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S L Atkin

Publications and source records attributed to S L Atkin.

At least 55 records · Page 3Linked to original sources
PubMed1999

Evidence for transcriptional activation of ERalpha by IL-1beta in breast cancer cells.

Estrogen is mitogenic in breast cancer where IL-1beta also fulfils a role. The aim of this study was to determine any relationship between IL-1beta and ERalpha in breast cancer. By RT-PCR, 26/77 tumours expressed IL-1beta, and 57/77 expressed ERalpha. Samples which were IL-1beta positive were categorised against those which expressed ERalpha. Of the 26 tumours which expressed IL-1beta, all were ERalpha positive. We next examined whether IL-1beta could directly activate ERalpha. MCF-7 cells stably transfected with a plasmid reporter (ERE-TK-LUC) were incubated with either 17beta-estradiol (E2, 10-9-10-13 M), IL-1beta (10 ng/ml), the pure antiestrogen ZM 182780 (10 nM) or combinations of these substances. Transcriptional activity was measured in cell lysates 48 h later. E2 caused a dose-dependent increase in luciferase activity. With IL-1beta, transcriptional activity was typically half of the E2 response. To determine the role of the IL-1 receptor, parallel cultures were incubated with IL-1 receptor antagonist. This reduced, but did not completely block the effect of IL-1beta, suggesting that IL-1beta was affecting transcriptional activity via another pathway. Confirmation that the effect was via ERalpha was verified using the pure antiestrogen, ZM 182370, which completely abrogated the effects of E2, when added alone or in combination with IL-1beta. These results provide compelling evidence for direct transcriptional activation of ERalpha by IL-1beta. Interactions of these factors may thus modulate hormonal activity in human breast tumours.

Breast Neoplasms↗
PubMed1998

Activity and gene expression of 17beta-hydroxysteroid dehydrogenase type I in primary cultures of epithelial and stromal cells derived from normal and tumourous human breast tissue: the role of IL-8.

17Beta-hydroxysteroid dehydrogenase (17-HSD) type I is present and active in most breast cancer cell lines where it modulates local estrogen availability. Currently no information is available on its expression in primary cultures. We have quantitatively determined the cellular localisation of both enzyme activity and expression of the 17-HSD type I gene using a series of primary epithelial and stromal cells derived from normal and tumourous breast. Regulation of 17-HSD type I by IL-8 in tumour-derived cultures was also studied. Reversible 17-HSD activity was observed in most samples. In cultures derived from normal breast, the oxidative pathway predominated by up to 51-fold in epithelial and 28-fold in stromal cells. In tumour-derived cultures, the reductive pathway predominated by up to 24-fold in epithelial and 20-fold in stromal cultures, with no preferred direction in the remaining samples. Expression of the 17-HSD type I gene was determined by quantitative RT-PCR. Although this was constitutively expressed by all samples from both tissue types, significantly higher levels of the gene were observed in tumour-derived cultures (P = 0.008, epithelial; P < 0.0001 stromal vs corresponding normal culture). IL-8 upregulated gene expression in epithelial cells but it was downregulated in stroma. This was reflected in 17-HSD type I activity. Thus, 17-HSD type I is constitutively expressed and active in normal and tumourous breast and can be regulated by IL-8.

Base Sequence↗
PubMed1998

Short-term primary culture of epithelial cells derived from human breast tumours.

As experimental models for breast cancer, most studies rely on established human breast cancer cell lines. However, many of these lines were established over 20 years ago, many from pleural effusions rather than the primary tumour, so the validity of using them as representative models is questionable. This paper describes our experiences, over a 3-year period, in establishing short-term epithelial-cell-enriched preparations from primary breast tumours based on differential centrifugation followed by culture in selective media. Epithelial cells were successfully cultured from 55% of samples, but culture success did not appear to be correlated with tumour histology, stage, grade or node status. Epithelial cell-enriched cultures were immunopositive for broad-spectrum cytokeratin and epithelial membrane antigen (EMA). Positivity for keratin 19 confirmed that the cultures contained tumour-derived cells, which additionally showed significantly higher activity of the reductive pathway of the steroid-converting enzyme 17beta-hydroxysteroid dehydrogenase type I. That the cultures contained tumour and not normal epithelial cells was further substantiated by the complete absence of the calmodulin-like gene NB-1 in tumour-derived cultures; this is only associated with normal breast epithelia. Eighty-five per cent of cultures established from oestrogen receptor (ER)-positive tumours expressed ER in vitro; this was functional in 66% of cultures, although ER-positive phenotype was gradually lost over time. In conclusion, epithelial cells can be isolated and maintained as short-term cultures from primary breast tumours irrespective of histopathological or clinical details, providing a model system with a greater biological and clinical relevance than breast cancer cell lines.

17-Hydroxysteroid Dehydrogenases↗
PubMed1998

Effect of cell density on hormonal secretion from human pituitary adenomas in vitro.

UNLABELLED: Cell density effects were investigated on tumorous hormonal secretion from 10 pituitary adenomas: 3 somatotrophinomas secreting GH and PRL; 7 gonadotrophinomas, 3 co-secreted both FSH and LH, all 7 secreted LH. Enzymatically dispersed tissue was plated out in 24-well plates at 5 x 10(5), 10(5), 5 x 10(4) and 10(4) cells/well in serum-free media. Media were collected weekly for 2 weeks. RESULTS: In 3 of 3 somatotrophinomas, GH and PRL secretion was higher (p < 0.05) at both week 1 and 2 from 10(4) cells/well, but similar at other cell densities. In all 3 gonadotrophinomas, the FSH secretory rate was highest at 5 x 10(5) cells/well which fell as cell density decreased. Conversely, in 7 of 7 gonadotrophinomas the LH secretory rate was highest at 10(4) cells/well (p < 0.01) which fell as cell density increased. CONCLUSION: These data suggest that paracrine factors may modulate tumorous GH, PRL, FSH and LH secretion, and show that FSH and LH secretion vary inversely as cell density increases.

Adenoma↗
PubMed1997

Identification of proliferating human anterior pituitary adenoma cells in vitro.

A method to determine whether dispersed human anterior pituitary adenoma cells proliferate in mixed culture was developed. Fifteen pituitary adenomas were dispersed enzymatically to single cells, following which twelve were double immunostained after eight days. Proliferating cells were identified immunologically following one hour of bromo-deoxyuridine incorporation. Adenoma cells were subsequently identified with an anti-neuron-specific enolase antibody system. A time course of bromo-deoxyuridine labelling was performed on three nonfunctional adenomas over a four day period, with bromo-deoxyuridine being added to cultures at one hour, 24 hours and four days prior to immunostaining. Double immunolabelled cells were unambiguously identified by a dark brown nucleus surrounded by red cytoplasm. Eight out of 12 pituitary adenomas (two prolactinomas, three nonfunctional, three growth hormone secreting) showed an increased bromo-deoxyuridine labelling index (range 0.1%-1.4%). Bromo-deoxyuridine incorporation over four days showed an increase in bromo-deoxyuridine from 0.02%, 0.03% and 3.3% at one hour to 10.1%, 1.3% and 5.0% at four days, respectively, but evidence of mitosis was scant. This study shows that pituitary adenomas may proliferate in vitro and that this double immunostaining method may be used as an in vitro proliferation assay in a mixed cell population.

Adult↗
PubMed1997

Apoptosis and p53 suppressor gene protein expression in human anterior pituitary adenomas.

Human anterior pituitary adenomas proliferate and express the p53 tumour suppressor gene protein, but it is not known if apoptosis (programmed cell death) occurs. Therefore, the detection of apoptosis was undertaken in tumorous human anterior pituitary tissue and compared with p53 protein expression, tumour type and tumour size. Apoptosis (detected by the in situ end labelling technique) and p53 suppressor gene protein (detected by DO.1-antibody immunocytochemistry) were determined in formalin-fixed and paraffin-embedded tissue from 37 human pituitary adenomas (2 macroprolactinomas, 9 somatotrophinomas and 26 non-functioning adenomas). Two normal anterior pituitaries were also included in this study. Pre-operative tumour size was scored 1 to 4 from magnetic resonance imaging radiology. Apoptosis was found in 7 of 29 tumours (24%), 11% of somatotrophinomas and 33% of non-functioning adenomas, although this difference was not significant. The p53 tumour suppressor protein was found in 7 of 31 tumours (23%), 33% of somatotrophinomas and 19% of non-functioning adenomas. Apoptosis and p53 protein expression were not found in normal anterior pituitary. In conclusion, apoptosis occurs in human anterior pituitary adenomas, but no significant association was found between apoptosis and p53 protein expression, tumour type or tumour size.

Adenoma↗
PubMed1997

A comparison of proliferation indices in human anterior pituitary adenomas using formalin-fixed tissue and in vitro cell culture.

The authors compared detection methods for cell proliferation in human anterior pituitary adenomas using histological sections and dispersed cell culture. After tumor cells had been grown for 4 days in dispersed culture, bromodeoxyuridine (BUdR), proliferating cell nuclear antigen (PCNA), and Ki-67 were compared by double immunostaining and contrasted with single staining of PCNA and Ki-67 indices in the corresponding histological sections from 12 human pituitary adenomas. In vitro, the BUdR labeling index was positive in six of 12 tumors (range < 0.1-5.1%), 10 of 12 tumors were PCNA-positive (range < 0.1-100%), and Ki-67 was positive in 10 of 12 adenomas (range < 0.1-8%). In vitro, BUdR and Ki-67 gave similar proliferative indices for 10 of 12 adenomas. In vivo, the PCNA labeling index was positive in 12 of 12 adenomas (range 0.9-95%) and Ki-67 was positive in 11 of 12 adenomas (range < 0.1-2%). Tumors with a labeling index less than 0.1% were considered to be negative for proliferation. High PCNA values were found in vitro and in vivo, whereas Ki-67 labeling indices were similar in vitro and in vivo for nine of 12 adenomas. It is concluded that Ki-67 proliferative indices in vivo reflect those found in vitro, at least after 4 days in dispersed culture, but that PCNA overestimates pituitary adenoma proliferation in histological sections as well as in dispersed culture.

Adenoma↗
PubMed1996

Treatment of diabetic gustatory sweating with topical glycopyrrolate cream.

A 42-year-old insulin-dependent diabetic man presented with severe bilateral gustatory sweating associated with a deterioration in his glycaemic control. Conventional oral antimuscarinic medication was contraindicated because of his cardiac insufficiency. Topical 0.5% glycopyrrolate cream was tried and applied on alternate days to his face, which resulted in the complete cessation of his gustatory sweating without side-effects. Topical glycopyrrolate cream is an effective treatment of diabetic gustatory sweating without the adverse effects commonly found with oral anti-muscarinic medication.

Administration, Topical↗
PubMed1996

Recurrent hypoglycaemia associated with first and second trimester insulin sensitivity in a patient with insulin-dependent diabetes.

A 35-year-old insulin-dependent diabetic woman presented at 8 weeks gestation with multiple severe hypoglycaemic episodes occurring during the day and night without warning. Her pre-pregnancy insulin dosage of 45 units daily was progressively reduced by 73% to 12 units daily by week 17 because of multiple hypoglycaemic episodes. Investigation showed no pathological cause for the hypoglycaemia. Insulin dosage increased to 16 units daily by week 19 and then increased sharply to 60 units daily at 23 weeks and finally to 72 units at week 37. Following delivery her insulin dosage returned to pre-pregnancy values. Insulin-dependent diabetic women may rarely develop exaggerated insulin sensitivity in the first trimester of pregnancy resulting in severe hypoglycaemia, but spontaneous improvement occurs with increasing insulin resistance in the second and third trimesters.

Adult↗
PubMed1996

Expression of the transferrin receptor in human anterior pituitary adenomas is confined to gonadotrophinomas.

OBJECTIVE: The human pituitary gland is affected selectively by conditions associated with iron deposition, but the mechanisms for this are unknown. In this study we have determined whether the transferrin receptor, which mediates iron uptake by cells, could be detected immunocytochemically in human pituitary adenomas in vitro. PATIENTS: Data were derived from 35 patients undergoing transsphenoidal surgery and included 13 with clinically non-functioning adenomas, 15 with acromegaly, 4 prolactinomas, 2 patients with Cushing's disease and one patient with Nelson's syndrome. MEASUREMENTS: Transferrin receptor immunopositivity was determined for each adenoma in dispersed cell culture using a specific monoclonal antibody. RESULTS: Eight of 13 clinically functionless adenomas showed immunopositive transferrin receptor expression, whilst adenomas from 15 patients with acromegaly, 4 prolactinomas, 2 Cushing's syndrome and one patient with Nelson's syndrome were negative. The eight transferrin receptor positive tumours were gonadotrophinomas and accounted for eight of the nine tumours which secreted and immunostained for FSH; all eight also secreted and immunostained for LH. CONCLUSIONS: These findings may reflect a special requirement for iron by gonadotrophin secreting cells in comparison to other pituitary cell types and this could underlie the reasons why in the normal pituitary these cells are especially susceptible to malfunction in iron overload syndromes such as genetic haemochromatosis and beta-thalassaemia.

Adenoma↗
PubMed1996

Cytokine expression in human anterior pituitary adenomas.

OBJECTIVE: There is increasing evidence for the role of cytokines in pituitary differentiated function and tumorigenesis, but the spectrum of cytokines found in the pituitary is unknown. Therefore profiles of cytokine expression were determined in different human anterior pituitary adenoma sub-types. DESIGN: The reverse transcriptase-linked polymerase chain reaction (PCR) was used to identify the presence of cytokine mRNA within human pituitary adenomas. PATIENTS: Seventeen pituitary adenoma biopsies removed at transsphenoidal surgery were examined: 4 somatotrophinomas, 7 non-functional adenomas, 4 prolactinomas, one case of Cushing's disease and one case of Nelson's syndrome. MEASUREMENTS: RNA was extracted from each adenoma biopsy and reverse transcribed into cDNA. This was specifically amplified in a PCR using oligonucleotide primers complementary to each cytokine. The cytokines investigated were interleukin (IL)-I alpha, IL-I beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, tumour necrosis factor (TNF)-alpha, TNF-beta and transforming growth factor (TGF)-beta 1, beta 2 and beta 3. The products of each PCR were visualized using agarose gel electrophoresis. RESULTS: All 17 adenomas expressed IL-8 transcripts, but no expression of IL-2, IL-5 or IL-7 was found. IL-6 was expressed in all 4 somatotrophinomas, 3 of 7 non-functional tumours, 2 of 4 prolactinomas and in the single case of Nelson's syndrome. At least one of the 3 isoforms of TGF-beta was found in all but 2 tumours; one prolactinoma and one non-functional adenoma. IL-1 alpha, IL-beta, IL-4, TNF-alpha and TNF-beta were expressed sporadically by individual adenomas. CONCLUSION: These data suggest that whilst IL-8 may be important, the local expression of the cytokines IL-2, IL-5 and IL-7 is not important in human anterior pituitary tumorigenesis.

Adenoma↗
PubMed1996

Hyponatraemia secondary to cerebral salt wasting syndrome following routine pituitary surgery.

A female aged 53 years was found to have a suprasellar lesion, which was shown to be a Rathke's cyst after removal by transsphenoidal surgery. She presented 16 days postoperatively, and following two grand mal seizures was found to be profoundly hyponatraemic (sodium 101 nmol/l). She was initially thought to have the syndrome of inappropriate antidiuretic hormone and was treated accordingly, but central venous pressure measurement revealed the hypovolaemia of cerebral salt wasting syndrome. The patient subsequently developed severe neurological sequelae after the correction of her hyponatraemia, following the development of extrapontine myelinolysis. Cerebral salt wasting syndrome is a rare cause of hyponatraemia following pituitary transsphenoidal surgery, which may mimic the syndrome of inappropriate antidiuretic hormone secretion. This case emphasizes the poor prognosis that may result from the rapid correction of profound hyponatraemia.

Brain↗
PubMed1995

Isolated adrenocorticotropin deficiency presenting as primary infertility.

A 31 year old female presented with primary infertility and gave a two year history of amenorrhea without symptoms or signs of endocrine dysfunction. Examination was normal and investigation showed low oestradiol and progesterone levels with decreased LH pulsatility. The cortisol responses were impaired following hypoglycaemic stress and a short synacthen test, but the cortisol response to a prolonged synacthen test was normal. An inadequate ACTH response to CRF testing confirmed the diagnosis of isolated ACTH deficiency. Hydrocortisone therapy was followed by an ovulatory menstrual cycle. Amenorrhea again ensued following the reduction of the steroid dose and normal menses resumed on normal steroid replacement therapy. Six hourly gonadotrophin pulsatility showed a significant increase in both pulse amplitude and mean LH and FSH levels following steroid treatment. Isolated ACTH deficiency is a rare but treatable cause of hypogonadism and infertility, and this case gives further insight on the role of cortisol on the hypothalamo-pituitary gonadal axis.

Adrenocorticotropic Hormone↗
PubMed1995

Effects of quinagolide (CV 205-502), a selective D2-agonist, on vascular reactivity in patients with a prolactin-secreting adenoma.

BACKGROUND: Quinagolide (CV 205 502) is a dopamine D2-receptor agonist which has proved effective in the treatment of prolactinomas, reducing both serum PRL and tumour size. Some of its D2-receptor effects are mediated via alpha-adrenoceptors, which have a major influence on the control of vascular tone. The aim of this study was to examine the influence of quinagolide on in-vivo dorsal hand vein vascular responses to noradrenaline in patients with a prolactinoma. DESIGN AND PATIENTS: Seven female patients with prolactinomas (age 37 (28-46) years), intolerant of bromocriptine, were studied before and after 3 months treatment with quinagolide (0.75-1.5 mg/day). Patients were otherwise disease free, were taking no other medication, and had been on no other medication (including bromocriptine) for at least 3 months prior to enrollment into the study. MEASUREMENTS: Vascular responses to locally infused noradrenaline were measured in dorsal hand veins using an established technique. PRL, oestradiol, FSH, LH, blood pressure and body mass index were also measured before and after 3 months treatment. RESULTS: Quinagolide significantly reduced PRL in all 7 patients (1795 (696-4680) (mean (range)) vs 488 (290-868) mU/l, P = 0.001), with no effect on the other parameters, including mean arterial pressure (88 (2) vs 87 (4) mmHg, P = 0.6). Vascular reactivity to noradrenaline was significantly increased after 3 months therapy: log10 dose estimated to cause 50% vasoconstriction (ED50) 1.37 (0.12) vs 0.85 (0.12) ng/min (P = 0.003; a lower ED50 indicates less noradrenaline is required to constrict the vein by 50%). CONCLUSIONS: Vasoconstrictor responses to noradrenaline were increased in all patients after 3 months treatment with quinagolide. Peripheral veins carry alpha-adrenoceptors analogous to those of systemic resistance vessels. If this increased vasoconstrictor response in patients with prolactinomas was occurring in hypophyseal vessels, it would lead to reduced tumour blood supply. Quinagolide may therefore reduce tumour blood flow, which may be one factor responsible for its effectiveness in these patients.

Adult↗