Association of frailty with clinical outcomes in myelofibrosis: a retrospective cohort study.

There is limited understanding of the impact of frailty on clinical outcomes in patients with myelofibrosis (MF). In this retrospective cohort study on 439 chronic phase MF patients [mean age: 68·7 ± 12 years; median follow-up: 3·4 years (IQR 0·4-8·6)] from 2004 till 2018, we used a 35-variable frailty index (FI) to categorise patient's frailty status as fit (FI < 0·2, reference), prefrail (FI 0·2-0·29) or frail (FI ≥ 0·3). The association of frailty with overall survival (OS) and cumulative JAK inhibitor (JAKi) therapy failure was measured using hazard ratio (HR, 95% CI). In multivariable analysis, prefrail (HR 1·7, 1·1-2·5) and frail patients (HR 2·9, 1·6-5·5), those with higher DIPSS score (HR 2·5, 1·6-3·9) and transfusion dependency (HR 1·9, 1·3-2·9) had shorter OS. In a subset analysis of patients on JAKi treatment (n = 222), frail patients (HR 2·5, 1·1-5·7), patients with higher DIPSS score (HR 1·7, 1·0-3·1) and transfusion dependence (HR 1·7, 1·1-2·7) had higher cumulative incidence of JAKi failure. Age, comorbidities, ECOG performance status, and MPN driver mutations did not impact outcomes. Thus, higher frailty scores are associated with worse OS and increased JAKi failure in MF, and is a superior indicator of fitness in comparison to age, comorbidities, and performance status.

Association of Factors Influencing Selection of Upfront Hematopoietic Cell Transplantation versus Nontransplantation Therapies in Myelofibrosis.

Despite the curative potential of allogeneic hematopoietic cell transplantation (HCT) for myelofibrosis (MF), a significant number of patients with MF do not undergo HCT. Factors influencing treatment preferences in these patients have not been well studied. This study was conducted to identify patient-, disease-, and donor-related factors influencing the decision regarding HCT in patients with MF. A secondary objective was to compare survival between patients who elected upfront HCT and those who opted for nontransplantation therapy. We conducted a retrospective chart review amongst patients meeting criteria for transplant indication, evaluating clinical characteristics, treatment preferences, and outcomes. Of the 183 study eligible patients age <70 years, 129 (70%) developed an HCT indication. Age >60 years was significantly associated with higher rates of HLA-typing refusal (13 of 72 versus 1 of 44; P = .02). Caucasian ethnicity was significantly associated with an increased rate of identifying well-matched donors compared with non-Caucasian ethnicity (75% versus 48%; P = .02). Of the 69 patients with well-matched donors, 34 (49%) preferred to not pursue upfront HCT despite an indication for transplantation. Patient preference for nontransplantation therapies was the most common reason for declining HCT. We did not find any difference in survival between patients pursuing upfront HCT and those opting for nontransplantation therapies, although more patients in the HCT arm were in remission at the last follow-up. Patients of Caucasian ethnicity were significantly more likely than non-Caucasian patients to identify a well-matched donor. Despite availability of a well-matched donor, a significant proportion of MF patients with an indication for transplantation do not pursue HCT. Patient age, donor type, and patient preference play major roles in the selection of upfront HCT. Although a survival difference was not observed between upfront HCT versus non-transplant therapy, more patients in the HCT arm were in remission at the last follow-up.

Measurable residual disease monitoring provides insufficient lead-time to prevent morphologic relapse in the majority of patients with core-binding factor acute myeloid leukemia.

Core-binding factor acute myeloid leukemia is characterized by t(8;21) or inv(16) and the fusion proteins RUNX1-RUNX1T1 and CBFB-MYH11. International guidelines recommend monitoring for measurable residual disease every 3 months for 2 years after treatment. However, it is unknown if serial molecular monitoring can predict and prevent morphologic relapse. We conducted a retrospective single-center study of 114 patients in complete remission who underwent molecular monitoring with RT-qPCR of RUNX1-RUNX1T1 or CBFB-MYH11 transcripts every 3 months. Morphologic relapse was defined as re-emergence of >5% blasts and molecular relapse as ≥1 log increase in transcript level between 2 samples. Over a median follow-up time of 3.7 years (range 0.2-14.3), remission persisted in 71 (62.3%) patients but 43 (37.7%) developed molecular or morphologic relapse. Patients who achieved <3 log reduction in RUNX1-RUNX1T1 or CBFB-MYH11 transcripts at end of chemotherapy had a significantly higher risk of relapse compared to patients who achieved ≥3 log reduction (61.1% vs. 33.7%, p=0.004). The majority of relapses (74.4%, n=32) were not predicted by molecular monitoring and occurred rapidly with <100 days from molecular to morphologic relapse. Molecular monitoring enabled the detection of impending relapse and permitted pre-emptive intervention prior to morphologic relapse in only 11 (25.6%) patients. The current practice of molecular monitoring every 3 months provided insufficient lead-time to identify molecular relapses and prevent morphologic relapse in the majority of patients with core-binding factor acute myeloid leukemia treated at our institution. Further research is necessary to determine the optimal monitoring strategies for these patients.

The mutational landscape of accelerated- and blast-phase myeloproliferative neoplasms impacts patient outcomes.

There is a paucity of data regarding the impact of mutations on outcomes in accelerated-phase (AP) and blast-phase (BP) myeloproliferative neoplasms (MPNs). Moreover, it is unknown whether mutational status affects survival, as seen in chronic-phase MPNs. Therefore, we performed a retrospective analysis of all patients treated at our institution with AP/BP MPNs (N = 122; AP = 14; BP = 108) to comprehensively describe the mutational profile and correlate with clinical outcomes. Targeted sequencing with a 54-gene panel was performed. Forty-four patients were treated with intensive therapy, 27 with nonintensive therapy, and 51 with best supportive care (BSC). The most common mutation was JAK2V617F, occurring in 55% of subjects; CALR was found in 13% of patients and MPL in 6%. Thirty-two (26%) patients were triple negative. Other frequently mutated genes were ASXL1 (30%), TET2 (25%), SRSF2 (22%), RUNX1 (20%), and TP53 (17%). Mutations in 1, 2, 3, and ≥4 genes were seen in 15%, 13%, 25%, and 46% of patients, respectively. There was no difference in survival between patients treated with intensive vs nonintensive therapy, and the benefit of intensive therapy was limited to patients who were able to undergo transplantation. TP53 was the only individual mutation to correlate with shorter overall survival (hazard ratio, 1.89; P = .03). In the multivariate analysis, mutated TP53, ≥4 mutations, low albumin, increased peripheral blood blasts, ≥3 cytogenetic abnormalities, and BSC were associated with shorter survival. In conclusion, mutational data enhance the understanding of patients with AP/BP MPN who are likely to benefit from current therapeutic options.

AML refractory to primary induction with Ida-FLAG has a poor clinical outcome.

We evaluated outcomes of 100 patients with high risk AML treated with Ida-FLAG induction as first-line therapy. 72 achieved remission with one cycle; 19 did not. High risk cytogenetics and TP53 mutations were associated with failure to achieve remission. In those reaching remission, allogeneic bone marrow transplantation was associated with better relapse-free and overall survival. Those not achieving remission with induction therapy were extremely unlikely to reach remission with further therapy and had a dismal prognosis. Exploratory molecular analysis confirmed persistence of the dominant genetic mutations identified at diagnosis. Ex vivo chemosensitivity did not demonstrate significant differences between responders and non-responders. Thus, Ida-FLAG induction has a high chance of inducing remission in patients with high risk AML. Those achieving remission require allogeneic transplantation to achieve cure; those not achieving remission rarely respond to salvage chemotherapy and have a dismal outcome. Alternatives to conventional chemotherapy must be considered in this group.

Frequency of common polymorphisms in Caveolin 1 (CAV1) gene in adults with high serum triglycerides from Colombian Caribbean Coast / Frecuencia de polimorfismos comunes en el gen de Caveolina 1 (CAV1) en adultos con hipertrigliceridemia en el Caribe Colombiano

Abstract Background: Caveolin 1 gene (CAV1) has been associated with insulin resistance, metabolic syndrome and hypertension in humans. Also, it has been related to high serum triglycerides in rodents, however there is little evidence of this relation in humans. Aim: To describe frequencies of common variations in CAV1 in adults with high serum triglycerides. Methods: A case-control study was carried out with adults from Colombian Caribbean Coast. A whole blood sample was employed to measure serum concentrations of triglycerides, glucose, total cholesterol and HDLc. Six common Single Nucleotide Polymorphism (SNP) in CAV1 were genotyped (rs926198, rs3779512, rs10270569, rs11773845, rs7804372 and rs1049337). Allelic and genotypic frequencies were determined by direct count and Hardy-Weinberg Equilibrium (HWE) was assessed. Case and control groups were compared with null-hypothesis tests. Results: A total of 220 cases and 220 controls were included. For rs3779512 an excess in homozygotes frequency was found within case group (40.4% (GG), 41.3% (GT) and 18.1% (TT); Fis=0.13, p=0.03). Another homozygotes excess among case group was found in rs7804372 (59.5% (TT), 32.3% (TA) and 8.2% (AA); Fis= 0.12, p= 0.04). In rs1049337, cases also showed an excess in homozygotes frequency (52.7% (CC), 35.0% (CT) and 12.3% (TT); Fis= 0.16, p= 0.01). Finally, for rs1049337 there were differences in genotype distribution between case and control groups (p <0.05). Conclusion: An increased frequency of homozygote genotypes was found in subjects with high serum triglycerides. These findings suggest that minor alleles for SNPs rs3779512, rs7804372 and rs1049337 might be associated to higher risk of hypertriglyceridemia.

Resumen Introducción: En humanos, el gen Caveolina 1 (CAV1) ha sido asociado con resistencia a la insulina, síndrome metabólico e hipertensión. Además, ha sido relacionado con hipertrigliceridemia en roedores, sin embargo existe poca evidencia de esta relación en humanos. Objetivo: Describir la frecuencia de variaciones comunes del gen CAV1 en adultos con hipertrigliceridemia. Métodos: Se realizó un estudio de casos y controles con adultos del Caribe Colombiano. Fue usada una muestra de sangre venosa periférica para medir las concentraciones séricas de triglicéridos, glucosa, colesterol total y colesterol HDL. Fueron genotipificados seis Polimorfismos de Nucleótido Simple (SNP) en CAV1 (rs926198, rs3779512, rs10270569, rs11773845, rs7804372 y rs1049337). Las frecuencias alélicas y genotípicas se determinaron por conteo directo y se evaluó el equilibrio de Hardy-Weinberg. Los grupos de casos y controles se compararon con pruebas de hipótesis nula. Resultados: Se incluyeron un total de 220 casos y 220 controles. Para rs3779512 se encontró un exceso de homocigotos en el grupo de casos (40.4% (GG), 41.3% (GT) y 18.1% (TT); Fis= 0.13, p= 0.03). Fue encontrado otro exceso de homocigotos en el grupo de casos al analizar el rs7804372 (59.5% (TT), 32.3% (TA) y 8.2% (AA); Fis= 0.12, p= 0.04). En rs1049337, los casos también tuvieron un exceso en la frecuencia de homocigotos (52.7% (CC), 35.0% (CT) y 12.3% (TT); Fis= 0.16, p= 0.01). Finalmente, hubo diferencias en la distribución genotípica del rs1049337 entre los grupos de casos y controles (p <0.05). Conclusiones: Se encontró una elevada frecuencia de homocigotos en los sujetos con hipertrigliceridemia. Estos hallazgos sugieren que los alelos menores de los SNPs rs3779512, rs7804372 y rs1049337 podrían estar asociados con trigliceridemia elevada.

Cancer patient perceptions on the ethical and legal issues related to biobanking.

BACKGROUND: Understanding the perception of patients on research ethics issues related to biobanking is important to enrich ethical discourse and help inform policy. METHODS: We examined the views of leukemia patients undergoing treatment in clinics located in the Princess Margaret Hospital in Toronto, Ontario, Canada. An initial written survey was provided to 100 patients (64.1% response rate) followed by a follow-up survey (62.5% response rate) covering the topics of informed consent, withdrawal, anonymity, incidental findings and the return of results, ownership, and trust. RESULTS: The majority (59.6%) preferred one-time consent, 30.3% desired a tiered consent approach that provides multiple options, and 10.1% preferred re-consent for future research. When asked different questions on re-consent, most (58%) reported that re-consent was a waste of time and money, but 51.7% indicated they would feel respected and involved if asked to re-consent. The majority of patients (62.2%) stated they had a right to withdraw their consent, but many changed their mind in the follow-up survey explaining that they should not have the right to withdraw consent. Nearly all of the patients (98%) desired being informed of incidental health findings and explained that the information was useful. Of these, 67.3% of patients preferred that researchers inform them and their doctors of the results. The majority of patients (62.2%) stated that the research institution owns the samples whereas 19.4% stated that the participants owned their samples. Patients had a great deal of trust in doctors, hospitals and government-funded university researchers, moderate levels of trust for provincial governments and industry-funded university researchers, and low levels of trust towards industry and insurance companies. CONCLUSIONS: Many cancer patients surveyed preferred a one-time consent although others desired some form of control. The majority of participants wanted a continuing right to withdraw consent and nearly all wanted to be informed of incidental findings related to their health. Patients had a great deal of trust in their medical professionals and publically-funded researchers as opposed to profit-based industries and insurance companies.

Comparación de métodos de extracción de ADN en tejidos parafinados y utilidad para amplificación por PCR / Comparison of DNA extraction methods from formalin-fixed paraffin sections for RCP amplification

Los tejidos fijados en formol e incluidos en parafina son una fuente de material para hallazgos moleculares en el ámbito clínico y científico, demostrándose que el ADN extraído de éstos, es adecuado para amplificación a través de la reacción en cadena de la polimerasa (RCP). En este estudio, se ensayaron tres métodos de extracción de ADN en tejidos incluidos en parafina, con el objetivo de comparar la eficiencia de estos para obtener ADN adecuado, además se analizó su utilidad en amplificación por RCP. Se emplearon tres muestras, correspondientes a una biopsia de pulmón, legrado endometrial y ganglio linfático, todas fijadas en formaldehido al 10% e incluidas en parafina. Utilizándose tres métodos diferentes de extracción de ADN (extracción por salting out, método modificado de Sambrook y kit comercial) El ADN obtenido se cuantificó por espectrofotometría, además se realizó electroforesis en gel de agarosa al 1%, para comprobar si el ADN era de buena calidad y se realizó RCP para el exón 3 del gen caveolina 1. Todos los métodos dieron como resultado una buen producto de ADN genómico, observándose mayor cantidad y pureza en los métodos de salting out y kit comercial, asimismo se obtuvo amplificación del producto esperado por estos dos métodos, no hubo buenos resultados con el ADN extraído por el método modificado "Preparation of Genomic DNA from Mouse Tails y Other Small samples, según Sambrook". El ADN obtenido a partir de tejidos FFIP puede ser amplificado por varios métodos, entre estos, la extracción por salting out es útil y con poca toxicidad, permite obtener ADN de buena calidad para amplificación por RCP.

Formalin-fixed and paraffin-embedded tissues are a source of important molecular findings in clinical and scientific, demonstrating that the DNA extracted from these is suitable for amplification by polymerase chain reaction (PCR). In this study, we tested three methods of DNA extraction, in order to compare the efficiency of these DNA for RCP amplification. Three samples were used, corresponding to a lung biopsy, endometrial curettage and lymph node, all fixed in 10% formaldehyde and embedded in paraffin. Three different methods were used for DNA extraction (extraction by salting out, modified Sambrook method and commercial kit) The DNA obtained was analyzed by spectrophotometry, and gel electrophoresis was performed in 1% agarose to check if the DNA was amplifiable. PCR was performed for exon 3 of caveolin-1 gene. All methods resulted in a good product of genomic DNA, obtaining more quality and purity in the salting out and commercial kit methods. Also, we obtained amplification of the product by these two methods, without favorable results with the DNA extracted by the modified "Preparation of Genomic DNA from Mouse Tails and Other Small samples, according to Sambrook et al." The DNA obtained from FFPE can be amplified by several methods, among them, salting out extraction is an easy, effective and low toxicity for obtaining good quality DNA for PCR amplification.

Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT).

CONTEXT: Secondary analyses of 2 randomized controlled trials and supportive epidemiologic and preclinical data indicated the potential of selenium and vitamin E for preventing prostate cancer. OBJECTIVE: To determine whether selenium, vitamin E, or both could prevent prostate cancer and other diseases with little or no toxicity in relatively healthy men. DESIGN, SETTING, AND PARTICIPANTS: A randomized, placebo-controlled trial (Selenium and Vitamin E Cancer Prevention Trial [SELECT]) of 35,533 men from 427 participating sites in the United States, Canada, and Puerto Rico randomly assigned to 4 groups (selenium, vitamin E, selenium + vitamin E, and placebo) in a double-blind fashion between August 22, 2001, and June 24, 2004. Baseline eligibility included age 50 years or older (African American men) or 55 years or older (all other men), a serum prostate-specific antigen level of 4 ng/mL or less, and a digital rectal examination not suspicious for prostate cancer. INTERVENTIONS: Oral selenium (200 microg/d from L-selenomethionine) and matched vitamin E placebo, vitamin E (400 IU/d of all rac-alpha-tocopheryl acetate) and matched selenium placebo, selenium + vitamin E, or placebo + placebo for a planned follow-up of minimum of 7 years and a maximum of 12 years. MAIN OUTCOME MEASURES: Prostate cancer and prespecified secondary outcomes, including lung, colorectal, and overall primary cancer. RESULTS: As of October 23, 2008, median overall follow-up was 5.46 years (range, 4.17-7.33 years). Hazard ratios (99% confidence intervals [CIs]) for prostate cancer were 1.13 (99% CI, 0.95-1.35; n = 473) for vitamin E, 1.04 (99% CI, 0.87-1.24; n = 432) for selenium, and 1.05 (99% CI, 0.88-1.25; n = 437) for selenium + vitamin E vs 1.00 (n = 416) for placebo. There were no significant differences (all P>.15) in any other prespecified cancer end points. There were statistically nonsignificant increased risks of prostate cancer in the vitamin E group (P = .06) and type 2 diabetes mellitus in the selenium group (relative risk, 1.07; 99% CI, 0.94-1.22; P = .16) but not in the selenium + vitamin E group. CONCLUSION: Selenium or vitamin E, alone or in combination at the doses and formulations used, did not prevent prostate cancer in this population of relatively healthy men. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT00006392.

MIP-1alpha (CCL3) is a downstream target of FGFR3 and RAS-MAPK signaling in multiple myeloma.

Overexpression of fibroblast growth factor receptor 3 (FGFR3) is a hallmark of t(4;14) multiple myeloma (MM). To dissect the mechanism of FGFR3 oncogenesis in MM, we used 3 FGFR selective kinase inhibitors-CHIR258, PD173074, and SU5402-and FGFR3-specific siRNA to modulate FGFR3 activity. Conversely, the ligand FGF was used to stimulate FGFR3 function in human MM cells. The transcriptional response to FGFR3 modification was recorded, and gene expression changes common to all 5 modifiers were documented. Ten genes were commonly regulated. Macrophage inflammatory protein-1 alpha (MIP-1alpha) was the single most differentially altered gene. MIP-1 alpha promoter function, gene expression, and protein secretion were each down-regulated following inhibition of FGFR3 signaling. Down-regulation of MIP-1 alpha was not, however, observed following FGFR3 inhibition in MM cells with RAS mutations implicating RAS-MAPK in MIP-1 alpha regulation. As confirmation, inhibition of ERK1 also down-regulated MIP-1 alpha in FGFR3 inhibitor-resistant cells harboring RAS mutations. MIP-1 alpha is implicated in the survival and proliferation of MM cells and the pathogenesis of MM bone disease. Our observation is the first to directly link an initiating IgH translocation not only to MM-cell growth and survival but also to the disease-associated bone disease.

Analysis of PTEN deletions and mutations in multiple myeloma.

Clonal plasma cells from patients with multiple myeloma (MM), plasma cell leukemia (PCL) and human myeloma cell lines (HMCLs) were analyzed for deletions/mutations of the tumor suppressor gene PTEN. By interphase-FISH, hemizygous PTEN deletions were detected in 4 (5.6%) of 71 MM patients, 2 (20%) of 10 PCLs, and 2 (20%) of 10 HMCLs. PTEN deletions were detected in 4 MM patients at diagnosis with stage III disease (Durie-Salmon). Of the six cases with PTEN deletions, 1 MM had a 13q deletion, 1 PCL had a t(11;14), and the other PCL had a t(14;16), a 13q deletion and a p53 deletion. Sequencing analysis did not detect PTEN mutations in 11 primary MM and 5 PCL cases. Our results indicate that alterations of PTEN are uncommon in MM patients, and PTEN deletions tend to occur in advanced disease suggesting that they are secondary, rather than primary, events in the pathogenesis of MM.

Advances in myeloma genetics and prospects for pharmacogenomic testing in multiple myeloma.

Pharmacogenomic studies in multiple myeloma, a neoplasia of clonally expanded malignant bone marrow plasma cells, are helping to set the stage for individualized therapy. Although relatively few in numbers, these studies are already providing new therapeutic targets and avenues for drug discoveries as well as contributing to novel prognostic markers in multiple myeloma. High-throughput mutation screening of the kinome promises to identify further novel targets for therapy. Genetics and gene expression profiling technology have improved molecular-based patient stratification and prognostic staging, expanded knowledge of the molecular mechanism of chemotherapeutic agents, and provided a better understanding of myeloma bone disease. The use of pharmacogenomic strategies in myeloma is thus already changing medical practice.

The SH3-SAM adaptor HACS1 is up-regulated in B cell activation signaling cascades.

HACS1 is a Src homology 3 and sterile alpha motif domain-containing adaptor that is preferentially expressed in normal hematopoietic tissues and malignancies including myeloid leukemia, lymphoma, and myeloma. Microarray data showed HACS1 expression is up-regulated in activated human B cells treated with interleukin (IL)-4, CD40L, and anti-immunoglobulin (Ig)M and clustered with genes involved in signaling, including TNF receptor-associated protein 1, signaling lymphocytic activation molecule, IL-6, and DEC205. Immunoblot analysis demonstrated that HACS1 is up-regulated by IL-4, IL-13, anti-IgM, and anti-CD40 in human peripheral blood B cells. In murine spleen B cells, Hacs1 can also be up-regulated by lipopolysaccharide but not IL-13. Induction of Hacs1 by IL-4 is dependent on Stat6 signaling and can also be impaired by inhibitors of phosphatidylinositol 3-kinase, protein kinase C, and nuclear factor kappaB. HACS1 associates with tyrosine-phosphorylated proteins after B cell activation and binds in vitro to the inhibitory molecule paired Ig-like receptor B. Overexpression of HACS1 in murine spleen B cells resulted in a down-regulation of the activation marker CD23 and enhancement of CD138 expression, IgM secretion, and Xbp-1 expression. Knock down of HACS1 in a human B lymphoma cell line by small interfering ribonucleic acid did not significantly change IL-4-stimulated B cell proliferation. Our study demonstrates that HACS1 is up-regulated by B cell activation signals and is a participant in B cell activation and differentiation.

Soluble interleukin-13Ralpha2 decoy receptor inhibits Hodgkin's lymphoma growth in vitro and in vivo.

Recent studies have demonstrated that the malignant Reed-Sternberg cells of Hodgkin's lymphoma (HL) secrete and are responsive to interleukin (IL)-13. We hypothesized that overexpression of a soluble IL-13 decoy receptor (sIL-13Ralpha2) via adenoviral-mediated gene transfer would inhibit IL-13-induced Reed-Sternberg cell proliferation. Western blot and ELISA analysis verified expression of sIL-13Ralpha2 in cell lysates and supernatants of AdsIL-13Ralpha2-transduced COS-7 cells. Treatment of two IL-13-responsive HL-derived cell lines, HDLM-2 and L-1236, with AdsIL-13Ralpha2-conditioned medium, resulted in the inhibition of cell proliferation, and down-regulated the phosphorylation of signal transducer and activator of transcription 6 (STAT6), an important mediator of IL-13 signaling. i.v. delivery of AdsIL-13Ralpha2 in NOD/SCID mice with s.c. implanted HDLM-2 cells delayed tumor onset and growth while enhancing survival compared with control mice. Intratumoral administration of AdsIL-13Ralpha2 led to the regression or stabilization of established tumors and was associated with diminished STAT6 phosphorylation. Our data demonstrate that AdsIL-13Ralpha2 can suppress HL growth in vitro and in vivo.

Insights from the gene expression profiling of multiple myeloma.

Recent gene expression profiling using high throughput sequencing and microarray analysis of multiple myeloma has shed new light on this morphologically homogeneous yet clinically heterogeneous disease. The biology of the disease has been interrogated in studies, which reveal that patients have unique gene expression clusters that correlate with disease severity. These studies have also revealed that some myeloma cells have gene expression characteristics that resemble the molecular profile of late-stage B cells. Expression profiling can identify hallmark immunoglobulin translocations and other common structural genetic changes that impart prognostic significance. Molecular profiling has been demonstrated to be of value in pharmacogenomic studies predicting response to therapy and revealing novel therapeutic targets. These studies are providing insight into many previously unexplained features of this difficult disease.

A molecular compendium of genes expressed in multiple myeloma.

We have created a molecular resource of genes expressed in primary malignant plasma cells using a combination of cDNA library construction, 5' end single-pass sequencing, bioinformatics, and microarray analysis. In total, we identified 9732 nonredundant expressed genes. This dataset is available as the Myeloma Gene Index (www.uhnres.utoronto.ca/akstewart_lab).Predictably, the sequenced profile of myeloma cDNAs mirrored the known function of immunoglobulin-producing, high-respiratory rate, low-cycling, terminally differentiated plasma cells. Nevertheless, approximately 10% of myeloma-expressed sequences matched only entries in the database of Expressed Sequence Tags (dbEST) or the high-throughput genomic sequence (htgs) database. Numerous novel genes of potential biologic significance were identified. We therefore spotted 4300 sequenced cDNAs on glass slides creating a myeloma-enriched microarray. Several of the most highly expressed genes identified by sequencing, such as a novel putative disulfide isomerase (MGC3178), tumor rejection antigen TRA1, heat shock 70-kDa protein 5, and annexin A2, were also differentially expressed between myeloma and B lymphoma cell lines using this myeloma-enriched microarray. Furthermore, a defined subset of 34 up-regulated and 18 down-regulated genes on the array were able to differentiate myeloma from nonmyeloma cell lines. These not only include genes involved in B-cell biology such as syndecan, BCMA, PIM2, MUM1/IRF4, and XBP1, but also novel uncharacterized genes matching sequences only in the public databases. In summary, our expressed gene catalog and myeloma-enriched microarray contains numerous genes of unknown function and may complement other commercially available arrays in defining the molecular portrait of this hematopoietic malignancy. GenBank Accession numbers include BF169967-BF176369, BF185966-BF185969, and BF177280-BF177455.