Expression of tropomyosin alpha 4 chain is increased in esophageal squamous cell carcinoma as evidenced by proteomic profiling by two-dimensional electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry

Serum DSG2 as a potential biomarker for diagnosis of esophageal squamous cell carcinoma and esophagogastric junction adenocarcinoma

BACKGROUND

Exploration of serum biomarkers for early detection of upper gastrointestinal cancer is required. Here, we aimed to evaluate the diagnostic potential of serum desmoglein-2 (DSG2) in patients with esophageal squamous cell carcinoma (ESCC) and esophagogastric junction adenocarcinoma (EJA).

METHODS

Serum DSG2 levels were measured by enzyme-linked immunosorbent assay (ELISA) in 459 participants including 151 patients with ESCC, 96 with EJA, and 212 healthy controls. Receiver operating characteristic (ROC) curves were used to evaluate diagnostic accuracy.

RESULTS

Levels of serum DSG2 were significantly higher in patients with ESCC and EJA than those in healthy controls (P<0.001). Detection of serum DSG2 demonstrated an area under the ROC curve (AUC) value of 0.724, sensitivity of 38.1%, and specificity of 84.8% for the diagnosis of ESCC in the training cohort, and AUC 0.736, sensitivity 58.2%, and specificity 84.7% in the validation cohort. For diagnosis of EJA, measurement of DSG2 provided a sensitivity of 29.2%, a specificity of 90.2%, and AUC of 0.698. Similar results were observed for the diagnosis of early-stage ESCC (AUC 0.715 and 0.722, sensitivity 36.3 and 50%, and specificity 84.8 and 84.7%, for training and validation cohorts, respectively) and early-stage EJA (AUC 0.704, sensitivity 44.4%, and specificity 86.9%). Analysis of clinical data indicated that DSG2 levels were significantly associated with patient age and histological grade in ESCC (P<0.05).

CONCLUSION

Serum DSG2 may be a diagnostic biomarker for ESCC and EJA.

Upregulation of tropomyosin alpha-4 chain in patients' saliva with oral squamous cell carcinoma as demonstrated by Phage display

Patients with oral squamous cell carcinoma (OSCC) present significant alterations in their saliva proteome. We have used the shotgun Phage Display (PD) technology to identify candidate proteins that were upregulated in saliva of OSCC by selecting ligands to salivary proteins from a single-chain variable fragment (scFv) PD combinatorial library. After two selection cycles, the highly reactive clone scFv-D09 was able to distinguish saliva of OSCC patients from healthy subjects by enzyme-linked immunosorbent assay (ELISA) with sensitivity and specificity of 96.67%. Additionally, the scFv-D09 clone presented a positive immunostaining for invasive malignant epithelial cells in the connective tissue, keratin pearls in the OSCC, and ducts of salivary glands. We have further identified the target protein as the tropomyosin alpha-4 chain (TPM4) by two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, and its binding to the scFV-D09 was demonstrated by bioinformatics. Briefly, we have identified TPM4 as upregulated salivary protein in patients with OSCC, which plays a central role in stabilizing cytoskeleton actin filaments, probably linked with tumor tissue remodeling. Long-term longitudinal studies are needed to validate TPM4 as a potential marker of a malignant process.

Considering the downregulation of Tpm1.6 and Tpm1.7 in squamous cell carcinoma of esophagus as a potent biomarker

AIM

Squamous cell carcinoma of esophagus (SCCE) is an aggressive disease with a poor prognosis. Tropomyosins attach to actin microfilaments, providing its stability. Nonmuscle cells express Tpm isoforms such as Tpm1.6 and Tpm1.7 which are involved in cytoskeleton functional properties regulation.

MATERIALS & METHODS

The expression of Tpm1.6 and Tpm1.7 was analyzed in SCCE tissues and its association with clinicopathological parameters and survival of patients was assessed.

RESULTS

Tpm1.6 and Tpm1.7, besides TPM1 mRNA decreased considerably in SCCE tissues relative to normal esophageal tissues (p < 0.001). TPM1 downregulation level was significantly associated with the degree of tumor differentiation (p = 0.017).

CONCLUSION

Tpm1.6 and Tpm1.7 suppression play a crucial role in esophagus tumorigenesis and could be associated with SCCE poor prognosis.

A panel of autoantibodies against multiple tumor-associated antigens in the immunodiagnosis of esophageal squamous cell cancer

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in China with very low 5-year survival rate mostly due to the paucity of effective early diagnostic methods. Serum autoantibodies against 9 tumor-associated antigens (TAAs) from ESCC patients and healthy controls were detected by enzyme-linked immunosorbent assay to evaluate their performances in the immunodiagnosis of ESCC. Logistic regression models were generated to predict the probability of individuals being diagnosed with ESCC in training cohort (648 participants) and further validated in another independent cohort (372 participants). Finally, a panel of four TAAs showed high diagnostic accuracy with areas under the receiver operating characteristic curve of 0.838 in training cohort and 0.872 in validation cohort, respectively. The percentages of individuals correctly classified were 77.01 % in training cohort and 78.49 % in validation cohort, respectively. This model could discriminate early-stage (AJCC stage 0, I and II) ESCC patients from normal controls, with true-positive rate (TPR) of 67.57 % in training cohort and TPR of 63.33 % in validation cohort, and the overall TPR for early-stage ESCC was 66.85 % when the two cohorts were combined. The diagnostic performance of this model showed no significant difference between early-stage and late-stage (AJCC stage III and IV) ESCC patients. In summary, the optimized model with 4 TAAs has a high diagnostic performance for ESCC detection, especially for early-stage ESCC.

Early Ankle Mobilization Promotes Healing in a Rabbit Model of Achilles Tendon Rupture

The use of early mobilization of the ankle joint without orthosis in the treatment of Achilles tendon rupture has been advocated as the optimal management. The goal of this study was to compare outcomes in a postoperative rabbit model of Achilles tendon rupture between early mobilization and immobilized animals using a differential proteomics approach. In total, 135 rabbits were randomized into the control group (n=15), the postoperative cast immobilization (PCI) group (n=60), and the early mobilization (EM) group (n=60). A rupture of the Achilles tendon was created in each animal model and repaired microsurgically, and tendon samples were removed at 3, 7, 14, and 21 days postoperatively. Proteins were separated using 2-dimensional polyacrylamide gel electrophoresis and identified using peptide mass fingerprinting, tandem mass spectrometry, NCBI database searches, and bioinformatics analyses. A series of differentially expressed proteins were identified between groups, some of which may play an important role in Achilles tendon healing. Notable candidate proteins that were upregulated in the EM group were identified, such as CRMP-2, galactokinase 1, tropomyosin-4, and transthyretin. The healing of ruptured Achilles tendons appears to be affected at the level of protein expression with the use of early mobilization. The classic postoperative treatment of Achilles tendon rupture with an orthosis ignored the self-protecting instinct of humans. With a novel operative technique, the repaired tendon can persist the load that comes from traction in knee and ankle joint functional movement. In addition, kinesitherapy provided an excellent experimental outcome via a mechanobiological mechanism.

Transgelins, cytoskeletal proteins implicated in different aspects of cancer development

Transgelin is an abundant protein of smooth muscle cells, where its role has been primarily studied. As a protein affecting dynamics of the actin cytoskeleton via stabilization of actin filaments, transgelin is both directly and indirectly involved in many cancer-related processes such as migration, proliferation, differentiation or apoptosis. Transgelin was previously reviewed as a tumor suppressor; however, recent data based on a number of proteomics studies indicate its pro-tumorigenic role, for example, in colorectal or hepatocellular cancer. We summarize these contradictory observations in both clinical and functional proteomics projects and analyze the role of transgelin in tumors in detail. Generally, the expression and biological role of transgelin seem to differ among various types of tumor cells and stroma, and possibly change during tumor progression. We also overview the recent data on transgelin-2, a sequence homolog of transgelin, whose role in the tumor development might be contradictory to the role of transgelin.

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

BACKGROUND

Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control.

RESULTS

We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm.

CONCLUSION

Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM.

Proteomic analysis of differentially expressed proteins in esophageal squamous cell carcinoma by MALDI-TOF-MS

AIM: To analyze differentially expressed proteins between human normal esophageal epithelial cells (NEEC) and esophageal squamous cell carcinoma (ESCC) cells.

METHODS: NEEC and ESCC cells were cut by laser capture microdissection (LCM), and total proteins of the cells were separated by two-dimensional gel electrophoresis (2-DE). 2-DE images were analyzed using Imagemaster 2D software. Differential proteins between NEEC and ESCC cells were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

RESULTS: A total of 43 protein spots were discovered and there were 17 differentially expressed proteins between NECC and ESCC. Of them, 15 (such as Trangelin2, HSP27, S100A11 and GSTP) were up-regulated and two (such as SCCA1) down-regulated in ESCC.

CONCLUSION: The differentially expressed proteins identified in this study may play a role in the carcinogenesis and development of ESCC and represent potential molecular biomarkers for ESCC.