LINC00460 promotes pancreatic cancer progression by sponging miR-491-5p.

BACKGROUND: A growing body of studies have suggested that LINC00460 is instrumental in tumorigenesis and tumour progression. Nonetheless, the biological function and mechanisms of LINC00460 in pancreatic ductal adenocarcinoma (PDAC) remain vague. METHODS: Analysis based on public databases and a quantitative reverse transcription-polymerase chain reaction were performed to screen for differentially expressed lncRNAs in PDAC and to detect LINC00460 expression in PDAC cell lines and clinical samples. The survival of patients in the up-regulated and down-regulated LINC00460 expression groups was compared by using the Kaplan-Meier method. In addition, the potential biological functions of LINC00460 in PDAC were explored by cell counting kit-8, colony formation, flow cytometry and transwell assays. Furthermore, bioinformatics analysis, luciferase reporter assays and rescue experiments were applied to demonstrate the mechanism by which LINC00460 could directly bind to and inhibit miR-491-5p. RESULTS: LINC00460 is up-regulated in PDAC and correlates with adverse survival outcomes. The results of functional tests verified that LINC00460 knockdown inhibited both cell proliferation and cell migration. Additionally, knockdown led to G0/G1 cell cycle blockage and enhanced cell apoptosis. Mechanistic investigations revealed that LINC00460 directly binds to and attenuates the tumour suppressor miR-491-5p, thus accelerating PDAC progression. CONCLUSIONS: This research showed that LINC00460 is overexpressed in PDAC and correlates with adverse clinical outcomes. Additionally, LINC00460 promotes the aggressiveness of PDAC by targeting miR-491-5p. Thus, LINC00460 may serve as diagnostic biomarker of PDAC and a new target for PDAC therapy.

Nomograms predict long-term survival for patients with periampullary adenocarcinoma after pancreatoduodenectomy.

BACKGROUND: The prognosis of patients with periampullary adenocarcinoma after pancreatoduodenectomy is diverse and not yet clearly illustrated. The aim of this study was to develop a nomogram to predict individual risk of overall survival (OS) and progression-free survival (PFS) in patients with periampullary adenocarcinoma after pancreatoduodenectomy. METHODS: A total of 205 patients with periampullary adenocarcinoma after pancreatoduodenectomy were retrospectively included. OS and PFS were evaluated by the Kaplan-Meier method. Two nomograms for predicting OS and PFS were established, and the predictive accuracy was measured by the concordance index (Cindex) and calibration plots. RESULTS: Lymph node ratio (LNR), carbohydrate antigen 19-9 (CA19-9) and anatomical location were incorporated into the nomogram for OS prediction and LNR, CA19-9; anatomical location and tumor differentiation were incorporated into the nomogram for PFS prediction. All calibration plots for the probability of OS and PFS fit well. The Cindexes of the nomograms for OS and PFS prediction were 0.678 and 0.68, respectively. The OS and PFS survival times were stratified significantly using the nomogram-predicted survival probabilities. CONCLUSIONS: The present nomograms for OS and PFS prediction can provide valuable information for tailored decision-making for patients with periampullary adenocarcinoma after pancreatoduodenectomy.

miR-133b, a muscle-specific microRNA, is a novel prognostic marker that participates in the progression of human colorectal cancer via regulation of CXCR4 expression.

BACKGROUND: MicroRNA-133b (miR-133b), which is a muscle-specific microRNA, has been reported to be downregulated in human colorectal carcinoma (CRC) when compared to adjacent non-tumor tissue. However, its diagnostic value and role in CRC have yet to be described. CXC chemokine receptor-4 (CXCR4), which participates in multiple cell processes such as cell invasion-related signaling pathways, was predicted to be a potential target of miR-133b. The aim of this study was to investigate the associations and functions of miR-133b and CXCR4 in CRC initiation and invasion. METHODS: Mature miR-133b and CXCR4 expression levels were detected in 31 tumor samples and their adjacent, non-tumor tissues from patients with CRC, as well as in 6 CRC cell lines, using real-time quantitative RT-PCR (qRT-PCR). Luciferase reporter assays and Western blots were used to validate CXCR4 as a putative target gene of miR-133b. Regulation of CXCR4 expression by miR-133b was assessed using qRT-PCR and Western blot analysis, and the effects of exogenous miR-133b and CXCR4 on cell invasion and migration were evaluated in vitro using the SW-480 and SW-620 CRC cell lines. RESULTS: A significant downregulation of miR-133b was observed in 93.55% of CRC tissues, and the expression of miR-133b was much lower in metastatic tumors (stage C and D, stratified by the Modified Dukes Staging System) than in primary tumors (stage A and B). In contrast, CXCR4 protein expression significantly increased in 52.63% of CRC samples, and increased CXCR4 expression in CRC was associated with advanced tumor stage. CXCR4 was shown to be a direct target of miR-133b by luciferase reporter assays, and transfection of miR-133b mimics inhibited invasion and stimulated apoptosis of SW-480 and SW-620 CRC cells. CONCLUSIONS: Our study demonstrated that downregulated miR-133b contributed to increased cell invasion and migration in CRC by negatively regulating CXCR4. These findings may be significant for the development of therapy target for CRC.

Oxidative stress induces monocyte-to-myofibroblast transdifferentiation through p38 in pancreatic ductal adenocarcinoma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are among the most prominent cells during the desmoplastic reaction in pancreatic ductal adenocarcinoma (PDAC). However, CAFs are heterogeneous and the precise origins are not fully elucidated. This study aimed to explore whether monocytes can transdifferentiate into fibroblasts in PDAC and evaluate the clinical significance of this event. METHODS: CD14+ monocytes were freshly isolated from human peripheral blood. Immunofluorescence, reverse transcription-quantitative PCR, western blot, flow cytometry and enzyme-linked immunosorbent assay were used to detect the expression of αSMA, fibronectin, and other relevant molecules. In addition, latex beads with a mean particle size of 2.0 µm were used to assess the phagocytic capacity. Moreover, RNA sequencing (RNA-seq) was performed to identify the differences induced by H2 O2 and the underlying mechanisms. RESULTS: Immunofluorescence identified αSMA and fibroblast-specific protein 1 expression by tumor-associated macrophages in PDAC. The in vitro experiment revealed that oxidative stress (H2 O2 or radiation) induced monocyte-to-myofibroblast transdifferentiation (MMT), as identified by upregulated αSMA expression at both the RNA and protein levels. In addition, compared with freshly isolated monocytes, human monocyte-derived macrophages increased fibronectin expression. RNA-seq analysis identified p53 activation and other signatures accompanying this transdifferentiation; however, the p53 stabilizer nutlin-3 induced αSMA expression through reactive oxygen species generation but not through the p53 transcription/mitochondria-dependent pathway, whereas the p38 inhibitor SB203580 could partially inhibit αSMA expression. Finally, MMT produced a unique subset of CAFs with reduced phagocytic capacity that could promote the proliferation of pancreatic cancer cells. CONCLUSIONS: Oxidative stress in the tumor microenvironment could induce MMT in PDAC, thus inducing reactive stroma, modulating immunosuppression, and promoting tumor progression. Reducing oxidative stress may be a promising future therapeutic regimen.

SYPL1 Inhibits Apoptosis in Pancreatic Ductal Adenocarcinoma via Suppression of ROS-Induced ERK Activation.

Synaptophysin-like 1 (SYPL1) is a neuroendocrine-related protein. The role of SYPL1 in pancreatic ductal adenocarcinoma (PDAC) and the underlying molecular mechanism remain unclarified. Here, after analyzing five datasets (GSE15471, GSE16515, GSE28735, TCGA, and PACA-AU) and 78 PDAC patients from Sun Yat-sen University Cancer Center, we demonstrated that SYPL1 was upregulated in PDAC and that a high level of SYPL1 indicated poor prognosis. Bioinformatics analysis implied that SYPL1 was related to cell proliferation and cell death. To validate these findings, gain-of-function and loss-of-function experiments were carried out, and we found that SYPL1 promoted cell proliferation in vitro and in vivo and that it protected cells from apoptosis. Mechanistic studies revealed that sustained extracellular-regulated protein kinase (ERK) activation was responsible for the cell death resulting from knockdown of SYPL1. In addition, bioinformatics analysis showed that the expression of SYPL1 positively correlated with antioxidant activity. Reactive oxygen species (ROS) were upregulated in cells with SYPL1 knockdown and vice versa. Upregulated ROS led to ERK activation and cell death. These results suggest that SYPL1 plays a vital role in PDAC and promotes cancer cell survival by suppressing ROS-induced ERK activation.

MORC2 promotes cell growth and metastasis in human cholangiocarcinoma and is negatively regulated by miR-186-5p.

Microrchidia family CW-type zinc finger 2 (MORC2) is a ubiquitously expressed protein that contributes to chromatin remodeling, DNA repair, and lipogenesis. However, its role in cholangiocarcinoma (CCA) remains largely unknown. The aim of this study was to investigate the expression profile of MORC2 and its potential functions in CCA progression. The results showed that MORC2 was upregulated in human CCA specimens and cell lines. MORC2 expression was significantly associated with serum CA19-9 levels (P = 0.009), TNM stage (P = 0.003) and lymph node invasion (P = 0.004). Furthermore, high MORC2 expression was associated with poor 5-year survival (P = 0.016). Functional experiments revealed that MORC2 knockdown could suppress CCA cell proliferation, migration, and invasion both in vivo and in vitro. Mechanically, we found that MORC2 promoted CCA cell metastasis through the EMT process and enhanced proliferation via the Akt signaling pathway. Moreover, MORC2 was negatively regulated by miR-186-5p. MiR-186-5p could influence CCA cell proliferation, migration and metastasis by regulating MORC2. Taken together, the findings of this study demonstrated the oncogenic role of MORC2 in CCA tumorigenesis and metastasis, and clarified an underlying regulatory mechanism mediating MORC2 upregulation, which may provide a novel therapeutic target in CCA treatment.

Nomogram to Predict Cancer-Specific Survival in Patients with Pancreatic Acinar Cell Carcinoma: A Competing Risk Analysis.

Background: The objective of this study was to evaluate the probability of cancer-specific death of patients with acinar cell carcinoma (ACC) and build nomograms to predict overall survival (OS) and cancer-specific survival (CSS) of these patients. Methods: Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Patients diagnosed with ACC between 2004 and 2014 were retrospectively collected. Cancer-specific mortality and competing risk mortality were evaluated. Nomograms for estimating 1-, 2- and 3-year OS and CSS were established based on Cox regression model and Fine and Grey's model. The precision of the 1-, 2- and 3-year survival of the nomograms was evaluated and compared using the area under receiver operating characteristic (ROC) curve (AUC). Results: The study cohort included 227 patients with ACC. The established nomograms were well calibrated, and had good discriminative ability, with a concordance index (C-index) of 0.742 for OS prediction and 0.766 for CSS prediction. The nomograms displayed better discrimination power than 7th or 8th edition Tumor-Node-Metastasis (TNM) stage systems in training set and validation set for predicting both OS and CSS. The AUC values of the nomogram predicting 1-, 2-, and 3-year OS rates were 0.784, 0.797 and 0.805, respectively, which were higher than those of 7th or 8th edition TNM stage systems. Regard to the prediction of CSS rates, the AUC values of the nomogram were also higher than those of 7th or 8th edition TNM stage systems. Conclusion: We evaluated the 1-, 2- and 3-year OS and CSS in patients with ACC for the first time. Our nomograms showed relatively good performance and could be considered as convenient individualized predictive tools for prognosis.

A Refined Staging Model for Resectable Pancreatic Ductal Adenocarcinoma Incorporating Examined Lymph Nodes, Location of Tumor and Positive Lymph Nodes Ratio.

Background: Nodal status and tumor site are prognostic factors for resectable pancreatic ductal adenocarcinoma (PDAC). Parameters for nodal status are diverse, and the number of examined lymph nodes (eNs) needed for good prognosis are uncertain. We try to modify staging system of resectable PDAC with parameters mentioned above by recursive partitioning analysis. Methods: Patients from the Surveillance, Epidemiology, and End Results (SEER) database were divided into training cohort and internal validation cohort, randomly. PDAC patients from Sun Yat-sen University Cancer Center were regarded as external validation cohort. The training cohort was used to refine staging model by recursive partitioning analysis, while the internal validation cohort and the external validation cohort were applied to assess discriminatory capacity of staging model. For parameters included in the modified model, their effects were studied. Results: The number of eNs, tumor site and tumor size were risk factors for positive nodal status. Lymph nodes ratio (LNR), tumor site, eNs and T stages of 8th the American Joint Committee on Cancer (AJCC) were selected to develop a refined model, dividing patients into 5 groups of different outcomes, preceding 8th AJCC classification. Besides, we found that (1) for small PDAC (diameter < 1cm), lymph node metastasis was rarely found; (2) enough eNs were needed to ensure better prognosis of node-negative patients; (3) tumors in the head of pancreas were prone to lymph nodes metastasis; (4) for node-positive patients, LNR was a better nodal parameter compared to positive lymph nodes (pNs). Conclusion: Our improved staging system helps to illuminate the interactions among tumor site, size and eNs.

Alpha-L-Fucosidase Serves as a Prognostic Indicator for Intrahepatic Cholangiocarcinoma and Inhibits Its Invasion Capacity.

Alpha-L-fucosidase (AFU) has been reported to be a predictor of survival in patients with several cancers, but it is unclear whether AFU is associated with prognosis in patients with intrahepatic cholangiocarcinoma (iCCA). In this study, we used receiver operating characteristic (ROC) analysis to generate the cutoff point of AFU for overall survival (OS). The prognostic influence of the AFU level in serum on OS was studied using Kaplan-Meier curves. Moreover, invasion assays and Western blotting were performed to explore the effects of AFU on iCCA invasion in vitro. We found that higher AFU levels (≥20.85 U/L) were significantly associated with favorable median OS (44.3 months versus 20.1 months; P = 0.022) in iCCA patients. Cox regression models' analyses showed that the AFU level was an independent predictor for OS (P = 0.006). Moreover, our results revealed that the AFU could impair the invasion capability of the iCCA cells, HuH28, and also downregulated the expression of matrix metalloproteinase 2 and matrix metalloproteinase 9. In conclusion, our results indicate that AFU is a significantly favorable prognostic factor in iCCA patients.

PARP inhibitor olaparib sensitizes cholangiocarcinoma cells to radiation.

Cholangiocarcinoma (CCA) is a highly malignant tumor with resistance to radiotherapy alone. Olaparib, a highly potent poly(ADP-ribose) polymerase (PARP) inhibitor, has been shown to sensitize many types of tumor to radiotherapy. However, the effect of olaparib, either as monotherapy or as combination therapy with radiotherapy, on CCA is not known, and our study aimed to explore this. To assess radiosensitization in three CCA cell lines (QBC939, HuH28 and TFK-1), viability and clonogenic assays were conducted. The absorbed radiation doses were 0 Gy, 2 Gy, 4 Gy, and 6 Gy; olaparib concentrations were 0 nmol/L, 1 nmol/L, 10 nmol/L, 100 nmol/L, 1000 nmol/L, 2500 nmol/L, 5000 nmol/L and 10 000 nmol/L. The mechanism of olaparib radiosensitization was explored by Western blotting. Immunofluorescence staining and flow cytometry were conducted to explore DNA damage and apoptosis. The radiosensitivity of CCA cells was enhanced by olaparib, which alone had little effect on the CCA cell lines without BRCA mutations. The degree of radiosensitization increased with increasing doses of olaparib by viability and clonogenic assays in vitro. Olaparib was able to enhance the effect of radiation by inhibiting PARP1, inducing DNA lesions and apoptosis. These findings emphasize the role of olaparib in the radiosensitization of CCA cells.

ELTD1 Function in Hepatocellular Carcinoma is Carcinoma-Associated Fibroblast-Dependent.

Introduction: EGF, latrophilin, and seven transmembrane domain containing 1 (ELTD1) constitutes an orphan G-protein-coupled receptor (GPCR) of the adhesion family. High expression of ELTD1 is correlated with favorable prognosis of hepatocellular carcinoma (HCC). After silencing ELTD1 expression, however, tumor invasiveness is drastically reduced. The underlying mechanism of this apparent contradictory phenomenon is unknown. Because adhesion GPCRs couple extracellular adhesion to intracellular signaling, as a member of this family, ELTD1 function may be related to its tumor microenvironment. We therefore investigated the interaction between ELTD1 and the HCC tumor microenvironment. Methods: ELTD1 expression was assessed by immunohistochemical analyses of tissue samples from two independent groups of 333 patients with HCC. Correlations between the ELTD1 expression and the clinicopathological values were examined. We also constructed ELTD1 overexpression and knockdown HCC cell lines and conducted a series of in vivo and in vitro ELTD1 functional assays. We further collected carcinoma associated fibroblast (CAF) culture supernatants to culture HCC cell lines and repeat the respective functional assays in comparison with the control group. Results: Clinicopathologic correlations and in vivo models indicated ELTD1 as a tumor suppressor gene, whereas in vitro experiments suggested that ELTD1 could promote malignancy in HCC cell lines. Immunohistochemical staining of the generated ELTD1 overexpression xenograft tumors demonstrated that the CAF markers vimentin and α-SMA were highly expressed compared to the control group. This suggests that ELTD1 expression is correlated to CAF distribution. In addition, culturing with CAF supernatants inhibited HCC cell proliferation and invasion rates, confirming the correlation between CAF and ELTD1. Conclusion: The results of this study indicated that ELTD1 regulation of HCC progression is CAF-dependent, suggesting that ELTD1 function is regulated by its tumor microenvironment. Further investigation is required to determine the underlying mechanisms.