Klotho inhibits EGF-induced cell migration in Caki-1 cells through inactivation of EGFR and p38 MAPK signaling pathways

Abstract

Klotho is a single-pass transmembrane protein with documented anti-cancer properties. Recent reports have implicated Klotho as an inhibitor of transforming growth factor β1 induced cell migration in renal fibrosis. Overexpression of epidermal growth factor receptor (EGFR) is known to promote tumor initiation and progression in clear-cell renal cell carcinoma (cRCC). We tested our hypothesis that Klotho inhibits EGF-mediated cell migration in cRCC by interfering with the EGFR signaling complex and mitogen-activated protein kinase (MAPK) pathways. We performed cell adhesion, migration, and biochemical studies in vitro using Caki-1 cell line. In addition, we validated the cell culture studies with expression analysis of six de-identified FFPE tissues from primary and metastatic cRCC patients. Our studies show that Klotho inhibited EGF-induced Caki-1 de-adhesion and decreased spreading on collagen type 1. Klotho also inhibited EGF-induced α2β1 integrin-dependent cell migration on collagen type 1. To test the involvement of MAPK pathways in EGF-induced Caki-1 cell motility, the cells were pretreated with either SB203580, a specific p38 MAPK inhibitor, or Klotho. SB203580 blocked the EGF-induced Caki-1 cell migration. Klotho had a comparable inhibitory effect. Our FFPE clinical specimens revealed decreased Klotho mRNA expression compared to a control, non-cancer kidney tissue. The decrease in Klotho mRNA levels correlated with increased c-Src expression, while E-Cadherin was relatively reduced in metastatic FFPE specimens where Klotho was least expressed. Taken together, these results suggest that secreted Klotho inhibits EGF-induced pro-migratory cell morphological changes and migration in Caki-1 cells. Our data additionally suggest that decreased Klotho expression may be involved in cRCC metastasis.

Heat injured stromal cells‐derived exosomal EGFR enhances prostatic wound healing after thulium laser resection through EMT and NF‐κB signaling

“…Among these cytokines, EGFR was upregulated for 13.72‐folds in WPMY‐HI vs WPMY‐1 groups. EGFR was the most abundant and frequently activated in various diseases (malignant and benign) and was reported to regulate the EMT and wound healing . EMT plays an important role in the development of proper re‐epithelialization during the wound healing .…”

“…EGFR was the most abundant and frequently activated in various diseases (malignant and benign) and was reported to regulate the EMT and wound healing. [27][28][29] EMT plays an important role in the development of proper re-epithelialization during the wound healing. 30 Next, we isolated exosomes from WPMY-1 and WPMY-HI cell culture supernatant and characterized them with the TEM and NTA ( Figure 3C and 3D).…”

Identification of low-dose multidrug combinations for sunitinib-naive and pre-treated renal cell carcinoma

“…The exact mechanism of this phenomenon is worth pursuing, and it could be related to the impaired migratory properties of these cells. 42 Interfering with the EGFR-MAPK signalling pathway can lead to such morphologic changes by increasing cell-cell contacts profoundly stabilising focal adhesions. 43 Therefore, it seems that the loss of motility may be induced by blocking EGFR-MAPK signalling, further modulating the cell-matrix and simultaneously enhancing cell-cell interactions.…”

“…43 Therefore, it seems that the loss of motility may be induced by blocking EGFR-MAPK signalling, further modulating the cell-matrix and simultaneously enhancing cell-cell interactions. 42 Malignant cells are capable of communicating with neighbouring cells, as well as the tumour microenvironment by forming tunnelling nanotubes (TNT). 44,45 Intercellular exchange of organelles, vesicles and signalling molecules can occur, which mediates the passage of resistance and the insensitivity to small-molecule drugs.…”

Towards Age-Related Anti-Inflammatory Therapy: Klotho Suppresses Activation of ER and Golgi Stress Response in Senescent Monocytes

“…Moreover, it has been shown that WIPI1 is associated with the lysosomal degradation of cytoplasmic components during starvation-induced autophagy [40]. Since WIPI1 is strictly involved in the phosphorylation of MAPK 1/3 [41] and klotho acts as an inhibitory modulator of MAPK signaling pathways [42], it is highly likely that the role of klotho in Golgi-mediated response in immunosenescent monocytes results from this loop. However, further studies need to be conducted to elucidate fully these interactions.…”