scholarly journals The Roles of Dietary PPAR Ligands for Metastasis in Colorectal Cancer

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroki Kuniyasu

Dietary peroxisome proliferator-activated receptor (PPAR) ligands, linoleic acid (LA) and conjugated linoleic acid (CLA), showed anticancer effects in colorectal carcinoma cells. LA is metabolized by two pathways. Cyclooxygenase (COX)-2 produces procarcinogenic prostaglandin E2, whereas 15-lipoxygenase (LOX)-1 produces PPAR ligands. The 15LOX-1 pathway, which is dominant in colorectal adenomas, was downregulated and inversely COX-2 was upregulated in colorectal cancer. LA and CLA inhibited peritoneal metastasis of colorectal cancer cells in nude mice. The inhibitory effect was abrogated by PPAR antisense treatment. A continuous LA treatment provided cancer cells quiescence. These quiescent cells formed dormant nests in nude mice administrated LA. The quiescent and dormant cells showed downregulated PPAR and upregulated nucleostemin. Thus, short-term exposure to dietary PPAR ligands inhibits cancer metastasis, whereas consistent exposure to LA provides quiescent/dormant status with possible induction of cancer stem and/or progenitor phenotype. The complicated roles of dietary PPAR ligands are needed to examine further.

1998 ◽  
Vol 274 (6) ◽  
pp. G1061-G1067 ◽  
Author(s):  
Hitoshi Sawaoka ◽  
Sunao Kawano ◽  
Shingo Tsuji ◽  
Masahiko Tsujii ◽  
Edhi S. Gunawan ◽  
...  

To clarify the role of mitogen-inducible cyclooxygenase (COX-2) in the development of malignant tumors, we investigated the effects of COX-2 inhibitors on the growth of gastric cancer xenografts in nude mice in vivo. MKN45 gastric cancer cells (5 × 106cells/animal) that overexpress COX-2 were inoculated subcutaneously into athymic mice. NS-398, a specific COX-2 inhibitor, or indomethacin, a nonspecific COX-2 inhibitor, was administered orally to animals every day for 20 days. These drugs reduced the tumor volume significantly. Immunohistochemistry using bromodeoxyuridine, nick end labeling, and electron microscopy showed that NS-398 induced apoptosis in cancer cells in a dose-dependent manner and inhibited cancer cell replication slightly. Indomethacin also induced apoptosis and suppressed replication of tumor cells. There was a significant negative correlation between tumor volume and apoptotic cell number within the tumor. These results are consistent with the hypothesis that COX-2 inhibitors suppress growth of gastric cancer xenografts mainly by inducing apoptosis and suppressing replication of the neoplastic cells. It follows that COX-2 plays an important role in the development of gastric cancer.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jinbing Sun ◽  
Zhihua Lu ◽  
Wei Fu ◽  
Kuangyi Lu ◽  
Xiuwen Gu ◽  
...  

Exosomes derived from cancer cells are deemed important drivers of pre-metastatic niche formation at distant organs, but the underlying mechanisms of their effects remain largely unknow. Although the role of ADAM17 in cancer cells has been well studied, the secreted ADAM17 effects transported via exosomes are less understood. Herein, we show that the level of exosome-derived ADAM17 is elevated in the serum of patients with metastatic colorectal cancer as well as in metastatic colorectal cancer cells. Furthermore, exosomal ADAM17 was shown to promote the migratory ability of colorectal cancer cells by cleaving the E-cadherin junction. Moreover, exosomal ADAM17 overexpression as well as RNA interference results highlighted its function as a tumor metastasis-promoting factor in colorectal cancer in vitro and in vivo. Taken together, our current work suggests that exosomal ADAM17 is involved in pre-metastatic niche formation and may be utilized as a blood-based biomarker of colorectal cancer metastasis.


Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 169
Author(s):  
Fakhria A. Al-Joufi ◽  
Aseem Setia ◽  
Mounir M. Salem-Bekhit ◽  
Ram Kumar Sahu ◽  
Fulwah Y. Alqahtani ◽  
...  

Colorectal cancer (CRC) is a serious disease that affects millions of people throughout the world, despite considerable advances in therapy. The formation of colorectal adenomas and invasive adenocarcinomas is the consequence of a succession of genetic and epigenetic changes in the normal colonic epithelium. Genetic and epigenetic processes associated with the onset, development, and metastasis of sporadic CRC have been studied in depth, resulting in identifying biomarkers that might be used to predict behaviour and prognosis beyond staging and influence therapeutic options. A novel biomarker, or a group of biomarkers, must be discovered in order to build an accurate and clinically useful test that may be used as an alternative to conventional methods for the early detection of CRC and to identify prospective new therapeutic intervention targets. To minimise the mortality burden of colorectal cancer, new screening methods with higher accuracy and nano-based diagnostic precision are needed. Cytotoxic medication has negative side effects and is restricted by medication resistance. One of the most promising cancer treatment techniques is the use of nano-based carrier system as a medication delivery mechanism. To deliver cytotoxic medicines, targeted nanoparticles might take advantage of differently expressed molecules on the surface of cancer cells. The use of different compounds as ligands on the surface of nanoparticles to interact with cancer cells, enabling the efficient delivery of antitumor medicines. Formulations based on nanoparticles might aid in early cancer diagnosis and help to overcome the limitations of traditional treatments, including low water solubility, nonspecific biodistribution, and restricted bioavailability. This article addresses about the molecular pathogenesis of CRC and highlights about biomarkers. It also provides conceptual knowledge of nanotechnology-based diagnostic techniques and therapeutic approaches for malignant colorectal cancer.


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