Studies demonstrated that mesenchymal stromal cells (MSC) from bone marrow stroma produced high concentration of interleukin-6 (IL-6) that promoted multiple myeloma cell growth. In view of the failure of IL-6 monoclonal antibody therapy to demonstrate substantial clinical responses in early clinical trials, more effective methods are needed in order to disrupt the favourable microenvironment provided by the bone marrow stroma. In this study, we evaluated the short interfering RNA (siRNA)-mediated silencing of IL-6 in MSC and the efficacy of these genetically modified MSC, with IL-6 suppression, on inhibition of U266 multiple myeloma cell growth. IL-6 mRNA and protein were significantly suppressed by 72h post IL-6 siRNA transfection without affecting the biological properties of MSC. Here we show significant inhibition of cell growth and IL-6 production in U266 cells co-cultured with MSC transfected with IL-6 siRNA when compared to U266 cells co-cultured with control MSC. We also show that the tumour volume and mitotic index of tumours in nude mice co-injected with U266 and MSC transfected with IL-6 siRNA were significantly reduced compared to tumours of mice co-injected with control MSC. Our results suggest potential use of RNA interference mediated therapy for multiple myeloma.
Discovery of imatinib mesylate (IM) as the targeted BCR-ABL protein tyrosine kinase inhibitor (TKI) has resulted in its use as the frontline therapy for chronic myeloid leukemia (CML) across the world. Although high response rates are observed in CML patients who receive IM treatment, a significant number of patients develop resistance to IM. Resistance to IM in patients has been associated with a heterogeneous array of mechanisms of which point mutations within the ABL tyrosine kinase domain (TKD) are the frequently documented. The types and frequencies of mutations reported in different population studies have shown wide variability. We screened 125 Malaysian CML patients on IM therapy who showed either TKI refractory or resistance to IM to investigate the frequency and pattern of BCR-ABL kinase domain mutations among Malaysian CML patients undergoing IM therapy and to determine the clinical significance. Mutational screening using denaturing high performance liquid chromatography (dHPLC) followed by DNA sequencing was performed on 125 IM resistant Malaysian CML patients. Mutations were detected in 28 patients (22.4%). Fifteen different types of mutations (T315I, E255K, G250E, M351T, F359C, G251E, Y253H, V289F, E355G, N368S, L387M, H369R, A397P, E355A, D276G), including 2 novel mutations were identified, with T315I as the predominant type of mutation. The data generated from clinical and molecular parameters studied were correlated with the survival of CML patients. Patients with Y253H, M351T and E355G TKD mutations showed poorer prognosis compared to those without mutation. Interestingly, when the prognostic impact of the observed mutations was compared inter-individually, E355G and Y253H mutations were associated with more adverse prognosis and shorter survival (P=0.025 and 0.005 respectively) than T315I mutation. Results suggest that apart from those mutations occurring in the three crucial regions (catalytic domain, P-loop and activation-loop), other rare mutations also may have high impact in the development of resistance and adverse prognosis. Presence of mutations in different regions of BCR-ABL TKD leads to different levels of resistance and early detection of emerging mutant clones may help in decision making for alternative treatment. Serial monitoring of BCR-ABL1 transcripts in CML patients allows appropriate selection of CML patients for BCR-ABL1 KD mutation analysis associated with acquired TKI resistance. Identification of these KD mutations is essential in order to direct alternative treatments in such CML patients.
This study aimed to assess the physical activity levels of pediatric patients with acute leukemia undergoing chemotherapy. Thirty-eight pediatric patients and matched controls, aged 3-12 years old, were measured for weight, height, and other anthropometric parameters. Physical activity was assessed using actical accelerometer and activity log book. Patients recorded significantly lower mean total activity counts (26.2±30.2 cpm vs. 192.2±68.8 cpm; p<0.01) and spent more time in sedentary activities (1301±121 min vs. 1020±101 min; p<0.001) compared to controls. They also achieved fewer 1-5-min bouts of moderate-vigorous physical activity (MVPA) compared to controls (1.50±5.95 vs. 37.38±40.36; p<0.001). In conclusion, patients had lower physical activity level and intensity; and simple exercise intervention programs may be needed to minimize the detrimental effects of prolonged sedentary behaviors.
Newcastle disease virus (NDV) is a member of the Paramyxoviridae that has caused severe economic losses in poultry industry worldwide. Several strains of NDV were reported to induce cytolysis to cancerous cell lines. It has prompted much interest as anticancer agent because it can replicate up to 10,000 times better in human cancer cells than in most normal cells. In this study, two NDV strains, viserotropic-velogenic strain AF2240 and lentogenic strain V4-UPM, showed cytolytic activity and apoptosis induction against Mouse myelomoncytic leukemia (WEHI 3B). The cytolytic effects of NDV strains were determined using microtetrazolium (MTT) assay. The cytolytic dose - fifty percent (CD(50)) were 2 and 8HAU for AF2240 and V4-UPM strains, respectively. Cells treated with NDV strains showed apoptotic features compared to the untreated cells under fluorescence microscope. NDV induced activation of caspase-3 and DNA laddering in agarose gel electrophoresis which confirmed the apoptosis. The anti-leukemic activity of both strains was evaluated on myelomoncytic leukemia BALB/c mice. The results indicated that both NDV strains significantly decreased liver and spleen weights. It also decreased blasts cell percentage in blood, bone marrow and spleen smears of treated mice (p<0.05). Histopathological studies for spleen and liver confirmed the hematological results of blood and bone marrow. From the results obtained, the exposure to both NDV stains AF2240 and V4-UPM showed similar results for Ara-c. In conclusion NDV strains AF2240 and V4-UPM can affect WEHI 3B leukemia cells in vitro and in vivo.
Typhonium flagelliforme (TF) is a tropical plant, traditionally used by the ethnic population of Malaysia for the cure of various cancers. This plant had shown to induce antiproliferative effect as well as apoptosis in cancer cells. However, there is no available information to address that TF affects murine leukemia cells in vitro and in vivo. Here, we investigated in vitro and in vivo effects of TF on murine leukemia WEHI-3 cells. It was found that the growth of leukemia cells in vitro was inhibited by the various extracts of TF. Among these fractions, the dichloromethane (DCM) tuber extracts of TF showed the lowest IC(50) (24.0 ± 5.2 μg/ml) and had demonstrated apoptogenic effect when observed under fluorescent microscope. We investigated the in vivo effects of DCM tuber extracts of TF on murine leukemia cells, and the results showed that the counts of immature granulocytes and monocytes were significantly decreased in peripheral blood of BALB/c leukemia mice after the oral administration of DCM tuber extracts of TF for 28 days with three doses (200, 400 and 800 mg/kg). These results were confirmed by observing the spleen histopathology and morphology of enlarged spleen and liver in leukemia mice when compared with the control. Furthermore, the cell death mechanism in the spleen tissue of treated mice was found via apoptosis.
Zerumbone (ZER) is a potential anticancer natural compound, isolated from Zingiber zerumbet Smith. In this investigation, the anticancer properties of ZER were evaluated on cancer cells of T-acute lymphoblastic leukemia, CEM-ss. The results showed that ZER has cytotoxic effect against CEM-ss cells with an IC(50) of 8.4 ± 1.9 μg/ml (coefficient of variation < 30%). Comparatively, 5-fluorouracil (positive control), imposed an inhibitory effect on CEM-ss cells with an IC(50) of 1.94 ± 0.06 μg/ml. Scanning electron microscopy (SEM) results revealed abnormalities such as membrane blebbing, holes and cytoplasmic extrusions, all of which are characteristics of apoptosis. In addition, ZER has increased the number of TUNEL-positive stain and the cellular level of caspase-3, the hallmarks of apoptosis, on treated CEM-ss cells. It could be concluded that, ZER was able to produce apoptosis on T-acute lymphoblastic leukemia, CEM-ss. The current findings suggest that ZER might be helpful for improving the usefulness of anticancer agents in the therapy of leukemia.
To study genetic epidemiology of childhood acute lymphoblastic leukemia (ALL) in the Chinese and Malays, we investigated 10 polymorphisms encoding carcinogen- or folate-metabolism and transport. Sex-adjusted analysis showed NQO1 609CT significantly protects against ALL, whilst MTHFR 677CT confers marginal protection. Interestingly, we observed that NQO1 609CT and MTHFR 1298 C-allele have greater genetic impact in boys than in girls. The combination of SLC19A1 80GA heterozygosity and 3'-TYMS -6bp/-6bp homozygous deletion is associated with reduced ALL risk in Malay boys. Our study has suggested the importance of gender and race in modulating ALL susceptibility via the folate metabolic pathway.
Granulocytic sarcoma (GS) can occur de novo or in association with intramedullary myeloid disorders. With the advent of sophisticated molecular detection techniques to detect diagnostic genes such as bcr-abl, PML-RARA and CBFB/MYH11 in bone marrow or peripheral blood, many cases of the so called 'primary' GS are questionable. We report a case of primary GS where the tumor mass bcr-abl translocation was demonstrated by fluorescent in situ hybridization in which there was no evidence of chronic myeloid leukemia (CML). This is an important finding as it highlights the possibility that CML may present as a sole extramedullary form, and illustrates potential treatment by tyrosine kinase inhibitor.
Chronic myeloid leukemia (CML) patients who do not achieve landmark responses following treatment with imatinib mesylate (IM) are considered IM-resistant. Although IM-resistance can be due to BCR-ABL kinase domain (KD) mutations, many IM-resistant patients do not have detectable BCR-ABL KD mutations. MicroRNAs (miRNAs) are short non-coding RNAs that control gene expression. To investigate the role of miRNAs in IM-resistance, we recruited 8 chronic phase CML patients with IM-resistance who tested negative for BCR-ABL KD mutations and 2 healthy normal controls. Using miRNA sequencing, we identified 54 differentially expressed miRNAs; 43 of them downregulated. The 3 most differentially downregulated miRNAs were miR-146a-5p, miR-99b-5p and miR-151a-5p. Using real-time quantitative reverse transcriptase-polymerase chain reaction, the expression patterns of the 3 miRNAs were validated on the same cohort of 8 patients in addition to 3 other IM-resistant CML patients. In-silico analysis showed that the predicted gene targets are ATRIP, ATR, WDR48, RAD51C and FANCA genes which are involved in the Fanconi Anemia/BRCA pathway. This pathway regulates DNA damage response (DDR) and influences disease response to chemotherapy. Thus it is conceivable that DDR constitutes a key component in IM-resistance. Further research is needed to elucidate miRNA modulation of the predicted gene targets.