Introduction
Materials and methods
Tissue samples
Characteristic |
n
| (Percentage) | ERBB2 expression (percentage) | P value | |||
---|---|---|---|---|---|---|---|
(0/1+/2+) | (3+) | ||||||
Number of patients | 55 | (100) | 40 | (73) | 15 | (27) | |
Tumor size | NS | ||||||
T1 | 20 | (36) | 16 | (80) | 4 | (20) | |
T2 | 29 | (53) | 20 | (69) | 9 | (31) | |
T3 | 6 | (11) | 4 | (67) | 2 | (33) | |
Lymph node status | NS | ||||||
Negative | 33 | (60) | 24 | (73) | 9 | (27) | |
Positive | 22 | (40) | 16 | (73) | 6 | (27) | |
Grade | |||||||
Not determined | 3 | (5) | / | ||||
I | 12 | (22) | 29 | (83) | 6 | (17) | 0.060 |
II | 23 | (42) | |||||
III | 17 | (31) | 10 | (59) | 7 | (41) | |
Histological type | NS | ||||||
Ductal | 40 | (73) | 28 | (70) | 12 | (30) | |
Lobular | 7 | (13) | 5 | (71) | 2 | (29) | |
Other | 8 | (14) | 7 | (87) | 1 | (13) | |
ER status | 0.035 | ||||||
Positive | 42 | (76) | 34 | (81) | 8 | (19) | |
Negative | 13 | (24) | 6 | (46) | 7 | (54) | |
PR status | 0.022 | ||||||
Positive | 32 | (58) | 27 | (84) | 5 | (16) | |
Negative | 23 | (42) | 13 | (57) | 10 | (43) | |
Menopausal status | NS | ||||||
Premenopausal | 9 | (16) | 8 | (89) | 1 | (11) | |
Postmenopausal | 46 | (84) | 32 | (70) | 14 | (30) | |
Ki67 | 0.018 | ||||||
Low | 29 | (53) | 25 | (86) | 4 | (14) | |
High | 26 | (47) | 15 | (58) | 11 | (42) | |
p53 | 0.052 | ||||||
Low | 46 | (84) | 36 | (78) | 10 | (22) | |
High | 9 | (16) | 4 | (44) | 5 | (56) |
Immunohistochemistry
Fluorescent in situhybridization
Statistics
Cell line
Small interfering RNAs
Sequence 5'-3' | Location | |
---|---|---|
siRNAs | ||
siAP-2α ss | CCGAAUUUCCUGCCAAAGCdTdT | |
siAP-2α as | GCUUUGGCAGGAAAUUCGGdTdT | |
siAP-2γ ss | UUAAAUAUUCUGCCACUGGdTdT | |
siAP-2γ as | CCAGUGGCAGAAUAUUUAAdTdT | |
siYY1 ss | GAACUCACCUCCUGAUUAUdTdT | |
siYY1 as | AUAAUCAGGAGGUGAGUUCdTdT | |
RT-PCR primers | ||
AP-2α forward | AGCTGAATTTCTCAACCGACAAC | 1,013 (exon 5) |
AP-2α reverse | TAGCCAGGAGCATGTTTTTTCTT | 1,083 (exon 6) |
AP-2γ forward | CAGAAGAGCCAAATCGAAAAATG | 1,041 (exons 5–6) |
AP-2γ reverse | ATTCAACCCAATCTTGTCCAACTT | 1,107 (exon 6) |
ERBB2 forward | CTGAACTGGTGTATGCAGATTGC | 2,617 (exon 20) |
ERBB2 reverse | TTCCGAGCGGCCAAGTC | 2,699 (exon 21) |
Results
Combined high AP-2a and YY1 levels are associated with expression of ERBB2 in breast cancer tissue samples
ERBB2 expression (percentage) | ||||||||
---|---|---|---|---|---|---|---|---|
n
| 0/1+ | 2+ | 3+ | P value | ||||
AP-2α expression | 0.003 | |||||||
Low | 32 | 19 | (59) | 5 | (16) | 8 | (25) | |
High | 23 | 4 | (17) | 12 | (52) | 7 | (31) | |
YY1 expression | 0.318 | |||||||
Low | 30 | 15 | (50) | 7 | (23) | 8 | (27) | |
High | 25 | 8 | (32) | 10 | (40) | 7 | (28) | |
Combination | 0.016 | |||||||
AP-2α lo/YY1 lo | 26 | 14 | (54) | 4 | (15) | 8 | (31) | |
AP-2α lo/YY1 hi or AP-2α hi/YY1 lo | 10 | 6 | (60) | 4 | (40) | 0 | (0) | |
AP-2α hi/YY1 hi | 19 | 3 | (16) | 9 | (47) | 7 | (37) |
Levels of both AP-2a and YY1 proteins are inversely associated with ERBB2 amplification status in primary breast cancer samples
ERBB2 FISH (percentage) | ||||||
---|---|---|---|---|---|---|
n
| Negative | Positive | P value | |||
AP-2α expression | 0.017 | |||||
Low | 12 | 4 | (33) | 8 | (67) | |
High | 18 | 15 | (83) | 3 | (17) | |
YY1 expression | 0.029 | |||||
Low | 14 | 6 | (43) | 8 | (57) | |
High | 16 | 13 | (81) | 3 | (19) | |
Combination | 0.006 | |||||
AP-2α lo/YY1 lo | 11 | 3 | (27) | 8 | (73) | |
AP-2α lo/YY1 hi or AP-2α hi/YY1 lo | 4 | 4 | (100) | 0 | (0) | |
AP-2α hi/YY1 hi | 15 | 12 | (80) | 3 | (20) |
ERBB2 expression (percentage) | ||||||||
---|---|---|---|---|---|---|---|---|
n
| 0/1+ | 2+ | 3+ | P value | ||||
AP-2α expression | <0.001 | |||||||
Low | 18 | 14 | (78) | 4 | (22) | 0 | (0) | |
High | 16 | 2 | (12) | 11 | (69) | 3 | (19) | |
YY1 expression | 0.106 | |||||||
Low | 16 | 10 | (63) | 6 | (37) | 0 | (0) | |
High | 18 | 6 | (33) | 9 | (50) | 3 | (17) | |
Combination | 0.015 | |||||||
AP-2α lo/YY1 lo | 13 | 10 | (77) | 3 | (23) | 0 | (0) | |
AP-2α lo/YY1 hi or AP-2α hi/YY1 lo | 8 | 4 | (50) | 4 | (50) | 0 | (0) | |
AP-2α hi/YY1 hi | 13 | 2 | (15) | 8 | (62) | 3 | (23) |
Inhibition of AP-2 and YY1 downregulates ERBB2 expression in vitro
AP-2 and YY1 protein levels are correlated both in mammary cancer cell line and tissue specimens
AP-2α expression (percentage) | ||||||
---|---|---|---|---|---|---|
n
| Low | High | P value | |||
YY1 expression | <0.001 | |||||
Low | 30 | 26 | (87) | 4 | (13) | |
High | 25 | 6 | (24) | 19 | (76) |