Circadian disruption has been implicated in tumour development, but the underlying mechanism remains unclear. Here, we show that the molecular clockwork within malignant human pancreatic epithelium is disrupted and that this disruption is mediated by miR-135b-induced BMAL1 repression. miR-135b directly targets the BMAL1 3′-UTR and thereby disturbs the pancreatic oscillator, and the downregulation of miR-135b is essential for the realignment of the cellular clock. Asynchrony between miR-135b and BMAL1 expression impairs the local circadian gating control of tumour suppression and significantly promotes tumourigenesis and resistance to gemcitabine in pancreatic cancer (PC) cells, as demonstrated by bioinformatics analyses of public PC data sets and in vitro and in vivo functional studies. Moreover, we found that YY1 transcriptionally activated miR-135b and formed a ‘miR-135b–BMAL1–YY1’ loop, which holds significant predictive and prognostic value for patients with PC. Thus, our work has identified a novel signalling loop that mediates pancreatic clock disruption as an important mechanism of PC progression and chemoresistance.
16 August 2019 in World Journal of Gastrointestinal Oncology
BACKGROUND Novel therapeutic strategies are urgently needed for patients with a delayed diagnosis of pancreatic ductal adenocarcinoma (PDAC) in order to improve their chances of survival. Recent studies have shown potent anti-neoplastic effects of curcumin and its analogues. In addition, the role of histone methyltransferases on cancer therapeutics has also been elucidated. However, the relationship between these two factors in the treatment of pancreatic cancer remains unknown. Our working hypothesis was that L48H37, a novel curcumin analog, has better efficacy in pancreatic cancer cell growth inhibition in the absence of histonelysine N-methyltransferase 2D (KMT2D). AIM To determine the anti-cancer effects of L48H37 in PDAC, and the role of KMT2D on its therapeutic efficacy. METHODS The viability and proliferation of primary (PANC-1 and MIA PaCa-2) and metastatic (SW1990 and ASPC-1) PDAC cell lines treated with L48H37 was determined by CCK8 and colony formation assay. Apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, and cell cycle profile were determined by staining the cells with Annexin-V/7-AAD, JC-1, DCFH-DA, and PI respectively, as well as flow cytometric acquisition. In vitro migration was assessed by the wound healing assay. The protein and mRNA levels of relevant factors were analyzed using Western blotting, immunofluorescence and real time-quantitative PCR. The in situ expression of KMT2D in both human PDAC and paired adjacent normal tissues was determined by immunohistochemistry. In vivo tumor xenografts were established by injecting nude mice with PDAC cells. Bioinformatics analyses were also conducted using gene expression databases and TCGA. RESULTS L48H37 inhibited the proliferation and induced apoptosis in SW1990 and ASPC-1 cells in a dose- and time-dependent manner, while also reducing MMP, increasing ROS levels, arresting cell cycle at the G2/M stages and activating the endoplasmic reticulum (ER) stress-associated protein kinase RNA-like endoplasmic reticulum kinase/eukaryotic initiation factor 2 alpha/activating transcription factor 4 (ATF4)/CHOP signaling pathway. Knocking down ATF4 significantly upregulated KMT2D in PDAC cells, and also decreased L48H37-induced apoptosis. Furthermore, silencing KMT2D in L48H37-treated cells significantly augmented apoptosis and the ER stress pathway, indicating that KMT2D depletion is essential for the anti-neoplastic effects of L48H37. Administering L48H37 to mice bearing tumors derived from control or KMT2D-knockdown PDAC cells significantly decreased the tumor burden. We also identified several differentially expressed genes in PDAC cell lines expressing very low levels of KMT2D that were functionally categorized into the extrinsic apoptotic signaling pathway. The KMT2D high- and low-expressing PDAC patients from the TCGA database showed similar survival rates,but higher KMT2D expression was associated with poor tumor grade in clinical and pathological analyses. CONCLUSION L48H37 exerts a potent anti-cancer effect in PDAC, which is augmented by KMT2D deficiency.
Background: To evaluate the long-term efficacy of transoral incisionless fundoplication (TIF) with Medigus Ultrasonic Surgical Endostapler (MUSE) for gastroesophageal reflux disease (GERD). Methods: A total of 16 patients with proton pump inhibitor-dependent gastroesophageal reflux disease had undergone TIF by MUSE in Shanghai General Hospital (Shanghai, China)from March 2017 to December 2018. Patients were followed up at 6 months, and the GERD-health-related quality of life (GERD-HRQL) questionnaire score, the GERD questionnaire (GERD-Q) score, high-resolution esophageal manometry (HREM) and 24 h esophageal pH parameters, the Hill grade of the gastroesophageal flap valve (GEFV) and daily Proton pump inhibitor (PPI) consumption before and after procedure were compared. Patients also were followed up at 3 years and 5 years using a structured questionnaire via phone which evaluated symptoms of reflux, dose of PPI medication and side effects. Results: Follow-up data were collected from 13 patients, ranging from 38 to 63 months, 53 months on average. 10/13 patients reported symptomatic improvement and daily PPI consumption was stopped or halved in 11/13. After procedure, the mean scores of GERD-HRQL and GERD-Q were significantly increased. The mean DeMeester score, the mean acid exposure time percentage and the mean number of acid reflux episodes were significantly lower. The mean rest pressure at lower esophageal sphincter (LES) had no significant difference. Conclusion: TIF by MUSE has significant efficacy in the treatment of PPI-dependent GERD, which can improve symptoms and life quality of patients, and reduce the acid exposure time for long-term. Chictr.org.cn. Trial Registration: ChiCTR2000034350.
Aim: In the present study, we aimed to investigate the effects of Fenbufen treatment on the SAP model induced by caerulein and lipopolysaccharide. Background: Severe acute pancreatitis (SAP) is an extremely dangerous disease with high mortality, which is associated with inflammatory response and acinar cell death. The caspase family plays an important role in cell death, such as caspase-1 and caspase-11 in pyroptosis. In recent years, caspases have been shown to be a novel pharmacological target of Fenbufen. Objective: Effects of Fenbufen on pancreatic tissue damage and serum levels of lipase and amylase in SAP in mice; Effect of Fenbufen on caspase-1 pathway in SAP in mice; Effect of Fenbufen on caspase-1/caspase-11-mediated pyroptosis of PACs in SAP in mice; Effect of Fenbufen on isolated PACs and caspase-1/caspase-11-mediated pyroptosis in vitro. Methods: In vivo, eighteen female C57BL/6 mice were randomly divided into 3 groups: the NC group, the SAP group, and the Fenbufen +SAP group with 6 mice in each group. The SAP model was induced by intraperitoneal injection of caerulein and lipopolysaccharide. The pathological changes in pancreatic and the serum levels of lipase and amylase and the relative gene and protein expressions in each group were compared. In vitro, pancreatic acinar cells were assigned to 5 groups: medium group, SAP group, Fenbufen 100μM group, Fenbufen 200μM group, and Fenbufen 400μM group. The cell damage and the relative gene and protein expressions in each group were evaluated. Results: Our results showed that Fenbufen ameliorated the severity of SAP and decreased the serum levels of lipase and amylase. Meanwhile, the in vivo and in vitro data demonstrated that Fenbufen inhibited the activation of caspase-1 and caspase-11, decreasing the levels of IL-1β, IL-18, and GSDMD. In in vitro experiments, we found that by inhibiting the activation of caspase-1 and caspase-11, Fenbufen significantly reduced lactate dehydrogenase (LDH) excretion by acinar cells. Conclusion: In general, our data showed that Fenbufen could protect the pancreatic acinar cell from injury by inhibiting pyroptosis.