High applicability of ASO-RQPCR for detection of minimal residual disease in multiple myeloma by entirely patient-specific primers/probes.

Allele-specific oligonucleotide real-time quantitative PCR (ASO-RQPCR) is a standardized technique for detection and monitoring of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) but not multiple myeloma (MM) due to a low applicability inherent with presence of somatic hypermutation. Herein, by a staged PCR approach and sequencing, clonality and tumor-specific complementarity-determining region 3 (CDR3) sequence were identified in 13/13 MM by sequential PCR of IgH VDJ (n = 10), IgH DJ (n = 2), or IgK VJ (n = 1). Using consensus primers/probes conventionally employed in ALL, ASO-RQPCR worked in three (23.

Methylation profiling of SOCS1, SOCS2, SOCS3, CISH and SHP1 in Philadelphia-negative myeloproliferative neoplasm.

Janus kinase-signal transducer and activator of transcription (JAK/STAT) signalling, pivotal in Philadelphia-negative (Ph-ve) myeloproliferative neoplasm (MPN), is negatively regulated by molecules including SOCSs, CISH and SHP1. SOCS1, SOCS2 and SOCS3 methylation have been studied in MPN with discordant results. Herein, we studied the methylation status of SOCS1, SOCS2 and SOCS3, CISH and SHP1 by methylation-specific polymerase chain reaction (MSP) in cell lines and 45 diagnostic marrow samples of Ph-ve MPN.

Methylation of miR-34a, miR-34b/c, miR-124-1 and miR-203 in Ph-negative myeloproliferative neoplasms.

Background: MicroRNA (miR) miR-34a, -34b/c, -124-1 and -203 are tumor suppressor miRs implicated in carcinogenesis.

Methods: We studied DNA methylation of these miRs in Philadelphia-negative (Ph-ve) myeloproliferative neoplasms (MPNs). Methylation-specific PCR (MSP), verified by direct sequencing of the methylated MSP products, was performed in cell lines, normal controls and diagnostic marrow samples of patients with MPNs.

Epigenetic dysregulation of the death-associated protein kinase/p14/HDM2/p53/Apaf-1 apoptosis pathway in multiple myeloma.

Aim: To study the role of gene promoter hypermethylation of the putative tumour suppressor genes involved in the death-associated protein (DAP) kinase/p14/HDM2/p53/Apaf-1 apoptosis pathway in multiple myeloma (MM).

Method: DNAs from 55 primary MM marrow samples and myeloma cell lines were analysed for aberrant promoter methylation of DAP kinase, p14 and Apaf-1 genes by methylation-specific polymerase chain reaction (MSP).

Result: In the methylated positive control, the sensitivity of M-MSP for DAP kinase was 1 x 10(-3).

Therapy-related lymphomas in patients with autoimmune diseases after treatment with disease-modifying anti-rheumatic drugs.

Ten patients developing lymphomas after disease modifying anti-rheumatic drugs (DMARD) (methotrexate, n = 3, mean cumulative dose = 3.4 g; cyclophosphamide, n = 2, mean dose = 70 g; azathioprine, n = 6, mean dose = 243 g) were investigated. Methotrexate-related lymphomas were Epstein-Barr virus (EBV)-positive, had infrequent aberrant methylation of p15 and p16, and responded well to methotrexate withdrawal or anti-CD20 antibody (rituximab) alone without concomitant chemotherapy, implying that defective immunosurveillance was important in lymphomagenesis.

SOCS1 and SHP1 hypermethylation in multiple myeloma: implications for epigenetic activation of the Jak/STAT pathway.

SOCS1 and SHP1 negatively regulate the Janus kinase/signal transducer and activator of transcription (Jak/STAT) signaling pathway. The role of promoter hypermethylation leading to epigenetic inactivation of SOCS1 and SHP1 in myeloma was investigated. The methylation-specific polymerase chain reaction (MSP) was used to define SOCS1 and SHP1 methylation in 34 diagnostic myeloma samples.