Invasion Of DLD-1 Cells Research Articles

Regenerating gene 4 promotes chemoresistance of colorectal cancer by affecting lipid droplet synthesis and assembly.

Regenerating gene 4 (REG4) has been proved to be carcinogenic in some cancers, but its manifestation and possible carcinogenic mechanisms in colorectal cancer (CRC) have not yet been elucidated. Our previous study found that the drug resistance of CRC cells may be closely linked to their fat metabolism. To explore the role of REG4 in CRC and its association with lipid droplet formation and chemoresistance. We conducted a meta-analysis and bioinformatics and pathological analyses of REG4 expression in CRC. The effects of REG4 on the phenotypes and related protein expression were also investigated in CRC cells. We detected the impacts of REG4 on the chemoresistance and lipid droplet formation in CRC cells. Finally, we analyzed how REG4 regulated the transcription and proteasomal degradation of lipogenic enzymes in CRC cells. Compared to normal mucosa, REG4 mRNA expression was high in CRC (P < 0.05) but protein expression was low. An inverse correlation existed between lymph node and distant metastases, tumor-node-metastasis staging or short overall survival and REG4 mRNA overexpression (P < 0.05), but vice versa for REG4 protein expression. REG4-related genes included: Chemokine activity; taste receptors; protein-DNA and DNA packing complexes; nucleosomes and chromatin; generation of second messenger molecules; programmed cell death signals; epigenetic regulation and DNA methylation; transcription repression and activation by DNA binding; insulin signaling pathway; sugar metabolism and transfer; and neurotransmitter receptors (P < 0.05). REG4 exposure or overexpression promoted proliferation, antiapoptosis, migration, and invasion of DLD-1 cells in an autocrine or paracrine manner by activating the epidermal growth factor receptor-phosphoinositide 3-kinase-Akt-nuclear factor-κB pathway. REG4 was involved in chemoresistance not through de novo lipogenesis, but lipid droplet assembly. REG4 inhibited the transcription of acetyl-CoA carboxylase 1 (ACC1) and ATP-citrate lyase (ACLY) by disassociating the complex formation of anti-acetyl (AC)-acetyl-histone 3-AC-histone 4-inhibitor of growth protein-5-si histone deacetylase;-sterol-regulatory element binding protein 1 in their promoters and induced proteasomal degradation of ACC1 or ACLY. REG4 may be involved in chemoresistance through lipid droplet assembly. REG4 reduces expression of de novo lipid synthesis key enzymes by inhibiting transcription and promoting ubiquitination-mediated proteasomal degradation.

PI3K/Akt/YAP signaling promotes migration and invasion of DLD-1 colorectal cancer cells.

Colorectal cancer (CRC) is one of the most prevalent malignant diseases and metastasis is the leading cause of poor prognosis in patients with CRC. Further knowledge of the molecular mechanism underlying metastasis in CRC and the identification of new therapeutic targets are needed. Yes-associated protein (YAP) is a transcriptional regulator that is important in tumorigenesis and tumor cell proliferation. The present study investigated whether YAP was crucial for CRC migration and invasion. The protein expression levels were detected via western blotting, and migration and invasion were analyzed by Transwell migration and invasion assays. Subsequently, YAP expression was silenced using small interfering RNA. The mRNA expression levels were detected via reverse transcription-quantitative PCR and cell viability was assessed via Trypan blue exclusion assay. The results revealed that YAP protein levels were associated with migration and invasion of CRC cells. Notably, YAP small interfering RNA inhibited the migration and invasion of DLD-1 cells. In addition, the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway inhibitor LY294002 suppressed the migration and invasion of DLD-1 cells by decreasing the expression of YAP. Notably, the present study demonstrated that verteporfin mediated the suppression of migration and invasion of DLD-1 cells due to the decreased expression of YAP. Therefore, targeting YAP may be valuable for developing therapeutic strategies against CRC, and verteporfin may be an effective therapy to suppress the migration and invasion of CRC.

The functional effects of microRNA-502-5p on colon cancer DLD-1 cells

Objective To investigate the effect of microRNA (miRNA, miR)-502-5p on colon cancer DLD-1 cells. Methods Colon cancer cell line DLD-1 was transfected by miR-502-5p mimic, control mimic, miR-502-5p inhibitor and control inhibitor respectively. The effect of miR-502-5p on the proliferation of DLD-1 cells was detected by cell counting kit-8 (CCK-8) assay. The effect of miR-502-5p on the colony forming ability of DLD-1 cells was detected by plate-cloning assay. Transwell assay was used to evaluate the effect of miR-502-5p on the migration and invasion of colon cells. Results The expression of miR-502-5p was significantly increased (319.31±33.16 vs. 1.08±0.22) in DLD-1 cells after transfection with miR-502-5p mimic (P 0.05), while migration [(621±90) cells vs. (174±32) cells] and invasion [(531±45) cells vs. (132±34) cells] ability were significantly increased (P 0.05), but the migration [(133±50) cells vs. (543±84) cells] and invasion [(119±45) cells vs. (458±57) cells] ability were decreased significantly (P<0.05). Conclusion MiR-502-5p may promote the migration and invasion of DLD-1 cells, but has no effect on the proliferation function. Key words: Colon cancer; MicroRNA-502-5p; Proliferation; Migration; Invasion

Expression of miRNA-1 in colorectal cancer tissues and its effect on proliferation and invasion of colorectal cancer DLD1 cells

Objective To investigate the expression of miRNA-1 (miR-1) in colorectal cancer (CRC) tissues and its effect on proliferation and invasion of CRC cells in vitro as well as its mechanism. Methods A total of 180 CRC tissues from the hospitalized patients who underwent excision surgery and 114 adjacent cancer tissues in the Affiliated Cancer Hospital of Shanxi Medical University between June 2015 and December 2015 were collected. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-1 in 58 cases of CRC tissues and adjacent cancer tissues. Immunohistochemistry was used to detect the expression of stromal cell-derived factor-1 (SDF-1) protein in 122 CRC tissues and effect of overexpression or knockdown of miR-1 on the proliferation, colony formation and invasiveness of DLD1 cells, respectively. Western blot was used to determine the effect of overexpression or knockdown of miR-1 on the expression of SDF-1 in DLD1 cells. Results RT-qPCR results showed that the expression of miR-1 in CRC tissues was decreased compared with the corresponding adjacent cancer tissues (the relative expression level ratio < 0.5), and the low expression rate of miR-1 in CRC was 82.8% (48/58). Immunohistochemistry results showed that the positive expression rate of SDF-1 in CRC tissues was higher than that in adjacent cancer tissues [81.1% (99/122) vs. 8.9% (5/56), χ2 = 82.415, P < 0.01]. Cell function experiment showed that, compared with the control group, the proliferative activity of DLD1 cells that transfected miR-1 mimics was decreased, meanwhile, the colony formation, invasion and SDF-1 expression were reduced (P < 0.05). The proliferative activity, colony formation, invasion and SDF-1 expression in DLD1 cells that transfected miR-1 inhibitor were improved compared with those in the control group (P < 0.05). Conclusions The expression of miR-1 in CRC tissues is low and it may act as a tumor suppressor gene through affecting proliferation and invasive potential of CRC cells by regulating the expression of SDF-1. Key words: Colorectal neoplasms; miRNA-1; Stromal cell-derived factor-1; Cell proliferation; Neoplasm metastasis

Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression.

MicroRNA-21 promotes proliferation, migration, and invasion of colorectal cancer, and tumor growth associated with down-regulation of sec23a expression

BackgroundMicroRNA-21 (miR-21) is up-regulated in many cancers, including colorectal cancer (CRC). Nevertheless, the function of miR-21 in CRC and the mechanism underlying that function is still unclear.MethodsAfter analyzing the expression of miR-21 and Sec23A in CRC cell lines, we transfected the highest miR-21 expressing cell line, SW-480, with a plasmid containing an miR-21 inhibitor and the lowest miR-21 expressing cell line, DLD-1, with a plasmid containing an miR-21 mimic and measured the effects on the expression of Sec23A and on cell proliferation, migration, and invasion. We also evaluated the effect of knocking down Sec23A on miR-21 expression and its effects on cell proliferation, migration, and invasion. Finally, we assessed the effect of miR-21 in a xenograft tumor model in mice. Tumor tissues from these mice were subjected to immunohistochemical staining to detect the expression of Sec23A.ResultsGenetic deletion of miR-21 suppressed the proliferation, migration, and invasion of SW-480 cells, while over-expression of miR-21 promoted proliferation, migration, and invasion of DLD-1 cells. Inhibition of miR-21 increased the expression of Sec23A protein in SW-480 cells while over-expression of miR-21 significantly suppressed the expression of Sec23A protein and Sec23A mRNA in DLD-1 cells. Knockdown of Sec23A increased the expression of miR-21 in SW480 and DLD-1 cells and their proliferation (DLD-1 only), migration, and invasion. Over-expression of miR-21 promoted tumor growth in BALB/c nude mice and suppressed tumor expression of Sec23A.ConclusionThese findings provide novel insight into the molecular functions of miR-21 in CRC, which may serve as a potential interesting target.

Microcystin-LR promotes migration and invasion of colorectal cancer through matrix metalloproteinase-13 up-regulation.

Microcystin-LR (MC-LR) is an environmental toxin from blooms of cyanobacteria and it has been shown to be one of the environmental carcinogens for the progression of colorectal carcinoma. However, there is no direct evidence that MC-LR can induce colorectal cancer migration and invasion. In the present study, 0.04 or 40 µg/kg/d (human tolerable daily intake value of MC-LR) MC-LR treatment was observed to induce Matrix Metalloproteinase-13 (MMP-13) expression in tumor tissues and local invasion in DLD-1 xenograft model. The results are consistent with those of cell test showing that MC-LR treatment enhanced migration and invasion of DLD-1, HT-29, and SW480 cells and are also correlated with the increased mRNA and protein levels of MMP-13 by Quantitative real-time PCR, Luciferase assay, and Western blot assay respectively in DLD-1 cells and HT-29 cells after MC-LR exposure. In addition, MMP-13 siRNA inhibited MC-LR induced migration and invasion enhancement and MMP-13 over-expression in DLD-1 cells and HT-29 cells. This is the first paper confirming MC-LR-induced MMP-13 expression can promote colorectal cancer invasion and migration. Further investigation revealed that phosphorylation of AKT increased in MC-LR-treated cells, and the phosphatidylinositol 3-kinase/Akt. (PI3-K/AKT) inhibitor LY294002 effectively abolished MC-LR-enhanced migration and invasion and MMP-13 expression. Therefore, based on these observations, we concluded that the activation of PI3K/AKT by MC-LR results in MMP-13 expression, leading to the migration and invasion of DLD-1 cells and HT-29 cells. The study provides a mechanistic insight into the promoting colorectal cancer functions of MC-LR.

Inhibition of Cell Survival and Invasive Potential of Colorectal Carcinoma Cells by the Tyrosine Kinase Inhibitor STI571

Inhibiting tyrosine kinases has recently emerged as a therapeutic modality in several forms of neoplasia. The tyrosine kinase inhibitor STI571 (IMATINIB MESYLATE; GLEEVEC; GLIVEC) is a case in point as it has shown promise in the treatment of malignancies expressing the BCR/ABL fusion protein. In addition to BCR/ABL, STI571 inhibits the tyrosine kinase moieties of several cell surface receptors including the platelet-derived growth factor (PDGF) receptors and c-Kit. Previous work demonstrated that c-Kit activation supports migration, invasion and, survival of certain colorectal carcinoma cells including DLD-1. Here we describe that blocking c-Kit with STI571 inhibits these malignant traits not only in DLD-1 cells but also in two early passage colorectal carcinoma cell strains. Specifically, STI571 inhibited anchorage-independent colony formation and cell scattering in semi-solid medium. Furthermore, it enhanced apoptosis susceptibility and abrogated invasion of DLD-1 cells through Matrigel. In addition, STI571 treatment affected the balance of the Bcl-2 family of apoptosis regulators on favor of a pro-apoptotic phenotype. Specifically, STI571 treatment of DLD1 cells was associated with lower levels of Bcl-2 expression accompanied by de novo expression of Bcl-xS. Finally, STI571 acted as a chemosensitizing agent in DLD-1 cells when used in combination with 5-fluorouracil.