Modification of globin gene expression by RNA targeting strategies.

Abstract

OBJECTIVE:

Sickle cell anemia is a genetic blood disease resulting from production of mutant beta-globin (beta(S)) and has severe clinical consequences. It is known that a higher cellular gamma-globin level, e.g., higher ratio of cellular gamma-globin to beta(S)-globin (gamma/beta(S) ratio), inhibits sickle hemoglobin (HbS) polymerization tendency. Hence, therapeutic treatment of sickle cell anemia has been focused on introducing gamma-globin gene into red blood cells to increase the cellular gamma/beta(S) ratio. Here, we have introduced ribozymes and small interfering RNAs (siRNAs) against beta(S)-globin mRNA into blood cells as a means to increase the gamma/beta(S) ratio.

MATERIALS AND METHODS:

Single and multiribozymes against beta(S)-globin mRNA have been tested in vitro and in human erythroleukemia K562beta(S) cells that stably express exogenous beta(S)-globin gene. Primary human hematopoietic progenitor cells were also transfected with multiribozyme and the gamma/(gamma + beta) ratio determined and compared with cells transfected with long hairpin beta-globin cDNA and synthetic siRNA genes.

RESULTS:

We have found that the multiribozyme zb21A containing two ribozyme units effectively reduces beta(S)-globin mRNA both in vitro and in K562beta(S) cells. The gamma-globin mRNA to beta(S)-globin mRNA ratio in the multiribozyme transfected cells is about a factor of 2 more than that in the control cells. We have also found that the gamma/(gamma + beta) ratio in the transfected hematopoietic progenitor cells is increased by more than twofold in cells treated with multiribozyme zb21A or siRNA ib5.

CONCLUSION:

Our results suggest that introducing multiribozymes or siRNAs into red blood cells is comparable in their effectiveness to increase the ratio of cellular gamma-globin mRNA to beta- or beta(S)-globin mRNA, providing possible strategies to increase the effectiveness of gamma-globin gene transfer as gene therapy for treatment of patients with sickle cell anemia.

• Authors: Tong-Jian Shen, Heather Rogers, Xiaobing Yu, Felix Lin, Constance T Noguchi, Chien Ho
• Journal: Experimental hematology (Exp Hematol) Vol. 35 Issue 8 Pg. 1209-18 (Aug 2007) ISSN: 0301-472X [Print] Netherlands
• PMID: 17662889 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• RNA, Messenger
• RNA, Small Interfering
• Globins

Topics

• Anemia, Sickle Cell (genetics)
• Base Sequence
• Cell Line, Tumor
• Exons
• Gene Expression Regulation
• Globins (genetics, physiology)
• Humans
• K562 Cells
• Molecular Sequence Data
• Plasmids
• RNA, Messenger (genetics)
• RNA, Small Interfering (genetics)