fenretinide and Carcinoma--Small-Cell

N-(4-hydroxyphenyl) retinamide [4-HPR], a synthetic retinoid, has been shown to inhibit tumor cell growth, invasion, and metastasis by a mechanism that is not fully understood. Because the nuclear factor-kappaB (NF-kappaB) has also been shown to regulate proliferation, invasion, and metastasis of tumor cells, we postulated that 4-HPR modulates the activity of NF-kappaB. To test this postulate, we examined the effect of this retinoid on NF-kappaB and NF-kappaB-regulated gene products. We found that 4-HPR potentiated the apoptosis induced by tumor necrosis factor (TNF) and chemotherapeutic agents, suppressed TNF-induced invasion, and inhibited RANKL-induced osteoclastogenesis, all of which are known to require NF-kappaB activation. We found that 4-HPR suppressed both inducible and constitutive NF-kappaB activation without interfering with the direct DNA binding of NF-kappaB. 4-HPR was found to be synergistic with Velcade, a proteasome inhibitor. Further studies showed that 4-HPR blocked the phosphorylation and degradation of IkappaBalpha through the inhibition of activation of IkappaBalpha kinase (IKK), and this led to suppression of the phosphorylation and nuclear translocation of p65. 4-HPR also inhibited TNF-induced Akt activation linked with IKK activation. NF-kappaB-dependent reporter gene expression was also suppressed by 4-HPR, as was NF-kappaB reporter activity induced by TNFR1, TRADD, TRAF2, NIK, and IKK but not that induced by p65 transfection. The expression of NF-kappaB-regulated gene products involved in antiapoptosis (IAP1, Bfl-1/A1, Bcl-2, cFLIP, and TRAF1), proliferation (cyclin D1 and c-Myc), and angiogenesis (vascular endothelial growth factor, cyclooxygenase-2, and matrix metalloproteinase-9) were also down-regulated by 4-HPR. This correlated with potentiation of apoptosis induced by TNF and chemotherapeutic agents.

Topics: Antineoplastic Agents; Apoptosis; Boronic Acids; Bortezomib; Carcinoma, Small Cell; Carrier Proteins; Cell Growth Processes; Cyclin D1; Cyclooxygenase 2; Down-Regulation; Drug Synergism; Enzyme Activation; Fenretinide; Genes, myc; Humans; I-kappa B Kinase; I-kappa B Proteins; Lung Neoplasms; Membrane Glycoproteins; NF-kappa B; NF-KappaB Inhibitor alpha; Oncogene Protein v-akt; Osteoclasts; Phosphorylation; Promoter Regions, Genetic; Proto-Oncogene Proteins c-myc; Pyrazines; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Transcription Factor RelA; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

The synthetic retinoid fenretinide [N-(4-hydroxyphenyl)retinamide, 4-HPR] has demonstrated growth inhibition and induction of apoptosis of various malignant cells, including lung cancer cell lines. 4-HPR is now being investigated in several clinical trials. In our study, we show that 4-HPR inhibits growth on a broad panel of lung cancer cell lines (12/12 small cell lung cancer and 9/12 nonsmall cell lung cancer cell lines), including cell lines unresponsive to all-trans-retinoic acid (ATRA). 4-HPR revealed a higher potency than ATRA in inhibiting cell growth with IC(50) values ranging from 3.3-8.5 microM. Furthermore, 4-HPR induces apoptosis in lung cancer cell lines as proven by TUNEL and annexin V assay. Despite this, we observed stimulation of growth in 2 SCLC cell lines at 1 microM 4-HPR. In advance to the clinical application of 4-HPR, we demonstrate that growth inhibition is reversible after removal of 4-HPR and that long-term application is necessary. Through long-term stimulation with 4-HPR, we cultivated 3 resistant cell lines that were still inhibited by 4-HPR after several weeks, however, exhibited almost no apoptosis. These cell lines exhibited morphologic changes, which in the case of the SCLC cell lines suggested differentiation. Our data show that 4-HPR inhibits growth in lung cancer cell lines by varying mechanisms including (i) cytostasis, (ii) apoptosis and (iii) presumably, differentiation. In contrast, the observed growth stimulation, reversibility of growth inhibition and development of resistance to apoptosis make successful cancer therapy uncertain and may limit clinical application of 4-HPR in lung cancer patients, although its inhibitory effects last over several weeks.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cell Differentiation; Cell Division; Cell Size; Dose-Response Relationship, Drug; Fenretinide; Flow Cytometry; Humans; In Situ Nick-End Labeling; Lung Neoplasms; Time Factors; Tretinoin; Tumor Cells, Cultured

Fenretinide [N-(4-hydroxyphenyl)retinamide, 4HPR], a synthetic retinoid, is a potent inducer of apoptosis in small-cell lung cancer (SCLC) cell lines that may act through the generation of reactive oxygen species, suggesting that it may enhance the activity of other cytotoxic agents. In light of 4HPR's clinical potential and potent activity against SCLC cells, we evaluated the in vitro activity of 4HPR in combination with cisplatin, etoposide or paclitaxel.. The growth-inhibitory activities of single-agent 4HPR, cisplatin, etoposide or paclitaxel, and combinations of 4HPR and individual chemotherapeutic agents, were evaluated using an MTT assay in two SCLC cell lines. Each two-drug combination was studied over a range of concentrations at a fixed ratio corresponding to the ratio of the IC5 values of the individual agents. Data were analyzed by median-effect analysis as previously applied to drug combination studies.. All four agents inhibited growth in a dose-dependent manner in the NCI-H82 and NCI-H446 SCLC cell lines. At clinically reported drug concentrations that resulted in over 50% growth inhibition, the activities of the combinations 4HPR and cisplatin and 4HPR and etoposide were more than additive in both cell lines, and the activity of 4HPR plus paclitaxel was more than additive in NCI-H446 cells.. 4HPR's potent single-agent activity, minimal toxicity, and potential synergy with standard cytotoxic drugs will allow for the development of promising investigational regimens for the treatment of patients with SCLC.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Cell Division; Cisplatin; Dose-Response Relationship, Drug; Drug Interactions; Etoposide; Fenretinide; Humans; Lung Neoplasms; Paclitaxel; Tumor Cells, Cultured

Most human non-small cell lung cancer (NSCLC) cell lines are refractory to all-trans-retinoic acid (ATRA). Recently, N-(4-hydroxyphenyl)retinamide (4HPR) was found to induce apoptosis in various tumor cells. In this study, we compared and contrasted the effects of 4HPR and ATRA on the growth and apoptosis of 10 NSCLC cell lines and normal human bronchial epithelial (NHBE) cells. All of the cancer cell lines and the NHBE cells were sensitive to 10 microM 4HPR, and their numbers decreased to <20% of the controls after a 5-day treatment, whereas ATRA decreased cell numbers to about 50% of the controls in three cell lines and was less effective in the rest of the tumor cell lines. ATRA inhibited the growth of the NHBE cells by 70-80%. 4HPR induced apoptosis in most of the cells, including the ATRA-resistant ones, as evidenced by a DNA fragmentation assay. No correlation was found between growth inhibition by 4HPR and the expression of retinoic acid receptor beta (determined by Northern blotting and PCR), p53, or Bcl-2 proteins (analyzed by Western blotting). These results demonstrate that 4HPR is more potent than ATRA in inducing apoptosis in NSCLC cells and suggest that further clinical trials for prevention and therapy of NSCLC using 4HPR are warranted.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cell Cycle; Cell Division; Drug Screening Assays, Antitumor; Fenretinide; Genes, bcl-2; Humans; Lung Neoplasms; Receptors, Retinoic Acid; Tretinoin; Tumor Cells, Cultured; Tumor Suppressor Protein p53

Topics: Anticarcinogenic Agents; Antineoplastic Agents; Apoptosis; Carcinoma, Small Cell; Fenretinide; Humans; Lung Neoplasms; Neoplasms; Retinoids; Tumor Cells, Cultured

Lung cancer is the major cause of cancer-related death in the United States, with small-cell lung cancer (SCLC) constituting approximately 20% of all cases of lung cancer. Numerous epidemiologic and molecular studies have suggested that alterations in retinoid-signaling pathways play a role in the pathogenesis of lung cancer. Fenretinide [N-(4-hydroxyphenyl)retinamide; HPR] is a synthetic retinoid with minimal toxicity and favorable pharmacokinetics during long-term administration to patients in clinical trials.. The aim of this investigation was to study the effect of HPR on the growth of SCLC cells in vitro.. Seven SCLC cell lines (NCI-H69, NCI-H82, NCI-H146, NCI-H209, NCI-H345, NCI-H446, and NCI-H510A) were exposed continuously to a broad range of concentrations of HPR or all-trans-retinoic acid (RA), and cell viability was determined on day 3 and day 7 by the trypan blue dye exclusion assay. The growth of these cells was compared with that of control vehicle-treated cells to determine survival fraction and the dose resulting in a 50% inhibition of growth when compared with growth of control cells (IC50). The induction of apoptosis was evaluated by fluorescent microscopy, DNA content analysis, and a terminal deoxyribonucleotidyl transferase-based assay that labels 3'-hydroxyl ends of DNA fragments (TUNEL assay) combined with flow cytometric analysis.. HPR inhibited growth of a panel of SCLC cell lines at IC50 values that ranged from 0.1 to 3.0 microM (concentrations that are clinically achievable). In all cell lines tested, HPR was a more potent growth inhibitor than RA. By use of fluorescent microscopy, HPR was found to induce morphologic changes consistent with apoptosis in NCI-H82 SCLC cells, including cellular shrinkage, chromatin condensation, and nuclear fragmentation. Flow cytometric analysis revealed decreased DNA content, and TUNEL assay showed increased digoxigenin-uridine triphosphate incorporation in HPR-treated NCI-H82 SCLC cells; these findings are consistent with the induction of apoptosis.. HPR inhibited the in vitro growth of SCLC cells. In NCI-H82 cells, HPR inhibited growth via the induction of apoptosis.

Topics: Anticarcinogenic Agents; Antineoplastic Agents; Apoptosis; Carcinoma, Small Cell; Cell Survival; DNA, Neoplasm; Fenretinide; Flow Cytometry; Humans; Lung Neoplasms; Microscopy, Fluorescence; Tumor Cells, Cultured