mRNA expression of telomere protection protein TIN2 and POT1 in bone marrow of patients with myelodysplastic syndrome / 中国实验血液学杂志

This study was purposed to explore the relationship between the mRNA expression of telomere protection protein TIN2 and POT1 and the pathogenesis of myelodysplastic syndrome (MDS). The expression of TIN2 and POT1 genes at the mRNA levels were detected by real-time fluorescence quantitative PCR in 51 patients with MDS and 10 normal controls. The results showed that the mRNA expressions of TIN2 in RA/RARS/RCMD/MDS-U, RAEB-1 and RAEB-2 groups according to the World Health Organization criteria were significantly higher than that in the controls (P < 0.05); the mRNA expressions of POT1 in RA/RARS/RCMD/MDS-U, RAEB-1 and RAEB-2 groups were significantly lower than that in the controls (P < 0.05). The mRNA expressions of TIN2 in high-risk group, inter risk-2 group and inter risk-1 group according to the international prognostic scoring system criteria were significantly higher than that in controls (P < 0.05). There was no significant difference between low risk group and the control group. The mRNA expressions of POT1 in high risk group, inter-risk-2 group and inter-risk-1 group were significantly lower than the controls (P < 0.05). There was no significant difference between low risk group and the control group. The mRNA expression of TIN2 in normal chromosome group was significantly lower than that in abnormal chromosome group (P < 0.05). There was no significant difference between normal chromosome group and the control group. The mRNA expression of POT1 in normal chromosome group was significantly higher than that in abnormal chromosome group (P < 0.05). There was no significant difference between normal chromosome group and the control group. It is concluded that the abnormal mRNA expression of TIN2 and POT1 may be involved in the regulation of telomere dynamics of MDS patients, the regulatory mechanism may be related to the telomere length and the pathogenesis of MDS.

Detection of tumor load in chronic myeloid leukemia during treatment with transplantation by conventional cytogenetics, nested-RT-PCR and FISH / 中国实验血液学杂志

This study was purposed to investigate the sensitivity and specificity of conventional cytogenetics (CC), nested-reverse transcriptase polymerase chain reaction (nested-RT-PCR) and dual-color/dual-fusion fluorescence in situ hybridization (D-FISH) technique in monitoring the tumor load of chronic myeloid leukemia (CML) during treatment with transplantation. CC, nested-RT-PCR and interphase D-FISH were simultaneously carried out to detect the tumor load of 7 CML patients during treatment with non-myeloablative allogeneic stem cell transplantation (allo-NSCT). 40 specimens from 7 CML patients before and after allo-NSCT were analyzed. The results showed that 29 specimens were Ph (+) with different positive ratio and 3 specimens with lower cells were not analyzed by CC. 36 specimens were bcr/abl mRNA (+) by RT-PCR. 4 specimens from case 1 at 12, 18, 26 and 38 months after allo-NSCT were Ph (-) and bcr/abl mRNA (-), 4 Ph (-) bcr/abl (+) specimens containing 2 from case 1 at 9 and 10 months after allo-NSCT, 1 from case 2 at 15 months after allo-NSCT, 1 from case 3 at 12 months after allo-NSCT showed 5.4%, 0%, 16.5% and 1.5% bcr/abl (+) cells by FISH. 3 specimens with lower cells containing 2 from case 5 at 20 and 60 days after allo-NSCT and 1 from case 7 at 40 days after allo-NSCT were analyzed by FISH and showed 55.0%, 27.5% and 73.5% bcr/abl (+) cells. The Ph (-) bcr/abl (-) specimen from case 1 at 12 months post-allo-NSCT showed 0% bcr/abl (+) cells by FISH. It is concluded that CC can be used as a basic tool to monitor the change of tumor load in CML during treatment. When specimen with lower cells can not be analyzed by CC in early period after allo-NSCT, or result of CC can not evaluate precisely dynamic change of tumor load and when tumor load in treated patient are lower to Ph (-) by CC while bcr/abl mRNA (+) by RT-PCR, FISH must be used to detect precisely tumor load and monitor dynamic change of it. More sensitive RT-PCR is used to monitor tumor load when it is lower to bcr/abl (-) by FISH during treatment.

Coexistence of tetrasomy 8 and trisomy 8 in acute promyelocytic leukemia (AML-M3) with t(15;17)(q22;q12) / 中国实验血液学杂志

This study was purposed to characterize the first case of acute promyelocitic leukemia (AML-M(3a)) with t(15;17), trisomy 8 and tetrasomy 8, and explore its characteristics of morphology, cytogenetics, molecular biology, immunology and clinical features. Morphological changes of peripheral blood and bone marrow smears were observed under microscope. Chromosome specimen was prepared by 24 h short-term culture of bone marrow cell, RHG-banding technique was used for karyotypic analysis. PML-RARa fusion gene transcript was detected by nested-reverse transcription-polymerase chain reaction (nested RT-PCR). Interphase fluorescence in situ hybridization (FISH) using chromosome 8 centromere specific probe were carried out to detect abnormal numbers of chromosome 8. Immunophenotypic analysis was performed by flow cytometry. The results showed that peripheral blood smear revealed 65% promyelocyte, and bone marrow aspirate was hypercellular with 72.4% promyelocyte, moderately basophilic cytoplasm with numerous azurophilic granules. Karyotype analysis demonstrated 48, XY, +8, +8, t(15;17)(q22;q12) [16]/47, XY, +8, t(15;17)(q22;q12) [3]/46, XY, t(15;17)(q22;q12) [1]. RT-PCR assay revealed PML-RARa fusion gene transcript (+). FISH showed that the percentages of cells exhibiting 1, 2, 3, 4, 5, 6 green fluorescence signals were 0.5, 7, 19, 55, 18 and 0.5, respectively. This confirmed the presence of tetrasomy 8 and trisomy 8 and also revealed a low percentage of a pentasomy 8 clone. Immunophenotypes of the blasts displayed that CD13 (96.2%), CD33 (55.9%), CYMPO (93.5%) were positive. All the lymphoid markers tested were negative. The patient survival time was just 10 days. It is concluded that tetrasomy 8 is secondary cytogenetic event after t(15;17) in this case. It may be a consequence of clonal evolution of trisomy 8. t(15;17) AML-M(3) with tetrasomy 8 heralds a poor prognosis.

Detection of abnormal numbers of chromosome 8 with interphase fluorescence in situ hybridization in hematologic malignancies / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the value of interphase fluorescence in situ hybridization (FISH) in the detection of abnormal numbers of chromosome 8 in patients with hematologic malignancies.</p><p><b>METHODS</b>Conventional cytogenetics(CC) and interphase FISH using chromosome 8 centromere specific probe were simultaneously carried out to detect the abnormal numbers of chromosome 8 in eight acute myeloid leukemia cases with CC unveiled abnormal numbers of chromosome 8, ten chronic myeloid leukemia cases in accelerated phase or blast crisis, and three normal individuals.</p><p><b>RESULTS</b>Nine cases that displayed trisomy 8 by means of CC were confirmed by FISH. Among them, Case 5 only displayed diploidy 8, trisomy 8 and tetrasomy 8 by CC, at the same time, FISH confirmed the presence of trisomy 8 and tetrasomy 8 and also revealed a low percentage of a pentasomy 8 clone. Case 3 and Case 17 had each only one cell with trisomy 8 by means of CC, and this could not determine whether they had the trisomy 8 clone, yet FISH confirmed the existence of trisomy 8 clone. Case 9 did not display trisomy 8 by CC, but FISH revealed the existence of trisomy 8 clone. In the other cases, the percentages of trisomy 8 cells determined by FISH were close to or significantly lower than those by CC, but for Case 16 where the percentage of trisomy 8 cells by FISH was significantly higher than that by CC.</p><p><b>CONCLUSION</b>Interphase FISH is a useful method for the detection of abnormal numbers of chromosome 8, especially in the patients with normal or unsure karyotype or with less and bad metaphases. It is an important complement to CC.</p>