Tumor cell-intrinsic programmed death-ligand 1 (PD-L1) signals mediate tumor initiation, progression and metastasis, but their effects in ameloblastoma (AM) have not been reported. In this comprehensive study, we observed marked upregulation of PD-L1 in AM tissues and revealed the robust correlation between elevated PD-L1 expression and increased tumor growth and recurrence rates. Notably, we found that PD-L1 overexpression markedly increased self-renewal capacity and promoted tumorigenic processes and invasion in hTERT⁺-AM cells, whereas genetic ablation of PD-L1 exerted opposing inhibitory effects. By performing high-resolution single-cell profiling and thorough immunohistochemical analyses in AM patients, we delineated the intricate cellular landscape and elucidated the mechanisms underlying the aggressive phenotype and unfavorable prognosis of these tumors. Our findings revealed that hTERT⁺-AM cells with upregulated PD-L1 expression exhibit increased proliferative potential and stem-like attributes and undergo partial epithelial‒mesenchymal transition. This phenotypic shift is induced by the activation of the PI3K-AKT-mTOR signaling axis; thus, this study revealed a crucial regulatory mechanism that fuels tumor growth and recurrence. Importantly, targeted inhibition of the PD-L1-PI3K-AKT-mTOR signaling axis significantly suppressed the growth of AM patient-derived tumor organoids, highlighting the potential of PD-L1 blockade as a promising therapeutic approach for AM.
Ameloblastoma/metabolism* ; Humans ; B7-H1 Antigen/metabolism* ; Neoplasm Recurrence, Local/pathology* ; Signal Transduction ; Cell Proliferation ; Up-Regulation ; TOR Serine-Threonine Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Telomerase/metabolism* ; Jaw Neoplasms/metabolism* ; Epithelial-Mesenchymal Transition ; Animals ; Cell Line, Tumor ; Female ; Male

Stem cells play a crucial role in maintaining tissue regenerative capacity and homeostasis. However, mechanisms associated with stem cell senescence require further investigation. In this study, we conducted a proteomic analysis of human dental pulp stem cells (HDPSCs) obtained from individuals of various ages. Our findings showed that the expression of NUP62 was decreased in aged HDPSCs. We discovered that NUP62 alleviated senescence-associated phenotypes and enhanced differentiation potential both in vitro and in vivo. Conversely, the knocking down of NUP62 expression aggravated the senescence-associated phenotypes and impaired the proliferation and migration capacity of HDPSCs. Through RNA-sequence and decoding the epigenomic landscapes remodeled induced by NUP62 overexpression, we found that NUP62 helps alleviate senescence in HDPSCs by enhancing the nuclear transport of the transcription factor E2F1. This, in turn, stimulates the transcription of the epigenetic enzyme NSD2. Finally, the overexpression of NUP62 influences the H3K36me2 and H3K36me3 modifications of anti-aging genes (HMGA1, HMGA2, and SIRT6). Our results demonstrated that NUP62 regulates the fate of HDPSCs via NSD2-dependent epigenetic reprogramming.
Humans ; Dental Pulp/cytology* ; Nuclear Pore Complex Proteins/genetics* ; Cellular Senescence/genetics* ; Stem Cells/metabolism* ; Epigenesis, Genetic ; Cell Proliferation ; Cell Differentiation ; Histone-Lysine N-Methyltransferase/metabolism* ; Cells, Cultured ; Cellular Reprogramming ; Cell Movement ; Proteomics

Tissue interactions play a crucial role in tooth development. Notably, extracellular vesicle-mediated interactions between the mandible and tooth germ are considered essential. Here, we revealed that mandible extracellular vesicles could modulate the proliferation and differentiation of dental mesenchymal cells by regulating the histone demethylase KDM2B. Further investigation showed that mandible derived extracellular vesicles could deliver miR-206 to KDM2B, thereby regulating tooth development. An animal study demonstrated that the miR-206/KDM2B pathway affected tooth morphogenesis and mineralization after eight weeks of subcutaneous transplantation in nude mice. In conclusion, this study suggested that the mandible played a critical role in tooth morphogenesis and mineralization, which could be a potential therapeutic target for abnormal tooth development and an alternative model for tooth regeneration.
Animals ; Extracellular Vesicles/metabolism* ; Jumonji Domain-Containing Histone Demethylases/metabolism* ; Swine ; MicroRNAs/metabolism* ; Mandible ; Mice, Nude ; Odontogenesis/physiology* ; Swine, Miniature ; Mice ; Cell Differentiation ; Cell Proliferation

Xerostomia (dry mouth) is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren's syndrome, with no permanent cure existing for this debilitating condition. To this end, in vitro platforms are needed to test therapies directed at salivary (fluid-secreting) cells. However, since these are highly differentiated secretory cells, the maintenance of their differentiated state while expanding in numbers is challenging. In this study, the efficiency of three reversible thermo-ionically crosslinked gels: (1) alginate-gelatin (AG), (2) collagen-containing AG (AGC), and (3) hyaluronic acid-containing AG (AGHA), to recapitulate a native-like environment for human salivary gland (SG) cell expansion and 3D spheroid formation was compared. Although all gels were of mechanical properties comparable to human SG tissue (~11 kPa) and promoted the formation of 3D spheroids, AGHA gels produced larger (>100 cells/spheroid), viable (>93%), proliferative, and well-organized 3D SG spheroids while spatially and temporally maintaining the high expression of key SG proteins (aquaporin-5, NKCC1, ZO-1, α-amylase) for 14 days in culture. Moreover, the spheroids responded to agonist-induced stimulation by increasing α-amylase secretory granules. Here, we propose alternative low-cost, reproducible, and reversible AG-based 3D hydrogels that allow the facile and rapid retrieval of intact, highly viable 3D-SG spheroids.
Humans ; Hydrogels/chemistry* ; Acinar Cells/cytology* ; Spheroids, Cellular/cytology* ; Salivary Glands/cytology* ; Gelatin/chemistry* ; Collagen/chemistry* ; Alginates/chemistry* ; Cell Culture Techniques/methods* ; Hyaluronic Acid/chemistry* ; Cell Proliferation ; Cell Survival ; Cells, Cultured

Insufficient alveolar bone thickness increases the risk of periodontal dehiscence and fenestration, especially in orthodontic tooth movement. Abaloparatide (ABL), a synthetic analog of human PTHrP (1-34) and a clinical medication for treating osteoporosis, has recently demonstrated its potential in enhancing craniofacial bone formation. Herein, we show that intraoral submucosal injection of ABL, when combined with mechanical force, promotes in situ alveolar bone thickening. The newly formed bone is primarily located outside the original compact bone, implying its origin from the periosteum. RNA sequencing of the alveolar bone tissue revealed that the focal adhesion (FA) pathway potentially mediates this bioprocess. Local injection of ABL alone enhances cell proliferation, collagen synthesis, and phosphorylation of focal adhesion kinase (FAK) in the alveolar periosteum; when ABL is combined with mechanical force, the FAK expression is upregulated, in line with the accomplishment of the ossification. In vitro, ABL enhances proliferation, migration, and FAK phosphorylation in periosteal stem cells. Furthermore, the pro-osteogenic effects of ABL on alveolar bone are entirely blocked when FAK activity is inhibited by a specific inhibitor. In summary, abaloparatide combined with mechanical force promotes alveolar bone formation via FAK-mediated periosteal osteogenesis. Thus, we have introduced a promising therapeutic approach for drug-induced in situ alveolar bone augmentation, which may prevent or repair the detrimental periodontal dehiscence, holding significant potential in dentistry.
Osteogenesis/drug effects* ; Periosteum/cytology* ; Parathyroid Hormone-Related Protein/administration & dosage* ; Animals ; Focal Adhesion Protein-Tyrosine Kinases/metabolism* ; Alveolar Process/drug effects* ; Cell Proliferation/drug effects* ; Phosphorylation ; Rats ; Male ; Humans ; Focal Adhesion Kinase 1/metabolism* ; Cell Movement/drug effects*

Protein liquid-liquid phase separation (LLPS), a pivotal phenomenon intricately linked to cellular processes, is regulated by various other proteins. However, there is still a lack of high-throughput methods for screening protein regulators of LLPS in target proteins. Here, we developed a CRISPR/Cas9-based screening method to identify protein phase separation regulators by integrating bimolecular fluorescence complementation (BiFC) and fluorescence-activated cell sorting (FACS). Using this newly developed method, we screened the RNA-binding proteins that regulate PABPN1 phase separation and identified the tumor suppressor QKI as a promoter of PABPN1 phase separation. Furthermore, QKI exhibits decreased expression levels and diminished nuclear localization in colorectal cancer cells, resulting in reduced PABPN1 phase separation, which, in turn, promotes alternative polyadenylation (APA), cell proliferation, and migration in colorectal cancer.
Humans ; Colorectal Neoplasms/genetics* ; RNA-Binding Proteins/genetics* ; Poly(A)-Binding Protein I/genetics* ; CRISPR-Cas Systems ; Flow Cytometry ; Cell Proliferation ; Cell Line, Tumor ; Cell Movement

Glutamine provides carbon and nitrogen to support the proliferation of cancer cells. However, the precise reason why cancer cells are particularly dependent on glutamine remains unclear. In this study, we report that glutamine modulates the tumor suppressor F-box and WD repeat domain-containing 7 (FBW7) to promote cancer cell proliferation and survival. Specifically, lysine 604 (K604) in the sixth of the 7 substrate-recruiting WD repeats of FBW7 undergoes glutaminylation (Gln-K604) by glutaminyl tRNA synthetase. Gln-K604 inhibits SCFFBW7-mediated degradation of c-Myc and Mcl-1, enhances glutamine utilization, and stimulates nucleotide and DNA biosynthesis through the activation of c-Myc. Additionally, Gln-K604 promotes resistance to apoptosis by activating Mcl-1. In contrast, SIRT1 deglutaminylates Gln-K604, thereby reversing its effects. Cancer cells lacking Gln-K604 exhibit overexpression of c-Myc and Mcl-1 and display resistance to chemotherapy-induced apoptosis. Silencing both c-MYC and MCL-1 in these cells sensitizes them to chemotherapy. These findings indicate that the glutamine-mediated signal via Gln-K604 is a key driver of cancer progression and suggest potential strategies for targeted cancer therapies based on varying Gln-K604 status.
Glutamine/metabolism* ; Myeloid Cell Leukemia Sequence 1 Protein/genetics* ; Humans ; Proto-Oncogene Proteins c-myc/genetics* ; Cell Proliferation ; Signal Transduction ; Neoplasms/pathology* ; F-Box-WD Repeat-Containing Protein 7/genetics* ; Cell Survival ; Cell Line, Tumor ; Apoptosis

The p60 subunit of the chromatin assembly factor-1 complex, that is, chromatin assembly factor-1 subunit B (CHAF1B), is a histone H3/H4 chaperone crucial for the transcriptional regulation of cell differentiation and self-renewal. CHAF1B is overexpressed in several cancers and may represent a potential target for cancer therapy. However, its expression and clinical significance in lung squamous-cell carcinoma (LUSC) remain unclear. In this study, we performed weighted gene correlation network analysis to analyze the Gene Expression Omnibus GSE68793 LUSC dataset and identified CHAF1B as one of the most important driver gene candidates. Immunohistochemical analysis of 126 LUSC tumor samples and 80 adjacent normal lung tissues showed the marked upregulation of CHAF1B in tumor tissues and the negative association of its expression level with patient survival outcomes. Silencing of CHAF1B suppressed LUSC proliferation in vitro and LUSC tumor growth in vivo. Furthermore, bulk RNA sequencing of CHAF1B knockdown cells indicated SET domain containing 7 (SETD7) as a significant CHAF1B target gene. In addition, CHAF1B competitively binds to the SETD7 promoter region and represses its transcription. Altogether, these results imply that CHAF1B plays a vital role in LUSC tumorigenesis and may represent a potential molecular target for this deadly disease.
Humans ; Lung Neoplasms/metabolism* ; Histone-Lysine N-Methyltransferase/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Gene Expression Regulation, Neoplastic ; Disease Progression ; Cell Proliferation/genetics* ; Cell Line, Tumor ; Chromatin Assembly Factor-1/metabolism* ; Animals ; Mice ; Male ; Female

Psoriasis is a chronic inflammatory skin disease, and its pathogenesis is largely modulated by abnormal angiogenesis. Previous research has indicated that AlkB homolog 5 (ALKBH5), an important demethylase affecting N⁶-methyladenosine (m⁶A) modification, plays a role in regulating angiogenesis in cardiovascular and eye diseases. Our present study found that ALKBH5 was upregulated and co-localized with cluster of differentiation 31 (CD31) in the skin of IMQ group compared with control group. ALKBH5-deficient mice decreased IMQ-induced psoriatic dermatitis and exhibited histological improvements, including decreased epidermal thickness, hyperkeratosis, numbers of dermal capillary vessels and inflammatory cell infiltration. ALKBH5-KO mice alleviated angiogenesis in psoriatic lesions by downregulating the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Additionally, the expression of ALKBH5 was significantly upregulated in IL-17A-induced human umbilical vein endothelial cells (HUVECs), which further promoted the expression of angiogenesis-related cytokines and endothelial cell proliferation. Cell proliferation and angiogenesis were suppressed in ALKBH5 knockdown group, whereas ALKBH5 overexpression promoted these processes. The regulation of angiogenesis in HUVECs by ALKBH5 was facilitated through the AKT-mTOR pathway. Collectively, ALKBH5 plays a pivotal role in psoriatic dermatitis and angiogenesis, which may offer a new potential targets for treating psoriasis.
Animals ; Psoriasis/chemically induced* ; Mice ; Humans ; Neovascularization, Pathologic/genetics* ; Human Umbilical Vein Endothelial Cells/metabolism* ; AlkB Homolog 5, RNA Demethylase/genetics* ; Proto-Oncogene Proteins c-akt/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Cell Proliferation ; Mice, Knockout ; Disease Models, Animal ; Signal Transduction ; Male ; Skin/blood supply* ; Mice, Inbred C57BL ; Angiogenesis

Trophoblast cells serve as the foundation for placental development. We analyzed published multiomics sequencing data and found that trophoblast cells highly expressed RRS1 compared to primitive endoderm and epiblast. We used HTR-8/SVneo cells for further investigation, and Western blot and immunofluorescence staining confirmed that HTR-8/SVneo cells highly expressed RRS1. RRS1 was successfully knocked down in HTR-8/SVneo cells using siRNA. Using IncuCyte S3 live-cell analysis system based on continuous live-cell imaging and real-time data, we observed that proliferation, migration, and invasion abilities were all significantly decreased in RRS1-knockdown cells. RNA-seq revealed that knockdown of RRS1 affected the gene transcription, and upregulated pathways in extracellular matrix organization, DNA damage response, and intrinsic apoptotic signaling, downregulated pathways in embryo implantation, trophoblast cell migration, and wound healing. Differentially expressed genes were enriched in diseases related to placental development. Consistent with these findings, human chorionic villus samples collected from spontaneous abortion cases exhibited significantly reduced RRS1 expression compared to normal controls. Our results highlight the functional importance of RRS1 in human trophoblasts and suggest that its deficiency contributes to early pregnancy loss.
Humans ; Trophoblasts/physiology* ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Female ; Pregnancy ; Abortion, Spontaneous/metabolism* ; Cell Line ; Placentation/genetics*