The ability of the foodborne pathogen Listeria monocytogenes to develop biofilm in food-processing environment is a major concern for the food safety, because biofilms allow bacteria to better resist environmental stresses. PrfA is a key transcriptional activator that positively regulates most of the known listerial virulence gene expression. In order to explore the role of PrfA on Listeria biofilm development, we compared the abilities of biofilm formation by L. monocytogenes wild type strains (EGD and EGDe) and their prfA deletion mutants (EGD∆prfA and EGDe∆prfA), nonpathogenic Listeria innocua, as well as the recombinant strains that express constitutively active mutant PrfA (PrfA*) in L. innocua (LI-pERL3-prfA*) and in EGDe∆prfA (EGDe∆prfA-pERL3-prfA*) at 37°C in brain heart infusion (BHI) medium using the polyvinyl chloride (PVC) microtiter plate assay and microscopic examination. Our results showed that the wild types of L. monocytogenes had strong abilities to develop biofilm with meshwork of bacterial aggregates, while biofilm with sparse small clumps were observed in L. innocua. The biofilm production of strains EGD∆prfA and EGDe∆prfA that lack funtional PrfA was reduced and could be recovered by the introduction of the PrfA*, however, the PrfA* had no impact on the biofilm forming ability of L. innocua. Our results suggest that PrfA plays a significant role in biofilm formation in L. monocytogenes but not in L. innocua, thus may reflect differences in the molecular mechanisms of biofilm formation by these two closely related species.
The foodborne pathogen Listeria monocytogenes has the ability to develop biofilm in food-processing environment, which becomes a major concern for the food safety. The biofilm formation is strongly influenced by the availability of nutrients and environmental conditions, and particularly enhanced in poor minimal essential medium (MEM) containing glucose rather than in rich brain heart infusion (BHI) broth. To gain better insight into the conserved protein expression profile in these biofilms, the proteomes from biofilm- and planktonic-grown cells from MEM with 50 mM glucose or BHI were compared using two-dimensional polyacrylamide gel electrophoresis followed by MALDI-TOF/TOF analysis. 47 proteins were successfully identified to be either up (19 proteins) or down (28 proteins) regulated in the biofilm states. Most (30 proteins) of them were assigned to the metabolism functional category in cluster of orthologous groups of proteins. Among them, up-regulated proteins were mainly associated with the pentose phosphate pathway and glycolysis, whereas a key enzyme CitC involved in tricarboxylic acid cycle was down-regulated in biofilms compared to the planktonic states. These data implicate the importance of carbon catabolite control for L. monocytogenes biofilm formation in response to nutrient availability.
Ovarian cancer (OC) has been the most fatal gynecological disease that threatens women’s health. Surgery and platinum-based chemotherapy are the basic ovarian cancer treatments that can improve survival, but the five-year survival rate has not improved because of delayed diagnosis, drug resistance, and recurrence. Novel treatments are needed to improve the prognosis and survival rate of ovarian cancer patients. In recent years, adoptive cell therapy (ACT) has received increasing attention as an emerging therapeutic strategy in the treatment of solid tumors including OC. ACT has shown promising results in many preclinical and clinical trials of OC. The application of ACT depends on different effector cells, such as lymphokine-activated killer (LAK) cells, tumor-infiltrating lymphocytes (TILs), and genetically modified T cells. In this review, we focus on adoptive immunotherapies in ovarian cancer and summarize completed and ongoing preclinical/clinical trials. The future development directions and obstacles for ACT in OC treatment are discussed.
Background ROS1 gene rearrangement has been reported in several types of cancers, including non-small cell lung cancer (NSCLC). It is reported that tyrosine kinase inhibitors are effective in the treatment of ROS1- rearranged NSCLC. Therefore, the identification of ROS1 rearrangement can be used as potential therapeutic target in lung cancer. Epidemiological data indicates that ROS1 gene rearrangement occurs in approximately 1–2% of NSCLC patients. The small sample sizes of the existing associated studies only represent the characteristics of patients in specific regions or countries, and there is still no latest statistical analysis on ROS1 gene rearrangement anywhere in the world. Methods We conducted a systematic search of the PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CBM, CNKI, Wanfang, and VIP databases to identify studies on ROS1 gene rearrangement in NSCLC patients from January 1, 2015 to October 27, 2019. We conducted a meta-analysis to investigate the relationship between ROS1 gene rearrangement and clinical characteristics of NSCLC patients. The four clinical features are as follows: gender, smoking status, pathological type, and lung cancer stage. Results Thirty-nine studies constituting of 25,055 NSCLC patients were eligible for inclusion in this meta-analysis. A prominently higher rate of ROS1 gene rearrangement was observed in female NSCLC patients (OR =1.94, 95% CI: 1.62–2.32%, P<0.05), patients with no smoking history (OR =2.82, 95% CI: 2.24–3.55%, P<0.05), patients with adenocarcinoma (OR =1.55, 95% CI: 1.14–2.11%, P<0.05), and patients with stage III–IV disease (OR =1.50, 95% CI: 1.15–1.94%, P<0.05). Our meta-analysis also showed that the prevalence of ROS1 rearrangement in adenocarcinoma was 2.49% (95% CI: 1.92–3.11%), while it was lower in non-adenocarcinoma patients (1.37%). Conclusions ROS1 gene rearrangement was more predominant in female patients, patients without smoking history, patients with adenocarcinoma and patients with advanced-stage disease (stages III to IV).
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