[Effects of hOCT1 and ABCB1 gene on the efficacy of imatinib mesylate in chronic myelocytic leukemia].

OBJECTIVE: To detect the expression of hOCT1 and ABCB1 in marrow cells and examine the efficacy of imatinib mesylate (IM) in patients with chronic myelocytic leukemia (CML). METHODS: hOCT1 and ABCB1 gene in 90 samples with chronic phase CML diagnosed at our hospital from January 2008 and June 2011 were detected by taqman probe real-time reverse transcription-PCR (RT-PCR). The samples were divided into 3 groups: drug-resistant group (n = 17), partial cytological remission (PCyR) group (n = 11) and complete cytogenetic remission (CCR) group (n = 62) according to IM efficacy and 3 - 6, 7 - 12, 13 - 24, 25 - 48, > 48 months five groups (n = 21, 8, 15, 29, 17) according to IM treatment course. The relationship was explored between two genes and different disease states, course of treatment and time from first CCR. RESULTS: The hOCT1 gene mRNA expression of CCR group (-3.77 ± 0.55) was higher than drug-resistant group (-4.12 ± 0.47) and PCyR group (-4.24 ± 0.35) (P = 0.047, 0.019). The ABCB1 gene mRNA expression of drug-resistant group (-2.93 ± 0.49) was higher than CCR group (-3.02 ± 0.56) and PCyR group (-3.51 ± 0.45) (P = 0.045, 0.021). The hOCT1 and ABCB1 mRNA expressions showed no significant difference between five groups divided by IM treatment course (P = 0.270, 0.367). The median follow-up time was 30 (3 - 117) months. In same IM treatment course patients, the CCR rates in hOCT1 and ABCB1 low-expression groups were higher than that in high-expression groups separately (P = 0.006, 0.049). CONCLUSIONS: The expression levels of hOCT1 and ABCB1 vary in different disease states of patients on IM. And these two genes may influence the time from first CCR. But there is no significant relationship with course of the treatment.

[Expression of Wilms' Tumor 1 Gene in Bone Marrow of Patients with Myelodysplastic Syndrome and Its Clinical Significance].

OBJECTIVE: To investigate the expression level and clinical significance of Wilms' tumor 1 (WT1) in bone marrow of patients with myelodysplastic syndromes (MDS). METHODS: The clinical data of 147 MDS patients who accepted real-time quantitative polymerase chain reaction (RT-PCR) to detect the expression level of WT1 in bone marrow before treated in Nanfang Hospital, Southern Medical University from January 2017 to April 2021 were retrospectively analyzed. According to the expression level of WT1, the patients were divided into WT1+ group and WT1- group, their clinical characteristics and prognosis were analyzed. RESULTS: The positive rate of WT1 in 147 MDS patients was 82.3%. There were significant differences in bone marrow blast count, aberrant karyotypes, WHO 2016 classification, and IPSS-R stratification between WT1+ group and WT1- group (all P<0.05). Furthermore, the higher the malignant degree of MDS subtype and the risk stratification of IPSS-R, the higher expression level of WT1. Compared with WT1- group, there were no differences in overall survival (OS) time and the time of transformation to AML in WT1+ group (both P>0.05). In patients who did not accept transplantation, the median OS time of WT1+ patients was significantly shorter than that of WT1- patients (P=0.049). Besides, regarding WT1+ group, patients who underwent transplantation had longer OS time and lower mortality than those who received hypomethylating agents (P=0.002, P=0.005). CONCLUSION: WT1 expression level directly reflects the disease progression, and it is also associated with prognosis of MDS patients.

[Influence of FLT3-ITD Mutation and ITD Length on the Outcome on Patients with Acute Myeloid Leukemia].

OBJECTIVE: To explore the influence of FLT3-ITD mutation and ITD length on the overall survival (OS) and relapse free survival(RFS) in patients with non-M3 acute myeloid leukemia. METHODS: Clinical features and therapeutic effect were retrospectively analyzed in 75 AML patients with FLT3-ITD mutation and 76 FLT3-ITD- AML patients with a normal karotype from June 2011 to April 2016. Genomic DNA was amplified by PCR, and FLT3-ITD mutation length was analyzed by DNA sequencing in 40 patients. RESULTS: AML patients with FLT3-ITD mutation had higher WBC count and the ratio of BM blast cells at initial diagnosis was also higher than those in AML patients without FLT3-ITD mutation (95.13 vs 10.85)(P<0.01); 72% vs 59%(P<0.01). The CR rates in AML patients with FLT3-ITD mutation less than those in AML patients without FLT3-ITD mutation(70.42% vs 94.7%)(P<0.01). OS (P<0.01) and RFS (P<0.01) were significantly increased in patients with AML who received allo-HSCT as compared with the patients who received consolidation chemotherapy and similar to AML patients without FLT3-ITD mutation who received HSCT. Patients with maintenance sorafenib after HSCT had longer OS (P<0.05) and RFS (P<0.05) than controls. ITDs exceeding 60 bp in length were associated with decreasing OS as compared with shorter ITD in AML patients with FLT3-ITD mutation (P<0.05). OS and RFS were similar among the 2 groups receiving consolidation chemotherapy. Besides, the patients with allo-HSCT had shorter ITDs and longer OS than ITDs exceeding 60 bp (P<0.05) and similar to AML patients without FLT3-ITD mutation. CONCLUSION: AML patients with FLT3-ITD mutation has poorer outcome, among which the prognosis was worse in patients with ITD exceeding 60 bp, and the chemotherapy alone can not improve the prognosis of FLT3-ITD+. Allo-HSCT is an effective treatment for AML patients with FLT3-ITD mutation; Sorafenib appears to be an effective maintenance therapy after allo-HSCT in FLT3-ITD AML.

Influence of initiation time and white blood cell count on the efficacy of cytotoxic agents in acute promyelocytic leukemia during induction treatment.

The present study retrospectively analyzed 96 newly diagnosed acute promyelocytic leukemia (APL) patients with low-intermediate mortality risk to identify the optimum timing to initiate cytotoxic chemotherapy following all-trans retinoic acid (ATRA) administration. Based on white blood cell (WBC) at chemotherapy initiation, the patients were divided into three groups: low WBC (WBC count ≤4×109/l), intermediate WBC (WBC count >4×109/l and <15×109/l) and high WBC group (WBC count ≥15×109/l). According to the period from ATRA commencement to chemotherapy, 96 patients were further divided into two groups: ≤3 days group (chemotherapy within 3 days of ATRA) and >3 days group (chemotherapy >3 days after ATRA). Clinical effects were compared by univariate analysis and multivariate analyses. The incidence rate of differentiation syndrome (DS; also termed retinoic acid syndrome) was 0.0, 11.1 and 40.0% in the low, intermediate and high WBC groups, respectively (P<0.001); complete remission (CR) rate was 90.5, 100.0 and 73.3%, respectively (P<0.001); and the rate of early mortality (defined as fatality during induction treatment) was 4.8, 0.0 and 26.7%, respectively (P<0.001). No differences were identified in clinicolaboratory parameters between the ≤3 days and >3 days groups, except in time to achieve CR (P=0.004) and rate of bleeding related to chemotherapy (P=0.009), both being higher in the >3 days group. Multivariate analyses indicated WBC count at chemotherapy was the only independent risk factor for the occurrence of DS [P=0.002; odds ratio (OR) =1.058, 95% confidence interval (CI) =1.021-1.095] and early mortality (P=0.036; OR =1.036, 95% CI =1.002-1.070). For newly diagnosed APL patients with low-intermediate risk, chemotherapy initiation should be recommended until WBC count rises to between 4×109/l and 15×109/l during induction treatment.

[Establishing the Ion Torrent PGM Sequencing Methods for the Clinical Diagnosis of MPN Patients].

OBJECTIVE: To investigate the feasibility and relibility of rapidly and accurately acquiring the informations of gene mutations in MPN patients by using self-designed custom MPN mutation-related multipe-PCR primer kit and next generation Ion Torrent PGM sequencing platform. METHODS: The bone marrow samples of 10 MPN patients with JAK2V617F and/or CALR+, Ph- confirmed by sanger sequencing method were collected and were re-detected by using next generation Ion Torrent PGM sequencing method, then the consistence of results of above-mentioned 2 kinds of detection methods was compared. RESULTS: In terms of JAK2V617F, MPL and CALR mutations, the results of Ion Torrent PGM sequencing were complete consistent with results of Sanger sequencing, except 52 bp deletion of CALR gene, which conld not be detected by next generation Ion Torrent PGM sequencing method in all bone marrow samples. CONCLUSION: The detection of multiple gene mutations in MPN patients by Ion Torrent PGM sequencing platform is feasible and can meet the needs of clinical testing. This method can complete detection of all 23 mutetions within 1-2 days, moreover, possesses advantages of high sensitivity, specificity, rapidity, high throughput and low cost.

Association between the concentration of imatinib in bone marrow mononuclear cells, mutation status of ABCB1 and therapeutic response in patients with chronic myelogenous leukemia.

Low concentrations of imatinib (IM) in bone marrow cells have been linked with poor prognosis in patients with chronic myeloid leukemia (CML), which may be caused by the emergence of ATP-binding cassette transporter B1 (ABCB1) mutations. The aim of present study was to investigate how clinical outcomes vary among patients with different single nucleotide polymorphisms (SNPs) of ABCB1. A total of 48 adult patients with CML and higher than median ABCB1 mRNA levels were selected for testing of ABCB1 SNPs. In 28 of the 48 patients, the IM concentration and expression levels of human organic cation transporter 1 (hOCT1) and ABCB1 in bone marrow mononuclear cells (BMMCs) were also tested. Correlations between treatment outcomes and IM concentration or the SNP status of ABCB1 were analyzed. Patients were classified by therapeutic response as major molecular response (MMR) (n=11), complete cytogenetic response (CCyR) (n=19) and non-CCyR (n=18) groups. It was found that the concentration of IM in BMMCs of the CCyR group was significant higher than that of the resistant groups (P=0.013). In addition, the IM concentration was positively correlated with the expression of hOCT1 mRNA (R=0.456, P=0.033), but negatively correlated with the expression of ABCB1 mRNA (R=-0.491, P=0.015). Furthermore, the mRNA expression level of ABCB1 was not associated with therapeutic response, but SNPs of the ABCB1 gene were associated with the response to IM. In conclusion, the concentration of IM in BMMCs may be regulated by the ABCB1 gene, and SNPs of the ABCB1 gene predict the therapeutic response to IM in patients with CML.

Immunophenotypes and immune markers associated with acute promyelocytic leukemia prognosis.

CD2+, CD34+, and CD56+ immunophenotypes are associated with poor prognoses of acute promyelocytic leukemia (APL). The present study aimed to explore the role of APL immunophenotypes and immune markers as prognostic predictors on clinical outcomes. A total of 132 patients with de novo APL were retrospectively analyzed. Immunophenotypes were determined by flow cytometry. Clinical features, complete remission (CR), relapse, and five-year overall survival (OS) rate were assessed and subjected to multivariate analyses. The CD13+CD33+HLA-DR-CD34- immunophenotype was commonly observed in patients with APL. Positive rates for other APL immune markers including cMPO, CD117, CD64, and CD9 were 68.7%, 26%, 78.4%, and 96.6%, respectively. When compared with patients with CD2- APL, patients with CD2+ APL had a significantly higher incidence of early death (50% versus 15.7%; P = 0.016), lower CR rate (50% versus 91.1%; P = 0.042), and lower five-year OS rate (41.7% versus 74.2%; P = 0.018). White blood cell (WBC) count before treatment was found to be the only independent risk factor of early death, CR failure, and five-year mortality rate. Flow cytometric immunophenotype analysis can facilitate prompt APL diagnosis. Multivariate analysis has demonstrated that WBC count before treatment is the only known independent risk factor that predicts prognosis for APL in this study population.

[Clinical significance of monitoring BK polyomavirus in patients after hematopoietic stem cell transplantation].

This study was aimed to establish a method for rapid detecting BK polyomavirus (BKV) and to investigate the feasibility and value used in leukemia patients undergoing hematopoietic stem cell transplantation. Primers were designed according to BKV gene sequence; the quantitative standards for BKV and a real-time fluorescent quantitative PCR for BKV were established. The BKV level in urine samples from 36 patients after hematopoietic stem cell transplantation were detected by established method. The results showed that the standard of reconstructed plasmid and real time fluorescent quantitative PCR method were successfully established, its good specificity, sensitivity and stability were confirmed by experiments. BKV was found in 55.56% of urine samples, and the BKV load in urine was 2.46 × 10(4) - 7.8 × 10(9) copy/ml. It is concluded that the establishment of real-time fluorescent quantitative PCR for BKV detection provides a method for early diagnosis of the patients with hemorrhagic cystitis after hematopoietic stem cell transplantation.

[Detection of the JAK2 gene mutation in familial myeloproliferative neoplasm and its clinical significance].

OBJECTIVE: To comprehend the abnormalities of JAK2, c-mp, EPOR, MPW515L/K and TET2 genes in patients with familial myeloproliferative neoplasm (MPN) and their relatives, and to explore mechanism of MPN pathogenesis. METHODS: The complete blood counts of 2 brothers diagnosed with MPN in out hospital and their family members (15 persons in together) were performed, and bone marrow (BM) examinations in patients with abnormal blood count were performed PCR, DNA sequencing were used to evaluate the expression of related genes. RESULTS: The elder brother was diagnosed with essential thrombocythemia (ET), the younger one was polycythemia vera (PV), and others had no clinical manifestation. The third MPN patient was diagnosed based on the blood count and BM examination. The PCR and sequencing results showed that there was JAK2V617F mutation in 3 patients, the elder brother was homozygous, the younger and their father were heterozygous. There were no BCR/ABL fusion gene and c-mp, EPOR, MPW515L/K, TET2 gene mutation in any member. By sequencing the full-length cDNA of familia JAK2 gene, we found that G380A heterozygous mutation was detected in 2 patients, which changed glycine at 127 into aspartic acid, C489T mutation was detected in 13 patients, G2490A mutation in 14, but both of them were synonymous mutations. CONCLUSIONS: JAK2V617F is one of the important indicators to diagnose MPN. The JAK2V617F mutation of this family involves two generations. For newly diagnosed MPN patients, their family members should consider screening, so some familial patients can be diagnosed as early as possible. Gene mutation besides JAK2V627F can be detected by sequencing the full-length of JAK2 gene.

Imatinib and bortezomib induce the expression and distribution of anaphase-promoting complex adaptor protein Cdh1 in blast crisis of chronic myeloid leukemia.

Anaphase promoting complex cofactor Cdh1 plays a critical role in tumor suppression and genomic stability in cancer. However, its role in chronic myeloid leukemia (CML) remains unclear. We treated both wild-type and imatinib-resistant K562 cells with imatinib or nilotinib and bortezomib, respectively. The siRNAs of Cdh1 and Skp2 were designed and transiently transfected with HiPerFect transfection reagent into CML cells. Expression of Cdh1-Skp2-p27 pathway proteins were detected by Western blotting. Cell cycle, cell apoptosis and cellular morphology were detected by flow cytometry and Wright staining. Our study revealed that Cdh1 was expressed at lower levels in imatinib-resistant CML blast crisis (BC) patients than imatinib-sensitive ones. Moreover, imatinib and bortezomib induced cell cycle quiescence or arrest, upregulation and nuclear relocation of Cdh1 in CML cells. Furthermore, nilotinib and bortezomib resulted in upregulation of Cdh1 in imatinib-resistant CML cells. Conversely, Cdh1 silencing resulted in stabilization of Skp2 and Cdc20, subsequently promoting G1-S transition and formation of multinucleated cells. Our study shows that TKIs and bortezomib can regulate the cell cycle and cell apoptosis via regulation of the expression and redistribution of Cdh1 in CML-BC, which sheds light on the orchestration of crosstalk between TKIs and bortezomib in imatinib-resistant CML-BC. Additionally, Cdh1 tends to play an important role in maintenance of genomic stability, the detailed mechanisms deserve further study.