Doroshow James H, Gaur Shikha
Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
React Oxyg Species (Apex). 2020 Mar;9(26):81-94.
To examine whether combining arsenic trioxide (ARS) and pamidronate (PAM), anticancer drugs that generate reactive oxygen species (ROS), enhanced targeting of redox sensitive growth signals, we studied cloning efficiency, protein tyrosine phosphatase (PTPase) activity, and epidermal growth factor receptor (EGFR) phosphorylation in DU-145 and PC-3 human prostate cancer cells in response to treatment with ARS and/or PAM for 24 h. IC concentrations in a clonogenic assay for ARS and PAM were 9 and 20 μM, respectively, in DU-145 cells; and 2 and 12 μM, in PC-3 cells. When combined, ARS and PAM demonstrated additive cytotoxicity in the DU-145 line (combination index [CI] of 1.10) and synergy for PC-3 cells (CI of 0.86). ARS (20 μM for 24 h) inhibited PTPase activity by 36 ± 7 %, p < 0.05 vs. untreated controls, in DU-145 cells; and by 58 ± 8%, p < 0.05, in the PC-3 line. PAM (20 μM for 24 h) decreased PTPase activity by 24 ± 9%, p = 0.06, and 8 ± 1%, p < 0.01, in DU-145 and PC-3 cells, respectively. Combining ARS and PAM significantly inhibited PTPase activity in both cell lines at lower concentrations of each drug. Pretreatment with -acetyl-L-cysteine reversed ARS- and PAM-induced inhibition of PTPase activity. PTPase inhibition by ARS and/or PAM treatment in both DU-145 and PC-3 cells was associated with prolonged EGFR activation. These experiments demonstrate additive or synergistic cell killing by the ARS/PAM combination in DU-145 or PC-3 cells and suggest that enhanced antitumor activity may be related to alterations in receptor tyrosine kinase signaling that occur, in part, due to ROS-mediated PTPase inhibition.
为了研究三氧化二砷（ARS）和帕米膦酸盐（PAM）这两种能产生活性氧（ROS）的抗癌药物联合使用时，是否增强了对氧化还原敏感生长信号的靶向作用，我们研究了DU - 145和PC - 3人前列腺癌细胞在接受ARS和/或PAM处理24小时后的克隆效率、蛋白酪氨酸磷酸酶（PTPase）活性以及表皮生长因子受体（EGFR）磷酸化情况。在DU - 145细胞中，ARS和PAM克隆形成试验的IC浓度分别为9 μM和20 μM；在PC - 3细胞中分别为2 μM和12 μM。联合使用时，ARS和PAM在DU - 145细胞系中表现出相加细胞毒性（联合指数[CI]为1.10），在PC - 3细胞中表现出协同作用（CI为0.86）。在DU - 145细胞中，ARS（20 μM，处理24小时）使PTPase活性抑制36 ± 7%，与未处理对照相比，p < 0.05；在PC - 3细胞系中抑制58 ± 8%，p < 0.05。PAM（20 μM，处理24小时）在DU - 145和PC - 3细胞中分别使PTPase活性降低24 ± 9%，p = 0.06，以及8 ± 1%，p < 0.01。联合使用ARS和PAM在每种药物较低浓度时就能显著抑制两种细胞系中的PTPase活性。用N - 乙酰 - L - 半胱氨酸预处理可逆转ARS和PAM诱导的PTPase活性抑制。在DU - 145和PC - 3细胞中，ARS和/或PAM处理导致的PTPase抑制与EGFR的持续激活相关。这些实验证明了ARS/PAM联合使用在DU - 145或PC - 3细胞中具有相加或协同的细胞杀伤作用，并表明增强的抗肿瘤活性可能与受体酪氨酸激酶信号传导的改变有关，这种改变部分是由于ROS介导的PTPase抑制所致。
