Preclinical evaluation of destruxin B as a novel Wnt signaling target suppressing proliferation and metastasis of colorectal cancer using non-invasive bioluminescence imaging.

In continuation to our studies toward the identification of direct anti-cancer targets, here we showed that destruxin B (DB) from Metarhizium anisopliae suppressed the proliferation and induced cell cycle arrest in human colorectal cancer (CRC) HT29, SW480 and HCT116 cells. Additionally, DB induced apoptosis in HT29 cells by decreased expression level of anti-apoptotic proteins Bcl-2 and Bcl-xL while increased pro-apoptotic Bax. On the other hand, DB attenuated Wnt-signaling by downregulation of β-catenin, Tcf4 and β-catenin/Tcf4 transcriptional activity, concomitantly with decreased expression of β-catenin target genes cyclin D1, c-myc and survivin. Furthermore, DB affected the migratory and invasive ability of HT29 cells through suppressed MMPs-2 and -9 enzymatic activities. We also found that DB targeted the MAPK and/or PI3K/Akt pathway by reduced expression of Akt, IKK-α, JNK, NF-κB, c-Jun and c-Fos while increased that of IκBα. Finally, we demonstrated that DB inhibited tumorigenesis in HT29 xenograft mice using non-invasive bioluminescence technique. Consistently, tumor samples from DB-treated mice demonstrated suppressed expression of β-catenin, cyclin D1, survivin, and endothelial marker CD31 while increased caspase-3 expression. Collectively, our data supports DB as an inhibitor of Wnt/β-catenin/Tcf signaling pathway that may be beneficial in the CRC management.

Yeh CT ，Rao YK ，Ye M ，Wu WS ，Chang TC ，Wang LS ，Wu CH ，Wu AT ，Tzeng YM ... -  《-》

A novel ent-kaurane diterpenoid executes antitumor function in colorectal cancer cells by inhibiting Wnt/β-catenin signaling.

Aberrant activation of Wnt signaling pathway is crucial for the onset and progression of human colorectal cancer (CRC). Owing to the persistent dependence on Wnt signaling for growth and survival, inhibition of this pathway is an attractive approach for new therapies. 11α, 12α-epoxyleukamenin E (EPLE) is a novel ent-kaurane diterpenoid that we previously isolated from Salvia cavaleriei, exhibiting antitumor activities in a variety of cancer cells. Herein, we found that whereas sparing normal human colon mucosal epithelial cells, EPLE selectively inhibited the proliferation of CRC cell lines as well as primary tumor cells. Mechanistically, we demonstrated EPLE exerted its function through suppressing Wnt signaling pathway, as evidenced by EPLE-mediated downregulation of Wnt target genes such as c-Myc, Axin2 and Survivin. Consistently, luciferase reporter assays showed that the EPLE directly blocked Wnt/β-catenin-mediated transcriptional activation. In combination of co-immunoprecipitation and protein structure-based analyses, we determined that the EPLE entered the interface of β-catenin/TCF4 complexes and blocked their interaction that is required for β-catenin-mediated transcriptional activation. Moreover, overexpression of β-catenin alleviated the cytotoxicity of EPLE in CRC cells, supporting Wnt signaling is a major and specific target of EPLE. Combined treatments of EPLE and 5-fluorouracil, the first-line chemotherapy for CRC patients, achieved a synergistic effect. More importantly, EPLE hampered tumor development in a CRC xenograft model. Our data thus establish EPLE as a novel inhibitor of Wnt signaling that holds great promise as a potential candidate for further preclinical evaluation for CRC treatments.

Ye Q ，Yao G ，Zhang M ，Guo G ，Hu Y ，Jiang J ，Cheng L ，Shi J ，Li H ，Zhang Y ，Liu H ... -  《-》

Destruxin B inhibits hepatocellular carcinoma cell growth through modulation of the Wnt/β-catenin signaling pathway and epithelial-mesenchymal transition.

The aberrant activation of Wnt/β-catenin signaling plays an important role in the carcinogenesis and progression of hepatocellular carcinoma (HCC). Therefore, the Wnt/β-catenin signaling molecules are attractive candidates for the development of targeted therapies for this disease. The present study showed that destruxin B (DB) inhibits the proliferation and induces the apoptosis of HCC cells by decreasing the protein expression of anti-apoptotic Bcl-2 and Bcl-xL and increasing the expression of the proapoptotic protein Bax. More importantly, DB also attenuates Wnt-signaling in HCC cells by downregulating β-catenin, Tcf4, and β-catenin/Tcf4 transcriptional activity, which results in the decreased expression of β-catenin target genes, such as cyclin D1, c-myc, and survivin. Furthermore, DB affects the migratory and invasive abilities of Sk-Hep1 cells through the suppression of markers of the epithelial-mesenchymal transition (EMT). A synergistic anti-proliferative and migratory effect was achieved using the combination of DB and sorafenib in Sk-Hep1 cells. In conclusion, DB acts as a novel Wnt/β-catenin inhibitor and reduces the aggressiveness and invasive potential of HCC by altering the cells' EMT status and mobility. DB in combination with sorafenib may be considered for future clinical use for the management of metastatic HCC.

Huynh TT ，Rao YK ，Lee WH ，Chen HA ，Le TD ，Tzeng DT ，Wang LS ，Wu AT ，Lin YF ，Tzeng YM ，Yeh CT ... -  《-》

Quercetin inhibit human SW480 colon cancer growth in association with inhibition of cyclin D1 and survivin expression through Wnt/beta-catenin signaling pathway.

Shan BE ，Wang MX ，Li RQ 《-》

Structure-based discovery of a novel inhibitor targeting the β-catenin/Tcf4 interaction.

Tian W ，Han X ，Yan M ，Xu Y ，Duggineni S ，Lin N ，Luo G ，Li YM ，Han X ，Huang Z ，An J ... -  《-》