ABSTRACT
PARP inhibitors are a new class of drugs that target cancer cells with defective DNA repair. Early trials have shown that PARP inhibitors have achieved satisfactory results, but the mechanism of resistance after drug treatment has not been fully revealed. Therefore, it is necessary to find more targeted drugs in combination with PARP inhibitors to kill tumor cells. In this paper, several potential drugs that can synergistically kill ovarian cancer cells with PARP inhibitors were identified based on the combined drug screening of 379 small molecule compound libraries and PARP inhibitor Niraparib through cell proliferation experiments, colony-formation survival experiments and immunofluorescence staining experiments. The results showed that there are eight small molecule compounds with good combination effects, including two small molecule inhibitors STF-118804 and Disulfiram that have been reported to have combined effects with PARP inhibitors. We selected GW441756, an inhibitor of tropomyosin receptor kinase A (TrKA), to verify a variety of tumor cells and explore the preliminary mechanism. The combined therapeutic effects of the Niraparib and the TrKA inhibitor increased the sensitivity of tumor cells to PARP inhibitors (P < 0. 05). Mechanistically, the number of γH2AX foci in the combined treatment group was significantly increased (P<0. 05), indicating that the TrKA inhibitor hindered the DNA damage repair ability. Moreover, combination therapy significantly reduced the formation of RAD51 foci (P<0. 05), a marker of homologous recombination repair (HRR), suggesting that TrKA inhibitors may inhibit DNA damage repair by inhibiting HRR efficiency. Overall, these results suggest that TrKA inhibitor can be used as a potential drug to kill ovarian cancer cells in combination with PARP inhibitors.
ABSTRACT
The influence of reward on behavior is one of the hottest research subjects in psychological research. Reward-induced motivation promotes the performance of the participants. In the field of emotional processing, the reward can influence the individual's processing of emotional information, but previous studies have not directly discussed the effect of reward on emotional regulation. The present study focused on whether emotional regulation ability would be improved under the reward condition. Experiment 1 and 2 investigated the effect of reward on negative emotional down-regulation and positive emotional up-regulation respectively. In experiment 1, monetary reward stimulation was introduced on the basis of the classic emotion regulation paradigm, and the subjects were asked to regulate their negative emotion under the condition of reward or non-reward, and evaluate their current affective state subsequently. Similar to experiment 1, experiment 2 required subjects to up-regulate positive emotions under the condition of reward or non-reward. The results of experiment 1 showed that under the reward condition, the negative emotional regulation effect was significantly higher than that under the non-reward condition (P < 0.05). Experiment 2 also showed that compared to non-reward condition, the positive emotion regulation effect was significantly increased under the reward condition (P < 0.05). These results suggested that compared to non-reward condition, participants can regulate their emotion better under the condition of the reward. It is worth noting that the results of Experiment 1 and 2 may be caused by the incentive motivation induced by monetary stimulus, or the positive emotion caused by positive value of money information. Therefore, we carried out experiment 3 and 4 to explore whether the positive emotions induced by money itself can influence the emotional regulation of individuals. In experiment 3, the money pictures were used to induce the positive emotions of subjects, and the subjects were asked to regulate their negative emotion after the presence of money pictures or non-monetary picture, and evaluate their current affective state subsequently. Similarly, experiment 4 required subjects to regulate their positive emotion after the presence of money pictures. The results of experiment 3 and 4 showed that there was no significant difference in the subjects' scores of emotional pleasantness after the presence of money pictures or non-monetary picture (P < 0.05). The results of experiment 3 and 4 excluded the possibility that the positive emotions induced by simple money stimulus pictures could improve individual's emotional regulation ability. To sum up, the improvement of individual's emotional regulation ability was indeed driven by reward motivation in this study, that is, the motivation induced by reward can effectively promote individual's emotional regulation ability.