Identification of differentially expressed genes in normal mucosa, adenoma and adenocarcinoma of colon by SSH.
OBJECTIVE
To construct subtracted cDNA libraries and further identify differentially expressed genes that are related to the development of colorectal carcinoma(CRC).


METHODS
Suppression subtractive hybridization(SSH) was done on cDNAs of normal mucosa, adenoma and adenocarcinoma tissues from the same patient. Three subtracted cDNA libraries were constructed and then hybridized with forward and backward subtracted probes for differential screening. Positive clones from each subtracted cDNA library were selected for sequencing and BLAST analysis. Finally, virtual Northern Blot confirmed such differential expression.


RESULTS
By this way, there were about 3-4 X 10(2) clones identified in each subtracted cDNA library, in which about 85% positive clones were differentially screened. Sequencing and BLAST homology search revealed some clones containing sequences of known gene fragments and several possibly novel genes showing few or no sequence homologies with any known sequences in the database.


CONCLUSIONS
All results confirmed the effectiveness and sensitivity of SSH. The differentially expressed genes during the development of CRC can be used to shed light on the pathogenesis of CRC and be useful genetic markers for early diagnosis and therapy.
Luo
M J
MJ
Department of Pathology, School of Medicine, Zhejiang University, Hangzhou 310031, China.
Lai
M D
MD
D000230:Adenocarcinoma / Q000235:genetics* / Q000503:physiopathology; D000236:Adenoma / Q000235:genetics* / Q000503:physiopathology; D015152:Blotting, Northern; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000503:physiopathology; D015972:Gene Expression Regulation, Neoplastic; D015723:Gene Library; D005819:Genetic Markers; D006801:Humans; D007413:Intestinal Mucosa / Q000503:physiopathology; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000032:analysis
D005819:Genetic Markers; D012333:RNA, Messenger