Proteome analysis of antiproliferative mechanism of 12-O-tetradecanoylphorbol 13-acetate on cultured nasopharyngeal carcinoma CNE2 cells

Four-dimensional trapped ion mobility spectrometry proteomics reveals circulating extracellular vesicles encapsulated drivers of nasopharyngeal carcinoma distant dissemination

Nasopharyngeal carcinoma (NPC) is a head and neck cancer with a high propensity for early metastatic spread. Emerging evidence shows that extracellular vesicles (EVs) are key players in cancer metastasis, but their role in NPC metastasis remains poorly understood. We here present the first description of the proteomic and functional profiles of serum-derived circulating small EVs in metastatic NPC patients. To enhance the capture of low-abundance signaling proteins in EVs, timsTOF-based four-dimensional label-free quantitative proteomics was employed. We found that metastatic NPC patients (M-NPC-EVs) exhibited the highest serum EV levels compared to locoregional patients (L-NPC-EVs) and healthy subjects (Normal-EVs). The proteome of M-NPC-EVs differed substantially from L-NPC-EVs and was functionally enriched in pathways regulating cell polarity and motility, glucose metabolism, and angiogenesis. Functional assays testing individual EV samples demonstrated that M-NPC-EVs pronouncedly enhanced NPC cell migration, invasion, and the formation of lamellipodia and filopodia in vitro, and promoted angiogenesis in subcutaneous Matrigel plugs in vivo. In silico analyses suggested that PTPRA, TPI1 and GPI highly enriched in M-NPC-EVs were putative drivers underlying the motogenic and angiogenic activities of M-NPC-EVs, and their high expression levels were associated with a poor prognosis of NPC patients. The increased expression of PTPRA, TPI1 and GPI in M-NPC-EVs was then validated in an independent cohort consisting of 175 NPC patients (locoregional n = 114; metastatic n = 61). Together, utilizing patient-derived EVs, we mimicked the potential pro-metastatic functions of EVs in NPC patients in vitro and in vivo and provided novel insights into their bioactive cargoes.

A Review: Proteomics in Nasopharyngeal Carcinoma

Although radiotherapy is generally effective in the treatment of major nasopharyngeal carcinoma (NPC), this treatment still makes approximately 20% of patients radioresistant. Therefore, the identification of blood or biopsy biomarkers that can predict the treatment response to radioresistance and that can diagnosis early stages of NPC would be highly useful to improve this situation. Proteomics is widely used in NPC for searching biomarkers and comparing differentially expressed proteins. In this review, an overview of proteomics with different samples related to NPC and common proteomics methods was made. In conclusion, identical proteins are sorted as follows: Keratin is ranked the highest followed by such proteins as annexin, heat shock protein, 14-3-3σ, nm-23 protein, cathepsin, heterogeneous nuclear ribonucleoproteins, enolase, triosephosphate isomerase, stathmin, prohibitin, and vimentin. This ranking indicates that these proteins may be NPC-related proteins and have potential value for further studies.

Omics-based identification of biomarkers for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a head and neck cancer that is highly found in distinct geographic areas, such as Southeast Asia. The management of NPC remains burdensome as the prognosis is poor due to the late presentation of the disease and the complex nature of NPC pathogenesis. Therefore, it is necessary to find effective molecular markers for early detection and therapeutic measure of NPC. In this paper, the discovery of molecular biomarker for NPC through the emerging omics technologies including genomics, miRNA-omics, transcriptomics, proteomics, and metabolomics will be extensively reviewed. These markers have been shown to play roles in various cellular pathways in NPC progression. The knowledge on their function will help us understand in more detail the complexity in tumor biology, leading to the better strategies for early detection, outcome prediction, detection of disease recurrence, and therapeutic approach.

Proteomic features of potential tumor suppressor NESG1 in nasopharyngeal carcinoma

We previously defined the recently revised NESG1 gene as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). Here, we further used proteomics technology to globally examine NESG1-controlled proteins in NPC cells. Twenty-six proteins were found to be deregulated by NESG1 using proteomics analysis while enolase 1 (alpha) (ENO1), heat shock protein 90 kDa beta (Grp94), member 1 (HSP90B1), and cathepsin D (CTSD) proteins were differentially expressed by Western blot. Interestingly, a-enolase (ENO1), an overexpressed gene in NPC, was confirmed as a NESG1-regulated protein in NPC cells. Overexpressed ENO1 not only restored cell proliferation and cell-cycle progression, but also antagonized the regulation of NESG1 to cell-cycle regulators p21 and CCNA1 expression as well as induced the expression of C-Myc, pRB, and E2F1 in NESG1-ovexpressed NPC cells. Real-time PCR and immunohistochemistry analysis showed that NESG1 expression is negatively correlated with ENO1 expression in NPC tissues. Our observations suggest that ENO1 downregulation plays an important role in NESG1-induced growth inhibition of NPC cancer cells.

PTEN deletion leads to deregulation of antioxidants and increased oxidative damage in mouse embryonic fibroblasts

Despite the significance of oxidative damage in carcinogenesis, the molecular mechanisms that lead to increased susceptibility to oxidative stress are not well understood. We now report a link between loss of protection against oxidative damage and loss of function of PTEN, a highly mutated tumor suppressor gene in a variety of human tumors. Using two-dimensional gel electrophoresis, combined with Western and Northern blot analyses, we found that PTEN deficiency in mouse embryonic fibroblasts (MEFs) displays deregulated expression of several antioxidant enzymes, including peroxiredoxins 1, 2, 5, and 6 and Cu, Zn superoxide dismutase. In these Pten-deleted MEFs, the basal levels of reactive oxygen species (ROS) were increased, and both the basal level and the ROS-induced oxidative damage of DNA were increased, as evidenced by increased levels of hydrogen peroxide (H2O2), superoxide anion, 8-hydroxy-2'-deoxyguanosine, and DNA double-strand breaks. We further show that Pten deletion is correlated with resistance to H2O2-induced expression of several antioxidants. These findings suggest an essential role for PTEN in maintaining the normal redox state of mouse embryonic fibroblasts against oxidative damage. They also provide a molecular link between PTEN, whose inactivation is known to be involved in a variety of human tumors, and antioxidants, whose perturbation leads to oxidative damage of cells.

Serum proteome analysis for profiling protein markers associated with carcinogenesis and lymph node metastasis in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), one of the most common cancers in population with Chinese or Asian progeny, poses a serious health problem for southern China. It is unfortunate that most NPC victims have had lymph node metastasis (LNM) when first diagnosed. We believe that the 2D based serum proteome analysis can be useful in discovering new biomarkers that may aid in the diagnosis and therapy of NPC patients. To filter the tumor specific antigen markers of NPC, sera from 42 healthy volunteers, 27 non-LNM NPC patients and 37 LNM NPC patients were selected for screening study using 2D combined with MS. Pretreatment strategy, including sonication, albumin and immunoglobulin G (IgG) depletion, was adopted for screening differentially expressed proteins of low abundance in serum. By 2D image analysis and MALDI-TOF-MS identification, twenty-three protein spots were differentially expressed. Three of them were further validated in the sera using enzyme-linked immunosorbent assay (ELISA). Our research demonstrates that HSP70, sICAM-1 and SAA, confirmed with ELISA at sera and immunohistochemistry, are potential NPC metastasis-specific serum biomarkers which may be of great underlying significance in clinical detection and management of NPC.

Differential proteomic analysis of human colorectal carcinoma cell lines metastasis-associated proteins

PURPOSE

Metastasis is a common phenomenon and the major lethal cause of colorectal carcinoma (CRC). To better comprehend the mechanism underlying CRC metastasis and to search for potential markers for predicting CRC metastasis, two CRC cell lines with different metastatic potentials, SW480 and SW620, were investigated by phenotypic analyses and proteomics technologies.

METHODS

The surgical orthotopic implantation (SOI) technique was originally used to develop a reproducible colorectal cancer model in nude mice with stable tumor growth and metastasizing course. Furthermore, differential proteome analysis of two CRC cell lines was conducted using two-dimensional (2-D) gel electrophoresis combined with matrix-assisted laser desorption/time of flight (MALDI-TOF) mass spectrometry.

RESULTS

Among the differential spots, 12 protein spots (11 proteins) were further identified using in-gel tryptic digestion and peptide mass fingerprinting (PMF). Interestingly, most of these proteins we identified have been reported to be associated with distinct aspect of tumor metastasis to some extent. Our immunohistochemistry assays of colorectal cancer revealed that heat shock protein (HSP) 27 overexpression relates to metastatic behavior of CRC cell.

CONCLUSIONS

The protein profile between two colorectal cell lines with different potential metastasis displayed obvious differences. The results imply that various different proteins may lead to CRC metastasis together. HSP27 overexpression played an important role in metastasis and progression of CRC.