Contribution of epigenetic silencing of tumor necrosis factor-related apoptosis inducing ligand receptor 1 (DR4) to TRAIL resistance and ovarian cancer.

Dysregulation of apoptosis may support tumorigenesis by allowing cells to live beyond their normally intended life span. The various receptors for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) are located on chromosome 8p21.2, a region frequently deleted in ovarian cancer. Lack of expression of TRAIL receptor 1 (death receptor 4, DR4) correlates with resistance to TRAIL-induced apoptosis in ovarian cancer cells. Reconstitution of DR4 in the TRAIL-resistant A2780 ovarian cancer cell line was investigated with the demethylating agent 5-aza-2'-deoxycytidine and transient gene transfer. Regulation of other genes in the TRAIL pathway by 5-aza-2'-deoxycytidine was assessed in DNA GeneChip experiments. Primary ovarian cancers were analyzed by methylation-specific PCR and immunohistochemical analysis of a tissue microarray. Regulation of DR4 expression by demethylation or transient transfection is of functional relevance for TRAIL resistance in an ovarian cancer cell line. Hypermethylation of the DR4 promoter could be found in 10 of 36 (27.7%) DNAs isolated from ovarian cancer tissue. In an independent set of 68 ovarian cancer cases, a complete loss or down-regulation of DR4 protein expression was observed 10.3% and 8.8% patients, respectively. A significant (P = 0.019) majority of these patients was below 50 years of age. Our findings show a functional relevance of the level of DR4 expression in ovarian cancer and suggest a substantial contribution of DR4 hypermethylation and consequent loss of DR4 expression to ovarian cancer pathogenesis, particularly in premenopausal patients.

Monitoring of serum Her-2/neu predicts response and progression-free survival to trastuzumab-based treatment in patients with metastatic breast cancer.

PURPOSE: The present pilot study was performed to elucidate whether early changes in serum Her-2/neu extracellular domain (ECD) levels during trastuzumab-based treatment would predict the clinical course of disease in patients with metastatic breast cancer. EXPERIMENTAL DESIGN: Sera from 55 patients with Her-2/neu-overexpressing metastatic breast cancer obtained immediately before each weekly administration of trastuzumab were analyzed by a serum Her-2/neu ELISA. RESULTS: Whereas response rates were significantly higher in patients with elevated (>or=15 ng/ml) ECD levels before initiation of treatment (35% versus 7%, P = 0.045), progression-free and overall survival did not differ significantly between patients with normal and elevated ECD levels. In patients responding to treatment, ECD levels decreased significantly as early as from day 8 of treatment onwards (all P for weekly measurements versus baseline <0.001). In contrast, no significant change in ECD levels was observed in patients with progressive disease. Multiple logistic regression analyses identified kinetics of ECD levels as the only factor that allowed for the accurate prediction of response likelihood as early as from day 8 of trastuzumab-based treatment onwards (P = 0.020). In addition, determination of serial ECD levels allowed for the prediction of the risk for disease progression within the observed period as early as day 15 of treatment (P = 0.010). CONCLUSIONS: Serial monitoring of the ECD may represent a valuable tool for early prediction of the probability of response and progression-free survival to trastuzumab-based treatment and is thus likely to contribute to an optimization of treatment and resource allocation.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments.

This review summarises results of previously conducted clinical trials and subsequently presents data arising from all phase II-III studies on chemotherapy for malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear somewhat more promising. This applies especially to the antimetabolites, and in particular to pemetrexed which produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine--applied as a single agent or in combination with cisplatin--as well as vinorelbine appear to improve quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. Publication of results from a phase III trial of pemetrexed with cisplatin in a peer reviewed journal may soon establish a standard of care.

Effect of carboplatin on the functional integrity of the human sperm membrane in vitro.

Although it is well known that carboplatin is a drug that binds directly to DNA, causing DNA-DNA and DNA-protein cross-links, which is the presumptive method for killing cells, the whole mechanism of action of carboplatin on spermatozoa is unclear. There are no published data in peer-reviewed journals focused on the interaction between carboplatin and cell membranes. Therefore, the purpose of this study was to investigate the minimal concentration of carboplatin that would affect the functional integrity of the human sperm membrane in an in vitro model. Human-ejaculated spermatozoa were obtained from 20 healthy normozoospermic donors. Solutions (SOL) of 0.5 mL of the semen samples and 0.5 mL NaCl (0.9%) containing increasing concentrations (7.5, 15, 30, and 60 ng) of carboplatin per 1 mL of SOL were prepared. Then, the hypoosmotic-swelling (HOS) test and the eosin test were performed on these samples and compared with the control (no carboplatin) group. Significant damage to the plasma membrane in the head region (eosin test positive) and in the tail region of spermatozoa, as assessed by the HOS test, was observed in concentrations of 30 and 60 ng carboplatin per 1 mL of SOL in comparison to the values evaluated in the control group. The results demonstrate that a minimal carboplatin concentration of 30 ng/mL causes significant damage to membrane integrity of spermatozoa in healthy volunteers.

Recurrent malignant Triton tumour: first report on a long time survivor.

Malignant Triton tumour represents an extremely rare mesenchymal malignancy exhibiting histopathologic patterns of peripheral nerve sheath tumours and rhabdomyoblastic components, the latter usually determining the mostly fatal outcome. We report on a 26-year old patient diagnosed with malignant Triton tumour who developed multiple recurrences despite repeated aggressive surgery, chemo- and radiotherapy during an 8-year period. After Northern blotting analysis of an excised in-transit metastasis had revealed expression of retinoic receptors alpha and gamma, the patient received experimental treatment with isotretinoin and interferon-alpha for one year and remains without any evidence of disease for more than three years. This is the first report on a long-term survivor of multiple recurrences of malignant Triton tumour.

Correlation of clinical outcome with p53 and p21 status in patients with advanced transitional-cell carcinoma treated with paclitaxel and carboplatin.

BACKGROUND: The purpose of the present study was to correlate the nuclear expression of p53 and p21 with response to paclitaxel and carboplatin, progression-free survival (PFS) as well as overall survival (OS), in patients with urothelial metastatic transitional-cell carcinoma (TCC). PATIENTS AND METHODS: Histological specimens of 23 patients with metastatic TCC, who were treated with paclitaxel and carboplatin, were investigated for p53 and p21 proteins and correlated with overall response (OR) to chemotherapy, PFS and OS. RESULTS: After a median follow-up of 33.2 months, the OR rate was 57%. Median PFS was 7.4 (range: 2.5-49.2) months while median OS was 13.2 (range: 4.2-49.5) months. The tumour specimens of 48% of patients were classified as p53-positive, whereas 57% were classified as p21-positive. Neither p53- nor p21-status were significantly associated with CR, CR and PR or CR, PR and SD. In addition, neither PFS nor OS were significantly influenced by p53- and p21-status. CONCLUSION: Previous findings on the efficacy of the combination of paclitaxel and carboplatin in metastatic TCC patients are thus re-confirmed even after a considerable duration of follow-up. Moroever, the clinically relevant results obtained were independent from p53- or p21-status thus suggesting the involvement of other, yet unidentified, pathways as prognostic indicators for the course of the disease under the present treatment.

Monitoring of serum Her-2/neu predicts histopathological response to neoadjuvant trastuzumab-based therapy for breast cancer.

BACKGROUND: This prospective pilot study was performed to elucidate whether early changes in serum levels of the Her-2/neu extracellular domain (ECD) reflect histopathological response to trastuzumab-based neoadjuvant therapy in patients with Her-2/neu-overexpressing breast cancer. PATIENTS AND METHODS: ECD levels were measured throughout neoadjuvant trastuzumab-based treatment in 16 patients using a Her-2/neu Microtiter ELISA. RESULTS: In 9 (56%) patients with Her-2/neu shedding tumors (ECD > 15 ng/ml), ECD values (in % of baseline) of non-responders vs. responders were 117% vs. 55% on day 8 (p=0.014), 157% vs. 58% on day 22 (p=0.061) and 114% vs. 46% at restaging (p=0.049). CONCLUSION: Serial monitoring of serum Her-2/neu ECD levels may represent a valuable tool to predict pathological response to trastuzumab-based neoadjuvant therapy in patients with Her-2/neu-overexpressing tumors.

A prospective, open label, randomized phase II trial of weekly docetaxel versus weekly vinorelbine as first line chemotherapy in patients with androgen independent prostate cancer.

PURPOSE: In previous phase I to III studies docetaxel and vinorelbine have shown promising activity in androgen independent prostate cancer. In the present trial we assessed the efficacy and tolerability of single agent low dose docetaxel vs vinorelbine in patients with advanced androgen independent prostate cancer. MATERIALS AND METHODS: A total of 40 chemotherapy naive patients with histologically proven androgen independent prostate cancer, adequate androgen ablation, and clinical and/or biochemical progression were randomly assigned to receive either 25 mg/m(2) docetaxel (arm A) or 25 mg/m(2) vinorelbine (arm B) weekly. Treatment was continued until clinical and/or biochemical progression. In cases of progression patients switched to the alternative treatment arm. The primary end point was time to disease progression. Secondary end points included prostate specific antigen response rates in sequential treatment, analgesic response and toxicity. RESULTS: The current analysis showed a doubled risk of progression in treatment arm B. The median time to first disease progression was 14.5 months for arm A vs 4.4 months for arm B. The proportion of patients with a greater than 50% prostate specific antigen decrease on first line therapy was significantly higher in arm A (62.5%) compared to arm B (11.1%) (p = 0.0033). After progression to docetaxel second line vinorelbine yielded a greater than 50% prostate specific antigen response rate of 28.6% vs 62.5% for second line docetaxel. Clinically significant toxicity occurred more often in arm B with neutropenia grade 4 seen in 22% and grade 3 in 28% of patients (p = 0.0005) during the first treatment phase. CONCLUSIONS: While weekly application of both cytotoxic agents was well tolerated, this study demonstrates the superiority of docetaxel vs vinorelbine as monotherapy in the treatment of androgen independent prostate cancer.

11C-acetate positron emission tomography imaging and image fusion with computed tomography and magnetic resonance imaging in patients with recurrent prostate cancer.

PURPOSE: To assess the clinical value of computed tomography (CT) and magnetic resonance imaging (MRI) image fusion with 11C-acetate (AC) positron emission tomography (PET) imaging for detection and exact location of clinically occult recurrences. PATIENTS AND METHODS: Fifty prostate cancer patients with elevated/increasing serum prostate-specific antigen levels after radical therapy underwent whole-body AC PET. Uptake was initially interpreted as normal, abnormal, or equivocal. In case of abnormal or equivocal uptake, additional conventional imaging techniques, such as CT, MRI, and bone scans, were performed. To precisely define the anatomic location of abnormal uptake and to improve characterization of equivocal lesions, a software-assisted image fusion (CT-PET, MRI-PET) was performed and evaluated as site-by-site analysis of 51 abnormal (n = 37) or equivocal (n = 14) sites of all 50 patients. In 17 patients, additional histopathologic evaluation was available. RESULTS: In five (10%), 13 (26%), and 32 (64%) of the 50 patients, AC PET studies demonstrated AC uptake judged as normal, equivocal, and abnormal, respectively. Image fusion changed characterization of equivocal lesions as normal in five (10%) of 51 sites and abnormal in nine (18%) of 51 sites. It precisely defined the anatomic location of abnormal uptake in 37 (73%) of 51 sites. AC PET findings did influence patient management in 14 (28%) of 50 patients. CONCLUSION: Retrospective fusion of AC PET and CT/MRI is feasible and seems to be essential for final diagnosis. This is particularly true in patients with AC uptake in the prostate region.

Common death receptor 4 (DR4) polymorphisms do not predispose to ovarian cancer.

OBJECTIVE: Polymorphisms of death receptor 4 (DR4) might impair the apoptotic signal transduction and lead to dysregulation of the homeostasis between cell survival and cell death, promoting tumor development and progression. METHODS: We performed an analysis of known DR4 polymorphisms, namely G442A, C626G, and A1322G, in germ line DNA of 97 ovarian cancer patients and controls as well as in established ovarian cancer cell lines. RESULTS: Patient and matched control populations were not differing significantly in case of G442A (P = 0.736) and C626G alterations (P = 0.699). For the A1322G transversion, we generated population data for the first time and could find a rate of 19% heterozygotes and 3% homozygotes. Again, we could not detect any significant difference between patients and controls (P = 0.326). CONCLUSION: To summarize, alterations of the DR4 gene do not lead to clinically relevant ovarian cancer predisposition and are therefore most unlikely to contribute to familial ovarian cancer.

Chemotherapy for malignant pleural mesothelioma.

This paper covers the outcome of previously conducted clinical trials on chemotherapy for malignant pleural mesothelioma and presents data from recent phase II and phase III trials. In contrast to conventional cytotoxic drugs, which have barely produced response rates exceeding 30%, recently introduced chemotherapeutic agents and their combinations promise to be more effective. Especially pemetrexed has yielded response rates of up to 45% in combination with platinum compounds. Furthermore, raltitrexed-oxaliplatin has shown promising activity and gemcitabine was found to improve quality of life in patients with malignant pleural mesothelioma when applied as a single agent or in combination with cisplatin. Based on robust phase III study results, pemetrexed-cisplatin may soon be considered with chemotherapy for this aggressive disease.

Resistance to TRAIL-induced apoptosis in ovarian cancer cell lines is overcome by co-treatment with cytotoxic drugs.

BACKGROUND: TRAIL, tumor necrosis factor-related apoptosis-inducing ligand, is a recently identified cytokine that preferentially kills transformed cells while sparing most normal cells. METHODS: We investigated the ability of TRAIL alone and TRAIL in combination with cytotoxic drugs to induce apoptosis in six ovarian cancer cell lines. To get some insight into the resistance to TRAIL, the expression of TRAIL receptors and selected downstream signaling elements was determined. RESULTS: TRAIL induced significant apoptosis (up to 80%) in three out of six ovarian cancer cell lines (MZ-26, CaOV-3, ES-2). In A2780 and A2780ADR cells, resistance to TRAIL-induced apoptosis correlated with their lack of DR4-expression. MZ-15 cells, which expressed the processed form of FLIP(L), p43 (FADD-like IL-1beta-converting enzyme (FLICE)-like inhibitory protein (FLIP)), and FLIP(S), were resistant to TRAIL in spite of the presence of DR4. When TRAIL-resistant cell lines were co-incubated with routinely used cytotoxic agents, TRAIL exerted a synergistic effect leading to apoptosis rates unachievable by incubation with cytotoxic agents alone. CONCLUSION: The ability of TRAIL to induce apoptosis in ovarian cancer cells as well as to potentiate the activity of chemotherapeutic agents even in cell lines that are resistant to TRAIL-induced cytotoxicity is a powerful promise in the fight against this deadly disease.