Research

Open AccessArticle

Lung Micrometastases Display ECM Depletion and Softening While Macrometastases Are 30-Fold Stiffer and Enriched in Fibronectin

by

Maria Narciso

,

África Martínez

,

Constança Júnior

,

Natalia Díaz-Valdivia

,

,

,

,

,

,

,

and

Cancers 2023, 15(8), 2404; https://doi.org/10.3390/cancers15082404 - 21 Apr 2023

Viewed by 1395

Abstract

Mechanical changes in tumors have long been linked to increased malignancy and therapy resistance and attributed to mechanical changes in the tumor extracellular matrix (ECM). However, to the best of our knowledge, there have been no mechanical studies on decellularized tumors. Here, we [...] Read more.

Mechanical changes in tumors have long been linked to increased malignancy and therapy resistance and attributed to mechanical changes in the tumor extracellular matrix (ECM). However, to the best of our knowledge, there have been no mechanical studies on decellularized tumors. Here, we studied the biochemical and mechanical progression of the tumor ECM in two models of lung metastases: lung carcinoma (CAR) and melanoma (MEL). We decellularized the metastatic lung sections, measured the micromechanics of the tumor ECM, and stained the sections for ECM proteins, proliferation, and cell death markers. The same methodology was applied to MEL mice treated with the clinically approved anti-fibrotic drug nintedanib. When compared to healthy ECM (~0.40 kPa), CAR and MEL lung macrometastases produced a highly dense and stiff ECM (1.79 ± 1.32 kPa, CAR and 6.39 ± 3.37 kPa, MEL). Fibronectin was overexpressed from the early stages (~118%) to developed macrometastases (~260%) in both models. Surprisingly, nintedanib caused a 4-fold increase in ECM-occupied tumor area (5.1 ± 1.6% to 18.6 ± 8.9%) and a 2-fold in-crease in ECM stiffness (6.39 ± 3.37 kPa to 12.35 ± 5.74 kPa). This increase in stiffness strongly correlated with an increase in necrosis, which reveals a potential link between tumor hypoxia and ECM deposition and stiffness. Our findings highlight fibronectin and tumor ECM mechanics as attractive targets in cancer therapy and support the need to identify new anti-fibrotic drugs to abrogate aberrant ECM mechanics in metastases. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Open AccessArticle

The KRAS-Mutant Consensus Molecular Subtype 3 Reveals an Immunosuppressive Tumor Microenvironment in Colorectal Cancer

Cancers 2023, 15(4), 1098; https://doi.org/10.3390/cancers15041098 - 08 Feb 2023

Cited by 1 | Viewed by 1342

Abstract

Colorectal cancers (CRC) with KRAS mutations (KRAS^mut) are frequently included in consensus molecular subtype 3 (CMS3) with profound metabolic deregulation. We explored the transcriptomic impact of KRAS^mut, focusing on the tumor microenvironment (TME) and pathways beyond metabolic deregulation. [...] Read more.

Colorectal cancers (CRC) with KRAS mutations (KRAS^mut) are frequently included in consensus molecular subtype 3 (CMS3) with profound metabolic deregulation. We explored the transcriptomic impact of KRAS^mut, focusing on the tumor microenvironment (TME) and pathways beyond metabolic deregulation. The status of KRAS^mut in patients with CRC was investigated and overall survival (OS) was compared with wild-type KRAS (KRAS^wt). Next, we identified CMS, and further investigated differentially expressed genes (DEG) of KRAS^mut and distinctive pathways. Lastly, we used spatially resolved gene expression profiling to define the effect of KRAS^mut in the TME regions of CMS3-classified CRC tissues. CRC patients with KRAS^mut were mainly enriched in CMS3. Their specific enrichments of immune gene signatures in immunosuppressive TME were associated with worse OS. Activation of TGFβ signaling by KRAS^mut was related to reduced pro-inflammatory and cytokine gene signatures, leading to suppression of immune infiltration. Digital spatial profiling in TME regions of KRAS^mut CMS3-classified tissues suggested up-regulated genes, CD40, CTLA4, ARG1, STAT3, IDO, and CD274, that could be characteristic of immune suppression in TME. This study may help to depict the complex transcriptomic profile of KRAS^mut in immunosuppressive TME. Future studies and clinical trials in CRC patients with KRAS^mut should consider these transcriptional landscapes. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Open AccessArticle

Identification and Characterization of Cancer-Associated Fibroblast Subpopulations in Lung Adenocarcinoma

by

,

,

,

,

,

,

,

,

,

,

,

and

Cancers 2022, 14(14), 3486; https://doi.org/10.3390/cancers14143486 - 18 Jul 2022

Cited by 4 | Viewed by 2265

Abstract

Cancer-associated fibroblasts (CAFs) reside within the tumor microenvironment, facilitating cancer progression and metastasis via direct and indirect interactions with cancer cells and other stromal cell types. CAFs are composed of heterogeneous subpopulations of activated fibroblasts, including myofibroblastic, inflammatory, and immunosuppressive CAFs. In this [...] Read more.

Cancer-associated fibroblasts (CAFs) reside within the tumor microenvironment, facilitating cancer progression and metastasis via direct and indirect interactions with cancer cells and other stromal cell types. CAFs are composed of heterogeneous subpopulations of activated fibroblasts, including myofibroblastic, inflammatory, and immunosuppressive CAFs. In this study, we sought to identify subpopulations of CAFs isolated from human lung adenocarcinomas and describe their transcriptomic and functional characteristics through single-cell RNA sequencing (scRNA-seq) and subsequent bioinformatics analyses. Cell trajectory analysis of combined total and THY1 + CAFs revealed two branching points with five distinct branches. Based on Gene Ontology analysis, we denoted Branch 1 as “immunosuppressive”, Branch 2 as “neoantigen presenting”, Branch 4 as “myofibroblastic”, and Branch 5 as “proliferative” CAFs. We selected representative branch-specific markers and measured their expression levels in total and THY1 + CAFs. We also investigated the effects of these markers on CAF activity under coculture with lung cancer cells. This study describes novel subpopulations of CAFs in lung adenocarcinoma, highlighting their potential value as therapeutic targets. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Open AccessArticle

Single-Cell Proteomic Analysis Dissects the Complexity of Tumor Microenvironment in Muscle Invasive Bladder Cancer

by

,

,

,

,

,

,

,

,

,

,

,

and

Cancers 2021, 13(21), 5440; https://doi.org/10.3390/cancers13215440 - 29 Oct 2021

Cited by 7 | Viewed by 2529

Abstract

Muscle invasive bladder cancer (MIBC) is a malignancy with considerable heterogeneity. The MIBC tumor microenvironment (TME) is highly complex, comprising diverse phenotypes and spatial architectures. The complexity of the MIBC TME must be characterized to provide potential targets for precision therapy. Herein, an [...] Read more.

Muscle invasive bladder cancer (MIBC) is a malignancy with considerable heterogeneity. The MIBC tumor microenvironment (TME) is highly complex, comprising diverse phenotypes and spatial architectures. The complexity of the MIBC TME must be characterized to provide potential targets for precision therapy. Herein, an integrated combination of mass cytometry and imaging mass cytometry was used to analyze tumor cells, immune cells, and TME spatial characteristics of 44 MIBC patients. We detected tumor and immune cell clusters with abnormal phenotypes. In particular, we identified a previously overlooked cancer stem-like cell cluster (ALDH⁺PD-L1⁺ER-β⁻) that was strongly associated with poor prognosis. We elucidated the different spatial architectures of immune cells (excluded, infiltrated, and deserted) and tumor-associated collagens (curved, stretched, directionally distributed, and chaotic) in the MIBC TME. The present study is the first to provide in-depth insight into the complexity of the MIBC TME at the single-cell level. Our results will improve the general understanding of the heterogeneous characteristics of MIBC, potentially facilitating patient stratification and personalized therapy. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Open AccessFeature PaperArticle

EphB6 Regulates TFEB-Lysosomal Pathway and Survival of Disseminated Indolent Breast Cancer Cells

by

,

,

,

,

,

,

,

,

,

and

Cancers 2021, 13(5), 1079; https://doi.org/10.3390/cancers13051079 - 03 Mar 2021

Cited by 8 | Viewed by 3460

Abstract

Late relapse of disseminated cancer cells is a common feature of breast and prostate tumors. Several intrinsic and extrinsic factors have been shown to affect quiescence and reawakening of disseminated dormant cancer cells (DDCCs); however, the signals and processes sustaining the survival of [...] Read more.

Late relapse of disseminated cancer cells is a common feature of breast and prostate tumors. Several intrinsic and extrinsic factors have been shown to affect quiescence and reawakening of disseminated dormant cancer cells (DDCCs); however, the signals and processes sustaining the survival of DDCCs in a foreign environment are still poorly understood. We have recently shown that crosstalk with lung epithelial cells promotes survival of DDCCs of estrogen receptor-positive (ER+) breast tumors. By using a lung organotypic system and in vivo dissemination assays, here we show that the TFEB-lysosomal axis is activated in DDCCs and that it is modulated by the pro-survival ephrin receptor EphB6. TFEB lysosomal direct targets are enriched in DDCCs in vivo and correlate with relapse in ER+ breast cancer patients. Direct coculture of DDCCs with alveolar type I-like lung epithelial cells and dissemination in the lung drive lysosomal accumulation and EphB6 induction. EphB6 contributes to survival, TFEB transcriptional activity, and lysosome formation in DDCCs in vitro and in vivo. Furthermore, signaling from EphB6 promotes the proliferation of surrounding lung parenchymal cells in vivo. Our data provide evidence that EphB6 is a key factor in the crosstalk between disseminated dormant cancer cells and the lung parenchyma and that the TFEB-lysosomal pathway plays an important role in the persistence of DDCCs. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Review

Jump to: Research, Other

Open AccessReview

Hypoxia as a Modulator of Inflammation and Immune Response in Cancer

by

Rosa A. Castillo-Rodríguez

,

Cristina Trejo-Solís

,

Alfredo Cabrera-Cano

,

Saúl Gómez-Manzo

and

Víctor Manuel Dávila-Borja

Cancers 2022, 14(9), 2291; https://doi.org/10.3390/cancers14092291 - 04 May 2022

Cited by 10 | Viewed by 2670

Abstract

A clear association between hypoxia and cancer has heretofore been established; however, it has not been completely developed. In this sense, the understanding of the tumoral microenvironment is critical to dissect the complexity of cancer, including the reduction in oxygen distribution inside the [...] Read more.

A clear association between hypoxia and cancer has heretofore been established; however, it has not been completely developed. In this sense, the understanding of the tumoral microenvironment is critical to dissect the complexity of cancer, including the reduction in oxygen distribution inside the tumoral mass, defined as tumoral hypoxia. Moreover, hypoxia not only influences the tumoral cells but also the surrounding cells, including those related to the inflammatory processes. In this review, we analyze the participation of HIF, NF-κB, and STAT signaling pathways as the main components that interconnect hypoxia and immune response and how they modulate tumoral growth. In addition, we closely examine the participation of the immune cells and how they are affected by hypoxia, the effects of the progression of cancer, and some innovative applications that take advantage of this knowledge, to suggest potential therapies. Therefore, we contribute to the understanding of the complexity of cancer to propose innovative therapeutic strategies in the future. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Graphical abstract

Open AccessReview

Cytokine-Induced Senescence in the Tumor Microenvironment and Its Effects on Anti-Tumor Immune Responses

by

Maximilian Rentschler

,

Heidi Braumüller

,

Priscilla S. Briquez

and

Thomas Wieder

Cancers 2022, 14(6), 1364; https://doi.org/10.3390/cancers14061364 - 08 Mar 2022

Cited by 12 | Viewed by 2317

Abstract

In contrast to surgical excision, chemotherapy or radiation therapy, immune checkpoint blockade therapies primarily influence cells in the tumor microenvironment, especially the tumor-associated lymphocytes and antigen-presenting cells. Besides complete remission of tumor lesions, in some patients, early tumor regression is followed by a [...] Read more.

In contrast to surgical excision, chemotherapy or radiation therapy, immune checkpoint blockade therapies primarily influence cells in the tumor microenvironment, especially the tumor-associated lymphocytes and antigen-presenting cells. Besides complete remission of tumor lesions, in some patients, early tumor regression is followed by a consolidation phase where residing tumors remain dormant. Whereas the cytotoxic mechanisms of the regression phase (i.e., apoptosis, necrosis, necroptosis, and immune cell-mediated cell death) have been extensively described, the mechanisms underlying the dormant state are still a matter of debate. Here, we propose immune-mediated induction of senescence in cancers as one important player. Senescence can be achieved by tumor-associated antigen-specific T helper 1 cells, cytokines or antibodies targeting immune checkpoints. This concept differs from cytotoxic treatment, which often targets the genetic makeup of cancer cells. The immune system’s ability to establish “defensive walls” around tumors also places the tumor microenvironment into the fight against cancer. Those “defensive walls” isolate the tumor cells instead of increasing the selective pressure. They also keep the tumor cells in a non-proliferating state, thereby correcting the derailed tissue homeostasis. In conclusion, strengthening the senescence surveillance of tumors by the immune cells of the microenvironment is a future goal to dampen this life-threatening disease. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Open AccessReview

The Neglected Liaison: Targeting Cancer Cell Metabolic Reprogramming Modifies the Composition of Non-Malignant Populations of the Tumor Microenvironment

by

Maria Iorio

,

Nikkitha Umesh Ganesh

,

,

,

and

Cancers 2021, 13(21), 5447; https://doi.org/10.3390/cancers13215447 - 29 Oct 2021

Cited by 3 | Viewed by 2038

Abstract

Metabolic reprogramming is a well-known hallmark of cancer, whereby the development of drugs that target cancer cell metabolism is gaining momentum. However, when establishing preclinical studies and clinical trials, it is often neglected that a tumor mass is a complex system in which [...] Read more.

Metabolic reprogramming is a well-known hallmark of cancer, whereby the development of drugs that target cancer cell metabolism is gaining momentum. However, when establishing preclinical studies and clinical trials, it is often neglected that a tumor mass is a complex system in which cancer cells coexist and interact with several types of microenvironment populations, including endothelial cells, fibroblasts and immune cells. We are just starting to understand how such populations are affected by the metabolic changes occurring in a transformed cell and little is known about the impact of metabolism-targeting drugs on the non-malignant tumor components. Here we provide a general overview of the links between cancer cell metabolism and tumor microenvironment (TME), particularly focusing on the emerging literature reporting TME-specific effects of metabolic therapies. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Other

Jump to: Research, Review

Open AccessBrief Report

A Lung Organotypic Coculture Reveals a Role for TFEB-Lysosomal Axis in the Survival of Disseminated Dormant Cancer Cells

by

,

,

,

,

,

and

Cancers 2021, 13(5), 1007; https://doi.org/10.3390/cancers13051007 - 28 Feb 2021

Cited by 4 | Viewed by 2253

Abstract

(1) Background: metastatic relapse following a prolonged period of disease-free survival is a common cause of mortality for many cancer patients. Disseminated dormant cancer cells (DDCCs) lie below the radar before waking up years, or even decades, after the removal of the primary [...] Read more.

(1) Background: metastatic relapse following a prolonged period of disease-free survival is a common cause of mortality for many cancer patients. Disseminated dormant cancer cells (DDCCs) lie below the radar before waking up years, or even decades, after the removal of the primary tumor. This implies that they are able to survive in a latent state in a foreign environment for an extended period of time supported by intrinsic and extrinsic factors still to be elucidated. (2) Methods: we employed a coculture of DDCCs with lung epithelial cells together with RNA sequencing analysis to understand the overlap in gene transcription between in vivo and cocultured DDCCs. (3) Results: we found a significant overlap between the processes activated in DDCCs from lungs and in the coculture, as well as in alveolar type I cells in vivo and in coculture. We identified the transcription factor EB (TFEB)-lysosomal axis as a relevant process activated in DDCCs upon dissemination to the lung and confirmed the results in our lung coculture. Interestingly, breast cancer patients with a higher expression of TFEB targets show increased likelihood of developing relapses. (4) Conclusions: we propose that lysosomal accumulation following TFEB activation is an important feature of breast cancer DDCCs that might be exploited for future therapeutic interventions. Full article

(This article belongs to the Special Issue Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Special Issue "Tumor Microenvironment: A Key Piece in the Puzzle of Cancer Heterogeneity"

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI