The Objective is to identify candidate
biomarkers for
Squamous cell carcinoma (ESCC) in three ethnics in Xinjiang as well as reveal molecular mechanism.
Proteins from 15 pairs of ESCC and matching adjacent normal esophageal tissues (five pairs in each ethnic of Kazakh, Uygur and Han) were separated by 2-DE and differentially
proteins were identified by matrix-assisted
laser desorption/ionization time-of-flight MS. After identified by Mascot database, some of interesting
proteins were confirmed in the other 175 pairs of ESCC by immuno histochemistry. Comparison of patterns revealed 20
proteins significantly changed, of which 12
protein with concordantly increased, such as ACTB
protein, COMT
protein, Syntaxin binding protein Pyruvate Kinase (PKM2),
Cathepsin D, Chromosome 1 open reading frame 8,
Heat shock protein 27, Cdc42, Proteosome, LLDBP,
Immunoglobulin,
TNF receptor associated
factor 7; and eight
protein spots with concordantly decreased intensity in ESCC, such as
Adenylate kinase 1, General
transcription factor II H, Smooth muscle
protein, Trangelin,
Early endosome antigen 1,
Annexin A2,
Fibrin beta, Tropomyosin. There were a significant difference in
protein overexpression of PKM2 (74.9%) and
Cathepsin D (85.1%) in ESCC compared to adjacent tissues (P < 0.05) by immunohistochemistry. Further, overexpression of
Cathepsin D was obvious difference in Hazakh ESCC (94.7%) than that in Uygur (78.6%) (P < 0.05). Interestingly, the overexpression of
Cathepsin D was reversely associated with ESCC differentiation (P < 0.05). Twenty
proteins differentially-expressed between ESCC and normal tissues were identified.
Cathepsin D and PKM2 were for the first time observed to be dysregulated in Kazakh's ESCC. Moreover,
Cathepsin D may play a complicated role both in
carcinogenesis and cell-differentiation of ESCC.