CXCR4/Let-7a Axis Regulates Metastasis and Chemoresistance of Pancreatic Cancer Cells Through Targeting HMGA2.

BACKGROUND/AIMS: Pancreatic cancer cells (PCC) is one of the most risky cancers and gemcitabine (GEM) is the standard first-line drug for treating PCC. The PCC will develop drug resistance to GEM after a period of treatment. However, the detailed molecular mechanism of pathogenesis and drug resistance remains unresolved. METHODS: we employed qRT-PCR and western blot to examine the expression level of CXCR4, let-7a and HMGA2. In addition, we used MTT assay to detect cell proliferation and transwell assay to measure migration and invasiveness. The expression level of epithelial marker E-cadherin and mesenthymal marker N-cadherin was detected by western blot. The apoptosis was determined using annexin V-FITC/PI apoptosis detection kit by flow cytometry. RESULTS: we first proved that CXCR4 negatively regulated let-7a in PCC. Next, let-7a was confirmed to play crucial role in tumorigenesis, metastasis and drug resistance of pancreatic cancer cells Bxpc-3 and Panc-1 in vitro and in vivo. Finally, we identified HMGA2 as important downsteam target of let-7a in PCC and overexpression of HMGA2 restores cell proliferation, metastasis and chemosensitivity of GEM inhibited by let-7a. Conlusion: Taken together, we show an important signaling pathway involved in pathogenesis and drug resistance of PCC, thereby providing deeper insight into molecular mechanism by which CXCR4/let-7a regulates tumorigenesis and drug resistance of PCC. These findings will help us develop new strategies for diagnosis and treatment of PCC.

Upregulation of microRNA-196a and microRNA-196b cooperatively correlate with aggressive progression and unfavorable prognosis in patients with colorectal cancer.

BACKGROUND: Both microRNA (miR)-196a and miR-196b are implicated in normal cell differentiation, proliferation, and in tumorigenesis of various cancer types. Especially, miR-196a exerts a pro-oncogenic influence in colorectal cancer (CRC) cells and miR-196b expression is upregulated in CRC tissues. The aim of this study was to evaluate the associations of miR-196a and miR-196b dysregulation with clinicopathological characteristics and prognosis in patients with CRC. METHODS: Quantitative real time-PCR (qRT-PCR) was performed to detect the expression levels of miR-196a and miR-196b in 126 pairs of fresh tumor samples matched with adjacent colorectal mucosa obtained from 126 patients with CRC. RESULTS: miR-196a and miR-196b expression levels in CRC tissues were significantly higher than those in adjacent colorectal mucosa (both P < 0.002). Interestingly, the expression levels of miR-196a in CRC tissues were positively correlated with those of miR-196b. Then, high miR-196a expression and high miR-196b expression, alone or in combination, were all statistically linked to the presence of lymph node metastasis, the poor differentiation grade, and the advanced TNM stage of CRC. Moreover, overall and disease-free survivals of CRC patients with high miR-196a expression, high miR-196b expression and miR-196a-high/miR-196b-high expression tended to be shorter than the corresponding control groups (log-rank statistic, all P < 0.001). Furthermore, multivariate analysis indicated miR-196a and/or miR-196b expression as independent prognostic indicators for CRC patients (all P < 0.05). CONCLUSIONS: Both miR-196a and miR-196b may be correlated with aggressive progression and unfavorable clinical outcome in CRC patients. Combined expression of miR-196a and miR-196b may be a promising biomarker in identifying a poor prognosis group of CRC.

A microfluidic 3D hepatocyte chip for drug toxicity testing.

We have developed a microfluidic 3D hepatocyte chip (3D HepaTox Chip) for in vitro drug toxicity testing to predict in vivo drug hepatotoxicity. The 3D HepaTox Chip is based on multiplexed microfluidic channels where a 3D microenvironment is engineered in each channel to maintain the hepatocytes' synthetic and metabolic functions. The multiplexed channels allow for simultaneous administration of multiple drug doses to functional primary hepatocytes while an incorporated concentration gradient generator enables the in vitro dose-dependent drug responses to predict in vivo hepatotoxicity. The IC(50) values of 5 model drugs derived from the dose-dependent on-chip testing correlate well with the reported in vivo LD(50) values. The 3D HepaTox Chip can be integrated with on-chip sensors and actuators as the next generation cell-based on-chip drug testing platform.

Microfabricated silicon nitride membranes for hepatocyte sandwich culture.

We have developed a hepatocyte sandwich culture with improved mass transport properties based on ultra-thin microfabricated porous silicon nitride (Si(3)N(4)) membranes. The dimensions and uniformity of the membrane pores can be configurable, which confers more control over the mass transport. Instead of collagen gels used in conventional sandwich culture, we utilized galactose ligands immobilized on the Si(3)N(4) membranes to support hepatocyte attachment and function in the sandwich culture. Diffusion studies using FITC-dextrans confirmed that mass transport of the microfabricated Si(3)N(4) membrane based sandwich was significantly better than conventional collagen gel sandwich and can be configured by varying the porosity of the Si(3)N(4) membrane. Hepatocytes cultured in the microfabricated Si(3)N(4) membrane based sandwich culture exhibited earlier apical repolarization and biliary excretion, improved differentiated functions and enhanced drug sensitivity compared to hepatocytes cultured in a collagen gel sandwich. The Si(3)N(4) membrane based sandwich culture allows for a systematic optimization of the mass transport properties of hepatocyte culture by changing the pore size and inter-pore distance. This will enable more effective drug testing applications where optimal mass transport is required for hepatocyte function maintenance and drug accessibility.

Nonlinear optical microscopy: use of second harmonic generation and two-photon microscopy for automated quantitative liver fibrosis studies.

Liver fibrosis is associated with an abnormal increase in an extracellular matrix in chronic liver diseases. Quantitative characterization of fibrillar collagen in intact tissue is essential for both fibrosis studies and clinical applications. Commonly used methods, histological staining followed by either semiquantitative or computerized image analysis, have limited sensitivity, accuracy, and operator-dependent variations. The fibrillar collagen in sinusoids of normal livers could be observed through second-harmonic generation (SHG) microscopy. The two-photon excited fluorescence (TPEF) images, recorded simultaneously with SHG, clearly revealed the hepatocyte morphology. We have systematically optimized the parameters for the quantitative SHG/TPEF imaging of liver tissue and developed fully automated image analysis algorithms to extract the information of collagen changes and cell necrosis. Subtle changes in the distribution and amount of collagen and cell morphology are quantitatively characterized in SHG/TPEF images. By comparing to traditional staining, such as Masson's trichrome and Sirius red, SHG/TPEF is a sensitive quantitative tool for automated collagen characterization in liver tissue. Our system allows for enhanced detection and quantification of sinusoidal collagen fibers in fibrosis research and clinical diagnostics.

Open surgical treatment of choledochocele: A case report and review of literature.

Choledochocele (also known as type III choledochal cyst according to Todani's classification) is a cystic dilation of the distal segment of the common bile duct protruding into the duodenal lumen. Cases are rare and the etiology remains unclear. It is usually misdiagnosed as peptic ulcer, as in the patient whose case is described here. Multislice spiral computed tomography and magnetic resonance cholangiopancreatography may be comparable to endoscopic retrograde cholangiography for diagnosis of choledochocele. Both endoscopic therapy and open surgical management are safe options, and size of the cyst plays a role in the decision-making for which approach to apply. A 50-year-old woman admitted to our hospital with upper abdominal pain caused by choledochocele with large size was successfully treated by open surgical management. We present the details of her case in this case report and discuss the recent literature on such cases and their therapeutic management.

[Surgical treatment of 2465 primary hepatolithiasis cases].

OBJECTIVE: To summarize the experience of surgical treatment of primary hepatolithiasis. METHODS: To analyze the clinical data, operation choice, postoperative complications of 2465 cases of primary hepatolithiasis retrospectively. RESULTS: Of the patients, 2034 received external drainage (82.5%) and 431 received internal drainage (17.5%) and 586 were performed adjunctive partial hepatectomy (23.8%). The postoperative complications were found in 211 cases (8.6%) and 17 cases (0.7%) died after the operation. One thousand seven hundred and sixty-seven cases (71.7%) have been followed up for 2 to 25 years, among them therapeutic effect of 1518 cases (85.9%) was excellent or good, 315 cases (17.8%) had residual stone and 115 cases (6.5%) recurred. CONCLUSIONS: It could decrease the incidence rate of complications, residual stone and recurrence in the patients with hepatolithiasis after surgical therapy to pinpoint the situs of the lithiasis and biliary stricture and managed properly before the surgery.

Berberine Increases Doxorubicin Sensitivity by Suppressing STAT3 in Lung Cancer.

Berberine (BBR), an alkaloid component isolated from Chinese medicinal herb Huang Lian, has aroused broad interests for its antitumor effect in recent years. The signal transducer and activator of transcription 3 (STAT3), plays critical roles in malignant transformation and progression and was found to be constitutively activated in a variety of human cancers. In this study, we show that BBR inhibited cell proliferation, induced apoptosis, and suppressed tumor spheroid formation of lung cancer cell lines. These effects were correlated with BBR-mediated suppression of both phosphorylated and total levels of STAT3 protein. Furthermore, BBR promoted STAT3 degradation by enhancing ubiquitination. Importantly, we demonstrated that BBR was able to inhibit doxorubicin (DOX)-mediated STAT3 activation and sensitize lung cancer cells to the cytotoxic effect of DOX treatment. Given that BBR is widely used in clinic with low toxicity, our results are potentially important for the development of a novel combinatorial therapy with BBR and DOX in the treatment of lung cancer.

Aberrant Expression of MicroRNA-15a and MicroRNA-16 Synergistically Associates with Tumor Progression and Prognosis in Patients with Colorectal Cancer.

The aim of this study was to reveal the associations of microRNA miR-15a and miR-16 dysregulation with clinicopathological characteristics and prognosis in patients with colorectal cancer. As a result, we found that miR-15a and miR-16 expression, detected by quantitative real time-PCR, were both significantly downregulated in colorectal cancer tissues compared with adjacent colorectal mucosa (both P < 0.001). Particularly, the expression levels of miR-15a in colorectal cancer tissues were positively correlated with those of miR-16 significantly (Spearman correlation coefficient r = 0.652, P < 0.001). In addition, miR-15a and/or miR-16 downregulation were all significantly associated with advanced TNM stage (all P < 0.05), poorly histological grade (all P < 0.05), and positive lymph node metastasis (all P < 0.05). Moreover, the survival analysis identified miR-15a expression, miR-16 expression, and miR-15a/miR-16 combination as independent predictors of both unfavorable overall survival and disease-free survival. Interestingly, the prognostic value of miR-15a/miR-16 combination was more significant than miR-15a or miR-16 expression alone. Collectively, the aberrant expression of miR-15a and miR-16 could be used to stratify patients with aggressive tumor progression of colorectal cancer. The combined pattern of miR-15a and miR-16 downregulation has a significant value for distinguishing patients with a worse prognosis of colorectal cancer after surgery.

Hepatocyte function within a stacked double sandwich culture plate cylindrical bioreactor for bioartificial liver system.

Bioartificial liver (BAL) system is promising as an alternative treatment for liver failure. We have developed a bioreactor with stacked sandwich culture plates for the application of BAL. This bioreactor design addresses some of the persistent problems in flat-bed bioreactors through increasing cell packing capacity, eliminating dead flow, regulating shear stress, and facilitating the scalability of the bioreactor unit. The bioreactor contained a stack of twelve double-sandwich-culture plates, allowing 100 million hepatocytes to be housed in a single cylindrical bioreactor unit (7 cm of height and 5.5 cm of inner diameter). The serial flow perfusion through the bioreactor increased cell-fluid contact area for effective mass exchange. With the optimal perfusion flow rate, shear stress was minimized to achieve high and uniform cell viabilities across different plates in the bioreactor. Our results demonstrated that hepatocytes cultured in the bioreactor could re-establish cell polarity and maintain liver-specific functions (e.g. albumin and urea synthesis, phase I&II metabolism functions) for seven days. The single bioreactor unit can be readily scaled up to house adequate number of functional hepatocytes for BAL development.

Tumor-enhancing activity of Basigin expression in gallbladder carcinoma and its prognostic role.

Basigin (EMMPRIN/CD147) is a multifunctional membrane glycoprotein that is overexpressed in many solid tumors and is involved in tumor invasion and angiogenesis. The main purpose of this study was to investigate the tumor-enhancing activity of Basigin in a gallbladder carcinoma (GC) cell line and in primary GC tissues. A system that blocks Basigin in the human primary GC cell line GBC-SD was developed using RNA interference. GBC-SD cells were transfected with the small interfering RNA that target Basigin, then the proliferative, invasive and migration activities of the cells were assayed in vitro. Additionally, tissue samples from 98 patients with GC and 26 patients with chronic cholecystitis were stained with anti-Basigin antibody for immunohistochemical analysis. Furthermore, the association of Basigin expression with the clinicopathological characteristics and prognosis of the patients was analyzed. siRNA-treated GBC-SD cells exhibited significantly decreased growth ability, invasion and migration capacities compared to control cells in vitro. Moreover, clinicopathological analysis demonstrated that the intensity of Basigin staining in cancerous tissue was significantly associated with the histological type (p=0.02), distant metastasis (p<0.01) and Nevin stage (p<0.01) of GC. A proportional hazards model revealed the survival rate of patients with stronger Basigin expression to be the lowest (p<0.01). These results suggest that Basigin is a prognostic marker and potential therapeutic target for patients with GC.

Laminar-flow immediate-overlay hepatocyte sandwich perfusion system for drug hepatotoxicity testing.

Drug hepatotoxicity testing requires in vitro hepatocyte culture to maintain the long-term and stable liver specific functions. We developed a drug testing platform based on laminar-flow immediate-overlay hepatocyte sandwich perfusion culture. The immediate-overlay sandwich (collagen-coated porous polymeric membrane as top overlay) protects the cells and integrity of the top collagen matrix from the impact of flow. A bioreactor was designed that allowed proper control of shear stress and mass transfer. The culture parameters such as the optimal perfusion initiation time and flow rate were systematically and mechanistically determined. The optimized system could re-establish hepatocyte polarity to support biliary excretion and to maintain other liver specific functions, such as the biotransformation enzyme activities, for two weeks that extended the usable in vitro hepatocyte-based drug testing window. When the perfusion cultured hepatocytes from days 7 or 14 were used for drug testing, the APAP-induced hepatotoxicity measurements were more sensitive and consistent over time than the static culture control, enabling further exploitations in large-scale drug testing applications.

Fibro-C-Index: comprehensive, morphology-based quantification of liver fibrosis using second harmonic generation and two-photon microscopy.

We develop a standardized, fully automated, quantification system for liver fibrosis assessment using second harmonic generation microscopy and a morphology-based quantification algorithm. Liver fibrosis is associated with an abnormal increase in collagen as a result of chronic liver diseases. Histopathological scoring is the most commonly used method for liver fibrosis assessment, where a liver biopsy is stained and scored by experienced pathologists. Due to the intrinsic limited sensitivity and operator-dependent variations, there exist high inter- and intraobserver discrepancies. We validate our quantification system, Fibro-C-Index, with a comprehensive animal study and demonstrate its potential application in clinical diagnosis to reduce inter- and intraobserver discrepancies.

[Expression and clinical significance of highly expressed protein in cancer (Hec 1) in human primary gallbladder carcinoma].

AIM: To investigate the relationship between the expression of highly expressed protein in cancer (Hec 1) and infiltration, metastasis and prognosis of human primary gallbladder carcinoma (PGC). METHODS: The expression of Hec 1 in was detected 108 patients with PGC by SABC immunohistochemistry with 15 cases of chronic cholecystitis as control. Then, a 5 year follow-up was carnedout in 96 out of 108 patients to analyze the correlation between Hec 1 and prognosis of the patients. RESULTS: The clinical pathological characteristics of PGC and clinical outcome of the patients were associated with the expression of Hec 1. Hec 1 was highhy expressed in cancer tissues with lymph node metastasis and poor differentiation. Especially, a statistical correlation was found with more advanced Nevin stages of PGC (P < 0.05). Moreover, the 5-year survival rate of the patients with PGC whose expression of Hec 1 was positive was significantly lower than that of the patients without Hec 1 expression (P < 0.01). CONCLUSION: Hec 1 may be associated with the development, infiltration and metastasis of PGC. The combination of Hec 1 expression in cancer tissues with clinical staging may faliliate the auurate predication of patients' prognosis.