Detection of PSA mRNA in blood by RT-PCR does not exclusively indicate prostatic tumor cells

Abstract Background The MYCN amplification is a defining hallmark of high-risk neuroblastoma. Due to irregular oncogenes orchestration, tumor cells exhibit distinct fatty acid metabolic features from non-tumor cells. However, the function of MYCN in neuroblastoma fatty acid metabolism reprogramming remains unknown. Methods Gas Chromatography-Mass Spectrometer (GC-MS) was used to find the potential target fatty acid metabolites of MYCN. Real-time PCR (RT-PCR) and clinical bioinformatics analysis was used to find the related target genes. The function of the identified target gene ELOVL2 on cell growth was detected through CCK-8 assay, Soft agar colony formation assay, flow Cytometry assay and mouse xenograft. Chromatin immunoprecipitation (ChIP) and Immunoprecipitation-Mass Spectrometer (IP-MS) further identified the target gene and the co-repressor of MYCN. Results The fatty acid profile of MYCN-depleted neuroblastoma cells identified docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid with anti-tumor activity, significantly increased after MYCN depletion. Compared with MYCN single-copy neuroblastoma cells, DHA level was significantly lower in MYCN-amplified neuroblastoma cells. RT-PCR and clinical bioinformatics analysis discovered that MYCN interfered DHA accumulation via ELOVL fatty acid elongase 2 (ELOVL2) which is a rate-limiting enzyme of cellular DHA synthesis. Enforced ELOVL2 expression in MYCN-amplified neuroblastoma cells led to decreased cell growth and counteracted the growth-promoting effect of MYCN overexpression both in vitro and vivo. ELOVL2 Knockdown showed the opposite effect in MYCN single-copy neuroblastoma cells. In primary neuroblastoma, high ELOVL2 transcription correlated with favorable clinical tumor biology and patient survival. The mechanism of MYCN-mediated ELOVL2 inhibition contributed to epigenetic regulation. MYCN recruited PRC1 (Polycomb repressive complex 1), catalysed H2AK119ub (histone 2A lysine 119 monoubiquitination) and inhibited subsequent ELOVL2 transcription. Conclusions The tumor suppressive properties of DHA and ELOVL2 are repressed by the MYCN and PRC1 jointly, which suggests a new epigenetic mechanism of MYCN-mediated fatty acid regulation and indicates PRC1 inhibition as a potential novel strategy to activate ELOVL2 suppressive functions.

Download Full-text

Detection of circulating tumor cells in patients with Ewing's sarcoma and peripheral primitive neuroectodermal tumor.

Journal of Clinical Oncology ◽

10.1200/jco.1997.15.2.583 ◽

1997 ◽

Vol 15 (2) ◽

pp. 583-588 ◽

Cited By ~ 86

Author(s):

D C West ◽

H E Grier ◽

M M Swallow ◽

G D Demetri ◽

L Granowetter ◽

...

Keyword(s):

Bone Marrow ◽

Tumor Cells ◽

Primitive Neuroectodermal Tumor ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Residual Disease ◽

Neuroectodermal Tumor ◽

Peripheral Primitive Neuroectodermal Tumor ◽

Rt Pcr ◽

Relapsed Disease

PURPOSE To determine the feasibility of detecting Ewing's sarcoma (ES) or peripheral primitive neuroectodermal tumor (PNET) through a reverse-transcriptase polymerase chain reaction (RT-PCR) of the t(11;22)(q24;q12) fusion transcript in blood and bone marrow samples from patients with these neoplasms. PATIENTS AND METHODS Peripheral-blood (PB) and/or bone marrow aspirate (BM) samples were obtained from 28 patients with ES or PNET at initial presentation or at relapse. Patients were divided into two groups: newly diagnosed patients with nonmetastatic disease and those with metastatic/relapsed disease. RNA was extracted from fractionated BM and PB samples, and RT-PCR was performed for the EWS/HumFLI1 fusion mRNA was transcribed across the t(11;22) breakpoint. RESULTS Among the 16 patients with nonmetastatic disease, three of 16 were RT-PCR positive for EWS/HumFLI1 RNA in BM and three of 10 were positive in PB. The total number of nonmetastatic patients who were positive in either PB or BM was four of 16 (25%). Among patients with metastatic/relapsed disease, two of six were positive in BM and five of 10 were positive in PB. The total fraction of patients with metastatic/relapsed disease that was positive in either BM or PB was six of 12 (50%). CONCLUSION In this study, we show that it is possible to amplify the EWS/HumFLI1 RNA by RT-PCR from the BM and PB of a subset of patients with both nonmetastatic and metastatic ES or PNET, which implies that occult tumor cells are present at these sites. The true biologic and clinical meaning of this information is unknown. However, it does suggest a possible application of RT-PCR for the monitoring of residual disease in patients who are undergoing therapy for ES or PNET. This approach may permit early identification of patients who may benefit from alternative therapy or who may be spared possible overtreatment.

Download Full-text

Abstract P1-04-10: Assessment of circulating tumor cells (CTC) by RT/PCR as a surrogate marker for PFS in metastatic breast cancer (MBC)

10.1158/0008-5472.sabcs13-p1-04-10 ◽

2013 ◽

Author(s):

MM Saber ◽

AA Bahnasy ◽

HM El-Zawahry ◽

NM Allahloubi ◽

MA El-Moetii ◽

...

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Surrogate Marker ◽

Metastatic Breast ◽

Rt Pcr

Download Full-text

Prognostic Value of Circulating Tumor Cells in Early Breast Cancer Patients Detected by RT-PCR of Mamaglobin

Annals of Oncology ◽

10.1016/s0923-7534(20)32869-6 ◽

2012 ◽

Vol 23 ◽

pp. ix111-ix112

Author(s):

A.M. Hilal ◽

H.M. Elzawahrey ◽

A.A. Abd Elwahab ◽

M.N. Abdelhafez ◽

M.M. Moneer ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Early Breast Cancer ◽

Prognostic Value ◽

Breast Cancer Patients ◽

Rt Pcr

Download Full-text

RT-PCR-Based Detection of Occult Disseminated Tumor Cells in Peripheral Blood and Bone Marrow of Patients with Solid Tumors: An Overview

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.2000.tb06600.x ◽

2006 ◽

Vol 906 (1) ◽

pp. 110-123 ◽

Cited By ~ 45

Author(s):

A. ZIPPELIUS ◽

K. PANTEL

Keyword(s):

Bone Marrow ◽

Solid Tumors ◽

Tumor Cells ◽

Peripheral Blood ◽

Disseminated Tumor Cells ◽

Rt Pcr

Download Full-text

Circulating Prostate Tumor Cells Detected by Reverse Transcription-PCR in Men with Localized or Castration-Refractory Prostate Cancer: Concordance with CellSearch Assay and Association with Bone Metastases and with Survival

Clinical Chemistry ◽

10.1373/clinchem.2008.117952 ◽

2009 ◽

Vol 55 (4) ◽

pp. 765-773 ◽

Cited By ~ 93

Author(s):

Pauliina Helo ◽

Angel M Cronin ◽

Daniel C Danila ◽

Sven Wenske ◽

Rita Gonzalez-Espinoza ◽

...

Keyword(s):

Prostate Cancer ◽

Bone Metastases ◽

Healthy Volunteers ◽

Real Time ◽

Tumor Cells ◽

Reverse Transcription ◽

Specific Antigen ◽

Rt Pcr ◽

Reverse Transcription Pcr ◽

Pcr Assays

Abstract Background: Reverse transcription-PCR (RT-PCR) assays have been used for analysis of circulating tumor cells (CTCs), but their clinical value has yet to be established. We assessed men with localized prostate cancer or castration-refractory prostate cancer (CRPC) for CTCs via real-time RT-PCR assays for KLK3 [kallikrein-related peptidase 3; i.e., prostate-specific antigen (PSA)] and KLK2 mRNAs. We also assessed the association of CTCs with disease characteristics and survival. Methods: KLK3, KLK2, and PSCA (prostate stem cell antigen) mRNAs were measured by standardized, quantitative real-time RT-PCR assays in blood samples from 180 localized-disease patients, 76 metastatic CRPC patients, and 19 healthy volunteers. CRPC samples were also tested for CTCs by an immunomagnetic separation system (CellSearch™; Veridex) approved for clinical use. Results: All healthy volunteers were negative for KLK mRNAs. Results of tests for KLK3 or KLK2 mRNAs were positive (≥80 mRNAs/mL blood) in 37 patients (49%) with CRPC but in only 15 patients (8%) with localized cancer. RT-PCR and CellSearch CTC results were strongly concordant (80%–85%) and correlated (Kendall τ, 0.60–0.68). Among CRPC patients, KLK mRNAs and CellSearch CTCs were closely associated with clinical evidence of bone metastases and with survival but were only modestly correlated with serum PSA concentrations. PSCA mRNA was detected in only 7 CRPC patients (10%) and was associated with a positive KLK mRNA status. Conclusions: Real-time RT-PCR assays of KLK mRNAs are highly concordant with CellSearch CTC results in patients with CRPC. KLK2/3-expressing CTCs are common in men with CRPC and bone metastases but are rare in patients with metastases diagnosed only in soft tissues and patients with localized cancer.

Download Full-text