Microenvironmental Snail1-induced immunosuppression promotes melanoma growth

Melanoma-associated fibroblasts in tumor-promotion flammation and antitumor immunity: novel mechanisms and potential immunotherapeutic strategies

Melanoma, renowned for its aggressive behavior and resistance to conventional treatments, stands as a formidable challenge in the oncology landscape. The dynamic and complex interplay between cancer cells and the tumor microenvironment has gained significant attention, revealing Melanoma-Associated Fibroblasts (MAFs) as central players in disease progression. The heterogeneity of MAFs endows them with a dual role in melanoma. This exhaustive review seeks to not only shed light on the multifaceted roles of MAFs in orchestrating tumor-promoting inflammation but also to explore their involvement in antitumor immunity. By unraveling novel mechanisms underlying MAF functions, this review aims to provide a comprehensive understanding of their impact on melanoma development. Additionally, it delves into the potential of leveraging MAFs for innovative immunotherapeutic strategies, offering new avenues for enhancing treatment outcomes in the challenging realm of melanoma therapeutics.

Dual role of Snail1 as transcriptional repressor and activator

Snail1 transcriptional factor plays a key role in the control of epithelial to mesenchymal transition, a process that remodels tumor cells increasing their invasion and chemo-resistance as well as reprograms their metabolism and provides stemness properties. During this transition, Snail1 acts as a transcriptional repressor and, as growing evidences have demonstrated, also as a direct activator of mesenchymal genes. In this review, I describe the different proteins that interact with Snail1 and are responsible for these two different functions on gene expression; I focus on the transcriptional factors that associate to Snail1 in their target promoters, both activated and repressed. I also present working models for Snail1 action both as repressor and activator and raise some issues that still need to be investigated.

Transcription factors in fibroblast plasticity and CAF heterogeneity

In recent years, research focused on the multifaceted landscape and functions of cancer-associated fibroblasts (CAFs) aimed to reveal their heterogeneity and identify commonalities across diverse tumors for more effective therapeutic targeting of pro-tumoral stromal microenvironment. However, a unified functional categorization of CAF subsets remains elusive, posing challenges for the development of targeted CAF therapies in clinical settings.The CAF phenotype arises from a complex interplay of signals within the tumor microenvironment, where transcription factors serve as central mediators of various cellular pathways. Recent advances in single-cell RNA sequencing technology have emphasized the role of transcription factors in the conversion of normal fibroblasts to distinct CAF subtypes across various cancer types.This review provides a comprehensive overview of the specific roles of transcription factor networks in shaping CAF heterogeneity, plasticity, and functionality. Beginning with their influence on fibroblast homeostasis and reprogramming during wound healing and fibrosis, it delves into the emerging insights into transcription factor regulatory networks. Understanding these mechanisms not only enables a more precise characterization of CAF subsets but also sheds light on the early regulatory processes governing CAF heterogeneity and functionality. Ultimately, this knowledge may unveil novel therapeutic targets for cancer treatment, addressing the existing challenges of stromal-targeted therapies.

Reactivation of embryonic genetic programs in tissue regeneration and disease

Embryonic genetic programs are reactivated in response to various types of tissue damage, providing cell plasticity for tissue regeneration or disease progression. In acute conditions, these programs remedy the damage and then halt to allow a return to homeostasis. In chronic situations, including inflammatory diseases, fibrosis and cancer, prolonged activation of embryonic programs leads to disease progression and tissue deterioration. Induction of progenitor identity and cell plasticity, for example, epithelial-mesenchymal plasticity, are critical outcomes of reactivated embryonic programs. In this Review, we describe molecular players governing reactivated embryonic genetic programs, their role during disease progression, their similarities and differences and lineage reversion in pathology and discuss associated therapeutics and drug-resistance mechanisms across many organs. We also discuss the diversity of reactivated programs in different disease contexts. A comprehensive overview of commonalities between development and disease will provide better understanding of the biology and therapeutic strategies.