Neurological adverse effects caused by cytotoxic and targeted therapies

Bioinspired exosome-mimetic nanovesicles for targeted delivery of chemotherapeutics to malignant tumors

Exosomes, the endogenous nanocarriers that can deliver biological information between cells, were recently introduced as new kind of drug delivery system. However, mammalian cells release relatively low quantities of exosomes, and purification of exosomes is difficult. Here, we developed bioinspired exosome-mimetic nanovesicles that deliver chemotherapeutics to the tumor tissue after systemic administration. The chemotherapeutics-loaded nanovesicles were produced by the breakdown of monocytes or macrophages using a serial extrusion through filters with diminishing pore sizes (10, 5, and 1 μm). These cell-derived nanovesicles have similar characteristics with the exosomes but have 100-fold higher production yield. Furthermore, the nanovesicles have natural targeting ability of cells by maintaining the topology of plasma membrane proteins. In vitro, chemotherapeutic drug-loaded nanovesicles induced TNF-α-stimulated endothelial cell death in a dose-dependent manner. In vivo, experiments in mice showed that the chemotherapeutic drug-loaded nanovesicles traffic to tumor tissue and reduce tumor growth without the adverse effects observed with equipotent free drug. Furthermore, compared with doxorubicin-loaded exosomes, doxorubicin-loaded nanovesicles showed similar in vivo antitumor activity. However, doxorubicin-loaded liposomes that did not carry targeting proteins were inefficient in reducing tumor growth. Importantly, removal of the plasma membrane proteins by trypsinization eliminated the therapeutic effects of the nanovesicles both in vitro and in vivo. Taken together, these studies suggest that the bioengineered nanovesicles can serve as novel exosome-mimetics to effectively deliver chemotherapeutics to treat malignant tumors.

Understanding, recognizing, and managing toxicities of targeted anticancer therapies

Answer questions and earn CME/CNE Advances in genomics and molecular biology have identified aberrant proteins in cancer cells that are attractive targets for cancer therapy. Because these proteins are overexpressed or dysregulated in cancer cells compared with normal cells, it was assumed that their inhibitors will be narrowly targeted and relatively nontoxic. However, this hope has not been achieved. Current targeted agents exhibit the same frequency and severity of toxicities as traditional cytotoxic agents, with the main difference being the nature of the toxic effects. Thus, the classical chemotherapy toxicities of alopecia, myelosuppression, mucositis, nausea, and vomiting have been generally replaced by vascular, dermatologic, endocrine, coagulation, immunologic, ocular, and pulmonary toxicities. These toxicities need to be recognized, prevented, and optimally managed.

Nutraceuticals and chemotherapy induced peripheral neuropathy (CIPN): a systematic review

Chemotherapy induced peripheral neuropathy [CIPN] is a common significant and debilitating side effect resulting from the administration of neurotoxic chemotherapeutic agents. These pharmaco-chemotherapeutics can include taxanes, vinca alkaloids and others. Moderate to severe CIPN significantly decreases the quality of life and physical abilities of cancer patients and current pharmacotherapy for CIPN e.g. Amifostine and antidepressants have had limited efficacy and may themselves induce adverse side effects. To determine the potential use of nutraceuticals i.e. vitamin E, acetyl-L-carnitine, glutamine, glutathione, vitamin B6, omega-3 fatty acids, magnesium, calcium, alpha lipoic acid and n-acetyl cysteine as adjuvants in cancer treatments a systematic literature review was conducted. Revised clinical studies comprised of randomized clinical trials that investigated the anti-CIPN effect of nutraceuticals as the adjuvant intervention in patients administered chemotherapy. Twenty-four studies were assessed on methodological quality and limitations identified. Studies were mixed in their recommendations for nutraceuticals. Currently no agent has shown solid beneficial evidence to be recommended for the treatment or prophylaxis of CIPN. The standard of care for CIPN includes dose reduction and/or discontinuation of chemotherapy treatment. The management of CIPN remains an important challenge and future studies are warranted before recommendations for the use of supplements can be made.

Growth inhibition effect of peptide P110 plus cisplatin on various cancer cells and xenotransplanted tumors in mice

The combined use of currently used anticancer genotoxins with other drugs is a therapeutic tool for potentially increasing the efficacy of the genotoxins. In the present study, the effects of a RasGAP-derived peptide, P110 (RasGAP301-316), designed to target Ras-GTPase activating protein SH3 domain-binding proteins (G3BPs), on the chemotherapeutic agent, cisplatin (DDP), were examined. P110 was demonstrated to enhance the effect of DPP in vitro and in vivo. The results indicate that P110 significantly increased the DDP-induced apoptosis in SGC-7901, HCT-116, HeLa and A-549 cells. Furthermore, P110 combined with DDP significantly suppressed the growth of C26 xenograft tumors in a dose-dependent manner. This synergistic effect may be associated with DDP-induced apoptosis, involving the downregulation of Bcl-2 and the upregulation of Bax, cytochrome c and caspase-3. The results of the present study indicate that P110, in combination with chemotherapeutics, is likely to represent a potential therapeutic strategy for cancer.

Diagnostic and therapeutic avenues for glioblastoma: no longer a dead end?

Glioblastomas are heterogeneous neoplasms that are driven by complex signalling pathways, and are among the most aggressive and challenging cancers to treat. Despite standard treatment with resection, radiation and chemotherapy, the prognosis of patients with glioblastomas remains poor. An increasing understanding of the molecular pathogenesis of glioblastomas has stimulated the development of novel therapies, including the use of molecular-targeted agents. Identification and validation of diagnostic, prognostic and predictive biomarkers has led to the advancement of clinical trial design, and identification of glioblastoma subgroups with a more-favourable prognosis and response to therapy. In this Review, we discuss common molecular alterations relevant to the biology of glioblastomas, targeted, antiangiogenic and immunotherapies that have impacted on the treatment of this disease, and the challenges and pitfalls associated with these therapies. In addition, we emphasize current biomarkers relevant to the management of patients with glioblastoma.

Management strategies for relapsed/refractory multiple myeloma: current clinical perspectives

In the last decade, the introduction of novel agents including the immunomodulatory drugs thalidomide and lenalidomide, and the first-in-class proteasome inhibitor bortezomib, has dramatically improved clinical outcome in patients with relapsed/refractory multiple myeloma (MM) compared to conventional chemotherapy alone. Although combination treatment approaches with traditional cytotoxic agents and novel agents have led to response rates as high as 85% in patients with relapsed/refractory disease, not all patients will respond to established novel agents, and even those who do respond will ultimately relapse or become refractory to currently available regimens. There is no generally accepted standard treatment for patients with relapsed/refractory disease; however, both disease-related (eg, quality and duration of response to previous therapies and the aggressiveness of the relapse) and patient-related (eg, preexisting toxicities, comorbid conditions, quality of life, age, and performance status) factors should be considered when selecting the best treatment option. This article will review up-to-date approaches for managing patients with relapsed/refractory MM, including the efficacy and safety of established novel agents, the use of adjunctive/supportive care, and strategies for tailored treatment.

Neurologic complications of cancer drug therapies

PURPOSE OF REVIEW

The purpose of this article is to review neurologic complications associated with systemic anticancer therapies.

RECENT FINDINGS

Although neurologic complications from traditional chemotherapies are well described, most neurologists are less familiar with complications from agents that target specific pathways or receptors. This article also reviews the most common neurologic adverse effects associated with newer targeted agents.

SUMMARY

Patients with cancer are living longer because of earlier diagnoses and remarkable improvements in treatments. Unfortunately, both traditional chemotherapies and newer targeted agents are known to cause neurologic symptoms that can impact quality of life and play a role in limiting potential treatments. Acute, subacute, and chronic syndromes may affect the central or peripheral nervous system. Since treatments for therapy-induced neurotoxicity are limited, awareness of common neurologic complications is important to prevent permanent damage.

Deaths reported from the accidental intrathecal administration of bortezomib

Medication errors due to the inadvertent intrathecal administration of vincristine and other antineoplastic agents continue to occur despite the development of preventative strategies. Three fatalities due to bortezomib being accidentally given intrathecally instead of by the intended intravenous route have recently been reported by the European Medicines Agency. The most effective method for preventing accidental intrathecal administration is to eliminate the syringe as a means of administrating neurotoxic agents and prepare them in a small volume minibag. However due to a lack of stability data for bortezomib in a minibag and the increasing use of bortezomib via the subcutaneous route necessitates the continued preparation of bortezomib in a syringe. A number of recommendations aimed at preventing the possibility of accidental intrathecal administration of bortezomib are made. These need to be incorporated into standard practice internationally and pharmacists must take the lead to ensure this occurs as a matter of urgency.

Saquinavir in steroid-dependent and -resistant nephrotic syndrome: a pilot study

BACKGROUND

Some difficult cases of idiopathic nephrotic syndrome (NS) have been treated with a HIV protease inhibitor provided with proteasome-inhibiting activity. The objective of this study was to limit nuclear factor κB (NF-κB) activation which is up-regulated in these patients, aiming at decreasing proteinuria and prednisone need.

METHODS

Ten cases with long-lasting (up to 15 years) history of NS with steroid dependence (six cases, of which three with secondary steroid resistance) or resistance to steroids (four cases) unsuccessfully treated with multiple immunosuppressive drugs, accepted a treatment with the protease inhibitor saquinavir. p50/p65 NF-κB nuclear localization and immunoproteasome/proteasome messenger RNA (mRNA) were monitored in peripheral blood mononuclear cells (PBMCs). The effects of saquinavir on NF-κB nuclear localization in cultured PBMCs and in immortalized human podocytes were assessed.

RESULTS

After a median follow-up of 14.7 months (6-68.7), 1/4 primary steroid-resistant NS (SRNS) and 5/6 steroid-dependent NS or secondary SRNS became infrequent (5) or frequent (1) relapsers, with 63% prednisone reduction (from 25.3 to 8.4 mg/kg/month, P = 0.015). Saquinavir was effective in association with low doses of calcineurin inhibitors (cyclosporine 2 mg/kg/day or tacrolimus 0.01-0.06 mg/kg/day). No side effects were observed apart from transitory mild diarrhoea. In PBMCs, NF-κB was down-regulated, while MECL-1 immunoproteasome/beta2 proteasome mRNA ratio was reversed to normal values. In culture, saquinavir blunted NF-κB activation in human podocytes and in PBMCs.

CONCLUSIONS

In this pilot study, a HIV antiprotease drug reduced proteinuria and had a steroid-sparing effect in some multidrug-resistant/-dependent NS. This observation warrants further investigation.

Long-term bortezomib treatment reduces allergen-specific IgE but fails to ameliorate chronic asthma in mice

BACKGROUND

Allergen-specific immunoglobulin (Ig) E initiates the effector cascade of allergic asthma and has been identified as a valuable target for therapeutic treatment of this disease. The proteasome inhibitor bortezomib was previously shown to deplete Ig-secreting plasma cells and to efficiently suppress Ig serum titers. The present study aimed at evaluating the therapeutic potential of the proteasome inhibitor bortezomib in allergic bronchial asthma.

METHODS

To address this question, a chronic experimental asthma mouse model was used in a therapeutic setting. Mice were sensitized to ovalbumin (OVA) and challenged with OVA aerosol for 12 weeks. After 6 weeks of challenge, bortezomib treatment was started and continued for 1 week (short-term) or 6 weeks (long-term) with a dosage of 0.75 mg/kg body weight twice a week. Lung function, lung histology, Ig serum titers and plasma cell numbers were assessed.

RESULTS

Whereas short-term treatment lowered bronchoalveolar lavage eosinophils, long-term treatment considerably reduced serum titers of anti-OVA IgE in mice with chronic experimental asthma. However, neither short-term nor long-term treatment significantly reduced plasma cell numbers, anti-OVA IgG1 serum titers or allergic airway inflammation or ablated airway hyperresponsiveness.

CONCLUSION

Our results suggest that bortezomib treatment has only limited value as plasma cell-depleting therapy against allergic bronchial asthma.

On the selectivity and efficacy of defense peptides with respect to cancer cells

Here, we review potential determinants of the anticancer efficacy of innate immune peptides (ACPs) for cancer cells. These determinants include membrane-based factors, such as receptors, phosphatidylserine, sialic acid residues, and sulfated glycans, and peptide-based factors, such as residue composition, sequence length, net charge, hydrophobic arc size, hydrophobicity, and amphiphilicity. Each of these factors may contribute to the anticancer action of ACPs, but no single factor(s) makes an overriding contribution to their overall selectivity and toxicity. Differences between the anticancer actions of ACPs seem to relate to different levels of interplay between these peptide and membrane-based factors.

Oral agents in cancer treatment: the context for adherence

OBJECTIVES

To review oral agents approved for cancer, discuss their mechanism of action and/or molecular targets, and outline side effects and challenges that impact adherence.

DATA SOURCES

Peer reviewed literature and on-line drug information.

CONCLUSION

Oral agents to treat cancer, although not new, are common and increasing dramatically. The context of adherence to oral agents is complicated by increased knowledge of food-drug interactions and combinations of agents with overlapping or synergistic toxicity profiles.

IMPLICATIONS FOR NURSING PRACTICE

The role of nursing in the administration and education of oral cancer treatments is critical to optimal treatment outcomes.

Review: incidence and clinical significance of Bevacizumab-related non-surgical and surgical serious adverse events in metastatic colorectal cancer

OBJECTIVE AND BACKGROUND

This review describes the extent, frequency and clinical importance of Bevacizumab(BV)-related serious adverse events (SAE) after surgery, during or after chemotherapy with BV in patients with metastatic colorectal cancer (mCRC).

METHODS

Detailed PubMed search in November 2009.

RESULTS

Addition of BV to first- or second-line chemotherapy in patients with mCRC results in a statistically significant benefit in OS, PFS and RR. Addition of BV to chemotherapy causes no clinically relevant aggravation of SAE and seems safe with the primary tumor still in situ. The risk of emergency surgery due to BV-related SAE is estimated 2.0%. SAE rate is low if a time to surgery of 5-6 weeks is respected. The majority of SAE are wound healing complications. Bleeding and GI perforation occur infrequently, even following major surgery after BV-treatment. Major surgery during the course of BV-treatment results in an SAE rate of 1.3-2.7%. Postoperatively, a period of minimally 28 days should be respected before starting BV.

CONCLUSION

Reported rates of BV-related SAE in relationship to surgery are low.

Bcl-2 homology domain 3-only proteins Puma and Bim mediate the vulnerability of CA1 hippocampal neurons to proteasome inhibition in vivo

Bcl-2 homology domain 3 (BH3)-only proteins are pro-apoptotic Bcl-2 family members that play important roles in upstream cell death signalling during apoptosis. Proteasomal stress has been shown to contribute to the pathology of cerebral ischaemia and many neurodegenerative disorders. Here we explored the contribution of BH3-only proteins in mediating proteasome-inhibition-induced apoptosis in the murine brain in vivo. Stereotactic intrahippocampal microinjection of the selective proteasome inhibitor epoxomicin (2.5 nmol) induced a delayed apoptosis within only the CA1 hippocampal neurons and not neurons within the CA3 or dentate gyrus regions, a selective vulnerability similar to that seen during ischaemia. This injury developed over a time-course of 3 days and was characterized by positive terminal deoxynucleotidyl transferase dUTP nick end labelling staining and nuclear condensation. Previous work from our laboratory has identified the BH3-only protein p53-upregulated mediator of apoptosis (Puma) as mediating proteasome-inhibition-induced apoptosis in cultured neural cells. Genetic deletion of puma reduced the number of terminal deoxynucleotidyl transferase dUTP nick end labelling-positive cells within the CA1 following epoxomicin microinjection but it did not provide a complete protection. Subsequent studies identified the BH3-only protein Bim as also being upregulated during proteasome inhibition in organotypic hippocampal slice cultures and after epoxomicin treatment in vivo. Interestingly, the genetic deletion of bim also afforded significant neuroprotection, although this protection was less pronounced. In summary, we demonstrate that the BH3-only proteins Puma and Bim mediate the delayed apoptosis of CA1 hippocampal neurons induced by proteasome inhibition in vivo, and that either BH3-only protein can only partly compensate for the deficiency of the other.

Neurological complications of systemic cancer

Neurological complications of systemic cancer-those arising outside the nervous system-can be distressing, disabling, and sometimes fatal. Diagnosis is often difficult because different neurological disorders may present with similar signs and symptoms. Furthermore, comorbid neurological illnesses, common in elderly patients with cancer, can complicate diagnosis. Early diagnosis and aggressive treatment can improve neurological symptoms and can substantially enhance a patient's quality of life. We approach the problem of neurological complications of systemic cancer as would a neurologist: first by identifying the anatomical area or areas that are affected (ie, brain, spinal cord, peripheral nerve), then by evaluating the diagnostic approach, considering the symptoms and signs and including appropriate laboratory tests, and finally, by recommending treatment. We focus on disorders that are difficult to diagnose, need neurological consultation, and for which effective treatments exist.

Microtubule-binding agents: a dynamic field of cancer therapeutics

Microtubules are dynamic filamentous cytoskeletal proteins composed of tubulin and are an important therapeutic target in tumour cells. Agents that bind to microtubules have been part of the pharmacopoeia of anticancer therapy for decades and until the advent of targeted therapy, microtubules were the only alternative to DNA as a therapeutic target in cancer. The screening of a range of botanical species and marine organisms has yielded promising new antitubulin agents with novel properties. In the current search for novel microtubule-binding agents, enhanced tumour specificity, reduced neurotoxicity and insensitivity to chemoresistance mechanisms are the three main objectives.

Neurologic complications of cancer and its treatment

The central nervous system (CNS) and peripheral nervous system (PNS) are very susceptible to cancer and its treatment. The most direct involvement of the nervous system manifests in the development of primary brain and spinal cord tumors. Many cancers exhibit a propensity toward spread to the CNS, and brain metastases are common problems seen in malignancies such as lung, breast, and melanoma. Such spread may involve the brain or spine parenchyma or the subarachnoid space. In the PNS, spread is usually through direct infiltration of nerve roots, plexi, or muscle by neighboring malignancies. In some cases, cancer has sudden, devastating effects on the nervous system: epidural spinal cord compression or cord transection from pathologic fractures of vertebra involved by cancer; increased intracranial pressure from intracranial mass lesion growth and edema; and uncontrolled seizure activity as a result of intracranial tumors (status epilepticus), which are neuro-oncologic emergencies. The best known indirect or remote effects of cancer on the nervous system are the neurologic paraneoplastic syndromes. Cancer can also result in a hypercoagulable state causing cerebrovascular complications. Treatment of cancer can have neurologic complications. The commonest of these complications are radiation-induced injury to the brain, spine, and peripheral nerves and chemotherapy-induced peripheral neuropathy. The suppressant effect of cancer and its treatment on the body's immune system can result in infectious complications within the nervous system.

Management of treatment-related adverse events in patients with multiple myeloma

The introduction of novel antimyeloma therapies, including thalidomide, lenalidomide and bortezomib, has expanded treatment options for patients with multiple myeloma. These compounds alter the natural history of multiple myeloma and help improve outcomes, but have different and specific toxicity profiles. The major adverse events associated with these treatments are somnolence (thalidomide), venous thromboembolism (thalidomide and lenalidomide), myelosuppression (lenalidomide and bortezomib), gastrointestinal disturbance, and peripheral neuropathy (thalidomide and bortezomib). These adverse events are predictable, consistent, and manageable with patient monitoring, supportive care, and dose reduction and interruption where appropriate. Herein we evaluate the incidence of treatment-related adverse events associated with each of these compounds. We further review the management of these adverse events with a view to delivering optimal therapeutic outcomes in patients with newly diagnosed and relapsed and/or refractory multiple myeloma.

Bevacizumab in combination with sequential high-dose chemotherapy in solid cancer, a feasibility study

We evaluated the feasibility and toxicity of bevacizumab in combination with sequential high-dose (HD) ifosfamide, carboplatin and etoposide refractory to standard chemotherapy in patients with sarcoma and germ cell cancer (GCC). Sixteen patients (13 sarcomas, 3 GCC) received SD-ICE followed by 4 cycles of HD-ICE, qd22 with stem cell support in combination with bevacizumab. All 16 patients were evaluable for toxicity and efficacy, and received 51 cycles (median 3.3). There was no increase in toxicity except of a relatively high incidence of ifosfamide encephalopathy in 17 cycles when compared with previous HD-ICE protocols. One almost complete response in the patient with GCC, previously progressive with three preceding protocols, was observed. Six patients had a partial response (sarcoma 4/13 patients; GCC 2/3 patients), and five patients stable disease (sarcoma 5/13 patients). The median PFS/OS for sarcoma was 5 months (confidence interval (CI): 3.1-6.9) and 13 months (CI: 3.6-24.4), respectively. To our knowledge, this is the first report of the addition of bevacizumab to HD-ICE. This combination did not show new unexpected toxicities except for a relatively high rate of ifosfamide encephalopathy. The efficacy in these heavily pretreated patients including possible reversal of chemotherapy resistance by the addition of bevacizumab indicates a possible potential of bevacizumab in this combination.

Matrix-assisted laser desorption/ionization imaging mass spectrometry of oxaliplatin derivatives in heated intraoperative chemotherapy (HIPEC)-like treated rat kidney

Oxaliplatin [1,2-diaminocyclohexane (dach)-Pt complex] is a platinum anticancer drug which is mainly used in the treatment of advanced colorectal cancer, particularly in Heated Intraoperative Chemotherapy (HIPEC) for the treatment of colorectal peritoneal carcinomatosis. In order to better understand the penetration of oxaliplatin in treated tissues we performed a direct imaging of tissue sections from HIPEC-like treated rat kidney using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. This procedure allowed the detection and localization of oxaliplatin and its metabolites, the monocysteine and monomethionine complexes, in kidney sections. Specifically, oxaliplatin and its metabolites were localized exclusively in the kidney cortex, suggesting that it did not penetrate deeply into the organ. Based on these results, an imaging analysis of human tumors collected after HIPEC is currently in progress to assess the distribution of oxaliplatin and/or metabolites with the aim of defining clinical conditions to improve drug penetration.

Liquid chromatography and tandem mass spectrometry for the quantitative determination of ixabepilone (BMS-247550, Ixempra) in human plasma: method validation, overcoming curve splitting issues and eliminating chromatographic interferences from degradants

A sensitive method was developed and validated for the measurement of ixabepilone (BMS-247550, Ixempra) using a demethylated analogue of ixabepilone (BMS-212188) as an internal standard. A 0.050 mL portion of each plasma sample was extracted with 0.450 mL of acetonitrile containing the internal standard via protein precipitation. The supernatant was analyzed on a LC-MS/MS system. Chromatography was carried out on a 2.0 mm x 100 mm YMC ODS-AQ 3 microm column using an isocractic mobile phase consisting of acetonitrile:10 mM ammonium acetate, pH 5.0 (70:30, v/v) at a flow rate of 0.30 mL/min. The mass spectrometer was fitted with a TurboIonSpray source and operated in negative ionization mode. Detection of ixabepilone and BMS-212188 were accomplished using multiple reaction monitoring (MRM) of precursor>product ion pairs of m/z 505.2>405.2, and 492.1>392.1, respectively. The assay range was 2.00-500 ng/mL and was fitted to a 1/x(2) weighted quadratic regression model. Replicate sample analysis indicated that intra- and inter-day accuracy and precision are within +/-15.0%. The recovery of ixabepilone from 0.050 mL of plasma containing 5.00 and 400 ng/mL was greater than 94%. The method was demonstrated to be sensitive, selective and robust, and was successfully used to support clinical studies. This paper also discussed approaches used for resolving a curve splitting issue observed during quantitative analysis of ixabepilone in biological matrices. Finally, to adapt the methodology to pharmacokinetics of ixabepilone after oral administration, the potential interference of chemical degradants on the determination of ixabepilone was evaluated.