RSPO1-mutated fibroblasts from non-tumoural areas of palmoplantar keratoderma display a cancer-associated phenotype.

R-spondin (RSPO)1 is a fibroblast-secreted protein that belongs to the R-spondin protein family which is essential for reproductive organ development, epithelial stem cell renewal and cancer induction or suppression. RSPO1 gene mutations cause palmoplantar hyperkeratosis with squamous cell carcinoma (SCC) of the skin, 46XX sex reversal and true hermaphroditism. To characterize RSPO1-deficient skin fibroblasts derived from two patients with mutations in RSPO1, with palmoplantar hyperkeratosis, recurrent SCC and 46XX sex reversal, to provide further insight into disease-related skin tumourigenesis. Fibroblast cultures from non-tumoural palmoplantar skin biopsies were established to evaluate features and properties that may be altered at cancer onset, i.e. proliferation, extracellular matrix contraction and invasion, as well as TGF-ß and matrix metalloproteinase (MMP) secretion. Fibroblasts demonstrated increased proliferative potential in vitro, a high level of collagen contraction and invasion by SCC cells, release of high levels of pro-inflammatory and pro-fibrotic TGF-ß, and increased expression of MMP1 and MMP3. Analysis of the expression of selected proteins associated with RSPO1-activated pathways confirmed sustained activation of the TGF-ß signalling pathway and indicated a loss of TGF-ß inhibitory feedback. Also, treatment of fibroblasts with a recombinant RSPO1 protein aggravated this pro-inflammatory phenotype, suggesting caution in designing therapeutic strategies based on restoration of protein function. Our findings indicate that fibroblasts from RSPO1-mutated patients behave similarly to cancer-associated fibroblasts. Chronic inflammation and fibrotic changes in palmoplantar skin may play a role in SCC development and recurrence, possibly by irreversibly activating the tumourigenic phenotype of fibroblasts.

Letter to the Editor: "Ion Channels in Brain Metastasis"-Ion Channels in Cancer Set up and Metastatic Progression.

The review by Klumpp, L. et al. entitled Ion Channels in Brain Metastasis [1] discusses the role of ion channels in breast cancer, lung cancer and melanoma in metastatic tropism to the brain [...].

Identification of serum regression signs in infantile hemangioma.

Vessel proliferation underlies a number of serious pathological conditions. Infantile Hemangioma (IH) is a low-aggressive vascular tumor, interesting as an in vivo model of spontaneous tumor regression. Identifying mechanisms underlying IH spontaneous regression may then help to elucidate vessel-growth control, strongly deregulated in other serious conditions such as sarcoma, melanoma, diabetic retinopathy. The present study was aimed at identifying early regression indicators within hematological parameters. Thirty-four blood samples were collected from IH diagnosed babies (20-months median age), spontaneously regressing with age. Nineteen serum standard blood-tests were carried out using diagnostic reagents; in addition, serum-expression of 27 cytokine/chemokines was measured. Samples were divided in three age-groups, namely ≤ 12, 13 to 24 and >24 months-age, respectively. Red-cells count, Hemoglobin, Hematocrit, Neutrophils, Lymphocytes, MCP-1 and MIP-1beta were significantly different in the three age-groups, according to one-way ANOVA analysis. The same parameters showed a significant Pearson-correlation with age, supporting the direct link of age with IH-regression. ROC analysis showed that red-cells count, Hemoglobin, Hematocrit, MCP-1 and MIP-1beta levels significantly discriminate IH in the proliferating-phase from IH in the regressing-phase. Such data indicate for the first time that standard hematological tests and cytokine serum-expression values may effectively discriminate proliferating- from regressing-IH, unrevealing early regression signs, and demonstrate that standard blood-tests may have novel unsuspected diagnostic/prognostic relevance in altered vessel-growth conditions.