ALBERT

Description: We have performed 2,000+ Fluorodeoxyglucose PET (PET) scans for multiple myeloma (MM) staging and restaging at our facility since October 2001. While the usefulness of the PET scan for MM is reported by us and others elsewhere, we have reviewed our list of “incidental” but important findings, some of which are unique or occur more commonly with MM patients and some of which are common to many patients, the more common of which we present below: Occult infection occurs very commonly in patients with MM due to direct tumor effect on the immune system and to medication (especially high dose dexamethasone). Of the 2000+ PET scans for MM done at our facility, 300+ infections (about one half occult) have been detected by PET. These most commonly involve central lines (septic thrombophlebitis), diskitis, lung (either bacterial or fungal), and periodontal abscesses (a source of bacteremia in these patients), though non-catheter related spontaneous septic thrombophlebitis also occurs. While related to MM, extramedullary disease from MM (EMD) is seen more commonly with PET than MRI since PET has a wider field of view. In our series of 172 patients with both baseline PET and MRI, PET detected EMD in 11/11 patients versus MRI detection rate of 7/11. On follow-up, PET detected three times more EMD (29/31 sites) than MRI (9/31sites). Detection of EMD by PET at baseline is a profoundly negative prognostic factor in our series (12 month EFS 20% for EMD+ vs. 47% for EMD−, p = 0.002, and OS 42% for EMD+ vs. 70% for EMD−, p=0.005, n=48). Following tumor response in hypo- or non-secretory disease is difficult by standard prognostic factors (SPFs). FDG PET results were actively used for clinical management in 10 of 11 non-secretory patients at our facility. A major pitfall of PET scanning for MM comes from the use of steroids. Treatment with chemotherapy in general and steroids (i.e. prednisone or dexamethasone) in particular can result in a false negative PET scan by producing a profound but transient suppression of tumor metabolism. In addition, the hyperglycemic effect of the steroids produces competitive inhibition of FDG (a glucose analog) uptake, also causing suppression of FDG tumor uptake that can lead to an underestimation of disease. Second primary malignancies are frequently seen the MM age group. In our population, we have found unsuspected breast cancer, breast lymphoma, thyroid cancer, melanoma, colon cancer and lung cancer. In addition, we have found several functioning thyroid adenomas and premalignant colon polyps. Being a whole body imaging device for metabolism, FDG PET is a powerful though nonspecific tool for imaging that can not only help stage and restage the malignancy under question but which can yield a plethora of additional clinically useful information if used properly and with its limitations understood.

Description: Background: Aberrant expression levels of several miRs have been reported to independently associate with outcome of patients (pts) with CN-AML. In these reports, miR expression was profiled using microarray assays, which interrogate a selected subset of miRs. The advent of next-generation sequencing (NGS) has allowed unbiased measurement of miR expression, but, to our knowledge, NGS has not been used to identify miRs associated with prognosis of AML pts. Here, we analyze small RNA sequencing (smRNA-seq) data from a large cohort of younger adults with CN-AML, for whom outcome data were available, with the goal to identify new prognostic miRs. Methods: We performed smRNA-seq in 281 younger adults (aged 18-59 y) with de novo CN-AML. Cytogenetic analyses were performed in Cancer and Leukemia Group B (CALGB)/Alliance institutional laboratories using standard banding techniques; mutational analyses were done centrally using a targeted DNA sequencing platform. All pts were treated on frontline CALGB/Alliance protocols. Results: We first evaluated which miRs associated with overall survival (OS) in univariable analysis; we detected 9 such miRs. We then used a machine-learning approach, namely random forests, to identify miRs whose concomitant expression could generate an effective outcome predictor in CN-AML. To account for the effect of co-existing prognostic gene mutations, we included the European LeukemiaNet (ELN) risk group status in the random forest analyses. A total of 8 prognostic miRs were identified, 4 of which were also found to be prognostic in univariable analysis (underlined below), thus bringing the total number of unique prognostic miRs to 13: miR-511, miR-1193, miR-155, miR-4517, miR-3681, miR-2355, miR-628, miR-1266, miR-6715a, miR-1180, miR-6715b, miR-132, miR-146b. We used partitioning around medoids to divide our pts into clusters, based on the combined expression levels of the 13 prognostic miRs. Two such clusters were identified: cluster 1 comprised 173 pts and cluster 2 contained 108 pts. Regarding pretreatment and molecular features, pts in cluster 1 had lower percent of bone marrow blasts (P=.04), and had more frequently biallelic CEBPA mutations (P

Description: Progressive myocardial dysfunction, which can lead to cardiomyopathy, congestive heart failure, and sudden cardiac death, is a well-recognized late effect of several agents used in the treatment of childhood cancer. While the mechanism of this damage is not yet fully characterized, mounting data from rodent models implicate treatment-induced mitochondrial DNA (mtDNA) mutations as one potential mechanism of late cardiotoxicity. In the current study, the Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia (ALL) Consortium collected peripheral blood mononuclear cell samples from 93 long-term ALL survivors who were 4 or more years post-doxorubicin and other multi-agent therapy including asparaginase, corticosteroids, vincristine, and methotrexate, as well as radiation therapy. Data from healthy newborn children (n=45) represented a negative control and data from children receiving highly active antiretroviral therapy (HAART) (mean age=11.3 years; SD=2.61; n=51) provided a positive control for mtDNA mutations. Maximum cumulative doxorubicin dose varied among patients by treatment protocol (median=300 mg/m2; range 45 mg/m2 to 470 mg/m2). Median age at treatment was 4.5 years (range=0.5 to 20.8 years) and at mtDNA screening, 14.9 years (range=6.0 to 41.1 years). The mitochondrial tRNA genes and flanking regions were screened via PCR-based denaturing gradient gel electrophoresis (DGGE). Preliminary data showed 47 confirmed polymorphisms or mutations in 39 of 93 ALL survivors screened (42%), occurring in PCR products from 6 of 13 primer sets. The mutation incidence in HIV positive controls receiving HAART was 35 changes in 25 of 51 patients (49%). To date, the negative control population data suggest the occurrence of very few to no polymorphisms or mutations. Most mtDNA changes in ALL survivors were distinct from those in children receiving HAART, and included some sequence variants with suggested pathogenic characteristics. Analysis of cardiac function is ongoing. These data suggest that childhood ALL and its treatment may lead to mutations, over-expression of rare polymorphisms, and the induction of persistent changes that when spontaneously occurring have been associated with clinically significant cardiac effects. Conclusive evidence that doxorubicin-containing multi-agent therapy leads to persistent mtDNA mutations fundamental to cardiac dysfunction might allow for the isolation and prevention of these cardiotoxic effects.

Description: Patients with multiple myeloma (MM) are at an increased risk for infections with bacteria that require opsonization with complement. Because Streptococcus pneumoniae is the most frequently encountered pathogen in these patients, we investigated the ability of serum from patients with MM to mediate the binding of C3b, the major opsonin of the complement system, to S. pneumoniae. S. pneumoniae types 3, 14, and 25 were chosen for study, since S. pneumoniae type 3 activates primarily the classical complement pathway (CCP), type 25 primarily the alternative complement pathway (ACP), and type 14 both pathways. S. pneumoniae were treated with normal serum or serum from 17 patients with MM, and the bound C3b was quantified with fluorescein-conjugated anti-C3 in a spectrophotofluorometric assay. Despite normal or elevated serum concentrations of C3, total hemolytic complement, and C-reactive protein in all of the MM sera, factor B in 16/17 such sera, and C4 in 14/17 MM sera studied, all 17 sera demonstrated a defect in C3b binding to type 3 (32.7% +/- 6% of normal). In addition, serum from 15/17 patients bound decreased amounts of C3b to types 14 (39.6% +/- 8%) and 25 (52.2% +/- 8%). Mixing normal serum with MM serum restored MM C3b binding activity to all three S. pneumoniae types, suggesting that the defect was related to a deficiency rather than an inhibitor of C3 activation. Although MM patients are unable to produce specific antibodies to bacterial antigens, the addition of anti-S. pneumoniae antibodies to MM serum did not enhance C3b binding to any of the S. pneumoniae types. However, when S. pneumoniae were opsonized in a mixture of MM serum and C3-depleted normal serum, C3b binding was restored to all three S. pneumoniae types, demonstrating that MM C3 functions normally in the presence of other normal serum factors. In the present studies, the MM C3b binding defect appeared to correlate with the incidence of S. pneumoniae infections. Serum from patients with a history of an S. pneumoniae infection bound significantly less C3 (20.5% +/- 4%) than those study patients without a history of an S. pneumoniae infection (55.8% +/- 8%) (p less than 0.0025). Thus, MM serum has a defect in the activation of C3, and this may contribute to the increased susceptibility of MM patients to S. pneumoniae infections.

Description: Erythroid progenitor cells in +/+ and Sl/Sld fetal livers manifested as burst-forming units-erythroid (BFU-E) and colony-forming units- erythroid (CFU-E) were assayed in vitro during early development. The proportion of BFU-E was higher as mutant than in normal fetal livers. On the other hand, the proportion of CFU-E was less in the mutant than in the normal. These results suggest that the defect in Sl/Sld fetal hepatic erythropoiesis is expressed at the steps of differentiation that effect the transition from BFU-E to CFU-E.

Description: Key Points IGH translocations in myeloma can occur through at least 5 mechanisms. t(11;14) and t(14;20) DH-JH rearrangement-mediated translocations occur indicating these appear to occur in a pregerminal center cell.

Description: Introduction - Multiple Myeloma (MM) is a hematologic malignancy characterized by clonal growth of differentiated plasma cells (PCs). Despite improvement in MM therapy, the disease remains mostly incurable and is characterized by recurrent relapses with development of resistant clones that eventually lead to patient death. The pathways that lead to resistant and aggressive MM are not fully understood highlighting the need to improve our understanding of MM biology to identify potential new pathways and therapeutical targets. PHD Finger Protein 19 (PHF19) is a regulator of Polycomb Repressive Complex 2 (PRC2), the sole methyltransferase complex capable of catalyzing H3K27me3 to induce and enforce gene repression. PRC2 employs enhancer of zeste homolog 1 and 2 (EZH1/EZH2) as enzymatic subunits to hypermethylate H3K27. While overexpression and gain of function mutations of EZH1/2 have been observed in many cancers the role of this particular pathway in MM remains poorly understood. In the present study, we report on PHF19 as a new candidate gene to play a potential crucial role in MM oncogenesis. Methods- Gene expression profiling (GEP; Affymetrix U133 Plus 2.0) was performed on 739 MM patients (from total therapy trials [TT] 3-5; low risk MM n=636, high risk MM n=103), 42 patients with monoclonal gammopathy of undetermined significance (MGUS), 73 smoldering MM patients, 42 patients with primary plasma cell leukemia and 34 healthy donors. Myeloma risk was determined by the GEP 70 signature as previously defined. To test the implications of functional PHF19 knock down (KD) we used TRIPZ inducible PHF19 shRNA vs. scrambled control (Dharmacon) in two MM cell lines (JJN3 and ARP1). Real time PCR as well as western blotting was used to confirm PHF19 KD as well as to elucidate the effect on H3K27me3 (Cell Signaling). Functional in vitro studies included proliferation (Promega), clonogenic assays (StemCell), cell cycle and apoptosis assays (both Invitrogen). In vivo studies were performed using SCID mice that were subjected to tail vain injection with PHF19 KD JJN3 cells (n=10) or scrambled shRNA control (n=10). Weekly ELISA (Bethyl) and in vivo imaging (Xenogen) were performed and survival was recorded. Results- GEP of the previously mentioned patient populations and healthy controls identified PHF19 (chr9q33.2) as a candidate gene that was consistently dysregulated in MM patients. Mean expression levels at different MM stages correlated with disease aggressiveness (ANOVA, p10.46) at diagnosis correlated significantly with adverse clinical parameters, including ISS III, anemia and elevated LDH, as well as worse overall survival (5 yr OS = 29% for patients with high PHF19 expression vs 77% for patients with low PHF19 expression [log275% reduction in both cell lines, p

Description: Platelet response to activation varies widely between individuals but shows interindividual consistency and strong heritability. The genetic basis of this variation has not been properly explored. We therefore systematically measured the effect on function of sequence variation in 97 candidate genes in the collagen and adenosine-diphosphate (ADP) signaling pathways. Resequencing of the genes in 48 European DNA samples nearly doubled the number of known single nucleotide polymorphisms (SNPs) and informed the selection of 1327 SNPs for genotyping in 500 healthy Northern European subjects with known platelet responses to collagen-related peptide (CRP-XL) and ADP. This identified 17 novel associations with platelet function (P 〈 .005) accounting for approximately 46% of the variation in response. Further investigations with platelets of known genotype explored the mechanisms behind some of the associations. SNPs in PEAR1 associated with increased platelet response to CRP-XL and increased PEAR1 protein expression after platelet degranulation. The minor allele of a 3′ untranslated region (UTR) SNP (rs2769668) in VAV3 was associated with higher protein expression (P = .03) and increased P-selectin exposure after ADP activation (P = .004). Furthermore the minor allele of the intronic SNP rs17786144 in ITPR1 modified Ca2+ levels after activation with ADP (P 〈 .004). These data provide novel insights into key hubs within platelet signaling networks.

Description: The acylation of megakaryocyte proteins was studied with special emphasis on the myristoylation and palmitoylation of the glycoprotein (GP) Ib complex. Guinea pig megakaryocytes were purified and separated into subpopulations at different phases of maturation. Cells were incubated with [3H]myristate, [3H]palmitate, or [3H]acetate to study endogenous protein acylation. Cycloheximide was used to distinguish between cotranslational and posttranslational acylation and hydroxylamine to distinguish between thioester and amide linkages. After incubations, delipidated proteins or GPIb complex subunits, immunoprecipitated with PG-1, AN-51 or FMC-25 monoclonal antibody, were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and assessed by fluorography. Radiolabeled fatty acids bound to GPIX and GPIb were also analyzed by high pressure liquid chromatography (HPLC) and scintillation spectrometry. With [3H]myristic acid and [3H]acetate, GPIX was found to be a major myristoylated protein in megakaryocytes and CHRF-288 cells. Myristic acid was linked to GPIX by an amide bond, and this process occurred cotranslationally. With [3H]acetate, GPIb was primarily palmitoylated, but with [3H]myristate, GPIb was acylated with about equal mounts of myristic acid and palmitic acids. Both fatty acids were linked to GPIb by thioester bonds, and acylation was posttranslational. The myristoylation of GPIX while the palmitoylation of GPIb occurred throughout megakaryocyte maturation. Myristoylation and palmitoylation may have different functions relevant to the assembly of the GPIb complex in megakaryocytes.

Description: Sickle cell disease (SCD) is most often due to homozygosity for the hemoglobin sickle (Hb S) missense mutation of the β-globin gene (HBB:c.20A〉T). SCD can also result from compound heterozygosity for Hb S and other β-chain variants or β-thalassemia (β-thal). Loss-of-function point mutations of the β-globin gene that abolish (β0) or reduce (β+) production of normal β-chains are the most common cause of β-thal, with a minority of alleles being larger deletions. Patients with Hb S/β0-thal typically have severe SCD, whereas residual β-chain synthesis in Hb S/β+-thal is associated with lower hemoglobin S concentrations and less severe disease. It has long been recognized that the high-level production of β-like chains throughout development is controlled by a cis regulatory element, the β-globin locus control region (βLCR). The βLCR is located 5.7 kb to 21.2 kb upstream of the ε-globin gene, and consists of five DNase I hypersensitivity sites designated HS1 through HS5. Twelve naturally occurring βLCR deletions have been reported, most resulting in complete loss of expression of the β-like genes and a carrier phenotype that resembles (εγδβ)0-thal. In these patients, neonatal hemolytic anemia is common due to impaired γ-chain synthesis required for Hb F. Once the γ→β switch has occurred during the first six months of infancy, the phenotype resolves to one of thalassemia trait with normal Hb A2. While the phenotype is well established for carriers of large deletions that remove all or most of the HS regions, the contribution of individual HS regions to β-globin gene expression in human has yet to be elucidated. To this end, it is important to identify and characterize naturally occurring deletions that involve individual HS regions or combinations thereof. Here, we report a case of SCD due to a novel βLCR deletion involving only HS3 and HS4. The proband is a 6-year old boy born to healthy non-sanguineous parents of Caribbean decent. Newborn screening was negative for SCD, with the Hb profile being consistent with Hb S trait (Hb F 79.1%, Hb A 6.0%, Hb S 4.0%, Hb Bart’s 9.1%). Postnatally there was no significant jaundice or clinically diagnosed anemia. The proband had no clinical complaints and growth and development were normal until age 5 years when he was diagnosed with SCD during an admission for unexplained abdominal pain and an enlarged spleen. He was noted to have microcytic anemia (Hb 87 g/L, MCV 68.2 fL), and the peripheral blood smear showed sickle cells, Howell-Jolly bodies and target cells. The Hb profile was suggestive of Hb S/β+-thal with 19.4% Hb A, 72.7% Hb S, and Hb A2 within normal range. He has had one vasoocclusive event since the diagnosis and had tonsillectomy for obstructive sleep apnea. Nucleotide sequence analysis demonstrated that the proband is heterozygous for the Hb S mutation (HBB:c.20A〉T) with no other mutations of the β-globin gene. He was also shown to be heterozygous for the 3.7 kb α-globin gene deletion (-α3.7/αα). As this genotype does not explain the reduced expression of Hb A and SCD phenotype, we investigated the possibility of compound heterozygosity for Hb S and a βLCR deletion. Multiplex ligation-dependent probe amplification (MLPA) (MRC-Holland) demonstrated the presence of a novel deletion encompassing HS3 and HS4. Sequence analysis of the junction fragment established that the deletion spans a total of 4,860 bp (HGVS nomenclature NG_000007.3:g.8510_13369del). To date, this is the smallest reported βLCR deletion that is associated with a clinically significant phenotype. Our patient had milder clinical picture with no SCD-related symptoms until 5 years of age and absence of a clinically significant hemolytic anemia at birth. The presence of 19.4% Hb A was compatible with the phenotype of Hb S/β+-thal. This indicates that deletions involving only HS3 and HS4 are associated with a significant but not complete reduction of β-globin gene expression. Interestingly, the newborn screening profile was typical of sickle trait, leading to the important observation that the βLCR is not required for the low level β-globin gene expression at birth, and providing further insight into the function of βLCR and its contribution to γ→β switching in humans. Disclosures No relevant conflicts of interest to declare.