CD200-CD200R affects cisplatin and paclitaxel sensitivity by regulating cathepsin K-mediated p65 NF-κB signaling in cervical cancer.

Background: CD200-CD200R plays a critical role in regulating the human tumor microenvironment, but its role in cervical cancer remains unclear. Methods: A total of 62 paraffin blocks of tumor tissues were collected from cervical cancer patients. Expression of CD200 and cathepsin K (CTSK) in cancer tissues and para-cancerous tissues was analyzed by immunohistochemistry. Stably transfected CD200 cells were established in HeLa and SiHa cells. Human THP-1 monocytes were induced to differentiate into M2 macrophages. HeLa and SiHa cells were cultured in conditioned medium from M2 macrophages to observe the effects of CD200-CD200R on invasion, CTSK, p65NF-κB, and cisplatin or paclitaxel sensitivity in cervical cancer cells. HeLa cells were injected to induce xenograft tumors in mice, and a CTSK inhibitor, MK-0822, was used to confirm the regulation of CTSK and paclitaxel sensitivity by CD200-CD200R in vivo. Results: A significant decrease in CD200 and CTSK expression was found in tumor cancer tissues compared with para-cancerous tissues. Only CD200 overexpression did not affect cervical cell invasion, but CD200-CD200R could enhance the cell invasion and resistance to cisplatin or paclitaxel. Meanwhile, expression of CTSK and p-p65NF-κB in cancer cells stably transfected with CD200 was obviously increased after culture in conditioned medium from M2 macrophages compared with transfection with the plasmid control. In vivo, CTSK inhibition significantly suppressed the effects of CD200-CD200R overexpression on the response to paclitaxel by suppressing the CTSK-mediated NF-κB pathway. Conclusions: CD200-CD200R regulates CTSK-mediated NF-κB pathway to affect cisplatin or paclitaxel sensitivity in cervical cancer, which provides a possible immunotherapeutic target and combination strategy for advanced cervical cancer.

Tricin attenuates diabetic retinopathy by inhibiting oxidative stress and angiogenesis through regulating Sestrin2/Nrf2 signaling.

To explore the potential function of tricin in diabetic retinopathy (DR) and investigate whether Sestrin2 is closely involved in DR. A single intraperitoneal injection of streptozotocin-induced diabetes model in Sprague-Dawley rats and a high glucose-induced retinal epithelial cell model in ARPE-19 cells were established. The retinas were removed and examined by hematoxylin-eosin (HE) staining and dihydroethidium (DHE) staining. The proliferation ability and reactive oxygen species (ROS) level of ARPE-19 cells were detected by 5-ethynyl-2'-deoxyuridine (EdU) and flow cytometry. Then, the content of superoxide dismutase (SOD), malonaldehyde (MDA), and glutathione peroxidase (GSH-Px) in serum or cell supernatant was tested using enzyme linked immunosorbent assay (ELISA). In addition, the expression of Sestrin2, nuclear factor erythroid-2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), platelet endothelial cell adhesion molecule-1 (CD31), and vascular endothelial growth factor receptor 2 (VEGFR2) in retina tissue or ARPE-19 cells were validated through western blot and immunofluorescence assays. With the increase of MDA and ROS concentration, Sestrin2 expression was downregulated significantly, and Nrf2 and HO-1 expression was also reduced in retina tissue or ARPE-19 cells of model group, whereas CD31 and VEGFR2 expression was upregulated. However, tricin ameliorated the oxidative stress and angiogenesis and rectified the abnormal expression of Sestrin2/Nrf2 in diabetic retinopathy. Further mechanistic studies showed that silence Sestrin2 reduced the protective effect of tricin on ARPE-19 cells, as well as abolished its regulating effect on the Nrf2 pathway. These results suggested that tricin inhibits oxidative stress and angiogenesis in retinal epithelial cells of DR rats via reinforcing Sestrin2/Nrf2 signaling.

Zerumbone combined with gefitinib alleviates lung cancer cell growth through the AKT/STAT3/SLC7A11 axis.

Zerumbone had been verified as a potential anti-cancer agent. Our research aimed to investigate the effect of zerumbone combined with gefitinib in lung cancer. Human pulmonary alveolar epithelial cells (HPAEpiC), A549, and H460 cell lines were used to detect the efficacy of zerumbone. BALB/c nude mice were randomly divided into five groups, including model, gefitinib (Gef, 10 mg/kg), low dose zerumbone (L-Zer, 20 mg/kg), high dose zerumbone (H-Zer, 40 mg/kg), and H-Zer + Gef groups, and the tumor growth in each group was monitored. TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect cell apoptosis. Immunohistochemistry (IHC), immunofluorescence, and western blot were used to analyze the protein expressions in tumor tissues. Glutathione (GSH) and malondialdehyde (MAD) were detected by special kits. Zerumbone inhibited the proliferation of lung cancer cells in vitro. Tumor volume and weight were reduced after gefitinib or zerumbone treatment. Gefitinib and zerumbone treatment significantly promoted the apoptosis of tumor cells. The expression of Bcl-2, Bax, and P53 proteins confirmed cell apoptosis. IHC results indicated that zerumbone and gefitinib treatment decreased tumor angiogenesis. Consistent with this result, the expression of EGFR, VEGFR2, and Ki-67 proteins decreased, while the expression of angiostatin and endostatin proteins increased. Interestingly, zerumbone treatment increased the level of MDA while decreasing GSH. Next, the levels of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) decreased after zerumbone and gefitinib treatment. Our study suggested that zerumbone combined with gefitinib could effectively inhibit lung cancer for multi-model therapies, including the inhibition of tumor growth, angiogenesis, induce cell apoptosis, and ferroptosis.

Tricin attenuates cerebral ischemia/reperfusion injury through inhibiting nerve cell autophagy, apoptosis and inflammation by regulating the PI3K/Akt pathway.

To elucidate the effect of tricin in cerebral ischemia/reperfusion (I/R) injury and examine its possible underlying mechanisms. Rats were randomly divided into Sham (exposed the right internal carotid arteries), I/R, and tricin (administered at various doses) groups. After the cerebral I/R injury model was established, a Morris water maze test and a tetrazolium chloride assay were performed. Apoptosis and autophagy were assessed in the nerve cells of hippocampus tissue, and the levels of inflammatory markers within animal serum were detected. Proteins related to apoptosis and the PI3K/Akt pathway were evaluated. To further investigate the mechanisms by which tricin affects brain damage, mouse neuroblastoma cells N2a were divided into control, oxygen-glucose deprivation and reoxygenation (OGD/R), tricin, PI3K/Akt activator, and tricin + PI3K/Akt inhibitor groups. The cell viability, apoptosis, inflammatory factors, and PI3K/Akt pathway related proteins in N2a cells were also detected. The results revealed that I/R-induced learning and memory dysfunction was improved by tricin treatment. The area of cerebral infarction, the levels of apoptosis and autophagy in nerve cells, and the serum inflammatory marker content were all decreased following tricin treatment. Additionally, the expression of Beclin-1 protein was downregulated, while the expression of Bcl-2 protein, p-PI3K/PI3K and p-Akt/Akt was upregulated after tricin treatment. Mechanistically, tricin or PI3K/Akt activator ameliorated OGD/R-induced apoptosis, autophagy, and inflammation. However, these effects were reversed following PI3K/Akt inhibitor treatment in OGD/R-induced N2a cells. In summary, this study suggested that tricin can against I/R-induced brain injury by inhibiting autophagy, apoptosis and inflammation, and activating the PI3K/Akt signaling pathway.

Design and synthesis of novel aza-ursolic acid derivatives: in vitro cytotoxicity and nitric oxide release inhibitory activity.

Aim: Inducible nitric oxide synthase (iNOS) is a validated target for anti-inflammatory treatment. Based on the authors' previous work, novel aza-ursolic acid derivatives were designed and synthesized and their inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) release from RAW264.7 cells was evaluated. Materials & results: 16 novel derivatives were screened for their in vitro inhibitory activity against NO release using Griess assays and the cytotoxicity was evaluated using MTT assays. The presence of furoxan joined to the A-ring of ursolic acid and N-methylpiperazine groups in the lead compound was identified for anti-inflammatory activity, and compound 21b showed 94.96% inhibition of NO release at 100 µM with an IC50 value of 8.58 µM. Conclusion: Compound 21b has potential anti-inflammatory activity with low cytotoxicity that warrants further preclinical study and evaluation.

Embelin-induced MCF-7 breast cancer cell apoptosis and blockade of MCF-7 cells in the G2/M phase via the mitochondrial pathway.

Embelin is a small molecular inhibitor extracted from Myrsinaceae plants that specifically inhibits XIAP, affecting the proliferation and apoptosis of various types of tumor cells. In our previous studies, we have demonstrated that embelin is able to induce the apoptosis of MCF-7 breast cancer cells in a dose-dependent manner. However, its mechanism of action is not yet clear. The purpose of this study was to investigate the involvement of the mitochondrial pathway in embelin-induced apoptosis and the effect of embelin on the cell cycle. Different doses of embelin were added to MCF-7 breast cancer cells and it was found that embelin was able to induce apoptosis of MCF-7 breast cancer cells in a dose- and time-dependent manner. Flow cytometry analysis revealed that embelin caused changes in the MCF-7 cell mitochondrial membrane potential and blocked the cell cycle of MCF-7 cells in the G2/M phase. Moreover, embelin was demonstrated to promote mitochondrial release of cytochrome C via regulation of Bax and Bcl-2, resulting in the activation of caspase-3 and -9, while no significant changes in the level of caspase-8 were observed. The results have demonstrated that embelin-induced apoptosis of MCF-7 breast cancer cells involves the mitochondrial pathway.