title: c-myc expression in the thyroid. I: Normal, adenomatous, and cancerous thyroid tissue.
abstract: Recent investigations have suggested that myc oncogene expression may be important in the development or progression of thyroid tumors. The purposes of the present study were to assess cellular (c)-myc expression in thyroid adenomas (n = 5), as well as in thyroid cancer (n = 4) and in normal thyrocytes (n = 7). Total RNA was prepared by extraction with guanididium thiocyanate and ultracentrifugation through a CsCl2 cushion. 30 micrograms total RNA was size fractionated on a 1% (w/v) agarose/formaldehyde gel and transferred to nylon membranes. These membranes were hybridized to a 32P-labelled third exon c-myc DNA. Following hybridization, blots were washed under high stringency and subjected to autoradiography; radioautographic bands were assessed visually or were quantitated by scanning densitometry. Nodular tissue had approximately the same degree of expression of the 2.4 Kb c-myc message as the surrounding normal tissue from the same gland (0.66 +/- 0.09 vs. 1.0 +/- 0.26, respectively); normal thyrocytes were capable in every instance of expressing the 2.4 Kb c-myc message. Thyroid cancer tissue expressed this message (0.91 +/- 0.17) but only at a level comparable to normal tissue. No other bands of hybridization were detected in any samples. We conclude that c-myc oncogene expression is comparable in normal thyrocytes and in thyroid nodules or thyroid cancer samples. These findings support a role for c-myc in both normal and neoplastic thyrocyte growth.
authors.affiliation: Department of Medicine, Walter Reed Army Medical Center, Washington, DC.
authors.forename: K D
authors.initials: KD
authors.lastname: Burman
authors.forename: Y Y
authors.initials: YY
authors.lastname: Djuh
authors.forename: R V
authors.initials: RV
authors.lastname: LaRocca
authors.forename: M E
authors.initials: ME
authors.lastname: Nunes
authors.forename: J C
authors.initials: JC
authors.lastname: D'Avis
authors.forename: D E
authors.initials: DE
authors.lastname: Nicholson
authors.forename: L
authors.initials: L
authors.lastname: Wartofsky
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D006801:Humans; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D013961:Thyroid Gland / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism*
chemical_list: D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D012334:RNA, Neoplasm