Fibroblasts in cancer: Defining target structures for therapeutic intervention

Prognostic and therapeutic potential of senescent stromal fibroblasts in prostate cancer

The stromal component of the tumour microenvironment in primary and metastatic prostate cancer can influence and promote disease progression. Within the prostatic stroma, fibroblasts are one of the most prevalent cell types associated with precancerous and cancerous lesions; they have a vital role in the structural composition, organization and integrity of the extracellular matrix. Fibroblasts within the tumour microenvironment can undergo cellular senescence, which is a stable arrest of cell growth and a phenomenon that is emerging as a recognized hallmark of cancer. Supporting the idea that cellular senescence has a pro-tumorigenic role, a subset of senescent cells exhibits a senescence-associated secretory phenotype (SASP), which, along with increased inflammation, can promote prostate cancer cell growth and survival. These cellular characteristics make targeting senescent cells and/or modulating SASP attractive as a potential preventive or therapeutic option for prostate cancer.

Macrophage-Related Gene Signatures for Predicting Prognosis and Immunotherapy of Lung Adenocarcinoma by Machine Learning and Bioinformatics

Background

In recent years, the immunotherapy of lung adenocarcinoma has developed rapidly, but the good therapeutic effect only exists in some patients, and most of the current predictors cannot predict it very well. Tumor-infiltrating macrophages have been reported to play a crucial role in lung adenocarcinoma (LUAD). Thus, we want to build novel molecular markers based on macrophages.

Methods

By non-negative matrix factorization (NMF) algorithm and Cox regression analysis, we constructed macrophage-related subtypes of LUAD patients and built a novel gene signature consisting of 12 differentially expressed genes between two subtypes. The gene signature was further validated in Gene-Expression Omnibus (GEO) datasets. Its predictive effect on prognosis and immunotherapy outcome was further evaluated with rounded analyses. We finally explore the role of TRIM28 in LUAD with a series of in vitro experiments.

Results

Our research indicated that a higher LMS score was significantly correlated with tumor staging, pathological grade, tumor node metastasis stage, and survival. LMS was identified as an independent risk factor for OS in LUAD patients and verified in GEO datasets. Clinical response to immunotherapy was better in patients with low LMS score compared to those with high LMS score. TRIM28, a key gene in the gene signature, was shown to promote the proliferation, invasion and migration of LUAD cell.

Conclusion

Our study highlights the significant role of gene signature in predicting the prognosis and immunotherapy efficacy of LUAD patients, and identifies TRIM28 as a potential biomarker for the treatment of LUAD.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Hydrolysable tannins as a potential therapeutic drug for the human fibrosis-associated disease

Fibrosis is a pathological change with abnormal tissue regeneration due to a response to persistent injury, which is extensively related to organ damage and failure, leading to high morbidity and mortality worldwide. Although the pathogenesis of fibrosis has been comprehensively elucidated, there are few effective therapies for treating fibrotic diseases. Natural products are increasingly regarded as an effective strategy for fibrosis with numerous favorable functions. Hydrolysable tannins (HT) are a type of natural products that have the potential to treat the fibrotic disease. In this review, we describe some biological activities and the therapeutic prospects of HT in organ fibrosis. Furthermore, the underlying mechanisms of inhibition of HT on fibrotic organs in relation to inflammation, oxidative stress, epithelial-mesenchymal transition, fibroblast activation and proliferation, and extracellular matrix accumulation are discussed. Understanding the mechanism of HT against fibrotic diseases will provide a new strategy for the prevention and attenuation of fibrosis progression.

Research Progress and Direction of Novel Organelle-Migrasomes

Migrasomes are organelles that are similar in structure to pomegranates, up to 3 μm in diameter, and contain small vesicles with a diameter of 50-100 nm. These membranous organelles grow at the intersections or tips of retracting fibers at the back of migrating cells. The process by which cells release migrasomes and their contents outside the cell is called migracytosis. The signal molecules are packaged in the migrasomes and released to the designated location by migrasomes to activate the surrounding cells. Finally, the migrasomes complete the entire process of information transmission. In this sense, migrasomes integrate time, space, and specific chemical information, which are essential for regulating physiological processes such as embryonic development and tumor invasion and migration. In this review, the current research progress of migrasomes, including the discovery of migrasomes and migracytosis, the structure of migrasomes, and the distribution and functions of migrasomes is discussed. The migratory marker protein TSPAN4 is highly expressed in various cancers and is associated with cancer invasion and migration. Therefore, there is still much research space for the pathogenesis of migratory bodies and cancer. This review also makes bold predictions and prospects for the research directions of the combination of migrasomes and clinical applications.

Crucial contribution of GPR56/ADGRG1, expressed by breast cancer cells, to bone metastasis formation

From a mouse triple-negative breast cancer cell line, 4T1, we previously established 4T1.3 clone with a high capacity to metastasize to bone after its orthotopic injection into mammary fat pad of immunocompetent mice. Subsequent analysis demonstrated that the interaction between cancer cells and fibroblasts in a bone cavity was crucial for bone metastasis focus formation arising from orthotopic injection of 4T1.3 cells. Here, we demonstrated that a member of the adhesion G-protein-coupled receptor (ADGR) family, G-protein-coupled receptor 56 (GPR56)/adhesion G-protein-coupled receptor G1 (ADGRG1), was expressed selectively in 4T1.3 grown in a bone cavity but not under in vitro conditions. Moreover, fibroblasts present in bone metastasis sites expressed type III collagen, a ligand for GPR56/ADGRG1. Consistently, GPR56/ADGRG1 proteins were detected in tumor cells in bone metastasis foci of human breast cancer patients. Deletion of GPR56/ADGRG1 from 4T1.3 cells reduced markedly intraosseous tumor formation upon their intraosseous injection. Conversely, intraosseous injection of GPR56/ADGRG1-transduced 4T1, TS/A (mouse breast cancer cell line), or MDA-MB-231 (human breast cancer cell line) exhibited enhanced intraosseous tumor formation. Furthermore, we proved that the cleavage at the extracellular region was indispensable for GPR56/ADGRG1-induced increase in breast cancer cell growth upon its intraosseous injection. Finally, inducible suppression of Gpr56/Adgrg1 gene expression in 4T1.3 cells attenuated bone metastasis formation with few effects on primary tumor formation in the spontaneous breast cancer bone metastasis model. Altogether, GPR56/ADGRG1 can be a novel target molecule to develop a strategy to prevent and/or treat breast cancer metastasis to bone.

Tumour neoantigen mimicry by microbial species in cancer immunotherapy

Tumour neoantigens arising from cancer-specific mutations generate a molecular fingerprint that has a definite specificity for cancer. Although this fingerprint perfectly discriminates cancer from healthy somatic and germline cells, and is therefore therapeutically exploitable using immune checkpoint blockade, gut and extra-gut microbial species can independently produce epitopes that resemble tumour neoantigens as part of their natural gene expression programmes. Such tumour molecular mimicry is likely not only to influence the quality and strength of the body's anti-cancer immune response, but could also explain why certain patients show favourable long-term responses to immune checkpoint blockade while others do not benefit at all from this treatment. This article outlines the requirement for tumour neoantigens in successful cancer immunotherapy and draws attention to the emerging role of microbiome-mediated tumour neoantigen mimicry in determining checkpoint immunotherapy outcome, with far-reaching implications for the future of cancer immunotherapy.

Extracellular vesicles derived from cancer-associated fibroblast carries miR-224-5p targeting SLC4A4 to promote the proliferation, invasion and migration of colorectal cancer cells

More and more studies indicated that extracellular vesicles (EVs) carrying miRNAs have been potential biomarkers of various cancers including colorectal cancer (CRC). This study aims to explore the function of miR-224-5p carried by EVs derived from cancer-associated fibroblasts (CAFs) in CRC. Here, we found that miR-224-5p was highly expressed while SLC4A4 was lowly expressed in CRC cells. Moreover, dual-luciferase reporter gene assay testified that miR-224-5p targeted SLC4A4. The expression of miR-224-5p in CAFs-derived EVs was found to be elevated. It was also testified that CAFs-derived EVs could transfer miR-224-5p into CRC cells. miR-224-5p in CAFs-derived EVs facilitated the proliferation, migration, invasion and anti-apoptosis of CRC cells. Overexpressing miR-224-5p increased the proliferative, migratory and invasive abilities of CRC cells and inhibit CRC cell apoptosis, while overexpressing SLC4A4 caused the opposite result. Research in vitro and in vivo further indicated that miR-224-5p promoted CRC cell progression via binding to its downstream target gene SLC4A4. Rescue assay also demonstrated that overexpressing miR-224-5p reversed the inhibitory effect of overexpressed SLC4A4 on cancer cell growth. In addition, in vivo assay identified that high level of miR-224-5p promoted the growth of cancer cells in mice in vivo. In conclusion, we explored the effect of miR-224-5p in CRC, which helps for further exploration of new methods for CRC targeted therapy.

MicroRNA-497-5p Is Downregulated in Hepatocellular Carcinoma and Associated with Tumorigenesis and Poor Prognosis in Patients

Background

MicroRNAs (miRNAs) have been demonstrated to exhibit important regulatory roles in multiple malignancies, including hepatocellular carcinoma (HCC). hsa-miR-497-5p was reported to involve in cancer progression and poor prognosis in many kinds of tumors. However, the expression and its clinical significance of hsa-miR-497-5p in HCC remain unclear.

Methods

In the present study, we investigated the expression of hsa-miR-497-5p in HCC and analyzed the correction of clinical features with prognosis. The expression levels of hsa-miR-497-5p and potential target genes were analyzed in HCC and adjacent noncancerous tissues using The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) datasets. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze hsa-miR-497-5p levels in 328 HCC tissues and 30 paired adjacent noncancer tissues. Overall survival (OS) and progression-free survival (PFS) of patients with HCC were assessed using the Kaplan-Meier method and the log-rank test.

Results

The hsa-miR-497-5p expression levels were decreased, and its target genes ACTG1, CSNK1D, PPP1CC, and BIRC5 were upregulated in HCC tissues compared with normal tissues. Lower levels of hsa-miR-497-5p expression and higher levels of the four target genes were significantly associated with higher tumor diameter. Moreover, patients with lower hsa-miR-497-5p expression and higher target genes levels had shorter OS.

Conclusion

The expression levels of hsa-miR-497-5p may play an important regulatory role in HCC and are closely correlated with HCC progression and poor prognosis in patients. The hsa-miR-497-5p may be a specific therapeutic target for the treatment of HCC.

Identification of a novel therapeutic candidate, NRK, in primary cancer-associated fibroblasts of lung adenocarcinoma microenvironment

PURPOSE

Lung adenocarcinoma (LUAD) accounts for approximately half of patients in lung cancer. Cancer-associated fibroblasts (CAFs) are the major component in the tumor microenvironment (TME). Targeting CAFs is a promising therapeutic strategy for cancer treatment. However, therapeutic targets of CAFs in LUAD remains largely unclear.

METHODS

Seven CAFs and nine normal fibroblasts (NFs) were isolated from tumor and paratumor tissues of LUAD patients undergoing surgery, respectively. RNA-seq and bioinformatics analysis were performed to identify the differentially expressed genes (DEGs) and their functions in CAFs compared with NFs. DEGs of ten overlaying were obtained from RNA-seq, our previously reported lncRNA microarray and public datasets (E-MTAB-6149, E-MTAB-6653) and validated by RT-qPCR. Nik-related kinase (NRK) was further validated by RT-qPCR, immunofluorescence (IF), Western Blot (WB) in vitro, and in Cancer Cell Line Encyclopedia (CCLE) database. Survival analysis was performed on Kaplan-Meier plotter.

RESULTS

A total of 1799 DEGs were identified, including 650 upregulated DEGs and 1149 downregulated DEGs. The upregulated and downregulated DEGs were mostly enriched in extracellular matrix (ECM) functions and in glycolysis/gluconeogenesis pathways. Interestingly, NRK was the most significantly upregulated overlaying DEGs which was rarely associated with CAFs before. NRK was predominantly expressed in CAFs, but weakly expressed in NFs, normal lung bronchial epithelial cell line BEAS-2B, LUAD cell lines A549 and H1299, as well as in the majority of 191 lung cancer cell lines including LUAD. Moreover, elevated NRK predicted poor survival in LUAD patients.

CONCLUSION

Here, we first report that NRK is significantly elevated in LUAD-associated CAFs and may function as a promising therapeutic target for cancer combination treatment. Besides, modulation of ECM and glycolysis/gluconeogenesis pathways may be an efficient approach to alter CAFs functionality in LUAD.

Emergence of Cancer-Associated Fibroblasts as an Indispensable Cellular Player in Bone Metastasis Process

Bone metastasis is frequently complicated in patients with advanced solid cancers such as breast, prostate and lung cancers, and impairs patients' quality of life and prognosis. At the first step of bone metastasis, cancer cells adhere to the endothelium in bone marrow and survive in a dormant state by utilizing hematopoietic niches present therein. Once a dormant stage is disturbed, cancer cells grow through the interaction with various bone marrow resident cells, particularly osteoclasts and osteoblasts. Consequently, osteoclast activation is a hallmark of bone metastasis. As a consequence, the drugs targeting osteoclast activation are frequently used to treat bone metastasis but are not effective to inhibit cancer cell growth in bone marrow. Thus, additional types of resident cells are presumed to contribute to cancer cell growth in bone metastasis sites. Cancer-associated fibroblasts (CAFs) are fibroblasts that accumulate in cancer tissues and can have diverse roles in cancer progression and metastasis. Given the presence of CAFs in bone metastasis sites, CAFs are emerging as an important cellular player in bone metastasis. Hence, in this review, we will discuss the potential roles of CAFs in tumor progression, particularly bone metastasis.

Focusing Heart Failure Research on Myocardial Fibrosis to Prioritize Translation

Heart failure (HF) has traditionally been defined by symptoms of fluid accumulation and poor perfusion, but it is now recognized that specific HF classifications hold prognostic and therapeutic relevance. Specifically, HF with reduced ejection fraction is characterized by reduced left ventricular systolic pump function and dilation and HF with preserved ejection fraction is characterized primarily by abnormal left ventricular filling (diastolic failure) with relatively preserved left ventricular systolic function. These forms of HF are distributed equally among patients with HF and likely require distinctly different strategies to mitigate the morbidity, mortality, and medical resource utilization of this disease. In particular, HF is a significant medical issue within the US Department of Veterans Affairs (VA) hospital system and constitutes a major translational research priority for the VA. Because a common underpinning of both HF with reduced ejection fraction and HF with preserved ejection fraction seems to be changes in the structure and function of the myocardial extracellular matrix, a conference was convened sponsored by the VA, entitled, "Targeting Myocardial Fibrosis in Heart Failure" to explore the extracellular matrix as a potential therapeutic target and to propose specific research directions. The conference was conceptually framed around the hypothesis that although HF with reduced ejection fraction and HF with preserved ejection fraction clearly have distinct mechanisms, they may share modifiable pathways and biological mediators in common. Inflammation and extracellular matrix were identified as major converging themes. A summary of our discussion on unmet challenges and possible solutions to move the field forward, as well as recommendations for future research opportunities, are provided.

Long Noncoding RNA OIP5-AS1 Promotes the Progression of Liver Hepatocellular Carcinoma via Regulating the hsa-miR-26a-3p/EPHA2 Axis

Numerous studies have suggested that dysregulated long noncoding RNAs (lncRNAs) contributed to the development and progression of many cancers. lncRNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to be increased in several cancers. However, the roles of OIP5-AS1 in liver hepatocellular carcinoma (LIHC) remain to be investigated. In this study, we demonstrated that OIP5-AS1 was upregulated in LIHC tissue specimens and its overexpression was associated with the poor survival of patients with LIHC. Furthermore, loss-of function experiments indicated that OIP5-AS1 promoted cell proliferation and inhibited cell apoptosis both in vitro and in vivo. Moreover, binding sites between OIP5-AS1 and hsa-miR-26a-3p as well as between hsa-miR-26a-3p and EPHA2 were confirmed by luciferase assays. Finally, a rescue assay was performed to prove the effect of the OIP5-AS1/hsa-miR-26a-3p/EPHA2 axis on LIHC cell biological behaviors. Based on all of the above findings, our results suggested that OIP5-AS1 promoted LIHC cell proliferation and invasion via regulating the hsa-miR-26a-3p/EPHA2 axis.

Prognostic impact of CD34 and SMA in cancer-associated fibroblasts in stage I-III NSCLC

Background

Epithelial‐to‐mesenchymal transition (EMT) is a crucial step in lung cancer pathogenesis. Among others, cancer‐associated fibroblasts (CAFs) are reported to regulate this process.

Objectives

To investigate the prognostic and clinical impact, we analyzed CD34+ and SMA+ CAFs in non‐small cell lung cancer (NSCLC).

Methods

Retrospectively, immunohistochemistry was performed to study stromal protein expression of both CD34 and SMA in 304 NSCLC patients with pTNM stage I‐III disease. All tissue samples were embedded on tissue microarrays (TMAs).

Results

Our analysis revealed an association for CD34+ CAFs with G1/2 tumors and adenocarcinoma histology. Moreover CD34+ CAFs were identified as an independent prognostic factor (both for progression free survival [PFS] and overall survival [OS] in stage I‐III NSCLC). Besides, SMA+ expression correlated with higher pTNM‐tumor stages and lymphatic spread (pN stage). In turn, SMA‐negativity was associated with improved PFS, but no prognostic impact was found on OS. Of interest, neither CD34+ CAFs nor SMA+ CAFs were associated with the primary tumor size, localization and depth of infiltration (pT stage).

Conclusions

CD34 was identified as an independent prognostic marker in pTNM stage I‐III NSCLC. Moreover, loss of CD34+ CAFs might influence the dedifferentiation of the NSCLC tumor from its cell origin. Finally, SMA+ CAFs are more prevalent in NSCLC tumors of higher stages and lymphonodal positive NSCLC.

Key points

Expression of CD34 on cancer associated fibroblasts (CAFs) is an independent prognostic factor in stage I‐III NSCLC.

SMA+ cancer associated fibroblasts are associated with higher tumor stages in NSCLC and might contribute to tumor progression in NSCLC.