Proteomic Characterization Reveals a Molecular Portrait of Nasopharyngeal Carcinoma Differentiation

S100 proteins in head and neck squamous cell carcinoma (Review)

The most common tumor affecting the head and neck is head and neck squamous cell carcinoma (HNSCC). The characteristics of HNSCC include a rapid onset, a lack of early diagnosis, drug resistance, relapse and systemic adverse effects, leading to inadequate prevention, diagnosis and treatment. Notably, previous research suggests that there is an association between S100 proteins and HNSCC. S100A8, S100A9 and S100A14 interfere with tumor cell proliferation by blocking the cell cycle. The present review discusses this association. S100A4 enhances cancer stem cell properties, and interacts with actin and tropomyosin to promote tumor cell migration. S100A1, S100A8, S100A9, S100A10, S100A14 and S100P are involved in the initiation and progression of HNSCC via Hippo, nuclear factor κB, phosphatidylinositol kinase/protein kinase B/mammalian target of rapamycin and other signaling pathways. In addition, certain long non-coding RNAs and microRNAs are involved in regulating the expression of S100 proteins in HNSCC. Reducing the expression of certain members of the S100 protein family may enhance the chemosensitivity of HNSCC. Collectively, it is suggested that S100 proteins may function as markers and targets for the prevention, diagnosis and treatment of HNSCC.

CapG promoted nasopharyngeal carcinoma cell motility involving Rho motility pathway independent of ROCK

Background

Gelsolin-like capping actin protein (CapG) modulates actin dynamics and actin-based motility with a debatable role in tumorigenic progression. The motility-associated functions and potential molecular mechanisms of CapG in nasopharyngeal carcinoma (NPC) remain unclear.

Methods

CapG expression was detected by immunohistochemistry in a cohort of NPC tissue specimens and by Western blotting assay in a variety of NPC cell lines. Loss of function and gain of function of CapG in scratch wound-healing and transwell assays were performed. Inactivation of Rac1 and ROCK with the specific small molecular inhibitors was applied to evaluate CapG’s role in NPC cell motility. GTP-bound Rac1 and phosphorylated-myosin light chain 2 (p-MLC2) were measured in the ectopic CapG overexpressing cells. Finally, CapG-related gene set enrichment analysis was conducted to figure out the significant CapG-associated pathways in NPC.

Results

CapG disclosed increased level in the poorly differentiated NPC tissues and highly metastatic cells. Knockdown of CapG reduced NPC cell migration and invasion in vitro, while ectopic CapG overexpression showed the opposite effect. Ectopic overexpression of CapG compensated for the cell motility loss caused by simultaneous inactivation of ROCK and Rac1 or inactivation of ROCK alone. GTP-bound Rac1 weakened, and p-MLC2 increased in the CapG overexpressing cells. Bioinformatics analysis validated a positive correlation of CapG with Rho motility signaling, while Rac1 motility pathway showed no significant relationship.

Conclusions

The present findings highlight the contribution of CapG to NPC cell motility independent of ROCK and Rac1. CapG promotes NPC cell motility at least partly through MLC2 phosphorylation and contradicts with Rac1 activation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02808-7.

FBP1 enhances the radiosensitivity by suppressing glycolysis via the FBXW7/mTOR axis in nasopharyngeal carcinoma cells

AIMS

The high glycolysis state of tumor cells is closely related to radioresistance. Fructose-1,6-bisphosphatase (FBP1) can regulate aerobic glycolysis and exerts tumor suppressor effects in many cancers, but its role in nasopharyngeal carcinoma (NPC) remains to be investigated.

MATERIALS AND METHODS

RT-qPCR was used to measure FBP1 mRNA level. Glucose consumption, lactic acid production and ATP level was determined to evaluate glycolysis. The sensitivity of NPC cells to radiation was analyzed by MTT assay. Apoptosis was performed using flow cytometry. Gain- and loss-of function assays were carried out to explore the specific role of FBP1 and FBXW7 (F-box and WD repeat domain-containing 7) in NPC cell functions. The interactions between FBXW7 and FBP1 or mTOR were validated with co-immunoprecipitation assay. The in vivo experiments with xenografts were used to evaluate the role of FBP1 in tumor growth.

KEY FINDINGS

FBP1 expression was lower in NPC tissues and cells than in normal controls and nasopharyngeal epithelial cells. Human recombinant FBP1 (rh-FBP1) treatment suppressed glycolysis in NPC cells. Besides, silencing FBP1 weakened the radiosensitivity and alleviated radiation-induced apoptosis and DNA damage by promoting glycolysis. Mechanism exploration found that FBP1 promoted FBXW7 protein level through suppressing the autoubiquitination of FBXW7. Then, FBXW7 restrained mTOR level by facilitating mTOR ubiquitination, thereby suppressing glycolysis and promoting radiation-induced apoptosis and DNA damage. Furthermore, overexpressing FBP1 in vivo hindered tumor growth and enhanced the antitumor activity of radiation.

SIGNIFICANCE

FBP1 promoted the radiosensitivity in NPC cells by inhibiting glycolysis through the FBXW7/mTOR axis.

Computational repositioning of dimethyl fumarate for treating alcoholic liver disease

Alcoholic liver disease (ALD) is a chronic alcohol-induced disorder of the liver for which there are few effective therapies for severe forms of ALD and for those who do not achieve alcohol abstinence. In this study, we used a systematic drug-repositioning bioinformatics approach querying a large compendium of gene-expression profiles to identify candidate U.S. Food and Drug Administration (FDA)–approved drugs to treat ALD. One of the top compounds predicted to be therapeutic for ALD by our approach was dimethyl fumarate (DMF), an nuclear factor erythroid 2-related factor 2 (NRF2) inducer. We experimentally validated DMF in liver cells and in vivo. Our work demonstrates that DMF is able to significantly upregulate the NRF2 protein level, increase NRF2 phosphorylation, and promote NRF2 nuclear localization in liver cells. DMF also reduced the reactive oxygen species (ROS) level, lipid peroxidation, and ferroptosis. Furthermore, DMF treatment could prevent ethanol-induced liver injury in ALD mice. Our results provide evidence that DMF might serve as a therapeutic option for ALD in humans, and support the use of computational repositioning to discover therapeutic options for ALD.

[Quantitative proteomics and differential signal enrichment in nasopharyngeal carcinoma cells with or without SETD2 gene knockout]

OBJECTIVE

To analyze the effects of alterations in the expressions of methyltransferase SETD2 on protein expression profiles in human nasopharyngeal carcinoma (NPC) cells and enrich the differential signaling pathways.

METHODS

The total protein was extracted from SETD2-knockout cell line CNE1^SETD2-KO and the wild-type cell line CNE1^WT, and the differentially expressed proteins were screened by tandem mass tag (TMT) labeled protein quantification technique and tandem mass spectrometry. GO analysis was used to annotate and enrich the differentially expressed proteins, and the KEGG database was used to enrich and analyze the pathways of the differential proteins.

RESULTS

With a fold change (FC)≥1.2 and P < 0.05 as the screening standard, 2049 differentially expressed proteins were identified in CNE1^SETD2-KO cells, among which 904 were up-regulated and 1145 were down-regulated. GO functional annotation results indicated that SETD2 knockout caused characteristic changes in multiple biological processes (cell processes and regulation, cell movement, metabolic processes, and biosynthesis of cellular components), molecular functions (catalytic activity and molecular binding, transcription factor activity), and cellular components (cell membrane, organelle, macromolecular complex). KEGG analysis showed that the differentially expressed proteins were involved in an array of signaling pathways closely related to tumors, including MAPK, PI3K-Akt, Ras, Rap1, mTOR, Hippo, HIF-1, Wnt, AMPK, FoxO, ErbB, P53 and JAK-STAT.

CONCLUSIONS

SETD2 knockout significantly changes the protein expression characteristics of NPC cells and affects a number of signal pathways closely related to tumors. The results provide evidence for investigation of the pathogenesis and therapeutic target screening of NPC.

Deciphering nasopharyngeal carcinoma pathogenesis via proteomics

Introduction: Nasopharyngeal carcinoma (NPC) is a distinct head and neck squamous cell carcinoma in its etiological association of Epstein-Barr virus (EBV) infection, hidden anatomical location, remarkable racial and geographical distribution, and high incidence of locoregional recurrence or metastasis. Thanks to the advancements in proteomics in recent decades, more understanding of the disease etiology, carcinogenesis, and progression has been gained, potentially deciphering the molecular characteristics of the malignancy. Areas covered: In this review, we provide an overview of the proteomic aberrations that are likely involved or drive NPC development and progression, focusing on the contributions of major EBV-encoded factors, intercommunication with environment, protein features of high metastasis and therapy resistance, and protein-protein interactions that allow NPC cells to evade immune recognition and elimination. Finally, multistep carcinogenesis and subtypes of NPC from a proteomic perspective are inquired. Expert commentary: Proteomic studies have covered various aspects involved in NPC pathogenesis, yet much remains to be uncovered. Coherent study designs, optimal conditions for obtaining high-quality data, and compelling interpretation are critical in ensuring the emergence of good science out of NPC proteomics. NPC proteogenomics and proteoform analysis are two promising fields to promote the application of the proteomic findings from bench to bedside.