298
Views
7
CrossRef citations to date
0
Altmetric
Research Articles

Inhibition of Hedgehog signaling induces monocytic differentiation of HL-60 cells

, , , , , , & show all
Pages 1196-1202 | Received 16 Jun 2011, Accepted 06 Nov 2011, Published online: 05 Jan 2012
 

Abstract

There is little evidence to demonstrate the importance of the Sonic hedgehog homolog (Shh) pathway to differentiation therapy in the treatment of hematological neoplasms. Here we characterize the changes in acute myelogenous leukemia (HL-60) cells after blocking the Shh pathway by an antagonist of Smoothened, cyclopamine. Cyclopamine induces apoptosis of HL-60 cells in a dose- and time-dependent manner with increased G0/G1 cycle fraction. Treatment with cyclopamine increases the expression of monocytic cell markers CD11b and CD14, but the expression of CD13, CD33 and CD38 is unchanged. The monocytic differentiation of HL-60 cells induced by cyclopamine is also evidenced by an increase in Egr-1 expression. Importantly, cyclopamine down-regulates the phosphorylation of Akt and ERK, but activates AMP-activated protein kinase (AMPK) signaling. Further investigations should determine the clinical application of modulating the Shh pathway in the treatment of hematological malignancies.

Acknowledgements

This work was supported by grants from the Taiwan Department of Health and China Medical University Hospital Cancer Research of Excellence (DOH99-TD-C-111-005), and China Medical University Hospital Research Grants (DMR-96-107, DMR-97-021, DMR-99-011). The sponsors had no role in the study design, collection, analysis and interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript. We sincerely thank Dr. Aaron Sargeant of Charles River Laboratories for suggestions and proofreading the manuscript.

Potential conflict of interest:

Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.