Attenuation of telomerase activity does not increase sensitivity of human melanoma cells to anticancer agents.

In tumour cells, replicative immortality is attained through stabilisation of telomeres by telomerase. Recent evidence suggests that telomerase plays an anti-apoptotic role. Since apoptosis is the primary mode of cell death induced by several drugs, telomerase could be involved in determining the chemosensitivity profile of tumour cells.

Sodium butyrate modulates cell cycle-related proteins in HT29 human colonic adenocarcinoma cells.

Sodium butyrate (NaB), a product of colonic fermentation of dietary fibre, has been shown to inhibit cell proliferation by blocking cells in the G0/G1 phase of the cell cycle through a mechanism of action still not completely understood. We investigated the effect of NaB on the level of some G1 phase-related proteins in a colon carcinoma cell line (HT29). In particular, we addressed our attention to cyclin D1 (the key regulator of G1S progression), p21waf1/cip1 (the main inactivator of the cyclin D/cdk complex), and p53 (the most important regulator of p21waf1/cip1 gene transcription).

Cell proliferation and outcome following doxorubicin plus CMF regimens in node-positive breast cancer.

At the Istituto Nazionale Tumori of Milan, a randomised adjuvant chemotherapy trial was carried out from 1982 to 1990 to compare alternating with sequential regimens of doxorubicin and CMF in 403 patients with more than 3 positive axillary nodes. Tumour proliferative activity was determined in 71% (285 cases) of women entering the clinical study. We investigated the relation between proliferative rate, determined as the [(3)H]thymidine labelling index (TLI) on tumour specimens obtained at diagnostic surgery, and clinical outcome following the 2 regimens, in which the same drugs were administered at the same dose intensity but with a different schedule.

Time-dependent relevance of steroid receptors in breast cancer.

Purpose: To analyze the time-dependent prognostic role of the investigated variables, considered, when appropriate, on a continuous scale, for the purpose of evaluating and describing the interrelationships between clinically relevant patient and tumor characteristics (age, size and histology, and estrogen receptor [ER] and progesterone receptor content) and the risk of new disease manifestation.

Patients And Methods: We applied a flexible statistical model to a case series of 1,793 patients with axillary lymph node-negative breast cancer with a minimal potential follow-up of 10 years. To avoid a potential confounding effect of adjuvant treatment, only patients given local-regional therapy until relapse were considered.

Inhibition of telomerase activity by a cell-penetrating peptide nucleic acid construct in human melanoma cells.

We investigated the effect of two peptide nucleic acids (PNAs), which are complementary to the RNA component of human telomerase, on the catalytic activity of the enzyme. PNAs induced a dose-dependent reduction of telomerase activity in cell extracts from human melanoma cell lines and surgical specimens. To down-regulate telomerase in intact cells, we generated a chimeric molecule synthesized by coupling the 13-mer PNA to the Antennapedia peptide.

Telomerase activity and telomere length in human ovarian cancer and melanoma cell lines: correlation with sensitivity to DNA damaging agents.

Since telomerase plays a role in cellular resistance to apoptosis, which is the primary mode of cell death induced by several drugs, telomerase could be involved in determining the chemosensitivity profile of tumor cells. Thus, we investigated the relationship between telomerase activity, telomere length and chemosensitivity to effective antitumor agents in a panel of human melanoma and ovarian cancer cell lines. Telomerase activity, as detected by the telomeric repeat amplification protocol, ranged from 0.

Clinical studies of Bcl-2 and treatment benefit in breast cancer patients.

Interest in translational studies aimed at investigating the role of biologic markers in predicting clinical outcome of breast cancer patients and, in particular, response to specific treatments, has progressively increased. Among biologic variables presently under investigation, apoptosis markers, in particular Bcl-2 and Bax expression, are receiving much attention for their relationship with the cellular response to genotoxic damage in experimental tumors. Retrospective, independent studies were carried out by several research groups on about 5000 patients with breast cancer at different stages and with an adequate follow-up.

Inhibition of telomerase activity by a hammerhead ribozyme targeting the RNA component of telomerase in human melanoma cells.

Reactivation of telomerase, an RNA-dependent DNA polymerase that synthesizes new telomeric repeats at the end of chromosomes, is a very common feature in human cancers. Telomerase is thought to be essential in maintaining the proliferative capacity of tumor cells and, as a consequence, it could represent an attractive target for new anti-cancer therapies. In this study, we generated a hammerhead ribozyme composed of a catalytic domain with flanking sequences complementary to the RNA component of human telomerase and designed to cleave specifically a site located at the end of the telomerase template sequence.

Biomarkers and outcome after tamoxifen treatment in node-positive breast cancers from elderly women.

The predictive role of tumour proliferative rate and expression of p53, bcl-2 and bax proteins, alone and in association with tumour size, nodal involvement and oestrogen receptors (ER), was analysed on 145 elderly patients (> or =70 years of age) with histologically assessed node-positive breast cancers treated with radical or conservative surgery plus radiotherapy followed by adjuvant tamoxifen for at least 1 year. The 7-year probability of relapse was significantly higher for patients with tumours rapidly proliferating (hazard ratio (HR) = 2.0, P = 0.

Cholesteryl butyrate in solid lipid nanospheres as an alternative approach for butyric acid delivery.

Background: Cholesteryl-butyrate chosen as lipid matrix of solid lipid nanospheres (SLNs) could be a suitable pro-drug to deliver butyric acid and overcome one of the most limiting disadvantages of the compound: the short half-life due to a rapid metabolism.

Methods: We evaluated the antiproliferative effect, with respect to that of sodium butyrate, of four SLNs (SLN1, SLN2, SLN3 and SLN4) characterized by a different concentration of cholesteryl-butyrate (range, 1.7-30 mM) on NIH-H460, a non-small cell lung carcinoma cell line.

Lack of p21waf1 and p27kip1 protein induction by interferon-alpha2a in human melanoma cell lines.

The ability of human recombinant interferon-alpha2a (IFNalpha2a) to induce the expression of cyclin-dependent kinase inhibitors p21waf1 and p27kip1 consequent to signal transducers and activators of transcription (STAT) protein activation was investigated in six human melanoma cell lines with different susceptibilities to the antiproliferative effect of the cytokine. All the cell lines expressed IFNalpha and IFNalpha/beta receptors. Exposure for 24 h to IFNalpha2a markedly enhanced the nuclear expression of STAT1 and STAT2 proteins in all the cell lines.

Biological markers as indicators of response to primary and adjuvant chemotherapy in breast cancer.

Interest in translational studies on breast cancer is presently devoted to identify biological predictors of treatment response. In patients with operable breast cancer, subjected to primary and adjuvant chemotherapy, we analyzed the predictivity on objective clinical response and relapse-free survival of biological markers related to different cellular aspects and functions. Tumour proliferative rate (evaluated as the (3)H-thymidine-labelling index, TLI), oestrogen and progesterone receptors (ER and PgR, evaluated by the dextran-coated-charcoal method), nuclear DNA ploidy and the immunocytochemical expression of p53, bcl-2 and bax proteins were determined before primary treatment, at the time of diagnosis, and after primary chemotherapy, at surgery.

Involvement of bcl-2 and p21waf1 proteins in response of human breast cancer cell clones to Tomudex.

Mechanisms of resistance to Tomudex include increased thymidylate synthase activity, as well as reduced intracellular drug uptake and polyglutamation. However, little is known about other mechanisms of resistance, such as a possible protection against Tomudex-induced apoptosis mediated by bcl-2. We transfected the MDA-MB-435 human breast cancer cell line, which is characterized by a mutated p53 gene, with cDNA of the bcl-2 gene and generated two clones (MDA-bcl4 and MDA-bcl7) characterized by bcl-2 expression twofold and fourfold that observed in the control cell clone (MDAneo).

Relationship between steroid receptors (as continuous variables) and response to adjuvant treatments in postmenopausal women with node-positive breast cancer.

In current clinical practice for breast cancer patients, estrogen (ER) and progesterone receptor (PgR) concentrations, quantified by the dextran-coated charcoal assay, are categorized by an arbitrary cutoff into a negative or positive status. However, although the results obtained with this approach are easy to interpret, such a representation could oversimplify the relationship between ER and PgR content and patient outcome and imply an assumption of monotonicity, which is generally expected but rarely proven. We evaluated the relationship between ER and PgR content (considered on a continuous scale) and clinical outcome, using a flexible statistical model, in a group of postmenopausal patients with N-positive operable tumors who were submitted to surgery and different adjuvant treatments (tamoxifen or CMF).

Hyaluronic acid as drug delivery for sodium butyrate: improvement of the anti-proliferative activity on a breast-cancer cell line.

The potential clinical utility of sodium butyrate, a natural compound known to inhibit tumor-cell growth, is hampered by the difficulty of achieving effective in-vivo concentrations. The short half-life (about 5 minutes) of sodium butyrate results in rapid metabolism and excretion. To increase the availability of sodium butyrate over a longer period of time, we co-valently linked it to hyaluronic acid (a component of the extracellular matrix).

Flexible modelling in survival analysis. Structuring biological complexity from the information provided by tumor markers.

The aim of the present article is to introduce and discuss the problem of optimal modelling of the prognostic information provided by putative prognostic variables, possibly measured on a quantitative scale. A number of methodological aspects will be treated, with particular reference to the role of spline functions and artificial neural networks, which will be discussed in the context of the analysis of survival data. The problem of the evaluation and the choice of the optimal statistical models will be examined, with particular attention to the critical aspects related to the definition of prognostic indexes on the basis of the results of the selected models.

Biological markers as indicators of pathological response to primary chemotherapy in oral-cavity cancers.

The predictive role in terms of pathological response and prognostic role of biomarkers such as GST-pi, p53, bcl-2 and bax expression, immuno-histochemically detected, and of the S-phase cell fraction, autoradiographically determined as thymidine labeling index (TLI), were investigated within a prospective randomized phase III clinical trial on squamous-cell carcinoma of the oral cavity, including surgery or primary chemotherapy (PCT), which foresaw the prospective determination of biological markers. Pathological response was defined as the achievement after PCT of a pathological complete remission or the presence of microresidual disease. The study was performed on tumors obtained from a series of 100 previously untreated patients with resectable T2-4N0-2M0 carcinoma.

Association between [18F]fluorodeoxyglucose uptake and postoperative histopathology, hormone receptor status, thymidine labelling index and p53 in primary breast cancer: a preliminary observation.

To investigate the possible role of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in the prognostic evaluation of primary breast cancer, we studied 86 patients with T1-3 (TNM classification) breast tumours before surgery and compared the tumour FDG uptake, calculated as a standardized uptake value (SUV), with postoperative histopathological findings, steroid hormone receptor status of the tumour, thymidine labelling index (LI) and tissular expression of p53. SUV was significantly higher in infiltrating ductal carcinomas (n = 68; median SUV = 5.6) than in lobular ones (n = 18; median SUV = 3.

[Chondro-costal abnormalities of anterior wall of the chest: operative indications and surgical technique].

The aim of this study is to evaluate the utility of surgical treatment in patients with pectus excavatum (PE) or pectus carinatum (PC). Fifteen patients underwent surgical treatment because of their psycological and anatomical condition, more serious in 6 patients (5 with PE and 1 with PC). The degree of these chest wall deformities was evaluated as resulting from CT scan of the thorax, by the ratio between the transversal and the front/back diameters, according to Haller.

The clinical predictivity of biomarkers of stage III-IV epithelial ovarian cancer in a prospective randomized treatment protocol.

Background: The aim of this study was to define the clinical relevance of functional biomarkers, prospectively assessed in a randomized clinical protocol, in patients with Stage III-IV epithelial ovarian cancer. The protocol compared cisplatin with polychemotherapy that included cisplatin and cyclophosphamide.

Methods: In a subset of 168 patients with invasive epithelial ovarian cancer cell proliferation was determined by the 3H-thymidine labeling index, DNA ploidy was assessed by flow cytometry, and the expression of p53, bcl-2, and glutathione S-transferase-pi (GST-pi) was evaluated by immunohistochemistry using the antibodies PAb1801, anti-bcl-2, and GST-pi, respectively.

P53 accumulation in primary breast cancer: a comparison between immunohistochemistry and a novel luminometric immunoassay.

The accumulation of p53 protein was evaluated by a novel luminometric immunoassay (LIA) in cytosol samples from a series of 245 primary breast cancers. The cytosolic p53 content was not related to nodal status or hormone receptor status, but it was significantly and directly associated with tumor size and cell proliferation. A matched comparison between immunohistochemistry (IHC) and LIA results of individual tumors showed a significant association, albeit with a correlation coefficient of only 0.