Interaction of homo-aza-steroidal ester of [p-[bis-(2-chloroethyl) amino]phenyl]acetic acid (ASE) with DNA of Ehrlich ascites tumor cells

Research on the anti-tumour effect of steroid lactam alkylator (NSC-294859) in comparison with conventional chemotherapeutics in malignant melanoma

Evidence indicating that hybrid steroid compounds of anti-cancer agents produce reduced toxicity, significantly lower than the cytotoxic components alone, and increased anti-cancer activity has prompted the design and development of such steroids, mostly alkylating esters. We investigated the in-vitro and in-vivo activity of a homo-aza-steroidal alkylating ester (HASE), in comparison with dacarbazine (DTIC), cisplatin (CPDD), carmustine (BCNU) and semustine (MeCCNU), in the treatment of malignant melanoma. Cytotoxicity was assessed in vitro by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using a panel of six human malignant melanoma cell lines, with or without the presence of rat liver microsome assay. B16 melanoma-bearing mice were used to evaluate in vivo the anti-tumour activity of the tested compounds. In all cases of in-vitro screening, HASE displayed a significantly higher (P<0.0001) cytostatic and cytotoxic effect than DTIC, BCNU and MeCCNU, but produced significantly lower (P<0.0001) activity than CPDD. HASE exhibited a significantly smaller range than CPDD between concentration levels that produced growth arrest and those that induced a cytotoxic effect against melanoma cells in vitro. The anti-tumour activity of HASE in B16 melanoma-bearing mice, as determined by tumour growth rate inhibition (<42%) and percentage survival prolongation (treated versus control, 167%), was significantly superior (P<0.001) to that achieved by DTIC, BCNU and MeCCNU and was equal to that of CPDD. HASE exhibited a toxicity similar to that of DTIC, BCNU and MeCCNU, but significantly lower than that of CPDD. It can be concluded that HASE displays significant in-vitro and in-vivo activity in the treatment of melanoma.

Lactandrate: a D-homo-aza-androsterone alkylator in the treatment of breast cancer

The sensitivity of breast neoplasms to hormonal control provides the basis of novel investigational treatments with steroidal alkylators. An androsterone D-lactam steroidal ester, the 3beta-hydroxy-13alpha-amino-13,17-seco- 5alpha-androstan-17-oic-13,17-lactam, p-bis(2-chloroethyl)amino phenyl acetate (lactandrate) was synthesized and tested for antitumor activity against six human breast cancer cell lines in vitro and against two murine and one xenograft mammary tumors in vivo. A docking study on the binding interactions of lactandrate with the ligand-binding domain (LBD) of estrogen receptor-alpha (ERalpha) was inquired. In vitro testing of lactandrate cytostatic and cytotoxic activity was performed on T47D, MCF7, MDA-MB-231, BT-549, Hs578T, MDA-MB-435 breast adenocarcinoma human cell lines. In vivo testing was performed on two murine mammary tumors, the MXT tumor and CD8F1 adenocarcinoma, as well as on human mammary carcinoma MX-1 xenograft. Molecular modeling techniques were adopted to predict a possible location and interaction mode of the molecule into LBD. Lactandrate induced significantly high antitumor effect against all tested in vitro and in vivo models. The cell lines with positive ER expression found to be significantly more sensitive to lactandrate. Moreover, lactandrate found to be positioned inside the binding cavity with its steroidal moiety, whilst the alkylating moiety protrudes out of receptor's pocket. Lactandrate produced important anticancer activity on breast cancer in vitro and in vivo. Some correlation between ER and lactandrate effect was demonstrated. Docking studies provide the basis for the structure-based design of improved steroidal alkylating esters for the treatment of estrogen-related cancers.

On the formation of 4-[N,N-bis(2-chloroethyl)amino]phenyl acetic acid esters of hecogenin and aza-homo-hecogenin and their antileukemic activity

The p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid esters of hecogenin and aza-homo-hecogenin have been prepared and their antineoplastic activity was evaluated against two basic drug screening systems in rodents, P388 lymphocytic and L1210 lymphoid murine leukemias. Among the compounds tested, the p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid ester of aza-homo-hecogenin was appeared to possess a significant higher antileukemic effect. These results support that the alkylating esters of hecogenin produce important antitumor activity as well as, indicate that the aza-homo-hecogenin ester exhibits significantly higher activity due to lactam group (-NHCO-) modification.

Preclinical studies on NSC290205 aza-steroid alkylator activity in combination with adriamycin against lymphoid leukaemia

Summary NSC290205 (A) is an hybrid synthetic antineoplastic ester that is a combination of a d-lactam derivative of androsterone and an alkylating derivative of N,N-bis(2-chloroethyl)aniline. We tested NSC290205 for synergistic antileukaemic activity with adriamycin (ADR), (i) in vitro against the human lymphoid leukaemia cell lines: CCRF-CEM, MOLT-4, and RPMI-8226, (ii) in vivo against P388 lymphocytic and L1210 lymphoid murine leukaemias (at incipient and advanced phase). Our results indicated significant cytostatic and cytotoxic synergy of NSC290205 and ADR in vitro. We further examined these results in vivo by replacing cyclophosphamide in the standard CHOP (cyclophosphamide, hydroxydaunomycin, Oncovin, prednisone) regimen with NSC290205 (AHOP) and comparing the efficiency of these two regimens in vivo. Although treatment of P388 and L1210 with cyclophosphamide or NSC290205 alone yielded equivalent results, AHOP produced a clear benefit for survival compared with CHOP against advanced leukaemias, confirming the in vitro observations [higher percentage increase in median lifespan of treated animals over the untreated (control): 188% and 239% in L1210, 308% and 353% in P388, P < 0.01, for CHOP and AHOP respectively]. AHOP also proved to be more genotoxic and cytostatic than CHOP, inducing higher sister chromatid exchange levels and cell division delays on P388 cells in vivo. NSC290205 showed superior antineoplastic potential against lymphoid leukaemia and significant synergy with ADR, producing an excellent therapeutic outcome.

Comparative study on cytogenetic damage induced by homo-aza-steroidal esters in human lymphocytes

The effect of P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-N-methyl-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 3) and 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstane (compound 2) on sister-chromatid exchange (SCE) frequencies and on human lymphocytes proliferation kinetics was studied. The results are compared with those of the P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 1). All compounds were found to be active in inducing markedly increased SCE rates and cell division delays. A correlation between potency for SCE induction, effectiveness in cell division delay and previously established antitumour activity of these compounds was observed.

Structure--anticancer and structure--genetic activity relationships of homo-aza-steroidal esters of N,N-bis(2-chloroethyl)aminocinnamic acid isomers

Four steroidal lactams of the A- and D-rings were used for the esterification in the C-3 or C-17 positions, respectively, of their nuclei with the N,N-bis(2-chloroethyl)aminocinnamic acid isomers. The condensation reaction of the hydroxylic group of the steroidal lactams with each mustard was effected in dichloromethane in the presence of the catalyst p-dimethylaminopyridine and dicyclohexylcarbodiimide as dehydrating agent. The esters were obtained in pure form after column chromatography, and their structures were verified and confirmed by analytical methods (IR and UV spectra). The 12 esters were tested in vivo against P388, L1210 leukemias, Ehrlich ascites tumor, and melanoma B16. The esters 3 alpha-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17- oic-13,17-lactam-o,m,p-N,N-bis(2-chloroethyl)aminocinnamates, in which the alkylating agents are linked to the modified steroid in the axial position, are inactive in the above experimental animal tumor systems. The effect of the homo-aza-steroidal esters of N,N-bis(2-chloroethyl)aminocinnamic acid isomers on the incorporation of radioactive precursors into DNA, RNA, and proteins of L1210, P388 leukemias, Ehrlich ascites tumor, and baby hamster kidney cells was investigated. Higher inhibitory effects on the incorporation of the radioactive precursors was obtained with the ortho-derivatives, yielding > 40% inhibition of thymidine incorporation in all tumor lines tested. The effect of four esters in which the m- N,N-bis(2-chloroethyl)aminocinnamic acid is linked to the modified steroids on sister chromatid exchanges in human lymphocyte culture was investigated.

Synergistic induction of cytogenetic damage by the homo-aza-steroidal ester of p-bis(2-chloroethyl)aminophenylacetic acid in combination with caffeine in human lymphocytes in vitro and in Ehrlich ascites tumour cells in vivo

We studied the effects of caffeine alone or in combination with homo-aza-steroidal ester of p-bis(2-chloroethyl)aminophenylacetic acid (ASE, NSC 290205) on the frequency of SCEs and lymphocyte proliferation kinetics. Caffeine was found to act synergistically with ASE on the induction of SCEs when the two components were administered in combination. Caffeine was also found to act synergistically with ASE in inducing cell-division delays. Enhanced cytogenetic damage by ASE was observed when Ehrlich ascites tumour cells (EAT cells) were exposed in vivo to caffeine. ASE alone or in combination with caffeine caused a dose-dependent increase in SCE rates and cell-division delays. SCEs were demonstrated in EAT-bearing mice, by the i.p. injection of BrdUrd adsorbed onto activated charcoal, 1 h after the i.p. injection of ASE and/or caffeine.