Sophie L. Corthals

Mechanisms of peripheral neuropathy associated with bortezomib and vincristine in patients with newly diagnosed multiple myeloma: a prospective analysis of data from the HOVON-65/GMMG-HD4 trial.

BACKGROUND Bortezomib-induced peripheral neuropathy is a dose-limiting toxicity in patients with multiple myeloma, often requiring adjustment of treatment and affecting quality of life. We investigated the molecular profiles of early-onset (within one treatment cycle) versus late-onset (after two or three treatment cycles) bortezomib-induced peripheral neuropathy and compared them with those of vincristine-induced peripheral neuropathy during the induction phase of a prospective phase 3 trial. METHODS In the induction phase of the HOVON-65/GMMG-HD4 trial, patients (aged 18-65 years) with newly diagnosed Salmon and Durie stage 2 or 3 multiple myeloma were randomly assigned to three cycles of bortezomib-based or vincristine-based induction treatment. We analysed the gene expression profiles and single-nucleotide polymorphisms (SNPs) of pretreatment samples of myeloma plasma cells and peripheral blood, respectively. This study is registered, number ISRCTN64455289. FINDINGS We analysed gene expression profiles of myeloma plasma cells from 329 (39%) of 833 patients at diagnosis, and SNPs in DNA samples from 369 (44%) patients. Early-onset bortezomib-induced peripheral neuropathy was noted in 20 (8%) patients, and 63 (25%) developed the late-onset type. Early-onset and late-onset vincristine-induced peripheral neuropathy was noted in 11 (4%) and 17 (7%) patients, respectively. Significant genes in myeloma plasma cells from patients that were associated with early-onset bortezomib-induced peripheral neuropathy were the enzyme coding genes RHOBTB2 (upregulated by 1·59 times; p=4·5×10(-5)), involved in drug-induced apoptosis, CPT1C (1·44 times; p=2·9×10(-7)), involved in mitochondrial dysfunction, and SOX8 (1·68 times; p=4·28×10(-13)), involved in development of peripheral nervous system. Significant SNPs in the same patients included those located in the apoptosis gene caspase 9 (odds ratio [OR] 3·59, 95% CI 1·59-8·14; p=2·9×10(-3)), ALOX12 (3·50, 1·47-8·32; p=3·8×10(-3)), and IGF1R (0·22, 0·07-0·77; p=8·3×10(-3)). In late-onset bortezomib-induced peripheral neuropathy, the significant genes were SOD2 (upregulated by 1·18 times; p=9·6×10(-3)) and MYO5A (1·93 times; p=3·2×10(-2)), involved in development and function of the nervous system. Significant SNPs were noted in inflammatory genes MBL2 (OR 0·49, 95% CI 0·26-0·94; p=3·0×10(-2)) and PPARD (0·35, 0·15-0·83; p=9·1×10(-3)), and DNA repair genes ERCC4 (2·74, 1·56-4·84; p=1·0×10(-3)) and ERCC3 (1·26, 0·75-2·12; p=3·3×10(-3)). By contrast, early-onset vincristine-induced peripheral neuropathy was characterised by upregulation of genes involved in cell cycle and proliferation, including AURKA (3·31 times; p=1·04×10(-2)) and MKI67 (3·66 times; p=1·82×10(-3)), and the presence of SNPs in genes involved in these processes-eg, GLI1 (rs2228224 [0·13, 0·02-0·97, p=1·18×10(-2)] and rs2242578 [0·14, 0·02-1·12, p=3·00×10(-2)]). Late-onset vincristine-induced peripheral neuropathy was associated with the presence of SNPs in genes involved in absorption, distribution, metabolism, and excretion-eg, rs1413239 in DPYD (3·29, 1·47-7·37, 5·40×10(-3)) and rs3887412 in ABCC1 (3·36, 1·47-7·67, p=5·70×10(-3)). INTERPRETATION Our results strongly suggest an interaction between myeloma-related factors and the patients genetic background in the development of treatment-induced peripheral neuropathy, with different molecular pathways being implicated in bortezomib-induced and vincristine-induced peripheral neuropathy.

Stability and prognostic influence of FLT3 mutations in paired initial and relapsed AML samples

In acute myeloid leukemia (AML), activating mutations in the fms-like tyrosine kinase 3 (FLT3) gene predict poor prognosis. We determined FLT3 internal tandem duplications (FLT3/ITD) and D835 point mutations in paired initial and relapse samples from 80 pediatric and adult AML patients. One D835 point mutation was found in an initial pediatric AML sample. Fms-like tyrosine kinase 3/ITDs were present in 21 initial and 22 relapse samples (26.3 and 27.5%, respectively). Interestingly, FLT3/ITD positivity was related to a significantly shorter time to relapse, most pronounced when the ITD-positive status was found at relapse (P<0.001). However, FLT3/ITD status changed between diagnosis and relapse in 14 cases. In four patients, the FLT3/ITD became undetectable at relapse in five patients FLT3/ITDs were only detected at relapse, and in five patients the length or number of FLT3/ITDs changed. Gain of FLT3/ITDs may suggest oligoclonality with selective outgrowth of the FLT3/ITD-positive clone, whereas losses may reflect ITDs in the more mature leukemic cells rather than in the leukemic stem cell, or, alternatively, that other genetic aberrations provided a greater selective advantage. Studying FLT3/ITD kinetics in minimal residual disease setting may provide some answers for the changes we observed. Fms-like tyrosine kinase 3/ITD is a relevant marker for prognosis, and remains an important target for therapeutic inhibition.

Genetic Factors Underlying the Risk of Thalidomide-Related Neuropathy in Patients With Multiple Myeloma

PURPOSE To indentify genetic variation that can modulate and predict the risk of developing thalidomide-related peripheral neuropathy (TrPN). PATIENTS AND METHODS We analyzed DNA from 1,495 patients with multiple myeloma. Using a custom-built single nucleotide polymorphism (SNP) array, we tested the association of TrPN with 3,404 SNPs. The SNPs were selected in predicted functional regions within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and adverse effects associated with myeloma and its therapy. Patient cases and controls were derived from two large clinical trials that compared thalidomide with conventional-based treatment in myeloma patients (Medical Research Council Myeloma-IX and HOVON-50/GMMG-HD3). RESULTS We report TrPN associations with SNPs-ABCA1 (rs363717), ICAM1 (rs1799969), PPARD (rs2076169), SERPINB2 (rs6103), and SLC12A6 (rs7164902)-where we show cross validation of the associations in both trials. To investigate whether TrPN SNP associations were related to exposure to thalidomide only or general drug-related peripheral neuropathy, we performed a second analysis on patients treated with vincristine. We report SNPs associated with vincristine neuropathy, with a seemingly distinct underlying genetic mechanism. CONCLUSION Our results are consistent with the hypothesis that an individuals risk of developing a peripheral neuropathy after thalidomide treatment can be mediated by polymorphisms in genes governing repair mechanisms and inflammation in the peripheral nervous system. These findings will contribute to the development of future neuroprotective strategies with thalidomide therapy and the better use of this important compound.

Micro-RNA-15a and micro-RNA-16 expression and chromosome 13 deletions in multiple myeloma

We have used copy number variation (CNV) analysis with SNP mapping arrays for miRNA-15a and miRNA-16-1 expression analysis in patients with multiple myeloma (MM) with or without deletion of chromosome 13q14. MiRNA-15a and miRNA-16 display a range of expression patterns in MM patients, independent of the chromosome 13 status. These findings suggest that genes other than miR-15a and miR-16 may explain the prognostic significance of 13q14 deletions.

MicroRNA signatures characterize multiple myeloma patients.

MicroRNAs (miRNAs) are a class of small non-coding single-stranded RNAs of ~22 nucleotides in length that regulate protein levels by binding to either partially or complete complementary sites in messenger RNAs (mRNAs), leading to translational repression or transcript degradation, respectively. MiRNAs have a role in critical biological processes including cellular growth and differentiation. Recent studies showed that miRNAs have an important role in the pathogenesis of multiple myeloma (MM) and that miRNA signatures are associated with different cytogenetic subtypes. Unsupervised analyses of miRNA expression in MM identified unique clusters, which were not associated with chromosomal abnormalities, while supervised analysis showed a specific miRNA expression pattern for MM subgroups.1, 2, 3

Abstract 4737: Genetic determinants associated with multiple myeloma risk in three large population sets

Classic epidemiological approaches aimed at identifying environmental exposures associated with aetiology of Multiple Myeloma (MM) have failed to identify a common cause. The majority of the studies aimed at identifying genetic risk in MM have been underpowered and limited in coverage. We have taken a candidate gene approach by assaying 3,404 single nucleotide polymorphism (SNPs) selected in approximately 983 candidate genes on a “Bank on a Cure” (BOAC) Targeted Genotyping assay, focusing on coding SNPs and SNPs in regulatory regions. SNPs were genotyped using DNA extracted from peripheral blood. 2595 presenting MM cases were derived from clinical trials held within the UK (1228), US (697) and the Netherlands (670). Genotype data were available from large population control datasets, which were used to examine 1809 SNPs for association with MM risk. The control population sets consisted of the UK Wellcome Trust Case-Control Consortium 2 (WTCCC2) study with 3,000 individuals from the 1958 British Birth Cohort and the UK Blood Service collections, genotyped on both the Illumina 1.2M Duo (Human1-2M-DuoCustom_v1) and the Affymetrix SNP 6.0 array; 2350 US Caucasian controls from the Nurses’ Health Study (NHS), genotyped on the Illumina 550K chip, and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), genotyped on Illumina 317K plus 240K; and 5974 Dutch >55yrs old population controls from the Erasmus Rotterdam Health for the Elderly (ERGO) study, genotyped on the Illumina 550K array. We have also used fluorescence in situ hybridization (FISH) status for 702 of the UK cases to perform a subset analysis for hyperdiploidy and IgH translocations, two of the major myeloma pathogenic subgroups. Quality control measures were performed on the datasets to protect against artificial effects, induced by population stratification, cross platform genotyping and low genotyping quality (95% call rate and HWE (p Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4737.