Pleiotropic effects of probenecid on three-dimensional cultures of prostate cancer cells

• Published in: Life sciences (1973) Vol. 278; p. 119554
• Main Authors: Uwada, Junsuke, Mukai, Shoichiro, Terada, Naoki, Nakazawa, Hitomi, Islam, Mohammad Sayful, Nagai, Takahiro, Fujii, Masato, Yamasaki, Koji, Taniguchi, Takanobu, Kamoto, Toshiyuki, Yazawa, Takashi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.08.2021; Elsevier BV
• Subjects: 3D culture; Anchorages; Cancer therapies; Cell culture; Chemoresistance; Chemosensitization; Chemotherapy; Cisplatin; Colonies; Compaction; Doxorubicin; Efflux; Focal adhesion kinase; Growth inhibition; Kinases; Multicellular tumor spheroid; Multicellular tumor spheroids; Multidrug resistance; Probenecid; Prostate cancer; Spheroids; Target recognition; Tumor cell lines; 3D culture; Focal adhesion kinase; Prostate cancer; Multicellular tumor spheroid; Chemoresistance; Probenecid
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2021.119554

Chemoresistance remains a persistent challenge in advanced prostate cancer therapy. Probenecid reportedly inhibits multiple drug-efflux transporters; hence, it can be employed as a potential sensitizer for chemotherapy. In the present study, we evaluated the effects of probenecid on three-dimensional (3D)-cultures of prostate cancer cells. Prostate cancer cell lines, 22Rv1 and PC-3 were cultured as multicellular tumor spheroids. The effects of probenecid were evaluated using the MTT assay for viability, microscopy for spheroid size, and soft agar colony formation assay for anchorage-independent growth. The 3D-cultured 22Rv1 cells were less sensitive to cisplatin and doxorubicin than two-dimensional (2D) cell culture. Co-administration of probenecid at a low (100 or 300 μM), but not high (500 μM), concentration increased the sensitivity to cisplatin or doxorubicin in 22Rv1 spheroids. Probenecid increased the expression of ABCG2, a multidrug resistance transporter, in a dose-dependent manner. Furthermore, treatment with probenecid alone reduced the growth of 22Rv1 spheroids. Conversely, probenecid inhibited spheroid compaction rather than growth inhibition in 3D-cultured PC-3 cells. Moreover, probenecid inhibited colony formation of 22Rv1 and PC-3 cells in soft agar, as well as downregulated focal adhesion kinase (FAK), a crucial factor in anchorage-independent growth. In 3D-cultured prostate cancer cells, probenecid demonstrated pleiotropic effects such as chemosensitization, growth suppression, inhibition of spheroid compaction, and suppression of anchorage-independent growth. Elucidating the detailed mechanism underlying these probenecid actions could result in the identification of novel therapeutic targets toward the advanced prostate cancer.