Efficacy of different sequences of radio- and chemotherapy in experimental models of human melanoma.

Although combination chemotherapy and radiotherapy have become the standard of care in numerous tumors, the mechanisms of interaction are often still unclear. The purpose of this study was to analyze the efficacy of radiation treatment and cisplatin sequences and to investigate their mechanisms of interaction. Three melanoma cell lines were used to evaluate in vitro radiation-induced cytotoxicity before and after cisplatin treatment. Expression levels of a panel of genes were determined by real-time RT-PCR. Cytotoxic effect was evaluated by flow cytometry analysis and Comet assay. We also used normal human dermal fibroblasts (HUDE) to evaluate the cytotoxicity of the two treatments by clonogenic assay. Radiation and cisplatin used singly were not particularly effective in reducing proliferation in melanoma cells. Conversely, radiation treatment followed by cisplatin showed a strong synergistic interaction in all cell lines, with a ratio index ranging from 16 to >100. The synergistic effect was accompanied by apoptosis induction (up to 40%) and an increase in the percentage of comet-shaped nucleoids from 85% to 99%. In parallel, our results also showed that radiation treatment of HUDE fibroblasts followed by cisplatin only induced weak cytotoxicity. Our findings highlight the efficacy of the sequence radiation → cisplatin in reducing cell proliferation and in inducing apoptosis in melanoma cell lines. This sequence also modulated a network of proteins involved in DNA damage repair.

Benefit from anthracyclines in relation to biological profiles in early breast cancer.

There are no validated predictors of benefit from anthracyclines. We compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF), and epirubicin in different sequences with CMF alone in a phase III trial on operable breast cancers. Outcomes were analyzed in relation to tumor biological profiles to identify potential predictors of the efficacy of different treatments/drug combinations. Patients with N- or 1-3N+ tumors, were randomized to receive (a) epirubicin (4 cycles) followed by CMF (4 cycles); (b) CMF (4 cycles) followed by epirubicin (4 cycles), or (c) CMF (6 cycles) alone. Immunohistochemical assessments of estrogen (ER) and progesterone (PgR) receptors, HER2 and Ki67 were available for 705 patients (arm A/B/C: 276/269/160). Prognostic and predictive relevance was analyzed by log-rank tests and Cox models. Ki67 > 20 % and absent/low expression of ER and PgR were associated with worsen disease-free (DFS) and overall survival (OS). In patients with triple negative tumors (ER-, PgR-, HER2-), epirubicin-containing regimens yielded better DFS (HR 0.33, 95 % CI 0.17-0.62, P = 0.0007) and OS (HR 0.24, 95 % CI 0.10-0.57, P = 0.001) compared with CMF alone, whereas no differences were found in patients with HER2-positive (HER2+, ER-, PgR-) subtype. Treatment by subtype interaction (HER2-positive vs. others) was significant for DFS (χ (2) = 6.72, P = 0.009). In triple unfavorable (ER-, PgR-, Ki67 > 20 %) tumors, the use of epirubicin yielded better DFS (HR 0.45,95 % CI 0.26-0.78, P = 0.005) and OS (HR 0.30, 95 % CI 0.15-0.63, P = 0.001). Epirubicin-containing regimens seem to be superior to CMF alone in patients with highly proliferating, triple negative or triple unfavorable tumors.

Peripheral blood miR-328 expression as a potential biomarker for the early diagnosis of NSCLC.

Lung cancer is often diagnosed at an advanced stage, with subsequently poor prognosis. There are no biomarkers available to facilitate early diagnosis or to discriminate between benign and malignant nodules. MicroRNAs (miRNAs) are stable molecules that can be found and measured in peripheral blood, thus representing potential diagnostic biomarkers. We evaluated 100 individuals comprising 86 patients with predominantly early-stage non-small cell lung cancer (NSCLC) and 24 healthy donors. RNA was extracted from peripheral blood samples and the expression of a panel of miRNAs was analyzed by Real-Time PCR method. Expression levels of miR-328, miR-18a, miR-339 and miR-140 were significantly higher in NSCLC patients than in healthy donors (p < 0.05). In particular, miR-328 showed good diagnostic accuracy in discriminating between patients with early NSCLC and healthy donors (AUC ROC 0.82, 95% CI 0.72-0.92), with 70% sensitivity and 83% specificity at the best relative expression cut-off of 300. Moreover, miR-339 was a good discriminant between healthy donors and late-stage NSCLC patients (AUC ROC 0.79, 95% CI 0.68-0.91). In conclusion, miR-328 represents a potential diagnostic biomarker of NSCLC, especially for the identification of early-stage tumors. Its role in discriminating between benign and malignant nodules detected by spiral CT warrants further investigation.

Organosulfur derivatives of the HDAC inhibitor valproic acid sensitize human lung cancer cell lines to apoptosis and to cisplatin cytotoxicity.

Lung cancer is the leading cause of cancer mortality worldwide and despite efforts made to improve clinical results, continuing poor survival rates indicate that novel therapeutic approaches are needed. Valproic acid (VPA), a short-chain branched fatty acid used mainly for the treatment of epilepsy and bipolar disorder, has been shown to inhibit class I histone deacetylases (HDAC-I), a group of enzymes involved in chromatin remodeling and which are thought to play a role in tumor development. Although evidence of VPA's therapeutic efficacy has also been observed in patients with solid tumors, the very high concentration required to induce antitumor activity limits its clinical usefulness. We used a panel of NSCLC cell lines to evaluate the activity and mechanisms of action of organosulfur valproic acid derivatives, a promising new class of compounds designed to improve the safety and efficacy of the valproic acid molecule and created by coupling it with a hydrogen sulfide (H(2) S)-releasing moiety. Our results highlighted the increased cytotoxic activity of the novel organosulfur derivatives, ACS33 and ACS2, with respect to VPA, starting from low concentrations. In particular, ACS2 exhibited important pro-apoptotic activity triggered by the mitochondrial pathway and also showed anti-invasion potential. Furthermore, our in vitro results identified a highly effective combination schedule of ACS2 and cisplatin capable of inducing a synergistic interaction even when the two drugs were used at low concentrations, which could prove a valid alternative to traditional chemotherapeutic regimens used for advanced lung cancer. Further studies are needed to confirm these preliminary findings.

Low-dose taxotere enhances the ability of sorafenib to induce apoptosis in gastric cancer models.

Despite the low efficacy of conventional antitumour drugs, chemotherapy remains an essential tool in controlling advanced gastric and oesophageal cancers. We aimed to provide a biological rationale based on the sorafenib-taxotere interaction for the clinical treatment of gastric cancer. In vitro experiments were performed on four human gastric cancer cell lines (GK2, AKG, KKP and NCI-N87). Cytotoxicity was evaluated by sulforhodamine B (SRB) assay, cell cycle perturbations, apoptosis and mitotic catastrophe were assessed by flow cytometric and microscopic analyses, and protein expression was studied by Western blot. In the in vivo experiments, nude mice xenografted with the most resistant line were treated with sorafenib and docetaxel singly or in association. Sorafenib inhibited cell growth (IG(50) values ranged from 3.4 to 8.1 µM) and caused down-regulation of MAP-K/ERK phosphorylation and of mcl-1 and p-bad expression after a 48-hr exposure. Apoptosis induction was associated with caspase-3 and -9 activation and mitochondrial membrane depolarization. The drug combination enhanced apoptosis (up to 80%) and produced a synergistic interaction when low doses of the taxane preceded administration of the antityrosine kinase. This synergism was probably due to the induction of an anomalous multidiploid G0-G1 peak and to consequent mitotic catastrophe, which increased sensitivity to sorafenib. Consistent with in vitro results, the docetaxel-sorafenib sequence exhibited high therapeutic efficacy in NCI-N87 mouse xenografts producing tumour weight inhibition (> 65%), tumour growth delay (up to 25 days) and increased mouse survival (30%). Our findings suggest the potential clinical usefulness of treatment with sorafenib and docetaxel for advanced gastric cancer.

Activity of different anthracycline formulations in hormone-refractory prostate cancer cell lines: role of Golgi apparatus.

The efficacy of therapy for hormone-refractory prostate cancer (HRPC) is still unsatisfactory and new agents and therapeutic modalities are needed. The aims of the present work were to examine the in vitro activity and mechanisms of action of doxorubicin (DX), pegylated liposomal DX (PLDX), and non-pegylated liposomal DX (NPLDX) in DU145 and taxane-resistant DU145-R HRPC cell lines. Drug activity and incorporation, apoptosis, and expression of cell death-related markers were evaluated by SRB test, cytofluorimetric assays, and Western blot, respectively. Among the different DX formulations, NPLDX showed the highest cytotoxic activity in both cell lines, with more than 50% of apoptotic cells at only 1/10 of the plasma peak concentration after 72 h exposure. Anthracyclines, in particular NPLDX, were highly concentrated in the Golgi apparatus. Moreover, a significant increase was observed in the expression of CD95 receptor, GD3 ganglioside and, caspase-2 and -8 active forms in both cell lines followed by caspase-3 activation and mitochondrial membrane depolarization. The Golgi apparatus, probably acting as a stress sensor, intensified the conventional apoptotic mechanism induced by anthracyclines. Our data support the hypothesis that organelle-dependent initiation of cell death other than that induced by mitochondria and nucleus is a research area worthy of pursuing and suggest that the Golgi apparatus could be an ideal target for anti-cancer therapy. Of note, the activity of NLPDX in taxane-resistant DU145-R cells warrants further evaluation as second-line treatment of advanced HRPC after taxane failure.

Randomized phase III trial of adjuvant epirubicin followed by cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) versus CMF followed by epirubicin in patients with node-negative or 1-3 node-positive rapidly proliferating breast cancer.

Adjuvant cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) have proven highly effective in rapidly proliferating breast cancer (RPBC). It has also been seen that sequential administration of doxorubicin and CMF is superior to their alternation, especially in indolent tumors. In a phase III study, we evaluated whether adjuvant epirubicin (E) followed by CMF is superior to the inverse sequence in RPBC. Patients with node-negative or 1-3 node-positive RPBC (Thymidine Labeling Index > 3% or histological grade 3 or S-phase > 10% or Ki67 > 20%) were randomized to receive E (100 mg/m(2) i.v. d1, q21 days for 4 cycles) followed by CMF (600, 40, 600 mg/m(2) i.v. d1 and 8, q28 days for 4 cycles) (E â†’ CMF) or CMF followed by E (CMF â†’ E) or CMF for 6 cycles. From November 1997 to December 2004, 1066 patients were enrolled: E â†’ CMF 440, CMF â†’ E 438, and CMF 188. At a median follow-up of 69 months, 5-year OS was 91% (95% CI 88-94) for E â†’ CMF and 93% (95% CI 90-95) for CMF â†’ E, with adjusted hazard ratio of 0.88 (95% CI 0.58-1.35), and DFS was 80% in both arms, with adjusted hazard ratio of 0.99 (95% CI 0.73-1.33, Cox model). Adverse events were similar, apart from a higher rate of neutropenia in the CMF â†’ E arm. No important differences in clinical outcome were observed between the two different sequences, making both a valid option in early breast cancer. Further molecular characterization of the tumors might help to identify subgroups achieving higher benefit from either sequence.

Peritoneal carcinomatosis from ovarian cancer: chemosensitivity test and tissue markers as predictors of response to chemotherapy.

BACKGROUND: Platinum-based regimens are the treatments of choice in ovarian cancer, which remains the leading cause of death from gynecological malignancies in the Western world. The aim of the present study was to compare the advantages and limits of a conventional chemosensitivity test with those of new biomolecular markers in predicting response to platinum regimens in a series of patients with peritoneal carcinomatosis from ovarian cancer. METHODS: Fresh surgical biopsy specimens were obtained from 30 patients with primary or recurrent peritoneal carcinomatosis from ovarian cancer. ERCC1, GSTP1, MGMT, XPD, and BRCA1 gene expression levels were determined by Real-Time RT-PCR. An in vitro chemosensitivity test was used to define a sensitivity or resistance profile to the drugs used to treat each patient. RESULTS: MGMT and XPD expression was directly and significantly related to resistance to platinum-containing treatment (p = 0.036 and p = 0.043, respectively). Significant predictivity in terms of sensitivity and resistance was observed for MGMT expression (75.0% and 72.5%, respectively; p = 0.03), while high predictivity of resistance (90.9%) but very low predictivity of sensitivity (37.5%) (p = 0.06) were observed for XPD. The best overall and significant predictivity was observed for chemosensitivity test results (85.7% sensitivity and 91.3% resistance; p = 0.0003). CONCLUSIONS: The in vitro assay showed a consistency with results observed in vivo in 27 out of the 30 patients analyzed. Sensitivity and resistance profiles of different drugs used in vivo would therefore seem to be better defined by the in vitro chemosensitivity test than by expression levels of markers.

Docetaxel-ST1481 sequence exerts a potent cytotoxic activity on hormone-resistant prostate cancer cells by reducing drug resistance-related gene expression.

BACKGROUND: The efficacy of current therapy for hormone-refractory prostate cancer is still unsatisfactory and new agents and therapeutic modalities are needed. The aims of the present work were to examine the in vitro activity and mechanisms of action of different antitumor drug combinations in hormone-resistant prostate cancer (HRPC) cell lines. METHODS: The activity of docetaxel (Doc), cisplatin (Cis), oxaliplatin (Oxa), SN-38 and ST1481, singly or in combination, was assessed in different HRPC cell lines (PC3, parental DU145 and taxane-resistant DU145-R) by SRB test. Apoptosis was evaluated by TUNEL and ANN-V assays. Extrusion pump activity was studied by Hoechst 33342 assay, while gene expression related to drug efflux mechanisms and DNA damage repair was analyzed by RT-PCR. RESULTS: Doc induced a high cytocidal effect in the HRPC cells, whereas Cis, Oxa, SN-38 and ST1481 exerted prevalently cytostatic activity. Doc followed by ST1481 proved to be the most effective drug sequence among those investigated, producing an important synergistic effect (R.I. from 2.0 to 5.2) in all the tested cell lines. Moreover, this sequence induced a significant downregulation of xenobiotic extrusion pump and DNA damage repair gene expression. ST1481 synergistically increased the cytocidal effect of Doc, probably through a downregulation of extrusion pump activity and DNA damage repair-related genes. CONCLUSIONS: Our results show that the Doc --> ST1481 sequence effectively reduces the cancer cell population and restores Doc activity in taxane-resistant HRPC, indicating its potential usefulness as first- or second-line treatment of hormone-refractory prostate cancer.

Research trends for early cancer biomarker detection in Italy: an integrated program in oncology (PIO) survey.

AIMS AND BACKGROUND: In 2007, an Italian Research Network proposed to the Ministry of Health a concerted action aimed at developing a specific pathway for the analytical and clinical validation of new biomarkers for early cancer diagnosis. The action, funded by the Italian Ministry of Health within the Integrated Program in Oncology (PIO) and coordinated by the National Cancer Institute of Bari, started in 2008 involving 37 national research teams. METHODS: To monitor the methodological and analytical needs of the studies proposed by the research teams of PIO as well as to explore the plausibility of planning external quality assessment programs for early cancer biomarker detection, the coordinating team developed an ad hoc questionnaire that was submitted to each research team. RESULTS: From the collected data it emerged that about 70% of the biomarkers under investigation were analyzed according to nonroutine laboratory practices. The biological material utilized for biomarker assessment consisted of solid tissue (normal or pathological) in 31% of studies, serum in 21%, urine in 15%, plasma in 15%, and whole blood in 11%. Specific training of personnel directly involved in the program was reported by 18% of the teams. In 2008, only 6% of laboratories involved in PIO participated in both external quality assessment and internal quality control schemes specifically designed for the biomarkers under consideration. Standard operating procedures for the determination of about half (52%) of the biomarkers proved to be lacking in at least one phase of the biomarker assessment process. CONCLUSIONS: On the basis of these results, we decided to give priority to the application of a four-phase process for the analytical validation of new potential biomarkers by setting up and applying standard operating procedures and developing external quality assessment and internal quality control schemes as specific steps of the workflow.

The impact of progesterone receptor expression on prognosis of patients with rapidly proliferating, hormone receptor-positive early breast cancer: a post hoc analysis of the IBIS 3 trial.

BACKGROUND: In the Italian Breast Cancer Intergroup Studies (IBIS) 3 phase III trial, we compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF) alone to sequential epirubicin/CMF regimens in patients with rapidly proliferating early breast cancer (RPEBC). We performed a post hoc analysis in the subgroup of patients with hormone-receptor-positive RPEBC on the prognostic role of progesterone receptor (PgR) status. METHODS: RPEBC was defined by thymidine labeling index (TLI) >3% or grade 3 or S-phase >10% or Ki67 >20%. We analyzed 466 patients with hormone-receptor-positive RPEBC receiving sequential epirubicin/CMF regimens followed by tamoxifen, and for whom the status of ER and PgR was available. RESULTS: Considering both cut-off values of 10% and 20%, PgR expression was significantly associated with age, menopausal status, and ER expression; HER2 status was associated with PgR status only at a cutoff value of 20% PgR. Upon univariate analysis, tumor size, nodal status, and PgR were significantly associated with disease-free survival (DFS) and overall survival (OS), while age class and local treatment type were associated only with DFS. Patients with PgR <20% showed lower 5- and 10-year DFS [hazard ratio (HR) = 1.48; 95%CI: 1.01-2.18; p = 0.044] and OS (HR = 1.85; 95%CI: 1.08-3.19, p = 0.025) rates compared with patients with PgR ⩾20%. Upon multivariate analysis, only tumor size, nodal status, and PgR were independent prognostic factors. CONCLUSIONS: Our results highlight the independent prognostic relevance of PgR expression in patients with hormone-receptor-positive RPEBC treated with adjuvant chemotherapy and endocrine therapy, where the definition of prognostic subgroups is still a major need.

Role of RAF/MEK/ERK pathway, p-STAT-3 and Mcl-1 in sorafenib activity in human pancreatic cancer cell lines.

Sorafenib is a multikinase inhibitor that has shown promising therapeutic results in different tumor histotypes, both as a single agent or in combination with other treatments. We analyzed the in vitro activity of sorafenib in pancreatic cancer, one of the most lethal and chemo-radio-resistant tumors, using four human pancreatic cancer cell lines (t3m4, Capan 1, Capan 2, and MiaPaca 2), characterized by different K-ras gene status and RAF/MEK/ERK profile. Sorafenib exerted a strong anti-proliferative effect independently of RAS/RAF/MEK/ERK and induced various degrees of apoptosis in the cell lines. The mechanisms involved were explored in detail in t3m4 and Capan 1, in which sorafenib induced the highest and lowest levels of apoptosis, respectively. In t3m4, the RAF/AKT/STAT-3 rather than the RAF/MEK/ERK pathway was involved, whereas in Capan 1 cells there was a strong decrease in pMEK and pERK which was not accompanied by an important reduction in RAF, AKT, and STAT-3 proteins or in their phosphorylation. Moreover, U0126-induced MEK inhibition did not induce apoptosis in any cell line, reinforcing the hypothesis of a MEK/ERK-independent mechanism of sorafenib activity. Mcl-1 appears to play a crucial role in sorafenib-induced apoptosis. In fact, both protein and mRNA were downregulated in t3m4 and upregulated in Capan 1, in which siRNA-induced silencing resulted in the same level of apoptosis as observed in t3m4. Our results show that sorafenib exerts anti-proliferative and pro-apoptotic activity in pancreatic cancer cells. Used singly or in combination with other drugs, it could therefore represent valid treatment for pancreatic cancer.

Accuracy of urine telomerase activity to detect bladder cancer in symptomatic patients.

Telomerase activity assessment in voided urine is an important noninvasive tool for bladder cancer diagnosis. In a previous case-control study we verified that this method can detect tumor cells in urine with high sensitivity and specificity, but few data are still available on its accuracy to detect tumors in patients with symptomatic urinary tract diseases. Following recently published guidelines on bladder cancer, we aimed to define the diagnostic accuracy of urine telomerase levels in symptomatic patients. Telomerase activity, expressed in arbitrary enzymatic units (AEUs), was evaluated in urine collected from 515 patients: 197 with urinary tract symptoms and 318 with a first diagnosis of bladder cancer. Telomerase repeat amplification protocol (TRAP) sensitivity ranged from 93% to 61% and specificity varied from 42% to 88% at the different AEU cutoff values. At the cutoff of 50, the sensitivity was 87% (95% CI 83-91), the specificity was 70% (95% CI 63-75), and the overall accuracy, in terms of true positives and true negatives, was 80%. Sensitivity did not vary in relation to tumor grade or stage at diagnosis, or to patient age. Our results indicate that urine telomerase activity is a good marker for the early diagnosis of bladder tumors in symptomatic patients, a subset which represents an "at-risk" population requiring close surveillance.

The Integrated Oncology Program of the Italian Ministry of Health. Analytical and clinical validation of new biomarkers for early diagnosis: network, resources, methodology, quality control, and data analysis.

In 2007, an Italian cancer research group proposed a specific concerted action aimed at the "analytical and clinica validation of new biomarkers for early diagnosis: Network, resources, methodology, quality control, and data analysis." The proposal united 37 national operative units involved in different biomarker studies and it created a strong coordinative body with the necessary expertise in methodologies, statistical analysis, quality control, and biological resources to perform ad hoc validation studies for new biomarkers of early cancer diagnosis. The action, financed by the Italian Ministry of Health within the Integrated Oncology Program (PIO) coordinated by NCI-Istituto Tumori Bari, started in 2007 and activated 7 projects, each of which focused on disease-specific biomarker studies. Overall, the 37 participating units proposed studies on 50 biomarkers, including analytical and clinical validation procedures. Clusters of units were specifically involved in research of early-detection biomarkers for cancers of the lung, digestive tract, prostate/bladder, and nervous system, as well as female cancers. Furthermore, a cluster involved in biomarkers for bioimaging and infection-related cancers was created. The first investigators' meeting, "Analytical and clinical validation of new biomarkers for early diagnosis," was held on 9 September 2008 in Bari. During this meeting, methodological aspects, scientific programs and preliminary results were presented and discussed.

The current role of telomerase in the diagnosis of bladder cancer.

Bladder cancer has an incidence of 15 cases per 100,000 persons in the global population and is the most common tumor of the urinary tract. Imaging techniques, cytoscopy, and cytology are either invasive or not sufficiently accurate to detect early stage tumors, and the need for new diagnostic markers still remains. Among the markers most recently proposed to improve diagnostic accuracy and especially sensitivity, increasing attention has been focused on the role of the ribonucleoprotein, telomerase. Relevant papers on the etiology, diagnosis, and evaluation of bladder cancer using telomerase in urine were searched for and considered. The PubMed search was performed using the text terms "bladder cancer", "diagnosis", and "telomerase". Previous studies have shown that the quantitative Telomerase Repeat Amplification Protocol (TRAP) assay performed in voided urine is an important non-invasive tool for the diagnosis of bladder tumors since it has very high sensitivity and specificity, even for early stage and low grade tumors. The main limitation of this test is the rate of false positive results due to the presence of inflammatory or non-tumor cells (i.e., epithelial cells from the lower genital tract), which express telomerase activity (TA). Consequently, an in situ analysis would seem to be important to identify the nature of telomerase-positive cells. Immunocytochemical detection of the hTERT subunit by a specific antibody seemed to open up the possibility to identify different cellular components of urine. However, the lack of a strict relationship between hTERT protein expression and telomerase activity has, to a certain extent, made this approach less relevant. In conclusion, telomerase activity in urine determined by TRAP seems to be marker of great potential, even more advantageous in cost/benefit terms when used in selected symptomatic patients or professionally high-risk subgroups.

Are Androgen and Estrogen Receptors in DCIS Patients Prognostic Indicators of Relapse Independently of Treatment?

Ductal carcinoma in situ (DCIS) is a highly heterogenous tumor that is now more frequently diagnosed because of the increased number of screening programs. Women with DCIS are mainly treated with conservative surgery almost always followed by radiotherapy. Although conventional biomarkers, i.e. ER, PgR, Ki67, and HER2, have been extensively investigated in invasive tumors, little is known about their role in DCIS, especially that of the androgen receptor (AR). In the present study, the expression of conventional biomarkers and AR was determined by immunohistochemistry in 85 DCIS samples from patients monitored for a maximum of 13 years: 43 patients were treated with quadrantectomy and 42 patients underwent quadrantectomy and radiotherapy. Of these, 5 and 11 patients relapsed, respectively. Our findings showed that ER and PgR were higher in nonrelapsed than in relapsed patients (P=0.025 and 0.0038). In contrast, AR expression and the AR/ER ratio were higher in relapsed patients than in the nonrelapsed group (P=0.0069 and 0.0012). At the best cut-off value of 1.1, the AR/ER ratio showed an overall accuracy of 92% and 80% in predicting in situ relapse or progression to invasive carcinoma in DCIS patients treated with surgery and those treated with surgery plus radiotherapy, respectively. AR would therefore appear to be an independent prognostic biomarker in the latter group. Our preliminary results highlight the potentially important role of the AR/ER ratio as a predictive indicator of DCIS relapse, independently of treatment.

Mitotic catastrophe and apoptosis induced by docetaxel in hormone-refractory prostate cancer cells.

Studies performed in different experimental and clinical settings have shown that Docetaxel (Doc) is effective in a wide range of tumors and that it exerts its activity through multiple mechanisms of action. However, the sequence of events induced by Doc which leads to cell death is still not fully understood. Moreover, it is not completely clear how Doc induces mitotic catastrophe and whether this process is an end event or followed by apoptosis or necrosis. We investigated the mechanisms by which Doc triggers cell death in hormone-refractory prostate cancer cells by analyzing cell cycle perturbations, apoptosis-related marker expression, and morphologic cell alterations. Doc induced a transient increase in G2/M phase followed by the appearance of G0/1 hypo- and hyperdiploid cells and increased p21 expression. Time- and concentration-dependent apoptosis was induced in up to 70% of cells, in concomitance with Bcl-2 phosphorylation, which was followed by caspase-2 and -3 activation. In conclusion, Doc would seem to trigger apoptosis in hormone-refractory prostate cancer cells via mitotic catastrophe through two forms of mitotic exit, in concomitance with increased p21 expression and caspase-2 activation.

Zoledronic acid increases docetaxel cytotoxicity through pMEK and Mcl-1 inhibition in a hormone-sensitive prostate carcinoma cell line.

BACKGROUND: In prostate cancer, the identification of drug combinations that could reduce the tumor cell population and rapidly eradicate hormone-resistant cells potentially present would be a remarkable breakthrough in the treatment of this disease. METHODS: The study was performed on a hormone-sensitive prostate cancer cell line (LNCaP) grown in normal or hormone-deprived charcoal-stripped (c.s.) medium. Cell viability and apoptosis were assessed by SRB assay and Annexin-V/TUNEL assays, respectively. Activated caspase-3, p21, pMEK and MCL-1 expression levels were detected by western blotting. RESULTS: The simultaneous exposure of zoledronic acid [100 microM] and docetaxel [0.01 microM] for 1 h followed by treatment with zoledronic acid for 72, 96 or 120 h produced a high synergistic interaction (R index = 5.1) with a strong decrease in cell viability. This cytotoxic effect was associated with a high induction of apoptosis in both LNCaP and in c.s. LNCaP cells. The induction of apoptosis was paralleled by a decrease in pMEK and Mcl-1 expression. CONCLUSION: The zoledronic acid-docetaxel combination produced a highly significant synergistic effect on the LNCaP cell line grown in normal or hormone-deprived medium, the principal molecular mechanisms involved being apoptosis and decreased pMEK and Mcl-1 expression. This experimentally derived schedule would seem to prevent the selection and amplification of hormone-resistant cell clones and could thus be potentially used alongside standard androgen deprivation therapy in the management of hormone-sensitive prostate carcinoma.

NCX 4040, an NO-donating acetylsalicylic acid derivative: efficacy and mechanisms of action in cancer cells.

Non-steroidal anti-inflammatory drugs (NSAIDs) have repeatedly shown to be effective in tumor prevention, but important side-effects limit their wide clinical use. Nitric oxide-releasing derivatives (NO-NSAIDs) are a promising class of compounds synthesized by combining a classic NSAID molecule with an NO-releasing moiety to counteract side-effects. These new chemical entities exhibit a significantly higher activity and much lower toxicity with respect to the parental drug. In the present paper, we report the results obtained from in in vitro experimental systems aimed to evaluate the activity and mechanisms of action of the novel NO-releasing aspirin derivative, NCX 4040. The in vitro studies were carried out on a panel of human colon (LoVo, LoVo Dx, WiDr, LRWZ), bladder (HT1376, MCR), and pancreatic (Capan-2, MIA PaCa-2, T3M4) cancer cell lines. With regard to colon cancer, NCX 4040 activity was also investigated in vitro in combination with drugs currently used in clinical practice and was validated in vivo on tumor-bearing mice xenografted with the aforementioned colon cancer cell lines. The in vitro studies showed a high cytotoxic activity of NCX 4040 in all tumor histotypes and demonstrated the pivotal role of the NO component in drug activity. It was also observed that NCX 4040 exerts a pro-apoptotic activity via a mitochondria-dependent pathway. Moreover, the in vivo studies on xenografted mice further confirmed the antitumor efficacy and low toxicity of NCX 4040 in colon cancer and highlighted its role as sensitizing agent of oxaliplatin cytotoxicity.