DNA Methylation of Tumor Suppressor and Metastasis Suppressor Genes in Circulating Tumor Cells

Chimonidou, Maria; Strati, Αreti; Tzitzira, Alexandra; Sotiropoulou, Georgia; Malamos, Nikos; Georgoulias, Vasilis; Lianidou, Evi

doi:10.1373/clinchem.2011.165902

Cited by 151 publications

(132 citation statements)

References 40 publications

(53 reference statements)

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“…For the isolation of CTCs, peripheral blood (20 mL collected in EDTA) was obtained at the midpoint of sample collection by venipuncture as previously described (14 ).…”

Section: Patients and Samplesmentioning

confidence: 99%

“…CTCs were isolated from 20 mL peripheral blood as previously described (14,20 ). More specifically, after dilution of peripheral blood with 20 mL PBS (pH 7.3), peripheral blood mononuclear cells were obtained by gradient density centrifugation using Ficoll-Paque TM PLUS (GE Healthcare, Bio-Sciences AB) at 670g for 30 min at room temperature.…”

Section: Positive Immunomagnetic Selection Of Ctcsmentioning

confidence: 99%

“…gDNA was extracted from CTCs as previously described (14 ). After removal of the aqueous phase of Trizol, DNA was precipitated (from the interphase) by adding 150 L of 100% ethanol.…”

Section: Dna Extraction From Ctcsmentioning

confidence: 99%

“…Promoters of the tumor suppressor genes cystatin E/M (CST6) and SRY (sex determining region Y)-box 17 (SOX17), and the metastasis suppressor gene breast cancer metastasis suppressor 1 (BRMS1) are methylated in CTCs isolated from the peripheral blood of patients with breast cancer (14 ). SOX17, a member of the Sry-related high mobility group box (SOX) family of transcription factors, is conserved in many species and plays critical roles in the regulation of development and stem/precursor cell function, at least partly through repression of the canonical Wnt/␤-catenin signaling pathway (15,16 ).…”

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SOX17 Promoter Methylation in Circulating Tumor Cells and Matched Cell-Free DNA Isolated from Plasma of Patients with Breast Cancer

et al. 2013

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INTRODUCTION Detection of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) in the peripheral blood of patients with solid tumors has been widely studied for the early detection of metastatic spread. We evaluated whether there was an association between the origin of cfDNA and CTCs. We investigated whether SRY (sex determining region Y)-box 17 (SOX17) promoter methylation in CTCs was associated with the methylation pattern of this gene in matched cfDNA isolated from plasma of patients with breast cancer. METHODS We examined SOX17 methylation in 79 primary breast tumors, in 114 paired samples of DNA isolated from CTCs and cfDNA, and in 60 healthy individuals. Isolated DNA was modified by sodium bisulfite and subjected to methylation specific PCR. RESULTS The SOX17 promoter was methylated in 68 (86.0%) of 79 of primary breast tumors. In CTCs, SOX17 was methylated in 19 (34.5%) of 55 patients with early breast cancer, 27 (45.8%) of 59 patients with metastatic cancer, and 1 (4.3%) of 23 healthy individuals, whereas in matched cfDNA SOX17 was methylated in 19 (34.5%) of 55, 24 (40.7%) of 59, and 1 (2.0%) of 49 of these same groups, respectively. There was a significant correlation between SOX17 methylation in cfDNA and CTCs in patients with early breast cancer (P = 0.008), but not in patients with verified metastasis (P = 0.283). CONCLUSIONS The SOX17 promoter is highly methylated in primary breast tumors, in CTCs isolated from patients with breast cancer, and in corresponding cfDNA samples. Our findings indicate a direct connection between the presence of CTCs and cfDNA in patients with operable breast cancer, after surgical removal of the primary tumor.

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“…For the isolation of CTCs, peripheral blood (20 mL collected in EDTA) was obtained at the midpoint of sample collection by venipuncture as previously described (14 ).…”

Section: Patients and Samplesmentioning

confidence: 99%

Section: Positive Immunomagnetic Selection Of Ctcsmentioning

confidence: 99%

“…gDNA was extracted from CTCs as previously described (14 ). After removal of the aqueous phase of Trizol, DNA was precipitated (from the interphase) by adding 150 L of 100% ethanol.…”

Section: Dna Extraction From Ctcsmentioning

confidence: 99%

mentioning

confidence: 99%

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SOX17 Promoter Methylation in Circulating Tumor Cells and Matched Cell-Free DNA Isolated from Plasma of Patients with Breast Cancer

et al. 2013

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“…Before performing such studies, however, the nature of these circulating EpCAM-positive and CKpositive cells has to be elucidated. Molecular characterization of CTCs can provide valuable information on (a) the expression of cancer-specific genes in these cells (11)(12)(13), (b) mutations in oncogenes or tumor suppressor genes (14 ), (c) epigenetic silencing of tumor suppressor genes and metastasis suppressors (15 ), and (d) fluorescence in situ hybridization-based detection of numerical chromosomal aberrations. As the authors have indicated, false-positive findings may be encountered with the current CTC assays without further molecular analysis of these cells.…”

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confidence: 99%

Circulating Tumor Cells—New Challenges Ahead

Lianidou

2012

Clinical Chemistry

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PIK3CA hotspot mutations in circulating tumor cells and paired circulating tumor DNA in breast cancer: a direct comparison study

et al. 2019

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Liquid biopsy analysis, mainly based on circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), provides an extremely powerful tool for the molecular profiling of cancer patients in real time. In this study, we directly compared PIK3CA hotspot mutations (E545K, H1047R) in EpCAM‐positive CTCs and paired plasma‐ctDNA in breast cancer (BrCa). PIK3CA hotspot mutations in CTCs and ctDNA were analyzed using our previously developed highly sensitive (0.05%), specific, and validated assay in plasma‐ctDNA from 77 early and 73 metastatic BrCa patients and 40 healthy donors. We further analyzed and directly compared PIK3CA hotspot mutations in DNAs isolated from CellSearch® cartridges (CTCs) and paired plasma‐ctDNA, in 56 cases of early and 27 cases of metastatic breast cancer, and 16 corresponding primary tumors. In plasma‐ctDNA,PIK3CA hotspot mutations were identified in 30/77(39.0%) early and 35/73(47.9%) metastatic BrCa cases; none (0/40, 0%) of the healthy donors’ plasma‐ctDNA samples were positive. Our direct comparison study in DNAs isolated from CellSearch® cartridges (CTCs) and paired plasma‐ctDNA from the same blood draws has shown a lack of concordance in early BrCa (27/56, 48.2%), while the concordance in the metastatic setting was higher (18/27, 66.6%). Our results were validated by ddPCR methodology, and the concordance between our assay and ddPCR for PIK3CA E545K hotspot mutation was 30/37 (81.1%). In many cases, PIK3CA hotspot mutations were detected in samples found to be negative for CTCs in CellSearch®. Our data demonstrated for the first time that (a) PIK3CA hotspot mutations are present at high frequencies in CTCs isolated from CellSearch® cartridges and paired plasma‐ctDNA both in early and metastatic BrCa, (b) the detection and concordance of PIK3CA hotspot mutations between plasma‐ctDNA and CTCs are higher in the metastatic setting, (c) PIK3CA mutational status significantly changes after therapeutic intervention, and (d) PIK3CA mutation detection in CTCs and plasma‐ctDNA provides complementary information.

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DNA Methylation of Tumor Suppressor and Metastasis Suppressor Genes in Circulating Tumor Cells

Cited by 151 publications

References 40 publications

SOX17 Promoter Methylation in Circulating Tumor Cells and Matched Cell-Free DNA Isolated from Plasma of Patients with Breast Cancer

SOX17 Promoter Methylation in Circulating Tumor Cells and Matched Cell-Free DNA Isolated from Plasma of Patients with Breast Cancer

Circulating Tumor Cells—New Challenges Ahead

PIK3CA hotspot mutations in circulating tumor cells and paired circulating tumor DNA in breast cancer: a direct comparison study

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