Back to Search
Start Over
CYP24, the enzyme that catabolizes the antiproliferative agent vitamin D, is increased in lung cancer
- Source :
- International Journal of Cancer. 119:1819-1828
- Publication Year :
- 2006
- Publisher :
- Wiley, 2006.
-
Abstract
- 1Alpha,25-dihydroxyvitamin D3 (1,25D3) displays potent antiproliferative activity in a variety of tumor model systems and is currently under investigation in clinical trials in cancer. Studies were initiated to explore its potential in nonsmall cell lung cancer (NSCLC), as effective approaches to the treatment of that disease are needed. In evaluating factors that may affect activity in NSCLC, the authors found that CYP24 (25-hydroxyvitamin D3-24-hydroxylase), the enzyme that catabolizes 1,25D3, is frequently expressed in NSCLC cell lines but not in the nontumorigenic bronchial epithelial cell line, Beas2B. CYP24 expression by RT-PCR was also detected in 10/18 primary lung tumors but in only 1/11 normal lung tissue specimens. Tumor-specific CYP24 upregulation was confirmed at the protein level via immunoblot analysis of patient-matched normal lung tissue and lung tumor extracts. Enzymatically active CYP24 is expected to desensitize NSCLC cells to 1,25D3. The authors therefore implemented a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay for 1,25D3 and its CYP24-generated metabolites to determine whether NSCLC cells express active enzyme. Analysis of NSCLC cell cultures revealed time-dependent loss of 1,25D3 coincident with the appearance of CYP24-generated metabolites. MK-24(S)-S(O)(NH)-Ph-1, a specific inhibitor of CYP24, slowed the loss of 1,25D3 and increased 1,25D3 half-life. Furthermore, combination of 1,25D3 with MK-24(S)-S(O)(NH)-Ph-1 resulted in a significant decrease in the concentration of 1,25D3 required to achieve maximum growth inhibition in NSCLC cells. These data suggest that increased CYP24 expression in lung tumors restricts 1,25D3 activity and support the preclinical evaluation of CYP24 inhibitors for lung cancer treatment.
- Subjects :
- Male
Cancer Research
medicine.medical_specialty
Gene Expression Regulation, Enzymologic
chemistry.chemical_compound
Carcinoma, Non-Small-Cell Lung
Cell Line, Tumor
Internal medicine
Carcinoma
medicine
Humans
RNA, Messenger
Enzyme Inhibitors
Vitamin D
Vitamin D3 24-Hydroxylase
Lung cancer
Aged
Cell Proliferation
Lung
business.industry
Respiratory disease
Cancer
Biological activity
Middle Aged
medicine.disease
respiratory tract diseases
Gene Expression Regulation, Neoplastic
Endocrinology
medicine.anatomical_structure
Oncology
chemistry
Cell culture
Steroid Hydroxylases
Cancer research
Female
Growth inhibition
business
Subjects
Details
- ISSN :
- 10970215 and 00207136
- Volume :
- 119
- Database :
- OpenAIRE
- Journal :
- International Journal of Cancer
- Accession number :
- edsair.doi.dedup.....8d9da5d9540ed6f17062ab941f4b24c4
- Full Text :
- https://doi.org/10.1002/ijc.22058