, staining was apparent in 14/24 (58%) and 22/26 (85%) of the breast cancers respectively. In paraffin sections fixed in ethanol, staining was present in 25/33 breast cancers (76%). In either type of section, staining was predominantly in the cytoplasm of the epithelial cells. When staining was scored by independent observers (2 or 3) and related to the tumour oestrogen receptor activity, determined by a standard biochemical technique, antigen was present in both receptor-positive and receptor-negative tumours. No significant association was found between the presence of antigen and receptors in the frozen sections, but for the series of paraffin sections, there was a weak association (r = +0.48) between the presence of the two proteins. Histochemical processing of paraffin sections from 9 tumours under conditions of higher sensitivity increased the staining significantly in 2/9 tumours, but did not alter the relationship between staining and receptor status. Six tissues were stained after exposure to 'receptor-translocating' conditions (25 degrees C/2 nM oestradiol/both for 1 h): this did not consistently change the subcellular staining pattern, though all tissues tended to stain more after exposure to 25 degrees C. Staining was not blocked by absorption of the D5 antiserum with a variety of pure proteins or human serum but at higher concentrations (approx. 2-15 mg protein ml-1), extracts from human uterus, an oestrogen-receptor-positive breast cancer and an oestrogen-receptor-negative breast cancer all effectively abolished staining in sections from another breast cancer. These results are consistent with other reports suggesting that the D5 antibody detects an antigen which is not the oestrogen receptor, but which may be associated with the receptor in its tissue distribution.

Antibodies, Monoclonal↗
PubMed1986

Estimation of oestrogen and progesterone receptors in chronic rhinitis.

The turbinates of 38 patients with chronic rhinitis were examined biochemically for oestrogen and progesterone receptors. Low levels of oestrogen-receptor-like activity (1-20 fmol/mg protein) were found in 50% of patients of both sexes. Progesterone receptor activity was also weak (1-16 fmol/mg protein) but was present only in 5 female patients. Immunocytochemical assay failed to demonstrate focal areas of oestrogen receptor activity. One juvenile nasopharyngeal angiofibroma was negative for both oestrogen and androgen receptors. Other possible mechanisms of hormonal action are considered.

Adult↗
PubMed1977

Hormonal sensitivity of human breast tumors in vitro: pentose-shunt activity.

Recent studies indicated that response to endocrine therapy might be predicted in human breast carcinomas using the sensitivity of the pentose-shunt pathway to hormones in organ culture. Thirty breast tumors were examined using this histochemical method, and three independent assessments were made. There was poor agreement between the observers, and we consider that this test is not reproducible in its present form.

Breast Neoplasms↗