Glioma Pericytes Promote Angiogenesis by Producing Periostin

Periostin-mediated activation of NF-κB signaling promotes tumor progression and chemoresistance in glioblastoma

Glioblastoma (GBM) is the most aggressive form of diffuse glioma, characterized by high lethality. Temozolomide (TMZ)-based chemotherapy is a standard treatment for GBM, but development of chemoresistance poses a significant therapeutic challenge. Despite advances in understanding GBM biology, the mechanisms driving TMZ resistance remain unclear. Identifying vital molecular players involved in this resistance is crucial for developing new therapies. Our results indicated that periostin (POSTN) was significantly upregulated in GBM cell lines and patient samples, correlating with poorer clinical outcomes. POSTN overexpression enhanced GBM cell proliferation, migration, invasion, and chemoresistance, while lentiviral suppression of POSTN significantly reduced these behaviors. In vivo, bioluminescence imaging further confirmed the enhanced tumor growth associated with POSTN overexpression. Bioinformatics analysis was performed to explore the underlying molecular mechanism. The results revealed a strong correlation between POSTN and epithelial-mesenchymal transition (EMT) process and the tumor necrosis factor α (TNFα)-NF-κB signaling pathway. Moreover, exogenous POSTN silencing reduced IκB-kinase α (IKKα) phosphorylation, thereby decreasing NF-κB expression by limiting IκBα degradation. Collectively, our study demonstrated that POSTN-induced activation of NF-κB signaling and EMT processes promoted the malignancy and chemoresistance of GBM, suggesting that POSTN may serve as a reliable prognostic biomarker and potential therapeutic target for GBM.

MicroRNA-429 overexpression overcomes imatinib resistance of glioma cells by negatively regulating lysophosphatidic acid receptor 1

BACKGROUND

Glioma is one of the most aggressive and lethal malignancies in central nervous system. It has been reported that miR-429 is declined in glioma and functions as a tumor suppressor. Nonetheless, the potential role of miR-429 in drug resistance of glioma is still ambiguous.

METHODS

Stable imatinib-resistant lines U251-AR and T98G-AR were established using glioma cell lines U251 and T98G. Cell apoptosis and cycle were analyzed by flow cytometry, and CCK-8 assay was utilized to measure cell viability. Protein and RNA levels were tested with western blot and RT-qPCR. The predicted binding site was confirmed by dual luciferase reporter assay.

RESULTS

Imatinib-resistant U251-AR and T98G-AR cells presented lower level of miR-429 and higher level of LPAR1. MiR-429 overexpression obviously promoted imatinib sensitivity in glioma cells, indicated by the reduced IC50 value, facilitated cell apoptosis and cell cycle arrest at G0/G1 phase, and downregulated multidrug resistance-related proteins. LPAR1 was verified as a direct target of miR-429 and its expression was negatively regulated by miR-429. Additionally, overexpression of LPAR1 restrained the biological function of miR-429 on imatinib chemoresistance.

CONCLUSION

MiR-429 partly sensitized glioma cells to imatinib via downregulation LPAR1, which might provide an approach to overcome imatinib chemoresistance during glioma treatment.

Experimental Study: The Development of a Novel Treatment for Chemotherapy-Resistant Tongue Cancer with the Inhibition of the Pathological Periostin Splicing Variant 1-2 with Exon 21

Tongue squamous cell carcinoma (TSCC) occurs frequently in the oral cavity, and because of its high proliferative and metastatic potential, it is necessary to develop a novel treatment for it. We have reported the importance of the inhibition of the periostin (POSTN) pathological splicing variant, including exon 21 (PN1-2), in various malignancies, but its influence is unclear in tongue cancer. In this study, we investigated the potential of POSTN exon 21-specific neutralizing antibody (PN21-Ab) as a novel treatment for TSCC. Human PN2 was transfected into the human TSCC (HSC-3) and cultured under stress, and PN2 was found to increase cell viability. PN2 induced chemotherapy resistance in HSC-3 via the phosphorylation of the cell survival signal Akt. In tissues from human TSCC and primary tumors of an HSC-3 xenograft model, PN1-2 was expressed in the tumor stroma, mainly from fibroblasts. The intensity of PN1-2 mRNA expression was positively correlated with malignancy. In the HSC-3 xenograft model, CDDP and PN21-Ab promoted CDPP's inhibition of tumor growth. These results suggest that POSTN exon 21 may be a biomarker for tongue cancer and that PN21-Ab may be a novel treatment for chemotherapy-resistant tongue cancer. The treatment points towards important innovations for TSCC, but many more studies are needed to extrapolate the results.

Tissue-resident glial cells associate with tumoral vasculature and promote cancer progression

Cancer cells are embedded within the tissue and interact dynamically with its components during cancer progression. Understanding the contribution of cellular components within the tumor microenvironment is crucial for the success of therapeutic applications. Here, we reveal the presence of perivascular GFAP+/Plp1+ cells within the tumor microenvironment. Using in vivo inducible Cre/loxP mediated systems, we demonstrated that these cells derive from tissue-resident Schwann cells. Genetic ablation of endogenous Schwann cells slowed down tumor growth and angiogenesis. Schwann cell-specific depletion also induced a boost in the immune surveillance by increasing tumor-infiltrating anti-tumor lymphocytes, while reducing immune-suppressor cells. In humans, a retrospective in silico analysis of tumor biopsies revealed that increased expression of Schwann cell-related genes within melanoma was associated with improved survival. Collectively, our study suggests that Schwann cells regulate tumor progression, indicating that manipulation of Schwann cells may provide a valuable tool to improve cancer patients' outcomes.

Identification of early biomarkers in saliva in genetically engineered mouse model C(3)1-TAg of breast cancer

Breast cancer is one of leading causes of death worldwide in the female population. Deaths from breast cancer could be reduced significantly through earlier and more efficient detection of the disease. Saliva, an oral fluid that contains an abundance of protein biomarkers, has been recognized as a promising diagnostic biofluid that is easy to isolate through non-invasive techniques. Assays on saliva can be performed rapidly and are cost-effective. Therefore, our work aimed to identify salivary biomarkers present in the initial stages of breast cancer, where cell alterations are not yet detectable by histopathological analysis. Using state-of-the-art techniques, we employed a transgenic mouse model of mammary cancer to identify molecular changes in precancerous stage breast cancer through protein analysis in saliva. Through corroborative molecular approaches, we established that proteins related to metabolic changes, inflammatory process and cell matrix degradation are detected in saliva at the onset of tumor development. Our work demonstrated that salivary protein profiles can be used to identify cellular changes associated with precancerous stage breast cancer through non-invasive means even prior to biopsy-evident disease.

Periostin in Angiogenesis and Inflammation in CRC-A Preliminary Observational Study

Background and Objectives: To assess the periostin level and the concentrations of pro-inflammatory cytokines: TNFα, IFN-γ, IL-1β and IL-17 in tumor and marginal tissues of CRC and to investigate the influence of periostin on angiogenesis by MVD (microvessel density) and concentration of VEGF-A in relation to clinicopathological parameters of patients. Materials and Methods: The study used 47 samples of tumor and margin tissues derived from CRC patients. To determinate the concentration of periostin, VEGF-A, TNFα, IFNγ, IL-1β and IL-17, we used the commercially available enzyme- linked immunosorbent assay kit. MVD was assessed on CD34-stained specimens. The MVD and budding were assessed using a light microscope Results: We found significantly higher concentrations of periostin, VEGF-A, IFN-γ, IL-1 β, IL-17 and TNFα in the tumor samples compared with surgical tissue margins. The tumor concentrations of periostin were correlated with tumor levels of VEGF-A, IFN-γ, IL-1β and TNFα. We observed significant correlation between margin periostin and VEGF-A, IFN-γ, IL-17 and TNFα in tumor and margin specimens. Additionally, we found a significantly negative correlation between periostin tumor concentration and microvessel density at the invasive front. Tumor periostin levels were also correlated positively with tumor budding. Conclusions: Periostin activity may be associated with pro-inflammatory cytokine levels: TNFα, IFN-γ, IL-1β and IL-17. Our results also suggest the role of periostin in angiogenesis in CRC and its upregulation in poorly vascularized tumors. Further research on the regulations between periostin and cytokines are necessary to understand the interactions between tumor and immune tumor microenvironment, which could be helpful in the development of new targeted therapy.

Sympathetic nerve-adipocyte interactions in response to acute stress

Psychological stress predisposes our body to several disorders. Understanding the cellular and molecular mechanisms involved in the physiological responses to psychological stress is essential for the success of therapeutic applications. New studies show, by using in vivo inducible Cre/loxP-mediated approaches in combination with pharmacological blockage, that sympathetic nerves, activated by psychological stress, induce brown adipocytes to produce IL-6. Strikingly, this cytokine promotes gluconeogenesis in hepatocytes, that results in the decline of tolerance to inflammatory organ damage. The comprehension arising from this research will be crucial for the handling of many inflammatory diseases. Here, we review recent advances in our comprehension of the sympathetic nerve-adipocyte axis in the tissue microenvironment.

Periostin Exon-21 Antibody Neutralization of Triple-Negative Breast Cancer Cell-Derived Periostin Regulates Tumor-Associated Macrophage Polarization and Angiogenesis

Simple Summary

Despite remarkable advances in breast cancer treatment, few strategies other than standard cytotoxic chemotherapy are available for patients with triple-negative breast cancer (TNBC) due to the lack of therapeutic target molecules. TNBC is still the most aggressive subtype, with a high risk of recurrence and metastasis within 2 years after initial treatment. Thus, there is an unmet medical need to develop new treatments for metastatic and recurrent TNBC patients. In this study we tested a new antibody, targeting extracellular periostin protein alternative splicing variants, which are induced by conventional chemotherapy or during the process of endothelial mesenchymal transition. This antibody reduced periostin-secreting TNBC in a mouse xenograft model, accompanied by a decrease in the number of M2 tumor-associated macrophages and tumor vessels. Periostin alternative splicing variants might be a specific and safe therapeutic target in patients with TNBC.

Abstract

Periostin (Pn) is involved in multiple processes of cancer progression. Previously, we reported that Pn expression is correlated with mesenchymal tumor markers and poor prognosis in triple-negative breast cancer (TNBC). In the TNBC xenograft model, chemotherapy increased expression of a Pn alternative splicing variant (ASV) with exon 21, and administration of the neutralizing antibody against Pn with exon 21 (Pn-21 Ab) overcame chemoresistance with a reduction in the mesenchymal cancer cell fraction. In the present study, the role of Pn ASV with exon 21 in TNBC progression has been addressed. We first established a stable cell line carrying a fluorescence-based splicing reporter. Pn-positive TNBC has higher expression of genes related to tumor-associated macrophage (TAM) recruitment and ECM-receptor interaction than Pn-negative cells. In a xenograft model, only Pn-positive cells initiated tumor formation, and the Pn-21 Ab suppressed tumor cell growth, accompanied by decreased M2 TAM polarization and the number of tumor vessels. These data suggest that cancer cell-derived Pn ASV educates TAMs and regulates angiogenesis, which in turn establishes a microenvironmental niche that is supportive of TNBC.

Pericytes cross-talks within the tumor microenvironment

Cancer cells are embedded within the tumor microenvironment and interact dynamically with its components during tumor progression. Understanding the molecular mechanisms by which the tumor microenvironment components communicate is crucial for the success of therapeutic applications. Recent studies show, by using state-of-the-art technologies, including sophisticated in vivo inducible Cre/loxP mediated systems and CRISPR-Cas9 gene editing, that pericytes communicate with cancer cells. The arising knowledge on cross-talks within the tumor microenvironment will be essential for the development of new therapies against cancer. Here, we review recent progress in our understanding of pericytes roles within tumors.

Sensory nerves in the spotlight of the stem cell niche

Niches are specialized tissue microenvironments that control stem cells functioning. The bone marrow mesenchymal stem cell niche defines a location within the marrow in which mesenchymal stem cells are retained and produce new cells throughout life. Deciphering the signaling mechanisms by which the niche regulates stem cell fate will facilitate the use of these cells for therapy. Recent studies, by using state-of-the-art methodologies, including sophisticated in vivo inducible genetic techniques, such as lineage-tracing Cre/loxP mediated systems, in combination with pharmacological inhibition, provide evidence that sensory neuron is an important component of the bone marrow mesenchymal stem cell niche. Strikingly, knockout of a specific receptor in sensory neurons blocked stem cell function in the bone marrow. The knowledge arising from these discoveries will be crucial for stem cell manipulation in the future. Here, we review recent progress in our understanding of sensory nerves biology in the stem cell niche.