The Tumor Microenvironment: Focus on Extracellular Matrix

Microbes, macrophages, and melanin: a unifying theory of disease as exemplified by cancer

It is widely accepted that cancer mostly arises from random spontaneous mutations triggered by environmental factors. Our theory challenges the idea of the random somatic mutation theory (SMT). The SMT does not fit well with Charles Darwin's theory of evolution in that the same relatively few mutations would occur so frequently and that these mutations would lead to death rather than survival of the fittest. However, it would fit well under the theory of evolution, if we were to look at it from the vantage point of pathogens and their supporting microbial communities colonizing humans and mutating host cells for their own benefit, as it does give them an evolutionary advantage and they are capable of selecting genes to mutate and of inserting their own DNA or RNA into hosts. In this article, we provide evidence that tumors are actually complex microbial communities composed of various microorganisms living within biofilms encapsulated by a hard matrix; that these microorganisms are what cause the genetic mutations seen in cancer and control angiogenesis; that these pathogens spread by hiding in tumor cells and M2 or M2-like macrophages and other phagocytic immune cells and traveling inside them to distant sites camouflaged by platelets, which they also reprogram, and prepare the distant site for metastasis; that risk factors for cancer are sources of energy that pathogens are able to utilize; and that, in accordance with our previous unifying theory of disease, pathogens utilize melanin for energy for building and sustaining tumors and metastasis. We propose a paradigm shift in our understanding of what cancer is, and, thereby, a different trajectory for avenues of treatment and prevention.

Decorin, an exercise-induced secretory protein, is associated with improved prognosis in breast cancer patients but does not mediate anti-tumorigenic tissue crosstalk in mice

PURPOSE

Regular exercise can reduce incidence and progression of breast cancer, but the mechanisms for such effects are not fully understood. The purpose of this study was to examine the mechanisms behind the protective effects of exercise.

METHODS

We used a variety of rodent and human experimental model systems to determine whether exercise training can reduce tumor burden in breast cancer and to identify mechanism associated with any exercise training effects on tumor burden.

RESULTS

We show that voluntary wheel running slows tumor development in the mammary specific polyomavirus middle T antigen overexpression (MMTV-PyMT) mouse model of breast cancer but only when mice are not housed alone. We identify the proteoglycan decorin as a contraction-induced secretory factor that systemically increases in patients with breast cancer immediately following exercise. Moreover, high expression of decorin in tumors is associated with improved prognosis in patients, while treatment of breast cancer cells in vitro with decorin reduces cell proliferation. Notwithstanding, when we overexpressed decorin in murine muscle or injected recombinant decorin systemically into mouse models of breast cancer, elevated plasma decorin concentrations did not result in higher tumor decorin levels and tumor burden was not improved.

CONCLUSION

Exercise training is anti-tumorigenic in a mouse model of luminal breast cancer, but the effect is abrogated by social isolation. The proteoglycan decorin is an exercise-induced secretory protein, and tumor decorin levels are positively associated with improved prognosis in patients. The hypothesis that elevated plasma decorin is a mechanism by which exercise training improves breast cancer progression in humans is not, however, supported by our pre-clinical data since elevated circulating decorin did not increase tumor decorin levels in these models.

Tumor microenvironment: A playground for cells from multiple diverse origins

Tumor microenvironment is formed by various cellular and non-cellular components which interact with one another and form a complex network of interactions. Some of these cellular components also attain a secretory phenotype and release growth factors, cytokines, chemokines etc. in the surroundings which are capable of inducing even greater number of signalling networks. All these interactions play a decisive role in determining the course of tumorigenesis. The treatment strategies against cancer also exert their impact on the local microenvironment. Such interactions and anticancer therapies have been found to induce more deleterious outcomes like immunosuppression and chemoresistance in the process of tumor progression. Hence, understanding the tumor microenvironment is crucial for dealing with cancer and chemoresistance. This review is an attempt to develop some understanding about the tumor microenvironment and different factors which modulate it, thereby contributing to tumorigenesis. Along with summarising the major components of tumor microenvironment and various interactions taking place between them, it also throws some light on how the existing and potential therapies exert their impact on these dynamics.

Construction and validation of a prognostic model for bladder cancer based on disulfidptosis-related lncRNAs

BACKGROUND

Bladder cancer (BLCA) is a prevalent and aggressive cancer associated with high mortality and poor prognosis. Currently, studies on the role of disulfidptosis-related long non-coding RNAs (DRLs) in BLCA are limited. This study aims to construct a prognostic model based on DRLs to improve the accuracy of survival predictions for patients and identify novel targets for therapeutic intervention in BLCA management.

METHODS

Transcriptomic and clinical datasets for patients with BLCA were obtained from The Cancer Genome Atlas. Using multivariate Cox regression and least absolute shrinkage and selection operator techniques, a risk prognostic signature defined by DRLs was developed. The model's accuracy and prognostic relevance were assessed through Kaplan-Meier survival plots, receiver operating characteristic curves, concordance index, and principal component analysis. Functional and pathway enrichment analyses, including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis, were conducted to elucidate the underlying biological processes. Immune cell infiltration was quantified using the CIBERSORT algorithm. Differences and functions of immune cells in different risk groups were evaluated through single-sample Gene Set Enrichment Analysis. The Tumor Immune Dysfunction and Exclusion predictor and tumor mutational burden (TMB) assessments were utilized to gauge the likelihood of response to immunotherapy. Drug sensitivity predictions were made using the Genomics of Drug Sensitivity in Cancer database.

RESULTS

A robust 8-DRL risk prognostic model, comprising LINC00513, SMARCA5-AS1, MIR4435-2HG, MIR4713HG, AL122035.1, AL359762.3, AC006160.1, and AL590428.1, was identified as an independent prognostic indicator. This model demonstrated strong predictive power for overall survival in patients with BLCA, revealing significant disparities between high- and low-risk groups regarding tumor microenvironment, immune infiltration, immune functions, TMB, Tumor Immune Dysfunction and Exclusion scores, and drug susceptibility.

CONCLUSION

This study introduces an innovative prognostic signature of 8 DRLs, offering a valuable prognostic tool and potential therapeutic targets for bladder carcinoma. The findings have significant implications for TMB, the immune landscape, and patient responsiveness to immunotherapy and targeted treatments.

FBLN5 as One Presumably Prognostic Gene Potentially Modulating Tumor Immune Microenvironment for Renal Clear Cell Carcinoma in Children and Young Adults

OBJECTIVE

To investigate the role of FBLN5in renal clear cell carcinoma (KIRC), in particular on the tumor's immune microenvironment, including children and young adults.

METHODS

FBLN5 expression in tumor and normal samples was explored using SangerBox, TIMER2.0, GEPIA, UALCAN, HPA databases. The Linkedomics database was used to obtain FBLN5 co-expressed genes in KIRC tissue. SangerBox was also used to estimate immune infiltration of FBLN5 in KIRC. The Kaplan-Meier plotter was used to investigate the survival effects of FBLN5 expression in the presence of immune infiltration. We then collected 48 cases from 7 hospitals over a-20 year period to calculate the impact of FBLN5 on the prognosis of children and young adults with KIRC.

RESULTS

FBLN5 expression was significantly reduced in KIRC tissue compared to normal adjacent tissue. FBLN5 was potentially involved in the immune-related biological processes. In addition, FBLN5 expression has been linked to a number of immune checkpoints, cytokines, chemokines and chemokine receptors in KIRC. At the same time, the expression of FBLN5 affected the survival rates differently in KIRC patients with high or low levels of immune infiltration. High expression of FBLN5 in children and young adults with KIRC was associated with a favorable prognosis.

CONCLUSION

This study shed light on the potential of FBLN5 as a prognostic marker in children and young adults with KIRC and as an immune-related target for clinical treatment.

Challenges and Opportunities Associated With Drug Delivery for the Treatment of Solid Tumors

In this review, we discuss the effectiveness of drug delivery system based on metal nanoparticles, and also, describe the problems associated with their delivery to tumor cells. Throughout recent years, more reports have appeared in the literature that demonstrate promising results for the treatment of various types of cancer using metal-based nanoparticles. Due to their unique physical and chemical properties, metal nanoparticles are effectively being used for the delivery of drug to the tumor cells, for cancer diagnosis and treatment. They can also be synthesized allowing the control of size and shape. However, the effectiveness of the metal nanoparticles for cancer treatment largely depends on their stability, biocompatibility, and ability to selectively affect tumor cells after their systemic or local administration. Another major problem associated with metal nanoparticles is their ability to overcome tumor tissue barriers such as atypical blood vessel structure, dense and rigid extracellular matrix, and high pressure of tumor interstitial fluid. The review also describes the design of tumor drug delivery systems that are based on metal nanoparticles. The mechanism of action of metal nanoparticles on cancer cells is also discussed. Considering the therapeutic safety and toxicity of metal nanoparticles, the prospects for their use for future clinical applications are being currently reviewed.

Stromal Changes in Colon Blastomogenesis Associated with Development of Hypoxia in the Foci of Dysplasia

We studied the features of reaction of the colon stromal cells (lymphohistiocytic population, fibroblasts, and blood vessels) to the appearance and progression of dysplasia in the colon epithelium against the background of increasing ischemia in the colon mucosa. The morphological material from 92 patients treated for benign processes and colon cancer in 2002-2016 was examined. Common histological methods and a complex immunohistochemical staining were used. The stromal cells of the colon mucosa, mainly lymphohistiocytic cells, undergo certain quantitative changes specific for each type of cells during progression of dysplasia and aggravation of ischemia in the mucosa. Some cells, e.g. plasma cells, presumably contribute to tissue hypoxia in the stroma. Most stromal cells, except interdigitating S100⁺ dendritic cells and CD10⁺ fibroblasts, decreased at the stage of grave dysplasia and cancer in situ. Low effectiveness of the immune defense can be partly explained by impairment of the function of stromal cells as a result of hypoxia in the microenvironment.

Perieccrine Coil Elastosis: An Unusual and Previously Unrecognized Aging-Related Phenomenon

ABSTRACT

Elastic fibers are present as a thin line around the normal secretory coil of eccrine and apocrine glands, although they are virtually imperceptible with hematoxylin-eosin staining. Skin aging is a consequence of intrinsic and extrinsic factors, and glycation and ultraviolet irradiation are involved in this process favoring elastosis. We report an unusual and prominent perieccrine elastosis on the left temple in the vicinity of a basal cell carcinoma in a 78-year old man with type 2 diabetes, dyslipidemia, and hypertension. Very thick multilamellar and tortuous elastic fibers surrounded the eccrine coils. This increased amount of elastic fibers was confirmed by orcein staining as well as amyloid-P and lysozyme immunostaining. Perieccrine coil elastosis is a very unusual phenomenon that to the best of our knowledge has not been reported. Similar to dermal actinic elastosis, the presence of perieccrine coil elastosis in a skin cancer microenvironment might hypothetically promote tumor growth because of the release of elastin-derived peptides.

Antitumor Therapy Targeting the Tumor Microenvironment

The development and progression of tumors in human tissues extensively rely on its surrounding environment, that is, tumor microenvironment which includes a variety of cells, molecules, and blood vessels. These components are modified, organized, and integrated to support and facilitate the growth, invasion, and metabolism of tumor cells, suggesting them as potential therapeutic targets in anticancer treatment. An increasing number of pharmacological agents have been developed and clinically applied to target the oncogenic components in the tumor microenvironment, and in this review, we will summarize these pharmacological agents that directly or indirectly target the cellular or molecular components in the tumor microenvironment. However, difficulties and challenges still exist in this field, which will also be reported in this literature.

Proteoglycans: Systems-Level Insight into Their Expression in Healthy and Diseased Placentas

Proteoglycan macromolecules play key roles in several physiological processes (e.g., adhesion, proliferation, migration, invasion, angiogenesis, and apoptosis), all of which are important for placentation and healthy pregnancy. However, their precise roles in human reproduction have not been clarified. To fill this gap, herein, we provide an overview of the proteoglycans' expression and role in the placenta, in trophoblast development, and in pregnancy complications (pre-eclampsia, fetal growth restriction), highlighting one of the most important members of this family, syndecan-1 (SDC1). Microarray data analysis showed that of 34 placentally expressed proteoglycans, SDC1 production is markedly the highest in the placenta and that SDC1 is the most upregulated gene during trophoblast differentiation into the syncytiotrophoblast. Furthermore, placental transcriptomic data identified dysregulated proteoglycan genes in pre-eclampsia and in fetal growth restriction, including SDC1, which is supported by the lower concentration of syndecan-1 in maternal blood in these syndromes. Overall, our clinical and in vitro studies, data analyses, and literature search pointed out that proteoglycans, as important components of the placenta, may regulate various stages of placental development and participate in the maintenance of a healthy pregnancy. Moreover, syndecan-1 may serve as a useful marker of syncytialization and a prognostic marker of adverse pregnancy outcomes. Further studies are warranted to explore the role of proteoglycans in healthy and complicated pregnancies, which may help in diagnostic or therapeutic developments.

Diabetes mellitus contribution to the remodeling of the tumor microenvironment in gastric cancer

Compelling pieces of evidence derived from both clinical and experimental research has demonstrated the crucial contribution of diabetes mellitus (DM) as a risk factor associated with increased cancer incidence and mortality in many human neoplasms, including gastric cancer (GC). DM is considered a systemic inflammatory disease and therefore, this inflammatory status may have profound effects on the tumor microenvironment (TME), particularly by driving many molecular mechanisms to generate a more aggressive TME. DM is an active driver in the modification of the behavior of many cell components of the TME as well as altering the mechanical properties of the extracellular matrix (ECM), leading to an increased ECM stiffening. Additionally, DM can alter many cellular signaling mechanisms and thus favoring tumor growth, invasion, and metastatic potential, as well as key elements in regulating cellular functions and cross-talks, such as the microRNAs network, the production, and cargo of exosomes, the metabolism of cell stroma and resistance to hypoxia. In the present review, we intend to highlight the mechanistic contributions of DM to the remodeling of TME in GC.

Substrate stiffness affects the morphology, proliferation, and radiosensitivity of cervical squamous carcinoma cells

Cervical cancer is associated with the highest morbidity rate among gynecological cancers. Radiotherapy plays an important role in the treatment of cervical cancer. However, a considerable number of patients are radiation resistant, leading to a poor prognosis. Matrix stiffness is related to the occurrence, development, and chemoresistance of solid tumors. The association between matrix stiffness and radiosensitivity in cervical cancer cells remains unknown. Here, we sought to determine the effect of matrix stiffness on the phenotype and radiosensitivity of cervical cancer cells. Cervical squamous carcinoma SiHa cells were grown on substrates of different stiffnesses (0.5, 5, and 25 kPa). Cell morphology, proliferation, and radiosensitivity were examined. Cells grown on hard substrates displayed stronger proliferative activity, larger size, and higher differentiation degree, which was reflected in a more mature skeleton assembly, more abundant pseudopodia formation, and smaller nuclear/cytoplasmic ratio. In addition, SiHa cells exhibited stiffness-dependent resistance to radiation, possibly via altered apoptosis-related protein expression. Our findings demonstrate that matrix stiffness affects the morphology, proliferation, and radiosensitivity of SiHa cells. Tissue stiffness may be an indicator of the sensitivity of a patient to radiotherapy. Thus, the data provide insights into the diagnosis of cervical cancer and the design of future radiotherapies.

Stimuli-Sheddable Nanomedicine Overcoming Pathophysiological Barriers for Potentiating Immunotherapy of Cancer

Immunotherapy displays potent potential for clinical cancer management by activating the protective immune response; however, the microenvironment of the immunosuppressive tumor restricts the efficiency of immunotherapies. Along with the complex pathophysiological barrier of the solid tumors, successful immunotherapeutic delivery remains a formidable challenge for conventional nanomedicine. Stimuli-sheddable nano vectors may facilitate the delivery of cargoes to tumors with minimal premature cargo leakage in blood circulation while enhancing the tumor penetration of nanomedicines by deshielding the polyethylene glycol (PEG) corona upon endogenous activity such as acidity, enzymes and glutathione, or external stimuli, such as laser irradiation. Throughout this study, researchers overviewed the recent advances of nanomedicine-based cancer immunotherapy using the stimuli-responsive deshielding nano vectors, which allowed researchers to integrate multiple therapeutic regimens for inducing immunogenic cell death. This aided in blocking the immune checkpoints, repolarizing the macrophages, and regulating the kynurenine metabolism. Furthermore, researchers discussed the critical issues in the development of stimuli-sheddable nanoimmunodulators, primarily aimed at speeding up their clinical translation. Finally, researchers provided novel perspectives for improving cancer management with the stimuli-sheddable nanomedicine.

Tumor-Associated Fibroblast-Targeting Nanoparticles for Enhancing Solid Tumor Therapy: Progress and Challenges

Even though nanoparticle drug delivery systems (nanoDDSs) have improved antitumor efficacy by delivering more drugs to tumor sites compared to free and unencapsulated therapeutics, achieving satisfactory distribution and penetration of nanoDDSs inside solid tumors, especially in stromal fibrous tumors, remains challenging. As one of the most common stromal cells in solid tumors, tumor-associated fibroblasts (TAFs) not only promote tumor growth and metastasis but also reduce the drug delivery efficiency of nanoparticles through the tumor's inherent physical and physiological barriers. Thus, TAFs have been emerging as attractive targets, and TAF-targeting nanotherapeutics have been extensively explored to enhance the tumor delivery efficiency and efficacy of various anticancer agents. The purpose of this Review is to opportunely summarize the underlying mechanisms of TAFs on obstructing nanoparticle-mediated drug delivery into tumors and discuss the current advances of a plethora of nanotherapeutic approaches for effectively targeting TAFs.

Interrogating the microenvironmental landscape of tumors with computational image analysis approaches

The tumor microenvironment is an interacting heterogeneous collection of cancer cells, resident as well as infiltrating host cells, secreted factors, and extracellular matrix proteins. With the growing importance of immunotherapies, it has become crucial to be able to characterize the composition and the functional orientation of the microenvironment. The development of novel computational image analysis methodologies may enable the robust quantification and localization of immune and related biomarker-expressing cells within the microenvironment. The aim of the review is to concisely highlight a selection of current and significant contributions pertinent to methodological advances coupled with biomedical or translational applications. A further aim is to concisely present computational advances that, to our knowledge, have currently very limited use for the assessment of the microenvironment but have the potential to enhance image analysis pipelines; on this basis, an example is shown for the detection and segmentation of cells of the microenvironment using a published pipeline and a public dataset. Finally, a general proposal is presented on the conceptual design of automation-optimized computational image analysis workflows in the biomedical and clinical domain.

Comprehensive analysis on the expression levels and prognostic values of LOX family genes in kidney renal clear cell carcinoma

BACKGROUNDS

Kidney renal clear cell carcinoma (KIRC) is a major pathological type of renal cell carcinoma (RCC), and the prognosis of advanced KIRC patients is often unsatisfactory. Some lysine oxidase (LOX) family genes have been proven to be upregulated in some malignancies and play pivotal roles in the carcinogenesis. However, their roles in KIRC remain unclear.

MATERIALS AND METHODS

Here, we used some online databases (eg, ONCOMINE, GEPIA, UALCAN, c-BioPortal, Human Protein Altas) to comprehensively explored the expression levels and the prognostic values of LOX family genes in KIRC using bioinformatic methods.

RESULTS

The results revealed that lysyl oxidase (LOX) and lysyl oxidase-like 2 (LOXL2) were significantly overexpressed in KIRC at the level of mRNA expression, protein expression, and RCC cell lines. Further analysis demonstrated that higher mRNA expression of LOX and LOXL2 were significantly correlated with poor survival, tumor grade, individual cancer stages, and nodal metastasis status. DNA copy number amplifications and mRNA upregulation, DNA deep deletion, and mRNA upregulation were the main genetic mutations of LOX and LOXL2, respectively. Prognostic analysis showed that the altered group had significantly poorer overall survival (OS) compared to the unaltered group (p = .0387). Co-expression analysis showed CP, PLOD2, and COL5A1 were significantly correlated with LOX, and COL1A2 was positively correlated with LOXL2. Further analysis confirmed that these co-expressed genes were significantly upregulated and predicted unfavorable prognosis in KIRC.

CONCLUSION

Multi-level analysis demonstrated that LOX and LOXL2 were significantly upregulated and predicted poor survival in KIRC, which may apply as promising biomarkers for diagnosis and therapy of KIRC in the future.