CEBPD表現在膀胱癌病人的預後意義

李威明^1,2,3、吳文正^1,3,4、李經家^1,3、柯宏龍^1,3、韋又菁⁵、葉信志^1,3,4、李香瑩^3,4

李健逢⁶、黃俊農^3,4、黃俊雄^1,3

高雄醫學大學附設中和紀念醫院泌尿部¹; 衛生福利部屏東醫院泌尿科²; 高雄醫學大學醫學系泌尿學科³; 高雄市立大同醫院泌尿科⁴; 高雄市立大同醫院病理科⁵; 奇美醫學中心病理部⁶

The prognostic significance of CEBPD expression in patients with bladder  urothelial carcinoma

Wei-Ming Li ^1,2,3, Wen-Jeng Wu ^1,3,4, Ching-Chia Li ^1,3, Hung-Lung Ke ^1,3, Yu-Ching Wei⁵, Hsin-Chin Yen^1,3,4, Hsiang-Ying Lee^3,4, Chien-Feng Li⁶, Chun-Nung Huang ^3,4, Chun-Hsiung Huang ^1,3

¹Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan

² Department of Urology, Pingtung Hospital, Ministry of Health and Welfare, Executive Yuan, Pingtung, Taiwan

³ Department of Urology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan

⁴ Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan

⁵ Department of Pathology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan

⁶Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan

Purpose: CCAAT/enhancer binding protein delta (CEBPD) is a transcription factor implicated in physiological processes such as cell differentiation, metabolism, inflammation, growth arrest and cell death, yet its role in urothelial carcinoma (UC) remains unclear. Through array-based genomic hybridization (aCGH) on 40 bladder UC samples, amplification of 8q11.21 was associated with cancer metastasis. Moreover, among the candidate genes harbored in 8q11.21, we identified that CEBPD mRNA expression was the most significantly upregulated in tumor samples featuring gains on 8q11.21, suggesting amplification-driven expression. Thus, we aimed to investigate the roles of CEBPD expression and its prognostic value in bladder UC in our cohort.

Materials and Methods: Clinicopathological data, fresh and formalin-fixed paraffin-embedded bladder UC tissues were analyzed retrospectively. We determined CEBPD expression using FISH qRT-PCR and immunohistochemical staining. CEBPD expression correlated with clinicopathological features and patient outcomes, including metastasis-free survival (MFS) and cancer-specific survival (CSS). We also investigated the biological effects of CEBPD using UC-derived cell lines. Statistical analyses were performed using Pearson’s chi-square test, Kaplan-Meier estimates of DSS and MFS, and the Cox proportional hazards model.

Results: By performing CEBPD-specific FISH and immunohistochemistry on 295 bladder UCs, we confirmed CEBPD amplification strongly correlated with CEBPD immunohistochemical overexpression (p<0.001). Moreover, both were associated with aggressive clinicopathologic features and worse MFS and CSS. Interestingly, CEBPD knockdown suppressed cell proliferation, migration and, most significantly, cell invasion ability in UC cells. The latter phenotype is attributed to downregulation of MMP2 as identified by RT² Profiler PCR array. Moreover, using promoter reporter assay and chromatin immunoprecipitation assay, we found that expression of CEBPD significantly enhanced MMP2 expression and transcriptional activation by directly binding to its promoter region.

Conclusions: CEBPD amplification is a mechanism driving increased mRNA and protein expression that confers aggressiveness in bladder UC through MMP2-mediated cell invasiveness. High CEBPD immunoexpression independently predicted worse prognosis, suggesting it could play roles in clinical risk stratification and therapy decisions.