bryostatin-1 and Melanoma

Topics: Animals; Antineoplastic Agents; Bryostatins; Cell Division; Humans; Lactones; Lymphocyte Activation; Macrolides; Melanoma; Protein Kinase C; Skin Neoplasms; Tumor Cells, Cultured

This study addressed the efficacy and toxicity of the novel compound Bryostatin-1 (NSC 339555), a novel agent with antineoplastic, hematopoietic and immunomodulatory activity in a variety of in vitro and in vivo systems.. This phase II study randomly assigned chemotherapy-naïve patients with untreated metastatic melanoma and measurable disease to two schedules of treatment: Arm A, 25 microg/m2 bryostatin-1 given as a 24 hour continuous infusion weekly or Arm B, 120 microg/m2 bryostatin-1 given as a 72 hour continuous infusion every 2 weeks. Although objective response was assessed using standard NCIC CTG criteria, antitumour activity was assessed using a multivariate endpoint incorporating both response (CR and PR) and early progression (PD at < or = 8 weeks). Seventeen patients were randomized to each arm.. Arm A was better tolerated with 86.7% of 15 evaluable patients receiving > or = 90% of planned dose intensity versus 76.5% of 17 evaluable patients in Arm B. On Arm B, three patients experienced serious adverse events and three patients had to be removed from protocol therapy due to toxicity. The most common side effect was myalgia (33% grade 1-2 on Arm A versus 65% on Arm B with 5 patients experiencing grade 3 and one patient grade 4). Lethargy was more common on Arm A but more severe on Arm B. Other side effects such as nausea, diarrhea and headache were generally mild to moderate in nature and occurred with a similar frequency on both arms. Hematologic and biochemical toxicity were minimal. This trial was closed early because the protocol-stopping rule was met based on lack of required responses and on the number of early progressions on both arms. No partial or complete responses were seen; 3 patients randomized to Arm A had stable disease (duration 9-24 weeks) as did 4 patients (duration 10-38 weeks) randomized to Arm B.. Arm A was better tolerated than Arm B. We conclude that bryostatin-1 has little efficacy in the treatment of metastatic melanoma with either of the schedules studied.

Topics: Adult; Aged; Antineoplastic Protocols; Bryostatins; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Lactones; Macrolides; Male; Melanoma; Middle Aged; Patients

In this phase II study we assessed the efficacy of bryostatin-1 (NSC 339555) in metastatic melanoma patients when given intravenously either once a week at a dose of 25 microg/m2 per day over 24 h for 3 weeks or at 40 microg/m2 per day over 72 h every 2 weeks. Treatment courses were repeated every 4 weeks. Patients who had received one prior chemotherapy regimen for advanced melanoma, with or without biotherapy, were randomized to one or the other bryostatin-1 dose schedules until 12 patients were registered to each arm. Because there was one confirmed response among the 12 patients who received the 72 h dose schedule, 25 more patients were added to that arm. No prophylactic medications were given. Objective tumour measurements were used to assess the efficacy of the regimen. The National Cancer Institutes common toxicity criteria were used to grade reactions. In total, 49 patients with metastatic melanoma, none having symptomatic brain metastasis, were studied. Of these, 12 patients received the 24 h bryostatin-1 regimen, while the remaining 37 received the 72 h regimen. One patient receiving the 72 h regimen had a partial response lasting over 7 months. Muscle pain occurred in over 90% of the patients and was the dose-limiting side effect of the 72 h regimen. Grade 3/4 nausea and vomiting were more common on the 24 h regimen than on the 72 h one (35% versus 5% of patients). There was no therapy-related thrombocytopenia. Neutropenia was mild and mainly limited to patients receiving the 72 h regimen. Bryostatin-1 has limited activity against melanoma when given by 72 h intravenous infusion.

Topics: Adolescent; Adult; Aged; Antineoplastic Agents; Blotting, Western; Bryostatins; Dose-Response Relationship, Drug; Down-Regulation; Female; Humans; Lactones; Macrolides; Male; Melanoma; Middle Aged; Neoplasm Metastasis; Protein Isoforms; Protein Kinase C; Time Factors

Bryostatin-1 is a protein kinase C regulator which has shown antitumour activity against B16 melanoma in animal models. Safety trials revealed this agent to be minimally toxic, thus a phase II trial of bryostatin-1 was conducted to determine its efficacy In patients with melanoma. Eighteen patients with metastatic melanoma, seven of whom had been previously treated, were enrolled in the study. Patients received bryostatin-1 25 microg/m2 intravenously weekly over 1 h for 3 out of 4 weeks. No objective responses were observed. One patient who had not previously received chemotherapy had stable disease for 4 months, and two patients (one previously treated) had a marked decrease in the skin component of their disease. The major toxicity was myalgia (one patient with grade III, two patients with grade II and five patients with grade I), with no grade IV toxicities reported. To Indirectly evaluate the stimulation of protein kinase C, a sensitive assay that measures the upregulation of the activated form of CD62 (glycoprotein IIb/IIIa) on platelets was performed. There was a statistically significant upregulation of this antigen 1 h after bryostatin-1 therapy. A bioassay based on the ability of bryostatin-1 to bind protein kinase C was used to measure bryostatin-1 levels in serum. This assay showed that bryostatin-1 has a volume of distribution of 2.1 l/m2, an elimination clearance of 32.9 ml/min per m2 and a half-life of 43.9 min. In conclusion, this phase II trial demonstrates that, although it is relatively non-toxic, bryostatin-1 therapy had minimal activity in metastatic melanoma.

Topics: Adult; Aged; Antineoplastic Agents; Bryostatins; Female; Humans; Lactones; Macrolides; Male; Melanoma; Middle Aged; Platelet Activation

Bryostatin 1 is a protein kinase C partial agonist which has both antineoplastic and immune-stimulatory properties, including the induction of cytokine release and expansion of tumour-specific lymphocyte populations. In phase I studies, tumour responses have been observed in patients with malignant melanoma, lymphoma and ovarian carcinoma. The dose-limiting toxicity is myalgia. Sixteen patients (age 35-76 years, median 57 years) with malignant melanoma were treated. All had received prior chemotherapy. In each cycle of treatment, patients received bryostatin 25 degrees g m(-2) weekly for three courses followed by a rest week. The drug was given in PET diluent (10 microg bryostatin ml(-1) of 60% polyethylene glycol, 30% ethanol, 10% Tween 80) and infused in normal saline over 1 h. The principal toxicities were myalgia (grade 2, eight patients and grade 3, six patients) and grade 2 phlebitis (four patients), fatigue (three patients) and vomiting (one patient). Of 15 patients evaluable for tumour response, 14 developed progressive disease. One patient developed stable disease for 9 months after bryostatin treatment. In conclusion, single-agent bryostatin appears ineffective in the treatment of metastatic melanoma in patients previously treated with chemotherapy. It should, however, be investigated further in previously untreated patients.

Topics: Adult; Aged; Antineoplastic Agents; Bryostatins; Disease Progression; Drug Resistance, Neoplasm; Female; Humans; Lactones; Macrolides; Male; Melanoma; Middle Aged; Skin Neoplasms; Treatment Outcome

The majority of melanoma cells express detectable levels of HLA class II proteins, and an increased threshold of cell surface class II is crucial for the stimulation of CD4+ T cells. Bryostatin-1, a protein kinase C (PKC) activator, has been considered as a potent chemotherapeutic agent in a variety of in vitro tumor models. Little is known about the role of bryostatin-1 in HLA class II Ag presentation and immune activation in malignant tumors, especially in melanoma. In this study, we show that bryostatin-1 treatment enhances CD4+ T cell recognition of melanoma cells in the context of HLA class II molecules. We also show that bryostatin-1 treatment of melanoma cells increases class II protein levels by upregulating the class II transactivator (CIITA) gene. Flow cytometry and confocal microscopic analyses revealed that bryostatin-1 treatment upregulated the expression of costimulatory molecules (CD80 and CD86) in melanoma cells, which could prolong the interaction of immune cells and tumors. Bryostatin-1 also induced cellular differentiation in melanoma cells, and reduced tumorigenic factors such as pro-cathepsins and matrix-metalloproteinase-9. These data suggest that bryostatin-1 could be used as a chemo-immunotherapeutic agent for reducing tumorigenic potential of melanoma cells while enhancing CD4+ T cell recognition to prevent tumor recurrence.

Topics: Antigen Presentation; B7-1 Antigen; B7-2 Antigen; Base Sequence; Bryostatins; Cathepsin B; Cathepsin D; CD4-Positive T-Lymphocytes; Cell Line, Tumor; Enzyme Inhibitors; Enzyme Precursors; HLA-D Antigens; Humans; Matrix Metalloproteinase Inhibitors; Melanoma; Nuclear Proteins; RNA, Neoplasm; Trans-Activators

Bryostatin 1 and phorbol esters reduce the intracellular melanin level in high metastatic overexpressing nPKCdelta BL6 (BL6T) cells, thereby inducing white experimental metastasis in syngeneic mice. We evaluate here the possible differences between white and black metastases induced by both treatments on the proliferative and metastatic potential as well as on the expression of some cytokines involved in the metastatic process such as TGFbeta, IL-10 and IFNgamma. The level of expression of gelatinase A is also considered. White and black metastases induced after the injection of bryostatin 1- or phorbol ester-treated cells into the tail vein of syngenic mice were isolated and analysed for the levels of LDH usually used as markers of cytotoxicity, for the levels of cytokines and gelatinase A or dissociated and cultured in vitro for a few passages. The cultured cells were analysed in vitro for the proliferative capacity and the melanin synthesis. The same cells were also re-injected into syngeneic mice and the number of experimental metastases were counted after 17 days or injected with matrigel in order to quantify the proliferative capacity in vivo. The results show only one significant difference between bryostatin I and phorbol ester, namely the cells obtained from white bryostatin 1-treated cells return to a black phenotype after a few passages in culture. This suggests that PKC mediates many of the biological effects of bryostatin 1 but that its effect is lost in vitro. On the other hand, white and black metastases (at least for metastases induced by BL6T cells treated with phorbol ester) do appear significantly different. In vivo white metastases show lower levels of LDH, lower levels of proliferative capacity into matrigel, higher levels of TGFbeta and IFNgamma and, when re-injected into syngeneic mice, give big black metastases. Therefore, in murine melanoma cells, the treatment with bryostatin I induces the appearance of a white population expressing different levels of TGFbeta, IFNgamma, IL-10 and gelatinase A. Such a white population is more difficult to diagnose and is capable of turning into a more aggressive phenotype under suitable environmental conditions.

Topics: Animals; Antineoplastic Agents; Bryostatins; Interferon-gamma; Interleukin-10; L-Lactate Dehydrogenase; Lactones; Lung Neoplasms; Macrolides; Matrix Metalloproteinase 2; Melanoma; Mice; Mice, Inbred C57BL; Protein Kinase C; Reverse Transcriptase Polymerase Chain Reaction; Tetradecanoylphorbol Acetate; Transforming Growth Factor beta

Topics: Antineoplastic Agents; Bryostatins; Clinical Protocols; Clinical Trials as Topic; Humans; Lactones; Leukemia; Lymphoma; Macrolides; Melanoma; Neoplasms; United States

Bryostatin 1 (Bryo) is a naturally occurring macrocyclic lactone with antineoplastic activity. Like the phorbol ester 12-O-tetradecanoyl-phorbol 13-acetate (TPA) it directly activates the calcium- and phospholipid-dependent protein kinase C (PKC), thus generating a number of different cellular responses. We investigated the effects of Bryo and TPA on DNA synthesis, proliferation, viability and c-myc protooncogene expression of the human carcinoma cell lines COLO-320, MEL-HO, and KB-3-1. TPA inhibited [3H]-thymidine incorporation in all three cell lines in a dose-dependent manner, whereas Bryo only inhibited the DNA synthesis in MEL-HO, but not in KB-3-1 and COLO-320 cells. Within the concentration ranges used, TPA and Bryo were found to have a low toxicity. Counting of the cells confirmed the observed inhibition of cell proliferation. However, the enzymatic conversion of MTT, applied as a colorimetric proliferation assay, was not significantly affected by both biomodulators. Time-course experiments revealed a rapid onset of the inhibitory effect on DNA synthesis. Bryo was further able to antagonize the TPA-mediated effects on proliferation suggesting an (at least partially) different mode of action of these PKC activators. Incubation of MEL-HO and COLO-320 cells with either of the two biomodulators resulted in a rapid and strong increase of c-myc mRNA. The present study emphasizes Bryo as an interesting, natural substance for the study of PKC-mediated biological effects.

Topics: Adenocarcinoma; Antineoplastic Agents; Bryostatins; Cell Division; Cell Survival; DNA; Dose-Response Relationship, Drug; Female; Gene Expression Regulation, Neoplastic; Genes, myc; Humans; Lactones; Macrolides; Melanoma; Protein Kinase C; Proto-Oncogene Proteins c-myc; RNA, Messenger; Sigmoid Neoplasms; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Uterine Cervical Neoplasms