Hair repigmentation associated with thalidomide use for the treatment of multiple myeloma

Rapamycin vs TORin-1 or Gleevec vs Nilotinib: Simple chemical evolution that converts PAK1-blockers to TOR-blockers or vice versa?

Both PAK1 (RAC/CDC42-activating kinase 1) and TOR (Target of Rapamycin) are among the major oncogenic/ageing kinases. However, they play the opposite role in our immune system, namely immune system is suppressed by PAK1, while it requires TOR. Thus, PAK1-blockers, would be more effective for therapy of cancers, than TOR-blockers. Since 2015 when we discovered genetically that PDGF-induced melanogenesis depends on "PAK1", we are able to screening a series of PAK1-blockers as melanogenesis-inhibitors which could eventually promote longevity. Interestingly, rapamycin, the first TOR-inhibitor, promotes melanogenesis, clearly indicating that TOR suppresses melanogenesis. However, a new TOR-inhibitor called TORin-1 no longer suppresses immune system, and blocks melanogenesis in cell culture. These observations strongly indicate that TORin-1 acts as PAK1-blockers, instead of TOR-blockers, in vivo. Thus, it is most likely that melanogenesis in cell culture could enable us to discriminate PAK1-blockers from TORblockers.

A Comprehensive Review of Mammalian Pigmentation: Paving the Way for Innovative Hair Colour-Changing Cosmetics

The natural colour of hair shafts is formed at the bulb of hair follicles, and it is coupled to the hair growth cycle. Three critical processes must happen for efficient pigmentation: (1) melanosome biogenesis in neural crest-derived melanocytes, (2) the biochemical synthesis of melanins (melanogenesis) inside melanosomes, and (3) the transfer of melanin granules to surrounding pre-cortical keratinocytes for their incorporation into nascent hair fibres. All these steps are under complex genetic control. The array of natural hair colour shades are ascribed to polymorphisms in several pigmentary genes. A myriad of factors acting via autocrine, paracrine, and endocrine mechanisms also contributes for hair colour diversity. Given the enormous social and cosmetic importance attributed to hair colour, hair dyeing is today a common practice. Nonetheless, the adverse effects of the long-term usage of such cosmetic procedures demand the development of new methods for colour change. In this context, case reports of hair lightening, darkening and repigmentation as a side-effect of the therapeutic usage of many drugs substantiate the possibility to tune hair colour by interfering with the biology of follicular pigmentary units. By scrutinizing mammalian pigmentation, this review pinpoints key targetable processes for the development of innovative cosmetics that can safely change the hair colour from the inside out.

Medication-Induced Repigmentation of Gray Hair: A Systematic Review

Hair graying is a common sign of aging resulting from complex regulation of melanogenesis. Currently, there is no medical treatment available for hair repigmentation. In this article we review the literature on medication-induced hair repigmentation, discuss the potential mechanisms of action, and review the quality of the literary data. To date, there have been 27 studies discussing medication-induced gray hair repigmentation, including 6 articles on gray hair repigmentation as a primary objective, notably with psoralen treatment or vitamin supplementation, and 21 reports on medication-induced gray hair repigmentation as an incidental finding. Medications noted in the literature include anti-inflammatory medications (thalidomide, lenalidomide, adalimumab, acitretin, etretinate, prednisone, cyclosporin, cisplatinum, interferon-α, and psoralen), stimulators of melanogenesis (latanoprost, erlotinib, imatinib, tamoxifen, and levodopa), vitamins (calcium pantothenate and para-amino benzoic acid), a medication that accumulates in tissues (clofazimine), and a medication with an undetermined mechanism (captopril). Diffuse repigmentation of gray hair can be induced by certain medications that inhibit inflammation or stimulate melanogenesis. There is also low-quality evidence that some vitamin B complex supplementation can promote gray hair darkening. While these compounds are not currently indicated for the treatment of gray hair, their mechanisms shed light on targets for future medications for hair repigmentation.

Spontaneous Hair Repigmentation in an 80-Year-Old Man: A Case of Melanoma-Associated Hair Repigmentation and Review of the Literature

Spontaneous hair repigmentation of physiologically white or gray hair is a rare occurrence that may be associated with melanoma in elderly individuals. We present the first case of this phenomenon in a man. A gray-haired, 80-year-old man presented to dermatology clinic with a 3-cm lock of black hair on his vertex scalp that developed over 1 year. Punch biopsies showed an increase in junctional dendritic melanocytes with rare pagetoid cells and extension along the follicular outer root sheath epithelium and interfollicular epidermis, associated with prominent dendritic melanocytic hyperplasia and pigment-containing melanocytes within the hair bulbs. Although the findings on the biopsies were not diagnostic of melanoma in situ, an irregular interfollicular distribution of melanocytes was concerning for an adjacent atypical process. A complete excision was performed and revealed melanoma in situ, lentigo maligna type. Rare reports describe spontaneous hair repigmentation as a harbinger of lentigo maligna in women. Repigmentation can occur in the setting of proliferation of malignant pigment-producing melanocytes or by paracrine stimulation of benign bulbar melanocytes through receptor tyrosine kinase KIT activation. Presence of prominent dendritic melanocytic hyperplasia and pigment-containing melanocytes within the hair bulbs in our patient's biopsies was suggestive of paracrine or physiologic stimulation of bulbar melanocytes. Given the importance of early melanoma detection and the low visibility of the scalp, this report raises awareness of an extraordinary presentation of lentigo maligna and exemplifies the importance of close clinicopathologic correlation to ensure optimal clinical management and patient outcome.

Hair Repigmentation During Immunotherapy Treatment With an Anti-Programmed Cell Death 1 and Anti-Programmed Cell Death Ligand 1 Agent for Lung Cancer

Importance

New targeted therapies for cancer have been released in recent years, opening new horizons in the treatment of patients with cancer. However, their related adverse events (AE) are not fully characterized. Hair repigmentation (HR) is a nondescribed effect secondary to anti-programmed cell death 1 (anti-PD-1) and anti-programmed cell death ligand 1 (anti-PD-L1 ) therapy for treatment of lung cancer (LC), in opposition to the vitiligo reactions that develop during melanoma treatment.

Objective

To describe a new adverse event occurring during anti-PD-1/anti-PD-L1 therapy for LC.

Design, Setting, and Participants

A case series from a descriptive observation of 14 patients with HR after anti-PD-1/anti-PD-L1 treatment, recruited between September and December, 2016, who were followed up to detect whether they developed cutaneous AE at the time HR was detected. The patients had all been treated in the dermatology department at Hospital Universitari Germans Trias i Pujol, Badalona, Spain.

Main Outcomes and Measures

Clinical observation of HR during anti-PD-1/anti-PD-L1 therapy for LC, proved by comparing old pictures provided by the patients and recent pictures taken during the follow-up.

Results

Fourteen patients (13 men and 1 woman; mean age, 64.9 years) receiving anti-PD-1 or anti-PD-L1 therapy for non-small-cell lung cancer (NSCLC) presented hair repigmentation during follow-up. This hair repigmentation consisted in a diffuse darkening of the hair in 13 of 14 patients, or in black patches between white hairs in 1. Thirteen of 14 patients presented a good clinical response to the treatment, with at least stable disease, and only 1 had to stop the therapy after only 4 cycles of treatment owing to a life-threatening progression of the disease.

Conclusions and Relevance

We present to our knowledge the first report of hair repigmentation owing to anti-PD-1/anti-PD-L1 therapy for lung cancer in a series of 14 patients. Hair repigmentation may be a good response marker in patients receiving anti-PD1/anti-PD-L1 therapy for LC.