ABSTRACT
PURPOSE OF REVIEW: Cutaneous T cell lymphomas (CTCLs) exhibit a wide variety of clinical features, histologic characteristics, and genetic drivers. We review novel molecular findings that inform our understanding of the pathogenesis of CTCL, with a focus on the tumor microenvironment (TME). RECENT FINDINGS: There is increasing evidence challenging the model of TCM:mycosis fungoides (MF) and TEM:Sézary syndrome (SS) phenotype. Phylogenetic analysis performed using whole-exome sequencing (WES) raises the possibility that MF can arise without a common ancestral T cell clone. The detection of ultraviolet (UV) marker signature 7 mutations in the blood of patients with SS raises questions about the role of UV exposure in CTCL pathogenesis. There is also increasing interest on the role of the TME in CTCL. Existing therapies such as the RXR retinoid bexarotene and the anti-CCR4 monoclonal antibody mogamulizumab may act through the CTCL TME by impacting the CCL22:CCR4 axis, while cancer-associated fibroblasts (CAFs) in the CTCL TME contribute to drug resistance, as well as a Th2 milieu and tumor growth via secretion of pro-tumorigenic cytokines. Staphylococcus aureus (SA) is a frequent cause of morbidity among CTCL patients. SA may positively select for malignant T cells through adaptive downregulation of alpha-toxin surface receptors and promotion of tumor growth via upregulation of the JAK/STAT pathway. Recent molecular advancements have contributed to our understanding of the pathogenesis of CTCL and shed light into the potential mechanisms of existing therapies. Further understanding of the CTCL TME may fuel the discovery of novel therapies for CTCL.
Subject(s)
Lymphoma, T-Cell, Cutaneous , Mycosis Fungoides , Sezary Syndrome , Skin Neoplasms , Humans , Janus Kinases , Phylogeny , Skin Neoplasms/etiology , Skin Neoplasms/genetics , STAT Transcription Factors , Signal Transduction , Lymphoma, T-Cell, Cutaneous/genetics , Lymphoma, T-Cell, Cutaneous/therapy , Mycosis Fungoides/pathology , Sezary Syndrome/genetics , Sezary Syndrome/therapy , Sezary Syndrome/pathology , Biomarkers , Tumor MicroenvironmentABSTRACT
pH variations influence the delivery of essential nutrients and CO2 solubility, which impact algae metabolism. In this study the microalgal growth and chlorophyll, lipid, and fatty acids content; along with the expression of some genes implicated in the biosynthesis of lipids were examined in Chlamydomonas reinhardtii subjected to pH values of 7.0, 7.8, and 8.5. At pH 7.8 an increase in cell growth was observed with a significant accumulation of chlorophyll (1.75-fold) when compared with growth at pH 7, while at pH 8.5 a sharp decrease in both parameters was observed when compared with the other pH values tested. Lipid content increased 3.0 (14.81% of dry cell weight, dcw) and 2.3 times (11.43% dcw) at pH 7.8 and 8.5, respectively, when compared with the experiment at pH 7 (4.97% dcw). The compositions of major fatty acids in the strains growing at pH 7.0, 7.8, or 8.5 were 25.7, 28.0, and 32.1% for palmitic acid; 17.3, 14.7, and 25.7% for oleic acid; and 9.8, 12.1, and 4.6% for linoleic acid; respectively. qRT-PCR analysis showed that the transcripts of ß-carboxyltransferase, Acyl carrier protein 1, acyl-ACP thiolase 1, acyl-sn-glycerol-3-phosphate acyltransferase, and diacylglycerol acyl transferase isoform 3 were significantly induced at pH 7.8 when compared with the other two pH conditions. These results indicate that the induction of genes implicated in the early and final steps of lipid biosynthesis contributes to their accumulation in the stationary phase. Our research suggests that a pH of 7.8 might be ideal to maximize growth and lipid accumulation.
