Spred2 inhibits epithelial‑mesenchymal transition of colorectal cancer cells by impairing ERK signaling

Abstract

Downregulation of the sprouty-related EVH1 domain protein 2 (Spred2) is closely associated with highly metastatic phenotypes in various tumors. However, the roles of Spred2 in the development and progression of colorectal cancer (CRC) are still largely unexplored. As anticipated, Spred2 expression was significantly downregulated in clinical tumor tissues. To restore Spred2 levels, Ad.Spred2, an adenoviral vector expressing Spred2, was transduced into CRC cells. It was revealed that Ad.Spred2 inhibited the proliferation and decreased the survival and migration of SW480 cells. Epithelial-mesenchymal transition (EMT) is an essential event during tumor metastasis to distant sites. It was revealed that Ad.Spred2 markedly inhibited EMT by promoting F-actin reorganization, upregulating E-cadherin levels and reducing vimentin protein expression. Notably, extracellular-regulated kinase (ERK) signaling inhibition by PD98059 induced similar effects on EMT in CRC cells, indicating that Ad.Spred2 regulated EMT in CRC cells in an ERK-dependent manner. Transforming growth factor β (TGF-β), a well-known inducer of EMT, increased E-cadherin expression, decreased vimentin expression and promoted migration in CRC cells. However, neither Ad.Spred2 nor PD98059 had an obvious effect on the expression of SMAD2/3 or SMAD4 in SW480 cells, indicating that Ad.Spred2 inhibited EMT in a SMAD-independent manner. Notably, Ad.Spred2 transduction downregulated SAMD2/3 and SMAD4 levels in HCT116 cells in an ERK-independent manner. It was speculated that Ad.Spred2 inhibited the EMT of HCT116 cells by both blocking ERK signaling and reducing SMAD signaling. It was concluded that Spred2 inhibited EMT in CRC cells by interfering with ERK signaling, with or without reduced SMAD signaling. Therefore, the introduction of the clinical application of Spred2 has great potential for development as a gene therapy approach for CRC.

Hyperactivation of MAPK Induces Tamoxifen Resistance in SPRED2-Deficient ERα-Positive Breast Cancer

“…SPRED2 protein levels are strongly inversely associated with tumor progression and metastasis. In colorectal cancer and hepatocellular carcinoma, SPRED2 can inhibit the epithelial-to-mesenchymal transition and cell motility [ 67 , 68 ]. In our study, we found that SPRED2 can act as a tumor suppressor in BC as well, and that decreased levels of SPRED2 can increase their cell proliferation and migration capacity.…”

Progress in experimental research on SPRED protein family

“…SPRED2 can inhibit activation of the Ras/Raf/ERK signaling pathway and the process of EMT. 32 , 33 Further, inhibiting the activation of the Ras/Raf/ERK signaling pathway can also reduce the secretion of matrix metalloproteinases and inhibit the migration and invasion of tumor cells. 70 Autophagy is closely implicated in the occurrence and treatment of tumor cells.…”

“…In prostate cancer, low expression of SPRED2 leads to increased levels of phosphorylated ERK, which promotes the proliferation and migration induced by various growth factors, thereby leading to carcinogenesis. 30 , 31 In addition to BC and prostate cancer, SPRED proteins have also been associated with colon cancer, 32 , 33 renal clear cell carcinoma, 34 lung tumors, 35 and esophageal cancer. 36 , 37 These findings indicate that SPRED proteins are important tumor suppressors that inhibit carcinogenesis and metastasis by inhibiting the Ras/Raf/ERK pathway.…”

Sprouty-related proteins with EVH1 domain (SPRED2) prevents high-glucose induced endothelial–mesenchymal transition and endothelial injury by suppressing MAPK activation

“…Additionally, SPRED2 takes part in EndMT. For example, SPRED2 inhibits epithelial–mesenchymal transition (EMT) of colorectal cancer cells by inhibiting ERK signaling pathway, which contributes to alleviate colorectal cancer progression [ 17 ]. SPRED2 also inhibits the cell motility and EMT of keratinocytes induced by TGF-β1 [ 18 ].…”