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Pathology International Jun 2024Exosomes from cancer cells function as carriers to spread or transport specific microRNAs (miRNAs) to distant sites to exert their effects, but the mechanism of exosomal...
Exosomes from cancer cells function as carriers to spread or transport specific microRNAs (miRNAs) to distant sites to exert their effects, but the mechanism of exosomal miRNA action in esophageal squamous cell carcinoma (ESCC) has not been fully explained. Therefore, in this study, we were interested in the impact of exosomal miR-196a-5p in ESCC progression. We found that miR-196a-5p was expressed enriched in clinical tissues, ESCC cells, and exosomes. Functionally, depletion of miR-196a-5p impeded ESCC cell growth, migration, and invasion, whereas overexpression of miR-196a-5p produced the opposite results. Moreover, enhancement of exosomal miR-196a-5p in recipient ESCC cells triggered more intense proliferation and migration. Mechanistically, we identified integral membrane protein 2B (ITM2B) as a direct target of miR-196a-5p. Silencing of ITM2B partially counteracted the inhibitory effect of miR-196a-5p inhibitors on the malignant phenotype of ESCC. Furthermore, in vivo, lower miR-196a-5p levels triggered by the introduction of antagomiR-196a-5p resulted in the generation of smaller volume and weight xenograft tumors. Thus, our results demonstrated novel mechanisms of exosomal and intracellular miR-196a-5p-mediated ESCC growth and migration and identify the interaction of miR-196a-5p with ITM2B. These works might provide new targets and basis for the development of clinical treatment options for ESCC.
PubMed: 38940569
DOI: 10.1111/pin.13459 -
MBio Jun 2024Merkel cell polyomavirus (MCPyV) is a double-stranded tumor virus that is the main causative agent of Merkel cell carcinoma (MCC). The MCPyV large T antigen (LT), an...
UNLABELLED
Merkel cell polyomavirus (MCPyV) is a double-stranded tumor virus that is the main causative agent of Merkel cell carcinoma (MCC). The MCPyV large T antigen (LT), an essential viral DNA replication protein, maintains viral persistence by interacting with host Skp1-Cullin 1-F-box (SCF) E3 ubiquitin ligase complexes, which subsequently induces LT's proteasomal degradation, restricting MCPyV DNA replication. SCF E3 ubiquitin ligases require their substrates to be phosphorylated to bind them, utilizing phosphorylated serine residues as docking sites. The MCPyV LT unique region (MUR) is highly phosphorylated and plays a role in multiple host protein interactions, including SCF E3 ubiquitin ligases. Therefore, this domain highly governs LT stability. Though much work has been conducted to identify host factors that restrict MCPyV LT protein expression, the kinase(s) that cooperates with the SCF E3 ligase remains unknown. Here, we demonstrate that casein kinase 1 alpha (CK1α) negatively regulates MCPyV LT stability and LT-mediated replication by modulating interactions with the SCF β-TrCP. Specifically, we show that numerous CK1 isoforms (α, δ, ε) localize in close proximity to MCPyV LT through proximity ligation assays (PLA) and CK1α overexpression mainly resulted in decreased MCPyV LT protein expression. Inhibition of CK1α using short hairpin RNA (shRNA) and treatment of a CK1α inhibitor or an mTOR inhibitor, TORKinib, resulted in decreased β-TrCP interaction with LT, increased LT expression, and enhanced MCPyV replication. The expression level of the gene transcripts is higher in MCPyV-positive MCC, suggesting a vital role of CK1α in limiting MCPyV replication required for establishing persistent infection.
IMPORTANCE
Merkel cell polyomavirus (MCPyV) large tumor antigen is a polyphosphoprotein and the phosphorylation event is required to modulate various functions of LT, including viral replication. Therefore, cellular kinase pathways are indispensable for governing MCPyV polyomavirus infection and life cycle in coordinating with the immunosuppression environment at disease onset. Understanding the regulation mechanisms of MCPyV replication by viral and cellular factors will guide proper prevention strategies with targeted inhibitors for MCPyV-associated Merkel cell carcinoma (MCC) patients, who currently lack therapies.
PubMed: 38940554
DOI: 10.1128/mbio.01117-24 -
Advanced Science (Weinheim,... Jun 2024Transmembrane protein 52B (TMEM52B), a newly identified tumor-related gene, has been reported to regulate various tumors, yet its role in nasopharyngeal carcinoma (NPC)...
Transmembrane protein 52B (TMEM52B), a newly identified tumor-related gene, has been reported to regulate various tumors, yet its role in nasopharyngeal carcinoma (NPC) remains unclear. Transcriptomic analysis of NPC cell lines reveals frequent overexpression of TMEM52B, and immunohistochemical results show that TMEM52B is associated with advanced tumor stage, recurrence, and decreased survival time. Depleting TMEM52B inhibits the proliferation, migration, invasion, and oncogenesis of NPC cells in vivo. TMEM52B encodes two isoforms, TMEM52B-P18 and TMEM52B-P20, differing in their N-terminals. While both isoforms exhibit similar pro-oncogenic roles and contribute to drug resistance in NPC, TMEM52B-P20 differentially promotes metastasis. This functional discrepancy may be attributed to their distinct subcellular localization; TMEM52B-P18 is confined to the cytoplasm, while TMEM52B-P20 is found both at the cell membrane and in the cytoplasm. Mechanistically, cytoplasmic TMEM52B enhances AKT phosphorylation by interacting with phosphoglycerate kinase 1 (PGK1), fostering NPC growth and metastasis. Meanwhile, membrane-localized TMEM52B-P20 promotes E-cadherin ubiquitination and degradation by facilitating its interaction with the E3 ubiquitin ligase NEDD4, further driving NPC metastasis. In conclusion, the TMEM52B-P18 and TMEM52B-P20 isoforms promote the metastasis of NPC cells through different mechanisms. Drugs targeting these TMEM52B isoforms may offer therapeutic benefits to cancer patients with varying degrees of metastasis.
PubMed: 38940427
DOI: 10.1002/advs.202402457 -
Histology and Histopathology Jun 2024Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor. Among the S100 protein family members, the imbalance of S100 calcium-binding protein A2 (S100A2) was...
Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor. Among the S100 protein family members, the imbalance of S100 calcium-binding protein A2 (S100A2) was related to the pathogenesis of several types of cancer, and S100A2 has been reported to be upregulated in the plasma of NPC patients; however, its specific role in NPC pathogenesis remains unclear. Thus, this study aims to determine the potential role of S100A2 in NPC to provide novel insights into NPC management. C666-1 and NPC/HK-1 cells were transfected with S100A2 silencing/overexpression (si/oe) constructs. For investigations, NPC/HK-1 cells were transfected with si/oe-S100A2 to induce tumor formation in nude mice. Cellular viability and apoptosis were assessed using the CCK8 assay, colony-forming assay, and flow cytometry. Glucose uptake and lactate production levels were quantified using biochemical assays. S100A2 expression was measured via RT-qPCR, Western blot, immunohistochemistry, and immunofluorescence were performed to determine the levels of S100A2, PI3K, AKT, p-PI3K, p-AKT, GLUT1, HK-2, LDHA, and ki-67 proteins. S100A2 expression levels were significantly higher in NPC cancer tissues than in adjacent tissues. Similarly, C666-1 and NPC/HK-1 cells exhibited increased S100A2 expression, and silencing S100A2 significantly inhibited NPC cell viability, proliferation, glucose uptake, and lactate production, and induced apoptosis and decreased the protein levels of GLUT1, LDHA, and HK2 in NPC cells. Conversely, S100A2 overexpression enhanced these characteristics in NPC cells but could be mitigated by the PI3K/AKT inhibitor (LY294002). Silencing S100A2 suppressed the tumor formation of NPC/HK-1 cells, while S100A2 overexpression promoted tumor formation and could be hindered by a GLUT1 inhibitor (WZB117). S100A2 is upregulated in cancer tissues of NPC patients and was found to promote proliferation, glycolysis, and tumor formation in NPC cells through its interaction with GLUT1.
PubMed: 38940398
DOI: 10.14670/HH-18-778 -
Oncology Reports Aug 2024Intrahepatic cholangiocarcinoma (ICC) is a type of liver cancer associated with poor prognosis and increased mortality; the limited treatment strategy highlights the...
Intrahepatic cholangiocarcinoma (ICC) is a type of liver cancer associated with poor prognosis and increased mortality; the limited treatment strategy highlights the urgent need for investigation. Traditional Chinese Medicine (TCM), used alone or in combination with other treatments, can enhance therapeutic efficacy, improve life quality of patients and extend overall survival. In total, two rounds of screening of a TCM library of 2,538 active compounds were conducted using a Cell Counting Kit‑8 assay and ICC cell lines. Cell proliferation and migration abilities were assessed through colony formation, 5‑ethynyl‑2'‑deoxyuridine, would healing and Transwell assays. The impact of digitoxin (DT) on signaling pathways was initially investigated using RNA sequencing and further validated using reverse transcription‑quantitative PCR, western blotting, lectin blotting and flow cytometry. ICC cells stably overexpressing ST6 β‑galactoside α‑2,6‑sialyltransferase 1 (ST6GAL1) were generated through lentiviral transfection. It was shown that DT emerged as a highly effective anti‑ICC candidate from two rounds high‑throughput library screening. DT could inhibit the proliferation and migration of ICC cells by suppressing NF‑κB activation and reducing nuclear phosphorylated‑NF‑κB levels, along with diminishing ST6GAL1 mRNA and protein expression. The aforementioned biological effects and signal pathways of DT could be counteracted by overexpressing ST6GAL1 in ICC cells. In conclusion, DT suppressed ICC cell proliferation and migration by targeting the NF‑κB/ST6GAL1 signaling axis. The findings of the present study indicated the promising therapeutic effects of DT in managing ICC, offering new avenues for treatment strategies.
Topics: Humans; Signal Transduction; NF-kappa B; Cell Proliferation; Sialyltransferases; Digitoxin; Cholangiocarcinoma; Cell Movement; Cell Line, Tumor; Bile Duct Neoplasms; Antigens, CD; Gene Expression Regulation, Neoplastic; beta-D-Galactoside alpha 2-6-Sialyltransferase
PubMed: 38940341
DOI: 10.3892/or.2024.8762 -
Frontiers in Bioscience (Landmark... Jun 2024Persistent hyperuricemia can lead to the generation and deposition of monosodium urate (MSU) crystals. This can trigger gouty arthritis (GA), which in turn induces...
BACKGROUND
Persistent hyperuricemia can lead to the generation and deposition of monosodium urate (MSU) crystals. This can trigger gouty arthritis (GA), which in turn induces inflammation. Activation of the Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome plays a critical role in the onset and progression of GA. Autophagy may have a dual effect on GA with regard to the NLRP3 inflammasome. Therefore, the present study aimed to gain a deeper comprehension of the interaction between autophagy and NLRP3 inflammasome activation is imperative for developing more efficacious treatments for GA.
METHODS
Peripheral blood monocytes (PBMCs) were first isolated from GA patients and healthy controls and underwent bulk RNA sequencing analysis. Overexpression and knockdown of dual specificity phosphatase 1 (DUSP1) was performed in THP-1 monocytes to investigate its role in the immune response and mitochondrial damage. The luciferase assay and Western blot analysis were used to study the interaction between autophagy and NLRP3 inflammasome activation.
RESULTS
Bulk RNA sequencing analysis showed significant upregulation of DUSP1 expression in PBMCs from GA patients compared to healthy controls. This result was subsequently verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). DUSP1 expression in human THP-1 monocytes was also shown to increase after MSU treatment. Downregulation of DUSP1 expression increased the secretion of inflammatory cytokines after MSU treatment, whereas the overexpression of DUSP1 decreased the secretion levels. Lipopolysaccharides (LPS) combined with adenosine-triphosphate (ATP) led to mitochondrial damage, which was rescued by overexpressing DUSP1. DUSP1 overexpression further increased the level of autophagy following MSU treatment, whereas downregulation of DUSP1 decreased autophagy. Treatment with the autophagy inhibitor 3-Methyladenine (3-MA) restored inflammatory cytokine secretion levels in the DUSP1 overexpression group. MSU caused pronounced pathological ankle swelling . However, DUSP1 overexpression significantly mitigated this phenotype, accompanied by significant downregulation of inflammatory cytokine secretion levels in the joint tissues.
CONCLUSIONS
This study revealed a novel function and mechanism for DUSP1 in promoting autophagy to mitigate the MSU-induced immune response in GA. This finding suggests potential diagnostic biomarkers and anti-inflammatory targets for more effective GA therapy.
Topics: Humans; Autophagy; Dual Specificity Phosphatase 1; Arthritis, Gouty; Uric Acid; NLR Family, Pyrin Domain-Containing 3 Protein; Inflammasomes; THP-1 Cells; Male; Monocytes; Case-Control Studies; Female; Leukocytes, Mononuclear; Middle Aged
PubMed: 38940057
DOI: 10.31083/j.fbl2906222 -
Frontiers in Bioscience (Landmark... Jun 2024This study aimed to elucidate the molecular mechanism through which C1q/tumor necrosis factor (TNF)-related protein 9 (CTRP9) acts in the formation and differentiation...
BACKGROUND
This study aimed to elucidate the molecular mechanism through which C1q/tumor necrosis factor (TNF)-related protein 9 (CTRP9) acts in the formation and differentiation of brown adipose tissue (BAT).
METHODS
Adenovirus particles encoding CTRP9 and green fluorescent protein were inoculated into the scapula of C57BL/6J mice and fed a high-fat diet for 8 weeks; the body weight, lipid droplet morphology, glucose tolerance, insulin tolerance, and protein expression levels were analyzed. In addition, CTRP9 adenovirus was transfected into brown preadipocytes, and differentiation was induced to identify the effect of CTRP9 overexpression on adipocyte differentiation.
RESULTS
CTRP9 overexpression significantly increased the weight gain of mice. Additionally, the CTRP9 overexpression group exhibited significantly increased adipose tissue weight and glucose clearance rates and decreased insulin sensitivity and serum triglyceride levels compared to the control group. Furthermore, CTRP9 overexpression significantly upregulated the adipose triglyceride lipase (ATGL) and perilipin 1 protein expression levels in BAT. The cell experiment results confirmed that CTRP9 overexpression significantly inhibited the adipogenesis of brown adipocytes as evidenced by the downregulation of uncoupling protein 1, beta-3 adrenergic receptor, ATGL, and hormone-sensitive lipase mRNA levels and the significant suppression of uncoupling protein 1, ATGL, and perilipin 1 protein levels in brown adipocytes.
CONCLUSIONS
The finding of this study demonstrated that CTRP9 promotes lipolysis by upregulating ATGL expression and inhibits the differentiation of brown preadipocytes .
Topics: Animals; Lipolysis; Diet, High-Fat; Adipose Tissue, Brown; Mice, Inbred C57BL; Male; Mice; Adiponectin; Insulin Resistance; Lipase; Cell Differentiation; Adipogenesis; Perilipin-1; Acyltransferases; Glycoproteins
PubMed: 38940054
DOI: 10.31083/j.fbl2906236 -
Frontiers in Bioscience (Landmark... Jun 2024Hormone receptors exert their function through binding with their ligands, which results in cellular signaling activation mediated by genomic or non-genomic mechanisms....
BACKGROUND
Hormone receptors exert their function through binding with their ligands, which results in cellular signaling activation mediated by genomic or non-genomic mechanisms. The intrinsic molecular communication of tick and its host comprises an endocrine regulation involving hormones. In the present study, we performed a molecular and analysis of a Membrane Associated Progesterone Receptor in (RmMAPRC).
METHODS
The RmMAPRC protein sequence was analyzed with bioinformatics tools, and its structure was characterized by three-dimensional (3D) modeling and molecular docking. A semi-quantitative reverse transcription and polymerase chain reaction (sqRT-PCR) assessed the gene presence and relative expression in tick organs and embryonic cells.
RESULTS
relative expression in salivary glands, ovaries, and embryonic cells showed overexpression of 3%, 13%, and 24%, respectively. Bioinformatic analysis revealed that RmMAPRC corresponded to a Progesterone Receptor Membrane Component 1 (RmPGRMC1) of ~23.7 kDa, with an N-terminal transmembrane domain and a C-terminal Cytochrome b5-like heme/steroid binding domain. The docking results suggest that RmPGRMC1 could bind to progesterone (P4), some progestins, and P4 antagonists. The phylogenetic reconstruction showed that spp. MAPRC receptors were clustered in a clade that includes , , and (RmMAPRC), and mammals and helminths MAPRC receptors clustered in two separated clades away from ticks.
CONCLUSIONS
The presence of RmPGRMC1 highlights the importance of transregulation as a conserved adaptive mechanism that has succeeded for arthropod parasites, making it a target for tick control.
Topics: Animals; Rhipicephalus; Receptors, Progesterone; Progesterone; Cattle; Molecular Docking Simulation; Host-Parasite Interactions; Female; Amino Acid Sequence; Protein Binding; Phylogeny
PubMed: 38940045
DOI: 10.31083/j.fbl2906238 -
Frontiers in Bioscience (Landmark... Jun 2024Gastric cancer (GC) is a leading cause of cancer-associated death worldwide. Its molecular mechanisms, especially concerning autophagy and various signaling pathways,...
BACKGROUND
Gastric cancer (GC) is a leading cause of cancer-associated death worldwide. Its molecular mechanisms, especially concerning autophagy and various signaling pathways, are not fully understood. Fatty Acid Binding Protein 6 () and RE1 Silencing Transcription Factor () emerge as potential key players in this context. This study sought to analyze the functional relationship of and concerning autophagy and their implications on the Akt/mTOR signaling pathway within GC cells.
METHODS
A comprehensive bioinformatics approach was used to identify key prognostic markers in GC. The effects of and on autophagy along with Akt/mTOR signaling pathways were analyzed by techniques including Western blotting (WB), flow cytometry, Transwell assay, dual luciferase reporter assay, and others.
RESULTS
was identified as overexpressed in GC, linked with poor prognosis. silencing reduces GC cell proliferation, induces S- and G2-phase arrest, and downregulates cyclins CDK2 and CDK4. It also inhibited GC cell invasion/migration and autophagy, effects that were counteracted by MG132. When combined with PI3K inhibitor LY294002c, knockdown showed synergistic anti-proliferative effects, modulating the Akt/mTOR pathway. Besides, the transcription factor has been shown to directly regulate expression, affecting autophagy and the Akt/mTOR signaling pathway in a -dependent manner.
CONCLUSIONS
positively regulates autophagy and negatively affects the Akt/mTOR signaling pathway in GC cells in a FABP6-dependent manner, providing valuable insights into regulatory networks involving and .
Topics: Humans; Stomach Neoplasms; TOR Serine-Threonine Kinases; Autophagy; Proto-Oncogene Proteins c-akt; Signal Transduction; Cell Line, Tumor; Fatty Acid-Binding Proteins; Cell Proliferation; Gene Expression Regulation, Neoplastic
PubMed: 38940038
DOI: 10.31083/j.fbl2906212 -
Frontiers in Bioscience (Landmark... Jun 2024L-Theanine, a nonproteinogenic amino acid derived from green tea, is being recognized as an anti-cancer candidate. However, it's roles in the development of cancer...
BACKGROUND
L-Theanine, a nonproteinogenic amino acid derived from green tea, is being recognized as an anti-cancer candidate. However, it's roles in the development of cancer chemoresistance is still unknown and the molecular mechanism is urgently to be explored.
METHODS
The effects of L-Theanine on lung cancer chemoresistance were validated by Cell Counting Kit-8 (CCK-8) assay, transwell assay, and tumor spheroid formation assay; the expression of proteins was detected by using polymerase chain reaction (PCR) and western blotting. RNA-sequencing (RNA-seq) and bioinformatics analysis were used to identify differentially expressed genes induced by L-Theanine. knockdown and overexpression were constructed by using a lentivirus-mediated transfection system.
RESULTS
L-Theanine improved the chemoresistance to -diamminedichloroplatinum (DDP) and inhibited stemness of DDP-resistant lung cancer cells but not non-resistant lung cancer cells. The results from RNA-seq analysis showed that STAT3/NOTCH1 pathway was a potential dominant signaling involved in L-Theanine improving the chemoresistance in DDP-resistant lung cancer. Mechanistically, L-Theanine impeded migration and stemness activation of DDP-resistant lung cancer cells via regulating the expression of STAT3/NOTCH1/BMAL1 signaling-induced stemness markers as well as inhibiting the expression levels of drug resistance-related genes. In addition, a combination of L-Theanine and Stat3 blockade synergistically improved the chemoresistance in DDP-resistant lung cancer.
CONCLUSION
L-Theanine improves the chemoresistance by regulating STAT3/NOTCH1/BMAL1 signaling, reducing stemness, and inhibiting the migration of DDP-resistant lung cancer cells. The finding might provide some evidence for therapeutic options in overcoming the chemoresistance in cancers, including lung cancer.
Topics: Humans; Glutamates; Drug Resistance, Neoplasm; Lung Neoplasms; Cisplatin; STAT3 Transcription Factor; Signal Transduction; Receptor, Notch1; Cell Line, Tumor; ARNTL Transcription Factors; Antineoplastic Agents; Gene Expression Regulation, Neoplastic; A549 Cells; Cell Movement
PubMed: 38940036
DOI: 10.31083/j.fbl2906226