Long noncoding RNA XIST regulates the EGF receptor to promote TGF-ß1-induced epithelial-mesenchymal transition in pancreatic cancer.

BACKGROUND: This study focuses on the lncRNA XIST (X inactive-specific transcript), an lncRNA involved in multiple human cancers, and investigates the functional significance of XIST and the molecular mechanisms underlying the epithelial-mesenchymal transition (EMT) in pancreatic cancer (PC). METHODS: Clinical specimens from 25 patients as well as 5 human PC cell lines were analyzed for XIST, YAP, and microRNA(miR)-34a by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. To investigate how XIST influences cell proliferation, invasiveness, and apoptosis in PC, we performed the CCK-8 assays, Transwell assays, and flow cytometry. Luciferase reporter assays, qRT-PCR, and Western blot were applied to prove that miR-34a directly binds to XIST. RESULTS: Up-regulation of XIST and Yes associated protein (YAP) and down-regulation of miR-34a were consistently observed in the clinical specimens and PC cell lines. Silencing XIST reduced the expression of YAP and suppressed transforming growth factor (TGF)-ß1-induced EMT, while over-expression of XIST increased the expression of YAP and promoted EMT. In addition, inhibition of epidermal growth factor receptor (EGFR) hampered the XIST-promoted EMT. The results from the luciferase reporter assays confirmed that miR-34a directly targets XIST and suggested that XIST regulates cell proliferation, invasiveness, and apoptosis in PC by sponging miR-34a. CONCLUSIONS: XIST promotes TGF-ß1-induced EMT by regulating the miR-34a-YAP-EGFR axis in PC.

[Mycophenolate mofetil-based calcineurin inhibitor reduced immunosuppressive protocol for the improvement of renal dysfunction after liver transplantation].

OBJECTIVE: Renal dysfunction caused by calcineurin inhibitor (CNI) after liver transplantation is a major complication among the long-term surviving recipients. Several studies have demonstrated that the adverse events could be prevented or avoided by mycophenolate mofetil (MMF)-based CNI reduced immunosuppressive protocol. In this retrospective study, we analyzed the middle-term effect of this regimen upon improving the CNI-associated renal dysfunction. METHODS: 124 OLT recipients' data within the recent three years were reviewed in this study. RESULTS: Renal dysfunction developed in 14 cases and its incidence was 11.29%. Five cases of them were from cyclosporine A (CsA) group and 9 from tacrolimus (TAC) group. The postoperative time ranged from 3-39 months with a mean follow-up duration of 19.26 +/- 9.30 months. The interval between renal impairment and surgery was 12.92 +/- 9.04 (1-31) months. CNI were reduced stepwise by about 55% in TAC group (TAC 2.60 +/- 1.14 mg/d vs 1.10 +/- 0.22 mg/d; t = 3.000, P = 0.040) and about 70% in CsA group (CsA 370 +/- 179 mg/d vs 105 +/- 27; t = 3.359, P = 0.028). Serum creatinine had decreased from 139 +/- 46 micromol/L to 122 +/- 46 micromol/L (t = 3.152, P = 0.004), 114 +/- 53 micromol/L (t = 4.180, P = 0.001) and 93 +/- 18 micromol/L (t = 4.721, P = 0.000) after administrating a mean MMF dose of 1.05 +/-0.15 g/d (0.5-1.5 g/d) for 1, 2 and 3 months respectively. And the creatinine clearance rate increased from 51.83 +/- 21.28 ml/min to 63 +/- 22 ml/min (t = -3.439, P = 0.004), 69 +/- 25 ml/min (t = -4.207, P = 0.001) and 79 +/- 25 m/min (t = -6.149, P = 0.000) during the corresponding period. Improvement was maintained within a follow-up period of 6.00 +/- 3.37 (3-14) months without major immunological or non-immunological side effects, except for 1 recipient from another institution who died of CNI-associated renal failure within 1 month after burst. 71.43% (10/14) of recipients achieved the normalization of serum creatinine and 21.43% (3/14) experienced a significant reduction in their serum creatinine levels. Conclusions MMF-based CNI reduced immunosuppressive protocol can improve substantially CNI-associated renal dysfunction after liver transplantation. And the long-term surviving recipients have excellent profiles of safety and tolerance.

Establishment of hepatocellular carcinoma multidrug resistant monoclone cell line HepG2/mdr1.

BACKGROUND: The multidrug resistance (MDR) associated with the expression of the mdr1 gene and its product P-glycoprotein is a major factor in the prognosis of hepatocellular carcinoma cell (HCC) patients treated with chemotherapy. Our study was to establish a stable HCC MDR cell line where a de novo acquisition of multidrug resistance specifically related to overexpression of a transgenic mdr1. METHODS: The 4.5-kb mdr1 cDNA obtained from the plasmid pHaMDR1-1 was cloned into the PCI-neo mammalian expression vector, later was transferred by liposome to human hepatocarcinoma cell line HepG2. Then the transfected HepG2 cells resisting G418 were clustered and cultured and the specific fragment of mdr1 cDNA, mRNA and the P-glycoprotein (Pgp) in these HepG2 cells were detected by PCR, RT-PCR and flow cytometry, respectively. The accumulation of the daunorubicin was determinated by flow cytometry simultaneously. The nude mice model of grafting tumour was established by injecting subcutaneously HepG2/mdr1 cells in the right axilla. When the tumour diameter reached 5 mm, adriamycin was injected into peritoneal cavity. The size and growth inhibition of tumour were evaluated. RESULTS: The mdr1 expression vector was constructed successfully and the MDR HCC line HepG2/mdr1 developed. The PCR analysis showed that the specific fragment of mdr1 cDNA in HepG2/mdr1 cells, but not in the control group HepG2 cells. Furthermore, the content of the specific fragment of mdr1 mRNA and Pgp expression in HepG2/mdr1 cells were (59.7 +/- 7.9)% and (12.28 +/- 2.09)%, respectively, compared with (16.9 +/- 3.2)% and (3.07 +/- 1.06)% in HepG2 cells. In the nude mice HCC model, the tumour genes of both groups were identified. After ADM therapy, the mean size of HepG2 cell tumours was significantly smaller than HepG2/mdr1 cell tumours. CONCLUSION: The approach using the transfer of mdr1 cDNA may be applicable to the development of MDR hepatocarcinoma cell line, whose MDR mechanism is known. This would provide the experimental basis of MDR research.

[Prophylaxsis against recurrance of hepatitis B virus after liver transplantation].

OBJECTIVE: To summarize the clinical data in preventing HBV recurrence after liver transplantation and explore a optimal individual protocol in prophylaxis of HBV recurrence. METHODS: We retrospected outcomes in 195 recipients who underwent a liver transplantation for HBV-related liver disease between June 2004 and July 2008. According to the anti-virus protocol these recipients are divided into two groups as following: group A received a protocol of combination treatment of lamivudine with HBIG, and group B with combination treatment of adefovir with HBIG. With mean follow-up of 23.7 months, HBV recurrent rate was observed in overall and each group separately. RESULTS: A total of 195 liver transplant recipients were identified that met the study criteria. At the sixth and eleventh month after operation, HBV recurrence appeared in 2 recipients, each in two groups, which were due to LAM cessation and HBV mutation respectively. Recurrent rate was 0.6% in group A, 3.7% in group B and 1% in total. There was no significant difference in HBV recurrent rate between group A and B. CONCLUSION: Lamivudine combined with HBIg should be considered as a reliable method in preventing HBV recurrence after liver transplantation. Better outcomes can be achieved by individual anti-virus protocol and HBIg administration according to HBV status in recipient.