Apoptosis regulating genes, bcl-2 and bax, and human telomerase reverse transcriptase messenger RNA expression in adrenal tumors: possible diagnostic and prognostic importance.
BACKGROUND
Apoptosis-suppressing gene, bcl-2, and apoptosis-inducing gene, bax, are expressed in various tumors. Human telomerase reverse transcriptase (hTERT) expression is increased in many cancers. The purpose of this investigation was to determine whether bcl-2 or bax gene expression differs between benign and malignant adrenal tumors, and whether hTERT gene expression correlates with the prognosis of patients with adrenal cancer.


METHODS
Expression of bcl-2 and bax from 52 adrenal surgical specimens was analyzed by reverse transcription-polymerase chain reaction. Expression of hTERT was analyzed by real-time quantitative reverse transcription-polymerase chain reaction, and expressed using the delta-delta threshold cycle method.


RESULTS
All normal adrenal tissues (n = 7) and benign adrenal tumors (n = 41) expressed bcl-2 and bax, whereas all adrenocortical cancers (n = 4) expressed bcl-2 but not bax. Expression of hTERT was increased in adrenocortical cancers compared with that in normal tissues (P <.05), cortical adenomas (n = 17) (P <.05), cortical hyperplasias (n = 4) (P <.05), and pheochromocytomas (n = 20) (P <.05). The one patient with an adrenocortical cancer without increased hTERT expression is alive with distant metastasis 5 years after adrenalectomy. The other 3 patients with adrenocortical cancer died 5 to 24 months after adrenalectomy.


CONCLUSIONS
Expression of bax gene appears to distinguish adrenal cancer from benign adrenal tumors. Gene expression of hTERT should be investigated as a prognostic marker in adrenal cortical cancers.
Kanauchi
Hajime
H
Department of Surgery, University of California San Francisco/Mount Zion Medical Center, 1600 Divisadero Street, Room 437, San Francisco, CA 94143-1674, USA.
Wada
Nobuyuki
N
Clark
Orlo H
OH
Duh
Quan-Yang
QY
D000236:Adenoma / Q000235:genetics / Q000473:pathology*; D000306:Adrenal Cortex Neoplasms / Q000235:genetics / Q000473:pathology*; D017209:Apoptosis / Q000235:genetics; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006965:Hyperplasia; D009369:Neoplasms / Q000235:genetics; D010673:Pheochromocytoma / Q000235:genetics / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D019098:Telomerase / Q000235:genetics*; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D019098:Telomerase