Loss of IGF-II imprinting in endometrial tumors: overexpression in carcinosarcoma

Cancer Lett. 2000 May 29;153(1-2):67-73. doi: 10.1016/s0304-3835(00)00347-5.


The genomic imprinting of the maternal allele defines the monoallelic expression of the IGF-II gene in most human tissues. The loss of imprinting (LOI) leading to biallelic overexpression of IGF-II has been reported in several human malignancies, including uterine leiomyosarcoma. To ascertain if LOI occurs in endometrial malignancies, the allelic expression of the IGF-II gene was examined in samples of normal human endometrium (n=22) and endometrial tumors (n=12) by assessing the ApaI polymorphism in cDNA segments amplified by RT-PCR. The biallelic overexpression of IGF-II mRNA, involving activation of all four (P1-P4) promoters, was detected in one normal endometrium and in one endometrial carcinosarcoma. Low level biallelic expression of IGF-II was also detected in two samples of hormone-unresponsive/Type II endometrial carcinomas. The level of IGF-I mRNA in these four samples was low. The IGF-IR mRNA was overexpressed in all endometrial cancers including the carcinosarcoma sample, but not in normal endometrium. These data suggest that LOI associated with overexpression of IGF-II and concomitant overexpression of IGF-IR may play a role in the rare carcinosarcoma of the endometrium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinosarcoma / genetics*
  • Endometrial Neoplasms / genetics*
  • Endometrium / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Genomic Imprinting*
  • Humans
  • Insulin-Like Growth Factor II / genetics*
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptor, IGF Type 1 / genetics
  • Receptor, IGF Type 1 / metabolism


  • RNA, Messenger
  • Insulin-Like Growth Factor II
  • Receptor, IGF Type 1