Down-regulation of transcription elogation factor A (SII) like 4 (TCEAL4) in anaplastic thyroid cancer.
BACKGROUND
Anaplastic thyroid cancer (ATC) is one of the most aggressive human malignancies and appears to arise mainly from transformation of pre-existing differentiated thyroid cancer (DTC). However, the carcinogenic mechanism of anaplastic transformation remains unclear. Previously, we investigated specific genes related to ATC based on gene expression profiling using cDNA microarray analysis. One of these genes, transcription elongation factor A (SII)-like 4 (TCEAL4), encodes a member of the transcription elongation factor A (SII)-like gene family. The detailed function of TCEAL4 has not been described nor has any association between this gene and human cancers been reported previously.


METHODS
To investigate the role of TCEAL4 in ATC carcinogenesis, we examined expression levels of TCEAL4 in ACLs as well as in other types of thyroid cancers and normal human tissue.


RESULTS
Expression of TCEAL4 was down-regulated in all 11 ACLs as compared to either normal thyroid tissues or papillary and follicular thyroid cancerous tissues. TCEAL4 was expressed ubiquitously in all normal human tissues tested.


CONCLUSIONS
To our knowledge, this is the first report of altered TCEAL4 expression in human cancers. We suggest that loss of TCEAL4 expression might be associated with development of ATC from DTC. Further functional studies are required.
Akaishi
Junko
J
Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, Kanagawa, Japan. s4067@nms.ac.jp <s4067@nms.ac.jp>
Onda
Masamitsu
M
Okamoto
Junichi
J
Miyamoto
Shizuyo
S
Nagahama
Mitsuji
M
Ito
Kouichi
K
Yoshida
Akira
A
Shimizu
Kazuo
K
D018263:Adenocarcinoma, Follicular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018450:Disease Progression; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013961:Thyroid Gland / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D035602:Transcriptional Elongation Factors / Q000096:biosynthesis / Q000235:genetics*
D018076:DNA, Complementary; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C515645:TCEAL4 protein, human; D035602:Transcriptional Elongation Factors