Background: Defective autophagy is thought to contribute to the pathogenesis of many diseases, including cancer. Human plasmacytoma variant translocation 1 (PVT1) is an oncogenic long non-coding RNA that has been identified as a prognostic biomarker in pancreatic ductal adenocarcinoma, but how PVT1 operates in the regulation of autophagy in pancreatic ductal adenocarcinoma (PDA) is unclear. Methods: PVT1 expression level was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and hybridization in situ (ISH). Western blot or qRT-PCR was performed to assess the ULK1 protein or mRNA level. Autophagy was explored via autophagic flux detection under a confocal microscope and autophagic vacuoles investigation under a transmission electron microscopy (TEM). The biological role of PVT1 in autophagy and PDA development was determined by gain-of-function and loss-of-function assays. Results: We found that PVT1 levels paralleled those of ULK1 protein in PDA cancer tissues. PVT1 promoted cyto-protective autophagy and cell growth by targeting ULK1 both in vitro and in vivo. Moreover, high PVT1 expression was associated with poor prognosis. Furthermore, we found that PVT1 acted as sponge to regulate miR-20a-5p and thus affected ULK1 expression and the development of pancreatic ductal adenocarcinoma. Conclusions: The present study demonstrates that the “PVT1/miR-20a-5p/ULK1/autophagy” pathway modulates the development of pancreatic ductal adenocarcinoma and may be a novel target for developing therapeutic strategies for pancreatic ductal adenocarcinoma.

Emerging evidence has demonstrated that circular RNAs (circRNAs) take part in the initiation and development of pancreatic ductal adenocarcinoma (PDA), a deadly neoplasm with an extremely low 5-year survival rate. Reprogrammed glucose metabolism is a key feature of tumour development, including PDA. In this research, we evaluated the role of circRNAs in reprogrammed glucose metabolism in PDA. RNA sequencing under various glucose incubation circumstances was performed. A new circMYOF was identified. Sanger sequencing and RNase R treatment confirmed its circular RNA characteristics. Real-time PCR indicated that it was highly expressed in PDA clinical specimens and cell lines. Gain-of- and loss-of-function assays showed that circMYOF induced progression in PDA. Mechanistically, RNA pull-down and luciferase reporter experiments elucidated that circMYOF, as a competing endogenous RNA for miR-4739, facilitated glycolysis via the VEGFA/PI3K/AKT pathway. Taken together, our findings indicate that circMYOF may work as a desirable biomarker and therapeutic target for PDA patients.

Early metastasis and resistance to traditional therapy are responsible for the poor prognosis of pancreatic adenocarcinoma patients. Metal-dependent protein phosphatases (PPMs) have been proven to play a crucial role in the initiation and progression of various tumors. Nevertheless, the expression and function of distinct PPMs in pancreatic adenocarcinoma have not been fully elucidated. In this study, we investigated the mRNA expression level, prognostic value, and the relationship between the expression of PPMs and the tumor microenvironment in pancreatic adenocarcinoma using Oncomine, TCGA and GTEx, GEO, Kaplan–Meier plotter, STRING, GeneMANIA, and HPA databases and R packages. GO and KEGG analysis revealed that PPMs and their differential co-expression genes are attributed to cell–cell adhesion and immune cell infiltration. Among these, PPM1K was downregulated in the tissue and peripheral blood of PAAD patients, whose expression level was negatively related to poor prognosis. Further to this, PPM1K was found to play a role in the epithelial–mesenchymal transition and immune infiltration. ROC curves showed that PPM1K had a good predictive value for pancreatic adenocarcinoma. The knockdown of PPM1K markedly promoted the proliferation and migration of pancreatic cancer cells, confirming its role in tumor suppressor activity in PAAD. This study demonstrates the potential clinical utility of PPM1K in tumor immunotherapy and brings about novel insights into the prognostic value of PPM1K in pancreatic adenocarcinoma.

Primary esophageal lymphoma is a rare malignant tumor, which is often misdiagnosed. To improve the diagnosis and treatment of this disease, we presented one case admitted at our institution and a literature review of primary esophageal lymphoma cases, including the clinical data, features of imaging, endoscopy and pathology, treatment, and prognosis. The symptoms were non-specific. Under endoscopy, most of the lesions were located in the middle and lower segment of the esophagus, behaving as ulcers, polyps, or submucosal masses, always accompanying with esophageal stricture. The diagnosis of primary esophageal lymphoma was highly dependent on pathological and immunohistochemical examination, hence stacked sampling was suggested to improve the positive rate of mucosal biopsy. Combination of chemotherapy and radiotherapy may be the first choice of treatment, surgical and endoscopic resections may be an alternative solution as well. The therapeutic effect and prognosis were slightly better than those of other esophageal malignant tumors.