FMNL2 is a positive regulator of cell motility and metastasis in colorectal carcinoma.

FMNL2 is a member of diaphanous-related formins which act as effectors of Rho family GTPases and control the actin-dependent processes such as cell motility or invasion. We previously found that FMNL2 overexpression in metastatic cell lines and tissues of colorectal carcinoma is associated with more aggressive tumour behaviour. Here we used gain-of-function and loss-of-function approaches to investigate the effects of FMNL2 on colorectal carcinoma in vitro and in vivo. Forced expression of FMNL2 caused a significant increase in tumour cell proliferation, motility, invasion in vitro, and metastasis in vivo, whereas FMNL2 depletion showed opposite effects. We examined gene expression profiles following knockdown of FMNL2 in SW480/M5 cells. Expression of 323 genes was up-regulated by more than two-fold, whereas 222 genes were down-regulated by more than two-fold in FMNL2-depleting SW480/M5 cells. Gene ontology analysis showed that most of genes belong to functional categories such as cell cycle, cytoskeleton, transcription factor, and G-protein modulator. Pathway analysis revealed that cytoskeletal regulation by the Rho GTPase pathway, the Wnt pathway, the G-protein pathway, and the P53 pathway were affected by FMNL2. Many of these genes are in functional networks associated with cell proliferation, metastasis, Wnt or the Rho signalling pathway involved in the regulation of FMNL2. The expression of five differentially expressed genes including CXXC4, CD200, VAV1, CSF1, and EPHA2 was validated by real-time PCR and western blot analysis. Thus, FMNL2 is a positive regulator of cell motility, invasion, and metastasis of colorectal carcinoma.

[Expression of FMNL2 and its relation to the metastatic potential of human colorectal cancer cells].

OBJECTIVE: To explore the association of FMNL2 expression with the metastatic potential of colorectal cancer cells. METHODS: FMNL2 mRNA and protein expressions in 6 human colorectal cancer cell lines were detected by real-time RT-PCR and immunohistochemical method, respectively, and analyzed for their correlations to the in vitro invasiveness of the cell lines evaluated by Boyden assay. In SW620 and SW480/M5 cell lines, the expression of FMNL2 was repressed by FMNL2 short hairpin RNA (shRNA), and the changes in the invasiveness of the cells were observed. RESULTS: FMNL2 was highly expressed in SW480/M5, LoVo and SW620 cells derived from metastatic colorectal cancers in comparison with that in LS174T, SW480 and HT29 cells, which were derived from primary colorectal cancers. In vitro analysis of the cell invasiveness demonstrated that SW480/M5, LoVo and SW620 cells had higher invasiveness than LS174T, SW480 and HT29 in vitro. In SW480/M5 and SW620 cells, transfection with FMNL2 shRNA resulted in significantly lowered cell invasiveness. CONCLUSION: FMNL2 may play an important role in the invasion and metastasis of colorectal cancer.

Overexpression of FMNL2 is closely related to metastasis of colorectal cancer.

BACKGROUND AND AIMS: Formin-like 2 (FMNL2) is a member of diaphanous-related formins which can control the actin-dependent processes such as cell motility and invasion. In this study, we investigated the expression of FMNL2 in colorectal cancer (CRC) and its correlation with CRC metastasis. PATIENTS-METHODS: Paraffin-embedded specimens of CRC (including 75 primary CRC tumors and 45 corresponding metastatic lymph nodes) and normal colorectal mucosa (30 samples) were immunostained with a FMNL2 antibody. Thirty-two paired snap-frozen tumor tissues and adjacent normal colorectal mucosa were subjected to real-time reverse-transcription polymerase chain reaction (RT-PCR). Six CRC cell lines (SW480, SW620, SW480/M5, LoVo, LS174T, and HT29) were assayed for FMNL2 expression by Western blotting and real-time RT-PCR. Their invasive abilities in vitro were determined by Boyden chamber assay. RESULTS: The immunohistochemical analysis showed FMNL2 expression was considerably higher in CRC tumors and corresponding metastatic lymph nodes than in normal colorectal mucosa (P < 0.05, respectively). Elevated FMNL2 expression was significantly correlated with lymphatic metastasis of CRC (P < 0.05). Real-time RT-PCR analysis confirmed the results obtained by immunohistochemistry. At mRNA and protein levels, FMNL2 expression was substantially upregulated in cell lines derived from CRC metastases (SW620, SW480/M5, and LoVo) compared to ones derived from primary CRC (HT29, LS174T, and SW480; P < 0.05). In vitro cell invasive assay demonstrated that the former three cell lines had higher invasive ability than the latter cell lines. CONCLUSIONS: FMNL2 may play an important role in the metastasis of CRC and may be a useful marker for metastasis of CRC.

[Galectin-1 expression in human colorectal carcinoma and its clinical significance].

OBJECTIVE: To investigate the correlation between galectin-1 expression and the biological behaviors of human colorectal carcinoma. METHODS: SP immunohistochemistry was used to detect the expression of galectin-1 in 158 paraffin-embedded specimens including 30 normal mucosa, 25 adenoma, 65 colorectal carcinoma and 38 metastatic tumor specimens. Real-time RT-PCR was used to detect galectin-1 mRNA expression in 32 fresh specimens of colorectal carcinoma and normal mucosa. RESULTS: The positive expression level of galectin-1 was significantly different between normal mucosa, adenoma, colorectal carcinomas and metastatic tumors, with positivity rate of 0, 8%, 66% and 86%, respectively (P<0.05). Galectin-1 expression in moderately or well differentiated colorectal carcinomas was significantly lower than that in poorly differentiated ones (P=0.031), and its expression in invasive carcinomas was significantly higher than that in non-invasive carcinomas (P=0.000). Galectin-1 expression in colorectal carcinomas was significantly related with lymph node metastasis (P=0.004). In poorly differentiated colorectal carcinomas, the expression of galectin-1 mRNA was about 2.27 times that in moderately or well differentiated colorectal carcinomas (P=0.00); galectin-1 mRNA expression in invasive carcinoma was 1.98 times that in non-invasive carcinoma (P=0.002). In tumors with lymph node metastasis, galectin-1 mRNA expression was 1.42 times that in tumors without metastasis (P=0.018). CONCLUSION: Galectin-1 can be involved in the development and progression of colorectal carcinoma, and may relate to the infiltration, differentiation and lymph node metastasis of colorectal carcinoma.

[Effect of AcSDKP on the proliferation and collagen synthesis in cultured rat cardiac fibroblasts stimulated by PDGF].

AIM: To investigate whether AcSDKP can inhibit proliferation and collagen synthesis in cultured rat cardiac fibroblasts mediated by PDGF. METHODS: Neonatal rat cardiac fibroblasts were isolated. The cell proliferation was observed by 3H-proline incorporation assay. RESULTS: On the culture of 0.4% FBS, PDGF stimulated cardiac fibroblasts proliferation and collagen synthesis with a dose-dependent manner at the concentrations from 1 ng/ml to 20 ng/ml, in which 10 ng/ml PDGF reached its peak. AcSDKP at the concentration from 10(-10) mol/L to 10(-8) mol/L could inhibit cardiac fibroblasts proliferation and collagen synthesis mediated by PDGF. 10(-9) mol/L AcSDKP attained its peak on inhibiting cardiac fibroblasts proliferation and collagen synthesis. CONCLUSION: AcSDKP can inhibit proliferation and collagen synthesis in cultured rat cardiac fibroblasts mediated by PDGF.

[Role of AcSDKP on collagen synthesis and degradation in cultured rat cardiac fibroblast].

OBJECTIVE: To investigate the role of AcSDKP on collagen synthesis and degradation in cultured rat cardiac fibroblasts. METHODS: Neonatal rat cardiac fibroblasts were isolated and stimulated by PDGF. The cell proliferation was observed by (3)H-TdR incorporation assay. The synthesis of collagen was measured by (3)H-proline incorporation assay. The expression of type I and type III collagen and MMP-1 protein were measured by Western blot. The MMP-2 and MMP-9 activity was evaluated with zymography assay. RESULTS: PDGF stimulated cardiac fibroblasts proliferation with increased collagen synthesis and type I and type III collagen protein expressions as well as MMP-2 and MMP-9 activities and MMP-1 expression. AcSDKP inhibited cardiac fibroblasts proliferation induced by PDGF and reduced collagen synthesis and type I and type III collagen protein expression. AcSDKP also further up-regulated MMP-2 and MMP-9 activities and MMP-1 expression in cardiac fibroblasts induced by PDGF. CONCLUSION: AcSDKP inhibited proliferation and collagen synthesis and up-regulated matrix metalloproteinases activity or expression induced by PDGF, which was possibly related with the effect of AcSDKP anti-fibrosis.