## Abstract Colorectal cancer is the third most common form of malignancy, behind prostate and lung cancers. Despite recent advances in medicine, mortality from colorectal cancer remains high, highlighting the need for improved therapies. Numerous studies have demonstrated increased activation of E
Loss of XIAP sensitizes rosiglitazone-induced growth inhibition of colon cancer in vivo
✍ Scribed by Yun Dai; Liang Qiao; Kwok Wah Chan; Bing Zou; Juan Ma; Hui Y. Lan; Qing Gu; Zesong Li; Yan Wang; Benny L.W. Wong; Benjamin C.Y. Wong
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- French
- Weight
- 437 KB
- Volume
- 122
- Category
- Article
- ISSN
- 0020-7136
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Ligands for peroxisome proliferator‐activated receptor gamma (PPARγ) possess anticancer properties. However, the efficacy of PPARγ ligands varies in different cancers. In colon cancer, the role of PPARγ and its ligands is controversial. We recently showed that downregulation of X‐linked inhibitor of apoptosis protein (XIAP) could sensitize colon cancer cells to troglitazone, and 15‐deoxy‐D12,14‐prostaglandin J2 (15‐PGJ2) induced cell killing. In our study, we aimed to examine whether rosiglitazone, another more clinically relevant PPARγ ligand, has any synergistic anticancer effect with XIAP downregulation in colon cancer. Human colon cancer cell lines HCT116‐XIAP^+/+^ cells and HCT116‐XIAP^−/−^ cells were treated with various concentrations of rosiglitazone. The effects of rosiglitazone on cell proliferation, apoptosis and growth of xenograft colon cancers were studied. Rosiglitazone barely suppressed the growth and only very weakly induced apoptosis in HCT116 cells in vitro. Loss of XIAP did not sensitize HCT116 cells to rosiglitazone‐induced growth inhibition or apoptosis. In vivo studies revealed that rosiglitazone strongly suppressed the growth of xenograft colon cancer, especially tumors derived from HCT116‐XIAP^−/−^ cells. The rosiglitazone‐treated tumor had reduced expression of ki‐67 and lowered mitotic rate. Downregulation of XIAP was associated with an impaired activation of PPARγ by its ligand. Rosiglitazone induced marked upregulation of PTEN in HCT116‐XIAP^−/−^ cells, as well as in xenograft tumors derived from HCT116‐XIAP^−/−^ cells. We concluded that rosiglitazone significantly suppresses the growth of xenograft colon cancer, and downregulation of XIAP sensitizes the xenograft tumors to rosiglitazone‐induced tumor suppression in vivo via upregulation of PTEN. © 2008 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
## Abstract A hallmark of cancer cells is an ability to evade apoptosis. Overexpression and/or activating mutations of prosurvival molecules such as the X‐linked inhibitor of apoptosis (XIAP) contribute to this inappropriate cell survival. Our objectives were to investigate the effects of downregul
## Abstract Although it is often assumed that the antitumor effects of nonsteroidal anti‐inflammatory drugs (NSAIDs) are due to inhibition of cyclooxgenase (COX) activity, specifically COX‐2, there is accumulating evidence that COX‐2 independent mechanisms can also play an important role. Studies w
## Abstract The effect of somatostatin analogue RC‐160 on the growth of DHD/K12 rat colon cancer has been investigated __in vivo__ as well as __in vitro.__ Twenty syngeneic BDIX rats with s.c. implanted tumors were divided randomly into 2 groups. The rats from each group received a daily s.c. injec
## Abstract Five autonomous sub lines, T4‐O1320, T4‐O1320CY, T4‐O1165, T4‐O1145 and T4‐O196, were established from the transplantable hormone‐dependent mouse mammary tumor, TPDMT‐4, by pass aging under different conditions. These autonomous tumors were characterized by rapid growth in DDD virgin mi
## Abstract The selective CB1 receptor antagonist rimonabant (SR141716) was shown to perform a number of biological effects in several pathological conditions. Emerging findings demonstrate that rimonabant exerts antitumor action in thyroid tumors and breast cancer cells. In our study, human colore