Hai Shi

Bmi‐1 is related to proliferation, survival and poor prognosis in pancreatic cancer

B‐cell‐specific Moloney murine leukemia virus insertion site 1 (BMI1) is a member of the polycomb group of transcriptional repressors. Until now, its expression and functional significance in pancreatic carcinogenesis was unknown. In the present study, we demonstrated that expression of BMI1 was markedly up‐regulated in pancreatic cancer cell lines and surgically resected cancer specimens. In addition, BMI1 expression levels correlated positively with the presence of lymph node metastases and negatively with patient survival rates, suggesting a role for BMI1 in the progression of pancreatic cancer. Furthermore, stable down‐regulation of BMI1 suppressed cell growth, delayed the G1/S transition, and enhanced the susceptibility of different pancreatic cell lines to apoptosis following expression of a lentiviral‐mediated shRNA targeted for BMI1. Expression of the short‐hairpin RNA also correlated with the up‐regulation of p21 and Bax and the down‐regulation of cyclin D1, cyclin‐dependent kinase (CDK)‐2 and ‐4, Bcl‐2, and phospho‐Akt. Finally, growth suppression following BMI1 depletion was confirmed in a nude mouse model. In conclusion, our findings indicate that BMI1 plays an important role in the late progression of pancreatic cancer and may represent a novel therapeutic target for the treatment of pancreatic cancer. (Cancer Sci 2010)

Reduced expression of N-Myc downstream-regulated gene 2 in human thyroid cancer

BackgroundNDRG2 (N-Myc downstream-regulated gene 2) was initially cloned in our laboratory. Previous results have shown that NDRG2 expressed differentially in normal and cancer tissues. Specifically, NDRG2 mRNA was down-regulated or undetectable in several human cancers, and over-expression of NDRG2 inhibited the proliferation of cancer cells. NDRG2 also exerts important functions in cell differentiation and tumor suppression. However, it remains unclear whether NDRG2 participates in carcinogenesis of the thyroid.MethodsIn this study, we investigated the expression profile of human NDRG2 in thyroid adenomas and carcinomas, by examining tissues from individuals with thyroid adenomas (n = 40) and carcinomas (n = 35), along with corresponding normal tissues. Immunohistochemistry, quantitative RT-PCR and western blot methods were utilized to determine both the protein and mRNA expression status of Ndrg2 and c-Myc.ResultsThe immunostaining analysis revealed a decrease of Ndrg2 expression in thyroid carcinomas. When comparing adenomas or carcinomas with adjacent normal tissue from the same individual, the mRNA expression level of NDRG2 was significantly decreased in thyroid carcinoma tissues, while there was little difference in adenoma tissues. This differential expression was confirmed at the protein level by western blotting. However, there were no significant correlations of NDRG2 expression with gender, age, different histotypes of thyroid cancers or distant metastases.ConclusionOur data indicates that NDRG2 may participate in thyroid carcinogenesis. This finding provides novel insight into the important role of NDRG2 in the development of thyroid carcinomas. Future studies are needed to address whether the down-regulation of NDRG2 is a cause or a consequence of the progression from a normal thyroid to a carcinoma.

Fast-track surgery could improve postoperative recovery in radical total gastrectomy patients

AIM To assess the impact of fast-track surgery (FTS) on hospital stay, cost of hospitalization and complications after radical total gastrectomy. METHODS A randomized, controlled clinical trial was conducted from November 2011 to August 2012 in the Department of Digestive Surgery, Xijing Hospital of Digestive Diseases, the Fourth Military Medical University. A total of 122 gastric cancer patients who met the selection criteria were randomized into FTS and conventional care groups on the first day of hospitalization. All patients received elective standard D2 total gastrectomy. Clinical outcomes, including duration of flatus and defecation, white blood cell count, postoperative pain, duration of postoperative stay, cost of hospitalization and complications were recorded and evaluated. Two specially trained doctors who were blinded to the treatment were in charge of evaluating postoperative outcomes, discharge and follow-up. RESULTS A total of 119 patients finished the study, including 60 patients in the conventional care group and 59 patients in the FTS group. Two patients were excluded from the FTS group due to withdrawal of consent. One patient was excluded from the conventional care group because of a non-resectable tumor. Compared with the conventional group, FTS shortened the duration of flatus (79.03 ± 20.26 h vs 60.97 ± 24.40 h, P = 0.000) and duration of defecation (93.03 ± 27.95 h vs 68.00 ± 25.42 h, P = 0.000), accelerated the decrease in white blood cell count [P < 0.05 on postoperative day (POD) 3 and 4], alleviated pain in patients after surgery (P < 0.05 on POD 1, 2 and 3), reduced complications (P < 0.05), shortened the duration of postoperative stay (7.10 ± 2.13 d vs 5.68 ± 1.22 d, P = 0.000), reduced the cost of hospitalization (43783.25 ± 8102.36 RMB vs 39597.62 ± 7529.98 RMB, P = 0.005), and promoted recovery of patients. CONCLUSION FTS could be safely applied in radical total gastrectomy to accelerate clinical recovery of gastric cancer patients.

Human differentiation-related gene NDRG1 is a Myc downstream-regulated gene that is repressed by Myc on the core promoter region

N-Myc downstream-regulated gene 1 (ndrg1) is up-regulated in N-Myc knockout mouse embryos. The human NDRG family consists of 4 highly homologous members and human Ndrg1 exhibits approximately 94% homology with mouse ndrg1. However, the regulatory mechanism of NDRG1 via Myc repression is as yet unknown. We previously identified human NDRG2 and demonstrated that this gene is transcriptionally down-regulated by Myc via Miz-1-dependent interaction with the core promoter region of NDRG2. Here, we provide evidence that human NDRG1 is regulated by Myc in a manner similar to NDRG2. We found that Ndrg1 expression levels were enhanced as Myc expression declined in differentiated cells, but were down-regulated following Myc induction. The data revealed that both N-Myc and c-Myc can repress human NDRG1 at the transcriptional level. We further determined that the core promoter region of human NDRG1 is required for Myc repression, and verified the interaction of Myc with the core promoter region. However, the presence of the protein synthesis inhibitor cycloheximide could reverse the repression of Myc, indicating the indirect repression of human NDRG1 by Myc. Moreover, we found that c-Myc-mediated repression can be inhibited by TSA, an HDACs inhibitor, which suggests the involvement of HDACs in the repression process. Taken together, our results demonstrate that, in common with NDRG2, human NDRG1 can be indirectly transcriptionally down-regulated by Myc via interaction with the NDRG1 core promoter.

Expression of NDRG2 in esophageal squamous cell carcinoma

N‐Myc downstream‐regulated gene 2 (NDRG2), a new member of the N‐Myc downstream‐regulated gene family, has been found to be a differentially expressed gene involved in a variety of cancers. The present study aimed to investigate the expression of NDRG2 in esophageal squamous cell carcinoma (ESCC). Immunohistochemistry was performed in 154 samples from patients with ESCC to detect the expression level of NDRG2 and C‐MYC. Results indicated that the expression level of NDRG2 in the cancer samples was significantly lower than that in normal tissues; the trend of C‐MYC was the reverse. The Wilcoxon–Mann–Whitney test showed significant difference in the expression of NDRG2 in patients with different T stage, TNM stage, and differentiation degree of cancers (P = 0.036, 0.031, 0.001, respectively). Patients in stages I and II were followed up for 5 consecutive years and Kaplan–Meier survival analysis demonstrated that the survival time of ESCC patients with high expression of NDRG2 was longer than those with low expression during the 5‐year follow‐up period (P = 0.0018). Cox regression analysis indicated that low expression of NDRG2, cancer stage of pT1, and distant organ metastasis (pM1) were the independent poor prognostic factors of ESCC (P = 0.004, 0.019, 0.0013, respectively). Furthermore, up‐regulation of NDRG2 was introduced to ESCC cell lines (EC9706 and EC109) by plasmid transfection. In vivo and in vitro studies indicated that overexpression of NDRG2 markedly reduced proliferation and promoted the apoptosis of EC9706 and EC109 cells. In summary, our results demonstrated that NDRG2 played an important role in the proliferation of ESCC cells and the expression of NDRG2 in ESCC was closely related with the prognosis.

Downregulation of MSP58 inhibits growth of human colorectal cancer cells via regulation of the cyclin D1–cyclin-dependent kinase 4–p21 pathway

We have investigated the expression and role of the 58‐kDa microspherule protein (MSP58) in colorectal carcinoma (CRC). By immuhistochemistry and immunofluorescence, we observed MSP58 in the nucleus and cytoplasm of CRC cells, and found MSP58 to be present in CRC specimens more often than in adjacent non‐tumor tissues (92.5 vs 36.3%, P < 0.01). The average staining score in adjacent non‐tumor tissues was significantly lower than in CRC tissues (2.05 ± 1.13 vs 5.23 ± 1.38, P < 0.01). Moreover, MSP58 mRNA and protein appeared to be upregulated in six fresh CRC samples compared to their adjacent non‐cancerous tissues. MSP58 expression was also detected in the human CRC‐derived cell lines LoVo, CoLo205, HCT116, HT‐29, SW620, and SW480. Downregulation of MSP58 inhibited in vitro growth and attenuated tumor growth in animal models by induction of cell cycle arrest, and was associated with reduced levels of cyclin D1, cyclin‐dependent kinase 4, phosphorylation‐Rb (p‐Rb), p21, and Retino blastoma (Rb) proteins. These results indicated that MSP58 might play an important role in the carcinogenesis of CRC via regulation of the cyclin D1–cyclin‐dependent kinase 4–p21 pathway. (Cancer Sci 2009; 100: 1585–1590)

R-Flurbiprofen Reverses Multidrug Resistance, Proliferation and Metastasis in Gastric Cancer Cells by p75NTR Induction†

Nonsteroidal anti-inflammatory drugs (NSAIDs) can inhibit cell growth and metastasis, and induce cell apoptosis in cancerous cells. They have been shown to reduce incidence and mortality of gastric cancer by an unknown mechanism. NSAIDs often exert their effects by Cox-2 inhibition, and Cox-2 is overexpressed in gastric cancer cells. Nevertheless, when gastric cancer cells were treated with different NSAIDs, the non-Cox-2-inhibiting R-flurbiprofen was most effective at reducing proliferation of gastric cancer cells in vitro. R-Flurbiprofen prevented the metastatic characteristics of gastric cancer cells in vitro, and reduced tumor size and metastasis in vitro, when gastric cancer cells were injected into nude mice. R-Flurbiprofen also affected multidrug resistance, increasing the sensitivity of resistant gastric cancer cells to chemotherapeutic agents. Mechanistically, R-flurbiprofen was found to have pleiotropic effects, changing levels of cell cycle factors like Cyclin D1 and CKD4, apoptotic protwins like caspase3 and Bcl-2, and protwins that affect metastasis, like metalloproteases. Consistent with reports on other cancer cell types, NSAID treatment with R-flurbiprofen increased levels of the tumor suppressor neurotrophin receptor (p75(NTR)) in gastric cancer cells. The anticancer effects of R-flurbiprofen were found to require induction of p75(NTR) via the p38 signaling pathway, suggesting a possible mechanism of action.

Survivin Knockdown Enhances Gastric Cancer Cell Sensitivity to Radiation and Chemotherapy In Vitro and in Nude Mice

Introduction: The aim is to assess the effect of survivin knockdown on the radio- and chemosensitivity of gastric cancer cells in vitro and in nude mice. Methods: Survivin messenger RNA and protein were detected by semiquantitative reverse transcription-polymerase chain reaction and Western blot. Survivin and control small hairpin RNA (shRNA) expression constructed vectors were stably transfected into gastric cancer SGC7901 cells. The cells were in turn subjected to irradiation, cisplatin or fluorouracil (5-FU) treatment for colony formation, methyl-thiazolyl-tetrazolium cell viability and flow cytometry assays in vitro. An in vivo nude mouse xenograft assay was performed to assess the effects of Survivin knockdown on regulation of the sensitivity of SGC7901 cells to irradiation, cisplatin or 5-FU treatment. Results: Survivin shRNA markedly inhibited levels of survivin messenger RNA and protein in SGC7901 cells and significantly increased sensitivity of the tumor cells to radiation treatment, ie, the mean lethal and quasi-threshold doses in survivin shRNA-transfected cells were significantly lower than that of the negative control shRNA-transfected and parental cells. The same is true for cisplatin- and 5-Fu-treated tumor cells, ie, colony formation and cell viability of the survivin-knocked down SGC7901 cells were reduced, while apoptosis was induced compared with the control cells. Furthermore, the xenograft assay showed survivin knockdown in SGC7901 cells suppressed tumor formation and growth compared with the controls. Conclusions: Knockdown of survivin expression enhanced sensitivity of gastric cancer cells to radiation, cisplatin and 5-FU treatment in vitro and in nude mice. These results demonstrate that clinical trails are warranted of survivin shRNA as an adjuvant therapy for gastric cancer patients.

Fast-track surgery combined with laparoscopy could improve postoperative recovery of low-risk rectal cancer patients: a randomized controlled clinical trial.

In this study we aimed to assess the feasibility and safety of fast‐track surgery (FTS) combined with laparoscopy for treating patients with rectal cancer and compare the results with those of the conventional perioperative intervention group.

Ex vivo resection of giant epidermoid cyst and vascularized partial splenic autotransplantation: 3.5-year follow-up

SPLENIC CYSTS are rare findings that are classified as either parasitic or nonparasitic. Approximately half of these cysts are diagnosed incidentally. For larger, nonparasitic cysts (>5 cm in diameter), either complete or partial splenectomy is the treatment of choice. The preservation of partial healthy splenic parenchyma is a preferred option as a result of increasing awareness of the risk of overwhelming postsplenectomy infections (OPSIs), especially in children. Various spleenpreserving procedures, such as cyst aspiration, partial or complete cystectomy, or partial splenectomy, have been reported in the literature. In recent years, laparoscopic spleen-preserving surgery has been the preferred treatment of choice for large cysts, especially those located in the pole of the spleen. Spleen-preserving surgery, however, is still a challenging procedure for large cysts with hilar location or multifocal lesions. In this report, we describe a case of a large splenic epidermoid cyst involving the hilum that was managed successfully by ex vivo resection of the cyst and partial splenic autotransplantation. To our knowledge, this is the first known case of vascularized partial splenic autotransplantation with a 3.5-year follow-up.