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Cancers May 2020(1) Background: Previous findings show that lactam steroidal alkylating esters display improved therapeutic efficacy with reduced toxicity. The aim of this study was to...
(1) Background: Previous findings show that lactam steroidal alkylating esters display improved therapeutic efficacy with reduced toxicity. The aim of this study was to evaluate the anticancer activity of two newly synthesized aza-steroid alkylators (ENGA-L06E and ENGA-L08E) against human ovarian carcinoma cells, and consequently, the dual inhibition of RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways, both of which are closely associated with ovarian cancer; (2) Methods: The in vitro cytostatic and cytotoxic effects of ENGA-L06E and ENGA-L08E were evaluated in a panel of five human ovarian cancer cell lines, as well as in in vivo studies. ENGA-L06E and ENGA-L08E, in addition to another two aniline-mustard alkylators, POPAM and melphalan (L-PAM), were utilized in order to determine the acute toxicity and antitumor efficacy on two human ovarian xenograft models. Also, in silico studies were performed in order to investigate the dual inhibition of ENGA-L06E and ENGA-L08E on RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways; (3) Results: Both, in vitro and in vivo studies demonstrated that ENGA-L06E and ENGA-L08E were significantly more effective with a lower toxicity profile in comparison to POPAM and L-PAM alkylators. Moreover, in silico studies demonstrated that the two new aza-steroid alkylators could act as efficient inhibitors of the phosphorylation of AKT and ERK1/2 molecules; and (4) Conclusions: Both ENGA-L06E and ENGA-L08E demonstrated high anticancer activity through the inhibition of the PI3K-AKT and KRAS-ERK signaling pathways against human ovarian carcinoma, and thus constituting strong evidence towards further clinical development.
PubMed: 32429466
DOI: 10.3390/cancers12051263 -
British Journal of Pharmacology Oct 2012Bendamustine with or without rituximab provides an effective and more tolerable alternative to the polytherapy cyclophosphamide-doxorubicin-vincristine-prednisolone...
BACKGROUND AND PURPOSE
Bendamustine with or without rituximab provides an effective and more tolerable alternative to the polytherapy cyclophosphamide-doxorubicin-vincristine-prednisolone (CHOP) in the treatment of haematological tumours and is currently approved for the treatment of many haematological malignancies. Navitoclax (ABT-263) is a potent inhibitor of Bcl-2, Bcl-x(L) and Bcl-w, which has demonstrated efficacy in haematological tumours alone and in combination with other agents. This paper describes the in vivo efficacy of combining either bendamustine or bendamustine plus rituximab (BR) with navitoclax in xenograft models of non-Hodgkin's lymphoma
EXPERIMENTAL APPROACH
Activity was tested in xenograft models of diffuse large B-cell lymphoma (DoHH-2, SuDHL-4), mantle cell lymphoma (Granta 519) and Burkitt's lymphoma (RAMOS). Activity was also monitored in a systemic model of Granta 519.
KEY RESULTS
Navitoclax potentiated bendamustine activity in all cell lines tested. Bendamustine activated p53 in Granta 519 tumours, concurrent with activation of caspase 3. Navitoclax also improved responses to bendamustine-rituximab (BR) in a subset of tumours.
CONCLUSIONS AND IMPLICATIONS
Navitoclax in combination with bendamustine and BR is a viable combination strategy for use in the clinic and demonstrated superior efficacy compared with previously reported data for navitoclax plus CHOP and rituximab-CHOP.
Topics: Aniline Compounds; Animals; Antibodies, Monoclonal, Murine-Derived; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bendamustine Hydrochloride; Cell Line, Tumor; Humans; Lymphoma, Non-Hodgkin; Mice; Mice, SCID; Nitrogen Mustard Compounds; Proto-Oncogene Proteins c-bcl-2; Rituximab; Sulfonamides; Tumor Burden; Xenograft Model Antitumor Assays
PubMed: 22624727
DOI: 10.1111/j.1476-5381.2012.02048.x -
The Journal of Biological Chemistry Sep 2011The antitumor agent 11β (CAS 865070-37-7), consisting of a DNA-damaging aniline mustard linked to an androgen receptor (AR) ligand, is known to form covalent DNA...
The antitumor agent 11β (CAS 865070-37-7), consisting of a DNA-damaging aniline mustard linked to an androgen receptor (AR) ligand, is known to form covalent DNA adducts and to induce apoptosis potently in AR-positive prostate cancer cells in vitro; it also strongly prevents growth of LNCaP xenografts in mice. The present study describes the unexpectedly strong activity of 11β against the AR-negative HeLa cells, both in cell culture and tumor xenografts, and uncovers a new mechanism of action that likely explains this activity. Cellular fractionation experiments indicated that mitochondria are the major intracellular sink for 11β; flow cytometry studies showed that 11β exposure rapidly induced oxidative stress, mitochondria being an important source of reactive oxygen species (ROS). Additionally, 11β inhibited oxygen consumption both in intact HeLa cells and in isolated mitochondria. Specifically, 11β blocked uncoupled oxygen consumption when mitochondria were incubated with complex I substrates, but it had no effect on oxygen consumption driven by substrates acting downstream of complex I in the mitochondrial electron transport chain. Moreover, 11β enhanced ROS generation in isolated mitochondria, suggesting that complex I inhibition is responsible for ROS production. At the cellular level, the presence of antioxidants (N-acetylcysteine or vitamin E) significantly reduced the toxicity of 11β, implicating ROS production as an important contributor to cytotoxicity. Collectively, our findings establish complex I inhibition and ROS generation as a new mechanism of action for 11β, which supplements conventional DNA adduct formation to promote cancer cell death.
Topics: Acetylcysteine; Aniline Mustard; Animals; Antineoplastic Agents, Alkylating; Cell Death; DNA Adducts; Electron Transport Complex I; Female; Free Radical Scavengers; HeLa Cells; Humans; Male; Mice; Mice, Nude; Mitochondria, Liver; Oxidative Stress; Oxygen Consumption; Rats; Reactive Oxygen Species; Vitamin E; Xenograft Model Antitumor Assays
PubMed: 21832047
DOI: 10.1074/jbc.M111.278390 -
British Journal of Haematology Feb 2005Summary NSC290205 (A) is an hybrid synthetic antineoplastic ester that is a combination of a d-lactam derivative of androsterone and an alkylating derivative of...
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.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Azasteroids; Cell Death; Cyclophosphamide; Doxorubicin; Drug Evaluation, Preclinical; Drug Synergism; Humans; Leukemia, Experimental; Leukemia, Lymphoid; Male; Mice; Mice, Inbred Strains; Neoplasm Transplantation; Nitrogen Mustard Compounds; Prednisone; Survival Analysis; Tumor Cells, Cultured; Vincristine
PubMed: 15667536
DOI: 10.1111/j.1365-2141.2004.05315.x -
Journal of the American Chemical Society Jul 2004A conjugate of a DNA mismatch-specific rhodium intercalator, containing the bulky chrysenediimine ligand, and an aniline mustard has been prepared, and targeting of...
A conjugate of a DNA mismatch-specific rhodium intercalator, containing the bulky chrysenediimine ligand, and an aniline mustard has been prepared, and targeting of mismatches in DNA by this conjugate has been examined. The preferential alkylation of mismatched over fully matched DNA is found by a mobility shift assay at concentrations where untethered organic mustards show little reaction. The binding site of the Rh intercalator was determined by DNA photocleavage, and the position of covalent modification was established on the basis of the enhanced depurination associated with N-alkylation. The site-selective alkylation at mismatched DNA renders these conjugates useful tools for the covalent tagging of DNA base pair mismatches and new chemotherapeutic design.
Topics: 2,2'-Dipyridyl; Alkylating Agents; Alkylation; Base Pair Mismatch; Binding Sites; Chrysenes; DNA; Intercalating Agents; Ligands; Macromolecular Substances; Molecular Structure; Organometallic Compounds; Phenanthrolines; Rhodium; Substrate Specificity
PubMed: 15250697
DOI: 10.1021/ja048543m -
Bioorganic & Medicinal Chemistry Letters Jul 2004A series of bifunctional compounds was prepared consisting of 17beta estradiol linked to a DNA damaging N,N-bis-(2-chloroethyl)aniline. The objective of our studies was...
A series of bifunctional compounds was prepared consisting of 17beta estradiol linked to a DNA damaging N,N-bis-(2-chloroethyl)aniline. The objective of our studies was to determine the characteristics of the linker that permitted both reaction with DNA and binding of the resultant covalent adducts to the estrogen receptor. Linker characteristics were pivotal determinants underlying the ability of the compounds to kill selectively breast cancer cells that express the estrogen receptor.
Topics: Aniline Compounds; Aniline Mustard; Antineoplastic Agents, Alkylating; Binding Sites; Breast Neoplasms; Cell Survival; DNA Adducts; Dose-Response Relationship, Drug; Drug Design; Estradiol; Evaluation Studies as Topic; Female; Humans; Receptors, Estrogen; Tumor Cells, Cultured
PubMed: 15203171
DOI: 10.1016/j.bmcl.2004.04.064 -
British Journal of Cancer Mar 2004An important feature of gene-directed enzyme-prodrug therapy is that prodrug activation can provide diffusible cytotoxic metabolites capable of generating a local...
An important feature of gene-directed enzyme-prodrug therapy is that prodrug activation can provide diffusible cytotoxic metabolites capable of generating a local bystander effect in tumours. Activation of the aziridinyl dinitrobenzamide CB 1954 by E. coli nitroreductase (NTR) provides a bystander effect assumed to be due to the potently cytotoxic 4-hydroxylamine metabolite. We show that there are four cytotoxic extracellular metabolites of CB 1954 in cultures of NTR-expressing tumour cells (the 2- and 4-hydroxylamines and their corresponding amines). The 4-hydroxylamine is the most cytotoxic in DNA crosslink repair defective cells, but the 2-amino derivative (CB 10-236) is of similar potency to the 4-hydroxylamine in human tumour cell lines. Importantly, CB 10-236 has much superior diffusion properties to the 4-hydroxylamine in multicellular layers grown from the SiHa human cervical carcinoma cell line. These results suggest that the 2-amine, not the 4-hydroxylamine, is the major bystander metabolite when CB 1954 is activated by NTR in tumours. The corresponding dinitrobenzamide nitrogen mustard SN 23862 is reduced by NTR to form a single extracellular metabolite (also the 2-amine), which has superior cytotoxic potency and diffusion properties to the CB 1954 metabolites. These results are consistent with the reported high bystander efficiency of SN 23862 as an NTR prodrug in multicellular layers and tumour xenografts.
Topics: Aniline Mustard; Antineoplastic Agents; Aziridines; Bystander Effect; Chromatography, High Pressure Liquid; Escherichia coli; Genetic Therapy; Genetic Vectors; Humans; Mass Spectrometry; Neoplasms; Nitroreductases; Prodrugs; Structure-Activity Relationship; Tumor Cells, Cultured
PubMed: 14997211
DOI: 10.1038/sj.bjc.6601612 -
Journal of the American Chemical Society Mar 2002We describe a novel strategy to increase the selective toxicity of genotoxic compounds. The strategy involves the synthesis of bifunctional molecules capable of forming...
We describe a novel strategy to increase the selective toxicity of genotoxic compounds. The strategy involves the synthesis of bifunctional molecules capable of forming DNA adducts that have high affinity for specific proteins in target cells. It is proposed that the association of such proteins with damaged sites in DNA can compromise protein function and/or DNA repair resulting in increased toxicity. We describe the synthesis of a bifunctional compound consisting of an aniline mustard linked to the 7alpha position of estradiol. This novel compound can form covalent DNA adducts that have high affinity for the estrogen receptor. Breast cancer cells that express high levels of the estrogen receptor showed increased sensitivity to the cytotoxic effects of the new compound.
Topics: Aniline Mustard; Antineoplastic Agents, Alkylating; Breast Neoplasms; DNA Adducts; Drug Design; Estradiol; Humans; Kinetics; Receptors, Estrogen; Substrate Specificity; Tumor Cells, Cultured
PubMed: 11866593
DOI: 10.1021/ja017344p -
International Journal of Cancer Dec 2001Antibody-directed enzyme prodrug therapy (ADEPT) has displayed antitumor activity in animal models and clinical trials. We examined whether antitumor immunity is...
Antibody-directed enzyme prodrug therapy (ADEPT) has displayed antitumor activity in animal models and clinical trials. We examined whether antitumor immunity is generated during ADEPT by employing an immunoenzyme composed of the monoclonal antibody (MAb) RH1 conjugated to beta-glucuronidase to target rat AS-30D hepatocellular carcinoma tumors. A glucuronide prodrug of p-hydroxyaniline mustard was used to treat malignant ascites after immunoenzyme localization at the cancer cells. ADEPT cured more than 96% of Sprague-Dawley rats bearing advanced malignant ascites, and all cured rats were protected from a lethal challenge of AS-30D cells. Immunization with radiation-killed AS-30D cells or AS-30D cells coated with immunoenzyme did not provide tumor protection. Likewise, ex vivo treatment of tumor cells by ADEPT before injection into rats did not protect against a tumor challenge. AS-30D and N1-S1 hepatocellular carcinoma cells but not unrelated syngeneic tumor cells were lysed by peritoneal exudate cells isolated from ADEPT-cured rats. Depletion of CD8(+) but not CD4(+) T cells or natural killer (NK) cells reduced the cytolytic activity of peritoneal lymphocytes. ADEPT did not cure tumor-bearing rats depleted of CD4(+) and CD8(+) T cells even though it was curative when given 7 days after tumor transplantation in rats with an intact immune system, indicating that ADEPT can synergize with host immunity to increase therapeutic efficacy. These results have important implications for the clinical application of ADEPT.
Topics: Aniline Mustard; Animals; Antibodies, Monoclonal; Antineoplastic Agents; Cytosine Deaminase; Glucuronidase; Liver Neoplasms, Experimental; Nucleoside Deaminases; Prodrugs; Rats; Rats, Sprague-Dawley; T-Lymphocytes, Cytotoxic
PubMed: 11745488
DOI: 10.1002/ijc.1550 -
British Journal of Cancer Mar 1999RHI-betaG-PEG, formed by linking poly(ethylene glycol)-modified beta-glucuronidase to Mab RH1, was employed to examine bystander killing of antigen-negative N1S1 rat...
RHI-betaG-PEG, formed by linking poly(ethylene glycol)-modified beta-glucuronidase to Mab RH1, was employed to examine bystander killing of antigen-negative N1S1 rat hepatoma cells by activation of a glucuronide prodrug (BHAMG) of p-hydroxyaniline mustard (pHAM) at antigen-positive AS-30D rat hepatoma cells. Sequential treatment of cells with 10 microg ml(-1) RH1-betaG-PEG and 20 microM BHAMG was not toxic to N1S1 cells but killed 99% of AS-30D cells. Over 98% of N1S1 cells, however, were killed in mixed populations containing as few as 2% AS-30D cells after identical treatment, demonstrating an in vitro bystander effect. Subcutaneous injection of AS-30D and N1S1 cells in BALB/c nu/nu mice produced solid tumours containing both cells. Uptake of radiolabelled RH1-betaG-PEG in solid AS-30D and mixed AS-30D/N1S1 tumours was 11.6 and 9.3 times greater than a control antibody conjugate 120 h after i.v. injection. Intravenous treatment with RH1-betaG-PEG and BHAMG cured seven of seven nude mice bearing solid s.c. AS-30D tumours and significantly delayed, compared with control conjugate and prodrug treatment, the growth of mixed N1S1/AS-30D tumours with one cure, showing that targeted activation of BHAMG kills bystander tumour cells in vivo.
Topics: Aniline Mustard; Animals; Antibodies, Monoclonal; Antineoplastic Agents, Alkylating; Diffusion; Drug Screening Assays, Antitumor; Glucuronidase; Immunohistochemistry; Immunotoxins; Liver Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Nude; Polyethylene Glycols; Prodrugs; Rats; Rats, Sprague-Dawley; Time Factors; Tumor Cells, Cultured
PubMed: 10188879
DOI: 10.1038/sj.bjc.6690221