Can probability of genetic mutation be an indicator of clinical relevance?

Nucleophosmin/B23 is a negative regulator of estrogen receptor α expression via AP2γ in endometrial cancer cells

Endometrial cancers expressing estrogen and progesterone receptors respond to hormonal therapy. The disappearance of steroid hormone receptor expression is common in patients with recurrent disease, ultimately hampering the clinical utility of hormonal therapy. Here, we demonstrate for the first time that nucleophosmin (NPM1/B23) suppression can restore the expression of estrogen receptor α (ESR1/ERα) in endometrial cancer cells. Mechanistically, B23 and activator protein-2γ (TFAP2C/AP2γ) form a complex that acts as a transcriptional repressor of ERα. Our results indicate that B23 or AP2γ knockdown can restore ERα levels and activate ERα-regulated genes (e.g., cathepsin D, EBAG9, and TFF1/pS2). Moreover, AP2γ knockdown in a xenograft model sensitizes endometrial cancer cells to megesterol acetate through the upregulation of ERα expression. An increased immunohistochemical expression of AP2γ is an adverse prognostic factor in endometrial cancer. In summary, B23 and AP2γ may act in combination to suppress ERα expression in endometrial cancer cells. The inhibition of B23 or AP2γ can restore ERα expression and can serve as a potential strategy for sensitizing hormone-refractory endometrial cancers to endocrine therapy.

Increased nucleophosmin expression is a strong predictor of recurrence and prognosis in patients with N0M0 upper tract urothelial carcinoma undergoing radical nephroureterectomy

PURPOSE

We aimed to evaluate whether increased nucleophosmin expression predicts recurrence and survival in upper tract urothelial carcinoma (UTUC).

METHODS

Specimens from 101 patients with N0M0 UTUC undergoing radical nephroureterectomy were evaluated. Nucleophosmin expression was determined immunohistochemically and categorized into two groups according to nucleophosmin staining intensity. The association between nucleophosmin expression and various clinicopathological factors including Ki-67 expression was analyzed. Multivariate analyses were performed to identify the independent predictors of extraurothelial recurrence and cancer-specific survival.

RESULTS

High nucleophosmin expression was significantly correlated with tumor location, pT ≥3, lymphovascular invasion, lymph node metastasis, and high Ki-67 expression. Patients whose tumors demonstrated high nucleophosmin expression had a significantly higher rate of extraurothelial recurrence and a lower survival rate than those with low nucleophosmin expression. Multivariate analysis showed that pT ≥3, lymph node metastasis, high nucleophosmin expression, and high Ki-67 expression were independent predictors of extraurothelial recurrence. When patients were stratified into three groups according to the number of risk factors, the 2-year extraurothelial recurrence-free survival rates were 92.9% in patients with 0 or 1 risk factor, 76.5% in patients with 2 risk factors, and 9.1% in patients with 3 or 4 risk factors. Regarding cancer-specific survival, lymphovascular invasion and high nucleophosmin expression were independent predictors.

CONCLUSIONS

Increased nucleophosmin expression was a strong predictor of extraurothelial recurrence and cancer-specific survival in patients with N0M0 UTUC undergoing radical nephroureterectomy. Our risk stratification models integrating nucleophosmin expression may provide valuable information on disease recurrence and prognosis.