Characterization of side population cells isolated from the colon cancer cell line SW480.

Side population (SP) cells may play a crucial role in tumorigenesis and the recurrence of cancer. Many types of cell lines and tissues have demonstrated the presence of SP cells, including colon cancer cell lines. This study aimed to identify cancer stem cells (CSCs) in the SP of the colon cancer cell line SW480. SP cells were isolated by fluorescence-activated cell sorting (FACS), followed by serum-free medium (SFM) culture. The self-renewal, differentiated progeny, clone formation, proliferation, invasion ability, cell cycle, chemosensitivity and tumorigenic properties in SP and non-SP (NSP) cells were investigated through in vitro culture and in vivo serial transplantation. The expression profiles of ATP-binding cassette (ABC) protein transporters and stem cell-related genes were examined by RT-PCR and western blot analysis. The human colon cancer cell lines SW480, Lovo and HCT116 contain 1.1 ± 0.10, 0.93 ± 0.11 and 1.33 ± 0.05% SP cells, respectively. Flow cytometry analysis revealed that SP cells could differentiate into SP and NSP cells. SP cells had a higher proliferation potency and CFE than NSP cells. Compared to NSP cells, SP cells were also more resistant to CDDP and 5-FU, and were more invasive and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA and protein expression of ABCG2, MDR1, OCT-4, NANOG, SOX-2, CD44 and CD133. SP cells isolated from human colon cancer cell lines harbor CSC properties that may be related to the invasive potential and therapeutic resistance of colon cancer.

An updated meta-analysis of randomized controlled trial assessing the effect of neoadjuvant chemotherapy in advanced gastric cancer.

Patients with locally advanced gastric cancer (AGC) have a poor outcome. We performed an updated meta-analysis to assess the effect of neoadjuvant chemotherapy (NAC). By searching electronic databases (PubMed, Embase, Cochrane Library) and ASCO proceedings from 1990 to 2012, all randomized controlled trials (RCTs) which compared the effect of NAC combined surgery versus surgery alone in advanced gastric and gastroesophageal cancer would be included. All calculations and statistical tests were performed. Twelve RCTs with a total of 1,820 patients were included. All patients had resectable gastric or gastroesophageal cancer and received NAC. NAC can slightly improve the survival rate [OR = 1.32, 95% confidence interval (CI): 1.07-1.64, P = 0.01], little, or no significant benefits were suggested in subgroup analyses between different population and regimens either. It can significantly improved the 3-year progression-free survival (PFS) [OR: 1.85 (1.39, 2.46), p < .0001], tumor down-staging rate [OR: 1.71 (1.26, 2.33), p = .0006] and R0 resection rate [OR: 1.38 (1.08, 1.78) p = .01] of patients with AGC. There were no difference between the two arms, in terms of relapse rates [OR: 1.03 (0.60, 1.78), p = 0.92], operative complications [OR: 1.20 (0.90, 1.58), p = 0.21], perioperative mortality [OR: 1.14 (0.64, 2.05), p = 0.65], and grade 3/4 adverse effects. NAC can significantly down-stage the tumor and improve R0 resection rate of patients with gastric and gastroesophageal cancer. It is safe and feasible, and can be tolerated. NAC can slightly improve the survival rate. It needs further prospective multinational multicenter RCTs to define the clinical benefits of NAC and the most effective strategies for gastric and gastroesophageal cancer.

Robotic versus laparoscopic total mesorectal excision for rectal cancer: a meta-analysis.

BACKGROUND: Robotic surgery has been used successfully in many branches of surgery; but there is little evidence in the literature on its use in rectal cancer (RC). We conducted this meta-analysis that included randomized controlled trials and nonrandomized controlled trials of robotic total mesorectal excision (RTME) versus laparoscopic total mesorectal excision (LTME) to evaluate whether the safety and efficacy of RTME in patients with RC are equivalent to those of LTME. MATERIALS AND METHODS: Pubmed, Embase, Cochrane Library, Ovid, and Web of Science databases were searched. Studies clearly documenting a comparison of RTME with LTME for RC were selected. Operative and recovery outcomes, early postoperative morbidity, and oncological parameters were evaluated. RESULTS: Eight studies were identified that included 1229 patients in total, 554 (45.08%) in the RTME and 675 (54.92%) in the LTME. Meta-analysis suggested that the conversion rate to open surgery in RTME was significantly lower than in LTME (P = 0.0004). There were no significant differences in operation time, estimated blood loss, recovery outcome, postoperative morbidity and mortality, length of hospital stay, and the oncological accuracy of resection and local recurrence between the two groups. The positive rate of circumferential resection margins (P = 0.04) and the incidence of erectile dysfunction (P = 0.002) were lower in RTME compared with LTME. CONCLUSIONS: RTME for RC is safe and feasible, and the short- and medium-term oncological and functional outcomes are equivalent or preferable to LTME. It may be an alternative treatment for RC. More multicenter randomized controlled trials investigating the long-term oncological and functional outcomes are required to determine the advantages of RTME over LTME in RC.

MiR-21 regulates biological behavior through the PTEN/PI-3 K/Akt signaling pathway in human colorectal cancer cells.

The aim of this study was to determine a role of microRNA-21 (miR-21) in colorectal cancer (CRC) and to elucidate the regulation of phosphatase and tensin homologue (PTEN) gene by miR-21. MiR-21 expression was investigated in 30 CRC samples and five CRC cell lines. In this study, we show that the expression of miR-21 was overexpressed in CRC compared with adenomas and normal tissues. Patients with poor differentiation, lymph node metastasis and advanced TNM stage showed significantly high expression of miR-21. Inhibition of miR-21 in the HCT116 cell line reduced cellular proliferation, migration and invasion, induced apoptosis and inhibited cell cycle progression. The PTEN protein levels in CRC tissues and cells had an inverse correlation with miR-21 expression. Anti-miR-21-transfected cells increased PTEN protein expression without changing the PTEN mRNA level and increased a luciferase-reporter activity. MiR-21 targets PTEN at the post-transcriptional level and regulates cell proliferation and invasion in CRC. It may serve as a novel therapeutic target in CRC.

Laparoscopic versus open total mesorectal excision for middle and low rectal cancer: a meta-analysis of results of randomized controlled trials.

BACKGROUND: Laparoscopic total mesorectal excision (LTME) for rectal cancer remains controversial. The aim of this meta-analysis of randomized controlled trials (RCTs) is to compare LTME and open total mesorectal excision (OTME) as the primary treatment for patients with middle and low rectal cancer with regard to short-term outcomes. MATERIALS AND METHODS: Literature searches of electronic databases (PubMed, Embase, and the Cochrane Library) and manual searches up to October 30, 2011 were performed. Prospective randomized clinical trials were eligible if they included patients with middle and low rectal cancer treated by LTME versus OTME. Fixed and random effects models were used. Review Manager version 5.1 software was used for pooled estimates. RESULTS: Four RCTs enrolling 624 participants (LTME group, 308 cases; OTME group, 316 cases) were included in the meta-analysis. LTME for rectal cancer was associated with a significantly longer operative time but significantly less intraoperative blood loss and earlier time to pass first flatus. We found no significant differences in the number of lymph nodes, overall morbidity, and perioperative mortality rates between the two groups. Time to resume liquid diet, time to resume normal diet, and length of hospital stay, although not significantly different between the two groups, did suggest a positive trend toward LTME. CONCLUSIONS: It may be concluded that LTME is a safe and effective alternative to OTME and is justifiable under the setting of clinical trials. Additional RCTs that compare LTME and OTME and investigate the long-term oncological outcomes of LTME are required to determine the advantages of LTME over OTME.

Robotic versus laparoscopic gastrectomy for gastric cancer: a meta-analysis of short outcomes.

BACKGROUND: Robotic gastrectomy (RG) for gastric cancer remains controversial. The main aim of this meta-analysis was to compare the safety and efficacy of robotic gastrectomy (RG) and conventional laparoscopic gastrectomy (LG) for gastric cancer. METHODS: Literature searches of electronic databases (PubMed, Embase, Cochrane Library Ovid, and Web of Science databases) and manual searches up to December 30, 2011 were performed. Comparative clinical trials were eligible if they reported perioperative outcomes for RG and LG for gastric cancer. Fixed and random effects models were used. The RevMan 5.1 was used for pooled estimates. RESULTS: Three NRCTs enrolling 918 patients (268 in the RG group and 650 in the LG group) were included in the meta-analysis. RG for gastric cancer was associated with a significantly longer operative time (WMD: 68.77, 95% CI: 35.09-102.45; P < 0.0001), but significantly less intraoperative blood loss (WMD: -41.88, 95% CI: -71.62 to -12.14; P = 0.006). We found no significant differences in the number of lymph nodes (WMD: -0.71, 95% CI: -6.78 to 5.36; P = 0.82), overall morbidity (WMD: 0.74, 95% CI: 0.47 to 1.16; P = 0.19), perioperative mortality rates (WMD: 1.80, 95% CI: 0.30 to 10.89; P = 0.52) and length of hospital stay (WMD: 0.42, 95% CI: -1.87 to 0.79; P = 0.42) between the two groups. CONCLUSIONS: It may be concluded that RG is a safe and effective alternative to LG and is justifiable under the setting of clinical trials. Additional RCTs that compare RG and LG and investigate the long-term oncological outcomes are required to determine potential advantages or disadvantages of RG.

Obturator hernia--a condition seldom thought of and hence seldom sought.

PURPOSE: Obturator hernia is an extremely rare type of hernia with an incidence of less than 1% of all abdominal wall hernias occurring predominantly in elderly females characterized by protrusion of the intra-abdominal viscera into the obturator foramen. It presents with pain along the medial aspect of the thigh referred to the knee due to compressed obturator nerve and sometimes as an uncommon cause of intestinal obstruction. It remains a clinical diagnostic dilemma and often perplexing the decision for surgery. This explanatory review emphasizes and illuminates its various facets under the rationale of its diagnosis and management to familiarize surgeons with the condition. METHODS: The data for the present review was obtained by searching in PubMed and other databases using key terms "obturator hernia", "abdominal hernia", "intestinal obstruction", and "Howship-Romberg sign". Many original articles, reviews, and case reports were selected. RESULTS: Since it is very rare that a mass can be found on inspection of the medial aspect of the thigh and the clinical signs are not always present, hence obturator hernia is a condition which leads to both difficult and delayed clinical diagnosis and consequently having a significant morbidity and mortality rates, especially in the elderly. CONCLUSION: Obturator hernia should always be in the differential diagnosis in septuagenarian to nonagenarian patients with nonspecific signs and symptoms of intestinal obstruction. Computed tomography of abdomen and pelvis has been found to be the gold standard for preoperative diagnosis and this condition necessitates immediate surgical reduction and repair of the defect either by open or laparoscopic approach.

RNAi-mediated inhibition of PDGF-D leads to decreased cell growth, invasion and angiogenesis in the SGC-7901 gastric cancer xenograft model.

Platelet-derived growth factor-D (PDGF-D) plays an important role in many types of human cancer. However, little is known about the function of this gene in gastric cancer. Here we demonstrated that PDGF-D is commonly overexpressed in gastric cancer. Silencing of PDGF-D using RNA interference significantly attenuated the proliferation and invasion potentials of SGC-7901 gastric cancer cells in which PDGF-D is overexpressed. Moreover, suppression of PDGF-D expression resulted in less activation of beta-catenin and its downstream effector genes, cyclin D1 and matrix metalloproteinases, which are known to be involved in cell proliferation and invasion, respectively. Further, downregulation of PDGF-D remarkably reduced VEGF expression and secretion and proangiogenic activities of SGC-7901 cells in vitro. Most importantly, PDGF-D downregulation caused a significant decrease in tumor growth and angiogenesis in a SGC-7901 xenograft model. Together these findings suggest that PDGF-D is involved in the promotion of gastric cancer growth, invasion and angiogenesis, and RNAi-mediated silencing of this gene may thus offer a promising therapeutic strategy for PDGF-D-overexpressing gastric cancer.

[Role of histone deacetylase in inhibiting invasion of human gastric carcinoma cell line SGC-7901 by PPARgamma-mediated pathway].

BACKGROUND AND OBJECTIVE: Histone deacetylase (HDAC) can attenuate the function of peroxisome proliferator-activated receptor gamma (PPARgamma) to drive adipocyte differentiation. PPARgamma activation is confirmed to inhibit the development and metastasis of a variety of malignant cells. This study was to investigate the role of HDAC in inhibiting the invasion of human gastric carcinoma SGC-7901 cells through PPARgamma-mediated pathway, and explore potential mechanism. METHODS: SGC-7901 cells were treated with different concentrations of Trichostatin A (TSA) and Rosiglitazone (ROZ) respectively to select the best combination through assessing cell proliferation by MTT assay. Then cells were randomly divided into control group, TSA group, ROZ group, and combination group. Cell proliferation was detected by MTT assay after 48 h; cell invasion was detected by Boyden chamber invasion test. The mRNA levels of PPARgamma and matrix metalloproteinase-2 (MMP-2) were assessed by reverse transcription-polymerase chain reaction (RT-PCR), and the protein level of MMP-2 was evaluated by Western blot. RESULTS: Both TSA and ROZ inhibited the proliferation of SGC-7901 cells in a dose-dependent manner. A combination of 20 nmol/L TSA and 5 mumol/L ROZ synergistically inhibited the invasion of SGC-7901 cells (q=1.41). ROZ down-regulated the mRNA and protein expression of MMP-2. TSA and ROZ in combination reduced MMP-2 expression more obviously than ROZ alone. TSA up-regulated the expression of PPARgamma mRNA. CONCLUSIONS: HDAC suppresses the activation of PPARgamma through a series of molecular mechanisms. The activity of ROZ in inhibiting invasion of human gastric carcinoma cells can be enhanced after the activity of HDAC is inhibited by TSA.

[Impact of chronic restraint stress on splenocyte immunity and growth of mouse forestomach carcinoma xenografts in Kunming mice].

BACKGROUND & OBJECTIVE: Recent study found psychosocial factors play some important roles in carcinogenesis and development of malignant tumors, but its mechanisms remain unclear. This study was to investigate the impact of chronic restraint stress on splenocyte immunity and growth of mouse forestomach carcinoma (MFC) xenografts in Kunming mice, and provide evidences for exploring the mechanisms of psychosocial factors function on malignant tumors. METHODS: A total of 60 Kunming mice were randomized into normal control group, restraint stress group, tumor-bearing group and tumor plus restraint stress group; each group contained 15 mice. Chronic restraint stress models were established in restraint stress group and tumor plus restraint stress group; MFC xenograft models were established in tumor-bearing group and tumor plus restraint stress group 4 weeks later. Mice were killed 10 days after inoculation of MFC cells. The weight of MFC xenografts were measured. The proliferation and cytotoxicity of splenocytes were detected by MTT assay. The level of interleukin-2 (IL-2) in splenocyte culture supernants was detected by enzyme-linked immunoabsorbent assay (ELISA). RESULTS: The weight of MFC xenografts was (1.39+/-0.39) g in tumor-bearing group and (2.10+/-0.52) g in tumor plus restraint stress group; MFC xenografts grew faster in tumor plus restraint stress group than in tumor-bearing group (P<0.01), with a tumor growth rate of 51.08%. In normal control group, restraint stress group, tumor-bearing group, and tumor plus restraint stress group, the stimulus indexes (SI) of T lymphocytes were 1.77+/-0.22, 1.70+/-0.17, 1.69+/-0.18, and 1.22+/-0.15, respectively; the SI of B lymphocytes were 1.73+/-0.14, 1.65+/-0.17, 1.64+/-0.21, and 1.33+/-0.11, respectively; the inhibition rate of MFC cell proliferation were (23.01+/-4.76)%, (19.47+/-3.70)%, (16.81+/-3.68)%, and (7.14+/-5.00)%, respectively, when the effector/target ratio was 5:1 and (33.03+/-3.91)%, (28.34+/-4.58)%, (24.94+/-2.97)%, and (13.49+/-7.94)%, respectively, when the effector/target ratio was 10:1; the levels of IL-2 in splenocyte culture supernatants were (260.03+/-14.96) pg/mL, (239.78+/-10.93) pg/mL, (238.11+/-13.50) pg/mL, and (186.34+/-10.42) pg/mL, respectively. Both chronic restraint stress and MFC xenografts impaired the proliferation, cytotoxicity, and IL-2 secretion of splenocytes; the two factors showed interactive effect (P<0.01), but the effect of chronic restraint stress was much more obvious. CONCLUSION: Chronic restraint stress may impair the immune function and promote the growth of MFC xenografts in mice.

RNA interference-mediated gene silencing of vascular endothelial growth factor in colon cancer cells.

AIM: To inhibit the expression of vascular endothelial growth factor (VEGF) in colon cancer cell line by RNA interference (RNAi). METHODS: Followed the service of E-RNAi, we designed and constructed two kinds of shRNA expression vectors aiming at the VEGF gene, then transfected them into colon cancer HT29 cells by lipofectamine(TM) 2000. The level of VEGF mRNA was investigated by RT-PCR and Northern blotting. The protein expression of VEGF was observed by immunofluoresence staining and Western blotting. RESULTS: We got two kinds of VEGF specific shRNA expression vectors which could efficiently inhibit the expression of VEGF in HT29 cells. RT-PCR, Northern blotting, immunofluoresence staining and Western blotting showed that inhibition rate for VEGF expression was up to 42%, 89%, 73% and 82%, respectively. CONCLUSION: The expression of VEGF can be inhibited by RNA interference in HT29 cells.

[Effects of glutamine granules on immunofunction in trauma patients: a double-blind randomized controlled, multi-center clinical trail with 120 patients].

OBJECTIVE: To evaluate the effect of glutamine granules on immunofunction in severe burns and trauma patients. METHODS: One hundred and twenty patients with severe burns, multiple trauma and post operation who met the requirements of the protocol joined this double-blind randomized controlled, multi-center clinical trail. Patients were randomly divided into two groups: placebo control group (P group, 60 patients) and glutamine granules treatment group (GLN group, 60 patients). There was isonitrogenous and isocaloric intake in both groups. GLN and P group patients had been given glutamine granules or placebo (glycine) at 0.5 g.kg(-1).d(-1) for 7 days, respectively. The level of plasma glutamine and some index of immunofunction were determined, and the complication and side effect were also observed. RESULTS: After 7 days of taking glutamine granules orally, plasma GLN concentration was significantly higher than that in P group [(593 +/- 185) micromol/L vs (407 +/- 190) micromol/L)] (P < 0.01). IL-2 level, CD(4)/CD(8) ratio, PMN swallow ratio in GLN group were significantly higher than those in P group (P < 0.05-0.01), but the concentration of IgG, IgM, C(3)/C(4) were not significantly different when compared with P group (P > 0.05). In addition, the occurrence of side effect in both groups was seldom. CONCLUSION: Taking glutamine granules could increase plasma GLN concentration, enhance body immunofunction, and using glutamine granules is safe.

[Repair of large abdominal wall defect with pedicle graft of greater omentum and polypropylene mesh].

OBJECTIVE: To evaluate the outcome of pedicle graft of greater omentum and polypropylene mesh in reconstruction of large defect of abdominal wall caused by surgical incision. METHODS: From 1994 to 2004, 12 cases of large abdominal wall defects were repaired with pedicle graft of greater omentum and polypropylene mesh after removal of abdominal wall tumor; the defect sizes of abdominal wall ranged from 10 cm x 7 cm to 25 cm x 17 cm. RESULTS: The abdominal wall wound in 12 cases were healed by first intention. After a follow-up of 1 to 5 years, no complications of abdominal hernia, infection and intestine obstruction occurred in all patients. CONCLUSION: It is reliable to repair abdominal wall defect caused by surgical incision with pedicle graft of greater omentum and polypropylene mesh instead of peritoneum.

[Analysis of the therapeutic effect and the safety of glutamine granules per os in patients with severe burns and trauma].

OBJECTIVE: To observe the therapeutic effect and possible side effects of glutamine granules per os in patients with trauma, burns and major operations. METHODS: Patients inflicted with severe burns, trauma and major operations were enrolled in the study. One hundred and twenty patients were randomly divided into two groups, 60 in control group (C) and 60 in glutamine group (Gln). Randomized double blind and placebo control methods were employed in the study. All the patients in both groups were given diet with equal calories and equal nitrogen content. The patients in Gln group received glutamine granules in dose of 0.5 g.kg(-1).d(-1) orally or by gavage, while those in C group received same dose of placebo (glycine) for 7 days. The changes in the intestinal mucosal barrier function, the protein metabolism, the immune function, hepatic and renal functions, and the incidence of side effects of the medication in both groups of patients were observed and compared before and after the supplementation of glutamine or glycine. RESULTS: The plasma contents of glutamine, proteins and interleukin 2 in both groups were all lower than normal values. But the plasma diamine oxidase (DAO) activity, endotoxin content, intestinal mucosal permeability (urine lactose/mannitol, L/M) and urine excretion of nitrogen increased obviously in both groups. The plasma glutamine concentration in Gln group increased by 38.04% after the administration of Gln for 7 days (P < 0.01). The plasma contents of pro-albumin, transferrin, and IL-2 were obviously higher than those in the C group (the increase rates were 21.19%, 51.11%, 57.54%, respectively, P < 0.01). The plasma DAO activity, L/M ratio, endotoxin content and urine nitrogen excretion in Gln group were evidently lower than those in C group (the decrease rates were 47.26%, 52.18, 22.22% and 27.78%, respectively, P < 0.05 or 0.01). There was no obvious difference in the plasma levels of total protein and albumin, the indices in blood and urine test, or the hepatic and renal functions between the two groups before and after the amino acid supplementation. Mild side effects such as nausea, diarrhea, constipation occurred in both groups, but all of them disappeared spontaneously afterwards (P > 0.05). CONCLUSION: Oral administration of glutamine could be helpful to increase plasma concentration of glutamine and to ameliorate obviously the intestinal mucosal injury, to promote systemic protein synthesis and to inhibit protein catabolism and to upgrade systemic immune function with little side effect in patients with severe injury.