Cyclophosphamide induces caspase 9-dependent apoptosis in 9L tumor cells

Parthenolide enhances the metronomic chemotherapy effect of cyclophosphamide in lung cancer by inhibiting the NF-kB signaling pathway

BACKGROUND

Parthenolide (PTL), a sesquiterpene lactone derived from the medicinal herb Chrysanthemum parthenium, exhibits various biological effects by targeting NF-kB, STAT3, and other pathways. It has emerged as a promising adjunct therapy for multiple malignancies.

AIM

To evaluate the in vitro and in vivo effect of PTL on cyclophosphamide (CTX) metronomic chemotherapy.

METHODS

The cytotoxicity of PTL and CTX on Lewis lung cancer cells (LLC cells) was assessed by measuring cell activity and apoptosis. The anti-tumor efficiency was evaluated using a tumor xenograft mice model, and the survival of mice and tumor volume were monitored. Additionally, the collected tumor tissues were analyzed for tumor microenvironment indicators and inflammatory factors.

RESULTS

In vitro, PTL demonstrated a synergistic effect with CTX in inhibiting the growth of LLC cells and promoting apoptosis. In vivo, metronomic chemotherapy combined with PTL and CTX improved the survival rate of tumor-bearing mice and reduced tumor growth rate. Furthermore, metronomic chemotherapy combined with PTL and CTX reduced NF-κB activation and improved the tumor immune microenvironment by decreasing tumor angiogenesis, reducing Transforming growth factor β, and α-SMA positive cells.

CONCLUSION

PTL is an efficient compound that enhances the metronomic chemotherapy effects of CTX both in vitro and in vivo, suggesting its potential as a supplementary therapeutic strategy in metronomic chemotherapy to improve the chemotherapy effects.

Long-Term Survival of Cellulose Sulphate-Encapsulated Cells and Metronomic Ifosfamide Control Tumour Growth in Pancreatic Cancer Models-A Prelude to Treating Solid Tumours Effectively in Pets and Humans

BACKGROUND

The use of encapsulated cells for the in vivo delivery of biotherapeutics is a promising new technology to potentiate the effectiveness of cell-based therapies for veterinary and human application. One use of the technology is to locally activate chemotherapeutics to their short-lived highly active forms. We have previously shown that a stable clone of HEK293 cells overexpressing a cytochrome P450 enzyme that has been encapsulated in immunoprotective cellulose sulphate beads can be implanted near solid tumours in order to activate oxazaphosphorines such as ifosfamide and cyclophosphamide to the tumour-killing metabolite phosphoramide mustard. The efficacy of this approach has been shown in animal models as well as in human and canine clinical trials. In these previous studies, the oxazaphosphorine was only given twice. An analysis of the Kaplan-Meier plots of the results of the clinical trials suggest that repeated dosing might result in a significant clinical benefit.

AIMS

In this study, we aimed to (i) demonstrate the stable long-term expression of cytochrome P450 from a characterized, transfected cell clone, as well as (ii) demonstrate that one implanted dose of these encapsulated cytochrome P450-expressing cells is capable of activating multiple doses of ifosfamide in animal models.

METHODOLOGY

We initially used cell and molecular methods to show cell line stability over multiple passages, as well as chemical and biological function in vitro. This was followed by a demonstration that encapsulated HEK293 cells are capable of activating multiple doses of ifosfamide in a mouse model of pancreatic cancer without being killed by the chemotherapeutic.

CONCLUSION

A single injection of encapsulated HEK293 cells followed by multiple rounds of ifosfamide administration results in repeated anti-tumour activity and halts tumour growth but, in the absence of a functioning immune system, does not cause tumour regression.

Differential immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel in breast cancer patients

BACKGROUND

Epirubicin/cyclophosphamide (EC) and docetaxel (D) are commonly used in a sequential regimen in the neoadjuvant treatment of early, high-risk or locally advanced breast cancer (BC). Novel approaches to increase the response rate combine this treatment with immunotherapies such as PD-1 inhibition. However, the expected stimulatory effect on lymphocytes may depend on the chemotherapy backbone. Therefore, we separately compared the immunomodulatory effects of EC and D in the setting of a randomized clinical trial.

METHODS

Tumor and blood samples of 154 patients from the ABCSG-34 trial were available (76 patients received four cycles of EC followed by four cycles of D; 78 patients get the reverse treatment sequence). Tumor-infiltrating lymphocytes, circulating lymphocytes and 14 soluble immune mediators were determined at baseline and at drug change. Furthermore, six BC cell lines were treated with E, C or D and co-cultured with immune cells.

RESULTS

Initial treatment with four cycles of EC reduced circulating B and T cells by 94% and 45%, respectively. In contrast, no comparable effects on lymphocytes were observed in patients treated with initial four cycles of D. Most immune mediators decreased under EC whereas D-treatment resulted in elevated levels of CXCL10, urokinase-type plasminogen activator (uPA) and its soluble receptor (suPAR). Accordingly, only the exposure of BC cell lines to D induced similar increases as compared to E. While treatment of BC cells with E was associated with cell shrinkage and apoptosis, D induced cell swelling and accumulation of cells in G2 phase.

CONCLUSION

The deleterious effect of EC on lymphocytes indicates strong immunosuppressive properties of this combination therapy. D, in contrast, has no effect on lymphocytes, but triggers the secretion of stimulatory proteins in vivo and in vitro, indicating a supportive effect on the immune system. Underlying differences in the induced cell death might be causal. These divergent immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel should be considered when planning future combinations with immunotherapies in breast cancer.

Partial Reversal of Anosmia Following Platinum-Based Chemotherapy in a Patient With Colorectal Adenocarcinoma

Platinum-based chemotherapy is known to cause taste and smell changes (TSCs) via a host of mechanisms, including altered receptor activity, saliva/mucus production, and induction of receptor destruction via mitotic inhibition. In the literature to date, these changes have primarily resulted in worsening of taste and smell. In this case report, we document the first instance of an individual regaining their sense of olfactory detection following treatment with oxaliplatin for colorectal adenocarcinoma. We theorize that the improvement in his sense of smell may have resulted from oxaliplatin-induced destruction of his nasal polyps through the caspase-9/procaspase-9 apoptotic pathway, a pathway shared with other mechanisms of nasal polyp destruction. These findings were supported by nasal endoscopy and sphenoid sinusoscopy, which demonstrated no clinical persistence of nasal polyps, in contrast to nasal endoscopy prior to chemotherapy which demonstrated persistent nasal polyposis. Objective smell testing post-treatment revealed a diminished ability to discriminate odors. Chemotherapy-induced TSCs play a key role in poor weight gain, food aversion, emotional distress, and an overall decrease in quality of life, and patients should be informed of these potential consequences prior to starting treatment. However, in patients with anosmia secondary to nasal polyposis, treatment with platinum-based chemotherapy may provide an additional therapeutic benefit. Further studies may help elucidate the potential therapeutic benefits of these agents in managing steroid-resistant polyposis for patients suffering from olfactory dysfunction.

Inhibition of extranodal NK/T-cell lymphoma by Chiauranib through an AIF-dependent pathway and its synergy with L-asparaginase

Extranodal NK/T-cell lymphoma (NKTL) is a rare and aggressive form of extranodal lymphoma with a poor prognosis. Currently, there are very limited treatment options for patients with advanced-stage disease or those with relapsed/recurrent disease. Here we show that Chiauranib, an orally small molecule inhibitor of select serine-threonine kinases (aurora B, VEGFRs, PDGFR, CSF1R, c-Kit), inhibited NKTL cell proliferation, induced cell cycle arrest, as well as suppressed the microvessel density in vitro and in vivo similar as in other types of cancer cells. Surprisingly, Chiauranib unfolded a new effect to induce apoptosis of NKTL cells by triggering AIF-dependent apoptosis other than the traditional cyt-c/caspase mitochondrial apoptosis pathway. The knockdown of AIF in vitro and in vivo dramatically blocked the efficacy of Chiauranib on NKTL. Mechanistically, the release of AIF from mitochondria is due to the upregulation of VDAC1 by the AKT-GSK3β pathway and activation of calcium-dependent m-calpain, which promotes the cleavage of VDAC1 and therefore permits the release of AIF. Notably, the low expression of Bax in both NKTL cells and patient tissues restrained the cyt-c release. It resulted in the inhibition of cyt-c/caspase mitochondrial pathway, suggesting that drugs targeting this traditional pathway may not be effective in NKTL. Furthermore, we found that L-asparaginase triggered CD95 (Fas/Apo-1)-caspase 8-caspase 3 apoptotic pathway in NKTL cells, and combination of Chiauranib and L-asparaginase exhibited a synergistic effect, suggesting a feasibility to combine these two drugs for effective treatment of NKTL. This study demonstrates Chiauranib's positive efficacy toward NKTL through the activation of the AIF-dependent apoptosis pathway for the first time. The novel and multi-targets of Chiauranib and the synergistic effect with L-asparaginase may provide a promising therapy for NKTL patients.

Cyclophosphamide depletes tumor infiltrating T regulatory cells and combined with anti-PD-1 therapy improves survival in murine neuroblastoma

The outcome for children with high-risk neuroblastoma is poor despite intensive multi-modal treatment protocols. Toxicity from current treatments is significant, and novel approaches are needed to improve outcome. Cyclophosphamide (CPM) is a key component of current chemotherapy regimens and is known to have immunomodulatory effects. However, this has not been investigated in the context of tumor infiltrating lymphocytes in neuroblastoma. Using murine models of neuroblastoma, the immunomodulatory effects of low-dose CPM were investigated using detailed immunophenotyping. We demonstrated that CPM resulted in a specific depletion of intratumoral T regulatory cells by apoptosis, and when combined with anti-PD-1 antibody therapy, this resulted in improved therapeutic efficacy. CPM combined with anti-PD-1 therapy was demonstrated to be an effective combinational therapy, with metronomic CPM found to be more effective than single dosing in more resistant tumor models. Overall, this pre-clinical data strongly support clinical evaluation of such combination strategies in neuroblastoma.

The Nitrogen Mustards

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve.

Cyclophosphamide-induced GPX4 degradation triggers parthanatos by activating AIFM1

Cyclophosphamide is an alkylating agent used to treat a variety of cancers, including leukemia. Here, we show a previously unrecognized role of cyclophosphamide in triggering the protein degradation of glutathione peroxidase 4 (GPX4), a phospholipid hydroperoxidase that protects cells from oxidative damage. Mechanistically, we found that the ubiquitin-proteasome system, but not autophagy, mediates cyclophosphamide-induced degradation of GPX4 in human leukemia cell lines. Surprisingly, cyclophosphamide-induced degradation of GPX4 leads to caspase-independent parthanatos, but not lipid peroxidation-mediated ferroptosis, through the nuclear translocation of apoptosis-inducing factor mitochondria-associated 1 (AIFM1). Consequently, the overexpression of GPX4 or the knockdown of AIFM1 limits the anticancer activity of cyclophosphamide in vitro and in xenograft tumor models. These findings establish a new framework for understanding the central role of GPX4 in blocking oxidative cell death.

Curcumin nanocrystals attenuate cyclophosphamide-induced testicular toxicity in mice

The cancer therapy using cyclophosphamide (CP) has been associated with adverse effects on the testicular function that raises concerns about the future fertility potential among cancer survivors. Curcumin, a polyphenol, has shown to possess a plethora of biological functions including tissue protective effects. In the present study, we investigated the protective effects of curcumin nanocrystals (NC) in mitigation of CP-induced testicular toxicity. Healthy adult (8-10 week) and prepubertal (2 week) male Swiss albino mice were injected with a single dose of CP (200 mg/kg) intraperitoneally (i.p). NC (4 mg/kg, i.p.) was administered every alternate day, for 35 days in adult mice while, a single dose of NC was injected intraperitoneally to prepubertal mice 1 h prior to CP. Administration of multiple doses of NC ameliorated CP-induced testicular toxicity in adult mice, which was evident from the improved sperm functional competence, sperm chromatin condensation, seminiferous tubule architecture and decreased apoptosis in testicular cells. Further, administration of NC 1 h prior to CP in prepubertal mice modulated the expression of genes pertaining to proliferation, pluripotency, DNA damage and DNA repair in spermatogonial cells at 24 h after the treatment. Overall, these results suggest that NC could be a promising chemoprotective agent, which can have potential application in male fertility preservation.

Effects of Green cardamom (Elettaria cardamomum Maton) and its combination with cyclophosphamide on Ehrlich solid tumors

Background

Cardamom (Elettaria cardamomum) is a spice and exhibits potent antioxidant and biological activities through distinct molecular mechanisms. However, the anticancer effect of cardamom was not explored yet in Ehrlich solid tumor (EST)-bearing mice.

Objectives

This investigation was aimed to evaluate the anti-cancer effects of green cardamom (GCar) alone or combined with the anti-cancer drug cyclophosphamide in an in vivo model to explore its mechanistic role in tumor cell death in EST-bearing mice.

Methods

Ehrlich ascites tumor cells were injected in the mice and 5 days later the animals treated with GCar and/or cyclophosphamide for 10 days. Twenty-four hours from the last treatment, animals were sacrificed for the different measurements.

Results

Data recorded for tumor size, percentage of tumor growth inhibition, tumor growth delay and mean survival time of EST-bearing mice demonstrated the effective role of GCar alone or combined with CPO as a promising anti-cancer agent because it reduced tumor size. GCar elevated the mean survival time of EST-bearing mice compared to that of untreated EST and EST + CPO groups. Analysis of qPCR mRNA gene and protein expression revealed that GCar alone or combined with CPO were promising anticancer agents. After the treatment of EST with GCar, the apoptotic-related genes and proteins were significantly modulated. GCar induced markedly significant decreases in oxidative stress biomarkers and a significant increment in glutathione levels and that of antioxidant enzymes. With a marked diminish in liver and kidney function biomarkers.

Conclusion

The results revealed that GCar could serve as an apoptotic stimulator agent, presenting a novel and potentially curative approach for cancer treatment, inducing fewer side effects than those of the commercially used anti-cancer drugs, such as CPO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03305-2.

Probing cytochrome P450 (CYP) bioactivation with chloromethylindoline bioprecursors derived from the duocarmycin family of compounds

The duocarmycins belong to a class of agent which has great potential for use in cancer therapy. Their exquisite potency means they are too toxic for systemic use, and targeted approaches are required to unlock their clinical potential. In this study, we have explored seco-OH-chloromethylindoline (CI) duocarmycin-based bioprecursors for their potential for cytochrome P450 (CYP)-mediated cancer cell kill. We report on synthetic and biological explorations of racemic seco-CI-MI, where MI is a 5-methoxy indole motif, and dehydroxylated analogues. We show up to a 10-fold bioactivation of de-OH CI-MI and a fluoro bioprecursor analogue in CYP1A1-transfected cells. Using CYP bactosomes, we also demonstrate that CYP1A2 but not CYP1B1 or CYP3A4 has propensity for potentiating these compounds, indicating preference for CYP1A bioactivation.

Investigation into the protective effects of Hypericum Triquetrifolium Turra seed against cyclophosphamide-induced testicular injury in Sprague Dawley rats

For centuries, Turkey has been a significant location here around 80 species of Hypericum with differing names widely occur, which is also known as Turkish folk medicine in treating some bacterial diseases as well as stomach and intestine inflammation. Recent studies have reported this herb family to contain numbers of bioactive compound contents. The study aims to investigate the protective effects of Hypericum triquetrifolium Turra (HT) upon oxidative stress and apoptosis in a rat model in which testes injury was induced by CP. The testicular injury was caused using CP (150 mg/kg). The rats were treated with a single dose (100 mg/kg) of methanol extract of HT to investigate various biochemical markers in the serum and plasma of blood samples apart from assessing the prognosis of CP-induced testicular damage. Added to that, histological analyses were performed to identify possible structural changes and apoptotic indicators, like Bax, Caspase-3, and Bcl-2. In CP Group, there was a rise in the levels of total oxidant status (TOS), malondialdehyde (MDA), oxidative stress index (OSI), Caspase-3, and Bax while superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), Bcl-2, and total antioxidant capacity (TAC) all decreased. Also, our histological analysis showed damaged testes. On the other hand, neither biochemical nor histological analysis showed testicular damage in HT Alone Group. In CP + HT Group, a significant number of the negatives changes due to CP were observed to have improved remarkably following an HT treatment. This study results suggest that HT could help improve CP-induced testicular injury thanks to its anti-oxidative and anti-apoptotic properties.

The Mechanism of Action of Cyclophosphamide and Its Consequences for the Development of a New Generation of Oxazaphosphorine Cytostatics

Although cyclophosphamide (CP) has been used successfully in the clinic for over 50 years, it has so far not been possible to elucidate the mechanism of action and to use it for improvement. This was not possible because the basis of the mechanism of action of CP, which was found by lucky coincidence, is apoptosis, the discovery of which was honored with the Nobel Prize only in 2002. Another reason was that results from cell culture experiments were used to elucidate the mechanism of action, ignoring the fact that in vivo metabolism differs from in vitro conditions. In vitro, toxic acrolein is formed during the formation of the cytotoxic metabolite phosphoreamidemustard (PAM), whereas in vivo proapoptotic hydroxypropanal (HPA) is formed. The CP metabolites formed in sequence 4-hydroxycyclophosphamide (OHCP) are the main cause of toxicity, aldophosphamide (ALDO) is the pharmacologically active metabolite and HPA amplifies the cytotoxic apoptosis initiated by DNA alkylation by PAM. It is shown that toxicity is drastically reduced but anti-tumor activity strongly increased by the formation of ALDO bypassing OHCP. Furthermore, it is shown that the anti-tumor activity against advanced solid P388 tumors that grow on CD2F1 mice is increased by orders of magnitude if DNA damage caused by a modified PAM is poorly repairable.

Aldophosphamide-thiazolidine (NSC-613060) an oxazaphosphorine cytostatic that crosses the blood brain barrier

The pharmacologically active metabolite of cyclophosphamide is aldophosphamide. With cysteine, aldophosphamide forms stable aldophosphamide-thiazolidine which under physiological pH and temperature conditions hydrolyzes to aldophosphamide and cysteine. Aldophosphamide-thiazolidine was synthesized and tested for its ability as a cytostatic. The LD50 after a single intraperitoneal injection in mice was determined to be 2162 mg/kg, but after intravenous bolus administration of 500 mg/kg or in chronic toxicity tests with daily intraperitoneal injections, neurological side effects were observed. Antitumor activity was determined in therapy experiments in CD2F1 mice bearing subcutaneously transplanted P388 mouse leukemia cells. Administration of 100 mg/kg (less than 5% LD50) days 1-5 after tumor transplantation yielded an ILS of 100%. Organ distribution studies showed that aldophosphamide-thiazolidine is evenly distributed in all tissues examined, including brain tissue. The possibilities to increase the antitumor activity of aldophosphamide-thiazolidine by modulating the alkylating function are discussed.

Gut microbiota: a new player in regulating immune- and chemo-therapy efficacy

Development of drug resistance represents the major cause of cancer therapy failure, determines disease progression and results in poor prognosis for cancer patients. Different mechanisms are responsible for drug resistance. Intrinsic genetic modifications of cancer cells induce the alteration of expression of gene controlling specific pathways that regulate drug resistance: drug transport and metabolism; alteration of drug targets; DNA damage repair; and deregulation of apoptosis, autophagy, and pro-survival signaling. On the other hand, a complex signaling network among the entire cell component characterizes tumor microenvironment and regulates the pathways involved in the development of drug resistance. Gut microbiota represents a new player in the regulation of a patient's response to cancer therapies, including chemotherapy and immunotherapy. In particular, commensal bacteria can regulate the efficacy of immune checkpoint inhibitor therapy by modulating the activation of immune responses to cancer. Commensal bacteria can also regulate the efficacy of chemotherapeutic drugs, such as oxaliplatin, gemcitabine, and cyclophosphamide. Recently, it has been shown that such bacteria can produce extracellular vesicles (EVs) that can mediate intercellular communication with human host cells. Indeed, bacterial EVs carry RNA molecules with gene expression regulatory ability that can be delivered to recipient cells of the host and potentially regulate the expression of genes involved in controlling the resistance to cancer therapy. On the other hand, host cells can also deliver human EVs to commensal bacteria and similarly, regulate gene expression. EV-mediated intercellular communication between commensal bacteria and host cells may thus represent a novel research area into potential mechanisms regulating the efficacy of cancer therapy.

The effects of magnesium sulfate on cyclophosphamide-induced ovarian damage: Folliculogenesis

Cyclophosphamide (CYP) is one of the alkylating chemotherapeutic agents and its adverse effects on folliculogenesis in the ovary are well-known due to the previous scientific research on this topic. Magnesium has various effects in organisms, including catalytic functions on the activation and inhibition of many enzymes, and regulatory functions on cell proliferation, cell cycle, and differentiation. In this study, the effects of magnesium sulfate (MgSO₄) on CYP induced ovarian damage were investigated. Immature Wistar-Albino female rats of 28-days were treated with pregnant mare serum gonadotrophin (PMSG) to develop the first generation of preovulatory follicles. Rats of the experimental groups were then treated with either CYP (100 mg/kg, i.p) and MgSO₄ (270 mg/kg loading dose; 27 mg/kg maintenance doseX12, i.p) solely or in combination. Following in-vivo 5-bromo-2-deoxyuridine (BrdU) labeling, animals were sacrificed and ovaries were embedded in paraffin and Epon. In the ovaries, added to the evaluation of general morphology and follicle count; BrdU and TUNEL-labeling, cleaved caspase-3 and p27 (cyclin-dependent kinase inhibitor) staining was also performed immunohistochemically and an ultrastructural evaluation was performed by transmission electron microscopy (TEM). The number of primordial follicles were decreased and multilaminar primary and atretic follicles were increased in CYP group. After MgSO₄ treatment, while primordial follicle pool were elevated, the number of atretic follicles were decreased. Additionally, decreased BrdU-labeling, increased cleaved caspase 3 immunoreactivity and increased TUNEL labeling were observed in CYP group. In CYP treated animals, observations showed that while MgSO₄ administration caused no alterations in BrdU proliferation index and caspase-3 immunoreactivity, it significantly reduced the TUNEL labeling. It was also observed that, while p27 immunoreactivity significantly increased in the nuclei of granulosa and theca cells in the CYP group; MgSO₄ treatment significantly reduced these immunoreactivities. The ultrastructural observations showed frequent apoptotic profiles in granulosa and theca cells in both early and advanced stages of follicles in the CYP group and the MgSO₄ treatment before the CYP application led to ultrastructural alleviation of the apoptotic process. In conclusion, our data suggest that MgSO₄ may provide an option of pharmacologic treatment for fertility preservation owing to the beneficial effects of on chemotherapy-induced accelerated follicular apoptotic process, and the protection of the primordial follicle pool.

Oxazaphosphorine cytostatics: from serendipity to rational drug design

On the basis of the discovery that the proapoptotic aldehyde 3-hydroxypropanal is a cyclophosphamide metabolite, a novel mechanism of action of oxazaphosphorine cytostatics is presented and confirmed by animal experiments. Furthermore, it is shown that new oxazaphosphorine cytostatics, which are on orders of magnitude more effective than already existing, can be developed on the basis of the new model for the mechanism of action.

Shuanghuang Shengbai granule cures myelosuppression and suppresses lung cancer progression: mechanism and therapeutic targets from the aspect of microRNAs

BACKGROUND

Shuanghuang Shengbai granule is effective in curing cyclophosphamide-induced myelosuppression without promoting lung cancer development. This study aims to investigate its mechanism and therapeutic targets.

METHODS

Nude mice with lung cancer were treated with physiological saline (control), cyclophosphamide, or cyclophosphamide + Shuanghuang Shengbai. MicroRNA microarray was used to investigate the differentially expressed microRNAs in lung cancer stem cells or bone marrow hematopoietic stem cells between the three groups. MicroRNA expressions were confirmed using quantitative real time-polymerase chain reaction.

RESULTS

Cyclophosphamide suppressed tumor growth and decreased the ratio of SP⁺ lung cancer stem cells (P<0.05). Shuanghuang Shengbai further decreased the ratios of SP⁺ and CD24⁺IGF1R⁺ lung cancer stem cells (P<0.05). Shuanghuang Shengbai completely reversed the cyclophosphamide-induced decreases in white blood cells, proliferation index of bone marrow cells, and the ratio of CD34⁺SCA1⁺ bone marrow hematopoietic stem cells (P<0.05). We found 45 and 343 altered microRNAs for SP⁺ lung cancer stem cells and CD34⁺SCA1⁺ bone marrow hematopoietic stem cells, respectively. Moreover, miR-32*, miR-466i-5p, and mmu-miR-669c in SP⁺ lung cancer stem cells were confirmed, as well as mmu-miR-106b*, mmu-miR-144, mmu-miR-669k*, mmu-miR-142-3p, mmu-miR-210, and mmu-miR-223 in CD34⁺SCA1⁺ bone marrow hematopoietic stem cells.

CONCLUSION

Shuanghuang Shengbai might promote the proliferation of CD34⁺SCA1⁺ bone marrow hematopoietic stem cells via up-regulating mmu-miR-106b*, mmu-miR-144, and mmu-miR-669k*, as well as down-regulating mmu-miR-142-3p, mmu-miR-210, and mmu-miR-223. Shuanghuang Shengbai might further inhibit the proliferation of SP⁺ lung cancer stem cells via enhancing the expressions of miR-32*, miR-466i-5p, and mmu-miR-669c. These might be the mechanism and therapeutic targets of Shuanghuang Shengbai granule.

Enzyme Catalyzed Decomposition of 4-Hydroxycyclophosphamide

According to general doctrine [1] canceroselectivity of Cyclophosphamide is based on different activities of the 4-hydroxycyclophosphamide (OHCP) detoxifying cellular enzyme aldehyde dehydrogenase in tumor and normal cells. Aldehyde dehydrogenase converts the OHCP tautomere aldophosphamide (ALDO) to the non-cytotoxic carboxyphosphamide. Due to different activities of the detoxifying enzyme more cytotoxic phosporamide mustard (PAM) is spontaneously released from OHCP/ALDO in tumor cells. PAM unfolds its cytotoxic activity by forming intrastrand and interstrand DNA crosslinks. This hypothesis is supported by in vitro experiments which show inverse correlations of aldehyde dehydrogenase activity and sensitivity of tumor cells against activated congeners of cyclophosphamide like mafosfamide which hydrolyses within a few minutes to OHCP. In protein free rat serum ultrafiltrate however free OHCP and its coexisting tautomer ALDO are stable compounds. Its half-life in protein free rat serum ultrafiltrate (pH7, 37oC) is more than 20 h. Contrary to protein free ultrafiltrate in whole serum ALDO is enzymatically decomposed to PAM and 3-hydroxypropionaldehyde (HPA) within minutes. The decomposing enzyme was identified as 3´-5´ phosphodiesterase, the Michaelis constant was determined to be 10-3M in human serum.

The experiments presented clearly demonstrate that ALDO is not only cleaved base catalyzed yielding acrolein and PAM [2, 3] but also cleaved enzymatically by serum phosphodiesterases yielding HPA and PAM. It is discussed that the reason of the high canceroselectivity of cyclophosphamide is not only due to enrichment of OHCP/ALDO in tumor cells due to less detoxification of ALDO in tumor cells than in normal cells. It is discussed that there is a good reason for an additional mechanism namely the amplification of apoptosis of PAM damaged cells by HPA.

A two step mechanism for the mechanism of action of OHCP/ALDO is discussed. During the first step, the DNA is damaged by alkylation by PAM. During the second step the cell containing damaged DNA is eliminated by apoptosis, supported by HPA.

Hepatoprotective activity of white horehound (Marrubium vulgare) extract against cyclophosphamide toxicity in male rats

The hepatoprotective activity of Marrubium vulgare against cyclophosphamide toxicity in Wistar rats was evaluated. Adult male rats were divided into 4 groups of 6 each: a control group, a group injected with cyclophosphamide (150 mg·kg−1) for 3 days, a group orally given a M. vulgare aqueous extract ((500 mg of dry leaves)·kg−1·day−1) for 30 days then treated with cyclophosphamide, and a group receiving only M. vulgare for 30 days. After 33 days of treatment, activities of alanine amino transferase (ALAT), aspartate amino transferase (ASAT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) were determined in serum. Moreover, lipid peroxidation level and superoxide dismutase (SOD) activities, catalase (CAT) and glutathione peroxidase (GPx) were measured in liver. Alterations of these hepatic biomarkers and increased lipid peroxidation confirmed cyclophosphamide-induced liver toxicity. Cyclophosphamide also decreased the enzymatic defense system against oxidative stress. However, when this drug was administered in rats given M. vulgare extract, all the biological parameters underwent much less alteration. Administration of M. vulgare extract was found to be beneficial by attenuating cyclophosphamide-induced liver damage. The protective effect of the plant is mainly attributed to its antioxidant properties and the existence of phenolic acids and flavonoids, as highlighted by HPLC-based analysis.

Activation of the Constitutive Androstane Receptor Increases the Therapeutic Index of CHOP in Lymphoma Treatment

The constitutive androstane receptor (CAR and NR1i3) is a key regulator of CYP2B6, the enzyme predominantly responsible for the biotransformation of cyclophosphamide (CPA) to its pharmacologically active metabolite, 4-hydroxycyclophosphamide (4-OH-CPA). Previous studies from our laboratory illustrated that CAR activation increases the formation of 4-OH-CPA; however, CPA is rarely used clinically outside of combination therapies. Here, we hypothesize that including a selective human CAR activator with the CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen can improve the efficacy without exacerbating off-target toxicity of this regimen in non-Hodgkin lymphoma treatment. In this study, we have developed a novel multiorgan coculture system containing human primary hepatocytes for hepatic metabolism, lymphoma cells as a model target for CHOP, and cardiomyocytes as a major site of off-target toxicity associated with this regimen. We found that a selective human CAR activator, CITCO (6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde-O-(3,4-dichlorobenzyl)oxime), altered expression of key drug-metabolizing enzymes and transporters in human hepatocytes, which positively affects the metabolic profile of CHOP. Coadministration of CITCO and CHOP in the coculture model led to significantly enhanced cytotoxicity in lymphoma cells but not in cardiomyocytes. Moreover, the beneficial effects of CITCO were abrogated when CAR knockout HepaRG cells were used in the coculture model. Importantly, synergistic anticancer effects were observed between CITCO and CHOP, in that inclusion of CITCO alongside the CHOP regimen offers comparable antineoplastic activity toward lymphoma cells at significantly reduced drug concentrations, and the decreased CHOP load attenuates cardiotoxicity. Overall, these findings provide a potentially promising novel strategy for facilitating CHOP-based chemotherapy.

A novel cytosporone 3-Heptyl-4,6-dihydroxy-3H-isobenzofuran-1-one: synthesis; toxicological, apoptotic and immunomodulatory properties; and potentiation of mutagenic damage

BACKGROUND

A large number of studies are attempting to identify alternative products from natural sources or synthesized compounds that effectively interact with cancer cells without causing adverse effects on healthy cells. Resorcinolic lipids are a class of bioactive compounds that possess anticancer activity and are able to interact with the lipid bilayer. Therefore, the objective of this study was to synthesize a novel resorcinolic lipid and test its biological proprieties.

METHODS

We aimed to synthesize a novel resorcinolic lipid belonging to the class of cytosporones, AMS049 (3-Heptyl-4,6-dihydroxy-3H-isobenzofuran-1-one) and to evaluate the toxicity of two concentrations of this lipid (7.5 and 10 mg/kg) by determining its genotoxic, mutagenic, immunomodulatory, and apoptotic effects, as well as any biochemical and histopathological alterations in mice treated with cyclophosphamide. The results were analyzed by ANOVA followed by the Tukey test A . level of significance of p < 0.05 was adopted.

RESULTS

The new cytosporone AMS049 was synthesized in only three steps and in satisfactory yields. The results indicate that the compound is neither genotoxic nor mutagenic and does not alter biochemical parameters. The histological alterations observed in the liver and kidneys did not compromise the function of these organs. Histology of the spleen suggested immunomodulation, although no changes were observed in splenic phagocytosis or differential blood cell count. The results also show that AMS049 potentiates the mutagenic effect of the chemotherapy drug cyclophosphamide and that the combination induces apoptosis.

CONCLUSION

These facts indicate a potential therapeutic application of this novel cytosporone as an important chemotherapeutic adjuvant.

Transcriptional profiling provides insights into metronomic cyclophosphamide-activated, innate immune-dependent regression of brain tumor xenografts

Background

Cyclophosphamide treatment on a six-day repeating metronomic schedule induces a dramatic, innate immune cell-dependent regression of implanted gliomas. However, little is known about the underlying mechanisms whereby metronomic cyclophosphamide induces innate immune cell mobilization and recruitment, or about the role of DNA damage and cell stress response pathways in eliciting the immune responses linked to tumor regression.

Methods

Untreated and metronomic cyclophosphamide-treated human U251 glioblastoma xenografts were analyzed on human microarrays at two treatment time points to identify responsive tumor cell-specific factors and their upstream regulators. Mouse microarray analysis across two glioma models (human U251, rat 9L) was used to identify host factors and gene networks that contribute to the observed immune and tumor regression responses.

Results

Metronomic cyclophosphamide increased expression of tumor cell-derived DNA damage, cell stress, and cell death genes, which may facilitate innate immune activation. Increased expression of many host (mouse) immune networks was also seen in both tumor models, including complement components, toll-like receptors, interferons, and cytolysis pathways. Key upstream regulators activated by metronomic cyclophosphamide include members of the interferon, toll-like receptor, inflammatory response, and PPAR signaling pathways, whose activation may contribute to anti-tumor immunity. Many upstream regulators inhibited by metronomic cyclophosphamide, including hypoxia-inducible factors and MAP kinases, have glioma-promoting activity; their inhibition may contribute to the therapeutic effectiveness of the six-day repeating metronomic cyclophosphamide schedule.

Conclusions

Large numbers of responsive cytokines, chemokines and immune regulatory genes linked to innate immune cell recruitment and tumor regression were identified, as were several immunosuppressive factors that may contribute to the observed escape of some tumors from metronomic CPA-induced, immune-based regression. These factors may include useful biomarkers that facilitate discovery of clinically effective immunogenic metronomic drugs and treatment schedules, and the selection of patients most likely to be responsive to immunogenic drug scheduling.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1358-y) contains supplementary material, which is available to authorized users.

Gene-directed enzyme prodrug therapy

As one targeting strategy of prodrug delivery, gene-directed enzyme prodrug therapy (GDEPT) promises to realize the targeting through its three key features in cancer therapy-cell-specific gene delivery and expression, controlled conversion of prodrugs to drugs in target cells, and expanded toxicity to the target cells' neighbors through bystander effects. After over 20 years of development, multiple GDEPT systems have advanced into clinical trials. However, no GDEPT product is currently marketed as a drug, suggesting that there are still barriers to overcome before GDEPT becomes a standard therapy. In this review, we first provide a general introduction of this prodrug targeting strategy. Then, we utilize the four most thoroughly studied systems to illustrate components, mechanisms, preclinical and clinical results, and further development directions of GDEPT. These four systems are herpes simplex virus thymidine kinase/ganciclovir, cytosine deaminase/5-fluorocytosine, cytochrome P450/oxazaphosphorines, and nitroreductase/CB1954 system. Later, we focus our discussion on bystander effects including local and distant bystander effects. Lastly, we discuss carriers that are used to deliver genes for GDEPT including virus carriers and non-virus carriers. Among these carriers, the stem cell-based gene delivery system represents one of the newest carriers under development, and may brought about a breakthrough to the gene delivery issue of GDEPT.

Protective effect of Satureja montana extract on cyclophosphamide-induced testicular injury in rats

The present study investigated the protective effect of Satureja montana extract against cyclophosphamide-induced testicular injury in rats. Total phenolic and flavonoid contents of the extract were 1.03% and 0.34%w/w of dry herb expressed as chlorogenic acid and quercetin, respectively. HPLC analysis identified caffeic, syringic and rosmarinic acids as the chief phenolic acids, and rutin as the major flavonoid in the extract. Oral daily administration of S.montana extract (50mg/kg/day) for 7days before and 7days after an intraperitoneal injection of cyclophosphamide (200mg/kg) restored the reduced relative testicular weight, serum testosterone level and testicular alkaline phosphatase activity, raised the lowered testicular sorbitol dehydrogenase and acid phosphatase activities, and decreased the elevated testicular hemoglobin absorbance. It also attenuated lipid peroxidation, restored the lowered glutathione content, glucose-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase activities, and improved total antioxidant capacity. Moreover, S.montana extract mitigated testicular DNA fragmentation, decreased the elevated Fas and Bax gene expression, up-regulated the decreased Bcl-2 and peroxisome proliferator-activated receptor-gamma (PPAR-γ) gene expression and normalized Akt1 protein level. Histopathological investigation confirmed the protective effects of the extract. Conclusively, S.montana extract protects the rat testis against cyclophosphamide-induced damage via anti-oxidative and anti-apoptotic mechanisms that seem to be mediated, at least in part, by PPAR-γ and Akt1 up-regulation.

Intermittent metronomic drug schedule is essential for activating antitumor innate immunity and tumor xenograft regression

Metronomic chemotherapy using cyclophosphamide (CPA) is widely associated with antiangiogenesis; however, recent studies implicate other immune-based mechanisms, including antitumor innate immunity, which can induce major tumor regression in implanted brain tumor models. This study demonstrates the critical importance of drug schedule: CPA induced a potent antitumor innate immune response and tumor regression when administered intermittently on a 6-day repeating metronomic schedule but not with the same total exposure to activated CPA administered on an every 3-day schedule or using a daily oral regimen that serves as the basis for many clinical trials of metronomic chemotherapy. Notably, the more frequent metronomic CPA schedules abrogated the antitumor innate immune and therapeutic responses. Further, the innate immune response and antitumor activity both displayed an unusually steep dose-response curve and were not accompanied by antiangiogenesis. The strong recruitment of innate immune cells by the 6-day repeating CPA schedule was not sustained, and tumor regression was abolished, by a moderate (25%) reduction in CPA dose. Moreover, an ∼20% increase in CPA dose eliminated the partial tumor regression and weak innate immune cell recruitment seen in a subset of the every 6-day treated tumors. Thus, metronomic drug treatment must be at a sufficiently high dose but also sufficiently well spaced in time to induce strong sustained antitumor immune cell recruitment. Many current clinical metronomic chemotherapeutic protocols employ oral daily low-dose schedules that do not meet these requirements, suggesting that they may benefit from optimization designed to maximize antitumor immune responses.

Adenoviral vectors for prodrug activation-based gene therapy for cancer

Cancer cell heterogeneity is a common feature - both between patients diagnosed with the same cancer and within an individual patient's tumor - and leads to widely different response rates to cancer therapies and the potential for the emergence of drug resistance. Diverse therapeutic approaches have been developed to combat the complexity of cancer, including individual treatment modalities designed to target tumor heterogeneity. This review discusses adenoviral vectors and how they can be modified to replicate in a cancer-specific manner and deliver therapeutic genes under multi-tiered regulation to target tumor heterogeneity, including heterogeneity associated with cancer stem cell-like subpopulations. Strategies that allow for combination of prodrug-activation gene therapy with a novel replication-conditional, heterogeneous tumor-targeting adenovirus are discussed, as are the benefits of using adenoviral vectors as tumor-targeting oncolytic vectors. While the anticancer activity of many adenoviral vectors has been well established in preclinical studies, only limited successes have been achieved in the clinic, indicating a need for further improvements in activity, specificity, tumor cell delivery and avoidance of immunogenicity.

The effect of rhG-CSF on spleen transcriptome in mouse leukopenia model induced by cyclophosphamide

CONTEXT

RhG-CSF significantly elevates the otherwise reduced numbers of leukocytes following chemotherapy. However, prior work has predominantly focused on the effect of rhG-CSF on the hematopoietic system, and few studies have focused on the immune system.

OBJECTIVE

We aimed to investigate the effect of rhG-CSF on the immune system transcriptome in a mouse leukopenia model that was induced by cyclophosphamide.

MATERIALS AND METHODS

A cyclophosphamide leukopenia model was established in C57BL/6 mice, which were randomly divided into a normal control group (CK), a cyclophosphamide model group (CY) and a rhG-CSF treatment group (rhG-CSF). After 3 d of rhG-CSF treatment, a mouse gene expression microarray enabled evaluation of changes in the transcriptome in the mouse spleen.

RESULTS

About 3552 differentially expressed genes occurred among the three experimental groups, of which 74.9% (2659) concentrated on three gene expression patterns. Gene ontology and pathway analysis of 2659 differential genes showed that early in treatment when leukocyte counts remained low, rhG-CSF recovered the transcription of genes that were related to DNA damage repair and metabolism of nucleotides and amino acids. By contrast, rhG-CSF inhibited the transcription of genes involved in transendothelial migration and endocytosis, and dampened the transcription of genes associated with cell proliferation as compared with the CY group.

CONCLUSIONS

Our study suggests that rhG-CSF recovered metabolism in immune cells, suppressed in vivo immune defense, and attenuated immune cell proliferation in a cyclophosphamide induced leukopenia model. Use of gene expression microarrays can macroscopically and systematically inform the mechanism of rhG-CSF on immune cells.

Inflammasomes are important mediators of cyclophosphamide-induced bladder inflammation

Bladder inflammation (cystitis) underlies numerous bladder pathologies and is elicited by a plethora of agents such as urinary tract infections, bladder outlet obstruction, chemotherapies, and catheters. Pattern recognition receptors [Toll-like receptors (TLRs) and Nod-like receptors (NLRs)] that recognize pathogen- and/or damage-associated molecular patterns (PAMPs and/or DAMPs, respectively) are key components of the innate immune system that coordinates the production (TLRs) and maturation (NLRs) of proinflammatory IL-1β. Despite multiple studies of TLRs in the bladder, none have investigated NLRs beyond one small survey. We now demonstrate that NLRP3 and NLRC4, and their binding partners apoptosis-associated speck-like protein containing a COOH-terminal caspase recruitment domain (ASC) and NLR family apoptosis inhibitory protein (NAIP), are expressed in the bladder and localized predominantly to the urothelia. Activated NLRs form inflammasomes that activate caspase-1. Placement of a NLRP3- or NLRC4-activating PAMP or NLRP3-activating DAMPs into the lumen of the bladder stimulated caspase-1 activity. To investigate inflammasomes in vivo, we induced cystitis with cyclophosphamide (CP, 150 mg/kg ip) in the presence or absence of the inflammasome inhibitor glyburide. Glyburide completely blocked CP-induced activation of caspase-1 and the production of IL-1β at 4 h. At 24 h, glyburide reduced two markers of inflammation by 30-50% and reversed much of the inflammatory morphology. Furthermore, glyburide reversed changes in bladder physiology (cystometry) induced by CP. In conclusion, NLRs/inflammasomes are present in the bladder urothelia and respond to DAMPs and PAMPs, whereas NLRP3 inhibition blocks bladder dysfunction in the CP model. The coordinated response of NLRs and TLRs in the urothelia represents a first-line innate defense that may provide an important target for pharmacological intervention.

Impact of tumor blood flow modulation on tumor sensitivity to the bioreductive drug banoxantrone

We investigated the hypoxia-dependent cytotoxicity of AQ4N (banoxantrone) using a panel of 13 cancer cell lines and studied its relationship to the expression of the quinone reductase DT-diaphorase (NQO1), which is widely found in cancer cells. We also investigated pharmacologic treatments that increase tumor hypoxia in vivo and their impact on AQ4N chemosensitivity in a solid tumor xenograft model. AQ4N showed ≥ 8-fold higher cytotoxicity under hypoxia than normoxia in cultures of 9L rat gliosarcoma and H460 human non-small-cell lung carcinoma cells but not for 11 other human cancer cell lines. DT-diaphorase protein levels and AQ4N chemosensitivity were poorly correlated across the cancer cell line panel, and AQ4N chemosensitivity was not affected by DT-diaphorase inhibitors. The vasodilator hydralazine decreased tumor perfusion and increased tumor hypoxia in 9L tumor xenografts, and to a lesser extent in H460 tumor xenografts. However, hydralazine did not increase AQ4N-dependent antitumor activity. Combination of AQ4N with the angiogenesis inhibitor axitinib, which increases 9L tumor hypoxia, transiently increased antitumor activity but with an increase in host toxicity. These findings indicate that the capacity to bioactivate AQ4N is not dependent on DT-diaphorase and is not widespread in cultured cancer cell lines. Moreover, the activation of AQ4N cytotoxicity in vivo requires tumor hypoxia that is more extensive or prolonged than can readily be achieved by vasodilation or by antiangiogenic drug treatment.

The constitutive androstane receptor is a novel therapeutic target facilitating cyclophosphamide-based treatment of hematopoietic malignancies

Cyclophosphamide (CPA) is one of the most widely used chemotherapeutic prodrugs that undergoes hepatic bioactivation mediated predominantly by cytochrome P450 (CYP) 2B6. Given that the CYP2B6 gene is primarily regulated by the constitutive androstane receptor (CAR, NR1I3), we hypothesize that selective activation of CAR can enhance systemic exposure of the pharmacologically active 4-hydroxycyclophosamide (4-OH-CPA), with improved efficacy of CPA-based chemotherapy. In this study, we have developed a unique human primary hepatocyte (HPH)-leukemia cell coculture model; the chemotherapeutic effects of CPA on leukemia cells can be directly investigated in vitro in a cellular environment where hepatic metabolism was well maintained. Our results demonstrated that activation of CAR preferentially induces the expression of CYP2B6 over CYP3A4 in HPHs, although endogenous expression of these enzymes in leukemia cells remains negligible. Importantly, coadministration of CPA with a human CAR activator led to significantly enhanced cytotoxicity in leukemia cells by inducing the apoptosis pathways, without concomitant increase in the off-target hepatotoxicity. Associated with the enhanced antitumor activity, a time and concentration-dependent increase in 4-OH-CPA formation was observed in the coculture system. Together, our findings offer proof of concept that CAR as a novel molecular target can facilitate CPA-based chemotherapy by selectively promoting its bioactivation.

Downregulation of oxidative and nitrosative apoptotic signaling by L-carnitine in Ifosfamide-induced Fanconi syndrome rat model

It is well documented that ifosfamide (IFO) therapy is associated with sever nephropathy in the form of Fanconi syndrome. Although oxidative stress has been reported as a major player in IFO-induced Fanconi syndrome, no mechanism for this effect has been ascertained. Therefore, this study has been initiated to investigate, on gene expression level, the mechanism of IFO-induce nephrotoxicity and those whereby carnitine supplementation attenuates this serious side effect of IFO. To achieve the ultimate goals of this study, adult male rats were assigned to one of four treatment groups, namely, control, L-carnitine, IFO, and IFO plus L-carnitine. Administration of IFO for 5 days significantly increased serum creatinine, blood urea nitrogen (BUN), and total nitrate/nitrite (NOx) production in kidney tissues. In addition, IFO significantly increased mRNA expression of inducible nitric oxide synthase (iNOS), caspase-9, and caspase-3 and significantly decreased expression of glutathione peroxides (GPx), catalase (CAT), and Bcl2 in kidney tissues. Administration of L-carnitine to IFO-treated rats resulted in a complete reversal of the all biochemical and gene expression changes, induced by IFO, to the control values. Data from this study suggest that L-carnitine prevents the development of IFO-induced nephrotoxicity via downregulation of oxidative and nitrosative apoptotic signaling in kidney tissues.

Klippel-Feil syndrome in a boy exposed inadvertently to cyclophosphamide during pregnancy: a case report

BACKGROUND

Cyclophosphamide (CPA) is an alkylating agent widely used as an immunosuppressive agent in the treatment of several autoimmune diseases, including systemic lupus erythematosus. Its teratogenic effect has been well studied in different experimental mammalian and non-mammalian animal models. In humans, 11 cases of CPA teratogenesis have been documented.

CASE

We present a case of a patient with Klippel-Feil syndrome inadvertently exposed to CPA and prednisone in utero during the first trimester. CONCLUSIONS This case of possible cyclophosphamide embryopathy provides evidence of teratogenesis as an etiologic agent in developmental field defects such as Klippel-Feil syndrome.

Extracts of Lycoris aurea induce apoptosis in murine sarcoma S180 cells

Lycoris species have been known since long ago as a multi-utility ethnomedicinal herbal in China. It has been reported to exhibit a number of properties such as anticancer, neuroprotective, and antibacterial activities. In the present study, the anticancer efficacy of dichloromethane extracts of Lycoris aurea (DELA), was evaluated both in vivo and in vitro using murine sarcoma 180 cells. To evaluate the effects of DELA on apoptotic cell death, flow cytometry and Western blotting were performed. DELA demonstrated promising inhibition effects on sarcoma 180 cells in vitro and a 53.49% inhibitory rate on cancer cells in vivo. DELA treatment increased thymus indices and spleen indices in vivo, indicating that it reduced tumours, but did not damage the main immune organs. The DELA-evoked increase in apoptotic cell death was accompanied by occurrence of cleaved caspase-3 and decreases in the ratio of Bcl-2/Bax. Further purification and LCMS analysis showed DELA contained homolycorine, 2α-hydroxyoduline, oduline, hippeastrine, 2α-hydroxy-6-O- methyloduline, and 2α-methoxy-6-O-methyloduline. These results indicate that DELA exerted its anticancer effects, at least in part, by inducing cancer cell apoptosis and thus can be considered as a potential candidate agent for treatment of cancer.

Very small size proteoliposomes derived from Neisseria meningitidis: an effective adjuvant for antigen-specific cytotoxic T lymphocyte response stimulation under leukopenic conditions

Leukopenia is a severe condition resulting from both pathological processes and some treatments, like chemotherapy in cancer patients. However, the activation of the patient immune system is required for the success of immunotherapeutic strategies, as cancer vaccines. In this regard, leukopenia constitutes a major hurdle to overcome, mainly due to the impairment of cytotoxic T lymphocyte (CTL) responses. Adjuvants are basic components of vaccine formulations, which might be useful to stimulate immunity under this immunosuppressed condition. To this aim, we tested the capacity of a novel nanoparticulated complex, very small size proteoliposomes (VSSP), to promote CTL even in a leukopenic scenario. Noteworthy, we observed that a VSSP-based OVA vaccine induced a normal antigen-specific CTL response in mice rendered leukopenia by the administration of high doses of the chemotherapeutic agent cyclophosphamide (CY), while under the same conditions the OVA antigen formulated in the TLR-3 agonist polyinosinic-polycytidylic acid (P(I:C)) was ineffective. Moreover, an appropriate combination of VSSP with the P(I:C) vaccine was able to restore the CD8(+) T cell effector function in leukopenic mice. VSSP induced not only a faster repopulation of immune cells in CY-receiving animals, but also enhanced the recovery of memory T lymphocytes and myeloid dendritic cells (DCs) while simultaneously abrogated the immunosuppressive capacity of myeloid-derived suppressor cells (MDSCs). Our results suggest that VSSP could be a particularly suitable immunomodulator to be used in CTL-promoting active immunotherapy strategies operating in severe immune compromised scenarios.

Downregulation of caspase-9 is a frequent event in patients with stage II colorectal cancer and correlates with poor clinical outcome

OBJECTIVE

 To evaluate the clinical significance of caspase-9 mRNA expression and investigate its prognostic value in stage II colorectal cancer.

METHOD

Quantitative real-time RT-PCR was used to analyse caspase-9 mRNA expression in cancer tissue and corresponding normal mucosa from 120 patients.

RESULTS

Compared with normal mucosa, the expression of caspase-9 mRNA was found to be downregulated in cancer tissue (P = 0.001). Poorly differentiated cancer showed lower mRNA expression than cancer with greater differentiation (P = 0.031). The Kaplan-Meier survival analysis demonstrated that patients with downregulated caspase-9 showed a worse overall survival (P = 0.012) and disease-free survival (P = 0.022). Cox's proportional hazards regression model confirmed that expression of caspase-9 was the strongest prognostic factor in stage II colorectal cancer.

CONCLUSION

The mRNA expression of caspase-9 can be used as an independent prognostic factor for patients with stage II colorectal cancer.

Programmed cell death 4 enhances chemosensitivity of ovarian cancer cells by activating death receptor pathway in vitro and in vivo

Chemoresistance is a major cause of treatment failure in ovarian cancer. Therefore, it is necessary to explore alternative therapeutic methods to overcome drug resistance for ovarian cancer treatment. We previously reported that programmed cell death 4 (PDCD4), a tumor suppressor, significantly suppresses the malignant phenotype of ovarian cancer cells and its lost or low expression in ovarian cancer is associated with unfavorable prognosis of patients. Here we show that PDCD4 improves the sensitivity of ovarian cancer cells to platinum-based chemotherapy. Overexpression of PDCD4 enhanced chemosensitivity in SKOV3 and CAOV3 cells with low levels of PDCD4, whereas knockdown of PDCD4 reduced chemosensitivity in OVCAR3 cells with high levels of PDCD4. Subsequently, the combination of enforced PDCD4 expression with cisplatin treatment significantly suppressed ovarian tumor growth in a xenograft animal model. The PDCD4 effect appears to be specific for cisplatin and carboplatin, not affecting cyclophosphamide, etoposide, or paclitaxel. Mechanistically, PDCD4 significantly increased cisplatin-induced cleavage of caspase-3 and caspase-8, but had only a slight impact on caspase-9 cleavage and the expression of Bax and Bcl-2 in vitro and in vivo. A specific caspase-8 inhibitor, Z-ITED-FMK, attenuated cisplatin-induced apoptosis in PDCD4-overexpressing ovarian cancer cells. Taken together, our results indicate that PDCD4 enhances cisplatin-induced apoptosis by mainly activating the death receptor pathway, and PDCD4 gene transfer in combination with cisplatin therapy may break the resistance of ovarian cancer cells to chemotherapy.

Adenoviral delivery of pan-caspase inhibitor p35 enhances bystander killing by P450 gene-directed enzyme prodrug therapy using cyclophosphamide+

Background

Cytochrome P450-based suicide gene therapy for cancer using prodrugs such as cyclophosphamide (CPA) increases anti-tumor activity, both directly and via a bystander killing mechanism. Bystander cell killing is essential for the clinical success of this treatment strategy, given the difficulty of achieving 100% efficient gene delivery in vivo using current technologies. Previous studies have shown that the pan-caspase inhibitor p35 significantly increases CPA-induced bystander killing by tumor cells that stably express P450 enzyme CYP2B6 (Schwartz et al, (2002) Cancer Res. 62: 6928-37).

Methods

To further develop this approach, we constructed and characterized a replication-defective adenovirus, Adeno-2B6/p35, which expresses p35 in combination with CYP2B6 and its electron transfer partner, P450 reductase.

Results

The expression of p35 in Adeno-2B6/p35-infected tumor cells inhibited caspase activation, delaying the death of the CYP2B6 "factory" cells that produce active CPA metabolites, and increased bystander tumor cell killing compared to that achieved in the absence of p35. Tumor cells infected with Adeno-2B6/p35 were readily killed by cisplatin and doxorubicin, indicating that p35 expression is not associated with acquisition of general drug resistance. Finally, p35 did not inhibit viral release when the replication-competent adenovirus ONYX-017 was used as a helper virus to facilitate co-replication and spread of Adeno-2B6/p35 and further increase CPA-induced bystander cell killing.

Conclusions

The introduction of p35 into gene therapeutic regimens constitutes an effective approach to increase bystander killing by cytochrome P450 gene therapy. This strategy may also be used to enhance other bystander cytotoxic therapies, including those involving the production of tumor cell toxic protein products.