Exosomes from ß-Cells Promote Differentiation of Induced Pluripotent Stem Cells into Insulin-Producing Cells Through microRNA-Dependent Mechanisms.

OBJECTIVE: Exosomes have emerged as potential tools for the differentiation of induced pluripotent stem cells (iPSCs) into insulin-producing cells (IPCs). Exosomal microRNAs are receiving increasing attention in this process. Here, we aimed at investigating the role of exosomes derived from a murine pancreatic ß-cell line and identifying signature exosomal miRNAs on iPSCs differentiation. METHODS: Exosomes were isolated from MIN6 cells and identified with TEM, NTA and Western blot. PKH67 tracer and transwell assay were used to confirm exosome delivery into iPSCs. qRT-PCR was applied to detect key pancreatic transcription gene expression and exosome-derived miRNA expression. Insulin secretion was determined using FCM and immunofluorescence. The specific exosomal miRNAs were determined via RNA-interference of Ago2. The therapeutic effect of 21 day-exosome-induced IPCs was validated in T1D mice induced by STZ. RESULTS: iPSCs cultured in medium containing exosomes showed sustained higher expression of MAFA, Insulin1, Insulin2, Isl1, Neuroud1, Nkx6.1 and NGN3 compared to control iPSCs. In FCM analysis, approximately 52.7% of the differentiated cells displayed insulin expression at the middle stage. Consistent with the gene expression data, immunofluorescence assays showed that Nkx6.1 and insulin expression in iPSCs were significantly upregulated. Intriguingly, the expression of pancreatic markers and insulin was significantly decreased in iPSCs cultured with siAgo2 exosomes. Transplantation of 21 day-induced IPCs intoT1D mice efficiently enhanced glucose tolerance and partially controlled hyperglycemia. The therapeutic effect was significantly attenuated in T1D mice that received iPSCs cultured with siAgo2 exosomes. Of the seven exosomal microRNAs selected for validation, miR-706, miR-709, miR-466c-5p, and miR-423-5p showed dynamic expression during 21 days in culture. CONCLUSION: These data indicate that differentiation of exosome-induced iPSCs into functional cells is crucially dependent on the specific miRNAs encased within exosomes, whose functional analysis is likely to provide insight into novel regulatory mechanisms governing iPSCs differentiation into IPCs.

Impact of examined lymph node count on prognosis in patients with lymph node-negative pancreatic body/tail ductal adenocarcinoma.

BACKGROUND: Because the overall prognosis remains dismal for patients with resected pancreatic cancer (PC), we aimed to explore the prognostic impact of examined lymph node (ELN) count on lymph node (LN)-negative pancreatic body/tail ductal adenocarcinoma. METHODS: Patients' data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (National Cancer Institute, USA) to investigate the relationship between ELN count and survival outcomes of LN-negative pancreatic body/tail ductal adenocarcinoma. RESULTS: A total of 700 patients were included, and the median number of ELNs was 11. The respective 1-, 3-, 5-year overall survival (OS) rates were 75.3%, 37.7%, 30.3%, and the 1-, 3-, 5-year cancer-specific survival (CSS) were 78.3%, 41.7%, 34.5%. The X-tile analysis showed that 14 was the most optimal cutoff for both OS and CSS. Kaplan-Meier survival analysis indicated that patients with ELNs >14 had better OS and CSS than ELNs ≤14. Multivariate Cox analysis showed ELNs ≤14 was an independent risk factor for both OS [hazard ratio (HR), 1.357; 95% confidence interval (CI), 1.080-1.704; P=0.009] and CSS (HR, 1.394; 95% CI, 1.092-1.778; P=0.008). CONCLUSIONS: ELN count is associated with the survival rate in patients with LN-negative pancreatic body/tail ductal adenocarcinoma. Accurate nodal staging for these patients requires more than 14 ELNs.

Clinicopathological Characteristics and Survival Outcomes of Primary Hepatic Neuroendocrine Tumor: A Surveillance, Epidemiology, and End Results (SEER) Population-Based Study.

BACKGROUND Primary hepatic neuroendocrine tumor (PHNET) is a rare primary liver tumor that remains poorly understood. Here, we explored the clinicopathological characteristics and survival outcomes of PHNET patients. MATERIAL AND METHODS PHNET patients diagnosed between 1988 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were enrolled in the cohort. Kaplan-Meier analysis was used to determine the survival outcomes. Multivariable Cox regression models were used to identify the risk factors for overall survival (OS) and disease-specific survival (DSS). RESULTS A total of 291 PHNET patients from the SEER database met the inclusion criteria for analysis. The majority of the patients were female (53.6%), white (77.7%), and married (49.5%). The 1-, 3-, and 5-year OS were 57.1%, 39.4%, and 30.2%, and the 1-, 3-, and 5-year DSS rates were 61.3%, 44.3%, and 36.7%, respectively. Multivariate Cox regression models showed that older age, unmarried status, poor differentiated grade, and no tumor-directed surgery were independent risk factors for poor OS and DSS. CONCLUSIONS Older age, unmarried status, poor differentiated grade, and no tumor-directed surgery were associated with poorer prognosis of PHNET. Surgical resection is an effective and reliable treatment method for patients with PHNET.

Do Elderly Patients With Stage I-II Hepatocellular Carcinoma Benefit From More Radical Surgeries? A Population-Based Analysis.

Background and Aims: The best treatment modalities for elderly patients with stage I-II HCC (hepatocellular carcinoma) remain controversial in an era of a shortage of liver donors. Methods: From the SEER database (Surveillance, Epidemiology, and End Results program), 2,371 elderly patients were sampled as Cohort 1. OS (Overall Survival) and CSS (Cancer-Specific Survival) were compared between the Non-surgery and Surgery groups. A stratification analysis in a CSS Cox model was also conducted among sub-groups, and propensity score matching was performed to generate Cohort 2 (746 pairs), reducing the influences of confounders. Results: For Cohort 1, the median follow-up times of the Non-surgery and Surgery groups were 11 months (95% CI, confidence interval: 9.74-12.26) vs. 49 months (44.80-53.21) in OS, and 14 months (12.33-15.67) vs. 74 months (64.74-83.26) in CSS, respectively. In the stratification analysis, for the elderly patients (age >= 70 years), Larger Resection was associated with a higher HR (hazard ratio) than Segmental Resection: 0.30 (95% CI, confidence interval: 0.22-0.41) vs. 0.29 (0.21-0.38) in 70-74 year-olds; 0.26 (0.18-0.38) vs. 0.23 (0.16-0.32) in 75-79 year-olds; 0.32 (0.21-0.49) vs. 0.21 (0.13-0.32) in those 80+ years old. For Cohort 2, a similar result could be seen in the CSS Cox forest plot. The HRs of Larger Resection and Segmental Resection were 0.27 (0.21-0.33) and 0.25 (0.20-0.31), respectively. Conclusions: It is cautiously recommended that, when liver transplantation is not available, segmental or wedge liver resection is the better treatment choice for elderly patients with stage I-II HCC (AJCC edition 6), especially those over 70 years old, compared with other surgeries, based on the SEER data.

Upregulated Expression of TUBA1C Predicts Poor Prognosis and Promotes Oncogenesis in Pancreatic Ductal Adenocarcinoma via Regulating the Cell Cycle.

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant disease and has the worst prognosis and survival rate. TUBA1C is a microtubule component implicated in multiple cancers, however, the clinical significance and biological functions of TUBA1C in the progression of PDAC remain unexplored. Methods: The Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis (GEPIA) data were employed to detect the TUBA1C mRNA expression and the relation between TUBA1C expression and overall survival (OS) in PDAC. Then, bioinformatic analysis was employed to determine the potential pathway and genes related to TUBA1C. Human pancreatic cancer tissue and adjacent non-tumor tissues samples were detected by immunochemistry (IHC) staining, and the correlation between TUBA1C expression and the clinicopathological features were investigated. Meanwhile, TUBA1C expression in PDAC cell lines was evaluated by western blotting. Furthermore, functional assays including cell viability, apoptosis, cell cycle, transwell assay, wound healing assay, and a xenograft tumor model were performed to determine the oncogenic role of TUBA1C in PDAC, respectively. Results: TUBA1C was overexpressed in the PDAC tissues and cells. IHC analysis showed that the TUBA1C overexpression was associated with short OS. Bioinformatic analysis indicated that TUBA1C overexpression was mainly associated with cell cycle regulation. The downregulation of TUBA1C significantly suppressed cell proliferation, induced cell apoptosis and cycle arrest, and inhibited invasion and migration in PDAC cells. Furthermore, TUBA1C downregulation also inhibited tumor growth in vivo. Conclusion: These findings suggested that TUBA1C downregulation suppressed PDAC aggressiveness via cell cycle pathway and that TUBA1C may serve as a potential prognostic marker for PDAC therapy.