Cell apoptosis induced by a synthetic carbazole compound LCY-2-CHO is mediated through activation of caspase and mitochondrial pathways

Ming Jen Hsu, Yee Chao, Ying Hsin Chang, Feng Ming Ho, Li Jiau Huang, Ya Ling Huang, Tien Yau Luh, Chih Ping Chen, Wan Wan Lin

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20 Citations (Scopus)


The mechanisms involved in the apoptotic effect of LCY-2-CHO [9-(2-chlorobenzyl)-9H-carbazole-3-carbaldehyde], a synthetic carbazole derivative identified as an anti-inflammatory compound, were studied. Cell cycle analysis by propidium iodide staining in human THP-1 monocytic leukemia cells showed the ability of LCY-2-CHO to increase cell population in sub-G1 stage with time- and concentration-dependent manners. LCY-2-CHO-mediated cell death was also demonstrated by DNA laddering and was not related to the release of lactate dehydrogenase. Apoptosis in THP-1 cells induced by LCY-2-CHO was accompanied by the Bid cleavage, collapse of mitochondrial transmembrane potential, the release of cytochrome c and the activation of caspase-3. The apoptotic effect of LCY-2-CHO was diminished by the presence of zVEID-fmk (caspase-6 inhibitor), zIETD-fmk (caspase-8 inhibitor), and zVAD-fmk (non-selective caspase inhibitor), but was not altered by several antioxidants, and cathepsin inhibitor. The Bid cleavage and loss of mitochondrial transmembrane potential, but not the cytochrome c release, were reversed by zIETD-fmk. Comparing the cell selectivity of LCY-2-CHO, we found T-cell acute lymphoblastic CEM leukemia cells were sensitive to 1 μM LCY-2-CHO, acute myeloid leukemia HL-60 cells underwent apoptosis at 10 μM, while adherent cancer cells, such as PC3, HT29 and MCF-7, were resistant to 30 μM LCY-2-CHO within 24-h incubation. Taken together in the present study, we demonstrated LCY-2-CHO might be apoptotic for malignant hematopoietic cells but not anchorage-dependent cells. This action is mediated by an intrinsic caspase-dependent apoptotic event involving mitochondria.

Original languageEnglish
Pages (from-to)102-112
Number of pages11
JournalBiochemical Pharmacology
Issue number1
Publication statusPublished - Jul 1 2005
Externally publishedYes



  • Apoptosis
  • Carbazole
  • Caspases
  • LCY-2-CHO
  • Mitochondria

ASJC Scopus subject areas

  • Pharmacology

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