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Pyroptosis may play an important role in the resistance of ovarian cancer (OC) to chemotherapy. However, the mechanism by which pyroptosis modulation can attenuate chemotherapy resistance has not been comprehensively studied in OC. Here, we demonstrated that RAS‐associated C3 botulinum toxin substrate 1 (RAC1) is highly expressed in OC and is negatively correlated with patient outcomes. Through cell function tests and in vivo tumor formation tests, we found that RAC1 can promote tumor growth by mediating paclitaxel (PTX) resistance. RAC1 can mediate OC progression by inhibiting pyroptosis, as evidenced by high‐throughput automated confocal imaging, the release of lactate dehydrogenase (LDH), the expression of the inflammatory cytokines IL‐1β/IL‐18 and the nucleotide oligomerization domain‐like receptor family pyrin domain‐containing 3 (NLRP3) inflammasome. Mechanically, RNA‐seq, gene set enrichment analysis (GSEA), coimmunoprecipitation (Co‐IP), mass spectrometry (MS), and ubiquitination tests further confirmed that RAC1 inhibits caspase‐1/gasdermin D (GSDMD)‐mediated canonical pyroptosis through the P21‐activated kinase 4 (PAK4)/mitogen‐activated protein kinase (MAPK) pathway, thereby promoting PTX resistance in OC cells. Finally, the whole molecular pathway was verified by the results of in vivo drug combination tests, clinical specimen detection and the prognosis. In summary, our results suggest that the combination of RAC1 inhibitors with PTX can reverse PTX resistance by inducing pyroptosis through the PAK4/MAPK pathway. [ABSTRACT FROM AUTHOR]

Purpose Angiotensin II (Ang II) has been shown to be involved in neurological disorders. Propofol demonstrated neuroprotective effects in neurons. Methods Mouse hippocampal HT22 cells were pre-treated with propofol, followed by Ang II treatment. The expression of synaptic proteins (synapsin I and PSD95) was examined. The effects of propofol on Ang II-induced NADPH oxidase expression and superoxide anion generation were examined. The effects of propofol on intracellular calcium concentration, the activation of calcium/calmodulin-dependent protein kinase II (CaMKII), and protein kinase C (PKC) were measured. Results Ang II reduced the expression of synapsin I and PSD95, which was attenuated by propofol. Ang II-induced effects were blocked by Ang II type 1 receptor (AT1 receptor) blocker. Ang II induced the expression of NADPH oxidase and caused superoxide anion accumulation, which were attenuated by propofol. In addition, propofol induced intracellular calcium concentration, and activated CaMKII as well as PKC[beta]. Importantly, the Ang II-mediated effects were diminished by [alpha]-tocopherol, and the propofol-mediated effects were alleviated by calcium chelator, CaMKII inhibitor, and PKC[beta] inhibitor. Conclusion Ang II, via AT1 receptor, induced oxidative stress and reduced the expression of synapsin I and PSD95 in HT22 cells. Propofol may increase synapsin I and PSD95 expression by inhibiting oxidative stress and stimulating calcium signaling pathway., Author(s): Xiaowei Ding [sup.1] , Xingzhu Ju [sup.2] , Yan Lu [sup.1] , Wei Chen [sup.1] , Jiaqiang Wang [sup.1] , Changhong Miao [sup.1] , Jiawei Chen [sup.1] Author Affiliations: [...]

Purpose: Precise radiological evaluation is pivotal for the management of platinum-sensitive recurrent ovarian cancer. We aimed to compare the value of [68 Ga]-FAPI and [18F]-FDG PET/CT for the detection of relapsed lesions. Methods: Twenty-nine suspected platinum-sensitive recurrent ovarian cancers were enrolled from January 2022 to July 2022. [18F]-FDG and [68 Ga]-FAPI PET/CT were obtained within 1 week for radiological evaluation. Treatment strategies, visual scores, and Eisenkop scores were recorded. A paired T test was used to compare differences between two scans. Sensitivity, specificity, PPV, NPV, and accuracy were also evaluated. Results: Up to 22 (75.86%) patients displayed inconsistency between two scans. Among them, 4 patients with negative [18F]-FDG imaging had measurable lesions in [68 Ga]-FAPI scans. The treatment strategies were changed in 5 patients (17.24%) due to discrepancies. Finally, 15 (35.7%) patients underwent surgeries, and 14 patients achieved complete resection, except for 1 patient who had milliarc residual disease. TBR, but not SUVmax, of [68 Ga]-FAPI was significantly higher than that of [18F]-FDG in recurrent lesions. Compared with [18F]-FDG, [68 Ga]-FAPI PET presented higher sensitivity and accuracy for lesion detection (96.30% vs. 49.07% and 97.40% vs. 63.87%, respectively). Additionally, [68 Ga]-FAPI PET showed a much higher visual score than [18F]-FDG PET (41 vs. 4), especially for peritoneal metastasis (35 vs. 1). [68 Ga]-FAPI PET also presented a larger tumor burden than [18F]-FDG according to the Eisenkop score (27 vs. 16, p = 0.025). Conclusions: [68 Ga]-FAPI was superior to [18F]-FDG PET/CT for the detection of recurrent lesions, which is pivotal for the individualized management of platinum-sensitive recurrent ovarian cancer. [ABSTRACT FROM AUTHOR]