Long-term outcome of L86 and L97 protocols for adult acute lymphoblastic leukemia

Andrographolide, isolated from Andrographis paniculata, induces apoptosis in monocytic leukemia and multiple myeloma cells via augmentation of reactive oxygen species production

Background: Andrographolide (Andro) is a diterpenoid component of the plant Andrographis paniculata that is known for its anti-tumor activity against a variety of cancer cells.  

Methods: We studied the effects of Andro on the viability of the human leukemia monocytic cell line THP-1 and the human multiple myeloma cell line H929. Andro was compared with cytosine arabinoside (Ara-C) and vincristine (VCR), which are well-established therapeutics against hematopoietic tumors. The importance of reactive oxygen species (ROS) production for the toxicity of each agent was investigated by using an inhibitor of ROS production, N-acetyl-L-cysteine (NAC).   

Results:  Andro reduced the viability of THP-1 and H929 in a concentration-dependent manner. H929 viability was highly susceptible to Andro, although only slightly susceptible to Ara-C. The agents Andro, Ara-C, and VCR each induced apoptosis, as shown by cellular shrinkage, DNA fragmentation, and increases in annexin V-binding, caspase-3/7 activity, ROS production, and mitochondrial membrane depolarization. Whereas Ara-C and VCR increased the percentages of cells in the G0/G1 and G2/M phases, respectively, Andro showed little or no detectable effect on cell cycle progression. The apoptotic activities of Andro were largely suppressed by NAC, an inhibitor of ROS production, whereas NAC hardly affected the apoptotic activities of Ara-C and VCR. 

Conclusions: Andro induces ROS-dependent apoptosis in monocytic leukemia THP-1 and multiple myeloma H929 cells, underlining its potential as a therapeutic agent for treating hematopoietic tumors. The high toxicity for H929 cells, by a mechanism that is different from that of Ara-C and VCR, is encouraging for further studies on the use of Andro against multiple myeloma.

Wee1 kinase inhibitor MK-1775 induces apoptosis of acute lymphoblastic leukemia cells and enhances the efficacy of doxorubicin involving downregulation of Notch pathway

Acute lymphoblastic leukemia (ALL) is an aggressive hematologic malignancy affecting pediatric and adult populations. Although the outcomes of ALL in children have improved markedly in previous years, limited treatment strategies are available at present for adult patients with ALL. Wee1 is a crucial cell cycle checkpoint kinase of G2/M that regulates cell cycle progression and maintains chromatin integrity. MK-1775, a selective inhibitor of Wee1 has recently been identified to be able to induce apoptosis of tumor cells by abrogating G2/M checkpoint. The present study investigated the anti-leukemic activity of MK-1775 alone and in combination with doxorubicin (Adriamycin^®; ADM) in various human ALL cell lines. MK-1775 treatment induced apoptosis of ALL cells, accompanied by unscheduled mitotic entry and downregulation of Notch pathway. The anti-leukemic activity of MK-1775 was in a concentration- and time-dependent manner. The data also indicated that it decreased the half-maximal inhibitory concentration (IC₅₀) of ADM compared with the control group. The combination of MK-1775 and ADM induced an increased apoptotic rate compared with each agent alone. In addition, the human bone marrow stromal cell HS-5 cell line was detected to exhibit an increased IC₅₀ value of MK-1775 treatment in contrast to ALL cell lines. It indicates that the hematopoietic supportive capability may remain intact during the treatment of MK-1775. Taken together, the Wee1 inhibitor MK-1775 may be an attractive agent in the treatment of patients with ALL.

Adolescents and young adults with acute lymphoblastic leukemia have a better outcome when treated with pediatric-inspired regimens: systematic review and meta-analysis

Survival of adults with acute lymphoblastic leukemia (ALL) is inferior to that of pediatric patients. Strategies to improve the outcome of adult population are warranted. This study aims to evaluate the efficacy and safety of pediatric-inspired regimens given to adolescents and young adults (AYA), usually defined as 16-39 years, with ALL. Systematic review and meta-analysis of comparative trials of AYA patients with ALL given induction chemotherapy with either pediatric-inspired regimens or conventional-adult chemotherapy was conducted. Relative risks (RR) with 95% confidence intervals (CIs) were estimated and pooled. Our search yielded 11 trials, including 2,489 patients. AYA patients given pediatric-inspired regimens had a statistically significant lower all cause mortality rate at 3 years (RR 0.58; 95% CI 0.51-0.67). Complete remission rate after induction chemotherapy and event free survival were superior in the pediatric-inspired regimens arm (RR 1.05; 95% CI 1.01-1.10 and RR 1.66; 95% CI 1.39-1.99, respectively). Relapse rate was also lower in patients given pediatric-inspired regimens (RR 0.51; 95% CI 0.39-0.66) with comparable nonrelapse mortality between the two groups (RR 0.53, 95% CI 0.19-1.48). Pediatric-inspired regimens are superior to conventional-adult chemotherapy in AYA ALL patients. Further randomized controlled studies to investigate this approach in adult ALL patients are warranted.