| 1. |
- Fang, Hsin-Yu, et al.
(författare)
-
Hypoxia-inducible factors 1 and 2 are important transcriptional effectors in primary macrophages experiencing hypoxia
- 2009
-
Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 114:4, s. 844-859
-
Tidskriftsartikel (refereegranskat)abstract
- Ischemia exists in many diseased tissues, including arthritic joints, atherosclerotic plaques, and malignant tumors. Macrophages accumulate in these sites and up-regulate hypoxia-inducible transcription factors (HIFs) 1 and 2 in response to the hypoxia present. Here we show that the gene expression profile in primary human and murine macrophages changes markedly when they are exposed to hypoxia for 18 hours. For example, they were seen to up-regulate the cell surface receptors, CXCR4 and GLUT1, and the potent, tumor-promoting cytokines, vascular endothelial growth factor A, interleukin (IL)-1 beta and IL-8, adrenomedullin, CXCR4, and angiopoietin-2. Hypoxia also stimulated their expression and/or phosphorylation of various proteins in the nuclear factor-kappa B (NF-kappa B) signaling pathway. We then used both genetic and pharmacologic methods to manipulate the levels of HIFs-1 alpha and 2 alpha or NF-kappa B in primary macrophages to elucidate their role in the hypoxic induction of many of these key genes. These studies showed that both HIF-1 and -2, but not NF-kappa B, are important transcriptional effectors regulating the responses of macrophages to such a period of hypoxia. Further studies using experimental mouse models are now warranted to investigate the role of such macrophage responses in the progression of various diseased tissues, such as malignant tumors. (Blood. 2009; 114: 844-859)
|
|
| 2. |
- Muthana, Munitta, et al.
(författare)
-
Use of Macrophages to Target Therapeutic Adenovirus to Human Prostate Tumors
- 2011
-
Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 71:5, s. 1805-1815
-
Tidskriftsartikel (refereegranskat)abstract
- New therapies are required to target hypoxic areas of tumors as these sites are highly resistant to conventional cancer therapies. Monocytes continuously extravasate from the bloodstream into tumors where they differentiate into macrophages and accumulate in hypoxic areas, thereby opening up the possibility of using these cells as vehicles to deliver gene therapy to these otherwise inaccessible sites. We describe a new cell-based method that selectively targets an oncolytic adenovirus to hypoxic areas of prostate tumors. In this approach, macrophages were cotransduced with a hypoxia-regulated E1A/B construct and an E1A-dependent oncolytic adenovirus, whose proliferation is restricted to prostate tumor cells using prostate-specific promoter elements from the TARP, PSA, and PMSA genes. When such cotransduced cells reach an area of extreme hypoxia, the E1A/B proteins are expressed, thereby activating replication of the adenovirus. The virus is subsequently released by the host macrophage and infects neighboring tumor cells. Following systemic injection into mice bearing subcutaneous or orthotopic prostate tumors, cotransduced macrophages migrated into hypoxic tumor areas, upregulated E1A protein, and released multiple copies of adenovirus. The virus then infected neighboring cells but only proliferated and was cytotoxic in prostate tumor cells, resulting in the marked inhibition of tumor growth and reduction of pulmonary metastases. This novel delivery system employs 3 levels of tumor specificity: the natural "homing" of macrophages to hypoxic tumor areas, hypoxia-induced proliferation of the therapeutic adenovirus in host macrophages, and targeted replication of oncolytic virus in prostate tumor cells.
|
|
| 3. |
- Suzuki, Toshiyasu, et al.
(författare)
-
b-Catenin Drives Butyrophilin-like Molecule Loss and gd T-cell Exclusion in Colon Cancer
- 2023
-
Ingår i: CANCER IMMUNOLOGY RESEARCH. - : AMER ASSOC CANCER RESEARCH. - 2326-6066. ; 11:8, s. 1137-1155
-
Tidskriftsartikel (refereegranskat)abstract
- Intraepithelial lymphocytes (IEL) expressing y8 T-cell receptors (y8TCR) play key roles in elimination of colon cancer. However, the precise mechanisms by which progressing cancer cells evade immu-nosurveillance by these innate T cells are unknown. Here, we investigated how loss of the Apc tumor suppressor in gut tissue could enable nascent cancer cells to escape immunosurveillance by cytotoxic y8IELs. In contrast with healthy intestinal or colonic tissue, we found that y8IELs were largely absent from the micro-environment of both mouse and human tumors, and that butyr-ophilin-like (BTNL) molecules, which can critically regulate y8IEL through direct y8TCR interactions, were also downregulated in tumors. We then demonstrated that 13-catenin activation through loss of Apc rapidly suppressed expression of the mRNA encoding the HNF4A and HNF4G transcription factors, preventing their binding to promoter regions of Btnl genes. Reexpression of BTNL1 and BTNL6 in cancer cells increased y8IEL survival and activation in coculture assays but failed to augment their cancer-killing ability in vitro or their recruitment to orthotopic tumors. However, inhibition of 13-catenin signaling via genetic deletion of Bcl9/Bcl9L in either Apc-deficient or mutant 13-catenin mouse models restored Hnf4a, Hnf4g, and Btnl gene expression and y8 T-cell infiltration into tumors. These observations highlight an immune-evasion mechanism specific to WNT-driven colon cancer cells that disrupts y8IEL immunosurveillance and furthers cancer progression.
|
|
