PA28γ coordinates the cross-talk between cancer-associated fibroblasts and tumor cells to promote OSCC progression via HDAC1/E2F3/IGF2 signaling.

PA28γ overexpression is aberrant and accompanied by poor patient prognosis in various cancers, the precise regulatory mechanism of this crucial gene in the tumor microenvironment remains incompletely understood. In this study, using oral squamous cell carcinoma as a model, we demonstrated that PA28γ exhibits high expression in cancer-associated fibroblasts (CAFs), and its expression significantly correlates with the severity of clinical indicators of malignancy. Remarkably, we found that elevated levels of secreted IGF2 from PA28γ+ CAFs can enhance stemness maintenance and promote tumor cell aggressiveness through the activation of the MAPK/AKT pathway in a paracrine manner. Mechanistically, PA28γ upregulates IGF2 expression by stabilizing the E2F3 protein, a transcription factor of IGF2. Further mechanistic insights reveal that HDAC1 predominantly mediates the deacetylation and subsequent ubiquitination and degradation of E2F3. Notably, PA28γ interacts with HDAC1 and accelerates its degradation via a 20S proteasome-dependent pathway. Additionally, PA28γ+ CAFs exert an impact on the tumor immune microenvironment by secreting IGF2. Excitingly, our study suggests that targeting PA28γ+ CAFs or secreted IGF2 could increase the efficacy of PD-L1 therapy. Thus, our findings reveal the pivotal role of PA28γ in cell interactions in the tumor microenvironment and propose novel strategies for augmenting the effectiveness of immune checkpoint blockade in oral squamous cell carcinoma.

Loss of PA28γ exacerbates imbalanced differentiation of bone marrow stromal cells during bone formation and bone healing in mice.

Proteasome activator subunit 3 (PA28γ) is a member of the proteasome activator family, which mainly regulates the degradation and stability of proteins. Studies have shown that it plays crucial roles in lipid formation, stemness maintenance, and blood vessel formation. However, few studies have clarified the association between PA28γ and bone diseases. Herein, we identified PA28γ as a previously unknown regulator of bone homeostasis that coordinates bone formation and lipid accumulation. PA28γ-knockout mice presented with the characteristics of low bone mass and accumulation of lipids. Suppressed expression of PA28γ restrained the osteogenic differentiation and enhanced the adipogenic differentiation of bone marrow stromal cells (BMSCs). Overexpression of PA28γ promoted osteogenic differentiation and inhibited adipogenic differentiation of BMSCs. Mechanistically, PA28γ interacted with Wnt5α, and the two interactors appeared to be positively correlated. PA28γ mainly activated the downstream Wnt/ß-catenin signaling pathway, which affects BMSCs differentiation homeostasis. Deletion of Wnt5α significantly delayed the promotion of osteogenic differentiation and partially alleviated the inhibitory effect of adipogenic differentiation of BMSCs in the PA28γ-overexpressing group. Furthermore, we demonstrated that PA28γ-knockout mice had an inhibited rate of bone healing in a drill-hole femoral bone defect model in vivo. Therefore, our results confirm the effects of PA28γ on bone formation and bone defect repair, indicating that PA28γ mainly interacts with Wnt5α to activate the Wnt/ß-catenin signaling pathway regulating BMSCs differentiation homeostasis. Our results reveal the function of PA28γ in bone diseases and provide a new theoretical basis for expanding the treatment of bone diseases.

Diagnostic strategies for diseases with fever in dental clinics. / å£è ”å‘çƒ­ç–¾ç— è¾¨æžç­–ç•¥.

Fever is an increase in body temperature beyond the normal range, acting as a protective inflammatory mechanism. This article summarizes diseases with fever encountered in dental clinics, including what is known about pyrexia in coronavirus infection, and further proposes a "six steps in one" identification and analysis strategy to guide the clinical work of stomatology.

Long Noncoding RNA LEMD1-AS1 Increases LEMD1 Expression and Activates PI3K-AKT Pathway to Promote Metastasis in Oral Squamous Cell Carcinoma.

Background: The survival rate of oral squamous cell carcinoma (OSCC) is only 50% due to a high incidence of metastasis. Long noncoding RNAs (lncRNAs) play a crucial role in OSCC genesis and progression, although their potential role in the metastasis of OSCC remains unclear. Methods: The transcriptome of 5 metastatic and 5 nonmetastatic OSCC samples were assessed by RNA sequencing. The biological functions and regulatory mechanisms of LEMD1-AS1 in OSCC were explored by in vitro and in vivo assays. Results: We identified 487 differentially expressed mRNAs (DEmRNAs) and 1507 differentially expressed lncRNAs (DElncRNAs) in OSCC with cervical lymph node (LN) metastasis relative to the nonmetastatic samples. In addition, both LEMD1-AS1 and its cognate LEMD1 were up-regulated in metastatic OSCC compared to nonmetastatic OSCC. Gain-of-function, loss-of-function, and rescue experiments indicated that LEMD1-AS1 upregulated LEMD1 to increase OSCC migration and invasion in vitro and in vivo. Mechanistically, LEMD1-AS1 stabilized LEMD1 and increased its mRNA and protein levels, and consequently activated the PI3K-AKT signaling pathway to facilitate OSCC metastasis. Conclusions: We established the lncRNA-mRNA landscape of metastatic OSCC, which indicated that LEMD1-AS1 enhanced OSCC metastasis by stabilizing its antisense transcript LEMD1. Thus, LEMD1-AS1 is a potential biomarker for predicting metastasis, as well as a therapeutic target of OSCC.

Identification of a BRAF/PA28γ/MEK1 signaling axis and its role in epithelial-mesenchymal transition in oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a chronic and insidious oral potentially malignant disorder associated with a 4-17% risk of oral squamous cell carcinoma (OSCC). Our previous study found that proteasomal activator 28 gamma (PA28γ) is frequently overexpressed in oral squamous cell carcinoma and negatively correlated with poor patient prognosis. However, the role of PA28γ in the occurrence and development of OSF remains unclear. Here, we screened PA28γ-related genes and investigated their function in OSF. We demonstrated that the expression of PA28γ was positively associated with MEK1 and gradually elevated from normal to progressive stages of OSF tissue. Arecoline, a pathogenic component of OSF, could upregulate the protein levels of PA28γ and phosphorylated MEK1 and contribute to epithelial to mesenchymal transition (EMT) in epithelial cells. Notably, PA28γ could interact with MEK1 and upregulate its phosphorylation level. Furthermore, arecoline upregulated BRAF, which can interact with PA28γ and upregulate its protein level. Additionally, BRAF, PA28γ, and MEK1 could form protein complexes and then enhance the MEK1/ERK signaling pathways. The concrete mechanism of the protein stability of PA28γ is that BRAF mediates its degradation by inhibiting its ubiquitination. These findings underscore the instrumental role of PA28γ in the BRAF/MEK1 pathway and enhanced EMT through MEK1/ERK activation in OSF.

Protocatechuic Acid-Based Supramolecular Hydrogel Targets SerpinB9 to Achieve Local Chemotherapy for OSCC.

Protocatechuic acid (PCA) is a natural phenolic acid present in daily vegetables and fruits. Notably, PCA was demonstrated to inhibit the biological function of SerpinB9 (Sb9) and exhibit an excellent antitumor effect, showing great potential in cancer treatment. However, the short half-life time limits PCA's wide application against cancers. To overcome this shortage of PCA, we integrated PCA and another natural product with strong self-assembling properties, isoguanosine (isoG), to develop a novel multifunctional supramolecular hydrogel with good biocompatibility and injectability, which remarkably lengthens the releasing time of PCA and exerts considerable anticancer effects in vitro and in vivo. Besides, we surprisingly found that PCA could not only target Sb9 but also restrain cancer development through activating the JNK/P38 pathway, decreasing the ROS level, and repairing cancer stemness. In all, our results demonstrate that this PCA-based hydrogel could act as a multifunctional hydrogel system equipped with considerable anticancer effects, providing potential local administration integrating with targeted therapy and chemotherapy in one simple modality.

Diagnostic strategies for oral manifestations of infectious diseases.

Infectious diseases are caused by infection of organism with pathogenic agents, which may lead to epidemics. Many infectious diseases such as syphilis, diphtheria, measles, and acquired immunodeficiency syndrome have specific and non-specific manifestations in the oral cavity. However, the same disease may have different oral manifestations in different patients clinically. We can apply the strategy of "three unusuals and one change" in clinical reasoning for diagnosis of infectious diseases with oral manifestations. The so-called "three unusuals" refer to unusual age, unusual location and unusual effect, and "one change" means the change from rare to common. In this article, we will give a comprehensive introduction about the oral manifestations of common communicable diseases and their diagnostic strategies.

The circEPSTI1/mir-942-5p/LTBP2 axis regulates the progression of OSCC in the background of OSF via EMT and the PI3K/Akt/mTOR pathway.

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSF) caused by areca nut chewing has a high incidence in Asia-Pacific countries. However, the molecular mechanism remains unclear. Here, we performed circRNA microarray analysis to screen the circRNA expression profiles in OSCC and OSF. We identified circEPSTI1 as a circRNA with consistent, sequential upregulation from normal buccal mucosa (NBM) to OSF to OSCC. Functionally, circEPSTI1 significantly promoted OSCC cell proliferation and invasion, as evidenced by the CCK8, colony formation, wound healing, and transwell assays with circEPSTI1 overexpression and silencing. OSCC patients with circEPSTI1high status exhibited poor prognoses. CircEPSTI1 sponged miR-942-5p and accelerated epithelial-mesenchymal transition (EMT) to increase LTBP2 expression in OSCC through phosphorylation of PI3K/Akt/mTOR signaling pathway components. Blocking the PI3K/Akt/mTOR signaling pathway with the dual PI3k/mTOR inhibitor BEZ235 reversed OSCC progression induced by overexpression of circEPSTI1 and LTBP2. Collectively, these results indicate that the circEPSTI1/miR-942-5p/LTBP2 axis affects OSCC cell proliferation and invasion via the acceleration of EMT and the phosphorylation of PI3K/Akt/mTOR signaling pathway components. CircEPSTI1 may be an independent diagnostic and prognostic marker and a potential therapeutic target for OSCC patients with OSF.

TCGA based integrated genomic analyses of ceRNA network and novel subtypes revealing potential biomarkers for the prognosis and target therapy of tongue squamous cell carcinoma.

OBJECTIVES: The study aimed to investigate the ceRNA network in biological development of Tongue Squamous Cell Carcinoma (TSCC) and to identify novel molecular subtypes of TSCC to screen potential biomarkers for target therapy and prognosis by using integrated genomic analysis based on The Cancer Genome Atlas (TCGA) database. MATERIAL AND METHODS: Data on gene expressions were downloaded from TCGA and GEO database. Differentially expressed RNAs(DERNAs) were shown by DESeq2 package in R. Functional enrichment analysis of DEmRNAs was performed using clusterprofilers in R. PPI network was established by referring to String website. Survival analysis of DERNAs was carried out by survival package in R. Interactions among mRNAs, miRNAs and lncRNAs were obtained from Starbase v3.0 and used to construct ceRNA network. Consensus Cluster Plus package was applied to identify molecular subtypes. All key genes were validated by comparing them with GEO microarray data. Statistical analyses of clinical features among different subtypes were performed using SPSS 22.0. RESULTS: A total of 2907 mRNAs (1366 up-regulated and 1541 down-regulated), 191miRNAs (98 up-regulated and 93 down-regulated) and 1831 lncRNAs (1151 up-regulated and 680 down-regulated) were identified from tumor and normal tissues. A ceRNA network was successfully constructed and 15 DEmRNAs, 1 DEmiRNA, 2 DElncRNAs associated with prognosis were employed. Furthermore, we firstly identified 2 molecular subtypes, basal and differentiated, and found that differentiated subtype consumed less alcohol and was related to a better overall survival. CONCLUSION: The study constructed a ceRNA network and identified molecular subtypes of TSCC, and our findings provided a novel insight into this intractable cancer and potential therapeutic targets and prognostic indicators.

Streptococcus salivarius-mediated CD8+ T cell stimulation required antigen presentation by macrophages in oral squamous cell carcinoma.

It has been shown that the peripheral blood mononuclear cells (PBMCs) from oral squamous cell carcinoma (OSCC) patients presented cytotoxic CD8 T cell response against Streptococcus salivarius (S. salivarius), of which the frequency was positively associated with recurrence-free survival in OSCC patients. To identify the conditions required for regulating S. salivarius-specific CD8 T cell-mediated cytotoxicity, we selectively depleted individual components of the PBMCs, and observed that the depletion of monocytes/macrophages, but not other immune cell subsets, significantly downregulated the S. salivarius-specific CD8 T cell cytotoxicity. Monocyte/macrophage alone was sufficient to reconstitute optimal granzyme B expression from S. salivarius-specific CD8 T cells. Also, both the memory and the naive CD8 T cells reacted to S. salivarius-stimulation, with the memory CD8 T cells presenting significantly higher S. salivarius-reactivity. Using M1- and M2-polarized macrophages from circulating monocytes, we found that M1-polarized macrophages, with significantly higher IL-12 expression and significantly lower IL-10 and MHC class II molecule expression, was more effective at promoting granzyme B responses in CD8 T cells, and required CD80/CD86 costimulating molecules for optimal responses. Interestingly, the tumor-associated macrophages (TAMs) from resected tumors presented characteristics of M2-polarized macrophages with high MHC class II expression and low IL-12 secretion. The frequency of tumor-infiltrating S. salivarius-specific cytotoxic CD8 T cell was inversely correlated with the level of IL-10 secretion and the MHC class II molecule expression in autologous TAMs. Together, we demonstrated that monocyte/macrophages presented essential antigen-presentation and costimulatory roles in CD8 T cell-mediated S. salivarius-specific granzyme B responses, and the polarization of macrophages could influence the potency of CD8 T cell responses.

Cytotoxic T cell responses to Streptococcus are associated with improved prognosis of oral squamous cell carcinoma.

Several species of Streptococcus, such as S. salivarius, S. mitis, and S. anginosus, are found to extensively colonize the oral cavity and the upper respiratory tract, and have been shown to increase in patients with oral squamous cell carcinoma (OSCC). Accumulating evidence have revealed that commensal bacteria are involved in antitumor immunity via T cell-mediated mechanisms, but the role of Streptococcus enrichment in OSCC is yet unclear. In this study, we stimulated peripheral blood mononuclear cells from non-cancer controls (NCs) and OSCC patients with S. salivarius, S. mitis, and S. anginosus. We observed that compared to NC subjects, OSCC patients at earlier stages had higher frequencies of granzyme B-expressing CD8 T cells for all Streptococcus species tested, while OSCC patients at more advanced stages had higher frequencies of granzyme B-expressing CD8 T cells for S. anginosus but not other Streptococcus species. In OSCC patients, the Streptococcus-reactive CD8 T cells presented significantly lower levels of PD-1 and TIM-3 expression than Streptococcus-nonreactive CD8 T cells. The clinical outcomes of OSCC patients in our cohort were tracked for 24 months after the resection of the primary tumor. In patients that did not present tumor recurrence, the frequencies of S. salivarius-reactive and S. mitis-reactive CD8 T cells were significantly higher than that in patients that developed recurrent tumor. Furthermore, in patients with tumor recurrence, the duration between primary tumor resection and tumor recurrence was positively associated with the frequencies of S. salivarius-reactive and S. anginosus-reactive CD8 T cells. Together, we demonstrated that Streptococcus-reactive CD8 T cell responses might contribute to antitumor immunity in OSCC patients.