Elliptinium Acetate Research Articles

Integrated analysis of single-cell RNA-seq and bulk RNA-seq revealed key genes for bone metastasis and chemoresistance in prostate cancer.

Prostate cancer (PCa) is a serious malignancy. The main causes of PCa aggravation and death are unexplained resistance to chemotherapy and bone metastases. This study aimed to investigate the molecular mechanisms associated with the dynamic processes of progression, bone metastasis, and chemoresistance in PCa. Through comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data, Gene Expression Omnibus (GEO) tumor progression and metastasis-related genes were identified. These genes were subjected to lasso regression modeling using the Cancer Genome Atlas (TCGA) database. Tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative PCR (RT-qPCR) were used to evaluate osteoclast differentiation. CellMiner was used to confirm the effect of LDHA on chemoresistance. Finally, the relationship between LDHA and chemoresistance was verified using doxorubicin-resistant PCa cell lines. 7928 genes were identified as genes related to tumor progression and metastasis. Of these, 7 genes were found to be associated with PCa prognosis. The scRNA-seq and TCGA data showed that the expression of LDHA was higher in tumors and associated with poor prognosis of PCa. In addition, upregulation of LDHA in PCa cells induces osteoclast differentiation. Additionally, high LDHA expression was associated with resistance to Epirubicin, Elliptinium acetate, and doxorubicin. Cellular experiments demonstrated that LDHA knockdown inhibited doxorubicin resistance in PCa cells. LDHA may play a potential contributory role in PCa initiation and development, bone metastasis, and chemoresistance. LDHA is a key target for the treatment of PCa.

5022 A retrospective study on the efficacy of elliptinium acetate in metastatic breast cancer patients

Human epidermal growth factor receptor 2 (HER2), a member of the ErbB family of transmembrane receptor tyrosine kinases, is amplified in 20–30% of invasive breast cancers. HER2 amplification is associated with metastasis and reduced survival. Two HER2-directed therapies have been approved by the United States Food and Drug Administration for the treatment of HER2-overexpressing breast cancer: trastuzumab, a humanized monoclonal antibody against the extracellular portion of HER2; and lapatinib, a dual HER2- and epidermal growth factor receptor-specific tyrosine kinase inhibitor. Despite the improvement in overall survival with the addition of HER2-targeted agents to chemotherapy, many patients do not benefit from these agents because of inherent resistance. In addition, many patients who achieve an initial response eventually acquire drug resistance. Currently, several mechanisms of resistance have been described, including mutations in other signaling pathways, expression of a truncated form of HER2, receptor crosstalk, and autophagy. There are several approaches under study to target these pathways of resistance, including blocking PI3 kinase and mammalian target of rapamycin signaling, blocking neoangiogenesis and the vascular endothelial growth factor axis, using monoclonal antibody targeting of the HER2 dimerization site, and using HER2 monoclonal antibody-drug conjugates. Here we will review the current scientific rationale for these agents and how combinations of these agents may yield additive or synergistic effects and lead to improved outcomes for patients with HER2-amplified breast cancer.

DNA topoisomerase targeting drugs: mechanisms of action and perspectives.

The nuclear enzymes DNA topoisomerases I and II appeared as cellular targets for several antitumor drugs: campthotecin derivatives interacting with topoisomerase I, and actinomycin D, anthracycline derivatives, elliptinium acetate, mitoxantrone, epipodophyllotoxine derivatives, amsacrine and a new olivacine derivative, NSC-6596871 (S 16020-2), which interact with topoisomerase II. The functions of these enzymes are numerous and important since they are critical for DNA functions and cell survival. Despite the fact that they share the same target, topoisomerase II inhibitors have different mechanisms of action. Two principle types of induced alterations are involved in cellular resistance to topoisomerase II drugs: qualitative or quantitative alteration of the enzyme and/or increased drug efflux due to overexpression of P-glycoprotein. S 16020-2, a new olivacine derivative with a high antitumor activity against solid tumors, shows a potent cytotoxic effect against tumor cells expressing P-glycoprotein. This observation suggests that the comprehension of the respective effects of topoisomerase inhibitors and the precise knowledge of their mechanisms of resistance would improve the use of this therapeutic class in the clinic within rational chemotherapeutic combinations.

In vitro cytotoxicity of S16020-2, a new olivacine derivative.

S16020-2 is a new olivacine derivative which has recently shown a marked antitumor activity in various experimental models. This study was undertaken in order to measure the inhibition of the proliferation of various sensitive and resistant tumor cell lines, by S16020-2, and to obtain information concerning its mechanism of action. For a continuous exposure, S16020-2 was as cytotoxic as adriamycin (ADR) (mean IC50 of about 28 nM) and on average, 46 fold more potent than elliptinium acetate (ELP), against a panel of 20 non-multidrug resistant cell lines. With a short exposure (1 hour) followed by a post-incubation of 95 hours in drug-free medium, S16020-2 was 5 and 6 fold more cytotoxic than ADR for human lung A549 and murine melanoma B16 cells, respectively. Furthermore, S16020-2 inhibited more actively the formation of colonies issued from proliferating cells, compared to colonies issued from quiescent A549 cells. Because quiescent cells demonstrated a 3 fold lower level of topoisomerase II alpha (topo II) than proliferating cells, these results suggest that this enzyme could be a potential target for S16020-2. In addition, as demonstrated by flow cytometric studies, S16020-2 intercalated into DNA and induced a cell cycle arrest in G2. Cell lines displaying the multidrug resistance (MDR) phenotype, P388/ADR-1, P388/ADR, P388/VCR-20, KB-A1, DC-3F/AD, S1/tMDR, and Colo320DM, were more sensitive to S16020-2 than to ADR or ELP, as shown by the mean resistance factors, 8, 201, and 23 respectively. In addition, the two cell lines displaying the pure classical MDR phenotype, linked exclusively to the P-glycoprotein (P-gp) overexpression (P388/VCR-20 and S1/tMDR), were as sensitive to S16020-2 as their sensitive parental counterparts, although they were resistant to ADR. S16020-2 is thus one of the most potent olivacine and ellipticine derivative yet characterized. The good cytotoxicity of S16020-2 against cells displaying a P-gp-mediated multidrug resistance, and its antitumor activity in vivo delineate an important chemotherapeutic potential for this drug.

Phase II study of elliptinium acetate salvage treatment of advanced breast cancer

Elliptinium acetate (Celiptium) is an intercalating agent belonging to the ellipticine family. This agent has demonstrated clinical activity as salvage treatment in breast cancer using a weekly regimen. However, its clinical use was hampered by important toxicities such as xerostomia and immune-mediated haemolytic reactions due to development of anti-elliptinium IgM antibodies. We have studied 83 patients previously treated for metastatic breast cancer using elliptinium acetate with a different schedule: 80 mg/m2 daily for 3 consecutive days every 21 days. In 80 evaluable patients, an objective response (complete + partial response) was obtained in 5 of 30 patients with visceral metastases (13%), in 6 of 21 patients with soft tissue metastases (29%), and in 3 of 20 patients with mixed metastases (15%). The overall objective response rate was 14/80 (18%, 95% confidence interval = 10-26%). Moderate to severe xerostomia occurred in 10% of patients, while no anti-elliptinium antibodies or haemolytic reactions were detected using this schedule. No significant haematological toxicity, as usually reported with this drug, was observed. Elliptinium acetate has modest but definite activity as salvage treatment of breast cancer. The 3-week schedule seems as active as and less toxic than the weekly schedule.

Phase II study of a combination of elliptinium and vinblastine in metastatic breast cancer

Thirty nine patients with metastatic breast cancer, all previously treated with chemotherapy including anthracycline, were given Elliptinium acetate (80 mg/m2/day) and a continuous infusion of Vinblastine (2 mg/m2/day) for 3 consecutive days every 4 weeks. Twenty nine patients had measurable metastatic disease. Nine (31%) achieved a partial response. No complete response was observed. Median duration of response was 6 months. The response rate was dependent on the number of metastatic sites and independent of the number of previous chemotherapy regimes. Side effects were dry mouth (27 patients), vomiting (9), neutropenia (3 patients with grade IV, 2 with grade III), muscle cramps (5) and thrombosis (3). Xerostomia and vomiting contributed to weight loss and fatigue (8 patients). We conclude that Elliptinium-Vinblastine combination has moderate activity as second line treatment in metastatic breast cancer. This combination causes xerostomia and fatigue with moderate myelosuppression.

Chemotherapy in Metastatic Nonanaplastic Thyroid Cancer: Experience at the Institut Gustave-Roussy

Forty-nine patients with metastatic nonanaplastic thyroid carcinoma were treated over a 10-year period. Five successive chemotherapeutic protocols were used: a combination of doxorubicin, etoposide, 5-fluorouracil and cyclophosphamide; elliptinium acetate; doxorubicin; cisplatin; and the combination of doxorubicin and cisplatin. Results obtained with the different protocols were very disappointing, with only two objective responses (3%). Phase II trials with new chemotherapeutic agents are warranted in selected cases of nonanaplastic metastatic thyroid carcinoma.

Elliptinium Acetate in Metastatic Breast Cancer – a Phase II Study

Thirty-five patients with metastatic breast cancer who had received one or two prior chemotherapeutic regimens were treated with elliptinium acetate at a dose of 80 mg/m2 for 3 days every 3 weeks. Of the 33 patients evaluable for response, 1 patient achieved complete remission, 4 achieved partial responses (15% overall objective response with 95% confidence interval of 5-32%), and 6 achieved minor response. Toxicity of the treatment was xerostomia, diarrhea, and nausea and vomiting. The drug was not myelosuppressive. Three patients showed evidence of elliptinium antibody, and treatment was discontinued. No episodes of hemolysis were observed. Elliptinium acetate showed modest antitumor activity in previously treated patients with metastatic breast cancer.

Elliptinium: phase II study in advanced measurable breast cancer.

Eighteen patients with advanced measurable breast cancer were treated with elliptinium acetate 100 mg/m2 x 3 days every 3 weeks. Fourteen of these patients had failed prior chemotherapy. Two patients had an objective tumor response of greater than 4 weeks. Myelosuppression, renal insufficiency and thrombophlebitis were rarely encountered and alopecia was not seen at all. This study demonstrates that elliptinium has minimal activity in recurrent breast cancer with a favorable toxicity profile.

Conjugates of elliptinium acetate with mouse monoclonal anti‐α‐fetoprotein antibodies or fab fragments: In vitro cytotoxic effects upon human hepatoma cell lines

Elliptinium acetate (EA) is a new anti-cancer compound displaying cytostatic activity against various malignancies including hepatoma. Using 3 hepatoma cell lines, we compared the in vitro activity of doxorubicin (reference drug), of EA and of conjugates made up with this latter drug and monoclonal antibodies (MAbs). The linkage was performed by a direct oxidation method. Specific immunoconjugates were prepared with an anti-alphafetoprotein (AFP) MAb (AF01) or its Fab fragment (Fab AF01). Non-specific conjugates were obtained with an anti-thyroglobulin MAb (TG01) or its Fab (Fab TG01). Direct membrane injury (51Cr-release), DNA and protein synthesis as well as AFP release were investigated for all compounds. Free EA displayed only weak activity on DNA and protein synthesis, at 10-fold higher molar concentration than doxorubicin. Conjugation of EA with whole AF01 allowed significant potentiation of protein synthesis inhibition without affecting the 3 other tests. In contrast, Fab AF01 x EA conjugates displayed a marked effect in the 4 tests; in particular, this conjugate was at least 100 times more efficient than any other compound when tested in the 51Cr-release test. Neither Fab AF01 nor free EA alone or in combination exhibited such an effect. Fab TG01 x EA conjugate was not directly cytotoxic but potentiated inhibition of DNA and protein synthesis between 2- and 10-fold. The mechanism of the direct cytotoxic effect of anti-AFP Fab x EA conjugate, which has never been described in any other immunodrug model, was investigated.

Phase II Trial with High-Dose Elliptinium Acetate in Metastatic Renal Cell Carcinoma

Sixteen patients with adult metastatic renal cell carcinoma were treated with elliptinium acetate, 80 mg/m2.day, for 3 consecutive days every 3 weeks. Among the 14 patients evaluable, no objective effects were observed. The toxicity was mild and no patients experienced intravascular hemolysis.

Hemoglobin-catalyzed transformation of elliptinium acetate into electrophilic species. Evidences for oxidative activation of the drug in human red blood cells

The anti-tumor drug N 2-methyl-9-hydroxyellipticinium acetate (NMHE, Celiptium®) after incubation with various N or S containing amino acids (alanine, histidine, aspartic acid, cysteine, glutathione) with hemoglobin and hydrogen peroxide or an organic peroxide (terbutylhydroperoxide) leads to the formation of the corresponding covalent binding adducts, via an oxidative activation. The formation of the covalent adduct glutathione-elliptinium was also demonstrated in human red blood cells. The importance of such process under in vivo conditions is discussed.

Ribonucleoside Diphosphate Adducts with Elliptinium Acetate, an Antitumor Agent

Abstract The oxidized form of the antitumor agent elliptinium acetate is able to arylate adenosine and uridine 5′-diphosphate by attack of the 2′-0 position of the ribose and cyclisation, leading to spiro derivatives. Ring opening occurs under reducing conditions and leads to the formation of adducts at 2′ or 3′ positions. Spiro and uncyclised adducts showed low cytotoxicity against L1210 cells in vitro.

Antibody recognition of substituted ammonium ions modulation by the counterion

Antibodies directed against elliptinium acetate, a quaternary ammonium compound with antineoplastic activity in man, were obtained in rabbits, after conjugation of the drug with haemocyanin. These antibodies are specific for the quaternary ammonium structure. However, the recognition of the drug can be markedly decreased (ten-fold) by changing the associated counterion. These observations were extended to other ellipticine derivatives that exist in two forms: acetate and chloride. In each case, the recognition of the acetate form was 7–11-fold higher than that of the chloride form. These results could be explained by high-energy strengths existing between the cation and the anion, resulting in a paired-ion antigen. This represents the first identification of antibodies directed to a paired-ion structure, with specificity for both the cation and anion used for immunization. Such results are relevant in the construction of immunoassays for quaternary ammonium compounds.

ChemInform Abstract: Ribose as the Preferential Target for the Oxidized Form of Elliptinium Acetate in Ribonucleos(t)ides. Biological Activities of the Resulting Adducts.

The covalent binding of the oxidized form of elliptinium acetate, an antitumor drug, to various ribonucleos(t)ides is described. In the absence of a strong nucleophile on the bases, e.g., a sulfhydryl group, the main target of this quinone imine derivative is the sugar moiety. With unmodified regular bases, the first electrophilic addition always occurs on the 2'-oxygen of ribose (more slowly for pyrimidine than for purine); in a second step, cyclization of the reoxidized product leads to a spiro derivative: only one stereoisomer is detected with purine nucleoside; the other stereoisomer appears as a minor product (10-20%) with nucleotides and pyrimidine nucleosides. With modified bases, no change is observed except for bases exhibiting an additional strong nucleophilic center: oxidized elliptinium alkylates thioguanine and thioguanosine on the sulfur atom and in this last case not on the ribose moiety. All spiro derivatives are less cytotoxic than the parent compound even if the base is an antimetabolite (azauridine); however, thio-elliptinium adducts maintain high cytotoxicity.

Polyclonal antibodies to elliptinium acetate: Structure — Activity relationships and comparison with human anti-elliptinium IgM

In order to elucidate the immune-mediated hemolytic disease induced in man by elliptinium acetate, a quaternary ammonium compound with antineoplastic activity, polyclonal antibodies directed against this hapten were raised in rabbits. The coupling step between drug and carrier was performed according to a putative human in vivo hapten conjugation mechanism. Structure — activity relationships of the resulting IgG were compared with the epitope site recognized by human anti-elliptinium IgM by using a panel of twelve elliptinium acetate analogues. Although both antibodies were directed principally against the quaternary ammonium ion, a poor correlation between the cross-reactivity indices was obtained. In fact, it appeared that both antibodies recognized specifically the ammonium group plus different regions of the molecule: the indole ring for human antibodies, the N-alkyl group and its vicinity for rabbit ones. The specificity of the obtained rabbit polyclonal antisera is discussed, with regard to the conjugation mechanism of the drug occuring in man.

Oxidative biotransformation of the antitumour agent elliptinium acetate: Structural characterization of its human and rat urinary metabolites

The electrophilic properties of the antitumour drug N(2)-methyl-9-hydroxyellipticinium acetate (Celiptium) are revealed by the detection of thiol-conjugate metabolites in man and rat urine. Besides the unchanged drug and its glucuronide, the cysteinyl- (in man) and the N-acetylcysteinyl- (in man and rat) conjugates have been unambiguously characterized using NMR, UV and mass spectral data. The urinary excretion profile exhibits total excreted products of 21% (in man) and 9% (in rat) with respect to the administered dose. The unchanged drug is found to be the major excreted compound from urine in both species (17% in man, 6.3% in rat); whereas the glucuronide (2.6% in man, 1.5% in rat), cysteinyl- (1.3% in man) and N-acetylcysteinyl- (0.2% in man, 1.2% in rat) conjugates represent the minor excreted compounds. The presence of the latter thio-conjugates provides an indirect proof of the in vivo generation of an oxidized intermediate form of the administered drug.

Ribose as the preferential target for the oxidized form of elliptinium acetate in ribonucleos(t)ides. Biological activities of the resulting adducts.

The covalent binding of the oxidized form of elliptinium acetate, an antitumor drug, to various ribonucleos(t)ides is described. In the absence of a strong nucleophile on the bases, e.g., a sulfhydryl group, the main target of this quinone imine derivative is the sugar moiety. With unmodified regular bases, the first electrophilic addition always occurs on the 2'-oxygen of ribose (more slowly for pyrimidine than for purine); in a second step, cyclization of the reoxidized product leads to a spiro derivative: only one stereoisomer is detected with purine nucleoside; the other stereoisomer appears as a minor product (10-20%) with nucleotides and pyrimidine nucleosides. With modified bases, no change is observed except for bases exhibiting an additional strong nucleophilic center: oxidized elliptinium alkylates thioguanine and thioguanosine on the sulfur atom and in this last case not on the ribose moiety. All spiro derivatives are less cytotoxic than the parent compound even if the base is an antimetabolite (azauridine); however, thio-elliptinium adducts maintain high cytotoxicity.

How can iron salts mediate the degradation of nucleos(t) ides by elliptinium acetate via free-radicals?

Elliptinium acetate (NSC 264137) is an antineoplastic agent currently used in anticancer chemotherapy. We report here the first evidence that this drug is able to modify DNA models via a redox process with iron salts. In presence of iron (III) salts, EDTA and H 2O 2, 9-OH-NME degrades deoxyguanosine. The two main products are guanine and 8-hydroxydeoxyguanosine which result from the formation of hydroxyl radicals. The biological implications of this phenomenon are briefly discussed.

Drug-induced antibodies during 2-N-methyl-9-hydroxyellipticinium acetate (NSC-264137) treatment: schedule dependency and relationship to hemolysis.

Drug-dependent antibodies were investigated in patients treated with elliptinium acetate, a cytostatic drug with activity in advanced breast cancer. Retrospective analysis of 83 patients, receiving weekly intravenous elliptinium, showed a high incidence of anti-elliptinium antibodies (20%). Hemolysis occurred among antibody-positive patients, apparently related to the antibody titer. The predictability of anti-elliptinium antibodies for hemolysis and the schedule dependency of antibody development was examined prospectively. Among 42 patients treated weekly for at least three courses, 40% developed antibodies. Of 30 patients receiving elliptinium daily for three days every three weeks, none developed either antibodies or hemolysis. Only antibody positive patients, with titers greater than or equal to 32 were at risk for hemolysis. The possible mechanisms are discussed.