Multiplatform Analysis of Intratumoral PTEN Heterogeneity in Melanoma

How Can Spatial Transcriptomic Profiling Advance Our Understanding of Skin Diseases?

Spatial transcriptomic (ST) profiling is the mapping of gene expression within cell populations with preservation of positional context and represents an exciting new approach to develop our understanding of local and regional influences upon skin biology in health and disease. With the ability to probe from a few hundred transcripts to the entire transcriptome, multiple ST approaches are now widely available. In this paper, we review the ST field and discuss its application to dermatology. Its potential to advance our understanding of skin biology in health and disease is highlighted through the illustrative examples of 3 research areas: cutaneous aging, tumorigenesis, and psoriasis.

Extraction, Purification, and Next-Generation Sequencing (NGS) Analysis of DNA and RNA from Formalin-Fixed and Paraffin-Embedded (FFPE) Tissue

Formalin fixed paraffin embedded (FFPE) tissues have long been used for immunohistological analyses. FFPE tissues can be stored at room temperature for several years enabling analyses to be performed later. Ease of storage and transport makes these tissues an attractive source of biological material. However, formalin fixation results in chemical modifications of proteins and nucleic acids that poses a major challenge to any type of analysis. Recovery of nucleic acids for quantitative assays is rendered difficult due to degradation resulting from fixation and long-term storage, producing low usable yields. Extensive efforts in the last 20 years have led to significant improvements in use of FFPE tissues for DNA and RNA analyses and resulted in development of sensitive assays for a wide range of applications, including next-generation sequencing. In this chapter, we describe the optimization of methods for sequential extraction of DNA and RNA from FFPE tissue and subsequent preparation of DNA-seq and RNA-seq libraries for use with the Illumina platform using commercially available reagents/kits.

Pholiotic acid promotes apoptosis in human metastatic melanoma cells

Mushrooms produce a great variety of secondary metabolites that can be successful in both prevention and treatment of various cancers. In particular, higher Basidiomycete mushrooms contain various types of biologically active low-molecular compounds in fruiting bodies with suggested anticarcinogenic effects. The polyamine analogue {(2R)-2-[(S)-3-hydroxy-3-methylglutaryloxy] putrescine dicinnamamide} indicated with the name pholiotic acid, isolated for the first time by us from the fruiting bodies of the Basidiomycete Pholiota spumosa (Fr.) Sing. (Strophariaceae), inhibited the viability of human prostate cancer cells, such as other polyamine synthetic analogues that have shown antitumor activity in several types of cancer, including melanoma. Melanoma is an aggressive skin cancer that can metastasize to other organs and presents a high resistance to conventional therapies. In light of these considerations, the present study was therefore designed to assess whether this putrescine derivative could inhibit the growth of human metastatic melanoma cell lines, M14 and A2058. The results obtained demonstrate that this natural compound, at 12.5-50 μM concentration, was able to reduce cell viability of both cancer cells inducing cell death by intrinsic apoptotic pathway that probably involves PTEN activity, inhibition of Hsp70 expression and reactive oxygen species production. On the other hand, the increased expression of enzymes involved in polyamine catabolism trigger apoptotic cell death leading to polyamine depletion and generation of reactive oxygen species as by-products. In conclusion, these findings, starting point for further investigation, implement available our data to support pholiotic acid as an attractive potential chemopreventive agent, and provide a basis for further research into the use of this polyamine derivative as potential anticancer agent for melanoma in combination with existing therapies to improve treatment efficacy and overcome the obstacle of drug resistance.