Diagnosis and surgical treatment of retroperitoneal paraganglioma: A single-institution experience of 34 cases.

The present study aimed at identifying the clinical, radiological and pathological characteristics of retroperitoneal paragangliomas, and determining the association between the tumor features and the prognosis of patients following surgery. A total of 34 patients with retroperitoneal paragangliomas, who underwent resection between November 1999 and December 2015, were included in the present retrospective study. The patients' demographics, clinical symptoms and signs, tumor functional status, surgical procedure, intraoperative results, tumor pathology, radiological results, and postoperative survival time were recorded and analyzed. Of the 34 patients, the most common type of presenting symptom was abdominal mass (46%), followed by hypertension (39%) and abdominal pain (32%). Functional tumors occurred in 20 patients (59%). Computed tomography (CT) and magnetic resonance imaging revealed soft-tissue masses, with marked enhancement in the arterial phase, indicative of retroperitoneal paragangliomas. The preoperative CT diagnostic accuracy rate between 2010 and 2015 was markedly improved, compared with that between 1999 and 2009. The tumors were primarily located close to the renal arteries and veins surrounding the abdominal aorta and inferior vena cava. With the exception of one malignant paraganglioma, the majority of paragangliomas were positive for chromogranin A, S-100 protein, vimentin and heat-shock protein 90, and exhibited decreased expression of Ki-67 antigen and insulin-like growth factor 2. All tumors were completely removed by surgery. Distant metastasis, but not tumor size, functional status and local invasion, was markedly associated with survival. The preoperative diagnostic accuracy rate of retroperitoneal paragangliomas may be improved by focusing on the predilection sites and CT characteristics. In addition, immunohistochemical markers were useful to determine tumor malignancy. Complete surgical resection was appropriate for all patients and postoperative survival time was identified to be associated with tumor metastasis.

GSK-3ß suppresses the proliferation of rat hepatic oval cells through modulating Wnt/ß-catenin signaling pathway.

AIM: Glycogen synthase kinase 3ß (GSK-3ß) plays a crucial role in hepatic biology, including liver development, regeneration, proliferation and carcinogenesis. In this study we investigated the role of GSK-3ß in regulation of growth of hepatic oval cells in vitro and in liver regeneration in partially hepatectomized rats. METHODS: WB-F344 cells, the rat hepatic stem-like epithelial cells, were used as representative of oval cells. Cell viability was examined using a WST-8 assay. The cells were transfected with a recombinant lentivirus expressing siRNA against GSK-3ß (GSK-3ßRNAiLV) or a lentivirus that overexpressed GSK-3ß (GC-GSK-3ßLV). Adult rats underwent partial (70%) hepatectomy, and liver weight and femur length were measured at d 7 after the surgery. The expression of GSK-3ß, phospho-Ser9-GSK-3ß, ß-catenin and cyclin D1 was examined with immunoblotting assays or immunohistochemistry. RESULTS: Treatment of WB-F344 cells with the GSK-3ß inhibitor SB216763 (5 and 10 µmol/L) dose-dependently increased the levels of phospho-Ser9-GSK-3ß, but not the levels of total GSK-3ß, and promoted the cell proliferation. Knockout of GSK-3ß with GSK-3ßRNAiLV increased the cell proliferation, whereas overexpression of GSK-3ß with GC-GSK-3ßLV decreased the proliferation. Both SB216763 and GSK-3ßRNAiLV significantly increased the levels of ß-catenin and cyclin D1 in the cells, whereas GSK-3ß overexpression decreased their levels. In rats with a partial hepatectomy, administration of SB216763 (2 mg/kg, ip) significantly increased the number of oval cells, the levels of phospho-Ser9-GSK-3ß, ß-catenin and cyclin D1 in liver, as well as the ratio of liver weight to femur length at d 7 after the surgery. CONCLUSION: GSK-3ß suppresses the proliferation of hepatic oval cells by modulating the Wnt/ß-catenin signaling pathway.

[Role of miR-21 in rat hepatic oval cell proliferation and activation].

OBJECTIVE: To investigate the possible mechanisms of miR-21-mediated regulation of proliferation and activation of hepatic oval cells. METHODS: The 2-acetamidofluorene/partial hepatectomy (2-AAF/PH) method was applied to generate hepatic oval cell activation model in male Sprague-Dawley rats; after the 7 days of 2-AAF/PH or PH alone (control), the rats were sacrificed at 0 h, 6 h, 12 h, 24 h, 72 h and 168 h. Expression of miR-21 was detected by real-time PCR and differences between groups were evaluated using the two-sample t-test. Differential transcription of miR-21 target genes was assessed bioinformatically, and with western blotting to detect changes in protein expression of the target gene. RESULTS: The rat hepatic oval cell activation model was successfully established.The 2-AAF/PH rats showed miR-21 expression beginning to increase at 12 h, peaking at 24 h, and decreasing thereafter until an increase at 168 h.For the control group, the miR-21 expression began to increase at 6 h, until 24 h when expression began steadily declining to reach the original level.Compared to the control group, the experimental group showed expression of miR-21 that was significantly less at 6 h (P=0.039, t =3.029) and significantly more at 24 h and 168 h (P=0.026, t =-3.433 and P=0.007, t =-5.105). Among the predicted target genes of miR-21 were WW domain containing E3 ubiquitin protein ligase 1 (WWD), Smad family member 7 (Smad7), and polybromo-1 (Pbrm1).Smad7 protein expression began to decrease at 6 h in the control group, until reaching its minimum at 24 h when it increased; in the experimental group, SMAD7 expression increased at 6 h, then began to decrease with the minimum detected at 168 hour.In the control group, the Smad7 mRNA expression decreased slightly at 6 h, then began to increase, reaching its peak at 24 h when the expression fell to the original level. In the experimental group, the Smad7 mRNA expression began to increase at 6 h and reached its peak at 24 h when it decreased; the expression was little more than its original level at 168 h.Smad7 protein expression was negatively correlated with miR-21, and Smad7 mRNA expression was positively correlated with miR-21 but negatively correlated with Smad7 protein expression. CONCLUSION: miR-21 may play a vital role in the activation and proliferation of hepatic oval cells.As a target gene of miR-21, Smad7 might be involved in the process.

[Effects of glycogen synthase kinase 3ß overexpression in rat and glycogen synthase kinase 3ß inhibitor SB-216763 on proliferation of hepatic oval cells].

OBJECTIVE: To research the effects of glycogen synthase kinase (GSK3ß) overexpression and GSK3ß inhibitor SB-216763 on the proliferation of hepatic oval cells in rats and its regulatory mechanisms by Wnt signaling pathway. METHODS: The hepatic oval cells WBF-344 were divided into the blank control group, GSK3ß over-expression group, DMSO control group and GSK3ß inhibitor groups, while the inhibitor groups set up three concentration gradients, that was 1, 5, 10 µmol/L. Using the GSK3ß over-expression lentivirus, which had been identified correctly, and SB-216763 dealt with the cells WBF-344. The cells morphology of each group was observed under the phase contrast inverted microscope, and the expression of fluorescence in the lentivirus-transfected group was observed under the fluorescent microscope. The proliferation of each group cells was tested by CCK8 kits. The cells' apoptosis was detected by AnnexinV-FITC/PI kits. The expression of GSK3ß, ß-catenin and cyclin D1 were detected by Western blot. RESULTS: The cells of GSK3ß over-expression group were fewer and obvious aging. However, in each inhibitor added group, the cells' division and proliferation was vigorous, and the condition was good. Moreover, the cells' proliferation was getting stronger with the concentration of SB-216763 increasing. A large number of green fluorescence was expressed in the lentivirus-transfected cells. The cells' proliferation in GSK3ß over-expression group restrained (t = 7.178, P < 0.01, as compared with control), while the cells' proliferation was vigorous in inhibitor groups (F = 45.030, P < 0.01, as compared with control). Flow Cytometry showed that the cells apoptosis was significant in GSK3ß over-expression group. Western blot showed that the expression of GSK3ß was increased, while the expression of ß-catenin and cyclin D1 was decreased in the over-expression group. The expression of GSK3ß had no significant difference among the control group and inhibitor groups. However, the expression of ß-catenin and cyclin D1 was significantly increased with the concentration of SB-216763 increasing. CONCLUSIONS: The overexpression of GSK3ß can inhibit the Wnt signaling pathway, thus restrain the cells' proliferation and promotes apoptosis. SB-216763 can activate the Wnt pathway, thus promotes cells' proliferation.

[Surgical treatment and prognostic analysis of retroperitoneal paragangliomas: a study of 19 cases].

OBJECTIVE: To investigate the clinical characteristics, surgical treatment and prognostic analysis of retroperitoneal paragangliomas and to enhance the diagnostic and therapeutic levels of retroperitoneal paragangliomas. METHODS: The clinical data of all patients undergoing paraganglioma resection at our department from November 1999 to March 2009 were retrospectively analyzed. The parameters included clinical manifestations, tumor function, surgical findings, operative approach, tumor pathology, imaging study and post-operative survival time. RESULTS: (1) The ratio of male to female was 1.375:1 and the median age 50 years old. The most common presenting symptom was abdominal mass (9/19, 47%). And the preoperative CT misdiagnosis rate was high (89%). (2) The most common tumor location was periaortic and percival (9/19, 47%). The average maximal diameter of tumors was 8.6 cm. 58% (11/19) tumors had integral peplow, 42% (8/19) adhered to adjacent organs and 26% (5/19) required adjacent organ resection. (3) The rate of functional tumor was 63% (12/19). Preoperative and intra-operative hypertension occurred in 67% (8/12) and 33% (4/12) respectively. (4) Immunohistochemical staining was performed in 18 tumors of 16 patients. Among all tumors, 89% (16/18) showed positive immunoreactivity for chromogranin and 67% (12/18) for S-100. PCNA staining showed different proliferative activities (0%-48% positive). Only malignant tumors showed positive immunoreactivity for Ki-67 staining and P53 staining (20% & 34% respectively). (5) The overall 5-year survival was 77%. Survival was significantly worse after metastasis (χ2=6.604, P=0.01). But it was not dependent on tumor diameter (χ2=3.208, P=0.201), the secreting function of tumor (χ2=0.121, P=0.728) and the status of tumor margins (χ2=0.036, P=0.849). CONCLUSION: It is difficult to make an early diagnosis of retroperitoneal paragangliomas. Survival is significantly worse after metastasis. Lifelong follow-up for recurrence is important. And it is absolutely essential to perform immunohistochemical staining for tumors.