Establishment and characterization of HXWMF-1: the first mouse fibroblastic tumor cell line derived from leukemia-associated fibroblasts

The role of cancer-associated fibroblasts and exosomal miRNAs-mediated intercellular communication in the tumor microenvironment and the biology of carcinogenesis: a systematic review

CAFs (cancer-associated fibroblasts) are highly flexible cells of the cancer microenvironment. They produce the extracellular matrix (ECM) constituents that form the structure of the tumor stroma but are also a source of metabolites, growth factors, chemokines, and exosomes that impact every aspect of the tumor, including its response to treatment. It is believed that exosomal miRNAs facilitate intercellular signaling, which is essential for the development of cancer. The role of miRNAs and CAFs in the tumor microenvironment (TME) and carcinogenesis is reviewed in this paper. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 guidelines were used to perform a systematic review. Several databases, including Web of Science, Medline, Embase, Cochrane Library, and Scopus, were searched using the following keywords: CAFs, CAF, cancer-associated fibroblasts, stromal fibroblasts, miRNA, exosomal miRNAs, exosome and similar terms. We identified studies investigating exosomal miRNAs and CAFs in the TME and their role in carcinogenesis. A total of 12,572 papers were identified. After removing duplicates (n = 3803), 8774 articles were screened by title and abstract. Of these, 421 were excluded from further analysis. It has been reported that if exosomal miRNAs in CAFs are not functioning correctly, this may influence the secretory phenotype of tip cells and contribute to increased tumor invasiveness, tumor spread, decreased treatment efficacy, and a poorer prognosis. Under their influence, normal fibroblasts (NFs) are transformed into CAFs. Furthermore, they participate in metabolic reprogramming, which allows for fast proliferation of the cancer cell population, adaptation to growing energy demands, and the capacity to avoid immune system identification.

Stromal bone marrow fibroblasts and mesenchymal stem cells support acute myeloid leukaemia cells and promote therapy resistance

The bone marrow (BM) is the primary site of adult haematopoiesis, where stromal elements (e.g. fibroblasts and mesenchymal stem cells [MSCs]) work in concert to support blood cell development. However, the establishment of an abnormal clone can lead to a blood malignancy, such as acute myeloid leukaemia (AML). Despite our increased understanding of the pathophysiology of the disease, patient survival remains suboptimal, mainly driven by the development of therapy resistance. In this review, we highlight the importance of bone marrow fibroblasts and MSCs in health and acute myeloid leukaemia and their impact on patient prognosis. We discuss how stromal elements reduce the killing effects of therapies via a combination of contact-dependent (e.g. integrins) and contact-independent (i.e. secreted factors) mechanisms, accompanied by the establishment of an immunosuppressive microenvironment. Importantly, we underline the challenges of therapeutically targeting the bone marrow stroma to improve acute myeloid leukaemia patient outcomes, due to the inherent heterogeneity of stromal cell populations. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc.

Cancer-associated fibroblasts in hematologic malignancies: elucidating roles and spotlighting therapeutic targets

Hematologic malignancies comprise a diverse range of blood, bone marrow, and organ-related disorders that present significant challenges due to drug resistance, relapse, and treatment failure. Cancer-associated fibroblasts (CAFs) represent a critical component of the tumor microenvironment (TME) and have recently emerged as potential therapeutic targets. In this comprehensive review, we summarize the latest findings on the roles of CAFs in various hematologic malignancies, including acute leukemia, multiple myeloma, chronic lymphocytic leukemia, myeloproliferative neoplasms, and lymphoma. We also explore their involvement in tumor progression, drug resistance, and the various signaling pathways implicated in their activation and function. While the underlying mechanisms and the existence of multiple CAF subtypes pose challenges, targeting CAFs and their associated pathways offers a promising avenue for the development of innovative treatments to improve patient outcomes in hematologic malignancies.

Cancer-associated fibroblasts in acute leukemia

Although the prognosis for acute leukemia has greatly improved, treatment of relapsed/refractory acute leukemia (R/R AL) remains challenging. Recently, increasing evidence indicates that the bone marrow microenvironment (BMM) plays a crucial role in leukemogenesis and therapeutic resistance; therefore, BMM-targeted strategies should be a potent protocol for treating R/R AL. The targeting of cancer-associated fibroblasts (CAFs) in solid tumors has received much attention and has achieved some progress, as CAFs might act as an organizer in the tumor microenvironment. Additionally, over the last 10 years, attention has been drawn to the role of CAFs in the BMM. In spite of certain successes in preclinical and clinical studies, the heterogeneity and plasticity of CAFs mean targeting them is a big challenge. Herein, we review the heterogeneity and roles of CAFs in the BMM and highlight the challenges and opportunities associated with acute leukemia therapies that involve the targeting of CAFs.