Chronic telogen effluvium and female pattern hair loss are separate and distinct forms of alopecia: a histomorphometric and immunohistochemical analysis.

BACKGROUND: Chronic telogen effluvium (CTE), a poorly understood condition, can be confused with or may be a prodrome to female pattern hair loss (FPHL). The pathogenesis of both is related to follicle cycle shortening and possibly to blood supply changes. AIM: To analyze a number of histomorphometric and immunohistochemical findings through vascular endothelial growth factor (VEGF), Ki-67, and CD31 immunostaining in scalp biopsies of 20 patients with CTE, 17 patients with mild FPHL and 9 controls. METHODS: Ki-67 index and VEGF optical density were analyzed at the follicular outer sheath using ImageJ software. CD31 microvessel density was assessed by a Chalkley grid. RESULTS: Significant follicle miniaturization and higher density of nonanagen follicles were found in FPHL, compared with patients with CTE and controls. Ki-67+ index correlated positively with FPHL histological features. The FPHL group showed the highest VEGF optical density, followed by the CTE and control groups. No differences were found in CD31 microvessel density between the three groups. CONCLUSIONS: Histomorphometric results establish CTE as a distinct disorder, separate from FPHL from its outset. Its pathogenic mechanisms are also distinct. These findings support the proposed mechanism of 'immediate telogen release' for CTE, leading to cycle synchronization. For FPHL, accelerated anagen follicular mitotic rates and, thus, higher Ki-67 and VEGF values, would leave less time for differentiation, resulting in hair miniaturization.

Deubiquitination of EGFR by Cezanne-1 contributes to cancer progression.

Once stimulated, the epidermal growth factor receptor (EGFR) undergoes self-phosphorylation, which, on the one hand, instigates signaling cascades, and on the other hand, recruits CBL ubiquitin ligases, which mark EGFRs for degradation. Using RNA interference screens, we identified a deubiquitinating enzyme, Cezanne-1, that opposes receptor degradation and enhances EGFR signaling. These functions require the catalytic- and ubiquitin-binding domains of Cezanne-1, and they involve physical interactions and transphosphorylation of Cezanne-1 by EGFR. In line with the ability of Cezanne-1 to augment EGF-induced growth and migration signals, the enzyme is overexpressed in breast cancer. Congruently, the corresponding gene is amplified in approximately one third of mammary tumors, and high transcript levels predict an aggressive disease course. In conclusion, deubiquitination by Cezanne-1 curtails degradation of growth factor receptors, thereby promotes oncogenic growth signals.

Combining epitope-distinct antibodies to HER2: cooperative inhibitory effects on invasive growth.

Monoclonal antibodies (mAbs) to HER2 are currently used to treat breast cancer, but low clinical efficacy, along with primary and acquired resistance to therapy, commonly limit clinical applications. We previously reported that combinations of antibodies directed at non-overlapping epitopes of HER2 are endowed with enhanced antitumor effects, probably due to accelerated receptor degradation. Here, we extend these observations to three-dimensional mammary cell models, and compare the effects of single mAbs with the effects of antibody combinations. Collectively, our in vitro assays and computational image analyses indicate that combining mAbs against different epitopes of HER2 better inhibits invasive growth. Importantly, while growth factors are able to reduce intraluminal apoptosis and induce an invasive phenotype, combinations of mAbs better than single mAbs can reverse the growth factor-induced phenotypes of HER2-overexpressing spheroids. In conclusion, our studies propose that mAb combinations negate the biological effects of growth factors on invasive growth of HER2-overexpressing cells. Hence, combining mAbs offers a therapeutic strategy, potentially able to enhance clinical efficacy of existing antireceptor immunotherapeutics.