Pyrvinium Pamoate Induces Cell Apoptosis and Autophagy in Colorectal Cancer.

BACKGROUND/AIM: In earlier research, we demonstrated that pyrvinium pamoate (PP) can effectively inhibit the proliferation and migration of colorectal cancer (CRC) cells. In the current study, we further explore the possibility of PP, as a potential therapeutic drug in the treatment of CRC. MATERIALS AND METHODS: Hoechst 33258 staining, immunofluorescence, and western blotting were used to further investigate the connection between PP and CRC cell apoptosis and autophagy. RESULTS: We found that PP promoted apoptosis and autophagy of CRC cells. At the protein level, the expression of proteins related to the PI3K/mTOR signaling pathway exhibited a negative correlation with the dosage of PP. PP may therefore induce apoptosis and autophagy by inhibiting the PI3K/mTOR signaling pathway. CONCLUSION: Our in vitro experiments demonstrated that PP could inhibit the progression of colorectal cancer cells by inducing apoptosis and autophagy. The detailed mechanism needs further investigation.

Perianal ulcerative tuberculosis: A case report.

Perianal tuberculosis (TB) is an extremely rare form of mycobacterial infection, in which the anal mucocutaneous junction becomes infected by autoinoculation from an active draining gastrointestinal tract infection. The case of a 73-year-old immunocompetent male patient, who came in with a refractory perianal ulcer is presented. The patient had no history of TB and his lab tests for TB were all negative. A chest X-ray showed streak and nodular opacities in both upper lungs. The ulcer was biopsied twice and a diagnosis of TB was finally rendered by histological examination with confirmatory Polymerase chain reaction (PCR). The lesion was finally cured by intensive anti-TB treatment. Perianal TB needs to be excluded in patients with a refractory perianal ulcer, including immunocompetent cases without TB history. Biopsies and microbiological tests should be performed for any suspicious lesion and repeated if there is high clinical concern. Consideration of differential diagnoses, especially inflammatory bowel disease, is essential. Early and sufficient antitubercular treatment should be initiated to minimize morbidity.

Robot-assisted versus laparoscopic surgery for rectal cancer: A systematic review and meta-analysis.

AIM: This study aimed to compare clinical and oncological outcomes of robot-assisted and laparoscopic surgery for rectal cancer. MATERIALS AND METHODS: We searched PubMed/Medline, Embase, the Cochrane Library, Yahoo, and Google Scholar databases for relevant articles published up to 2017. Studies based on comparability between robot-assisted and laparoscopic surgery for rectal cancer were designated. Clinical outcomes included operative time, conversion to open surgery, estimated blood loss (EBL), bowel function recovery time, length of hospital stay (LOS), anastomosis leak, and postoperative complications. Oncological outcomes comprised the number of lymph nodes extracted, the positive circumferential margin (PCRM), and the distal resection margin (DRM). RESULTS: Twenty studies were designated totaling 5496 patients, comprising a robot-assisted surgery patient group (n = 2168, 39.4%) and a laparoscopic surgery patient group (n = 3328, 60.6%). The robot-assisted surgery group was associated with longer operative time (odds ratio [OR] 0.48, 95% confidence interval [CI]; 0.14, 0.82), lower conversion to open surgery rate (OR 0.55, 95% CI; 0.44, 0.69), shorter LOS (OR - 0.15, 95% CI; -0.30, 0.00), faster bowel function recovery (OR - 0.38, 95% CI; -0.74, -0.02), and lower postoperative complications (OR 0.79, 95% CI; 0.65, 0.97). EBL, anastomosis leak rate, and oncological outcomes including the number of lymph nodes extracted, the DRM, and the PCRM showed no significant differences between groups. CONCLUSION: Robot-assisted surgery for rectal cancer showed longer operative time, lower conversion, faster bowel function recovery rates, and shorter hospital stay, and similar oncological outcomes compared to laparoscopic surgery.

A novel RON splice variant lacking exon 2 activates the PI3K/AKT pathway via PTEN phosphorylation in colorectal carcinoma cells.

Abnormal expression of the Recepteur d'Origine Nantais (RON) receptor tyrosine kinase is accompanied by the generation of multiple splice or truncated variants, which mediate many critical cellular functions that contribute to tumor progression and metastasis. Here, we report a new RON splice variant in the human colorectal cancer (CRC) cell line HT29. This variant is a 165 kda protein generated by alternative pre-mRNA splicing that eliminates exon 2, causing an in-frame deletion of 63 amino acids in the extracellular domain of the RON ß chain. The deleted transcript was a single chain expressed in the intracellular compartment. Although it lacked tyrosine phosphorylation activity, the RONΔ165E2 variant could phosphorylate phosphatase and tensin homolog (PTEN), thereby activating the PI3K/AKT pathway. In addition, in vitro and in vivo experiments showed that the RONΔ165E2 promoted cell migration and tumor growth. Finally, in an investigation of 67 clinical CRC samples, the variant was highly expressed in about 58% of the samples, and was positively correlated with the invasive depth of the tumor (P < 0.05). These results demonstrate that the novel RONΔ165E2 variant promoted tumor progression while activating the PI3K/AKT pathway via PTEN phosphorylation.

Suppressing the growth of rectal cancer xenografts derived from patient tumors by an adenovector expressing small hairpin RNA targeting Bcl-XL.

BACKGROUND: Bcl-XL, a mitochondria membrane protein, is overexpressed in colorectal cancers and promotes cell survival. We have previously shown that the adenovector expressing small hairpin (sh)RNA targeting Bcl-XL could induce significantly apoptosis in colon cancer cells. In the present study, we aimed to further detect the anti-cancer effect of adenovector expressing the shRNA targeting Bcl-XL (Ad/Bcl-XL shRNA) on rectal cancer xenografts that were derived from patient tumors. METHODS: We first established three rectal cancer xenografts. These xenografts were subsequently treated with Ad/Bcl-XL shRNA alone or in combination with 5-fluouracil (5-Fu). Finally, the inhibition of tumor growth, survival time and induction of apoptosis were analyzed. RESULTS: The results obtained demonstrated that Ad/Bcl-XL shRNA could effectively suppress the tumor growth of all three rectal cancer xenografts and prolong their survival time. After being combined with 5-Fu, the suppressing effect of Ad/Bcl-XL shRNA was enhanced further. In addition, the data also showed that Ad/Bcl-XL shRNA combined with 5-Fu could significantly increase the apoptotic ratio in the rectal cancer xenograft. CONCLUSIONS: These data indicate that Ad/Bcl-XL shRNA with or without 5-Fu has effective anti-tumor effects on the patient tumor-derived rectal cancer xenografts, suggesting that it could be a potential strategy for rectal cancer therapy.

A novel variant of the RON receptor tyrosine kinase derived from colorectal carcinoma cells which lacks tyrosine phosphorylation but induces cell migration.

Generation of splice variants in the RON receptor tyrosine kinase facilitates the invasive phenotype of colorectal cancers. Here, we report a new splice variant of RON in the human colorectal cancer cell line HCT116. This variant is encoded by a transcript differing from the full-length RON mRNA by an in-frame deletion of 106 amino acids in the extracellular domain of RON ß-chain. The deleted transcript originates by an alternative deletion of exon 2 and exon 3. The molecular weight of this variant is 160 kDa. Thus, we named this variant RONΔ160(E2E3). This variant is a single-chain protein and expressed in the intracellular compartment. We found that RONΔ160(E2E3) had no tyrosine phosphorylation ability, but it has constitutively activated Akt activity in transfected HEK293 epithelial cells. The expression of this variant in HEK293 cells resulted in an increased migratory activity in vitro mediated through the PI-3K/Akt pathway. Our data describes a new splice variant of RON and suggests a novel role for the RON receptor in the progression of metastasis in colorectal cancer.

Identification of EFEMP2 as a serum biomarker for the early detection of colorectal cancer with lectin affinity capture assisted secretome analysis of cultured fresh tissues.

Early diagnosis plays a decisive role in the outcome of colorectal cancer (CRC) therapy. The ex vivo culture of fresh CRC tissues and paired normal colorectal tissues provides a feasible way to explore potential serum biomarkers for CRC early detection under near-physiological conditions. In the present work, we applied a lectin affinity based approach to enrich and increase the detection number of secreted proteins in the conditioned media of cultured tissues. The captured proteins were then analyzed by the proteomic strategy of one-dimensional gel electrophoresis coupled to liquid chromatography-tandem mass spectrometry. By quantification with label-free spectral counting, we found 123 differentially expressed secreted proteins (DESPs) with 68 DESPs up-regulated in CRC tissues. EFEMP2, one of the top 10 up-regulated DESPs, was further validated by immunohistochemistry at tissue level and enzyme-linked immunosorbent assay at serum level. We found the expression level of EFEMP2 was dramatically increased in CRC patients, even at the early stage. Moreover, the diagnostic accuracy of EFEMP2 was superior to the established CRC biomarker carcinoembryonic antigen evidenced by the area under the receiver operating characteristic curve for the two biomarkers were 0.923 and 0.728, respectively. These results indicated EFEMP2 is a promising serum biomarker for CRC early detection.

Blocking tumorigenic activities of colorectal cancer cells by a splicing RON receptor variant defective in the tyrosine kinase domain.

Altered expression of the RON receptor tyrosine kinase, accompanied by generation of splicing variants, contributes to the pathogenesis of epithelial cancers such as invasive growth of colorectal caners. In this study, we have studied a novel RON variant (designated as RONdelta170) that regulates tumorigenic activities of colorectal cancer cells by blocking RON-mediated tumorigenic signals. RONdelta170 is a splicing variant with a deletion of exon 19 that encodes 46 amino acids in the catalytic kinase domain. This deletion also causes a reading-frame shift and creates a new stop codon, which effectively eliminates the multi-functional docking site and truncates the RON C-terminus. As a RON variant without kinase activities and the C-terminal docking domain, RONdelta170 acts as a variant receptor that negatively regulates biochemical and biological activities mediated by RON or its oncogenic variant RONdelta160. In NIH3T3 expressing RONdelta160, RONdelta170 formed a complex with RONdelta160 and prevented RONdelta160-mediated activation of signaling proteins such as Erk1/2 and AKT. These effects resulted in decreased cell proliferation, reduced colony formation, and diminished cell migration. These negative activities were also observed in colorectal cancer cells naturally expressing RON or RONdelta160 including HT-29, HCT116 and SW620. Introduction of RONdelta170 into HCT116 cells blocked MSP-induced Erkl/2 and AKT phosphorylation, reduced cytoplasmic beta-catenin accumulation, restored glycogen synthase kinase-beta activity, and attenuated various tumorigenic activities. Moreover, RONdelta170 expression significantly reduced SW620 cell-mediated tumor growth in vivo. Thus, RONdelta170 is a naturally occurring variant with dominant negative activities and has potential for inhibiting RON-mediated tumorigenic activities in colorectal cancer cells.

[Activity of the TNF-related apoptosis-inducing ligand gene expressed from the hTERT promoter on colon cancer cell line HT-29].

OBJECTIVE: To evaluate the expression and activity of TNF-related apoptosis-inducing ligand (TRAIL) gene expressed from the hTERT promoter on colon cancer cell line HT-29. METHODS: GFP/TRAIL gene expressed from the hTERT promoter was transfected into HT-29 with adenoviral vectors system, expression and apoptosis inducing ability of GFP/TRAIL protein were determined with fluorescence-activated cell sorting (FACS) method. RESULTS: The expression of GFP gene was 31.4 % and 67.0 % with either hTERT promoter or CMV promoter in DLD1 cells; GFP/TRAIL gene was able to inhibit cell growth (74.2%) and induce apoptosis (25.8%) of HT-29 cells. There was significant difference between Ad/hTERT-gTRAIL and the other two control groups (PBS and Ad/CMV-GFP, P<0.05). CONCLUSION: The GFP/TRAIL gene with hTERT promoter transfected by adenoviral vector was successfully expressed in HT-29 cell, which can both inhibit cell growth and induce apoptosis of colon cancer cell line HT-29.

Anti-liver cancer activity of TNF-related apoptosis-inducing ligand gene and its bystander effects.

AIM: To observe the anti-liver cancer activity of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene and its bystander effects on hepatocellular carcinoma (HCC) cell line SMMC7721. METHODS: Full-length cDNA of human TRAIL was transferred into SMMC7721 cells with a binary adenoviral vector system. Polymerase-chain reaction following reverse transcription (RT-PCR) was used to determine the expression of TRAIL gene. Effects of the transfected gene on proliferation of SMMC7721 cells were measured by MTT assay. Its influence on apoptosis was demonstrated by fluorescence-activated cell sorting (FACS). The bystander effect was observed by co-culturing the SMMC7721 cells with and without the transfected TRAIL gene at different ratios, and the culture medium supernatant from the transfected cells was also examined for its influence on SMMC7721 cells. RESULTS: The growth-inhibition rate and apoptotic cell fraction in the cells transfected with the TRAIL gene, Bax gene or only LacZ gene were 91.2%, 48.0%, 28.8% and 29.1%, 12.5%, 6.6%, respectively. The growth-inhibition rate of transfection with these three sequences in normal human fibroblasts was 6.1%, 45.5% and 7.6%, respectively, indicating a discriminative inhibition of TRAIL transfection on the cancer cells. In the co-culturing test, addition of the transfected TRAIL to SMMC7721 cells in proportions of 5%, 25%, 50%, 75% and 100%, resulted in a growth-inhibition of 15.9%, 67%, 80.2%, 86.4% and 87.7%, respectively. We failed to observe a significant growth-inhibition effect of the culture medium supernatant on SMMC7721 cells. CONCLUSION: TRAIL gene transferred by a binary adenoviral vector system can inhibit proliferation of SMMC7721 cells and induce their apoptosis. A bystander effect was observed, which seemed not to be mediated by soluble factors.

[Effects of sodium hyaluronate on growth and adhesion of two human colorectal cancer cell lines in vitro].

OBJECTIVE: To investigate the effects of sodium hyaluronate on the growth and adhesion of colorectal cancer cells. METHODS: Human colorectal cancer cell lines SW620 and Colo205 were treated with sodium hyaluronate (25 -2,500 microg/ml), and cancer cell proliferation was measured by MTT assay in vitro. Flow-cytometric analysis was applied to detect expression of CD44 on SW620 and Colo205 cells. RESULT: In vitro sodium hyaluronate enhanced proliferation of Colo205 cells, but it had no appreciable effect on SW620 growth under the same doses, Meantime, CD44 expression on cancer cells decreased compared with controls. CONCLUSION: In vitro sodium hyaluronate has different effects on growth of different colorectal cancer cell lines, but can inhibit CD44 expression of colorectal cancer cells and influence their ability of adhesion.