8202

NCOA3

nuclear receptor coactivator 3;NCOA3;nuclear receptor coactivator 3

CBP-interacting protein|amplified in breast cancer 1 protein|class E basic helix-loop-helix protein 42|receptor-associated coactivator 3|steroid receptor coactivator protein 3|thyroid hormone receptor activator molecule 1

20q12

protein-coding

INTRODUCTION: Nuclear receptor coactivator amplified in breast cancer-1 (AIB1), a new oncogenic coactivator, is commonly overexpressed and amplified in variety of human cancers. However, the expression of AIB1 in papillary thyroid carcinoma (PTC), the major histologic type of thyroid cancer, and its clinical significance are still unclear. MATERIALS AND METHODS: AIB1 expression in PTC was examined by immunohistochemistry using tissue microarrays comprised of 90 primary PTC, 46 matched lymph node, and 20 normal thyroid tissue specimens in this study. RESULTS: In the normal thyroid specimens, AIB1 expression was either absent or at low levels. In contrast, AIB1 overexpression was detected in 50 of 83 (60.2 %) primary PTC specimens. Up-regulated AIB1 was evident in 39 of 46 (73.5 %) matched lymph nodes. Overexpression of AIB1 was observed more frequently in PTCs with lymph node metastasis [N1a/N1b, 39/46 (73.5 %)] versus PTCs without lymph node metastasis [N0, 14/34 (41.2 %)]. Furthermore, high-level AIB1 expression was only observed in the lymph node-positive specimens. Moreover, we found no correlation between AIB1 expression and ER expression in PTC tissues. CONCLUSIONS: Our findings suggest that overexpression of AIB1 may be a biomarker for tumorigenesis and progression of PTC and may play an important role in its acquisition of a metastatic phenotype.

AIB1, a candidate oncogene in breast cancer, is commonly amplified and overexpressed in several types of human cancers. In this study, expression and amplification of AIB1 in nasopharyngeal carcinoma (NPC) were studied by immunohistochemical analysis and fluorescence in situ hybridization using tissue microarrays, including 80 specimens of NPC and 20 specimens of nonneoplastic nasopharyngeal mucosa. In this NPC cohort, overexpression and amplification of AIB1 was detected in 36 (51%) of 71 and 3 (7%) of 46 NPCs, respectively. Overexpression of AIB1 was observed more frequently in NPCs in late T stages (T3/T4, 24/35 [69%]) than in earlier stages (T1/T2, 12/36 [33%]; P < .05). In addition, 18 (72%) of 25 NPCs with lymph node metastasis (N1-3) showed overexpression of AIB1; the frequency was significantly higher than that in NPCs without node metastasis (N0, 18/49 [39%]; P < .05). These findings suggest that overexpression of AIB1 in NPCs may be important in the acquisition of an invasive and/or metastatic phenotype.

BACKGROUND: The amplified in breast cancer 1 (AIB1) gene has been considered to play an oncogenic role in human cancers, but its clinical/prognostic significance in non-small-cell lung cancer (NSCLC) is still unclear. PATIENTS AND METHODS: The methods of immunohistochemistry and FISH were utilized to examine protein expression and amplification of AIB1 in 230 informative surgically resected NSCLCs and in 30 samples of normal lung tissues. RESULTS: Overexpression and amplification of AIB1 were found in 48.3% and 8.2% of NSCLCs, respectively. AIB1 overexpression was associated with AIB1 gene amplification and cell proliferation but not related to estrogen receptor (ER)-alpha, ER-beta, progesterone receptor or androgen receptor status. A positive correlation between AIB1 overexpression and an ascending pathologic node stage in lung adenocarcinoma (ADC) was observed (P = 0.043). Univariate survival analysis demonstrated a significant association of AIB1 overexpression with shortened patient survival, especially for those with stage III disease (P < 0.001). Importantly, AIB1 expression was evaluated as the most significant predictor for survival in multivariate analysis (hazards ratio = 2.069, P < 0.001). CONCLUSION: Overexpression of AIB1 might provide a selective advantage for lymph node metastasis of lung ADC and serve as a useful biomarker for poor prognosis for NSCLC patients.

Steroid receptor coactivator-3 (SRC-3)/AIB1 is a member of the p160 nuclear receptor coactivator family involved in development and cell cycle progression. We previously showed that SRC-3/AIB1 is required for prostate cancer cell proliferation and survival. Here, we reported that the elevated SRC-3/AIB1 expression is significantly correlated with human prostate cancer seminal vesicle invasion and lymph node metastasis. Furthermore, SRC-3/AIB1 is associated with increased prostate cancer cell migration and invasion. SRC-3/AIB1 is required for focal adhesion turnover and focal adhesion kinase activation. In addition, SRC-3/AIB1 directly regulates transcription of matrix metalloproteinase (MMP)-2 and MMP-13 through its coactivation of AP-1 and PEA3. Taken together, these data suggest that SRC-3/AIB1 plays an essential role in prostate cancer cell invasion and metastasis.

INTRODUCTION: Nuclear receptor coactivator amplified in breast cancer-1 (AIB1), a new oncogenic coactivator, is commonly overexpressed and amplified in variety of human cancers. However, the expression of AIB1 in papillary thyroid carcinoma (PTC), the major histologic type of thyroid cancer, and its clinical significance are still unclear. MATERIALS AND METHODS: AIB1 expression in PTC was examined by immunohistochemistry using tissue microarrays comprised of 90 primary PTC, 46 matched lymph node, and 20 normal thyroid tissue specimens in this study. RESULTS: In the normal thyroid specimens, AIB1 expression was either absent or at low levels. In contrast, AIB1 overexpression was detected in 50 of 83 (60.2 %) primary PTC specimens. Up-regulated AIB1 was evident in 39 of 46 (73.5 %) matched lymph nodes. Overexpression of AIB1 was observed more frequently in PTCs with lymph node metastasis [N1a/N1b, 39/46 (73.5 %)] versus PTCs without lymph node metastasis [N0, 14/34 (41.2 %)]. Furthermore, high-level AIB1 expression was only observed in the lymph node-positive specimens. Moreover, we found no correlation between AIB1 expression and ER expression in PTC tissues. CONCLUSIONS: Our findings suggest that overexpression of AIB1 may be a biomarker for tumorigenesis and progression of PTC and may play an important role in its acquisition of a metastatic phenotype.