Dongfeng Cheng

Amplification of Long Noncoding RNA ZFAS1 Promotes Metastasis in Hepatocellular Carcinoma

Despite progress in the diagnostics and treatment of hepatocellular carcinoma (HCC), its prognosis remains poor. In this study, we globally assessed long noncoding RNAs (lncRNA) for contributions to HCC using publicly available microarray data, in vitro and in vivo assays. Here, we report that ZFAS1, encoding a lncRNA that is frequently amplified in HCC, is associated with intrahepatic and extrahepatic metastasis and poor prognosis of HCC. ZFAS1 functions as an oncogene in HCC progression by binding miR-150 and abrogating its tumor-suppressive function in this setting. miR-150 repressed HCC cell invasion by inhibiting ZEB1 and the matrix metalloproteinases MMP14 and MMP16. Conversely, ZFAS1 activated ZEB1, MMP14, and MMP16 expression, inhibiting these effects of miR-150. Our results establish a function for ZFAS1 in metastatic progression and suggest its candidacy as a new prognostic biomarker and target for clinical management of HCC.

Solid-pseudopapillary tumor of the pancreas: Clinical features, pathological characteristics, and origin†‡§

To study clinically pathological features and origin of solid‐pseudopapillary tumor of pancreas (SPT).

miR-150-5p Inhibits Hepatoma Cell Migration and Invasion by Targeting MMP14

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor because the molecular mechanisms underlying hepatocarcinogenesis are not well understood. In the study, we focused on identifying the role of miRNAs in HCC progression. miRNA microarray was used to analyze the differentially expressed miRNAs, and the results were validated by qPCR. We found that the miR-150-5p expression is down-regulated in HCC tissues compared with pair non-tumor tissues. miR-150-5p expression is also decreased in metastatic cancer tissues compared with pair primary tissues, indicating that miR-150-5p may be involved in HCC metastasis. Functionally, miR-150-5p inhibition significantly promotes hepatoma cell migration and invasion, whereas miR-150-5p overexpression suppresses cancer cell migration and invasion in vitro. The matrix metalloproteinase 14 (MMP14) is identified as a new target gene of miR-150-5p. miR-150-5p markedly inhibits MMP14 expression in hepatoma cells, and miR-150-5p expression is negative correlation with MMP14 expression in vivo. More important, re-expression of MMP14 in hepatoma cells partially reverses the effect of miR-150-5p in inhibiting cell invasion.

Long noncoding RNA NORAD, a novel competing endogenous RNA, enhances the hypoxia-induced epithelial-mesenchymal transition to promote metastasis in pancreatic cancer

BackgroundPancreatic cancer, one of the top two most fatal cancers, is characterized by a desmoplastic reaction that creates a dense microenvironment, promoting hypoxia and inducing the epithelial-to-mesenchymal transition (EMT) to facilitate invasion and metastasis. Recent evidence indicates that the long noncoding RNA NORAD may be a potential oncogenic gene and that this lncRNA is significantly upregulated during hypoxia. However, the overall biological role and clinical significance of NORAD remains largely unknown.MethodsNORAD expression was measured in 33 paired cancerous and noncancerous tissue samples by real-time PCR. The effects of NORAD on pancreatic cancer cells were studied by overexpression and knockdown in vitro. Insights into the mechanism of competitive endogenous RNAs (ceRNAs) were gained from bioinformatics analyses and luciferase assays. In vivo, metastatic potential was identified using an orthotopic model of PDAC and quantified using bioluminescent signals. Alterations in RhoA expression and EMT levels were identified and verified by immunohistochemistry and Western blotting.ResultsNORAD is highly expressed in pancreatic cancer tissues and upregulated in hypoxic conditions. NORAD upregulation is correlated with shorter overall survival in pancreatic cancer patients. Furthermore, NORAD overexpression promoted the migration and invasion of pancreatic carcinoma cells, while NORAD depletion inhibited EMT and metastasis in vitro and in vivo. In particular, NORAD may function as a ceRNA to regulate the expression of the small GTP binding protein RhoA through competition for hsa-miR-125a-3p, thereby promoting EMT.ConclusionsElevated expression of NORAD in pancreatic cancer tissues is linked to poor prognosis and may confer a malignant phenotype upon tumor cells. NORAD may function as a ceRNA to regulate the expression of the small GTP binding protein RhoA through competition for hsa-miR-125a-3p. This finding may contribute to a better understanding of the role played by lncRNAs in hypoxia-induced EMT and provide a potential novel diagnostic and therapeutic target for pancreatic cancer.

Middle-preserving pancreatectomy: report of two cases and review of the literature

BackgroundMiddle-preserving pancreatectomy (MPP) is a parenchyma-sparing surgical procedure which has recently been sporadically reported for the treatment of multicentric periampullary-pancreatic lesions. However, a comprehensive recognition of this procedure has not been clearly elucidated.Case presentationWe herein report two patients undergoing MPP due to synchronous multicentric pancreatic neoplasm. Patient one was a 24-year-old woman with a multicentric solid pseudopapillary neoplasm (SPN) and patient two was a 36-year-old woman with a multicentric serous cystic neoplasm (SCN). Simultaneous atypical pancreaticoduodenectomy and atypical left pancreatectomy were performed in patient one; simultaneous standard pancreaticoduodenectomy and atypical left pancreatectomy with spleen preservation were performed in patient two. Approximately 6 cm and 5 cm segments of the middle portion of the pancreas were preserved, respectively. At follow-up at 36 months and 6 months respectively, patient one had developed diabetes and malabsorption requiring dietary control, exercise and pancreatic enzyme supplement whereas patient two showed normal fasting blood glucose without diarrhea. Both patients were disease-free and in good nutritional condition. We reviewed twenty cases of MPP that were previously reported in the literature. Patient characteristics, surgical techniques and short- and long-term outcomes were analyzed.ConclusionMPP is mainly beneficial for multicentric noninvasive periampullary-pancreatic lesions. However, for multicentric periampullary-pancreatic lesions involving even primary invasive cancers, as long as the invasive cancers affect only one side of the pancreas (proximal or distal), MPP could serve as a rational choice in well-selected patients.

Minimally invasive distal pancreatectomy for PNETs: laparoscopic or robotic approach?

Background The most effective and radical treatment for pancreatic neuroendocrine tumors (PNETs) is surgical resection. Minimally invasive surgery has been increasingly used in pancreatectomy. Initial results in robotic distal pancreatectomy (RDP) have been encouraging. Nonetheless, data comparing outcomes of RDP with those of laparoscopic distal pancreatectomy (LDP) in treating PNETs are rare. The aim of this study was to compare the safety and efficacy of RDP and LDP for PNETs. Methods From September 2010 to January 2017, operative parameters and perioperative outcomes in an initial experience with 43 consecutive patients undergoing RDP were collected and compared with those in 31 patients undergoing LDP. Results Patients undergoing RDP and LDP demonstrated equivalent age, sex, ASA score, tumor location and tumor size. Operating time, length of resected pancreas, postoperative length of hospital stay and rates of conversion to open, pancreatic fistula, transfusion and reoperation were not statistically different. Patients in the RDP group were associated with significantly higher overall (79.1 vs. 48.4 %, P = 0.006) and Kimura spleen preservation rates (72.1 vs. 16.1%, P < 0.001) and had reduced risk of excessive blood loss (50 vs. 200mL, P < 0.001). Oncological outcomes in this series were superior for the RDP group with more lymph node harvest for G2 and G3 PNETs (3.5 vs. 2, P = 0.034). Conclusions Both RDP and LDP are efficacious and safe methods in treating PNETs located in the body or tail of pancreas. Robotic approach offers advantages with less intraoperative blood loss, higher spleen preservation rate and more lymph node harvest. It may be sensible to choose RDP for patients who fit indications for scheduled spleen preservation.

MicroRNA-300 Promotes Apoptosis and Inhibits Proliferation, Migration, Invasion and Epithelial-Mesenchymal Transition via the Wnt/β-catenin Signaling Pathway by Targeting CUL4B in Pancreatic Cancer Cells†

The study aims to verify the hypothesis that up‐regulation of microRNA‐300 (miR‐300) targeting CUL4B promotes apoptosis and suppresses proliferation, migration, invasion, and epithelial‐mesenchymal transition (EMT) of pancreatic cancer cells by regulating the Wnt/β‐catenin signaling pathway. Pancreatic cancer tissues and adjacent tissues were collected from 110 pancreatic cancer patients. Expression of miR‐300, CUL4B, Wnt, β‐catenin, E‐cadherin, N‐cadherin, Snail, GSK‐3β, and CyclinD1 were detected using qRT‐PCR and Western blot. CFPAC‐1, Capan‐1, and PANC‐1 were classified into blank, negative control (NC), miR‐300 mimics, miR‐300 inhibitors, siRNA‐CUL4B, and miR‐300 inhibitors + siRNA‐CUL4B groups. The proliferation, migration, invasion abilities, the cell cycle distribution, and apoptosis rates were measured in CCK‐8 and Transwell assays. Pancreatic cancer tissues showed increased CUL4B expression but decreased miR‐300 expression. When miR‐300 was lowly expressed, CUL4B was upregulated which in‐turn activated the Wnt/β‐catenin pathway to protect the β‐catenin expression and thus induce EMT. When miR‐300 was highly expressed, CUL4B was downregulated which in‐turn inhibited the Wnt/β‐catenin pathway to prevent EMT. Weakened cell migration and invasion abilities and enhanced apoptosis were observed in the CUL4B group. The miR‐300 inhibitors group exhibited an evident increase in growth rate accompanied the largest tumor volume. Smaller tumor volume and slower growth rate were observed in the miR‐300 mimics and siRNA‐CUL4B group. Our study concludes that lowly expressed miR‐300 may contribute to highly expressed CUL4B activating the Wnt/β‐catenin signaling pathway and further stimulating EMT, thus promoting proliferation and migration but suppressing apoptosis of pancreatic cancer cells.

Microencapsulated tumor assay: Evaluation of the nude mouse model of pancreatic cancer

AIM To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation. METHODS The assay is based on microencapsulation technology, wherein human tumor cells are encapsulated in small microcapsules (approximately 420 μm in diameter) constructed of semipermeable membranes. We implemented two kinds of subcutaneous implantation models in nude mice using the injection of single tumor cells and encapsulated pancreatic tumor cells. The size of subcutaneously implanted tumors was observed on a weekly basis using two methods, and growth curves were generated from these data. The growth and metastasis of orthotopically injected single tumor cells and encapsulated pancreatic tumor cells were evaluated at four and eight weeks postimplantation by positron emission tomography-computed tomography scan and necropsy. The pancreatic tumor samples obtained from each method were then sent for pathological examination. We evaluated differences in the rates of tumor incidence and the presence of metastasis and variations in tumor volume and tumor weight in the cancer microcapsules vs single-cell suspensions. RESULTS Sequential in vitro observations of the microcapsules showed that the cancer cells in microcapsules proliferated well and formed spheroids at days 4 to 6. Further in vitro culture resulted in bursting of the membrane of the microcapsules and cells deviated outward and continued to grow in flasks. The optimum injection time was found to be 5 d after tumor encapsulation. In the subcutaneous implantation model, there were no significant differences in terms of tumor volume between the encapsulated pancreatic tumor cells and cells alone and rate of tumor incidence. There was a significant difference in the rate of successful implantation between the cancer cell microencapsulation group and the single tumor-cell suspension group (100% vs 71.43%, respectively, P = 0.0489) in the orthotropic implantation model. The former method displayed an obvious advantage in tumor mass (4th wk: 0.0461 ± 0.0399 vs 0.0313 ± 0.021, t = -0.81, P = 0.4379; 8th wk: 0.1284 ± 0.0284 vs 0.0943 ± 0.0571, t = -2.28, respectively, P = 0.0457) compared with the latter in the orthotopic implantation model. CONCLUSION Encapsulation of pancreatic tumor cells is a reliable method for establishing a pancreatic tumor animal model.

Liquefying panniculitis associated with intraductal papillary mucinous neoplasm

We report a case of a 64-year-old man who presented with liquefying panniculitis associated with intraductal papillary mucinous neoplasm (IPMN) after the Whipple operation.

Robot-Assisted Middle Pancreatectomy for Elderly Patients: Our Initial Experience

Background The aim of this study was to evaluate the indications, safety, feasibility, and short- and long-term outcomes for elderly patients who underwent robot-assisted middle pancreatectomies (MPs). Material/Methods Ten patients (≥60 years) underwent robot-assisted middle pancreatectomies from 2012 to 2015. The perioperative data, including tumor size, operating time, rate of postoperative pancreatic fistula (POPF), postoperative morbidity, and other parameters, were analyzed. We collected and analyzed the follow-up information. Results The mean age of patients was 64.30 years (range, 60–73 years). The average tumor size was 2.61 cm. The 10 cases were all benign or low-grade malignant lesions. The mean operating time was 175.00 min. The mean blood loss was 113.00 ml with no blood transfusion needed. Postoperative fistulas developed in 5 patients; there were 2 Grade A fistulas and 3 grade B fistulas. There were 3 patients who underwent postoperative complications, including 2 Grade 1 or 2 complications and 1 Grade 3 complication. No reoperation and postoperative mortality occurred. The mean hospital stay was 19.91 days. After a median follow-up of 23 months, new onset of diabetes mellitus developed in 1 patient and none suffered from deterioration of previously diagnosed diabetes or exocrine insufficiency, and no tumor recurrence happened. Conclusions Robot-assisted middle pancreatectomy was safe and feasible for elderly people. It had low risk of exocrine or endocrine dysfunction and benefited patients’ long-term outcomes. Incidence of POPF was relatively high but we could prevent it from resulting in bad outcomes by scientific perioperative care and systemic treatment.