Malignant transformation rate of oral leukoplakia in the past 20 years: A systematic review and meta-analysis.

BACKGROUND: This meta-analysis aimed to assess the rate of malignant transformation (MT) of oral leukoplakia (OL) and to study potential risk factors for the MT of OL into oral squamous cell carcinoma (OSCC). METHOD: We performed a bibliographic search on nine electronic databases, including PubMed, MEDLINE, and Wanfang Data, for data on the MT rate of OL. Possible risk factors were calculated using Comprehensive Meta-Analysis and Open Meta [Analyst] software. RESULTS: The pooled proportion of OL MT for the total population described in the 26 selected studies was 7.20% (95% confidence interval: 5.40-9.10%). Nonhomogeneous type lesions, higher grades of dysplasia, the location of the lesion (tongue and multifocal), and female sex had significant effects on the MT of OL. CONCLUSION: OL tended to develop into OSCC (7.2%), and those with significant MT risk factors should be subjected to regular follow-up and observation. However, we require large-scale prospective studies to validate these results, together with unified clinicopathological diagnostic criteria, standardized risk factor recording/assessment methods, and long-term follow-up guidelines.

Superior pancreatic lymphadenectomy with portal vein priority via posterior common hepatic artery approach in laparoscopic radical gastrectomy.

BACKGROUND: D2 lymph node dissection for advanced gastric cancer is advocated, and station 8p lymph node should be considered in selected patients, which is, however, technically difficult. AIM: To introduce a new and easy-to-perform procedure for dissection of the lymph nodes superior to the pancreas. METHODS: A series of patients who underwent laparoscopic gastrectomy for gastric cancer were retrospectively included with utilization of a new procedure for superior pancreatic lymphadenectomy (LND) with portal vein priority via the posterior common hepatic artery approach (SPLD-PPPH) based on a newly defined portal triangle. The surgical outcome of the patients, as well as the efficacy and safety of SPLD-PPPH are reported. RESULTS: A total of 51 patients were included with most of them being male (n = 34, 66.7%). According to the 8th edition of AJCC TNM staging, there were four (7.8%) patients in stage I, 13 (25.5%) in stage II, 33 (64.7%) in stage III and one (2.0%) in stage IV. The average duration for LND was about 1 h (67.7 ± 6.9 min). After surgery, four patients developed morbidities, but all were treated successfully with no perioperative mortality. Among the 51 patients included, the percentage of patients who had lymph node metastasis at station 8p was 9.8%. Of note, with a total of 14 lymph nodes harvested at station 8p, the incidence of nodal metastasis was 14.3%. CONCLUSION: About one in 10 patients with advanced gastric cancer had nodal metastasis at station 8p. The new approach of SPLD-PPPH is safe and effective for D2+ LND during laparoscopic radical gastrectomy.

Author Correction: Laparoscopic Versus Open Liver Resection for Colorectal Liver Metastases: A Comprehensive Systematic Review and Meta-analysis.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Distinct MDCT imaging features to differential diagnosis of hepatic paragonimiasis and small hepatocellular carcinoma.

We used multi-row detector computed tomography (MDCT) to identify the distinguishing characteristics of hepatic paragonimiasis and small hepatocellular carcinoma lesions. We analyzed a cohort of 60 patients, of which 26 had hepatic paragonimiasis and 34 with a small (≤ 3cm) hepatocellular carcinoma. MDCT detected 65 lesions that were retrospectively reviewed and analyzed based on their imaging features. Both groups showed distinct MDCT imaging features that could contribute to an accurate diagnosis. In the paragonimiasis group, 75% (21/28) lesions were located in the hepatic subcapsular region, whereas only 10.8% (4/37) of lesions in the hepatocellular carcinoma group were subcapsular. Most hepatic paragonimiasis lesions (57.1%; 16/28) also showed characteristic tubular or tunnel features that were not present in hepatocellular carcinomas. Further, 71.4% (20/28) paragonimiasis lesions were rim enhanced with irregular tract-like non-enhanced internal areas with a characteristic target loop, while 94.6% (35/37) of small hepatocellular carcinoma lesions showed homogenous enhancement in the arterial and venous phase. In addition, the period CT values for hepatic paragonimiasis were less than those of hepatic carcinomas (P<0.001). These clinically significant findings illustrate the diagnostic features that enable one to distinguish hepatic paragonimiasis from small hepatocellular carcinomas.

Laparoscopic Versus Open Liver Resection for Colorectal Liver Metastases: A Comprehensive Systematic Review and Meta-analysis.

The effects of laparoscopic liver resection (LLR) and open liver resection (OLR) on oncological outcomes for colorectal cancer liver metastases (CCLM) remain inconclusive. Major databases were searched from January 1992 to October 2016. Effects of LLR vs OLR were determined. The primary endpoints were oncological outcomes. In total, 32 eligible non-randomized studies with 4697 patients (LLR: 1809, OLR: 2888) were analyzed. There were higher rates of clear surgical margins (OR: 1.64, 95%CI: 1.32 to 2.05, p < 0.00001) in the LLR group, without significant differences in disease recurrence, 3- or 5-year overall survival(OS) and disease free survival(DFS) between the two approaches. LLR was associated with less intraoperative blood loss (WMD: -147.46 [-195.78 to -99.15] mL, P < 0.00001) and fewer blood transfusions (OR: 0.41 [0.30-0.58], P < 0.00001), but with longer operation time (WMD:14.44 [1.01 to 27.88] min, P < 0.00001) compared to OLR. Less overall morbidity (OR: 0.64 [0.55 to 0.75], p < 0.00001) and shorter postoperative hospital stay (WMD: -2.36 [-3.06 to -1.66] d, p < 0.00001) were observed for patients undergoing LLR, while there was no statistical difference in mortality. LLR appears to be a safe and feasible alternative to OLR in the treatment of CCLM in selected patients.

The research progress of Gli1 in the regulation of epithelial mesenchymal transition in oral squamous cell car-cinoma / 口腔疾病防治

@#HH (hedgehog) signal pathway consists the hedgehoge ligand (Shh、Ihh and Dhh), the Patch and Smo membrane protein complex and Zinc finger transcription factor Gli (Gli1, Gli2, Gli3). In HH (hedgehog) signaling pathway, Gli1 not only plays a dominant and decisive role in the zinc finger transcription factor Gli (Glioma-associated oncogene homolog) family, but also includes epithelial-mesenchymal transition (EMT) and oral squamous cell carcinoma, tumor invasion and metastasis. The research on oral squamous cell carcinoma and Shh/Gli1 signal axis is rare. In this paper, the squamous cell carcinoma of oral epithelial mesenchymal transformation and correlation study of quality Gli1 is reviewed.

Clinical impact of preoperative acute pancreatitis in patients who undergo pancreaticoduodenectomy for periampullary tumors.

AIM: To investigate the impact of preoperative acute pancreatitis (PAP) on the surgical management of periampullary tumors. METHODS: Fifty-eight patients with periampullary tumors and PAP were retrospectively analyzed. Thirty-four patients who underwent pancreaticoduodenectomy (PD) and 4 patients who underwent total pancreatectomy were compared with a control group of 145 patients without PAP during the same period. RESULTS: The preoperative waiting time was significantly shorter for the concomitant PAP patients who underwent a resection (22.4 d vs 54.6 d, P < 0.001) compared to those who did not. The presence of PAP significantly increased the rate of severe complications (Clavien grade 3 or higher) (17.6% vs 4.8%, P = 0.019) and lengthened the hospital stay (19.5 d vs 14.5 d, P = 0.006). A multivariate logistic regression analysis revealed that PAP was an independent risk factor for postoperative pancreatic fistula (OR = 2.91; 95%CI: 1.10-7.68; P = 0.032) and severe complications (OR = 4.70; 95%CI: 1.48-14.96; P = 0.009) after PD. There was no perioperative mortality. CONCLUSION: PAP significantly increases the incidence of severe complications and lengthens the hospital stay following PD. PD could be safely performed in highly selective patients with PAP.

EGCG inhibits properties of glioma stem-like cells and synergizes with temozolomide through downregulation of P-glycoprotein inhibition.

RATIONAL: Combination therapy to inhibit cancer stem cells may have important clinical implications. Here, we examine the molecular mechanisms by which epigallocatechin gallate (EGCG), a bioactive polyphenol in green tea, inhibits the stem cell characteristics of glioma stem-like cells (GSLCs) and synergizes with temozolomide (TMZ), a DNA-methylating agent commonly used as first-line chemotherapy in gliomas. GSLCs were enriched from the human glioblastoma cell line U87 using neurosphere culture. Cells were analyzed using flow cytometry, quantitative PCR, and western blotting. Compared to U87 cells, a higher percentage of U87 GSLCs remained in the G0/G1 phase, with downregulation of the cell-cycle protein CylinD1 and overexpression of stem cell markers CD133 and ALDH1. The drug-resistance gene ABCB1 (but not ABCG2 or MGMT) also showed high mRNA and protein expression. The resistance index of U87 GSLCs against TMZ and carmustine (BCNU) was 3.0 and 16.8, respectively. These results indicate that U87 GSLCs possess neural stem cell and drug-resistance properties. Interestingly, EGCG treatment inhibited cell viability, neurosphere formation, and migration in this cell model. EGCG also induced apoptosis, downregulation of p-Akt and Bcl-2, and cleaving PARP in a dose-dependent manner. Importantly, EGCG treatment significantly downregulated P-glycoprotein expression but not that of ABCG2 or MGMT and simultaneously enhanced sensitivity to TMZ. Our study demonstrates that the use of EGCG alone or in combination with TMZ may be an effective therapeutic strategy for glioma.

Solid pseudopapillary tumor of the pancreas in male patients: report of 16 cases.

AIM: To investigate the clinical characteristics, surgical strategies and prognosis of solid pseudopapillary tumors (SPTs) of the pancreas in male patients. METHODS: From July 2003 to March 2013, 116 patients were diagnosed with SPT of the pancreas in our institution. Of these patients, 16 were male. The patients were divided into two groups based on gender: female (group 1) and male (group 2). The groups were compared with regard to demographic characteristics, clinical presentations, surgical strategies, complications and follow-up outcomes. RESULTS: Male patients were older than female patients (43.1 ± 12.3 years vs 33.1 ± 11.5 years, P = 0.04). Tumor size, location, and symptoms were comparable between the two groups. All patients, with the exception of one, underwent complete surgical resection. The patients were regularly followed up. The mean follow-up period was 58 mo. Two female patients (1.7%) developed tumor recurrence or metastases and required a second resection, and two female patients (1.7%) died during the follow-up period. CONCLUSION: Male patients with SPT of the pancreas are older than female patients. There are no significant differences between male and female patients regarding surgical strategies and prognosis.

Synergistic mechanism for tetrandrine on fluconazole against Candida albicans through the mitochondrial aerobic respiratory metabolism pathway.

We found that tetrandrine (TET) can reverse the resistance of Candida albicans to fluconazole (FLC) and that this interaction is associated with the inhibition of drug efflux pumps. Mitochondrial aerobic respiration, which plays a major role in C. albicans metabolism, is the primary source of ATP for cellular processes, including the activation of efflux pumps. However, it was unclear if TET exerts its synergistic action against C. albicans via its impact on the mitochondrial aerobic respiratory metabolism. To investigate this mechanism, we examined the impact of FLC in the presence or absence of TET on two C. albicans strains obtained from a single parental source (FLC-sensitive strain CA-1 and FLC-resistant strain CA-16). We analysed key measures of energy generation and conversion, including the activity of respiration chain complexes I and III (CI and CIII), ATP synthase (CV) activity, and the generation of reactive oxygen species (ROS), and studied intracellular ATP levels and the mitochondrial membrane potential (ΔΨm), which has a critical impact on energy transport. Mitochondrial morphology was observed by confocal microscopy. Our functional analyses revealed that, compared with strains treated only with FLC, TET+FLC increased the ATP levels and decreased ΔΨm in CA-1, but decreased ATP levels and increased ΔΨm in CA-16 (P<0.05). Additionally, CI, CIII and CV activity decreased by 23-48%. The production of ROS increased by two- to threefold and mitochondrial morphology was altered in both strains. Our data suggested that TET impacted mitochondrial aerobic respiratory metabolism by influencing the generation and transport of ATP, reducing the utilization of ATP, and resulting in the inhibition of drug efflux pump activity. This activity contributed to the synergistic action of TET on FLC against C. albicans.

4E-BP1 regulates the sensitivity of human glioma cells to chemotherapy through PI3K/Akt/mTOR-independent pathway.

Drug resistance is one of the most formidable obstacles for treatment of glioma. Eukaryotic initiation factor 4E-binding protein (4E-BP1), a key component in the rate-limiting step of protein translation initiation, is closely associated with poor prognosis in multiple tumor types. However, it is unclear whether 4E-BP1 is involved in the drug resistance of human glioma. Herein we show that the expression of 4E-BP1 in human SWOZ2-BCNU drug-resistant glioma cells is significantly lower than that of the parent SWOZ2 cell line. Moreover, down-regulation of 4E-BP1 by short interfering RNA significantly impaired the sensitivity of SWOZ2 and U251 cells to carmustine (BCNU). Furthermore, overexpression of 4E-BP1 with plasmid transfection regained this sensitivity. Clinical studies showed that the expression levels of 4E-BP1 in primary glioma tissues were markedly higher than those of recrudescent glioma tissues. Taken together, our results suggest that 4E-BP1 is a novel protein that contributes to acquired drug resistance and it may be a potential target for reversing drug resistance in human glioma.

Epithelial-to-mesenchymal transition is involved in BCNU resistance in human glioma cells.

Chemotherapy has been considered as an effective treatment for malignant glioma; however, it becomes increasingly ineffective with tumor progression. Epithelial-to-mesenchymal transition (EMT) is a process whereby cells acquire morphologic and molecular alterations that facilitate tumor metastasis and progression. Emerging evidence associates chemoresistance with the acquisition of EMT in cancer. However, it is not clear whether this phenomenon is involved in glioma. We used the previously established human glioma cell lines SWOZ1, SWOZ2 and SWOZ2-BCNU to assess cellular morphology, molecular changes, migration and invasion. We found that BCNU-resistant cells showed multiple drug resistance and phenotypic changes consistent with EMT, including spindle-shaped morphology and enhanced pseudopodia formation. Decreased expression of the epithelial adhesion molecule E-cadherin and increased expression of the mesenchymal marker vimentin were observed in BCNU-resistant SWOZ1 and SWOZ2-BCNU cells compared to SWOZ2 cells. Migratory and metastatic potentials were markedly enhanced in SWOZ1 and SWOZ2-BCNU cells compared to SWOZ2 cells. These data suggest that there is a possible link between drug resistance and EMT induction in glioma cells. Gaining further insight into the mechanisms underlying chemoresistance and EMT may enable the restoration of chemosensitivity or suppression of metastasis.

Laparoscopic vs open total gastrectomy for gastric cancer: a meta-analysis.

AIM: To conduct a meta-analysis comparing laparoscopic total gastrectomy (LTG) with open total gastrectomy (OTG) for the treatment of gastric cancer. METHODS: Major databases such as Medline (PubMed), Embase, Academic Search Premier (EBSCO), Science Citation Index Expanded and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library were searched for studies comparing LTG and OTG from January 1994 to May 2013. Evaluated endpoints were operative, postoperative and oncological outcomes. Operative outcomes included operative time and intraoperative blood loss. Postoperative recovery included time to first flatus, time to first oral intake, hospital stay and analgesics use. Postoperative complications comprised morbidity, anastomotic leakage, anastomotic stenosis, ileus, bleeding, abdominal abscess, wound problems and mortality. Oncological outcomes included positive resection margins, number of retrieved lymph nodes, and proximal and distal resection margins. The pooled effect was calculated using either a fixed effects or a random effects model. RESULTS: Fifteen non-randomized comparative studies with 2022 patients were included (LTG - 811, OTG - 1211). Both groups had similar short-term oncological outcomes, analgesic use (WMD -0.09; 95%CI: -2.39-2.20; P = 0.94) and mortality (OR = 0.74; 95%CI: 0.24-2.31; P = 0.61). However, LTG was associated with a lower intraoperative blood loss (WMD -201.19 mL; 95%CI: -296.50--105.87 mL; P < 0.0001) and overall complication rate (OR = 0.73; 95%CI: 0.57-0.92; P = 0.009); fewer wound-related complications (OR = 0.39; 95%CI: 0.21-0.72; P = 0.002); a quicker recovery of gastrointestinal motility with shorter time to first flatus (WMD -0.82; 95%CI: -1.18--0.45; P < 0.0001) and oral intake (WMD -1.30; 95%CI: -1.84--0.75; P < 0.00001); and a shorter hospital stay (WMD -3.55; 95%CI: -5.13--1.96; P < 0.0001), albeit with a longer operation time (WMD 48.25 min; 95%CI: 31.15-65.35; P < 0.00001), as compared with OTG. CONCLUSION: LTG is safe and effective, and may offer some advantages over OTG in the treatment of gastric cancer.

Glycogen Synthase Kinase 3ß Inhibitor (2'Z,3'E)-6-Bromo-indirubin- 3'-Oxime Enhances Drug Resistance to 5-Fluorouracil Chemotherapy in Colon Cancer Cells.

OBJECTIVE: To explore the effects and mechanism of glycogen synthase kinase 3ß (GSK-3ß) inhibitor (2'Z,3'E)-6-bromo-indirubin-3'-oxime (BIO) on drug resistance in colon cancer cells. METHODS: The colon cancer SW480 and SW620 cells were treated with BIO, 5-fluorouracil (5-FU) and BIO/5-FU, separately. Cell cycle distribution, apoptosis level and efflux ability of rhodamine 123 (Rh123) were detected by flow cytometry. The protein expressions of P-glycoprotein (P-gp), multidrug resistance protein 2 (MRP2), thymidylate synthase (TS), ß-catenin, E2F-1 and Bcl-2 were detected by Western blot. ß-catenin and P-gp were stained with double immunofluorescence and observed under a confocal microscope. RESULTS: BIO up-regulated ß-catenin, P-gp, MRP2 and TS, enhanced the efflux ability of Rh123, decreased Bcl-2 protein and gave the opposite effect to E2F-1 protein in SW480 and SW620 cells. Furthermore, BIO significantly inhibited cell apoptosis, increased S and G(2)/M phase cells, and reduced the cell apoptosis induced by 5-FU in SW480 cells, whereas the effects were slight or not obvious in SW620 cells. CONCLUSION: GSK-3ß was involved in drug resistance regulation, and activation of ß-catenin and inhibition of E2F-1 may be the most responsible for the enhancement of 5-FU chemotherapy resistance induced by GSK-3ß inhibitor BIO in colon cancer.

Silencing of MGMT with small interference RNA reversed resistance in human BCUN-resistant glioma cell lines.

BACKGROUND: Our previous study had cloned two glioma cell lines SWOZ1 and SWOZ2 isolated from parental glioma cell line SWO38. The 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) resistance of SWOZ1 was higher than that of SWOZ2. Since O6-methylguanine-DNA methyltransferase (MGMT) was thought to be closely related to BCNU resistance in glioma, this study aimed to explore the function of MGMT in glioma resistant to BCNU. METHODS: A BCNU resistant glioma cell line SWOZ2-BCNU was established. The expression of MGMT was detected in SWOZ1, SWOZ2 and SWOZ2-BCNU. Small interferencing RNA targeting MGMT was used to silence the expression of MGMT in resistant cell lines SWOZ1 and SWOZ2-BCNU. The cytotoxicity of BCNU to these cells was measured using the cell counting kit-8 assay. Statistical analysis was carried out by one-way analysis of variance in statistical package SPSS 13.0. RESULTS: The resistance of SWOZ1 and SWOZ2-BCNU against BCNU was 4.9-fold and 5.3-fold higher than that of SWOZ2. The results of quantitative RT-PCR and Western blotting confirmed that MGMT was both significantly increased in SWOZ1 and SWOZ2-BCNU compared to SOWZ2. After transfection with small interferencing RNA targeting MGMT, a decreased level of MGMT mRNA expression in SWOZ1 and SWOZ2-BCNU for more than 75% compared to negative control was found and confirmed by Western blotting. As a result, the resistance against BCNU was reversed for about 50% both in the BCNU-resistant cell lines SWOZ1 and SWOZ2-BCNU. CONCLUSIONS: Silencing MGMT with specific small interferencing RNA can reverse the BCNU resistant phenotype in these glioma cell lines. MGMT may play an important role both in intrinsic and acquired BCNU-resistance in glioma.

Association of ABCC2 and CDDP-Resistance in Two Sublines Resistant to CDDP Derived from a Human Nasopharyngeal Carcinoma Cell Line.

Cisplatin (CDDP) is one of the most active drugs to treat nasopharyngeal carcinoma (NPC) patients. To further understand the mechanisms of CDDP-resistance in NPC, two CDDP-resistant sublines (CNE2-CDDP and CNE2-CDDP-5Fu) derived from parental NPC cell line CNE2 were established. It was found that at the IC50 level, the resistance of CNE2-CDDP and CNE2-CDDP-5Fu against CDDP was 2.63-fold and 5.35-fold stronger than that of parental CNE2, respectively. Of the four ABC transporters (ABCB1, ABCC1, ABCC2 and ABCG2) related to MDR, only ABCC2 was found to be elevated both in CDDP-resistant sublines, with ABCC2 located in nucleus of CNE2-CDDP-5Fu but not in CNE2-CDDP and parental CNE2. Further research showed that compared to untreated CNE2, the intracellular levels of CDDP were decreased by 2.03-fold in CNE2-CDDP and 2.78-fold in CNE2-CDDP-5Fu. After treatment with PSC833, a modulator of MDR associated transporters including ABCC2, the intracellular level of CDDP was increased in CDDP-resistant sublines, and the resistance to CDDP was partially reversed from 2.63-fold to 1.62-fold in CNE2-CDDP and from 5.35-fold to 4.62-fold in CNE2-CDDP-5Fu. These data indicate that ABCC2 may play an important role in NPC resistant to CDDP.

Establishment and characterization of a new drug surviving cell line Am1010, derived directly from muscle metastases of a human lung adenocarcinoma patient with multi-drug-resistance to cisplatin, taxol, and gefitinib.

AIM: To Characterize a new human lung cancer cell line Am1010, derived from drug-surviving cells (DSCs). METHODS: The Am1010 cell line was established after 4 cycles of chemotherapy from an arm muscle metastatic tumor of a patient diagnosed with lung adenocarcinoma. The cell line has been remained in continuous culture for more than one year during this study. RESULTS: The Am1010 cell line demonstrated in vitro multi-drug-resistance to cisplatin, taxol, and gefitinib. The Am1010 cell doubling time without drug treatment was 42.395 h. The IC(50) value of cisplatin was 4.299 micromol/L and >10 micromol/L for the Am1010 and P0318 (a cell line derived from non-DSCs) cells, respectively. The IC(50) value of taxol was 0.067 micromol/L and >1 micromol/L for the Am1010 and P0318 cells, respectively. The IC(50) value of gefitinib was 15.233 micromol/L and >70 micromol/L for Am1010 and P0318 cells, respectively. 11 genes involved in the focal adhesion and cell adhesion pathways were found to be differentially expressed. The cells of Am1010 have a significantly larger chromosome number than most lung cancer cell lines. CONCLUSION: This novel DSCs derived lung cancer cell line will be a valuable in vitro tool for the investigation of lung cancer drug resistance and metastasis.

Expression and significance of tumor drug resistance related proteins and beta-catenin in esophageal squamous cell carcinoma.

BACKGROUND AND OBJECTIVE: As chemotherapy is generally used in the clinical treatment of cancer, the problem of multidrug resistance (MDR) of tumors against the chemotherapeutic agents becomes more and more serious. It has been the major cause for the failure of the chemotherapy. We detected the expressions of beta-catenin and tumor drug resistance related proteins, MRP2, P-gp, and Bcl-2, in esophageal squamous cell carcinoma (ESCC) to explore their function and correlation in the occurrence and development of MDR in ESCC. METHODS: We used the tissue microarray technique, immunohistochemistry, and image analysis methods to detect the expressions of MRP2, P-gp, beta-catenin, and Bcl-2 proteins and analyze their relationships with clinical data in a ESCC tissue microarray consisting of 582 specimens of ESCC, 294 specimens of normal mucosa, 92 specimens of basal cell hyperplasia, and 87 specimens of dysplasia adjacent to cancer tissue. RESULTS: The integral optical density (IOD) of MRP2 and Bcl-2, which was 195.7 +/- 175.9 x 10(3)) and 90.5 +/- 112.5 x 10(3)), respectively, was significantly higher in ESCC than in normal mucosa, which was 104.8 +/- 86.1 x103) and 25.2 +/- 46.6 x 10(3)), respectively (P < 0.01). The IOD of P-gp and beta-catenin, which was 57.7 +/- 75.5 x 10(3)) and 32.0 +/- 47.0 x 10(3)) respectively, was significantly lower in ESCC than in normal mucosa, which was 114.8 +/- 106.6 x 10(3)) and 46.1 +/- 35.7 x 10(3)), respectively (P < 0.01). According to the following order, well differentiated moderately differentiated poorly differentiated, the IOD of MRP2 increased in ESCC (P < 0.01). The IOD of beta-catenin was higher in poorly differentiated ESCC than in well or moderately differentiated ESCC (P < 0.01). The IOD of Bcl-2 was lower in well differentiated ESCC than in poorly and moderately differentiated ESCC (P < 0.01). The IOD of beta-catenin and Bcl-2 was higher in the ESCC of specimens with infiltration depths that were in membrane mucosa than those in the muscular layer or serous coat (P < 0.01). The IOD of Bcl-2 was significantly higher in cases with lymph node metastasis than in cases without (P < 0.01). Positive correlations which were respectively between the expressions of P-gp and MRP2, the expressions of P-gp and Bcl-2 were found (r = 0.288 and r = 0.253, respectively, P < 0.01). CONCLUSIONS: MRP2, P-gp, and Bcl-2 may be taken as prognostic factors for MDR of ESCC. beta-catenin may play an important role in carcinogenesis and progression of ESCC.

[Establishment of a stable nasopharyngeal carcinoma cell line with lentivirus-mediated RNA interference for EIF4G1 gene silencing].

OBJECTIVE: To establish a nasopharyngeal carcinoma (NPC) cell line with stable EIF4G1 gene silencing induced by small interfering RNA (siRNA). METHODS: The EIF4G1 mRNA levels in 8 NPC cell lines including 5-8F, 6-10B, C666-1, CNE1, CNE2, HNE1, HONE1, and SUNE1 were detected by fluorescence quantitative RT-PCR (QRT-PCR). The recombinant lentivirus shRNA expression plasmid targeting EIF4G1 gene was packaged into mature lentivirus by 293FT cells and used to infect 5-8F cells. After blasticidin selection of NPC cells with constant expression of the EIF4G1-siRNA, the efficiency of EIF4G1 mRNA expression interference was determined using QRT-PCR. RESULTS: The 8 NPC cell lines showed differential expression of EIF4G1 mRNA, among which 5-8F cells had the highest EIF4G1 expression. The recombinant lentivirus plasmid pLenti6/BLOCK-iT-DEST/EIF4G1-shRNA was successfully constructed and verified by PCR and sequencing. The EIF4G1 mRNA level of 5-8F cells infected with shRNA-EIF4G1 lentivirus was significantly reduced as compared with the negative control and the blank control cells. CONCLUSION: The recombinant lentivirus vector pLenti6/BLOCK- iT-DEST/EIF4G1-shRNA we constructed results in marked downregulation of EIF4G1 mRNA expression and constant expression of EIF4G1-siRNA after infection of 5-8F cells.

Lentivirus-mediated RNAi silencing targeting ABCC2 increasing the sensitivity of a human nasopharyngeal carcinoma cell line against cisplatin.

BACKGROUND: High resistance to drug is taken as a characteristic of human tumors, which is usually mediated by multidrug resistance-associated genes. ABCC2, an ATP-binding cassette multidrug resistance transporter, is found to be expressed in a variety of human cancers. In this study the effect of a RNAi construct targeting ABCC2 on the chemosensitivity of NPC cell line CNE2 against cisplatin was investigated. METHODS: Lentiviral vectors were constructed to allow an efficient expression of anti-ABCC2 siRNA. The effective target sequence comprised nucleotides 1707-1727 of the human ABCC2 mRNA. The cell clones expressing the construct were picked and expanded, followed by identification using qRT-PCR and western blot method. As control, lentiviral vector containing invalid RNAi sequence was transfected to CNE2 cells. In vitro, cellular accumulation of cisplatin was detected by HPLC. The capacity of cellular growth and sensitivity of cells against cisplatin were detected by MTT assay. In vivo, the sensitivity of the tumor tissues against cisplatin were evaluated by transplanted CNE2 nude mice model. RESULTS: Two CNE2 cell clones with reduced expression of targeted ABCC2 mRNA and protein for more than 70% by qRT-PCR and western blot were established, and no differences were shown in proliferation rates compared to control CNE2 cells by growth curves analysis. In vitro the accumulation of intracellular cisplatin in these CNE2 cell clones with reduced expression of ABCC2 increased markedly, accompanied by increased sensitivity against cisplatin. In vivo, the growth of CNE2 solid tumors with a stably transfected anti-ABCC2 siRNA construct was significantly inhibited by cisplatin in transplanted nude mice model. CONCLUSION: Our investigation demonstrated that lentivirus-mediated RNAi silencing targeting ABCC2 might reverse the ABCC2-related drug resistance of NPC cell line CNE2 against cisplatin.