journal contribution
posted on 2023-04-03, 15:03 authored by Yong Zhang, Yinhui Dong, Michael W. Melkus, Shutao Yin, Su-Ni Tang, Peixin Jiang, Kartick Pramanik, Wei Wu, Sangyub Kim, Min Ye, Hongbo Hu, Junxuan Lu, Cheng Jiang Figure S1 shows A. Concentration-dependent reduction of number of adherent LNCaP cells exposed to increasing concentrations of bufalin for 96 h; B. Representative photomicrograph of LNCaP cells exposed to bufalin at 2 concentrations for 48 h. Figure S2 shows A, Western blot detection of c-PARP, AR, PSA in LNCaP cells exposed to bufalin for 48 h. B, Western blot detection of c-PARP, AR, PSA in LNCaP cells exposed to bufalin for 24 h. Figure S3 shows gross appearance of paraffin embedded tumors (3rd-8th ranked for each group) selected for biomarker analyses. Figure S4 shows Western blot detection of HK2 (hexokinase-2), p-AKT and AKT in tumors from vehicle- or bufalin-treated mice. PC3 cell extract and LNCaP extract (LN) were used as positive control for HK2 and active AKT (p-AKT), respectively. Figure S5 shows a schematic integration of bufalin induced cellular effects to inhibit LNCaP prostate tumor growth.
Funding
Texas Tech University Health Sciences Center School of Pharmacy
Penn State Hershey College of Medicine
National Institutes of Health National Cancer Institute
History
ARTICLE ABSTRACT
Bufalin is a major cardiotonic compound in the traditional Chinese medicine, Chansu, prepared from toad skin secretions. Cell culture studies have suggested an anticancer potential involving multiple cellular processes, including differentiation, apoptosis, senescence, and angiogenesis. In prostate cancer cell models, P53-dependent and independent caspase-mediated apoptosis and androgen receptor (AR) antagonism have been described for bufalin at micromolar concentrations. Because a human pharmacokinetic study indicated that single nanomolar bufalin was safely achievable in the peripheral circulation, we evaluated its cellular activity within range with the AR-positive and P53 wild-type human LNCaP prostate cancer cells in vitro. Our data show that bufalin induced caspase-mediated apoptosis at 20 nmol/L or higher concentration with concomitant suppression of AR protein and its best-known target, PSA and steroid receptor coactivator 1 and 3 (SRC-1, SRC-3). Bufalin exposure induced protein abundance of P53 (not mRNA) and P21CIP1 (CDKN1A), G2 arrest, and increased senescence-like phenotype (SA-galactosidase). Small RNAi knocking down of P53 attenuated bufalin-induced senescence, whereas knocking down of P21CIP1 exacerbated bufalin-induced caspase-mediated apoptosis. In vivo, daily intraperitoneal injection of bufalin (1.5 mg/kg body weight) for 9 weeks delayed LNCaP subcutaneous xenograft tumor growth in NSG SCID mice with a 67% decrease of final weight without affecting body weight. Tumors from bufalin-treated mice exhibited increased phospho-P53 and SA-galactosidase without detectable caspase-mediated apoptosis or suppression of AR and PSA. Our data suggest potential applications of bufalin in therapy of prostate cancer in patients or chemo-interception of prostate precancerous lesions, engaging a selective activation of P53 senescence. Mol Cancer Ther; 17(11); 2341–52. ©2018 AACR.
