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

Hypoxia and aberrant activation of epidermal growth factor receptor (EGFR) are considered important features of various malignancies. However, whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear. In this study, we demonstrated that in oral cancer, a typical hypoxic tumor, hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands. Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia. In hypoxic HN4 and HN6 cells, ubiquitination-mediated endocytosis, lysosomal sorting, and degradation lead to low levels of EGFR phosphorylation. However, in CAL-27 and HN30 cells, a novel HIF-1α-induced long noncoding RNA (lncRNA), EUDAL, can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR, stabilizing phosphorylated EGFR (pEGFR) and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling. STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance. A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients. Collectively, hypoxia can induce noncanonical ligand-independent EGFR phosphorylation. High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/pathology* ; RNA, Long Noncoding/genetics* ; Drug Resistance, Neoplasm/genetics* ; Cell Line, Tumor ; Phosphorylation ; Signal Transduction ; STAT3 Transcription Factor/metabolism* ; Cell Hypoxia ; Autophagy ; Proto-Oncogene Proteins c-cbl/metabolism*

The transcription factor HOXB13 plays crucial roles in cancer development. HOXB13 is abnormally expressed in most cancers, which makes it a valuable therapeutic target for cancer therapy. The level of HOXB13 differs significantly between healthy and cancer tissues, which indicates that the level of HOXB13 is closely related to carcinogenesis. The regulatory network mediated by HOXB13 in cancer proliferation, metastasis, and invasion has been systematically investigated. Moreover, HOXB13 variants play distinct roles in different cancers and populations. By understanding the molecular mechanisms and mutation features of HOXB13, we provide a comprehensive overview of carcinogenesis networks dependent on HOXB13. Finally, we discuss advancements in anticancer therapy targeting HOXB13 and the roles of HOXB13 in drug resistance to molecular-targeted therapies, which serves as a foundation for developing HOXB13-targeted drugs for clinical diagnosis and cancer therapies.
Humans ; Neoplasms/metabolism* ; Homeodomain Proteins/metabolism* ; Carcinogenesis/genetics* ; Mutation ; Gene Expression Regulation, Neoplastic ; Molecular Targeted Therapy ; Drug Resistance, Neoplasm/genetics*

BACKGROUND: Enzalutamide, a second-generation androgen receptor (AR) pathway inhibitor, is widely used in the treatment of castration-resistant prostate cancer. However, after a period of enzalutamide treatment, patients inevitably develop drug resistance. In this study, we characterized leucine-rich repeated G-protein-coupled receptor 5 (LGR5) and explored its potential therapeutic value in prostate cancer. METHODS: A total of 142 pairs of tumor and adjacent formalin-fixed paraf-fin-embedded tissue samples from patients with prostate cancer were collected from the Pathology Department at Sun Yat-sen Memorial Hos-pital. LGR5 was screened by sequencing data of enzalutamide-resistant cell lines combined with sequencing data of lesions with different Gleason scores from the same patients. The biological function of LGR5 and its effect on enzalutamide resistance were investigated in vitro and in vivo . Glutathione-S-transferase (GST) pull-down, coimmunoprecipitation, Western blotting, and immunofluorescence assays were used to explore the specific binding mechanism of LGR5 and related pathway changes. RESULTS: LGR5 was significantly upregulated in prostate cancer and negatively correlated with poor patient prognosis. Overexpression of LGR5 promoted the malignant progression of prostate cancer and reduced sensitivity to enzalutamide in vitro and in vivo . LGR5 promoted the phosphorylation of glycogen synthase kinase-3β (GSK-3β) by binding heat shock protein 90,000 alpha B1 (HSP90AB1) and mediated the activation of the Wingless/integrated (WNT)/β-catenin signaling pathway. The increased β-catenin in the cytoplasm entered the nucleus and bound to the nuclear AR, promoting the transcription level of AR, which led to the enhanced tolerance of prostate cancer to enzalutamide. Reducing HSP90AB1 binding to LGR5 significantly enhanced sensitivity to enzalutamide. CONCLUSIONS LGR5 directly binds to HSP90AB1 and mediates GSK-3β phosphorylation, promoting AR expression by regulating the WNT/β-catenin signaling pathway, thereby conferring resistance to enzalutamide treatment in prostate cancer.
Male ; Humans ; Phenylthiohydantoin/pharmacology* ; Benzamides ; Receptors, G-Protein-Coupled/genetics* ; Nitriles ; Cell Line, Tumor ; HSP90 Heat-Shock Proteins/metabolism* ; Drug Resistance, Neoplasm/genetics* ; Prostatic Neoplasms/drug therapy* ; beta Catenin/metabolism* ; Receptors, Androgen/genetics* ; Animals ; Mice ; Wnt Signaling Pathway/physiology*

BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

The Kirsten rat sarcoma viral oncogene homolog ( KRAS ) mutation is one of the most prevalent activating alterations in cancer. It indicates a poor overall prognosis due to its highly invasive nature. Although several KRAS inhibitors have been developed in recent years, a significant clinical challenge has emerged as a substantial proportion of patients eventually develop resistance to these therapies. Therefore, identifying determinants of drug resistance is critical for guiding treatment strategies. This review provides a comprehensive overview of the mutation landscape and molecular mechanisms of KRAS activity in various cancers. Meanwhile, it summaries the progress and prospects of small molecule KRAS inhibitors undergoing clinical trials. Furthemore, this review explores potential strategies to overcome drug resistance, with the ultimate goal of steering toward patient-centric precision oncology in the foreseeable future.
Humans ; Drug Resistance, Neoplasm/drug effects* ; Proto-Oncogene Proteins p21(ras)/metabolism* ; Mutation/genetics* ; Neoplasms/genetics* ; Antineoplastic Agents/therapeutic use*

Objective To study the impacts of curcumin on the proliferation, migration and cisplatin (DDP) resistance of bladder cancer cells by regulating the liver kinase B1-AMP activated protein kinase-microtubule-associated protein 1 light chain 3 (LKB1-AMPK-LC3) signaling pathway. Methods Human bladder cancer cell line T24 was cultured in vitro, and its DDP resistant T24/DDP cells were induced by cisplatin (DDP). After treating T24 and T24/DDP cells with different concentrations of curcumin, the optimal concentration of curcumin was screened by MTT assay. T24 cells were randomly grouped into control group, curcumin group, metformin group, and combination group of curcumin and metformin. After treatment with curcumin and LKB1-AMPK activator metformin, the proliferation, autophagy, migration, and apoptosis of T24 cells in each group were detected by MTT assay, monodansylcadavrine (MDC) fluorescence staining, cell scratch assay, and flow cytometry, respectively. Western blot was used to detect the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24 cells of each group. T24/DDP cells were randomly assigned into control group, curcumin group, metformin group, and combination group of curcumin and metformin. Cells were treated with curcumin and metformin according to grouping and treated with different concentrations of DDP simultaneously. Then, the effect of curcumin on the DDP resistance coefficient of T24/DDP cells was detected by MTT assay. T24/DDP cells were randomly grouped into control group, DDP group, combination groups of DDP and curcumin, DDP and metformin, DDP, curcumin and metformi. After treatment with DDP, curcumin, and metformin, the proliferation, autophagy, migration, apoptosis, drug resistance, and the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24/DDP cells of each group were detected with the same methods. Results Compared with the control group, the activity of T24 cells, relative number of autophagosomes, migration rate, Phosphorylated-LKB1 (p-LKB1)/LKB1, Phosphorylated-AMPK (p-AMPK)/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the curcumin group were lower, and the apoptosis rate of T24 cells was higher; the changes in various indicators in the metformin group were opposite to those in the curcumin group. Compared with the curcumin group, the activity of T24 cells, relative number of autophagosomes, migration rate, p-LKB1/LKB1, p-AMPK/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the combination group of curcumin and metformin were higher, and the apoptosis rate of T24 cells was lower. Compared with the control group, there were no obvious changes in various indicators of T24/DDP cells in the DDP group. Compared with the control group and DDP group, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-glycoprotein (P-gp) protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP and curcumin were lower, and the apoptosis rate of T24/DDP cells was higher; the changes in the above indicators in the combination group of DDP and metformin were opposite to those in the combination group of DDP and curcumin. Compared with the combination group of DDP and curcumin, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-gp protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP, curcumin and metformin were higher, and the apoptosis rate of T24/DDP cells was lower. Conclusion Curcumin can reduce the activity of LKB1-AMPK-LC3 signaling pathway, thereby inhibiting autophagy, proliferation and migration of bladder cancer cells, promoting their apoptosis, and weakening their resistance to DDP.
Humans ; Cisplatin/pharmacology* ; Curcumin/pharmacology* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects* ; Protein Serine-Threonine Kinases/genetics* ; AMP-Activated Protein Kinases/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Urinary Bladder Neoplasms/pathology* ; Cell Line, Tumor ; Cell Movement/drug effects* ; AMP-Activated Protein Kinase Kinases ; Microtubule-Associated Proteins/metabolism* ; Apoptosis/drug effects* ; Antineoplastic Agents/pharmacology* ; Metformin/pharmacology* ; Autophagy/drug effects*

Objective To investigate the effect of basic helix-loop-helix family member E40 (BHLHE40) on the invasion and migration of osteosarcoma (OS) cells, and to explore the role of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in the biological behavior of OS mediated by BHLHE40, providing a scientific basis for targeted therapy of OS. Methods On the basis of clinical OS samples and OS cell lines, the expression differences of BHLHE40 between OS and adjacent tissues, as well as those between OS cells and normal osteoblast cell lines, were analyzed. BHLHE40 knockdown OS cells were obtained through shRNA transfection. The effects of BHLHE40 on OS cell proliferation, migration, and invasion were examined using CCK-8, EdU staining, wound healing, and Transwell assays. The involvement of the PI3K/AKT signaling pathway was assessed by Western blotting. Further validation was conducted in vivo experiments. Results The expression of BHLHE40 was significantly higher in OS tissues compared to adjacent tissues. In OS cell lines, BHLHE40 protein expression levels were increased compared to normal osteoblasts, and the cell line with the highest BHLHE40 expression was selected for subsequent knockdown experiments. Compared with the knockdown control group, the BHLHE40 knockdown group exhibited reduced cell viability, EdU-positive cell count, colony number, cell migration, and invasion abilities, along with downregulation of phosphorylated PI3K(p-PI3K)/PI3K and p-AKT/AKT protein expression. The aforementioned functions of BHLHE40 were also reproduced in in vivo experiments. Conclusion BHLHE40 is highly expressed in OS tissues, and its knockdown can significantly inhibit OS cell proliferation, migration, and invasion, while reducing PI3K/AKT signaling pathway activity. This suggests that BHLHE40 could serve as a novel therapeutic target for OS.
Osteosarcoma/metabolism* ; Humans ; Proto-Oncogene Proteins c-akt/genetics* ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Signal Transduction/genetics* ; Phosphatidylinositol 3-Kinases/genetics* ; Cell Line, Tumor ; Animals ; Neoplasm Invasiveness ; Basic Helix-Loop-Helix Transcription Factors/metabolism* ; Bone Neoplasms/metabolism* ; Mice ; Gene Knockdown Techniques ; Male ; Female ; Mice, Nude

Objective To explore the mechanism of TPT1-AS1 targeting miR-324/TWIST1 axis to regulate the proliferation, invasion, migration and angiogenesis of epithelial ovarian cancer (EOC) cells, thereby affecting ovarian cancer (OC) progression. Methods RT-qPCR was used to detect the expression of TPT1-AS1 and miR-324 in 29 OC lesions and adjacent tissue samples. The two OC cell models of TPT1-AS1 overexpression and miRNA324 knockdown were constructed, and the cell proliferation, invasion and migration abilities were detected by CCK-8, Transwell^TM and scratch test. Western blot analysis was used to detect the protein expression levels of TWIST1, epithelial cadherin (E-cadherin), Vimentin, and vascular endothelial growth factor A (VEGF-A) in OC cells. Fluorescence in situ hybridization (FISH) and RNA pull-down experiments were used to verify the interaction between TPT1-AS1 and miR-324. Immunohistochemistry and Targetscan bioinformatics analysis were used to verify the negative regulatory role of miR-324 in the epithelial-mesenchymal transition (EMT) process. Results The TPT1-AS1 expression was significantly higher in OC tissues than that in para-cancerous tissues, while the miR-324 expression was significantly lower. In SKOV3 cells with TPT1-AS1 overexpression, the miR-324 expression decreased significantly, and TPT1-AS1 was negatively correlated with miR-324. It was also found that TPT1-AS1 and miR-324 were co-expressed in OC cells, and there was a direct binding relationship between them. Down-regulation of miR-324 significantly promoted the proliferation, invasion and migration of SKOV3 cells. Further studies revealed that miR-324 had a binding site at the 3'-UTR end of the TWIST1, a key transcription factor for EMT. Inhibiting miR-324 expression increased the transcription level of TWIST1, leading to a decrease in E-cadherin protein expression and an increase in Vimentin protein expression. Additionally, the downregulation of miR-324 resulted in an increased expression level of VEGF-A protein, which in turn enhanced angiogenesis of OC. Conclusion TPT1-AS1 promotes EOC cell proliferation, invasion, migration and angiogenesis by negatively regulating the miR-324/TWIST1 axis, thus promoting the development of OC. These findings provide new potential targets for the diagnosis and treatment of OC.
Humans ; MicroRNAs/metabolism* ; Female ; Cell Movement/genetics* ; Ovarian Neoplasms/blood supply* ; Twist-Related Protein 1/metabolism* ; Cell Line, Tumor ; Neovascularization, Pathologic/genetics* ; Neoplasm Invasiveness ; Carcinoma, Ovarian Epithelial/metabolism* ; Nuclear Proteins/metabolism* ; Cell Proliferation/genetics* ; Epithelial-Mesenchymal Transition/genetics* ; Gene Expression Regulation, Neoplastic ; RNA, Long Noncoding/metabolism* ; Cadherins/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Vimentin/genetics* ; Angiogenesis

OBJECTIVE: To investigate the expression levels of EZH2 and KMT2D in patients with diffuse large B-cell lymphoma (DLBCL) and their relationship with pathological features. METHODS: 84 patients with DLBCL treated in our hospital from January 2021 to June 2022 were selected as the study subjects, and clinical characteristics such as sex, age and pathological classification of the patients were collected. Immunohistochemistry was used to detecet the expression of KMT2D and EZH2 proteins in tumor tissue cells of the DLBCL patients. The differential expression of KMT2D and EZH2 in subgroups of different sexes, ages, primary sites, clinical stages, Hans subtypes, etc. were compared. The correlation between the expression of KMT2D and EZH2 protein and BCL-6, CD79A was analyzed and validated through the interaction of protein molecular structures. We followed up and recorded the survival status of the patients for 12 months, and analyzed the factors that affect the mortality of DLBCL patients. RESULTS: The positive rate of KMT2D and EZH2 was high (over 95%) in DLBCL patients. There was no significant difference in the expression of EZH2 and KMT2D among subgroups of different sexes, ages and stages (P >0.05). However, patients with different levels of BCL-6 and CD79A expression showed differences in EZH2 and KMT2D expression (P < 0.05). EZH2 and KMT2D were positively correlated with BCL-6 (r =0.391, r =0.332) and CD79A (r =0.309, r =0.258), respectively, and there were interactions in the protein molecular structures. The risk factors for mortality in DLBCL patients include male sex (OR =1.106, 95%CI : 1.082-1.130, P < 0.001), stage II (OR =1.778, 95%CI : 1.567-2.016, P < 0.001), stage IV (OR =2.233, 95%CI : 2.021-2.467, P < 0.001), EZH2 positive (OR =2.762, 95%CI : 1.304-5.850, P =0.008), BCL-6 positive (OR =7.309, 95%CI : 1.340-39.859, P =0.022), age≥74 years (OR =3.080, 95%CI : 1.658-5.723, P < 0.001), and 63-73 years old (OR =2.400, 95%CI : 1.564-3.682, P < 0.001), while KMT2D positive (OR =0.180, 95%CI : 0.054-0.608, P =0.006) and 41-51 years old (OR =0.406, 95%CI : 0.274-0.603, P < 0.001) were factors which could reduce the risk of mortality. CONCLUSION EZH2 and KMT2D are highly expressed in patients with DLBCL, and they are positively correlated with BCL-6 and CD79A, and affect the prognosis of DLBCL patients.
Humans ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Lymphoma, Large B-Cell, Diffuse/metabolism* ; DNA-Binding Proteins/metabolism* ; Female ; Male ; Middle Aged ; Adult ; Neoplasm Proteins/metabolism* ; Aged ; Immunohistochemistry ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Prognosis