Role of ACSL3 expression in suppressing prostate cancer cell metastasis

AIM:To analyze the difference of long-chain acyl-CoA synthetase 3 (ACSL3) expression between normal prostate epithelial cells and prostate cancer cells.METHODS:ACLS3 mRNA expression between normal prostate epithelial cells and prostate cancer cells was compared using RT-PCR. Meanwhile, ACSL3 gene was amplified from prostate cancer cells, and the eukaryotic expression plasmid pCDNA3.1(+)-Flag-ACLS3 and lentivirus Lenti-ACLS3 were constructed. After transfection of ACSL3-plasmid and lentivirus into the prostate cancer cells, ACSL3 expressive was detected by RT-PCR and Western blotting, and then Matrigel invasion assay was performed to investigate the alteration of the invasive ability of the prostate cancer cells with over-expression of ACSL3. RESULTS:A significant difference of ACSL3 mRNA level between normal prostate epithelial cells and prostate cancer cells was observed. ACSL3 was highly expressed in localized prostate cancer cells compared to metastatic prostate cancer cells, while ACSL3 expression was higher in androgen-dependent prostate cancer cells than that in androgen-independent prostate cancer cells. Furthermore, the eukaryotic expression plasmid and lentivirus containing ACLS3 gene were successfully constructed. The prostate cancer cell line which stably over-expressed ACLS3 was established. Up-regulation of ACSL3 inhibited the invasive ability of prostate cancer cells. CONCLUSION:ACSL3 plays an antagonistic role in invasiveness of prostate cancer.     

Advances of phosphatase of regenerating liver-3 in hematological malignancies

In recent years,accumulating evidence shows that phosphatase of regenerating liver-3(PRL-3) is closely implicated in tumor progression,especially in the stages of invasion and metastasis of various solid tumors,including colorectal cancer,gastric cancer and breast cancer.However,the study of PRL-3 in hematological malignancies is relatively lagged, but there are some advances in leukemia and myeloma,in which PRL-3 up-regulation is tightly associated with poor prognosis,while the underlying mechanism of signal transduction is gradually explored.In this review,we summarized the recent advances of PRL-3 in hematological malignancies such as acute myeloid leukemia,multiple myeloma and chronic myeloid leukemia,as well as the molecular mechanism of PRL-3 in pathogenesis.     

Expression of ERK5 in colorectal cancer tissues and its correlation with distant metastasis in colorectal cancer patients

AIM: To investigate the expression of extracellular signal-regulated kinase 5 (ERK5) in primary colorectal cancer (CRC) and adjacent normal mucosa, and to analyze the relationship between ERK5 expression and clinicopathological parameters for exploring the functions of ERK5 in the occurrence and development of CRC. METHODS: The expression of ERK5 in carcinoma tissues and normal mucosa was examined by a set of tissue microarrays and the method of immunohistochemistry. The potential relationship between ERK5 expression and clinicopathological features was also analyzed. RESULTS: ERK5 expression was significantly higher in CRC tissues (134/338, 39.6%) than that in normal tissues (21/80, 26.2%; P<0.05). Overexpression of ERK5 in CRC tissues was significantly correlated with distant metastasis (P<0.05). However, no correlation between ERK5 expression and age at surgery, sex, tumor location, the depth of invasion, lymph node metastasis, TNM staging or differentiation grade was found (P>0.05). According to the Kaplan-Meier analysis, there is no significant difference in 5-year overall survival between the patients with ERK5 expression at high level and at low level. CONCLUSION: ERK5 protein is highly expressed in CRC with distant metastasis. This may be a promotive factor in the process of distant metastasis.     

Relationship between expression of MKK-4 and MMP-9 genes in primary hepatic carcinoma with or without invasion and metastasis

AIM：To investigate the expression of mitogen activated protein kinase kinase 4 (MKK-4) and MMP-9 mRNA in primary hepatic carcinoma (PHC), and to analyze its relationship with invasion and metastasis. METHODS：The expression of MKK-4 and MMP-9 mRNA in 34 cases of hepatic carcinoma tissues and adjacent tissues,and in 12 cases of normal liver tissues were detected with RT-PCR. RESULTS：(1) The expression level of MMP-9 mRNA was higher in metastatic cancer tissues than that in other tissuses (P<0.01). (2) There was significant statistical difference among the expression level of MKK-4 mRNA, but the level in metastatic cancer was low (P<0.01). (3) There was no statistical difference among the expression level of MKK-4 or MMP-9 mRNA among the adjacent tissues and normal tissues (P>0.05). (4) MMP-9 mRNA had a tendency to rise as PHC became invasive and metastatic.The expression level of MKK-4 had a tendency to decline in PHC became invasive and metastatic. (5) The expression level of MMP-9 or MKK-4 mRNA had no correlations with tumor volume,or cell differentiation (P>0.05). (6) There were correlations between expressions of MKK-4 and MMP-9 mRNA in PHC (Pearson Correlation, r=-0.925, P<0.01). CONCLUSION：There are high MMP-9 mRNA expression and low MKK-4 mRNA expression in PHC.The expression level of MKK-4 or MMP-9 mRNA is correlated with tumor metastasis.     

Relationship between expression level of TIMP-3 and invasion/metastasis of hepatocellular carcinoma

AIM: To detect the levels of tissue inhibitor of metalloproteinase-3 (TIMP-3) in both plasma and the tissue of hepatocellular carcinoma (HCC), and to elucidate their association with clinical features.METHODS: Plasma protein levels of TIMP-3 in 56 HCC patients and 30 cases of controls were detected by ELISA.The mRNA and protein levels of TIMP-3 in 30 HCC tissue samples with their portal vein tumor embolus and lymphatic metastasis tissues, and in normal liver tissues from 30 controls were detected by RT-PCR and Western blotting.The relationship between mRNA and protein levels and their clinic-pathological data were analyzed.RESULTS: The plasma TIMP-3 protein levels in the extrahepatic metastasis patients were obviously lower than those in the non-extrahepatic metastasis patients (P<0.05).The mRNA levels of TIMP-3 in normal liver, carcinoma in situ, portal vein tumor embolus and lymphatic metastasis tissues were 0.78±0.09, 0.52±0.09, 0.42±0.07 and 0.40±0.08, respectively, with significant differences among them (P<0.05).The protein levels of TIMP-3 in these 4 kinds of tissues were 115.08±8.60, 77.04±8.83, 64.43±3.80 and 62.80±3.73, respectively, also with significant differences among them (P<0.05).CONCLUSION: The expression of TIMP-3 significantly decreases in the carcinoma in situ tissues of HCC patients, and decreases more obviously in the portal vein tumor embolus and lymphatic metastasis tissues, indicating that low expression of TIMP-3 may play an important role in HCC invasiveness and metastasis.     

Cultivation and identification of human colon cancer stem cell-like cells and antiproliferative effects of n-3 polyunsaturated fatty acids

AIM: To cultivate stem-like spheres from SW620 cell line in the specific serum-free medium and evaluate the features of the cancer stem cells, and to investigate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the growth of SW620 stem cell-like cells. METHODS: Human colon cancer stem cell-like cells (CSCLC) were obtained from SW620 spheres cultured in serum-free medium. These cells were tested for the expression of SSEA-1 and TRA-1-81 by immunofluorescence staining. The mRNA expression of Sox-2 and Oct-4 was detected by real-time PCR. The efficiency of colony formation on a soft agar gel and tumor formation in the nude mice was compared between SW620 adherent cells and CSCLC. The inhibitory effects of 5-fluorouracil (5-FU) and mitomycin C on both types of cells were measured by MTS assay. MTS assay, Annexin V/PI staining and trypan blue staining were used to determine the effects of DHA and EPA on both types of cells. MTS assay was also used to analyze the combined effect of DHA or EPA with chemotherapeutic drugs on SW620 CSCLC. RESULTS: SW620 cells formed spheres in serum-free culture. The cells from spheres highly expressed SSEA-1 and TRA-1-81, transiently expressed Sox-2 and Oct-4genes and were more resistant to 5-FU and mitomycin C treatments. These cells exhibited a greater ability in clone formation and tumorigenicity, indicating that these cells carried stem cell-like features, hence were considered SW620-derived CSCLC. DHA and/or EPA suppressed SW620 CSCLC by inhibiting cell growth, inducing cell apoptosis and sensitizing them to chemotherapeutic drugs. CONCLUSION: The cells with stem cell-like features, such as high efficiency in clonogenicity, tumorigenicity and resistance to chemotherapeutic drugs, can be obtained from SW620 spheres cultured in serum-free condition. DHA and EPA induce apoptosis in SW620-derived CSCLC and sensitize them to chemotherapeutic drugs.     

Effects of GOLPH3 gene silencing mediated by lentivirus on proliferation,invasion and metastasis of human gastric cancer cell line SGC-7901

AIM：To investigate the effect of Golgi phosphoprotein 3 (GOLPH3) gene silencing on the proliferation, invasion and metastasis of human gastric cancer SGC-7901 cell in vitro. METHODS：SGC-7901 cells were transfected with lentiviral vector carrying GOLPH3 shRNA to construct a stable GOLPH3-silencing cell line LV-GOLPH3-RNAi. The expression of GOLPH3 at mRNA and protein levelss were detected by real-time PCR and Western blotting, respectively. The cell proliferation was analyzed by MTT assay. Transwell migration and invasion experiments were performed to measure the migration and invasion abilities, respectively. RESULTS：The stable GOLPH3-silencing cell line was successfully established. The expression of GOLPH3 at mRNA and protein levels was reduced significantly (P<0.05), leading to the inhibition of cell proliferation in LV-GOLPH3-RNAi group compared with scrambled group and blank control group, as well as the capacities of migration (56.7±1.5 vs 186.0±3.4 and 183.3±4.2, P<0.05) and invasion (33.5±3.0 vs 85.0±3.9 and 83.1±4.4, P<0.05). CONCLUSION：GOLPH3 silencing suppresses the capacities of proliferation, migration and invasion of human gastric cancer SGC-7901 cells, suggesting that GOLPH3 may be a potential tumor marker and independent prognostic factor.     

Role of VEGF-C in lymphangiogenesis and lymphatic metastasis of breast cancer

AIM: To study the inhibitory effect of VEGF-C/Flt-4 system on lymphangiogenesis and lymphatic metastasis of breast cancer. METHODS: Lymphatic endothelial cells (LEC) were cultured in vitro, the effects of VEGF-C and anti-Flt-4 antibody on the proliferation of treated cells were observed. The antisense oligodeoxynucleotides (ASODN) targeting VEGF-C was designed and its effect on VEGF-C gene expression in vitro experiments was observed. The nude mice transplantation tumor model was made and the effects of VEGF-C ASODN on lymphangiogenesis and metastasis in the model were determined. RESULTS: The supernatant of cultured PC3 cells promoted LEC proliferation obviously while the cells treated with anti-Flt-4 antibody were obviously decreased whenever cell counting. The mRNA and protein expression of VEGF-C in MCF-7 cells treated with ASODN were significantly lower than that in control groups in vitro. In vivo ASODN also significantly reduced the VEGF-C mRNA expression detected by RT-PCR. The result of 5-Nase-ALPase enzyme -histochemistry showed that ASODN had obvious inhibitory effect on tumor lymphangiogenesis. Tumor growth velocity in ASODN group was much slower than that in control group. ASODN also inhibited tumor volume and lymphatic metastasis. CONCLUSION: The strong relationships between VEGF-C/Flt-4 system and lymphangiogenesis and lymphatic metastasis of breast cancer have been observed. If the expression of Flt-4 is blocked, the proliferation of LEC induced by tumor cells can be blocked in some degree. ASODN inhibits tumor lymphangiogenesis and lymphatic metastasis by down-regulating VEGF-C expressions.     

Priliminary analysis of microRNA expression profiles of side population cells in human colon cancer cell lines

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 microRNA 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 potential microRNA biomarkers of SP cells in colon cancer.     

Effect of norcantharidin on proliferation and invasion of human breast cancer cell line SKBR3 in vitro

AIM: To investigate the effect of norcantharidin（NCTD）on proliferation and invasion of human breast cancer cell line SKBR3 in vitro and its anticancer mechanisms.METHODS: MTT assay was used to determine SKBR3 cell proliferation. Light and FACScan were used to detect apoptosis and cell cycle. The invasiveness of SKBR3 was evaluated by the adhesion test，Matrigel experiment and the crossing-river test.RESULTS: NCTD had inhibitive effects on growth of SKBR3 cells in a dose and time-dependent manner, with the IC₅₀ value of 12.5 mg/L at 24 h．The cells treated with 10 mg/L NCTD for 24 h and 48 h showed typical apoptotic morphology and hypodiploid peak before G₁ phase. The cell cycle was arrested at G₂/M phase. The apoptosis percentage was up to 3.44% and 6.17%, and the G₂/M percentage was up to 35.82% and 38.70%. NCTD also could inhibit obviously the adhesion, movement and invasive capability simulating human basement membrane of SKBR3. Its effect was also in a dose-dependent manner. In the NCTD-treated group, crossing-river time was prolonged significantly and passing-membrane cells markedly decreased. CONCLUSION: NCTD in vitro inhibits not only the proliferation and growth of human breast cancer cells but also invasion and metastasis of the cells at relatively low concentration. NCTD shows prominent anti-tumor effects.     

Effects of different chemotherapeutic agents on reversing the acquired resistance to TRAIL gene in DLD1 colon cancer cells

AIM:To evaluate effects of different chemotherapeutic agents on reversing the acquired resistance to TRAIL gene and clarify the involved mechanisms in DLD1-TRAIL/R colon cancer cells. METHODS:Human colon cancer cell line DLD1-TRAIL/R cells that were resistant to TRAIL-expressing adenovector (Ad/gTRAIL) were treated with Ad/gTRAIL combined with different chemotherapeutic agents. Then, the cell viability was measured by MTT method, and apoptotic signaling conditions, including activation of caspase-3 and caspase-8, expression of Bax and Bcl-XL, were measured by Western blotting analysis. RESULTS:In vitro data showed that several chemotherapeutic agents, including 5-fluorouracil (5-FU) and mitomycin c (MMC), overcome the acquired resistance to TRAIL gene in DLD1-TRAIL/R colon cancer cells. The combination of Ad/gTRAIL and 5-FU effectively suppressed tumor growth in vivo in subcutaneous tumors established from DLD1-TRAIL/R cells. Further data showed that treatment with the combination of Ad/gTRAIL and 5-FU or MMC led to enhance the activation of caspase-3. Moreover, MMC but not 5-FU induced overexpression of Bax gene that was sufficient to overcome the resistance to TRAIL gene in DLD1-TRAIL/R cells. CONCLUSION:Chemotherapeutic agents, such as 5-FU and MMC, overcome the acquired resistance to TRAIL gene in DLD1-TRAIL/R cells. The candidate mechanisms for MMC but not 5-FU to overcome this resistance might involve the induction of over-expressed Bax protein in DLD1-TRAIL/R cells.     

Stat5b signaling pathway regulates the expression of Survivin and promotes apoptosis in human colon cancer cells

AIM: The purpose of the study was to examine colon cancer cell lines to determine whether Stat5b/Survivin plays an important role in the process of apoptosis in colon cancer cells. METHODS: Protein lysates were extracted from colon cancer cells. Human colon cancer cell line HT29 was transfected with Stat5b antisense oligonucleotide mediated by liposome. MTT assay was used to measure the proliferation. Flow cytometry was applied to analyze the cell cycle and apoptosis. EMSA was used to detect the activity of Stat5. Western blotting was applied to measure the expression of Stat5, p-Stat5, cyclin D1, Survivin, Bcl-2 and Bcl-x L. RESULTS: Targeting of Stat5 using antisense oligonucleotide against the translation site resulted in apoptosis and downregulaed the expressions of Stat5, p-Stat5, cyclin D1 and Survivin, but not Bcl-2 and Bcl-xL. CONCLUSION: Constitutive activation of Stat5 is associated with the carcinogenesis of colon cancer cells. Blocking of Stat5 signaling inhibits the expression of Survivin and induces apoptosis in colon cancer cells.     

Expressions of VEGF,ANG-1,ANG-2 and TSP-1 in cholangiocellular carcinoma and relationship with tumor angiogenesis,differentiation,invasion and metastasis

AIM: To investigate the angiogenesis status,the expression of vascular endothelial growth factor (VEGF),angiopoietin-1 (ANG-1),angiopoietin-2 (ANG-2),thrombospondin-1 (TSP-1) in cholangiocellular carcinoma (CCC) and relationship with tumor angiogenesis,differentiation,invasion and metastasis.METHODS: 33 specimen of surgically resected CCC were investigated.Immunohistochemical staining of CD34,VEGF,ANG-1,ANG-2 and TSP-1 was carried out.RESULTS: The mean MVD was (87.2±52.6)/mm2.VEGF positive expression was found in 75.6% cases;ANG-1 positive expression was observed in 36% cases;ANG-2 positive was detected in 57.6% cases and 45.5% cases exhibited positive TSP-1 expression.VEGF and ANG-2 expressions were found to be associated with significant higher level of MVD (P<0.01 and P<0.05,respectively).TSP-1 expression was found to be associated with significant low level of MVD (P<0.01).Positive TSP-1 expression was also found to be associated with higher level of intrahepatic metastasis (46.7% vs 5.6%,P<0.05).CONCLUSION: Considerable angiogenesis compared to other solid tumors can be observed in CCC.VEGF and ANG-2 might play a proangiogenic role and TSP-1 may play an inhibitory role.Although TSP-1 may increase the intrahepatic metastasis of CCC,neither MVD levels nor the expression of VEGF,ANG-1,or ANG-2 is associated with tumor differentiation,invasion and metastasis.     

Effect of indomethacin on tumor invasion in human laryngeal cancer Hep-2 cells

AIM: To assess the effect of indomethacin on tumor invasion in a human laryngeal cancer Hep-2 cell line in vitro. METHODS: Hep-2 cells were exposed to indomethacin at different concentrations for 48 h. Then cell growth rate, the colony formation in soft agar medium and cell mobility were examined, and monolayer invasion assay was performed to assess cell invasion index. RESULTS: Preteatment with indomethacin inhibited the colony formation of Hep-2 cells and the cell mobility, and decreased the invasion index. CONCLUSION: Indomethacin can inhibit the invasion of Hep-2 cells.     

αvβ6-ERK pathway participates in norcantharidin-induced apoptosis of HT-29 colon cancer cells

AIM: To investigate the pharmacological mechanism of norcantharidin (NCTD)-induced apoptosis of HT-29 colon cancer cells. METHODS: Hoechst 33258 staining was used to analyze the apoptosis of HT-29 cells treated with NCTD. The effects of NCTD on the expression of integrin in HT-29 cells were determined by flow cytometry. The effects of several functional blocking antibodies on HT-29 cells were detected by MTT method. The expression and the phosphorylation of mitogen activated protein kinases (MAPKs) in HT-29 cells were measured by Western blotting. Co-immunoprecipitation assay was used to detect the activity of αvβ6-extracellular signal-regulated kinase (ERK) direct linkage in HT-29 cells.RESULTS: NCTD induced the apoptosis of HT-29 colon cancer cells. The expression of integrin αvβ6 in HT-29 cells treated with NCTD was reduced, but the expression of αvβ3 and αvβ5 was not changed. A function-blocking antibody to αvβ6,10D5,strengthened the growth inhibitory effect of NCTD on HT-29 cells ,but LM609 (a function-blocking antibody to αvβ3) and P1F6 (a function-blocking antibody to αvβ5) did not. The level of phosphorylated ERK (p-ERK) was decreased substantially after treated with NCTD in a dose-and time-dependent manner. NCTD also affected the association of αvβ6 and ERK. CONCLUSION: NCTD decreases the expression of integrin αvβ6 and interferes with the phosphorylation of ERK. As a result, the formation of αvβ6-ERK direct linkage is affected and the signal transduction mediated by αvβ6 is disturbed. The mechanism of NCTD-induced HT-29 cell apoptosis is involved in the αvβ6-ERK signaling pathway.     

Expression of 2 SYK protein isoforms in breast cancer cells and their effect on cell invasion

AIM: This study was to explore the expression of spleen tyrosine kinase(SYK)(L) and SYK(S) in breast cancer cells and their effects on invasive phenotype of breast cancer cell line MB435. METHODS: The expression of SYK in breast cancer cell lines MB435, ZR75.1, MB468, T47D and MCF 7 were detected by Western blotting. MB435 cells were transfected with pcDNA3.1-SYK(L), pcDNA3.1-SYK(S) or pcDNA3.1 respectively, G418-resistant stable clones were pooled and the SYK expression was measured by Western blotting. Chemoinvasion assays were performed to study the effects of SYK(L) and SYK(S) on breast cancer cell invasion.RESULTS: SYK(L) and SYK(S) were simultaneously expressed in most detected breast cancer cells. Pooled SYK(L) and SYK(S) stable clones were made by Fugene 6 transfection and G418 selection. The expression of SYK(L) suppressed the invasive ability of breast cancer cells, while SYK(S) didnt.CONCLUSION: The simultaneously expression of SYK(L) and SYK(S) in breast cancer cells is a common phenomenon. Among SYK(L) and SYK(S),only SYK(L) protein is capable of suppressing the invasion of breast cancer cells.     

Expression of VEGFR-3, CD31 and their correlation with metastasis in ovarian epithelial tumors

AIM: To investigate the expression of vascular endothelial growth factor receptor-3 (VEGFR-3) and CD31 in relation to metastasis in ovarian epithelial tumors. METHODS: VEGFR-3 and CD31 expression were examined by immunohistochemical methods, VEGFR-3 positive microlymphatic count (MLC) and microvessel density (MVD) were assessed by the image analysis. RESULTS: Both MLC and MVD in ovarian epithelial carcinomas were higher than those in benign tumors(MLC, P＜0.05; MVD, P＜0.01). In ovarian epithelial carcinomas, MLC and MVD were higher in the cases of clinical stage Ⅲ-Ⅳ and with lymphatic metastasis than those of clinical stage Ⅰ-Ⅱ and without lymphatic metastasis, respectively (P＜0.05 or P＜0.01) . There were no significant differences between MLC, MVD and histologic type, histologic grade(differentiation) in ovarian epithelial carcinomas(P＞0.05). CONCLUSIONS: VEGFR-3 and CD31 expression correlate significantly with metastasis, MLC and MVD might predict peritumoral lymphangiogenesis and angiogenesis, which may be as a biologic marker for metastasis in ovarian epithelial tumors.     

Effects of integrin αvβ6 on endo-exocytotic cycle of integrin αvβ5 in colon cancer cells

AIM: To investigate the effects of integrin αvβ6 on the endo-exocytotic cycle of integrin αvβ5 in colon cancer cells. METHODS: The expression of integrin αvβ6 and αvβ5 in SW480 cells, SW480 wild-type β6 cells and SW480 mock cells was detected by Western blotting. The trafficking of integrin αvβ6 and αvβ5 was examined by endocytosis assay, exocytosis assay and capture-ELISA. The adhesive and migration abilities of these 3 cell lines towards fibronectin or vitronectin were measured by cell adhesion assay and cell migration assay. RESULTS: The expression of integrin αv and β5 subunits was similar in these 3 cell lines (P>0.05), while the expression of integrin β6 subunit in SW480 wild-type β6 cells was much higher than that in the other 2 cell lines (P<0.05). The transfection of integrin β6 subunit into SW480 cells was able to slow down the endocytosis and exocytosis of integrin αvβ5, and subsequently inhibited the cellular adhesion and migration abilities towards vitronectin. CONCLUSION: Integrin αvβ6 and αvβ5 share the same αv subunit. In the process of endocytosis and exocytosis, there might be some competitive relationship between these 2 integrin isoforms. Compared with integrin αvβ5, integrin αvβ6 has the priority to get into the trafficking process, and it has subsequent effects on the adhesion and migration of colon cancer cells.     

Effect of long non-coding RNA MEG3 on invasion and migration of colorectal cancer cells

AIM: To investigate the expression of long non-coding RNA maternally expressed gene 3(MEG3) in colorectal cancer(CRC) cells, and to observe the effect of MEG3 on the invasion and migration of CRC cells. METHODS: The levels of MEG3 in human normal colon cell NCM460 and CRC cells SW48 and LoVo were detected by real- time PCR. MEG3 was over-expressed by plasmid transfection, and the effects of MEG3 on the invasion and migration of SW48 and LoVo cells were analyzed by Transwell assay and wound healing assay. The expression of matrix metalloproteinase(MMP) family proteins was determined by Western blotting. RESULTS: The level of MEG3 was down-regulated in CRC cells compared with normal colon cell NCM460. The invasion and migration of CRC cells were reduced after MEG3 over-expression. Transwell invasion and migration assays showed that the numbers of transmembrane SW48 and LoVo cells were smaller in MEG3 over-expression group than control group(CONCLUSION: The expression of MEG3 is down-regulated in CRC cells. Over-expression of MEG3 inhibits the invasion and migration of CRC cells. TIMP-2, MMP-2 and MMP-9 might play an important role in this regulation.