Periostin Promotes Colorectal Tumorigenesis through Integrin-FAK-Src Pathway-Mediated YAP/TAZ Activation

The combined tumour-based Fascin/Snail and stromal periostin reveals the effective prognosis prediction in colorectal cancer patients

Colorectal cancer (CRC) is the third most common malignancy cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) promotes cancer metastasis and a tumour-based Glasgow EMT score was associated with adverse clinical features and poor prognosis. In this study, the impact of using the established five tumour-based EMT markers consisting of E-cadherin (E-cad), β-catenin (β-cat), Snail, Zeb-1, and Fascin in combination with the stromal periostin (PN) on the prediction of CRC patients' prognosis were invesigated. Formalin-fixed paraffin-embedded tissues of 202 CRC patients were studies the expressions of E-cad, β-cat, Snail, Zeb-1, Fascin, and PN by immunohistochemistry. Individually, cytoplasmic Fascin (Fc), cytoplasmic Snail (Sc), nuclear Snail (Sn), stromal Snail (Ss), and stromal PN (Ps) were significantly associated with reduced survival. A combination of Ps with Fc, Fs, and Sn was observed in 2 patterns including combined Fc, Fs, and Ps (FcFsPs) and Fc, Sn, and Ps (FcSnPs). These combinations enhanced the prognostic power compared to individual EMT markers and were independent prognostic markers. As the previously established scoring method required five markers and stringent criteria, its clinical use might be limited. Therefore, using these novel combined prognostic markers, either FcFsPs or FcSnPs, may be useful in predicting CRC patient outcomes.

Knockout of integrin αvβ6 protects against renal inflammation in chronic kidney disease by reduction of pro-inflammatory macrophages

Integrin αvβ6 holds promise as a therapeutic target for organ fibrosis, yet targeted therapies are hampered by concerns over inflammatory-related side effects. The role of αvβ6 in renal inflammation remains unknown, and clarifying this issue is crucial for αvβ6-targeted treatment of chronic kidney disease (CKD). Here, we revealed a remarkable positive correlation between overexpressed αvβ6 in proximal tubule cells (PTCs) and renal inflammation in CKD patients and mouse models. Notably, knockout of αvβ6 not only significantly alleviated renal fibrosis but also reduced inflammatory responses in mice, especially the infiltration of pro-inflammatory macrophages. Furthermore, conditional knockout of αvβ6 in PTCs in vivo and co-culture of PTCs with macrophages in vitro showed that depleting αvβ6 in PTCs suppressed the migration and pro-inflammatory differentiation of macrophages. Screening of macrophage activators showed that αvβ6 in PTCs activates macrophages via secreting IL-34. IL-34 produced by PTCs was significantly diminished by αvβ6 silencing, and reintroduction of IL-34 restored macrophage activities, while anti-IL-34 antibody restrained macrophage activities enhanced by αvβ6 overexpression. Moreover, RNA-sequencing of PTCs and verification experiments demonstrated that silencing αvβ6 in PTCs blocked hypoxia-stimulated IL-34 upregulation and secretion by inhibiting YAP expression, dephosphorylation, and nuclear translocation, which resulted in the activation of Hippo signaling. While application of a YAP agonist effectively recurred IL-34 production by PTCs, enhancing the subsequent macrophage migration and activation. Besides, reduced IL-34 expression and YAP activation were also observed in global or PTCs-specific αvβ6-deficient injured kidneys. Collectively, our research elucidates the pro-inflammatory function and YAP/IL-34/macrophage axis-mediated mechanism of αvβ6 in renal inflammation, providing a solid rationale for the use of αvβ6 inhibition to treat kidney inflammation and fibrosis.

Honokiol regulates ovarian cancer cell malignant behavior through YAP/TAZ pathway modulation

BACKGROUND

Ovarian cancer (OVCA) stands as one of the most fatal gynecological malignancies. Honokiol (HNK) has been substantiated by numerous studies for its anti-tumor activity against malignancies including OVCA. Consequently, this work was designed to elucidate the impact of HNK-mediated modulation of the YAP/TAZ pathway on the biological functions of OVCA cells.

METHODS

OVCA cells were subjected to treatment with varying concentrations (0, 25, 50, 75, and 100 μM) of HNK, concomitant with the administration of YAP agonist (XMU). Assessment of cellular viability was executed employing the CCK-8 assay, while quantification of cellular proliferation transpired via colony formation assays. Apoptosis was ascertained using flow cytometry, and expression of apoptosis-related proteins (caspase-3, Bcl-2, Bax), EMT-related proteins (E-cadherin, N-cadherin), migration-associated proteins (MMP-2, MMP-9), and YAP/TAZ pathway-related proteins was evaluated by western blot. Transwell experiments were conducted to assess cellular migratory and invasive propensities. Xenograft tumor models were built to observe tumor growth (volume and weight), apoptosis was assessed by TUNEL staining, and Ki67 expression was evaluated through IHC.

RESULTS

HNK exerted inhibitory effects on the viability and proliferative capacity of OVCA cells, elicited apoptotic responses, curtailed the migratory and invasive tendencies of cells, and downregulated the YAP/TAZ pathway. Stimulation with YAP agonist (XMU-MP-1) partially attenuated the impacts of HNK on OVCA cell biology. Experiments in vivo confirmed that HNK inhibited OVCA tumor growth.

CONCLUSION

The outcomes of this investigation conclusively established that HNK orchestrated the modulation of the YAP/TAZ pathway, thereby exerting control over the malignant phenotypic manifestations of OVCA cells. The ascertained function of HNK in restraining cellular proliferation and tumor progression provided novel evidence of its anti-proliferative activity within OVCA cells.

Periostin regulates lysyl oxidase through ERK1/2 MAPK-dependent serum response factor in activated cardiac fibroblasts

Collagen crosslinking, mediated by lysyl oxidase, is an adaptive mechanism of the cardiac repair process initiated by cardiac fibroblasts postmyocardial injury. However, excessive crosslinking leads to cardiac wall stiffening, which impairs the contractile properties of the left ventricle and leads to heart failure. In this study, we investigated the role of periostin, a matricellular protein, in the regulation of lysyl oxidase in cardiac fibroblasts in response to angiotensin II and TGFβ1. Our results indicated that periostin silencing abolished the angiotensin II and TGFβ1-mediated upregulation of lysyl oxidase. Furthermore, the attenuation of periostin expression resulted in a notable reduction in the activity of lysyl oxidase. Downstream of periostin, ERK1/2 MAPK signaling was found to be activated, which in turn transcriptionally upregulates the serum response factor to facilitate the enhanced expression of lysyl oxidase. The periostin-lysyl oxidase association was also positively correlated in an in vivo rat model of myocardial infarction. The expression of periostin and lysyl oxidase was upregulated in the collagen-rich fibrotic scar tissue of the left ventricle. Remarkably, echocardiography data showed a reduction in the left ventricular wall movement, ejection fraction, and fractional shortening, indicative of enhanced stiffening of the cardiac wall. These findings shed light on the mechanistic role of periostin in the collagen crosslinking initiated by activated cardiac fibroblasts. Our findings signify periostin as a possible therapeutic target to reduce excessive collagen crosslinking that contributes to the structural remodeling associated with heart failure.

Preliminary Mechanism of Glial Maturation Factor β on Pulmonary Vascular Remodeling in Pulmonary Arterial Hypertension

Recent evidence suggests that glia maturation factor β (GMFβ) is important in the pathogenesis of pulmonary arterial hpertension (PAH), but the underlying mechanism is unknown. To clarify whether GMFβ can be involved in pulmonary vascular remodeling and to explore the role of the IL-6-STAT3 pathway in this process, the expression of GMFβ in PAH rats is examined and the expression of downstream molecules including periostin (POSTN) and interleukin-6 (IL-6) is measured using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The location and expression of POSTN is also tested in PAH rats using immunofluorescence. It is proved that GMFβ is upregulated in the lungs of PAH rats. Knockout GMFβ alleviated the MCT-PAH by reducing right ventricular systolic pressure (RVSP), mean pulmonary arterial pressure (mPAP), and pulmonary vascular remodeling. Moreover, the inflammation of the pulmonary vasculature is ameliorated in PAH rats with GMFβ absent. In addition, the IL-6-STAT3 signaling pathway is activated in PAH; knockout GMFβ reduced POSTN and IL-6 production by inhibiting the IL-6-STAT3 signaling pathway. Taken together, these findings suggest that knockout GMFβ ameliorates PAH in rats by inhibiting the IL-6-STAT3 signaling pathway.

Pan-cancer analysis predict that FAT1 is a therapeutic target and immunotherapy biomarker for multiple cancer types including non-small cell lung cancer

FAT1, a substantial transmembrane protein, plays a pivotal role in cellular adhesion and cell signaling. Numerous studies have documented frequent alterations in FAT1 across various cancer types, with its aberrant expression being linked to unfavorable survival rates and tumor progression. In the present investigation, we employed bioinformatic analyses, as well as in vitro and in vivo experiments to elucidate the functional significance of FAT1 in pan-cancer, with a primary focus on lung cancer. Our findings unveiled FAT1 overexpression in diverse cancer types, including lung cancer, concomitant with its association with an unfavorable prognosis. Furthermore, FAT1 is intricately involved in immune-related pathways and demonstrates a strong correlation with the expression of immune checkpoint genes. The suppression of FAT1 in lung cancer cells results in reduced cell proliferation, migration, and invasion. These collective findings suggest that FAT1 has potential utility both as a biomarker and as a therapeutic target for lung cancer.

Impact of STAT-signaling pathway on cancer-associated fibroblasts in colorectal cancer and its role in immunosuppression

Colorectal cancer (CRC) remains one of the most commonly diagnosed and deadliest types of cancer worldwide. CRC displays a desmoplastic reaction (DR) that has been inversely associated with poor prognosis; less DR is associated with a better prognosis. This reaction generates excessive connective tissue, in which cancer-associated fibroblasts (CAFs) are critical cells that form a part of the tumor microenvironment. CAFs are directly involved in tumorigenesis through different mechanisms. However, their role in immunosuppression in CRC is not well understood, and the precise role of signal transducers and activators of transcription (STATs) in mediating CAF activity in CRC remains unclear. Among the myriad chemical and biological factors that affect CAFs, different cytokines mediate their function by activating STAT signaling pathways. Thus, the harmful effects of CAFs in favoring tumor growth and invasion may be modulated using STAT inhibitors. Here, we analyze the impact of different STATs on CAF activity and their immunoregulatory role.

Multicellular ecotypes shape progression of lung adenocarcinoma from ground-glass opacity toward advanced stages

Lung adenocarcinoma is a type of cancer that exhibits a wide range of clinical radiological manifestations, from ground-glass opacity (GGO) to pure solid nodules, which vary greatly in terms of their biological characteristics. Our current understanding of this heterogeneity is limited. To address this gap, we analyze 58 lung adenocarcinoma patients via machine learning, single-cell RNA sequencing (scRNA-seq), and whole-exome sequencing, and we identify six lung multicellular ecotypes (LMEs) correlating with distinct radiological patterns and cancer cell states. Notably, GGO-associated neoantigens in early-stage cancers are recognized by CD8+ T cells, indicating an immune-active environment, while solid nodules feature an immune-suppressive LME with exhausted CD8+ T cells, driven by specific stromal cells such as CTHCR1+ fibroblasts. This study also highlights EGFR(L858R) neoantigens in GGO samples, suggesting potential CD8+ T cell activation. Our findings offer valuable insights into lung adenocarcinoma heterogeneity, suggesting avenues for targeted therapies in early-stage disease.

Hippo pathway in cell-cell communication: emerging roles in development and regeneration

The Hippo pathway is a central regulator of tissue growth that has been widely studied in mammalian organ development, regeneration, and cancer biology. Although previous studies have convincingly revealed its cell-autonomous functions in controlling cell fate, such as cell proliferation, survival, and differentiation, accumulating evidence in recent years has revealed its non-cell-autonomous functions. This pathway regulates cell-cell communication through direct interactions, soluble factors, extracellular vesicles, and the extracellular matrix, providing a range of options for controlling diverse biological processes. Consequently, the Hippo pathway not only dictates the fate of individual cells but also triggers multicellular responses involving both tissue-resident cells and infiltrating immune cells. Here, we have highlighted the recent understanding of the molecular mechanisms by which the Hippo pathway controls cell-cell communication and discuss its importance in tissue homeostasis, especially in development and regeneration.

UTX inhibition suppresses proliferation and promotes apoptosis in patient-derived glioblastoma stem cells by modulating periostin expression

Glioblastoma stem cells (GSCs) exert a crucial influence on glioblastoma (GBM) development, progression, resistance to therapy, and recurrence, making them an attractive target for drug discovery. UTX, a histone H3K27 demethylase, participates in regulating multiple cancer types. However, its functional role in GSCs remains insufficiently explored. This study aims to investigate the role and regulatory mechanism of UTX on GSCs. Analysis of TCGA data revealed heightened UTX expression in glioma, inversely correlating with overall survival. Inhibiting UTX suppressed GBM cell growth and induced apoptosis. Subsequently, we cultured primary GSCs from three patients, observing that UTX inhibition suppressed cell proliferation and induced apoptosis. RNA-seq was performed to analyze the gene expression changes after silencing UTX in GSCs. The results indicated that UTX-mediated genes were strongly correlated with GBM progression and regulatory tumor microenvironment. The transwell co-cultured experiment showed that silencing UTX in the transwell chamber GSCs inhibited the well plate cell proliferation. Protein-protein interaction analysis revealed that periostin (POSTN) played a role in the UTX-mediated transcriptional regulatory network. Replenishing POSTN reversed the effects of UTX inhibition on GSC proliferation and apoptosis. Our study demonstrated that UTX inhibition hindered POSTN expression by enhancing the H3K27me2/3 level, eventually resulting in inhibiting proliferation and promoting apoptosis of patient-derived GSCs. Our findings may provide a novel and effective strategy for the treatment of GBM.

Regulation of Dihydroartemisinin on the pathological progression of laryngeal carcinoma through the periostin/YAP/IL-6 pathway

Objective

Laryngeal cancer (LC) is one of the most common squamous cell carcinomas of the head and neck in clinical practice, and its incidence has been increasing in recent years, but the prognosis of the patients is not favorable. Hence, it is critical to re-understand and deeply study the causes and mechanisms of LC and explore new effective treatment methods and strategies. In this study, we analyzed the effect of Dihydroartemisinin (DHA) on the pathological progression of LC through the periostin (POSTN)/Yes-associated protein (YAP)/interleukin (IL)-6 pathway, which can provide new clinical references and guidelines.

Methods

POSTN, YAP, and IL-6 levels in 18 pairs of fresh LC tissues and adjacent counterparts in our hospital were detected. Additionally, LC TU686 cell line was purchased for DHA treatment of various concentrations to detect changes in cell biological behavior. Finally, we built a tumor-bearing mouse model with C57BL/6 mice and intragastrically administrated DHA to the animals to observe the growth of living tumors and to measure POSTN, YAP, and IL-6 expression in tumor tissues.

Results

As indicated by PCR, Western blotting, and immunohistochemistry, POSTN, YAP, and IL-6 presented higher expression in LC tissues than in adjacent counterparts. In cell experiments, the cloning rate of LC cells decreased and the apoptosis rate increased after DHA intervention, with 160 μmol/L DHA contributing to the most significant effect on LC activity inhibition. Furthermore, DHA-intervened cells exhibited markedly reduced POSTN, YAP, and IL-6 levels. Finally, the tumorigenesis experiment in nude mice showed inhibited tumor growth after DHA administration. And consistently, the expressions of POSTN, YAP, and IL-6 in living tumors decreased.

Conclusions

DHA can inhibit POSTN/YAP/IL-6 transduction, accelerate LC cell apoptosis, and alleviate the malignant progression of LC.

ALK upregulates POSTN and WNT signaling to drive neuroblastoma

Neuroblastoma is the most common extracranial solid tumor of childhood. While MYCN and mutant anaplastic lymphoma kinase (ALKF1174L) cooperate in tumorigenesis, how ALK contributes to tumor formation remains unclear. Here, we used a human stem cell-based model of neuroblastoma. Mis-expression of ALKF1174L and MYCN resulted in shorter latency compared to MYCN alone. MYCN tumors resembled adrenergic, while ALK/MYCN tumors resembled mesenchymal, neuroblastoma. Transcriptomic analysis revealed enrichment in focal adhesion signaling, particularly the extracellular matrix genes POSTN and FN1 in ALK/MYCN tumors. Patients with ALK-mutant tumors similarly demonstrated elevated levels of POSTN and FN1. Knockdown of POSTN, but not FN1, delayed adhesion and suppressed proliferation of ALK/MYCN tumors. Furthermore, loss of POSTN reduced ALK-dependent activation of WNT signaling. Reciprocally, inhibition of the WNT pathway reduced expression of POSTN and growth of ALK/MYCN tumor cells. Thus, ALK drives neuroblastoma in part through a feedforward loop between POSTN and WNT signaling.

TMEM120B strengthens breast cancer cell stemness and accelerates chemotherapy resistance via β1-integrin/FAK-TAZ-mTOR signaling axis by binding to MYH9

BACKGROUND

Breast cancer stem cell (CSC) expansion results in tumor progression and chemoresistance; however, the modulation of CSC pluripotency remains unexplored. Transmembrane protein 120B (TMEM120B) is a newly discovered protein expressed in human tissues, especially in malignant tissues; however, its role in CSC expansion has not been studied. This study aimed to determine the role of TMEM120B in transcriptional coactivator with PDZ-binding motif (TAZ)-mediated CSC expansion and chemotherapy resistance.

METHODS

Both bioinformatics analysis and immunohistochemistry assays were performed to examine expression patterns of TMEM120B in lung, breast, gastric, colon, and ovarian cancers. Clinicopathological factors and overall survival were also evaluated. Next, colony formation assay, MTT assay, EdU assay, transwell assay, wound healing assay, flow cytometric analysis, sphere formation assay, western blotting analysis, mouse xenograft model analysis, RNA-sequencing assay, immunofluorescence assay, and reverse transcriptase-polymerase chain reaction were performed to investigate the effect of TMEM120B interaction on proliferation, invasion, stemness, chemotherapy sensitivity, and integrin/FAK/TAZ/mTOR activation. Further, liquid chromatography-tandem mass spectrometry analysis, GST pull-down assay, and immunoprecipitation assays were performed to evaluate the interactions between TMEM120B, myosin heavy chain 9 (MYH9), and CUL9.

RESULTS

TMEM120B expression was elevated in lung, breast, gastric, colon, and ovarian cancers. TMEM120B expression positively correlated with advanced TNM stage, lymph node metastasis, and poor prognosis. Overexpression of TMEM120B promoted breast cancer cell proliferation, invasion, and stemness by activating TAZ-mTOR signaling. TMEM120B directly bound to the coil-coil domain of MYH9, which accelerated the assembly of focal adhesions (FAs) and facilitated the translocation of TAZ. Furthermore, TMEM120B stabilized MYH9 by preventing its degradation by CUL9 in a ubiquitin-dependent manner. Overexpression of TMEM120B enhanced resistance to docetaxel and doxorubicin. Conversely, overexpression of TMEM120B-∆CCD delayed the formation of FAs, suppressed TAZ-mTOR signaling, and abrogated chemotherapy resistance. TMEM120B expression was elevated in breast cancer patients with poor treatment outcomes (Miller/Payne grades 1-2) than in those with better outcomes (Miller/Payne grades 3-5).

CONCLUSIONS

Our study reveals that TMEM120B bound to and stabilized MYH9 by preventing its degradation. This interaction activated the β1-integrin/FAK-TAZ-mTOR signaling axis, maintaining stemness and accelerating chemotherapy resistance.

Simultaneous Expression of CD70 and POSTN in Cancer-Associated Fibroblasts Predicts Worse Survival of Colorectal Cancer Patients

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers worldwide, with high morbidity and mortality rates. The evidence for the tumor-supporting capacities of cancer-associated fibroblasts (CAFs) that modulate cancer cell proliferation, invasion, metastasis, and tumor immunity, including in CRC, has been attracting attention. The present study examined the expression status of CD70 and POSTN in CRC and analyzed their association with clinicopathological features and clinical outcomes. In the present study, in total 15% (40/269) and 44% (119/269) of cases exhibited CD70 and POSTN expression on CAFs, respectively. Co-expression of CD70 and POSTN was detected in 8% (21/269) of patients. Fluorescent immunohistochemistry identified the co-expression of CD70 and POSTN with FAP and PDPN, respectively. ACTA2 was not co-expressed with CD70 or POSTN in CRC CAFs. CRC with CD70+/POSTN+ status in CAFs was significantly associated with distant organ metastasis (p = 0.0020) or incomplete resection status (p = 0.0011). CD70+/POSTN+ status tended to associate with advanced pT stage (p = 0.032) or peritoneal metastasis (p = 0.0059). Multivariate Cox hazards regression analysis identified CD70+/POSTN+ status in CAFs [hazard ratio (HR) = 3.78] as a potential independent risk factor. In vitro experiments revealed the activated phenotypes of colonic fibroblasts induced by CD70 and POSTN, while migration and invasion assays identified enhanced migration and invasion of CRC cells co-cultured with CD70- and POSTN-expressing colonic fibroblasts. On the basis of our observations, CD70 and POSTN immunohistochemistry can be used in the prognostication of CRC patients. CRC CAFs may be a promising target in the treatment of CRC patients.

Periostin-TGF-β feedforward loop contributes to tumour-stroma crosstalk in liver metastatic outgrowth of colorectal cancer

BACKGROUND

This study aimed to investigate the underlying mechanisms of matricellular protein periostin (POSTN) on tumour-stroma crosstalk in the liver metastatic microenvironment of colorectal cancer (CRC).

METHODS

Postn-knockout mice and hepatic Postn-overexpressing mice were used to investigate the functions of POSTN on the formation of fibrotic microenvironment and the tumour-stroma crosstalk in the liver metastatic microenvironment of CRC. Clinical samples and database were analyzed to show the correlation between POSTN expression and fibrotic features and TGF-β signalling in metastatic livers of CRC.

RESULTS

POSTN deficiency reduced hepatic stellate cell (HSC) activation and liver metastasis, whereas POSTN overexpression in the liver significantly augmented the formation of a fibrotic microenvironment to support the liver metastatic growth of CRC cells in mice. Moreover, HSC-derived POSTN promoted TGF-β1 expression in CRC cells through the integrin/FAK/ERK/STAT3 pathway; conversely, tumour cell-derived TGF-β1 induced POSTN expression in HSCs via the Smad pathway. POSTN levels correlated with fibrotic features and TGF-β signalling in metastatic liver tissues of CRC patients.

CONCLUSIONS

POSTN and TGF-β1 cooperatively contribute to the tumour-stroma crosstalk by forming a supporting fibrotic microenvironment to promote liver metastasis of CRC cells via the POSTN/integrin/FAK/ERK/STAT3/TGF-β axis in tumour cells and TGF-β/Smad/POSTN signalling in activated HSCs.

Periostin is associated with prognosis and immune cell infiltration in pancreatic adenocarcinoma based on integrated bioinformatics analysis

BACKGROUND

Pancreatic cancer is one of the most aggressive human malignancies. Previous research has shown that periostin (POSTN) promotes pancreatic cancer cell proliferation, migration, and invasion. Further, POSTN is involved in tumor microenvironment remodeling during tumor progression. However, the relationship between POSTN expression, immune cell infiltration, and the efficacy of immunotherapy in pancreatic cancer is unclear.

METHODS

We conducted a comprehensive evaluation of POSTN differential expression, examining mRNA and protein levels. To gather data, we utilized various databases including gene expression profiling interactive analysis 2 (GEPIA2), gene expression omnibus (GEO), and the human protein atlas (HPA). To investigate the correlation between POSTN expression and clinical characteristics, we analyzed data from the Kaplan-Meier plotter database and clinical data sourced from the cancer genome atlas (TCGA). Furthermore, we performed gene ontology (GO) analysis, Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, and gene set enrichment analysis (GSEA). Additionally, we explored the relationship between POSTN expression and immune cell infiltration, as well as the immunophenoscore (IPS), by leveraging the cancer immunome atlas (TCIA) database. Lastly, we examined the tumor mutational burden (TMB) in pancreatic cancer in relation to POSTN expression.

RESULTS

When compared with healthy pancreatic tissues, pancreatic cancer tissues displayed significantly higher levels of POSTN, which was indicative of a worse prognosis. POSTN expression was closely associated with extracellular matrix (ECM) organization, ECM-receptor interaction, and focal adhesion by GO, KEGG pathway, and GSEA analyses. Higher expression of POSTN was associated with increased infiltration of M2 macrophages. Additionally, increased IPS was linked to lower POSTN expression. IPS scores for CTLA4, PD-1/PDL1, and CTLA4/PD-1/PDL1 immune checkpoint inhibitors were also higher in the POSTN-low expression group, suggesting that lower expression of POSTN is associated with a better outcome with checkpoint inhibitor treatment.

CONCLUSION

POSTN is related to pancreatic cancer prognosis, and may influence immune cell infiltration. High expression of POSTN is predicted to correlate with lower sensitivity to immunotherapy with checkpoint inhibitors in pancreatic cancer.

Exploring Tumor-Promoting Qualities of Cancer-Associated Fibroblasts and Innovative Drug Discovery Strategies With Emphasis on Thymoquinone

Tumor epithelial development and chemoresistance are highly promoted by the tumor microenvironment (TME), which is mostly made up of the cancer stroma. This is due to several causes. Cancer-associated fibroblasts (CAFs) stand out among them as being essential for the promotion of tumors. Understanding the fibroblastic population within a single tumor is made more challenging by the undeniable heterogeneity within it, even though particular stromal alterations are still up for debate. Numerous chemical signals released by tumors improve the connections between heterotypic fibroblasts and CAFs, promoting the spread of cancer. It becomes essential to have a thorough understanding of this complex microenvironment to effectively prevent solid tumor growth. Important new insights into the role of CAFs in the TME have been revealed by recent studies. The objective of this review is to carefully investigate the relationship between CAFs in tumors and plant secondary metabolites, with a focus on thymoquinone (TQ). The literature published between 2010 and 2023 was searched in PubMed and Google Scholar with keywords such as TQ, TME, cancer-associated fibroblasts, mechanism of action, and flavonoids. The results showed a wealth of data substantiating the activity of plant secondary metabolites, particularly TQ's involvement in blocking CAF operations. Scrutinized research also clarified the wider effect of flavonoids on pathways related to cancer. The present study highlights the complex dynamics of the TME and emphasizes the critical role of CAFs. It also examines the possible interventions provided by secondary metabolites found in plants, with TQ playing a vital role in regulating CAF function based on recent literature.

AMPK signaling inhibits the differentiation of myofibroblasts: impact on age-related tissue fibrosis and degeneration

Disruption of the extracellular matrix (ECM) and an accumulation of fibrotic lesions within tissues are two of the distinctive hallmarks of the aging process. Tissue fibroblasts are mesenchymal cells which display an impressive plasticity in the regulation of ECM integrity and thus on tissue homeostasis. Single-cell transcriptome studies have revealed that tissue fibroblasts exhibit a remarkable heterogeneity with aging and in age-related diseases. Excessive stress and inflammatory insults induce the differentiation of fibroblasts into myofibroblasts which are fusiform contractile cells and abundantly secrete the components of the ECM and proteolytic enzymes as well as many inflammatory mediators. Detrimental stresses can also induce the transdifferentiation of certain mesenchymal and myeloid cells into myofibroblasts. Interestingly, many age-related stresses, such as oxidative and endoplasmic reticulum stresses, ECM stiffness, inflammatory mediators, telomere shortening, and several alarmins from damaged cells are potent inducers of myofibroblast differentiation. Intriguingly, there is convincing evidence that the signaling pathways stimulated by the AMP-activated protein kinase (AMPK) are potent inhibitors of myofibroblast differentiation and accordingly AMPK signaling reduces fibrotic lesions within tissues, e.g., in age-related cardiac and pulmonary fibrosis. AMPK signaling is not only an important regulator of energy metabolism but it is also able to control cell fate determination and many functions of the immune system. It is known that AMPK signaling can delay the aging process via an integrated signaling network. AMPK signaling inhibits myofibroblast differentiation, e.g., by suppressing signaling through the TGF-β, NF-κB, STAT3, and YAP/TAZ pathways. It seems that AMPK signaling can alleviate age-related tissue fibrosis and degeneration by inhibiting the differentiation of myofibroblasts.

The phase separation of extracellular matrix protein matrilin-3 from cancer-associated fibroblasts contributes to gastric cancer invasion

Cancer-associated fibroblast (CAF) has emerged as a key contributor to the remodeling of tumor microenvironment through the expression and secretion of extracellular matrix (ECM) proteins, thereby promoting carcinogenesis. However, the precise contribution of ECM proteins from CAFs to gastric carcinogenesis remains poorly understood. In this study, we find that matrilin-3 (MATN3), an upregulated ECM protein associated with poorer prognosis in gastric cancer patients, originates from CAFs in gastric cancer tissues. Ectopic expression of MATN3 in CAFs significantly promotes the invasion of gastric cancer cells, which can be attenuated by neutralizing MATN3 with its antibody. Notably, a portion of MATN3 protein is found to form puncta in gastric cancer tissues ECM. MATN3 undergoes phase separation, which is mediated by its low complexity (LC) and coiled-coil (CC) domains. Moreover, overexpression of MATN3 deleted with either LC or CC in CAFs is unable to promote the invasion of gastric cancer cells, suggesting that LC or CC domain is required for the effect of CAF-secreted MATN3 in gastric cancer cell invasion. Additionally, orthotopic co-injection of gastric cancer cells and CAFs expressing MATN3, but not its ΔLC and ΔCC mutants, leads to enhanced gastric cancer cell invasion in mouse models. Collectively, our works suggest that MATN3 is secreted by CAFs and undergoes phase separation, which promotes gastric cancer invasion.

Emerging Role of Non-collagenous Bone Proteins as Osteokines in Extraosseous Tissues

Bone is a unique tissue, composed of various types of cells embedded in a calcified extracellular matrix (ECM), whose dynamic structure consists of organic and inorganic compounds produced by bone cells. The main inorganic component is represented by hydroxyapatite, whilst the organic ECM is primarily made up of type I collagen and non-collagenous proteins. These proteins play an important role in bone homeostasis, calcium regulation, and maintenance of the hematopoietic niche. Recent advances in bone biology have highlighted the importance of specific bone proteins, named "osteokines", possessing endocrine functions and exerting effects on nonosseous tissues. Accordingly, osteokines have been found to act as growth factors, cell receptors, and adhesion molecules, thus modifying the view of bone from a static tissue fulfilling mobility to an endocrine organ itself. Since bone is involved in a paracrine and endocrine cross-talk with other tissues, a better understanding of bone secretome and the systemic roles of osteokines is expected to provide benefits in multiple topics: such as identification of novel biomarkers and the development of new therapeutic strategies. The present review discusses in detail the known osseous and extraosseous effects of these proteins and the possible respective clinical and therapeutic significance.

The role of periostin in cardiac fibrosis

Cardiac fibrosis, which is the buildup of proteins in the connective tissues of the heart, can lead to end-stage extracellular matrix (ECM) remodeling and ultimately heart failure. Cardiac remodeling involves changes in gene expression in cardiac cells and ECM, which significantly leads to the morbidity and mortality in heart failure. However, despite extensive research, the elusive intricacies underlying cardiac fibrosis remain unidentified. Periostin, an extracellular matrix (ECM) protein of the fasciclin superfamily, acts as a scaffold for building complex architectures in the ECM, which improves intermolecular interactions and augments the mechanical properties of connective tissues. Recent research has shown that periostin not only contributes to normal ECM homeostasis in a healthy heart but also serves as a potent inducible regulator of cellular reorganization in cardiac fibrosis. Here, we reviewed the constitutive domain of periostin and its interaction with other ECM proteins. We have also discussed the critical pathophysiological functions of periostin in cardiac remodeling mechanisms, including two distinct yet potentially intertwined mechanisms. Furthermore, we will focus on the intrinsic complexities within periostin research, particularly surrounding the contentious issues observed in experimental findings.

Glycolysis Reprogramming in Idiopathic Pulmonary Fibrosis: Unveiling the Mystery of Lactate in the Lung

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by excessive deposition of fibrotic connective tissue in the lungs. Emerging evidence suggests that metabolic alterations, particularly glycolysis reprogramming, play a crucial role in the pathogenesis of IPF. Lactate, once considered a metabolic waste product, is now recognized as a signaling molecule involved in various cellular processes. In the context of IPF, lactate has been shown to promote fibroblast activation, myofibroblast differentiation, and extracellular matrix remodeling. Furthermore, lactate can modulate immune responses and contribute to the pro-inflammatory microenvironment observed in IPF. In addition, lactate has been implicated in the crosstalk between different cell types involved in IPF; it can influence cell-cell communication, cytokine production, and the activation of profibrotic signaling pathways. This review aims to summarize the current research progress on the role of glycolytic reprogramming and lactate in IPF and its potential implications to clarify the role of lactate in IPF and to provide a reference and direction for future research. In conclusion, elucidating the intricate interplay between lactate metabolism and fibrotic processes may lead to the development of innovative therapeutic strategies for IPF.

Role of c-Src in Carcinogenesis and Drug Resistance

The aberrant transformation of normal cells into cancer cells, known as carcinogenesis, is a complex process involving numerous genetic and molecular alterations in response to innate and environmental stimuli. The Src family kinases (SFK) are key components of signaling pathways implicated in carcinogenesis, with c-Src and its oncogenic counterpart v-Src often playing a significant role. The discovery of c-Src represents a compelling narrative highlighting groundbreaking discoveries and valuable insights into the molecular mechanisms underlying carcinogenesis. Upon oncogenic activation, c-Src activates multiple downstream signaling pathways, including the PI3K-AKT pathway, the Ras-MAPK pathway, the JAK-STAT3 pathway, and the FAK/Paxillin pathway, which are important for cell proliferation, survival, migration, invasion, metastasis, and drug resistance. In this review, we delve into the discovery of c-Src and v-Src, the structure of c-Src, and the molecular mechanisms that activate c-Src. We also focus on the various signaling pathways that c-Src employs to promote oncogenesis and resistance to chemotherapy drugs as well as molecularly targeted agents.

IL-6 induces periostin production in human ACL remnants: a possible mechanism causing post-traumatic osteoarthritis

OBJECTIVE

Perostin (POSTN) and IL-6 consistently elevated after ACL injury, and ACL has been proposed as the major source of POSTN. However, there is a lack of evidence whether IL-6 induces ACL remnants to produce POSTN. This study aimed to investigate the effect of IL-6 on POSTN production in ACL fibroblasts, which may help us understand more about the mechanism of PTOA after ACL injury and ACL reconstruction.

METHODS

ACL remnants were harvested from 27 patients undergoing ACL reconstruction. Quantitative real-time polymerase chain reaction (PCR) was performed to examine the POSTN gene expression of ACL fibroblasts after treatment of different concentrations of IL-6. The POSTN protein production of ACL fibroblasts was determined using western blot analysis. The blockers of possible signaling pathways, including PI3K/Akt, Ras/MAPK, and JAK/STAT pathways, were added to test whether the effect of IL-6 on ACL fibroblast could be attenuated. ACL fibroblast and chondrocyte co-culture was carried out to determine the influence of ACL and IL-6 on chondrocytes.

RESULTS

Quantitative real-time PCR showed that IL-6 time-dependently and dose-dependently increased POSTN gene expression of ACL fibroblast. Western blot analysis also revealed that IL-6 dose-dependently induced POSTN protein production. Regarding the chronicity of ACL injury, the POSTN protein production was comparable between ACL remnants which were derived within 3 months of injury and at least 6 months after injury. PI3K/Akt blockers could attenuate the effect of IL-6 on ACL remnants, whereas Ras/MAPK and JAK/STAT did not decrease POSTN production. The coexistence of ACL and IL-6 induced more MMP-13 and ADAMTS-4 by chondrocytes.

CONCLUSIONS

IL-6 induced ACL remnants to produce POSTN. This effect could be attenuated by the PI3K/Akt blocker. Coexistence of IL-6 and ACL remnants may accelerate post-traumatic arthritis.

Matrix Stiffness Triggers Lipid Metabolic Cross-talk between Tumor and Stromal Cells to Mediate Bevacizumab Resistance in Colorectal Cancer Liver Metastases

Bevacizumab is an anti-VEGF monoclonal antibody that plays an important role in the combination treatment of advanced colorectal cancer. However, resistance remains a major hurdle limiting bevacizumab efficacy, highlighting the importance of identifying a mechanism of antiangiogenic therapy resistance. Here, we investigated biophysical properties of the extracellular matrix (ECM) related to metabolic processes and acquired resistance to bevacizumab. Evaluation of paired pre- and posttreatment samples of liver metastases from 20 colorectal cancer patients treated with combination bevacizumab therapy, including 10 responders and 10 nonresponders, indicated that ECM deposition in liver metastases and a highly activated fatty acid oxidation (FAO) pathway were elevated in nonresponders after antiangiogenic therapy compared with responders. In mouse models of liver metastatic colorectal cancer (mCRC), anti-VEGF increased ECM deposition and FAO in colorectal cancer cells, and treatment with the FAO inhibitor etomoxir enhanced the efficacy of antiangiogenic therapy. Hepatic stellate cells (HSC) were essential for matrix stiffness-mediated FAO in colon cancer cells. Matrix stiffness activated lipolysis in HSCs via the focal adhesion kinase (FAK)/yes-associated protein (YAP) pathway, and free fatty acids secreted by HSCs were absorbed as metabolic substrates and activated FAO in colon cancer cells. Suppressing HSC lipolysis using FAK and YAP inhibition enhanced the efficacy of anti-VEGF therapy. Together, these results indicate that bevacizumab-induced ECM remodeling triggers lipid metabolic cross-talk between colon cancer cells and HSCs. This metabolic mechanism of bevacizumab resistance mediated by the physical tumor microenvironment represents a potential therapeutic target for reversing drug resistance.

SIGNIFICANCE

Extracellular matrix stiffening drives bevacizumab resistance by stimulating hepatic stellate cells to provide fuel for mCRC cells in the liver, indicating a potential metabolism-based therapeutic strategy for overcoming resistance.

Interference of periostin attenuates pathological changes, proinflammatory markers and renal fibrosis in diabetic kidney injury

BACKGROUND

Diabetic nephropathy (DN) is a prevalent complication of diabetes, in which inflammation and fibrosis are the significant pathogenesis. Periostin is a matricellular protein that functions on stabilizing the extracellular matrix by binding to integrins during development. This study aimed to explored the role of periostin in DN.

METHODS

The animal and cell models of DN were constructed in streptozocin (STZ)-induced mice and high glucose-challenged human mesangial cells (HMCs). The role of periostin in pathological changes, inflammation and fibrosis in DN was investigated through biochemical detection, HE and Masson staining and scores, western blot, enzyme‑linked immunosorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) assays.

RESULTS

Knockdown of periostin counteracted the STZ-induced the ratio of kidney weight and body weight, and the concentrations of urine albumin excretion (UAE), serum creatinine (Scr), urine albumin/creatinine ratio (UACR) and blood urea nitrogen (BUN) in mice. Moreover, silencing of periostin alleviated the pathological manifestations and reduced the concentrations of IL-6, TNF-α and IL-1β in mice kidney tissues and sera. Also, downregulation of periostin decreased the relative protein expression of fibronectin, collagen IV and α-SMA in kidney tissues. Meanwhile, interference of periostin attenuated the levels of pro-inflammation factors and the expressions of fibrosis markers in HG-induced HMCs.

CONCLUSION

Interference of periostin resisted DN via attenuating the pro-inflammatory cytokines release and renal fibrosis in diabetic kidney injury. Our study establishes a basis for its further study and underlying application in clinical practice in diagnosing and treating diabetic kidney injury or other relevant diseases.

PP2 alleviates the progression of osteoarthritis by inhibiting Wnt/β-catenin and activating TGF-β/Smad signaling

OBJECTIVE

We aimed to explore the effect and mechanism of the Src inhibitor PP2 on osteoarthritis (OA) progression.

METHODS

The protein expressions of Src, p-Src (y418) and p-FAK in normal and OA human chondrocytes were detected by immunofluorescence (IF) analysis. Chondrocytes from the femur and tibial plateau of 3-day-old mice were extracted and inoculated into 6-well plates. The chondrocytes were co-cultured with IL-1β and different doses of PP2, and then the degeneration of extracellular matrix was analyzed. A mouse OA model was induced by destabilizing medial meniscectomy of the right knee. Two weeks after the operation, different doses of PP2 were injected intraperitoneally. The drug was given three times a week for 6 weeks, and then the mice were sacrificed. Histopathological, IF and immunoblotting analyses were used to detect key OA catabolic markers and protein expression and related signaling.

RESULTS

The levels of Src, p-Src (y418) and p-FAK in the knee cartilage tissue of patients with OA were abnormally increased. After chondrocytes were co-treated with IL-1β and different doses of PP2, the results showed that PP2 reduced the abnormal increase of β-catenin, p-β-catenin and other proteins induced by IL-1β, and reversed the decrease of p-Smad3, aggrecan and collagen Ⅱ protein levels. Meanwhile, intraperitoneal injection of PP2 in vivo significantly reduced the degeneration of articular cartilage in the OA mouse model.

CONCLUSION

Our data indicate that targeting Src with PP2 protected against cartilage destruction in an OA mouse model by inhibiting Wnt/β-catenin and activating TGF-β/Smad signaling, suggesting that Src may be a potential therapeutic target for OA treatment.

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.

The diverse nature of intestinal fibroblasts in development, homeostasis, and disease

Only in recent years have we begun to appreciate the involvement of fibroblasts in intestinal development, tissue homeostasis, and disease. These insights followed the advent of single-cell transcriptomics that allowed researchers to explore the heterogeneity of intestinal fibroblasts in unprecedented detail. Since researchers often defined cell types and their associated function based on the biological process they studied, there are a plethora of partially overlapping markers for different intestinal fibroblast populations. This ambiguity complicates putting different research findings into context. Here, we provide a census on the function and identity of intestinal fibroblasts in mouse and human. We propose a simplified framework consisting of three colonic and four small intestinal fibroblast populations to aid navigating the diversity of intestinal fibroblasts.

Stromal heterogeneity may explain increased incidence of metaplastic breast cancer in women of African descent

The biologic basis of genetic ancestry-dependent variability in disease incidence and outcome is just beginning to be explored. We recently reported enrichment of a population of ZEB1-expressing cells located adjacent to ductal epithelial cells in normal breasts of women of African ancestry compared to those of European ancestry. In this study, we demonstrate that these cells have properties of fibroadipogenic/mesenchymal stromal cells that express PROCR and PDGFRα and transdifferentiate into adipogenic and osteogenic lineages. PROCR + /ZEB1 + /PDGFRα+ (PZP) cells are enriched in normal breast tissues of women of African compared to European ancestry. PZP: epithelial cell communication results in luminal epithelial cells acquiring basal cell characteristics and IL-6-dependent increase in STAT3 phosphorylation. Furthermore, level of phospho-STAT3 is higher in normal and cancerous breast tissues of women of African ancestry. PZP cells transformed with HRasG12V ± SV40-T/t antigens generate metaplastic carcinoma suggesting that these cells are one of the cells-of-origin of metaplastic breast cancers.

Mechanosensitive Piezo1 channel in physiology and pathophysiology of the central nervous system

Since the discovery of the mechanosensitive Piezo1 channel in 2010, there has been a significant amount of research conducted to explore its regulatory role in the physiology and pathology of various organ systems. Recently, a growing body of compelling evidence has emerged linking the activity of the mechanosensitive Piezo1 channel to health and disease of the central nervous system. However, the exact mechanisms underlying these associations remain inadequately comprehended. This review systematically summarizes the current research on the mechanosensitive Piezo1 channel and its implications for central nervous system mechanobiology, retrospects the results demonstrating the regulatory role of the mechanosensitive Piezo1 channel on various cell types within the central nervous system, including neural stem cells, neurons, oligodendrocytes, microglia, astrocytes, and brain endothelial cells. Furthermore, the review discusses the current understanding of the involvement of the Piezo1 channel in central nervous system disorders, such as Alzheimer's disease, multiple sclerosis, glaucoma, stroke, and glioma.

Matrix stiffening facilitates the collective invasion of breast cancer through the periostin-integrin mechanotransduction pathway

Matrix rigidity is a critical contributor to tumor progression; however, whether and how matrix stiffness modulates the collective invasion of tumor cells remain unknown. Here we demonstrate that increased matrix stiffness activates YAP to promote the secretion of periostin (POSTN) in cancer-associated fibroblasts, which in turn augments the matrix rigidity of mammary glands and breast tumor tissues by facilitating collagen crosslinking. Moreover, decreased tissue stiffening resulted from the POSTN deficiency impairs peritoneal metastatic potential of orthotopic breast tumors. Increased matrix stiffness also promotes three-dimensional (3D) collective breast tumor cell invasion via multicellular cytoskeleton remodeling. POSTN triggers the integrin/FAK/ERK/Cdc42/Rac1 mechanotransduction pathway during 3D collective invasion of breast tumor. Clinically, high POSTN expression correlates with high collagen levels in breast tumors and cooperatively determines the metastatic recurrence potential in breast cancer patients. Collectively, these findings indicate that matrix rigidity promotes 3D collective invasion of breast tumor cells via the YAP-POSTN-integrin mechanotransduction signaling.

YAP/TAZ: Molecular pathway and disease therapy

The Yes-associated protein and its transcriptional coactivator with PDZ-binding motif (YAP/TAZ) are two homologous transcriptional coactivators that lie at the center of a key regulatory network of Hippo, Wnt, GPCR, estrogen, mechanical, and metabolism signaling. YAP/TAZ influences the expressions of downstream genes and proteins as well as enzyme activity in metabolic cycles, cell proliferation, inflammatory factor expression, and the transdifferentiation of fibroblasts into myofibroblasts. YAP/TAZ can also be regulated through epigenetic regulation and posttranslational modifications. Consequently, the regulatory function of these mechanisms implicates YAP/TAZ in the pathogenesis of metabolism-related diseases, atherosclerosis, fibrosis, and the delicate equilibrium between cancer progression and organ regeneration. As such, there arises a pressing need for thorough investigation of YAP/TAZ in clinical settings. In this paper, we aim to elucidate the signaling pathways that regulate YAP/TAZ and explore the mechanisms of YAP/TAZ-induce diseases and their potential therapeutic interventions. Furthermore, we summarize the current clinical studies investigating treatments targeting YAP/TAZ. We also address the limitations of existing research on YAP/TAZ and propose future directions for research. In conclusion, this review aims to provide fresh insights into the signaling mediated by YAP/TAZ and identify potential therapeutic targets to present innovative solutions to overcome the challenges associated with YAP/TAZ.

Peptide encoded by lncRNA BVES-AS1 promotes cell viability, migration, and invasion in colorectal cancer cells via the SRC/mTOR signaling pathway

Long non-coding RNAs (lncRNAs) have been revealed to harbor open reading frames (ORFs) that can be translated into small peptides. The peptides may participate in the pathogenesis of colorectal cancer (CRC). Herein, we investigated the role of a lncRNA BVES-AS1-encoded peptide in colorectal tumorigenesis. Through bioinformatic analysis, lncRNA BVES-AS1 was predicted to have encoding potential and to be associated with poor prognosis of patients with CRC. In CRC cells, BVES-AS1 was validated to encode a 50-aa-length micro-peptide, named BVES-AS1-201-50aa, through a western blotting method. BVES-AS1-201-50aa enhanced cell viability and promoted the migratory and invasive capacities of HCT116 and SW480 CRC cells in vitro, validated via CCK-8 assay and transwell assay, respectively. Immunofluorescence assay showed that BVES-AS1-201-50aa increased the expression of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase 9 (MMP9) in CRC cells. We further verified that BVES-AS1-201-50aa targeted and activated the Src/mTOR signaling pathway in CRC cells by co-immunoprecipitation (Co-IP) experiment, qualitative proteomic analysis, and western blotting. Our findings demonstrated that BVES-AS1 could encode a micro-peptide, which promoted CRC cell viability, migration, and invasion in vitro. Our current work broadens the diversity and breadth of lncRNAs in human carcinogenesis.

Integrin β6 mediates epithelial-mesenchymal transition in diabetic kidney disease

The progression of diabetic kidney disease (DKD) is associated with increased fibronectin (FN) levels in proximal tubular epithelial cells. Bioinformatics analysis showed that integrin β6 and cell adhesion function were significantly changed in the cortices of db/db mice. Remodelling of cell adhesion is one of the core changes during epithelial-mesenchymal transition (EMT) in DKD. Integrin is a family of transmembrane proteins that regulates cell adhesion and migration, and extracellular FN is the major ligand of integrin β6. We found that the expression of integrin β6 was elevated in the proximal tubules of db/db mice and FN-induced renal proximal tubule cells. The levels of EMT were also significantly increased in vivo and in vitro. In addition, FN treatment activated the Fak/Src pathway, increased the expression of p-YAP, and then upregulated the Notch1 pathway in diabetic proximal tubules. Knockdown of integrin β6 or Notch1 attenuated reversed the EMT aggravation induced by FN. Furthermore, urinary integrin β6 was significantly increased in DKD patients. Our findings reveal a critical role of integrin β6 in regulating EMT in proximal tubular epithelial cells and identify a novel direction for the detection and treatment of DKD.

Distinct functions of FASCILIN-LIKE ARABINOGALACTAN PROTEINS relate to domain structure

The role of glycoproteins as key cell surface molecules during development and stress is well established; yet, the relationship between their structural features and functional mechanisms is poorly defined. FASCICLIN-LIKE ARABINOGALACTAN PROTEINs (FLAs), which impact plant growth and development, are an excellent example of a glycoprotein family with a complex multidomain structure. FLAs combine globular fasciclin-like (FAS1) domains with regions that are intrinsically disordered and contain glycomotifs for directing the addition of O-linked arabinogalactan (AG) glycans. Additional posttranslational modifications on FLAs include N-linked glycans in the FAS1 domains, a cleaved signal peptide at the N terminus, and often a glycosylphosphatidylinositol (GPI) anchor signal sequence at the C terminus. The roles of glycosylation, the GPI anchor, and FAS1 domain functions in the polysaccharide-rich extracellular matrix of plants remain unclear, as do the relationships between them. In this study, we examined sequence-structure-function relationships of Arabidopsis (Arabidopsis thaliana) FLA11, demonstrated to have roles in secondary cell wall (SCW) development, by introducing domain mutations and functional specialization through domain swaps with FLA3 and FLA12. We identified FAS1 domains as essential for FLA function, differentiating FLA11/FLA12, with roles in SCW development, from FLA3, specific to flowers and involved in pollen development. The GPI anchor and AG glycosylation co-regulate the cell surface location and release of FLAs into cell walls. The AG glycomotif sequence closest to the GPI anchor (AG2) is a major feature differentiating FLA11 from FLA12. The results of our study show that the multidomain structure of different FLAs influences their subcellular location and biological functions during plant development.

Dual roles of FAK in tumor angiogenesis: A review focused on pericyte FAK

Focal adhesion kinase (FAK), also known as protein tyrosine kinase 2 (PTK2), is a ubiquitously expressed non-receptor tyrosine kinase, that plays a pivotal role in integrin-mediated signal transduction. Endothelial FAK is upregulated in many types of cancer and promotes tumorigenesis and tumor progression. However, recent studies have shown that pericyte FAK has the opposite effect. This review article dissects the mechanisms, by which endothelial cells (ECs) and pericyte FAK regulate angiogenesis, with an emphasis on the Gas6/Axl pathway. In particular, this article discusses the role of pericyte FAK loss on angiogenesis during tumorigenesis and metastasis. In addition, the existing challenges and future application of drug-based anti-FAK targeted therapies will be discussed to provide a theoretical basis for further development and use of FAK inhibitors.

SEMA6C: a novel adhesion-independent FAK and YAP activator, required for cancer cell viability and growth

Transmembrane semaphorins are signaling molecules, controlling axonal wiring and embryo development, which are increasingly implicated in human diseases. Semaphorin 6C (Sema6C) is a poorly understood family member and its functional role is still unclear. Upon targeting Sema6C expression in a range of cancer cells, we observed dramatic growth suppression, decreased ERK phosphorylation, upregulation of cell cycle inhibitor proteins p21, p27 and p53, and the onset of cell senescence, associated with activation of autophagy. These data are consistent with a fundamental requirement for Sema6C to support viability and growth in cancer cells. Mechanistically, we unveiled a novel signaling pathway elicited by Sema6C, and dependent on its intracellular domain, mediated by tyrosine kinases c-Abl and Focal Adhesion Kinase (FAK). Sema6C was found in complex with c-Abl, and induced its phosphorylation, which in turn led to FAK activation, independent of cell-matrix adhesion. Sema6C-induced FAK activity was furthermore responsible for increased nuclear localization of YAP transcriptional regulator. Moreover, Sema6C conferred YAP signaling-dependent long-term cancer cell survival upon nutrient deprivation. In conclusion, our findings demonstrate that Sema6C elicits a cancer promoting-signaling pathway sustaining cell viability and self-renewal, independent of growth factors and nutrients availability.

Stiff Extracellular Matrix Promotes Invasive Behaviors of Trophoblast Cells

The effect of extracellular matrix (ECM) stiffness on embryonic trophoblast cells invasion during mammalian embryo implantation remains largely unknown. In this study, we investigated the effects of ECM stiffness on various aspects of human trophoblast cell behaviors during cell-ECM interactions. The mechanical microenvironment of the uterus was simulated by fabricating polyacrylamide (PA) hydrogels with different levels of stiffness. The human choriocarcinoma (JAR) cell lineage was used as the trophoblast model. We found that the spreading area of JAR cells, the formation of focal adhesions, and the polymerization of the F-actin cytoskeleton were all facilitated with increased ECM stiffness. Significantly, JAR cells also exhibited durotactic behavior on ECM with a gradient stiffness. Meanwhile, stiffness of the ECM affects the invasion of multicellular JAR spheroids. These results demonstrated that human trophoblast cells are mechanically sensitive, while the mechanical properties of the uterine microenvironment could play an important role in the implantation process.

Extracellular matrix remodeling in tumor progression and immune escape: from mechanisms to treatments

The malignant tumor is a multi-etiological, systemic and complex disease characterized by uncontrolled cell proliferation and distant metastasis. Anticancer treatments including adjuvant therapies and targeted therapies are effective in eliminating cancer cells but in a limited number of patients. Increasing evidence suggests that the extracellular matrix (ECM) plays an important role in tumor development through changes in macromolecule components, degradation enzymes and stiffness. These variations are under the control of cellular components in tumor tissue via the aberrant activation of signaling pathways, the interaction of the ECM components to multiple surface receptors, and mechanical impact. Additionally, the ECM shaped by cancer regulates immune cells which results in an immune suppressive microenvironment and hinders the efficacy of immunotherapies. Thus, the ECM acts as a barrier to protect cancer from treatments and supports tumor progression. Nevertheless, the profound regulatory network of the ECM remodeling hampers the design of individualized antitumor treatment. Here, we elaborate on the composition of the malignant ECM, and discuss the specific mechanisms of the ECM remodeling. Precisely, we highlight the impact of the ECM remodeling on tumor development, including proliferation, anoikis, metastasis, angiogenesis, lymphangiogenesis, and immune escape. Finally, we emphasize ECM "normalization" as a potential strategy for anti-malignant treatment.

Periostin deficiency reduces PD-1+ tumor-associated macrophage infiltration and enhances anti-PD-1 efficacy in colorectal cancer

Periostin, a multifunctional extracellular protein, plays an important role in inflammatory disorders and tumorigenesis. Our previous work has demonstrated that periostin deficiency inhibits colorectal cancer (CRC) progression. Here, we aim to clarify the role of periostin in the immune microenvironment of CRC. We find that periostin deficiency significantly decreases the infiltration of programmed death receptor 1 (PD-1)+ tumor-associated macrophages (TAMs) in CRC tissues. Periostin promotes the expression of PD-1 on TAMs by integrin-ILK-nuclear factor κB (NF-κB) signaling, and PD-1+ TAMs produce interleukin-6 (IL-6) and interferon γ (IFN-γ) to induce the expression of PD-L1 on colorectal tumor cells. Moreover, combined inhibition of periostin and PD-1 significantly suppresses CRC progression compared with the inhibition of periostin or PD-1 alone. In summary, our results suggest that periostin deficiency reduces the infiltration of PD-1+ TAMs and enhances the efficacy of anti-PD-1 treatment in CRC.

Periostin Protects Against Alcohol-related Liver Disease by Activating Autophagy by Interacting With Protein Disulfide Isomerase

BACKGROUND & AIMS

The matricellular protein periostin plays a critical role in liver inflammation, fibrosis, and even carcinoma. Here, the biological function of periostin in alcohol-related liver disease (ALD) was investigated.

METHODS

We used wild-type (WT), Postn-null (Postn^-/-) mice and Postn^-/- mice with periostin recovery to investigate the biological function of periostin in ALD. Proximity-dependent biotin identification analysis identified the protein that interacted with periostin, and coimmunoprecipitation analysis validated the interaction between protein disulfide isomerase (PDI) and periostin. Pharmacological intervention and genetic knockdown of PDI were used to investigate the functional correlation between periostin and PDI in ALD development.

RESULTS

Periostin was markedly upregulated in the livers of mice that were fed ethanol. Interestingly, periostin deficiency severely aggravated ALD in mice, whereas the recovery of periostin in the livers of Postn^-/- mice significantly ameliorated ALD. Mechanistic studies showed that the upregulation of periostin alleviated ALD by activating autophagy through inhibition of the mechanistic target of rapamycin complex 1 (mTORC1) pathway, which was verified in murine models treated with the mTOR inhibitor rapamycin and the autophagy inhibitor MHY1485. Furthermore, a protein interaction map of periostin was generated by proximity-dependent biotin identification analysis. Interaction profile analysis identified PDI as a key protein that interacted with periostin. Intriguingly, periostin-mediated enhancement of autophagy by inhibiting the mTORC1 pathway in ALD depended on its interaction with PDI. Moreover, alcohol-induced periostin overexpression was regulated by transcription factor EB.

CONCLUSIONS

Collectively, these findings clarify a novel biological function and mechanism of periostin in ALD and the periostin-PDI-mTORC1 axis is a critical determinant of ALD.

Periostin secreted from podoplanin-positive cancer-associated fibroblasts promotes metastasis of gastric cancer by regulating cancer stem cells via AKT and YAP signaling pathway

Cancer-associated fibroblasts (CAFs) are heterogeneous stromal cells present in the tumor microenvironment (TME), which play a critical role in gastric cancer (GC) progression. Here, we examined a subset of CAFs with high podoplanin (PDPN) expression, which is correlated with tumor metastasis and poor survival in GC patients. Animal models of gastric cancer liver metastasis monitored by micro-PET/CT confirmed that periostin (POSTN) derived from PDPN(+) CAFs regulated CAFs' pro-migratory ability. Mechanistically, PDPN(+) CAFs secreted POSTN to modulate cancer stem cells (CSCs) through FAK/AKT phosphorylation. Furthermore, POSTN could also activate FAK/YAP signaling in GC cells to produce increased amounts of IL-6, which in turn induced phosphorylation of PI3K/AKT in PDPN(+) CAFs. Prolonged PI3K/AKT pathway activation in PDPN(+) CAFs maintains the production of POSTN and the effect on CSC enrichment and GC cell migration. In conclusion, our study demonstrated a positive feedback loop between PDPN(+) CAFs and CSCs during GC progression and suggested a selective target for GC treatment.

Long-term platinum-based drug accumulation in cancer-associated fibroblasts promotes colorectal cancer progression and resistance to therapy

A substantial proportion of cancer patients do not benefit from platinum-based chemotherapy (CT) due to the emergence of drug resistance. Here, we apply elemental imaging to the mapping of CT biodistribution after therapy in residual colorectal cancer and achieve a comprehensive analysis of the genetic program induced by oxaliplatin-based CT in the tumor microenvironment. We show that oxaliplatin is largely retained by cancer-associated fibroblasts (CAFs) long time after the treatment ceased. We determine that CT accumulation in CAFs intensifies TGF-beta activity, leading to the production of multiple factors enhancing cancer aggressiveness. We establish periostin as a stromal marker of chemotherapeutic activity intrinsically upregulated in consensus molecular subtype 4 (CMS4) tumors and highly expressed before and/or after treatment in patients unresponsive to therapy. Collectively, our study underscores the ability of CT-retaining CAFs to support cancer progression and resistance to treatment.

Periostin increased by mechanical stress upregulates interleukin-6 expression in the ligamentum flavum

Ligamentum flavum (LF) hypertrophy is a major cause of lumbar spinal canal stenosis. Although mechanical stress is thought to be a major factor involved in LF hypertrophy, the exact mechanism by which it causes hypertrophy has not yet been fully elucidated. Here, changes in gene expression due to long-term mechanical stress were analyzed using RNA-seq in a rabbit LF hypertrophy model. In combination with previously reported analysis results, periostin was identified as a molecule whose expression fluctuates due to mechanical stress. The expression and function of periostin were further investigated using human LF tissues and primary LF cell cultures. Periostin was abundantly expressed in human hypertrophied LF tissues, and periostin gene expression was significantly correlated with LF thickness. In vitro, mechanical stress increased gene expressions of periostin, transforming growth factor-β1, α-smooth muscle actin, collagen type 1 alpha 1, and interleukin-6 (IL-6) in LF cells. Periostin blockade suppressed the mechanical stress-induced gene expression of IL-6 while periostin treatment increased IL-6 gene expression. Our results suggest that periostin is upregulated by mechanical stress and promotes inflammation by upregulating IL-6 expression, which leads to LF degeneration and hypertrophy. Periostin may be a pivotal molecule for LF hypertrophy and a promising therapeutic target for lumbar spinal stenosis.

Stromal POSTN Enhances Motility of Both Cancer and Stromal Cells and Predicts Poor Survival in Colorectal Cancer

Evidence for the tumor-supporting capacities of cancer-associated fibroblasts (CAFs) has rapidly been accumulating. To uncover clinicopathological importance of periostin (POSTN) expression in colorectal cancer (CRC), the present study immunohistochemically examined its expression status. Furthermore, to reveal its mechanisms involved, molecular experiments were performed. In CRC tissues, 44% of the cases (119/269) exhibited POSTN expression in the CAFs. In contrast, CRC cells expressed POSTN at almost undetectable levels. Survival analyses identified that patients with POSTN-positive CRC had a significantly worse 5-year survival rate (63.2% vs. 81.2%; p = 0.011). Univariate analyses revealed that POSTN positivity was associated with peritoneal (p = 0.0031) and distant organ metastasis (p < 0.001). Furthermore, immunohistochemical analyses identified a significant association between POSTN and p53 complete loss status in CRC cells. Decorin and fibroblast activation protein expression in CAFs was also associated with POSTN. POSTN significantly enhanced the migration of both CRC cells and fibroblasts with FAK and AKT or STAT3 activation, and co-culture assays demonstrated the communication between CRC cells and fibroblasts, which enhanced STAT3 activation in fibroblasts. On the basis of our results, we speculated that stromal POSTN accelerated metastasis via stromal remodeling capacity and activated the migration of both tumor and stromal cells.

Intimate communications within the tumor microenvironment: stromal factors function as an orchestra

Extensive studies of the tumor microenvironment (TME) in the last decade have reformed the view of cancer as a tumor cell-centric disease. The tumor microenvironment, especially termed the "seed and soil" theory, has emerged as the key determinant in cancer development and therapeutic resistance. The TME mainly consists of tumor cells, stromal cells such as fibroblasts, immune cells, and other noncellular components. Within the TME, intimate communications among these components largely determine the fate of the tumor. The pivotal roles of the stroma, especially cancer-associated fibroblasts (CAFs), the most common component within the TME, have been revealed in tumorigenesis, tumor progression, therapeutic response, and tumor immunity. A better understanding of the function of the TME sheds light on tumor therapy. In this review, we summarize the emerging understanding of stromal factors, especially CAFs, in cancer progression, drug resistance, and tumor immunity with an emphasis on their functions in epigenetic regulation. Moreover, the importance of epigenetic regulation in reshaping the TME and the basic biological principles underpinning the synergy between epigenetic therapy and immunotherapy will be further discussed.

Inside the stemness engine: Mechanistic links between deregulated transcription factors and stemness in cancer

Cell identity is largely determined by its transcriptional profile. In tumour, deregulation of transcription factor expression and/or activity enables cancer cell to acquire a stem-like state characterised by capacity to self-renew, differentiate and form tumours in vivo. These stem-like cancer cells are highly metastatic and therapy resistant, thus warranting a more complete understanding of the molecular mechanisms downstream of the transcription factors that mediate the establishment of stemness state. Here, we review recent research findings that provide a mechanistic link between the commonly deregulated transcription factors and stemness in cancer. In particular, we describe the role of master transcription factors (SOX, OCT4, NANOG, KLF, BRACHYURY, SALL, HOX, FOX and RUNX), signalling-regulated transcription factors (SMAD, β-catenin, YAP, TAZ, AP-1, NOTCH, STAT, GLI, ETS and NF-κB) and unclassified transcription factors (c-MYC, HIF, EMT transcription factors and P53) across diverse tumour types, thereby yielding a comprehensive overview identifying shared downstream targets, highlighting unique mechanisms and discussing complexities.

Periostin: an emerging activator of multiple signaling pathways

Matricellular proteins are responsible for regulating the microenvironment, the behaviors of surrounding cells, and the homeostasis of tissues. Periostin (POSTN), a non-structural matricellular protein, can bind to many extracellular matrix proteins through its different domains. POSTN usually presents at low levels in most adult tissues but is highly expressed in pathological sites such as in tumors and inflamed organs. POSTN can bind to diverse integrins to interact with multiple signaling pathways within cells, which is one of its core biological functions. Increasing evidence shows that POSTN can activate the TGF-β, the PI3K/Akt, the Wnt, the RhoA/ROCK, the NF-κB, the MAPK and the JAK pathways to promote the occurrence and development of many diseases, especially cancer and inflammatory diseases. Furthermore, POSTN can interact with some pathways in an upstream and downstream relationship, forming complicated crosstalk. This article focuses on the interactions between POSTN and different signaling pathways in diverse diseases, attempting to explain the mechanisms of interaction and provide novel guidelines for the development of targeted therapies.