Yuhong Huang

Annexin A7 gene is an important factor in the lymphatic metastasis of tumors

In the tumor malignancy progression, lymph node metastasis (LNM) is recognized as an important factor. In this study, RNA interference (RNAi) was employed to down-regulate ANXA7 gene in Hca-F cells, a hepatocarcinoma cell line with high LNM rate. There was no significant effect on cell proliferation ability, but cell division, motility, and invasion abilities were markedly inhibited. By contrast, up-regulating the expression of ANXA7 gene in Hca-P cells with lower LNM rate, cell migration ability was improved and the percentage of cells in S phase was significantly decreased in vitro. Here, we reported that the expression of Ech1, GSN and JNK1 genes, which were relevant to tumor lymphatic metastasis, had been inhibited due to down-regulation ANXA7 gene and promoted due to up-regulation ANXA7 gene by western blot analysis. These results indicated that ANXA7 is a critical factor in the development of lymphatic metastasis in hepatocarcinoma progression.

Subcellular proteomics: determination of specific location and expression levels of lymphatic metastasis associated proteins in hepatocellular carcinoma by subcellular fractionation.

BACKGROUND Subcellular fractionation and proteomics form an ideal partnership when it comes to specific location and analysis of intracellular organelles and expression levels of multiprotein complexes. Lymphatic metastasis is the major complicated system involving multiple factors. However, to date lymphatic metastatic mechanism is poorly understood. AIM To specifically locate expression site by subcellular fractionation, based on expression levels, interpret the involvement of different lymphatic metastasis associated proteins in hepatocellular carcinoma cell lines with different lymphatic metastasis potential. METHOD Mouse hepatocellular cell lines Hca-F and Hca-P are used to evaluate the location and expression levels of some lymphatic metastasis-associated proteins in the cell by using subcellular fractionation kit and Western blot analysis. The proteins under studies were Gelsolin, JNK and Annexin 7. RESULTS Gelsolin was sequestered in cytoplasm, membrane and cytoskeleton in F-cells but in P-cells, it was found in cytoplasm and cytoskeleton .JNK was located in nuclear fraction and cytoskeleton in F and P cells, Annexin7 was in cytoplasm with its two isoforms only at this location, cell membrane and cytoskeleton in F and P cells. With the high expression level of Gelsolin, JNK and Annexin 7 in Hca-F cell line than Hca-P cell line. CONCLUSION With subcellular fractionation specific location of Gelsolin, JNK and Annexin 7 at various cell sites during lymphatic metastasis were determined. High expression levels were found in high lymphatic metastasis potential cell lines which indicate their roles according to different expression sites in the disease.

Inhibition of annexin A7 gene and protein induces the apotosis and decreases the invasion, migration of the hepatocarcinoma cell line.

Our previous studies have shown that annexin A7 (ANXA7) gives different expressions in the mouse hepatocarcinoma cell lines with low or high lymphatic metastatic potential in both gene and protein levels. In this study, whether by using RNA interference (RNAi) technique downregulating ANXA7 in the gene level or by using antibody against ANXA7 in the protein level, the depressed expression of ANXA7 could induce apotosis and decrease the invasion, migration capacities of the Hca-P cell, a hepatocarcinoma cell line with low lymphatic metastatic potential in vitro. The results indicate that ANXA7 is an important factor in tumors with the lymphatic metastasis.

Down-regulated expression of Annexin A7 induces apoptosis in mouse hepatocarcinoma cell line by the intrinsic mitochondrial pathway

Our previous studies have shown that decreased expression of Annexin A7 elevates apoptosis in Hca-P cells, a hepatocarcinoma cell line with lymphatic metastatic potential. In this study, RNA interference technique was used to down-regulate the expression of Annexin A7, and unmanipulated Hca-P cells and transfected nonspecific-sequence Hca-P cells as control. The down-regulation of Annexin A7 declined the cell viability after cisplatin exposure. And the reduced expression of Annexin A7 decreased the expression of Bcl2, increased the expression of Cytochrome-C in the cytoplasme, and then improved the expression of Caspase-3. However there was no significant effect on the expression of Bax, Caspase-12, Fas, FasL and Caspase-8. The results indicate that the decreased expression of Annexin A7 could inhibit the proliferation, and increase the apoptosis of Hca-P cells by affecting the expression of the apoptosis associated proteins by the mitochondrial pathway.

Down-regulation of ANXA7 decreases metastatic potential of human hepatocellular carcinoma cells in vitro

We report for the first time the influence of ANXA7 gene on human hepatocellular carcinoma cells (HCC). We down-regulated ANXA7 in human HCC cell line (HepG2) using siRNA method. By Western Blot analysis, we confirmed about 70% down-regulation of the gene in the shRNA-ANXA7 transfected cells (shRNA-ANXA7-HepG2) compared to the non-specific sequence shRNA transfected cells (control-shRNA-HepG2) and the un-manipulated-HepG2 cells. We used CCK-8 cell proliferation kit and observed about 65% reduction in the shRNA-ANXA7-HepG2 cells where the two controls exhibited comparable cell proliferation rates. Also, by using PI staining followed by flow cytometry, we noticed a cell cycle arrest at G0/G1 with more than one fold reduction of shRNA-ANXA7-HepG2 cell population in the S-phase of the cell cycle. Also of particular note was a significant aneuploidy in the controls compared to zero aneuploidy in the ANXA7 down-regulated cells. Migration of the cells was detected using Boydens transwell chamber and scratch wound healing assay which showed 50% and 30% respective reductions in shRNA-ANXA7-HepG2 cells migration. Furthermore, the control-shRNA-HepG2 cells and the un-manipulated-HepG2 cells invaded through the ECM-coated transwell plates two times more than the shRNA-ANXA7-HepG2 cells. We have found ANXA7 to be functioning like a tumour promoter in HepG2 human hepatocellular carcinoma cells and could have a potential as a therapeutic window into the management of liver cancer.

Enhanced tumorigenesis and lymphatic metastasis of CD133+ hepatocarcinoma ascites syngeneic cell lines mediated by JNK signaling pathway in vitro and in vivo.

Cancer stem cells (CSCs), stem-like cells, or tumor-initiating cells (TICs) may initiate tumorigenesis and metastasis, but neither the basic cell biology of CSCs nor the mechanisms of CSC-mediated tumor growth and lymphoid node metastasis are understood. Evidence suggests that CSC phenotype is maintained, at least in part, by altered JNK signaling. In this study, factors influencing the growth and metastatic potential of CSCs were examined by comparing CD133 surface antigen expression, proliferation, clonogenicity, invasive capacity, tumorigenicity, and expression of JNK-associated signaling molecules between the highly metastatic mouse hepatocarcinoma ascites syngeneic cell line Hca-F and the low metastasis potential line Hca-P. The Hca-F line exhibited higher clonogenic, proliferative, and invasive capacities than Hca-P cells, and a greater proportion of Hca-F cells were CD133 positive. In both cell lines, the CD133+ subpopulation showed significantly enhanced tumorigenicity and metastatic potential. An in vivo tumorigenicity assay in nude mice indicated that Hca-F cells possessed significantly higher tumorigenicity than Hca-P cells as indicated by larger tumors after inoculation. Expression levels of E-cadherin (CDH1), annexin VII, and JNK1 proteins were inversely correlated with CD133 expression in both Hca-F and Hca-P cells. These results demonstrate that CD133+ subpopulations of both Hca-F and Hca-P lines show CSC-like properties. However, Hca-F cells showed greater tumorigenicity and invasiveness, consistent with greater lymphatic metastasis capacity. We propose that tumorigenesis and lymphatic metastasis are regulated by JNK/P53/annexin VII and JNK/ATF-2/CDH1/annexin VII signal transduction pathways.

Ech1 is a potent suppressor of lymphatic metastasis in hepatocarcinoma.

We have previously demonstrated that Ech1 is involved in the lymphatic metastasis of tumors in vitro. Here, we gain an insight into the role that Ech1 is playing in Hca-F cell. The expression of Annexin A7, Gelsolin and Clic1 genes, which were also relevant to tumor lymphatic metastasis, had been inhibited due to downregulation Ech1 gene by Western blot analysis. And downregulated of Ech1 inhibits the metastasic capability of Hca-F cells to peripheral lymph nodes in vivo. Our work indicates although the involvement of Ech1 in tumor metastasis development and progression, but the subcellular location of Ech1 has not much contribution to that.

Pathway-related molecules of VEGFC/D-VEGFR3/NRP2 axis in tumor lymphangiogenesis and lymphatic metastasis

Precondition for tumor lymphatic metastasis is that tumor cells induce formation of original and newborn lymphatic vessels and invade surrounding lymphatic vessels in tumor stroma, while some pathway-related molecules play an important role in mechanisms associated with proliferation and migration of lymphatic endothelial cells (LECs) and tumor cells. In lymphangiogenesis and lymphatic metastasis, the pathway-related molecules of VEGFC/D-VEGFR3/NRP2 axis, such as Furin-like enzyme, CNTN1, Prox1, LYVE-1, Podoplanin, SOX18, SDF1 and CXCR4, are direct constitutors as a portion of VEGFC/D-VEGFR3/NRP2 axis, and their biological activities rely on this ligand-receptor system. These axis-related signal molecules could gradually produce waterfall-like cascading effects, mediate differentiation and maturation of LECs, remodel original and neonatal lymphatic vessels, as well as ultimately promote tumor cell chemotaxis, migration, invasion and metastasis to lymphoid tracts. This review summarizes the structure and function features of pathway-related molecules of VEGFC/D-VEGFR3/NRP2 axis, the expression changes of these molecules in different anatomic organs or histopathologic types or development stages of various tumors, the characteristics of transduction, implementation, integration of signal networks, the interactive effects on biological behaviors between tumor cells and lymphatic endothelial cells, and their molecular mechanisms and significances in tumor lymphangiogenesis and lymphatic metastasis.

Evaluation of Annexin A7, Galectin-3 and Gelsolin as possible biomarkers of hepatocarcinoma lymphatic metastasis.

We have previously demonstrated that Annexin A7 is involved in the lymphatic metastasis of hepatocarcinoma in vitro. The expression of Galectin-3 and Gelsolin, which were also relevant to tumor lymphatic metastasis, had shown the same tendency concordantly with the expression of Annexin A7 alteration by qRT-PCR and Western blot analysis. Here, we gain an insight into the role that Annexin A7 is playing in Hca-P, PAnxa7-upregulated and PAnxa7-downregulated cells in vivo. Then, Hca-P, PAnxa7-upregulated and PAnxa7-downregulated cells were injected into a mouse footpad to establish primary tumors in mice. On the fourth week after HCC cells inoculation, the mice were sacrificed for inspection the expression of Annexin A7, Galectin-3 and Gelsolin in primary tumors and in serum. Our work indicates that Annexin A7 and Gelsolin are both valuable in tumors and in serum evaluating lymph node metastasis in mice with hepatocarcinoma; Galectin-3 in tumors is significant but no much contribution in serum.

Guanine nucleotide-binding protein subunit beta-2-like 1, a new Annexin A7 interacting protein.

We report for the first time that Guanine nucleotide-binding protein subunit beta-2-like 1 (RACK1) formed a complex with Annexin A7. Hca-F and Hca-P are a pair of syngeneic mouse hepatocarcinoma cell lines established and maintained in our laboratory. Our previous study showed that both Annexin A7 and RACK1 were expressed higher in Hca-F (lymph node metastasis >70%) than Hca-P (lymph node metastasis <30%). Suppression of Annexin A7 expression in Hca-F cells induced decreased migration and invasion ability. In this study, knockdown of RACK1 by RNA interference (RNAi) had the same impact on metastasis potential of Hca-F cells as Annexin A7 down-regulation. Furthermore, by co-immunoprecipitation and double immunofluorescence confocal imaging, we found that RACK1 was in complex with Annexin A7 in control cells, but not in the RACK1-down-regulated cells, indicating the abolishment of RACK1-Annexin A7 interaction in Hca-F cells by RACK1 RNAi. Taken together, these results suggest that RACK1-Annexin A7 interaction may be one of the means by which RACK1 and Annexin A7 influence the metastasis potential of mouse hepatocarcinoma cells in vitro.