Journal: Cellular and Molecular Life Sciences: CMLS
Article Title: In long-lasting cellular stress phases of melanoma cells, stress granules are dissolved by HSP70
doi: 10.1007/s00018-025-05939-8
Figure Lengend Snippet: G3BP1 and (phospho-)EIF2S1 expression in malignant melanoma. ( a ) Western blot analysis of G3BP1 protein expression in normal human epidermal melanocytes (NHEM) from different donors and passages (P5–P14), and in melanoma cell lines derived from metastases (SK-Mel-28, SK-Mel-3) and primary tumors (WM1366, Mel Juso, Mel Ho, WM35). ACTINB served as a loading control. Densitometric quantification of G3BP1 level is shown. ( b ) Analysis of G3BP1 expression in skin cutaneous melanoma (SKCM) samples (red) compared to non-tumor samples (grey). Data obtained from GEPIA database, p-value cut-off = 0.01, |Log2FC| Cut-off = 1, retrieved on August 21, 2025. (c) Immunofluorescence staining of G3BP1 (green) in tissue sections of malignant melanoma, illustrating representative samples with positive (+) and negative (–) G3BP1 staining. DAPI (blue) was used for nuclear counterstaining. Hematoxylin and eosin (HE) staining was performed to visualize tissue morphology. Quantification of G3BP1-positive and -negative samples in tissue microarrays (nevi: n = 12; melanoma: n = 13) is shown. ( d ) Western blot analysis of phosphorylated (P-) and total EIF2S1 in melanoma and non-melanoma cell lines following sodium arsenite treatment (+ SA) (600 µM) or under untreated conditions. (e ) Quantification of the P-EIF2S1/EIF2S1 ratio in each cell line (mean of n = 3 biological replicates). ( f ) Immunofluorescence staining of G3BP1 in Mel Im melanoma cells following treatment with 600 µM sodium arsenite (SA), 2,2′-Dipyridyl (DP), 2-(N-morpholino)ethanesulfonic acid (MES), or hydrogen peroxide (H₂O₂), to assess stress-induced SG formation. Magnification: 40x. Data are presented as mean ± SEM (** p < 0.01)
Article Snippet: Normal Human Epidermal Melanocytes derived from neonatal foreskin (NHEM, PromoCell, Heidelberg, Germany) were cultivated in M2 melanocyte growth medium (M2 with Supplementary Mix containing growth factors and hormones; PromoCell, Heidelberg, Germany) under a humidified atmosphere of 5% CO 2 at 37 °C.
Techniques: Expressing, Western Blot, Derivative Assay, Control, Immunofluorescence, Staining