Guidelines for establishing a cytometry laboratory.

The purpose of this document is to provide guidance for establishing and maintaining growth and development of flow cytometry shared resource laboratories. While the best practices offered in this manuscript are not intended to be universal or exhaustive, they do outline key goals that should be prioritized to achieve operational excellence and meet the needs of the scientific community. Additionally, this document provides information on available technologies and software relevant to shared resource laboratories. This manuscript builds on the work of Barsky et al. 2016 published in Cytometry Part A and incorporates recent advancements in cytometric technology. A flow cytometer is a specialized piece of technology that require special care and consideration in its housing and operations. As with any scientific equipment, a thorough evaluation of the location, space requirements, auxiliary resources, and support is crucial for successful operation. This comprehensive resource has been written by past and present members of the International Society for Advancement of Cytometry (ISAC) Shared Resource Laboratory (SRL) Emerging Leaders Program https://isac-net.org/general/custom.asp?page=SRL-Emerging-Leaders with extensive expertise in managing flow cytometry SRLs from around the world in different settings including academia and industry. It is intended to assist in establishing a new flow cytometry SRL, re-purposing an existing space into such a facility, or adding a flow cytometer to an individual lab in academia or industry. This resource reviews the available cytometry technologies, the operational requirements, and best practices in SRL staffing and management.

Endothelin-1 in the tumor microenvironment correlates with melanoma invasion.

Endothelin-1 (ET-1) is a vasoactive peptide that also plays a role in the tanning response of the skin. Animal and cell culture studies have also implicated ET-1 in melanoma progression, but no association studies have been performed to link ET-1 expression and melanoma in humans. Here, we present the first in-vivo study of ET-1 expression in pigmented lesions in humans: an ET-1 immunohistochemical screen of melanocytic nevi, melanoma in situ lesions, invasive melanomas, metastatic melanomas, and blue nevi was performed. Twenty-six percent of melanocytic nevi and 44% of melanoma in situ lesions demonstrate ET-1 expression in the perilesional microenvironment, whereas expression in nevus or melanoma cells was rare to absent. In striking contrast, 100% of moderately to highly pigmented invasive melanomas contained numerous ET-1-positive cells in the tumor microenvironment, with 79% containing ET-1-positive melanoma cells, confirmed by co-staining with melanoma tumor marker HMB45. Hypopigmented invasive melanomas had reduced ET-1 expression, suggesting a correlation between ET-1 expression and pigmented melanomas. ET-1-positive perilesional cells were CD68-positive, indicating macrophage origin. Sixty-two percent of highly pigmented metastatic melanomas demonstrated ET-1 expression in melanoma cells, in contrast to 28.2% of hypopigmented specimens. Eighty-nine percent of benign nevi, known as blue nevi, which have a dermal localization, were associated with numerous ET-1-positive macrophages in the perilesional microenvironment, but no ET-1 expression was detected in the melanocytes. We conclude that ET-1 expression in the microenvironment increases with advancing stages of melanocyte transformation, implicating a critical role for ET-1 in melanoma progression, and the importance of the tumor microenvironment in the melanoma phenotype.