title: Components of the hematopoietic compartments in tumor stroma and tumor-bearing mice.
abstract: Solid tumors are composed of cancerous cells and non-cancerous stroma. A better understanding of the tumor stroma could lead to new therapeutic applications. However, the exact compositions and functions of the tumor stroma are still largely unknown. Here, using a Lewis lung carcinoma implantation mouse model, we examined the hematopoietic compartments in tumor stroma and tumor-bearing mice. Different lineages of differentiated hematopoietic cells existed in tumor stroma with the percentage of myeloid cells increasing and the percentage of lymphoid and erythroid cells decreasing over time. Using bone marrow reconstitution analysis, we showed that the tumor stroma also contained functional hematopoietic stem cells. All hematopoietic cells in the tumor stroma originated from bone marrow. In the bone marrow and peripheral blood of tumor-bearing mice, myeloid populations increased and lymphoid and erythroid populations decreased and numbers of hematopoietic stem cells markedly increased with time. To investigate the function of hematopoietic cells in tumor stroma, we co-implanted various types of hematopoietic cells with cancer cells. We found that total hematopoietic cells in the tumor stroma promoted tumor development. Furthermore, the growth of the primary implanted Lewis lung carcinomas and their metastasis were significantly decreased in mice reconstituted with IGF type I receptor-deficient hematopoietic stem cells, indicating that IGF signaling in the hematopoietic tumor stroma supports tumor outgrowth. These results reveal that hematopoietic cells in the tumor stroma regulate tumor development and that tumor progression significantly alters the host hematopoietic compartment.
authors.affiliation: Department of Physiology and Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: HoangDinh
authors.initials: H
authors.lastname: Huynh
authors.forename: Junke
authors.initials: J
authors.lastname: Zheng
authors.forename: Masato
authors.initials: M
authors.lastname: Umikawa
authors.forename: Robert
authors.initials: R
authors.lastname: Silvany
authors.forename: Xian-Jin
authors.initials: XJ
authors.lastname: Xie
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Wu
authors.forename: Martin
authors.initials: M
authors.lastname: Holzenberger
authors.forename: Qianming
authors.initials: Q
authors.lastname: Wang
authors.forename: Cheng Cheng
authors.initials: CC
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002451:Cell Compartmentation; D002452:Cell Count; D002454:Cell Differentiation; D049109:Cell Proliferation; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D051379:Mice; D009369:Neoplasms / Q000473:pathology*; D011230:Precancerous Conditions / Q000473:pathology; D017154:Stromal Cells / Q000473:pathology