Photothermal therapy( PTT) is an extremely promising tumor therapeutic modality.H owever,e xcessive heat inevitably injures normal tissues near tumors,a nd the damage to cancer cells caused by mild hyperthermia is easily repaired by stress-induced heat shock proteins (HSPs). Thus, maximizing the PTT efficiency and minimizing the damage to healthy tissues simultaneously by adopting appropriate therapeutic temperatures is imperative.H erein, an innovative strategy is reported:f erroptosis-boosted mild PTT based on as ingle-atom nanozyme (SAzyme). The Pd SAzyme with atom-economical utilization of catalytic centers exhibits peroxidase (POD) and glutathione oxidase (GSHOx) mimicking activities,a nd photothermal conversion performance,w hich can result in ferroptosis featuring the up-regulation of lipid peroxides (LPO) and reactive oxygen species (ROS). The accumulation of LPO and ROSprovides apowerfulapproach for cleaving HSPs,which enables Pd SAzyme-mediated mildtemperature PTT.

Background: Abberant aryl hydrocarbon receptor (AhR) expression and AhR pathway activation are involved in gastric carcinogenesis. However, the relationship between AhR pathway activation and gastric cancer progression is still unclear. In present study, we used 2,3,7,8-tetrachlorodibenzopara-dioxin (TCDD), a classic and most potent ligand of AhR, to activate AhR pathway and investigated the effect of AhR pathway activation on human gastric cancer AGS cell invasion and explored the corresponding mechanism.

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AIM:To determine the functional significance of aryl hydrocarbon receptor (AhR) in gastric carcinogenesis, and to explore the possible role of AhR in gastric cancer (GC) treatment.

BackgroundGastrokine-1 (GKN1), a secreted protein, is specifically expressed in gastric mucosa to protect and maintain the integrity of gastric epithelium. The present study investigated differential expression of GKN1 in normal, precancerous, and cancerous gastric tissues, and explored the biological functions of GKN1 protein in gastric cancer cells.MethodsRT-PCR, Western blot, and immunohistochemistry were performed to detect GKN1 expression in normal, precancerous, cancerous gastric tissues and seven gastric cancer cell lines. Gene transfection was used to restore GKN1 expression in gastric cancer AGS cells. Phenotypic changes (i.e., cell viability, apoptosis, cell cycle modulation, and sensitivity of gastric cancer cells to fluorouracil (5-FU)) were assayed in the transfected cells. DNA microarrays were used to analyze expression changes of apoptosis-related genes.ResultsSignificant downregulation or absence of GKN1 expression in seven gastric cancer cell lines were detected and progressive decrease of GKN1 expression from normal mucosa, precancerous tissue, to cancer tissues was observed. Moreover, restoration of GKN1 expression suppressed gastric cancer cell viability and induced the cells to undergo apoptosis. GKN1 expression also enhanced tumor cell sensitivity to 5-FU treatment. Moreover, it was found that GKN1 expression in AGS cells modulated expression of 19 apoptosis-related genes.ConclusionsExpression of GKN1 is progressively lost from normal mucosa, precancerous to cancerous gastric tissues, while restoration of GKN1 expression induces gastric cancer cells to undergo apoptosis, and enhances sensitivity of gastric cancer cells to 5-FU-induced apoptosis.