Issues in current management of chronic myeloid leukemia: Importance of molecular monitoring on long term outcome

Potential effect of Imatinib on some sex hormones for male patients of Chronic Myelogenous Leukemia in Baghdad province

Imatinib Mesylate is an oral chemotherapy drug that has been used to treat Chronic Myelogenous Leukemia (CML). It works as an inhibitor of oncogene tyrosine kinase BCR-ABLI as a target therapeutic agent. Despite the drug is well tolerated in most patients, impaired testosterone production and Gynecomastia after therapy might happen. The current study aims to evaluate the impact of Imatinib Mesylate on sex hormones of CML male patients in Baghdad province. Blood specimens were collected from (42) CML patients aged 23 to 68 years who used Imatinib drug for more than two years, and (45) normal persons aged 25 to 65 years as a control group. Exclusion criteria were performed for both control and CML patient's groups, including people with diabetes, hypertensive, and males complaining of infertility after taking medical history for every participant. The blood level of hemoglobin (Hb), white blood cells (WBC), platelet count, testosterone, LH, and FSH were evaluated and investigated. The obtained results showed a significantly lower level of testosterone (2.73+- 0.97) ng/mL than the control group (4.72 ±1.02) ng/mL with a p-value of 0.000. While LH (4.53±2.1) mIU/mL and FSH (5.12 ± 2.83) mIU/mL were significantly higher than the control group (3.77± 0.8) mIU/mL and (3.85±0.807) mIU/mL with p-value of 0.026 and 0.005 respectively. Moreover, the outcomes revealed a moderate positive correlation (r = +0.348) between LH hormone levels with a duration increasing time of using Imatinib, while platelet showed a moderate negative correlation (r = -0.321) with time-consuming using that drug. In conclusion, Imatinib might harm testis functions and some hematological parameters that could increase using this drug.

CT-721, a Potent Bcr-Abl Inhibitor, Exhibits Excellent In Vitro and In Vivo Efficacy in the Treatment of Chronic Myeloid Leukemia

Kinase inhibitors that target Bcr-Abl are highly effective in the treatment of chronic myeloid leukemia (CML). However, these inhibitors are often invalidated due to the drug resistance. Therefore, the discovery and development of novel Bcr-Abl inhibitors is required to overwhelm the drug resistance in the treatment of CML resistant to the currently used first-line Bcr-Abl inhibitors. Herein we have described a newly developed Bcr-Abl inhibitor CT-721, which displayed potent inhibitory effects on wild-type and T315I mutant Bcr-Abl. It functioned as a typically ATP-competitive inhibitor, superior to other existing Bcr-Abl inhibitors. CT-721 also demonstrated time-dependent inhibition of Bcr-Abl activation and the resultant downstream signaling transduction pathways in Bcr-Abl positive cells. Furthermore, CT-721 induced cell apoptosis and cell cycle arrest, and efficaciously inhibited tumor growth in Bcr-Abl-expressed K562 and KU812 xenograft models in a mechanism-based manner. Further PK/PD studies revealed a positive in vivo correlation between the compound concentration and inhibition of Bcr-Abl activity. Taken together, CT-721 is a potent and time-dependent Bcr-Abl kinase inhibitor, and has shown strong in vitro and in vivo anti-CML activities with a favorable pharmacokinetic profile, differentiating it from other Bcr-Abl kinase inhibitors already approved and current in development for the treatment of CML.

Wogonoside induces growth inhibition and cell cycle arrest via promoting the expression and binding activity of GATA-1 in chronic myelogenous leukemia cells

GATA-1, a zinc finger transcription factor, has been demonstrated to play a key role in the progression of leukemia. In this study, we investigate the effects of wogonoside, a naturally bioactive flavonoid derived from Scutellaria baicalensis Georgi, on cell growth and cell cycle in chronic myeloid leukemia (CML) cells, and uncover its underlying mechanisms. The experimental design comprised CML cell lines K562, imatinib-resistant K562 (K562r) cells, and primary CML cells, treated in vitro or in vivo, respectively, with wogonoside; growth and cell cycle were then evaluated. We found that wogonoside could induce growth inhibition and G0/G1 cell cycle arrest in both normal and K562r cells. Wogonoside promotes the expression of GATA-1 and facilitates the binding to methyl ethyl ketone (MEK) and p21 promoter, thus inhibiting MEK/extracellular signal-regulated kinase signaling and cell cycle checkpoint proteins, including CDK2, CDK4, cyclin A, and cyclin D1, and increasing p21 expression. Furthermore, in vivo studies showed that administration of wogonoside decreased CML cells and prolonged survival in NOD/SCID mice with CML cell xenografts. In conclusion, these results clearly revealed the inhibitory effect of wogonoside on the growth in CML cells and suggested that wogonoside may act as a promising drug for the treatment of imatinib-resistant CML.