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).

[Clinical characteristics and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia arising from malignant tumors]

Objective: To investigate the clinical characteristics, cytogenetics, molecular biology, treatment, and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) secondary to malignancies. Methods: The clinical data of 86 patients with t-MDS/AML in West China Hospital of Sichuan University between January 2010 and April 2023 were retrospectively analyzed. The clinical characteristics, primary tumor types, and tumor-related therapies were analyzed. Results: The study enrolled a total of 86 patients with t-MDS/AML, including 67 patients with t-AML, including 1 patient with M(0), 6 with M(1), 27 with M(2), 9 with M(3), 12 with M(4), 10 with M(5), 1 with M(6), and 1 with M(7). Sixty-two patients could be genetically stratified, with a median overall survival (OS) of 36 (95% CI 22-52) months for 20 (29.9%) patients in the low-risk group and 6 (95% CI 3-9) months for 10 (14.9%) in the intermediate-risk group. The median OS time was 8 (95% CI 1-15) months in 32 (47.8%) patients in the high-risk group. For patients with non-acute promyelocytic leukemia (APL) and AML, the median OS of the low-risk group was 27 (95% CI 18-36) months, which was significantly longer than that of the non-low-risk group (χ(2)=5.534, P=0.019). All 9 APL cases were treated according to the initial treatment, and the median OS was not reached, and the 1-, 2-, and 3-year OS rates were 100.0%, (75.0±6.2) %, and (75.0±6.2) % respectively. Of the 58 patients with non-APL t-AML (89.7%), 52 received chemotherapy, and 16 achieved complete remission (30.8%) after the first induction chemotherapy. The 1-, 2-, and 3-year OS rates of the non-APL t-AML group were (42.0 ± 6.6) %, (22.9±5.7) %, and (13.4±4.7) %, respectively. The median OS of patients who achieved remission was 24 (95% CI 18-30) months, and the median OS of those who did not achieve remission was 6 (95% CI 3-9) months (χ(2)=10.170, P=0.001). Bone marrow CR was achieved in 7 (53.8%) of 13 patients treated with vineclar-containing chemotherapy, with a median OS of 12 (95% CI 9-15) months, which was not significantly different from that of vineclar-containing chemotherapy (χ(2)=0.600, P=0.437). In 19 patients with t-MDS, the 1-, 2-, and 3-year OS rates were (46.8±11.6) %, (17.5±9.1) %, and (11.7±9.1) % with a median OS of 12 (95% CI 7-17) months, which was not significantly different from that in t-AML (χ(2)=0.232, P=0.630) . Conclusions: Breast cancer, bowel cancer, and other primary tumors are common in patients with t-MDS/AML, which have a higher risk of adverse genetics. Patients with APL had a high induction remission rate and a good long-term prognosis, whereas patients without APL had a low remission rate and a poor long-term prognosis.

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.

Maintenance of cellular annexin A1 level is essential for PI3K/AKT/mTOR-mediated proliferation of pancreatic beta cells

Annexin A1 (AnxA1, also known as lipocortin-1), is a calcium-dependent phospholipid binding protein with diverse functions. Previous studies have indicated that AnxA1 is associated with age-related β-cell dysfunction and aging, which lead to decreased β-cell proliferation capacity. However, it has been uncertain whether AnxA1 affects the proliferation of pancreatic beta (β) cells. In the present study, we reduced AnxA1 expression in the MIN6 islet β-cell line using small interfering RNA (AnxA1-siRNA), then measured cell cycle distribution and cellular proliferation. We also measured the expression levels of cell cycle-related proteins such as cyclin D1, cyclin E, and cyclin-dependent kinase 2 (CDK2) by Western blot analysis. We investigated the phosphatidylinositol 3-kinase (PI3K)/ serine/threonine protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway to explore the potential mechanism underlying the observed effects. Knockdown of AnxA1 expression using siRNA reduced the rates of MIN6 cell proliferation. The proportions of cells in S and G2/M phases also decreased upon inhibition of AnxA1. Moreover, AnxA1 protein expression in MIN6 cells was positively related to the protein levels of cyclin D1, cyclin E, and CDK2. Activation of the PI3K/Akt/mTOR signaling pathway by AnxA1 may be involved in the signaling cascade to regulate cell proliferation. This study identified a positive correlation between AnxA1 protein and pancreatic β-cell proliferation. AnxA1 protein expression might affect the proliferation of MIN6 cells via regulation of cyclin D1, cyclin E, and CDK2 proteins, as well as the PI3K/Akt/mTOR signaling pathway.

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.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

[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.

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.

[Clinical analysis of 314 children with maxillofacial fracture]

A total of three hundred and fourteen patients with maxillofacial fracture under 14 years old were treated at Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University from October 2010 to October 2017 were collected and retrospective analysis was conducted. Age, gender, injury factors, type of fracture, associated injuries and treatment has been analysed. There were 196 male and 118 female. The most common injury factor was fall (148 cases), accounting for 47.1% of all patients. The most common fracture type was mandible fracture (221 cases). Children are not very cooperative with clinical examination, which often leading to misdiagnosis. Age, gender, fracture injury factors, comorbidity and treatment were analyzed to provide the reference for the prevention, diagnosis and treatment.

[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.

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.

[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.

[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.

Prevalence, characteristics and natural history of cold intolerance after the reverse digital artery flap

This retrospective study was designed to investigate the prevalence, characteristics and natural history of cold intolerance after the use of the reverse digital artery flap. A total of 123 patients were treated between 2010 and 2013. After excluding patients who were lost to follow-up, 87 patients were studied. The mean follow-up time was 34 months (range 14-61). Cold intolerance occurred in 60% (52) of patients after the reverse digital artery flap procedure. The condition improved in only 15% (8) of the patients. Significant differences were observed in the age and the specific digit involved between the groups with and without cold intolerance. There was a lower incidence in younger patients, and the ring finger group showed a lower incidence than in other fingers. Furthermore, the Cold Intolerance Symptom Severity score was positively correlated with the temperature at which cold intolerance was triggered.

LEVEL OF EVIDENCE

IV.

Comparative study of functional and aesthetically outcomes of reverse digital artery and reverse dorsal homodigital island flaps for fingertip repair

This retrospective study was designed to compare functional and cosmetic outcomes of the reverse digital artery island flap and reverse dorsal homodigital island flap in fingertip repair. A total of 23 patients were followed for 24 to 30 months. The reverse digital artery island flap was used in 12 patients, and reverse dorsal homodigital island flap in another 11 patients. Flap sensibility was assessed using the Semmes-Weinstein monofilament test and static 2-point discrimination test. Patient satisfaction, active motion of the finger joints, complications and cold intolerance were evaluated. The static 2-point discrimination and Michigan Hand Outcomes Questionnaire (appearance) of the fingers treated with a reverse digital artery flap were significantly better than those with a reverse dorsal homodigital flap. The static 2-point discrimination of the skin-grafted donor sides after dorsal homodigital flap were poorer than that in the contralateral finger. No significant differences were found between the two flaps for pressure or touch sensibility, active ranges of digital motion, complications and cold intolerance.

LEVEL OF EVIDENCE

III.

The MEK1/2 inhibitor U0126 reverses imatinib resistance through down-regulating activation of Lyn/ERK signaling pathway in imatinib-resistant K562R leukemia cells

Chronic myelogenous leukemia (CML) is triggered by the constitutively activated BCR-ABL oncoprotein and multiple downstream signaling pathways, including the Raf/MEK/ERK, Akt/mTOR, SRC, and STAT5 pathways. The BCR-ABL tyrosine kinase inhibitor imatinib is the standard treatment for CML. However, the development of imatinib resistance has become a new challenge for CML treatment. Here, we investigated the expression levels of the signaling pathways to explore the cause of imatinib resistance and seek new reversing drugs. Our results showed that abnormal activation of the BCR-ABL-independent Lyn/ERK signaling pathway was involved in imatinib-resistance of K562R cells. Furthermore, p-Lyn and p-ERK were up-regulated after treatment with imatinib alone. However, U0126, a MEK1/2 inhibitor, could counteract the up-regulation induced by imatinib, and the combination of imatinib and U0126 could overcome the resistance to imatinib in K562R cells. In conclusion, our studies suggest that the combination of imatinib and an inhibitor of the ERK signaling pathway may be effective in imatinib-resistant CML patients.

Efficient detection of the V600E mutation of the BRAF gene in papillary thyroid carcinoma using multiplex allele-specific polymerase chain reaction combined with denaturing high-performance liquid chromatography

Mutations in the V-raf murine sarcoma viral oncogene homolog B1 gene (BRAF) play an important role in the pathogenesis of papillary thyroid cancer (PTC). In this study, a BRAF V600E mutation was detected in formalin-fixed and paraffin-embedded PTC samples using multiplex allele-specific polymerase chain reaction and denaturing high-performance liquid chromatography. The sensitivity of the assays was validated in two cell lines, K1 and RO82-W-1, which were respectively positive and negative for the mutation. The method enabled detection of very low concentrations (~1%) of the mutation, with positive findings obtained in 119 of the 187 samples (63.6%). The mutation was not detected in 20 cases of benign thyroid diseases. The presence of the mutation was significantly associated with ages >45 years, the tumor-nodes-metastasis stage, region of metastasis, and clinical outcome (P < 0.05). Although no correlation was found between the mutation and lymph node metastasis, the proportions of patients carrying a mutation differed significantly between central and lateral cervical lymph node metastasis (P < 0.05). Multivariate logistic regression analysis also indicated the presence of mutation, tumor size, and cervical lymph node metastasis to be independent predictors for recurrence and distant metastasis. We conclude that a high proportion of PTC cases likely harbors the BRAF V600E mutation. This mutation can be used as an independent factor for predicting the recurrence and distal metastasis of PTC tumors.

[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.

Recognition roles of the carbohydrate glycotopes of human and bovine lactoferrins in lectin-N-glycan interactions

BACKGROUND

Lactoferrin is an iron-binding protein belonging to the transferrin family. In addition to iron homeostasis, lactoferrin is also thought to have anti-microbial, anti-inflammatory, and anticancer activities. Previous studies showed that all lactoferrins are glycosylated in the human body, but the recognition roles of their carbohydrate glycotopes have not been well addressed.

METHODS

The roles of human and bovine lactoferrins involved in lectin-N-glycan recognition processes were analyzed by enzyme-linked lectinosorbent assay with a panel of applied and microbial lectins.

RESULTS AND CONCLUSIONS

Both native and asialo human/bovine lactoferrins reacted strongly with four Man-specific lectins - Concanavalia ensiformis agglutinin, Morniga M, Pisum sativum agglutinin, and Lens culinaris lectin. They also reacted well with PA-IIL, a LFuc>Man-specific lectin isolated from Pseudomonas aeruginosa. Both human and bovine lactoferrins also recognized a sialic acid specific lectin-Sambucus nigra agglutinin, but not their asialo products. Both native and asialo bovine lactoferrins, but not the human ones, exhibited strong binding with a GalNAc>Gal-specific lectin-Wisteria floribunda agglutinin. Human native lactoferrins and its asialo products bound well with four Gal>GalNAc-specific type-2 ribosome inactivating protein family lectins-ricin, abrin-a, Ricinus communis agglutinin 1, and Abrus precatorius agglutinin (APA), while the bovine ones reacted only with APA.

GENERAL SIGNIFICANCE

This study provides essential knowledge regarding the different roles of bioactive sites of lactoferrins in lectin-N-glycan recognition processes.

[Studies on the predictors of response to immunosuppressive therapy in severe aplastic anemia patients]

OBJECTIVE

To assay the factors that may predict the response to immunosuppressive therapy (IST) in severe aplastic anemia patients.

METHODS

The blood samples were collected from 37 patients diagnosed as severe aplastic anemia in West China Hospital of Sichuan University and West China Second Hospital of Sichuan University during February, 2006 to March, 2007. Twenty healthy blood donors were used as normal control. The plasma levels of IFN-gamma and IL-2 were measured by enzyme linked immunosorbent assay, and the gene phenotype of HLA-DRB1 * 15 and HLA-DRB1 * 1501 was analyzed by polymerase chain reaction with sequence specific primer. The expressions of CD55 and CD59 on the cellular membrane of red blood cell and white blood cells also were measured.

RESULTS

The response rate in the patients who had higher IL-2 level before IST was significantly better than that in the patients with lower IL-2 level (66.7% vs 28.6%, P<0.05), while similar result was observed to IFN-gamma (73.7% vs 25.0%, P<0.05). The response rate in the patients with positive HLA-DRB1 * 15 was higher than that in those negative patients (62.5% vs 44.4%, P>0.05), but there was no different found in different HLA-DRB1 * 1501 phenotypes (50% vs 50%, P>0.05). The response rates in the patients with deficient CD55 and CD59 expression were higher than those expressed CD55 and CD59 normally (80.0% vs 40.0%, P>0.05); the response rate of patients younger than 40 years was higher than those older than 40 years (60.0% vs 14.3%, P<0.05); the response rate in female patients was higher than male patients (62.5% vs 42.9%, P<0.05).

CONCLUSION

The concentration of IL-2, IFN-gamma before IST, and age can be used as the predicting factors to immunosuppressive therapy, while the predicting value of HLA-DRB1 * 15, HLA- DRB1 * 1501 and CD55, CD59 to the response of IST still remain unclear.

Overexpression of Cripto and its prognostic significance in breast cancer: a study with long-term survival

INTRODUCTION

Cripto is a founding member of the EGF-CFC family, and plays an important role in tumourigenesis, tumour cell proliferation and migration. We aimed to determine the significance of Cripto expression on the survival of patients with breast cancer.

METHODS

Immunohistochemical detection of Cripto was performed by using mAb C13 on 120 formalin-fixed paraffin-embedded breast tumour specimens in tissue microarrays. This cohort comprises a series of 120 patients with primary operable breast cancer diagnosed between 1989 and 1995, retrieved from the Concord Repatriation General Hospital breast carcinoma database.

RESULTS

Using a cutoff value of 80%, Cripto overexpressed in 57 of the 120 (47.5%) patients. We found significant associations between overexpression of Cripto and the Nottingham Prognostic Index (NPI, p<0.01), histological grade (p<0.01), pathological tumour type (p=0.04), PR (p=0.02) as well as Ki-67 (p=0.02). Univariate analysis reveals that there is a significant correlation between overexpression of Cripto and survival (p=0.0003). Cox regression analysis indicates that the overexpression of Cripto is an independent prognostic factor in breast cancer (HR 2.79, 95%CI 1.20-6.50).

CONCLUSION

The unique epitope recognized by mAb C13 is overexpressed on breast tumour tissues. In this series of invasive breast cancers, overexpression of Cripto was more often found in high grade and poor prognosis tumours compared to low grade and good prognosis breast cancers. Moreover, overexpression of Cripto was significantly associated with decreased patient survival.

Comparison of Pgp- and MRP-mediated multidrug resistance in leukemia cell lines

Drug resistance is a major cause of the failure of anticancer chemotherapy. Multidrug resistance is often caused by overexpression of the P-glycoprotein (Pgp) or the multidrug resistance-related protein (MRP). In the present study, we compared daunorubicin (DNR) accumulation, subcellular distribution, and the effect of modulators on drug accumulation and subcellular distribution in the Pgp-expressing K562 cell line and the MRP-expressing HL60 cell line using reverse-transcriptase polymerase chain reaction, MTT (3-[4, 5-dimethylthiazol-z-yl]-2,5-diphenyltetrazolium bromide) drug cytotoxicity assay, fluorocytometry, and confocal laser scanning microscopy. The 2 resistant cell lines exhibit similar levels of resistance to DNR and decreased drug accumulation. Altered drug subcellular distribution in the resistant cell lines compared to that in the sensitive cell lines was shown and, moreover, differences in drug distributions between the 2 resistant cell lines were found. DNR fluorescence in the resistant HL60 cell line was distributed into punctate regions in the cytoplasm; the nucleus and other cytoplasm were almost negative. In contrast, the resistant K562 cells showed a bright fluorescent signal located in the peripheral cytoplasm and perinuclear region; the nucleus and other cytoplasmic regions showed no signal. Use of the modulator verapamil increased drug accumulation and restored the altered subcellular distribution of the drug in the 2 resistant cell lines. The Golgi apparatus inhibitor brefeldin A had similar action in the resistant HL60 line but had little effect in the resistant K562 line. Therefore, our study suggested that there were differences between the 2 resistant cell lines in the compartments sequestering DNR.

First isolation of Xanthomonas campestris from the blood of a Chinese woman

Xanthomonas campestris isolated from the blood of a patient with a fever was first reported. Xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. Chinese cabbage, etc. Human infection due to X. campestris has not been reported so far. The characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. We believe that X. campestris is also one of the opportunistic pathogens, which can infect compromised host.