SASH1 S519N variant links skin hyperpigmentation and premature hair graying to dysfunction of melanocyte lineage.

A better understanding of human melanocyte (MC) and melanocyte stem cell (McSC) biology is essential for treating melanocyte-related diseases. This study employed an inherited pigmentation disorder carrying the SASH1S519N variant in a Hispanic family to investigate the SASH1 function in the MC lineage and the underlying mechanism for this disorder. We used a multidisciplinary approach, including clinical exams, human cell assays, yeast two-hybrid screening, and biochemical techniques. Results linked early hair graying to the SASH1S519N variant, a previously unrecognized clinical phenotype in hyperpigmentation disorders. In vitro, we identified SASH1 as a regulator in McSC maintenance and discovered that TNKS2 is crucial for SASH1's role. Additionally, the S519N variant is located in one of multiple tankyrase-binding motifs and alters the binding kinetics and affinity of the interaction. In summary, this disorder links both gain and loss of pigmentation in the same individual, hinting to accelerated aging in human McSC. The findings offer insights into the roles of SASH1 and TNKS2 in McSC maintenance and the molecular mechanisms of pigmentation disorders. We propose that a comprehensive clinical evaluation of patients with MC-related disorders should include an assessment and history of hair pigmentation loss.

SASH1 interacts with TNKS2 and promotes human melanocyte stem cell maintenance.

Both aging spots (hyperpigmentation) and hair graying (lack of pigmentation) are associated with aging, two seemingly opposite pigmentation phenotypes. It is not clear how they are mechanistically connected. This study investigated the underlying mechanism in a family with an inherited pigmentation disorder. Clinical examinations identified accelerated hair graying and skin dyspigmentation (intermixed hyper and hypopigmentation) in the family members carrying the SASH1 S519N variant. Cell assays indicated that SASH1 promoted stem-like characteristics in human melanocytes, and SASH1 S519N was defective in this function. Multiple assays showed that SASH1 binds to tankyrase 2 (TNKS2), which is required for SASH1's promotion of stem-like function. Further, the SASH1 S519N variant is in a bona fide Tankyrase-binding motif, and SASH1 S519N alters the binding kinetics and affinity. Results here indicate SASH1 as a novel protein regulating the appropriate balance between melanocyte stem cells (McSC) and mature melanocytes (MCs), with S519N variant causing defects. We propose that dysfunction of McSC maintenance connects multiple aging-associated pigmentation phenotypes in the general population.

Evaluation of the long-term tolerability and clinical benefit of vorinostat in patients with advanced cutaneous T-cell lymphoma.

INTRODUCTION: Vorinostat, an orally active histone deacetylase inhibitor, was approved in October 2006 by the US Food and Drug Administration for the treatment of cutaneous manifestations of cutaneous T-cell lymphoma (CTCL) in patients with progressive, persistent, or recurrent disease during or after treatment with 2 systemic therapies. PATIENTS AND METHODS: A multicenter, open-label phase IIb trial evaluated the activity and safety of vorinostat 400 mg orally daily in patients with > or = stage IB, persistent, progressive, or treatment-refractory mycosis fungoides or Sézary syndrome CTCL subtypes. We report the safety and tolerability of long-term vorinostat therapy in patients who experienced clinical benefit in the previous phase IIb study. RESULTS: As of December 11, 2008, 6 of 74 patients enrolled in the original study had received vorinostat for > or = 2 years: median age, 65 years; median number of previous therapies, 2.5; median time from diagnosis to enrollment, 1.8 years. At enrollment into the continuation phase, 5 of the 6 patients had achieved an objective response, and 1 patient had prolonged stable disease. During the follow-up study, the most common drug-related grade 1-4 adverse events (AEs) were diarrhea, nausea, fatigue, and alopecia (6, 5, 4, and 3 patients, respectively). Incidence of grade 3/4 AEs was low: anorexia (n = 1), increased creatinine phosphokinase (n = 1), pulmonary embolism (n = 1), rash (n = 1), and thrombocytopenia (n = 1). Five patients have discontinued the study drug, and 1 patient is continuing therapy. CONCLUSION: This post hoc subset analysis provides evidence for the long-term safety and clinical benefit of vorinostat in heavily pretreated patients with CTCL, regardless of previous treatment failures.

Hyperthermia induces endoplasmic reticulum-mediated apoptosis in melanoma and non-melanoma skin cancer cells.

Hyperthermia has been revived as a promising approach for cancer treatment. To understand the underlying mechanisms of hyperthermic killing of cancer cells, we examined the cytotoxic effects of hyperthermia on various skin cancer cell lines using cell viability, morphological analyses, and caspase activation assays. Hyperthermia induced cytotoxicity in a time- and temperature-dependent manner. At middle dose/time combinations, heat-induced apoptosis, whereas at higher doses, necrosis was the mechanism of cell death. To investigate the mechanisms of hyperthermia-induced apoptosis, we examined the activation of extrinsic (Caspase 8) and intrinsic (Caspase 9) apoptotic pathways. Hyperthermia did not activate Caspases 8 or 9, but did activate Caspase 3/7, suggesting a non-conventional apoptotic pathway. Last, analysis of Grp78 expression and Caspase 12 or 4 activation indicated that hyperthermia induced endoplasmic reticulum-mediated apoptosis. Thus, hyperthermia induced apoptosis in two types of skin cancer cells through endoplasmic reticulum-mediated apoptosis and not through the classical intrinsic or extrinsic apoptosis pathways. Hyperthermia may be a promising treatment for basal cell carcinoma and melanoma, bypassing the antiapoptotic defenses concentrated in the intrinsic and extrinsic apoptosis pathways. These results also raise the possibility that heat may be combined with other approaches for induction of apoptosis to achieve synergistic killing of skin cancers.

Phase IIb multicenter trial of vorinostat in patients with persistent, progressive, or treatment refractory cutaneous T-cell lymphoma.

PURPOSE: To evaluate the activity and safety of the histone deacetylase inhibitor vorinostat (suberoylanilide hydroxamic acid) in persistent, progressive, or recurrent mycosis fungoides or Sézary syndrome (MF/SS) cutaneous t-cell lymphoma (CTCL) subtypes. PATIENTS AND METHODS: Patients with stage IB-IVA MF/SS were treated with 400 mg of oral vorinostat daily until disease progression or intolerable toxicity in this open-label phase IIb trial (NCT00091559). Patients must have received at least two prior systemic therapies at least one of which included bexarotene unless intolerable. The primary end point was the objective response rate (ORR) measured by the modified severity weighted assessment tool and secondary end points were time to response (TTR), time to progression (TTP), duration of response (DOR), and pruritus relief ( > or = 3-point improvement on a 10-point visual analog scale). Safety and tolerability were also evaluated. RESULTS: Seventy-four patients were enrolled, including 61 with at least stage IIB disease. The ORR was 29.7% overall; 29.5% in stage IIB or higher patients. Median TTR in stage IIB or higher patients was 56 days. Median DOR was not reached but estimated to be >or = 185 days (34+ to 441+). Median TTP was 4.9 months overall, and 9.8 months for stage IIB or higher responders. Overall, 32% of patients had pruritus relief. The most common drug-related adverse experiences (AE) were diarrhea (49%), fatigue (46%), nausea (43%), and anorexia (26%); most were grade 2 or lower but those grade 3 or higher included fatigue (5%), pulmonary embolism (5%), thrombocytopenia (5%), and nausea (4%). Eleven patients required dose modification and nine discontinued due to AE. CONCLUSION: Oral vorinostat was effective in treatment refractory MF/SS with an acceptable safety profile.

Café au lait macules and juvénile polyps.

Several hereditary and nonhereditary gastrointestinal tract polyposis syndromes exhibit extra-intestinal manifestations, including cutaneous findings. However, a lack of information exists regarding cutaneous features of juvenile polyposis. Our objective was to document the prevalence of cutaneous hyperpigmented lesions in children with juvenile polyposis coli or juvenile polyposis coli and their first degree relatives.Children seen in the gastroenterology practice at The Children's Hospital in Denver, Colorado with polyps (juvenile polyposis coli, sporadic juvenile polyps, and familial adenomatous polyposis coli) and their first degree relatives were invited to participate in the study. A comprehensive skin examination was performed on those who consented to participate. We found that 8 of 14 patients (eight with juvenile polyposis coli, four with juvenile polyposis, and two with familial adenomatous polyposis coli) had at least one café-au-lait macule, compared with three of 27 relatives (p=0.003).The prevalence of at least one café-au-lait macule in our patients (8/14 or 57.1%, CI: 28.9­82.3%) was significantly higher than the general population prevalence of 28.5% (p=0.023). However, if the two patients with familial adenomatous polyposis coli were excluded, the comparison with the general population prevalence did not reach statistical significance (p=0.095). The prevalence of multiple cafe´-au-lait macules in our patients (4/14 or 28.6%; CI:8.4­58.1%) was significantly higher than the general population prevalence of 5.2% (p » 0.005). A notable finding was the presence of multiple café -au-lait macules in 4 of 12 juvenile polyposis coli/juvenile polyposis patients.Two patients with juvenile polyposis coli also had lentigines. In this selected case series, we observed single or multiple café-au-lait macules in a high proportion of children with the three types of polyps. Further studies are needed to assess a possible common pathway for hamartomatous polypsand café-au-lait macules.

Incontinentia pigmenti in male patients.

BACKGROUND: Incontinentia pigmenti (IP) is a rare X-linked dominant genodermatosis that is typified by distinctive cutaneous findings and often by abnormalities of teeth, hair, nails, eyes, musculoskeletal system, and central nervous system. The gene that is mutated in patients with IP has been mapped to Xq28 and encodes the NF-kappaB essential modulator, NEMO. Female patients with IP show functional mosaicism and cutaneous manifestations follow Blaschko's lines of ectodermal embryologic development. The condition is generally considered to be lethal in utero in male fetuses, suggesting that having some normal gene expression is critical for survival. OBSERVATIONS: We observed 9 boys with IP. All had normal karotypes and no apparent family history of IP. In 8 of these 9 patients, lesions were localized to one extremity at presentation. The diagnosis was confirmed by histopathologic examination that showed eosinophils within intraepidermal, multiloculated vesicles. One of the boys later developed dental and neurologic abnormalities. LIMITATIONS: The case series was small and the workup for these patients from different sites was not uniform. CONCLUSIONS: Male individuals may show cutaneous and noncutaneous features of IP in a limited distribution that allows survival. Postzygotic mutation/somatic mosaicism is the likely mechanism. Given the potential sequelae associated with this condition, continuing follow-up of these patients is recommended.

Is high mole count a marker of more than melanoma risk? Eczema diagnosis is associated with melanocytic nevi in children.

BACKGROUND: The number of melanocytic nevi is the best single marker of increased melanoma risk. In a previous study, adults with severe eczema were reported to have significantly fewer nevi than adults without eczema. OBSERVATIONS: In a nested case-control design within a randomized, controlled interventional trial of additional sun protection vs standard care in 269 children, a history of eczema was reported by the parents of 44 (16%) of the children. More nevi were found in children with a parental report of previous eczema diagnosis than in children without reported eczema (median, 7.5 nevi vs 5.0 nevi; P =.01). Eczema diagnosis was most significantly associated with more melanocytic nevi in children with lightly pigmented skin (8.5 nevi vs 6.0 nevi; P <.001). In multivariate logistical regression analysis, including assessment of hair color, sun protection practices, and study assignment (intervention vs standard care), eczema status remained significantly predictive of nevi number in children (P <.001). CONCLUSIONS: In contrast to a previous study that associated severe eczema with fewer nevi in adults, in the present study children with a reported history of eczema had more nevi than children without a reported history of eczema.

Extramedullary plasmacytoma in cardiac transplant recipients.

Extramedullary plasmacytomas are an immunoproliferative, monoclonal disease of B-cell lineage and are classified as non-Hodgkin's lymphomas. Cutaneous extramedullary plasmacytomas are rare. We report 2 cases of transplantation-associated cutaneous extramedullary plasmacytomas in a setting of chronic immunosuppression.