title: Long-term engraftment of p18(INK4C)-deficient hematopoietic stem cells is enhanced in the sublethally-irradiated recipients.
abstract: Non-myeloablative regimens for host conditioning have been widely used in clinical hematopoietic stem cell transplantation due to their reduced toxicity on the recipients. But a milder conditioning regimen may require a higher engrafting ability of donor stem cells in competing with endogenous stem cells. Thus, new strategies for enhancing the competitiveness of donor stem cells in non-myeloablative recipients would have important implications for current clinical stem cell transplantation. It is known that the absence of p18(INK4C) (p18) gene can enhance the self-renewal potential of hematopoietic stem cells (HSCs). We applied the approach of competitive bone marrow transplantation to evaluate the impact of p18 gene deletion on long-term engraftment of HSCs in sublethally irradiated hosts. We found that p18(-/-) HSCs had a significant advantage over wild-type HSCs during long-term engraftment in the mouse recipients that received a sub-lethal irradiation (5-Gy). The engraftment efficiency of p18(-/-) HSCs in the sub-lethally irradiated recipients was similar to that in the lethally irradiated (10-Gy) recipients. Our current study demonstrates that enhanced engraftment of donor HSCs in the absence of p18 does not strictly depend on the dose of irradiation used for host conditioning. Therefore, p18 might serve as a potential drug target for increasing the efficacy of stem cell transplant in the patients that are preconditioned with either a myeloablative or non-myeloablative regimen.
authors.affiliation: Department of Hematology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Xianmin
authors.initials: X
authors.lastname: Song
authors.forename: Youzhong
authors.initials: Y
authors.lastname: Yuan
authors.forename: Hongmei
authors.initials: H
authors.lastname: Shen
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Paulina
authors.initials: P
authors.lastname: Huang
authors.forename: Donna
authors.initials: D
authors.lastname: Shields
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Cheng
mesh_terms: D000818:Animals; D050763:Cyclin-Dependent Kinase Inhibitor p18 / Q000172:deficiency / Q000235:genetics*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism* / Q000528:radiation effects; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: C493971:CDKN2C protein, human; D050763:Cyclin-Dependent Kinase Inhibitor p18