A phase I study of the combination of ro4929097 and cediranib in patients with advanced solid tumours (PJC-004/NCI 8503).

BACKGROUND: The Notch signalling pathway has been implicated in tumour initiation, progression, angiogenesis and development of resistance to vascular endothelial growth factor (VEGF) targeting, providing a rationale for the combination of RO4929097, a γ-secretase inhibitor, and cediranib, a VEGF receptor tyrosine kinase inhibitor. METHODS: Patients received escalating doses of RO4929097 (on a 3 days-on and 4 days-off schedule) in combination with cediranib (once daily). Cycle 1 was 42 days long with RO4929097 given alone for the first 3 weeks followed by the co-administration of both RO4929097 and cediranib starting from day 22. Cycle 2 and onwards were 21 days long. Soluble markers of angiogenesis were measured in plasma samples. Archival tumour specimens were assessed for expression of three different components of Notch signalling pathway and genotyping. RESULTS: In total, 20 patients were treated in three dose levels (DLs). The recommended phase II dose was defined as 20 mg for RO4929097 on 3 days-on and 4 days-off schedule and 30 mg daily for cediranib. The most frequent treatment-related adverse events (AEs) were diarrhoea, hypertension, fatigue and nausea. Eleven patients had a best response of stable disease and one patient achieved partial response. We did not detect any correlation between tested biomarkers of angiogenesis or the Notch pathway and treatment effect. There was no correlation between mutational status and time to treatment failure. CONCLUSION: RO4929097 in combination with cediranib is generally well tolerated at the DLs tested. Preliminary evidence of antitumour efficacy with prolonged disease stabilisation in some patients with progressive malignancies warrants further clinical investigation of this treatment strategy.

Phase I clinical, pharmacokinetic and pharmacodynamic study of SB939, an oral histone deacetylase (HDAC) inhibitor, in patients with advanced solid tumours.

BACKGROUND: SB939 is an orally available, competitive histone deacetylase (HDAC) inhibitor selective for class I, II and IV histone deacetylases. Preclinical evaluation of SB939 revealed a profile suggesting improved efficacy compared to other HDAC inhibitors. This phase I study was carried out to determine the safety, dose-limiting toxicity, recommended phase II dose (RPTD), as well as pharmacokinetic (PK) and pharmacodynamic (PD) profiles of SB939 in a daily × 5 schedule in advanced solid tumours. METHODS: Sequential dose-escalating cohorts of patients were enrolled into 8 dose levels. At dose level 1, SB939 was taken on days 1-3 and 15-17 every 4 weeks, then on days 1-5 and 15-19 for other dose levels. Detailed PK sampling was performed in cycle 1, days 1 and 5. Peripheral blood mononuclear cells (PBMCs) were collected on cycle 1 at various time points for determination of acetylated histone H3 (AcH3) levels. RESULTS: In total, 38 patients received a total of 96 cycles of treatment. The maximal administered dose was 90 mg and the RPTD was 60 mg given 5 consecutive days every 2 weeks. The most frequent non-hematologic adverse events (AEs) of at least possible attribution to SB939 were fatigue, nausea, vomiting, anorexia and diarrhoea. Pharmacokinetic analysis showed dose-proportional increases in AUC across the doses evaluated. Elimination half-life was 5.6-8.9 h. There was no clear relationship between AcH3 changes and dose level or anti-tumour response. CONCLUSIONS: SB939 is well tolerated in patients with advanced solid tumours. The RPTD of this drug is 60 mg on a schedule of 5 consecutive days every 2 weeks. The toxicities of SB939 are consistent with other HDAC inhibitors.

Novel developments in angiogenesis cancer therapy.

A greater understanding of the factors and pathways controlling angiogenesis in tumours has allowed the development of a number of agents that selectively inhibit the pathways mediating that activity. The results to date of clinical trials with such agents and future research opportunities are reviewed.

Optimal chemotherapy treatment for women with recurrent ovarian cancer.

QUESTION: What is the optimal chemotherapy treatment for women with recurrent ovarian cancer who have previously received platinum-based chemotherapy? PERSPECTIVES: Currently, standard primary therapy for advanced disease involves a combination of maximal cytoreductive surgery and chemotherapy with carboplatin plus paclitaxel or with carboplatin alone. Despite initial high response rates, a large proportion of patients relapse, resulting in a therapeutic challenge. Because these patients are not curable, the goal of therapy becomes improvement in both quality and length of life. The search has therefore been to find active agents for women with recurrent disease following platinum-based chemotherapy. OUTCOMES: Outcomes of interest included any combination of tumour response rate, progression-free survival, overall survival, adverse events, and quality of life. METHODOLOGY: The MEDLINE, EMBASE, and Cochrane Library databases were systematically searched for primary articles and practice guidelines. The resulting evidence informed the development of clinical practice recommendations. The systematic review and recommendations were approved by the Report Approval Panel of the Program in Evidence-Based Care, and by the Gynecology Cancer Disease Site Group (DSG). The practice guideline was externally reviewed by a sample of practitioners from Ontario, Canada. RESULTS: Thirteen randomized trials compared various chemotherapy regimens for patients with recurrent ovarian cancer. In five of the thirteen trials in which 100% of patients were considered sensitive to platinum-containing chemotherapy, further platinum-based combination chemotherapy significantly improved response rates (two trials), progression-free survival (four trials), and overall survival (three trials) when compared with single-agent chemotherapy involving carboplatin or paclitaxel. Only two of these randomized trials compared the same chemotherapy regimens: carboplatin alone versus the combination of carboplatin and paclitaxel. Both trials were consistent in reporting improved survival outcomes with the combination of carboplatin and paclitaxel. In one trial, the combination of carboplatin and gemcitabine resulted in significantly higher response rates and improved progression-free survival when compared with carboplatin alone. Median survival with carboplatin alone ranged from 17 months to 24 months in four trials. In eight of the thirteen trials in which 35%-100% of patients had platinum-refractory or -resistant disease, one trial reported a statistically significant 2-month improvement in overall survival with liposomal doxorubicin as compared with topotecan (15 months vs. 13 months, p = 0.038; hazard ratio: 1.23; 95% confidence interval: 1.01 to 1.50). In that trial, because of the limited clinical benefit and the unusual finding that a survival difference emerged only after a year of treatment with no corresponding improvement in the rate of response or of progression-free survival, the authors concluded that further confirmation by results from randomized trials were needed to establish the superiority of one agent over another in their trial. In one trial, topotecan was superior to treosulphan in patient progression-free survival by a span of approximately 2 months (5.4 months vs. 3.0 months, p < 0.001). Toxicity was reported in all of the randomized trials, and although data on adverse events varied by treatment regimen, the observed adverse events correlated with known toxicity profiles. As expected, combination chemotherapy was associated with higher rates of adverse events. TARGET POPULATION: This clinical recommendation applies to women with recurrent epithelial ovarian cancer who have previously received platinum-based chemotherapy. Of specific interest are women who have previously shown sensitivity to platinum therapy and those who previously were refractory or resistant to platinum-based chemotherapy. As a general categorization within what is actually a continuum, "platinum sensitivity" refers to disease recurrence 6 months or more after prior platinum-containing chemotherapy, and "platinum resistance" refers to a response to platinum-based chemotherapy followed by relapse less than 6 months after chemotherapy is stopped. "Platinum-refractory disease" refers to a lack of response or to progression while on platinum-based chemotherapy. RECOMMENDATIONS: Although the body of evidence that informs the clinical recommendations is based on randomized trial data, those data are incomplete. Based on the available data and expert consensus opinion, the Gynecology Cancer DSG makes these recommendations: Systemic therapy for recurrent ovarian cancer is not curative. It is therefore recognized that each patient must be individually assessed to determine optimal therapy in terms of recurrence, sensitivity to platinum, toxicity, ease of administration, and patient preference. All suitable patients should be offered the opportunity to participate in randomized trials, if available.In the absence of contraindications, combination platinum-based chemotherapy should be considered for patients with prior sensitivity to platinum-containing chemotherapy. As compared with carboplatin alone, the combination of carboplatin and paclitaxel significantly improved both progression-free and overall survival.If combination platinum-based chemotherapy is not indicated, then a single platinum agent should be considered. Carboplatin has demonstrated efficacy across trials and has a manageable toxicity profile.If a single platinum agent is not being considered, then monotherapy with paclitaxel, topotecan, or pegylated liposomal doxorubicin are seen as reasonable treatment options.Some patients may be repeatedly sensitive to treatment and may benefit from multiple lines of chemotherapy.For patients with platinum-refractory or platinum-resistant disease, the goals of treatment should be to improve quality of life by extending the symptom-free interval, by reducing symptom intensity, and by increasing progression-free interval, and, if possible, to prolong life.With non-platinum agents, monotherapy should be considered because no advantage appears to accrue to the use of non-platinum-containing combination chemotherapy in this group of patients. Single-agent paclitaxel, topotecan, or pegylated liposomal doxorubicin have demonstrated activity in this patient population and are reasonable treatment options.No evidence either supports or refutes the use of more than one line of chemotherapy in patients with platinum-refractory or platinum-resistant recurrence. Many treatment options have shown modest response rates, but their benefits over best supportive care have not been studied in clinical trials.

Chemotherapy for recurrent, metastatic, or persistent cervical cancer: a systematic review.

To determine the front-line chemotherapeutic options for women with recurrent, metastatic, or persistent cervical cancer. The Medline, Embase, and Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing chemotherapy regimens for patients with recurrent, metastatic, or persistent cervical cancer. Studies were included if response rate, survival, toxicity, or quality of life data were reported. Fifteen RCTs were identified. The proportion of patients with prior chemoradiotherapy ranged from 0% to 57%. Four of the 15 RCTs detected significant improvements in overall response with combination cisplatin-based chemotherapy when compared with single-agent cisplatin. One of the 15 RCTs reported a significant median survival advantage with topotecan and cisplatin when compared with single-agent cisplatin (9.4 vs 6.5 months, P = 0.017); 57% of patients in this trial had previous chemoradiotherapy. Significant increases in grade 3 and 4 adverse events, especially severe hematologic toxicities, were detected among patients treated with that combination of chemotherapy. Thus, we conclude that cisplatin and topotecan should be discussed as a reasonable treatment option for appropriate patients who may wish to maximize the response and survival benefits associated with combination chemotherapy. Patients should understand that prior chemoradiotherapy with cisplatin may moderate the benefits observed, and that the relative benefits in response and survival outcomes come at the expense of increased toxicity. The improvement in median survival of 2.9 months represents a novel survival benefit in this difficult-to-treat patient population. Further randomized trials are needed to inform the role of single-agent or combination chemotherapy regimens, particularly in patients with prior chemoradiotherapy.

Phase I trial of UCN-01 in combination with topotecan in patients with advanced solid cancers: a Princess Margaret Hospital Phase II Consortium study.

BACKGROUND: 7-Hydroxystaurosporine (UCN-01) inhibits serine-threonine kinases including the Ca2+ and phospholipid-dependent protein kinase C (PKC), CDKs 2, 4, 6, Chk-1 and PDK1. UCN-01 mediates distinct effects in vitro/in vivo: cell cycle arrest in G1, abrogation of G2 arrest by inhibiting chk1, induction of apoptosis and potentiation of cytotoxicity of S-phase-active chemotherapeutics including the topoisomerase 1 inhibitor topotecan (T). This phase I study was designed to determine the maximal tolerated dose (MTD), recommended phase 2 dose (RPTD), toxicity profile, pharmacokinetics and antitumor activity of T and UCN-01 in patients with refractory solid tumors. DESIGN: Both agents were administered every 21 days intravenously through central venous access in escalating doses to eligible patients. On day 1, following antiemetic prophylaxis with dexamethasone and a serotonin type 3(A) receptor (5HT3) inhibitor, UCN-01 was infused over 3 h, followed by T infused over 30 min. On days 2-5, patients received T only. UCN-01 doses were reduced by 50% in cycles 2 and beyond because of its prolonged half-life. RESULTS: Thirty-three patients were entered in three cohorts: Dose Level (DL) 1 (UCN-01 70 mg/m2, T 0.75 mg/m2), three patients; DL 2 (UCN-01 70 mg/m2, T 1.0 mg/m2), 24 patients; DL 3 (UCN-01 90 mg/m2, T 1.0 mg/m2), six patients. All but three patients were PS 0 or 1, median age was 54 years (range, 29-72), 91% were female. Primary tumor types: ovary/peritoneal (23 patients), colon (three patients), salivary gland (two patients), others (five patients). All patients were eligible for adverse event (AE) analysis and 22 patients were eligible for survival and tumor response analysis. Two of six patients had dose limiting toxicity (DLT) at DL 3 (grade 3 N/V; grade 4 neutropenia with infection). One DLT was seen in one patient at DL 2, consisting of grade 4 leukopenia. This cohort was expanded and no further DLTs were observed. Most common drug-related AEs were mild (grade 1-2). Non-hematological grade 3-4 AEs consisted of transient hyperglycemia (4), infection (3), coagulation, fatigue, hypotension, nausea (2), hypomagnesemia, vomiting, headache (1). Hematologic toxicities occurred in 100% of patients. Grade 3-4 hematologic abnormalities included neutropenia (16, including three with infection), leukopenia (11), lymphopenia (7), thrombocytopenia (5). Best response for 22 evaluable patients was PD (8), SD for at least six cycles (12), PR (1: carcinoma of ovary, dose level 2) and one not assessable. Pharmacokinetic analysis confirmed the prolonged half-life of UCN-01 of approximately 15 days. CONCLUSIONS: DLT was observed at DL 3 and RPTD was determined to be DL 2. To date, this combination has been relatively well tolerated with some preliminary evidence of efficacy. A phase II study of this combination in patients with ovarian cancer is underway.

Phase I study to determine the safety and pharmacokinetics of the novel Raf kinase and VEGFR inhibitor BAY 43-9006, administered for 28 days on/7 days off in patients with advanced, refractory solid tumors.

BACKGROUND: BAY 43--9006, an oral multi-kinase inhibitor, targets serine-threonine kinases and receptor tyrosine kinases, and affects the tumor and vasculature in preclinical models. Based on its pharmacologic effect, it may be a useful cancer treatment. This study determined the maximum tolerated dose (MTD) of BAY 43-9006 in 42 patients with advanced, refractory metastatic or recurrent solid tumors. Dose-limiting toxicities (DLTs), safety, pharmacokinetics and tumor response were also evaluated. PATIENTS AND METHODS: In this open-label, phase I, dose-escalation study, BAY 43--9,006 was administered orally in repeated cycles of 35 days (28 days on/7 days off). Eight doses were investigated: from 50 mg every fourth day to 600 mg twice daily. Treatment continued until unacceptable toxicity, tumor progression or death. RESULTS: The MTD was 400 mg twice daily. BAY 43-9006 was well tolerated, with mild to moderate toxicities; only six patients discontinued study therapy due to adverse events. DLTs consisted of hand-foot skin reaction in three of seven patients receiving 600 mg twice daily. Stable disease was achieved in 22% of patients; median duration of stable disease was 7.2 months. Consistent with its observed half-life of approximately 27 h, BAY 43-9, 006 accumulated on multiple dosing. Increases in exposure were less than proportional to the increases in dose. CONCLUSIONS: Results indicate that further clinical investigation of BAY 43--9006 is warranted, and suggest it could be a promising future therapy for patients with cancer.

A phase I study of OSI-211 and cisplatin as intravenous infusions given on days 1, 2 and 3 every 3 weeks in patients with solid cancers.

BACKGROUND: OSI-211 (also known as NX211) is a liposomal preparation of the topoisomerase I inhibitor, lurtotecan, which has shown antitumor activity in phase I and II clinical trials. Cisplatin is a widely used antineoplastic agent with activity in a broad range of tumor types. This phase I trial was conducted to determine the recommended doses of these agents, and their pharmacokinetic properties and toxicities in patients with advanced solid malignancies. PATIENTS AND METHODS: Fourteen patients with advanced and/or metastatic solid malignancies were enrolled in this trial. The first planned dose level was OSI-211 0.9 mg/m(2) with cisplatin 25 mg/m(2) administered intravenously daily for the first three consecutive days of a 21-day cycle. Patients were evaluated for hematological and non-hematological toxicities, and pharmacokinetic studies were performed on both agents. RESULTS: The recommended phase II dose was determined to be 0.7 mg/m(2) OSI-211 given with 25 mg/m(2) cisplatin. Dose-limiting neutropenia was seen in two of three patients at the starting dose level. Three of 11 patients at the second (lower) dose level experienced dose-limiting thrombocytopenia; febrile neutropenia was also seen in one patient. Non-hematological toxicities were generally manageable and included fatigue, nausea and vomiting. Considerable variability was seen in both hematological toxicities and pharmacokinetics. One complete response and three partial responses were seen. CONCLUSIONS: The recommended phase II dose for this combination is 0.7 mg/m(2) OSI-211 with 25 mg/m(2) cisplatin given as an intravenous infusion on days 1, 2 and 3 of a 21-day cycle. The main toxicity was myelosuppression. Preliminary evidence of antitumor activity was seen.

Malignant ascites fluid (MAF), including ovarian-cancer-associated MAF, contains angiostatin and other factor(s) which inhibit angiogenesis.

OBJECTIVE: The aim was to determine whether human malignant ascites fluid (MAF) associated with abdominal cancer, including ovarian cancer, contained factors which inhibit angiogenesis as well as others which stimulate this process. METHODS: MAF was collected from six patients, four with ovarian cancer, one with gastric cancer, and one with liver metastases. Using the chick chorioallantoic membrane (CAM) the effect of MAF on 7-day-old CAM capillaries was examined for 48 h. Vascular endothelial growth factor (VEGF) was evaluated by ELISA. Five samples of MAF were fractionated by lysine-Sepharose chromatography and the lysine-bound and -unbound fractions were eluted by epsilon-amino-n-hexanoic acid. Whole MAF, the lysine-bound and -unbound fractions, and human angiostatin were subjected to SDS-PAGE/Western blot analysis and immunostained after exposure to anti-human plasminogen. Human plasminogen was exposed to conditioned medium from ovarian epithelial cancer (HEY) cells and subjected to similar Western blot analysis. RESULTS: Despite containing VEGF, each MAF sample examined caused a loss of capillaries from the CAM; a similar response was seen using purified human angiostatin. Whole MAF and the lysine-bound fraction contained plasminogen (90 kDa) and a 55-kDa protein which migrated in a similar manner to human angiostatin on Western blot. Both the lysine-bound and -unbound fractions caused a loss of capillaries in the CAM. Human plasminogen exposed to conditioned medium from HEY cells yielded a fragment which was similar in size to angiostatin. CONCLUSIONS: MAF from patients with various clinical presentations contains angiostatin and VEGF as well as other factors which are capable of inhibiting angiogenesis.

Chemotherapy for recurrent epithelial ovarian cancer previously treated with platinum--a systematic review of the evidence from randomized trials.

PURPOSE: To evaluate the chemotherapeutic options for women with recurrent epithelial ovarian cancer who have received platinum-based chemotherapy. METHODS: A systematic search of the Medline, CancerLit and Cochrane Library databases was performed for the period from 1984 to June 2001 to find randomized trials comparing second- or higher-line chemotherapy regimens in patients with recurrent platinum-pretreated epithelial ovarian cancer. RESULTS: Seven randomized trials have failed to demonstrate the clear superiority of any one chemotherapy regimen in terms of improvements in long-term survival, quality of life or response rate. One trial detected a statistically significant difference between treatments in progression-free survival, which was longer with cyclophosphamide/doxorubicin/cisplatin than with paclitaxel in women with platinum-sensitive ovarian cancer. Another trial did not show a difference between liposomal doxorubicin and topotecan overall in women with recurrent ovarian cancer but a subgroup analysis detected a significant survival advantage for liposomal doxorubicin over topotecan in women with platinum-sensitive disease. CONCLUSION: The evidence available does not support firm conclusions about the preferred chemotherapy regimen for recurrent ovarian cancer. Randomized trials that compare new drugs with current standard treatments are needed.

Quantification of matrix metalloproteinase activity in plasma of patients enrolled in a BAY 12-9566 phase I study.

The expression of matrix metalloproteinases (MMPs) is often associated with invasiveness or grade of tumours. Increased blood levels of MMP proteins, including MMP-1, MMP-2, MMP-3 and MMP-9 have been detected in various types of cancers. With the exception of one study, MMPs in serum and plasma have been determined using ELISA. In the present study we measured the activity of the MMPs found in human plasma samples using gelatin enzymography and fluorimetric degradation assays. We used plasma samples from healthy control subjects and cancer patients enrolled in a dose-finding study for the MMP inhibitor, BAY 12-9566, to assess the activity of MMPs found in plasma and screen for efficacy of the MMP inhibitor. BAY 12-9566 has inhibitory activity toward MMP-2, MMP-3 and MMP-9. Patients with advanced solid tumours were enrolled in our study and plasma was collected on day 1 before dosing and at steady-state of the drug on day 15. Our results show that BAY 12-9566 was effective in lowering the plasma gelatinolytic activity in the group of 29 patients when considering the data obtained from a fluorimetric gelatinase assay. The data obtained from gelatin enzymography, however, did not reach significance. The fluorimetric degradation assay could be a useful tool to screen plasma from cancer patients in other clinical trials assessing MMP inhibitors.

Induction of hTERT expression and telomerase activity by estrogens in human ovary epithelium cells.

In mammals, molecular mechanisms and factors involved in the tight regulation of telomerase expression and activity are still largely undefined. In this study, we provide evidence for a role of estrogens and their receptors in the transcriptional regulation of hTERT, the catalytic subunit of human telomerase and, consequently, in the activation of the enzyme. Through a computer analysis of the hTERT 5'-flanking sequences, we identified a putative estrogen response element (ERE) which was capable of binding in vitro human estrogen receptor alpha (ERalpha). In vivo DNA footprinting revealed specific modifications of the ERE region in ERalpha-positive but not ERalpha-negative cells upon treatment with 17beta-estradiol (E2), indicative of estrogen-dependent chromatin remodelling. In the presence of E2, transient expression of ERalpha but not ERbeta remarkably increased hTERT promoter activity, and mutation of the ERE significantly reduced this effect. No telomerase activity was detected in human ovary epithelial cells grown in the absence of E2, but the addition of the hormone induced the enzyme within 3 h of treatment. The expression of hTERT mRNA and protein was induced in parallel with enzymatic activity. This prompt estrogen modulation of telomerase activity substantiates estrogen-dependent transcriptional regulation of the hTERT gene. The identification of hTERT as a target of estrogens represents a novel finding which advances the understanding of telomerase regulation in hormone-dependent cells and has implications for a potential role of hormones in their senescence and malignant conversion.

Treatment of advanced ovarian carcinoma with carboplatin and paclitaxel in a patient with renal failure.

Platinum-based chemotherapy is the standard treatment for ovarian cancer. Since carboplatin elimination occurs largely through the kidneys, its use in patients with hemodialysis-dependent renal failure requires dose adjustments befitting the level of renal function. We employed the AUC (area under the concentration-time curve)- directed dosing strategy (the Calvert formula) to determine the carboplatin dose appropriate for an ovarian cancer patient with renal failure. Our approach is compared and defended against the empiric and thrombocyte nadir-directed dosing strategies. Since carboplatin clearance follows creatinine clearance, we also provide a review of methods and formulas used to determine creatinine clearance. An accurate method to determine creatinine clearance will enable others to use the AUC-directed dosing strategy to establish the carboplatin dose appropriate for patients with some residual renal function.

Transforming growth factor beta1 acts as an inducer of matrix metalloproteinase expression and activity in human bone-metastasizing cancer cells.

Bone metastases are a common complication in prostate and breast cancer patients. It leads to extensive morbidity and eventually mortality. Matrix metalloproteinases (MMPs) are known to be involved in the metastatic process. MMP activity can be down-regulated by transforming growth factor beta1 (TGF-beta1), a growth-modulating factor, found in high concentrations in the bone. TGF-beta1 acts through the TGF-beta1 inhibitory element (TIE) element, a cis-acting element found in the promoter region of most MMP genes, with the exception of MMP-2. We used three human cell lines relevant for bone metastases, namely prostate adenocarcinoma PC-3, breast adenocarcinoma MDA-MB-231, and adenocarcinoma cells of unknown origin, Hs696, and one human osteosarcoma cell line, SAOS-2, and showed that in these cell lines TGF-beta1 partially lost its repressing action on MMP expression. TGF-beta1 was able to induce MMP-9 activity and protein expression in all three bone-metastatic tumour cell types, whereas MMP-9 protein levels were repressed in SAOS-2 cells. In PC-3 cells, TGF-beta1 repressed MMP-1 expression, whereas in MDA-MB-231 and SAOS-2 cells, an increase in the expression of MMP-1 protein was detected. Additionally, an increase in MMP-3 expression was observed in Hs696 cells. Expression and activity of the tissue inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, were found increased in both PC-3 and MDA-MB-231 cells. With respect to cell proliferation, TGF-beta1 was able to induce a dose-dependent growth inhibition of up to 50% in primary human mammary epithelial cells. However, in none of the tumour cell lines was TGF-beta1 able to suppress growth substantially. Data presented in this paper support the hypothesis that TGF-beta1 can potentially disrupt the balance existing between osteoclast- and osteoblast-derived MMP activity by inducing altered expression of matrix metalloproteinases and their tissue inhibitors derived from bone-metastasizing cancer cells. This could eventually lead to skeletal destruction in patients with advanced metastatic disease.

A randomized trial of paracentesis plus intraperitoneal tumor necrosis factor-alpha versus paracentesis alone in patients with symptomatic ascites from recurrent ovarian carcinoma.

PURPOSE: Previous phase I and II studies of intraperitoneal recombinant human tumor necrosis factor-alpha (rhTNF-alpha) suggested a high degree of efficacy in reducing or eliminating ascitic fluid. To more accurately determine the efficacy of this agent, the role of paracentesis versus paracentesis plus intraperitoneal rhTNF-alpha was studied in a randomized trial. PATIENTS AND METHODS: Thirty-nine patients with symptomatic ascites with a volume of > 1000 ml from recurrent epithelial ovarian carcinoma or primary peritoneal carcinoma, which was refractory to standard therapy, were randomized either to receive 0.06 mg/m2 rhTNF-alpha (Knoll, Canada) (the dose determined optimal from phase I and II studies) intraperitoneally after drainage of fluid or to receive drainage alone. A maximum of three treatments were given at weekly intervals. Eighteen patients were randomized to receive rhTNF-alpha. RESULTS: None of 18 evaluable rhTNF-alpha patients had either a complete response (CR) (no clinical evidence of ascites and < 400 ml of fluid on ultrasound) or a partial response (PR) (asymptomatic ascites and < or = 1000 ml of fluid ultrasound). There were no CRs or PRs in the 17 evaluable patients who received drainage alone. The intraperitoneal infusion of rhTNF-alpha was generally well tolerated. Moderate to severe toxicity consisted of pain/discomfort in 42.1%, fever/chills in 36.9%, nausea/vomiting in 10.5%, edema in 10.5%, and hypotension in 5.3% of patients receiving rhTNF-alpha. CONCLUSION: rhTNF-alpha, as given in this study, was not effective in preventing recurrence of ascites in this patient population.

Use of tetracycline as an inhibitor of matrix metalloproteinase activity secreted by human bone-metastasizing cancer cells.

Bone metastases are a common complication in prostate and breast cancer patients. It leads to extensive morbidity and eventually mortality. Matrix metalloproteinases are implicated in various steps of development of metastasis, through their ability to degrade the extracellular matrix. Increased matrix metalloproteinase activity of tumor cells has been associated with a higher metastatic potential. Inhibitors of metalloproteinases have been shown to effectively reduce or prevent the formation of metastases. The family of tetracyclines is able to inhibit matrix metalloproteinase activity through chelation of the zinc ion at the active site of the enzyme. Using tumor cell lines relevant to bone metastases, i.e. PC-3, MDA-MB-231, Hs696, B16/F1, we showed that tetracycline and derivatives of tetracycline, namely doxycycline and minocycline, also induced cytotoxicity. The effective concentrations are relatively high for plasma, but are clinically achievable in the bone, since tetracyclines are osteotropic. All four bone-metastasizing tumor cells produced and secreted various matrix metalloproteinases. Doxycycline was able to inhibit the activity of 72- and 92-kDa type IV collagenase secreted by bone-metastasizing cells by 79-87%. These characteristics could make tetracycline a unique candidate as a therapeutic agent to prevent bone metastases in cancer patients with a high likelihood for development of bone metastasis. Studies using animal models of experimental bone metastasis will be necessary to confirm this.

Telomerase activity associated with acquisition of malignancy in human colorectal cancer.

Shortening of telomeres may contribute to the control of the proliferative capacity of normal cells, and telomerase, the enzyme that elongates telomeric DNA, may be essential for unlimited cell proliferation. We have shown previously that telomerase activity is present in human cells immortalized in vitro and in metastatic ovarian carcinoma cells but is undetectable in normal cultured cells or normal tissues. We have determined the temporal pattern of telomerase activity during colorectal carcinogenesis in man. We report that telomerase activity is associated with acquisition of malignancy as it is detectable in colorectal carcinoma but not in adenomatous polyps. Mutations leading to reactivation or upregulation of the enzyme may represent an additional required event in the multistep development of colorectal cancer.

Establishment and characterization of four human epithelial ovarian carcinoma cell lines.

BACKGROUND: To develop in vitro models of human ovarian carcinoma, fresh tumour cells derived from malignant effusions were cultured in vitro in the presence or absence of serum to establish cell lines. METHODS: Cell lines established were characterized by morphology in culture, surface marker expression, cytogenetic analysis, and growth in anchorage-dependent and anchorage-independent conditions. RESULTS: Four cell lines (MAC-2, RIC-2, SCHM-1, and SIB-1) were established from tumor cells isolated from the malignant effusions of four patients with epithelial ovarian carcinoma. These lines were able to grow in the presence of low concentrations of serum (3%), and two lines grew in the absence of serum (MAC-2 and SIB-1). All cell lines have been grown continuously for longer than 6 months. One cell line (SCHM-1) grew only in liquid medium whereas the other lines grew in both liquid and semi-solid media. Chromosome analysis revealed aneuploidy in three of the four lines. All of the lines stained positively for CA-125 and HMFG-2, consistent with an epithelial origin. CONCLUSION: The ability of these cells to grow in low concentrations of serum or in serum-free conditions should prove useful for the in vitro study of factors affecting the growth of human ovarian carcinoma. The serum-free medium developed will be of use in the isolation of factors from the conditioned medium of these cell lines and previously established cell lines.

Telomerase activity in human ovarian carcinoma.

Telomeres fulfill the dual function of protecting eukaryotic chromosomes from illegitimate recombination and degradation and may aid in chromosome attachment to the nuclear membrane. We have previously shown that telomerase, the enzyme which synthesizes telomeric DNA, is not detected in normal somatic cells and that telomeres shorten with replicative age. In cells immortalized in vitro, activation of telomerase apparently stabilizes telomere length, preventing a critical destabilization of chromosomes, and cell proliferation continues even when telomeres are short. In vivo, telomeres of most tumors are shorter than telomeres of control tissues, suggesting an analogous role for the enzyme. To assess the relevance of telomerase and telomere stability in the development and progression of tumors, we have measured enzyme activity and telomere length in metastatic cells of epithelial ovarian carcinoma. We report that extremely short telomeres are maintained in these cells and that tumor cells, but not isogenic nonmalignant cells, express telomerase. Our findings suggest that progression of malignancy is ultimately dependent upon activation of telomerase and that telomerase inhibitors may be effective antitumor drugs.