Expression of cell proliferating genes in patients with non-small cell lung cancer by immunohistochemistry and cDNA profiling.

Abstract

Thymidine kinase 1 (TK1) is a key enzyme involved in the synthesis of DNA precursors and thus, cell proliferation-dependent. Antibodies against TK1 have provided attractive tools for cancer diagnosis. Expression of TK1 in 158 non-small cell lung cancer (NSCLC) patients with 59 adenocarcinoma (AC) and 99 squamous cell carcinoma (SCC) was determined by anti-TK1 monoclonal antibody (mAb) 1E3 (AC, n=50; SCC, n=70). Parallel tumor sections were stained for Ki-67 (MIB-1), and TK1 expression was also investigated with anti-TK1 chicken IgY Ab (AC, n=9; SCC, n=29; normal lung tissues, n=10). In one AC and one SCC patient, gene profiling was done by cDNA array. Using the mAb 1E3, a significantly higher TK1 labeling index (LI) of AC patients was found (68%) compared to the LI of Ki-67 (36%). This difference was due to a significantly higher TK1 LI of tumor stage II and grade 2. Although no difference in the LI of TK1 and Ki-67 of SCC patients was found (54 vs. 53%), significantly higher TK1 LI of SCC patients of tumor grade 1 was found. Using the anti-TK1 IgY Ab, a higher TK1 LI of AC patients (78%) and SCC patients (66%) was found compared to staining with mAb 1E3 (68 vs. 54%), but it was not significantly different. Samples stained only for TK1 represented mostly tumor stages I and II and grades 1 and 2 of both AC and SCC. AC patients whose samples stained only for Ki-67 were found to be in stage I and grade 1. cDNA profiling showed that the expression of BRCA1, cyclin B1 and cdc2p34 was higher in AC compared to SCC, while the expression of IGFBP-3 and EGFR was higher in SCC. TK1 is apparently a more reliable marker in AC patients than Ki-67. However, a combination of the two markers may help identify patients of different stages and grades more efficiently, and cyclin/kinase complexes and growth factors/receptors may be useful markers in distinguishing AC from SCC.

• Authors: Yongrong Mao, Jainping Wu, Sven Skog, Staffan Eriksson, Yiwei Zhao, Ji Zhou, Qimin He
• Journal: Oncology reports (Oncol Rep) Vol. 13 Issue 5 Pg. 837-46 (May 2005) ISSN: 1021-335X [Print] Greece
• PMID: 15809747 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Complementary
• Ki-67 Antigen
• Peptide Fragments
• Thymidine Kinase
• thymidine kinase 1

Topics

• Adenoma (genetics, pathology)
• Amino Acid Sequence
• Carcinoma, Non-Small-Cell Lung (genetics, pathology)
• Carcinoma, Squamous Cell (genetics, pathology)
• Cell Division (genetics)
• DNA Fingerprinting
• DNA, Complementary (genetics)
• Gene Expression Regulation, Neoplastic
• Humans
• Ki-67 Antigen (genetics)
• Lung Neoplasms (genetics, pathology)
• Molecular Sequence Data
• Neoplasm Staging
• Peptide Fragments (chemistry)
• Thymidine Kinase (genetics)