Cholesterol and Immune Microenvironment: Path Towards Tumorigenesis.

PURPOSE OF REVIEW: Since obesity is a major risk factor for many different types of cancer, examining one of the most closely associated comorbidities, such as hypercholesterolemia, is crucial to understanding how obesity causes cancer. Hypercholesterolemia is usually associated with many cardiovascular complications such as hypertension, angina, and atherosclerosis. In addition, cholesterol may be a major factor in increasing cancer risk. Cancer patients who received statins, an anti-hypercholesteremic medicine, demonstrated improved prognosis possibly through its effect on tumor proliferation, apoptosis, and oxidative stress. Cholesterol could also aid in tumor progression through reprogramming tumor immunological architecture and mediators. This review focuses on the immunomodulatory role of cholesterol on cellular and molecular levels, which may explain its oncogenic driving activity. We look at how cholesterol modulates tumor immune cells like dendritic cells, T cells, Tregs, and neutrophils. Further, this study sheds light on the modification of the expression pattern of the common cancer-related immune mediators in the tumor immune microenvironment, such as programmed cell death 1 (PD-1), cytotoxic T lymphocyte antigen-4 (CTLA-4), transforming growth factor-beta (TGF-ß), interleukin 12 (IL-12), IL-23, and forkhead box protein P3 (FOXP3). RECENT FINDINGS: We highlight relevant literature demonstrating cholesterol's immunosuppressive role, leading to a worse cancer prognosis. This review invites further research regarding the pathobiological role of cholesterol in many obesity-related cancers such as uterine fibroids, post-menopausal breast, colorectal, endometrial, kidney, esophageal, pancreatic, liver, and gallbladder cancers. This review suggests that targeting cholesterol synthesis may be a fruitful approach to cancer targeting, in addition to traditional chemotherapeutics.

The Role of Nanomedicine in Benign Gynecologic Disorders.

Nanomedicine has revolutionized drug delivery in the last two decades. Nanoparticles appear to be a promising drug delivery platform in the treatment of various gynecological disorders including uterine leiomyoma, endometriosis, polycystic ovarian syndrome (PCOS), and menopause. Nanoparticles are tiny (mean size < 1000 nm), biodegradable, biocompatible, non-toxic, safe, and relatively inexpensive materials commonly used in imaging and the drug delivery of various therapeutics, such as chemotherapeutics, small molecule inhibitors, immune mediators, protein peptides and non-coding RNA. We performed a literature review of published studies to examine the role of nanoparticles in treating uterine leiomyoma, endometriosis, PCOS, and menopause. In uterine leiomyoma, nanoparticles containing 2-methoxyestradiole and simvastatin, promising uterine fibroid treatments, have been effective in significantly inhibiting tumor growth compared to controls in in vivo mouse models with patient-derived leiomyoma xenografts. Nanoparticles have also shown efficacy in delivering magnetic hyperthermia to ablate endometriotic tissue. Moreover, nanoparticles can be used to deliver hormones and have shown efficacy as a mechanism for transdermal hormone replacement therapy in individuals with menopause. In this review, we aim to summarize research findings and report the efficacy of nanoparticles and nanotherapeutics in the treatment of various benign gynecologic conditions.

Senescence-associated secretory phenotype (SASP) and uterine fibroids: Association with PD-L1 activation and collagen deposition.

Uterine fibroids (or uterine leiomyoma, UFs) are one of the most prevalent benign uterine tumors with high proliferation and collagen synthesis capabilities. UFs are a significant worldwide health issue for women, affecting their physical and financial well-being. Risk factors for UFs include age, racial disparities, obesity, uterine infections, hormonal variation, and lifestyle (i.e., diet, exercise, stress, and smoking). Senescence and its associated secretory phenotypes (SASPs) are among the most salient changes accompanying the aging process. As a result, SASPs are suggested to be one of the major contributors to developing UFs. Interleukin 6 (IL-6), IL-8, IL-1, chemokine ligand 20 (CCL-20), and transforming growth factor-beta (TGF-ß) are the most prominent SASPs associated with aging. In addition, different processes contribute to UFs such as collagen deposition and the changes in the immune microenvironment. Programmed death ligand 1 is a major player in the tumor immune microenvironment, which helps tumor cells evade immune attacks. This review focuses on the correlation of SASPs on two axes of tumor progression: immune suppression and collagen deposition. This review opens the door towards more investigations regarding changes in the UF immune microenvironment and age-UFs correlation and thus, a novel targeting approach for UF treatment.

Immunosuppressive tumor microenvironment and uterine fibroids: Role in collagen synthesis.

Uterine fibroids (UF), also called uterine leiomyoma, is one of the most prevalent uterine tumors. UF represents a serious women's health global problem with a significant physical, emotional, and socioeconomic impact. Risk factors for UF include racial disparities, age, race, hormonal factors, obesity, and lifestyle (diet, physical activity, and stress. There are several biological contributors to UF pathogenesis such as cellular proliferation, angiogenesis, and extracellular matrix (ECM) accumulation. This review addresses tumor immune microenvironment as a novel mediator of ECM deposition. Polarization of immune microenvironment towards the immunosuppressive phenotype has been associated with ECM deposition. Immunosuppressive cells include M2 macrophage, myeloid-derived suppressor cells (MDSCs), and Th17 cells, and their secretomes include interleukin 4 (IL-4), IL-10, IL-13, IL-17, IL-22, arginase 1, and transforming growth factor-beta (TGF-ß1). The change in the immune microenvironment not only increase tumor growth but also aids in collagen synthesis and ECM disposition, which is one of the main hallmarks of UF pathogenesis. This review invites further investigations on the change in the UF immune microenvironment as well as a novel targeting approach instead of the traditional UF hormonal and supportive treatment.