Real time quantification in plasma of human telomerase reverse transcriptase (hTERT) mRNA in patients with colorectal cancer.
BACKGROUND
Increased telomerase activity can be found in almost 90% of colorectal tumours. We aim to describe the preliminary results for quantification in plasma of hTERT mRNA in colorectal cancer patients.


METHODS
Fifty patients undergoing surgery for colorectal cancer and a control group of 50 healthy volunteers were prospectively studied. Pre-operative venous blood samples were taken from all cancer patients and volunteers. Plasma hTERT expression was determined from peripheral blood based on real-time quantitative RT-PCR (qRT-PCR) method normalized to the amount of RNA input using 18S rRNA gene expression. Plasma pre-operative CEA levels were also determined.


RESULTS
Median values for normalized hTERT (hTERT(N)) gene expression were higher in colorectal cancer patients (11.62, range 0.23-47.67) than healthy volunteers (0.29, range 0.00-4.63) (P < 0.001). Individual data showed that 82% of colorectal cancer patients had hTERT(N) expression values superior to the maximum value observed in the control group. Sensitivity and specificity of the assay for colorectal cancer detection were 98% and 64%, respectively. No significant differences in hTERT(N) expression between gender or with age (P > 0.05). No significant correlation was found between hTERT(N) expression and CEA values (Spearman's rank test = 0.136, P = 0.348).


CONCLUSIONS
These results show that detection of mRNA based on the qRT-PCR of the telomerase hTERT(N) gene in plasma clearly differentiates between healthy and colorectal cancer patients and that hTERT(N) can be detected and quantified in plasma. This opens up a new field as a noninvasive blood test for colorectal cancer diagnosis.
Lledó
S M
SM
Department of General Surgery, Hospital Clinico Universitario, Valencia, Spain. lledo_sal@gva.es
Garcia-Granero
E
E
Dasí
F
F
Ripoli
R
R
García
S A
SA
Cervantes
A
A
Aliño
S F
SF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000097:blood* / Q000235:genetics / Q000378:metabolism / Q000601:surgery; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D012333:RNA, Messenger / Q000096:biosynthesis / Q000097:blood* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D019098:Telomerase / Q000096:biosynthesis / Q000097:blood* / Q000235:genetics
D002272:Carcinoembryonic Antigen; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D019098:Telomerase