Ginsenoside Rh2 activates α‑catenin phosphorylation to inhibit lung cancer cell proliferation and invasion

Abstract

The efficacy of ginsenoside Rh2 (Rh2) in cancer therapy has been reported; however, its function in lung cancer remains unknown. To analyze the role of Rh2 in the inhibition of lung cancer cell proliferation in the present study, protein expression levels of E-cadherin, vimentin, β-catenin, Smo, Gli1, and α-catenin were assessed by western blotting, whilst mRNA expression levels of TCF7 FZD8, Smo, Gli1, Gli2, and Gli3 were determined by reverse transcription-quantitative PCR in the A549 cell line. Phosphorylation sites were detected by proteomic methods and cell proliferation was analyzed by MTT assay. The present study revealed that Rh2 treatment significantly inhibited cell proliferation. Western blotting indicated that the expression levels of E-cadherin were increased and vimentin was downregulated in Rh2-treated cells compared with control cells. Treatment of A549 cells with Rh2 suppressed phosphorylation of five distinct proteins and increased phosphorylation of nine proteins. Among them, the phosphorylation of α-catenin at S641 was significantly induced. Rh2 treatment suppressed the expression levels of key genes involved in Wnt (Wnt3, transcription factor 7 and frizzled class receptor 8) and hedgehog [smoothened, frizzled class receptor (Smo), GLI family zinc finger (Gli)1, Gli2, and Gli3] signaling. Immunoblotting results indicated that β-catenin, Smo and Gli1 protein expression levels were also suppressed by treatment with Rh2 compared with control treatment. Expression of α-catenin S641D, a phosphomimetic form of α-catenin, inhibited the accumulation of β-catenin and Gli1 and inhibited cell proliferation and invasion. Furthermore, knockdown of β-catenin (CTNNB1) or Gli1 with specific small interfering RNAs inhibited cell proliferation, whereas overexpression of these genes had an opposite effect. Additionally, overexpression of β-catenin or Gli1 activated cell proliferation, even in the presence of Rh2, suggesting that Rh2 affects A549 cell proliferation through inhibition of Wnt and hedgehog signaling by phosphorylation of α-catenin at S641. Together, these data suggested that Rh2 treatment may inhibit the proliferation of A549 lung cancer cells. Further exploration of the underlying mechanism by which Rh2 inhibits cell proliferation is warranted.

Expression and prognostic impact of FZDs in pancreatic adenocarcinoma

“…Mounting evidences showed that FZD8 was involved in various malignant tumors including prostate cancer [ 31 – 33 ], lung cancer[ 34 ], breast cancer [ 35 ], and gastric cancer[ 36 ]. Yin et al [ 37 ] suggested that FZD8 had an important role in resistance to treatment with cisplatin plus TRAIL in patients triple-negative breast cancer, thus making it a potential target for chemosensitization.…”

Expression and Prognostic Impact of FZDs in Pancreatic Adenocarcinoma

“…Mounting evidences showed that FZD8 was involved in various malignant tumors including prostate cancer [31][32][33], lung cancer [34], breast cancer [35], and gastric cancer [36]. Yin et al [37] suggested that FZD8 had an important role in resistance to treatment with cisplatin plus TRAIL in patients triple-negative breast cancer, thus making it a potential target for chemosensitization.…”

Untitled

“…The results indicated that Rh1 inhibited the proliferation of A549 cells by suppressing the Wnt signaling pathway. Zhang, et al [13] found that ginsenoside Rh2 (Rh2) significantly up-regulated E-cadherin expression and downregulated the expression of vimentin, suggested that Rh2 inhibited A549 cells proliferation. Rh2 also suppressed key Wnt signaling genes, Wnt3, TCF7 and FZD8, and hedgehog signaling genes, Smo, Gli1, Gli2 and Gli3.…”