Role of cancer microenvironment in metastasis: focus on colon cancer

Integrating bulk and single-cell sequencing reveals metastasis-associated CAFs in head and neck squamous cell carcinoma

AIMS

Cancer-associated fibroblasts (CAFs) have been shown to promote the metastasis of head and neck squamous cell carcinoma (HNSCC), but the underlying mechanisms remain unclear. The purpose of this study is to identify gene in CAFs that are associated with metastasis and to preliminarily validate its impact on the metastasis of HNSCC.

MATERIALS AND METHODS

Scissor analysis was utilized to process single-cell and bulk RNA sequencing datasets, identifying genes associated with the metastasis of HNSCC through differential gene expression analysis. A risk model was constructed using LASSO regression analysis. Quantitative real time-PCR and Western blot were employed to measure mRNA and protein expressions, respectively. Multiplex immunohistochemistry (mIHC) was used to assess protein expression in CAFs. siRNA was utilized to achieve gene knockdown. CCK-8 and Transwell assays were employed to evaluate the biological characteristics of HNSCC cells.

KEY FINDINGS

Compare to the nonmetastatic primary CAFs (nmCAFs), tissue inhibitors of metalloproteinase-1 (TIMP1) was founded to be overexpressed in the cells and tissues of metastatic primary CAFs (mCAFs). Knocking down TIMP1 in CAFs can signifucantly inhibit the proliferation, invasion, and migration of HNSCC cells.

SIGNIFICANCE

CAFs facilitate HNSCC cell metastasis by upregulating TIMP1, highlighting TIMP1 as a potential therapeutic target in HNSCC metastasis management.

A narrative review on therapeutic potential of naringenin in colorectal cancer: Focusing on molecular and biochemical processes

Colorectal cancer (CRC) is a common and highly metastatic cancer affecting people worldwide. Drug resistance and unwanted side effects are some of the limitations of current treatments for CRC. Naringenin (NAR) is a naturally occurring compound found in abundance in various citrus fruits such as oranges, grapefruits, and tomatoes. It possesses a diverse range of pharmacological and biological properties that are beneficial for human health. Numerous studies have highlighted its antioxidant, anticancer, and anti-inflammatory activities, making it a subject of interest in scientific research. This review provides a comprehensive overview of the effects of NAR on CRC. The study's findings indicated that NAR: (1) interacts with estrogen receptors, (2) regulates the expression of genes related to the p53 signaling pathway, (3) promotes apoptosis by increasing the expression of proapoptotic genes (Bax, caspase9, and p53) and downregulation of the antiapoptotic gene Bcl2, (4) inhibits the activity of enzymes involved in cell survival and proliferation, (5) decreases cyclin D1 levels, (6) reduces the expression of cyclin-dependent kinases (Cdk4, Cdk6, and Cdk7) and antiapoptotic genes (Bcl2, x-IAP, and c-IAP-2) in CRC cells. In vitro CDK2 binding assay was also performed, showing that the NAR derivatives had better inhibitory activities on CDK2 than NAR. Based on the findings of this study, NAR is a potential therapeutic agent for CRC. Additional pharmacology and pharmacokinetics studies are required to fully elucidate the mechanisms of action of NAR and establish the most suitable dose for subsequent clinical investigations.

Microbiota in colorectal cancer related to liver metastasis

The prevalence of colorectal cancer (CRC) is increasing annually and metastasis is the principal cause of death in patients with CRC, with the liver being the most frequently affected site. Many studies have shown a strong interplay between the gut flora, particularly Fusobacterium nucleatum (F. nucleatum), Escherichia coli, and Bacteroides fragilis, and the development of gut tumors. Some strains can induce gut inflammation and produce toxins that directly harm gut epithelial cells, ultimately accelerating the onset and progression of CRC. However, little clinical evidence exists on the specific interplay between the gut microflora and colorectal cancer liver metastasis (CRLM). Some research showed the existence of viable F. nucleatum in distant metastasis of CRC. Subsequently, gut microbiota products, such as lipopolysaccharides, sodium butyrate, and protein cathepsin K, were also found to affect the development of CRC. This article summarizes the mechanism and research status of the interplay between gut microflora and CRLM, discusses the importance of gut microflora in the treatment of CRLM, and proposes a new approach to understanding the mechanism of CRLM and potential treatments for the microbiome. It is anticipated that the gut microbiota will be a formidable therapeutic and prophylactic tool for treating and preventing CRLM.

Necrotizing Pneumonia, a Skeletal Muscle Lesion, and a Fungating Duodenal Mass: An Atypical Presentation of Rapidly Progressing Lung Adenocarcinoma

Lung adenocarcinoma, the predominant subtype of non-small cell lung cancer, typically metastasizes to common sites such as the liver and adrenal glands. However, rare instances involve skeletal muscle metastasis. We present a case of a 45-year-old female with a medical history of hypertension, epilepsy, and fibromyalgia, who presented to the emergency department with hemoptysis and multifocal pain. Chest imaging revealed a cavitary lesion which appeared to be necrotizing pneumonia. Further investigations uncovered a fluid collection in the left thigh, which would be identified as poorly differentiated carcinoma. Subsequent testing identified the lung as the primary source of metastasis. Despite radiation treatment, the patient's condition deteriorated over the next 50 days, highlighting the aggressive nature of the disease.

Unique characteristics of the tumor immune microenvironment in young patients with metastatic colorectal cancer

Introduction

Metastatic colorectal cancer (mCRC) remains a common and highly morbid disease, with a recent increase in incidence in patients younger than 50 years. There is an acute need to better understand differences in tumor biology, molecular characteristics, and other age-related differences in the tumor microenvironment (TME).

Methods

111 patients undergoing curative-intent resection of colorectal liver metastases were stratified by age into those <50 years or >65 years old, and tumors were subjected to multiplex fluorescent immunohistochemistry (mfIHC) to characterize immune infiltration and cellular engagement.

Results

There was no difference in infiltration or proportion of immune cells based upon age, but the younger cohort had a higher proportion of programmed death-ligand 1 (PD-L1)+ expressing antigen presenting cells (APCs) and demonstrated decreased intercellular distance and increased cellular engagement between tumor cells (TCs) and cytotoxic T lymphocytes (CTLs), and between TCs and APCs. These trends were independent of microsatellite instability in tumors.

Discussion

Age-related differences in PD-L1 expression and cellular engagement in the tumor microenvironment of patients with mCRC, findings which were unrelated to microsatellite status, suggest a more active immune microenvironment in younger patients that may offer an opportunity for therapeutic intervention with immune based therapy.

Prognostic Value of Tumor Size in Colon Cancer-Smaller is Better?

BACKGROUND

The prognostic value of tumor size in colon cancer remains controversial. This study aimed to reveal the correlation between tumor size and prognosis of colon cancer.

METHODS

A total of 491 patients with colon cancer were included in this study. The correlation of tumor size with prognosis, mismatch repair status, and other clinicopathological characteristics as well as tumor microenvironment was analyzed.

RESULTS

For stage IIA microsatellite stable (MSS) colon cancer, tumors sized <3.5 cm and ≥5 cm were associated with a poorer disease free survival (DFS) compared with tumors sized between 3.5 and 5 cm (P = .002). Small tumor size (HR = 5.098, P = .001) and large tumor size (HR = 2.749, P = .029) were found to be independent prognostic factors for stage IIA MSS colon cancer. Moreover, high expression of transgelin (TAGLN), a marker of cancer-associated fibroblasts (CAFs), was found to be an independent prognostic factor for poorer DFS (HR = 9.651, P = .009), which was also associated with smaller tumor size (P = .027).

CONCLUSION

Small (<3.5 cm) and large (≥5 cm) tumor sizes are associated with decreased DFS in stage IIA MSS colon cancer. Enrichment of TAGLN+ CAFs is associated with decreased DFS and small tumor size.

Theranostic signature of tumor-derived exosomes in cancer

Cancer is the most challenging global health crisis. In the recent times, studies on extracellular vesicles (EVs) are adding a new chapter to cancer research and reports on EVs explores cancer in a new dimension. Exosomes are a group of subpopulations of EVs. It originates from the endosomes and carries biologically active molecules to the neighboring cells which in turn transforms the recipient cell activity. In general, it plays a role in cellular communication. The correlation between exosomes and cancer is fascinating. Tumor-derived exosomes (TEXs) play a dynamic role in cancer progression and are associated with uncontrolled cell growth, angiogenesis, immune suppression, and metastasis. Its molecular cargo is an excellent source of cancer biomarkers. Several advanced molecular profiling approaches assist in exploring the TEXs in depth. This paves the way for a strong foundation for identifying and detecting more specific and efficient biomarkers. TEXs are also gaining importance in scientific society for its role in cancer therapy and several clinical trials based on TEXs is a proof of its significance. In this review, we have highlighted the role of TEXs in mediating immune cell reprogramming, cancer development, metastasis, EMT, organ-specific metastasis, and its clinical significance in cancer theranostics. TEXs profiling is an effective method to understand the complications associated with cancer leading to good health and well-being of the individual and society as a whole.

Molecular mechanisms targeting drug-resistance and metastasis in colorectal cancer: Updates and beyond

Colorectal cancer (CRC) is the third most diagnosed malignancy and a major leading cause of cancer-related deaths worldwide. Despite advances in therapeutic regimens, the number of patients presenting with metastatic CRC (mCRC) is increasing due to resistance to therapy, conferred by a small population of cancer cells, known as cancer stem cells. Targeted therapies have been highly successful in prolonging the overall survival of patients with mCRC. Agents are being developed to target key molecules involved in drug-resistance and metastasis of CRC, and these include vascular endothelial growth factor, epidermal growth factor receptor, human epidermal growth factor receptor-2, mitogen-activated extracellular signal-regulated kinase, in addition to immune checkpoints. Currently, there are several ongoing clinical trials of newly developed targeted agents, which have shown considerable clinical efficacy and have improved the prognosis of patients who do not benefit from conventional chemotherapy. In this review, we highlight recent developments in the use of existing and novel targeted agents against drug-resistant CRC and mCRC. Furthermore, we discuss limitations and challenges associated with targeted therapy and strategies to combat intrinsic and acquired resistance to these therapies, in addition to the importance of implementing better preclinical models and the application of personalized therapy based on predictive biomarkers for treatment selection.

Cardiac Glycoside Oleandrin Suppresses EMT Ability in Endometrial Carcinoma Cells

Endometrial carcinoma is one of the most common types of cancer among women. The progression of cancer occurs via the Epithelial- Mesenchymal Transition (EMT) pathway. Cells lose their epithelial properties and become mobile. For this reason, the EMT process is one of the most important step to be targeted in cancer treatment. Oleandrin is a cardiac glycoside and its use is limited due to its narrow therapeutic index. In this study, we aimed to evaluate effects of lower level Oleandrin doses on EMT process in endometrial carcinoma. Oleandrin was administrated to Ishikawa endometrial adenocarcinoma cells at different doses and times. IC50 dose was determined by XTT proliferation test. Expression analysis of EMT-related genes was then performed by qRT-PCR. Invasion and colony formation abilities of cells were examined microscopically. Finally, the migration analysis of cancer cells was determined by the Wound Healing Assay. The IC50 dose of Oleandrin applied to Ishikawa cells was determined as 75.3 nM at the 48 h. According to qRT-PCR analysis, expression levels of ZEB1, FN1, ITGB1, VIM, SMAD2, SNAI1, SNAI2, SNAI3, and TGFB3 genes significantly decreased, but TIMP2, TIMP3, ITGAV and GSK3B genes significantly increased. In addition, Oleandrin significantly reduced colony formation and invasion of Ishikawa cells. According to the Wound Healing analysis, the migratory abilities of the Oleandrin-treated cells were reduced compared to the control. Low dose Oleandrin suppresses the EMT pathway in Ishikawa cells. It has been shown that Oleandrin significantly suppresses the cell's colony formation, invasion and migration ability both in gene expression analyzes and microscopically.

Multiplex Fluorescent Immunohistochemistry for Preservation of Tumor Microenvironment Architecture and Spatial Relationship of Cells in Tumor Tissues

The tumor microenvironment (TME), composed of immune cells, antigens, and local soluble factors, is integral to cancer development and progression. Traditional techniques such as immunohistochemistry, immunofluorescence, or flow cytometry limit the analysis of spatial data and cellular interactions within the TME, as they are restricted to colocalization of a small number of antigens or the loss of tissue architecture. Multiplex fluorescent immunohistochemistry (mfIHC) allows for detection of multiple antigens within a single tissue sample, providing a more comprehensive description of tissue composition and spatial interactions within the TME. This technique utilizes antigen retrieval, application of primary and secondary antibodies, followed by a tyramide-based chemical reaction to covalently bind a fluorophore to an epitope of interest and, eventually, stripping of the antibodies. This allows for multiple rounds of antibody application without concern for species cross-reactivity, as well as signal amplification which abrogates the autofluorescence that frequently plagues analysis of fixed tissues. As such, mfIHC can be used to quantify multiple cellular populations and their interactions, in situ, unlocking key biologic data that was previously unavailable. This chapter provides an overview of the experimental design, staining, and imaging strategies using a manual technique in formalin-fixed paraffin-embedded tissue sections.

The Role of Transforming Growth Factor Beta and Smad Receptors in Determining Prognosis in High-Grade Primary Brain Tumors: Glioblastoma Multiforme

Introduction High-grade primary brain tumors cause serious morbidity and mortality. This study aimed to investigate the role of transforming growth factor beta (TGF-β) and suppressor of mothers against decapentaplegic (Smad) receptors in high-grade primary brain tumors.

Material and Method Thirteen patients with a pathological diagnosis of glioblastoma multiforme were included in the study. Pathological preparations of each patient were analyzed retrospectively in histochemistry and immunohistochemistry laboratories. Transforming growth factor beta 1, TGF-β2, TGF-β3, Smad 1/2/3, Smad 6, and Smad 7 stainings were evaluated, and the immunoreactivity densities were examined.

Result We found out an increase in the expression of TGF-β1 and TGF-β3 protein. Regarding the inhibitin receptors, Smad 6 showed much more expression than Smad 7. Thus, we found that Smad 6 has a protective effect and role in the tissue. Immunhistochemically, TGF-β family stains, which are activated by types I-and -II receptors, and the stainless staining of the Smad family might also be showing that the TGF-β family is taking action with a secondary pathway other than the Smad family.

Conclusion In addition to Smad family receptors, Shc-GBR2, SARA, and Ras-Erk1/2 receptors should be investigated in future research. After that, the prognosis, diagnosis, and patient-based chemotherapy strategies for the treatment of glioblastoma multiforme may take a more prominent role.

MHC Class II Expression Influences the Composition and Distribution of Immune Cells in the Metastatic Colorectal Cancer Microenvironment

Despite advances in therapy over the past decades, metastatic colorectal cancer (mCRC) remains a highly morbid disease. While the impact of MHC-I on immune infiltration in mCRC has been well studied, data on the consequences of MHC-II loss are lacking. Multiplex fluorescent immunohistochemistry (mfIHC) was performed on 149 patients undergoing curative intent resection for mCRC and stratified into high and low human leukocyte antigen isotype DR (HLA-DR) expressing tumors. Intratumoral HLA-DR expression was found in stromal bands, and its expression level was associated with different infiltrating immune cell makeup and distribution. Low HLA-DR expression was associated with increased intercellular distances and decreased population mixing of T helper cells and antigen-presenting cells (APC), suggestive of decreased interactions. This was associated with less co-localization of tumor cells and cytotoxic T lymphocytes (CTLs), which tended to be in a less activated state as determined by Ki67 and granzyme B expression. These findings suggest that low HLA-DR in the tumor microenvironment of mCRC may reflect a state of poor helper T-cell interactions with APCs and CTL-mediated anti-tumor activity. Efforts to restore/enhance MHC-II presentation may be a useful strategy to enhance checkpoint inhibition therapy in the future.

AKR1B10 accelerates the production of proinflammatory cytokines via the NF-κB signaling pathway in colon cancer

Aldo-keto reductase family one, member B10 (AKR1B10) has been reported to be involved in the tumorigenesis of various cancers. It has been reported that colorectal cancer is closely associated with chronic inflammation, but the underlying molecular mechanisms are still elusive. In our study, we evaluated the relationship between AKR1B10 expression and clinicopathological characteristics of colon cancer and showed that AKR1B10 expression was significantly correlated with the T stage and clinical stage of colon cancer. Knockdown of AKR1B10 significantly decreased the expression of the inflammatory cytokines IL1α and IL6 induced by lipopolysaccharide by inhibiting the NF-κB signaling pathway. Furthermore, AKR1B10 depends on its reductase activity to affect the NF-κB signaling pathway and subsequently affect the production of inflammatory cytokines. In addition, knockdown of AKR1B10 effectively reduced cell proliferation and clonogenic growth, indicating the biological role of AKR1B10 in colon cancer. Together, our findings provide important insights into a previously unrecognized role of AKR1B10 in colon cancer.

Drainage of senescent astrocytes from brain via meningeal lymphatic routes

Recent progress on the central lymphatic system has greatly increased our understanding of how the brain maintains its own waste homeostasis. Here, we showed that perivascular spaces and meningeal lymphatic vessels form a functional route for clearance of senescent astrocytes from the aging brain. Blocking meningeal lymphatic drainage by ligation of the deep cervical lymph nodes impaired clearance of senescent astrocytes from brain parenchyma, subsequently increasing neuroinflammation in aged mice. By contrast, enhancing meningeal lymphatic vessel diameter by a recombinant adeno-associated virus encoding mouse vascular endothelial growth factor-C (VEGF-C) improved clearance of senescent astrocytes and mitigated neuroinflammation. Mechanistically, VEGF-C was highly expressed in senescent astrocytes, contributing themselves to migrate across lymphatic vessels along C-C motif chemokine ligand 21 (CCL21) gradient by interacting with VEGF receptor 3. Moreover, intra-cisternal injection of antibody against CCL21 hampered senescent astrocytes into the lymphatic vessels and exacerbated short memory defects of aged mice. Together, these findings reveal a new perspective for the meningeal lymphatics in the removal of senescent astrocytes, thus offering a valuable target for therapeutic intervention.

Investigating key cell types and molecules dynamics in PyMT mice model of breast cancer through a mathematical model

The most common kind of cancer among women is breast cancer. Understanding the tumor microenvironment and the interactions between individual cells and cytokines assists us in arriving at more effective treatments. Here, we develop a data-driven mathematical model to investigate the dynamics of key cell types and cytokines involved in breast cancer development. We use time-course gene expression profiles of a mouse model to estimate the relative abundance of cells and cytokines. We then employ a least-squares optimization method to evaluate the model’s parameters based on the mice data. The resulting dynamics of the cells and cytokines obtained from the optimal set of parameters exhibit a decent agreement between the data and predictions. We perform a sensitivity analysis to identify the crucial parameters of the model and then perform a local bifurcation on them. The results reveal a strong connection between adipocytes, IL6, and the cancer population, suggesting them as potential targets for therapies.

One of the outstanding challenges of the mathematical modeling of cancer progression is the existence of many unknown parameters. In this work, we develop a data-driven mathematical model of breast cancer progression by deriving a system of ordinary differential equations for the interaction networks of key cell types and molecules in breast tumors. To overcome the limitations of unknown parameters, we utilize a time course data of a PyMT mice model of breast cancer and estimate parameters using an optimization method. Although the predicted dynamics of cancer and necrotic cells using the obtained values of parameters are in good agreement with the data, the predicted values for a few other variables do not match the data. This might indicate that there are some other key interactions that have not been modeled, and/or there is a noise in the data. The sensitivity and bifurcation analyses show that the most important parameters in controlling the cancer cells population are the proliferation and death rates of cancer cells and adipocytes. These results are in agreement with some biological and clinical studies of breast cancer, which have reported a link between adipocytes and breast cancer progression.

The Impact of Obesity, Adipose Tissue, and Tumor Microenvironment on Macrophage Polarization and Metastasis

Simple Summary

The inflammatory adipose microenvironment in obesity plays a crucial role in cancer development and metastases. By focusing on adipocytes and macrophages, as well as the extracellular matrix, the cellular and molecular mechanisms that link inflammation, obesity, and cancer will be addressed by this review. After describing the tumor microenvironment and extracellular matrix, the influence of M1, M2, and tumor-associated macrophages will be explored through their origin, classification, polarization, and regulatory networks, including their potential role in angiogenesis, invasion, metastasis, and immunosuppression, with a specific focus on the roles of adipocytes in this process.

Abstract

Tumor metastasis is a major cause of death in cancer patients. It involves not only the intrinsic alterations within tumor cells, but also crosstalk between these cells and components of the tumor microenvironment (TME). Tumorigenesis is a complex and dynamic process, involving the following three main stages: initiation, progression, and metastasis. The transition between these stages depends on the changes within the extracellular matrix (ECM), in which tumor and stromal cells reside. This matrix, under the effect of growth factors, cytokines, and adipokines, can be morphologically altered, degraded, or reorganized. Many cancers evolve to form an immunosuppressive TME locally and create a pre-metastatic niche in other tissue sites. TME and pre-metastatic niches include myofibroblasts, immuno-inflammatory cells (macrophages), adipocytes, blood, and lymphatic vascular networks. Several studies have highlighted the adipocyte-macrophage interaction as a key driver of cancer progression and dissemination. The following two main classes of macrophages are distinguished: M1 (pro-inflammatory/anti-tumor) and M2 (anti-inflammatory/pro-tumor). These cells exhibit distinct microenvironment-dependent phenotypes that can promote or inhibit metastasis. On the other hand, obesity in cancer patients has been linked to a poor prognosis. In this regard, tumor-associated adipocytes modulate TME through the secretion of inflammatory mediators, which modulate and recruit tumor-associated macrophages (TAM). Hereby, this review describes the cellular and molecular mechanisms that link inflammation, obesity, and cancer. It provides a comprehensive overview of adipocytes and macrophages in the ECM as they control cancer initiation, progression, and invasion. In addition, it addresses the mechanisms of tumor anchoring and recruitment for M1, M2, and TAM macrophages, specifically highlighting their origin, classification, polarization, and regulatory networks, as well as their roles in the regulation of angiogenesis, invasion, metastasis, and immunosuppression, specifically highlighting the role of adipocytes in this process.

Potential Application of Exosomes in Vaccine Development and Delivery

Exosomes are cell-derived components composed of proteins, lipid, genetic information, cytokines, and growth factors. They play a vital role in immune modulation, cell-cell communication, and response to inflammation. Immune modulation has downstream effects on the regeneration of damaged tissue, promoting survival and repair of damaged resident cells, and promoting the tumor microenvironment via growth factors, antigens, and signaling molecules. On top of carrying biological messengers like mRNAs, miRNAs, fragmented DNA, disease antigens, and proteins, exosomes modulate internal cell environments that promote downstream cell signaling pathways to facilitate different disease progression and induce anti-tumoral effects. In this review, we have summarized how vaccines modulate our immune response in the context of cancer and infectious diseases and the potential of exosomes as vaccine delivery vehicles. Both pre-clinical and clinical studies show that exosomes play a decisive role in processes like angiogenesis, prognosis, tumor growth metastasis, stromal cell activation, intercellular communication, maintaining cellular and systematic homeostasis, and antigen-specific T- and B cell responses. This critical review summarizes the advancement of exosome based vaccine development and delivery, and this comprehensive review can be used as a valuable reference for the broader delivery science community.

A reciprocal feedback of miR-548ac/YB-1/Snail induces EndMT of HUVECs during acidity microenvironment

Background

Researches indicated the process of Endothelial-Mesenchymal-Transition (EndMT) of vascular endothelial cells (ECs) was critically involved in the progression of tumor. ECs demonstrated functional and phenotypic heterogeneity when located under different microenvironments. The extracellular pH of tumor tissues was acidic compared to that of normal tissues. However, there was still unclear whether the acidic microenvironment affected the EndMT of vascular ECs.

Methods

Human Umbilical Vein Endothelial Cell (HUVECs) was cultured under the normal or acidic medium to evaluate the alteration of morphology, migration, permeability, and EndMT markers. Microarray assay was adopted to analyze the differential expression of miRNAs in the acidity-treated HUVECs. Gain- and loss- of function experiments were performed to evaluate the functional role of miRNA-548ac on acidity-induced EndMT of HUVECs. Luciferase reporter and Chromatin-immunoprecipitation assays were conducted to assess the downstream pathway of miRNA-548ac in acidity-induced EndMT of HUVECs.

Results

Our results showed that HUVECs demonstrated mesenchymal transition under acidic conditions with the increase of migration, permeability, and expression of α-SMA and Vimentin, but the expression of vascular endothelial cadherin (VE-cadherin) and CD31 were reduced. In addition, the acidity-treated HUVECs remarkably facilitated the transmigration of pancreatic cancer cells. The expression of miRNA-548ac was significantly decreased in the acidity-treated HUVECs. Moreover, overexpression of miR-548ac inhibited the EndMT of HUVECs and consequently impeded the transmigration of pancreatic cancer cells. The miR-548ac inhibited the expression of YB-1 by binding to the 3’UTR of its mRNA, and YB-1 promoted the translation of Snail which was a critical regulator of EndMT. What’s more, Snail transcriptionally inhibited the expression of miR-548ac through binding to the promoter of its host gene.

Conclusions

Our data implicated that the acidic microenvironment promoted the EndMT of HUVECs by the miR-548ac/YB-1/Snail axis, which could contribute to the metastasis of pancreatic cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02388-8.

Yerba Mate Modulates Tumor Cells Functions Involved in Metastasis in Breast Cancer Models

Breast cancer (BC) is the most frequent cancer in women and tumor metastasis is a major cause of cancer-related deaths. Our aim was to evaluate anti-metastatic properties of yerba mate extract (YMe) in BC models. 4T1, F3II, MCF-7, and MDA-MB231 cell lines were used to perform in vitro assays. The F3II syngeneic mammary carcinoma model in BALB/c mice was used to evaluate tumor progression, BC metastasis and survival. Cells were inoculated subcutaneously into the flank for the heterotopic model and into the mammary fat pad for the orthotopic model. YMe was administered p.o. in a dose of 1.6 g/kg/day. In vitro YMe inhibited cell proliferation and reduced tumor cell adhesion, migration and invasion. These biological effects were cell-line dependent. In vivo YMe reduced tumor metastasis and increased mice survival in both models. Our preclinical results suggest that YMe could modulate tumor progression and metastasis in BC models.

Extracellular Matrix Biomarkers in Colorectal Cancer

The cellular microenvironment composition and changes therein play an extremely important role in cancer development. Changes in the extracellular matrix (ECM), which constitutes a majority of the tumor stroma, significantly contribute to the development of the tumor microenvironment. These alterations within the ECM and formation of the tumor microenvironment ultimately lead to tumor development, invasion, and metastasis. The ECM is composed of various molecules such as collagen, elastin, laminin, fibronectin, and the MMPs that cleave these protein fibers and play a central role in tissue remodeling. When healthy cells undergo an insult like DNA damage and become cancerous, if the ECM does not support these neoplastic cells, further development, invasion, and metastasis fail to occur. Therefore, ECM-related cancer research is indispensable, and ECM components can be useful biomarkers as well as therapeutic targets. Colorectal cancer specifically, is also affected by the ECM and many studies have been conducted to unravel the complex association between the two. Here we summarize the importance of several ECM components in colorectal cancer as well as their potential roles as biomarkers.

Extreme value theory as a framework for understanding mutation frequency distribution in cancer genomes

Currently, the population dynamics of preclonal cancer cells before clonal expansion of tumors has not been sufficiently addressed thus far. By focusing on preclonal cancer cell population as a Darwinian evolutionary system, we formulated and analyzed the observed mutation frequency among tumors (MFaT) as a proxy for the hypothesized sequence read frequency and beneficial fitness effect of a cancer driver mutation. Analogous to intestinal crypts, we assumed that sample donor patients are separate culture tanks where proliferating cells follow certain population dynamics described by extreme value theory (EVT). To validate this, we analyzed three large-scale cancer genome datasets, each harboring > 10000 tumor samples and in total involving > 177898 observed mutation sites. We clarified the necessary premises for the application of EVT in the strong selection and weak mutation (SSWM) regime in relation to cancer genome sequences at scale. We also confirmed that the stochastic distribution of MFaT is likely of the Fréchet type, which challenges the well-known Gumbel hypothesis of beneficial fitness effects. Based on statistical data analysis, we demonstrated the potential of EVT as a population genetics framework to understand and explain the stochastic behavior of driver-mutation frequency in cancer genomes as well as its applicability in real cancer genome sequence data.

Cancer-Associated Fibroblasts Modulate Transcriptional Signatures Involved in Proliferation, Differentiation and Metastasis in Head and Neck Squamous Cell Carcinoma

Simple Summary

Cancer-associated fibroblasts (CAFs) are the major cellular component of the tumor microenvironment and have been shown to stimulate tumor growth, epithelial-to-mesenchymal transition (EMT), invasion, and radio-resistance. Radio-resistance leading to disease relapse is one of the major challenges in long-term survival and outcome in head and neck squamous cell carcinoma (HNSCC). Therefore, it is essential to search for predictive markers and new targets for treatment using clinically relevant in vitro tumor models. We show that CAFs alter the expression of HNSCC tumor cell genes, many of which are associated with proliferation, differentiation, and metastasis. Moreover, the expression pattern of selected CAF-regulated genes differed between HNSCC tumor tissue and the adjacent non-tumoral tissue. Two CAF-regulated genes, MMP9 and FMOD, were found to be associated with overall survival (OS) in patients treated with radiotherapy.

Abstract

Cancer-associated fibroblasts (CAFs) are known to increase tumor growth and to stimulate invasion and metastasis. Increasing evidence suggests that CAFs mediate response to various treatments. HNSCC cell lines were co-cultured with their patient-matched CAFs in 2D and 3D in vitro models, and the tumor cell gene expression profiles were investigated by cDNA microarray and qRT-PCR. The mRNA expression of eight candidate genes was examined in tumor biopsies from 32 HNSCC patients and in five biopsies from normal oral tissue. Differences in overall survival (OS) were tested with Kaplan–Meier long-rank analysis. Thirteen protein coding genes were found to be differentially expressed in tumor cells co-cultured with CAFs in 2D and 81 in 3D when compared to tumor cells cultured without CAFs. Six of these genes were upregulated both in 2D and 3D (POSTN, GREM1, BGN, COL1A2, COL6A3, and COL1A1). Moreover, two genes upregulated in 3D, MMP9 and FMOD, were significantly associated with the OS. In conclusion, we demonstrated in vitro that CAF-derived signals alter the tumor cell expression of multiple genes, several of which are associated with differentiation, epithelial-to-mesenchymal transition (EMT) phenotype, and metastasis. Moreover, six of the most highly upregulated genes were found to be overexpressed in tumor tissue compared to normal tissue.

Granulin: An Invasive and Survival-Determining Marker in Colorectal Cancer Patients

Background: Granulin is a secreted, glycosylated peptide—originated by cleavage from a precursor protein—which is involved in cell growth, tumor invasion and angiogenesis. However, the specific prognostic impact of granulin in human colorectal cancer has only been studied to a limited extent. Thus, we wanted to assess the expression of granulin in colorectal cancer patients to evaluate its potential as a prognostic biomarker. Methods: Expressional differences of granulin in colorectal carcinoma tissue (n = 94) and corresponding healthy colon mucosa were assessed using qRT-PCR. Immunohistochemistry was performed in colorectal cancer specimens (n = 97), corresponding healthy mucosa (n = 47) and colorectal adenomas (n = 19). Subsequently, the results were correlated with histopathological and clinical patients’ data. HCT-116 cells were transfected with siRNA for invasion and migration assays. Results: Immunohistochemistry and qRT-PCR revealed tumoral over expression of granulin in colorectal cancer specimens compared to corresponding healthy colon mucosa and adenomas. Tumoral overexpression of granulin was associated with a significantly impaired overall survival. Moreover, downregulation of granulin by siRNA significantly diminished the invasive capacities of HCT-116 cells in vitro. Conclusion: Expression of granulin differs in colorectal cancer tissue, adenomas and healthy colon mucosa. Furthermore, granulin features invasive and migrative capabilities and overexpression of granulin correlates with a dismal prognosis. This reveals its potential as a prognostic biomarker and granulin could be a worthwhile molecular target for individualized anticancer therapy.

Construction of an immune-related signature with prognostic value for colon cancer

BACKGROUND

Colon cancer is the third most common malignant tumor in the world. Although immunotherapy has been used in cancer treatment, there is still no first-line immunotherapy method for colon cancer. Therefore, it is essential to search for potential immunotherapy targets and molecular biomarkers for early diagnosis and prognosis.

METHODS

In this study, we downloaded transcriptome data from The Cancer Genome Atlas (TCGA) and immune-related genes from the ImmPort database. Then we filtered genes with prognostic value and constructed an immune-related signature. Patients were classified into low- and high-risk groups, and we exerted a series of analysis between the signature and clinical phenotypes. Additionally, we used protein-protein interaction networks, gene set enrichment analysis (GSEA) and single-sample gene-set enrichment analysis (ssGSEA) to explore the underlying mechanism of this signature. Furthermore, the accuracy of this signature was verified, using two data sets from Gene Expression Omnibus (GEO).

RESULTS

We selected 12 immune-related genes to construct the immune-related signature. Low-risk group had a higher level of immunity compared to high-risk group. The expression level of HLA genes and checkpoint-related genes were statistically different in low- and high-risk groups. This signature showed its prognostic value in TCGA cohort and 2 GEO data sets. The signature also had strong correlation with TNM classification, stage, survival state and lymphatic invasion. The mechanism of the signature may be related to several transcription factors and CD8+ T cell in the tumor microenvironment.

CONCLUSION

In conclusion, this immune-related signature is of great prognosis value for colon cancer and its biofunction might be correlated with HLA genes, checkpoint-related genes and high-infiltrating T cells in tumor tissues.

Site of Recurrence and Survival After Surgery for Colorectal Peritoneal Metastasis

BACKGROUND

Multimodal treatment, including systemic treatment and surgery, improved the prognosis of peritoneal metastasis (PM). Despite all efforts, recurrence rates remain high, and little data are available about clinical behavior or molecular patterns of PM in comparison to hematogenous metastasis. Here, we aimed to analyze recurrence patterns after multimodal treatment for PM from colorectal cancer.

METHODS

Patients with colorectal PM undergoing multimodal treatment including systemic chemotherapy and cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) between 2005 and 2017 at 4 centers were analyzed retrospectively.

RESULTS

A total of 505 patients undergoing CRS/HIPEC were analyzed. Of the patients, 82.1% received preoperative chemotherapy. Median peritoneal cancer index was 6 (interquartile range = 3-11). Median disease-free and overall survival was 12 (95% confidence interval [CI] = 11 to 14) months and 51 (95% CI = 43 to 62) months, respectively. Disease recurred in 361 (71.5%) patients, presenting as isolated peritoneal recurrence in 24.6%, isolated hematogenous recurrence in 28.3%, and mixed recurrence in 13.9% of patients. Recurrence to the peritoneum was associated with an impaired time from recurrence to death of 21 (95% CI = 18 to 31) months for isolated peritoneal and 22 (95% CI = 16 to 30) months for mixed recurrence, compared with 43 (95% CI = 31 to >121) months for hematogenous recurrence (hazard ratio [HR] = 1.79, 95% CI = 1.27 to 2.53; P = .001; and HR = 2.44, 95% CI = 1.61 to 3.79; P < .001). On multiple logistic regression analysis, RAS mutational status (odds ratio [OR] = 2.42, 95% CI = 1.11 to 5.47; P = .03) and positive nodal stage of the primary (OR = 3.88, 95% CI = 1.40 to 11.86; P = .01) were identified as predictive factors for peritoneal recurrence.

CONCLUSIONS

This study highlights the heterogeneity of peritoneal metastasis in patients with colorectal cancer. Recurrent peritoneal metastasis after radical treatment represents a more aggressive subset of metastatic colorectal cancer.

Exosomes: The protagonists in the tale of colorectal cancer?

Exosomes, which facilitate intercellular communication, antigen presentation and shuttling of biological agents, were initially thought as the cell's garbage cargo but today, after about 40 years of their discovery, we are now beginning to understand their potential role in diagnosis and therapy of several diseases including cancers. Various studies over the decades have signified the role of exosomes in different stages of cancer. Exosomes play a key role in colorectal cancer initiation (CRC), promotion of anti- apoptotic signaling pathways, regulating tumor microenvironment, enhancing tumorigenicity, promotion of angiogenesis, stem cell proliferation and endothelial cell migration, establishment of immune suppressive environment, formation of pre- metastatic niche and metastasis. Exosomes also elicits drug resistance. Since, they have the ability to cross the biological barrier, exosomes are now being explored as an efficient target specific drug delivery system that facilitates the shipping of different biomolecules and therapeutic drugs. However, cautious and strong investigative approaches are required before approving exosomes as therapeutics or drug delivery systems. In this review, we summarize the role of exosomes in different stages of CRC and also elaborate on the applications of exosomes in diagnosis and therapy with respect to CRC.

A System Biology-Based Approach for Designing Combination Therapy in Cancer Precision Medicine

In this paper, we have used an agent-based stochastic tumor growth model and presented a mathematical and theoretical perspective to cancer therapy. This perspective can be used to theoretical study of precision medicine and combination therapy in individuals. We have conducted a series of in silico combination therapy experiments. Based on cancer drugs and new findings of cancer biology, we hypothesize relationships between model parameters which in some cases represent individual genome characteristics and cancer drugs, i.e., in our approach, therapy players are delegated by biologically reasonable parameters. In silico experiments showed that combined therapies are more effective when players affect tumor via different mechanisms and have different physical dimensions. This research presents for the first time an algorithm as a theoretical viewpoint for the prediction of effectiveness and classification of therapy sets.

Significance of E-cadherin and Vimentin as epithelial-mesenchymal transition markers in colorectal carcinoma prognosis

Colorectal cancer is the most common malignancy of the gastrointestinal tract with very high mortality. One of the most distinguishing features for the establishment of an epithelial-mesenchymal transition phenotype is the alteration of mesenchymal markers and structural adhesion proteins. We investigated the level of Vimentin and E-cadherin expression in relation to invasion and metastasis on colorectal cancer patients. Tissue specimens were collected consecutively from thirty-nine colorectal carcinoma patients during surgeries. The patients were diagnosed and treated between 2013 and 2016. In order to histological staging, tissue sections were prepared from formalin-fixed paraffin-embedded blocks and stained with Hematoxylin and Eosin. Also for evaluating the epithelial-mesenchymal transition markers, E-cadherin and Vimentin, all patient samples were stained and detected via immunohistochemistry, and afterwards the results were analyzed to determine whether these markers could be useful prognostic markers for predicting colorectal cancer patient outcomes. The expression of Vimentin as a mesenchymal marker along with rising grade of cancer, pathological stages, and metastasis to regional lymph nodes increased furthermore, in cancers with vascular invasion, Vimentin value was high. Reversely, the expression of E-cadherin with climbing grade, stages and colon cancer categories decreased and also in cancers with vascular invasion reduced. Variation of the markers had no relation to age and sex. In summary, along with cancer progression level of Vimentin expression varies inversely with E-cadherin expression and by increasing metastasis and invasion the Vimentin expression elevates. Further evaluation in this area might lead to a good method for predicting progressive clone cancer.

Hypomethylating Agent Azacitidine Is Effective in Treating Brain Metastasis Triple-Negative Breast Cancer Through Regulation of DNA Methylation of Keratin 18 Gene

Breast cancer patients presenting with symptomatic brain metastases have poor prognosis, and current chemotherapeutic agents are largely ineffective. In this study, we evaluated the hypomethylating agent azacitidine (AZA) for its potential as a novel therapeutic in preclinical models of brain metastasis of breast cancer. We used the parental triple-negative breast cancer MDA-MB-231 (231) cells and their brain colonizing counterpart (231Br) to ascertain phenotypic differences in response to AZA. We observed that 231Br cells have higher metastatic potential compared to 231 cells. With regard to therapeutic value, the AZA IC50 value in 231Br cells is significantly lower than that in parental cells (P < .01). AZA treatment increased apoptosis and inhibited the Wnt signaling transduction pathway, angiogenesis, and cell metastatic capacity to a significantly higher extent in the 231Br line. AZA treatment in mice with experimental brain metastases significantly reduced tumor burden (P = .0112) and increased survival (P = .0026) compared to vehicle. Lastly, we observed a decreased expression of keratin 18 (an epithelial maker) in 231Br cells due to hypermethylation, elucidating a potential mechanism of action of AZA in treating brain metastases from breast cancer.

β-Carotene exerts anti-colon cancer effects by regulating M2 macrophages and activated fibroblasts

The tumor microenvironment (TME), consisting of stromal fibroblasts, immune cells, cancer cells and other cell types, plays a crucial role in cancer progression and metastasis. M2 macrophages and activated fibroblasts (AFs) modulate behavior of cancer cells in the TME. Since nutritional effects on cancer progression, including colorectal cancer (CRC), may be mediated by alterations in the TME, we determined the ability of β-carotene (BC) to mediate anti-cancer effects through regulation of macrophage polarization and fibroblast activation in CRC. The M2 macrophage phenotype was induced by treating U937 cells with phorbol-12-myristate-13-acetate and interleukin (IL)-4. Treatment of these M2 macrophages with BC led to suppression of M2-type macrophage-associated markers and of the IL-6/STAT3 signaling pathway. In separate experiments, AFs were induced by treating CCD-18Co cells with transforming growth factor-β1. BC treatment suppressed expression of fibroblast activation markers. In addition, conditioned media from BC-treated M2 macrophages and AF inhibited cancer stem cell markers, colon cancer cell invasiveness and migration, and the epithelial-mesenchymal transition (EMT). In vivo, BC supplementation inhibited tumor formation and the expression of M2 macrophage markers in an azoxymethane/dextran sodium sulfate-induced colitis-associated CRC mouse model. To our knowledge, the present findings provide the first evidence suggesting that the potential therapeutic effects of BC on CRC are mediated by the inhibition of M2 macrophage polarization and fibroblast activation.

Localization of Rolling and Firm-Adhesive Interactions Between Circulating Tumor Cells and the Microvasculature Wall

INTRODUCTION

The adhesion of tumor cells to vessel wall is a critical stage in cancer metastasis. Firm adhesion of cancer cells is usually followed by their extravasation through the endothelium. Despite previous studies identifying the influential parameters in the adhesive behavior of the cancer cell to a planer substrate, less is known about the interactions between the cancer cell and microvasculature wall and whether these interactions exhibit organ specificity. The objective of our study is to characterize sizes of microvasculature where a deformable circulating cell (DCC) would firmly adhere or roll over the wall, as well as to identify parameters that facilitate such firm adherence and underlying mechanisms driving adhesive interactions.

METHODS

A three-dimensional model of DCCs is applied to simulate the fluid-structure interaction between the DCC and surrounding fluid. A dynamic adhesion model, where an adhesion molecule is modeled as a spring, is employed to represent the stochastic receptor-ligand interactions using kinetic rate expressions.

RESULTS

Our results reveal that both the cell deformability and low shear rate of flow promote the firm adhesion of DCC in small vessels ( < 10 μ m ). Our findings suggest that ligand-receptor bonds of PSGL-1-P-selectin may lead to firm adherence of DCC in smaller vessels and rolling-adhesion of DCC in larger ones where cell velocity drops to facilitate the activation of integrin-ICAM-1 bonds.

CONCLUSIONS

Our study provides a framework to predict accurately where different DCC-types are likely to adhere firmly in microvasculature and to establish the criteria predisposing cancer cells to such firm adhesion.

Crosstalk between cancer-associated fibroblasts and immune cells in cancer

Multiple studies have shown that cancer‐associated fibroblasts (CAFs) play an important role in tumour progression, including carcinogenesis, invasion, metastasis and the chemoresistance of cancer cells. Immune cells, including macrophages, natural killer cells, dendritic cells and T cells, play a dual role in the tumour microenvironment. Although increasing research has focused on studying interactions between distinct cells in the tumour microenvironment, the complex relationships between CAFs and immune cells remain unclear and need further study. Here, we summarize our current understanding of crosstalk between CAFs and immune cells, which may help clarify their diagnostic and therapeutic value in tumour progression.

Natural product pectolinarigenin exhibits potent anti-metastatic activity in colorectal carcinoma cells in vitro and in vivo

Colorectal carcinoma (CRC) is one of the most common cancers with high metastatic potential, explaining why identifying new drug candidates that inhibit tumour metastasis is an urgent need. The aim of this study was to evaluate the biological activities of pectolinarigenin (PEC, a natural flavonoid present in Cirsium chanroenicum) in CRC in vitro and in vivo and to determine its underlying mechanism of action. Here, we observed that treatment with PEC could inhibit cell viability and induce apoptosis in cancer cells in a concentration- and time-dependent manner. The occurrence of apoptosis was associated with activation of caspase-3 and Bax and decreased expression of Bcl-2. In addition, PEC markedly impaired CRC cell migration and invasion by downregulating the expression of matrix metalloproteinase (MMP-9) and phosphorylated-Stat3^Tyr705. Moreover, our studies showed that PEC inhibited abdominal metastasis models of murine colorectal cancer. In addition, histological and immunohistochemical analyses revealed a decrease in Ki67-positive cells, MMP9-positive cells and p-Stat3^Tyr705 cells upon treatment with PEC compared to control samples. Furthermore, PEC reduced the number of myeloid-derived suppressor cells (MDSCs) in the blood and tumours, which was accompanied by the increased infiltration of CD8⁺T cells in the blood. Taken together, our findings suggested that PEC could be used as a natural drug to inhibit CRC metastasis.

MiRNAs roles in the diagnosis, prognosis and treatment of colorectal cancer

Introduction: The liver is the main location for metastasization in stage IV colorectal cancers. Areas covered: This review intends to comprehensively present the most important studies conducted in the past few years concerning the role of miRNAs in colorectal cancer liver metastases, trying to clarify some aspects regarding tumor biology and favorite liver metastasization site. Expert commentary: Recent advances in tissue and serum RNA extraction has considerably improved the field of microRNAs studies. These molecules known to play a crucial role in the metastatic stage indicate a starting point in the development of clinical biomarkers with a possible role in the stratification of high-risk patients for adequate treatment.

A Deregulated PI3K-AKT Signaling Pathway in Patients with Colorectal Cancer

BACKGROUND

Molecular switches in phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway may serve as potential targets for the treatment of colorectal cancer (CRC). This study aims to profile the gene alterations involved in PI3K-AKT signaling pathway in patients with CRC.

METHODS

Tumoral and matched peritumoral tissues were collected from 15 CRC patients who went routine surgery. A human PI3K-AKT signaling pathway polymerase chain reaction (PCR) array, which profiled the transcriptional changes of a total number of 84 genes involved in the PI3K-AKT pathway, was then applied to determine the gene alterations in CRC tumoral tissue with matched peritumoral tissue as a healthy control. Subsequent real-time reverse transcription PCR and western blot (WB) with different subgroups of CRC patients were then performed to further validate the array findings.

RESULTS

The PCR array identified 14 aberrantly expressed genes involved in the PI3K-AKT signaling pathway in CRC tumoral tissue, among which 12 genes, CCND1, CSNK2A1, EIF4E, EIF4EBP1, EIF4G1, FOS, GRB10, GSK3B, ILK, PTK2, PTPN11, and PHEB were significantly up-modulated (> two fold) while the remaining two, PDK1 and PIK3CG, were down-regulated (> two fold). These genes involve in the regulation of gene transcription and translation, cell cycle, and cell growth, proliferation, and differentiation. The real-time reverse transcription PCR validation agreed with the array data towards the tested genes, CCND1, EIF4E, FOS, and PIK3CG, while it failed to obtain similar result for PDK1. Interestingly, the WB analyses were further consistent with the PCR results that the protein levels of CCND1, EIF4E, and FOS were apparently up-regulated and that protein PIK3CG was down-modulated.

CONCLUSION

Taken together, the present study identified a deregulated PI3K-AKT signaling pathway in CRC patients, which might serve as therapeutic target(s).

Colorectal cancer-associated ~ 6 kDa hyaluronan serves as a novel biomarker for cancer progression and metastasis

Low molecular weight hyaluronan (LMW-HA) is believed to accumulate in tumors and to exert protumor effects. This study aimed to identify colorectal cancer (CRC)-associated LMW-HA, precisely determine its MW, and elucidate its role in predicting tumor progression. The MW distribution of HA extracted from CRC and paired noncancerous tissues was evaluated. We found that the level of HA with a MW below 30 kDa was markedly elevated in CRC tissues, and we defined HA with a MW of ~ 6 kDa as CRC-associated LMW-HA. In line with this finding, ~ 6 kDa HA was significantly accumulated in cancer tissues relative to total HA, and this LMW-HA played a critical role in tumor metastasis. Moreover, serum ~ 6 kDa HA levels in CRC patients were significantly increased and positively correlated with the levels in matched cancer tissues. Elevated serum ~ 6 kDa HA levels could be used to discriminate patients with or without CRC and was associated with early relapse, advanced tumor-node-metastasis stage, lymphovascular invasion, and lymph node (LN) metastasis. Notably, serum ~ 6 kDa HA levels were significantly reduced after tumor resection. Our study suggests that ~ 6 kDa HA may serve as a new biomarker for estimating tumor progression, predicting LN metastasis, and monitoring tumor recurrence.

Exosomes: composition, biogenesis, and mechanisms in cancer metastasis and drug resistance

Tumor-derived exosomes (TDEs) participate in formation and progression of different cancer processes, including tumor microenvironment (TME) remodeling, angiogenesis, invasion, metastasis and drug-resistance. Exosomes initiate or suppress various signaling pathways in the recipient cells via transmitting heterogeneous cargoes. In this review we discuss exosome biogenesis, exosome mediated metastasis and chemoresistance. Furthermore, tumor derived exosomes role in tumor microenvironment remodeling, and angiogenesis is reviewed. Also, exosome induction of epithelial mesenchymal transition (EMT) is highlighted. More importantly, we discuss extensively how exosomes regulate drug resistance in several cancers. Thus, understanding exosome biogenesis, their contents and the molecular mechanisms and signaling pathways that are responsible for metastasis and drug-resistance mediated by TDEs may help to devise novel therapeutic approaches for cancer progression particularly to overcome therapy-resistance and preventing metastasis as major factors of cancer mortality.

Spatial and phenotypic immune profiling of metastatic colon cancer

Paramount to the efficacy of immune checkpoint inhibitors is proper selection of patients with adequate tumor immunogenicity and a robust but suppressed immune infiltrate. In colon cancer, immune-based therapies are approved for patients with DNA mismatch repair (MMR) deficiencies, in whom accumulation of genetic mutations results in increased neoantigen expression, triggering an immune response that is suppressed by the PD-L1/PD-1 pathway. Here, we report that characterization of the microenvironment of MMR-deficient metastatic colorectal cancer using multiplex fluorescent immunohistochemistry (mfIHC) identified increased infiltration of cytotoxic T lymphocytes (CTLs), which were more often engaged with epithelial cells (ECs) and improved overall survival. A subset of patients with intact MMR but a similar immune microenvironment to MMR-deficient patients was identified and found to universally express high levels of PD-L1, suggesting that they may represent a currently untreated, checkpoint inhibitor-responsive population. Further, PD-L1 expression on antigen-presenting cells (APCs) in the tumor microenvironment (TME) resulted in impaired CTL/EC engagement and enhanced infiltration and engagement of Tregs. Characterization of the TME by mfIHC highlights the interconnection between immunity and immunosuppression in metastatic colon cancer and may better stratify patients for receipt of immunotherapies.

Tumor suppressive role of rottlerin in cancer therapy

Cancer as a major public health problem is a big trouble to be cured at present in the world. Thus, it is essential to discover better anticancer drugs to treat cancer patients. It has been reported that rottlerin, a natural polyphenolic compound from the mature fruits of Mallotus philippinensis, possesses multiple anti-cancer biological activities. Rottlerin exhibited its antitumor property in a variety of human cancers, suggesting that rottlerin could be a potential agent for treating cancers. In this review we discuss the recent literature regarding the biological functions and tumor suppressive mechanisms of rottlerin in cancers. We hope rottlerin will be further exploited for potential treatment of human cancers.

Up-regulation of collagen proteins in colorectal liver metastasis compared with normal liver tissue

Changes to extracellular matrix (ECM) structures are linked to tumor cell proliferation and metastasis. We previously reported that naturally occurring peptides of collagen type I are elevated in urine of patients with colorectal liver metastasis (CRLM). In the present study, we took an MS-based proteomic approach to identify specific collagen types that are up-regulated in CRLM tissues compared with healthy, adjacent liver tissues from the same patients. We found that 19 of 22 collagen-α chains are significantly up-regulated (p < 0.05) in CRLM tissues compared with the healthy tissues. At least four collagen-α chains were absent or had low expression in healthy colon and adjacent tissues, but were highly abundant in both colorectal cancer (CRC) and CRLM tissues. This expression pattern was also observed for six noncollagen colon-specific proteins, two of which (CDH17 and PPP1R1B/DARP-32) had not previously been linked to CRLM. Furthermore, we observed CRLM-associated up-regulation of 16 proteins (of 20 associated proteins identified) known to be required for collagen synthesis, indicating increased collagen production in CRLM. Immunohistochemistry validated that collagen type XII is significantly up-regulated in CRLM. The results of this study indicate that most collagen isoforms are up-regulated in CRLM compared with healthy tissues, most likely as a result of an increased collagen production in the metastatic cells. Our findings provide further insight into morphological changes in the ECM in CRLM and help explain the finding of tumor metastasis-associated proteins and peptides in urine, suggesting their utility as metastasis biomarkers.

The Dynamic Roles of Mesenchymal Stem Cells in Colon Cancer

Colon cancer is still one of the most common causes of cancer in human and is characterized by lymphocyte infiltrates and originates from the epithelial cells found in the lining of colon or rectum of the gastrointestinal tract. Mesenchymal stem cells (MSCs) are composed of the multipotent stem cell group of stroma and can be differentiated as various cell lineages, such as fibroblasts, osteoblasts, and adipocytes. MSCs provide mechanical and structural support and have potential functions during tumor growth and metastasis. The efficacy of MSC-based therapies is partly dependent on the migration and homing of MSCs to tumors and metastatic sites. However, their migratory and engraftment potential is poorly understood. In this review, the characteristics and mechanisms of MSC's dynamic interaction with colon cancer were summarized, particularly the potential functions of MSCs on colon cancer, including its role in improving tumor growth and as a potential candidate for tumor therapy. Understanding MSC homing provides new insights into the manipulation of MSC and the improvement of their efficacy for colon cancer therapy.

The Dual Role of MicroRNAs in Colorectal Cancer Progression

Colorectal cancer (CRC) is responsible for one of the major cancer incidence and mortality worldwide. It is well known that MicroRNAs (miRNAs) play vital roles in maintaining the cell development and other physiological processes, as well as, the aberrant expression of numerous miRNAs involved in CRC progression. MiRNAs are a class of small, endogenous, non-coding, single-stranded RNAs that bind to the 3’-untranslated region (3′-UTR) complementary sequences of their target mRNA, resulting in mRNA degradation or inhibition of its translation as a post-transcriptional regulators. Moreover, miRNAs also can target the long non-coding RNA (lncRNA) to regulate the expression of its target genes involved in proliferation and metastasis of CRC. The functions of these dysregulated miRNAs appear to be context specific, with evidence of having a dual role in both oncogenes and tumor suppression depending on the cellular environment in which they are expressed. Therefore, the unique expression profiles of miRNAs relate to the diagnosis, prognosis, and therapeutic outcome in CRC. In this review, we focused on several oncogenic and tumor-suppressive miRNAs specific to CRC, and assess their functions to uncover the molecular mechanisms of tumor initiation and progression in CRC. These data promised that miRNAs can be used as early detection biomarkers and potential therapeutic target in CRC patients.

Characterization and In Vivo Validation of a Three-Dimensional Multi-Cellular Culture Model to Study Heterotypic Interactions in Colorectal Cancer Cell Growth, Invasion and Metastasis

Colorectal cancer (CRC) is the third cause of cancer-related mortality in industrialized countries. Local invasion and metastasis formation are events associated with poor prognosis for which today there are no effective therapeutic options. Invasion and metastasis are strongly modulated by cells of the tumor microenvironment (TME), in particular fibroblasts and endothelial cells. Unraveling interactions between tumor cells and cells of the TME may identify novel mechanisms and therapeutic targets to prevent or treat metastasis. We report here the development and in vivo validation of a 3D tumor spheroid model to study the interactions between CRC cells, fibroblasts and endothelial cells in vitro. Co-cultured fibroblasts promoted SW620 and HCT116 CRC spheroid invasion, and this was prevented by the SRC and FGFR kinase inhibitors Dasatinib and Erdafitinib, respectively. To validate these findings in vivo, we injected SW620 cells alone or together with fibroblasts orthotopically in the caecum of mice. Co-injection with fibroblasts promoted lung metastasis growth, which was fully reversed by treatment with Dasatinib or Erdafitinib. Co-culture of SW620 or HCT116 CRC spheroids with endothelial cells suppressed spheroid growth while it had no effect on cancer cell migration or invasion. Consistent with this in vitro effect, co-injected endothelial cells significantly inhibited primary tumor growth in vivo. From these experiments we conclude that effects on cancer cell invasion and growth induced by co-cultured TME cells and drug treatment in the 3D spheroid model in vitro, are predictive of in vivo effects. The 3D spheroid model may be considered as an attractive model to study the effect of heterotypic cellular interactions and drug activities on cancer cells, as animal testing alternative. This model may be adapted and further developed to include different types of cancer and host cells and to investigate additional functions and drugs.

Resveratrol Chemosensitizes TNF-β-Induced Survival of 5-FU-Treated Colorectal Cancer Cells

Objective: Resveratrol, a safe and multitargeted natural agent, has been linked with inhibition of survival and invasion of tumor cells. Tumor Necrosis Factor-β (TNF-β) (Lymphotoxin α) is known as an inflammatory cytokine, however, the underlying mechanisms for its pro-carcinogenic effects and whether resveratrol can suppress these effects in the tumor microenvironment are poorly understood. Methods: We investigated whether resveratrol modulates the effects of 5-Fluorouracil (5-FU) and TNF-β on the malignant potential of human colorectal cancer (CRC) cells (HCT116) and their corresponding isogenic 5-FU-chemoresistant derived clones (HCT116R) in 3D-alginate tumor microenvironment. Results: CRC cells cultured in alginate were able to migrate from alginate and the numbers of migrated cells were significantly increased in the presence of TNF-β, similar to TNF-α, and dramatically decreased by resveratrol. We found that TNF-β promoted chemoresistance in CRC cells to 5-FU compared to control cultures and resveratrol chemosensitizes TNF-β-induced increased capacity for survival and invasion of HCT116 and HCT116R cells to 5-FU. Furthermore, TNF-β induced a more pronounced cancer stem cell-like (CSC) phenotype (CD133, CD44, ALDH1) and resveratrol suppressed formation of CSC cells in two different CRC cells and this was accompanied with a significant increase in apoptosis (caspase-3). It is noteworthy that resveratrol strongly suppressed TNF-β-induced activation of tumor-promoting factors (NF-κB, MMP-9, CXCR4) and epithelial-to-mesenchymal-transition-factors (increased vimentin and slug, decreased E-cadherin) in CRC cells. Conclusion: Our results clearly demonstrate for the first time that resveratrol modulates the TNF-β signaling pathway, induces apoptosis, suppresses NF-κB activation, epithelial-to-mesenchymal-transition (EMT), CSCs formation and chemosensitizes CRC cells to 5-FU in a tumor microenvironment.

Tuning Enzymatically Crosslinked Silk Fibroin Hydrogel Properties for the Development of a Colorectal Cancer Extravasation 3D Model on a Chip

Microfluidic devices are now the most promising tool to mimic in vivo like scenarios such as tumorigenesis and metastasis due to its ability to more closely mimic cell's natural microenvironment (such as 3D environment and continuous perfusion of nutrients). In this study, the ability of 2% and 3% enzymatically crosslinked silk fibroin hydrogels with different mechanical properties are tested in terms of colorectal cancer cell migration, under different microenvironments in a 3D dynamic model. Matrigel is used as control. Moreover, a comprehensive comparison between the traditional Boyden chamber assay and the 3D dynamic microfluidic model in terms of colorectal cancer cell migration is presented. The results show profound differences between the two used biomaterials and the two migration models, which are explored in terms of mechanical properties of the hydrogels as well as the intrinsic characteristics of the models. Moreover, the developed 3D dynamic model is validated by demonstrating that hVCAM-1 plays a major role in the extravasation process, influencing extravasation rate and traveled distance. Furthermore, the developed model enables precise visualization of cancer cell migration within a 3D matrix in response to microenvironmental cues, shedding light on the importance of biophysical properties in cell behavior.

Noninvasive Biomarkers of Colorectal Cancer: Role in Diagnosis and Personalised Treatment Perspectives

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. It has been estimated that more than one-third of patients are diagnosed when CRC has already spread to the lymph nodes. One out of five patients is diagnosed with metastatic CRC. The stage of diagnosis influences treatment outcome and survival. Notwithstanding the recent advances in multidisciplinary management and treatment of CRC, patients are still reluctant to undergo screening tests because of the associated invasiveness and discomfort (e.g., colonoscopy with biopsies). Moreover, the serological markers currently used for diagnosis are not reliable and, even if they were useful to detect disease recurrence after treatment, they are not always detected in patients with CRC (e.g., CEA). Recently, translational research in CRC has produced a wide spectrum of potential biomarkers that could be useful for diagnosis, treatment, and follow-up of these patients. The aim of this review is to provide an overview of the newer noninvasive or minimally invasive biomarkers of CRC. Here, we discuss imaging and biomolecular diagnostics ranging from their potential usefulness to obtain early and less-invasive diagnosis to their potential implementation in the development of a bespoke treatment of CRC.

An Optimal Orthotopic Mouse Model for Human Colorectal Cancer Primary Tumor Growth and Spontaneous Metastasis

BACKGROUND

Colorectal cancer is a leading cause of cancer-related death. Small animal models allow for the study of different metastatic patterns, but an optimal model for metastatic colorectal cancer has not been established.

OBJECTIVE

The purpose of this study was to determine which orthotopic model most accurately emulates the patterns of primary tumor growth and spontaneous liver and lung metastases seen in patients with colorectal cancer.

DESIGN

Using luciferase-tagged HT-29 cells coinoculated with lymph node stromal analog HK cells, 3 tumor cell delivery models were compared: intrarectal injection, intracecal injection, and acid enema followed by cancer cell instillation. Tumor growth was monitored weekly by bioluminescent imaging, and mice were sacrificed based on primary tumor size or signs of systemic decline. Liver and lungs were evaluated for metastases via bioluminescent imaging and histology.

SETTINGS

The study was conducted at a single university center.

MAIN OUTCOME MEASURES

Primary tumor and metastasis bioluminescent imaging were measured.

RESULTS

Intrarectal injection had the lowest mortality at 4.0% (1/25) compared with the intracecal group at 17.4% (4/23) and the acid enema followed by cancer cell instillation group at 15.0% (3/20).The primary tumors in intrarectal mice had the highest average bioluminescence (3.78 × 10 ± 4.94 × 10 photons) compared with the mice in the intracecal (9.52 × 10 ± 1.92 × 10 photons; p = 0.012) and acid enema followed by cancer cell instillation groups (6.23 × 10 ± 1.23 × 10 photons; p = 0.0016). A total of 100% of intrarectal and intracecal mice but only 35% of mice in the acid enema followed by cancer cell instillation group had positive bioluminescent imaging before necropsy. Sixty percent of intrarectal mice had liver metastases, and 56% had lung metastases. In the intracecal group, 39% of mice had liver metastases, and 35% had lung metastases. Only 2 acid enema followed by cancer cell instillation mice developed metastases.

LIMITATIONS

Tumor injections were performed by multiple investigators. Distant metastases were confirmed, but local lymph node status was not evaluated.

CONCLUSIONS

Intrarectal injection is the safest, most reproducible, and successful orthotopic mouse model for human colorectal cancer primary tumor growth and spontaneous metastasis.

Three-Dimensional Spatiotemporal Modeling of Colon Cancer Organoids Reveals that Multimodal Control of Stem Cell Self-Renewal is a Critical Determinant of Size and Shape in Early Stages of Tumor Growth

We develop a three-dimensional multispecies mathematical model to simulate the growth of colon cancer organoids containing stem, progenitor and terminally differentiated cells, as a model of early (prevascular) tumor growth. Stem cells (SCs) secrete short-range self-renewal promoters (e.g., Wnt) and their long-range inhibitors (e.g., Dkk) and proliferate slowly. Committed progenitor (CP) cells proliferate more rapidly and differentiate to produce post-mitotic terminally differentiated cells that release differentiation promoters, forming negative feedback loops on SC and CP self-renewal. We demonstrate that SCs play a central role in normal and cancer colon organoids. Spatial patterning of the SC self-renewal promoter gives rise to SC clusters, which mimic stem cell niches, around the organoid surface, and drive the development of invasive fingers. We also study the effects of externally applied signaling factors. Applying bone morphogenic proteins, which inhibit SC and CP self-renewal, reduces invasiveness and organoid size. Applying hepatocyte growth factor, which enhances SC self-renewal, produces larger sizes and enhances finger development at low concentrations but suppresses fingers at high concentrations. These results are consistent with recent experiments on colon organoids. Because many cancers are hierarchically organized and are subject to feedback regulation similar to that in normal tissues, our results suggest that in cancer, control of cancer stem cell self-renewal should influence the size and shape in similar ways, thereby opening the door to novel therapies.

p38 and JNK pathways control E-selectin-dependent extravasation of colon cancer cells by modulating miR-31 transcription

Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to vascular endothelial cells. It requires the interaction between adhesion receptors such as E-selectin present on endothelial cells and their ligands on cancer cells. Notably, E-selectin influences the metastatic potential of breast, bladder, gastric, pancreatic, and colorectal carcinoma as well as of leukemia and lymphoma. Here, we show that E-selectin expression induced by the pro-inflammatory cytokine IL-1β is directly and negatively regulated by miR-31. The transcription of miR-31 is activated by IL-1β. This activation depends on p38 and JNK MAP kinases, and their downstream transcription factors GATA2, c-Fos and c-Jun. The miR-31-mediated repression of E-selectin impairs the metastatic potential of colon cancer cells by decreasing their adhesion to, and migration through, the endothelium. These results highlight for the first time that microRNA mediates E-selectin-dependent extravasation of colon cancer cells.