[Application of matrix assisted laser desorption ionization-time of flight-mass spectrometry in detecting K-ras gene mutation of colorectal cancer].
OBJECTIVE
To investigate the clinical value of matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in detecting K-ras gene mutation.


METHODS
Sixty-one paraffin-embeded specimens of colorectal cancer were selected. MALDI-TOF-MS and regular sequencing were used to test the mutation of codon 12 and 13 in K-ras exon 2.


RESULTS
Only 47 specimens could be detected successfully in regular sequencing, while all the specimens were tested successfully in MALDI-TOF-MS. Fourteen specimens had K-ras mutation in regular sequencing (30.0%), while 22 specimens had mutation in MALDI-TOF-MS (36.1%). Six specimens with mutation were found in MALDI-TOF-MS but were wild-type in regular sequencing. Same mutation types from 14 specimens were confirmed by both regular sequencing and MALDI-TOF-MS. MALDI-TOF-MS was able to detect the mutation in 2 specimens that was not identified in regular sequencing.


CONCLUSIONS
MALDI-TOF-MS is a feasible approach of K-ras gene mutation testing in colorectal cancer, which is less demanding in terms of specimen quality and is more sensitive as compared to regular sequencing.
Peking University Cancer Hospital and Institute, Beijing, China.
Jia-di
JD
Xing
Lian-hai
LH
Zhang
Jing-jing
JJ
Li
Zi-yu
ZY
Li
Xiang-qian
XQ
Su
Jia-fu
JF
Ji
D015179:Colorectal Neoplasms / Q000235:genetics*; D011905:Genes, ras; D006801:Humans; D009154:Mutation; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*