Lncap

Human prostate cancer cell lines, prostatic carcinoma-3 (PC-3) (low expression of PSMA), and lymph node carcinoma of the prostate (LNCaP) (high expression of PSMA) were obtained from the RIKEN Cell Bank (Tsukuba, Japan). Cells were maintained in a culture medium, Roswell Park Memorial Institute 1640 medium (FUJIFILM Wako Pure Chemical Corporation, Osaka, Japan), supplemented with 10% heat-inactivated fetal bovine serum (Gibco) and 1% penicillin-streptomycin (FUJIFILM Wako Pure Chemical). The medium for LNCaP was supplemented with 1% sodium pyruvate (FUJIFILM Wako Pure Chemical) in a culture medium. Cells were seeded in 24-well plates (5 × 10⁴/well) and cultured for 2 days. After washing twice with phosphate-buffered saline (PBS) (−), the culture medium was changed to Hanks’ balanced salt solution (+). After treatment with [²¹¹At]PSMA1 or [²¹¹At]PSMA5 (approximately 30–50 kBq/well), cells were washed twice with PBS (–). After washing, all cells were lysed with 0.1 N sodium hydroxide, and the radioactivity of the cells was calculated using a 2480 Wizard² γ counter (Perkin Elmer, MA, USA). Protein levels were measured using a plate reader (MultiScan FC, Thermo Fisher) and the BCA Protein Assay Kit (FUJIFILM Wako Pure Chemical). Uptake (%uptake/mg protein) was compared between PC-3 and LNCaP cells at 30 min after incubation with [²¹¹At]PSMA1 or [²¹¹At]PSMA5.