Search PubMed⌕ Search

Biomedical subjects

F Di Carlo

Publications and source records attributed to F Di Carlo.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Evidence for functional beta-adrenoceptor subtypes in CG-5 breast cancer cell.

beta-adrenergic receptors (beta-ARs) were identified in CG-5 breast cancer cells using a radiometric assay. The total beta-AR concentration was measured using the highly potent beta-adrenergic antagonist (-)[3H]CGP 12177, and the densities of beta-AR subtypes were discriminated in the presence of highly selective unlabelled ligands (CGP 20712A and ICI 118551). Scatchard analysis revealed good linearity (r > 0.95) and Kd values (0.05-1 nM) indicated the presence of high affinity binding sites in CG-5 cell membranes. beta 2-AR concentrations (74%) were significantly (P < 0.05) higher than beta 1-AR concentrations (36%). Displacement studies indicated that tested adrenergic agonists displaced (-) [3H]CGP 12177 from its specific binding sites in the order of potency (-)isoproterenol > (+/-)clenbuterol > (-)adrenaline > (+/-)dobutamine > > (-)noradrenaline, whereas beta-adrenergic antagonists inhibited the binding in the following order of potency: (-)propranolol > > ICI 118 551 > > CGP 20712A. The functionality of beta-ARs identified in CG-5 cell membranes was demonstrated by the significant increase in cAMP production induced by different concentrations of isoproterenol vs unstimulated cells (control). The pathophysiological role of beta-ARs in breast cancer cells is still undefined, but their presence suggests the possible adrenergic regulation of some cellular activities such as proliferation and/or differentiation.

Breast Neoplasms↗
PubMedDate not supplied

[Mechanism of action of progestins in the treatment of hormone-dependent breast cancer (author's transl)].

The in vitro interference of some gestagens with the binding of 3H-17-beta-oestradiol to cytosol specific receptors was investigated with a view to elucidating the mechanism of action of progestins in the treatment of human hormone-dependent breast cancer. A decrease (up to 85%) of oestradiol binding capacity was observed with high concentrations of progesterone, clogestone and medrogestone. These findings are in good agreement with those previously obtained by the same progestins in our laboratory on rat uterine estrogen receptors in vitro or in vivo. These results provide the support for the hypothesis that the mode of action of progestins in the therapy of mammary and perhaps uterine carcinomas is to some extent related to the inhibition of oestradiol binding to cytosol specific receptors.

Breast Neoplasms↗
PubMedDate not supplied

A combined histological, immunocytochemical and biochemical approach in the evaluation of estrogen receptors in breast carcinomas.

Correlation of structural and functional data might lead to better identification of hormone-dependent tumors. Sixty breast cancer specimens, sent to the biochemistry laboratory for estrogen receptor (ER) analysis, were studied here by a combined morpho-functional approach. Histological examination of needle biopsies on frozen tissue blocks showed that 12 cases (10%) were free of tumor cells; these cases mostly proved ER negative. On the other 48 cases, an immunocytochemical reaction was performed on the biopsy sections with a monoclonal antibody directed against p 29, an estrogen receptor related antigen. The staining values for p 29 and the biochemical ER findings were significantly correlated. A combined histological, immunocytochemical study seems to offer advantages in the selection of patients for hormonal therapy.

Biomarkers, Tumor↗
PubMedDate not supplied

Correlation between pS2 protein positivity, steroid receptor status and other prognostic factors in breast cancer.

The cytosolic levels of pS2, an estrogen-regulated protein, were measured in 100 cases of primary breast cancer and related to several conventional histological and biochemical prognostic factors. The data were statistically analyzed on the basis of two different cutoff point for pS2: 4 and 11 ng/mg of cytosolic proteins. pS2 positivity (cutoff 11 ng/mg) was shown to be associated with small tumor size (p = 0.05), a higher differentiation grade (p = 0.007) and a smaller number of mitoses (p = 0.004), but not with menopausal status, lymph node involvement, cathepsin D levels, or proliferative activity determined by the monoclonal antibody Ki67. With the cutoff of 4 ng/mg, the statistical significance was confirmed only for the number of mitoses (p = 0.03), which was also the most closely related covariate in multivariate analysis (p = 0.008). As regards steroid receptor status, a significant difference was observed between pS2+ and pS2- cases (Chi-square = 8.9; p = 0.04, cutoff 4 ng/mg). in conclusion, pS2 positivity, being preferentially expressed in hormone-dependent cells and related to other well-known positive markers, may either indicate a good prognosis or predict responsiveness to endocrine treatment.

Adult↗
PubMedDate not supplied

Opposite effects of dehydroepiandrosterone on the growth of 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinomas.

The effect of dehydroepiandrosterone (DHEA) (2 mg, twice daily p.o.) on the growth of the dimethylbenz (a) anthracene (DMBA)-induced mammary carcinoma was studied in intact and ovariectomized adult female rats. DHEA treatment stimulated the tumor growth in ovariectomized animals. Conversely, the tumors of intact rats treated with DHEA progressed to a lesser extent than those of intact untreated animals (p < 0.01). Plasma levels of DHEA were higher in DHEA-fed than in untreated animals (p < .01), whereas E2 concentrations were unchanged after DHEA administration. Estrogen receptor (ER) concentrations in tumor tissue of ovariectomized animals given DHEA were no different form those found in intact rats, whereas ER were undetectable in untreated ovariectomized rats. The data indicate that DHEA stimulates the growth of DMBA-induced mammary tumors in ovariectomized rats, while it reduces the tumor progression in intact animals.

9,10-Dimethyl-1,2-benzanthracene↗
PubMedDate not supplied

[Action of drugs in relation to the administration route].

The factors capable of modifying the activity of a given drug may be divided into two categories: those related to the patient (age, sex, weight, state of health, genetic factors, etc.) and those related to the drug (pharmaceutical formulation, dose, dose frequency, interaction with other drugs taken more or less simultaneously and administration mode). One example of a drug whose action varies according to the mode of administration adopted is offered by the estrogens which may be given orally (estradiol valerianate, estriol, conjugated estrogens, etc.) or parenterally (estradiol valerianate intramuscularly; conjugated estrogens and estriol vaginally, estradiol as a skin gel, by subcutaneous implant or transdermally). Blood concentrations of estradiol and estrogen after the same dose vary considerably according to the administration mode adopted so that doses may have to be adjusted in order to achieve the same levels of the circulating hormone. Having no first pass effect on the liver, parenteral administrations have less influence than oral ones on the synthesis of certain proteins by the liver (increased SHBG, CBG, TBG, transferrin, ceruloplasmin, angiotensinogen, clotting factors VII, IX, X and X complex; decreased antithrombin III and anti Xa) and on lipid metabolism (increased biliary cholesterol, triglycerides and HDL, especially HDL2; reduced LDL). In particular, it has been found that estradiol (differently from other estrogens) when administered transdermically is able to relieve menopausal symptoms at doses which do not influence the liver synthesis of proteins.

Administration, Cutaneous↗
PubMedDate not supplied

Induction of 2'-5' oligoadenylate synthetase and activation of ribonuclease in tamoxifen treated human breast cancer cell lines.

In the present study the intracellular activity of oligoadenylate synthetase and ribonuclease have been evaluated in two human breast cancer cell lines treated with tamoxifen, a well known antiestrogenic drug. Increased levels of oligoadenylate synthetase and enhanced ribonuclease activity have been found in the cultures of CG5 cell line treated with concentrations of tamoxifen inhibiting cell growth. In the experiments with the EVSA-T cell line we found neither an antiproliferative effect nor an increased oligoadenylate synthetase and ribonuclease activity. It is likely that these enzymes are involved in the mechanisms by which this drug acts as an antiproliferative agent.

2',5'-Oligoadenylate Synthetase↗