Biomedical subjects

Carlo Vicentini

Publications and source records attributed to Carlo Vicentini.

At least 19 recordsLinked to original sources

PubMed2007

Bladder outlet obstruction index and maximal flow rate during urodynamic study as powerful predictors for the detection of urodynamic obstruction in women.

AIMS: To evaluate whether bladder outlet obstruction index (BOOI), a mathematical index of outlet resistance, in association with maximal flow rate (Qmax) obtained during multichannel urodynamics (UDS) or detrusor pressure at maximal flow rate (PdetQmax) could help the identification of obstruction in women. METHODS: From January 2004 to February 2005, 401 women were assessed in our urodynamic unit. Of these, 133 were neurologically intact women, referred symptoms suggestive of voiding disorders and had an abnormal non-intubated uroflussometry (NIF) (BOO group). A normal NIF was defined as a bell-shaped curve in presence of a Qmax >15 ml/sec and a PVR <50 ml. Symptoms of voiding disorders were ascertained by interview and rated positive if they occurred more than occasionally. Thirty-seven women were enrolled as unobstructed if they presented a normal NIF and symptoms suggestive of voiding disorders less than occasionally (unobstructed group). RESULTS: ROC curve demonstrated similar diagnostic accuracy in the diagnosis of urodynamic obstruction for Qmax obtained during UDS (AUC = 0.908; P < 0.0001; CI99% = 0.831 to 0.985) and BOOI (AUC = 0.879; P < 0.0001; CI99% = 0.794 to 0.918) and the least was seen for PdetQmax (AUC = 0.706; P = 0.001; CI99% = 0.620 to 0.830). A Qmax obtained during UDS cut-off < or =15 ml/sec provides specificity of 85.9% and sensitivity of 78.9%. A BOOI cut-off > or = -8 provides a sensitivity of 80.8% and specificity of 86.1%. The weakest sensitivity (64.2%) and specificity (64.6%) was recorded for PdetQmax > or =28 cmH(2)O. CONCLUSIONS: BOOI and Qmax obtained during UDS appears to be the most discriminating urodynamic parameters of female BOO. The use of these cutoff might facilitate the identification of women with functional and anatomical obstruction.

Aged↗

PubMed2007

Tyrosine kinase inhibitor CEP-701 blocks the NTRK1/NGF receptor and limits the invasive capability of prostate cancer cells in vitro.

In the prostate, cellular growth and differentiation are finely regulated by a complex interaction between stromal and epithelial cells under the control of both autocrine and paracrine regulatory factors such as the nerve growth factor (NGF). However, the role of NGF and its receptors including the high-affinity p-140 TrkA and the low-affinity p75 NTR receptors remains controversial. Moreover prostate tissues stored other neutrophins such as NT3, NT4 and brain derived neutrophic factor (BDNF) as well as the corresponding receptors (NTRs). Different members of NTRs are expressed during prostate cancer (PCa) progression, suggesting their involvement in cell proliferation, anoikis protection and malignancy. Therefore, we analyzed the expression of NTRs including NTRK1 (TrkA), NTRK2 (TrkB), NTRK3 (TrkC) and p75 NGFR in a panel of 7 well-characterized PCa cell lines and 12 cell derivatives from PC3 (4), DU145 (2), CWR22R (4) and LnCap (2) cell lines possessing different proliferative/invasive capabilities. We evaluated also the role of NGF, BDNF and NT3 in the modulation of cell migration and invasion and, finally, the effects of a pan Trk inhibitor, CEP-701 which has been included in some clinical trials for the treatment of PCa. We observed the following: i) TrkA and TrkB expression was significantly higher in AR-negative compared to AR-positive cells; ii) TrkA and TrkB expression was related to the invasive capacity/malignancy of PCa cells; iii) p75 NGFR could be considered a tumor suppressor gene which is present at high levels only in AR-positive cells; and iv) that NGF and BDNF (targeting TrkA/p75 NTR and TrKB, respectively) induced cell migration and this was inhibited by the CEP-701 treatment. In conclusion, the malignancy of PCa seems to be accompanied by increased TrkA and TrkB signaling (with a reduction of p75 NGFR expression) and CEP-701 could be used to reduce the metastasis formation in advanced PCa. CEP-701 is a trademark of Cephalon Inc., West Chester, PA, USA.

Brain-Derived Neurotrophic Factor↗

PubMed2006

Sexual function in women with urinary incontinence treated by pelvic floor transvaginal electrical stimulation.

INTRODUCTION: Women's sexual dysfunctions (WSD) have been commonly associated with urinary incontinence (UI). Women with UI and who scored low on the Female Sexual Function Index (FSFI) showed an improvement in urinary leakage and also in their sexual life following treatment by transvaginal electrical stimulation (TES). AIMS: To determine the effects of TES in 37 women complaining of UI, of whom 23 also had WSD, and to compare the FSFI scores of women with UI and 43 women not affected by UI who underwent routine urologic evaluation. METHODS: Thirty-seven women complaining of UI were evaluated by voiding diary and with FSFI before and after 3 months of TES. All had a urogynecologic evaluation and urodynamic study. MAIN OUTCOME MEASURES: In the voiding diary the women reported the types of liquid they ingested, urinary frequency, and episodes of urgency and urine leakage. The domain scores of the FSFI, including desire, arousal, lubrication, orgasm, satisfaction, and pain, were calculated. TES was conducted for 15-30 minutes, twice a week for 3 months, using biphasic intermittent current with a frequency of 50 Hz for stress UI (SUI) and 20 Hz for urge UI (UUI), and the most tolerable intensity of stimulation. RESULTS: After TES, only two of the 10 women with UUI experienced a few leakage incidents; patients with SUI were completely dry during TES; and only three reported a few episodes of UI during intense activities. The five patients with mixed UI improved mainly as regards urgency. The FSFI scores of patients complaining of UI showed significantly lower desire and sexual satisfaction, and higher sexual pain than controls. After 3 months, the 23 women affected by WSD, of the 37 participants with UI, reported a remarkable improvement in their sexual life. CONCLUSIONS: TES was found to be a safe and effective therapy for selected patients affected by mild to moderate UI. Because women with UI also complain of WSD compared with the general female population, an investigation of female sexuality is suggested for these patients.

Arousal↗

PubMed2006

Pyrazolo[3,4-d]pyrimidines c-Src inhibitors reduce epidermal growth factor-induced migration in prostate cancer cells.

During its biological progression, prostate cancer frequently develops dependence on growth factor receptors and their downstream signalling messengers, including c-Src. Evidence for this supports the choice of c-Src as a therapeutic target in the prevention of tumour spreading. Two new pyrazolo[3,4-d]pyrimidines c-Src inhibitors, SI35 and SI40, were used to investigate the role of c-Src in the control of the aggressive phenotype of prostate carcinoma cell line, PC3. SI molecules reduced the proliferation of PC3 cells in a time- and dose-dependent manner, with an IC50 of approximately 50 microM. PC3 cells responded to the presence of epidermal growth factor (EGF) by increasing their migratory ability, and this effect was strongly reduced by the addition of SI at concentrations less than IC50. Further observations demonstrated that SI molecules modulated cell morphology and their adhesive capacity on different physiological substrates. The action of SI molecules appeared to involve, in parallel with c-Src inhibition, the down-modulation of the active forms of paxillin and extracellular signal-regulated kinase (ERK). Our data suggest a promising role for pyrazolo[3,4-d]pyrimidines c-Src inhibitors in the control of a highly invasive tumour phenotype.

Cell Adhesion↗

PubMed2006

Valproic acid induces apoptosis in prostate carcinoma cell lines by activation of multiple death pathways.

Valproic acid is a well-known antiepileptic drug that was recently discovered to have a wide-spectrum antitumoral action in several tumors. In our work, we tested the proapoptotic activity of valproic acid in prostate cancer. Valproic acid-induced apoptosis was described by several in-vitro assays in three prostate cancer cell lines: two representing the prototype of advanced, clinically untreatable stages of prostate progression, PC3 and DU145, and one resembling a more differentiated androgen-sensitive tumor, LNCaP. We observed that valproic acid was a potent and early apoptotic inducer, mainly in less-differentiated prostate cancer cell lines. The molecular analysis of the apoptotic machinery involved in valproic acid action revealed a central role in Bcl-2 downmodulation. When prostate cancer cells were treated for a longer time with valproic acid, we detected an enhancement of Fas-dependent apoptosis associated with an overexpression in Fas and Fas ligand. Our data indicate that the use of valproic acid may be a suitable therapeutic agent in the control of prostate cancer progression and its action appears particularly relevant in the control of refractory stages of prostate cancer.

Antineoplastic Agents↗

PubMed2006

Uncommon complication of endoscopic ureterolithotripsy: the stone granuloma.

Endoscopic management of urolithiasis is one of the commonest urological procedures today. It is usually safe and effective but one of the possible complications is ureteral obstruction. Stone fragmentation after ballistic lithotripsy and ureteral wall perforation could explain the mechanism responsible for this occurrence. We report a case of stone granuloma, occurring after a ballistic ureterolithotripsy.

Adult↗

PubMed2006

Suppression of EGF-R signaling reduces the incidence of prostate cancer metastasis in nude mice.

The activation of epidermal growth factor receptor (EGF-R) plays a key role in the promotion of proliferation and invasion in prostatic carcinoma (PCa). Gefitinib (Iressa; ZD1839), an orally active EGF-R tyrosine kinase inhibitor, has shown an important anti-proliferative activity in tumors expressing EGF-R both in vitro and in vivo. Our aim was to elucidate the role of gefitinib in the modulation of the metastatic spread of PCa cells. The therapeutic role of gefitinib was investigated by evaluating the proliferative and invasive ability of the PCa cell line PC3 and of its high metastatic sub-line, PCb2, by in vitro assays and intracardiac injection in nude mice. The inhibitory effect of gefitinib was tested in vivo by injecting PCa cells subcutaneously or in the left ventricle of nude mice and by administering daily 150 mg/kg of gefitinib. While xenograft growth was equally reduced in all PCa lines (about 50%), the bone metastasis formation was inhibited especially for the high metastatic PCb2 sub-line (81%) in comparison to PC3 cells (47%). The comparative in vitro analysis among PCa cell lines showed that PCb2 cells were more sensitive to the inhibitory effect of gefitinib in their invasive ability compared to parental PC3 cells but not in their proliferation rate. Moreover, PCb2 cells demonstrated an increased invasive ability in vitro in response to bone stromal cell conditioned medium (BCM). The simultaneous presence of 0.1 ng/ml gefitinib was sufficient to reduce the number of invaded cells in the presence of both EGF and BCM. The molecular characterization of the highly aggressive PCa sub-lines demonstrated that this phenomenon was associated with an increment in uPA/uPAR axis but not in EGF-R expression. In conclusion, our data suggest that the use of gefitinib as a therapeutic agent may be indicated in the control of PCa spreading to bone.

Animals↗

PubMed2006

Retroperitoneal cysts: a case report.

Retroperitoneal cysts are rare lesions, variable from asymptomatic cases with incidental discovery to case with acute or chronic abdominal discomfort. A 50-year-old female after a car crash refered chronic abdominal pain. An X-ray revealed the presence of sternal and multiple costal fractures. Abdominal ultrasonography (US) and computed tomography (CT) lead to the discovery of a retroperitoneal cyst too. As the patient was well after fractures solution, we decided to control the cyst in the time. In symptomatic cases surgery is the treatment of choice. The advent of laparoscopic surgery allows resection of these cysts to be achieved without full laparotomy.

Cysts↗

PubMed2005

Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cells in vitro.

Progression from an androgen-dependent to an androgen-independent state often occurs in patients with prostate cancer (PCa) who undergo hormonal therapy. We have investigated whether inhibition of the epidermal growth factor receptor (EGFR) signaling pathway affects the antitumor effect of a nonsteroidal antiandrogen. Gefitinib (Iressa), an EGFR tyrosine kinase inhibitor, and bicalutamide (Casodex), a nonsteroidal antiandrogen [androgen receptor (AR) antagonist], were administered alone and in combination to AR-positive human PCa cell lines. FACS analysis showed lower EGFR expression levels on AR-positive cells (LNCaP, CWR22, CWR22R 2152 and AR-transfected DU145 cell lines) compared with AR-negative cells (DU145, PC3 and TSU-Pr1). Moreover, in AR-transfected DU145 cells, chronic treatment with bicalutamide increased EGFR expression to levels similar to androgen-independent DU145 cells. All AR-positive PCa cell lines were sensitive to gefitinib (IC50 = 0.1-0.6 microM), whereas higher concentrations of bicalutamide were needed to reduce AR-positive PCa cell line proliferation (IC50 = 0.8-2.0 microM). Low doses of gefitinib increased the antitumor effects of bicalutamide by strongly reducing the IC50 of bicalutamide (approximately 10-fold). Similarly, bicalutamide increased the antiproliferative effects of gefitinib by reducing the IC50 of gefitinib (approximately 5-fold). Taken together, our data suggest that in androgen-dependent cell lines, addition of gefitinib in combination with bicalutamide results in concurrent dual inhibition of AR and EGFR/HER2 pathways. This causes a significant delay in the onset of EGFR-driven androgen independence.

Androgen Antagonists↗

PubMed2005

Effects of 5 alpha reductase inhibitors on androgen-dependent human prostatic carcinoma cells.

PURPOSE: To investigate the effects of MK906, a selective 5 alpha reductase (5alphaR) type 2 (5alphaR2) inhibitor, and of MK386, a specific 5alphaR1 inhibitor, on the cellular proliferation of androgen-dependent human prostatic cancer (PCa) cells in cultures of cells derived from bioptic and surgical tissues. METHODS: In this study we tested the effects of MK906 and MK386 in 30 cultures derived from PCa, 6 from PIN and 10 from benign prostatic hyperplasia specimens. RESULTS: Prostate primary cultures under short-term conditions (with <4 subcultures) represent a mixture of epithelial and stromal cells. Epithelial cells require testosterone (T) for optimal growth, but were not able to grow in the presence of T under long-term conditions even if DHT was able to induce cellular proliferation to a similar extent in both conditions, suggesting that 5alphaR can be lost in long-term cultures. Therefore, our studies were performed under short-term conditions. Both 5alphaR inhibitors decreased cell proliferation significantly and dose-dependently in all the samples tested. MK906 was more efficient than MK386 in 7 out of 10 cultures derived from BPH tissues, in 4 out of 6 cultures derived from PIN and in 18 out of 30 cultures derived from PCa. In 3 out of 10 BPH, in 2 out of 6 PIN and in 5 out of 30 PCa-derived cultures, both inhibitors presented similar efficacy, whereas in 1 out of 10 BPH and 7 out of 30 PCa-derived cultures MK386 was more efficient than MK906. In addition, MK386 was more efficient than MK906 in 4 out of 15 non-metastatic PCa and 2 out of 7 metastatic PCa-derived cultures. CONCLUSIONS: Considering that 5alphaR1 (responsible primarily for androgenic catabolism) is mostly expressed in epithelial cells and that 5alphaR2 (responsible for local DHT synthesis and release) is expressed in the stromal cells (which provides several paracrine growth factors and DHT itself to the epithelial cells), our experiments suggest that the inhibition of both 5alphaR1 and 5alphaR2 by MK386 and MK906, respectively, may have therapeutic potential in order to reduce the growth and progression of human prostatic cancers, through the inhibition of autocrine or paracrine mechanisms involving the stromal cell compartment. In addition, some effects of 5alphaR inhibitors could be mediated by estrogens, which are synthesized by the aromatase enzyme present in the epithelial cells. These aspects could be considered in order to improve the therapeutical management of PCa and for future clinical trials.

5-alpha Reductase Inhibitors↗

PubMed2005

Tamsulosin treatment increases clinical success rate of single extracorporeal shock wave lithotripsy of renal stones.

OBJECTIVES: To design a randomized, no-treatment, controlled, prospective study to determine whether the administration of tamsulosin, as adjunctive medical therapy, increases the efficacy of one extracorporeal shock wave lithotripsy (ESWL) session to treat renal stones and decreases the use of analgesic drugs after the procedure. METHODS: A total of 130 patients underwent a single ESWL session to treat solitary radiopaque renal stones 4 to 20 mm in diameter. After treatment, all patients were randomly assigned to receive our standard medical therapy alone (controls) or in association with 0.4 mg tamsulosin daily for a maximum of 12 weeks. All 130 patients were followed up for 3 months or until an alternative treatment was given. RESULTS: Of the 130 patients, 78.5% of those receiving tamsulosin and 60% of controls had achieved clinical success at 3 months (P = 0.037). When we stratified patients according to stone size, for those with a stone size larger than 10 mm, the success rate was significantly greater in the tamsulosin group (P = 0.028). Renoureteral colic occurred in 76.9% of patients treated with standard therapy but in only 26.1% of those receiving tamsulosin (P < 0.001). The mean cumulative diclofenac dose was 375 mg per patient in the tamsulosin group and 675 mg per patient in the control group (P < 0.001). CONCLUSIONS: The results of our study have demonstrated that tamsulosin therapy, as an adjunctive medical therapy after ESWL, is more effective than lithotripsy alone for the treatment of patients with large renal stones and is equally safe. In addition, our results also indicated that adjunctive treatment with tamsulosin could decrease the use of analgesic drugs after ESWL.

Combined Modality Therapy↗

PubMed2005

Epidermal growth factor modulates prostate cancer cell invasiveness regulating urokinase-type plasminogen activator activity. EGF-receptor inhibition may prevent tumor cell dissemination.

Urokinase-type plasminogen activator receptor (uPAR) and Epidermal Growth Factor Receptor (EGFR) are ubiquitous receptors involved in the control of a variety of cellular processes frequently found altered in cancer cells. The EGFR has been recently described to play a transduction role of uPAR stimuli, mediating uPA-induced proliferation in highly malignant cells that overexpress uPAR. We compared the uPA production, the presence of uPAR, AR, EGFR and Her2 with the chemotaxis and the Matrigel invasion in ten human PCa cell lines and observed that: (1) the levels of Her2, but not of EGFR, as well as the uPA secretion, cell motility and Matrigel invasion were statistically higher in AR negative than in AR positive PCa cells; (2) the uPA secretion and uPA Rexpression were positively related to Matrigel invasion; (3) the EGF was able to stimulate chemotaxis and Matrigel invasion in a dose-dependent manner; (4) the EGF-induced cell migration was statistically higher inAR negative than in AR positive cells with a similar increase with respect to basal value (about 2.6 fold); (5) the Matrigel invasion was statistically higher in AR negative than in AR positive PCa cells also if the increment of Matrigel invasion after EGF treatment was statistically higher in AR positive respect to AR negative cells; (6) the EGF induced uPA secretion and its membrane uptake through the increment of uPAR; and (7) these effects were blocked by EGFR/Her2 tyrosine kinase inhibitors with IC(50) lower than those needed to inhibit cell proliferation and required PI3K/Akt, MAPK and PI-PLC activities as verified by inhibition experiments. These enzymatic activities were regulated in different manners in PTEN positive and negative cells. In fact, the inhibition of PI3K blocked the EGF-induced invasiveness in PTEN positive cells but not in PTEN negative cells, in which PI3K activity was not influenced by EGFR/Her2 activation, whereas the inhibition of MAPK was able to block the invasive phenomena in both cell types. Taken together, our data suggest that the blockade of EGFR could attenuate the invasive potential of PCa cells. In addition, considering that the EGFR expression is related to higher Gleason grade of PCa and that EGFR levels are increased after anti androgenic therapy, this therapeutic approach could slow down the metastasis formation which represents the most dramatic event of PCa progression.

Cell Line, Tumor↗

PubMed2005

Epithelial and prostatic marker expression in short-term primary cultures of human prostate tissue samples.

Despite the high incidence and mortality of prostate cancer (PCa), molecular and genetic events involved in its progression remain poorly understood due to difficulty in establishing premalignant lesions and primary tumors in vitro. The most used cancer cell lines, which have been established primarily from metastatic lesions, do not accurately recapitulate the biological behaviour of primary tumors as compared to primary cultures generated from clinical PCa specimens. However, prostate primary cultures contain a mixture of different cell types which must be characterized completely to obtain reproducible information for studying the biology of single tumors and for evaluating the effectiveness of therapeutical approaches. In this report we show the differential expression of epithelial and prostatic markers in 30 PCa-, 6 high grade prostate intraepithelial neoplasia (PIN)- and 6 BPH-derived primary cell cultures. After organoids attached, outgrowths appeared with cells maintaining close cell-to-cell associations: cell colonies express either cyto-keratin 14 [K14 (20-60%)], or cytokeratin 18 [K18 (10-70%)] with moderately high levels of androgen receptor (AR), prostate-specific antigen (PSA) and kallikrein (hK2). The differences observed for K14 immunostaining was not statistically different between PIN- and BPH-derived cultures, whereas the difference of expression of the same marker resulted highly significant (p<0.001) in the comparison between PIN- and PCa-derived cultures and between BPH- and PCa-derived cultures. In addition, the percentage of positivity for lumenal K18 was statistically lower for BPH cultures respect to the positivity observed for both PIN and PCa-derived cultures (p<0.05 and p<0.001, respectively). A reduced expression of K18+ cells, without modification in K14 expression, was evident in high grade PCa in which we observed also an increment in K5 expression representing an intermediate basal/differentiating epithelial cell marker. The primary cultures derived from prostatic tissues can be an extremely important method to study genetic and molecular changes involved in PCa progression.

Biomarkers, Tumor↗

PubMed2004

Osteopontin enhances the cell proliferation induced by the epidermal growth factor in human prostate cancer cells.

BACKGROUND: Susceptibility to extracellular matrix and growth factors has been demonstrated to play a critical role in the development of prostate cancer (PCa) metastases. The aim of this study was to elucidate some mechanisms by which stroma controls tumor progression. METHODS: In our study we tested the growth ability of the LNCaP human prostatic cell line in steroid-free culture conditions in response to osteopontin (OPN), a non-collageneous matrix protein, localized in large amounts in the bone. RESULTS: In the LNCaP cell model, OPN stimulates cell proliferation in serum-free medium and colony growth at high dilution but this effect is visible only in presence of epidermal growth factor (EGF). Proliferation induced by OPN is accompanied by a sustained activation of EGF receptor (EGFR) whose phosphorylation is detectable up to 12 hr after treatment in association with EGF. The colocalization of integrin beta1, a ligand of OPN, and of EGFR on the cellular membrane, suggests that the association of these cell surface receptors may be the principal mechanism involved in the long-term activation of the EGFR. CONCLUSIONS: Our data describe a new possible mechanism involved in the establishment of bone metastases which may also account for the formation of androgen-independent cellular clones, frequently responsible of the clinical progression of PCa.

Bone Neoplasms↗

PubMed2004

Detection of telomerase activity in prostate massage samples improves differentiating prostate cancer from benign prostatic hyperplasia.

PURPOSE: We performed a case-control study in which we tested the ability of a non-invasive assay to detect telomerase activity and to distinguish between prostatic cancer (Pca) and benign prostatic hyperplasia (BPH) on samples of epithelial cells obtained after prostatic massage. METHODS: Telomerase activity was determined by a telomeric repeat amplification protocol (TRAP) assay. We selected 60 patients with histologically proven Pca (30 cases) or BPH (30 cases). Specimens included in this study were from patients who had no suspicious findings on digital rectal examination for cancer, had clinical evidence of lower urinary tract symptoms, had no sonographic signs of Pca at the transrectal ultrasound evaluation, had total PSA values moderately elevated (2.6-15 ng/ml), and had no evidence of other urological cancers. The whole procedure was conducted in double blind between pathologists and molecular biology operators. RESULTS: Telomerase activity was detected in 90% of Pca cases and in 13% of BPH cases. The sensitivity (90%) and specificity (76%) of this method were calculated. The positive predictive value, negative predictive value, and diagnostic efficiency were 87%, 90%, and 88% respectively. CONCLUSION: Our data indicate that telomerase activity detected by TRAP assay on prostate epithelial cells collected by prostate massage can substantially improve the distinction between Pca and BPH conditions. One of the clinical benefits resulting from the use of this new assay would be to refine the biopsy indication and to avoid for several patients without Pca the unnecessary cost and the complications of prostate biopsy.

Aged↗

PubMed2004

Long-term presence of androgens and anti-androgens modulate EGF-receptor expression and MAP-kinase phosphorylation in androgen receptor-prostate positive cancer cells.

Prostate cancer (Pca) progression from an androgen-dependent to an androgen-independent state occurs in patients who undergo hormonal therapy. There is evidence indicating that deregulation of the epidermal growth factor receptor (EGFR) pathway plays a critical role in this phenomenon. In this study we addressed the question by stably transfecting the androgen receptor (AR) cDNA into the AR-negative Pca cell line DU145 that expresses high levels of EGFR. The resulting cell line has been named DU145-AR. We showed that the introduction of the AR restored positive androgen regulation of tumour cell growth and gene expression in vitro. The DU145-AR cells grown in culture medium containing androgens exhibited a transient up-regulation of EGFR levels with a subsequent down-regulation. This phenomenon was reversible, upon addition of hydroxiflutamide (HF) to the culture medium, but after prolonged treatment. When the EGFR repression is relieved in the presence of HF, the cells become more responsive either to EGF mediated growth or to anti-proliferative effect of PKI166, an inhibitor of EGFR phosphorylation. Moreover, we found a significant increase of the activated form of mitogen-activated-protein kinase (MAPK) in cells treated with HF. PKI166 blocked this HF mediated-MAPK activation, suggesting that the activation of MAPK is an event dependent on EGFR function. Our data demonstrate that hormone sensitive Pca cells possess a mechanism able to limit EGFR expression. Up-regulation of EGFR in response to long-term HF treatment could represent an attempt to rescue cell growth through a compensatory survival pathway.

Androgen Antagonists↗

PubMed2004

Evaluation of metastatic potential in prostate carcinoma: an in vivo model.

Prostate cancer is frequently associated with bone metastases, which are in fact the main cause of morbidity and mortality for this tumor. To better investigate this process, animal models of bone and bone marrow metastases need to be developed. However, experimental prostate cancer bone metastases are difficult to be obtained in vivo, and some typical clinical patterns remain irreproducible. In this study, we injected PC3 prostate cancer cells into the left cardiac ventricle of nude mice, thus reproducing the basic biological phenomenon of tumor cell spreading in the arterious blood stream, and compared the outcome with direct injection of cells in the bone marrow cavity of the tibia. Mice were monitored by X-ray analysis. After 40 days, 100% of intratibially-injected and 64% of heart-injected mice revealed osteolytic lesions. The heart injection was then used to select PC3 cell subpopulations by serial inoculation and recovery from bone metastasis. One of the resulting cell populations, obtained by a second round of selection and denominated PCb2, showed a more invasive phenotype compared to parental PC3, both in vitro and in vivo. Although PCb2 cells had a growth rate comparable to that of PC3 cells, they generated a higher number of bone lesions in nude mice and crossed more easily the Matrigel barrier in vitro in the presence of several chemoattractants. This phenomenon was partially due to an increased capacity to adhere to laminin and to release MMP-2 at higher level relative to the original PC3 cells. This study demonstrates that heart injection of prostate cancer cells in nude mice may represent a good experimental model to investigate the pathophysiology of bone and bone marrow metastases in vivo.

Animals↗

PubMed2003

Prostate cancer cell proliferation is strongly reduced by the epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 in vitro on human cell lines and primary cultures.

PURPOSE: To investigate the effects of the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) ZD1839 ('Iressa') on the cellular proliferation of androgen-sensitive and androgen-independent human prostatic cancer cell lines and primary cultures in vitro. EXPERIMENTAL DESIGN: In this study, we investigated the effects of the quinazoline ZD1839, a potent, selective EGFR-TKI, on the EGFR autophosphorylation and cellular proliferation of androgen-sensitive (ND1, LNCaP, and ALVA-31) and androgen-independent (PC3, DU145, and TSU-Pr1) human prostatic cancer cell lines and 20 primary cultures derived from human prostatic cancer tissue. RESULTS: EGFR was present and phosphorylated in all cell lines tested. ZD1839 reduced EGFR autophosphorylation in intact cell lines with IC(50)s of 0.46-0.97 microM, and inhibited cellular proliferation with IC(50)s of 0.37-1.03 microM. Constitutive EGFR autophosphorylation was low in primary cell cultures, but addition of EGF (50 ng/ml) caused marked EGFR autophosphorylation; cellular proliferation in the presence of EGF was inhibited by ZD1839 with a mean IC(50) of 0.45 microM. At doses >1 microM, ZD1839 induced apoptosis in both androgen-dependent and androgen-independent PCa cell lines. CONCLUSION. Our experiments suggest that EGFR-TKIs such as ZD1839 may have potential in blocking the growth and progression of human prostatic cancers even in early phases of the disease.

Antineoplastic Agents↗