Differential expression of STAT5 and Bcl-xL, and high expression of Neu and STAT3 in non-small-cell lung carcinoma.
Experimental evidence suggests that in lung cancer, development, progression and an increased proliferation rate can be linked to apoptosis-related factors. The objective of this study is to evaluate the status of Neu, signal transducer and activator of transcription (STAT)-3, STAT5 and Bcl-xL expression in non-small-cell lung cancer. We investigated the immunohistochemical expression of these proteins in 92 non-small-cell lung cancer specimens to establish their role in lung cancer pathogenesis. Neu was overexpressed in 65% of cases, and although STAT3 was overexpressed in 52.1% in cytoplasm, it was expressed in nucleus (activated) in 60.8%. Meanwhile, STAT5 was found overexpressed in 41.3% in cytoplasm and 32.6% in nucleus. Thus, Bcl-xL was overexpressed in cytoplasm in 81.5%. Interestingly, we found nuclear expression of Bcl-xL in 30.4% of cases. Finally, we found correlation among histological types of lung cancer and nuclear expression of both STAT5 (P=0.005) and nuclear Bcl-xL (P=0.003). Besides, nuclear expression of Bcl-xL was correlated with TNM stage IV (distant metastasis) (P=0.02). These results suggest for the first time, a relevant role for STAT5 and Bcl-xL as apoptosis-regulatory proteins in the pathogenesis of lung cancer, and overexpression of both Neu and activated STAT3, could be related with the proliferation rate in lung carcinoma cells.
Sánchez-Ceja
S G
SG
Laboratorio de Patología, Instituto Nacional de Enfermedades Respiratorias, Secretaria de Salud, México, D. F., Héroe de Nacozari No. 137, Col. Centro, C.P. 58000 Morelia, Michoacán, Mexico. sergutica@yahoo.com
Reyes-Maldonado
E
E
Vázquez-Manríquez
M E
ME
López-Luna
J J
JJ
Belmont
A
A
Gutiérrez-Castellanos
S
S
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D018287:Carcinoma, Large Cell / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D050799:STAT5 Transcription Factor / Q000378:metabolism*; D051020:bcl-X Protein / Q000378:metabolism*
D018719:Erb-b2 Receptor Tyrosine Kinases; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; D051020:bcl-X Protein; C494086:STAT3 protein, human