scholarly journals Homeobox Gene Deregulation: Impact on the Hallmarks of Cancer

2013 ◽  
Vol 1 (2) ◽  
pp. 67-76 ◽  
Author(s):  
Dhwani Haria ◽  
Honami Naora
2020 ◽  
Vol 41 (10) ◽  
pp. 1341-1352
Author(s):  
Hee-Jin Kim ◽  
Eun-Hye Seo ◽  
Dong Hyuck Bae ◽  
Keeok Haam ◽  
Hay-Ran Jang ◽  
...  

Abstract Pathological changes in the epigenetic landscape of chromatin are hallmarks of cancer. The caudal-type homeobox gene CDX2 is not expressed in normal gastric epithelia but rather in adult intestinal epithelia, and it is overexpressed in intestinal metaplasia (IM). However, it remains unclear how CDX2 transcription is suppressed in normal gastric epithelial cells and overexpressed in IM. Here, we demonstrate that methylation of the CDX2 promoter increases with age in Helicobacter pylori-positive, noncancerous gastric tissue, whereas the promoter is demethylated in paired gastric tumors in which CDX2 is upregulated. Moreover, we also found that the CDX2 promoter is demethylated in IM as well as gastric tumor. Immunohistochemistry revealed that CDX2 is present in foci of parts of the gastric mucosae but highly expressed in IM as well as in gastric tumors, suggesting that the elevated level of CDX2 in IM and gastric tumors may be attributable to promoter demethylation. Our data suggest that CDX2 repression may be associated with promoter methylation in noncancerous H. pylori-positive mucosa but its upregulation might be attributable to increased promoter activity mediated by chromatin remodeling during gastric carcinogenesis.


Author(s):  
Shamim Mushtaq

Uninhibited proliferation and abnormal cell cycle regulation are the hallmarks of cancer. The main role of cyclin dependent kinases is to regulate the cell cycle and cell proliferation. These protein kinases are frequently down regulated or up regulated in various cancers. Two CDK family members, CDK 11 and 12, have contradicting views about their roles in different cancers. For example, one study suggests that the CDK 11 isoforms, p58, inhibits growth of breast cancer whereas, the CDK 11 isoform, p110, is highly expressed in breast tumor. Studies regarding CDK 12 show variation of opinion towards different parts of the body, however there is a consensus that upregulation of cdk12 increases the risk of breast cancer. Hence, CDK 11 and CDK 12 need to be analyzed to confirm their mechanism and their role regarding therapeutics, prognostic value, and ethnicity in cancer. This article gives an outline on both CDKs of information known up to date from Medline, PubMed, Google Scholar and Web of Science search engines, which were explored and thirty relevant researches were finalized.


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