Alpha-fetoprotein upregulates hepatocellular carcinoma cell-intrinsic PD-1 expression through the LATS2/YAP/TEAD1 pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) cell-intrinsic programmed death 1 (PD-1) promotes tumor progression. However, the mechanisms that regulate its expression are unclear. This study investigated the impact of alpha-fetoprotein (AFP) on HCC cell-intrinsic PD-1 expression. METHODS: The expression of PD-1 and AFP at the gene and protein levels was detected using real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and western blotting (WB). Proteins interacting with AFP were examined by co-immunoprecipitation (CO-IP). Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were used to identify transcription-enhanced association domain 1 (TEAD1) binding to the promoter of PD-1. RESULTS: The expression of HCC cell-intrinsic PD-1 was positively correlated with AFP. Mechanistically, AFP inhibited the phosphorylation of large tumor suppressor 2 (LATS2) and yes-associated protein (YAP). As a result, YAP is transferred to the nucleus and forms a transcriptional complex with TEAD1, promoting PD-1 transcription by binding to its promoter. CONCLUSION: AFP is an upstream regulator of the HCC cell-intrinsic PD-1 and increases PD-1 expression via the LATS2/YAP/TEAD1 axis. GENERAL: Our findings provide insight into the mechanisms of HCC development and offer new ideas for further in-depth studies of HCC.

Cellulase Promotes Mycobacterial Biofilm Dispersal in Response to a Decrease in the Bacterial Metabolite Gamma-Aminobutyric Acid.

Biofilm dispersal contributes to bacterial spread and disease transmission. However, its exact mechanism, especially that in the pathogen Mycobacterium tuberculosis, is unclear. In this study, the cellulase activity of the M. tuberculosis Rv0062 protein was characterized, and its effect on mycobacterial biofilm dispersal was analyzed by observation of the structure and components of Rv0062-treated biofilm in vitro. Meanwhile, the metabolite factors that induced cellulase-related biofilm dispersal were also explored with metabolome analysis and further validations. The results showed that Rv0062 protein had a cellulase activity with a similar optimum pH (6.0) and lower optimum temperature (30 °C) compared to the cellulases from other bacteria. It promoted mycobacterial biofilm dispersal by hydrolyzing cellulose, the main component of extracellular polymeric substrates of mycobacterial biofilm. A metabolome analysis revealed that 107 metabolites were significantly altered at different stages of M. smegmatis biofilm development. Among them, a decrease in gamma-aminobutyric acid (GABA) promoted cellulase-related biofilm dispersal, and this effect was realized with the down-regulation of the bacterial signal molecule c-di-GMP. All these findings suggested that cellulase promotes mycobacterial biofilm dispersal and that this process is closely associated with biofilm metabolite alterations.

Mycobacterium tuberculosis Rv1987 protein attenuates inflammatory response and consequently alters microbiota in mouse lung.

Introduction: Healthy lung microbiota plays an important role in preventing Mycobacterium tuberculosis (Mtb) infections by activating immune cells and stimulating production of T-helper cell type 1 cytokines. The dynamic stability of lung microbiota relies mostly on lung homeostasis. In our previous studies, we found that Mtb virulence factor, Rv1987 protein, can mediate host immune response and enhance mycobacterial survival in host lung. However, the alteration of lung microbiota and the contribution of lung microbiota dysbiosis to mycobacterial evasion in this process are not clear so far. Methods: M. smegmatis which does not contain the ortholog of Rv1987 protein was selected as a model strain to study the effects of Rv1987 on host lung microbiota. The lung microbiota, immune state and metabolites of mice infected by M. smegmatis overexpressing Rv1987 protein (MS1987) were detected and analyzed. Results: The results showed that Rv1987 inhibited inflammatory response in mouse lung and anaerobic bacteria and Proteobacteria, Bacteroidota, Actinobacteriota and Acidobacteriota bacteria were enriched in the lung tissues correspondingly. The immune alterations and microbiota dysbiosis affected host metabolic profiles, and some of significantly altered bacteria in MS1987-infected mouse lung, such as Delftia acidovorans, Ralstonia pickettii and Escherichia coli, led to anti-inflammatory responses in mouse lung. The secretory metabolites of these altered bacteria also influenced mycobacterial growth and biofilm formation directly. Conclusion: All these results suggested that Rv1987 can attenuate inflammatory response and alter microbiota in the lung, which in turn facilitates mycobacterial survival in the host.

lncRNA ELFN1-AS1 promotes proliferation, migration and invasion and suppresses apoptosis in colorectal cancer cells by enhancing G6PD activity.

Tumour cells change their metabolic patterns to support high proliferation rates and cope with oxidative stress. The lncRNA ELFN1-AS1 is highly expressed in a wide range of cancers and is essential to the proliferation and apoptosis of tumour cells. Nevertheless, its function in the metabolic reprogramming of tumour cells is unclear. Here we show that ELFN1-AS1 promotes glucose consumption as well as lactate and NADPH production. Database searching, bioinformatics analysis, RNA immunoprecipitation (RIP) and RNA pull-down assays show that ELFN1-AS1 enhances glucose-6-phosphate dehydrogenase ( G6PD) expression and activates the pentose phosphate pathway (PPP) by promoting TP53 degradation. In addition, luciferase reporter assay and chromatin immunoprecipitation (ChIP) show that YY1 binds to the ELFN1-AS1 promoter to promote transcriptional activation of ELFN1-AS1. Consistent with the in vitro experiments, knockdown of ELFN1-AS1 impedes the growth of tumours transplanted into mice by inhibiting the expression of G6PD. In conclusion, this study reveals that ELFN1-AS1 activates the PPP, and validates the regulatory role of the YY1/ ELFN1-AS1/ TP53/ G6PD axis in colorectal cancer.

Licoricidin combats gastric cancer by targeting the ICMT/Ras pathway in vitro and in vivo.

Licoricidin, a type of isoflavonoid, is extracted from the root of Glycyrrhiza glabra. It has been widely proven that licoricidin possesses multiple biological activities, including anti-cancer effects and a powerful antimicrobial effect against Helicobacter pylori (H. pylori). However, the exact mechanism of licoricidin against gastric cancer remains unclear. In this study, we comprehensively explored the effects of licoricidin on MGC-803 gastric cancer cells in vitro and in vivo and further elucidated its mechanism of action. Our results revealed that licoricidin exhibited multiple anti-gastric cancer activities, including suppressing proliferation, inducing apoptosis, arresting the cell cycle in G0/G1 phase, and inhibiting the migration and invasion abilities of MGC-803 gastric cancer cells. In addition to this, a total of 5861 proteins were identified by quantitative proteomics research strategy of TMT labeling, of which 19 differential proteins (two upregulated and 17 downregulated) were screened out. Combining bioinformatics analyses and the reported roles in cancer progression of the 19 proteins, we speculated that isoprenyl carboxyl methyltransferase (ICMT) was the most likely target of licoricidin. Western blot assays and IHC assays subsequently proved that licoricidin significantly downregulated the expression of ICMT, both in MGC-803 cells and in xenograft tumors. Moreover, licoricidin effectively reduced the level of active Ras-GTP and blocked the phosphorylation of Raf and Erk, which may be involved in its anti-gastric cancer effects. In summary, we first demonstrated that licoricidin exerted favorable anti-gastric cancer activities via the ICMT/Ras pathway, which suggests that licoricidin, as a natural product, could be a novel candidate for the management of gastric cancer.

Measurement of soluble PD-1 and soluble PD-L1 as well as PD-L1 and PD-1 from perioperative patients with gastric carcinoma.

BACKGROUND: Till now, no experiment has been performed to detect programmed death ligand 1 (PD-L1)/programmed death 1 (PD-1), soluble PD-L1/soluble PD-1 simultaneously in perioperative patients of gastric carcinoma. Our experiment aims at determining the clinical significance and possible mechanism of soluble PD-L1/soluble PD-1 in gastric carcinoma. METHODS: Thirty patients undergone gastrectomy were selected as the experimental group. Tissue's programmed death ligand 1 and peripheral programmed death 1 were detected using immunofluorescence and flow cytometry. Soluble PD-L1 and soluble PD-1 were detected using enzyme-linked immunosorbent assay. RESULTS: First, preoperative programmed death 1 was higher than control group and decreased to normal post-operatively. Preoperatively ,elevated levels of programmed death 1 on cluster of differentiation (CD)4 T cells indicated less lymphatic metastasis (P < 0.01) and small tumor volume (P < 0.01); elevated programmed death 1 of CD8 T cells indicated big tumor volume (P < 0.01) and well histological differentiation (P < 0.01). Second, preoperative soluble PD-L1 and soluble PD-1 are lower than in control group. Post-operatively, the soluble PD-1 rose to normal, but the soluble PD-L1 showed no change. Third, programmed death ligand 1 can be observed in carcinoma tissue. Fourth, the area under the curve of soluble PD-1 (0.675) for diagnosis was worse than that of soluble PD-L1 (0.885). Kaplan-Meier analysis showed that soluble PD-1 < 245.26 pg/ml in post-operative serum predicted a poor prognosis (overall survival percentage: 60%) at 2 years (P < 0.05). Multivariate analysis revealed that carcinoembryonic antigen (>5 ng/l) and soluble PD-1 after gastrectomy (>245.26 pg/ml) were independent prognostic factors for overall survival (hazard ratio: 20.812, 95% confidence interval: 1.217-355.916, P = 0.036; hazard ratio: 0.028, 95% confidence interval: 0.001-0.786, P = 0.036, respectively). CONCLUSIONS: We propose that soluble PD-1 combined with programmed death ligand 1 are effective not only in protecting T cells from the adhesion by programmed death ligand 1 but also in preventing the occurrence and the development of tumor as well. Through multivariate analysis, we found that soluble PD-1 was an independent protective factor for post-operative prognosis of gastric carcinoma patients, which indirectly verified the vital function of soluble PD-1. Soluble PD-1 might be promising predictive biomarkers for the diagnosis and prognosis of gastric carcinoma patients.

Efficacy and safety of targeted drugs in advanced or metastatic gastric and gastroesophageal junction cancer: A network meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: An increasing number of targeted drugs have been used to treat advanced or metastatic gastric cancer (GC) and gastroesophageal junction cancer (GEJC). However, the optimal treatment efficacy of these drugs is still controversial. The aims of this study are to systematically summarize the efficacy and safety of current targeted drugs for advanced or metastatic GC and GEJC. METHODS: PubMed, EmBase, Cochrane Library, Web of Science and ClinicalTrials were searched for double-blind randomized controlled trials (RCTs) on GC and GEJC up to December 2019. Additionally, we updated the literature search from Jan, 1, 2020 to September 30, 2021. Narrative and quantitative analysis were performed to analyse the efficacy and safety. STATA 15.1 was used to identify publication bias, and the SUCRA (surface under the cumulative ranking) curve was conducted to rank the treatments for each outcome. RESULTS: A total of 27 RCTs with 9295 GC and GEJC patients treated by 19 drugs were included. SUCRA showed that regorafenib was the most likely to improve patients' progression-free survival (96.4%), followed by apatinib (90.7%), nivolumab (82.4%), everolimus (76.5%) and pertuzumab (68.5%). Meanwhile, apatinib (92.4%) was most likely to improve overall survival, followed by nivolumab (87.9%), regorafenib (72.5%), olaparib (67.7%) and lapatinib (63.2%). Additionally, neutropenia, diarrhoea and fatigue were the most common adverse events caused by these drugs, followed by pain, nausea, decreased appetite, anaemia and vomiting. WHAT IS NEW AND CONCLUSION: Regorafenib and nivolumab have higher efficacy and tolerability and are the most advantageous for advanced GC and GEJC. Moreover, apatinib has higher efficacy but lower tolerability. Everolimus and pertuzumab combined with chemotherapy have best secondary higher efficacy for progression-free survival and good tolerability. Lapatinib and olaparib combined with chemotherapy have moderate efficacy for overall survival and good tolerability.

Long non-coding RNA TNK2 AS1/microRNA-125a-5p axis promotes tumor growth and modulated phosphatidylinositol 3 kinase/AKT pathway.

BACKGROUND AND AIM: Long non-coding RNA (lncRNA) TNK2 AS1 is a noncoding RNA with the capability of affecting microRNAs (miRNAs) levels and gene expression. The study was designed to investigate the mechanism of TNK2 AS1 in gastric cancer. METHODS: The loss and gain of function of TNK2 AS1 were investigated by analyzing the malignant behavior of AGS cells including the abilities of migration, invasion, and epithelial-mesenchymal transition (EMT) process via wound healing and transwell assay, as well as western blot. The targeting relationship of LncRNA TNK2 AS1 was analyzed through searching bioinformatics database, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. Tumor-bearing experiment in nude mice was performed to further confirm the regulatory role of TNK2 AS1 in vivo. Immunofluorescence assay for Ki67 expression was carried out in tumor tissues of mice model. RESULTS: The results showed that TNK2 AS1 overexpression promoted the malignant behaviors of AGS cells, which could be weakened by miR-125a-5p mimic addition. In addition, Jumonji, At-rich interaction domain (JARID2), and phosphatidylinositol 3 kinase (PI3K)/AKT pathway were regulated by TNK2-AS1/miR-125a-5p axis. In vivo, TNK2 AS1/miR-125a-5p axis promoted tumor growth and led to increases in green fluorescence intensity and vimentin expression and a decrease in E-cadherin level, which could be mediated by JARID2 and PI3K/AKT pathway. CONCLUSION: Therefore, a conclusion was drawn that TNK2-AS1/miR-125a-5p promoted the progression of gastric cancer.