Expression Level and Correlation of miR-211, miR-155, C-myc in Acute T Lymphocytic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression and correlation of miR-211, miR-155, and C-myc in acute T lymphocytic leukemia (T-ALL), aiming to provide evidence for the diagnosis and treatment.@*METHODS@#A total of 96 T-ALL patients who were diagnosed and treated in People's Hospital of Zhengzhou from June 2014 to June 2017 were selected, and 69 healthy volunteers who had a physical examination were selected as control group in the same period. Real-time fluorescent quantitative PCR (RT-PCR) was used to determine the expression levels of miR-211, miR-155, and C-myc in peripheral blood mononuclear cells in each group. Kaplan-Meier was used to analyze the survival of T-ALL patients and correlation of miR-211, miR-155, and C-myc with prognosis. Pearson correlation analysis was used to evaluate the correlation of miR-211, miR-155, and C-myc with disease risk.@*RESULTS@#The expression levels of miR-211 mRNA, miR-155 mRNA, and C-myc mRNA in T-ALL group were higher than those in the control group (P<0.01), those in non-remission group were higher than those in remission group (P<0.01), and those in high-risk group were also higher than those in low-risk group and intermediate-risk group (P<0.01). The survival time of T-ALL patients with low miR-211 expression was longer than that with high miR-211 expression (P<0.01), that with low miR-155 expression was longer than that with high miR-155 expression (P<0.01), and that with low C-myc expression was also longer than that with high C-myc expression (P<0.01). The high expression of miR-211, miR-155, and C-myc was linearly positively correlated with high risk of disease (r=0.749, 0.781, 0.804).@*CONCLUSION@#The expressions of miR-211, miR-155, and C-myc are up-regulated in T-ALL patients, closely related to prognosis, and linearly positively correlated with disease risk.

Clinicopathological features and prognosis of high-grade B-cell lymphoma with MYC and bcl-2 and/or bcl-6 rearrangements / 中华病理学杂志

Objective: To investigate the clinicopathological characteristics and prognosis of high-grade B-cell lymphoma (HGBL) involving combined rearrangements of MYC, bcl-2 and bcl-6. Methods: A total of 1 138 cases of large B cell lymphoma (LBL) that were treated at the Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine from January 2017 to September 2020 were analyzed using fluorescence in situ hybridization (FISH) with probes against MYC, bcl-2 and bcl-6. The clinical and pathological data of the 45 patients with HGBL that had rearrangements of MYC and bcl-2 and/or bcl-6 were collected and retrospectively analyzed. Results: Among the 1 138 LBL, 45 (4.0%) cases had combined rearrangements of MYC, bcl-2 and/or bcl-6 that included 6 HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, 14 HGBL cases with MYC and bcl-2 rearrangements, and 25 HGBL cases with MYC and bcl-6 rearrangements. Of these 45 patients, 29 patients were male, and 16 patients were female, aged 29 to 83 years. HGBL with MYC, bcl-2 and bcl-6 rearrangements and HGBL with MYC and bcl-2 rearrangement were reclassified as the germinal center B-cell (GCB) subtype using the Hans algorithm. HGBL with MYC and bcl-6 rearrangement were reclassified as the GCB subtype (68.0%) and the non-GCB subtype (32.0%). The vast majority of HGBL cases had a high Ki-67 proliferation index. Most HGBL patients had advanced stage disease with a high IPI score and an increased LDH level. Also, some patients had clinical features including elevated plasma β2-microglobulin levels, B symptoms, and bone marrow involvement. The IPI scores and LDH levels were significantly different between the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements and the HGBL cases with MYC and bcl-6 rearrangements (P<0.05). Compared with the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the HGBL cases with MYC and bcl-2 or bcl-6 rearrangements had a lower incidence of bone marrow involvement (P<0.05). There were no significant differences in the prognosis among HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the cases with MYC and bcl-2 rearrangements, and the cases with MYC and bcl-6 rearrangements (P>0.05). Conclusions: HGBL with MYC, bcl-2 and/or bcl-6 rearrangements are rare types of B-cell lymphoma with high degree of malignancy and have a short overall survival. To reduce misdiagnosis and improve diagnostic accuracy, it is necessary to assess the patients' clinical features and conduct histopathological, immunohistochemical and FISH analyses.

Targeting "undruggable" c-Myc protein by synthetic lethality / 医学前沿

Synthetic lethal screening, which exploits the combination of mutations that result in cell death, is a promising method for identifying novel drug targets. This method provides a new avenue for targeting "undruggable" proteins, such as c-Myc. Here, we revisit current methods used to target c-Myc and discuss the important functional nodes related to c-Myc in non-oncogene addicted network, whose inhibition may cause a catastrophe for tumor cell destiny but not for normal cells. We further discuss strategies to identify these functional nodes in the context of synthetic lethality. We review the progress and shortcomings of this research field and look forward to opportunities offered by synthetic lethal screening to treat tumors potently.

Silencing of Long Non-Coding RNA MALAT1 Promotes Apoptosis of Glioma Cells

The metastasis-associated lung adenocarcinoma transcription 1 (MALAT1) is a highly conserved long non-coding RNA (lncRNA) gene. However, little is known about the pathological role of lncRNA MALAT1 in glioma. In the present study, we explored the expression level of lncRNA MALAT1 in primary glioma tissues as well as in U87 and U251 glioma cell lines. Using qRT-PCR, we found that the expression of lncRNA MALAT1 was significantly increased in glioma tissues compared with that of paracancerous tissues. Meanwhile, the expression of MALAT1 was highly expressed in U98 and U251 cells. In order to explore the function of MALAT1, the expression of MALAT1 was greatly reduced in U87 and U251 cells transfected with siRNA specifically targeting MALAT1. Consequently, cell viability of U87 and U251 cells were drastically decreased after the knockdown of MALAT1. Concomitantly, the apoptosis rate of the two cell lines was dramatically increased. Furthermore, the expression levels of some tumor markers were reduced after the knockdown of MALAT1, such as CCND1 and MYC. In summary, the current study indicated a promoting role of MALAT1 in the development of glioma cell.

beta-TrCP1 degradation is a novel action mechanism of PI3K/mTOR inhibitors in triple-negative breast cancer cells

An F-box protein, beta-TrCP recognizes substrate proteins and destabilizes them through ubiquitin-dependent proteolysis. It regulates the stability of diverse proteins and functions as either a tumor suppressor or an oncogene. Although the regulation by beta-TrCP has been widely studied, the regulation of beta-TrCP itself is not well understood yet. In this study, we found that the level of beta-TrCP1 is downregulated by various protein kinase inhibitors in triple-negative breast cancer (TNBC) cells. A PI3K/mTOR inhibitor PI-103 reduced the level of beta-TrCP1 in a wide range of TNBC cells in a proteasome-dependent manner. Concomitantly, the levels of c-Myc and cyclin E were also downregulated by PI-103. PI-103 reduced the phosphorylation of beta-TrCP1 prior to its degradation. In addition, knockdown of beta-TrCP1 inhibited the proliferation of TNBC cells. We further identified that pharmacological inhibition of mTORC2 was sufficient to reduce the beta-TrCP1 and c-Myc levels. These results suggest that mTORC2 regulates the stability of beta-TrCP1 in TNBC cells and targeting beta-TrCP1 is a potential approach to treat human TNBC.

Pediatric B-cell Lymphoma, Unclassifiable, With Intermediate Features Between Those of Diffuse Large B-cell Lymphoma and Burkitt Lymphoma: A Report of Two Cases

No abstract available.

Isochromosome 1q in Childhood Burkitt Lymphoma: The First Reported Case in Korea

No abstract available.

MYC Rearrangement Involving a Novel Non-immunoglobulin Chromosomal Locus in Precursor B-cell Acute Lymphoblastic Leukemia

MYC rearrangement, a characteristic cytogenetic abnormality of Burkitt lymphoma and several subsets of other mature B-cell neoplasms, typically involves an immunoglobulin gene partner. Herein, we describe a case of precursor B-cell lymphoblastic leukemia harboring a MYC rearrangement with a novel non-immunoglobulin partner locus. The patient was a 4-yr-old Korean boy with ALL of the precursor B-cell immunophenotype. At the time of the second relapse, cytogenetic analyses revealed t(4;8)(q31.1;q24.1) as a clonal evolution. The MYC rearrangement was confirmed by FISH analysis. He died 3 months after the second relapse without achieving complete remission. To our knowledge, this is the first report of a case of MYC rearrangement with a non-immunoglobulin partner in precursor B-cell lymphoblastic leukemia.

CD5-negative Blastoid Variant Mantle Cell Lymphoma with Complex CCND1/IGH and MYC Aberrations

The coexistence of CCND1/IGH and MYC rearrangements in mantle cell lymphoma (MCL) is a rare finding associated with a very poor prognosis. In this study, a patient with blastoid variant (MCL) is reported. The disease was clinically aggressive and refractory to chemotherapy, and the patient only survived for 1 month following diagnosis. Conventional cytogenetic study, FISH, and multicolor FISH (mFISH) demonstrated the involvement of the BCL1/CCND1 locus in a complex translocation, t(3;11)(q25;p15)t(11;14)(q13;q32). In addition, subclonal abnormalities in the 8q24 region, manifested as a t(8;14)(q24;q32)/MYC rearrangement, were identified. To the best of our knowledge, this is the first MCL case in Korea bearing these complex genomic aberrations.

Suppression of Aurora-A oncogenic potential by c-Myc downregulation

The abnormality of serine/threonine kinase Aurora-A is seen in many types of cancers. Although in physiological context it has been shown to play a vital role in cellular mitosis, how this oncogene contributes to tumorigenesis remains unclear. Here we demonstrate that Aurora-A overexpression enhances both the expression level and transcriptional activity of c-Myc. The inhibition of c-Myc expression by RNA interference significantly impaired the oncogenic potential of Aurora-A, resulting in attenuated cellular proliferation and transformation rates as well as fewer centrosomal aberrations. Furthermore, downregulation of c-Myc effectively overcame Aurora-A-induced resistance to cisplatin in esophageal cancer cells. Taken together, our results suggest an important role for c-Myc in mediating the oncogenic activity of Aurora-A, which may in turn allow for future targeting of c-Myc as a potential therapeutic strategy for tumors with Aurora-A overexpression.

Prevalence of c-myc expression in breast lesions associated with microcalcifications detected by routine mammography / Expressão de c-myc em lesões mamárias associadas a microcalcificações detectadas por mamografia de rotina

CONTEXT AND OBJECTIVE: Genetic abnormalities in cell proliferation-regulating genes have been described in premalignant lesions. The aims here were to evaluate c-myc protein expression in non-palpable breast lesions associated with microcalcifications, detected by screening mammography, and to compare these results with histopathological, clinical and epidemiological variables. DESIGN AND SETTING: Analytical cross-sectional study, with retrospective data collection, in a university hospital in São Paulo. METHODS: Seventy-nine female patients who underwent routine mammography between 1998 and 2004 were studied. Lesions classified by the Breast Imaging Reporting and Data System (BI-RADS) as 4 or 5 underwent percutaneous biopsy using a large-core needle. Ninety-eight lesions were studied anatomopathologically. Paraffin blocks properly representing the lesions were selected for immunohistochemical analyses using the streptavidin-biotin-peroxidase technique with monoclonal mouse c-myc antibodies. RESULTS: Among the 98 lesions, 29 (29.6 percent) contained malignant neoplasia; 40 (40.8 percent) had a positive immunohistochemical reaction for c-myc. When the groups were divided between lesions without atypias versus atypical lesions plus malignant lesions, 31.03 percent of the 58 lesions without atypias were positive for c-myc and 55 percent of the 40 malignant and atypical lesions (P = 0.018). Comparing the atypical lesions with ductal carcinoma in situ versus the benign lesions without atypias, c-myc was present in 51.61 percent of the 31 atypical lesions and 31.03 percent of the benign lesions without atypias (P = 0.057). CONCLUSION: C-myc protein was more frequently expressed in atypical and malignant lesions than in benign lesions without atypias. C-myc expression correlated with the presence of atypias (P = 0.018).

CONTEXTO E OBJETIVO: Alterações nos genes reguladores da proliferação celular foram descritas em lesões pré-malignas. Os objetivos foram avaliar a expressão da proteína c-myc em biópsias de lesões mamárias não-palpáveis associadas a microcalcificações detectadas em mamografias de rastreamento e comparar estes resultados com as variáveis histopatológicas, clínicas e epidemiológicas. DESENHO E LOCAL: Estudo retrospectivo, em um hospital universitário em São Paulo. MÉTODOS: Setenta e nove pacientes do sexo feminino submetidas a mamografia de rotina de 1998 a 2004 foram estudadas. As lesões classificadas pelo sistema BI-RADS (Breast Imaging Reporting and Data) como 4 e 5 sofreram biópsias percutâneas com agulha grossa. Do ponto de vista anatomopatológico, foram estudadas 98 lesões. Os blocos com representação adequada para estudo imunoistoquímico com a técnica da estreptoavidina-biotina-peroxidase com o anticorpo monoclonal de camundongo c-myc foram incluídos. RESULTADOS: Das 98 lesões, 29 (29,6 por cento), continham neoplasia maligna; 40 (40,8 por cento) tiveram reação de imunoistoquímica positiva para o c-myc. Quando divididos os grupos em lesões sem atipia versus lesões atípicas mais lesões malignas, encontramos o c-myc positivo em 31,03 por cento das 58 lesões sem atipias e 55 por cento das 40 lesões atípicas e malignas (P = 0,018). Quando agrupamos as lesões atípicas com o carcinoma ductal in situ (CDIS) versus as lesões benignas sem atipias, observamos a presença do c-myc em 51,61 por cento das 31 lesões atípicas e 31,03 por cento das lesões benignas sem atipias (P = 0,057). CONCLUSÃO: A proteína c-myc está mais frequentemente expressa em lesões atípicas e malignas do que em lesões benignas sem atipia. A expressão do c-myc está correlacionada com a presença de atipia (P = 0,018).

Effect of growth factors on the expression of proto-oncogenes c-fos and c-myc in FRTL-5 cell line

This study was performed to prove the hypothesis that oncogene expressions would have the same patterns with those of cellular growth to growth factors in FRTL-5 cells. Ribonucleic acids of FRTL-5 were extracted at 15', 30', 60' and 120' after administration of growth factors to quiescent FRTL-5, and blotted to the nitrocellulose membrane. They were hybridized with radiolabelled c-fos, c-myc and beta-actin probes. Hybridized dot blots were autoradiographed and the amount of radioactivity was measured by densitometry. Densitometric readings were used as the indices of oncogene expressions. Expressions of c-fos and c-myc were more prominent in combined administrations of TSH (10 mU/ml) and IGF-I (100 ng/ml) or IgG of Graves' disease (Graves' IgG; 1 mg/ml) and IGF-I than in combined administration of TSH and Graves' IgG. IgG of primary myxedema suppressed oncogene expressions by TSH or Graves' IgG, but not by IGF-I. From the above results, it was suggested that expressions of c-fos and c-myc to growth factors would have similar patterns with those of cell growth to growth factors in FRTL-5, and the actions of TSH and Graves' IgG would be manifested through same signal transduction system, but IGF-I would be manifested by its own.