Molecular detection of tyrosinase transcripts in peripheral blood from patients with malignant melanoma: correlation of PCR sensitivity threshold with clinical and pathologic disease characteristics

Abstract

We conclude that reduced-sensitivity rather than ultra-sensitive PCR conditions correlate with clinical stage in melanoma patients.

Tyrosinase mRNA levels in the blood of uveal melanoma patients: correlation with the number of circulating tumor cells and tumor progression

“…In agreement with data already reported by other groups on melanoma [11,29], as well as on other neoplastic diseases [30,31], some patients of our control group were slightly positive; thus, we propose the value of 1.44 copies of tyrosinase mRNA (corresponding to 0.08 SK-MEL-28 cell equivalents/ml blood) as the cut-off value for positive results.…”

“…The first study reporting the presence of CTC in the blood from uveal melanoma patients by PCR-based methods dates back to 1993 [28]. Promising results of this approach have been extensively reported on cutaneous melanoma in which tyrosinase was shown to be related to the stage of the disease [14,29] and prognosis. Only recently, a study that focused on uveal melanoma was published [6] showing the usefulness of CTC detection by qRT-PCR.…”

Combined androgen blockade therapy can convert RT-PCR detection of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) transcripts from positive to negative in the peripheral blood of patients with clinically localized prostate cancer and increase biochemical failure-free survival after curative therapy

“…Obviously, the majority of disseminated cancer cells into the host tissue do not progress to tumor growth and development of clinically apparent metastasis (34,35). Nevertheless, molecular evidence of tumor cell dissemination into sites outside the primary tumor, such as the PB, bone marrow, lymphatic vessels and lymph nodes, can define, at least in concept, the group of patients with high risk to develop clinically apparent metastasis (36).…”

Circulating Tumor Cells in Gastrointestinal Malignancies: Current Techniques and Clinical Implications

“…Furthermore, RT-PCR of tumor-specific mRNA is characterized by a higher sensitivity in comparison to protein-based methods and usually ranges within a detection range of 1 to 10 tumor cells among 10 6 -10 7 blood mononuclear cells [50, 51]. Nevertheless, the high sensitivity of RT-PCR, although important for its clinical use, is problematic when false positive results are encountered, as it is the case with sample contamination (genomic DNA versus cDNA), illegitimate transcription (low-level nonspecific transcription of certain genes), or amplification of pseudogenes [52, 53]. Another limitation is the selection of mRNA markers used, since the ideal marker would likely be highly overexpressed in all tumor cells from a given tumor, but not expressed at all in white blood cells and nonepithelial circulating cells.…”