An in vitro redox adaptation model for metastatic prostate cancer: Establishing, characterizing and Cabazitaxel response evaluating

Abstract

Little is known about the redox-adapted cancer cells for understanding their pharmacologically targetable features and chemotherapeutic responses. Thus, we present the first in vitro redox adaptation model for metastatic prostate cancer (mPC), LNCaP-hydrogen peroxide resistant (LNCaP-HPR), with enhanced oxidative stress resistance accompanying poor Cabazitaxel response. After establishing, the cells were characterized by comparing the viability, death, oxidative stress, total glutathione (GSH) levels and the mRNA and protein levels of the redox-sensitive transcription factors responsible for the adaptation, Nrf-2, NF-κB and HIF-1α. Then, the apoptotic effect of Cabazitaxel was evaluated in LNCaP mPC, LNCaP-HPR and C4-2 metastatic castration-resistant (mCRPC) cells. In response to H 2 O 2 , viability, oxidative stress and the total GSH levels of LNCaP-HPR cells have confirmed the oxidative stress resistance. Nrf-2, NF-κB and HIF-1α were upregulated in LNCaP-HPR cells, not in LNCaP, confirming that resistant cells were much less affected by exogenous oxidative stress. Unlike LNCaP, LNCaP-HPR cells were less sensitive to Cabazitaxel, as closer to the response of C4-2 mCRPC cells, indicating that redox adaptation decreased Cabazitaxel response. This is the first evaluated association between redox adaptation and poor Cabazitaxel response, suggesting that in vitro Cabazitaxel efficiency is affected by PC cells' endogenous oxidative stress tolerance.

Association between the apoptotic effect of Cabazitaxel and its pro-oxidant efficacy on the redox adaptation mechanisms in prostate cancer cells with different resistance phenotypes

“…Moreover, after the adaptation, the Cab response of the redox-adapted cells also resembled those of more aggressive C4–2 mCRPC cells, unlike LNCaP. 12 This time, the association between the apoptotic effect of Cab and its pro-oxidant efficacy on the redox adaptation mechanisms in PC cells has been evaluated. Moreover, being reported that the oxidative stress states of PC cells were directly proportional to the aggressive characteristics, 16 we used four cells with different aggressivity, including LNCaP mPC, redox-adapted LNCaP-HPR mPC, C4–2 mCRPC, and RWPE-1 benign cells.…”

“…The C4–2 mCRPC cells were kindly provided by Dr. Thalmann from the Urology Department, University of Bern. LNCaP-H 2 O 2 resistant-(HPR) cells were established by continuously applying 50 μM H 2 O 2 to parental LNCaP cells as we reported previously, 12 and the H 2 O 2 concentration to which the cells adapt was added to the complete media. The culture conditions were previously reported for LNCaP, LNCaP-HPR, and C4–2 cells.…”

“…The culture conditions were previously reported for LNCaP, LNCaP-HPR, and C4–2 cells. 12 RWPE-1 cells were cultured using 1X keratinocyte SFM. The cultures were maintained at 37°C and 5% CO 2 in a humid incubator (Panasonic, Japan).…”

“… 10 , 11 Thus, redox adaptation can alter the drug sensitivity, as we previously reported the reduced apoptotic effect of Cab in the first introduced mPC redox adaptation model. 12 We showed that the process is mainly driven by the increase of ROS tolerance of the cells due to some biological differences between the oxidative stress-resistant and sensitive ones, such as the upregulation of the redox adaptation modulators, including nuclear factor erythroid-2-related factor-2 (Nrf-2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and hypoxia-inducible factor-1α (HIF-1α). Consequently, the Cab sensitivity of redox-adapted mPC (LNCaP-HPR) cells decreased compared to the sensitive ones.…”

“…Consequently, the Cab sensitivity of redox-adapted mPC (LNCaP-HPR) cells decreased compared to the sensitive ones. 12 …”