Tumor Microenvironment—A Short Review of Cellular and Interaction Diversity

Machine learning predictions of tumor progression: How reliable are we?

BACKGROUND

Cancer continues to pose significant challenges in healthcare due to the complex nature of tumor progression. In this digital era, artificial intelligence has emerged as a powerful tool that can potentially transform multiple aspects of cancer care.

METHODS

In the current study, we conducted a comprehensive literature search across databases such as PubMed, Scopus, and IEEE Xplore. Studies published between 2014 and 2024 were considered. The selection process involved a systematic screening based on predefined inclusion and exclusion criteria. Studies were included if they focused on applying machine learning techniques for tumor progression modeling, diagnosis, or prognosis, were published in peer-reviewed journals or conference proceedings, were available in English, and presented experimental results, simulations, or real-world applications. In total, 87 papers were included in this review, ensuring a diverse and representative analysis of the field. A workflow is included to illustrate the procedure followed to achieve this aim.

RESULTS

This review delves into the cutting-edge applications of machine learning (ML), including supervised learning methods like Support Vector Machines and Random Forests, as well as advanced deep learning (DL). It focuses on the integration of ML into oncological research, particularly its application in tumor progression through the tumor microenvironment, genetic data, histopathological data, and radiological data. This work provides a critical analysis of the challenges associated with the reliability and accuracy of ML models, which limit their clinical integration.

CONCLUSION

This review offers expert insights and strategies to address these challenges in order to improve the robustness and applicability of ML in real-world oncology settings. By emphasizing the potential for personalized cancer treatment and bridging gaps between technology and clinical needs, this review serves as a comprehensive resource for advancing the integration of ML models into clinical oncology.

Identification of Natural Killer Cell Enhancers Through Mimicking of the Tumor Microenvironment

The tumor microenvironment (TME) is a pro-cancerous niche harboring immunosuppressive factors that are secreted by cancer cells and the surrounding cancer-supportive tissue, such as kynurenine, prostaglandin E2 and transforming growth factor β (TGFβ). These factors dampen the activity of cytotoxic lymphocytes like natural killer (NK) cells, allowing evasion of immune cell-mediated killing. To identify small molecules that counteract the immunosuppressive effect of the TME and restore NK cell-mediated cytotoxicity, we developed a phenotypic co-culture assay of cancer cells and primary lymphocytes suitable for medium-throughput screening. We discovered small molecules that restore NK cell-mediated cytotoxicity through diverse mechanisms. The potent TGFβ type I receptor (TGFβR-1) inhibitor, RepSox, stood out as superior to other TGFβR-1 inhibitors due to its ability to abolish the effects of both inhibitory factors used in our setup. This mode of action goes beyond TGFβR-1 inhibition and is related to the simultaneous abrogation of cyclooxygenase 1 (COX1) activity.

Interrogation of the tumor microenvironment by nanoparticles

The tumor microenvironment (TME) plays a pivotal role in cancer progression by fostering intricate multicellular crosstalk among cancer cells, stromal cells, and immune cells. This review explores the emerging paradigm of utilizing nanoparticles to disrupt this crosstalk within the TME as a therapeutic strategy. Nanoparticles are engineered with precise physicochemical properties to target specific cell types and deliver therapeutic payloads, thereby inhibiting critical signaling pathways involved in tumor growth, invasion, and metastasis. The mechanisms involved include modulation of the immune response, interference with growth factor signaling, and induction of programmed cell death in cancer cells. Challenges such as biocompatibility, efficient delivery, and potential development of resistance are discussed alongside promising advancements in nanoparticle design. Moving forward, integration of nanoparticle-based therapies with existing treatment modalities holds great potential for enhancing therapeutic efficacy and personalized medicine in cancer therapy.

Rab3B Proteins: Cellular Functions, Regulatory Mechanisms, and Potential as a Cancer Therapy Target

RAB3 proteins, a pivotal subgroup within the Rab protein family, are known to be highly expressed in brain and endocrine gland tissues, with detectable levels also observed in exocrine glands, adipose tissue, and other peripheral tissues. They play an indispensable role in the trafficking of cellular products from the endoplasmic reticulum (ER) to the Golgi apparatus and ultimately to secretory vesicles, participating in vesicle transport, mediating cell membrane adhesion, and facilitating membrane fusion during exocytosis. Among these, Rab3B, a specific subtype of RAB3, is a low-molecular-weight (approximately 25 kD) GTP-binding protein (GTPase) characterized by its typical GTPase fold, composed of seven β-strands (six parallel and one antiparallel) surrounded by six α-helices. Previous studies have proved the significant roles of Rab3B in vesicle transport and hormone trafficking. However, its involvement in cancer remains largely unexplored. This review aims to dig into the potential mechanisms of Rab3B in various cancers, including hepatocellular cancer, lung adenocarcinoma, pancreatic cancer, breast cancer, prostate cancer, neuroblastoma and cervical cancer. Given its pivotal functions and underexplored status in oncology, Rab3B stands out as a promising target for both diagnosis and therapy in cancer treatment, with investigations into its biological mechanisms in tumorigenesis offering significant potential to advance future diagnostic and therapeutic strategies across various malignancies.

From silent partners to potential therapeutic targets: macrophages in colorectal cancer

Cancer cells grow and survive in the tumor microenvironment, which is a complicated process. As a key part of how colorectal cancer (CRC) progresses, tumor-associated macrophages (TAMs) exhibit a double role. Through angiogenesis, this TAM can promote the growth of cancers. Although being able to modify and adjust immune cells is a great advantage, these cells can also exhibit anti-cancer properties including direct killing of cancer cells, presenting antigens, and aiding T cell-mediated responses. The delicate regulatory mechanisms between the immune system and tumors are composed of a complex network of pathways regulated by several factors including hypoxia, metabolic reprogramming, cytokine/chemokine signaling, and cell interactions. Decoding and figuring out these complex systems become significant in building targeted treatment programs. Targeting TAMs in CRC involves disrupting chemokine signaling or adhesion molecules, reprogramming them to an anti-tumor phenotype using TLR agonists, CD40 agonists, or metabolic modulation, and selectively removing TAM subsets that promote tumor growth. Multi-drug resistance, the absence of an accurate biomarker, and drug non-specificity are also major problems. Combining macrophage-targeted therapies with chemotherapy and immunotherapy may revolutionize treatment. Macrophage studies will advance with new technology and multi-omics methodologies to help us understand CRC and build specific and efficient treatments.

Complement activation at the interface between adipocytes and cancer cells drives tumor progression

The omentum is the primary site of metastasis for ovarian cancer (OC). Interactions between cancer cells and adipocytes drive an invasive and prometastatic phenotype. Here we studied cancer cell-adipocyte crosstalk by using a direct coculture model with immortalized human visceral nondiabetic pre-adipocytes (VNPADs) and OC cells. We demonstrated increased proliferation, invasiveness, and resistance to cisplatin of cocultured compared with monocultured OC cells. RNA sequencing of OC cells from coculture versus monoculture revealed significant transcriptomic changes, identifying over 200 differentially expressed genes common to OVCAR5 and OVCAR8 cell lines. Enriched pathways included PI3K/AKT and complement activation. Lipid transfer into OC cells from adipocytes induced upregulation of complement C3 and C5 proteins. Inhibiting C3 or C5 reversed the invasive phenotype and C3 knockdown reduced tumor progression in vivo. Increased C3 expression was observed in omental implants compared with primary ovarian tumors and C3 secretion was higher in OC ascites from high-BMI versus low-BMI patients. C3 upregulation in OC cells involved activation of the ATF4-mediated integrated stress response (ISR). Overall, adipocyte-cancer cell interactions promoted invasiveness and tumorigenesis via lipid transfer, activating the ISR, and upregulating complement proteins C3 and C5.

Modulating exosomal communication between macrophages and melanoma cancer cells via cyclodextrin-based nanosponges loaded with doxorubicin

The cellular components of the tumor microenvironment (TME) comprise cancer cells and nonmalignant cells including stromal and immune cells. Exosomes are extracellular vesicles secreted by various types of cells that play a crucial role in intercellular communications within TME. The main goal of this study was to elucidate how exosomes of macrophage cells treated with doxorubicin (DOX) and DOX-loaded cyclodextrin-based nanosponges (DOX-CDNSs), affect melanoma cancer cell proliferation. For this aim, the exosomes of the murine macrophage cell line (RAW 264.7) were isolated and characterized after treating the cells with DOX and DOX-CDNSs. The results demonstrated that DOX-CDNSs at a treatment concentration of 1 µg/mL, were nontoxic for macrophages and remarkably toxic against cancer cells. However, DOX was nontoxic for both cell types at the same treatment concentration. DOX and DOX-CDNSs remarkably declined the viability of both cell types at higher concentrations (25 and 50 µg/mL). Intriguingly, the exosomes of DOX-CD-NSs treated macrophages promoted the viability of cancer cells at the treatment concentrations of 1, 20, and 40 µg/mL. While the exosomes of DOX-treated macrophages increased cell viability of cancer cells only at the lowest concentration. In conclusion, this study suggests that utilization of CD-NSs may augment the toxicity of DOX against cancer cells, while it could direct macrophages toward secreting exosomes that favor the growth of cancer cells.

Emerging Role of Extracellular pH in Tumor Microenvironment as a Therapeutic Target for Cancer Immunotherapy

Identifying definitive biomarkers that predict clinical response and resistance to immunotherapy remains a critical challenge. One emerging factor is extracellular acidosis in the tumor microenvironment (TME), which significantly impairs immune cell function and contributes to immunotherapy failure. However, acidic conditions in the TME disrupt the interaction between cancer and immune cells, driving tumor-infiltrating T cells and NK cells into an inactivated, anergic state. Simultaneously, acidosis promotes the recruitment and activation of immunosuppressive cells, such as myeloid-derived suppressor cells and regulatory T cells (Tregs). Notably, tumor acidity enhances exosome release from Tregs, further amplifying immunosuppression. Tumor acidity thus acts as a "protective shield," neutralizing anti-tumor immune responses and transforming immune cells into pro-tumor allies. Therefore, targeting lactate metabolism has emerged as a promising strategy to overcome this barrier, with approaches including buffer agents to neutralize acidic pH and inhibitors to block lactate production or transport, thereby restoring immune cell efficacy in the TME. Recent discoveries have identified genes involved in extracellular pH (pHe) regulation, presenting new therapeutic targets. Moreover, ongoing research aims to elucidate the molecular mechanisms driving extracellular acidification and to develop treatments that modulate pH levels to enhance immunotherapy outcomes. Additionally, future clinical studies are crucial to validate the safety and efficacy of pHe-targeted therapies in cancer patients. Thus, this review explores the regulation of pHe in the TME and its potential role in improving cancer immunotherapy.

Targeting anticancer immunity in melanoma tumour microenvironment: unleashing the potential of adjuvants, drugs, and phytochemicals

Melanoma poses a challenge in oncology because of its aggressive nature and limited treatment modalities. The tumour microenvironment (TME) in melanoma contains unique properties such as an immunosuppressive and high-density environment, unusual vasculature, and a high number of stromal and immunosuppressive cells. In recent years, numerous experiments have focused on boosting the immune system to effectively remove malignant cells. Adjuvants, consisting of phytochemicals, toll-like receptor (TLR) agonists, and cytokines, have shown encouraging results in triggering antitumor immunity and augmenting the therapeutic effectiveness of anticancer therapy. These adjuvants can stimulate the maturation of dendritic cells (DCs) and infiltration of cytotoxic CD8+ T lymphocytes (CTLs). Furthermore, nanocarriers can help to deliver immunomodulators and antigens directly to the tumour stroma, thereby improving their efficacy against malignant cells. The remodelling of melanoma TME utilising phytochemicals, agonists, and other adjuvants can be combined with current modalities for improving therapy outcomes. This review article explores the potential of adjuvants, drugs, and their nanoformulations in enhancing the anticancer potency of macrophages, CTLs, and natural killer (NK) cells. Additionally, the capacity of these agents to repress the function of immunosuppressive components of melanoma TME, such as immunosuppressive subsets of macrophages, stromal and myeloid cells will be discussed.

Fibroblast stromal support model for predicting human papillomavirus-associated cancer drug responses

Currently, there are no specific antiviral therapeutic approaches targeting Human papillomaviruses (HPVs), which cause around 5% of all human cancers. Specific antiviral reagents are particularly needed for HPV-related oropharyngeal cancers (HPV+OPCs) whose incidence is increasing and for which there are no early diagnostic tools available. We and others have demonstrated that the estrogen receptor alpha (ERα) is overexpressed in HPV+OPCs, compared to HPV-negative cancers in this region, and that these elevated levels are associated with an improved disease outcome. Utilizing this HPV+-specific overexpression profile, we previously demonstrated that estrogen attenuates the growth and cell viability of HPV+ keratinocytes and HPV+ cancer cells in vitro. Expansion of this work in vivo failed to replicate this sensitization. The role of stromal support from the tumor microenvironment (TME) has previously been tied to both the HPV lifecycle and in vivo therapeutic responses. Our investigations revealed that in vitro co-culture with fibroblasts attenuated HPV+-specific estrogen growth responses. Continuing to monopolize on the HPV+-specific overexpression of ERα, our co-culture models then assessed the suitability of the selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen, and showed growth attenuation in a variety of our models to one or both of these drugs in vitro. Utilization of these SERMs in vivo closely resembled the sensitization predicted by our co-culture models. Therefore, the in vitro fibroblast co-culture model better predicts in vivo responses. We propose that utilization of our co-culture in vitro model can accelerate cancer therapeutic drug discovery.

IMPORTANCE

Human papillomavirus-related cancers (HPV+ cancers) remain a significant public health concern, and specific clinical approaches are desperately needed. In translating drug response data from in vitro to in vivo, the fibroblasts of the adjacent stromal support network play a key role. Our study presents the utilization of a fibroblast 2D co-culture system to better predict translational drug assessments for HPV+ cancers. We also suggest that this co-culture system should be considered for other translational approaches. Predicting even a portion of treatment paradigms that may fail in vivo with a co-culture model will yield significant time, effort, resource, and cost efficiencies.

Delineating the Immunotherapeutic Potential of Vitamin E and Its Analogues in Cancer: A Comprehensive Narrative Review

Cancer is a disease resulting from uncontrolled cell division, which significantly contributes to human mortality rates. An alternative approach to cancer treatment, such as cancer immunotherapy, is needed as the existing chemotherapy and radiotherapy approaches target the cancer cells and healthy dividing cells. Vitamin E is a plant-derived lipid-soluble antioxidant with numerous health-promoting benefits, including anticancer and immunomodulatory properties. Vitamin E comprises eight natural isoforms: tocopherols (α, β, δ, and γ) and tocotrienols (α, β, δ, and γ). While initial research focused on the anticancer properties of α-tocopherol, there is growing interest in other natural forms and modified synthetic analogues of vitamin E due to their unique properties and enhanced anticancer effects. Hence, this review is aimed at outlining the effect of vitamin E and its analogues at various steps of the cancer-immunity cycle that can be used to stimulate anticancer immune responses.

Phenotypically plastic drug-resistant chronic myeloid leukaemia cell line displays enhanced cellular dynamics in a zebrafish xenograft model

Understanding the mechanisms by which cancer cells switch between different adaptive states and evade therapeutic interventions is essential for clinical management. In this study, the in vivo cellular dynamics of a new chronic myeloid leukaemia cell line displaying altered phenotype and resistance to tyrosine kinase inhibitors were investigated in correlation with their parental cells for invasiveness/metastasis, angiogenic potential and population kinetics. We showed that the cells exhibiting drug resistance and plastic phenotype possess an increased capacity for invasion compared to their parental cells, that exposure to imatinib mesylate has the potential to enhance cellular motility and that in a leukaemic cell population, even a minority of plastic cells exhibit improved migratory ability. Furthermore, we show that these plastic cells have angiogenic and extravasation potential. The present study provides significant insights into the cellular dynamics displayed by a TKI-resistant, phenotypically plastic CML cell line, using a zebrafish (Danio rerio) xenograft model.

Spontaneous Regression of a Large Gastric Adenoma Following Gynecologic Surgery

Gastric adenomas are defined as polypoid lesions of neoplastic epithelium in the stomach. They are rare, occurring much less frequently than fundic gland polyps and hyperplastic polyps, and are typically associated with mucosal atrophy and intestinal metaplasia. Gastric adenomas also carry a risk of malignant transformation. We report a case of a 66-year-old woman with a gastric adenoma of the corpus found during a preoperative esophagogastroduodenoscopy before abdominal surgery for an ovarian tumor. The patient demonstrated spontaneous regression of her gastric adenoma 14 months after her initial endoscopy and subsequent hysterectomy with salpingo-oophorectomy without undergoing endoscopic resection or any other intervention. To our knowledge, this is the first well-documented case of spontaneous regression of a gastric adenoma.

Non-equilibrium physics of multi-species assembly applied to fibrils inhibition in biomolecular condensates and growth of online distrust

Self-assembly is a key process in living systems-from the microscopic biological level (e.g. assembly of proteins into fibrils within biomolecular condensates in a human cell) through to the macroscopic societal level (e.g. assembly of humans into common-interest communities across online social media platforms). The components in such systems (e.g. macromolecules, humans) are highly diverse, and so are the self-assembled structures that they form. However, there is no simple theory of how such structures assemble from a multi-species pool of components. Here we provide a very simple model which trades myriad chemical and human details for a transparent analysis, and yields results in good agreement with recent empirical data. It reveals a new inhibitory role for biomolecular condensates in the formation of dangerous amyloid fibrils, as well as a kinetic explanation of why so many diverse distrust movements are now emerging across social media. The nonlinear dependencies that we uncover suggest new real-world control strategies for such multi-species assembly.

Metabolic crosstalk: Extracellular ATP and the tumor microenvironment in cancer progression and therapy

Adenosine 5'-triphosphate (ATP) is a vital element in energy information. It plays a critical role in transmitting signals inside the body, which is necessary for controlling the life activities of all cells, including tumor cells [1]. Its significance extends from intracellular signaling pathways to tumor regression. Purinergic signaling, a form of extracellular paracrine signaling, relies on purine nucleotides. Extracellular ectonucleotidases convert these purine nucleotides to their respective di and mono-phosphate nucleoside forms, contributing significantly to immune biology, cancer biology, and inflammation studies. ATP functions as a mighty damage-linked molecular pattern when released outside the cell, accumulating in inflammatory areas. In the tumor microenvironment (TME), purinergic receptors such as ATP-gated ion channels P2X1-5 and G protein-coupled receptors (GPCR) (P2Y) interact with ATP and other nucleotides, influencing diverse immune cell activities. CD39 and CD73-mediated extracellular ATP degradation contributes to immunosuppression by diminishing ATP-dependent activation and generating adenosine (ADO), potentially hindering antitumor immunity and promoting tumor development. Unraveling the complexities of extracellular ATP (e-ATP) and ADO effects on the TME poses challenges in identifying optimal treatment targets, yet ongoing investigations aim to devise strategies combating e-ATP/ADO-induced immunosuppression, ultimately enhancing anti-tumor immunity. This review explores e-ATP metabolism, its purinergic signaling, and therapeutic strategies targeting associated receptors and enzymes.

Epigenetic regulation of the tumor microenvironment: A leading force driving pancreatic cancer

Dysregulation of the epigenomic landscape of tumor cells has been implicated in the pathogenesis of pancreatic cancer. However, these alterations are not only restricted to neoplastic cells. The behavior of other cell populations in the tumor stroma such as cancer-associated fibroblasts, immune cells, and others are mostly regulated by epigenetic pathways. Here, we present an overview of the main cellular and acellular components of the pancreatic cancer tumor microenvironment and discuss how the epigenetic mechanisms operate at different levels in the stroma to establish a differential gene expression to regulate distinct cellular phenotypes contributing to pancreatic tumorigenesis.

Dissection of pro-tumoral macrophage subtypes and immunosuppressive cells participating in M2 polarization

Alternatively activated macrophage (M2) polarization can result in one of four subtypes based on cytokines and signaling pathways associated with macrophage activation: M2a, M2b, M2c, and M2d macrophages. The majority of M2 subtypes are anti-inflammatory and pro-angiogenic, secreting growth factors (VEGF, PDGF) and matrix metalloproteinases (MMP2, MMP9) which boost tumor growth, metastasis, and invasion. M2-polarized macrophages are associated with immune suppressor cells harboring Myeloid derived suppressor cells, Regulatory T cells (Tregs), Regulatory B cells as well as alternatively activated (N2) neutrophils. Treg cells selectively support the metabolic stability, mitochondrial integrity, and survival rate of M2-like TAMs in an indirect environment. Also, the contribution of Breg cells influences macrophage polarization towards the M2 direction. TAM is activated when TAN levels in the tumor microenvironment are insufficient or vice versa, suggesting that macrophage and its polarization are fine-tuned. Understanding the functions of immune suppressive cells, mediators, and signaling pathways involved with M2 polarization will allow us to identify potential strategies for targeting the TAM repolarization phenotype for innovative immunotherapy approaches. In this review, we have highlighted the critical factors for M2 macrophage polarization, differential cytokine/chemokine profiles of M1 and M2 macrophage subtypes, and other immune cells' impact on the polarization within the immunosuppressive niche.

Expanding horizons in cancer therapy by immunoconjugates targeting tumor microenvironments

Immunoconjugates are promising molecules combining antibodies with different agents, such as toxins, drugs, radionuclides, or cytokines that primarily aim to target tumor cells. However, tumor microenvironment (TME), which comprises a complex network of various cells and molecular cues guiding tumor growth and progression, remains a major challenge for effective cancer therapy. Our review underscores the pivotal role of TME in cancer therapy with immunoconjugates, examining the intricate interactions with TME and recent advancements in TME-targeted immunoconjugates. We explore strategies for targeting TME components, utilizing diverse antibodies such as neutralizing, immunomodulatory, immune checkpoint inhibitors, immunostimulatory, and bispecific antibodies. Additionally, we discuss different immunoconjugates, elucidating their mechanisms of action, advantages, limitations, and applications in cancer immunotherapy. Furthermore, we highlight emerging technologies enhancing the safety and efficacy of immunoconjugates, such as antibody engineering, combination therapies, and nanotechnology. Finally, we summarize current advancements, perspectives, and future developments of TME-targeted immunoconjugates.

Remodeling of tumor microenvironment by extracellular matrix protein 1a differentially regulates ovarian cancer metastasis

We previously reported that extracellular matrix protein 1 isoform a (ECM1a) promotes epithelial ovarian cancer (EOC) through autocrine signaling by binding to cell surface receptors αXβ2. However, the role of ECM1a as a secretory molecule in the tumor microenvironment is rarely reported. In this study, we constructed murine Ecm1-knockout mice and human ECM1a-knockin mice and further generated orthotopic or peritoneal xenograft tumor models to mimic the different metastatic stages of EOC. We show that ECM1a induces oncogenic metastasis of orthotopic xenograft tumors, but inhibits early-metastasis of peritoneal xenograft tumors. ECM1a remodels extracellular matrices (ECM) and promotes remote metastases by recruiting and transforming bone marrow mesenchymal stem cells (BMSCs) into platelet-derived growth factor receptor beta (PDGFRβ+) cancer-associated fibroblasts (CAFs) and facilitating the secretion of angiopoietin-like protein 2 (ANGPTL2). Competing with ECM1a, ANGPTL2 also binds to integrin αX through the P1/P2 peptides, resulting in negative effects on BMSC differentiation. Collectively, this study reveals the dual functions of ECM1a in remodeling of TME during tumor progression, emphasizing the complexity of EOC phenotypic heterogeneity and metastasis.

Fibroblast Stromal Support Model for Predicting Human Papillomavirus-Associated Cancer Drug Responses

Currently, there are no specific antiviral therapeutic approaches targeting Human papillomaviruses (HPVs), which cause around 5% of all human cancers. Specific antiviral reagents are particularly needed for HPV-related oropharyngeal cancers (HPV+OPCs) whose incidence is increasing and for which there are no early diagnostic tools available. We and others have demonstrated that the estrogen receptor alpha (ERalpha) is overexpressed in HPV+OPCs, compared to HPV-negative cancers in this region, and that these elevated levels are associated with an improved disease outcome. Utilizing this HPV+ specific overexpression profile, we previously demonstrated that estrogen attenuates the growth and cell viability of HPV+ keratinocytes and HPV+ cancer cells in vitro. Expansion of this work in vivo failed to replicate this sensitization. The role of stromal support from the tumor microenvironment (TME) has previously been tied to both the HPV lifecycle and in vivo therapeutic responses. Our investigations revealed that in vitro co-culture with fibroblasts attenuated HPV+ specific estrogen growth responses. Continuing to monopolize on the HPV+ specific overexpression of ERalpha, our co-culture models then assessed the suitability of the selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen, and showed growth attenuation in a variety of our models to one or both of these drugs in vitro. Utilization of these SERMs in vivo closely resembled the sensitization predicted by our co-culture models. Therefore, the in vitro fibroblast co-culture model better predicts in vivo responses. We propose that utilization of our co-culture in vitro model can accelerate cancer therapeutic drug discovery.

Translational insights into the hormetic potential of carbon dioxide: from physiological mechanisms to innovative adjunct therapeutic potential for cancer

Background

Carbon dioxide (CO2), traditionally viewed as a mere byproduct of cellular respiration, plays a multifaceted role in human physiology beyond simple elimination through respiration. CO2 may regulate the tumor microenvironment by significantly affecting the release of oxygen (O2) to tissues through the Bohr effect and by modulating blood pH and vasodilation. Previous studies suggest hypercapnia (elevated CO2 levels) might trigger optimized cellular mechanisms with potential therapeutic benefits. The role of CO2 in cellular stress conditions within tumor environments and its impact on O2 utilization offers a new investigative area in oncology.

Objectives

This study aims to explore CO2's role in the tumor environment, particularly how its physiological properties and adaptive responses can influence therapeutic strategies.

Methods

By applying a structured translational approach using the Work Breakdown Structure method, the study divided the analysis into six interconnected work packages to comprehensively analyze the interactions between carbon dioxide and the tumor microenvironment. Methods included systematic literature reviews, data analyses, data integration for identifying critical success factors and exploring extracellular environment modulation. The research used SMART criteria for assessing innovation and the applicability of results.

Results

The research revealed that the human body's adaptability to hypercapnic conditions could potentially inform innovative strategies for manipulating the tumor microenvironment. This could enhance O2 utilization efficiency and manage adaptive responses to cellular stress. The study proposed that carbon dioxide's hormetic potential could induce beneficial responses in the tumor microenvironment, prompting clinical protocols for experimental validation. The research underscored the importance of pH regulation, emphasizing CO2 and carbonic acid's role in modulating metabolic and signaling pathways related to cancer.

Conclusion

The study underscores CO2 as vital to our physiology and suggests potential therapeutic uses within the tumor microenvironment. pH modulation and cellular oxygenation optimization via CO2 manipulation could offer innovative strategies to enhance existing cancer therapies. These findings encourage further exploration of CO2's therapeutic potential. Future research should focus on experimental validation and exploration of clinical applications, emphasizing the need for interdisciplinary and collaborative approaches to tackle current challenges in cancer treatment.

Advancements in computer vision and pathology: Unraveling the potential of artificial intelligence for precision diagnosis and beyond

The integration of computer vision into pathology through slide digitalization represents a transformative leap in the field's evolution. Traditional pathology methods, while reliable, are often time-consuming and susceptible to intra- and interobserver variability. In contrast, computer vision, empowered by artificial intelligence (AI) and machine learning (ML), promises revolutionary changes, offering consistent, reproducible, and objective results with ever-increasing speed and scalability. The applications of advanced algorithms and deep learning architectures like CNNs and U-Nets augment pathologists' diagnostic capabilities, opening new frontiers in automated image analysis. As these technologies mature and integrate into digital pathology workflows, they are poised to provide deeper insights into disease processes, quantify and standardize biomarkers, enhance patient outcomes, and automate routine tasks, reducing pathologists' workload. However, this transformative force calls for cross-disciplinary collaboration between pathologists, computer scientists, and industry innovators to drive research and development. While acknowledging its potential, this chapter addresses the limitations of AI in pathology, encompassing technical, practical, and ethical considerations during development and implementation.

Sentient cells as basic units of tissues, organs and organismal physiology

Cells evolved some 4 billion years ago, and since then the integrity of the structural and functional continuity of cellular life has been maintained via highly conserved and ancient processes of cell reproduction and division. The plasma membrane as well as all the cytoplasmic structures are reproduced and inherited uninterruptedly by each of the two daughter cells resulting from every cell division. Although our understanding of the evolutionary emergence of the very first cells is obscured by the extremely long timeline since that revolutionary event, the generally accepted position is that the de novo formation of cells is not possible; all present cells are products of other prior cells. This essential biological principle was first discovered by Robert Remak and then effectively coined as Omnis Cellula e Cellula (every cell of the cell) by Rudolf Virchow: all currently living cells have direct structural and functional connections to the very first cells. Based on our previous theoretical analysis, all cells are endowed with individual sentient cognition that guides their individual agency, behaviour and evolution. There is a vital consequence of this new sentient and cognitive view of cells: when cells assemble as functional tissue ecologies and organs within multicellular organisms, including plants, animals and humans, these cellular aggregates display derivative versions of aggregate tissue- and organ-specific sentience and consciousness. This innovative view of the evolution and physiology of all currently living organisms supports a singular principle: all organismal physiology is based on cellular physiology that extends from unicellular roots.

Pericytes Are Immunoregulatory Cells in Glioma Genesis and Progression

Vascular co-option is a consequence of the direct interaction between perivascular cells, known as pericytes (PCs), and glioblastoma multiforme (GBM) cells (GBMcs). This process is essential for inducing changes in the pericytes' anti-tumoral and immunoreactive phenotypes. Starting from the initial stages of carcinogenesis in GBM, PCs conditioned by GBMcs undergo proliferation, acquire a pro-tumoral and immunosuppressive phenotype by expressing and secreting immunosuppressive molecules, and significantly hinder the activation of T cells, thereby facilitating tumor growth. Inhibiting the pericyte (PC) conditioning mechanisms in the GBM tumor microenvironment (TME) results in immunological activation and tumor disappearance. This underscores the pivotal role of PCs as a key cell in the TME, responsible for tumor-induced immunosuppression and enabling GBM cells to evade the immune system. Other cells within the TME, such as tumor-associated macrophages (TAMs) and microglia, have also been identified as contributors to this immunomodulation. In this paper, we will review the role of these three cell types in the immunosuppressive properties of the TME. Our conclusion is that the cellular heterogeneity of immunocompetent cells within the TME may lead to the misinterpretation of cellular lineage identification due to different reactive stages and the identification of PCs as TAMs. Consequently, novel therapies could be developed to disrupt GBM-PC interactions and/or PC conditioning through vascular co-option, thereby exposing GBMcs to the immune system.

CD3 and CD20 Expressions and Infiltrating Patterns in Salivary Gland Tumors

Tumor-infiltrating lymphocytes (TILs) represent a subset of immunological constituents within the tumor microenvironment that can influence cancer growth. We retrospectively evaluate the density and pattern of CD3 and CD20 expression in salivary gland tumors and their relation to clinical pathologic parameters. A total of 44 formalin-fixed paraffin-embedded blocks of salivary gland tumors were included. These tumors were stained immunohistochemically with CD3 and CD20. The chi-square test was used to relate immune scoring, intensity, and clinical pathological parameters to different salivary tumors. p-value < 0.05 was considered statistically significant. The intra-tumoral CD3 infiltrating count was high and diffused in (71.4%) of pleomorphic adenomas (PAs) followed by mucoepidermoid carcinomas (MECs) (66.7%). At the same time, adenoid cystic carcinomas (AdCCs) exhibited significantly low infiltration (71.4%) (p = 0.046). The three types of tumors exhibited high tumor-infiltrating counts diffused in peripheral areas with significant differences between malignant tumors (p = 0.047). The intra-tumoral CD20 infiltrating count significantly differed among the tumors (p = 0.002); it was low in all PAs and AdCCs, while MECs showed an equal percentage of expression. However, in the peripheral area, PAs and MECs exhibited significantly (p = 0.007) high infiltrating counts (69.2% and 84.6), and the lowest infiltrating count was predominantly found for AdCCs. The two markers had a significant positive correlation between the mean of CD3 in the intra-tumoral and peripheral regions and CD20 in the peripheral zone across the total samples. In conclusion, the density of CD3 expression is notably higher than CD20 across tumor types. PAs and MECs showed high-density scores, while AdCCs were characterized by low scores. TIL expression was found to be significantly associated with patients' outcomes in the intra-tumoral area.

Extracellular vesicles in neuroblastoma: role in progression, resistance to therapy and diagnostics

Neuroblastoma (NB) is the most common extracranial solid pediatric cancer, and is one of the leading causes of cancer-related deaths in children. Despite the current multi-modal treatment regimens, majority of patients with advanced-stage NBs develop therapeutic resistance and relapse, leading to poor disease outcomes. There is a large body of knowledge on pathophysiological role of small extracellular vesicles (EVs) in progression and metastasis of multiple cancer types, however, the importance of EVs in NB was until recently not well understood. Studies emerging in the last few years have demonstrated the involvement of EVs in various aspects of NB pathogenesis. In this review we summarize these recent findings and advances on the role EVs play in NB progression, such as tumor growth, metastasis and therapeutic resistance, that could be helpful for future investigations in NB EV research. We also discuss different strategies for therapeutic targeting of NB-EVs as well as utilization of NB-EVs as potential biomarkers.

Exosome as a crucial communicator between tumor microenvironment and gastric cancer (Review)

Gastric cancer is one of the most common malignancies and has relatively high morbidity and mortality rates. Exosomes are nanoscale extracellular vesicles that originate from a diverse array of cells and may be found throughout various bodily fluids. These vesicles are endogenous nanocarriers in their natural state with the unique ability to transport lipids, proteins, DNA and RNA. Exosomes contain DNA, RNA, proteins, lipids and other bioactive components that have crucial roles in the transmission of information and regulation of cell activities in gastric cancer. This paper begins with an exploration of the composition, formation and release mechanisms of exosomes. Subsequently, the role of exosomes in the tumor microenvironment is reviewed in terms of the immune cell population, nonimmune cell population and other factors. Finally, the current status and challenges of exosome‑based research on the progression, diagnosis and therapeutic methods of gastric cancer are summarized. This holistic review offers insight that may guide future research directions for exosomes and potentially pave the way for novel therapeutic interventions in the management of gastric cancer.

Manipulating the tumor immune microenvironment to improve cancer immunotherapy: IGF1R, a promising target

Cancer immunotherapy has made impressive advances in improving the outcome of patients affected by malignant diseases. Nonetheless, some limitations still need to be tackled to more efficiently and safely treat patients, in particular for those affected by solid tumors. One of the limitations is related to the immunosuppressive tumor microenvironment (TME), which impairs anti-tumor immunity. Efforts to identify targets able to turn the TME into a milieu more auspicious to current immuno-oncotherapy is a real challenge due to the high redundancy of the mechanisms involved. However, the insulin-like growth factor 1 receptor (IGF1R), an attractive drug target for cancer therapy, is emerging as an important immunomodulator and regulator of key immune cell functions. Here, after briefly summarizing the IGF1R signaling pathway in cancer, we review its role in regulating immune cells function and activity, and discuss IGF1R as a promising target to improve anti-cancer immunotherapy.

E2F1 mediates competition, proliferation and response to cisplatin in cohabitating resistant and sensitive ovarian cancer cells

Background

Tumor heterogeneity is one of the key factors leading to chemo-resistance relapse. It remains unknown how resistant cancer cells influence sensitive cells during cohabitation and growth within a heterogenous tumors. The goal of our study was to identify driving factors that mediate the interactions between resistant and sensitive cancer cells and to determine the effects of cohabitation on both phenotypes.

Methods

We used isogenic ovarian cancer (OC) cell lines pairs, sensitive and resistant to platinum: OVCAR5 vs. OVCAR5 CisR and PE01 vs. PE04, respectively, to perform long term direct culture and to study the phenotypical changes of the interaction of these cells.

Results

Long term direct co-culture of sensitive and resistant OC cells promoted proliferation (p < 0.001) of sensitive cells and increased the proportion of cells in the G1 and S cell cycle phase in both PE01 and OVCAR5 cells. Direct co-culture led to a decrease in the IC50 to platinum in the cisplatin-sensitive cells (5.92 µM to 2.79 µM for PE01, and from 2.05 µM to 1.51 µM for OVCAR5). RNAseq analysis of co-cultured cells showed enrichment of Cell Cycle Control, Cyclins and Cell Cycle Regulation pathways. The transcription factor E2F1 was predicted as the main effector responsible for the transcriptomic changes in sensitive cells. Western blot and qRT-PCR confirmed upregulation of E2F1 in co-cultured vs monoculture. Furthermore, an E2F1 inhibitor reverted the increase in proliferation rate induced by co-culture to baseline levels.

Conclusion

Our data suggest that long term cohabitation of chemo-sensitive and -resistant cancer cells drive sensitive cells to a higher proliferative state, more responsive to platinum. Our results reveal an unexpected effect caused by direct interactions between cancer cells with different proliferative rates and levels of platinum resistance, modelling competition between cells in heterogeneous tumors.

The nexus of natural killer cells and melanoma tumor microenvironment: crosstalk, chemotherapeutic potential, and innovative NK cell-based therapeutic strategies

The metastasis of melanoma cells to regional lymph nodes and distant sites is an important contributor to cancer-related morbidity and mortality among patients with melanoma. This intricate process entails dynamic interactions involving tumor cells, cellular constituents, and non-cellular elements within the microenvironment. Moreover, both microenvironmental and systemic factors regulate the metastatic progression. Central to immunosurveillance for tumor cells are natural killer (NK) cells, prominent effectors of the innate immune system with potent antitumor and antimetastatic capabilities. Recognizing their pivotal role, contemporary immunotherapeutic strategies are actively integrating NK cells to combat metastatic tumors. Thus, a meticulous exploration of the interplay between metastatic melanoma and NK cells along the metastatic cascade is important. Given the critical involvement of NK cells within the melanoma tumor microenvironment, this comprehensive review illuminates the intricate relationship between components of the melanoma tumor microenvironment and NK cells, delineating their multifaceted roles. By shedding light on these critical aspects, this review advocates for a deeper understanding of NK cell dynamics within the melanoma context, driving forward transformative strategies to combat this cancer.

Tumor-associated macrophages: an effective player of the tumor microenvironment

Cancer progression is primarily caused by interactions between transformed cells and the components of the tumor microenvironment (TME). TAMs (tumor-associated macrophages) make up the majority of the invading immune components, which are further categorized as anti-tumor M1 and pro-tumor M2 subtypes. While M1 is known to have anti-cancer properties, M2 is recognized to extend a protective role to the tumor. As a result, the tumor manipulates the TME in such a way that it induces macrophage infiltration and M1 to M2 switching bias to secure its survival. This M2-TAM bias in the TME promotes cancer cell proliferation, neoangiogenesis, lymphangiogenesis, epithelial-to-mesenchymal transition, matrix remodeling for metastatic support, and TME manipulation to an immunosuppressive state. TAMs additionally promote the emergence of cancer stem cells (CSCs), which are known for their ability to originate, metastasize, and relapse into tumors. CSCs also help M2-TAM by revealing immune escape and survival strategies during the initiation and relapse phases. This review describes the reasons for immunotherapy failure and, thereby, devises better strategies to impair the tumor-TAM crosstalk. This study will shed light on the understudied TAM-mediated tumor progression and address the much-needed holistic approach to anti-cancer therapy, which encompasses targeting cancer cells, CSCs, and TAMs all at the same time.

Investigating Ecological Interactions in the Tumor Microenvironment using Joint Species Distribution Models for Point Patterns

The tumor microenvironment (TME) is a complex and dynamic ecosystem that involves interactions between different cell types, such as cancer cells, immune cells, and stromal cells. These interactions can promote or inhibit tumor growth and affect response to therapy. Multitype Gibbs point process (MGPP) models are statistical models used to study the spatial distribution and interaction of different types of objects, such as the distribution of cell types in a tissue sample. Such models are potentially useful for investigating the spatial relationships between different cell types in the tumor microenvironment, but so far studies of the TME using cell-resolution imaging have been largely limited to spatial descriptive statistics. However, MGPP models have many advantages over descriptive statistics, such as uncertainty quantification, incorporation of multiple covariates and the ability to make predictions. In this paper, we describe and apply a previously developed MGPP method, the saturated pairwise interaction Gibbs point process model , to a publicly available multiplexed imaging dataset obtained from colorectal cancer patients. Importantly, we show how these methods can be used as joint species distribution models (JSDMs) to precisely frame and answer many relevant questions related to the ecology of the tumor microenvironment.

Non-Coding RNAs: Foes or Friends for Targeting Tumor Microenvironment

Non-coding RNAs (ncRNAs) are a group of molecules critical for cell development and growth regulation. They are key regulators of important cellular pathways in the tumor microenvironment. To analyze ncRNAs in the tumor microenvironment, the use of RNA sequencing technology has revolutionized the field. The advancement of this technique has broadened our understanding of the molecular biology of cancer, presenting abundant possibilities for the exploration of novel biomarkers for cancer treatment. In this review, we will summarize recent achievements in understanding the complex role of ncRNA in the tumor microenvironment, we will report the latest studies on the tumor microenvironment using RNA sequencing, and we will discuss the potential use of ncRNAs as therapeutics for the treatment of cancer.

Modulation of Radiation Doses and Chimeric Antigen Receptor T Cells: A Promising New Weapon in Solid Tumors-A Narrative Review

Tumor behavior is determined by its interaction with the tumor microenvironment (TME). Chimeric antigen receptor (CART) cell therapy represents a new form of cellular immunotherapy (IT). Immune cells present a different sensitivity to radiation therapy (RT). RT can affect tumor cells both modifying the TME and inducing DNA damage, with different effects depending on the low and high doses delivered, and can favor the expression of CART cells. CART cells are patients' T cells genetically engineered to recognize surface structure and to eradicate cancer cells. High-dose radiation therapy (HDRT, >10-20 Gy/fractions) converts immunologically "cold" tumors into "hot" ones by inducing necrosis and massive inflammation and death. LDRT (low-dose radiation therapy, >5-10 Gy/fractions) increases the expansion of CART cells and leads to non-immunogenetic death. An innovative approach, defined as the LATTICE technique, combines a high dose in higher FDG- uptake areas and a low dose to the tumor periphery. The association of RT and immune checkpoint inhibitors increases tumor immunogenicity and immune response both in irradiated and non-irradiated sites. The aim of this narrative review is to clarify the knowledge, to date, on CART cell therapy and its possible association with radiation therapy in solid tumors.

Cancer Bioenergetics and Tumor Microenvironments-Enhancing Chemotherapeutics and Targeting Resistant Niches through Nanosystems

Cancer is an impending bottleneck in the advanced scientific workflow to achieve diagnostic, prognostic, and therapeutic success. Most cancers are refractory to conventional diagnostic and chemotherapeutics due to their limited targetability, specificity, solubility, and side effects. The inherent ability of each cancer to evolve through various genetic and epigenetic transformations and metabolic reprogramming underlies therapeutic limitations. Though tumor microenvironments (TMEs) are quite well understood in some cancers, each microenvironment differs from the other in internal perturbations and metabolic skew thereby impeding the development of appropriate diagnostics, drugs, vaccines, and therapies. Cancer associated bioenergetics modulations regulate TME, angiogenesis, immune evasion, generation of resistant niches and tumor progression, and a thorough understanding is crucial to the development of metabolic therapies. However, this remains a missing element in cancer theranostics, necessitating the development of modalities that can be adapted for targetability, diagnostics and therapeutics. In this challenging scenario, nanomaterials are modular platforms for understanding TME and achieving successful theranostics. Several nanoscale particles have been successfully researched in animal models, quite a few have reached clinical trials, and some have achieved clinical success. Nanoparticles exhibit an intrinsic capability to interact with diverse biomolecules and modulate their functions. Furthermore, nanoparticles can be functionalized with receptors, modulators, and drugs to facilitate specific targeting with reduced toxicity. This review discusses the current understanding of different theranostic nanosystems, their synthesis, functionalization, and targetability for therapeutic modulation of bioenergetics, and metabolic reprogramming of the cancer microenvironment. We highlight the potential of nanosystems for enhanced chemotherapeutic success emphasizing the questions that remain unanswered.

Preliminary study of some of the main intratumor stroma components in gastric carcinomas

AIM

The relationship between stromal compartment and tumor behavior in gastric carcinomas is still poorly understood and defined. Therefore, the authors started, with this preliminary study, an analysis of stromal compartment morphology and behavior in tumors arising from gastric mucosa epithelium.

MATERIALS AND METHODS

The study group included 75 patients operated for gastric carcinoma. Five parameters describing tumor morphology and behavior and eight parameters describing tumor stroma (TS) morphology were assessed. Histopathological examination included six serial sections of formalin-fixed, paraffin-embedded tumor tissue samples, stained with three classical stains and three antibodies to reveal the different parameters. For data comparison, Pearson's correlation test and the chi-squared (χ²) correlation test were used.

RESULTS

Studied tumors were, usually, infiltrating, undifferentiated∕diffuse type, invasive in subserous spaces and with a Ki67 index higher than 20%. Collagen fibers dominated the stromal components, with a predominance of mature type and an average fibrillary index of 2.7. The whole amount of stromal components accounted for around one quarter of the tumor area. Mature collagen fibers were in opposite correlation with their immature counterpart, and both were in opposite correlation with smooth muscle fibers and expressed an opposite trend of correlation with components of vascular compartment. The whole amount of stromal components had divergent behavior with the components of vascular compartment. The latter expressed generally an opposite trend of correlation with individual fibrillary stromal components. We found only isolated relationships statistically significant between stromal components and tumor characteristics.

CONCLUSIONS

TS is in a continuous remodeling process in relation to the evolution of tumor parenchyma, tumors less differentiated proving to have an immature stroma, with newly formed collagen fibers and higher vascular density. Further studies are required.

Molecular Mechanisms of Tumor Cell Stemness Modulation during Formation of Spheroids

Cancer stem cells (CSCs), their properties and interaction with microenvironment are of interest in modern medicine and biology. There are many studies on the emergence of CSCs and their involvement in tumor pathogenesis. The most important property inherent to CSCs is their stemness. Stemness combines ability of the cell to maintain its pluripotency, give rise to differentiated cells, and interact with environment to maintain a balance between dormancy, proliferation, and regeneration. While adult stem cells exhibit these properties by participating in tissue homeostasis, CSCs behave as their malignant equivalents. High tumor resistance to therapy, ability to differentiate, activate angiogenesis and metastasis arise precisely due to the stemness of CSCs. These cells can be used as a target for therapy of different types of cancer. Laboratory models are needed to study cancer biology and find new therapeutic strategies. A promising direction is three-dimensional tumor models or spheroids. Such models exhibit properties resembling stemness in a natural tumor. By modifying spheroids, it becomes possible to investigate the effect of therapy on CSCs, thus contributing to the development of anti-tumor drug test systems. The review examines the niche of CSCs, the possibility of their study using three-dimensional spheroids, and existing markers for assessing stemness of CSCs.

The Role of Pathogenesis Associated with the Tumor Microclimate in the Differential Diagnosis of Uterine Myocytic Tumors

Myocytic tumors of the uterus present vast morphological heterogeneity, which makes differential diagnosis between the different entities necessary. This study aims to enrich the existing data and highlight new potential therapeutic targets regarding aspects related to the pathogenic process and the tumor microenvironment in order to improve the quality of life of women. We performed a 5-year retrospective study, including particular cases of uterine myocyte tumors. Immunohistochemical analyses of pathogenic pathways (p53, RB1, and PTEN) and tumor microclimate using markers (CD8, PD-L1, and CD105), as well as genetic testing of the PTEN gene, were performed. The data were statistically analyzed using the appropriate parameters. In cases of atypical leiomyoma, a significant association was observed between PTEN deletion and an increased number of PD-L1+ T lymphocytes. For malignant lesions and STUMP, PTEN deletion was associated with the advanced disease stage. Advanced cases were also associated with an increased mean CD8+ T cell count. An increased number of lymphocytes was associated with an increased percentage of RB1+ nuclei. The study corroborated clinical and histogenetic data, highlighting the importance of the differential diagnosis of these tumors to improve the management of patients and increase their quality of life.

Immunotherapy Plus Radiotherapy for the Treatment of Sarcomas: Is There a Potential for Synergism?

Soft tissue sarcoma (STS) is a highly heterogeneous malignant tumor derived from mesenchymal tissue. Advanced STS has a poor response to the current anti-cancer therapeutic options, with a median overall survival of less than two years. Thus, new and more effective treatment methods for STS are needed. Increasing evidence has shown that immunotherapy and radiotherapy have synergistic therapeutic effects against malignant tumors. In addition, immunoradiotherapy has yielded positive results in clinical trials for various cancers. In this review, we discuss the synergistic mechanism of immunoradiotherapy in cancer treatment and the application of this combined regimen for the treatment of several cancers. In addition, we summarize the existing evidence on the use of immunoradiotherapy for the treatment of STS and the relevant clinical trials that are currently ongoing. Furthermore, we identify challenges in the use of immunoradiotherapy for the treatment of sarcomas and propose methods and precautions for overcoming these challenges. Lastly, we propose clinical research strategies and future research directions to help in the research and treatment of STS.

The interactions of docetaxel with tumor microenvironment

There are several interactions within the tumor microenvironment (TME) that affect the response of cancer cells to therapy. There are also a large number of cells and secretions in TME that increase resistance to therapy. Following the release of immunosuppressive, pro-angiogenic, and metastatic molecules by certain cells such as tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), and cancer cells, immune evasion, angiogenesis, and metastasis may be induced. However, natural killer (NK) cells and cytotoxic CD8 + T lymphocytes (CTLs) can responsively release anticancer molecules. In addition, anticancer drugs can modulate these cells and their interactions in favor of either cancer resistance or therapy. Docetaxel belongs to taxanes, a class of anti-tumor drugs, which acts through the polymerization of tubulin and the induction of cell cycle arrest. Also, it has been revealed that taxanes including docetaxel affect cancer cells and the other cells within TME through some other mechanisms such as modulation of immune system responses, angiogenesis, and metastasis. In this paper, we explain the basic mechanisms of docetaxel interactions with malignant cells. Besides, we review the diverse effects of docetaxel on TME and cancer cells in consequence. Lastly, the modulatory effects of docetaxel alone or in conjunction with other anticancer agents on anti-tumor immunity, cancer cell resistance, angiogenesis, and metastasis will be discussed.

Targeting Tumor Microenvironment Akt Signaling Represents a Potential Therapeutic Strategy for Aggressive Thyroid Cancer

Effects of the tumor microenvironment (TME) stromal cells on progression in thyroid cancer are largely unexplored. Elucidating the effects and underlying mechanisms may facilitate the development of targeting therapy for aggressive cases of this disease. In this study, we investigated the impact of TME stromal cells on cancer stem-like cells (CSCs) in patient-relevant contexts where applying in vitro assays and xenograft models uncovered contributions of TME stromal cells to thyroid cancer progression. We found that TME stromal cells can enhance CSC self-renewal and invasiveness mainly via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. The disruption of Akt signaling could diminish the impact of TME stromal cells on CSC aggressiveness in vitro and reduce CSC tumorigenesis and metastasis in xenografts. Notably, disrupting Akt signaling did not cause detectable alterations in tumor histology and gene expression of major stromal components while it produced therapeutic benefits. In addition, using a clinical cohort, we discovered that papillary thyroid carcinomas with lymph node metastasis are more likely to have elevated Akt signaling compared with the ones without metastasis, suggesting the relevance of Akt-targeting. Overall, our results identify PI3K/Akt pathway-engaged contributions of TME stromal cells to thyroid tumor disease progression, illuminating TME Akt signaling as a therapeutic target in aggressive thyroid cancer.

The Overview of Perspectives of Clinical Application of Liquid Biopsy in Non-Small-Cell Lung Cancer

The standard diagnostics procedure for non-small-cell lung cancer (NSCLC) requires a pathological evaluation of tissue samples obtained by surgery or biopsy, which are considered invasive sampling procedures. Due to this fact, re-sampling of the primary tumor at the moment of progression is limited and depends on the patient's condition, even if it could reveal a mechanism of resistance to applied therapy. Recently, many studies have indicated that liquid biopsy could be provided for the noninvasive management of NSCLC patients who receive molecularly targeted therapies or immunotherapy. The liquid biopsy of neoplastic patients harbors small fragments of circulating-free DNA (cfDNA) and cell-free RNA (cfRNA) secreted to the circulation from normal cells, as well as a subset of tumor-derived circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA). In NSCLC patients, a longitudinal assessment of genetic alterations in "druggable" genes in liquid biopsy might improve the follow-up of treatment efficacy and allow for the detection of an early progression before it is detectable in computed tomography or a clinical image. However, a liquid biopsy may be used to determine a variety of relevant molecular or genetic information for understanding tumor biology and its evolutionary trajectories. Thus, liquid biopsy is currently associated with greater hope for common diagnostic and clinical applications. In this review, we would like to highlight diagnostic challenges in the application of liquid biopsy into the clinical routine and indicate its implications on the metastatic spread of NSCLC or monitoring of personalized treatment regimens.