| 1. |
- Carlier, Charlotte, et al.
(författare)
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Preclinical activity of melflufen (J1) in ovarian cancer
- 2016
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:37, s. 59322-59335
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian cancer carries a significant mortality. Since symptoms tend to be minimal, the disease is often diagnosed when peritoneal metastases are already present. The standard of care in advanced ovarian cancer consists of platinum-based chemotherapy combined with cytoreductive surgery. Unfortunately, even after optimal cytoreduction and adjuvant chemotherapy, most patients with stage III disease will develop a recurrence. Intraperitoneal administration of chemotherapy is an alternative treatment for patients with localized disease. The pharmacological and physiochemical properties of melflufen, a peptidase potentiated alkylator, raised the hypothesis that this drug could be useful in ovarian cancer and particularily against peritoneal carcinomatosis. In this study the preclinical effects of melflufen were investigated in different ovarian cancer models. Melflufen was active against ovarian cancer cell lines, primary cultures of patient-derived ovarian cancer cells, and inhibited the growth of subcutaneous A2780 ovarian cancer xenografts alone and when combined with gemcitabine or liposomal doxorubicin when administered intravenously. In addition, an intra-and subperitoneal xenograft model showed activity of intraperitoneal administered melflufen for peritoneal carcinomatosis, with minimal side effects and modest systemic exposure. In conclusion, results from this study support further investigations of melflufen for the treatment of peritoneal carcinomatosis from ovarian cancer, both for intravenous and intraperitoneal administration.
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| 2. |
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| 3. |
- Gullbo, Joachim, et al.
(författare)
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Antitumor activity of the novel melphalan containing tripeptide J3 (L-prolyl-melphalanyl-p-L-fluorophenylalanine ethyl ester) : Comparison with its m-L-sarcolysin analogue P2
- 2003
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Ingår i: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 2:12, s. 1331-1339
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Tidskriftsartikel (refereegranskat)abstract
- Peptichemio (PTC), a mixture of six oligopeptides all containing m-L-sarcolysin, has previously shown impressive results in clinical trials. The tripeptide P2 (L-prolyl-m-L-sarcolysyl-p-L-fluorophenylalanine ethyl ester) has been suggested as the main contributor to PTC activity. In contrast to its analogue melphalan, m-L-sarcolysin never reached clinical use. To allow a direct comparison, the corresponding melphalan containing tripeptide J3 (L-prolyl-L-melphalanyl-p-L-fluorophenylalanine ethyl ester) was synthesized and its activity was compared with that of P2; the activities of melphalan and m-L-sarcolysin were studied in parallel. Cytotoxic activity in human tumor cell lines and some fresh human tumor specimens were analyzed as well as effects on cellular metabolism, macromolecular synthesis, and preliminary evaluation of the cell death characteristics. The results show that melphalan and m-L-sarcolysin display similar activity in these systems and that the tripeptides were more active than their parent monomers. Surprisingly however, the melphalan containing tripeptide J3 demonstrated a significantly more rapid and stronger activity than the m-L-sarcolysin analogue P2. Finally, the in vivo toxicity and activity of melphalan and J3 were investigated in mice bearing human leukemia cells in s.c. fibers. The in vitro results seem translatable into the in vivo situation, demonstrating better antileukemic effect of J3 but similar side effects as melphalan.
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| 4. |
- Gullbo, Joachim, et al.
(författare)
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Antitumor efficacy and acute toxicity of the novel dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) in vivo.
- 2004
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Ingår i: Investigational new drugs. - 0167-6997. ; 22:4, s. 411-20
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Tidskriftsartikel (refereegranskat)abstract
- The novel alkylating dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) was evaluated for acute toxicity and antitumor activity in mice, with melphalan as a reference. To determine a safe and tolerable dose for efficacy studies the acute toxicity following intravenous injection in the tail vein was monitored using a 14-day schedule with up to four doses. The highest tested dose, 25 micromoles/kg, was considered close to this level, with minor effects on body weight gain but significant effects on hematological parameters. Melphalan and J1 appeared equitoxic with no statistically significant differences. Subsequently a mouse hollow fiber model was employed with subcutaneous implantation of fibers containing human tumor cells. Three different human tumor cell lines as well as two samples of primary human tumor cells (ovarian carcinoma and chronic lymphatic leukemia) were used as tumor models. At the dose level tested there was a marked and statistically significant decrease in both T-cell leukemia CCRF-CEM and small cell lung cancer NCI-H69 tumor cell growth and viability in response to J1 as compared with both placebo and melphalan treated groups. In primary ovarian carcinoma cells only J1 treatment resulted in significant tumor regression (net cell kill). In summary the results indicate that, despite an expected short half time in the blood circulation, the promising in vitro data from the previous studies of J1 seems translatable into the in vivo situation. At equal doses of alkylating units J1, compared to melphalan, was more active in the mouse hollow-fiber model, but showed similar general toxicity.
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| 5. |
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| 6. |
- Gullbo, Joachim, et al.
(författare)
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Structure activity relationship for alkylating dipeptide nitrogen mustard derivatives
- 2003
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Ingår i: Oncology Research. - : Computers, Materials and Continua (Tech Science Press). - 0965-0407 .- 1555-3906. ; 14:3, s. 113-132
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Tidskriftsartikel (refereegranskat)abstract
- The strategy of using small peptides for effective targeting of tumor cells in chemotherapy has proven beneficial. Recently we showed that J1 (L-melphalanyl-p-L-fluorophenylalanine ethyl ester), an alkylating nitrogen mustard-containing dipeptide, exhibited strong cytotoxic activity in fresh human tumor samples in addition to rapid and pronounced inhibition of macromolecular syntheses and cellular respiration in the human tumor lymphoma cell line U-937 GTB. In this study, an additional series of 17 nitrogen mustard-containing dipeptides has been synthesized and analyzed for cytotoxic activity in a panel of 10 human tumor cell lines. The results were compared to the single amino acid mustard derivative melphalan and its ethyl and isopropyl esters. Also P2 (L-prolyl-m-L-sarcolysyl-p-L-fluorophenylalanine ethyl ester), a tripeptide that previously has shown impressive effects in human tumor cells, was used as reference. The tested compounds displayed various activities in the different cell lines but also showed a high correlation, indicating a similar mechanism of action. Factors like amino acid composition, amino acid sequence, modifications of the C- and N-termini, and to a minor extent the lipophilicity of the dipeptide derivatives appear to influence the in vitro activity. The results indicate that the activity of these compounds not only relies on their chemical reactivity, but also on active biological interactions such as transport across membranes and/or enzymatic liberation of reactive molecular entities.
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| 7. |
- Orre, Lukas M., et al.
(författare)
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p53 is involved in clearance of ionizing radiation-induced RAD51 foci in a human colon cancer cell line
- 2006
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 342:4, s. 1211-7
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated p53-related differences in cellular response to DNA damaging agents, focusing on p53s effects on RAD51 protein level and sub-cellular localization post exposure to ionizing radiation. In a human colon cancer cell line, HCT116 and its isogenic p53-/- subcell line we show here p53-independent RAD51 foci formation but interestingly the resolution of RAD51 foci showed clear p53 dependence. In p53 wt cells, but not in p53-/- cells, RAD51 protein level decreased 48 h post irradiation and fluorescence immunostaining showed resolution of RAD51 foci and relocalization of RAD51 to nucleoli at time points corresponding to the decrease in RAD51 protein level. Both cell lines rejoined DNA double strand breaks efficiently with similar kinetics and p53 status did not influence sensitivity to DNA damaging agents. We suggest that p53 has a role in RAD51 clearance post DSB repair and that nucleoli might be sites of RAD51 protein degradation.
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| 8. |
- Wickström, Malin, et al.
(författare)
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The alkylating prodrug J1 can be activated by aminopeptidase N, leading to a possible target directed release of melphalan
- 2010
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Ingår i: Biochemical Pharmacology. - : Elsevier BV. - 0006-2952 .- 1356-1839 .- 1873-2968. ; 79:9, s. 1281-1290
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Tidskriftsartikel (refereegranskat)abstract
- The alkylating prodrug of melphalan, J1 (melphalanyl-l-p-fluorophenylalanyl ethyl ester) is currently in early clinical trials. Preclinical studies have shown that J1-mediated cytotoxicity is dependent on hydrolytic activity of tumor cells. In this report we have analyzed potential peptidases and esterases of importance for release of free melphalan from J1. Exposure of tumor cell lines to J1 resulted in a significant increased level of free intracellular melphalan, at least tenfold at Cmax, compared to exposure to melphalan at the same molar concentration. This efficient intracellular delivery could be inhibited in both magnitude and in time by bestatin, a broad spectrum inhibitor of the aminopeptidases, including the metalloproteinase aminopeptidase N (APN, EC 3.4.11.2.), and ebelactone A, an esterase inhibitor. These effects resulted, as expected, in decreased cytotoxic effects of J1. A specific role of APN in hydrolyzing J1 releasing free melphalan was demonstrated in vitro with pure APN enzyme. By using plasmid-based overexpression of APN or down regulation of endogenous APN with siRNA in different tumor cell lines we here confirm the involvement of APN in J1-mediated cytotoxic and apoptotic signaling. In conclusion, this study demonstrates a role of APN in the activation of the melphalan prodrug J1 and subsequently, its cytotoxicity. Given that APN is shown to be overexpressed in several solid tumors our data suggest that J1 may be activated in a tumor selective manner.
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| 9. |
- Wickström, Malin, et al.
(författare)
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The novel melphalan prodrug J1 inhibits neuroblastoma growth in vitro and in vivo
- 2007
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Ingår i: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 6:9, s. 2409-2417
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is the most common extracranial solid tumor of childhood. The activity of J1 (l-melphalanyl-p-l-fluorophenylalanine ethyl ester), an enzymatically activated melphalan prodrug, was evaluated in neuroblastoma models in vitro and in vivo. Seven neuroblastoma cell lines with various levels of drug resistance were screened for cytotoxicity of J1 alone or in combination with standard cytotoxic drugs, using a fluorometric cytotoxicity assay. J1 displayed high cytotoxic activity in vitro against all neuroblastoma cell lines, with IC50 values in the submicromolar range, significantly more potent than melphalan. The cytotoxicity of J1, but not melphalan, could be significantly inhibited by the aminopeptidase inhibitor bestatin. J1 induced caspase-3 cleavage and apoptotic morphology, had additive effects in combination with doxorubicin, cyclophosphamide, carboplatin, and vincristine, and synergistically killed otherwise drug-resistant cells when combined with etoposide. Athymic rats and mice carrying neuroblastoma xenografts [SH-SY5Y, SK-N-BE(2)] were treated with equimolar doses of melphalan, J1, or no drug, and effects on tumor growth and tissue morphology were analyzed. Tumor growth in vivo was significantly inhibited by J1 compared with untreated controls. Compared with melphalan, J1 more effectively inhibited the growth of mice with SH-SY5Y xenografts, was associated with higher caspase-3 activation, fewer proliferating tumor cells, and significantly decreased mean vascular density. In conclusion, the melphalan prodrug J1 is highly active in models of neuroblastoma in vitro and in vivo, encouraging further clinical development in this patient group.
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