Sequencing and G-quadruplex folding of the canine proto-oncogene KIT promoter region: might dog be used as a model for human disease?

PLoS One. 2014 Aug 1;9(8):e103876. doi: 10.1371/journal.pone.0103876. eCollection 2014.

Abstract

Downregulation of gene expression by induction of non-canonical DNA structures at promotorial level is a novel attractive anticancer strategy. In human, two guanine-rich sequences (h_kit1 and h_kit2) were identified in the promotorial region of oncogene KIT. Their stabilization into G-quadruplex structures can find applications in the treatment of leukemias, mastocytosis, gastrointestinal stromal tumor, and lung carcinomas which are often associated to c-kit mis-regulation. Also the most common skin cancer in domestic dog, mast cell tumor, is linked to a mutation and/or to an over-expression of c-kit, thus supporting dog as an excellent animal model. In order to assess if the G-quadruplex mediated mechanism of regulation of c-kit expression is conserved among the two species, herein we cloned and sequenced the canine KIT promoter region and we compared it with the human one in terms of sequence and conformational equilibria in physiologically relevant conditions. Our results evidenced a general conserved promotorial sequence between the two species. As experimentally confirmed, this grants that the conformational features of the canine kit1 sequence are substantially shared with the human one. Conversely, two isoforms of the kit2 sequences were identified in the analyzed dog population. In comparison with the human counterpart, both of them showed an altered distribution among several folded conformations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dogs
  • G-Quadruplexes*
  • Humans
  • Promoter Regions, Genetic / genetics*
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins c-kit / genetics*

Substances

  • MAS1 protein, human
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins c-kit

Grants and funding

This research was supported by the Italian Ministry of Education (PRIN 2010-11, code 20105YY2HL) and by University of Padova (grant #CPDA114388). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.