Expression of Intratumoral IGF-II Is Regulated by the Gene Imprinting Status in Triple Negative Breast Cancer from Vietnamese Patients

Abstract

African American women suffer higher incidence and mortality of triple negative breast cancer (TNBC) than Caucasian women. TNBC is very aggressive, causing the worst clinical outcome. We previously demonstrated that tumors from these patients express high IGF-II and exhibit high activation of the IGF signaling pathways. IGF-II gene expression is imprinted (monoallelic), promotes tumor progression, and metastasis and regulates Survivin, a TNBC prognostic marker. Since BC mortality has increased among young Vietnamese women, we analyzed 48 (paired) TNBC samples from Vietnamese patients to assess IGF-II expression. We analyzed all samples by qrtPCR for identification of IGF-II heterozygosity and to determine allelic expression of the IGF-II gene. We also analyzed the tissues for proIGF-II and Survivin by RT-PCR and Western blotting. A total of 28 samples displayed IGF-II heterozygosity of which 78% were biallelic. Tumors with biallelic IGF-II gene expression exhibited the highest levels of proIGF-II and Survivin. Although 100% of these tissues corresponding normal samples were biallelic, they expressed significantly lower levels of or no proIGF-II and Survivin. Thus, IGF-II biallelic gene expression is differentially regulated in normal versus tumor tissues. We propose that intratumoral proIGF-II is dependent on the IGF-II gene imprinting status and it will promote a more aggressive TNBC.

Alteration of Metabolic Conditions Impacts the Regulation of IGF-II/H19 Imprinting Status in Prostate Cancer

“…There are six IGFBPs: IGFBP1-6 and they bind to IGF-I and -II with high affinity [ 48 ]. More specifically, IGFBP2 binds to IGF-II with very high affinity [ 49 ]. Therefore, the inconsistency of IGF-II staining is likely due to the presence of peptide bound to IGFBP-2.…”

Corrigendum to “Expression of Intratumoral IGF-II Is Regulated by the Gene Imprinting Status in Triple Negative Breast Cancer from Vietnamese Patients”

“…In the article titled “Expression of Intratumoral IGF-II Is Regulated by the Gene Imprinting Status in Triple Negative Breast Cancer from Vietnamese Patients” [ 1 ], there were errors in Figures 2 and 4. There was lane duplication and undeclared splicing in Figure 2, where the bands used for the sample 11M(BA), 12N(BA) were duplicated as lanes 21M(BA), 22N(BA) and the lanes for 15M(BA), 16N(BA) were triplicated as lanes 17M(BA), 18N(BA) and 39M(BA), 40N(BA).…”

Parent of Origin and Prognosis in Familial Breast Cancer in Sweden

“…Imprinted regions in invasive breast cancer have been associated with negative hormonal receptor status, a prognostic factor for poor breast cancer prognosis (3). Furthermore, the imprinting status of insulin-like growth factor 2 has been associated with a more aggressive triplenegative breast cancer phenotype (4).…”