Enhancing detection of circulating tumor cells with activating KRAS oncogene in patients with colorectal cancer by weighted chemiluminescent membrane array method.
BACKGROUND
In 2008, the National Comprehensive Cancer Network suggested conducting a KRAS mutations test in metastatic colorectal cancer (mCRC) patients prior to administering therapy that uses anti-epidermal growth factor receptor (EGFR) monoclonal antibody. However, tests of KRAS mutations have been limited when traditional molecular techniques, such as polymerase chain reaction (PCR) combined direct sequencing, are used to obtain and analyze patients' cancer tissues. If the primary tumor or metastatic tissues of patients with mCRC is unavailable, then such analysis will not be feasible. Our laboratory has successfully established a colorimetric membrane array analysis platform that could detect activating KRAS mutations from the peripheral blood of patients with various malignancies.


METHODS
The current research aims to improve the above-mentioned technique not only by using chemiluminescence detection to replace color development, but also to add scores weighted according to the relevance of each gene to activating KRAS mutations.


RESULTS
Our results show that the described weighted chemiluminescent membrane array (WCHMA) can detect circulating tumor cells (CTCs) harboring activating KRAS mutations in the peripheral blood in CRC. The sensitivity, specificity, and accuracy were 90.2, 94.9, and 93.5%, respectively, and the detection limitation was three colon tumor cells per millimeter of blood. The current study would significantly improve the detection sensitivity and accuracy over that of our previously designed membrane array method.


CONCLUSIONS
These findings also highlight the need to prompt further prospective studies on more cases of CRC to further establish the clinical relevance of activating KRAS mutation detection from peripheral blood in anti- EGFR-based chemotherapy that uses activating KRAS detection chips and the WCHMA analysis method.
Yang
Ming-Je
MJ
Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chiu
Hua-Hsien
HH
Wang
Hwei-Ming
HM
Yen
Li-Chen
LC
Tsao
Der-An
DA
Hsiao
Chao-Peng
CP
Chen
Yi-Fang
YF
Wang
Jaw-Yuan
JY
Lin
Shiu-Ru
SR
D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D001943:Breast Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000235:genetics / Q000473:pathology; D015179:Colorectal Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D049449:Luminescence; D008175:Lung Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology; D008297:Male; D008567:Membranes, Artificial; D009360:Neoplastic Cells, Circulating / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011518:Proto-Oncogene Proteins / Q000097:blood* / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D012680:Sensitivity and Specificity; D018631:ras Proteins / Q000097:blood* / Q000235:genetics
D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D008567:Membranes, Artificial; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins