Display Settings:


Send to:

Choose Destination
Breast Cancer Res Treat. 2012 Nov;136(1):129-42. doi: 10.1007/s10549-012-2246-7. Epub 2012 Sep 29.

Prognostic value of LINE-1 retrotransposon expression and its subcellular localization in breast cancer.

Author information

  • 1John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.


Long interspersed nuclear element 1 (L1) belongs to a family of retrotransposons. Expression of the normally repressed L1 retrotransposons has been shown to induce genome instability by creating DNA double-stranded breaks and chromosomal rearrangements through the process of retrotransposition. At present, little is known about the expression of L1-encoded ORF1p and ORF2p which are indispensable for its retrotransposition activity. Given its potentially harmful effects on the genome, we investigated the implications of both ORF1p and ORF2p expression and their subcellular localization in a range of breast cancer cell lines and breast tumor tissues including 15 normal breast tissues, 25 fibroadenomas, 25 ductal carcinomas in situ (DCIS), and 95 invasive cancers. Clinicopathologic parameters and survival outcomes were investigated in association with the cytoplasmic and nuclear expression of ORF1p and ORF2p using univariate and multivariate analysis. High cytoplasmic expression of ORF1p and ORF2p was seen in DCIS tumors, but they were not related with survival outcome. The majority of invasive cancers were found to express both ORF1p and ORF2p in the cytoplasm, while nuclear expression was also seen in a subclass of those invasive cancers in the range of 28-31 %. Tumors with high nuclear expression of ORF1p and ORF2p were more significantly associated with lymph node metastasis (p = 0.001) and the worst patient survival (p < 0.0001) than those with cytoplasmic expression. This is the first study examining the effects of both ORF1p and ORF2p expression in breast cancer tissues. Our observation shows altered expression patterns of ORF1p and ORF2p within invasive cancers, which are related to differences in overall patient survival. The differing patterns of both cytoplasmic and nuclear ORF1p and ORF2p expression indicate that further studies of the biology and function of L1 retrotransposons are required in breast cancer.

[PubMed - indexed for MEDLINE]
Free PMC Article

Images from this publication.See all images (5)Free text

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for Springer Icon for PubMed Central
    Loading ...
    Write to the Help Desk