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Sergio Bracarda

Publications and source records attributed to Sergio Bracarda.

7 recordsLinked to original sources
PubMed2006

Mechanism of 2-chloroadenosine toxicity to PC3 cell line.

BACKGROUND: 2-CADO inhibits the growth of several types of cells and causes apoptosis by a mechanism which involves adenosine receptors or cellular uptake or both. METHODS: Androgen-independent (PC3) prostate cancer cells were used in the study and proliferation, cell-cycle progression, and apoptosis analyzed. Deoxy-and ribonucleoside triphosphate pools were determined by HPLC. The molecular mechanism was examined by assessing the involvement of DNA synthesizing enzymes in the cellular response. RESULTS: 2-CADO treatment dramatically reduced the number of prostate cancer cells and permanently stopped cell-cycle progression in the S-phase. The role of 2-CADO in prostate cancer cells is uptake-mediated and followed by sequential phosphorylations to 2-Cl-ATP that irreversibly inhibits several key-enzymes for DNA biosynthesis. CONCLUSIONS: Arrest of DNA synthesis responsible for toxicity of 2-CADO to PC3 cells is due to the lack of substrates for DNA polymerization caused by irreversible inhibition of purine/pyrimidine ribo-and 2-deoxyribonucleotides salvage enzymes.

2-Chloroadenosine↗
PubMed2006

Targeting of EGFR tyrosine kinase by ZD1839 ("Iressa") in androgen-responsive prostate cancer in vitro.

EGFR, highly expressed in a variety of human malignancies, is correlated with poor tumour differentiation, high tumour growth and metastatic rate. EGF and several other ligands, such as transforming growth factor-alpha, amphiregulin, heparin-binding EGF, and betacellulin, activate Ras/Raf mitogen-activated protein kinases (MAPKs) and phosphatidyl inositol 3'-kinase (PI3K)/Akt signalling pathways. Therefore, EGFR can regulate multiple processes, i.e., gene expression, cellular proliferation, angiogenesis, and inhibition of apoptosis, which contribute to the development of malignancy. In this review, we discuss the inhibition of EGFR by the specific tyrosine kinase inhibitor Iressa (ZD1839) focusing on its effects in prostate cancer.

Androgens↗
PubMed2005

Cancer of the prostate.

Prostate carcinoma, with about 190,000 new cases occurring each year (15% of all cancers in men), is the most frequent cancer among men in northern and western Europe. Causes of the disease are essentially unknown, although hormonal factors are involved, and diet may exert an indirect influence; some genes, potentially involved in hereditary prostate cancer (HPC) have been identified. A suspect of prostate cancer may derive from elevated serum prostate-specific antigen (PSA) values and/or a suspicious digital rectal examination (DRE) finding. For a definitive diagnosis, however, a positive prostate biopsy is requested. Treatment strategy is defined according to initial PSA stage, and grade of the disease and age and general conditions of the patient. In localized disease, watchful waiting is indicated as primary option in patients with well or moderately differentiated tumours and a life expectancy <10 years, while radical prostatectomy and radiotherapy (with or without hormone-therapy) could be appropriate choices in the remaining cases. Hormone-therapy is the treatment of choice, combined with radiotherapy, for locally advanced or bulky disease and is effective, but not curative, in 80-85% of the cases of advanced disease. Patients who develop a hormone-refractory prostate cancer disease (HRPC) have to be evaluated for chemotherapy because of the recent demonstration of improved overall survival (2-2.5 months) and quality of life with docetaxel in more than 1,600 cases.

Antineoplastic Protocols↗
PubMed2002

Long-term results of induction chemotherapy followed by concurrent chemotherapy and thoracic irradiation in limited small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) is a chemoresponsive tumor but overall survival remains poor even in limited disease (LD). With the aim of eradicating chemoresistant tumor cells and reducing toxicity, we investigated in this phase II trial the feasibility and outcome of a sequential approach of induction chemotherapy (CT) followed, in responding patients with LD-SCLC, by intensified platinum-based CT and concurrent thoracic irradiation (TI). MATERIALS AND METHODS: We treated 55 consecutive LD-SCLC patients with three 21-day cycles of cyclophosphamide, epiadriamycin and vincristine (CEV) as induction CT. In 44 (80%) patients there was an objective response and they received treatment intensification consisting of TI and concomitant CT with carboplatin and etoposide plus recombinant granulocite colony stimulating factor. Twenty-five (57%) patients were submitted to twice-daily thoracic irradiation (TDTI; 1.5 Gy per fraction, to a total dose of 45 Gy) and 19 (43%) to once-daily thoracic irradiation (ODTI; 2 Gy per fraction, to a total dose of 50 Gy). RESULTS: Median follow up was 75 months (range, 42-102). Of 44 patients submitted to intensification with TI plus CT, 32 (73%) had a complete and 12 (27%) a partial response. Median overall survival of all 55 patients was 17 months with actuarial survival probabilities of 2 and 5 years, 32 and 25%, respectively. Analysis of patient sub-groups showed a 5-month median survival in non-responders, 19 in TDTI and 17 in ODTI patients, respectively. Two and 5 year survival probabilities were 0% in non-responders, 40 and 35% in TDTI and 39 and 21% in ODTI patients, respectively. At present, 13 of 44 responders are still alive, of which nine (20%) have been progression-free from 45 to 93 months (median 60). Treatment failure was registered in 31 (70%) of 44 patients who received both induction and intensification treatment. One-half of patients had intrathoracic recurrence, eight of which only local and the remaining seven local and distant. Fourteen (32%) patients had brain metastases. Grade 3-4 neutropenia occurred in 24 (55%) patients with no differences between treatment groups. Grade 3 esophagitis was registered in four (9%) patients: in 3/25 (12%) and 1/19 (5%) of those who received TDTI and ODTI, respectively (P=not significant). Acute radiation pneumonitis occurred in three (12%) patients submitted to TDTI. No clinically debilitating pulmonary fibrosis, permanent esophageal stricture or toxic death was observed. CONCLUSIONS: In LD-SCLC patients late concurrent CT plus TI is feasible and effective. Our long-term results are similar to the best reported in the literature. Despite the high incidence of complete response obtained, however, one-half of the patients had intrathoracic relapse and one-third brain metastases.

Adult↗