Cancer-associated splicing variants of the CDCA1 and MSMB genes expressed in cancer cell lines and surgically resected gastric cancer tissues.
BACKGROUND
Alternative splicing is a molecular mechanism by which different combinations of exons can be alternatively spliced to produce different mRNA isoforms. Recently, several databases have been published to predict the alternative splicing of mRNA; cancer-specific alternative splicing has also been predicted with these databases. Those variants may be potentially useful targets for cancer therapy, however, the accuracy and veracity of these databases have yet to be confirmed.


METHODS
In this study, we analyzed 17 genes by reverse transcriptase-polymerase chain reaction (RT-PCR) that were predicted to have cancer-specific alternative splicing by using the splicing database, the Alternative Splicing Annotation Project (ASAP) by Lee et al, between 38 cancer cell lines from various organs and 9 corresponding normal tissues. By designing 2 types of primer sets for RT-PCR including (1) primers flanking the alternatively spliced exons and (2) primers spanning the exon/exon junctions, cancer-associated splicing variants were investigated.


RESULTS
The alternatively splicing events were detected in 15 of 17 genes (88%); 35 of 43 variants (81%) were detected successfully with RT-PCR. Among these variants, M-RIP, HYAL2, CDCA1, and MSMB genes showed differential expressions between cancer cell lines and corresponding normal tissues. Furthermore, RT-PCR with surgically resected gastric cancer tissues (diffuse type, 6; intestinal type, 4) confirmed that 2 variants of CDCA1 were upregulated in cancer tissues, whereas both variants of MSMB were expressed predominantly in normal tissues.


CONCLUSIONS
Alternative splicing variants, especially in CDCA1, were detected in this study and may be potentially useful as diagnostic markers and/or novel targets for anticancer therapy.
Ohnuma
Shinobu
S
Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Miura
Koh
K
Horii
Akira
A
Fujibuchi
Wataru
W
Kaneko
Naoyuki
N
Gotoh
Osamu
O
Nagasaki
Hideki
H
Mizoi
Takayuki
T
Tsukamoto
Nobukazu
N
Kobayashi
Terutada
T
Kinouchi
Makoto
M
Okabe
Mitsunori
M
Sasaki
Hiroyuki
H
Shiiba
Ken-ichi
K
Miyagawa
Kikuo
K
Sasaki
Iwao
I
D000328:Adult; D000368:Aged; D017398:Alternative Splicing; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D018929:Cell Culture Techniques; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D058851:GPI-Linked Proteins; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D014644:Genetic Variation; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D029584:Prostatic Secretory Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D015815:Cell Adhesion Molecules; D018797:Cell Cycle Proteins; D058851:GPI-Linked Proteins; D020690:GTPase-Activating Proteins; C490197:NUF2 protein, human; D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein; C473096:Hyal2 protein, human; D006821:Hyaluronoglucosaminidase; C472718:AGAP3 protein, human; D019204:GTP-Binding Proteins