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Aim: To investigate macrophage migration inhibitory factor (MIF) expression and its clinical relevance in gastric cancer, and effects of MIF knockdown on proliferation of gastric cancer cells., Methods: Tissue microarray containing 117 samples of gastric cancer and adjacent non-cancer normal tissues was studied for MIF expression by immunohistochemistry (IHC) semiquantitatively, and the association of MIF expression with clinical parameters was analyzed. MIF expression in gastric cancer cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Two pairs of siRNA targeting the MIF gene (MIF si-1 and MIF si-2) and one pair of scrambled siRNA as a negative control (NC) were designed and chemically synthesized. All siRNAs were transiently transfected in AGS cells with Oligofectamine(TM) to knock down the MIF expression, with the NC group and mock group (Oligofectamine(TM) alone) as controls. At 24, 48, and 72 h after transfection, MIF mRNA was analyzed by RT-PCR, and MIF and proliferating cell nuclear antigen (PCNA) proteins were detected by Western blot. The proliferative rate of AGS cells was assessed by methylthiazolyl tetrazolium (MTT) assay and colony forming assay., Results: The tissue microarray was informative for IHC staining, in which the MIF expression in gastric cancer tissues was higher than that in adjacent non-cancer normal tissues (P < 0.001), and high level of MIF was related to poor tumor differentiation, advanced T stage, advanced tumor stage, lymph node metastasis, and poor patient survival (P < 0.05 for all). After siRNA transfection, MIF mRNA was measured by real-time PCR, and MIF protein and PCNA were assessed by Western blot analysis. We found that compared to the NC group and mock group, MIF expression was knocked down successfully in gastric cancer cells, and PCNA expression was downregulated with MIF knockdown as well. The cell counts and the doubling times were assayed by MTT 4 d after transfection, and colonies formed were assayed by colony forming assay 10 d after transfection; all these showed significant changes in gastric cancer cells transfected with specific siRNA compared with the control siRNA and mock groups (P < 0.001 for all)., Conclusion: MIF could be of prognostic value in gastric cancer and might be a potential target for small-molecule therapy.

Aim: To evaluate the 5-year survival after laparoscopic surgery vs open surgery for stages II and III rectal cancer., Methods: This study enrolled 406 consecutive patients who underwent curative resection for stages II and III rectal cancer between January 2000 and December 2009 [laparoscopic rectal resection (LRR), n = 152; open rectal resection (ORR), n = 254]. Clinical characteristics, operative outcomes, pathological outcomes, postoperative recovery, and 5-year survival outcomes were compared between the two groups., Results: Most of the clinical characteristics were similar except age (59 years vs 55 years, P = 0.033) between the LRR group and ORR group. The proportion of anterior resection was higher in the LRR group than that in the ORR group (81.6% vs 66.1%, P = 0.001). The LRR group had less estimated blood loss (50 mL vs 200 mL, P < 0.001) and a lower rate of blood transfusion (4.6% vs 11.8%, P = 0.019) compared to the ORR group. The pathological outcomes of the two groups were comparable. The LRR group was associated with faster recovery of bowel function (2.8 d vs 3.7 d, P < 0.001) and shorter postoperative hospital stay (11.7 d vs 13.7 d, P < 0.001). The median follow-up time was 63 mo in the LRR group and 65 mo in the ORR group. As for the survival outcomes, the 5-year local recurrence rate (16.0% vs 16.4%, P = 0.753), 5-year disease-free survival (DFS) rate (63.0% vs 63.1%, P = 0.589), and 5-year overall survival (OS) rate (68.1% vs 63.5%, P = 0.682) were comparable between the LRR group and the ORR group. Stage by stage, there were also no statistical differences between the LRR group and the ORR group in terms of the 5-year local recurrence rate (stage II: 6.3% vs 8.7%, P = 0.623; stage III: 26.4% vs 23.2%, P = 0.747), 5-year DFS rate (stage II: 77.5% vs 77.6%, P = 0.462; stage III: 46.5% vs 50.9%, P = 0.738), and 5-year OS rate (stage II: 81.4% vs 74.3%, P = 0.242; stage III: 53.9% vs 54.1%, P = 0.459)., Conclusion: LRR for stages II and III rectal cancer can yield comparable long-term survival while achieving short-term benefits compared to open surgery.

Aim: To illustrate the critical techniques and feasibility of laparoscopic extended right hemicolectomy (LERH), according to our previous experience., Methods: Anatomical relationship and operative techniques were demonstrated. One hundred and five consecutive patients who underwent extended right hemicolectomy with D3 lymphadenectomy between January 2008 and May 2011 were included in the present study [laparoscopic group (n = 48) vs open group (n = 57)]., Results: The right retrocolic space was the main surgical plan of the LERH. The superior mesenteric vein was the most important anatomical landmark for vascular dissection. The medial-to-lateral dissection approach made the LERH performed efficiently. Compared with the open group, the LERH group had less blood loss (111.7 ± 127.8 mL vs 170.2 ± 49.7 mL, P = 0.023), faster return of flatus (3.0 ± 1.6 d vs 3.7 ± 1.3 d, P = 0.019), and earlier diet (4.2 ± 1.4 d vs 5.0 ± 1.2 d, P = 0.005). Five patients (10.4%) underwent conversion during laparoscopic surgery. The cancer recurrence rates between the two groups were comparable (laparoscopic vs open, 8.6% vs 9.1%, P = 0.335)., Conclusion: For an advanced tumor located at the hepatic flexure or proximal transverse colon, LERH with D3 lymphadenectomy using a medial-to-lateral approach seems to be safe and feasible when the superior mesenteric vein serves as the main anatomical landmark and the right retrocolic space severed as the surgical plan.

Aim: To investigate the regulative effect of miRNA (miR)-221 on colorectal carcinoma (CRC) cell radiosensitivity and the underlying mechanisms., Methods: A human CRC-derived cell line was cultured conventionally and exposed to different doses of X-rays (0, 2, 4, 6 and 8 Gy). The total RNA and protein of the cells were extracted 24 h after irradiation, and the alteration of miR-221 and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction (PCR). The protein alteration of PTEN in the cells was detected by Western blotting. Caco2 cells were pretreated with or without anti-PTEN-siRNA prior to the addition of pre-miR-221 or anti-miR-221 using Lipofectamine 2000. Colony formation assay and flow cytometry analysis were used to measure the surviving cell fraction and the sensitizing enhancement ratio after irradiation. Additionally, PTEN 3'-untranslated region fragment was PCR amplified and inserted into a luciferase reporter plasmid. The luciferase reporter plasmid construct was then transfected into CRC cells together with pre-miR-221 or anti-miR-221, and the luciferase activity in the transfected cells was detected., Results: The X-ray radiation dose had a significant effect on the expression of miR-221 and PTEN protein in human Caco2 cells in a dose-dependent manner. The miR-221 expression level improved gradually with the increase in irradiation dose, while the PTEN protein expression level reduced gradually. miR-221 expression was significantly reduced in the anti-miR-221 group compared with the pre-miR-221 and negative control groups (P < 0.01). Anti-miR-221 upregulated expression of PTEN protein and enhanced the radiosensitivity of Caco2 cells (P < 0.01). Moreover, the inhibitory effect was dramatically abolished by pretreatment with anti-PTEN-siRNA, suggesting that the enhancement of radiosensitivity was indeed mediated by PTEN. A significant increase of luciferase activity was detected in CRC cells that were cotransfected with the luciferase reporter plasmid construct and anti-miR-221 (P < 0.01)., Conclusion: Anti-miR-221 can enhance the radiosensitivity of CRC cells by upregulating PTEN.

Aim: To investigate the regulative effect of miRNA-338-3p (miR-338-3p) on cell growth in colorectal carcinoma (CRC)., Methods: The lentiviral vector pLV-THM-miR-338-3p and pLV-THM-miR-338-3p-inhibitor were constructed. The recombinant viral vector encoding the pre-miR-338-3p or miR-338-3p-inhibitor and the two packaging plasmids psPAX2 and pMD2.G were cotransfected into human embryonic kidney 293T cells to package lentivirus. The supernatant containing the lentivirus particles was harvested to determine the viral titer, and this supernatant was then used to transduce CRC-derived cell line, SW-620. Flow cytometry was utilized for sorting the green fluorescent protein (GFP)⁺ cells to establish the SW-620 cell line stably expressing pre-miR-338-3p or miR-338-3p-inhibitor. Moreover, the expression of miR-338-3p was determined by real-time reverse transcriptase polymerase chain reaction, and Western blotting was used to detect the expression of the smoothened (SMO, the possible target of miR-338-3p) protein in SW-620 cells. Furthermore, the status of CRC cell proliferation and apoptosis were detected by 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry, respectively., Results: Restriction enzyme digestion and DNA sequencing demonstrated that the lentiviral vector pLV-THM-miR-338-3p and pLV-THM-miR-338-3p-inhibitor were constructed successfully. GFP was expressed after the SW-620 cells were transduced by the lentivirus. Expression of miR-338-3p in SW-620 cells transduced with the lentivirus pLV-THM-miR-338-3p was significantly increased (relative expression 3.91 ± 0.51 vs 2.36 ± 0.44, P < 0.01). Furthermore, overexpression of miR-338-3p inhibited the expression of SMO protein in SW-620 cells, which showed obviously suppressed proliferation ability [cellular proliferation inhibition rate (CPIR) 61.9% ± 5.2% vs 41.6% ± 4.8%, P < 0.01]. Expression of miR-338-3p in SW-620 cells transduced with the lentivirus pLV-THM-miR-338-3p-inhibitor was significantly decreased (relative expression 0.92 ± 0.29 vs 2.36 ± 0.44, P < 0.01). Moreover, the downregulated expression of miR-338-3p caused upregulated expression of the SMO protein in SW-620 cells, which showed significantly enhanced proliferation ability (CPIR 19.2% ± 3.8% vs 41.6% ± 4.8%, P < 0.01). However, anti-SMO-siRNA largely, but not completely, reversed the effects induced by blockage of miR-338-3p, suggesting that the regulative effect of miR-338-3p on CRC cell growth was indeed mediated by SMO., Conclusion: miR-338-3p could suppress CRC growth by inhibiting SMO protein expression.

Aim: To establish a method to detect the expression of the tumor specific growth factor TSGF, CA242 and CA19-9 in serum and evaluate their value in diagnosis of pancreatic cancer., Methods: ELISA and Biochemical colorimetric assay were used to detect the serum content of TSGF, CA242 and CA19-9 in 200 normal cases, 52 pancreatitis patients and 96 pancreatic cancer patients., Results: The positive likelihood ratios of TSGF, CA242 and CA19-9 were 5.4, 12.6 and 6.3, respectively, and their negative likelihood ratios were 0.10, 0.19 and 0.17, respectively. With single tumor marker diagnosed pancreatic cancer, the highest sensitivity and specificity of TSGF were 91.6% and 93.5%. In combined test with 3 markers, when all of them were positive, the sensitivity changed to 77.0% and the specificity and the positive predictive value were 100%. The levels of TSGF and CA242 were significantly higher in the patients with pancreatic cancer of head than those in the patients with pancreatic cancer of body, tail and whole pancreas, but the expression of CA19-9 had no correlation with the positions of the pancreatic cancer. The sensitivity of TSGF, CA242 and CA19-9 was increased with the progress in stages of pancreatic cancer. In stage I, the sensitivity of TSGF was markedly higher than CA242 and CA19-9., Conclusion: The combined use of TSGF, CA242 and CA19-9 expressions can elevate the specificity for pancreatic cancer diagnosis. And it shows that it plays an important role to differentiate positions and tissue typing. It is a forepart diagnosis for the pancreatic cancer by combination checking. There is very important correlation between the three markers and the pancreatic cancer.