Identification of prothymosin alpha (PTMA) as a biomarker for esophageal squamous cell carcinoma (ESCC) by label-free quantitative proteomics and Quantitative Dot Blot (QDB)

Abstract

Background Esophageal cancer (EC) is one of the malignant tumors with a poor prognosis. The early stage of EC is asymptomatic, so identification of cancer biomarkers is important for early detection and clinical practice. Methods In this study, we compared the protein expression profiles in esophageal squamous cell carcinoma (ESCC) tissues and adjacent normal esophageal tissues from five patients through high-resolution label-free mass spectrometry. Through bioinformatics analysis, we found the differentially expressed proteins of ESCC. To perform the rapid identification of biomarkers, we adopted a high-throughput protein identification technique of Quantitative Dot Blot (QDB). Meanwhile, the QDB results were verified by classical immunohistochemistry. Results In total 2297 proteins were identified, out of which 308 proteins were differentially expressed between ESCC tissues and normal tissues. By bioinformatics analysis, the four up-regulated proteins (PTMA, PAK2, PPP1CA, HMGB2) and the five down-regulated proteins (Caveolin, Integrin beta-1, Collagen alpha-2(VI), Leiomodin-1 and Vinculin) were selected and validated in ESCC by Western Blot. Furthermore, we performed the QDB and IHC analysis in 64 patients and 117 patients, respectively. The PTMA expression was up-regulated gradually along the progression of ESCC, and the PTMA expression ratio between tumor and adjacent normal tissue was significantly increased along with the progression. Therefore, we suggest that PTMA might be a potential candidate biomarker for ESCC. Conclusion In this study, label-free quantitative proteomics combined with QDB revealed that PTMA expression was up-regulated in ESCC tissues, and PTMA might be a potential candidate for ESCC. Since Western Blot cannot achieve rapid and high-throughput screening of mass spectrometry results, the emergence of QDB meets this demand and provides an effective method for the identification of biomarkers.

System biology analysis reveals the role of voltage‐dependent anion channel in mitochondrial dysfunction during non‐alcoholic fatty liver disease progression into hepatocellular carcinoma

“…VDAC1 expression was detected by IHC in NAFLD‐driven HCC and adjacent non‐tumor liver tissues. The method was consistent with our previous report 12 ; in short, the paraffin section of liver tissues was heated at 60°C for 30 min, then deparaffinized with gradient ethanol, and incubated in boiling citrate buffer (0.01 mol/L, pH 6.0) for 10 min to accomplish the antigen retrieval. After treated with 3% hydrogen peroxide for 30 min, the samples were blocked with bovine serum albumin for 30 min at 37°C, and incubated in the VDAC1 antibody (CSB‐RA025821A0HU, CUSABIO, 1:100), then followed by the Histostain‐SP (streptavidin‐peroxidase) kit (SP‐0023, BIOSS) protocol.…”

“…The protocol was similar to that described in our previous work 12 . In short, tissues samples were suspended and homogenized in lysis buffer (9 mol/L urea, 20 m mol/L HEPES) containing proteinase inhibitor cocktail (Thermo, A32961).…”

A Novel Classifier Based on Urinary Proteomics for Distinguishing Between Benign and Malignant Ovarian Tumors

“…Our experiments showed higher expression of PTMA in the malignant relative to the benign ovarian tumor group, supporting the tumor biomarker potential of PTMA. Accumulating evidence supports the utility of PTMA as a novel therapeutic target in several diseases, including cancer and inflammation (Samara et al, 2017;Zhu et al, 2019). FIBA (fibrinogen alpha), also designated fibrinogen alpha chain, is one of three polypeptide chains that make up the blood-borne glycoprotein fibrinogen.…”

Multi-Omics Analysis to Characterize Cigarette Smoke Induced Molecular Alterations in Esophageal Cells

“…Mutations in tumor suppressor genes or oncogenes enables uncontrolled growth and aid in development of cancer ( 12 ). Alterations at the genomic, transcriptomic and proteomic level has been reported in both smokers and non-smokers ( 13 – 15 ). Despite these early studies, molecular alterations associated with cigarette smoke exposure that leads to malignancy are poorly understood.…”