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Biomedical subjects

A Makki

Publications and source records attributed to A Makki.

7 recordsLinked to original sources
PubMed1998

Vaccination with IL-7 gene-modified autologous melanoma cells can enhance the anti-melanoma lytic activity in peripheral blood of patients with a good clinical performance status: a clinical phase I study.

Recently, cytokine gene transfer into tumour cells has been shown to mediate tumour regression in animal models via immunomodulation. Consequently, a number of clinical protocols have been developed to treat cancer patients with cytokine gene-modified tumour cells. Here, we report the results of a clinical phase I trial using for the first time autologous, interleukin 7 gene-modified tumour cells for vaccination of ten patients with disseminated malignant melanoma. Melanoma cells were expanded in vitro from surgically removed metastases, transduced by a ballistic gene transfer technique and were then injected after in vitro irradiation s.c. at weekly intervals. Clinically, there was no major toxicity except for mild fever, and no major clinical response towards vaccination was observed. Eight of ten patients completed the initial three s.c. vaccinations and were eligible for immunological evaluation. Post vaccination, peripheral mononuclear cells (PBMCs) were found to contain an increased number of tumour-reactive proliferative as well as cytolytic cells, as determined by a limiting dilution analysis. In three of six patients, the frequencies of anti-melanoma cytolytic precursor cells increased between 2.6- and 28-fold. Two of these patients showed a minor clinical response. Analysis of the autologous tumour cell vaccines regarding IL-7 secretion after gene transfer, HLA class I and class II cell surface expression, secretion of immunosuppressive mediators (TGF-beta1, IL-10) and various melanoma-associated tumour antigens revealed a very diverse expression profile. In conclusion, vaccination using gene-modified autologous melanoma cells induced immunological changes in a group of advanced, terminally ill patients. These changes can be interpreted as an increased anti-tumour immune response. However, immunological modulation was most pronounced in patients in good physical condition. Therefore, patients with minimal tumour load or minimal residual disease might preferentially benefit from tumour cell vaccination in further studies. In order to evaluate the effects of the cytokine gene-modified tumour cell vaccines more precisely, an antigenically better defined vaccine is needed.

Adult↗
PubMed1998

Combined treatment of stage IV melanoma patients with amifostine and fotemustine--a pilot study.

Amifostine (Ethyol) is a new chemoprotective agent that has been shown to have significant activity in the prevention of nephro-, oto-, neuro- and haemotoxicity. In preclinical models as well as in clinical trials carried out in patients suffering from various malignancies, the adverse effects and signs of toxicity related to a number of cytostatic drugs, including cisplatin, cyclophosphamide, carboplatin and mitomycin C, were prevented. In Europe fotemustine (Muphoran) is widely used in the treatment of brain metastases in melanoma patients. However, the dose is often limited by severe bone marrow toxicity after induction cycles, particularly in heavily pretreated patients. In order to test whether amifostine treatment might promote bone marrow protective effects when combined with fotemustine chemotherapy, we conducted a preliminary study in 10 patients suffering from stage IV disseminated malignant melanoma. The patients received amifostine (740 mg/m2) prior to fotemustine chemotherapy (100 mg/m2). Six of the patients had failed one or two other prior chemotherapy regimens. Seven patients had brain metastases. Among the 10 patients treated with amifostine and fotemustine, no major clinical responses (complete response or partial response) were achieved, with four patients showing stabilization of the disease over more than 3 months. No patient in the amifostine plus fotemustine treatment group showed severe myelosuppression (WHO grade III/IV), in contrast to a historical control group treated with fotemustine alone, in which about 40% developed major thrombocytopenia and about 45% developed severe leucopenia (WHO grade III/IV). Therefore, we conclude that the combination of amifostine with fotemustine was well tolerated in this small series of patients and further studies are warranted to test the amelioration of myelosuppression by the addition of amifostine.

Amifostine↗
PubMed1996

Metastatic potential of human melanoma cells in nude mice--characterisation of phenotype, cytokine secretion and tumour-associated antigens.

Incidence and mortality of human malignant melanoma has risen rapidly over recent decades. Although the notorious resistance to treatment is characteristic for metastatic malignant melanoma, only a few experimental models have been established to study the metastatic cascade or to test new alternative treatment modalities. Thus, new human models are wanted. Here, we describe the metastatic behaviour of seven human melanoma cell lines derived from two primary cutaneous melanomas (WM 98-1, WM 1341) and five metastases established from liver (UKRV-Mel-4), skin (M7, M13), pleural effusion (UKRV-Mel-2) and lymph node (MV3). All cell lines were analysed for their capacity to grow in nude mice after s.c. and i.v. administration. M13 cells developed liver metastases spontaneously after s.c. injection, and subsequent passages of M13 and M7 melanoma cells caused liver metastases after i.v. injection, whereas MV3 and WM98-1 gave rise to lung metastases, using the same inoculation route. In contrast, WM 1341, UKRV-Mel-2 and UKRV-Mel-4 grew only very slowly in nude mice after s.c. injection and did not cause any metastases after i.v. or s.c. administration. The pattern of metastases or growth kinetics did not correlate with the interleukin 8 or tumour necrosis factor secretion of cell lines. Adhesion molecules and growth factor receptor expression on the cell lines differed widely, as determined by flow cytometry, with the low metastatic cell lines (UKRV-Mel-2, UKRV-Mel-4 and WM 1341) demonstrating a marked reduction in VLA-1 and VLA-5 expression compared with the metastatic lines (M7, M13, MV3 and WM 98-1). Expression of pigment-related proteins such as tyrosinase, TRP-1, TRP-2, Melan-A/MART-1, gp100, MAGE1 or MAGE-3 was not associated with growth and metastatic characteristics of the melanoma cell lines analysed. In conclusion, the established human melanoma cell lines exhibited diverse growth behaviour in nude mice in congruence with some early established prognostic markers such as VLA-1 and VLA-5. The xenografts provide good models for further study of metastatic processes as well as for evaluation of alternative treatment modalities including new pharmaceutical drugs and gene therapeutic targeting using tissue-specific gene regulatory elements for gene targeting.

Animals↗
PubMed1996

Treatment of melanoma cells with the synthetic retinoid CD437 induces apoptosis via activation of AP-1 in vitro, and causes growth inhibition in xenografts in vivo.

Human malignant melanoma is notoriously resistant to pharmacological modulation. We describe here for the first time that the synthetic retinoid CD437 has a strong dose-dependent antiproliferative effect on human melanoma cells (IC50: 5 x 10(-6) M) via the induction of programmed cell death, as judged by analysis of cell morphology, electron microscopical features, and DNA fragmentation. Programmed cell death was preceded by a strong activation of the AP-1 complex in CD437-treated cells as demonstrated by gel retardation and chloramphenicol transferase (CAT) assays. Northern blot analysis showed a time-dependent increase in the expression of c-fos and c-jun encoding components of AP-1, whereas bcl-2 and p53 mRNA levels remained constant. CD437 also exhibited a strong growth inhibitory effect on MeWo melanoma cells in a xenograft model. In tissue sections of CD437-treated MeWo tumors from these animals, apoptotic melanoma cells and c-fos overexpressing cells were colocalized by TdT-mediated deoxyuridine triphosphate-digoxigenin nick end labeling (TUNEL) staining and in situ hybridization. Taken together, this report identifies CD437 as a retinoid that activates and upregulates the transcription factor AP-1, leading eventually to programmed cell death of exposed human melanoma cells in vitro and in vivo. Further studies are needed to evaluate whether synthetic retinoids such as CD437 represent a new class of retinoids, which may open up new ways to a more effective therapy of malignant melanoma.

Animals↗
PubMed1995

Interferon-gamma downregulates epidermal growth factor receptors on human melanoma cells.

Unregulated expression of epidermal growth factor receptor (EGF-R) is a common event in neoplastic transformation and has been shown to be associated with melanocytic tumor progression. Modulation of such a receptor by pharmacological agents could therefore be of clinical interest. We have studied EGF-R expression, its response to epidermal growth factor (EGF) and modulation effects by interferon gamma (IFN gamma) on human melanoma cells. Addition of EGF, anti-EGF and anti-EGF-R antibodies had no effect on proliferation of six melanoma cell lines tested. We report in this communication that EGF-R expression on human melanoma cells can be modulated by IFN-gamma. In the melanoma cell lines treated with IFN gamma, proliferative behavior was not affected; however, we demonstrate a downregulation of EGF-R expression on the protein level, by immunohistochemistry and flow cytometric analysis, and an accumulation of EGF-R mRNA by Northern blot analysis. The results suggest that IFN gamma downregulates EGF-R expression at a posttranscriptional level on human melanoma cells. This EGF/EGF-R interaction and its modulation by IFN gamma on human melanoma cells needs to be further clarified regarding its in vivo significance for the treatment and prognosis of malignant melanoma.

Blotting, Northern↗
PubMed1995

Membrane transport proteins associated with drug resistance expressed in human melanoma.

Melanoma cells often display a multidrug-resistant phenotype, but the mechanisms involved are largely unknown. We have studied here the recently identified transport-associated proteins, MRP and LRP, and the well-known drug resistance marker P-glycoprotein using a panel of 16 human melanoma cell lines and 71 benign and malignant melanocytic tissue samples. By flow cytometry and immunohistochemistry, expression of P-glycoprotein was not detectable on the protein level in the 10 cell lines analyzed, although by reverse transcriptase polymerase chain reaction, MDR-1 gene expression was demonstrated in 2 of 10 cell lines. In addition, immunohistology revealed P-glycoprotein expression in only 1 of 71 melanocytic lesions. In contrast, MRP was detected in a subset of melanoma cell lines by reverse transcriptase polymerase chain reaction and immunohistology (4 of 10). LRP expression was observed in 8 of 10 melanoma cell lines by immunochemistry and in 10 of 10 by reverse transcriptase polymerase chain reaction. Furthermore, MRP was detected immunohistologically in almost 50% of primary and metastatic melanoma specimens, although no significant differences were found between metastases taken before or after chemotherapy. Expression of LRP was detected in a subset of nevi with nevus cells exhibiting up to 25% positive LRP reactivity. In 13 of 21 primary melanomas and 23 of 37 metastases, more than 25% of tumor cells were stained by the LRP-56 monoclonal antibody. Particularly in the group of metastases with more than 50% of LRP-positive cells, 7 of 11 of the metastases had been previously exposed to chemotherapeutic drugs. Although the expression of membrane transport proteins may explain only the chemoresistance toward lipophilic, natural compounds and not resistance against alkylating agents, the lack of P-glycoprotein expression after chemotherapeutic treatment and the significant expression of MRP and LRP in melanoma cells provide first insights into the drug-resistant phenotype in melanoma. Additional studies analyzing the role of MRP and LRP in chemoresistance of melanoma are warranted.

ATP Binding Cassette Transporter, Subfamily B, Mem↗