Targeting IL-17A in multiple myeloma: a potential novel therapeutic approach in myeloma

We have previously demonstrated that interleukin-17A (IL-17) producing Th17 cells are significantly elevated in blood and bone marrow (BM) in multiple myeloma (MM) and IL-17A promotes MM cell growth via the expression of IL-17 receptor. In this study, we evaluated anti-human IL-17A human monoclonal antibody (mAb), AIN457 in MM. We observe significant inhibition of MM cell growth by AIN457 both in the presence and absence of BM stromal cells (BMSC). While IL-17A induces IL-6 production, AIN457 significantly down-regulated IL-6 production and MM cell-adhesion in MM-BMSC co-culture. AIN-457 also significantly inhibited osteoclast cell–differentiation. More importantly, in the SCIDhu model of human myeloma administration of AIN-457 weekly for 4 weeks after the first detection of tumor in mice led to a significant inhibition of tumor growth and reduced bone damage compared to isotype control mice. To understand the mechanism of action of anti-IL-17A mAb, we report here, that MM cells express IL-17A. We also observed that IL-17A knock-down inhibited MM cell growth and their ability to induce IL-6 production in co-cultures with BMSC. These pre-clinical observations suggest efficacy of AIN 457 in myeloma and provide the rationale for its clinical evaluation for anti-myeloma effects and for improvement of bone disease.

A patient with polymerase E1 deficiency (POLE1): clinical features and overlap with DNA breakage/instability syndromes

Background

Chromosome instability syndromes are a group of inherited conditions associated with chromosomal instability and breakage, often leading to immunodeficiency, growth retardation and increased risk of malignancy.

Case presentation

We performed exome sequencing on a girl with a suspected chromosome instability syndrome that manifested as growth retardation, microcephaly, developmental delay, dysmorphic features, poikiloderma, immune deficiency with pancytopenia, and myelodysplasia. She was homozygous for a previously reported splice variant, c.4444 + 3A > G in the POLE1 gene, which encodes the catalytic subunit of DNA polymerase E.

Conclusion

This is the second family with POLE1-deficency, with the affected individual demonstrating a more severe phenotype than previously described.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0177-y) contains supplementary material, which is available to authorized users.

Genetic variation within the histamine pathway among patients with asthma--a pilot study

OBJECTIVE

Histamine is an important mediator in the pathophysiology of asthma. We have previously reported that HRH1 is differentially expressed among those with asthma compared to those without asthma. Single histamine-related genes have also been associated with asthma. We aimed to evaluate known single nucleotide polymorphisms (SNPs) in genes along the histamine biotransformation and response pathway, and determine their association with asthma and HRH1 mRNA expression.

METHODS

We enrolled children and adults (n = 93) with/without asthma who met inclusion/exclusion criteria. Genotyping was performed for nine known SNPs in the HDC, HRH1, HRH4, HNMT and ABP1 genes. HRH1 mRNA expression was determined on RNA from buccal tissue. General linear model, Fisher's exact test and Chi-square test were used to determine differences in allele, genotype and haplotype frequency between subjects with and without asthma and differential HRH1 mRNA expression relative to genotype. Statistical significance was determined by p < 0.05.

RESULTS

No difference was observed in genotype/allele frequency for the nine SNPs between subjects with and without asthma. The HNMT-1639C/-464C/314C/3'UTRA haplotype was more frequently observed in those without asthma than those with asthma (p = 0.03). We also observed genetic differences relative to race and gender. HNMT 314 genotype CT was more frequent in males with asthma compared to those without asthma (p = 0.04).

CONCLUSIONS

Histamine pathway haplotype was associated with a diagnosis of asthma in our cohort but allele and genotype were not. Subgroup evaluations may also be important. Further studies are needed to determine the potential biological/clinical significance of our findings.

Utility of next generation sequencing in clinical primary immunodeficiencies

Primary immunodeficiencies (PIDs) are a group of genetically heterogeneous disorders that present with very similar symptoms, complicating definitive diagnosis. More than 240 genes have hitherto been associated with PIDs, of which more than 30 have been identified in the last 3 years. Next generation sequencing (NGS) of genomes or exomes of informative families has played a central role in the discovery of novel PID genes. Furthermore, NGS has the potential to transform clinical molecular testing for established PIDs, allowing all PID differential diagnoses to be tested at once, leading to increased diagnostic yield, while decreasing both the time and cost of obtaining a molecular diagnosis. Given that treatment of PID varies by disease gene, early achievement of a molecular diagnosis is likely to enhance treatment decisions and improve patient outcomes.

AT7519, A novel small molecule multi-cyclin-dependent kinase inhibitor, induces apoptosis in multiple myeloma via GSK-3beta activation and RNA polymerase II inhibition

Dysregulated cell cycling is a universal hallmark of cancer and is often mediated by abnormal activation of cyclin-dependent kinases (CDKs) and their cyclin partners. Overexpression of individual complexes are reported in multiple myeloma (MM), making them attractive therapeutic targets. In this study, we investigate the preclinical activity of a novel small-molecule multi-CDK inhibitor, AT7519, in MM. We show the anti-MM activity of AT7519 displaying potent cytotoxicity and apoptosis; associated with in vivo tumor growth inhibition and prolonged survival. At the molecular level, AT7519 inhibited RNA polymerase II (RNA pol II) phosphorylation, a CDK9, 7 substrate, associated with decreased RNA synthesis confirmed by [(3)H] Uridine incorporation. In addition, AT7519 inhibited glycogen synthase kinase 3beta (GSK-3beta) phosphorylation; conversely pretreatment with a selective GSK-3 inhibitor and shRNA GSK-3beta knockdown restored MM survival, suggesting the involvement of GSK-3beta in AT7519-induced apoptosis. GSK-3beta activation was independent of RNA pol II dephosphorylation confirmed by alpha-amanitin, a specific RNA pol II inihibitor, showing potent inhibition of RNA pol II phosphorylation without corresponding effects on GSK-3beta phosphorylation. These results offer new insights into the crucial, yet controversial role of GSK-3beta in MM and show significant anti-MM activity of AT7519, providing the rationale for its clinical evaluation in MM.

Lenalidomide, bortezomib, and dexamethasone in relapsed/refractory multiple myeloma (MM): Encouraging outcomes and tolerability in a phase II study

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Background: Lenalidomide (Revlimid, Len), bortezomib (VELCADE, Bz; maximum tolerated dose [MTD] 15 mg/1.0 mg/m2) ± dexamethasone (Dex; 20–40 mg; RVD) was well tolerated in a phase I study in relapsed/refractory MM patients (pts), with 58% ≥MR. This multicenter phase 2 study evaluated RVD efficacy and safety at the MTD. Methods: Patients received up to eight 21-day cycles of Len 15 mg (days 1–14), Bz 1.0 mg/m2 (days 1, 4, 8, 11), and Dex 40/20 mg (cycles 1–4/5–8, days of/after Bz dosing). After cycle 8, patients with stable/responding disease received maintenance (Len, days 1–14; Bz, days 1, 8; doses per end of cycle 8; Dex 10 mg, days 1, 2, 8, 9) until progression or unacceptable toxicity. Pts with significant peripheral neuropathy were excluded. Results: Among 64 pts, 38 (59%) had relapsed and 26 (41%) refractory/relapsed MM. Median number of prior therapies was two, including Len (8%), Bz (55%), Dex (92%), thalidomide (77%), and stem cell transplant (SCT, 36%). Forty-one pts (64%) completed 8 cycles, 33 continue on maintenance, 22 discontinued early (11 due to progressive disease). Toxicities were manageable, primarily grade (G) 1/2 myelosuppression; 2 developed DVT on aspirin, 2 G3 atrial fibrillation, 1 G3 peripheral neuropathy. One pt died on-study (fungal pneumonia, possibly due to Dex). Overall response rate (62 evaluable patients) was 84% ≥MR, including 21% CR/nCR, 68% ≥PR, which was independent of high-risk features and prior treatment ( Table ). Median duration of response is 24 weeks (range 6–81). Time-to-events data including median time to progression, progression-free survival, and 1-year survival rates will be presented. Conclusions: RVD is active and well tolerated in pts with relapsed/refractory MM, including pts who have received prior Len, Bz, thalidomide, and SCT. Durable responses have been observed and appear independent of adverse cytogenetics and other recognized risk factors.

[Table: see text]

[Table: see text]

Effect of the specific P53 stabilizer CBS9106 on multiple myeloma (MM)

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Background: The mutations of P53 tumor suppressor protein are associated with progressive in Multiple Myeloma (MM), conversely, stabilization of P53 leads to cell cycle arrest and apoptosis. In this study, we examined p53 protein expression and demonstrated the effect of P53 stabilization using a novel specific P53 stabilizer CBS9106 in MM. Method: We examined P53 protein expression using Immunoblot analysis, as well as the growth inhibitory effect of CBS9106 in MM cell lines and primary tumor cells from MM patients. We also defined whether CBS9106 can overcome the growth promoting effect of exogenous cytokines and bone marrow stroma cells (BMSCs) using [3H]-thymidine uptake assay. Results: Expression of P53 protein was observed in 3/3 primary tumor cells from MM patients and 6/6 MM cell lines. CBS9106 at low nM levels triggered cytotoxicity against p53 wild type MM cell lines and primary tumor cells from MM patients, associated with phosphorylation of P53 (serine15 and 20). In contrast, CBS9106 did not affect the survival of normal peripheral blood mononuclear cells from healthy volunteers at concentrations as high as 10 μM. This agent also induced G1 cell cycle arrest, followed by apoptosis associated with cleavage of caspase-3, -8, -9 and PARP. Neither growth stimulating cytokines (IL-6 and IGF-1) nor BMSCs protected against apoptotic effect of CBS9106. Moreover, we demonstrate that combination of CBS9106 with MDM2 inhibitor Nutrin3 or proteasome inhibitor bortezomib induces synergistic anti-MM activity in both P53 wild type MM cell lines and primary tumor cells from MM patients. Conclusions: Stabilizing P53 by CBS9106 represents a novel promising p53-based therapy in MM. These results provide the preclinical framework supporting evaluation of CBS9106 in clinical trials to improve patient outcome in MM.

No significant financial relationships to disclose.

Ascorbic acid inhibits antitumor activity of bortezomib in vivo

Earlier studies have shown that ascorbic acid (vitamin C) inhibits bortezomib-induced cytotoxicity against cancer cells in vitro. However, the clinical significance of vitamin C on bortezomib treatment is unclear. In this study, we examined whether daily oral intake of vitamin C inhibits antimultiple myeloma (MM) activities of bortezomib. Vitamin C, at orally achievable concentrations, inhibited in vitro MM cell cytotoxicity of bortezomib and blocked its inhibitory effect on 20S proteasome activity. Specifically, plasma collected from healthy volunteers taking 1 g/day vitamin C reduced bortezomib-induced MM cell death in vitro. This antagonistic effect of vitamin C against proteasome inhibitors is limited to the boronate class of inhibitors (bortezomib and MG262). In vivo activity of this combination treatment was then evaluated using our xenograft model of human MM in SCID (severe combined immune-deficient) mice. Bortezomib (0.1 mg/kg twice a week for 4 weeks) significantly inhibits in vivo MM cell growth, which was blocked by oral vitamin C (40 mg/kg/day). Therefore, our results for the first time show that vitamin C can significantly reduce the activity of bortezomib treatment in vivo; and importantly, suggest that patients receiving treatment with bortezomib should avoid taking vitamin C dietary supplements.

Higher risk factor burden and worse outcomes in urban carotid endarterectomy patients

BACKGROUND AND PURPOSE

Previous multicenter carotid endarterectomy (CEA) studies had screening criteria for patient comorbidities and very few blacks. We assessed the hypothesis that CEA results from two urban hospitals would approximate those of the previous multicenter trials.

METHODS

A retrospective chart review was completed at two urban hospitals for CEA procedures done in 2003 and 2004. Demographic information and past medical history was recorded. In hospital perioperative complications (stroke or myocardial infarction [MI]) were noted. We calculated an expected perioperative stroke rate based on trial figures and our proportion of symptomatic and asymptomatic patients.

RESULTS

Patients in our cohort had significantly higher rates of hypertension, diabetes, smoking, black race, and elderly status compared to previous trials. The expected perioperative stroke was 3.1%, and the observed stroke rate was 4.7% (P=0.36). Observed rates of MI (6.7%, P<0.001)) and stroke or MI (11.3%, P<0.0001) were higher than expected based on the previous trials. The stroke or MI rate in black subjects was higher (15.4% versus 5.6%, P=0.065) and this was significant at the hospital with lower CEA volume.

CONCLUSIONS

In two urban hospitals, CEA results were significantly worse than previous trials. Patient selection is likely to play a role because our cohort had higher numbers of hypertensives, diabetics, smokers, blacks, and elderly patients. Clinicians need to carefully consider the risk/benefit ratio of CEA in urban patients because our study shows that these patients have a large number of medical comorbidities and worse outcomes after CEA.

Novel etodolac analog SDX-308 (CEP-18082) induces cytotoxicity in multiple myeloma cells associated with inhibition of beta-catenin/TCF pathway

We have reported previously that R-enantiomer of etodolac (R-etodolac), which is under investigation in phase 2 clinical trials in chronic lymphocytic leukemia, induces potent cytotoxicity at clinically relevant concentrations in multiple myeloma (MM) cells. In this study, we demonstrated that SDX-308 (CEP-18082), a novel analog of etodolac, has more potent cytotoxicity than R-etodolac against both MM cell lines and patient MM cells, including tumor cells resistant to conventional (dexamethasone, doxorubicine, melphalan) and novel (bortezomib) therapies. SDX-308-induced cytotoxicity is triggered by caspase-8/9/3 activation and poly (ADP-ribose) polymerase cleavage, followed by apoptosis. SDX-308 significantly inhibits beta-catenin/T-cell factor pathway by inhibiting nuclear translocation of beta-catenin, thereby downregulating transcription and expression of downstream target proteins including myc and survivin. Neither interleukin-6 nor insulin-like growth factor-1 protect against growth inhibition triggered by SDX-308. Importantly, growth of MM cells adherent to bone marrow (BM) stromal cells is also significantly inhibited by SDX-308. Our data therefore indicate that the novel etodolac analog SDX-308 can target MM cells in the BM milieu.

A novel Bcl-2/Bcl-X(L)/Bcl-w inhibitor ABT-737 as therapy in multiple myeloma

Bcl-2 or Bcl-X(L) confers resistance to chemotherapy in multiple myeloma (MM). Here we characterized the effects of ABT-737, a potent small-molecule inhibitor of antiapoptotic proteins Bcl-2, Bcl-X(L) and Bcl-w with markedly higher affinity than previously reported compounds, on human MM cells. ABT-737 induces apoptosis in MM cells, including those resistant to conventional therapy. Examination of purified patient MM cells demonstrated similar results, without significant toxicity against normal peripheral blood mononuclear cells and MM bone marrow stromal cells. Importantly, ABT-737 decreases the viability of bortezomib-, dexamethasone-(Dex) and thalidomide-refractory patient MM cells. Additionally, ABT-737 abrogates MM cell growth triggered by interleukin-6 or insulin-like growth factor-1. Mechanistic studies show that ABT-737-induced apoptosis is associated with activation of caspase-8, caspase-9 and caspase-3, followed by poly(ADP-ribose) polymerase cleavage. Combining ABT-737 with proteasome inhibitor bortezomib, melphalan or dexamethasone induces additive anti-MM activity. Taken together, our study provides the rationale for clinical protocols evaluating ABT-737, alone and together with botezomib, mephalan or dexamethasone, to enhance MM cell killing, overcome drug resistance conferred by Bcl-2 and improve patient outcome in MM.