Phenotypic characterization of human prostatic stromal cells in primary cultures derived from human tissue samples

Emerging evidence has shown that the tumor microenvironment plays a crucial role in prostate cancer (PCa) development and progression. However, the mechanism(s) through which stromal cells regulate epithelial cells and the differences among prostatic stromal cells of different histological/pathological origin in PCa progression remain unclear. Therefore, it is necessary to characterize the stromal cell populations present in benign prostatic hyperplasia (BPH) and PCa. To this end, we used cultures from stromal cells obtained from BPH-derived (15 cases) and PCa-derived (30 cases) primary cultures. In culture, stromal cells are a mixture of fibroblasts, myofibroblasts (MFs) and muscle cells. Fibroblasts are characterized for the expression of vimentin, MFs for the co-expression of α-smooth muscle actin (α-SMA) and vimentin, whereas muscle cells for the expression of α-SMA and desmin. Fibroblasts were present in large amounts in the BPH-compared to the PCa-derived cultures, whereas MFs were more representative of PCa-as opposed to BPH-derived cultures. Some α-SMA-positive cells retained the expression of basal cytokeratin K14. This population was defined as myoepithelial cells and was associated with senescent cultures. The percentage of MFs was higher in high-grade compared to moderate-and low-grade PCa-derived cultures, whereas the number of myoepithelial cells was lower in high-grade compared to moderate-and low-grade PCa-derived cultures. In addition, we analyzed the expression of p75NTR, as well as the expression of matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitors of MMPs (TIMPs). p75NTR expression was elevated in the stromal cultures derived from PCa compared to those derived from BPH and in cultures derived from cases with Gleason scores.7 compared to those derived from cases with Gleason scores <7, as well as in cultures with a high concentration of MFs compared to those with a high concentration of fibroblasts. MMP-2 was secreted by all primary cultures, whereas MMP-9 secretion was observed only in some PCa-derived stromal cells, when the percentage of MFs was significantly higher compared to BPH-derived cultures. TIMP1, TIMP2 and TIMP3 were secreted in elevated amounts in the BPH-compared to the PCa-derived stromal cultures, suggesting the differential regulation of extracellular matrix (ECM) degradation. When we used 22rv1 and PC3 PCa xenograft models for the isolation and characterization of murine cancer-associated fibroblasts (CAFs) we noted that the angiogenic wave was concurrent with the appearance of a reactive stroma phenotype, as determined by staining for α-SMA, vimentin, tenascin, calponin, desmin and Masson's trichrome. In conclusion, MF stromal cells from PCa participate in the progression and metastasis of PCa, modualting inflammation, angiogenesis and epithelial cancer cell proliferation

Clinical Study Effectiveness and Safety of Intensive Triplet Chemotherapy Plus Bevacizumab, FIr-B/FOx, in Young-Elderly Metastatic Colorectal Cancer Patients

Four-drug regimens, such as FIr-B/FOx schedule, can improve efficacy of first-line treatment of metastatic colorectal cancer (MCRC) patients. The present study specifically evaluates feasibility of FIr-B/FOx first-line intensive regimen in fit young-elderly MCRC patients, representing approximately 40% of overall MCRC patients. Activity, efficacy, and safety were equivalent to overall MCRC patients, not significantly different according to KRAS genotype. Clinical outcome was significantly prolonged in liverlimited compared to other/multiple metastatic disease. Safety evaluation of the individual young-elderly patient showed that limiting toxicity syndromes (LTS) in multiple sites were significantly increased, compared to LTS in single site, with respect to non-elderly patients

"Poker" association of weekly alternating 5-fluorouracil, irinotecan, bevacizumab and oxaliplatin (FIr-B/FOx) in first line treatment of metastatic colorectal cancer: a phase II study

<p>Abstract</p> <p>Background</p> <p>This phase II study investigated efficacy and safety of weekly alternating Bevacizumab (BEV)/Irinotecan (CPT-11) or Oxaliplatin (OHP) associated to weekly 5-Fluorouracil (5-FU) in first line treatment of metastatic colorectal carcinoma (MCRC).</p> <p>Methods</p> <p>Simon two-step design: delta 20% (p₀50%, p₁70%), power 80%, α 5%, β 20%. Projected objective responses (ORR): I step, 8/15 patients (pts); II step 26/43 pts. Schedule: weekly 12 h-timed-flat-infusion/5-FU 900 mg/m², days 1-2, 8-9, 15-16, 22-23; CPT-11 160 mg/m²plus BEV 5 mg/kg, days 1,15; OHP at three dose-levels, 60-70-80 mg/m², days 8, 22; every 4 weeks.</p> <p>Results</p> <p>Fifty consecutive, unselected pts < 75 years were enrolled: median age 63; young-elderly (yE) 24 (48%); liver metastases (LM) 33 pts, 66% Achieved OHP recommended dose, 80 mg/m². ORR 82% intent-to-treat and 84% as-treated analysis. Median progression-free survival 12 months. Equivalent efficacy was obtained in yE pts. Liver metastasectomies were performed in 26% of all pts and in 39% of pts with LM. After a median follow-up of 21 months, median overall survival was 28 months. Cumulative G3-4 toxicities per patient: diarrhea 28%, mucositis 6%, neutropenia 10%, hypertension 2%. They were equivalent in yE pts. Limiting toxicity syndromes (LTS), consisting of the dose-limiting toxicity, associated or not to G2 or limiting toxicities: 44% overall, 46% in yE. Multiple versus single site LTS, respectively: overall, 24% versus 20%; yE pts, 37.5% versus 8%.</p> <p>Conclusion</p> <p>Poker combination shows high activity and efficacy in first line treatment of MCRC. It increases liver metastasectomies rate and can be safely administered.</p> <p>Trial registration</p> <p>Osservatorio Nazionale sulla Sperimentazione Clinica dei Medicinali (OsSC) Agenzia Italiana del Farmaco (AIFA) Numero EudraCT 2007-004946-34</p

The prevalent KRAS exon 2 c.35 G>A mutation in metastatic colorectal cancer patients: A biomarker of worse prognosis and potential benefit of bevacizumab-containing intensive regimens?

Bevacizumab-containing chemotherapy differently predict increased efficacy in KRAS exon 2 mutant and wild-type metastatic colorectal cancer (MCRC) patients. Mutant compared to wild-type status did not significantly affect progression-free survival (PFS) and overall survival (OS) in patients fit for first line bevacizumab-containing FIr-B/FOx regimen, and after progression. In patients unfit for intensive regimens, mutant status significantly affected PFS, while not OS. Codon 12 KRAS mutations differentially affect GTPase function, and confer worse clinical behaviour. Prognostic relevance of the prevalent c.35 G. >. A KRAS mutation was retrospectively evaluated. Fit c.35 G. >. A mutant patients showed significantly worse OS compared to wild-type and to other mutant. After progression and in unfit patients, c.35 G. >. A mutation affected significantly worse PFS and OS. c.35 G. >. A mutant status does not significantly affect worse PFS in patients fit for first line FIr-B/FOx, and it may depend upon effectiveness of anti-VEGF-containing intensive regimen

BRCA1 and BRCA2: The genetic testing and the current management options for mutation carriers

Approximately 5-10% of breast carcinomas and 10% of ovarian carcinomas are ascribable to a genetic susceptibility. Of these, about 40% are related to genetic mutations in the genes BRCA1 and BRCA2. Despite the increasing demand for genetic testing arising from the patients and their relatives, the genetic testing can be offered yet only to individuals belonging to high-risk families in which the probability that there is a germline mutation in a BRCA gene is high and thus cancer occurrence is likely the expression of a highly penetrant genetic predisposition. In this article, we review how the current knowledge on the biological mechanisms underlying BRCA1 and BRCA2 dysfunction may contribute to the understanding of breast and ovarian cancer predisposition. The most currently employed methods for genetic testing are critically overviewed, together with some indications for the interpretation of the test outcome and the clinical management of mutation carriers. © 2005 Elsevier Ireland Ltd. All rights reserved

Effectiveness and Safety of Intensive Triplet Chemotherapy Plus Bevacizumab, FIr-B/FOx, in Young-Elderly Metastatic Colorectal Cancer Patients

Four-drug regimens, such as FIr-B/FOx schedule, can improve efficacy of first-line treatment of metastatic colorectal cancer (MCRC) patients. The present study specifically evaluates feasibility of FIr-B/FOx first-line intensive regimen in fit young-elderly MCRC patients, representing approximately 40% of overall MCRC patients. Activity, efficacy, and safety were equivalent to overall MCRC patients, not significantly different according to KRAS genotype. Clinical outcome was significantly prolonged in liver-limited compared to other/multiple metastatic disease. Safety evaluation of the individual young-elderly patient showed that limiting toxicity syndromes (LTS) in multiple sites were significantly increased, compared to LTS in single site, with respect to non-elderly patients

Effects of EGFR Tyrosine Kinase Inhibitor Erlotinib in Prostate Cancer Cells In Vitro

BACKGROUND. Erlotinib is a small-molecule tyrosine kinase inhibitor targeted EGFR, known to be overexpressed in a variety of cancers, including prostate cancer. Clinical trials showed insignificant clinical benefit in patients with castration resistant prostate cancer both when EGFR inhibitors were administered as monotherapy or in association with antiandrogens or chemotherapeutics. Why, differently to other tumors, have EGFR inhibitors been so ineffective in human prostate cancer? This is the question that we have set in this report. METHODS. For this purpose, the effectiveness of erlotinib, a selective EGFR inhibitor, in a wide range of prostate cancer cells (wild type or engineered to overexpress peculiar proteins including androgen receptor and PTEN). RESULTS. We demonstrated that the effectiveness of erlotinib was inversely correlated to the EGFR/Her2 ratio rather than EGFR/p-EGFR or Her2/p-Her2 levels. Chronic treatment with bicalutamide induced overexpression of Her2 and reduction of EGFR/Her2ratio and this was associated with increased Akt and Erk activity. In these conditions of treatment a reduced efficacy of erlotinib was observed. At the same time, an increased efficacy versus erlotinib was documented in cancer cells chronically exposed to DHT. In these culture conditions low levels of Her2 and increased EGFR/Her2 ratio were evidenced. CONCLUSIONS. Taken together, our results seem to suggest that a low EGFR/Her2 ratio and PTEN absence are the main factors responsible of erlotinib inefficacy. Therefore the inhibition of EGFR could have important antitumor effects in hormone-naive rather than in hormonally treated patients. Prostate 69: 1529-1537, 2009. (C) 2009 Wiley-Liss, Inc

Dual PI3K/mTOR inhibitor, XL765 (SAR245409), shows superior effects to sole PI3K [XL147 (SAR245408)] or mTOR [rapamycin] inhibition in prostate cancer cell models

Deregulation of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway contributes to prostate cancer development and progression. Here, we compared the in vitro effects of the dual PI3K/mTOR inhibitor (XL765) with those observed with the sole PI3K (XL147) or mTOR (rapamycin) inhibition in 2 non-tumor prostate epithelial cell lines, 8 prostate cancer cell lines, and 11 prostate cancer cell derivatives. We demonstrated that the XL765 treatment showed superior and proliferative effects of XL147 or rapamycin. The XL765 effects were associated to increasing the chromosome region maintenance 1 (CRM1)-mediated nuclear localization of glycogen synthase kinase 3 beta (GSK3β) and Foxo-1a with higher induction of apoptosis when compared to those observed in XL147 and rapamycin treatments. IC50 values were calculated in phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-positive and PTEN-negative cell lines as well as after PTEN transfection or PTEN downmodulation by siRNA strategy revealing that the presence of this protein was associated with reduced sensitivity to PI3K and mTOR inhibitors. The comparison of IC50 values was also calculated for androgen-dependent and -independent cell lines as well as after androgen receptor (AR) transfection or the AR downmodulation by siRNA strategy revealing that androgen independence was associated with enhanced responsiveness. Our results provide a rationale to use the dual PI3K/Akt/mTOR inhibitors in hormone-insensitive prostate cancer models due to the overactivity of PI3K/Akt/mTOR in this disease condition