OBJECTIVES: To investigate the role of nucleolar pre-rRNA processing protein NIP7 (NIP7) in maintaining the malignant phenotype of anaplastic thyroid cancer (ATC) and its molecular mechanisms. METHODS: NIP7 expression in ATC tissues and its gene knock-out effects in ATC cells were analyzed using gene expression microarray (GSE33630), proteome database (IPX0008941000) and the Dependency Map database, respectively. Expression and localization of NIP7 in normal thyroid cells, papillary thyroid cancer cells, and ATC cells were detected by Western blotting. Small interfering RNA (siRNA) was transfected into ATC cells, and the knockdown efficiency of NIP7 was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. Cell proliferation was assessed by CCK-8 assay, colony formation was evaluated by colony formation assay, and tumor growth was assessed by xenograft tumor model in nude mice. SUnSET (surface sensing of translation) assay combined with co-immunoprecipitation were employed to evaluate the effect of NIP7 silencing on ubiquitin-conjugating enzyme E2 C (UBE2C) translation. Finally, gene set enrichment analysis was used to identify shared pathways of NIP7 and UBE2C, which were validated by qRT-PCR. RESULTS: Compared with normal tissues and papillary thyroid cancer, NIP7 was significantly upregulated in ATC tissues, and had a gene knock-out fitness effect on different ATC cell lines. The relative protein levels of NIP7 in ATC cells were significantly higher than those in normal thyroid follicular cells, and the protein was mainly expressed in the nucleus. NIP7 silencing significantly inhibited cell proliferation and reduced colony formation. Xenograft tumor model showed that NIP7 knockdown significantly slowed down the growth of ATC xenograft, and the tumor volume and weight were significantly lower than those in the control group (all P<0.05). NIP7 silencing downregulated the protein level of UBE2C, but did not affect the expression of UBE2C mRNA. Compared to the control group, UBE2C silencing significantly inhibited ATC cells proliferation (P<0.01) and colony formation (P<0.05). UBE2C overexpression reversed the proliferation-inhibitory effect induced by NIP7 silencing (P<0.01). Gene set enrichment analysis indicated that NIP7 and UBE2C were both involved in DNA replication. NIP7 or UBE2C silencing could significantly downregulate the expression levels of DNA polymerase epsilon, catalytic subunit 2 and replication factor C4 in DNA replication pathway. CONCLUSIONS NIP7 promotes ATC tumor growth by upregulating UBE2C to mediate DNA replication.
Humans ; Ubiquitin-Conjugating Enzymes/genetics* ; Thyroid Neoplasms/genetics* ; Thyroid Carcinoma, Anaplastic/genetics* ; Animals ; Mice, Nude ; Mice ; Cell Line, Tumor ; Cell Proliferation ; Up-Regulation ; RNA, Small Interfering/genetics* ; Nuclear Proteins/metabolism* ; Gene Expression Regulation, Neoplastic

OBJECTIVE: To investigate the metabolic characteristics of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in myeloid leukemia by in vitro culture of myeloid leukemia cells and construction of tumor-bearing nude mouse model. METHODS: U937, THP-1, HL60 and K562 cells were cultured in vitro. The cells in logarithmic growth phase (l×10 ⁵ cells/well) were added with ¹⁸F-FDG, and the uptake rate of ¹⁸F-FDG was measured at 15, 30, 60 and 120 min after addation, respectively. The four kinds of cells were inoculated subcutaneously into the hind limbs of nude mice to establish a tumor-bearing nude mouse model. When the tumor size was about 500 mm³, ¹⁸F-FDG was injected through the tail vein of the mice, and positron emission tomography/computed tomography was performed at 60 min after injection. The morphology of tumor-bearing cells was observed by hematoxylin-eosin (HE) staining in serial pathological sections. RESULTS: After co-incubation with ¹⁸F-FDG, the ¹⁸F-FDG uptake rates of U937 cells were significantly higher than THP-1, HL60 and K562 cells at 4 time points (all P <0.05), and THP-1 cells were higher than K562 cells (all P <0.05). The uptake rate of ¹⁸F-FDG by leukemia cells was rapid in the first 60 min, then tended to be stable. Pathological analysis showed that subcutaneous inoculation of U937, THP-1, HL60 and K562 cells could successfully establish tumor-bearing nude mouse models of myeloid leukemia. The ¹⁸F-FDG uptake value in U937 tumor-bearing nude mice was significantly higher than THP-1, HL60 and K562 tumor-bearing nude mice (all P <0.01). The ¹⁸F-FDG uptake values in THP-1 and HL60 tumor-bearing nude mice were significantly higher than that in K562 tumor-bearing nude mice (both P <0.01). CONCLUSION The tumor-bearing nude mouse model of myeloid leukemia can be successfully constructed by subcutaneous inoculation. The ¹⁸F-FDG uptake rate of acute myeloid leukemia (AML) cells is higher in cells cultured in vitro and tumor-bearing nude mouse model. ¹⁸F-FDG may have better clinical application value for AML.
Animals ; Fluorodeoxyglucose F18/metabolism* ; Mice, Nude ; Mice ; Humans ; Leukemia, Myeloid/diagnostic imaging* ; HL-60 Cells ; K562 Cells ; Cell Line, Tumor ; U937 Cells

BACKGROUND: Abnormalities of the switch/sucrose nonfermentable (SWI/SNF) chromatin-remodeling complex are closely related to various cancers, and ARID1B (AT-rich interaction domain 1B) is one of the core subunits of the SWI/SNF complex. Mutations or copy number deletions of the ARID1B gene are associated with impaired DNA damage response and altered chromatin accessibility. However, whether ARID1B deficiency affects the proliferation, migration and invasion abilities of non-small cell lung cancer (NSCLC) cells and its molecular mechanisms remain poorly understood. This study aims to reveal the regulatory role of ARID1B gene deletion on the malignant phenotype of NSCLC cells and its molecular mechanism. METHODS: Online databases were used to analyze the relationship between ARID1B and the prognosis of patients with lung cancer, and the expression levels of ARID1B in lung cancer tissues. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat) technology was employed to construct stable ARID1B gene knockout (KO) cell lines. The plate colony formation assay was used to detect cell proliferation, and the Transwell cell migration and invasion assays were used to detect changes in cell migration ability. RNA-Seq was utilized for the expression and enrichment analysis of differentially expressed genes. Western blot (WB) was used to verify the knockout effect of the ARID1B gene and to detect the expression changes of epithelial-mesenchymal transition (EMT) markers and mitogen-activated protein kinases (MAPK) signaling pathway-related proteins. Nude mouse tumor models were constructed and the tumorigenic abilities of control and ARID1B-deficient cells were compared. RESULTS: Patients with low ARID1B expression have poor overall survival. ARID1B is differentially expressed in lung cancer and normal tissues, and its expression level being lower in cancer cells. ARID1B-deficient cells had significantly enhanced in vitro proliferation, migration and invasion abilities. In animal experiments, the tumor formation speed of ARID1B gene deficient cells was significantly accelerated. Enrichment analysis of RNA-Seq results revealed that the differentially expressed genes were mainly enriched in MAPK, phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) and other signaling pathways. WB experiments demonstrated that the expressions of E-cadherin, N-cadherin and Vimentin changed in ARID1B gene deficient cells, and the expressions of MAPK and p-MAPK was increased. CONCLUSIONS The A549-ARID1B KO and PC9-ARID1B KO cell lines were successfully established. The ARID1B-deficient cell lines demonstrated high migration, invasion and proliferation potential at both in vitro and in vivo biological behavior levels and at the transcriptome sequencing level. The changes in the expression of EMT markers and the activation of the MAPK signaling pathway suggest possible metastasis mechanisms of ARID1B-deficient NSCLC.
Humans ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Lung Neoplasms/metabolism* ; Animals ; Carcinoma, Non-Small-Cell Lung/physiopathology* ; Transcription Factors/metabolism* ; Neoplasm Invasiveness ; Mice ; DNA-Binding Proteins/metabolism* ; Gene Deletion ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Mice, Nude ; Gene Expression Regulation, Neoplastic

BACKGROUND: The transcription factor POU2F1 regulates the expression levels of microRNAs in neoplasia. However, the miR-29b1/a cluster modulated by POU2F1 in gastric cancer (GC) remains unknown. METHODS: Gene expression in GC cells was evaluated using reverse-transcription polymerase chain reaction (PCR), western blotting, immunohistochemistry, and RNA in situ hybridization. Co-immunoprecipitation was performed to evaluate protein interactions. Transwell migration and invasion assays were performed to investigate the biological behavior of GC cells. MiR-29b1/a cluster promoter analysis and luciferase activity assay for the 3'-UTR study were performed in GC cells. In vivo tumor metastasis was evaluated in nude mice. RESULTS: POU2F1 is overexpressed in GC cell lines and binds to the miR-29b1/a cluster promoter. POU2F1 is upregulated, whereas mature miR-29b-3p and miR-29a-3p are downregulated in GC tissues. POU2F1 promotes GC metastasis by inhibiting miR-29b-3p or miR-29a-3p expression in vitro and in vivo . Furthermore, PIK3R1 and/or PIK3R3 are direct targets of miR-29b-3p and/or miR-29a-3p , and the ectopic expression of PIK3R1 or PIK3R3 reverses the suppressive effect of mature miR-29b-3p and/or miR-29a-3p on GC cell metastasis and invasion. Additionally, the interaction of PIK3R1 with PIK3R3 promotes migration and invasion, and miR-29b-3p , miR-29a-3p , PIK3R1 , and PIK3R3 regulate migration and invasion via the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway in GC cells. In addition, POU2F1 , PIK3R1 , and PIK3R3 expression levels negatively correlated with miR-29b-3p and miR-29a-3p expression levels in GC tissue samples. CONCLUSIONS The POU2F1 - miR-29b-3p / miR-29a-3p-PIK3R1 / PIK3R1 signaling axis regulates tumor progression and may be a promising therapeutic target for GC.
MicroRNAs/metabolism* ; Humans ; Stomach Neoplasms/pathology* ; Cell Line, Tumor ; Cell Movement/physiology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Animals ; Mice ; Octamer Transcription Factor-1/metabolism* ; Mice, Nude ; Class Ia Phosphatidylinositol 3-Kinase/metabolism* ; Neoplasm Invasiveness ; Gene Expression Regulation, Neoplastic/genetics* ; Male ; Immunohistochemistry ; Female

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

BACKGROUND: Growing evidence suggests that long non-coding RNAs (lncRNAs) exert pivotal roles in fostering chemoresistance across diverse tumors. Nevertheless, the precise involvement of lncRNAs in modulating chemoresistance within the context of gallbladder cancer (GBC) remains obscure. This study aimed to uncover how lncRNAs regulate chemoresistance in gallbladder cancer, offering potential targets to overcome drug resistance. METHODS: To elucidate the relationship between gemcitabine sensitivity and small nucleolar RNA host gene 1 ( SNHG1 ) expression, we utilized publicly available GBC databases, GBC tissues from Renji Hospital collected between January 2017 and December 2019, as well as GBC cell lines. The assessment of SNHG1, miR-23b-3p, and phosphatase and tensin homolog (PTEN) expression was performed using in situ  hybridization, quantitative real-time polymerase chain reaction, and western blotting. The cell counting kit-8 (CCK-8) assay was used to quantify the cell viability. Furthermore, a GBC xenograft model was employed to evaluate the impact of SNHG1 on the therapeutic efficacy of gemcitabine. Receiver operating characteristic (ROC) curve analyses were executed to assess the specificity and sensitivity of SNHG1. RESULTS: Our analyses revealed an inverse correlation between the lncRNA SNHG1 and gemcitabine resistance across genomics of drug sensitivity in cancer (GDSC) and Gene Expression Omnibus (GEO) datasets, GBC cell lines, and patients. Gain-of-function investigations underscored that SNHG1 heightened the gemcitabine sensitivity of GBC cells in both in vitro and in vivo  settings. Mechanistic explorations illuminated that SNHG1 could activate PTEN -a commonly suppressed tumor suppressor gene in cancers-thereby curbing the development of gemcitabine resistance in GBC cells. Notably, microRNA (miRNA) target prediction algorithms unveiled the presence of miR-23b-3p binding sites within SNHG1 and the 3'-untranslated region (UTR) of PTEN . Moreover, SNHG1 acted as a sponge for miR-23b-3p, competitively binding to the 3'-UTR of PTEN , thereby amplifying PTEN expression and heightening the susceptibility of GBC cells to gemcitabine. CONCLUSION The SNHG1/miR-23b-3p/PTEN axis emerges as a pivotal regulator of gemcitabine sensitivity in GBC cells, holding potential as a promising therapeutic target for managing GBC patients.
Humans ; Deoxycytidine/pharmacology* ; PTEN Phosphohydrolase/genetics* ; Gemcitabine ; RNA, Long Noncoding/metabolism* ; MicroRNAs/genetics* ; Gallbladder Neoplasms/genetics* ; Cell Line, Tumor ; Animals ; Mice ; Drug Resistance, Neoplasm/genetics* ; Mice, Nude ; Antimetabolites, Antineoplastic ; Gene Expression Regulation, Neoplastic

BACKGROUND: Pancreatic cancer is a lethal malignancy prone to gemcitabine resistance. The single-strand selective monofunctional uracil DNA glycosylase (SMUG1), which is responsible for initiating base excision repair, has been reported to predict the outcomes of different cancer types. However, the function of SMUG1 in pancreatic cancer is still unclear. METHODS: Gene and protein expression of SMUG1 as well as survival outcomes were assessed by bioinformatic analysis and verified in a cohort from Fudan University Shanghai Cancer Center. Subsequently, the effect of SMUG1 on proliferation, cell cycle, and migration abilities of SMUG1 cells were detected in vitro . DNA damage repair, apoptosis, and gemcitabine resistance were also tested. RNA sequencing was performed to determine the differentially expressed genes and signaling pathways, followed by quantitative real-time polymerase chain reaction and Western blotting verification. The cancer-promoting effect of forkhead box Q1 (FOXQ1) and SMUG1 on the ubiquitylation of myelocytomatosis oncogene (c-Myc) was also evaluated. Finally, a xenograft model was established to verify the results. RESULTS: SMUG1 was highly expressed in pancreatic tumor tissues and cells, which also predicted a poor prognosis. Downregulation of SMUG1 inhibited the proliferation, G1 to S transition, migration, and DNA damage repair ability against gemcitabine in pancreatic cancer cells. SMUG1 exerted its function by binding with FOXQ1 to activate the Protein Kinase B (AKT)/p21 and p27 pathway. Moreover, SMUG1 also stabilized the c-Myc protein via AKT signaling in pancreatic cancer cells. CONCLUSIONS SMUG1 promotes proliferation, migration, gemcitabine resistance, and c-Myc protein stability in pancreatic cancer via protein kinase B signaling through binding with FOXQ1. Furthermore, SMUG1 may be a new potential prognostic and gemcitabine resistance predictor in pancreatic ductal adenocarcinoma.
Humans ; Pancreatic Neoplasms/pathology* ; Forkhead Transcription Factors/genetics* ; Signal Transduction/genetics* ; Animals ; Cell Line, Tumor ; Proto-Oncogene Proteins c-akt/metabolism* ; Cell Proliferation/physiology* ; Mice ; Uracil-DNA Glycosidase/genetics* ; Female ; Male ; Gemcitabine ; Mice, Nude ; Apoptosis/physiology* ; Deoxycytidine/analogs & derivatives* ; Cell Movement/genetics*

This study aims to investigate the optimal ratio of Astragali Radix-Curcumae Rhizoma(AC) for inhibiting the proliferation of 143B osteosarcoma cells, and to investigate the mechanism by which AC inhibits osteosarcoma growth and metastasis through angiogenesis and cell adhesion mediated by the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/hypoxia inducible factor-1α(HIF-1α) pathway. A subcutaneous 143B tumor-bearing nude mouse model was successfully established and randomly divided into the model group, and the AC 1∶1, 2∶1, and 4∶1 groups. Body weight, tumor volume, and tumor weight were recorded. Real-time quantitative polymerase chain reaction(RT-qPCR) and Western blot were used to detect the mRNA and protein expression levels of PI3K, Akt, phosphorylated Akt(p-Akt), HIF-1α, vascular endothelial growth factor A(VEGFA), transforming growth factor-β1(TGF-β1), epithelial cadherin(E-cadherin), neural cadherin(N-cadherin), vimentin, matrix metalloproteinase 2(MMP2), matrix metalloproteinase 9(MMP9), B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and caspase-3 in the hypoxic core region of the tumor tissue. A cell hypoxia model was established, and the effects of AC-medicated serum(model group, AC 1∶1, 2∶1, and 4∶1 groups) on angiogenesis, proliferation, adhesion, invasion, and migration of 143B osteosarcoma cells were examined through CCK-8, flow cytometry, Transwell assay, cell adhesion assay, and HUVEC tube formation assay. The results showed that compared with the model group, the tumor weight and volume were smallest in the 2∶1 group. The expression levels of PI3K, Akt, p-Akt, HIF-1α, VEGFA, and TGF-β1 were significantly decreased, and the protein expression of E-cadherin was significantly increased, while the protein expression of N-cadherin, vimentin, MMP2, and MMP9 was significantly decreased. Additionally, the protein expression of Bax and caspase-3 was significantly increased, and Bcl-2 protein expression was significantly decreased. In vitro experiments showed that after intervention with AC-medicated serum at a 2∶1 ratio, the cell activity, adhesion, invasion, and migration of 143B cells were significantly reduced, apoptosis was significantly increased, and HUVEC tube formation was significantly decreased. In conclusion, the 2∶1 ratio of AC showed the most effective inhibition of 143B cell growth. AC can inhibit the growth and metastasis of osteosarcoma 143B cells by regulating the PI3K/Akt/HIF-1α signaling pathway, inhibiting angiogenesis and reducing cell adhesion, invasion, and migration.
Osteosarcoma/pathology* ; Animals ; Proto-Oncogene Proteins c-akt/genetics* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Humans ; Mice ; Cell Adhesion/drug effects* ; Cell Proliferation/drug effects* ; Neovascularization, Pathologic/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Phosphatidylinositol 3-Kinases/genetics* ; Cell Line, Tumor ; Mice, Nude ; Signal Transduction/drug effects* ; Astragalus Plant/chemistry* ; Bone Neoplasms/physiopathology* ; Male ; Rhizome/chemistry* ; Mice, Inbred BALB C ; Angiogenesis

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

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