[Effect of hexamethylene bisacetamine on proliferation and apoptosis of human leukemia cells in vitro and relevant mechanisms].

Abstract

OBJECTIVES:

To investigate the in vitro effect of hexamethylene bisacetamine (HMBA) on the proliferation, cell cycle regulation, and apoptosis of human leukemia cells and to study the relevant mechanisms.

METHODS:

K562 and U937 human leukemia cells were cultured and then suspensions thereof without HMBA or with HMBA of different concentrations (1, 2, and 4 mmol/L) were made. The optical absorbance value at 595 nm of these suspensions were tested every 24 hours. The suspensions were mixed with 4% trypan blue dye solution. Live and dead cells were observed with microscope and the live cell rate was calculated. Double staining of cellular cyclin A protein/DNA was used to detect the expression levels of cyclin A protein in cytoplasm. Fluorescein isothiocyanate (FITC)-labeled annexin V/Propidiumiodide) was used to detect the apototic cells fluorescence-activated cell sorter. Gel electrophoresis was conducted to detect DNA contents.

RESULT:

After exposure to HMBA for 6 days, the optical absorbance values at 595nm of K562 leukemia cells of the control group and groups with 1, 2, and 4mmol/L HMBA were 1.03, 0.81, 0.58, and 0.36 respectively. After treatment of HMBA, the percentages of cyclin A positive K562 leukemia cells in control group and groups with 1, 2, and 4 mmol/L HMBA were 34.4% +/- 5.2%, 16.1% +/- 2.5%, 9.9% +/- 1.7%, and 7.6% +/- 2.0% respectively (P < 0.01). No drug-related apoptosis was found in both cell lines.

CONCLUSION:

HMBA inhibits cell proliferation and reduces S-phase-fraction in both cell lines dose-dependently through down-regulating the expression of cyclin A. Apoptosis is not a consequence of the proceeding mitosis arrest and is induced p53-dependently by HMBA. In both leukemia cell lines (U937 and K562) lacking wt-p53, a nonapoptotic death pathway may exist during HMBA induction.

• Authors: Hui Yu, Huazhong Lu, Bin Zheng, Huahua Fan, Yi Xie
• Journal: Zhonghua yi xue za zhi (Zhonghua Yi Xue Za Zhi) Vol. 82 Issue 8 Pg. 549-52 (Apr 25 2002) ISSN: 0376-2491 [Print] China
• PMID: 12133503 (Publication Type: English Abstract, Journal Article)

Chemical References

• Acetamides
• Antineoplastic Agents
• Cyclin A
• DNA, Neoplasm
• hexamethylene bisacetamide

Topics

• Acetamides (pharmacology)
• Antineoplastic Agents (pharmacology)
• Apoptosis
• Cell Division (drug effects)
• Cyclin A (biosynthesis)
• DNA, Neoplasm (analysis)
• Dose-Response Relationship, Drug
• Electrophoresis, Agar Gel (methods)
• Humans
• K562 Cells
• Leukemia
• S Phase
• Tumor Cells, Cultured
• U937 Cells