Expression of peroxiredoxin and thioredoxin in human lung cancer and paired normal lung.
BACKGROUND
Peroxiredoxins (Prxs) have been implicated in regulating many cellular processes including cell proliferation, differentiation and apoptosis. However, the pathophysiological significance of Prx proteins, especially in lung disease, has not been defined. Therefore, the authors investigated the distribution and expression of various Prx isoforms in lung cancer and compared this with normal lung from human and mouse.


METHODS
Patients diagnosed with lung cancer who underwent surgery at Ajou Medical Center were enrolled. Expression of Prxs, thioredoxin and thioredoxin reductase was analysed by proteomic techniques. Immunohistochemistry was performed to localize Prx proteins.


RESULTS
Immunohistochemical staining showed that the isoforms of Prx I, II, III and V were predominantly expressed in bronchial and alveolar epithelium as well as in alveolar macrophages of the normal mouse lung. The isoforms I, III and thioredoxin were overexpressed in lung cancer tissues compared with normal lungs. There was also an increased amount of oxidized form of Prx I and a putative truncated form of Prx III in lung cancer samples when analysed on two-dimensional electrophoresis. In addition, a 40-kDa intermediate MW protein band and high MW bands of over 20 kDa, recognized by anti-Prx (a-Prx) I antibody, were present in tissue extracts of lung cancer patients on one-dimensional electrophoresis.


CONCLUSIONS
The upregulation of Prx I, Prx III and thioredoxin in lung cancer tissue may represent an attempt by tumour cells to adjust to the microenvironment in a manner that is advantageous to survival and proliferation.
Park
Joo Hun
JH
Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
Kim
Young Sun
YS
Lee
Hye Lim
HL
Shim
Jin Young
JY
Lee
Keu Sung
KS
Oh
Yoon Jung
YJ
Shin
Seung Soo
SS
Choi
Young Hwa
YH
Park
Kwang Joo
KJ
Park
Rae Woong
RW
Hwang
Sung Chul
SC
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D004273:DNA, Neoplasm / Q000235:genetics*; D004586:Electrophoresis; D029968:Escherichia coli Proteins; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D008875:Middle Aged; D010544:Peroxidases / Q000096:biosynthesis*; D054464:Peroxiredoxins; D011379:Prognosis; D013879:Thioredoxins / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D029968:Escherichia coli Proteins; D013879:Thioredoxins; D010544:Peroxidases; D054464:Peroxiredoxins