Effect of PAIP1 on the metastatic potential and prognostic significance in oral squamous cell carcinoma

Impact of Non-SMC Condensin I Complex Subunit D2 Upregulation on Oral Squamous Cell Carcinoma Prognosis

OBJECTIVE

To explore the influence of non-SMC condensin I complex subunit D2 (NCAPD2) on the prognosis of oral squamous cell carcinoma (OSCC) and the correlation between NCAPD2 and OSCC.

METHODS

In this study, NCAPD2 gene expression profiles of OSCC and normal tissues were collected from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). The real-time quantitative polymerase chain reaction (RT-qPCR) was employed to preliminarily validate OSCC cell strains and normal epithelial cell strains. Besides EdU, cell scratch, and transwell assays were performed to assess the proliferation, migration, and invasion of OSCC cell strains with the silence of NCAPD2. Moreover, immunohistochemistry (IHC) staining was utilised to measure the expression of NCAPD2 and tumour-related markers in 74 OSCC specimens. Finally, the Kaplan-Meier analysis was performed to evaluate the influence of NCAPD2 in the prognosis of OSCC.

RESULTS

The expression of NCAPD2 in OSCC tissues was higher than that in normal tissues. Inhibiting NCAPD2 can reduce the proliferation and migration of OSCC cell lines and inhibit the invasion of these cells. The IHC staining results indicated that the high expression of NCAPD2 in OSCC tissues was positively correlated with T stages, Ki67 expression, and affected sites. The Kaplan-Meier analysis results validated that the up-regulated expression of NCAPD2 was significantly correlated with the poor overall survival (OS) of OSCC patients.

CONCLUSION

NCAPD2 is a potential molecular marker for the poor prognosis of OSCC, and it is expected to become a target for the treatment of this carcinoma.

Knockdown of PAIP1 Inhibits Breast Cancer Cell Proliferation by Regulating Cyclin E2 mRNA Stability

Polyadenylate-binding protein-interacting protein 1 (PAIP1) is a protein that modulates translation initiation in eukaryotic cells. Studies have shown that PAIP1 was overexpressed in various type of cancers, and drives cancer progression by promoting cancer cell proliferation, invasion, and migration. In our previous study, we identified that PAIP1 was overexpressed in breast cancer, and the expression was correlated with poor prognosis. However, the biological function of PAIP1 in breast cancer has not been clearly understood. In this study, we constructed PAIP1 specifically silenced breast cancer cells. Then, cell proliferation, cell cycle distribution, and apoptosis were detected in PAIP1 knockdown cells. RNA-seq analysis was performed to predict the downstream target of PAIP1, and the molecular mechanism was explored. As a results, we found that knockdown of PAIP1 repressed cell proliferation, induced cell cycle arrest, and triggers apoptosis. Xenograft mouse model showed that knockdown of PAIP1 inhibits cell growth in vivo. RNA-seq predicted that CCNE2 mRNA was one of the downstream targets of PAIP1. In addition, we identified that knockdown of PAIP1-inhibited cell proliferation through modulating cyclin E2 expression. Mechanically, knockdown of PAIP1 reduces the expression of cyclin E2 by regulating the mRNA stability of cyclin E2. Moreover, in breast cancer tissues, we found that the expression of PAIP1 was positively correlated with cyclin E2. Taken together, our findings establish the role and mechanism of PAIP1 in breast cancer progression, indicating that PAIP1 would be a new therapeutic target for breast cancer treatment.

Network pharmacology and molecular docking to explore the potential molecular mechanism of chlorogenic acid treatment of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a tumor type with a high mortality rate. Chlorogenic acid, abundant in resources and widely utilized in cancer treatments, has seen limited studies regarding its efficacy against OSCC. This paper investigates chlorogenic acid's mechanism in treating OSCC, aiming to guide the development of novel drugs. The study employed network pharmacology, molecular docking, and survival analysis methods. Network pharmacological analysis revealed chlorogenic acid targets 23 OSCC-related proteins, including ESR1, MMP2, MMP9, SRC, MAPK8, MAPK1, CDC42, ERBB2, ATM, and BRAF. Molecular docking simulations indicated that the primary target exhibits significant binding capacity with chlorogenic acid, with MMP9 associated with tumor migration and angiogenesis standing out. Survival analysis demonstrated that the downregulation of most primary targets correlates with improved survival rates in OSCC patients. Enrichment analysis of therapeutic targets highlighted the pivotal role of MAPK-ERK and MAPK-JNK signaling pathways in chlorogenic acid's efficacy against OSCC. This paper predicts chlorogenic acid's potential targets and proposes its molecular mechanism in treating OSCC, offering a theoretical foundation for its application in OSCC treatment. We used traditional Chinese medicine, a disease pharmacology-related information base, and an analysis platform to predict targets. The Cytoscape 3.9.1 and STING databases were used to address common targets for drugs and diseases, establish networks of protein interaction relationships, and screen core targets. Meastro11.5 was used for molecular docking simulation. R4.2.2 was used for survival analysis and joint target enrichment analysis. Network pharmacological analysis identified chlorogenic acid acting on 23 OSCC targets. Molecular docking simulations revealed a strong binding affinity of chlorogenic acid compounds with these targets, particularly MMP9, essential for tumor migration and angiogenesis. Survival analysis indicated that the downregulation of most core targets was correlated with improved OSCC patient survival. Enrichment analysis of therapeutic targets highlighted the critical roles of the MAPK-ERK and MAPK-JNK signaling pathways in the effectiveness of chlorogenic acid against OSCC. This study predicted the potential targets of chlorogenic acid in OSCC treatment and hypothesized its molecular mechanism, offering a theoretical foundation for its use in OSCC therapy.

Identification of activating transcription factor 6 (ATF6) as a novel prognostic biomarker and potential target in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is originating from oral mucosal epithelial cells. Autophagy plays a crucial role in cancer treatment by promoting cellular self-degradation and eliminating damaged components, thereby enhancing therapeutic efficacy. In this study, we aim to identify a novel autophagy-related biomarker to improve OSCC therapy.

METHODS

We firstly utilized Cox and Lasso analyses to identify that ATF6 is associated with OSCC prognosis, and validated the results by Kaplan-Meier survival analysis. We further identified the downstream pathways and related genes by enrichment analysis and WGCNA analysis. Subsequently, we used short interfering RNA to investigate the effects of ATF6 knockdown on proliferation, migration, apoptosis, and autophagy in SCC-9 and SCC-15 cells through cell viability assay, transwell assay, EdU incorporation assay, flow cytometry analysis, western blot analysis and immunofluorescence analysis, etc. RESULTS: Bioinformatics analyses showed that ATF6 overexpression was associated with prognosis and detrimental to survival. In vitro studies verified that ATF6 knockdown reduced OSCC cell proliferation and migration. Mechanistically, ATF6 knockdown could promote cellular autophagy and apoptosis.

CONCLUSION

We propose that ATF6 holds potential as a prognostic biomarker linked to autophagy in OSCC. This study provides valuable clues for further exploration of targeted therapy against OSCC.

IRF2BP2 drives lymphatic metastasis in OSCC cells by elevating mitochondrial fission-dependent fatty acid oxidation

Lymph node metastasis (LNM) is a major determinant for the poor outcome of oral squamous cell carcinoma (OSCC). Interferon regulatory factor 2 binding protein 2 (IRF2BP2) has been reported to modulate the development and progression of several types of cancers, while its role in OSCC with LNM has not been reported yet. The expression of IRF2BP2 and its association with LNM were evaluated by immunohistochemistry and qualitative reverse transcription polymerase chain reaction in clinically collected OSCC tissues. Then, loss-of-function and rescue assays were conducted to identify the role of IRF2BP2-mediated fatty acid oxidation (FAO) in the invasion, lymphoinvasion, and epithelial-mesenchymal transition (EMT) in OSCC cells. Importantly, confocal microscope, transmission electron microscope, immunofluorescence, and Western blot were applied to identify the involvement of mitochondrial fission in IRF2BP2-regulated FAO. Lastly, the in vivo models were established to evaluate the role of IRF2BP2 in OSCC. IRF2BP2 overexpression has been associated with LNM in OSCC, whose knockdown inhibited invasion, lymphoinvasion, and EMT of OSCC cells, as well as retarded FAO rate with CPT1A downregulation. And CPT1A overexpression rescued invasion, lymphoinvasion, and induced EMT in IRF2BP2-silenced OSCC cells. Mechanically, IRF2BP2 accelerated mitochondrial fission by contributing to Drp1 S616 phosphorylation and mitochondrial localization, resulting in the upregulation of CPT1A. In addition, IRF2BP2 knockdown significantly inhibited tumor growth and LNM in vivo. The highly expressed IRF2BP2 may induce the phosphorylation and mitochondrial translocation of Drp1 to activate mitochondrial fission, which upregulated CPT1A expression and FAO rate, resulting in LNM in OSCC. This highlighted a potential therapeutic vulnerability for the treatment of LNM+ OSCC via targeting IRF2BP2-FAO.

The role of phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) in regulating the progression of oral squamous cell carcinoma

OBJECTIVE

The aim of this study was to explore the role of the tumor suppressor phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) on oral squamous cell carcinoma (OSCC) and its molecular mechanism.

DESIGN

Immunohistochemistry detected the expression of PAG1 in normal and tumor tissues. The PAG1 overexpressed OSCC cell lines were constructed by lentivirus transfection. Cell Counting Kit-8 assay (CCK-8), clone formation and flow cytometry evaluated the impact of PAG1 on the proliferation and apoptosis of OSCC cells. RNA sequencing (RNA-seq) detected the changes in intracellular genes, and transmission electron microscope (TEM) was used to compare the number of autophagosomes in OSCC cells between Negative and PAG1 group. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western blot were used to determine the expression of signaling pathway-related mRNA and proteins respectively.

RESULTS

In contrast to the normal tissues, PAG1 expression was significantly downregulated in tumor tissues. Treatment with lentivirus transfection, the expression of PAG1 in the OSCC cell lines was increase. Notably, transfected with PAG1-overexpressing lentivirus cells inhibited the proliferation of OSCC cells and promoted OSCC cells apoptosis. RNA-seq revealed that PAG1 mainly modulated the mitophagy and autophagy pathway, and many autophagosomes were observed in the PAG1 group using TEM. Mechanistically, we found that PAG1 upregulated the expression of autophagy related factors through inhibiting PI3K/Akt/mTOR signal pathway activation.

CONCLUSION

Overexpression of PAG1 inhibited OSCC progression by activating autophagy, its mechanism might be related to inhibition of PI3K/Akt/mTOR signal pathway phosphorylation.