The effects of vascular endothelial growth factor C knockdown in esophageal squamous cell carcinoma

BRCA1-Associated Protein Increases Invasiveness of Esophageal Squamous Cell Carcinoma

BACKGROUND & AIMS

We performed a screen for genes whose expression correlates with invasiveness of esophageal squamous cell carcinoma (ESCC) cells. We studied the effects of overexpression and knockdown of these genes in cell lines and expression levels in patient samples.

METHODS

We selected genes for analysis from 11 loci associated with risk of ESCC. We analyzed the effects of knocking down expression of 47 of these genes using RNA interference on-chip analysis in ESCC cells and HeLa cells. Cells with gene overexpression and knockdown were analyzed in migration and invasion assays or injected into nude mice and metastasis of xenograft tumors was quantified. We collected ESCC and non-tumor esophageal tissues from 94 individuals who underwent surgery in China from 2010 and 2014; clinical information was collected and survival time was measured from the date of diagnosis to the date of last follow-up or death. Levels of messenger RNAs (mRNAs) were quantified by RNA sequencing, and levels of proteins were determined from immunoblot analyses. Patient survival was compared with mRNA levels using Kaplan-Meier methods and hazard ratios were calculated by Cox models.

RESULTS

We identified 8 genes whose disruption increased migration and 10 genes whose disruption reduced migration. Knockdown of BRCA1-associated protein gene (BRAP) significantly reduced migration of KYSE30, KYSE150, and HeLa cells. In patient tumors, 90% of ESCCs examined had higher levels of BRAP protein than paired non-tumor tissues, and 63.8% had gains in BRAP DNA copy number. Levels of BRAP mRNA in ESCC tissues correlated with patient survival time, and high expression increased risk of death 2.4-fold compared with low expression. ESCCs that had metastasized to lymph node had significantly higher levels of BRAP mRNA than tumors without metastases. Knockdown of BRAP in ESCC and HeLa cell lines significantly reduced migration and invasiveness; these cell lines formed less metastases in mice than control cells. Nuclear translocation of the nuclear factor-κB (NF-κB) P65 subunit and phosphorylation of inhibitor of NF-κB kinase subunit β (IKBKB or IKKβ) increased in cells that overexpressed BRAP and decreased in cells with BRAP knockdown. In immunoprecipitation assays, BRAP interacted directly with IKKβ. Expression of matrix metalloproteinase 9 and vascular epithelial growth factor C, which are regulated by NF-κB, was significantly reduced in cells with knockdown of BRAP and significantly increased in cells that overexpressed BRAP.

CONCLUSIONS

Expression of BRAP is increased in ESCC samples compared with non-tumor esophageal tissues; increased expression correlates with reduced patient survival time and promotes metastasis of xenograft tumors in mice. BRAP overexpression leads to increased activity of NF-κB and expression of matrix metalloproteinase 9 and vascular epithelial growth factor C.

MicroRNA-101 suppresses migration and invasion via targeting vascular endothelial growth factor-C in hepatocellular carcinoma cells

MicroRNAs (miRNAs) are a class of non-coding RNAs 18-25 nucleotides in length, which play important roles in the regulation of cancer progression through gene silencing. miRNA (miR)-101 has been suggested to be associated with hepatocellular carcinoma (HCC). However, the detailed role of miR-101 in HCC metastasis and the underlying mechanism remain largely unclear. The present study demonstrated that the expression of miR-101 was significantly reduced in HCC tissues compared with that in matched normal adjacent tissues. miR-101 was also found to be downregulated in four HCC cell lines compared with its expression in a normal liver cell line. Vascular endothelial growth factor (VEGF)-C was further identified as a direct target of miR-101, and the protein expression of VEGF-C was downregulated by miR-101 in HepG2 HCC cells. Furthermore, the overexpression of miR-101 and the knockdown of VEGF-C significantly inhibited HepG2 cell migration and invasion, while restoration of VEGF-C reversed the inhibitory effect of miR-101 overexpression on HepG2 cell migration and invasion. Finally, the expression of VEGF-C was notably increased in HCC tissues and cell lines. These findings suggest that miR-101 exerts a suppressive effect on HCC cell migration and invasion, at least in part through the direct inhibition of VEGF-C protein expression. Therefore, the miR-101/VEGF-C axis may serve as a potential therapeutic target for HCC metastasis.

Cytokines association with clinical and pathological changes in esophageal squamous cell carcinoma

Carcinogenic transformation of cells in esophageal squamous cell carcinoma (ESCC) is characterized on molecular level by, among other things, changes in protein expression. Among all proteins related to inflammation, cytokines may be implicated as possible biological markers of esophageal cancer. These biomarkers, near imaging techniques, may be helpful in diagnosis and monitoring therapy in ESCC patients. This review demonstrates findings of researches on dysregulation of cytokines in ESCC and their clinical and pathological implications. Articles on cytokines were selected according to the following criteria: (i) the study was performed at protein level, (ii) the differences in cytokines expression or concentration were detected in tissues or serum from ESCC patients, (iii) the alterations of cytokines levels were detected by: immunohistochemistry (IHC), western blot (WB) and enzyme-linked immunosorbent assay (ELISA). Members of VEGF family seem to play an essential role as potential markers in ESCC. The results of all cytokines researches are promising but further studies are necessary to establish the biological significance of these peptydes in ESCC, their potential usefulness for early diagnosis, pre- and postoperative prognosis and monitoring of the respond to chemo- and radiotherapy of cancer patients.

Expression and significance of vascular endothelial growth factor C from multiple specimen sources in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a common malignancy with a very poor prognosis. Vascular endothelial growth factor C (VEGF-C) plays an important role in angiogenesis and lymphangiogenesis. This study was designed to analyze the correlation of VEGF-C expression with clinicopathological features and survival in multiple specimen sources from patients with ESCC.

MATERIAL AND METHODS

The expression of VEGF-C in tissues (tVEGF-C), serum (sVEGF-C), and lymph fluid (lVEGF-C) from 48 patients with ESCC was detected by different methods.

RESULTS

There were significant correlations between a high level of tVEGF-C expression and tumor differentiation, tumor depth, lymph node metastasis, TNM stage and metastasis. sVEGF-C was only significantly related to lymph node metastasis, TNM stage and metastasis. The results of lVEGF-C expression were similar to those of tVEGG-C expression, but no relationship to tumor depth was found. High expression levels of tVEGF-C, sVEGF-C and lVEGF-C were significantly associated with shorter overall survival times in univariate analysis (log-rank test).

CONCLUSIONS

The expression of VEGF-C in multiple specimen sources from patients with ESCC was associated with certain clinicopathological parameters. High expression of VEGF-C may be an important factor related to a poor prognosis of ESCC.

The role of the VEGF-C/VEGFRs axis in tumor progression and therapy

Vascular endothelial growth factor C (VEGF-C) has been identified as a multifaceted factor participating in the regulation of tumor angiogenesis and lymphangiogenesis. VEGF-C is not only expressed in endothelial cells, but also in tumor cells. VEGF-C signaling is important for progression of various cancer types through both VEGF receptor-2 (VEGFR-2) and VEGF receptor-3 (VEGFR-3). Likewise, both receptors are expressed mainly on endothelial cells, but also expressed in tumor cells. The dimeric VEGF-C undergoes a series of proteolytic cleavage steps that increase the protein binding affinity to VEGFR-3; however, only complete processing, removing both the N- and C-terminal propeptides, yields mature VEGF-C that can bind to VEGFR-2. The processed VEGF-C can bind and activate VEGFR-3 homodimers and VEGFR-2/VEGFR-3 heterodimers to elicit biological responses. High levels of VEGF-C expression and VEGF-C/VEGFRs signaling correlate significantly with poorer prognosis in a variety of malignancies. Therefore, the development of new drugs that selectively target the VEGF-C/VEGFRs axis seems to be an effective means to potentiate anti-tumor therapies in the future.

Overexpression of MMP-1 and VEGF-C is associated with a less favorable prognosis in esophageal squamous cell carcinoma

BACKGROUND

This study addresses the association of matrix metalloproteinase-1 (MMP-1) and vascular endothelial growth factor-C (VEGF-C) expression in esophageal squamous cell carcinoma (SCC) with clinicopathologic characteristics in the patients.

MATERIAL AND METHODS

We profiled the expression of MMP-1 and VEGF-C by cDNA microarray in 4 cases and by reverse transcription-polymerase chain reaction (RT-PCR) in 14 cases of esophageal SCC. Another 90 cases were reviewed by immunohistochemical examination of paraffin-embedded sections.

RESULTS

Expression of MMP-1 and VEGF-C mRNA in normal esophageal tissue and tumor tissue was compared. Data were fully consistent with the results of RT-PCR. Immunohistochemistry showed that compared to the normal mucosa MMP-1 and VEGF-C protein expression was upregulated in both esophageal atypical hyperplasia (n = 16) and esophageal SCC. Depth of tumor invasion, lymph node metastasis, and clinical stage were directly associated with prognosis in all cases. Furthermore, median overall survival and disease-free survival were significantly shorter in patients with a higher expression of MMP-1 and VEGF-C than in patients with lower expression levels.

CONCLUSION

We demonstrated that the expression of both MMP-1 and VEGF-C mRNA and protein was upregulated in esophageal SCC tissues. Protein expression was associated with progressive tumor stage and poor prognosis in patients with esophageal SCC.