Combination Therapy of Insulin-Like Growth Factor Binding Protein-3 and Retinoid X Receptor Ligands Synergize on Prostate Cancer Cell Apoptosis In vitro and In vivo

Abstract We previously described that cathepsin E specifically induces growth arrest and apoptosis in several human prostate cancer cell lines in vitro by catalyzing the proteolytic release of soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) from the tumor cell surface. It also prevents tumor growth and metastasis in vivo through multiple mechanisms, including induction of apoptosis, angiogenesis inhibition and enhanced immune responses. Using the prostate cancer cell line PPC-1, which is relatively resistant to cell death by doxorubicin (40–50% cytotoxicity), we first report that a combination treatment with cathepsin E can overcome resistance of the cells to this agent. In vitro studies showed that combined treatment of PPC-1 cells with the two agents synergistically induces viability loss, mainly owing to down-regulation of a short form of the FLICE inhibitory protein FLIP. The enhanced antitumor activity was corroborated by in vivo studies with athymic mice bearing PPC-1 xenografts. Intratumoral application of cathepsin E in doxorubicin-treated mice results in tumor cell apoptosis and tumor regression in xenografts by enhanced TRAIL-induced apoptosis through doxorubicin-induced c-FLIP down-regulation and by a decrease in tumor cell proliferation. These results indicate that combination of cathepsin E and doxorubicin is sufficient to overcome resistance to TRAIL-mediated apoptosis in chemoresistant prostate cancer PPC-1 cells, thus indicating therapeutic potential for clinical use.

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Erratum: OTUB1 de-ubiquitinating enzyme promotes prostate cancer cell invasion in vitro and tumorigenesis in vivo

Molecular Cancer ◽

10.1186/s12943-015-0341-1 ◽

2015 ◽

Vol 14 (1) ◽

Cited By ~ 3

Author(s):

Diego Iglesias-Gato ◽

Yin-Choy Chuan ◽

Ning Jiang ◽

Charlotte Svensson ◽

Jing Bao ◽

...

Keyword(s):

Prostate Cancer ◽

Cancer Cell ◽

Cell Invasion ◽

Prostate Cancer Cell ◽

Cancer Cell Invasion

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MiR-543 Promotes Proliferation and Epithelial-Mesenchymal Transition in Prostate Cancer via Targeting RKIP

Cellular Physiology and Biochemistry ◽

10.1159/000464120 ◽

2017 ◽

Vol 41 (3) ◽

pp. 1135-1146 ◽

Cited By ~ 36

Author(s):

Yang Du ◽

Xiu-heng Liu ◽

Heng-cheng Zhu ◽

Lei Wang ◽

Jin-zhuo Ning ◽

...

Keyword(s):

Prostate Cancer ◽

Cancer Cells ◽

Cancer Cell ◽

Prostate Cancer Cell ◽

Epithelial Mesenchymal Transition ◽

In Vivo Studies ◽

Mesenchymal Transition ◽

Proliferation And Metastasis

Background/Aims: MicroRNAs (miRNAs, miRs) have emerged as important post-transcriptional regulators in various cancers. miR-543 has been reported to play critical roles in hepatocellular carcinoma and colorectal cancer, however, the role of miR-543 in the pathogenesis of prostate cancer has not been fully understood. Methods: Expression of miR-543 and Raf Kinase Inhibitory Protein (RKIP) in clinical prostate cancer specimens, two prostate cancer cell lines, namely LNCAP and C4-2B, were determined. The effects of miR-543 on proliferation and metastasis of tumor cells were also investigated with both in vitro and in vivo studies. Results: miR-543 was found to be negatively correlated with RKIP expression in clinical tumor samples and was significantly upregulated in metastatic prostate cancer cell line C4-2B compared with parental LNCAP cells. Further studies identified RKIP as a direct target of miR-543. Overexpression of miR-543 downregulated RKIP expression and promoted the proliferation and metastasis of cancer cells, whereas knockdown of miR-543 increased expression of RKIP and suppressed the proliferation and metastasis of cancer cells in vitro and in vivo. Conclusion: Our study demonstrates that miR-543 promotes the proliferation and metastasis of prostate cancer via targeting RKIP.

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