Specific detection of circulating tumor cells by reverse transcriptase-polymerase chain reaction of a beta-casein-like protein, preferentially expressed in malignant neoplasms

Beta-casein-like protein (BCLP) is a putative protein on cervical cancer an d exhibits immunological characteristics similar to those of bovine beta -c asein. We evaluated if BCLP mRNA detection in the blood is useful in gyneco logic malignancies. We examined 30 patients with uterine cancer, nine cultu red cancer cell lines and 26 healthy women volunteers. From these study pop ulations and samples, total RNA was obtained. Reverse transcriptase-PCR (RT -PCR) of BCLP was performed on each sample. Eighteen (60.0%) patients and 4 (15.4%) volunteers were positive for BCLP mRNA. The RTPCR reached sensitiv ity and specificity of 60.0% and 84.6%, respectively. Of eight patients hav ing diagnosed recurrence, 7 (87.5%) were positive for BCLP mRNA. In patient s with recurrence, sensitivity and specificity were 87.5% and 50%, respecti vely. The expression of mRNA showed a correlation with recurrence, but no c orrelation with metastasis or histological type. BCLP was specifically expr essed in cancer cells and might be an aid in clinical diagnosis.