Phosphoramide Mustard Research Articles

Cyclophosphamide, hydroxycyclophosphamide and carboxyethyl phosphoramide mustard quantification with liquid chromatography mass spectrometry in a single run human plasma samples: A rapid and sensitive method development

A novel method for simultaneous quantification of cyclophosphamide along with its two major metabolites namely 4-hydroxycyclophosphamide (HCy) and carboxyethyl phosphoramide mustard (CEPM) in a single sample run was demonstrated in the present study. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) instrument was used for analysis. Semicarbazide was used as a stabilizing agent for HCy whereas ifosfamide, hexamethyl phosphoramide mustard and deuterated CEPM were the internal standards for quantification of Cy, HCy and CEPM respectively. Chromatographic separation was achieved by Chromsystems C18 reverse-phase column (50 mm × 4.6 mm, particle size 3.2 µm). The mobile phase was composed of eluent A (2 mM ammonium acetate in water with 2% formic acid) and eluent B (100 % acetonitrile). The flow rate was 1 ml/min. Linearity of the assay was assured in the range of 19.53 ng/ml to 10,000 ng/ml concentration in human plasma, which is adequate for pharmacokinetic studies of any dose Cy used clinically. The quality control(QC) accuracy was between 99.58% and 101.62%, 97.85% to 103.53% and 99.64% to 100.10% for Cy, HCy and CEPM respectively. Precision limits for QC samples were between 3.9% and 9.4%, 5.2% to 8.9% and 1.8% to 9.2% respectively. The analytical method was validated in ten leukaemia patients undergoing haploidentical hematopoietic cell transplantation.

Protective effects of a SIRT1 inhibitor on primordial follicle activation and growth induced by cyclophosphamide: insights from a bovine in vitro folliculogenesis system

PurposeAlthough oncological advances have improved survival rates of female cancer patients, they often suffer a reduced fertility due to treatment side effects. In the present study, we evaluated the potential fertoprotective effects of the specific inhibitor of SIRT1, EX-527, on the gonadotoxic action exerted by cyclophosphamide (CPM) on loss of primordial follicles (PFs).MethodsThe effects of the CPM metabolite phosphoramide mustard (PM) on follicle activation, growth and viability and the protective action of EX-527 against PM effects were evaluated on bovine ovarian cortical strips in vitro cultured for 1 or 6 days. To understand whether PFs exposed to PM plus EX-527 were able to activate and grow to the secondary stage after suspension of the treatment, strips cultured for 3 days in PM plus EX-527 for 3 days were transferred to plain medium until day 6. Follicle growth and health were evaluated through histology and viability assay at a confocal microscope. In order to investigate the molecular pathways underlying the ovarian response to PM in the presence of EX-527, we analysed the protein level of SIRT1, HuR, PARP1 and SOD2 after 1 day of in vitro culture.ResultsWe found that (1) PM, the main CPM active metabolite, promotes PF activation; (2) the ovarian stress response induced by PM includes a SIRT1-dependent pathway; and (3) EX-527 reduces PF activation and growth induced by PM.ConclusionSIRT1 can represent a candidate molecule to be targeted to protect ovarian follicles from alkylating agents and EX-527 could represent a potential fertoprotective agent for cancer patients.

Effects of cyclophosphamide related genetic variants on clinical outcomes of adult hematopoietic cell transplant patients.

Genetic variants may influence the pharmacokinetics and pharmacodynamics (PKPD) of cyclophosphamide (CY). CY plays a critical role in conditioning chemotherapy for hematopoietic cell transplantation (HCT), but its use is limited by toxicity. We explored the effect of genetic variants, potentially affecting PKPD of CY, and outcomes after HCT. This observational pharmacogenomic study included 85 adults with hematologic malignancies who received reduced intensity conditioning with CY, fludarabine, and total body irradiation. We collected recipient DNA prior to HCT and evaluated 97 candidate variants in 66 genes and 3 metabolism phenotypes potentially involved in PKPD pathways of CY. In multivariable analysis we investigated the association between the genotypes and four clinical outcomes: Day 180 non-relapse mortality (NRM) and day 180 overall survival (OS), acute graft-versus-host-disease(aGVHD) grades 2-4, and engraftment. p values were not adjusted for multiple testing. The median recipient age was 63years (range 21-75). Acute myeloid leukemia was the most common diagnosis (34%; n = 29). In multivariable analysis adjusted for exposure to phosphoramide mustard, the final active metabolite of CY, we identified 6 variants in 6 genes associated with at least one of theclinical outcomes. An ABCC4 variant (rs9561778) was associated with poor Day 180 NRM (p < 0.01), MUTYH variant (rs3219484) with higher Day 180 NRM and aGVHD (both p < 0.01), and SYNE1 variant (rs4331993) with better Day 180 OS and engraftment (both p ≤ 0.01). The present study suggests that genetic variants influencing the PKPD of CY may help identify patients at risk for inferior outcomes after HCT using CY-based reduced-intensity conditioning.

Mechanism of Action and Efficacy of Immunosupressors in Lupus Nephritis.

Approximately 70% of the patients with systemic lupus erythematosus will have clinical evidence of kidney damage during their evolution. Patients with impaired renal function at onset and those with recurrent flares have a poor prognosis. Understanding the mechanism of action of immunosuppressants is essential for proper prescription. Steroids inhibit the DNA sequence that promotes the release of inflammatory cytokines. Phosphoramide mustard, metabolite of cyclophosphamide, cross-link with the DNA, causing the aggregation of an alkyl group, causing cell death. Mycophenolate inhibits inosine monophosphate dehydrogenase, prevents de novo synthesis of guanine, inducing cell arrest in S phase. Azathioprine blocks the synthesis of purines and induces apoptosis. Calcineurin inhibitors prevent the dephosphorylation of NFAT and reduce the production of interleukin 2. Antimalarials alter the enzymatic release of lysosomes by increasing intravesicular pH. The mechanism of action of rituximab is related to complement-dependent cytotoxicity and the elimination of anti-CD20-labeled B cells. Progress in the knowledge and management of low doses of steroids may change the current paradigm and reduce the frequency of related adverse events. Mycophenolate seems to be a better choice than cyclophosphamide for induction, it is also preferred over azathioprine as a maintenance immunosuppressive agent, although azathioprine is preferred in women with a desire for conception, those pregnant, or with low resources. For treatment-resistant cases, tacrolimus, rituximab or belimumab may be effective. Ongoing clinical trials with new drugs offer promising results.

Intracellular activation of 4-hydroxycyclophosphamide into a DNA-alkylating agent in human leucocytes

1.The conversion of the cyclophosphamide intermediate metabolite 4-hydroxycyclophosphamide (4-OHCP) to the final cytotoxic metabolite phosphoramide mustard (PAM) is classically assumed to occur via chemical hydrolysis of the phospho-ester bond. Whilst it has been suggested previously that this reaction could be enzyme-catalysed, there was only indirect evidence for this (i.e. formation of the by-product acrolein). 2. Using an assay to detect formation of DNA-alkylating adducts which block PCR amplification (QPCR-block assay), we have demonstrated that 4-OHCP can be activated by peripheral blood mononuclear cells (PBMC). The DNA-alkylating potency of 4-OHCP in PBMC increased >18-fold compared to the intrinsic reactivity of 4-OHCP for purified gDNA. 3. We also found that immortalised T-cells (Jurkat) had a similar ability to activate 4-OHCP into a DNA alkylating agent, whereas there was no appreciable activation in epithelial derived (Caco-2) cells. This suggests the possibility of tissue-specific enzyme expression. 4. Of the candidate enzymes tested only recombinant human cAMP-phosphodiesterase-PDE4B and snake-venom phosphodiesterase (PDE-I) could catalyse this activation into a DNA-alkylating agent. 5. This enzymatic catalysis of the phospho-ester bond (P-O-C) is a hitherto unrecognised feature of this important immunomodulatory drug and should be investigated further.

Higher Fludarabine and Cyclophosphamide Exposures Lead to Worse Outcomes in Reduced-Intensity Conditioning Hematopoietic Cell Transplantation for Adult Hematologic Malignancy

Reduced-intensity conditioning regimens using fludarabine (Flu) and cyclophosphamide (Cy) have been widely used in hematopoietic cell transplantation (HCT) recipients. The optimal exposure of these agents remains to be determined. We aimed to delineate the exposure-outcome associations of Flu and Cy separately and then both combined on HCT outcomes. This is a single-center, observational, pharmacokinetic (PK)-pharmacodynamic (PD) study of Flu and Cy in HCT recipients age ≥18 years who received Cy (50 mg/kg in a single dose), Flu (150 to 200 mg/m2 given as 5 daily doses), and total body irradiation (TBI; 200 cGy). We measured trough concentrations of 9-β-D-arabinosyl-2-fluoradenine (F-ara-A), an active metabolite of Flu, on days -5 and -4 (F-ara-ADay-5 and F-ara-ADay-4, respectively), and measured phosphoramide mustard (PM), the final active metabolite of Cy, and estimated the area under the curve (AUC). The 89 enrolled patients had a nonrelapse mortality (NRM) of 9% (95% confidence interval [CI], 3% to 15%) at day +100 and 15% (95% CI, 7% to 22%) at day +180, and an overall survival (OS) of 73% (95% CI, 63% to 81%) at day +180. In multivariate analysis, higher PM area under the curve (AUC) for 0 to 8 hours (PM AUC0-8 hr) was an independent predictor of worse NRM (P < .01 at both day +100 and day +180) and worse day +180 OS (P < .01), but no associations were identified for F-ara-A trough levels. We observed lower day +100 NRM in those with both high F-ara-ADay-4 trough levels (≥40 ng/mL; >25th percentile) and low PM AUC0-8 hr (<34,235 hr ng/mL; <75th percentile), compared with high exposures to both agents (hazard ratio, 0.06; 95% CI, 0.01 to 0.48). No patients with low F-ara-ADay-4 (<40 ng/mL; <25th percentile) had NRM by day +100, regardless of PM AUC. The interpatient PK variability was large in F-ara-ADay-4 trough and PM AUC0-8 hr (29-fold and 5.0-fold, respectively). Flu exposure alone was not strongly associated with NRM or OS in this reduced Flu dose regimen; however, high exposure to both Flu and Cy was associated with a >16-fold higher NRM. These results warrant further investigation to optimize reduced-intensity regimens based on better PK-PD understanding and possible adaptation to predictable factors influencing drug clearance.

Chemistry, Cyclophosphamide, Cancer Chemotherapy, and Serendipity: Sixty Years On

Cambridge Dictionary: serendipity | noun | the phenomenon of finding interesting or valuable things by chance.&#x0D; The year 2019 marked the 60th anniversary of the approval of cyclophosphamide (CP) as an anticancer by the U.S. Food &amp; Drug Administration in 1959 for the treatment of lymphoma. Between 1959 and 2019 there were ~50,000 publications listed in PubMed that have CP in the title and/or abstract, with these annual numbers showing a continual increase, and over 1,800 such articles in 2019 alone. The discovery of CP is a prime example of serendipity in science, which also applies to key elements of the metabolism and pharmacological basis for the specificity of the cytotoxicity of CP toward cancer cells. Phosphoramide mustard (PM), HO(H2N)P(O)N(CH2CH2Cl)2, the principal metabolite of CP with DNA alkylating activity, was synthesized and reported by Friedman and Seligman in 1954 prior to the discovery of CP. Interestingly, the original drug design premise for synthesizing PM, which was based on elevated phosphamidase enzyme activity in cancer cells proved to be incorrect. While this wrong premise also led to the synthesis of CP, as a six-membered ring cyclic phosphamidase-activated precursor of PM, the actual metabolic conversion of CP to PM was subsequently found to involve a surprisingly complex array of metabolites and metabolic pathways, all completely unrelated to phosphamidase. Although the molecular structure of CP has an asymmetrically substituted, i.e. chiral phosphorus center, the racemic mixture of the Rp and Sp enantiomers of CP was used throughout its initial investigations and subsequent clinical trials despite the involvement of an initial enzyme-mediated metabolic activation step, which could, in principle, be stereoselective for only one of the enantiomers of CP. Stereochemical investigations along those lines were eventually carried out, but the results did not warrant replacement of racemic CP with either enantiomer in the clinic. Amazingly, there are now ~4,000 structural congeners of PM listed Chemical Abstracts, but none have led to an anticancer drug superior to CP. This account provides a synopsis of the key chemistry and stereochemistry investigations that comprise this story of CP, as a remarkable instance of serendipity in science, and my chance involvement in the unfolding of this fascinating story.

Similar Repair Effects of Human Placenta, Bone Marrow Mesenchymal Stem Cells, and Their Exosomes for Damaged SVOG Ovarian Granulosa Cells.

Background This study is aimed at investigating the repairing effect of mesenchymal stem cells and their exosomes from different sources on ovarian granulosa cells damaged by chemotherapy drugs—phosphoramide mustard (PM). Methods In this study, we choose bone marrow mesenchymal stem cells (BMSCs) and human placental mesenchymal stem cells (HPMSCs) for research. Then, they were cocultured with human ovarian granulosa cells (SVOG) injured by phosphoramide mustard (PM), respectively. β-Galactosidase staining, flow cytometry, and Western blot were used to detect the changes in the senescence and apoptosis of SVOG cells before and after their coculture with the above two types of MSCs. Subsequently, exosomes from these two types of MSCs were extracted and added to the culture medium of SVOG cells after PM injury to test whether these two types of exosomes played a role similar to that of MSCs in repairing damaged SVOG cells. Results PM treatment-induced apoptotic SVOG cells were significantly decreased after HPMSCs and BMSCs as compared with control group. After coculturing with these two types of MSCs, PM-treated SVOG cells showed significantly reduced senescence and apoptosis proportions as well as cleaved-Caspase 3 expression, and HPMSCs played a slightly stronger role than BMSCs in repairing SVOG cells in terms of the above three indicators. In addition, the ratios of senescent and apoptotic SVOG cells were also significantly reduced by the two types of exosomes, which played a role similar to that of MSCs in repairing cell damages. Conclusions The results indicated that BMSCs, HPMSCs, and their exosomes all exerted a certain repair effect on SVOG cells damaged by PM, and consistent repair effect was observed between exosomes and MSCs. The repair effect of exosomes secreted from BMSCs and HPMSCs on the SVOG cells was studied for the first time, and the results fully demonstrated that exosomes are the key carriers for MSCs to play their role.

Association of Gene Polymorphisms in Cyclophosphamide Metabolism Pathway with Complications after Haploidentical Hematopoietic Stem Cell Transplantation

INTRODUCTION Allogeneic hematopoietic stem cell transplantation (alloHSCT) has been established as a powerful treatment modality for patients with hematological malignancies. The graft-versus-leukemia effect, however, is strongly associated with the occurrence of graft-versus-host disease (GVHD) and subsequent transplant-related mortality (TRM). Several strategies are applied in order to prevent GVHD, the post-transplant cyclophosphamide (PT-Cy) is one of the most used in Haploidentical HSCT (Haplo-HSCT). Cyclophosphamide (CY) is an alkylating agent with antineoplastic and immunosuppressive activities. CY is metabolized by highly polymorphic enzymes to produce phosphoramide mustard which is a bifunctional DNA alkylating agent, is the therapeutically active metabolite. Thus, the aim of our study is to identity polymorphisms in the genes of the CY metabolism and correlated with complications post-HSCT (GVHD, TRM, veno-occlusive disease (VOD) or hemorrhagic cystitis (HC)). METHODS We selected 182 consecutive patients who received an Haplo-HSCT from 2007 to 2019. Eleven genes related to CY metabolism were analyzed (Table 1). The genotyping was performed in peripheral blood samples for recipient using an enrichment-capture custom gene panels (IDT probes) in a MiSeq platform (Illumina, USA). The bioinformatic analysis was carried out with BaseSpace software (Illumina, USA). Variants located in coding region and splicing sites were analyzed. We selected polymorphisms corresponding to read depth ≥30X in the canonical isoform with an allele frequency ≥0.4 and represented in at least 5% in our cohort. The collected clinical variables were age/gender recipient and donor, pathology, pretransplant status, conditioning regimen, total body irradiation, basal ferritin and CMV reactivation. Fisher test was used to compare the differences among groups. Statistical Package for the Social Sciences (SPSS, Chicago, USA) was used for statistical test. RESULTS The cumulative incidence rates for aGVHD of II-IV and III-IV grades at 100 days was 39% and 12% respectively. The cumulative incidence rates for cGVHD, moderate or severe cGVHD and TRM at 1000 days were 37%, 19% and 29%, respectively. Among the cases analyzed, 9% developed VOD and 25% HC. Patients who received ablative conditioning regimen presented a higher incidence of TRM (p=0.005). No other clinical data was associated with complications post HSCT. Forty polymorphisms were detected in 9 genes by bioinformatic analysis. The variants that presents some correlation (p&amp;lt;0.05) with complications post HSCT are shown in Table 1. Overall, polymorphisms related with decrease activity of enzymes that active cyclophosphamide (level lor active metabolite) were correlated with higher aGVHD, cGVHD, TRM and VOD (Table 1). On the other hand, polymorphisms associated with low activity in detoxification enzymes were correlated with higher toxicity (TRM). As described in bibliography, GSTM1 null allele were correlated with higher probability of developing VOD. CONCLUSIONS Genetic analysis of CY metabolism genes correlated with several post HSCT complications. The analyses of this variants before transplant could facilitate personalized risk and clinical management of patients undergoing Haplo HSCT. Results must validated in others cohorts of patients. Disclosures Kwon: Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Jazz: Consultancy, Honoraria.

Uroprotective mechanisms of natural products against cyclophosphamide-induced urinary bladder toxicity: A comprehensive review.

One of the widely used anticancer drugs for the treatment of various neoplasms is cyclophosphamide (CYP). The inactive prodrug CYP is metabolized by cytochrome P450 enzyme into active metabolites, phosphoramide mustard and acrolein. The accumulation of acrolein metabolite inside the urothelium results in hemorrhagic cystitis (HC) which is a urotoxic adverse effect associated with the use of CYP. To counteract the occurrence of HC induced by CYP, Mesna is usually used, with allergic reactions reported in some cases. Therefore, several natural products have drawn much attention as alternative safe therapies to reduce the urotoxicity produced from the use of CYP. This review will focus on certain uroprotective mechanisms related to some medicinal plants that are used to ameliorate the CYP-induced urotoxicity in experimental models. The mechanisms involving oxidative stress, inflammation, immune system, apoptosis, DNA fragmentation, uroplakins, purinergic signaling and muscarinic receptors, and CytoP450 metabolism are discussed.

Oxazaphosphorines combined with immune checkpoint blockers: dose-dependent tuning between immune and cytotoxic effects

BackgroundOxazaphosphorines (cyclophosphamide (CPA), ifosfamide (IFO)) are major alkylating agents of polychemotherapy protocols but limiting their toxicity and increasing their efficacy could be of major interest. Oxazaphosphorines are prodrugs that require...

Synthesis of cyclophosphamide metabolites by a peroxygenase from Marasmius rotula for toxicological studies on human cancer cells

Cyclophosphamide (CPA) represents a widely used anti-cancer prodrug that is converted by liver cytochrome P450 (CYP) enzymes into the primary metabolite 4-hydroxycyclophosphamide (4-OH-CPA), followed by non-enzymatic generation of the bioactive metabolites phosphoramide mustard and acrolein. The use of human drug metabolites as authentic standards to evaluate their toxicity is essential for drug development. However, the chemical synthesis of 4-OH-CPA is complex and leads to only low yields and undesired side products. In past years, fungal unspecific peroxygenases (UPOs) have raised to powerful biocatalysts. They can exert the identical selective oxyfunctionalization of organic compounds and drugs as known for CYP enzymes with hydrogen peroxide being used as sole cosubstrate. Herein, we report the efficient enzymatic hydroxylation of CPA using the unspecific peroxygenase from Marasmius rotula (MroUPO) in a simple reaction design. Depending on the conditions used the primary liver metabolite 4-OH-CPA, its tautomer aldophosphamide (APA) and the overoxidized product 4-ketocyclophosphamide (4-keto-CPA) could be obtained. Using a kinetically controlled approach 4-OH-CPA was isolated with a yield of 32% (purity > 97.6%). Two human cancer cell lines (HepG2 and MCF-7) were treated with purified 4-OH-CPA produced by MroUPO (4-OH-CPAUPO). 4-OH-CPAUPO–induced cytotoxicity as measured by a luminescent cell viability assay and its genotoxicity as measured by γH2AX foci formation was not significantly different to the commercially available standard. The high yield of 4-OH-CPAUPO and its biological activity demonstrate that UPOs can be efficiently used to produce CYP-specific drug metabolites for pharmacological assessment.

Synthesis and evaluation of new 4-peptidamido-2-fluorobenzyl phosphoramide mustard conjugates as prodrugs activated by prostate-specific antigen

In our continued efforts to develop targeted prodrugs activated by prostate-specific antigen (PSA), we designed and synthesized novel phosphoramide mustard peptide conjugates using previously optimized PSA substrates. Initial Nu/Nu mouse PK studies indicated that prodrug I (glutaryl-Hyp-Ala-Ser-Chg-Gln-NH-2-F-Bn-phosphoramide mustard) exhibits high clearance with significant extrahepatic metabolism in vivo. Substrate optimization studies were thus carried out to further improve PSA specificity and enable the design of prodrugs with reduced in vivo clearance and enhanced tumor selectivity. To assess the utility of the newly optimized sequences as promoieties, they were coupled to phosphoramide mustard using a 4-amino-2-fluorobenzyl alcohol linker akin to prodrug I. In the presence of human PSA, prodrug I was rapidly cleaved with a half-life (t1/2) of 35 min. Prodrugs II (glutaryl-Ser-Ala-Ser-Chg-Gln-NH-2-F-Bn-phosphoramide mustard) and III (GABA ← mGly-Ala-Ser-Chg-Gln-NH-2-F-Bn-phosphoramide mustard) were hydrolyzed at slower rates with t1/2 values of 80 and 107 min, respectively. These results we observed here are different from our previously reported data but may be explained by the fact that PSA-activated release of phosphoramide mustard and reactive quinonimine methides resulted in mechanism-based inhibition of PSA, thereby preventing further hydrolysis of prodrugs I–III. Prodrug I was cytotoxic to PSA-producing LNCaP cells with an IC50 value of 7.3 μM and demonstrated 14-fold selectivity over the non-PSA-producing DU145. Despite its poor in vitro antiproliferative activity (IC50 = 30 µM), prodrug III was found to be more stable against non-PSA-mediated hydrolysis compared with prodrug I as revealed by metabolite profiling studies, which was in agreement with its improved stability in human hepatocyte cultures. These results suggested that a combination of the peptide sequence GABA ← mGly-Ala-Ser-Chg-Gln with optimal linkers and/or other cytotoxic agents can help achieve an adequate balance between PSA cleavage rate and enhanced resistance to non-PSA-mediated hydrolysis.

Design, synthesis and evaluation of targeted hypoxia-activated prodrugs applied to chondrosarcoma chemotherapy.

The tumor microenvironment in chondrosarcoma (CHS), a chemo- and radio-resistant cancer provides unique hallmarks for developing a chondrosarcoma targeted drug-delivery system. Tumor targeting could be achieved using a quaternary ammonium function (QA) as a ligand for aggrecan, the main high negative charged proteoglycan of the extracellular matrix of CHS, and a 2-nitroimidazole as trigger that enables hypoxia-responsive drug release. In a previous work, ICF05016 was identified as efficient proteoglycan-targeting hypoxia-activated prodrug in a human extraskeletal myxoid chondrosarcoma model in mice and a first study of the structure-activity relationship of the QA function and the alkyl linker length was conducted. Here, we report the second part of the study, namely the modification of the nitro-aromatic trigger and the position of the proteoglycan-targeting ligand at the aromatic ring as well as the nature of the alkylating mustard. Synthetic approaches have been established to functionalize the 2-nitroimidazole ring at the N-1 and C-4 positions with a terminal tertiary alkyl amine, and to perform the phosphorylation step namely through the use of an amine borane complex, leading to phosphoramide and isophosphoramide mustards and also to a phosphoramide mustard bearing four 2-chloroethyl chains. In a preliminary study using a reductive chemical activation, QA-conjugates, except the 4-nitrobenzyl one, were showed to undergo efficient cleavage with release of the corresponding mustard. However N,N,N-trimethylpropylaminium tethered to the N-1 or C-4 positions of the imidazole seemed to hamper the enzymatic reduction of the prodrugs and all tested compounds featured moderate selectivity toward hypoxic cells, likely not sufficient for application as hypoxia-activated prodrugs.

Distinct effects of epirubicin, cisplatin and cyclophosphamide on ovarian somatic cells of prepuberal ovaries.

In vitro culture models were used to characterize the effects of chemotherapeutic drugs and of LH on somatic cells from prepuberal mouse ovaries. All cell types (pre- and granulosa cells, pre-thecal and OSE cells) underwent apoptosis following Epirubicin (0.5μM) exposure for 24hrs (about 60%) and 48hrs (>80%). Cisplatin (10μM) and the Cyclophosphamide active metabolite, Phosphoramide Mustard (10μM), didn’t cause apoptosis in 90% of pre-thecal and pre-granulosa cells up to 72hrs of exposure, although they suffered extensive DNA damage and cell cycle arrest, and acquired stress induced premature senescence (SIPS) features. Cultured granulosa cells didn’t show evident DNA damage and remained viable without acquiring SIPS features; OSE cells were resistant to apoptosis and SIPS but not to DNA damage. These latter, like pre-thecal and pre-granulosa cells, were able of efficient DNA repair involving MLH1-dependent MMR pathways. SIPS features were also observed in ovary after in vivo treatment with Cisplatin. LH (200mIU/mL) didn’t significantly influence apoptosis, SIPS and DNA damage but favoured DNA repair. These results show that somatic cells of prepuberal ovary response to drugs in different ways, either undergoing apoptosis or SIPS, either showing resistance to Cisplatin and Phosphoramide Mustard. Moreover, a new role of LH in promoting DNA repair was shown.

Ataxia-telangiectasia mutated coordinates the ovarian DNA repair and atresia-initiating response to phosphoramide mustard.

Ataxia-telangiectasia-mutated (ATM) protein recognizes and repairs DNA double strand breaks through activation of cell cycle checkpoints and DNA repair proteins. Atm gene mutations increase female reproductive cancer risk. Phosphoramide mustard (PM) induces ovarian DNA damage and destroys primordial follicles, and pharmacological ATM inhibition prevents PM-induced follicular depletion. Wild-type (WT) C57BL/6 or Atm+/- mice were dosed once intraperitoneally with sesame oil (95%) or PM (25mg/kg) in the proestrus phase of the estrous cycle and ovaries harvested 3days thereafter. Atm+/- mice spent ~25% more time in diestrus phase than WT. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) on ovarian protein was performed and bioinformatically analyzed. Relative to WT, Atm+/- mice had 64 and 243 proteins increased or decreased in abundance, respectively. In WT mice, PM increased 162 and decreased 20 proteins. In Atm+/- mice, 173 and 37 proteins were increased and decreased, respectively, by PM. Exportin-2 (XPO2) was localized to granulosa cells of all follicle stages and was 7.2-fold greater in Atm+/- than WT mice. Cytoplasmic FMR1-interacting protein 1 was 6.8-fold lower in Atm+/- mice and was located in the surface epithelium with apparent translocation to the ovarian medulla post-PM exposure. PM induced γH2AX, but fewer γH2AX-positive foci were identified in Atm+/- ovaries. Similarly, cleaved caspase-3 was lower in the Atm+/- PM-treated, relative to WT mice. These findings support ATM involvement in ovarian DNA repair and suggest that ATM functions to regulate ovarian atresia.

The importance of both CYP2C19 and CYP2B6 germline variations in cyclophosphamide pharmacokinetics and clinical outcomes.

Cyclophosphamide is an alkylating agent used in the treatment of solid and haematological malignancies and as an immunosuppressive agent. As a prodrug, it is dependent on bioactivation to the active phosphoramide mustard metabolite to elicit its therapeutic effect. This focused review will highlight the evidence for the role of germline pharmacogenetic variation in both plasma pharmacokinetics and clinical outcomes. There is a substantial indication from 13 pharmacokinetic and 17 therapeutic outcome studies, in contexts as diverse as haematological malignancy, breast cancer, systemic lupus erythematosus and myeloablation, that pharmacogenetic variation in both CYP2C19 and CYP2B6 influence the bioactivation of cyclophosphamide. An additional role for pharmacogenetic variation in ALDH1A1 has also been reported. Future studies should comprehensively assess these 3 pharmacogenes and undertake appropriate statistical analysis of gene-gene interactions to confirm these findings and may allow personalised treatment regimens.

Fluorescent cyclic phosphoramide mustards and their cytotoxicity against cancer and cancer stem cells

Two fluorescent cyclic phosphoramides, 1,3-dihydronaphtho[1,8-cd][1,2,6]phosphdiazine-2-oxide-(2-bis(2-chloroethyl)amide) (1) and 2,3-dihydro-2-oxo-1H-anthra[1,2-d][1,3,2]diazaphosphole-6,11-dione-2[N,N-bis(2-chloroethyl)]amide (2) were synthesized and characterized using standard analytical techniques. The single crystal X-ray diffraction studies of 1 showed that it crystallizes in triclinic space group P1¯. The comparison of the bond distances and angles data of the single crystal structure of 1 with the theoretical value obtained from DFT calculations show that they are well commensurate with each other. 1H and 31P NMR studies reveal that 1 is more stable than 2 towards hydrolysis and formation of the active phosphoramide. 1 showed no dissociation in 48 h but 25% dissociation of 2 was observed using DMSO-phosphate buffer pH 7.4 (8:2 v/v). Compound 1 and 2 exhibit blue (λem = 375 nm) and orange fluorescence (λem = 585 nm) respectively. However, the ligand of 2 daq exhibits red fluorescence (λem = 635 nm) in its free form. 1 and 2 showed cytotoxicity to cancer cells (MCF-7, A549, HepG2 and HeLaWT) and the toxicity enhanced in vitro, in presence of the cellular reducing agent ascorbic acid. The fluorescent imaging study of 2 showed that the intact compound enters organelles like mitochondria within 1 h of treatment. The compound localizes in other organelles too and upon 10 h incubation red emissions from endoplasmic reticulum, mitochondria and lysozome suggests that the ligand daq dissociated from 2. Compound 2 depolarises the mitochondria. Both 1 and 2 are efficient in killing the slow growing cancer stem cells (CSCs), known to cause cancer relapse. 1 and 2 also exhibit excellent anti cell migratory activity at IC10 dosage even after 48 h of removal of the compounds and causes cell death by apoptosis.

3D-QSAR, molecular docking, and dynamics simulation of quinazoline–phosphoramidate mustard conjugates as EGFR inhibitor

In silico Analysis of 3D-QSAR and Molecular Docking for Bcl-2 Inhibitors to Potential Anticancer Drug DevelopmentRamachandran M, Balwin Nambikkairaj, Kumaran K, Arun Kumar De and G.Ramesh Kumar

Managing a side effect: Cyclophosphamide-induced hemorrhagic cystitis

Cyclophosphamide is a nonphase-specific cytotoxic agent that can kill cells at any phase of the cell cycle. The drug is metabolized by hepatic cytochrome P450 microsomal enzymes, which results in the formation of the active metabolites phosphoramide mustard and acrolein. It is the acrolein which is responsible for hemorrhagic cystitis as a complication of cyclophosphamide therapy. An early diagnosis and prompt management holds the key in its management.