Reversible posterior encephalopathy syndrome associated with bortezomib

Posterior reversible encephalopathy syndrome (PRES) and myeloma

Posterior reversible encephalopathy syndrome (PRES) has rarely been described in myeloma, but chemotherapy is a known risk factor. We report 3 patients with myeloma who developed PRES, and analyzed them with 13 published cases, mostly women. The most frequent causative agents were proteasome inhibitors and autologous stem cell transplantation. Risk factors were frequently associated: hypertension, infection or renal failure. Symptoms included headache, blurred vision, altered mental status, seizures. Most patients experienced rapid clinical recovery, without relapse even after resuming treatment. Although rare, we must remain vigilant about PRES in myeloma patients. Stricter control of blood pressure could limit its occurrence.

Endothelial TFEB signaling-mediated autophagic disturbance initiates microglial activation and cognitive dysfunction

Cognitive impairment caused by systemic chemotherapy is a critical question that perplexes the effective implementation of clinical treatment, but related molecular events are poorly understood. Herein, we show that bortezomib exposure leads to microglia activation and cognitive impairment, this occurs along with decreased nuclear translocation of TFEB (transcription factor EB), which is linked to macroautophagy/autophagy disorder, STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL23A (interleukin 23 subunit alpha) expression. Pharmacological enhancement of TFEB nuclear translocation by digoxin restores lysosomal function and reduces STAT3-dependent endothelial IL23A secretion. As a consequence, we found that brain endothelial-specific ablation of Il23a ameliorated both microglia activation and cognitive dysfunction. Thus, the endothelial TFEB-STAT3-IL23A axis in the brain represents a critical cellular event for initiating bortezomib-mediated aberrant microglial activation and synapse engulfment. Our results suggest the reversal of TFEB nuclear translocation may provide a novel therapeutic approach to prevent symptoms of cognitive dysfunction during clinical use of bortezomib.Abbreviations: AAV: adeno-associated virus; BBB: blood-brain barrier; BTZ: bortezomib; DG: digoxin; DGs: dentate gyrus; DLG4/PSD95: discs large MAGUK scaffold protein 4; HBMECs: human brain microvascular endothelial cells; HP: hippocampus; IL23A: interleukin 23 subunit alpha; MBVECs: mouse brain vascular endothelial cells; mPFC: medial prefrontal cortex; NORT: novel object recognition test; OLT: object location test; PLX5622: 6-fluoro-N-([5-fluoro-2-methoxypyridin-3-yl]methyl)-5-(5-methyl-1H-pyrrolo[2,3-b]pyridin-3- yl)methyl; PPP3/calcineurin: protein phosphatase 3; SBEs: STAT3 binding elements; shRNA: small hairpin RNA; SLC17A7/VGLUT1: solute carrier family 17 member 7; SLC32A1/VGAT: solute carrier family 32 member 1; STAT3: signal transducer and activator of transcription 3, TFEB: transcription factor EB; Ub: ubiquitin.

[Central nervous system toxicity caused by bortezomib: five case reports and a review of literature]

目的

探讨硼替佐米中枢神经系统（CNS）毒性的临床特点、诊断和治疗。

方法

报道5例由硼替佐米引起的CNS毒性患者并结合现有文献探讨其临床特点。

结果

5例患者中有4例在应用硼替佐米后出现了中枢性发热，主要表现为持续性高热、周身无汗、未能找到感染病灶、对退热药不敏感，停用硼替佐米后症状好转。4例患者中有3例伴随顽固性低钠血症，1例明确诊断为抗利尿不当综合征（SIAD），可能是硼替佐米同时影响了下丘脑体温调节中枢和抗利尿激素神经分泌细胞所致。1例患者诊断为可逆性后部脑病综合征（PRES），表现为应用硼替佐米后出现意识障碍，头CT示双侧半卵圆中心白质密度减低，停用硼替佐米后患者症状消失且未再复发。此外，我们还发现血小板计数可能与硼替佐米CNS毒性的严重程度相关。

结论

硼替佐米的CNS毒性非常罕见，表现为3种形式：SIAD、PRES和中枢性发热，及时识别和治疗对于预防不可逆的神经并发症非常重要。

Posterior reversible encephalopathy syndrome and takotsubo cardiomyopathy associated with lenvatinib therapy for thyroid cancer: a case report and review

As immunotherapies including tyrosine kinase inhibitors become more widely used for the treatment of a variety of malignancies, it is important for prescribers and patients to understand the potential adverse effects associated with these drugs. It is especially important to understand the potentially fatal side effects associated with these drugs to further determine risk factors for their development. The review presents a case of posterior reversible encephalopathy syndrome with concomitant Takotsubo cardiomyopathy, associated with use of lenvatinib therapy for thyroid cancer. It discusses the interventions performed and outcome. Potential mechanisms for development of these rare adverse effects, as well as cases in which these adverse effects are seen with use of other tyrosine-kinase inhibitors will be presented. It is important to continue to report these side effects, and further studies are needed to elucidate potential risk factors for their development, as well as to determine prognosis after development.

An analysis of the safety profile of proteasome inhibitors for treating various cancers

INTRODUCTION

Emerging evidence demonstrates that the ubiquitin-proteasome pathway is a promising target for cancer therapy. Bortezomib (Velcade) exhibits great efficacy against multiple myeloma (MM) since the first clinical application. However, there are still several limitations associated with the use of bortezomib, including severe toxicities. To overcome bortezomib's shortcomings and to improve its safety profile, several second-generation proteasome inhibitors, for example, carfilzomib, ixazomib, oprozomib and marizomib, have been developed and currently tested in various clinical trials.

AREAS COVERED

A literature search was carried out using PubMed and Google Scholar. The activity and safety profiling of proteasome inhibitors in treatment of various cancers were reviewed.

EXPERT OPINION

Bortezomib, as a single or in combination therapy, demonstrates efficacy against MM or other hematological malignancies in clinical settings. However, it encounters two major problems, the acquired resistance and the severe side effects. Future direction in bortezomib-based therapy should focus on how to increase or retain its efficacy but improve its safety profile through, for example, rational combination therapies. Second-generation proteasome inhibitors have shown benefits in both overcoming bortezomib resistance and reducing related side effects, although these encouraging results should be further confirmed in a larger clinic population.

Posterior reversible encephalopathy syndrome resulting from repeat bortezomib usage

Bortezomib is a chemotherapeutic agent that acts via proteasome inhibition resulting in cellular apoptosis and inhibition of angiogenesis. Although widely accepted as treatment of multiple myeloma and non-Hodgkin's lymphoma, it has also been shown to be efficacious in a variety of solid tumours such as pancreatic and colonic. Posterior reversible encephalopathy syndrome (PRES) is a neuroradiological syndrome characterised by vasogenic oedema involving the postero-occipital cortical and subcortical white matter resulting in visual disturbances, seizures and altered mental status. Although in most cases PRES is reversible with removal of the provoking condition or drug, if not appropriately recognised and treated it may lead to permanent and life-threatening sequelae such as intracerebral haemorrhage and ischaemic infarction. We report a case of PRES associated with bortezomib therapy and contrast it with four other previously reported cases. Recognition of this potentially severe neurological complication is important with the increasingly widespread use of bortezomib.

Bortezomib-induced posterior reversible encephalopathy syndrome: clinical and imaging features

Posterior reversible encephalopathy syndrome (PRES) is a rare and potentially harmful complication in patients receiving targeted chemotherapy. We herein present a case of PRES that occurred after 33 days of high-dose bortezomib treatment and propose both overwhelmed cerebral autoregulation and toxin-mediated blood-brain barrier damage as the underlying mechanisms based on the imaging findings. A favorable recovery was observed two days after achieving stringent hypertension control and withholding bortezomib. Follow-up images obtained two weeks later unveiled a dramatic remission, with faint areas of subcortical hyperintensity in the bilateral parieto-occipital regions. With explicit clinical and imaging features, this case highlights the need for early recognition of PRES during the clinical course of bortezomib therapy.

[Central nervous system complications in patients undergoing cytotoxic chemotherapy and targeted therapies]

Anti-cancer treatments (cytotoxic chemotherapies, targeted therapies and hormonotherapies) are known to induce early and delayed neurological toxicities. Acute encephalopathies and posterior reversible encephalopathies are better known and described, physiopathological hypotheses are emerging. It is difficult to discriminate what drug is causing the symptoms in patients treated with multiple cytotoxic drugs. Methotrexate and ifosfamide are responsible for acute encephalopathies. L-asparaginase and methotrexate or targeted therapies may induce cerebrovascular complications. As life expectancy increases and more complex regimen including innovative targeted therapies are developed, new toxicity profiles can be expected. To be able to provide an early diagnosis, prevention, and treatment (when existing) of these pathologies remains a tremendous challenge that would allow a good quality of life with social and professional life after their cancer is cured.

Reversible posterior leukoencephalopathy syndrome after carboplatin and paclitaxel regimen for lung cancer

Reversible posterior leukoencephalopathy syndrome (RPLS) is uncommon neurological syndrome that is characterized by specific clinical and radiologic findings. Previous reported associations of RPLS include hypertension, eclampsia, renal impairment and drugs. Prompt diagnosis and therapy is critical to ensure resolution of the neurological disability. Some cases have been reported in association with the increased use of antineoplastic agents in cancer patients. We report the case of a 62-year-old man who was diagnosed with RPLS after receiving carboplatin and paclitaxel chemotherapy for lung cancer. This case appears to be the first recognized association of RPLS with this regimen.

Changes in proteasome pool in human papillary thyroid carcinoma development

Searching the antitumor drug targets among proteasomes, “ubiquitous” enzyme systems, may provide a new impulse to the antitumor drug discovery. In this study, changes in the proteasome pool in the development of human papillary thyroid carcinoma were determined. Proteasome activities were evaluated by hydrolysis of commercial fluorogenic peptides. Changes in the expression of the total proteasome pool, proteasome 19S activator and proteolytic constitutive subunits X(β5), Y(β1) and immune subunits LMP7 (β5i) and LMP2 (β1i) were investigated by Western blotting. The distribution of the proteasome subunits in thyroid gland cells was detected by immunohistochemistry. It was shown that the chymotrypsin- and caspase-like activities as well as the expression of the total proteasome pool, proteasome 19S activator and immune subunits increased gradually in the tumors at the T2N0M0 and T3N0M0 stages in comparison with the control tissues. Among the structures studied, the expression of the 19S activator and immune proteasomes, which contain the LMP2 (β1i) subunit, was enhanced to the largest degree in tumor cells. The data obtained may be implicated in a new therapeutic strategy. Taking into consideration the antitumor function of the immune proteasomes, we advance the 19S activator as the target for the development of a novel antitumor therapy.