Periostin (POSTN), a member of the matricellular protein family, is a secreted adhesion-related protein produced in the periosteum and periodontal ligaments. Matricellular proteins are a nonstructural family of extracellular matrix (ECM) proteins that regulate a wide range of biological processes in both normal and pathological conditions. Recent studies have demonstrated the key roles of these ECM proteins in the tumor microenvironment. Furthermore, periostin is an essential regulator of bone and tooth formation and maintenance, as well as cardiac development. Also, periostin interacts with multiple cell-surface receptors, especially integrins, and triggers signals that promote tumor growth. According to recent studies, these signals are implicated in cancer cell survival, epithelial-mesenchymal transition (EMT), invasion, and metastasis. In this review, we will summarize the most current data regarding periostin, its structure and isoforms, expressions, functions, and regulation in normal and cancerous tissues. Emphasis is placed on its association with cancer progression, and also future potential for periostin-targeted therapeutic approaches will be explored.

Background: Relapse and metastasis in colorectal cancer (CRC) are often attributed to cancer stem-like cells (CSCs), as small sub-population of tumor cells with ability of drug resistance. Accordingly, development of appropriate models to investigate CSCs biology and establishment of effective therapeutic strategies is warranted. Hence, we aimed to assess the capability of two widely used and important colorectal cancer cell lines, HT-29 and Caco-2, in generating spheroids and their detailed morphological and molecular characteristics.Methods: CRC spheroids were developed using hanging drop and forced floating in serum-free and non-attachment conditions and their morphological features were evaluated by scanning electron microscopy (SEM). Then, the potential of CSCs enrichment in spheroids was compared to their adherent counterparts by analysis of serial sphere formation capacity, real-time PCR of key stemness genes (KLF4,OCT4,SOX2,NANOG,C-MYC) and the expression of potential CRC-CSCs surface markers (CD166, CD44, and CD133) by flow cytometry. Finally, the expression level of some EMT-related (Vimentin,SNAIL1,TWIST1,N-cadherin,E-cadherin,ZEB1) and multi-drug resistant (ABCB1,ABCC1,ABCG2) genes was evaluated.Results: Although with different morphological features, both cell lines were formed CSCs-enriched spheroids, indicated by ability to serial sphere formation, significant up-regulation of stemness genes,SOX2,C-MYC, NANOGandOCT4in HT-29 andSOX2,C-MYCandKLF4in Caco-2 spheroids (p-value < 0.05) and increased expression of CRC-CSC markers compared to parental cells (p-value < 0.05). Additionally, HT-29 spheroids exhibited a significant higher expression of bothABCB1andABCG2(p-value = 0.02). The significant up-regulation of promoting EMT genes,ZEB1,TWIST1,E-cadherinandSNAIL1in HT-29 spheroids (p-value = 0.03),SNAIL1andVimentinin Caco-2 spheroids (p-value < 0.05) andN-cadherindown-regulation in both spheroids were observed.Conclusion: Enrichment of CSC-related features in HT-29 and Caco-2 (for the first time without applying special scaffold/biochemical) spheroids, suggests spheroid culture as robust, reproducible, simple and cost-effective model to imitate the complexity of in vivo tumors including self-renewal, drug resistance and invasion for in vitro research of CRC-CSCs.

Matrix stiffness is a mechanical characteristic of the extracellular matrix (ECM) that increases from the tumor core to the tumor periphery in a gradient pattern in a variety of solid tumors and can promote proliferation, invasion, metastasis, drug resistance, and recurrence. Cancer stem cells (CSCs) are a rare subpopulation of tumor cells with self-renewal, asymmetric cell division, and differentiation capabilities. CSCs are thought to be responsible for metastasis, tumor recurrence, chemotherapy resistance, and consequently poor clinical outcomes. Evidence suggests that matrix stiffness can activate receptors and mechanosensor/mechanoregulator proteins such as integrin, FAK, and YAP, modulating the characteristics of tumor cells as well as CSCs through different molecular signaling pathways. A deeper understanding of the effect of matrix stiffness on CSCs characteristics could lead to development of innovative cancer therapies. In this review, we discuss how the stiffness of the ECM is sensed by the cells and how the cells respond to this environmental change as well as the effect of matrix stiffness on CSCs characteristics and also the key malignant processes such as proliferation and EMT. Then, we specifically focus on how increased matrix stiffness affects CSCs in breast, lung, liver, pancreatic, and colorectal cancers. We also discuss how the molecules responsible for increased matrix stiffness and the signaling pathways activated by the enhanced stiffness can be manipulated as a therapeutic strategy for cancer.

The tumor microenvironment (TME), particularly the extracellular matrix (ECM), plays a crucial role in regulating breast cancer progression. Among ECM components, collagen type I—accounting for over 90% of fibrillar collagen in the human body—is the primary structural component of the tumor ECM. It critically modulates tumor cell behavior, influencing migration, invasion, and therapy resistance. The structural organization of collagen type I fibers can significantly impact clinical outcomes. This systematic review aimed to assess the association between tumor-stromal collagen type I characteristics and clinical outcomes in breast cancer. A comprehensive search strategy identified studies from major databases, which were appraised using quality assessment tools. Data on collagen quantity, morphology, alignment, and organization were extracted and analyzed to explore their relationship with survival, metastasis, therapy resistance, and clinical characteristics of breast cancer. Our analysis revealed that increased collagen density—particularly with an organized/aligned fiber orientation—was strongly associated with poor prognosis. Specifically, increased intratumoral collagen quantity was linked to reduced overall survival (HR = 7.84, p = 0.031). Stage III tumors exhibiting elevated collagen uniformity showed higher metastasis rates (p = 0.004), and HER2⁺ tumors with high collagen content correlated with resistance to HER2-targeted therapies (p < 0.05). Furthermore, higher collagen curviness was associated with better outcomes, including a reduced recurrence risk (HR = 0.77, p < 0.001). Subtype-specific trends emerged as ER/PR-negative tumors more frequently exhibited a perpendicular collagen arrangement (p = 0.02), whereas ER/PR-positive tumors showed elevated COL1A1 expression (p < 0.0001). Despite these patterns, the heterogeneity of study methodologies and the complexity of the tumor microenvironment highlight the need for unified frameworks to advance clinical translation. This review highlights the prognostic significance of tumor-stromal collagen characteristics in breast cancer, suggesting that future research should focus on the molecular mechanisms underlying collagen remodeling and its potential as a cancer biomarker and therapeutic target.

Background: Despite the conventional cancer therapeutic, cancer treatment remains a medical challenge due to neoplasm metastasis and cancer recurrence; therefore, new approaches promoting therapeutic strategies are highly desirable. As a new therapy, the use of whole neoplastic stem cells or cancer stem cell (CSC)-based vaccines is one strategy to overcome these obstacles. We investigated the effects of whole CSC-based vaccines on the solid tumor development, metastasis, and survival rate.Methods: Primary electronic databases (PubMed/MEDLINE, Scopus, Embase, and Web of Science) and a major clinical registry were searched. Interventional studies of whole CSC-based vaccines in rodent cancer models (38 studies) and human cancer patients (11 studies) were included; the vaccine preparation methodologies, effects, and overall outcomes were evaluated.Results: Preclinical studies were divided into 4 groups: CSC-lysates/ inactivated-CSC-based vaccines, CSC-lysate-loaded dendritic cell (CSC-DC) vaccines, cytotoxic T-cell (CTL) vaccines generated with CSC-DC (CSC-DC-CTL), and combinatorial treatments carried out in the prophylactic and therapeutic experimental models. The majority of preclinical studies reported a promising effect on tumor growth, survival rate, and metastasis. Moreover, whole CSC-based vaccines induced several antitumor immune responses. A small number of clinical investigations suggested that the whole CSC-based vaccine treatment is beneficial; however, further research is required.Conclusions: This comprehensive review provides an overview of the available methods for assessing the efficacy of whole CSC-based vaccines on tumor development, metastasis, and survival rate. In addition, it presents a set of recommendations for designing high-quality clinical studies that may allow to determine the efficacy of whole CSC-based-vaccines in cancer therapy.