WNT3 promotes chemoresistance to 5-Fluorouracil in oral squamous cell carcinoma via activating the canonical ß-catenin pathway.

BACKGROUND: 5-Fluorouracil (5FU) is a primary chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC). However, the development of drug resistance has significantly limited its clinical application. Therefore, there is an urgent need to determine the mechanisms underlying drug resistance and identify effective targets. In recent years, the Wingless and Int-1 (WNT) signaling pathway has been increasingly studied in cancer drug resistance; however, the role of WNT3, a ligand of the canonical WNT signaling pathway, in OSCC 5FU-resistance is not clear. This study delved into this potential connection. METHODS: 5FU-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells underwent RNA sequencing analysis, which was then substantiated via Real-time quantitative PCR (RT-qPCR) and western blot tests. The influence of the WNT signaling on OSCC chemoresistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor methyl 3-benzoate (MSAB) was probed for its capacity to boost 5FU efficacy. RESULTS: In this study, the WNT/ß-catenin signaling pathway was notably activated in 5FU-resistant OSCC cell lines, which was confirmed through transcriptome sequencing analysis, RT-qPCR, and western blot verification. Additionally, the key ligand responsible for pathway activation, WNT3, was identified. By knocking down WNT3 in resistant cells or overexpressing WNT3 in parental cells, we found that WNT3 promoted 5FU-resistance in OSCC. In addition, the WNT inhibitor MSAB reversed 5FU-resistance in OSCC cells. CONCLUSIONS: These data underscored the activation of the WNT/ß-catenin signaling pathway in resistant cells and identified the promoting effect of WNT3 upregulation on 5FU-resistance in oral squamous carcinoma. This may provide a new therapeutic strategy for reversing 5FU-resistance in OSCC cells.

Exploring new avenues of health protection: plant-derived nanovesicles reshape microbial communities.

Symbiotic microbial communities are crucial for human health, and dysbiosis is associated with various diseases. Plant-derived nanovesicles (PDNVs) have a lipid bilayer structure and contain lipids, metabolites, proteins, and RNA. They offer unique advantages in regulating microbial community homeostasis and treating diseases related to dysbiosis compared to traditional drugs. On the one hand, lipids on PDNVs serve as the primary substances that mediate specific recognition and uptake by bacteria. On the other hand, due to the multifactorial nature of PDNVs, they have the potential to enhance growth and survival of beneficial bacterial while simultaneously reducing the pathogenicity of harmful bacteria. In addition, PDNVs have the capacity to modulate bacterial metabolism, thus facilitating the establishment of a harmonious microbial equilibrium and promoting stability within the microbiota. These remarkable attributes make PDNVs a promising therapeutic approach for various conditions, including periodontitis, inflammatory bowel disease, and skin infection diseases. However, challenges such as consistency, isolation methods, and storage need to be addressed before clinical application. This review aims to explore the value of PDNVs in regulating microbial community homeostasis and provide recommendations for their use as novel therapeutic agents for health protection.

A unilateral increase in the occlusal vertical dimension of growing rats results in mandibular deviation.

OBJECTIVE: The effects of unilateral increased occlusal vertical dimension (iOVD) on bilateral craniofacial, mandibular and alveolar development in growing rats were investigated via cone-beam computed tomography (CBCT). The role of Wnt/ß-catenin signalling in this process was examined. MATERIALS AND METHODS: Forty-eight female Sprague-Dawley rats were randomly allocated into unilateral iOVD and sham groups. At 2, 4 and 8 weeks, the rats were scanned via CBCT to analyse cranial, maxillary, mandibular and dental morphology. Changes in temporomandibular joint (TMJ) cartilage histology and Wnt/ß-catenin signalling were assessed by histochemical and immunohistochemical staining and qRT-PCR. RESULTS: Dorsal cephalograms revealed that the mandible in the iOVD group tilted approximately 4° to the right. Unilateral iOVD had little effect on cranial and maxillary growth but inhibited mandibular growth (mandibular length and ramal height), especially on the deviated side (DS). Moreover, unilateral iOVD increased the length of the lower incisors and decreased the height of the molars on the DS. Unilateral iOVD induced bilateral osteoarthritis-like changes in the bilateral TMJ condylar cartilage and activated Wnt/ß-catenin signalling in the condylar cartilage, especially on the contralateral side (CLS). CONCLUSION: Occlusion with unilateral iOVD induced mandibular deviation, significantly inhibited mandibular growth and produced compensatory changes in the alveolar bone. In the iOVD group, the mandibular body length and ramal height were greater on the CLS than on the DS. Moreover, the greater ß-catenin protein expression in the TMJ condylar cartilage on the CLS than on the DS may account for the difference in asymmetrical mandibular development.

Plant-derived nanovesicles: harnessing nature's power for tissue protection and repair.

Tissue damage and aging lead to dysfunction, disfigurement, and trauma, posing significant global challenges. Creating a regenerative microenvironment to resist external stimuli and induce stem cell differentiation is essential. Plant-derived nanovesicles (PDNVs) are naturally bioactive lipid bilayer nanovesicles that contain proteins, lipids, ribonucleic acid, and metabolites. They have shown potential in promoting cell growth, migration, and differentiation into various types of tissues. With immunomodulatory, microbiota regulatory, antioxidant, and anti-aging bioactivities, PDNVs are valuable in resisting external stimuli and facilitating tissue repair. The unique structure of PDNVs provides an optimal platform for drug encapsulation, and surface modifications enhance their stability and specificity. Moreover, by employing synergistic administration strategies, PDNVs can maximize their therapeutic potential. This review summarized the progress and prospects of PDNVs as regenerative tools, provided insights into their selection for repair activities based on existing studies, considered the key challenge for clinical application, and anticipated their continued prominent role in the field of biomedicine.

Exploring the Role of Wnt Ligands in Osteogenic Differentiation of Human Periodontal Ligament Stem Cells.

OBJECTIVES: This study aimed to investigate the functions of 19 types of Wnt ligands during the process of osteogenic differentiation in human periodontal ligament stem cells (hPDLSCs), with particular attention to WNT3A and WNT4. MATERIALS AND METHODS: The expression levels of 19 types of Wnt ligands were examined using real-time quantitative polymerase chain reaction (real-time qPCR) during hPDLSCs osteogenic differentiation at 7, 10, and 14 days. Knockdown of WNT3A and WNT4 expression was achieved using adenovirus vectors, and conditioned medium derived from WNT3A and WNT4 overexpression plasmids was employed to investigate their roles in hPDLSCs osteogenesis. Osteogenic-specific genes were analyzed using real-time qPCR. Alkaline phosphatase (ALP) and alizarin red S activities and staining were employed to assess hPDLSCs' osteogenic differentiation ability. RESULTS: During hPDLSCs osteogenic differentiation, the expression of 19 types of Wnt ligands varied, with WNT3A and WNT4 showing significant upregulation. Inhibiting WNT3A and WNT4 expression hindered hPDLSCs' osteogenic capacity. Conditioned medium of WNT3A promoted early osteogenic differentiation, while WNT4 facilitated late osteogenesis slightly. CONCLUSION: Wnt ligands, particularly WNT3A and WNT4, play an important role in hPDLSCs' osteogenic differentiation, highlighting their potential as promoters of osteogenesis. CLINICAL RELEVANCE: Given the challenging nature of alveolar bone regeneration, therapeutic strategies that target WNT3A and WNT4 signaling pathways offer promising opportunities. Additionally, innovative gene therapy approaches aimed at regulating of WNT3A and WNT4 expression hold potential for improving alveolar bone regeneration outcomes.

CDH4 inhibits ferroptosis in oral squamous cell carcinoma cells.

BACKGROUND: The cadherin-4 gene (CDH4), a member of the cadherin family genes, encodes R-cadherin (R-cad); however, the function of this gene in different types of cancer remains controversial. The function of CDH4 in OSCC (oral squamous cell carcinoma) is unknown. MATERIALS AND METHODS: We use the Cancer Genome Atlas (TCGA) database to find the expression of CDH4 in OSCC is more than normal tissue. Our tissue samples also confirmed that CDH4 gene was highly expressed in OSCC. The related cell function assay detected that CDH4 promotes the ability of cell proliferation, migration, self-renewal and invasion. Cell staining experiment confirmed that the change of CDH4 expression would change the cell mortality. The western blot of GPX4 (glutathione-dependent peroxidase-4), GSH (reduced glutathione) test assay and MDA(Malondialdehyde) test assay show that the expression of CDH4 may resist the sensitivity of ferropotosis in OSCC. RESULTS: CDH4 was upregulated in OSCC samples and was correlation with poor survival of patients. High expression of CDH4 effectively promotes the proliferation, mobility of OSCC cells and reduce the sensitivity of OSCC cells to ferroptosis. CDH4 is positively correlated with EMT pathway genes, negatively correlated with fatty acid metabolism pathway genes and peroxisome pathway genes, and positively correlated with ferroptosis suppressor genes in OSCC. CONCLUSIONS: These results indicate that CDH4 may play a positive role in tumor progression and resistance ferroptosis and may be a potential therapeutic target for OSCC.

Antitumor effect of toosendanin on oral squamous cell carcinoma via suppression of p-STAT3.

BACKGROUND: Toosendanin (TSN) exhibits potent antitumor activity against various tumor cell lines. However, its efficacy against oral squamous cell carcinoma (OSCC) remains unknown. Here, we investigated the effects of TSN on OSCC cells in vitro and verified them in vivo using a patient-derived xenograft (PDX) model. METHODS: The effect of TSN on OSCC cells was investigated by cytotoxicity assays and flow cytometry. The expression of proteins was detected by western blotting. An OSCC PDX model was constructed to further investigate the role of TSN in regulating the function of OSCC. RESULTS: The cell viability of CAL27 and HN6 cells decreased as the concentration of TSN increased within the experimental range. Compared with controls, TSN at lower doses inhibited cell proliferation and induced apoptosis through S-phase cell cycle arrest. TSN inhibited OSCC cell proliferation by downregulating the STAT3 pathway through the inhibition of STAT3 phosphorylation. After successful construction of the OSCC PDX model with high pathological homology to the primary tumor and treatment with an intraperitoneal injection of TSN, we showed that TSN significantly reduced the tumor size of the PDX model mice without obvious toxicity. CONCLUSIONS: Both in vitro and in vivo, TSN significantly inhibits the proliferation and promoted apoptosis of OSCC cells. Furthermore, TSN demonstrates potent inhibition of STAT3 phosphorylation, indicating its potential as a promising therapeutic agent for OSCC. Therefore, TSN holds great promise as a viable drug candidate for the treatment of OSCC.

High expression of Notch2 drives tongue squamous cell carcinoma carcinogenesis.

Tongue squamous cell carcinoma (TSCC) is one of the most common cancers in the oral cavity. Notch signaling is frequently dysregulated in cancer. However, the role of Notch2 in TSCC is not well understood. The aim of this study was to investigate the effect of abnormal expression of Notch2 in TSCC. The expression of Notch2 was tested in 47 pairs of tissues from tongue cancer and normal samples by using immunohistochemical staining. Tongue cancer cells were transfected with siRNA or plasmid. The proliferation of the cells was tested by the CCK8 assay and colony formation assay. Subcutaneous tumor model was established to observe tumor growth. Transwell assay was used to detect the changes of cell migration and invasion ability. A humanized anti-Notch2 antibody was used to TSCC cells. We found that Notch2 was upregulated in tongue carcinoma tissues. Knocking down the expression of Notch2 by siRNA in the TSCC cell lines decreased proliferation ability both in vitro and in vivo. In addition, migration and invasion abilities were inhibited by knockdown of Notch2 in the TSCC cells. However, overexpression of Notch2 increased tongue cancer cell proliferation, invasion and migration. The humanized anti-Notch2 antibody inhibited TSCC cell growth. The results indicated that Notch2 is an oncogene in tongue squamous cell carcinoma and may become the target of a new approach for treating TSCC.

DnaJ/Hsc70 chaperone complexes control the extracellular release of neurodegenerative-associated proteins.

It is now known that proteins associated with neurodegenerative disease can spread throughout the brain in a prionlike manner. However, the mechanisms regulating the trans-synaptic spread propagation, including the neuronal release of these proteins, remain unknown. The interaction of neurodegenerative disease-associated proteins with the molecular chaperone Hsc70 is well known, and we hypothesized that much like disaggregation, refolding, degradation, and even normal function, Hsc70 may dictate the extracellular fate of these proteins. Here, we show that several proteins, including TDP-43, α-synuclein, and the microtubule-associated protein tau, can be driven out of the cell by an Hsc70 co-chaperone, DnaJC5. In fact, DnaJC5 overexpression induced tau release in cells, neurons, and brain tissue, but only when activity of the chaperone Hsc70 was intact and when tau was able to associate with this chaperone. Moreover, release of tau from neurons was reduced in mice lacking the DnaJC5 gene and when the complement of DnaJs in the cell was altered. These results demonstrate that the dynamics of DnaJ/Hsc70 complexes are critically involved in the release of neurodegenerative disease proteins.

Elevated matrix metalloproteinase 7 expression promotes the proliferation, motility and metastasis of tongue squamous cell carcinoma.

BACKGROUND: Matrix metalloproteinase 7 (MMP7), as the smallest member of the matrix metalloproteinase family, has been verified to be implicated in cancer progression, especially metastasis. However, its expression pattern and function in tongue cancer is not clear. METHODS: The expression of MMP7 in human tongue squamous cell carcinoma (TSCC) specimens compared with their respective paired nontumour tissues by real-time PCR and immunohistochemical staining. The effect of MMP7 on the proliferation, apoptosis, migration, invasion of tongue cancer cells was tested in appropriate ways after MMP7 siRNA knockdown or overexpression. The effect of MMP7 on lymph node metastasis in vivo was analyzed using a high-metastasis orthotopic nude mouse tongue transplanted tumour model. RESULTS: We found markedly elevated expression of MMP7 in human TSCC specimens compared with their respective paired nontumour tissues, and this high expression was correlated with the patients' lymph node metastasis. Furthermore, the results of molecular functional assays confirmed that MMP7 promotes cell proliferation, migration and invasion of TSCC cells. Knockdown of MMP7 inhibited lymph nodes metastasis in vivo. CONCLUSIONS: MMP7 plays an oncogenic role in carcinogenesis and metastasis of tongue cancer, and may serve as a potential therapeutic target for tongue cancer.

Human cyclophilin 40 unravels neurotoxic amyloids.

The accumulation of amyloidogenic proteins is a pathological hallmark of neurodegenerative disorders. The aberrant accumulation of the microtubule associating protein tau (MAPT, tau) into toxic oligomers and amyloid deposits is a primary pathology in tauopathies, the most common of which is Alzheimer's disease (AD). Intrinsically disordered proteins, like tau, are enriched with proline residues that regulate both secondary structure and aggregation propensity. The orientation of proline residues is regulated by cis/trans peptidyl-prolyl isomerases (PPIases). Here we show that cyclophilin 40 (CyP40), a PPIase, dissolves tau amyloids in vitro. Additionally, CyP40 ameliorated silver-positive and oligomeric tau species in a mouse model of tau accumulation, preserving neuronal health and cognition. Nuclear magnetic resonance (NMR) revealed that CyP40 interacts with tau at sites rich in proline residues. CyP40 was also able to interact with and disaggregate other aggregating proteins that contain prolines. Moreover, CyP40 lacking PPIase activity prevented its capacity for disaggregation in vitro. Finally, we describe a unique structural property of CyP40 that may permit disaggregation to occur in an energy-independent manner. This study identifies a novel human protein disaggregase and, for the first time, demonstrates its capacity to dissolve intracellular amyloids.

Hsp90 activator Aha1 drives production of pathological tau aggregates.

The microtubule-associated protein tau (MAPT, tau) forms neurotoxic aggregates that promote cognitive deficits in tauopathies, the most common of which is Alzheimer's disease (AD). The 90-kDa heat shock protein (Hsp90) chaperone system affects the accumulation of these toxic tau species, which can be modulated with Hsp90 inhibitors. However, many Hsp90 inhibitors are not blood-brain barrier-permeable, and several present associated toxicities. Here, we find that the cochaperone, activator of Hsp90 ATPase homolog 1 (Aha1), dramatically increased the production of aggregated tau. Treatment with an Aha1 inhibitor, KU-177, dramatically reduced the accumulation of insoluble tau. Aha1 colocalized with tau pathology in human brain tissue, and this association positively correlated with AD progression. Aha1 overexpression in the rTg4510 tau transgenic mouse model promoted insoluble and oligomeric tau accumulation leading to a physiological deficit in cognitive function. Overall, these data demonstrate that Aha1 contributes to tau fibril formation and neurotoxicity through Hsp90. This suggests that therapeutics targeting Aha1 may reduce toxic tau oligomers and slow or prevent neurodegenerative disease progression.

The oncogenic effects of HES1 on salivary adenoid cystic carcinoma cell growth and metastasis.

BACKGROUND: Our previous study demonstrated a close relationship between NOTCH signaling pathway and salivary adenoid cystic carcinoma (SACC). HES1 is a well-known target gene of NOTCH signaling pathway. The purpose of the present study was to further explore the molecular mechanism of HES1 in SACC. METHODS: Comparative transcriptome analyses by RNA-Sequencing (RNA-Seq) were employed to reveal NOTCH1 downstream gene in SACC cells. Immunohistochemical staining was used to detect the expression of HES1 in clinical samples. After HES1-siRNA transfected into SACC LM cells, the cell proliferation and cell apoptosis were tested by suitable methods; animal model was established to detect the change of growth ability of tumor. Transwell and wound healing assays were used to evaluate cell metastasis and invasion. RESULTS: We found that HES1 was strongly linked to NOTCH signaling pathway in SACC cells. The immunohistochemical results implied the high expression of HES1 in cancerous tissues. The growth of SACC LM cells transfected with HES1-siRNAs was significantly suppressed in vitro and tumorigenicity in vivo by inducing cell apoptosis. After HES1 expression was silenced, the SACC LM cell metastasis and invasion ability was suppressed. CONCLUSIONS: The results of this study demonstrate that HES1 is a specific downstream gene of NOTCH1 and that it contributes to SACC proliferation, apoptosis and metastasis. Our findings serve as evidence indicating that HES1 may be useful as a clinical target in the treatment of SACC.

MicroRNA-511 Binds to FKBP5 mRNA, Which Encodes a Chaperone Protein, and Regulates Neuronal Differentiation.

Single nucleotide polymorphisms in the FKBP5 gene increase the expression of the FKBP51 protein and have been associated with increased risk for neuropsychiatric disorders such as major depression and post-traumatic stress disorder. Moreover, levels of FKBP51 are increased with aging and in Alzheimer disease, potentially contributing to disease pathogenesis. However, aside from its glucocorticoid responsiveness, little is known about what regulates FKBP5 In recent years, non-coding RNAs, and in particular microRNAs, have been shown to modulate disease-related genes and processes. The current study sought to investigate which miRNAs could target and functionally regulate FKBP5 Following in silico data mining and initial target expression validation, miR-511 was found to suppress FKBP5 mRNA and protein levels. Using luciferase p-miR-Report constructs and RNA pulldown assays, we confirmed that miR-511 bound directly to the 3'-UTR of FKBP5, validating the predicted gene-microRNA interaction. miR-511 suppressed glucocorticoid-induced up-regulation of FKBP51 in cells and primary neurons, demonstrating functional, disease-relevant control of the protein. Consistent with a regulator of FKBP5, miR-511 expression in the mouse brain decreased with age but increased following chronic glucocorticoid treatment. Analysis of the predicted target genes of miR-511 revealed that neurogenesis, neuronal development, and neuronal differentiation were likely controlled by these genes. Accordingly, miR-511 increased neuronal differentiation in cells and enhanced neuronal development in primary neurons. Collectively, these findings show that miR-511 is a functional regulator of FKBP5 and can contribute to neuronal differentiation.

Androgen receptor-regulated miRNA-193a-3p targets AJUBA to promote prostate cancer cell migration.

Background Dysregulation of microRNA (miRNA) expression is implicated in cancer development and progression by modulating oncogenes or tumor suppressors at the post-transcriptional level. Methods To investigate the role of miRNAs in prostate cancer (PCa) progression, we performed small RNA-sequencing (RNA-seq) analysis in androgen-dependent LNCaP cells and LNCaP-derived castration-resistant prostate cancer (CRPC) C4-2B cells. For functional validation, we specifically investigated miR-193a-3p, which is highly upregulated in C4-2B cells and modulated by the androgen receptor (AR). We elucidated the role of miR-193a-3p and its downstream target gene in PCa cell migration using biochemical approaches. Results We identified a subset of differentially expressed miRNAs in C4-2B cells compared to LNCaP cells. Computational analysis shows that the targets of upregulated miRNAs are significantly associated with downregulated protein-coding mRNAs in C4-2B cells. Gene Ontology analysis further reveals that these downregulated mRNAs are significantly enriched in cell-cell adhesion functions. Downregulation of these miRNA-targeted genes may change PCa cell motility resulting in the acquisition of metastatic potential. We then focus on miR-193a-3p and demonstrate overexpression of miR-193a-3p increases cell migration through downregulating its target AJUBA. AJUBA is a LIM domain protein and contributes to the formation and stability of cadherin-mediated cell-cell adhesion. Loss of AJUBA enhances PCa migration and downregulation of AJUBA expression is observed in metastatic PCa tumors. Conclusions Our results suggest a novel AR/miR-193a-3p/AJUBA pathway implicated in PCa progression. MiR-193a-3p is a potential therapeutic target for metastatic PCa.

Notch2 signaling contributes to cell growth, invasion, and migration in salivary adenoid cystic carcinoma.

Many studies have explored whether the Notch signaling pathway has a tumor-suppressive or an oncogenic role in various tumors; however, the role of the Notch signaling pathway in salivary adenoid cystic carcinoma (SACC) is still unknown. In this study, we attempt to define the role of Notch2 signaling in cell growth, invasion, and migration in SACC. We compared Notch2 expression in clinical SACC samples with that of normal samples by using immunohistochemical staining. Then, we down-regulated Notch2 expression to observe the effect of Notch2 on proliferation, invasion, migration, and the expression of known target genes of Notch signal pathway. According to our results, Notch2 expression was higher in SACC tissues compared with normal tissues. Knockdown of Notch2 inhibited cell proliferation, invasion, and migration in vitro and down-regulated the expression of HEY2 and CCND1. The results of this study suggest that Notch2 has an essential role in the cell growth, invasion, and migration of SACC. Notch2 may therefore be a potential target gene for the treatment of SACC by interfering with cell growth and metastasis.

A nucleus-targeted alternately spliced Nix/Bnip3L protein isoform modifies nuclear factor κB (NFκB)-mediated cardiac transcription.

Several Bcl2 family proteins are expressed both as mitochondrial-targeted full-length and as cytosolic truncated alternately spliced isoforms. Recombinantly expressed shorter Bcl2 family isoforms can heterotypically bind to and prevent mitochondrial localization of their full-length analogs, thus suppressing their activity by sequestration. This "sponge" role requires 1:1 expression stoichiometry; absent this an alternate role is suggested. Here, RNA sequencing revealed coordinate regulation of BH3-only protein Nix/Bnip3L (Nix) and its alternately spliced soluble form (sNix) in hearts, but relative sNix/Nix expression of ∼1:10. Accordingly, we examined other putative functions of sNix. Although Nix expressed in H9c2 rat myoblasts localized to mitochondria, sNix showed variable cytoplasmic and nuclear distribution. Tumor necrosis factor α (TNFα) induced rapid and complete sNix nucleoplasmic translocation concomitant with nuclear translocation of the p65/RelA subunit of NFκB. sNix co-localized and co-precipitated with p65/RelA after TNFα stimulation; TNFα-induced sNix nuclear translocation did not occur in p65/RelA null murine embryonic fibroblasts. ChIP sequencing of TNFα-stimulated H9c2 cells revealed sNix suppression of p65/RelA binding to a subset of weaker DNA binding sites, accounting for its ability to alter gene expression in cultured cells and in vivo mouse hearts. These findings reveal TNFα-stimulated cytoplasmic-nuclear shuttling of the alternately spliced non-mitochondrial Nix isoform and uncover a role for sNix as a modulator of TNFα/NFκB-stimulated cardiac gene expression. Transcriptional co-regulation of sNix and Nix, combined with sNix posttranslational regulation by TNFα, comprises a previously unknown mechanism for molecular cross-talk between extrinsic death receptor and intrinsic mitochondrial apoptosis pathways.

Persistent androgen receptor-mediated transcription in castration-resistant prostate cancer under androgen-deprived conditions.

The androgen receptor (AR) is a ligand-inducible transcription factor that mediates androgen action in target tissues. Upon ligand binding, the AR binds to thousands of genomic loci and activates a cell-type specific gene program. Prostate cancer growth and progression depend on androgen-induced AR signaling. Treatment of advanced prostate cancer through medical or surgical castration leads to initial response and durable remission, but resistance inevitably develops. In castration-resistant prostate cancer (CRPC), AR activity remains critical for tumor growth despite androgen deprivation. Although previous studies have focused on ligand-dependent AR signaling, in this study we explore AR function under the androgen-deprived conditions characteristic of CRPC. Our data demonstrate that AR persistently occupies a distinct set of genomic loci after androgen deprivation in CRPC. These androgen-independent AR occupied regions have constitutively open chromatin structures that lack the canonical androgen response element and are independent of FoxA1, a transcription factor involved in ligand-dependent AR targeting. Many AR binding events occur at proximal promoters, which can act as enhancers to augment transcriptional activities of other promoters through DNA looping. We further show that androgen-independent AR binding directs a gene expression program in CRPC, which is necessary for the growth of CRPC after androgen withdrawal.

MDMX in Cancer: A Partner of p53 and a p53-Independent Effector.

The p53 tumor suppressor protein plays an important role in physiological and pathological processes. MDM2 and its homolog MDMX are the most important negative regulators of p53. Many studies have shown that MDMX promotes the growth of cancer cells by influencing the regulation of the downstream target gene of tumor suppressor p53. Studies have found that inhibiting the MDMX-p53 interaction can effectively restore the tumor suppressor activity of p53. MDMX has growth-promoting activities without p53 or in the presence of mutant p53. Therefore, it is extremely important to study the function of MDMX in tumorigenesis, progression and prognosis. This article mainly reviews the current research progress and mechanism on MDMX function, summarizes known MDMX inhibitors and provides new ideas for the development of more specific and effective MDMX inhibitors for cancer treatment.

Investigating diagnostic potential of long non-coding RNAs in head and neck squamous cell carcinoma using TCGA database and clinical specimens.

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and prognostically challenging cancer worldwide. The role of long non-coding RNAs (lncRNAs) in cancer regulation is progressively being understood. This study aims to identify lncRNAs with diagnostic potential as biomarkers for HNSCC. Statistical analysis was performed on expression data from the Cancer Genome Atlas (TCGA) database to identify potential lncRNAs associated with HNSCC. Four selected lncRNAs were validated using real-time quantitative reverse transcription polymerase chain reaction and correlated with clinical factors. Functional roles were further investigated. A total of 488 differentially expressed lncRNAs were identified in TCGA-HNSC. After rigorous evaluation based on p-values, survival analysis, and ROC analysis, 24 lncRNAs were prioritized for additional investigation. LINC00460, LINC00941, CTC-241F20.4, and RP11-357H14.17 were established as candidate diagnostic biomarkers. These lncRNAs exhibited elevated expression in HNSCC tissues and were associated with poor prognosis. Combining them showed high diagnostic accuracy. Notably, LINC00460 and CTC-241F20.4 demonstrated a significant elevation in the advanced stages of HNSCC. We constructed an lncRNA-mRNA regulatory network, and the array of significant regulatory pathways identified included focal adhesion, regulation of epithelial cell migration, and others. Additionally, these lncRNAs were found to influence immune responses by modulating immune cell infiltration in the HNSCC microenvironment. Our research indicates that LINC00460, LINC00941, RP11-357H14.17, and CTC-241F20.4 may have diagnostic and prognostic importance in HNSCC. Furthermore, we have gained insights into their potential functional roles, particularly about immune responses and interactions in the microenvironment.