Patients with Parkinson’s disease (PD) exhibit distinct gut microbiota, which may promote gut-derived inflammation. Rifaximin is a nonabsorbable antibiotic that can modify gut microbiota. The present study investigated the effect of rifaximin on gut microbiota and inflammation status in PD. The study examined the effect of long-term rifaximin treatment on in vivo transgenic PD mice (MitoPark) and short-term rifaximin treatment on patients with PD. Rifaximin treatment caused a significant change in gut microbiota in the transgenic PD mice; in particular, it reduced the relative abundance of Prevotellaceae UCG-001 and increased the relative abundance of Bacteroides, Muribaculum, and Lachnospiraceae UCG-001. Rifaximin treatment attenuated serum interleukin-1β, interleukin-6 and tumor necrosis factor-α, claudin-5 and occludin, which indicated the reduction of systemic inflammation and the protection of the blood–brain barrier integrity. The rifaximin-treated MitoPark mice exhibited better motor and memory performance than did the control mice, with lower microglial activation and increased neuronal survival in the hippocampus. In the patients with PD, 7-day rifaximin treatment caused an increase in the relative abundance of Flavonifractor 6 months after treatment, and the change in plasma proinflammatory cytokine levels was negatively associated with the baseline plasma interleukin-1α level. In conclusion, the present study demonstrated that rifaximin exerted a neuroprotective effect on the transgenic PD mice by modulating gut microbiota. We observed that patients with higher baseline inflammation possibly benefited from rifaximin treatment. With consideration for the tolerability and safety of rifaximin, randomized controlled trials should investigate the disease-modification effect of long-term treatment on select patients with PD.

It is well-known that human epidermal growth factor receptor 2 (HER2) is critical for breast cancer (BC) development and progression. Several studies have revealed the role of the ubiquitin/proteasome system (UPS) in cancer. In this study, we investigated the expression level of Proteasome 26S subunit, non-ATPase 3 (PSMD3) in BC using BC cell lines, human BC tissue samples, Oncomine, and TCGA databases and studied the PSMD3-HER2 protein interaction. PSMD3 was upregulated in BC, particularly in the HER2+ subtype. PSMD3 immunostaining was detected in the cytoplasm and nucleus of BC tumor tissues. Strong interaction between PSMD3 and HER2 at the protein level was observed. Knockdown of PSMD3 significantly impaired the stability of HER2, inhibited BC cell proliferation and colony formation, and induced cell apoptosis. Ubiquitination process was strongly enhanced after knockdown of PSMD3 in association with decreased HER2 level. Accumulation and Localization of LAMP-1 in the cell membrane with decreased HER2 immunostaining was observed after knockdown of PSMD3. High expression level of PSMD3 was associated with HER2 expression (p < 0.001), tumor size (p < 0.001), and clinical stage (p = 0.036). High expression level of PSMD3 predicted a short overall survival (OS), particularly for HER2+. Overall, we provide a novel function for PSMD3 in stabilizing HER2 from degradation in HER2+ BC, which suggests that PSMD3 is a novel target for HER2+ BC.

Non-small cell lung cancer (NSCLC)-carrying specific epidermal growth factor receptor (EGFR) mutations can be effectively treated by a tyrosine kinase inhibitor such as gefitinib. However, the inevitable development of acquired resistance leads to the eventual failure of therapy. In this study, we show the combination effect of omega-3 fatty acid-enriched fish oil (FO) and selenium (Se) on reversing the acquired gefitinib-resistance of HCC827 NSCLC cells. The gefitinib-resistant subline HCC827GR possesses lowered proapoptotic CHOP (CCAAT/enhancer-binding protein homologous protein) and elevated cytoprotective GRP78 (glucose regulated protein of a 78 kDa molecular weight) endoplasmic reticulum (ER) stress response elements, and it has elevated β-catenin and cyclooxygenase-2 (COX-2) levels. Combining FO and Se counteracts the above features of HCC827GR cells, accompanied by the suppression of their raised epithelial-to-mesenchymal transition (EMT) and cancer stem markers, such as vimentin, AXL, N-cadherin, CD133, CD44, and ABCG2. Accordingly, an FO and Se combination augments the gefitinib-mediated growth inhibition and apoptosis of HCC827GR cells, along with the enhanced activation of caspase -3, -9, and ER stress-related caspase-4. Intriguingly, gefitinib further increases the elevated ABCG2 and cancer stem-like side population in HCC827GR cells, which can also be diminished by the FO and Se combination. The results suggest the potential of combining FO and Se in relieving the acquired resistance of NSCLC patients to targeted therapy.

Anticancer therapies reportedly promote pro-survival autophagy in cancer cells that confers drug resistance, rationalizing the concept to combine autophagy inhibitors to increase their therapeutic potential. We previously identified that MPT0L145 is a PIK3C3/FGFR inhibitor that not only increases autophagosome formation due to fibroblast growth factor receptor (FGFR) inhibition but also perturbs autophagic flux via PIK3C3 inhibition in bladder cancer cells harboring FGFR activation. In this study, we hypothesized that combined-use of MPT0L145 with agents that induce pro-survival autophagy may provide synthetic lethality in cancer cells without FGFR activation. The results showed that MPT0L145 synergistically sensitizes anticancer effects of gefitinib and gemcitabine in non-small cell lung cancer A549 cells and pancreatic cancer PANC-1 cells, respectively. Mechanistically, drug combination increased incomplete autophagy due to impaired PIK3C3 function by MPT0L145 as evidenced by p62 accumulation and no additional apoptotic cell death was observed. Meanwhile, drug combination perturbed survival pathways and increased vacuolization and ROS production in cancer cells. In conclusion, the data suggest that halting pro-survival autophagy by targeting PIK3C3 with MPT0L145 significantly sensitizes cancer cells to targeted or chemotherapeutic agents, fostering rational combination strategies for cancer therapy in the future.

Pediatric ependymomas are a type of malignant brain tumor that occurs in children. The overall 10-year survival rate has been reported as being 45–75%. Maximal safe surgical resection combined with adjuvant chemoradiation therapy is associated with the highest overall and progression-free survival rates. Despite aggressive treatment, one-third of ependymomas exhibit recurrence within 2 years of initial treatment. Therefore, this study aimed to find new agents to overcome chemoresistance and defer radiotherapy treatment since, in addition, radiation exposure may cause long-term side effects in the developing brains of young children. By using integrated bioinformatics and through experimental validation, we found that at least one of the genes CCND1 and CDK4 is overexpressed in ependymomas. The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell-cycle-related and DNA-repair-related gene expression via the suppression of RB phosphorylation, which was determined through RNA-seq and Western blot analyses. Furthermore, abemaciclib effectively induced cell death in vitro. The efficiency of abemaciclib was validated in vivo using subcutaneously implanted ependymoma tissues from patient-derived xenografts (PDXs) in mouse models. Treatment with abemaciclib showed encouraging results in preclinical pediatric ependymoma models and represents a potential therapeutic strategy for treating challenging tumors in children.