Faecal tumour M2 pyruvate kinase: a new, sensitive screening tool for colorectal cancer.
Proliferating cells, especially tumour cells, express a special isoenzyme of pyruvate kinase, termed M2-PK, which can occur in a tetrameric form with a high affinity to its substrate, phosphoenolpyruvate (PEP), and in a dimeric form with a low PEP affinity. In tumour cells, the dimeric form is usually predominant and is therefore termed Tumour M2-PK. The levels of Tumour M2-PK within tumours and in EDTA-plasma correlate with staging and the ability of the tumour cells to metastasise. Since most colorectal tumours grow intraluminally, it appeared interesting to determine whether Tumour M2-PK is detectable in the faeces of tumour patients. Stool samples were tested by ELISA from controls without colorectal cancer and colorectal cancer patients. Whereas Tumour M2-PK levels were low in the control group (mean value+/-s.e.m.: 3.3+/-0.4, n=144), they were high in the case of colorectal cancer (56.1+/-15.3, n=60). At a cutoff value of 4 U ml(-1), the sensitivity was 73%. TNM and Dukes' classification of the tumours revealed a strong correlation between faecal Tumour M2-PK levels and staging. The determination of Tumour M2-PK in faeces provides a new promising screening tool for colorectal tumours.
Hardt
P D
PD
Third Medical Department and Policlinic, Giessen University Hospital, Justus-Liebig-University of Giessen, Rodthohl 6, Giessen 35392, Germany. Philip.D.Hardt@innere.uni-giessen.de
Mazurek
S
S
Toepler
M
M
Schlierbach
P
P
Bretzel
R G
RG
Eigenbrodt
E
E
Kloer
H U
HU
D014408:Biomarkers, Tumor / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000201:enzymology*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D011770:Pyruvate Kinase / Q000032:analysis*; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D011770:Pyruvate Kinase