Detection of the t(11;14)(q13;q32) without CCND1/IGH fusion in a case of acute myeloid leukemia

Prediction of deleterious single nucleotide polymorphisms and their effect on the sequence and structure of the human CCND1 gene

Objective

The CCND1 gene expresses a protein, G1/S-specific cyclin, that regulates the G1/S transition in the cell cycle and also inhibits retinoblastoma (RB) proteins. Overexpression or rearrangements of this gene can result in various tumours. This study aimed to identify possible deleterious non-synonymous single nucleotide polymorphisms (SNP's) of CCND1 using computational methods.

Methods

SNPs in the human CCND1 gene were retrieved from dbSNP. These SNPs were screened by the Sorting Intolerant From Tolerant (SIFT) algorithm and the PredictSNP classification. Mutants with deleterious SNPs were built using Discovery Studio 3.5, and dynamics studies were performed on native and mutant varieties.

Results

In Homo sapiens, 1194 SNPs were found, of which 94 were missense and 2 were nonsense SNPs. Three SNPs were found to be deleterious. Molecular dynamics and trajectory analysis showed that there was a significant deviation of the root mean square deviation (RMSD) values in the N216K mutant from the values of the native protein.

Conclusion

Based on this study, we propose that the SNP with SNP ID rs112525097 (NM_053056.2:c.648C>G) might cause aberrations in CCND1, which might lead to a change in the function of the G1/S-specific cyclin protein. This, in turn, may lead to the development of acute myeloid leukaemia (AML).

Characterization of genetic rearrangements in esophageal squamous carcinoma cell lines by a combination of M-FISH and array-CGH: further confirmation of some split genomic regions in primary tumors

Background

Chromosomal and genomic aberrations are common features of human cancers. However, chromosomal numerical and structural aberrations, breakpoints and disrupted genes have yet to be identified in esophageal squamous cell carcinoma (ESCC).

Methods

Using multiplex-fluorescence in situ hybridization (M-FISH) and oligo array-based comparative hybridization (array-CGH), we identified aberrations and breakpoints in six ESCC cell lines. Furthermore, we detected recurrent breakpoints in primary tumors by dual-color FISH.

Results

M-FISH and array-CGH results revealed complex numerical and structural aberrations. Frequent gains occurred at 3q26.33-qter, 5p14.1-p11, 7pter-p12.3, 8q24.13-q24.21, 9q31.1-qter, 11p13-p11, 11q11-q13.4, 17q23.3-qter, 18pter-p11, 19 and 20q13.32-qter. Losses were frequent at 18q21.1-qter. Breakpoints that clustered within 1 or 2 Mb were identified, including 9p21.3, 11q13.3-q13.4, 15q25.3 and 3q28. By dual-color FISH, we observed that several recurrent breakpoint regions in cell lines were also present in ESCC tumors. In particular, breakpoints clustered at 11q13.3-q13.4 were identified in 43.3% (58/134) of ESCC tumors. Both 11q13.3-q13.4 splitting and amplification were significantly correlated with lymph node metastasis (LNM) (P = 0.004 and 0.022) and advanced stages (P = 0.004 and 0.039). Multivariate logistic regression analysis revealed that only 11q13.3-q13.4 splitting was an independent predictor for LNM (P = 0.026).

Conclusions

The combination of M-FISH and array-CGH helps produce more accurate karyotypes. Our data provide significant, detailed information for appropriate uses of these ESCC cell lines for cytogenetic and molecular biological studies. The aberrations and breakpoints detected in both the cell lines and primary tumors will contribute to identify affected genes involved in the development and progression of ESCC.

Day 15 bone marrow driven double induction in young adult patients with acute myeloid leukemia: feasibility, toxicity, and therapeutic results

The strategy named double induction (DI) in acute myeloid leukemia (AML) consists of two courses of chemotherapy irrespective of the degree of cytoreduction in the bone marrow (BM) after the first course, unless severe complications prohibit its application. We describe treatment results from a series of 33 patients in whom DI was adopted only after demonstration of persistence of more than 10% blast cells at day 15 (D15) examination of BM. All patients received as induction idarubicin, cytarabine, and etoposide. As second induction, we administered the combination of fludarabine, intermediate dose cytarabine, and Granulocyte colony stimulating factor (G-CSF). The median blast count at D15 was 30 (15-90). Overall, 30 of 33 patients were judged as eligible to receive DI, reasons for exclusion being in all cases active infection in the context of severe pancytopenia. Nineteen patients (63%) had unfavorable karyotype and 11 (37%) normal karyotype; seven of these had Fms-like tyrosine kinase gene internal tandem duplication (FLT3/ITD) mutation. Overall, complete remission (CR) was achieved in 20/30 patients (67%), while eight patients (27%) were refractory and two died of infectious complications. All refractory patients had unfavorable cytogenetics. All patients achieving CR were programmed to receive allogeneic stem cell transplantation (allo-SCT), which was actually performed in 11 patients. Our study suggest that D15 driven DI represents a feasible and effective therapeutic strategy in young adult AML patients, improving therapeutic results and not compromising feasibility of allo-SCT. When compared with conventional DI, it offers the potential to avoid unnecessary toxicity in a consistent proportion of patients.