Recently, the need to develop a robust three-dimensional (3D) cell culture system that serves as a valuable in vitro tumor model has been emphasized. This system should closely mimic the tumor growth behaviors observed in vivo and replicate the key elements and characteristics of human tumors for the effective discovery and development of anti-tumor therapeutics. Therefore, in this study, we developed an effective 3D in vitro model of human prostate cancer (PC) using a marine collagen-based biomimetic 3D scaffold. The model displayed distinctive molecular profiles and cellular properties compared with those of the 2D PC cell culture. This was evidenced by (1) increased cell proliferation, migration, invasion, colony formation, and chemoresistance; (2) upregulated expression of crucial multidrug-resistance- and cancer-stemness-related genes; (3) heightened expression of key molecules associated with malignant progressions, such as epithelial–mesenchymal transition transcription factors, Notch, matrix metalloproteinases, and pluripotency biomarkers; (4) robust enrichment of prostate cancer stem cells (CSCs); and (5) enhanced expression of integrins. These results suggest that our 3D in vitro PC model has the potential to serve as a research platform for studying PC and prostate CSC biology, as well as for screening novel therapies targeting PC and prostate CSCs.

Ovarian cancer (OC) is the second most common female reproductive cancer and the most lethal gynecological malignancy worldwide. Most human OCs are characterized by high rates of drug resistance and metastasis, leading to poor prognosis. Improving the outcomes of patients with relapsed and treatment-resistant OC remains a challenge. This study aimed to investigate the role of epidermal growth factor-like domain 8 (EGFL8) in human OC by examining the effects of siRNA-mediated EGFL8 knockdown on cancer progression. EGFL8 knockdown in human OC cells promoted aggressive traits associated with cancer progression, including enhanced proliferation, colony formation, migration, invasion, chemoresistance, and reduced apoptosis. Additionally, knockdown upregulated the expression of epithelial–mesenchymal transition (EMT) markers (Snail, Twist1, Zeb1, Zeb2, and vimentin) and cancer stem cell biomarkers (Oct4, Sox2, Nanog, KLF4, and ALDH1A1), and increased the expression of matrix metallopeptidases (MMP-2 and MMP-9), drug resistance genes (MDR1 and MRP1), and Notch1. Low EGFL8 expression also correlated with poor prognosis in human OC. Overall, this study provides crucial evidence that EGFL8 inhibits the proliferation and cancer aggressiveness of human OC cells by suppressing ERK/MAPK signaling. Therefore, EGFL8 may serve as a valuable prognostic biomarker and a potential target for developing novel human OC therapies.

Prolonged thymic involution results in decreased thymopoiesis and thymic output, leading to peripheral T-cell deficiency. Since the thymic-dependent pathway is the only means of generating fully mature T cells, the identification of strategies to enhance thymic regeneration is crucial in developing therapeutic interventions to revert immune suppression in immunocompromised patients. The present study clearly shows that fish collagen peptides (FCPs) stimulate activities of thymic epithelial cells (TECs), including cell proliferation, thymocyte adhesion, and the gene expression of thymopoietic factors such as FGF-7, IGF-1, BMP-4, VEGF-A, IL-7, IL-21, RANKL, LTβ, IL-22R, RANK, LTβR, SDF-1, CCL21, CCL25, CXCL5, Dll1, Dll4, Wnt4, CD40, CD80, CD86, ICAM-1, VCAM-1, FoxN1, leptin, cathepsin L, CK5, and CK8 through the NF-κB signal transduction pathway. Furthermore, our study also revealed the cytoprotective effects of FCPs on TECs against cyclophosphamide-induced cellular injury through the NF-κB signaling pathway. Importantly, FCPs exhibited a significant capability to facilitate thymic regeneration in mice after cyclophosphamide-induced damage via the NF-κB pathway. Taken together, this study sheds light on the role of FCPs in TEC function, thymopoiesis, and thymic regeneration, providing greater insight into the development of novel therapeutic strategies for effective thymus repopulation for numerous clinical conditions in which immune reconstitution is required.

Polydopamine (PDA) surface coatings are widely used in biomedical engineering to enhance cell–substrate interactions; however, their effects on cancer-cell behavior remain unclear. In this study, we investigated how PDA-coated two-dimensional (2D) culture surfaces influence oncogenic traits of human prostate cancer (PC) cells in vitro. Using LNCaP, DU145, and PC3 cell lines, we found that PDA-coated substrates markedly increased the adhesion, migration, invasion, proliferation, and colony formation in a dose- and time-dependent manner. PDA exposure also induced epithelial–mesenchymal transition (EMT), upregulated cancer stem cell markers (CD44, CD117, CD133, Sox2, Oct4, and Nanog), and elevated expression of metastasis- and chemoresistance-associated molecules (MMP-2, MMP-9, MDR1, and MRP1). Mechanistically, PDA coatings enhanced integrin α₂β₁-associated cell adhesion, accompanied by increased focal adhesion kinase (FAK) phosphorylation and downstream activation of JNK signaling. Pharmacological inhibition of integrin α₂β₁ (BTT-3033), FAK (PF573228) and JNK (SP600125) effectively abrogated PDA-induced malignant phenotypes and restored chemosensitivity to cabazitaxel, cisplatin, docetaxel, curcumin, and enzalutamide. Collectively, these findings identify PDA-coated surfaces as a simple, efficient, and reductionist in vitro platform for studying adhesion-mediated signaling and phenotypic plasticity in PC cells, while acknowledging that further validation in three-dimensional (3D) and patient-derived models will be required to establish in vivo relevance.

The development of physiologically relevant three-dimensional (3D) culture systems is essential for modeling tumor complexity and improving the translational impact of cancer research. We established a 3D in vitro model of human hepatocellular carcinoma (HCC) using a marine collagen peptide-based (MCP-B) biomimetic hydrogel scaffold optimized for multicellular spheroid growth. Compared with conventional two-dimensional (2D) cultures, the MCP-B hydrogel more accurately recapitulated native tumor biology while offering simplicity, reproducibility, bioactivity, and cost efficiency. HCC cells cultured in MCP-B hydrogel displayed tumor-associated behaviors, including enhanced proliferation, colony formation, migration, invasion, and chemoresistance, and enriched cancer stem cell (CSC) populations. Molecular analyses revealed upregulated expression of genes associated with multidrug resistance; stemness regulation and markers; epithelial–mesenchymal transition (EMT) transcription factors, markers, and effectors; growth factors and their receptors; and cancer progression. The spheroids also retained liver-specific functions, suppressed apoptotic signaling, and exhibited extracellular matrix remodeling signatures. Collectively, these findings demonstrate that the 3D HCC model using MCP-B hydrogel recapitulates key hallmarks of tumor biology and provides a robust, physiologically relevant platform for mechanistic studies of HCC and CSC biology. This model further holds translational value for preclinical drug screening and the development of novel anti-HCC and anti-CSC therapeutics.

Natural killer (NK) cells, key effectors of innate immunity, are classically categorized into CD56^dim and CD56^bright subsets in humans. While murine NK cell heterogeneity has become increasingly recognized, the classification of mature NK cell subsets remains incompletely defined. Here, we comprehensively characterized CD127⁺ NK cells in mice and identified them as a distinct, mature subset, developing independently of the thymus and interleukin (IL)-15 signaling. Flow cytometric analyses revealed that CD127⁺ NK cells are broadly distributed across lymphoid and non-lymphoid tissues—including in C57BL/6 wild-type and athymic Foxn1^−/− mice—and exhibit a surface phenotype distinct from CD127⁻ NK and thymus-derived CD127⁺ NK cells. Functional assays demonstrated that CD127⁺ NK cells produce interferon-γ and exert cytotoxic activity, despite expressing markers typically associated with immature NK cells. CD127⁺ NK cells were absent in IL-7Rα^−/− mice but present in IL-15^−/− and IL-15Rα^−/− mice, indicating a selective dependence on IL-7 signaling. IL-7 promoted their proliferation and activation both in vitro and in vivo. These findings revise current models of NK cell development by identifying a novel, IL-7-responsive, IL-15-independent, thymus-independent, and functionally competent CD127⁺ NK cell subset that is phenotypically distinct from helper-like innate lymphoid cells (ILCs). This study provides a framework for future investigations on NK cell heterogeneity, tissue specialization, and cytokine-mediated regulation.