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Zipper-interacting protein kinase promotes epithelial-mesenchymal transition, invasion and metastasis through AKT and NF-kB signaling and is associated with metastasis and poor prognosis in gastric cancer patients.

Li J, Deng Z, Wang Z, Wang D, Zhang L, Su Q, Lai Y, Li B, Luo Z, Chen X, Chen Y, Huang X, Ma J, Wang W, Bi J, Guan X - Oncotarget (2015)

Bottom Line: Zipper-interacting Protein Kinase (ZIPK) belongs to the death-associated protein kinase family.Increased expression of ZIPK in lymph node metastases was significantly associated with stage VI and abdominal organ invasion.Survival analysis revealed that patients with increased ZIPK expression in metastatic lymph nodes had poor disease-specific survival.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of General Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.

ABSTRACT
Zipper-interacting Protein Kinase (ZIPK) belongs to the death-associated protein kinase family. ZIPK has been characterized as a tumor suppressor in various tumors, including gastric cancer. On the other hand, ZIPK also promotes cell survival. In this study, both in vitro and in vivo assays indicated that ZIPK promoted cell growth, proliferation, migration, invasion, tumor formation and metastasis in nude mice. ZIPK induced epithelial-mesenchymal transition (EMT) with increasing expression of β-catenin, mesenchymal markers, Snail and Slug, and with decreasing expression of E-cadherin. Furthermore, ZIPK activated the AKT/IκB/NF-κB pathway, which can promote EMT and metastasis. Additionally, ZIPK expression was detected in human primary gastric cancer and their matched metastatic lymph node samples by immunohistochemistry. Increased expression of ZIPK in lymph node metastases was significantly associated with stage VI and abdominal organ invasion. Survival analysis revealed that patients with increased ZIPK expression in metastatic lymph nodes had poor disease-specific survival. Taken together, our study reveals that ZIPK is a pro-oncogenic factor, which promotes cancer metastasis.

No MeSH data available.


Related in: MedlinePlus

ZIPK increases tumor growth and proliferation in vitro and in vivo(A) XTT assay showed that over-expression of ZIPK increased cell proliferation, and ablation of endogenous ZIPK inhibited cell proliferation. The results were expressed as the mean ± SD of three independent experiments (**indicates P < 0.01 in independent Student's t-test). (B) Foci formation assay was used to compare the frequency of foci formation between ZIPK- and vector-transfected cells. Quantitative analyses of foci numbers was shown in the right panel. Values was reflected as the mean ± SD of at least three independent experiments (***indicates P < 0.001, independent Student's t-test). (C) Ability to form colony in soft agar increased significantly in ZIPK-transfected cells compared with vector cells (**P < 0.01, independent Student's t-test. Scale bars: 100 μm). (D) ZIPK- and empty vector-transfected cells were injected into the left and right dorsal area of the nude mice, respectively. ZIPK mediated tumor growth in vivo. The average tumor volume was expressed as the mean ± SD of five inoculated sites for each group (***P < 0.001).
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Figure 1: ZIPK increases tumor growth and proliferation in vitro and in vivo(A) XTT assay showed that over-expression of ZIPK increased cell proliferation, and ablation of endogenous ZIPK inhibited cell proliferation. The results were expressed as the mean ± SD of three independent experiments (**indicates P < 0.01 in independent Student's t-test). (B) Foci formation assay was used to compare the frequency of foci formation between ZIPK- and vector-transfected cells. Quantitative analyses of foci numbers was shown in the right panel. Values was reflected as the mean ± SD of at least three independent experiments (***indicates P < 0.001, independent Student's t-test). (C) Ability to form colony in soft agar increased significantly in ZIPK-transfected cells compared with vector cells (**P < 0.01, independent Student's t-test. Scale bars: 100 μm). (D) ZIPK- and empty vector-transfected cells were injected into the left and right dorsal area of the nude mice, respectively. ZIPK mediated tumor growth in vivo. The average tumor volume was expressed as the mean ± SD of five inoculated sites for each group (***P < 0.001).

Mentions: To characterize the biological effect of ZIPK on cell growth and proliferation in gastric cancer cell lines, ZIPK was stably transfected into BGC-823 cells (ZIPK clone1 or ZIPK clone2). Empty vector–transfected cells were used as control (Vec-BGC823). Meanwhile, ZIPK in SGC-7901 and SNU-1 cells were silenced by siRNAs. Ectopic overexpression and decreased expression of ZIPK were determined by RT-PCR and Western blotting (Supplementary Figure 1). XTT assays showed that ZIPK overexpression markedly increased BGC-823 cell proliferation. Conversely, silencing ZIPK inhibited cell proliferation in SGC-7901 and SNU-1 cells (P < 0.01 Figure 1A). Anchorage-dependent foci formation and anchorage-independent colony formation in soft agar yielded a higher number and larger colonies (P < 0.01) in the ZIPK-transfected cells compared to the control cells (Figure 1B, 1C). The tumorigenic potential of ZIPK was also evaluated by xenograft tumor formation in athymic nude mice. Subcutaneous visible tumors were observed in the left flank (ZIPK clone1) in all 5 tested animals on day 7 after injection. However, visible tumor in the right flank (Vec-BGC823) was only observed in 2 nude mice on day 14. Xenograft tumor growth curve indicated that tumors induced by ZIPK-transfeced cells grew much more rapidly than tumors induced by Vec-BGC823 cells (P < 0.001; Figure 1D). On day 28 after injection, tested mice were sacrificed and the tumors were excised for further analysis. The average volume of tumors induced by ZIPK clone cells (186 ± 48.8 mm3) was significantly increased compared with tumors induced by Vec-BGC823 cells (8.8 ± 10.5 mm3, P < 0.001; Figure 1D).


Zipper-interacting protein kinase promotes epithelial-mesenchymal transition, invasion and metastasis through AKT and NF-kB signaling and is associated with metastasis and poor prognosis in gastric cancer patients.

Li J, Deng Z, Wang Z, Wang D, Zhang L, Su Q, Lai Y, Li B, Luo Z, Chen X, Chen Y, Huang X, Ma J, Wang W, Bi J, Guan X - Oncotarget (2015)

ZIPK increases tumor growth and proliferation in vitro and in vivo(A) XTT assay showed that over-expression of ZIPK increased cell proliferation, and ablation of endogenous ZIPK inhibited cell proliferation. The results were expressed as the mean ± SD of three independent experiments (**indicates P < 0.01 in independent Student's t-test). (B) Foci formation assay was used to compare the frequency of foci formation between ZIPK- and vector-transfected cells. Quantitative analyses of foci numbers was shown in the right panel. Values was reflected as the mean ± SD of at least three independent experiments (***indicates P < 0.001, independent Student's t-test). (C) Ability to form colony in soft agar increased significantly in ZIPK-transfected cells compared with vector cells (**P < 0.01, independent Student's t-test. Scale bars: 100 μm). (D) ZIPK- and empty vector-transfected cells were injected into the left and right dorsal area of the nude mice, respectively. ZIPK mediated tumor growth in vivo. The average tumor volume was expressed as the mean ± SD of five inoculated sites for each group (***P < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4480755&req=5

Figure 1: ZIPK increases tumor growth and proliferation in vitro and in vivo(A) XTT assay showed that over-expression of ZIPK increased cell proliferation, and ablation of endogenous ZIPK inhibited cell proliferation. The results were expressed as the mean ± SD of three independent experiments (**indicates P < 0.01 in independent Student's t-test). (B) Foci formation assay was used to compare the frequency of foci formation between ZIPK- and vector-transfected cells. Quantitative analyses of foci numbers was shown in the right panel. Values was reflected as the mean ± SD of at least three independent experiments (***indicates P < 0.001, independent Student's t-test). (C) Ability to form colony in soft agar increased significantly in ZIPK-transfected cells compared with vector cells (**P < 0.01, independent Student's t-test. Scale bars: 100 μm). (D) ZIPK- and empty vector-transfected cells were injected into the left and right dorsal area of the nude mice, respectively. ZIPK mediated tumor growth in vivo. The average tumor volume was expressed as the mean ± SD of five inoculated sites for each group (***P < 0.001).
Mentions: To characterize the biological effect of ZIPK on cell growth and proliferation in gastric cancer cell lines, ZIPK was stably transfected into BGC-823 cells (ZIPK clone1 or ZIPK clone2). Empty vector–transfected cells were used as control (Vec-BGC823). Meanwhile, ZIPK in SGC-7901 and SNU-1 cells were silenced by siRNAs. Ectopic overexpression and decreased expression of ZIPK were determined by RT-PCR and Western blotting (Supplementary Figure 1). XTT assays showed that ZIPK overexpression markedly increased BGC-823 cell proliferation. Conversely, silencing ZIPK inhibited cell proliferation in SGC-7901 and SNU-1 cells (P < 0.01 Figure 1A). Anchorage-dependent foci formation and anchorage-independent colony formation in soft agar yielded a higher number and larger colonies (P < 0.01) in the ZIPK-transfected cells compared to the control cells (Figure 1B, 1C). The tumorigenic potential of ZIPK was also evaluated by xenograft tumor formation in athymic nude mice. Subcutaneous visible tumors were observed in the left flank (ZIPK clone1) in all 5 tested animals on day 7 after injection. However, visible tumor in the right flank (Vec-BGC823) was only observed in 2 nude mice on day 14. Xenograft tumor growth curve indicated that tumors induced by ZIPK-transfeced cells grew much more rapidly than tumors induced by Vec-BGC823 cells (P < 0.001; Figure 1D). On day 28 after injection, tested mice were sacrificed and the tumors were excised for further analysis. The average volume of tumors induced by ZIPK clone cells (186 ± 48.8 mm3) was significantly increased compared with tumors induced by Vec-BGC823 cells (8.8 ± 10.5 mm3, P < 0.001; Figure 1D).

Bottom Line: Zipper-interacting Protein Kinase (ZIPK) belongs to the death-associated protein kinase family.Increased expression of ZIPK in lymph node metastases was significantly associated with stage VI and abdominal organ invasion.Survival analysis revealed that patients with increased ZIPK expression in metastatic lymph nodes had poor disease-specific survival.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of General Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.

ABSTRACT
Zipper-interacting Protein Kinase (ZIPK) belongs to the death-associated protein kinase family. ZIPK has been characterized as a tumor suppressor in various tumors, including gastric cancer. On the other hand, ZIPK also promotes cell survival. In this study, both in vitro and in vivo assays indicated that ZIPK promoted cell growth, proliferation, migration, invasion, tumor formation and metastasis in nude mice. ZIPK induced epithelial-mesenchymal transition (EMT) with increasing expression of β-catenin, mesenchymal markers, Snail and Slug, and with decreasing expression of E-cadherin. Furthermore, ZIPK activated the AKT/IκB/NF-κB pathway, which can promote EMT and metastasis. Additionally, ZIPK expression was detected in human primary gastric cancer and their matched metastatic lymph node samples by immunohistochemistry. Increased expression of ZIPK in lymph node metastases was significantly associated with stage VI and abdominal organ invasion. Survival analysis revealed that patients with increased ZIPK expression in metastatic lymph nodes had poor disease-specific survival. Taken together, our study reveals that ZIPK is a pro-oncogenic factor, which promotes cancer metastasis.

No MeSH data available.


Related in: MedlinePlus