An ECOG phase II study of amonafide in unresectable or recurrent carcinoma of the head and neck (PB390). Eastern Cooperative Oncology Group

Cytotoxicity evaluation of a new set of 2-aminobenzo[de]iso-quinoline-1,3-diones

A new series of 2-amino-benzo[de]isoquinoline-1,3-diones was synthesized and fully characterized in our previous paper. Here, their cytotoxic effects have been evaluated in vitro in relation to colon HCT-116, hepatocellular Hep-G2 and breast MCF-7 cancer cell lines, using a crystal violet viability assay. The IC₅₀-values of the target compounds are reported in µg/mL, using doxorubicin as a reference drug. The findings revealed that compounds 14, 15, 16, 21 and 22 had significant cytotoxic effects against HCT-116, MCF-7 and Hep-G2 cell lines. Their IC₅₀ values ranged between 1.3 and 8.3 μg/mL in relation to doxorubicin (IC₅₀ ≈ 0.45–0.89 μg/mL). Therefore, these compounds could be used as templates for furthering the development and design of more potent antitumor agents through structural modification.

6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis

Background

Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones) are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl) naphthalimides (compounds 1a-j) were evaluated as antitumor agents.

Methods

Compounds 1a-j were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds 1d and 1i were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound 1i treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound 1i were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with 1i was examined under light microscope and transmission electron microscope. ³H-Thymidine and ³H-uridine incorporation in S-180 cells in vitro following treatment with 8 μM concentration of compounds 1d and 1i were studied.

Results

6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione (compound 1i), has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC₅₀ value 273 μM). Cell cycle analysis of compound 1i treated MOLT-4 cells demonstrated rise in sub-G₁ fraction and concomitant accumulation of cells in S and G₂/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and transmission electron microscopic studies corroborated its apoptosis inducing efficacy at a concentration of 10 μM in MOLT-4 cells. Its apoptosis induction was also observed in HL-60 cells to an extent much greater than well known apoptosis inducing agents as camptothecin and cis-platin at 10 μM concentration each. It significantly inhibited DNA and RNA synthesis in S-180.

Conclusions

In essence, compound 1i showed potential as an antitumor agent.

Arylamine N-acetyltransferases and drug response

Arylamine N-acetyltransferases (NATs) play an important role in the interaction of competing metabolic pathways determining the fate of and response to xenobiotics as therapeutic drugs, occupational chemicals and carcinogenic substances. Individual susceptibility for drug response and possible adverse drug reactions are modulated by the genetic predisposition (manifested for example, by polymorphisms) and the phenotype of these enzymes. For all drugs metabolized by NATs, the impact of different in vivo enzyme activities is reviewed with regard to therapeutic use, prevention of side effects and possible indications for risk assessment by phenotyping and/or genotyping. As genes of NATs are susceptibility genes for multifactorial adverse effects and xenobiotic-related diseases, risk prediction can only be made possible by taking the complexity of events into consideration.

Recurrent squamous-cell carcinoma of the head and neck: overview of current therapy and future prospects

Locoregional recurrence is the most common cause of failure after head and neck cancer surgery. It is a disease which causes significant morbidity especially on speech and swallowing. There are many different treatments available including surgery, reirradiation and chemotherapy. However, none of these have produced any significant survival benefit. Because of this, there has been considerable interest in the development of new biological therapies such as gene therapy and immunotherapy for this disease. The objectives of this article are to provide an overview of the currently available therapies for recurrent head and neck cancer including gene therapy and immunotherapy. Prevention of recurrent disease by the detection and treatment of minimal residual disease is also discussed.