Chengwen Li

The Impact of Clone Size on the Prognostic Value of Chromosome Aberrations by Fluorescence In Situ Hybridization in Multiple Myeloma

Purpose: Accumulating evidence indicates that intratumor heterogeneity is prevalent in multiple myeloma and that a collection of multiple, genetically distinct subclones are present within the myeloma cell population. It is not clear whether the size of clonal myeloma populations harboring unique cytogenetic abnormalities carry any additional prognostic value. Experimental Design: We analyzed the prognostic impact of cytogenetic aberrations by fluorescence in situ hybridization at different cutoff values in a cohort of 333 patients with newly diagnosed myeloma and 92 patients with relapsed myeloma. Results: We found that nearly all IgH-related arrangements were observed in a large majority of the purified plasma cells; however, 13q deletion, 17p deletion, and 1q21 amplification appeared in different percentages within the malignant plasma cell population. Based on the size of subclones carrying these cytogenetic aberrations, the patients were divided into four groups: 0%–10%, 10.5%–20%, 20.5%–50%, and >50%. Receiver-operating characteristics analysis was applied to determine the optimal cutoff value with the greatest differential survival and showed that the most powerful clone sizes were 10% for 13q deletion, 50% for 17p deletion, and 20% for 1q21 gains, which provided the best possible cutoffs for predicting poor outcomes. Conclusions: Our study indicated that the impact of clone size on prognostic value varies between specific genetic abnormalities. Prognostic value was observed for even a subgroup of plasma cells harboring the cytogenetic aberration of 13q deletion and 1q21 gains; however, 17p deletion displayed the most powerful cutoff for predicting survival only if the predominant clones harbored the abnormality. Clin Cancer Res; 21(9); 2148–56. ©2015 AACR.

TBLR1 fuses to retinoid acid receptor α in a variant t(3;17)(q26;q21) translocation of acute promyelocytic leukemia.

The majority of acute promyelocytic leukemia (APL) cases are characterized by the PML-RARα fusion gene. Although the PML-RARα fusion gene can be detected in >98% of APL cases, RARα is also found to be fused with other partner genes, which are also related to all-trans retinoic acid (ATRA)-dependent transcriptional activity and cell differentiation. In this study, we identified a novel RARα fusion gene, TBLR1-RARα (GenBank KF589333), in a rare case of APL with a t(3;17)(q26;q21),t(7;17)(q11.2;q21) complex chromosomal rearrangement. To our knowledge, TBLR1-RARα is the 10th RARα chimeric gene that has been reported up to now. TBLR1-RARα contained the B-F domains of RARα and exhibited a distinct subcellular localization. It could form homodimers and also heterodimers with retinoid X receptor α. As a result, TBLR1-RARα exhibited diminished transcriptional activity by recruitment of more transcriptional corepressors compared with RARα. In the presence of pharmacologic doses of ATRA, TBLR1-RARα could be degraded, and its homodimerization was abrogated. Moreover, when treated with ATRA, TBLR1-RARα could mediate the dissociation and degradation of transcriptional corepressors, consequent transactivation of RARα target genes, and cell differentiation induction in a dose- and time-dependent manner.

EUTOS score predicts survival and cytogenetic response in patients with chronic phase chronic myeloid leukemia treated with first-line imatinib

Sokal, Euro and newly developed EUTOS scoring systems were validated in 220 Chinese chronic phase chronic myeloid leukemia (CP-CML) patients treated with frontline imatinib. In the EUTOS low-risk and high-risk groups, the 5-year OS was 98.7% vs. 71.4% (P<0.0001), and the 5-year cumulative incidence of complete cytogenetic response (CCyR) was 92.4% vs. 53.8% (P<0.0001). EUTOS score also predicted progression-free survival and duration of CCyR. Low EUTOS index predicted for CCyR. However, Sokal and Euro scores mainly could not discriminate the intermediate-risk from high-risk group in either survival or CCyR. EUTOS score forecasts the prognosis of CP-CML patients treated with first-line imatinib.

High incidence of MYC and BCL2 abnormalities in mantle cell lymphoma, although only MYC abnormality predicts poor survival

The incidence and prognostic role of MYC and BCL2 rearrangements in mature B-cell lymphomas have been extensively studied, except the infrequent mantle cell lymphoma (MCL). Here, we analyzed the MYC and BCL2 abnormalities and other cytogenetic aberrations by fluorescence in situ hybridization (FISH) in 50 MCL patients with bone marrow involvement. Eighteen patients (36.0%) had MYC gains and/or amplifications, and twelve patients (24.0%) had BCL2 gains and/or amplifications. Among the 18 patients with MYC abnormality, four had simultaneous MYC translocations, but no BCL2 translocation was detected among patients with BCL2 abnormality. Only two patients (4.0%) had both MYC and BCL2 abnormalities. The patients with a MYC abnormality had a significantly higher tumor burden, a higher percentage of medium/high risk MIPI group and genomic instability compared to those without this abnormality. However, no significant difference was observed between patients with or without a BCL2 abnormality in terms of clinical and cytogenetic factors. Patients with a MYC abnormality had poorer progress-free survival (PFS) (9.0 vs. 48.0 months, p = .000) and overall survival (OS) (12.0 vs. 94.5 months, p = .000), but the presence of a BCL2 abnormality did not significantly influence either PFS or OS. In multivariate analysis, the MYC abnormality was the independent adverse factor for both PFS and OS, and intensive chemotherapy did not improve the outcome of these patients. Thus, the presence of a MYC but not BCL2 abnormality predicted the poor survival of MCL patients, and a new treatment strategy should be developed for these patients.

Identification of characteristic and prognostic values of chromosome 1p abnormality by multi-gene fluorescence in situ hybridization in multiple myeloma

Identification of characteristic and prognostic values of chromosome 1p abnormality by multi-gene fluorescence in situ hybridization in multiple myeloma

Del17p does not always significantly influence the survival of B-cell chronic lymphoproliferative disorders

B-cell chronic lymphoproliferative disorders (B-CLPD) comprise several entities with indolent clinical manifestations but heterogeneous survival. Cytogenetic aberrations are now the standard prognostic predictors in chronic lymphocytic leukemia (CLL) but have been less investigated in other subtypes of B-CLPD. In this study, we detected cytogenetic aberrations by fluorescence in situ hybridization (FISH) in 875 B-CLPD patients, based on a panel probes locating at 13q14, 11q22, 17p13 and CEP12. We identified del17p acted as the independent adverse cytogenetic predictor for overall survival (OS) in CLL. Del13q, del11q and del17p were adverse factors for OS in Waldenströms macroglobulinemia in the univariate analysis but lost their role in the multivariate analysis. Trisomy 12 acted as an independent poor factor for both marginal zone lymphoma (MZL) and unclassified B-CLPD (BCLPD-U) subtype. Del17p did not impact survival in MZL and BCLPD-U patients. These contrasting results indicate different roles of the same cytogenetic aberrations in the pathogenesis of each B-CLPD subtype. As del17p contributed to the poorest survival in CLL and desired extraordinary treatment strategy, the imitation of CLL strategy to other B-CLPD with del17p should be carefully advocated based on this study.

A novel variant translocation (1;9)(p22;q34) resulting in a DEK/NUP214 fusion gene in a patient with acute myeloid leukemia: A case report

The present case report describes a 46-year-old female patient diagnosed with M4 acute myeloid leukemia (AML), accompanied with a t(1;9)(p22;q34) chromosomal abnormality. Transcriptome sequencing identified a DEK proto-oncogene (DEK)/nucleoporin (NUP)214 fusion gene, which results from the t(6;9)(p23;q34) chromosomal translocation. Polymerase chain reaction analysis and fluorescence in situ hybridization were used to verify the existence of the DEK/NUP214 fusion gene. Few patients with AML with the t(6;9)(p23;q34) chromosomal translocation have been reported to have other chromosomal or karyotype changes. To our knowledge, no AML patient with the DEK/NUP214fusion gene but without the classic t(6;9)(p23;q34) translocations had been reported until now. The prognosis of AML cases with the DEK/NUP214 fusion gene is poor. The rate of complete remission is ~65% (71% in children, 58% in adult patients), while the estimated 5-year survival rate is 28% for children and 9% for adults. The 2008 revision of World Health Organization classification have defined the DEK/NUP214 mutation as a recurrent genetic abnormality of AML. The overall survival of the patient in the current report was ~29 months, and they relapsed twice. To the best of our knowledge, this is the first report of at(1;9)(p22;q34) variant translocation that results in expression of the DEK/NUP214 fusion gene.

The discussion of t(1;17)(p11;q21) translocation in acute promyelocytic leukemia patient on molecular remission

Some chromosomal aberrations emerging in the course of treatment are probably not related to disease progression, but attribute to the germline alteration. Therefore, the dynamic genetic tests should be performed during the whole treatment process, which is significantly essential for efficacy evaluation and treatment decision‐ making.