Ixazomib-based frontline therapy followed by ixazomib maintenance in frail elderly newly diagnosed with multiple myeloma: a prospective multicenter study.

Background: Frail elderly patients with newly diagnosed multiple myeloma (NDMM) have inferior survival and less benefit from high-dose therapies. This prospective study aimed to investigate the efficacy, safety, and quality of life (QoL) of induction treatment of ixazomib/lenalidomide/dexamethasone (IRd) and ixazomib/pegylated liposomal doxorubicin/dexamethasone (IDd) followed by ixazomib/dexamethasone (Id) maintenance therapy in frail, elderly patients with NDMM. Methods: From July 2019 to December 2021, this non-randomized concurrent controlled clinical study enrolled 120 NDMM patients aged ≥65 years with frailty defined by the International Myeloma Working Group (IMWG) frailty score or Mayo geriatric scoring system. The enrolled patients received 6-8 cycles of IRd or IDd followed by Id maintenance therapy for a minimum of 2 years at the discretion of physicians based on patient's clinical characteristics (chiCTR1900024917). Findings: The median age was 71 years and 55% of the patients were males. The overall response rate (ORR) was 82% and 77%, complete response (CR) rate was 25% and 12% for IRd and IDd groups, respectively. The difference in ORR of the Idd group minus the IRd group was -5.36% (95% CI: -18.9% to 8.19%), indicating that the ORR of the IDd group was neither inferior nor non-inferior to the IRd group. After a median follow-up of 34.3 months, the median progression-free survival (PFS) was 21.6 and 13.9 months, OS was not reached and 29.2 months in IRd and IDd groups, respectively. 28 and 33 patients discontinued induction therapy, 20 and 19 discontinued maintenance therapy in IRd and IDd groups, respectively. Cumulative Grade 3 or higher hematological adverse events (AEs) occurred in 10 of the 60 patients (17%) and non-hematological AEs occurred in 15 of the 60 patients (25%) in the IRd group, while 13 of the 60 patients (22%) and 21 of the 60 patients (35%) in the IDd group. Patients were observed with clinically significant improvement in QoL when compared with that at baseline in both IRd and IDd groups by evaluation per cycle (P < 0.0001). Interpretation: The results demonstrated that compared with IRd regimen, IDd regimen showed no significant advantage, but the survival of the IDd group was shorter than that of the IRd group, indicating an all-oral outpatient triplet regimen with IRd, which has low toxicity and has improved QoL, could be the viable first-line treatment option for frail NDMM patients. Funding: The Young Elite Scientist sponsorship program by bast of Beijing Association for Science and Technology (No. BYESS2023116) and Beijing Medical Award Foundation (No. YXJL-2018-0539-0073).

Tanshinone IIA potentiates the efficacy of imatinib by regulating the AKT-MDM2-P53 signaling pathway in Philadelphia chromosome-positive acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by breakpoint cluster region-abelson leukemia virus (BCR/ABL) kinase. Targeting BCR/ABL kinase with tyrosine kinase inhibitors combined with chemotherapy is the standard first-line therapy for Ph+ ALL. Imatinib and dasatinib are the preferred agents for the treatment of Ph+ ALL. Dasatinib treatment can induce a faster and deeper remission than imatinib treatment; however, the side effects of dasatinib, especially the cardiovascular side effects, are markedly greater than those of imatinib. Patients will benefit from treatments that improve the efficacy of imatinib without increasing its side effects. The present study revealed that tanshinone IIA markedly potentiated the cytotoxic and apoptotic induction effects of imatinib by regulating the AKT-MDM2-P53 signaling pathway and inhibiting the anti-apoptotic proteins BCL2 and MCL1 apoptosis regulator, BCL2 family member in Ph+ ALL cell lines. In vitro studies, MTT assay, flow cytometry, western blotting and reverse transcription-quantitative PCR were performed in the present study to detect cell viability, cell apoptosis, protein expression and gene expression, respectively. In a Ph+ ALL mouse model, imatinib combined with tanshinone IIA also exhibited a synergistic effect on the reduction in leukemia burden without increasing the toxic side effects of imatinib. These results demonstrated that imatinib combined with tanshinone IIA might be a promising treatment strategy for patients with Ph+ ALL.

Inhibition of long noncoding RNA MALAT1 suppresses high glucose-induced apoptosis and inflammation in human umbilical vein endothelial cells by suppressing the NF-κB signaling pathway.

The study investigated the expression of long noncoding RNA (lncRNA) MALAT1 in high glucose (HG)-induced human vascular endothelial cells (HUVECs) and the role of MALAT1 in the apoptosis of HG-induced HUVECs. The HUVECs were cultured and induced with 25 mmol/L HG. After that, the HUVECs were transfected with MALAT1 siRNA. The expression levels of MALAT1 were detected with qPCR, whereas the expression levels of Bax, Bcl-2, cleaved-caspase-3, cleaved-caspase-9, p-65, and p-p65 were detected using Western blot. The roles of MALAT1 in cell activities, including apoptosis, were evaluated using the CCK-8 assay, TUNEL staining, and flow cytometry. The expression levels of inflammatory factors (TNF-α and IL-6) were measured using ELISA. The expression levels of MALAT1, TNF-α, and IL-6 in HUVECs were increased in the HG environment; however, when MALAT1 was silenced in the HUVECs, cell proliferation increased significantly, the expression levels of TNF-α, IL-6, Bax, cleaved-caspase-3, and cleaved-caspase-9 decreased, and the rate of apoptosis also decreased. Silencing MALAT1 inhibited the expression of p-p65 in HG-induced HUVECs. In conclusion, our study demonstrated that MALAT1 is upregulated in HG-induced HUVECs, and inhibition of MALAT1 inhibits HG-induced apoptosis and inflammation in HUVECs by suppression of the NF-κB signaling pathway.

[Relationship of Cystic Fibrosis Transmembrane Conductance Regulator Expression with Clinical Features and Prognosis in Patients with Acute Leukemia].

OBJECTIVE: To investigate the expression of cystic fibrosis transmembrane conductance regulator (CFTR) protein in patients with acute leukemia and its relationship to clinical features and prognosis of acute leukemia. METHODS: A total of115 patients with acute leukemia were enrolled in the experimental group and 20 healthy individuals were used as control. Peripheral blood or bone marrow samples were collected, and mononuclear cells were isolated. The expression of CFTR protein was detected by Western blot. The relationships of CFTR protein expression to clinical features and prognosis was analyzed. RESULTS: The expression of CFTR protein was not detected in peripheral blood mononuclear cells of normal control, while it was positive in more than half of acute leukemias including acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), but negative in the patients with acute promyelocytic leukemia (M3). In the patients with AML, there was no difference in peripheral white blood cells (WBC), peripheral blast cells, platelet and hemoglobin (HGB) between CFTR-positive and CFTR-negative patients. There was no relationship between the expression of CFTR protein and gene mutations such as NPM1, CEBPA, FLT3-ITD, and C-Kit. Complete remission (CR) rate after two course in CFTR-negative patients was slightly higher than that in positive patients. The survival time of CFTR-negative patients was little longer than that of positive patients, but the difference was not statistically significant. CONCLUSIONS: The expression of CFTR protein seems not associated with clinical features, treatment response and prognosis in the patients with acute leukemia.

The combination of Nutlin-3 and Tanshinone IIA promotes synergistic cytotoxicity in acute leukemic cells expressing wild-type p53 by co-regulating MDM2-P53 and the AKT/mTOR pathway.

P53 dysfunction has been associated with various malignant tumors, including acute leukemia. The overexpression of mouse double minute 2 (MDM2) causes the inactivation of p53 in acute leukemia. MDM2 inhibitors that activate p53 and induce apoptosis are currently being developed for potential treatment of acute leukemia. However, MDM2 inhibitors alone have limited efficacy in acute leukemia therapeutics. Combining other drugs to enhance the efficacy of MDM2 inhibitors is the thus considered as a potential treatment scheme. Here, we report that the combination of Nutlin-3 and Tanshinone IIA synergistically induces cytotoxicity, cell cycle arrest, apoptosis, and autophagic cell death, thereby imparting anti-leukemia effect in an acute leukemia cell line with wild-type p53 by effectively activating p53, inhibiting the AKT/mTOR pathway, and activating the RAF/MEK pathway. Using primary samples from acute leukemia patients, we show that the combination of Nutlin-3 plus Tanshinone IIA synergistically induces cytotoxicity by activating p53 and inhibiting the AKT/mTOR pathway. This specific combination of Nutlin-3 and Tanshinone IIA is also effective in preventing the recurrence of refractory leukemia, such as Ph+ ALL with the ABL kinase T315I mutation and AML with the FLT3-ITD mutation. Taken together, the results of this study demonstrate that the Nutlin-3 plus Tanshinone IIA combination exerts synergistic anti-leukemia effects by regulating the p53 and AKT/mTOR pathways, although further investigation is warranted. Small-molecule MDM2 antagonists plus Tanshinone IIA may thus be a promising strategy for the treatment of acute leukemia.

[Clinic analysis of 198 elder patients with maxillofacial fracture].

OBJECTIVE: The purpose of the study was to analyze the characteristics of elder patients with maxillofacial fracture. METHODS: We retrospectively analyzed the characteristics of maxillofacial fractures in the elder patients, who were treated from July 2010 to October 2017. The clinical characteristics of the etiology, fracture site, combined injury, systemic disease, and treatment method were analyzed. RESULTS: In the 198 elderly patients with maxillofacial fractures, the male-to-female ratio was 3.95︰1, and the mean age was 66.15 years old. Traffic accident injury (78 patients, 39.39%), fall injury (49 patients, 24.75%), high fall injury (33 patients, 16.67%) were the main factors of maxillofacial fracture in elderly patients. The most frequently observed fracture site was the mandible (120 patients). A total of 60 patients demonstrated associated injuries, in which limb injuries were the most prevalent (28 patients); whereas 66 patients had other systemic medical conditions, in which cardiovascular diseases was the most frequent (50 patients). The main treatment method of 198 patients was rigid internal fixation with small or micro-plates. CONCLUSIONS: Falling and traffic accidents are the main factors of maxillofacial fracture in elderly patients. Thus, interference measures should be observed for the prevention of maxillofacial fractures in elderly patients.

Chinese guidelines for treatment of adult primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

[Anti-Leukemia Effect and Mechanism of Oridonin on Imatinib-Sensitive and Imatinib-Resistant K562 Cells].

OBJECTIVE: To explore the molecular mechanism of resistance to imatinib in K562 cells(K562-R) and the anti-proliferative effect of oridonin (OR), as well as its mechanism in imatinib-sensitive and imatinib-resistant K562 cells (K562-S and K562-R cells). METHODS: The expression of p-Lyn in K562-S and K562-R cells were detected by Western blot. The anti-proliferative effect of OR in K562-S and K562-R cells was assayed by MTT, the morphological changes were examined with microscope, the cell apoptosis was detected by flow cytometry, the expressions of BCL-2 and Akt/mTOR signaling pathway were detected by Western blot. RESULTS: The over-expression of p-Lyn was detcected in K562-R cells, OR inhibited the proliferation of K562-S and K562-R cells and the value of IC50 was 4.23±1.30, 4.97±2.23 µmol/L, respectively. The apoptotic rate was obviously enhanced after OR treatment for 24 h, compared with control group. OR down-regulated the expression of p-Lyn, mTOR signaling pathway and BCL-2 protein. CONCLUSION: Over-expression of p-Lyn may be involved in the mechanism of resistance to imatinib. OR can inhibit the proliferation of K562-S and K562-R cells through down-regulating p-Lyn, inhibiting mTOR signaling pathway and down-regulating expression of BCL-2 protein.

Nutlin-3 plus tanshinone IIA exhibits synergetic anti-leukemia effect with imatinib by reactivating p53 and inhibiting the AKT/mTOR pathway in Ph+ ALL.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by BCR/ABL kinase. Recent efforts focused on the development of more potent tyrosine kinase inhibitors (TKIs) that also inhibit mutant tyrosine kinases such as nilotinib and dasatinib. Although major advances in the treatment of this aggressive disease with potent inhibitors of the BCR/ABL kinases, patients in remission frequently relapse due to drug resistance possibly mediated, at least in part, by compensatory activation of growth-signaling pathways and protective feedback signaling of leukemia cells in response to TKI treatment. Continuous activation of AKT/mTOR signaling and inactivation of p53 pathway were two mechanisms of TKI resistance. Here, we reported that nutlin-3 plus tanshinone IIA significantly potentiated the cytotoxic and apoptotic induction effects of imatinib by down-regulation of the AKT/mTOR pathway and reactivating the p53 pathway deeply in Ph+ ALL cell line. In primary samples from Ph+ ALL patients, nutlin-3 plus tanshinone IIA also exhibited synergetic cytotoxic effects with imatinib. Of note, three samples from Ph+ ALL patients harboring T315I mutation also showed sensitivity to the combined treatment of imatinib, nutlin-3 plus tanshinone IIA. In Ph+ ALL mouse models, imatinib combined with nutlin-3 plus tanshinone IIA also exhibited synergetic effects on reduction in leukemia burden. These results demonstrated that nutlin-3 plus tanshinone IIA combined TKI might be a promising treatment strategy for Ph+ ALL patients.

[The Mechanism of Combination using mTORC1/2 Inhibitor and Imatinib to Suppress Cell Proliferation of Ph +ALL Cell Line].

OBJECTIVES: To investigate the anti-leukemia effect and mechanism of mTORC1/2 inhibitor PP242 combined with imatinib (IM) on the proliferation of Ph+ acute lymphoblastic leukemia (ALL) cell line SUP-B15. METHODS: SUP-B15 cell line was treated with PP242, imatinib (IM), or PP242 plus IM for 72 h, IC50 values (the concentration of drug required to kill 50% of the cells) and the combination index (CI ) of synergistic cytotoxicity was determined using MTT methods. The expressions of PI3K/Akt/mTOR and apoptosis associated proteins were examined by Western blot test. RESULTS: The IC50 value of IM alone was (1.50±0.09) µmol/L, however, the IC50 values were (0.81±0.030) µmol/L, (0.36±0.140) µmol/L and (0.02±0.002) µmol/L combined with 20 nmol/L, 30 nmol/L and 50 nmol/L of PP242, and the CI values were 0.764, 0.545 and 0.507, indicating two drugs had highly synergistic effect on anti-proliferation in the SUP-B15 cell line. The expressions of p-Akt, p-4EBP1, p-elF4E, p-cAbl, p-mTOR and p-P70 were down-regulated significantly in a dose-dependent and time-dependent manner after PP242 treatment#.Compared with PP242 or IM alone, the down-regulation of PI3K/Akt/mTOR signaling pathway and the up-regulation of the apoptosis associated proteins (bax and cleaved caspase-3) were more significant in the combination of two drugs. CONCLUSION: The combination of IM and PP242 could increase the inhibition of PI3K/Akt/mTOR signaling pathway and apoptosis mediated by bax and caspase-3 in SUP-B15 cell line.

[The Roles of Glut5 in Imatinib Resistance in the Ph+ Acute Lymphoblastic Leukemia Cell].

OBJECTIVES: To explore the possible roles of glucose transport 5 (Glut5) in imatinib resistance in the Ph+ acute lymphoblastic leukemia cell (Ph+ ALL). METHODS: The gene chip technique was used to detect different gene expression between Ph+ ALL cell line SUP-B15/R (imatinib resistant cell line) and SUP-B15/S (imatinib sensitive cell line), the gene of solute carrier family 2 member 5 (SLC2A5) and its coded protein Glut5 were screened out and were reconfirmed by qPCR and Western blot assay. The imatinib half maximal inhibitory concentration (IC50) to SUP-B15/S cells with or without fructose treatment was further detected by MTT assay, simultaneously signal pathway gene was detected by qPCR assay. RESULTS: Metabolism related gene SLC2A5 was screened out with gene chip technique and the Western blot assay and qPCR confirmed the high expression of SLC2A5 gene and its coded protein Glut5 in SUP-B15/R cells. IC50 values of imatinib to SUP-B15/S cells after treatment with 25 µmol/L fructose were increased from (44.50±2.38) µmol/L to (64.71±1.69) µmol/L, in the meanwhile, PI3K and AKT mRNA level also increased in fructose treated SUP-B15/S cells compared to the control. CONCLUSIONS: High expression of SLC2A5 and Glut5 protein in SUP-B15/R cells leads to increased fructose absorption, and further activates PI3K/AKT pathway which cause the SUP-B15 cell resistance to imatinib.

[Effect of tanshinone II A on leukemia cell line K562].

OBJECTIVE: To determine the anti-proliferative effect of Tanshinone II A (TAT) on leukemia K562 cell line and its mechanism. METHODS: The proliferation of K562 cell line was detected by MTT assay. The morphological changes of the cells were examined with light microscope. The cell apoptosis was detected by flow cytometry. The expressions of BCL-2, BAX and m-TOR signaling pathway were examined by Western blot assay. RESULTS: TAT inhibited the proliferation of K562 cell line, with a value of IC50 (7.75 +/- 2.47) micromol/L after treatment for 96 h. Significant morphological changes were found after incubation of the cells for 24 h. The apoptotic rate accelerated after TAT treatment for 24 h compared with the controls. TAT down-regulated the expression of mTOR signaling pathway and BCL-2 protein, and up-regulated proapoptotic protein BAX. CONCLUSION: TAT can inhibit the proliferation of K562 cells through down-regulating mTOR signaling pathway, inducing apoptosis.

Transcription factor SCL/TAL1 mediates the phosphorylation of MEK/ERK pathway in umbilical cord blood CD34⁺ stem cells during hematopoietic differentiation.

Transcription factor stem cell leukemia (SCL), also known as the T-cell acute lymphocytic leukemia 1 (TAL1), plays a key role in the regulation of hematopoiesis, but the molecular mechanisms are not well understood. The aim of the present study is to elucidate the effects of the epidermal growth factor receptor (EGFR) signal pathways underlying the biologic activity of SCL/TAL1 on normal hematopoietic development. Lentiviral vectors with up or down-regulation of SCL/TAL1 were transfected into umbilical cord blood CD34 stem cells. EGFR signaling pathways (including MEK/ERK and Akt/mTOR) and surface hematopoietic markers were analyzed in the process of hematopoietic differentiation. The data revealed that up or down-regulation of SCL/TAL1 gene was accompanied positively by the expressions of p-MEK and p-ERK1/2 protein, but the changes of Akt/mTOR were unobvious. MEK/ERK inhibitor U0126 and SCL/TAL1 down-regulation showed similar inhibitory effects on erythroid, myeloid, and megakaryoid differentiation. However, Akt/mTOR pathway altered insignificantly. MEK/ERK inhibitor U0126 could not affect the expression of SCL/TAL1 mRNA or protein. Taken together, these findings fully illustrated that SCL/TAL1 is located in the up-stream of MEK/ERK pathway and partially regulates hematopoiesis by modulating the phosphorylation level of the key proteins in MEK/ERK pathway.

[Anti-leukemia effect of oridonin on T-cell acute lymphoblastic leukemia].

OBJECTIVE: To investigate the antileukemia effect of oridonin on T-cell acute lymphoblastic leukemia cell line CEM. METHODS: Human T-cell acute lymphoblastic leukemia cell line CEM was cultured in vitro. The 50% inhibition concentration (IC50) of oridonin against CEM cells was examined using modified MTT assay. The cellular morphologic changes were observed using a light microscope. The percent of apoptosis of CEM cells after drug treatment was evaluated by flow cytometric analysis. The active levels of AKT/mTOR, RAF/MEK/ ERK, STAT5 signaling pathways and the expression levels of Bcl-2 and BAX were examined by Western blot. RESULTS: Oridonin inhibited the growth of CEM cells in time- and dose dependent manner and the ICs0 of oridonin was (7. 37± 1. 99) µmol/L after 72 h treatment. The cellular membrane of CEM cells treated with oridonin became unsharp, some of them disintegrated. Oridonin induced apoptosis in CEM cells and the percent of apoptosis rate after 0, 5, 7.5, 10 µmol/L oridonin treatment for 24 h were (4. 8±2. 11)%, (19.03±12.54)% ,(40.27± 3.31) / and (57. 23 ± 6. 69)% respectively. Oridonin inhibited activation of mTOR, P70S6, 4EBP1, RAF. ERK and STAT5 signaling protein, which were constitutively activated in CEM cells, however, oridonin had no inhibitory effect on AKT kinase. Oridonin down-regulated the level of anti apoptotic protein Bcl-2 and up-regulated the expression of pro-apoptotic protein Bax. CONCLUSION: Oridonin exerted antileukemia effect in CEM cells by inhibiting the activation of mTOR/P70/4EBP1, RAF/ERK and STATS signaling pathways, down-regulating the expression of Bel-2 and up-regulating the expression of BAX.

[The optimization of method for lentiviral vector to transfect CD34+ hematopoietic stem cells from human cord].

OBJECTIVE: To identify the best transfect conditions for lentiviral vector to transfect CD34+ stem cells from human cord blood. METHODS: CD34+ hematopoietic stem cells from human cord blood were transduced with pTRIPdU3-RNAiTALh-EF1a-GFP plasmid expressing GFP by the second generation and third generation lentiviral vector system. The transfect conditions such as the concentration of the virus, polybrene, transfect volume and media, multiplicity of infection (MOI) values, incubating time and centrifugation in 12-well plate at 200 x g were tested to obtain optimal transfect conditions. The number of CFU were counted and the types of CFU were identified by light microscope after the transfected cells (non-infected stem cells served as control) were cultured for 14 days at a 37 degrees C, 5% CO2 incubator. RESULTS: The second-generation lentiviral vector plasmid had higher infect rate than the third-generation. The optimal transfect conditions were determined as: fresh sorting CD34+ cells, 10(7) TU virus concentration, Polybrene 2 microg/mL in opti-MEM medium, centrifuged at 200 x g for 1 h and then co-culture 8 h for cells and virus mixture in one well in flat-bottomed 12-well plate (repeated once). Both infected and non-infected CD34+ stem cells developed CFUs with similar numbers and types of colonies after being cultured for 14 days in the cytokine-containing 1:1 liquid medium/semi-solid medium. CONCLUSION: The identified optimal conditions can enable effective lentiviral vector transduction of CD34+ without interrupting the differentiation potential of the hematopoietic stem cells.

[Multidrug resistant gene MDR1 contributes to development of imatinib-resistance in Ph (+) acute lymphoblastic leukemia cell line SUP-BS15RI].

OBJECTIVE: To investigate the contribution of multidrug-resistant gene MDR1 to development of imatinib-resistance in Ph(+) acute lymphoblastic leukemia cell line SUP-B15/RI. METHODS: RT-PCR was used to examine MDR1 mRNA levels, cytotoxic effects of imatinib (IM), daunorubicin (DNR), vincristine (VCR), etoposide (VP-16) and the synergetic antiproliferation with P-gp inhibitor verapamil on sensitive SUP-B15 and SUP-B15/RI cell lines were detected by the MTT assay. The P-gp function was measured by flow cytometry. RESULTS: Increased expression of MDR1 gene in SUP-B15/RI than that of SUP-B15 cell line (P < 0.05) was observed when detected with RT-PCR. The IC50 values of SUP-B15/RI cell line inhibited by IM, DNR, VCR, VP-16 for 72 hours was higher than that of SUP-B15 (P < 0.05) and the resistant factor (RF) was (20.52 +/- 2.34), (10.33 +/- 1.88), (9.78 +/- 1.27), (3.84 +/- 0.69) respectively. The IC50 values of IM, DNR, VCR, VP-16 combined with P-gp inhibitor verapamil were decreased in SUP-B15/RI cells (P < 0.05), reversal of drug resistance was (1.44 +/- 0.43), (3.20 +/- 0.17), (1.44 +/- 0.12), (1.33 +/- 0.14) respectively. The activity of P-gp in SUP-B15/RI measured by flow cytometry was higher than that of P-gp in SUP-B15/RI cell line. CONCLUSION: The overexpression of MDR1 mRNA and higher activity of P-gp is partially responsible for acquiring of imatinib resistance in SUP-B15/RI cell line. P-gp inhibitor verapamail can partially restored the sensitivity of the SUP-B15/RI cell line to anticancer agents.

[Anti-leukemia effect of oridonin on Ph(+) acute lymphoblastic leukemia cell SUP-B15].

OBJECTIVE: To investigate the anti-leukemia effect of oridonin on Ph(+) acute lymphoblastic leukemia (ALL) cell line SUP-B15. METHODS: Human Ph(+) ALL cell line was cultured in vitro. The 50% inhibition concentration (IC(50)) of oridonin against SUP-B15 cell line was examined using modified MTT assay. The cellular morphologic changes were observed using a light microscope. The percent of apoptosis of SUP-B15 cell line after drug treatment was evaluated by flow cytometric analysis. The active levels of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK, STAT5 signaling pathways and the expression levels of Bcl-2 and BAX were examined by Western blot. RESULTS: Oridonin inhibited the growth of SUP-B15 cell line in both time- and dose-dependent manner with the IC(50) of oridonin as (7.08 ± 1.21) µmol/L after 72 h treatment. The cellular membrane of SUP-B15 cell line treated with oridonin became unsharp, some of them disintegrated. Oridonin induced apoptosis in SUP-B15 cell line with the apoptosis rates following 0, 5, 10 µmol/L oridonin treatment for 24 h were (6.67 ± 0.83)%, (18.30 ± 1.79)% and (37.63 ± 7.12)%, respectively. Oridonin inhibited activation of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK and STAT5 signaling pathways, which were constitutively activated in SUP-B15 cell line, down-regulated the level of anti- apoptotic protein Bcl-2 and up-regulated the expression of pro-apoptotic protein Bax. CONCLUSION: Oridonin exerted anti-leukemia effect in Ph(+)ALL cell line SUP-B15 by inhibiting the activation of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK and STAT5 signaling pathways, down-regulating the expression of Bcl-2 and up-regulating the expression of BAX.

[The effect of knockdown of transcription factor SCL/TAL-1 gene on the erythroid differentiation in EPO-induced K562 cell line].

OBJECTIVE: To investigate the role of transcript factor SCL/TAL-1 gene in the erythroid differentiation through the knockdown of SCL/TAL-1 mRNA by RNA interference. METHODS: The plasmid of pTRIP-dU3-RNAiTALh-EF1a-GFP with SCL/TAL1 shRNA was transfected into EPO-induced K562 cell line with erythroid differentiation via lentiviral vector system and the expression of SCL/TAL-1 mRNA decreased. The plasmid pTRIP-dU3- RNAiluc-EF1-GFP expressing EGFP gene was as control. The mRNA levels of SCL/TAL-1 and erythroid related RhD, GPA, CD47 in the cell lines were detected by RT-PCR, and erythroid antigen CD71, CD235a were examined by flow cytometry. RESULTS: (1) After 48 h of transfect, more than 95% of K562 cells were GFP positive, indicating the infection rate of the plasmids in the K562 cells more than 95%. (2) The results of RT-PCR showed SCL/TAL-1 mRNA expression in the K562 cell line of knockdown of SCL/TAL-1 was significantly lower than that in the control (P < 0.05). The mRNA levels of CD47 and RhD were also significantly lower, however, GPA decreased slightly in comparison with the control. (3) The expressions of CD71 and CD235a markedly reduced in the K562 cell line of knockdown of SCL/TAL-1 with positive rates as 10.4% and 76.5%, while the positive rates in the control as 94.3% and 83.6%. CONCLUSION: Our findings suggested that transcription factor SCL/TAL-1 might play an positive role in erythroid differentiation.

[Anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines].

OBJECTIVE: To study the anti-tumor effect of tanshinon II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines SUP-B15, K562, CEM, HL-60 and NB4. METHODS: To study the anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, The leukemia cell lines were exposed to the six Chinese herbal components for 96 hours. The proliferative inhibitory effects were detected with MTT and described by IC50 value. RESULTS: Tanshinone II A inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines, with HL-60 showing the least impact. Tetrandrine, honokiol, curcumin and oridonin inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines and there was no significant difference between the cell lines. Paeonol did not have significant inhibitory effect on leukemia cell lines. CONCLUSION: Tetrandrine, honokiol, curcumin and oridonin inhibit the proliferation of five cell lines SUP-B15, K562, CEM, HL-60, NB4, and the effects are similar, which means that their anticancer effects are quite broad. Tanshinone II A has better anti-leukemia effects on SUP-B15, K562, CEM, NB4 than on HL-60. The effect of paeonol against leukemia cell lines is poor.