Chen Lj

miR-17-92 cluster microRNAs confers tumorigenicity in multiple myeloma

miRNAs play important roles in the regulation of cell proliferation, differentiation and apoptosis. The deregulation of miRNAs expression contributes to tumorigenesis by modulating oncogenic and tumor suppressor signaling pathways. Oncogenic transcription factor Myc can control expression of a large set of microRNAs (miRNAs). Previous studies have shown that the expression of miR-17-92 cluster, a polycistron encoding six microRNAs (miRNA), has close relationship with the expression of Myc. In current study, silencing Myc in multiple myeloma (MM)cells induced cell death and growth inhibition, and downregulated expression of miR-17-92 cluster. Overexpression of miR-17 or miR-18 could partly abrogated Myc-knockdown-induced MM cell apoptosis. One of the mechanism of Myc inhibiting MM cell apoptosis is through Myc activates miR-17-92 cluster and subsequently down-modulates proapoptotic protein Bim. Although miR-17-92 cluster are located at 13q31.3, the expression of miR-18, miR-19 and miR-20 (especially miR-19) in patients with del(13q14) was higher than those without del(13q14). Patients with miR-17, miR-20 and miR-92 high-expression had shorter PFS compared to those with miR-17, miR-20 and miR-92 low-expression. These results suggest the Myc-inducible miR-17-92 cluster miRNAs contribute to tumorigenesis and poor prognosis in multiple myeloma.

Distinctive IgVH gene segments usage and mutation status in Chinese patients with chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVES The incidence of chronic lymphocytic leukemia (CLL) in Asian countries is lower than that in the Western ones, where CLL is the most common leukemia. It is a clinically heterogeneous disease, with survival ranging from a few months to decades. The mutation status of the immunoglobulin variable heavy chain (IgVH) gene has significantly improved prediction of the risk for disease progression. We investigated the frequency and mutation status of IgVH gene expression in Chinese patients with CLL. METHODS IgVH gene segments usage and mutation status were investigated by multiplex RT-PCR, and the relationship between IgVH somatic mutation status and the expression of CD38 and ZAP-70 was analyzed in 65 CLL patients. RESULTS Forty-five (69.2%) patients had mutated IgVH, and 20 (30.8%) had unmutated IgVH. The most frequently expressed VH gene family was found to be VH3 (47.7%) followed by VH4 (40%), VH1 (6.2%), VH2 (4.6%) and VH7 (1.5%), with no expression of VH5 or VH6 gene families. VH1-69 and VH3-21 which commonly overused in Western CLL were very low in our cohort. IgVH gene mutation status was significantly associated with the expression of CD38. CONCLUSIONS The frequency of IgVH gene families indicates significant difference in Chinese CLL patients compared with Western patients, suggesting involvement of ethnic and/or environmental factors in CLL disease initiation. The expression of them may be simple and reliable surrogates for the identification of IgVH mutations.

MiR-15a, miR-16-1 and miR-17-92 cluster expression are linked to poor prognosis in multiple myeloma.

Multiple myeloma (MM) is characterized by a profound genomic instability of potential prognostic relevance. Loss of chromosome 13, observed in almost half of patients, negatively affects prognosis. MiR-15a, miR16-1 and miR-17-92 cluster, located on 13q, play important roles in the regulation of cell proliferation, differentiation and apoptosis. Therefore, we investigated a possible correlation of miRNA expression with chromosome 13 deletions (del(13)) and prognosis. We measured the expression of miR-15a, miR16-1 in 70 newly diagnosed MM patients and miR-17-92 cluster in 85 newly diagnosed MM patients by quantitative real-time PCR analyses. MiR-15a, miR-16-1 and miR-17-92 cluster expression levels are independent of the del(13). High levels of miR-15a, miR-16-1, miR-17, miR-20a and miR-92-1 are associated with shorter progression-free survival (PFS), suggesting poor prognosis. Our data suggest that the expression of specific miRNAs may be contributing to MM prognosis.

Utility of gonadotropin-releasing hormone agonists for prevention of chemotherapy-induced ovarian damage in premenopausal women with breast cancer: a systematic review and meta-analysis

Background Premature ovarian failure and infertility following chemotherapy are major concerns for premenopausal women with breast cancer. A potential ovarian function preservation strategy is administration of gonadotropin-releasing hormone (GnRH) agonists during adjuvant chemotherapy; however, studies of the clinical efficacy of GnRH agonists to protect chemotherapy-induced ovarian damage have shown mixed results. Objective This meta-analysis study was designed to estimate the efficacy of GnRH agonists administered concurrently with chemotherapy to prevent chemotherapy-induced ovarian damage in premenopausal women with breast cancer. Methods Electronic literature databases (PubMed, EMBASE, MEDLINE, Cochrane Library databases searching, China National Knowledge Infrastructure, Web of Science, and the Wanfang Data) were searched for relevant randomized controlled trials (RCTs) published until September 2015. Only RCTs that examined the effect of GnRH agonists for chemotherapy-induced ovarian failure in premenopausal women with breast cancer were selected. The rate of spontaneous resumption of menses and spontaneous pregnancy were collected. All data were analyzed by RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) and Stata 12.0 (StataCorp, College Station, TX, USA). Results Eleven RCTs with a total of 1,062 participants (GnRH agonists administered concurrently with chemotherapy, n=541; chemotherapy alone, n=521) were included in the meta-analysis. A significantly greater number of women treated with GnRH agonist experienced spontaneous resumption of menses after the adjuvant chemotherapy, yielding a pooled odds ratio of 2.57 (versus chemotherapy alone, 95% confidence interval (CI)=1.65, 4.01; P<0.0001). A subgroup analysis showed that addition of GnRH agonists significantly improved the resumption of menses rate in patients who were hormone-insensitive. However, the two treatment groups experienced similar spontaneous pregnancy (odds ratio =0.177; 95% CI=0.92, 1.40; P=0.09). Conclusion GnRH agonists cotreatment with chemotherapy in premenopausal women with breast cancer plays a beneficial role in resumption of ovarian function, with a higher rate of resumption of menses. However, treatment with GnRH agonists does not appear to exhibit its protective effects in fertility.

Argonaute 2 promotes myeloma angiogenesis via microRNA dysregulation

BackgroundDysregulated microRNA (miRNA) expression contributes to cancer cell proliferation, apoptosis and angiogenesis. Angiogenesis is a hallmark of multiple myeloma (MM) development and progression. Argonaute 2 (AGO2) protein, a core component of the RNA-induced silencing complex (RISC), can directly bind to miRNAs and mediate target messenger RNA (mRNA) degradation. A previous study showed that AGO2 knockdown suppressed human umbilical vein endothelial cell (HUVEC) growth and tube formation. However, the roles and molecular mechanisms of AGO2-induced myeloma angiogenesis are not yet fully understood. The aim of this study was to characterize these roles and effects and their associated mechanisms.ResultsSupernatants from AGO2-overexpressing MM lines induced HUVEC migration and accelerated tube formation. Conversely, supernatants from AGO2-knockdown MM lines suppressed HUVEC cell migration and tube formation. Moreover, a chick chorioallantoic membrane (CAM) assay was used to demonstrate that AGO2 could drive neovessel formation in MM lines in vivo. Using an miRNA microarray, we observed that 25 miRNAs were upregulated and 7 were downregulated in response to AGO2. Most let-7 family members and 2 miR-17/92 cluster members (miR-17a and miR-92-1), all known pro-angiogenic miRNAs, were positively regulated by AGO2 whereas anti-angiogenic miRNAs such as miR-145 and miR-361 were negatively regulated by AGO2.ConclusionsWe conclude that AGO2 can drive neovessel formation in vitro and in vivo by dysregulating the expression of some angiogenic miRNAs. The pro-angiogenic miRNAs of the let-7 family and the miR-17/92 cluster, along with the anti-angiogenic miRNA miR-145, play crucial roles in AGO2-mediated angiogenesis by targeting angiogenesis-related genes.

The prognostic evaluation of CLLU1 expression levels in 50 Chinese patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the relentless accumulation of monoclonal B cells with the appearance of small mature lymphocytes and a characteristic CD5 and CD19 co-expression immunophenotype. The incidence of CLL is lower in Asian countries than in Western countries, where CLL is the most common leukemia. To investigate CLLU1 expression in CLL and explore the relationship between CLLU1 expression and alternative prognostic markers, we measured CLLU1 expression levels by semiquantitative RT-PCR in a cohort of 50 Chinese patients with CLL. Analyses of IgVH somatic mutational status, ZAP-70 expression, CD38 expression, and chromosomal aberrations were also performed. The expression of CLLU1 mRNA was determined in 26 of the 50 cases (52%), among which 7 at Binet A (7/21, 33.33%) and 19 at Binet B + C (19/29, 65.52%). The expression levels of CLLU1 were significantly increased in B + C CLL patients at Binet stage compared with those at Binet stage A (P = 0.005). Data for the IgVH somatic mutational status were available for 20 patients with known CLLU1 expression. Five (25%) patients, all expressed CLLU1 mRNA, displayed unmutated IgVH gene usage. While in 15 patients (15/20, 75%) with mutated IgVH gene, only 6 were CLLU1 positive. Patients with unmutated IgVH genes expressed higher levels of CLLU1 than did those with IgVH mutations (P < 0.05). Among 24 CD38+-CLL cases, 17 (70.83%) were CLLU1 positive, whereas only 9 (34.62%) positive cases were identified in 26 CD38−-CLL patients. Thus, the expression of CLLU1 in CD38+-CLL was significantly higher than that in CD38−-CLL. However, no significant difference of CLLU1 expression was found between ZAP-70+ (14/22, 63.64%) and ZAP-70− (12/28, 42.86%) patients (P > 0.05). We conclude that CLLU1 expression was significantly associated with clinical stages, IgVH somatic mutational status and CD38 expression, and might be an important prognostic factor in CLL patients.

Identification of the STAT5B‐RARα fusion transcript in an acute promyelocytic leukemia patient without FLT3, NPM1, c‐Kit and C/EBPα mutation

T(15;17) is the most common chromosomal aberration in patients with acute promyelocytic leukemia (APL), leading to the formation of PML‐RARα fusion gene. In a small subset of patients with APL, the RARα gene is fused with different partners. Here, we report a rare APL case with STAT5B‐RARα fusion transcript. Cytomorphologic and immunophenotypic analyses showed typical features of APL. However, cytogenetic analysis showed normal karyotype, and interphase fluorescence in situ hybridization (FISH) showed PML‐RARα negative. Quantitative RT‐PCR also showed PML‐RARα negative but STAT5B‐RARα positive and sequencing analysis confirmed the result. Molecular markers including FLT3, NPM1, c‐Kit and C/EBPα mutation were all negative. To our knowledge, this is the first APL patient with STAT5B‐RARα in Chinese population and the fifth patient around the world according to published paper.

Bortezomib in combination with dexamethasone for a young multiple myeloma with t(8; 14)

Multiple myeloma (MM) is a malignant plasma cell disrder which generally occurs in older adults with a peak f age between 60 and 70 [1]. Approximately, only 2% of atients with multiple myeloma are younger than the age of 0 [2]. It is extremely rarely seen in patients younger than the ge of 30. In recent years, proteasome inhibitor bortezomib as shown an encouraging effect in the treatment of multiple yeloma. Recently, a 23-year-old male of multiple myeloma ith chromosomal translocation t(8; 14) is noted. He was reated with bortezomib in combination with dexamethasone ollowed by autologous peripheral hematopoietic stem cell ransplantation and exhibited a significant improvement.

Trisomy 22 as the Sole Abnormality is an Important Marker for the Diagnosis of Acute Myeloid Leukemia with Inversion 16

Background: The inversion of chromosome 16 (inv(16) (p13q22)) and the related t(16;16)(p13;q22) are chromosomal aberrations observed in approximately 10% of de novo acute myeloid leukemia (AML), mostly classified as M4Eo subtype, and associated with a relatively favorable outcome. However, it is a cryptic rearrangement and often difficult to recognize in conventional cytogenetics (CC). Trisomy 22 is an uncommon karyotypic aberration in AML and is often associated with inv(16)(p13q22). The aim of this study was to explore the value of trisomy 22 in the diagnosis of AML with inv(16). Patients and Meth-ods: Dual-color interphase fluorescence in situ hybridization (FISH) was performed in 19 AML cases with trisomy 22 abnormality shown by R-banding CC. The probe was a two-color break-apart probe for CBFβon the centromeric side and the telomeric side. Results: R-banding CC did not reveal inv(16) in any of the 19 AML with trisomy 22, but FISH analysis showed inv(16) in 11 cases and del(16)(q22) in 1 case. Among the 11 cases with inv(16), 9 showed trisomy 22 as the sole abnormality, 1 was complicated by trisomy 8, and 1 was del(16)(q22). Conclusion: This study further confirmed that trisomy 22 as the sole abnormality can be regarded as an important marker for inv(16) in AML.

An analysis of complex chromosomal aberrations in seven cases of myelodysplastic syndromes by M-FISH and whole chromosome painting

Complex chromosomal aberrations (CCAs) can be detected in a substantial proportion of myelodysplastic syndrome (MDS). Comprehensive analysis of the chromosomal rearrangements in these CCAs has been hampered by the limitations of conventional cytogenetics (CC). Multiplex fluorescence in situ hybridization (M-FISH) is a new generation FISH technique which allows simultaneous identification of all the 24 human chromosomes. So it is very useful in clarifing CCAs, identifing cryptic interchromosomal rearrangements and characterizing marker chromosomes. But it also has some limitations. We used M-FISH and whole chromosome painting (WCP) to accurately refine the CCAs revealed by R-banding CC in seven cases with MDS. The composition and origin of 6 kinds of marker chromosomes, nine kinds of chromosomes with additional material undetermined and five kinds of derivative chromosomes undefined by CC were defined after M-FISH analysis. Four kinds of cryptic translocations overlooked by CC were found on derivative chromosomes and previously normal appearing chromosomes. In addition, M-FISH revealed some nonrandom aberrations which most frequently involved chromosome 17 (5/7) and -5/5q-(4/7). Fluorescence flaring is a main factor leading to misinterpretations. Some misclassified and missed chromosomal aberrations by M-FISH were corrected by WCP. M-FISH is a powerful molecular cytogenetic tool in clarification of CCAs. Complementary WCP can further identify misclassified and missed chromosomal aberrations by M-FISH. CC in combination with molecular cytogenetic techniques including M-FISH and WCP can more precisely unravel CCAs.