Search

Keloids are benign skin tumors that develop in individuals who have a positive family history of keloid disorders. Keloids are characterized by a deregulated wound‑healing process, atypical fibroblasts with extreme deposition of extracellular matrix components, particularly collagen, increased cell proliferation and associated failure of apoptosis. Recently ingenol‑mebutate has been used as a novel agent with anti‑proliferative activity on human keloids as an alternative treatment option in patients, once conventional therapies have failed. We hypothesized that microRNAs (miR/miRNA) may be involved in the balance between lesion formation and repair. A comprehensive understanding of the molecular mechanism underlying the Ingenol‑mebutate response in keloid fibroblast following Ingenol‑mebutate exposure has been established previously. Therefore, the present study analyzed changes in miRNAs and apoptotic gene regulation in Ingenol‑mebutate treated keloid fibroblast, by reverse transcription‑quantitative polymerase chain reaction and a DNA fragmentation assay. The range of upregulated miRNAs and downregulated genes encoding cell death appeared to be associated with the degree of the morphological alterations in Ingenol‑mebutate treated keloids. In particular, the upregulation of miR‑34a was detected in keloid fibroblasts during and following Ingenol‑mebutate exposure. Keloid fibroblasts that overexpressed miR‑34a showed differential expression of genes involved in the apoptotic signaling pathway such as p53. In conclusion, the Ingenol‑mebutate treatment used here was effective in reducing keloid fibroblast growth in cell culture experiments and the expression of particular miRNAs modulated the pro‑apoptotic gene expression following Ingenol-mebutate treatment.

Background: Ingenol-mebutate has been used for the treatment of actinic keratosis. It has been shown that ingenol-mebutate inhibits the growth of cancer cells or induces tumor cell death through pro-apoptotic effects. Keloids are benign skin tumours and are the effect of a deregulated wound-healing process in genetically predisposed patients. Increased cell proliferation, which accounts for the progressive and hypertrophic nature of keloids, correlates with the failure of apoptosis and plays a role in the process of pathological scarring. Keloid cells show a mutated p53 gene resulting in functionally inactive p53 protein which cannot control genomic integrity. They tend to escape from apoptosis which leads to keloid development by means of accumulation of continuously proliferating cells. Currently, the treatment of keloids remains a challenge for high recurrence rates. However, the design and the development of pro-apoptotic therapeutic strategies would be beneficial to keloids treatment., Case Presentation: A 55-year-old caucasian woman presented recurrent keloids on a presternal scar. Standard surgical intervention was used to treat the scar. However, this was unsuccessful and a year later the patient sought treatment again, but only by alternative means as the patient refused further surgical intervention. Consequently, based on past research and experience, the authors attempted to treat these lesions with ingenol mebutate gel, due to the pro-apoptotic effects., Conclusion: After 1 month, there was a clinical resolution of lesions, with a slightly squamous, post-inflammatory erythema. A cutaneous biopsy proved the absence of residual keloids and deregulated expression of molecular markers. The last follow-up of the patient, 1 year after treatment, showed that the patient was still free of keloids recurrence.

In this study, selenocystine, a nutritionally available selenoamino acid, was identified for the first time as a novel agent with anti proliferative activity on human keloids. The 20 μM concentration after 48 h treatment used here was the most effective to reduce keloid fibroblast growth. We analyzed the gene expression profile of selenocystine treatment response in keloid fibroblasts by the microarray system to characterize the effects of selenocystine on human keloids. The major alterations in keloid fibroblasts following selenocystine exposure included up-regulation of the genes encoding cell death and transcription factors. Prominent down-regulation of genes involved in development, cell adhesion and cytoskeleton, as well as extra cellular matrix genes, usually strongly up-regulated in keloids, resulted following selenocystine exposure. The range of the down-regulated genes and the degree of the decreased expression appeared to be correlated with the degree of the morphological alterations in selenocystine treated keloids., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Keloids are benign skin tumors that are the effect of a dysregulated wound-healing process in genetically predisposed patients. They are inherited with an autosomal dominant mode with incomplete clinical penetrance and variable expression. Keloids are characterized by formation of excess scar tissue beyond the boundaries of the wound. The exact etiology is still unknown and there is currently no appropriate treatment for keloid disease., Methods: We analyzed sample tissues were obtained from 20 patients with keloid skin lesions and normal skin was obtained from 20 healthy donors. The telomeres were measured by Terminal Restriction Fragment (TRF) analysis and Real-Time PCR assay. Quantitative Real-Time RT-PCR analysis of hTERT gene expression was performed and intracellular ROS generation was measured., Results: In this study, we determined whether telomeric shortening and the expression of human telomerase reverse transcriptase (hTERT) occurs in keloid patients. Using Terminal Restriction Fragment (TRF) analysis and Real-Time PCR assay, we detected a significant telomere shortening of 30% in keloid specimens compared to normal skin. Using quantitative Real-Time RT-PCR, telomerase activity was found absent in the keloid tissues. Moreover, an increase in ROS generation was detected in fibroblasts cell cultures from keloid specimens as more time elapsed compared to fibroblasts from normal skin., Conclusion: Telomere shortening has been reported in several metabolic and cardiovascular diseases. We found that telomere shortening can also be associated with human keloids. Chronic oxidative stress plays a major role in the pathophysiology of several chronic inflammatory diseases. Here we found increased ROS generation in fibroblasts from keloid fibroblasts cell cultures when compared to normal skin fibroblasts. Hence we conclude that oxidative stress might be an important modulator of telomere loss in keloid because of the absence of active telomerase that counteracts telomere shortening.

Keloids are benign skin tumors and are the effect of a dysregulated wound-healing process in genetically predisposed patients. They are characterized by formation of excess scar tissue beyond the boundaries of the wound. Keloids are often confused with hypertrophic scars because of an apparent lack of morphologic differences. The molecular distinction between scars and keloid is still controversial and, until today, there is no appropriate treatment yet for keloid disease. In this study, we have found, for the first time, p53 mutations in both hypertrophic scar and keloids fibroblasts from cultured cells to various extents. Since p53 plays a central role in the DNA damage response by inducing cell cycle arrest and/or apoptotic cell death, we also set up time course experiments making cell cultures at different times to investigate the phenomenon of apoptosis and its involvement in the process of pathological scarring in both hypertrophic scars and keloids. The extent of apoptosis in this study was investigated by DNA fragmentation and MTT assays, propidium iodide staining, p53 expression, and subcellular distribution. Moreover, the correlation of apoptosis and ROS levels in keloid and hypertrophic scars fibroblasts was assessed. Understanding the molecular mechanisms that determine the regulation of apoptosis during wound healing might allow us to therapeutically modulate these pathways so that apoptotic cell death is reactivated in dysregulated and hypertrophic cells.

The p63 gene belongs to the p53 gene family and encodes for sequence-specific transcription factors. p63 has been characterized primarily in the context of epidermis where is implicated in the establishment of keratinocyte cell fate and in maintenance of epithelial self-renewal. DeltaNp63 isoform has been showed to be involved in several kinds of human tumors of epidermal origin, even nonmalignant, for the neoplastic and proliferative potential. Here, we report the differential expression and the cellular localization of the DeltaNp63 isoform in fibroblasts isolated from human keloids and hypertrophic scars compared to normal skin. Differently from hypertrophic scar, our results show that DeltaNp63 has a nuclear localization and is overexpressed only in keloid fibroblasts, suggesting an essential role of DeltaNp63 in vivo in human keloids. Consistent with our results, we hypothesize that DeltaNp63 overexpression may be oncogenic because of its ability to block the activity of p53 since p53 is underexpressed in fibroblasts from keloids.

Keloids are benign skin tumors that develop following wounding. A cDNA product from human keloid specimens was identified using the differential display technique. The full-length cDNA was cloned by RT-PCR using human keloid mRNA as template. The predicted product of the cDNA was found to be 99% identical to the DeltaN-p63 gamma isotype of p63, a transcription factor that belongs to the family that includes the structurally related tumor suppressor p53 and p73. The DeltaN-p63 isotype lacks the acidic N terminal region corresponding to the transactivation domain of p53. Since this can potentially block p53-mediated target gene transactivation, it may serve as a dominant-negative isoform. Real-Time RT-PCR analysis of RNAs from normal skin tissue and keloids showed that the DeltaN-p63 isotype is specifically expressed in keloids, but is virtually undetectable in normal skin. Immunostaining of p63 in normal skin revealed that only basal cells of the epithelium expressed the protein, while in keloid tissues the antigen was detected in the nuclei of cells scattered through all layers of the epithelium and in fibroblast-like cells in the dermis. These results may indicate that aberrant p63 expression plays a role not only in malignant tumors but also in benign skin diseases that show hyperproliferation of epidermal cells in vivo. Moreover, this isoform of p63 could serve as a specific molecular marker for this human disease.