Lee, SeungBaek

Abstract Prostate-Specific Antigen (PSA) is a well-known diagnosis maker for detecting prostate cancer (PCa) using a serum test. However, PSA testing remains controversial because it shows a high false-positive rate and lacks the sensitivity of PCa patients with low PSA levels, although patients have metastasis. Recently, we found an E3 ubiquitin ligase, WSB1, highly expressed in PCa patients with low PSA levels. Overexpressed WSB1 is found in various human cancers, such as pancreatic cancer, lung cancer, breast cancer, and PCa. Especially with PCa, WSB1 is highly expressed in metastatic PCa. Using RNA seq. database from PCa patients (65 primaries and 25 metastasis), we found that WSB1 is highly expressed in 90% (9/10) of patients among ten primary patients with normal PSA levels and 100% (6/6) of patients among six metastasis patients with normal PSA levels. WSB1 expression shows a significant correlation with aggressive PCa progression. Furthermore, WSB1 can secrete into cell culture media like PSA. Therefore, we suggest that WSB1 could be a highly efficient marker combined with PSA for PCa diagnosis as well as being developed as a screening test for the early detection of PCa in the high-risk group. Citation Format: SeungBaek Lee, JungJin Kim. The development of a highly efficient diagnostic marker combined with PSA of prostate cancer (PCa) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 462.

Abstract Cell division cycle 20 (Cdc20) is the main activator of the anaphase-promoting complex (APC/C) and is essential in mitosis regulation. Recently, several papers reported that Cdc20 is highly conserved in various human cancers such as pancreatic, prostate, and lung cancers yet its relation to breast cancer is unclear. Here, we found that Cdc20 gene was highly expressed in three different TNBC cell lines among the mitosis regulator genes through the National Center for Biotechnology Information (NCBI). High Cdc20 level is positively correlated with metastasis-free patient survival and relapse-free patient survival in breast cancer patient database. We also checked that Cdc20 is highly conserved in all TNBC cell lines compared to other subtypes of breast cancer cell lines and the knockdown of this gene decreased cell growth and invasion in TNBC. Furthermore, we investigated that the mitosis-related small molecule protein kinase inhibitors such as VX-680, ZM447439, BI2536, and apcin also inhibit tumor cell proliferation, migration, and invasion. In conclusion, Cdc20 has an important role in TNBC cell growth and metastasis. Cdc20 might serve as a potential marker of disease progression and as a principal potential therapeutic target. Also, mitosis-related protein kinase inhibitors are additional potential therapy to suppress cancer cell progression and invasion in TNBC effectively. Citation Format: Chaeun Song, SeungBaek Lee. Mitotic inhibitors suppresses tumor formation and metastasis of triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2890.