title: Progenitor cell line (hPheo1) derived from a human pheochromocytoma tumor.
abstract: BACKGROUND
  Pheochromocytomas are rare tumors generally arising in the medullary region of the adrenal gland. These tumors release excessive epinephrine and norepinephrine resulting in hypertension and cardiovascular crises for which surgery is the only definitive treatment. Molecular mechanisms that control tumor development and hormone production are poorly understood, and progress has been hampered by the lack of human cellular model systems. To study pheochromocytomas, we developed a stable progenitor pheochromocytoma cell line derived from a primary human tumor.
  
  
  METHODS
  After IRB approval and written informed consent, human pheochromocytoma tissue was excised, minced, dispersed enzymatically, and cultured in vitro. Primary pheochromocytoma cells were infected with a lentivirus vector carrying the catalytic subunit of human telomerase reverse transcriptase (hTERT). The hTERT immortalized cells (hPheo1) have been passaged >300 population doublings. The resulting cell line was characterized morphologically, biochemically and for expression of neuroendocrine properties. The expression of marker enzymes and proteins was assessed by immunofluorescence staining and immunoblotting. Telomerase activity was determined by using the telomeric repeat amplification protocol (TRAP) assay.
  
  
  RESULTS
  We have established a human pheochromocytoma precursor cell line that expresses the neuroendocrine marker, chromogranin A, when differentiated in the presence of bone morphogenic protein 4 (BMP4), nerve growth factor (NGF), and dexamethasone. Phenylethanolamine N-methyltransferase (PNMT) expression is also detected with this differentiation regimen. CD-56 (also known as NCAM, neural cell adhesion molecule) is expressed in these cells, but CD31 (also known as PECAM-1, a marker of endothelial cells) is negative.
  
  
  CONCLUSIONS
  We have maintained hTERT-immortalized progenitor cells derived from a pheochromocytoma (hPheo1) in culture for over 300 population doublings. This progenitor human cell line is normal diploid except for a deletion in the p16 region and has inducible neuroendocrine biomarkers. These cells should be a valuable reagent for studying mechanisms of tumor development and for testing novel therapeutic approaches.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Hans K
authors.initials: HK
authors.lastname: Ghayee
authors.forename: Vikash J
authors.initials: VJ
authors.lastname: Bhagwandin
authors.forename: Victor
authors.initials: V
authors.lastname: Stastny
authors.forename: Arielle
authors.initials: A
authors.lastname: Click
authors.forename: Liang-Hao
authors.initials: LH
authors.lastname: Ding
authors.forename: Dario
authors.initials: D
authors.lastname: Mizrachi
authors.forename: Ying S
authors.initials: YS
authors.lastname: Zou
authors.forename: Raj
authors.initials: R
authors.lastname: Chari
authors.forename: Wan L
authors.initials: WL
authors.lastname: Lam
authors.forename: Robert M
authors.initials: RM
authors.lastname: Bachoo
authors.forename: Alice L
authors.initials: AL
authors.lastname: Smith
authors.forename: Michael D
authors.initials: MD
authors.lastname: Story
authors.forename: Stan
authors.initials: S
authors.lastname: Sidhu
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Robinson
authors.forename: Fiemu E
authors.initials: FE
authors.lastname: Nwariaku
authors.forename: Adi F
authors.initials: AF
authors.lastname: Gazdar
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Auchus
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Shay
mesh_terms: D059786:Abnormal Karyotype; D000328:Adult; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D016130:Immunophenotyping; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D010673:Pheochromocytoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D034622:RNA Interference; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome; D014161:Transduction, Genetic
chemical_list: C509186:TERT protein, human; D019098:Telomerase