Expression of ANRIL-Polycomb Complexes-CDKN2A/B/ARF Genes in Breast Tumors: Identification of a Two-Gene (EZH2/CBX7) Signature with Independent Prognostic Value.
ANRIL, a long noncoding RNA (lncRNA), has recently been reported to have a direct role in recruiting polycomb repressive complexes PRC2 and PRC1 to regulate the expression of the p15/CDKN2B-p16/CDKN2A-p14/ARF gene cluster. Expression analysis of ANRIL, EZH2, SUZ12, EED, JARID2, CBX7, BMI1, p16, p15, and p14/ARF genes was evaluated in a large cohort of invasive breast carcinomas (IBC, n = 456) by qRT-PCR and immunohistochemistry (IHC) was performed on CBX7, EZH2, p14, p15, p16, H3K27me3, and H3K27ac. We observed significant overexpression in IBCs of ANRIL (19.7%) and EZH2 (77.0%) and an underexpression of CBX7 (39.7%). Correlations were identified between these genes, their expression patterns, and several classical clinical and pathologic parameters, molecular subtypes, and patient outcomes, as well as with proliferation, epithelial-mesenchymal transition, and breast cancer stem cell markers. Multivariate analysis revealed that combined EZH2/CBX7 status is an independent prognostic factor (P = 0.001). In addition, several miRNAs negatively associated with CBX7 underexpression and EZH2 overexpression. These data demonstrate a complex pattern of interactions between lncRNA ANRIL, several miRNAs, PRC2/PRC1 subunits, and p15/CDKN2B-p16/CDKN2A-p14/ARF locus and suggest that their expression should be considered together to evaluate antitumoral drugs, in particular the BET bromodomain inhibitors.



This study suggests that the global pattern of expression rather than expression of individual family members should be taken into account when defining functionality of repressive Polycomb complexes and therapeutic targeting potential. Mol Cancer Res; 14(7); 623-33. ©2016 AACR.
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France. Platform of Investigative Pathology, Curie Institute, Paris, France.
Didier
D
Meseure
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France.
Sophie
S
Vacher
Platform of Investigative Pathology, Curie Institute, Paris, France.
Kinan Drak
KD
Alsibai
Platform of Investigative Pathology, Curie Institute, Paris, France.
Andre
A
Nicolas
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France.
Walid
W
Chemlali
Department of Biopathology, Curie Institute, Paris, France.
Martial
M
Caly
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France.
Rosette
R
Lidereau
Faculty of Pharmaceutical and Biological Sciences, Paris Descartes University, Paris, France.
Eric
E
Pasmant
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France.
Celine
C
Callens
Unit of Pharmacogenomics, Department of Genetics, Curie Institute, Paris, France. Faculty of Pharmaceutical and Biological Sciences, Paris Descartes University, Paris, France. ivan.bieche@curie.fr.
Ivan
I
Bieche
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050763:Cyclin-Dependent Kinase Inhibitor p18 / Q000235:genetics; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008875:Middle Aged; D005810:Multigene Family; D063150:Polycomb Repressive Complex 1 / Q000235:genetics; D063146:Polycomb-Group Proteins / Q000096:biosynthesis* / Q000235:genetics; D011379:Prognosis; D062085:RNA, Long Noncoding / Q000096:biosynthesis* / Q000235:genetics
C503627:CBX7 protein, human; C000614131:CDKN2A protein, human; C561518:CDKN2B antisense RNA, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050763:Cyclin-Dependent Kinase Inhibitor p18; D063146:Polycomb-Group Proteins; D062085:RNA, Long Noncoding; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063150:Polycomb Repressive Complex 1