AIM:To investigate the role of side population ( SP) cells in multidrug resistance of colon cancer cells and microRNA biomarkers of SP cells in colon cancer cells .METHODS:SP cells in colon cancer cells were sorted by flow cytometry .The cell viability was measured by MTT method .MicroRNA expression profiles were detected by mi-croRNA chip.MicroRNA expression was verified by real-time PCR.RESULTS:The ratios of SP cells in HCT-15, HT-29 and LoVo colon cancer cell lines were 16.75%, 13.02%and 9.52%, respectively.In all 3 colon cancer cell lines, IC50 of the antitumor drugs including 5-fluorouracil , oxaliplatin and adriamycin for the SP cells were significantly higher than those for non-SP cells (P<0.05).MicroRNA profiling showed that miR-5000-3p, miR-5009-3p and miR-552 were all up-regulated in the SP cells of all 3 colon cancer cell lines .This result was verified by real-time PCR.CONCLUSION:miR-5000-3p, miR-5009-3p and miR-552 are all up-regulated in the SP cells of colon cancer cell lines , and may be the poten-tial microRNA biomarkers of SP cells in colon cancer .

AIM:To synthesize a safe , efficient and targeted nanoparticulate carrier for siRNA delivery to pan-creatic cancer cells .METHODS: Iron oxide nanocrystal with carboxylic acid group-polyethyleneimine ( IONP-PEI ) was synthesized and investigated as a nonviral carrier of siRNA to the pancreatic cells .The size, surface and charge using zeta potential were characterized .The perfect charge ratio between amino groups of IONP-PEI and phosphate groups of siRNA ( N/P) was determined by the transfection efficiency detection , gel retardation assay and MTS assay .An antibody-directed nonviral vector , scFvCD44v6-IONP-PEI nanoparticle attaching to the cancer-associated CD44v6 single-chain variable frag-ment, was constructed as a cancer-targeting nanocarrier for siRNA delivery .Prussian blue staining and immunofluorescent staining were performed to detect the distribution of scFv CD44v6-IONP-PEI/siRNA complexes in the cells .The transfection efficiency , fluorescence intensity and the expression of KRAS at mRNA and protein levels in the cells transfected by IONP -PEI/siRNA and scFv CD44v6-IONP-PEI/siRNA were detected by flow cytometry , fluorescence microscopy , real-time PCR and Western blotting, respectively.RESULTS:The mass ratio of IONP to PEI was 0.75.The suitable ratio of N/P was 20. The averaged size and surface zeta potential of IONP-PEI/siRNA in deionized water were (51.3 ±2.2)nm (diameter) and (21.73 ±8.07)mV, respectively.Red fluorescence was seen in both targeting and nontargeting groups , which clearly re-vealed the intracellular distribution of siRNA and delivery agents .Transfection efficiencies in targeting and nontargeting groups were (89.75 ±1.81)%and (59.87 ±4.52)%, respectively.Down-regulation of the KRAS mRNA in Panc-1 cells transfected with siKRAS by scFvCD44v6-IONP-PEI and IONP-PEI was up to (34.02 ±6.15)%and (51.09 ±6.70)%, re-spectively .The protein level of KRAS was lower in targeting group than that in nontargeting group .CONCLUSION:scFvCD44v6-IONP-PEI is a safe and efficient nanoparticulate carrier for gene delivery .It is more effective to transfer siRNA into the cells and mediate gene silencing effect in vitro than the nontargeting group .

Objective To explore the effect of inhibiting placental growth factor ( PIGF ) by small interfering RNA ( siRNA) on migration, invasion and chemoresistance of human pancreatic cancer cell line PANC1.Methods Three specific siRNAs targeting PIGF (siRNA-PIGF) were designed.PANC1 cells were transfected with siRNA-PIGF by liposome transfection using untransfected cells as blank controls and nonspecific siRNA ( siRNA-NC) transfected cells as negative controls .The PIGF mRNA and protein expression was examined by real-time RT-PCR and ELISA.MTT method was used to assess the inhibition rate of chemotherapeutic reagents on cell proliferation .The abilities of migration and invasion were evaluated by Transwell assay.Results The inhibition rate of PIGF mRNA in PANC1 cells transfected by 3 siRNA-PIGF were (64.38 ±8.92)%, (70.48 ±7.72)% and (81.25 ±6.02)%, which was lowest in siRNA-PIGF-3 transfected cells.The expression of PIGF mRNA in PANC1 cells were decreased by (63.72 ±8.20)%at 24 h after siRNA-PIGF transfection compared with siRNA-NC transfected cells;and the level of PIGF protein in the supernatant of cultured PANC1 cells was lowered by (42.92 ±1.34)% compared with siRNA-NC transfected cells and by (46.25 ±3.64)% compared with untransfected cells at 48h after transfection, which all had significant difference .There was no statistical difference between untransfected and siRNA-NC transfected cells.After 3 ng/L gemicitabine treatment , the inhibition rate of cell proliferation in siRNA-PIGF group was even higher than that in siRNA-NC and untransfected group [(44.35 ±5.05)% vs(34.29 ±3.60)% and (31.01 ±1.08)%;both P<0.05], and no significant difference was not observed after 5-FU and adriamycin treatment.In migration and invasion assay , the number of transmembrane cells from siRNA-PIGF group was 38.1%and 28.2%of that from siRNA-NC group and 40.8% and 36.2% of that from untransfected group , which had statistical difference (all P<0.05).Conclusions PIGF silencing could significantly suppress the migration and invasion of PANC 1 cells and improve the sensitivity to gemicitabine .

OBJECTIVETo investigate the risk factors on initial surgery in Crohn's disease.

METHODSThe clinical data of 173 patients with Crohn's disease who were treated during 2010 and 2014 years in the Second Affiliated Hospital of Sun Yat-Sen University, were analyzed retrospectively. The patients who had received intestinal resection or whose initial symptoms occurred at least 5 years at the end of the follow-up were recruited. Montreal classification was used to evaluate lesion location and disease behavior. The risk factors of the initial surgery were analyzed by using Logistic regression model.

RESULTSEighty-five patients (49.1%) received intestinal resection in 5 years after the onset of symptoms. The result of univariate analysis showed that the probability of surgical treatment is high in patients who were male and those older than 40 years at diagnosis (P<0.05). Lesions involving upper digestive tract, stenosis and penetrating lesions were also the risk factors on initial surgery in Crohn's disease (P<0.05). The result of multivariate analysis showed the relative risk of initial surgery was increased in male gender (OR=2.02, 95%CI:1.04-3.92) and in those who were older than 40 years at diagnosis (OR=2.34,95%CI:1.05-5.22). However, in patients with Crohn's disease involving colon alone, the relative risk of initial surgery was decreased (OR=0.35, 95%CI:0.13-0.97).

CONCLUSIONAbdominal pain is the most common clinical presentation in Crohn's disease. Disease behavior and operation is closely related. Older than 40 years at diagnosis and male gender is high risk factor for surgery while colonic lesion alone is protective factor.

Abdominal Pain ; Colon ; Constriction, Pathologic ; Crohn Disease ; Follow-Up Studies ; Humans ; Logistic Models ; Male ; Protective Factors ; Retrospective Studies ; Risk Factors

Objective To investigate the risk factors on initial surgery in Crohn's disease. Methods The clinical data of 173 patients with Crohn's disease who were treated during 2010 and 2014 years in the Second Affiliated Hospital of Sun Yat-Sen University, were analyzed retrospectively. The patients who had received intestinal resection or whose initial symptoms occurred at least 5 years at the end of the follow-up were recruited. Montreal classification was used to evaluate lesion location and disease behavior. The risk factors of the initial surgery were analyzed by using Logistic regression model. Results Eighty-five patients(49.1%) received intestinal resection in 5 years after the onset of symptoms. The result of univariate analysis showed that the probability of surgical treatment is high in patients who were male and those older than 40 years at diagnosis(P<0.05). Lesions involving upper digestive tract, stenosis and penetrating lesions were also the risk factors on initial surgery in Crohn's disease (P<0.05). The result of multivariate analysis showed the relative risk of initial surgery was increased in male gender(OR=2.02, 95%CI:1.04-3.92) and in those who were older than 40 years at diagnosis (OR=2.34,95%CI:1.05-5.22). However, in patients with Crohn's disease involving colon alone, the relative risk of initial surgery was decreased (OR=0.35, 95%CI:0.13-0.97). Conclusion Abdominal pain is the most common clinical presentation in Crohn's disease. Disease behavior and operation is closely related. Older than 40 years at diagnosis and male gender is high risk factor for surgery while colonic lesion alone is protective factor.

Objective To investigate the risk factors on initial surgery in Crohn's disease. Methods The clinical data of 173 patients with Crohn's disease who were treated during 2010 and 2014 years in the Second Affiliated Hospital of Sun Yat-Sen University, were analyzed retrospectively. The patients who had received intestinal resection or whose initial symptoms occurred at least 5 years at the end of the follow-up were recruited. Montreal classification was used to evaluate lesion location and disease behavior. The risk factors of the initial surgery were analyzed by using Logistic regression model. Results Eighty-five patients(49.1%) received intestinal resection in 5 years after the onset of symptoms. The result of univariate analysis showed that the probability of surgical treatment is high in patients who were male and those older than 40 years at diagnosis(P<0.05). Lesions involving upper digestive tract, stenosis and penetrating lesions were also the risk factors on initial surgery in Crohn's disease (P<0.05). The result of multivariate analysis showed the relative risk of initial surgery was increased in male gender(OR=2.02, 95%CI:1.04-3.92) and in those who were older than 40 years at diagnosis (OR=2.34,95%CI:1.05-5.22). However, in patients with Crohn's disease involving colon alone, the relative risk of initial surgery was decreased (OR=0.35, 95%CI:0.13-0.97). Conclusion Abdominal pain is the most common clinical presentation in Crohn's disease. Disease behavior and operation is closely related. Older than 40 years at diagnosis and male gender is high risk factor for surgery while colonic lesion alone is protective factor.

Objective To investigate the related factors for the survival of the patients with pancreatic cancer.Methods A total of 1 620 patients confirmed as pancreatic cancer admitted in Sun Yat-sen Memorial Hospital affiliated with Sun Yat-sen University,Tumor prevention and treatment center affiliated with Sun Yat-sen University and People's Hospital of Guangdong Province from 2004 to 2016 were retrospectively analyzed,and the effects of TNM staging,surgical treatment,palliative chemotherapy and postoperative assisted chemotherapy on the survival of the patients with pancreatic cancer were examined by life table and Log-rank test.Results The median survival time of all 1 620 cases was 7.15 months.The median survival time of TNM stage Ⅰ,Ⅱ,Ⅲ and Ⅳ was 12.50 months,10.12 months,9.56 months and 5.43 months,and there was statistically significant difference (P =0.001).The median survival time of cases who did not undergo surgery was 6.10 months,which of patients who underwent radical surgery was 13.67 months,and the difference was statistically significant (P =0.001).The median survival time of cases without chemotherapy was 5.55 months,which of patients who underwent palliative chemotherapy was 7.58 months,and the difference was statistically significant (P =0.001).The median survival time of cases with pure radical surgery without chemotherapy was 12.38 months,which of patients who underwent adjuvant chemotherapy was 14.50 months,and the difference was no statistically significant (P =0.561).Conclusions Early diagnosis followed closely by radical surgery is the key to prolong the survival of pancreatic cancer patients.And adjuvant chemotherapy for patients who lose surgery opportunity may improve clinical prognosis to a certain extent.