Using Human 'Personalized' Cybrids to Identify Drugs/Agents That Can Regulate Chronic Lymphoblastic Leukemia Mitochondrial Dysfunction

This study uses personalized chronic lymphoblastic leukemia (CLL) cybrid cells to test various drugs/agents designed to improve mitochondrial function and cell longevity. Age-matched control (NL) and CLL cybrids were created. The NL and CLL cybrids were treated with ibrutinib (Ibr-10 μM), mitochondrial-targeted nutraceuticals such as alpha lipoic acid (ALA-1 mM), amla (Aml-300 μg), melatonin (Mel-1 mM), resveratrol (Res-100 μM) alone, or a combination of ibrutinib with nutraceuticals (Ibr + ALA, Ibr + Aml, Ibr + Mel, or Ibr + Res) for 48 h. MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide), H2DCFDA(2',7' Dichlorodihydrofluorescein diacetate), and JC1 assays were used to measure the cellular metabolism, intracellular ROS levels, and mitochondrial membrane potential (∆ψm), respectively. The expression levels of genes associated with antioxidant enzymes (SOD2, GPX3, and NOX4), apoptosis (BAX and CASP3), and inflammation (IL6, IL-1β, TNFα, and TGFβ) were measured using quantitative real-time PCR (qRT-PCR). CLL cybrids treated with Ibr + ALA, Ibr + Aml, Ibr + Mel, and Ibr + Res had (a) reduced cell survivability, (b) increased ROS production, (c) increased ∆ψm levels, (d) decreased antioxidant gene expression levels, and (e) increased apoptotic and inflammatory genes in CLL cybrids when compared with ibrutinib-alone-treated CLL cybrids. Our findings show that the addition of nutraceuticals makes the CLL cybrids more pro-apoptotic with decreased cell survival compared with CLL cybrids exposed to ibrutinib alone.

TIM-3 in Leukemia; Immune Response and Beyond

T cell immunoglobulin and mucin domain 3 (TIM-3) expression on malignant cells has been reported in some leukemias. In myelodysplastic syndrome (MDS), increased TIM-3 expression on TH1 cells, regulatory T cells, CD8+ T cells, and hematopoietic stem cells (HSCs), which play a role in the proliferation of blasts and induction of immune escape, has been reported. In AML, several studies have reported overexpression of TIM-3 on leukemia stem cells (LSCs) but not on healthy HSCs. Overexpression of TIM-3 on exhausted CD4+ and CD8+ T cells and leukemic cells in CML, ALL, and CLL patients could be a prognostic risk factor for poor therapeutic response and relapse in patients. Currently, several TIM-3 inhibitors are used in clinical trials for leukemias, and some have shown encouraging response rates for MDS and AML treatment. For AML immunotherapy, blockade TIM-3 may have dual effects: directly inhibiting AML cell proliferation and restoring T cell function. However, blockade of PD-1 and TIM-3 fails to restore the function of exhausted CD8+ T cells in the early clinical stages of CLL, indicating that the effects of TIM-3 blockade may be different in AML and other leukemias. Thus, further studies are required to evaluate the efficacy of TIM-3 inhibitors in different types and stages of leukemia. In this review, we summarize the biological functions of TIM-3 and its contribution as it relates to leukemias. We also discuss the effects of TIM-3 blockade in hematological malignancies and clinical trials of TIM-3 for leukemia therapy.

Ginkgetin inhibits proliferation of human leukemia cells via the TNF-α signaling pathway

Ginkgetin is known to be an anticancer agent in many studies. However, its effectiveness in treating chronic myeloid leukemia [corrected] remains unknown. The present study aimed to evaluate the effects of ginkgetin on the growth of the K562 cell line. The MTT assay was employed to examine the proliferation of K562, and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining was conducted to detect the apoptotic rates. Furthermore, changes of tumor necrosis factor-α (TNF-α) were detected by Western blot analysis. Ginkgetin inhibited the proliferation of K562 cells in a dose- and time-dependent manner. Concentrations of ginkgetin required to induce 50% death of K562 at 24, 48 and 72 h were 38.9, 31.3 and 19.2 μM, respectively. Moreover, treatment of ginkgetin increased K562 apoptosis in vitro along with increased levels of TNF-α. Interestingly, anti-TNF-α antibody prevented ginkgetin-induced K562 cell apoptosis and growth inhibition via deactivation of caspase-8, caspase-9 and caspase-3. Concomitantly, downregulation of TNF-α by etanercept in vivo attenuated ginkgetin-induced inhibitory effects on the tumor growth in an xenograft mouse model. Our results indicate that ginkgetin effectively inhibits K562 cell proliferation, and TNF-α plays a key role in ginkgetin-induced cell apoptosis.

Increasing survival from leukemia among adolescents and adults in Canada: A closer look

BACKGROUND

Survival from adult onset leukemia has increased substantially in Canada since at least the early 1990s. However, an analysis of the extent of this improvement by type of leukemia is lacking.

DATA AND METHODS

Data are from the Canadian Cancer Registry, with mortality follow-up through record linkage to the Canadian Vital Statistics Death Database. Increases in five-year relative survival ratios (RSRs) between 1992-to-1994 and 2006-to-2008 were calculated by age and sex for all leukemias combined and for each of the main types.

RESULTS

Increases in five-year RSRs were significant for all leukemia types studied, ranging from 9.2 percentage units for acute myeloid leukemia (AML) to 24.9 percentage units for chronic myeloid leukemia (CML). For all leukemias combined, additional adjustment for case-mix reduced the increase in survival from 14.6 to 11.8 units; increases were significant among both sexes and each age group. Improvement in survival for chronic lymphocytic leukemia (CLL) was greater at older ages. For AML, improvements were greater among people younger than age 55; no significant change was detected among those diagnosed at ages 75 to 99. A significant survival advantage for women relative to men was apparent in the 2006-to-2008 period for all leukemias combined and for CLL and CML.

INTERPRETATION

Despite recent significant gains in survival for each main type of leukemia, room remains for improvement.