High levels of bcl-2 protein expression do not correlate with genetic abnormalities but predict worse prognosis in patients with lymphoblastic lymphoma

A CpG Methylation Classifier to Predict Relapse in Adults with T-Cell Lymphoblastic Lymphoma

PURPOSE

Adults with T-cell lymphoblastic lymphoma (T-LBL) generally benefit from treatment with acute lymphoblastic leukemia (ALL)-like regimens, but approximately 40% will relapse after such treatment. We evaluated the value of CpG methylation in predicting relapse for adults with T-LBL treated with ALL-like regimens.

EXPERIMENTAL DESIGN

A total of 549 adults with T-LBL from 27 medical centers were included in the analysis. Using the Illumina Methylation 850K Beadchip, 44 relapse-related CpGs were identified from 49 T-LBL samples by two algorithms: least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE). We built a four-CpG classifier using LASSO Cox regression based on association between the methylation level of CpGs and relapse-free survival in the training cohort (n = 160). The four-CpG classifier was validated in the internal testing cohort (n = 68) and independent validation cohort (n = 321).

RESULTS

The four-CpG-based classifier discriminated patients with T-LBL at high risk of relapse in the training cohort from those at low risk (P < 0.001). This classifier also showed good predictive value in the internal testing cohort (P < 0.001) and the independent validation cohort (P < 0.001). A nomogram incorporating five independent prognostic factors including the CpG-based classifier, lactate dehydrogenase levels, Eastern Cooperative Oncology Group performance status, central nervous system involvement, and NOTCH1/FBXW7 status showed a significantly higher predictive accuracy than each single variable. Stratification into different subgroups by the nomogram helped identify the subset of patients who most benefited from more intensive chemotherapy and/or sequential hematopoietic stem cell transplantation.

CONCLUSIONS

Our four-CpG-based classifier could predict disease relapse in patients with T-LBL, and could be used to guide treatment decision.

Diagnostic Challenges of Lymphoblastic Lymphomas of the Mediastinum

Background:

Lymphoblastic lymphomas (LL) of the mediastinum are rare tumours that present a challenging diagnosis. The positive diagnosis is based on microscopic findings. Our aim was to highlight the diagnostic difficulties in such situations.

Methods:

We conducted a descriptive retrospective study including 31 patients presenting mediastinal LL.

Results:

Radiologic features consisted in all cases in a mediastinal infiltrating mass. Microscopic examination showed in all cases a crowded tumour with many artefacts made of diffuse tumour cells. Immunohistochemial study was performed in all cases. It was quite difficult to interprete in the samples used for extemporaneous examination and repeated in 10 cases.

Conclusion:

The diagnosis of LL is based on the microscopic examination which is usually performed on small samples with crowding artefacts. Thus, this pathology must be managed by a trained team that is used to deal with such a specimen in order to avoid repeating the biopsy and inducing diagnostic delay.

Prognostic and predictive value of a microRNA signature in adults with T-cell lymphoblastic lymphoma

New prognostic factors are needed to establish indications for haematopoietic stem cell transplantation (HSCT) in first complete remission (CR1) for T-cell lymphoblastic lymphoma (T-LBL) patients. We used microarray to compare T-LBL tissue samples (n = 75) and fetal thymus tissues (n = 20), and identified 35 differentially expressed miRNAs. Using 107 subjects as the training group, we developed a five-miRNA-based classifier to predict patient survival with LASSO Cox regression: lower risk was associated with better prognosis (disease-free survival (DFS): hazard ratio (HR) 4.548, 95% CI 2.433-8.499, p < 0.001; overall survival (OS): HR 5.030, 95% CI 2.407-10.513, p < 0.001). This classifier displayed good performance in the internal testing set (n = 106) and the independent external set (n = 304). High risk was associated with more favorable response to HSCT (DFS: HR 1.675, 95% CI 1.127-2.488, p = 0.011; OS: HR 1.602, 95% CI 1.055-2.433, p = 0.027). When combined with ECOG-PS and/or NOTCH1/FBXW7 status, this classifier had even better prognostic performance in patients receiving HSCT (DFS: HR 2.088, 95% CI 1.290-3.379, p = 0.003; OS: HR 1.996, 95% CI 1.203-3.311, p = 0.007). The five-miRNA classifier may be a useful prognostic biomarker for T-LBL adults, and could identify subjects who could benefit from HSCT.

Pediatric-Like Acute Lymphoblastic Leukemia Therapy in Adults With Lymphoblastic Lymphoma: The GRAALL-LYSA LL03 Study

Purpose

This study evaluated the efficacy of pediatric-like acute lymphoblastic leukemia (ALL) therapy in adults with lymphoblastic lymphoma (LL).

Patients and Methods

This was a prospective phase II study in adults 18 to 59 years old with previously untreated LL. Patients were treated with an adapted pediatric-like ALL protocol, which included a corticosteroid prephase, a five-drug induction reinforced by sequential cyclophosphamide administration, dose-dense consolidation, late intensification, CNS prophylaxis, and a 2-year maintenance phase. Treatment response was assessed by computed tomography and optional positron emission tomography. Allogeneic hematopoietic stem cell transplant was offered to selected patients in first complete remission (CR) or unconfirmed CR.

Results

The study enrolled 148 patients (131 with T-lineage LL [T-LL] and 17 with B-lineage LL [B-LL]). A total of 119 patients with T-LL (90.8%) and 13 with B-LL (76.5%) reached CR/unconfirmed CR, including 26 with T-LL and two with B-LL who needed a second induction salvage course. Relapse occurred in 34 patients with T-LL and four with B-LL. In patients with T-LL, 3-year event-free survival was 63.3% (95% CI, 54.2% to 71.0%), disease-free survival was 72.4% (95% CI, 63.0% to 79.7%), and overall survival was 69.2% (95% CI, 60.0% to 76.7%). Multivariate analysis identified serum lactate dehydrogenase level and the NOTCH1/FBXW7/RAS/PTEN oncogene (a four-gene oncogenetic classifier) status but not positron emission tomography or hematopoietic stem cell transplant as independent prognostic factors for outcome in T-LL.

Conclusion

In adults with LL, an intensive pediatric-like ALL treatment protocol was associated with a good response rate and outcome. In patients with T-LL, the four-gene oncogenetic classifier and lactate dehydrogenase level were independent prognostic indicators.

c-Myc plays part in drug resistance mediated by bone marrow stromal cells in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant and aggressive disease not sensitive to chemotherapy. The dynamic interaction between AML cells and bone marrow (BM) microenvironment plays a critical role in response of this disease to chemotherapy. It is reported that mesenchymal stromal cells (MSC) are essential component of bone marrow microenvironment which affects the survival of AML cells. The aim of our research is to elucidate the mechanism of drug resistance of AML cells associated with MSC. We found that adhesion of AML cell lines U937, KG1a and primary AML cells to MSC inhibited cytotoxic drug-induced apoptosis. Western blot showed that c-Myc of AML cells cocultured with stroma was up-regulated. Treatment with 10058-F4, a small molecule inhibitor of MYC-MAX heterodimerization, or c-Myc siRNA significantly induced apoptosis. Western blot analysis further showed that inhibition of c-Myc induced expression of caspases-3, cleavage of PARP and reduced expression of Bcl-2, Bcl-xL and vascular endothelial growth factor (VEGF). Thus, we conclude that MSCs protected leukemia cells from apoptosis, at least in part, through c-Myc dependent mechanisms, and that c-Myc contributed to microenvironment-mediated drug resistance in AML. In summary, we declared that c-Myc is a potential therapeutic target for overcoming drug resistance in AML.

The genetic basis for inactivation of Wnt pathway in human osteosarcoma

BACKGROUND

Osteosarcoma is a highly genetically unstable tumor with poor prognosis. We performed microarray-based comparative genomic hybridization (aCGH), transcriptome sequencing (RNA-seq), and pathway analysis to gain a systemic view of the pathway alterations of osteosarcoma.

METHODS

aCGH experiments were carried out on 10 fresh osteosarcoma samples. The output data (Gene Expression Omnibus Series accession number GSE19180) were pooled with published aCGH raw data (GSE9654) to determine recurrent copy number changes. These were analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to identify altered pathways in osteosarcoma. Transcriptome sequencing of six osteosarcomas was performed to detect the expression profile of Wnt signaling pathway genes. Protein expression of WNT1, β-catenin, c-myc, and cyclin D1 in the Wnt pathway was detected by immunohistochemistry (IHC) in an independent group of 46 osteosarcoma samples.

RESULTS

KEGG pathway analysis identified frequent deletions of Wnt and other Wnt signaling pathway genes. At the mRNA level, transcriptome sequencing found reduced levels of mRNA expression of Wnt signaling pathway transcripts. While WNT1 protein expression was detected by IHC in 69.6% (32/46) of the osteosarcomas, no β-catenin protein was detected in the nucleus. β-catenin protein expression was, however, detected in the membrane and cytoplasm of 69.6% (32/46) of the osteosarcomas. c-myc protein expression was detected in only 47.8% (22/46) and cyclin D1 protein expression in 52.2% (24/46) of osteosarcoma samples. Kaplan-Meier survival analysis showed that WNT1-negative patients had a trend towards longer disease free survival than WNT1-positive patients. Interestingly, in WNT1-negative patients, those who were also cyclin D1-negative had significantly longer disease free survival than cyclin D1-positive patients. However, there was no significant association between any of the investigated proteins and overall survival of human osteosarcoma patients.

CONCLUSIONS

Frequent deletions of Wnt and other Wnt signaling pathway genes suggest that the Wnt signaling pathway is genetically inactivated in human osteosarcoma.

BTG1 expression correlates with the pathogenesis and progression of breast carcinomas

This study aimed to analyze the expression, clinical significance of B cell translocation gene 1 (BTG1) in breast carcinoma and the biological effect in its cell line by BTG1 overexpression. Immunohistochemistry and western blot were used to analyze BTG1 protein expression in 72 cases of breast cancer and 36 cases of normal tissues to study the relationship between BTG1 expression and clinical factors. Recombinant lentiviral vector was constructed to over-express EMP-1 and then infect breast cancer MCF-7 cell line. Quantitative real-time RT-PCR (qRT-PCR) and western blot were used to detect the mRNA level and protein of BTG1. MTT assay, cell apoptosis, cell cycles, migration and invasion assays were also conducted as to the influence of the upregulated expression of BTG1 that might be found on MCF-7 cells biological effect. The level of BTG1 protein expression was found to be significantly lower in breast cancer tissue than normal tissues (P < 0.05). Decreased expression of BTG1 was significantly correlated with tumor invasion, lymph node metastasis, clinic stage and histological grade of patients with breast cancer (P < 0.05). Meanwhile, loss of BTG1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function shown that MCF-7 cell transfected BTG1 had a lower survival fraction, higher percentage of the G0/G1 phases, higher cell apoptosis, significant decrease in migration and invasion, and lower CyclinD1, Bcl-2, and MMP-9 protein expression compared with MCF-7 cell untransfected BTG1 (P < 0.05). BTG1 expression decreased in breast cancer and correlated significantly lymph node metastasis, clinic stage, histological grade, poor overall survival, proliferation, and metastasis in breast cancer cell by regulating CyclinD1, Bcl-2, and MMP-9 protein expression, suggesting that BTG1 may play important roles as a negative regulator to breast cancer cell.

The expression of BTG1 is downregulated in NSCLC and possibly associated with tumor metastasis

This study aimed to analyze the expression, clinical significance of B cell translocation gene 1 (BTG1) in nonsmall cell lung cancer (NSCLC) and the biological effect in its cell line by BTG1 overexpression. Immunohistochemistry and western blot were used to analyze BTG1 protein expression in 82 cases of NSCLC and 38 cases of normal tissues to study the relationship between BTG1 expression and clinical factors. Recombinant lentiviral vector was constructed to overexpress EMP-1 and then infect NSCLC H1299 cell line. Quantitative real-time RT-PCR and western blot were used to detect the mRNA level and protein of BTG1. 3-[4,5-dimethylthiazol -2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, cell apoptosis, cell cycles, and migration and invasion assays were also conducted as to the influence of the upregulated expression of BTG1 that might be found on H1299 cells biological effect. The level of BTG1 protein expression was found to be significantly lower in NSCLC tissue than normal tissues (P < 0.05). Decreased expression of BTG1 was significantly correlated with lymph node metastasis, clinic stage, and histological grade of patients with NSCLC (P < 0.05). Meanwhile, loss of BTG1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function show that H1299 cell transfected BTG1 had a lower survival fraction; higher percentage of the G0/G1 phases; higher cell apoptosis; significant decrease in migration and invasion; and lower CyclinD1, Bcl-2, and MMP-9 protein expression compared with H1299 cell untransfected BTG1 (P < 0.05). BTG1 expression decreased in NSCLC and correlated significantly with lymph node metastasis; clinical stage; histological grade; poor overall survival; cell proliferation; cell cycles; cell apoptosis; and migration and invasion in NSCLC cell by regulating CyclinD1, Bcl-2, and MMP-9 protein expression, suggesting that BTG1 may play important roles as a negative regulator to NSCLC cell.

Role of polymorphisms in BCL-2 and BAX genes in modulating the risk of developing non-Hodgkin lymphoma

The aim of this study was to investigate whether polymorphisms of - 938C/A and Thr43Ala in the BCL-2 gene and G - 248A in the BAX gene are associated with the risk of developing non-Hodgkin lymphoma (NHL). We genotyped polymorphisms of - 938C/A and Thr43Ala in the BCL-2 gene and G-248A in the BAX gene among 424 patients with NHL and 446 controls. We found that the - 938AA genotype of the BCL2 gene was significantly associated with the risk of developing NHL (p < 0.001) and this genotype was associated with advanced stage (p = 0.01). Meanwhile, individuals having - 248AG + AA genotypes were significantly associated with an increased risk of NHL (p = 0.01), and these genotypes were associated with larger tumor size (p = 0.02). The present study demonstrated that the - 938AA genotype of the BCL-2 gene and - 248AG + AA genotype of the BAX gene may be susceptible genotypes for NHL. There appeared to be an impact of the BCL2 - 938AA genotype on advanced stage and - 248AG + AA genotypes on tumor size in NHL.