Aberrant type I and type III collagen gene expression in human breast cancer in vivo

Delivery of miR-29a improves the permeability of cisplatin by downregulating collagen I expression

In the clinical setting, chemotherapy is the most widely used antitumor treatment, however, chemotherapy resistance significantly limits its efficacy. Reduced drug influx is a key mechanism of chemoresistance, and inhibition of the complexity of the tumor microenvironment (TME) may improve chemotherapy drug influx and therapeutic efficiency. In the current study, we identified that the major extracellular matrix protein collagen I is more highly expressed in lung cancer tissues than adjacent tissues in patients with lung cancer. Furthermore, Kaplan-Meier analysis suggested that COL1A1 expression was negatively correlated with the survival time of patients with lung cancer. Our previous study demonstrated that miR-29a inhibited collagen I expression in lung fibroblasts. Here, we investigated the effect of miR-29a on collagen I expression and the cellular behavior of lung cancer cells. Our results suggest that transfection with miR-29a could prevent Lewis lung carcinoma (LLC) migration by downregulating collagen I expression, but did not affect the proliferation, apoptosis, and cell cycle of LLC cells. In a 3D tumoroid model, we demonstrated that miR-29a transfection significantly increased cisplatin (CDDP) permeation and CDDP-induced cell death. Furthermore, neutral lipid emulsion-based miR-29a delivery improved the therapeutic effect of cisplatin in an LLC spontaneous tumor model in vivo. In summary, this study shows that targeting collagen I expression in the TME contributes to chemotherapy drug influx and improves therapeutic efficacy in lung cancer.

Biomechanical stimulation promotes blood vessel growth despite VEGFR-2 inhibition

BACKGROUND

Angiogenesis, or the growth of new vasculature from existing blood vessels, is widely considered a primary hallmark of cancer progression. When a tumor is small, diffusion is sufficient to receive essential nutrients; however, as the tumor grows, a vascular supply is needed to deliver oxygen and nutrients into the increasing mass. Several anti-angiogenic cancer therapies target VEGF and the receptor VEGFR-2, which are major promoters of blood vessel development. Unfortunately, many of these cancer treatments fail to completely stop angiogenesis in the tumor microenvironment (TME). Since these therapies focus on the biochemical activation of VEGFR-2 via VEGF ligand binding, we propose that mechanical cues, particularly those found in the TME, may be a source of VEGFR-2 activation that promotes growth of blood vessel networks even in the presence of VEGF and VEGFR-2 inhibitors.

RESULTS

In this paper, we analyzed phosphorylation patterns of VEGFR-2, particularly at Y1054/Y1059 and Y1214, stimulated via either VEGF or biomechanical stimulation in the form of tensile strains. Our results show prolonged and enhanced activation at both Y1054/Y1059 and Y1214 residues when endothelial cells were stimulated with strain, VEGF, or a combination of both. We also analyzed Src expression, which is downstream of VEGFR-2 and can be activated through strain or the presence of VEGF. Finally, we used fibrin gels and microfluidic devices as 3D microtissue models to simulate the TME. We determined that regions of mechanical strain promoted increased vessel growth, even with VEGFR-2 inhibition through SU5416.

CONCLUSIONS

Overall, understanding both the effects that biomechanical and biochemical stimuli have on VEGFR-2 activation and angiogenesis is an important factor in developing effective anti-angiogenic therapies. This paper shows that VEGFR-2 can be mechanically activated through strain, which likely contributes to increased angiogenesis in the TME. These proof-of-concept studies show that small molecular inhibitors of VEGFR-2 do not fully prevent angiogenesis in 3D TME models when mechanical strains are introduced.

Primary breast tumor induced extracellular matrix remodeling in premetastatic lungs

The premetastatic niche hypothesis proposes an active priming of the metastatic site by factors secreted from the primary tumor prior to the arrival of the first cancer cells. We investigated several extracellular matrix (ECM) structural proteins, ECM degrading enzymes, and ECM processing proteins involved in the ECM remodeling of the premetastatic niche. Our in vitro model consisted of lung fibroblasts, which were exposed to factors secreted by nonmalignant breast epithelial cells, nonmetastatic breast cancer cells, or metastatic breast cancer cells. We assessed ECM remodeling in vivo in premetastatic lungs of female mice growing orthotopic primary breast tumor xenografts, as compared to lungs of control mice without tumors. Premetastatic lungs contained significantly upregulated Collagen (Col) Col4A5, matrix metalloproteinases (MMPs) MMP9 and MMP14, and decreased levels of MMP13 and lysyl oxidase (LOX) as compared to control lungs. These in vivo findings were consistent with several of our in vitro cell culture findings, which showed elevated Col14A1, Col4A5, glypican-1 (GPC1) and decreased Col5A1 and Col15A1 for ECM structural proteins, increased MMP2, MMP3, and MMP14 for ECM degrading enzymes, and decreased LOX, LOXL2, and prolyl 4-hydroxylase alpha-1 (P4HA1) for ECM processing proteins in lung fibroblasts conditioned with metastatic breast cancer cell media as compared to control. Taken together, our data show that premetastatic priming of lungs by primary breast tumors resulted in significant ECM remodeling which could facilitate metastasis by increasing interstitial fibrillar collagens and ECM stiffness (Col14A1), disruptions of basement membranes (Col4A5), and formation of leaky blood vessels (MMP2, MMP3, MMP9, and MMP14) to promote metastasis.

Collagen-I influences the post-translational regulation, binding partners and role of Annexin A2 in breast cancer progression

Introduction

The extracellular matrix (ECM) has been heavily implicated in the development and progression of cancer. We have previously shown that Annexin A2 is integral in the migration and invasion of breast cancer cells and in the clinical progression of ER-negative breast cancer, processes which are highly influenced by the surrounding tumor microenvironment and ECM.

Methods

We investigated how modulations of the ECM may affect the role of Annexin A2 in MDA-MB-231 breast cancer cells using western blotting, immunofluorescent confocal microscopy and immuno-precipitation mass spectrometry techniques.

Results

We have shown that the presence of collagen-I, the main constituent of the ECM, increases the post-translational phosphorylation of Annexin A2 and subsequently causes the translocation of Annexin A2 to the extracellular surface. In the presence of collagen-I, we identified fibronectin as a novel interactor of Annexin A2, using mass spectrometry analysis. We then demonstrated that reducing Annexin A2 expression decreases the degradation of fibronectin by cancer cells and this effect on fibronectin turnover is increased according to collagen-I abundance.

Discussion

Our results suggest that Annexin A2's role in promoting cancer progression is mediated by collagen-I and Annexin A2 maybe a therapeutic target in the bi-directional cross-talk between cancer cells and ECM remodeling that supports metastatic cancer progression.

Breast tissue analysis using a clinically compatible combined time-resolved fluorescence and diffuse reflectance (TRF-DR) system

OBJECTIVE

This work aims to develop a clinically compatible system that can perform breast tissue analysis in a more time efficient process than conventional histopathological assessment. The potential for such a system to be used in vivo in the operating room or surgical suite to improve patient outcome is investigated.

METHOD

In this work, 80 matched pairs of invasive ductal carcinoma and adjacent normal breast tissue were measured in a combined time-resolved fluorescence and diffuse reflectance (DA) system. Following measurement, the fluorescence intensity of collagen and flavin adenine dinucleotide (FAD); the fluorescence lifetime of collagen, nicotinamide adenine dinucleotide (NADH), and FAD; the DA; absorption coefficient; and reduced scattering coefficient were extracted. Samples then underwent histological processing and H&E staining to classify composition as tumor, fibroglandular, and/or adipose tissue.

RESULTS

Statistically significant differences in the collagen and FAD fluorescence intensity, collagen and FAD fluorescence lifetime, DA, and scattering coefficient were found between each tissue group. The NADH fluorescence lifetime and absorption coefficient were statistically different between the tumor and fibroglandular groups, and the tumor and adipose groups. While many breast tissue analysis studies label fibroglandular and adipose together as "normal" breast tissue, this work indicates that some differences between tumor and fibroglandular tissue are not the same as differences between tumor and adipose tissue. Observations of the reduced scatter coefficient may also indicate further classification to include fibro-adipose may be necessary. Future work would benefit from the additional tissue classification.

CONCLUSION

With observable differences in optical parameters between the three tissue types, this system shows promise as a breast analysis tool in a clinical setting. With further work involving samples of mixed composition, this combined system could potentially be used intraoperatively for rapid margin assessment.

Cancer immune exclusion: breaking the barricade for a successful immunotherapy

Immunotherapy has changed the course of cancer treatment. The initial steps were made through tumor-specific antibodies that guided the setup of an antitumor immune response. A new and successful generation of antibodies are designed to target immune checkpoint molecules aimed to reinvigorate the antitumor immune response. The cellular counterpart is the adoptive cell therapy, where specific immune cells are expanded or engineered to target cancer cells. In all cases, the key for achieving positive clinical resolutions rests upon the access of immune cells to the tumor. In this review, we focus on how the tumor microenvironment architecture, including stromal cells, immunosuppressive cells and extracellular matrix, protects tumor cells from an immune attack leading to immunotherapy resistance, and on the available strategies to tackle immune evasion.

The Matrix Reloaded—The Role of the Extracellular Matrix in Cancer

As the core component of all organs, the extracellular matrix (ECM) is an interlocking macromolecular meshwork of proteins, glycoproteins, and proteoglycans that provides mechanical support to cells and tissues. In cancer, the ECM can be remodelled in response to environmental cues, and it controls a plethora of cellular functions, including metabolism, cell polarity, migration, and proliferation, to sustain and support oncogenesis. The biophysical and biochemical properties of the ECM, such as its structural arrangement and being a reservoir for bioactive molecules, control several intra- and intercellular signalling pathways and induce cytoskeletal changes that alter cell shapes, behaviour, and viability. Desmoplasia is a major component of solid tumours. The abnormal deposition and composition of the tumour matrix lead to biochemical and biomechanical alterations that determine disease development and resistance to treatment. This review summarises the complex roles of ECM in cancer and highlights the possible therapeutic targets and how to potentially remodel the dysregulated ECM in the future. Furthering our understanding of the ECM in cancer is important as the modification of the ECM will probably become an important tool in the characterisation of individual tumours and personalised treatment options.

Transcriptomic Profile of Canine Mammary Ductal Carcinoma

Dogs can be excellent models for spontaneous studies about breast cancers, presenting similarities in clinical behavior and molecular pathways of the disease. Thus, analyses of the canine transcriptome can identify deregulated genes and pathways, contributing to the identification of biomarkers and new therapeutic targets, benefiting humans and animals. In this context, this study aimed to determine the transcriptional profile of canine mammary ductal carcinoma and contribute to the clarification of the importance of deregulated molecules in the molecular pathways involved in the disease. Therefore, we used mammary ductal carcinoma tissue samples and non-tumor mammary tissue from the radical mastectomy of six female dogs. Sequencing was performed on the NextSeq-500 System platform. A comparison of carcinoma tissue and normal tissue revealed 633 downregulated and 573 upregulated genes, which were able to differentiate the groups by principal component analysis. Gene ontology analysis indicated that inflammatory, cell differentiation and adhesion, and extracellular matrix maintenance pathways were mainly deregulated in this series. The main differentially expressed genes observed in this research can indicate greater disease aggressiveness and worse prognosis. Finally, the study of the canine transcriptome indicates that it is an excellent model to generate information relevant to oncology in both species.

Identification of the collagen family as prognostic biomarkers in papillary thyroid carcinoma

OBJECTIVE

The aim of this study was to construct a collagen-related prognostic model for thyroid cancer and to investigate prognostic value of collagen family genes for thyroid cancer.

METHODS

A LASSO Cox regression model for thyroid cancer was developed based on the expression profiles of collagen-related genes. Kaplan-Meier survival analysis was performed for high and low risk groups. The ROC method was used to assess its predictive performance. Predictive independence was verified by multivariate Cox regression analysis. The relationship between this feature and immune cell infiltration was analyzed by tumor microenvironment. COL18A1 was validated by immunohistochemistry and RT-PCR in thyroid cancer tissues. The effect of COL18A1 on cell proliferation, migration and invasion ability of tumor cells were further valuated by CCK-8 assay and transwell assay. The effect of COL18A1 on the immune escape ability of tumor cells was further valuated by cytotoxicity assays.

RESULTS

A model including 4 collagen family genes was developed to predict thyroid cancer prognosis. Patients with high-risk score had a poorer prognosis than those with low-risk scores for 1-, 2-, 3-, and 5- year survival. The model independently predicted prognosis after adjusting for other prognostic factors. A nomogram combining risk score and age was constructed with high sensitivity and specificity. This feature was significantly associated with immune cell infiltration. COL18A1 was aberrantly over-expressed in thyroid cancer compared with control tissues and significantly increased proliferative capacity, migration capacity, invasion capacity, and immune escape ability of tumor cells.

CONCLUSION

Our findings establish a signature associated with collagen family genes that can be a promising tool to predict the prognosis of thyroid cancer. High COL18A1 expression significantly correlates with the poor prognosis of patients and enhances the immune escape ability of tumor cells.

Secretome analysis reveals reduced expression of COL4A2 in hypoxic cancer-associated fibroblasts with a tumor-promoting function in gastric cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) are major components of the tumor microenvironment (TME). Hypoxic TME is known to promote tumor progression. However, how a hypoxic condition regulates CAFs remains elusive.

METHODS

To investigate the underlying mechanism involved in the regulation of gastric cancer (GC) progression by hypoxic CAFs, we performed secretome profiling. Normoxic or hypoxic CAFs conditioned media (CM) were filter-concentrated and in-gel trypsin digested. Resulting peptides were analyzed with LC-MS/MS.

RESULTS

We observed that CM derived from hypoxic CAFs could promote migration of a panel of GC cell lines (AGS, SNU668, SNU638). Mass spectrometry analysis of hypoxic or normoxic CAFs CM identified 1595 proteins, of which 19 proteins (10 upregulated and 9 downregulated) were differentially expressed in the hypoxic secretome. We focused on COL4A2, whose expression was significantly decreased in hypoxic CAFs in HIF-1α-independent manner. Silencing of COL4A2 expression in normoxic CAFs phenocopied the effect of hypoxic CAFs in promoting GC cell migration.

CONCLUSIONS

The reduced expression of COL4A2 in a hypoxic environment might be associated with the tumor-promoting role of hypoxic CAFs in GC.

Noncanonical Wnt/Ror2 signaling regulates cell-matrix adhesion to prompt directional tumor cell invasion in breast cancer

Cell-extracellular matrix (ECM) interactions represent fundamental exchanges during tumor progression, yet how particular signal-transduction factors prompt the conversion of tumor cells into migratory populations capable of systemic spread during metastasis remains elusive. We demonstrate that the noncanonical Wnt receptor, Ror2, regulates tumor cell-driven matrix remodeling and invasion in breast cancer. Ror2 loss-of-function (LOF) triggers the disruption of E-cadherin within tumor cells, accompanied by an increase in tumor cell invasion and collagen realignment in three-dimensional cultures. RNA sequencing of Ror2-deficient organoids further uncovered alterations in actin cytoskeleton, cell adhesion, and collagen cross-linking gene expression programs. Spatially, we pinpoint the up-regulation and redistribution of α5 and β3 integrins together with the production of fibronectin in areas of invasion downstream of Ror2 loss. Wnt/β-catenin-dependent and Wnt/Ror2 alternative Wnt signaling appear to regulate distinct functions for tumor cells regarding their ability to modify cell-ECM exchanges during invasion. Furthermore, blocking either integrin or focal adhesion kinase (FAK), a downstream mediator of integrin-mediated signal transduction, abrogates the enhanced migration observed upon Ror2 loss. These results reveal a critical function for the alternative Wnt receptor, Ror2, as a determinant of tumor cell-driven ECM exchanges during cancer invasion and metastasis.

Three-dimensional in vitro culture models in oncology research

Cancer is a multifactorial disease that is responsible for 10 million deaths per year. The intra- and inter-heterogeneity of malignant tumors make it difficult to develop single targeted approaches. Similarly, their diversity requires various models to investigate the mechanisms involved in cancer initiation, progression, drug resistance and recurrence. Of the in vitro cell-based models, monolayer adherent (also known as 2D culture) cell cultures have been used for the longest time. However, it appears that they are often less appropriate than the three-dimensional (3D) cell culture approach for mimicking the biological behavior of tumor cells, in particular the mechanisms leading to therapeutic escape and drug resistance. Multicellular tumor spheroids are widely used to study cancers in 3D, and can be generated by a multiplicity of techniques, such as liquid-based and scaffold-based 3D cultures, microfluidics and bioprinting. Organoids are more complex 3D models than multicellular tumor spheroids because they are generated from stem cells isolated from patients and are considered as powerful tools to reproduce the disease development in vitro. The present review provides an overview of the various 3D culture models that have been set up to study cancer development and drug response. The advantages of 3D models compared to 2D cell cultures, the limitations, and the fields of application of these models and their techniques of production are also discussed.

Phenanthroindolizidine Alkaloids Isolated from Tylophora ovata as Potent Inhibitors of Inflammation, Spheroid Growth, and Invasion of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC), representing the most aggressive form of breast cancer with currently no targeted therapy available, is characterized by an inflammatory and hypoxic tumor microenvironment. To date, a broad spectrum of anti-tumor activities has been reported for phenanthroindolizidine alkaloids (PAs), however, their mode of action in TNBC remains elusive. Thus, we investigated six naturally occurring PAs extracted from the plant Tylophora ovata: O-methyltylophorinidine (1) and its five derivatives tylophorinidine (2), tylophoridicine E (3), 2-demethoxytylophorine (4), tylophoridicine D (5), and anhydrodehydrotylophorinidine (6). In comparison to natural (1) and for more-in depth studies, we also utilized a sample of synthetic O-methyltylophorinidine (1s). Our results indicate a remarkably effective blockade of nuclear factor kappa B (NFκB) within 2 h for compounds (1) and (1s) (IC50 = 17.1 ± 2.0 nM and 3.3 ± 0.2 nM) that is different from its effect on cell viability within 24 h (IC50 = 13.6 ± 0.4 nM and 4.2 ± 1 nM). Furthermore, NFκB inhibition data for the additional five analogues indicate a structure–activity relationship (SAR). Mechanistically, NFκB is significantly blocked through the stabilization of its inhibitor protein kappa B alpha (IκBα) under normoxic as well as hypoxic conditions. To better mimic the TNBC microenvironment in vitro, we established a 3D co-culture by combining the human TNBC cell line MDA-MB-231 with primary murine cancer-associated fibroblasts (CAF) and type I collagen. Compound (1) demonstrates superiority against the therapeutic gold standard paclitaxel by diminishing spheroid growth by 40% at 100 nM. The anti-proliferative effect of (1s) is distinct from paclitaxel in that it arrests the cell cycle at the G0/G1 state, thereby mediating a time-dependent delay in cell cycle progression. Furthermore, (1s) inhibited invasion of TNBC monoculture spheroids into a matrigel®-based environment at 10 nM. In conclusion, PAs serve as promising agents with presumably multiple target sites to combat inflammatory and hypoxia-driven cancer, such as TNBC, with a different mode of action than the currently applied chemotherapeutic drugs.

The biomimetic extracellular matrix: a therapeutic tool for breast cancer research

A deeper knowledge of the functional versatility and dynamic nature of the ECM has improved the understanding of cancer biology. Translational Significance: This work provides an in-depth view of the importance of the ECM to develop more mimetic breast cancer models, which aim to recreate the components and architecture of tumor microenvironment. Special focus is placed on decellularized matrices derived from tissue and cell culture, both in procurement and applications, as they have achieved great success in cancer research and pharmaceutical sector. The extracellular matrix (ECM) is increasingly recognized as a master regulator of cell behavior and response to breast cancer (BC) treatment. During BC progression, the mammary gland ECM is remodeled and altered in the composition and organization. Accumulated evidence suggests that changes in the composition and mechanics of ECM, orchestrated by tumor-stromal interactions along with ECM remodeling enzymes, are actively involved in BC progression and metastasis. Understanding how specific ECM components modulate the tumorigenic process has led to an increased interest in the development of biomaterial-based biomimetic ECM models to recapitulate key tumor characteristics. The decellularized ECMs (dECMs) have emerged as a promising in vitro 3D tumor model, whose recent advances in the processing and application could become the biomaterial by excellence for BC research and the pharmaceutical industry. This review offers a detailed view of the contribution of ECM in BC progression, and highlights the application of dECM-based biomaterials as promising personalized tumor models that more accurately mimic the tumorigenic mechanisms of BC and the response to treatment. This will allow the design of targeted therapeutic approaches adapted to the specific characteristics of each tumor that will have a great impact on the precision medicine applied to BC patients.

Herpesvirus-induced spermidine synthesis and eIF5A hypusination for viral episomal maintenance

Spermidine is essential for cellular growth and acts as a prerequisite of hypusination, a post-translational modification of eukaryotic initiation factor 5A (eIF5A), allowing the translation of polyproline-containing proteins. Here, we show that oncogenic Kaposi's sarcoma-associated herpesvirus (KSHV) increases spermidine synthesis and eIF5A hypusination to enhance expression of polyproline-containing latency-associated nuclear antigen (LANA) for viral episomal maintenance. KSHV upregulates intracellular spermidine levels by dysregulating polyamine metabolic pathways in three-dimensional (3D) culture and 2D de novo infection conditions. Increased intracellular spermidine leads to increased eIF5A hypusination, ultimately enhancing LANA expression. In contrast, inhibition of spermidine synthesis or eIF5A hypusination alleviates LANA expression, decreasing viral episomal maintenance and KSHV-infected cell proliferation in vitro and in vivo, which is reversed by spermidine supplement. This demonstrates that KSHV hijacks spermidine synthesis and eIF5A hypusination pathways to enhance LANA expression for viral episomal maintenance, suggesting polyamine metabolism and eIF5A hypusination as therapeutic targets for KSHV-induced tumorigenesis.

Origin and evolution of animal multicellularity in the light of phylogenomics and cancer genetics

The rise of animals represents a major but enigmatic event in the evolutionary history of life. In recent years, numerous studies have aimed at understanding the genetic basis of this transition. However, genome comparisons of diverse animal and protist lineages suggest that the appearance of gene families that were previously considered animal specific indeed preceded animals. Animals' unicellular relatives, such as choanoflagellates, ichthyosporeans, and filastereans, demonstrate complex life cycles including transient multicellularity as well as genetic toolkits for temporal cell differentiation, cell-to-cell communication, apoptosis, and cell adhesion. This has warranted further exploration of the genetic basis underlying transitions in cellular organization. An alternative model for the study of transitions in cellular organization is tumors, which exploit physiological programs that characterize both unicellularity and multicellularity. Tumor cells, for example, switch adhesion on and off, up- or downregulate specific cell differentiation states, downregulate apoptosis, and allow cell migration within tissues. Here, we use insights from both the fields of phylogenomics and tumor biology to review the evolutionary history of the regulatory systems of multicellularity and discuss their overlap. We claim that while evolutionary biology has contributed to an increased understanding of cancer, broad investigations into tissue-normal and transformed-can also contribute the framework for exploring animal evolution.

A brief glimpse of a tangled web in a small world: Tumor microenvironment

A tumor is a result of stepwise accumulation of genetic and epigenetic alterations. This notion has deepened the understanding of cancer biology and has introduced the era of targeted therapies. On the other hand, there have been a series of attempts of using the immune system to treat tumors, dating back to ancient history, to sporadic reports of inflamed tumors undergoing spontaneous regression. This was succeeded by modern immunotherapies and immune checkpoint inhibitors. The recent breakthrough has broadened the sight to other players within tumor tissue. Tumor microenvironment is a niche or a system orchestrating reciprocal and dynamic interaction of various types of cells including tumor cells and non-cellular components. The output of this complex communication dictates the functions of the constituent elements present within it. More complicated factors are biochemical and biophysical settings unique to TME. This mini review provides a brief guide on a range of factors to consider in the TME research.

Metabolic reprogramming and crosstalk of cancer-related fibroblasts and immune cells in the tumor microenvironment

It is notorious that cancer cells alter their metabolism to adjust to harsh environments of hypoxia and nutritional starvation. Metabolic reprogramming most often occurs in the tumor microenvironment (TME). TME is defined as the cellular environment in which the tumor resides. This includes surrounding blood vessels, fibroblasts, immune cells, signaling molecules and the extracellular matrix (ECM). It is increasingly recognized that cancer cells, fibroblasts and immune cells within TME can regulate tumor progression through metabolic reprogramming. As the most significant proportion of cells among all the stromal cells that constitute TME, cancer-associated fibroblasts (CAFs) are closely associated with tumorigenesis and progression. Multitudinous studies have shown that CAFs participate in and promote tumor metabolic reprogramming and exert regulatory effects via the dysregulation of metabolic pathways. Previous studies have demonstrated that curbing the substance exchange between CAFs and tumor cells can dramatically restrain tumor growth. Emerging studies suggest that CAFs within the TME have emerged as important determinants of metabolic reprogramming. Metabolic reprogramming also occurs in the metabolic pattern of immune cells. In the meanwhile, immune cell phenotype and functions are metabolically regulated. Notably, immune cell functions influenced by metabolic programs may ultimately lead to alterations in tumor immunity. Despite the fact that multiple previous researches have been devoted to studying the interplays between different cells in the tumor microenvironment, the complicated relationship between CAFs and immune cells and implications of metabolic reprogramming remains unknown and requires further investigation. In this review, we discuss our current comprehension of metabolic reprogramming of CAFs and immune cells (mainly glucose, amino acid, and lipid metabolism) and crosstalk between them that induces immune responses, and we also highlight their contributions to tumorigenesis and progression. Furthermore, we underscore potential therapeutic opportunities arising from metabolism dysregulation and metabolic crosstalk, focusing on strategies targeting CAFs and immune cell metabolic crosstalk in cancer immunotherapy.

Advances in molecular pathogenesis of hidradenitis suppurativa: Dysregulated keratins and ECM signaling

Hidradenitis suppurativa (HS) is characterized by deep-seated, highly inflamed, and painful lumps/abscesses, fistulae, and sinus tracts that grow extensively deep in the dermis and are highly immunogenic in nature. In about one-third of the HS patients there is strong evidence for the role of γ-secretase mutations along with dysregulated Notch signaling. However, the contribution of dysregulated Notch signaling in HS pathogenesis in relation to hair follicle alterations and hyper-activation of the immune system remains undefined. A genome-wide association study (GWAS), proteomic data and functional investigations of identified sequence variants in HS pathology are not fully revealing. The disease initiation or progression may involve bacterial infection besides intrinsic functional defects in keratinocytes, which may be key to further exacerbate immune cell infiltration and cytokine production in and around the lesional tissue. The absence of a suitable animal model that could fully recapitulate the pathogenesis of HS is a major impediment for proper understanding the underlying mechanisms and development of effective treatments. The presence of extracellular matrix (ECM) degradation products along with dysregulation in keratinocytes and, dermal fibroblasts ultimately affect immune regulation and are various components of HS pathogenesis. Bacterial infection further exacerbates the complexity of the disease progression. While anti-TNFα therapy shows partial efficacy, treatment to cure HS is absent. Multiple clinical trials targeting various cytokines, complement C5a and ECM products are in progress. This review provides state-of-the-art information on these aspects with a focus on dysregulated keratinocyte and immune cells; and role of ECM, and Keratin functions in this regard.

COL5A1 Promotes the Progression of Gastric Cancer by Acting as a ceRNA of miR-137-3p to Upregulate FSTL1 Expression

MicroRNAs (miRNAs) and their target genes have been shown to play an important role in gastric cancer but have not been fully clarified. Therefore, our goal was to identify the key miRNA-mRNA regulatory network in gastric cancer by utilizing a variety of bioinformatics analyses and experiments. A total of 242 miRNAs and 1080 genes were screened from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), respectively. Then, survival-related differentially expressed miRNAs and their differentially expressed target genes were screened. Twenty hub genes were identified from their protein-protein interaction network. After weighted gene co-expression network analysis was conducted, we selected miR-137-3p and its target gene, COL5A1, for further research. We found that miR-137-3p was significantly downregulated and that overexpression of miR-137-3p suppressed the proliferation, invasion, and migration of gastric cancer cells. Furthermore, we found that its target gene, COL5A1, could regulate the expression of another hub gene, FSTL1, by sponging miR-137-3p, which was confirmed by dual-luciferase reporter assays. Knockdown of COL5A1 inhibited the proliferation, invasion, and migration of gastric cancer cells, which could be rescued by the miR-137-3p inhibitor or overexpression of FSTL1. Ultimately, bioinformatics analyses showed that the expression of FSTL1 was highly correlated with immune infiltration.

Decellularization of tumours: A new frontier in tissue engineering

Cancer is one of the leading causes of death worldwide. The tumour extracellular matrix (ECM) has unique features in terms of composition and mechanical properties, resulting in a structurally and chemically different ECM to that of native, healthy tissues. This paper reviews to date the efforts into decellularization of tumours, which in the authors’ view represents a new frontier in the ever evolving field of tumour tissue engineering. An overview of the ECM and its importance in cancer is given, ending with examples of research using decellularized tumours, which has already indicated potential therapeutic targets, unravelled malignancy mechanisms or response to chemotherapy agents. The review highlights that more research is needed in this area, which can answer important questions related to tumour formation and progression to ultimately identify new and effective therapeutic targets. Within the near-future of personalized medicine, this research can create patient-specific tumour models and therapeutic regimes.

Extracellular matrix in cancer progression and therapy

The tumor ecosystem with heterogeneous cellular compositions and the tumor microenvironment has increasingly become the focus of cancer research in recent years. The extracellular matrix (ECM), the major component of the tumor microenvironment, and its interactions with the tumor cells and stromal cells have also enjoyed tremendously increased attention. Like the other components of the tumor microenvironment, the ECM in solid tumors differs significantly from that in normal organs and tissues. We review recent studies of the complex roles the tumor ECM plays in cancer progression, from tumor initiation, growth to angiogenesis and invasion. We highlight that the biomolecular, biophysical, and mechanochemical interactions between the ECM and cells not only regulate the steps of cancer progression, but also affect the efficacy of systemic cancer treatment. We further discuss the strategies to target and modify the tumor ECM to improve cancer therapy.

Collagen Biomarkers Quantify Fibroblast Activity In Vitro and Predict Survival in Patients with Pancreatic Ductal Adenocarcinoma

The use of novel tools to understand tumour-fibrosis in pancreatic ductal adenocarcinoma (PDAC) and novel anti-fibrotic treatments are highly needed. We established a pseudo-3D in vitro model including humane pancreatic fibroblasts (PFs) and pancreatic cancer-associated fibroblasts (CAFs) in combination with clinical collagen biomarkers, as a translational anti-fibrotic drug screening tool. Furthermore, we investigated the prognostic potential of serum collagen biomarkers in 810 patients with PDAC. PFs and CAFs were cultured in Ficoll-media. Cells were treated w/wo TGF-ß1 and the anti-fibrotic compound ALK5i. Biomarkers measuring the formation of type III (PRO-C3) and VI (PRO-C6) collagens were measured by ELISA in supernatant at days 3, 6, 9, and 12. PRO-C3 and PRO-C6, and their association with overall survival (OS), were evaluated in serum with PDAC (n = 810). PRO-C3 and PRO-C6 were upregulated in CAFs compared to PFs (p < 0.0001.). TGF-ß1 increased PRO-C3 in both PFs and CAFs (p < 0.0001). The anti-fibrotic compound ALK5i inhibited both PRO-C3 and PRO-C6 (p < 0.0001). High serum levels of PRO-C3 and PRO-C6 in patients with PDAC were associated with short OS (PRO-C3: HR = 1.48, 95%CI: 1.29-1.71, p < 0.0001 and PRO-C6: HR = 1.31, 95%CI: 1.14-1.50, p = 0.0002). PRO-C3 and PRO-C6 have the potential to be used both pre-clinically and clinically as a measure of tumor fibrosis and CAF activity.

Mechanoregulation of Vascular Endothelial Growth Factor Receptor 2 in Angiogenesis

The endothelial cells that compose the vascular system in the body display a wide range of mechanotransductive behaviors and responses to biomechanical stimuli, which act in concert to control overall blood vessel structure and function. Such mechanosensitive activities allow blood vessels to constrict, dilate, grow, or remodel as needed during development as well as normal physiological functions, and the same processes can be dysregulated in various disease states. Mechanotransduction represents cellular responses to mechanical forces, translating such factors into chemical or electrical signals which alter the activation of various cell signaling pathways. Understanding how biomechanical forces drive vascular growth in healthy and diseased tissues could create new therapeutic strategies that would either enhance or halt these processes to assist with treatments of different diseases. In the cardiovascular system, new blood vessel formation from preexisting vasculature, in a process known as angiogenesis, is driven by vascular endothelial growth factor (VEGF) binding to VEGF receptor 2 (VEGFR-2) which promotes blood vessel development. However, physical forces such as shear stress, matrix stiffness, and interstitial flow are also major drivers and effectors of angiogenesis, and new research suggests that mechanical forces may regulate VEGFR-2 phosphorylation. In fact, VEGFR-2 activation has been linked to known mechanobiological agents including ERK/MAPK, c-Src, Rho/ROCK, and YAP/TAZ. In vascular disease states, endothelial cells can be subjected to altered mechanical stimuli which affect the pathways that control angiogenesis. Both normalizing and arresting angiogenesis associated with tumor growth have been strategies for anti-cancer treatments. In the field of regenerative medicine, harnessing biomechanical regulation of angiogenesis could enhance vascularization strategies for treating a variety of cardiovascular diseases, including ischemia or permit development of novel tissue engineering scaffolds. This review will focus on the impact of VEGFR-2 mechanosignaling in endothelial cells (ECs) and its interaction with other mechanotransductive pathways, as well as presenting a discussion on the relationship between VEGFR-2 activation and biomechanical forces in the extracellular matrix (ECM) that can help treat diseases with dysfunctional vascular growth.

Organ on Chip Technology to Model Cancer Growth and Metastasis

Organ on chip (OOC) has emerged as a major technological breakthrough and distinct model system revolutionizing biomedical research and drug discovery by recapitulating the crucial structural and functional complexity of human organs in vitro. OOC are rapidly emerging as powerful tools for oncology research. Indeed, Cancer on chip (COC) can ideally reproduce certain key aspects of the tumor microenvironment (TME), such as biochemical gradients and niche factors, dynamic cell-cell and cell-matrix interactions, and complex tissue structures composed of tumor and stromal cells. Here, we review the state of the art in COC models with a focus on the microphysiological systems that host multicellular 3D tissue engineering models and can help elucidate the complex biology of TME and cancer growth and progression. Finally, some examples of microengineered tumor models integrated with multi-organ microdevices to study disease progression in different tissues will be presented.

Loss of SDHB Induces a Metabolic Switch in the hPheo1 Cell Line toward Enhanced OXPHOS

BACKGROUND

Enzymes of tricarboxylic acid (TCA) have recently been recognized as tumor suppressors. Mutations in the SDHB subunit of succinate dehydrogenase (SDH) cause pheochromocytomas and paragangliomas (PCCs/PGLs) and predispose patients to malignant disease with poor prognosis.

METHODS

Using the human pheochromocytoma cell line (hPheo1), we knocked down SDHB gene expression using CRISPR-cas9 technology.

RESULTS

Microarray gene expression analysis showed that >500 differentially expressed gene targets, about 54%, were upregulated in response to SDHB knock down. Notably, genes involved in glycolysis, hypoxia, cell proliferation, and cell differentiation were up regulated, whereas genes involved in oxidative phosphorylation (OXPHOS) were downregulated. In vitro studies show that hPheo1 proliferation is not affected negatively and the cells that survive by shifting their metabolism to the use of glutamine as an alternative energy source and promote OXPHOS activity. Knock down of SDHB expression results in a significant increase in GLUD1 expression in hPheo1 cells cultured as monolayer or as 3D culture. Analysis of TCGA data confirms the enhancement of GLUD1 in SDHB mutated/low expressed PCCs/PGLs.

CONCLUSIONS

Our data suggest that the downregulation of SDHB in PCCs/PGLs results in increased GLUD1 expression and may represent a potential biomarker and therapeutic target in SDHB mutated tumors and SDHB loss of activity-dependent diseases.

Transcriptional control of a collagen deposition and adhesion process that promotes lung adenocarcinoma growth and metastasis

A fibrotic stroma accumulates in advanced cancers, and invasive cancer cells migrate along collagen fibers that facilitate dissemination from the primary tumor. However, the ways in which tumor cells govern these processes remain unclear. Here, we report that the epithelial-mesenchymal transition–activating transcription factor ZEB1 increased type I collagen (Col1) secretion and enhanced tumor cell adherence to Col1. Mechanistically, ZEB1 increased the levels of α₁β₁ integrin (encoded by Itga1 and Itgb1) by inhibiting PP2A activity, which reduced nuclear accumulation of HDAC4 and, thereby, derepressed Itga1 gene transcription. In parallel, ZEB1 relieved the miRNA-148a-mediated silencing of Itga1. High levels of Itga1 enhanced tumor cell adherence to Col1 and were essential for Col1-induced tumor growth and metastasis. Furthermore, ZEB1 enhanced Col1 secretion by increasing the expression of a kinesin protein that facilitated transport and secretion of Col1-containing vesicles. Our findings elucidate a transcriptional mechanism by which lung adenocarcinoma cells coordinate a collagen deposition and adhesion process that facilitates tumor progression.

Breast Cancer CAFs: Spectrum of Phenotypes and Promising Targeting Avenues

Activationof the tumor-associated stroma to support tumor growth is a common feature observed in different cancer entities. This principle is exemplified by cancer-associated fibroblasts (CAFs), which are educated by the tumor to shape its development across all stages. CAFs can alter the extracellular matrix (ECM) and secrete a variety of different molecules. In that manner they have the capability to affect activation, survival, proliferation, and migration of other stromal cells and cancer cell themselves. Alteration of the ECM, desmoplasia, is a common feature of breast cancer, indicating a prominent role for CAFs in shaping tumor development in the mammary gland. In this review, we summarize the multiple roles CAFs play in mammary carcinoma. We discuss experimental and clinical strategies to interfere with CAFs function in breast cancer. Moreover, we highlight the issues arising from CAFs heterogeneity and the need for further research to identify CAFs subpopulation(s) that can be targeted to improve breast cancer therapy.

The oncogenic role of meiosis-specific Aurora kinase C in mitotic cells

Aberrant expression of meiosis-specific genes in cancer has recently emerged as a driver of some cancer formation. Aurora kinase C (AURKC) is a member of the Aurora kinase family of proteins known to regulate chromosome segregation during cell divisions. AURKC is normally expressed in meiotic cells; however, elevated levels of AURKC mRNA and protein are frequently measured in cancer cells. To understand the function of AURKC in cancer cells, expression was induced in noncancerous, human retina pigmented epithelial cells. While AURKC expression did not alter cell proliferation over 72 h, it did increase cell migration and anchorage independent growth in soft agar suggesting an oncogenic role in mitotically dividing cells. To evaluate AURKC as a potential therapeutic target, a frameshift mutation in the gene was introduced in U2OS osteosarcoma cells using CRISPR-Cas9 technology resulting in a premature stop codon. Cancer cells lacking AURKC displayed no change in cell proliferation over 72 h but did migrate less and formed fewer colonies in soft agar. Whole transcriptome sequencing analysis uncovered over 400 differentially expressed genes in U2OS cells with and without AURKC. GO analysis revealed alterations in proteinaceous extracellular matrix genes including COL1A1. These data indicate that therapeutics targeting AURKC could decrease cancer cell metastasis and disease progression. Because AURKC is transcriptionally silenced in normal mitotic cells, its disruption could specifically target cancer cells limiting the toxic side effects associated with current therapeutics.

3D Tumor Models for Breast Cancer: Whither We Are and What We Need

Three-dimensional (3D) models have led to a paradigm shift in disease modeling in vitro, particularly for cancer. The past decade has seen a phenomenal increase in the development of 3D models for various types of cancers with a focus on studying stemness, invasive behavior, angiogenesis, and chemoresistance of cancer cells, as well as contributions of its stroma, which has expanded our understanding of these processes. Cancer biology is moving into exploring the emerging hallmarks of cancer, such as inflammation, immune evasion, and reprogramming of energy metabolism. Studies into these emerging concepts have provided novel targets and treatment options such as antitumor immunotherapy. However, 3D models that can investigate the emerging hallmarks are few and underexplored. As commonly used immunocompromised mice and syngenic mice cannot accurately mimic human immunology, stromal interactions, and metabolism and require the use of prohibitively expensive humanized mice, there is tremendous scope to develop authentic 3D tumor models in these areas. Taking the specific case of breast cancer, we discuss the currently available 3D models, their applications to mimic signaling in cancer, tumor-stroma interactions, drug responses, and assessment of drug delivery systems and therapies. We discuss the lacunae in the development of 3D tumor models for the emerging hallmarks of cancer, for lesser-explored forms of breast cancer, and provide insights to develop such models. We discuss how the next generation of 3D models can provide a better mimic of human cancer modeling compared to xenograft models and the scope toward preclinical models and precision medicine.

Extracellular Matrices and Cancer-Associated Fibroblasts: Targets for Cancer Diagnosis and Therapy?

Solid cancer progression is dictated by neoplastic cell features and pro-tumoral crosstalks with their microenvironment. Stroma modifications, such as fibroblast activation into cancer-associated fibroblasts (CAFs) and extracellular matrix (ECM) remodeling, are now recognized as critical events for cancer progression and as potential therapeutic or diagnostic targets. The recent appreciation of the key, complex and multiple roles of the ECM in cancer and of the CAF diversity, has revolutionized the field and raised innovative but challenging questions. Here, we rapidly present CAF heterogeneity in link with their specific ECM remodeling features observed in cancer, before developing each of the impacts of such ECM modifications on tumor progression (survival, angiogenesis, pre-metastatic niche, chemoresistance, etc.), and on patient prognosis. Finally, based on preclinical studies and recent results obtained from clinical trials, we highlight key mechanisms or proteins that are, or may be, used as potential therapeutic or diagnostic targets, and we report and discuss benefits, disappointments, or even failures, of recently reported stroma-targeting strategies.

A five-gene signature is a prognostic biomarker in pan-cancer and related with immunologically associated extracellular matrix

The tumor microenvironment (TME) is related to extracellular matrix (ECM) dynamics and has a broad fundamental and mechanistic role in tumorigenesis and cancer progression. We hypothesized that ECM regulators might play an essential role in pan‐cancer attribution by causing a generic effect through its regulation of the dynamics of ECM alteration. By analyzing data from TCGA using GSEA and univariate Cox regression analysis, we found that ECM regulator genes were significantly enriched and contributed to mortality in various cancer types. Notably, UMAP analysis revealed that ECM regulator genes dominated the differences between tumor and adjacent normal tissues based on 59 or 31 pan‐survival‐related ECM gene sets. Subsequently, a five‐gene signature consisting of the predominant ECM regulators ADAM12, MMP1, SERPINE1, PLOD3, and P4HA3 was identified. We found that this five‐gene signature was pro‐mortality in 18 types of cancer in TCGA, and validated eleven other cancer types in TCGA and seven types in the TARGET and CoMMpass databases using overall survival analysis. KEGG pathway enrichment and Pearson correlation analysis indicated that these five component genes that were correlated with specific ECM proteins involved in tumorigenesis from the ECM receptor interaction gene set. Additionally, the fitted results of a linear model were applied to strengthen the discovery, demonstrating that the five genes were correlated with immune infiltration score and especially associated with typically immunologically “cold” tumors. We thus conclude that the ADAM12, MMP1, SERPINE1, PLOD3, and P4HA3 signature showed a close association with a pan‐cancer effect on prognosis and is related to ECM proteins in the TME which corresponding with immunologically “cold” cancer types.

The Biological and Biomechanical Role of Transglutaminase-2 in the Tumour Microenvironment

Transglutaminase-2 (TG2) is the most highly and ubiquitously expressed member of the transglutaminase enzyme family and is primarily involved in protein cross-linking. TG2 has been implicated in the development and progression of numerous cancers, with a direct role in multiple cellular processes and pathways linked to apoptosis, chemoresistance, epithelial-mesenchymal transition, and stem cell phenotype. The tumour microenvironment (TME) is critical in the formation, progression, and eventual metastasis of cancer, and increasing evidence points to a role for TG2 in matrix remodelling, modulation of biomechanical properties, cell adhesion, motility, and invasion. There is growing interest in targeting the TME therapeutically in response to advances in the understanding of its critical role in disease progression, and a number of approaches targeting biophysical properties and biomechanical signalling are beginning to show clinical promise. In this review we aim to highlight the wide array of processes in which TG2 influences the TME, focussing on its potential role in the dynamic tissue remodelling and biomechanical events increasingly linked to invasive and aggressive behaviour. Drug development efforts have yielded a range of TG2 inhibitors, and ongoing clinical trials may inform strategies for targeting the biomolecular and biomechanical function of TG2 in the TME.

miR-29a-3p-dependent COL3A1 and COL5A1 expression reduction assists sulforaphane to inhibit gastric cancer progression

The antitumor properties of cruciferous vegetables are mainly due to their high content of isothiocyanates, and sulforaphane (SFA) is the most well-known compound. The aim of this study was to determine the mechanism of SFA inhibiting gastric cancer (GC) progression. After verifying SFA suppressing GC growth in vivo, we utilized the GSE79973 and GSE118916 datasets to identify the GC development signatures that overlap with the RNA-seq analysis in SFA-treated AGS cells. GSEA of the RNA-seq data indicated that SFA regulation of GC progression was related to extracellular matrix and collagens; thus, we identified COL3A1 and COL5A1 as the targets of SFA, which functioned as oncogenes. We found positive correlations between COL3A1 and COL5A1 expression in GC cells, and confirmed that miR-29a-3p is the common regulator of their expression. RNA immunoprecipitation assays based on Ago2, Dicer, and exportin-5 showed that SFA could promote mature miR-29a-3p generation. We also proved that SFA inactivated the Wnt/β-catenin pathway in GC cells in a miR-29a-3p-dependent manner. Overall, SFA boosts miR-29a-3p maturation to downregulate COL3A1 and COL5A1 and inactivate the Wnt/ β -catenin pathway to suppress GC progression.

Inhibition of Tumor VEGFR2 Induces Serine 897 EphA2-Dependent Tumor Cell Invasion and Metastasis in NSCLC

Anti-angiogenic treatment targeting vascular endothelial growth factor (VEGF)-VEGFR2 signaling has shown limited efficacy in lung cancer patients. Here, we demonstrate that inhibition of VEGFR2 in tumor cells, expressed in ∼20% of non-squamous non-small cell lung cancer (NSCLC) patients, leads to a pro-invasive phenotype. Drug-induced inhibition of tumor VEGFR2 interferes with the formation of the EphA2/VEGFR2 heterocomplex, thereby allowing RSK to interact with Serine 897 of EphA2. Inhibition of RSK decreases phosphorylation of Serine 897 EphA2. Selective genetic modeling of Serine 897 of EphA2 or inhibition of EphA2 abrogates the formation of metastases in vivo upon VEGFR2 inhibition. In summary, these findings demonstrate that VEGFR2-targeted therapy conditions VEGFR2-positive NSCLC to Serine 897 EphA2-dependent aggressive tumor growth and metastasis. These data shed light on the molecular mechanisms explaining the limited efficacy of VEGFR2-targeted anti-angiogenic treatment in lung cancer patients.

The Dynamic Interaction between Extracellular Matrix Remodeling and Breast Tumor Progression

Desmoplastic tumors correspond to a unique tissue structure characterized by the abnormal deposition of extracellular matrix. Breast tumors are a typical example of this type of lesion, a property that allows its palpation and early detection. Fibrillar type I collagen is a major component of tumor desmoplasia and its accumulation is causally linked to tumor cell survival and metastasis. For many years, the desmoplastic phenomenon was considered to be a reaction and response of the host tissue against tumor cells and, accordingly, designated as "desmoplastic reaction". This notion has been challenged in the last decades when desmoplastic tissue was detected in breast tissue in the absence of tumor. This finding suggests that desmoplasia is a preexisting condition that stimulates the development of a malignant phenotype. With this perspective, in the present review, we analyze the role of extracellular matrix remodeling in the development of the desmoplastic response. Importantly, during the discussion, we also analyze the impact of obesity and cell metabolism as critical drivers of tissue remodeling during the development of desmoplasia. New knowledge derived from the dynamic remodeling of the extracellular matrix may lead to novel targets of interest for early diagnosis or therapy in the context of breast tumors.

Integrative RNA-Seq and H3 Trimethylation ChIP-Seq Analysis of Human Lung Cancer Cells Isolated by Laser-Microdissection

Simple Summary

Tissue heterogeneity is one of the major problems in cancer genomics. Thus, we developed and conducted an RNA-Seq and ChIP-Seq integrative analysis of clinical lung tissue samples with the isolation of specific cell populations using laser-microdissection microscopy (LMD). The transcriptomic profile was successfully captured and somatically altered regions marked by histone H3 lysine 4 trimethylation (H3K4me3) were identified in lung cancer. We also observed the differential expressions of cancer-related genes near the altered proximal H3K4me3 regions, while altered distal H3K4me3 regions were overlapped with enhancer activity annotations of cancer regulatory genes. Additionally, proximal tumor-gained promoters were associated with the core components of polycomb repressive complex 2. Our study demonstrates the practical workflow of using LMD on clinical samples for integrative analyses, which improves the overall understanding of genetic and epigenetic dysregulation of malignancy.

Abstract

Our previous integrative study in gastric cancer discovered cryptic promoter activation events that drive the expression of important developmental genes. However, it was unclear if such cancer-associated epigenetic changes occurred in cancer cells or other cell types in bulk tissue samples. An integrative analysis consisting of RNA-Seq and H3K4me3 ChIP-Seq was used. This workflow was applied to a set of matched normal lung tissues and non-small cell lung cancer (NSCLC) tissues, for which the stroma and tumor cell parts could be isolated by laser-microdissection microscopy (LMD). RNA-Seq analysis showed subtype-specific differential expressed genes and enriched pathways in NSCLC. ChIP-Seq analysis results suggested that the proximal altered H3K4me3 regions were located at differentially expressed genes involved in cancer-related pathways, while altered distal H3K4me3 regions were annotated with enhancer activity of cancer regulatory genes. Interestingly, integration with ENCODE data revealed that proximal tumor-gained promoters were associated with EZH2 and SUZ12 occupancies, which are the core components of polycomb repressive complex 2 (PRC2). This study used LMD on clinical samples for an integrative analysis to overcome the tissue heterogeneity problem in cancer research. The results also contribute to the overall understanding of genetic and epigenetic dysregulation of lung malignancy.

Thyroid Cancer Stem-Like Cells: From Microenvironmental Niches to Therapeutic Strategies

Thyroid cancer (TC) is the most common endocrine malignancy. Recent progress in thyroid cancer biology revealed a certain degree of intratumoral heterogeneity, highlighting the coexistence of cellular subpopulations with distinct proliferative capacities and differentiation abilities. Among those subpopulations, cancer stem-like cells (CSCs) are hypothesized to drive TC heterogeneity, contributing to its metastatic potential and therapy resistance. CSCs principally exist in tumor areas with specific microenvironmental conditions, the so-called stem cell niches. In particular, in thyroid cancer, CSCs' survival is enhanced in the hypoxic niche, the immune niche, and some areas with specific extracellular matrix composition. In this review, we summarize the current knowledge about thyroid CSCs, the tumoral niches that allow their survival, and the implications for TC therapy.

Tumor extracellular matrix: lessons from the second-harmonic generation microscopy

Extracellular matrix (ECM) represents more than a mere intercellular cement. It is physiologically active in cell communication, adhesion and proliferation. Collagen is the most abundant protein, making up to 90% of ECM, and 30% of total protein weight in humans. Second-harmonic generation (SHG) microscopy represents an important tool to study collagen organization of ECM in freshly unfixed tissues and paraffin-embedded tissue samples. This manuscript aims to review some of the applications of SHG microscopy in Oncologic Pathology, mainly in the study of ECM of epithelial tumors. It is shown how collagen parameters measured by this technique can aid in the differential diagnosis and in prognostic stratification. There is a tendency to associate higher amount, lower organization and higher linearity of collagen fibers with tumor progression and metastasizing. These represent complex processes, in which matrix remodeling plays a central role, together with cancer cell genetic modifications. Integration of studies on cancer cell biology and ECM are highly advantageous to give us a more complete picture of these processes. As microscopic techniques provide topographic information allied with biologic characteristics of tissue components, they represent important tools for a more complete understanding of cancer progression. In this context, SHG has provided significant insights in human tumor specimens, readily available for Pathologists.

Breast tumor-on-chip models: From disease modeling to personalized drug screening

Breast cancer is one of the leading causes of mortality worldwide being the most common cancer among women. Despite the significant progress obtained during the past years in the understanding of breast cancer pathophysiology, women continue to die from it. Novel tools and technologies are needed to develop better diagnostic and therapeutic approaches, and to better understand the molecular and cellular players involved in the progression of this disease. Typical methods employed by the pharmaceutical industry and laboratories to investigate breast cancer etiology and evaluate the efficiency of new therapeutic compounds are still based on traditional tissue culture flasks and animal models, which have certain limitations. Recently, tumor-on-chip technology emerged as a new generation of in vitro disease model to investigate the physiopathology of tumors and predict the efficiency of drugs in a native-like microenvironment. These microfluidic systems reproduce the functional units and composition of human organs and tissues, and importantly, the rheological properties of the native scenario, enabling precise control over fluid flow or local gradients. Herein, we review the most recent works related to breast tumor-on-chip for disease modeling and drug screening applications. Finally, we critically discuss the future applications of this emerging technology in breast cancer therapeutics and drug development.

Identification of potential biomarkers associated with immune infiltration in the esophageal carcinoma tumor microenvironment

Tumor immune cell infiltration was significantly correlated with the progression and the effect of immunotherapy in cancers including esophageal carcinoma (ESCA). However, no biomarkers were identified which were associated with immune infiltration in ESCA. In the present study, a total of 128 common differentially expressed genes (DEGs) were identified between esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinomas (EAC). The results of gene ontology (GO) enrichment and Reactome pathway analysis displayed that the up-regulated DEGs were mainly involved in the regulation of extracellular matrix (ECM), while the down-regulated DEGs were mainly involved in the regulation of cornification and keratinocyte differentiation. The most significant module of up-regulated DEGs was selected by Molecular Complex Detection (MCODE). Top ten similar genes of COL1A2 were explored, then validation and the prognostic analysis of these genes displayed that COL1A2, COL1A1, COL3A1, ZNF469 and Periostin (POSTN) had the prognostic value which were up-regulated in ESCA. The expressions of COL1A2 and its four similar genes were mainly correlated with infiltrating levels of macrophages and dendritic cells (DCs) and showed strong correlations with diverse immune marker sets in ESCA. To summarize, COL1A2 and its four similar genes were identified as the potential biomarkers associated with immune infiltration in ESCA. These genes might be applied to immunotherapy for ESCA.

Trisulfide linked cholesteryl PEG conjugate attenuates intracellular ROS and collagen-1 production in a breast cancer co-culture model

The progression of cancer has been closely-linked with augmentation of cellular reactive oxygen species (ROS) levels and ROS-associated changes in the tumour microenvironment (TME), including alterations to the extracellular matrix and associated low drug uptake. Herein we report the application of a co-culture model to simulate the ROS based cell-cell interactions in the TME using fibroblasts and breast cancer cells, and describe how novel reactive polymers can be used to modulate those interactions. Under the co-culture conditions, both cell types exhibited modifications in behaviour, including significant overproduction of ROS in the cancer cells, and elevation of the collagen-1 secretion and stained actin filament intensity in the fibroblasts. To examine the potential of using reactive antioxidant polymers to intercept ROS communication and thereby manipulate the TME, we employed H2S-releasing macromolecular conjugates which have been previously demonstrated to mitigate ROS production in HEK cells. The specific conjugate used, mPEG-SSS-cholesteryl (T), significantly reduced ROS levels in co-cultured cancer cells by approximately 50%. This reduction was significantly greater than that observed with the other positive antioxidant controls. Exposure to T was also found to downregulate levels of collagen-1 in the co-cultured fibroblasts, while exhibiting less impact on cells in mono-culture. This would suggest a possible downstream effect of ROS-mitigation by T on stromal-tumour cell signalling. Since fibroblast-derived collagens modulate crucial steps in tumorigenesis, this ROS-associated effect could potentially be harnessed to slow cancer progression. The model may also be beneficial for interrogating the impact of antioxidants on naturally enhanced ROS levels, rather than relying on the application of exogenous oxidants to simulate elevated ROS levels.

Advances in biofabrication techniques for collagen-based 3D in vitro culture models for breast cancer research

Collagen is the most abundant component of the extracellular matrix (ECM), therefore it represents an ideal biomaterial for the culture of a variety of cell types. Recently, collagen-based scaffolds have shown promise as 3D culture platforms for breast cancer-based research. Two-dimensional (2D) in vitro culture models, while useful for gaining preliminary insights, are ultimately flawed as they do not adequately replicate the tumour microenvironment. As a result, they do not facilitate proper 3D cell-cell/cell-matrix interactions and often an exaggerated response to therapeutic agents occurs. The ECM plays a crucial role in the development and spread of cancer. Alterations within the ECM have a significant impact on the pathogenesis of cancer, the initiation of metastasis and ultimate progression of the disease. 3D in vitro culture models that aim to replicate the tumour microenvironment have the potential to offer a new frontier for cancer research with cell growth, morphology and genetic properties that more closely match in vivo cancers. While initial 3D in vitro culture models used in breast cancer research consisted of simple hydrogel platforms, recent advances in biofabrication techniques, including freeze-drying, electrospinning and 3D bioprinting, have enabled the fabrication of biomimetic collagen-based platforms that more closely replicate the breast cancer ECM. This review highlights the current application of collagen-based scaffolds as 3D in vitro culture models for breast cancer research, specifically for adherence-based scaffolds (i.e. matrix-assisted). Finally, the future perspectives of 3D in vitro breast cancer models and their potential to lead to an improved understanding of breast cancer diagnosis and treatment are discussed.

Collagen biology making inroads into prognosis and treatment of cancer progression and metastasis

Progression through dissemination to tumor-surrounding tissues and metastasis development is a hallmark of cancer that requires continuous cell-to-cell interactions and tissue remodeling. In fact, metastization can be regarded as a tissue disease orchestrated by cancer cells, leading to neoplastic colonization of new organs. Collagen is a major component of the extracellular matrix (ECM), and increasing evidence suggests that it has an important role in cancer progression and metastasis. Desmoplasia and collagen biomarkers have been associated with relapse and death in cancer patients. Despite the increasing interest in ECM and in the desmoplastic process in tumor microenvironment as prognostic factors and therapeutic targets in cancer, further research is required for a better understanding of these aspects of cancer biology. In this review, published evidence correlating collagen with cancer prognosis is retrieved and analyzed, and the role of collagen and its fragments in cancer pathophysiology is discussed.

Next Generation Imaging Techniques to Define Immune Topographies in Solid Tumors

In recent years, cancer immunotherapy experienced remarkable developments and it is nowadays considered a promising therapeutic frontier against many types of cancer, especially hematological malignancies. However, in most types of solid tumors, immunotherapy efficacy is modest, partly because of the limited accessibility of lymphocytes to the tumor core. This immune exclusion is mediated by a variety of physical, functional and dynamic barriers, which play a role in shaping the immune infiltrate in the tumor microenvironment. At present there is no unified and integrated understanding about the role played by different postulated models of immune exclusion in human solid tumors. Systematically mapping immune landscapes or "topographies" in cancers of different histology is of pivotal importance to characterize spatial and temporal distribution of lymphocytes in the tumor microenvironment, providing insights into mechanisms of immune exclusion. Spatially mapping immune cells also provides quantitative information, which could be informative in clinical settings, for example for the discovery of new biomarkers that could guide the design of patient-specific immunotherapies. In this review, we aim to summarize current standard and next generation approaches to define Cancer Immune Topographies based on published studies and propose future perspectives.

High expression of hypoxia inducible factor 1α related with acquired resistant to EGFR tyrosine kinase inhibitors in NSCLC

The acquired resistance of the first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is a main factor leading to poor prognosis of non-small cell lung cancer (NSCLC), so we researched whether the high expression of hypoxia-inducible factor-1α (HIF-1α) in EGFR-TKIs sensitive NSCLC tissue tends to induce the acquired resistance. We detected the HIF-1α in normal lung tissue, EGFR-TKIs sensitive NSCLC tissue, the first generation EGFR-TKIs acquired resistant NSCLC tissue and acquired EGFR T790M mutation NSCLC tissue with the method of immunohistochemistry. Then, we compared the expression of HIF-1α in these tissues, and evaluate the effect of HIF-1α expression to the occurrence of acquired resistance. The expression of HIF-1α was much higher in the EGFR-TKIs sensitive NSCLC tissue than that in normal lung tissue. HIF-1α level became higher after the occurrence acquired resistance. There was negative correlation between HIF-1α level before receiving treatment and the time of acquired resistance occurring as well as the acquired EGFR T790M mutation occurring. As the treatment going on, EGFR-TKIs sensitivity rate of low HIF-1α level group was much higher than that of high level group. The high expression of HIF-1α related with the acquired resistance of the first generation EGFR-TKIs, and HIF-1α can be a biomarker to predict the early occurrence of acquired resistance.

Hypoxia and the phenomenon of immune exclusion

Over the last few years, cancer immunotherapy experienced tremendous developments and it is nowadays considered a promising strategy against many types of cancer. However, the exclusion of lymphocytes from the tumor nest is a common phenomenon that limits the efficiency of immunotherapy in solid tumors. Despite several mechanisms proposed during the years to explain the immune excluded phenotype, at present, there is no integrated understanding about the role played by different models of immune exclusion in human cancers. Hypoxia is a hallmark of most solid tumors and, being a multifaceted and complex condition, shapes in a unique way the tumor microenvironment, affecting gene transcription and chromatin remodeling. In this review, we speculate about an upstream role for hypoxia as a common biological determinant of immune exclusion in solid tumors. We also discuss the current state of ex vivo and in vivo imaging of hypoxic determinants in relation to T cell distribution that could mechanisms of immune exclusion and discover functional-morphological tumor features that could support clinical monitoring.

Intratumoral heterogeneity of second-harmonic generation scattering from tumor collagen and its effects on metastatic risk prediction

Background

Metastases are the leading cause of breast cancer-related deaths. The tumor microenvironment impacts cancer progression and metastatic ability. Fibrillar collagen, a major extracellular matrix component, can be studied using the light scattering phenomenon known as second-harmonic generation (SHG). The ratio of forward- to backward-scattered SHG photons (F/B) is sensitive to collagen fiber internal structure and has been shown to be an independent prognostic indicator of metastasis-free survival time (MFS). Here we assess the effects of heterogeneity in the tumor matrix on the possible use of F/B as a prognostic tool.

Methods

SHG imaging was performed on sectioned primary tumor excisions from 95 untreated, estrogen receptor-positive, lymph node negative invasive ductal carcinoma patients. We identified two distinct regions whose collagen displayed different average F/B values, indicative of spatial heterogeneity: the cellular tumor bulk and surrounding tumor-stroma interface. To evaluate the impact of heterogeneity on F/B’s prognostic ability, we performed SHG imaging in the tumor bulk and tumor-stroma interface, calculated a 21-gene recurrence score (surrogate for OncotypeDX®, or S-ODX) for each patient and evaluated their combined prognostic ability.

Results

We found that F/B measured in tumor-stroma interface, but not tumor bulk, is prognostic of MFS using three methods to select pixels for analysis: an intensity threshold selected by a blinded observer, a histogram-based thresholding method, and an adaptive thresholding method. Using both regression trees and Random Survival Forests for MFS outcome, we obtained data-driven prediction rules that show F/B from tumor-stroma interface, but not tumor bulk, and S-ODX both contribute to predicting MFS in this patient cohort. We also separated patients into low-intermediate (S-ODX < 26) and high risk (S-ODX ≥26) groups. In the low-intermediate risk group, comprised of patients not typically recommended for adjuvant chemotherapy, we find that F/B from the tumor-stroma interface is prognostic of MFS and can identify a patient cohort with poor outcomes.

Conclusions

These data demonstrate that intratumoral heterogeneity in F/B values can play an important role in its possible use as a prognostic marker, and that F/B from tumor-stroma interface of primary tumor excisions may provide useful information to stratify patients by metastatic risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07713-4.

LncRNA HOTAIR promotes the growth and metastasis of gastric cancer by sponging miR-1277-5p and upregulating COL5A1

BACKGROUND

Emerging studies have shown that HOTAIR acts as an oncogene in gastric cancer (GC). However, its role in the extracellular matrix and in tumor immune infiltration remains unknown.

METHODS

HOTAIR and COL5A1 levels were analyzed by bioinformatics analysis and validated by qRT-PCR, western blotting and immunohistochemistry assays. The regulatory relationships between components of the HOTAIR/miR-1277-5p/COL5A1 axis and the role of this axis in GC were predicted by bioinformatics analysis, and validated by in vitro and in vivo experiments. The correlation between COL5A1 and GC immune infiltration was assessed by bioinformatics analysis and a COL5A1-based predictive nomogram was established using the Stomach Adenocarcinoma dataset from The Cancer Genome Atlas.

RESULTS

We found that HOTAIR and COL5A1 were overexpressed in GC compared to normal controls, which predicted poor prognosis. The regulatory relationship of the HOTAIR/miR-1277-5p/COL5A1 axis in GC was demonstrated, and HOTAIR and COL5A1 were found to promote GC growth while miR-1277-5p exerted the reverse effects. In addition, COL5A1 was negatively associated with tumor purity but positively associated with immune infiltration, which suggested that COL5A1-mediated GC growth may be partially mediated by the regulation of immune infiltration. Additionally, the established COL5A1-based nomogram showed that COL5A1 can serve as a prognostic biomarker in GC.

CONCLUSIONS

HOTAIR regulates GC growth by sponging miR-1277-5p and upregulating COL5A1, and COL5A1-mediated GC cell proliferation may be mediated by effects on the tumor microenvironment, which provides novel targets for GC treatment.

Mechanoactivation of NOX2-generated ROS elicits persistent TRPM8 Ca2+ signals that are inhibited by oncogenic KRas

Changes in the mechanical microenvironment and mechanical signals are observed during tumor progression, malignant transformation, and metastasis. In this context, understanding the molecular details of mechanotransduction signaling may provide unique therapeutic targets. Here, we report that normal breast epithelial cells are mechanically sensitive, responding to transient mechanical stimuli through a two-part calcium signaling mechanism. We observed an immediate, robust rise in intracellular calcium (within seconds) followed by a persistent extracellular calcium influx (up to 30 min). This persistent calcium was sustained via microtubule-dependent mechanoactivation of NADPH oxidase 2 (NOX2)-generated reactive oxygen species (ROS), which acted on transient receptor potential cation channel subfamily M member 8 (TRPM8) channels to prolong calcium signaling. In contrast, the introduction of a constitutively active oncogenic KRas mutation inhibited the magnitude of initial calcium signaling and severely blunted persistent calcium influx. The identification that oncogenic KRas suppresses mechanically-induced calcium at the level of ROS provides a mechanism for how KRas could alter cell responses to tumor microenvironment mechanics and may reveal chemotherapeutic targets for cancer. Moreover, we find that expression changes in both NOX2 and TRPM8 mRNA predict poor clinical outcome in estrogen receptor (ER)-negative breast cancer patients, a population with limited available treatment options. The clinical and mechanistic data demonstrating disruption of this mechanically-activated calcium pathway in breast cancer patients and by KRas activation reveal signaling alterations that could influence cancer cell responses to the tumor mechanical microenvironment and impact patient survival.