Kazuo Koyanagi

Predictive Utility of Circulating Methylated DNA in Serum of Melanoma Patients Receiving Biochemotherapy

PURPOSE Currently, no validated blood-based assays accurately predict treatment response or outcome in melanoma patients. We hypothesized that methylation of tumor-related genes detected in serum DNA could predict disease outcome and therapeutic response in patients receiving concurrent biochemotherapy (BC) for metastatic melanoma. PATIENTS AND METHODS American Joint Committee on Cancer stage IV melanoma patients (N = 50) had blood drawn before administration of BC. Patients (n = 47) were classified as BC responders or nonresponders. Responders (n = 23) demonstrated a complete or partial response following BC; nonresponders (n = 24) demonstrated progressive disease. Hypermethylation of Ras association domain family 1 (RASSF1A), retinoic acid receptor-beta2 (RAR-beta2), and O6-methylguanine DNA methyltransferase (MGMT) genes were assessed by methylation-specific polymerase chain reaction. RESULTS Circulating methylated RASSF1A was significantly less frequent for responders (three of 23 patients; 13%) than nonresponders (10 of 24 patients; 42%; P = .028). Patients with RASSF1A, RAR-beta2, or at least one serum methylated gene had significantly worse overall survival than patients with no methylated genes (log-rank, P = .013, .021, and .01, respectively). Methylated RASSF1A was the only factor that significantly correlated with overall survival and BC response (risk ratio, 2.38; 95% CI, 1.16 to 4.86; P = .018; odds ratio = 0.21; 95% CI, 0.05 to 0.90; P = .036). CONCLUSION Detection of circulating methylated DNA in serum can predict response to BC and disease outcome.

Prognostic impact of micrometastases in colon cancer: interim results of a prospective multicenter trial.

Objective:The 25% rate of recurrence after complete resection of stage II colon cancer (CC) suggests the presence of occult nodal metastases not identified by hematoxylin and eosin staining (H&E). Interim data from our ongoing prospective multicenter trial of sentinel node (SN) biopsy indicate a 29.6% rate of micrometastases (MM) identified by immunohistochemical staining (IHC) of H&E-negative SNs in CC. We hypothesized that these MM have prognostic importance. Methods:Between March 2001 and August 2006, 152 patients with resectable colorectal cancer were enrolled in the trial. IHC and quantitative RT-PCR (qRT) assay were performed on H&E-negative SNs. Results were correlated with disease-free survival. Results:The sensitivity of lymphatic mapping was significantly better in CC (75%) than rectal cancer (36%), P < 0.05. Of 92 node-negative CC patients 7 (8%) were upstaged to N1 and 18 (22%) had IHC MM. Four patients negative by H&E and IHC were positive by qRT. At a mean follow-up of 25 months, 15 patients had died from noncancer-related causes, 12 had developed recurrence, 5 had died of CC (2 with macrometastases, 3 with MM), and 7 were alive with disease. The 12 recurrences included 4 patients with SN macrometastases and 6 with SN MM (2 by IHC, 4 by qRT). One of the 2 SN-negative recurrences had other positive lymph nodes by H&E. All patients with CC recurrences had a positive SN by either H&E/IHC or qRT. No CC patient with a negative SN by H&E and qRT has recurred (P = 0.002). Conclusion:This is the first prospective evaluation of the prognostic impact of MM in colorectal cancer. These results indicate that the detection of MM may be clinically relevant in CC and may improve the selection of patients for adjuvant systemic chemotherapy. Patients with CC who are node negative by cumulative detection methods (H&E/IHC and qRT) are likely to be cured by surgery alone.

Epigenetic up-regulation of C-C chemokine receptor 7 and C-X-C chemokine receptor 4 expression in melanoma cells.

Histone deacetylation and DNA methylation establish epigenetic modifications, which through chromatin remodeling may result in gene silencing. We hypothesized that chemokine receptors C-C chemokine receptor 7 (CCR7) and C-X-C chemokine receptor 4 (CXCR4) on melanoma cells undergo epigenetic regulation. We investigated whether a histone deacetylase inhibitor and a demethylating agent influence CCR7 and CXCR4 expression on melanoma cells. Initially, microarray analysis was done to screen changes in chemokine receptor expression on melanoma cells after treatment with trichostatin A (TSA) and 5-Aza-2-deoxycytidine (5-Aza). CCR7 and CXCR4 mRNA expression were uniformly altered and selected for further investigation. Quantitative real-time reverse transcription-PCR assay, immunohistochemistry, and Western blot analysis were used to assess changes in mRNA and protein expression induced by TSA and 5-Aza in melanoma lines. Cell migration assays were conducted to assess the effects of altered CCR7 and CXCR4 expression on cell function. Treatment with TSA or 5-Aza increased gene expression of both CCR7 and CXCR4 in melanoma lines. TSA was the strongest enhancer. With combined treatment, CCR7 and CXCR4 mRNA expression was also up-regulated. Immunohistochemistry after combined treatment showed enhanced staining of both CCR7 and CXCR4 compared with control cells. Melanoma cell migration in TSA- and 5-Aza-treated cells was 7- and 2-fold higher than control cells for CCR7 and CXCR4, respectively. In summary, a histone deacetylase inhibitor and a demethylating agent up-regulated CCR7 and CXCR4 expression on melanoma cells. This increase in chemokine receptor expression correlated with functional activity. Most importantly, we have identified an epigenetic mechanism that may endogenously regulate chemokine receptor expression on melanoma cells.

Aberrant hypermethylation of ID4 gene promoter region increases risk of lymph node metastasis in T1 breast cancer

ID4 gene is a member of the inhibitor of DNA-binding (ID) family, which inhibits DNA binding of basic helix–loop–helix transcription factors. Certain human primary breast cancers reportedly have low or no expression of ID4 protein, but its role in carcinogenesis and cancer progression is unknown. To determine its possible role, we examined epigenetic inactivation of ID4 gene by promoter hypermethylation in human breast cell lines and T1 breast cancer tissues. Methylation status of ID4 promoter CpG island was assessed by methylation-specific PCR (MSP); ID4 mRNA level was assessed by quantitative real-time RT–PCR. Of eight cell lines, two were fully methylated, four were partially methylated, and two were not methylated. ID4 mRNA level was suppressed in fully methylated cell lines. ID4 hypermethylation was observed in 16 of 24 (67%) node-positive and seven of 36 (19%) node-negative T1 primary breast cancers matched by patient age and tumor diameter. It was a significant risk factor for nodal metastasis (OR 13.1, P=0.0004). ID4 mRNA level was suppressed in hypermethylated cancer specimens (P=0.014). ID4 may play an important suppressive role in tumor progression, and its silencing by hypermethylation may increase the risk of regional lymph node metastasis.

Detection of circulating tumor cells in early-stage breast cancer metastasis to axillary lymph nodes.

Purpose: Clinical and pathologic prognostic factors do not always accurately predict disease outcome. Patients with early-stage breast cancer may harbor clinically significant but undetected systemic disease. We hypothesized that a multimarker quantitative real-time reverse transcription-PCR (qRT) assay could detect circulating tumor cells (CTC) in patients with early-stage breast cancer and correlate with sentinel lymph node (SLN) and non-SLN metastasis status. Experimental Design: Blood samples from 90 women with the American Joint Committee on Cancer stages I to III breast cancer and 39 age-matched normal healthy volunteers were assessed by qRT for mRNA expression of three markers: stanniocalcin-1 (STC-1), N-acetylgalactosaminyltransferase (GalNacT), and melanoma antigen gene family-A3 (MAGE-A3). CTC biomarker detection was correlated with overall axillary LN (ALN), SLN, and non-SLN histopathology status. Results: CTCs were detected in 39 of 90 (43%) patients, but not in normal volunteers. At least one CTC biomarker was detected in 10 of 35 (29%) stage I patients, 19 of 42 (45%) stage II patients, and 10 of 13 (77%) stage III patients. In multivariate analysis, only lymphovascular invasion and ≥2 CTC biomarkers detected significantly correlated with ALN metastasis [odds ratio (OR), 12.42; 95% confidence interval (95% CI), 3.52-43.77, P < 0.0001; and OR, 3.88; 95% CI, 1.69-8.89, P = 0.001, respectively]. The number of CTC biomarkers detected similarly correlated with SLN and non-SLN metastasis status (P = 0.0004). At least one CTC biomarker was detected in 10 of 11 (91%) patients with non-SLN metastases. Conclusion: The detection of CTCs offers a novel means to assess the presence of systemic disease spreading relative to SLN and ALN histopathology status.

Serial Monitoring of Circulating Melanoma Cells During Neoadjuvant Biochemotherapy for Stage III Melanoma: Outcome Prediction in a Multicenter Trial

PURPOSE Circulating tumor cells (CTCs) in blood may be important in assessing tumor progression and treatment response. We hypothesized that quantitative real-time reverse transcriptase polymerase chain reaction using multimarker mRNA assays could detect CTCs and be used as a surrogate predictor of outcome in patients receiving neoadjuvant biochemotherapy (BC) for melanoma. PATIENTS AND METHODS Blood specimens were collected at four sampling points from 63 patients enrolled on a prospective multicenter phase II trial of BC before and after surgical treatment of American Joint Committee on Cancer stage III melanoma. Each specimen was assessed by quantitative real-time reverse transcriptase polymerase chain reaction for expression of four melanoma-associated markers: melanoma antigen recognized by T cells 1; beta1 --> 4-N-acetylgalactosaminyltransferase; paired box homeotic gene transcription factor 3; and melanoma antigen gene-A3 family, and the changes of CTCs during treatment and prognostic effect of CTCs after overall treatment on recurrence and survival were investigated. RESULTS At a median postoperative follow-up time of 30.4 months, 44 (70%) patients were clinically disease free. In relapse-free patients, the number of detected markers significantly decreased during preoperative BC (P = .036), during postoperative BC (P = .002), and during overall treatment (P < .0001). Marker detection after overall treatment was associated with significant decreases in relapse-free and overall survival (P < .0001). By multivariate analysis using a Cox proportional-hazards model, the number of markers detected after overall treatment was a significant independent prognostic factor for overall survival (risk ratio, 12.6; 95% CI, 3.16 to 50.5; P = .0003). CONCLUSION Serial monitoring of CTCs in blood may be useful for indicating systemic subclinical disease and predicting outcome of patients receiving neoadjuvant BC for metastatic melanoma.

Prognostic Relevance of Occult Nodal Micrometastases and Circulating Tumor Cells in Colorectal Cancer in a Prospective Multicenter Trial

Purpose: Nodal micrometastasis and circulating tumor cells detected by multimarker quantitative real-time reverse transcription-PCR (qRT-PCR) may have prognostic importance in patients with colorectal cancer. Experimental Design: Paraffin-embedded sentinel lymph nodes from 67 patients and blood from 34 of these patients were evaluated in a prospective multicenter trial of sentinel lymph node mapping in colorectal cancer. Sentinel lymph nodes were examined by H&E staining and cytokeratin immunohistochemistry. Sentinel lymph nodes and blood were examined by a four-marker qRT-PCR assay (c-MET, melanoma antigen gene-A3 family, β1→4-N-acetylgalactosaminyltransferase, and cytokeratin-20); qRT-PCR results were correlated with disease stage and outcome. Results: In H&E-negative sentinel lymph node patients that recurred, cytokeratin immunohistochemistry and qRT-PCR detected metastasis in 30% and 60% of patients, respectively. Disease-free survival differed significantly by multimarker qRT-PCR upstaged sentinel lymph node (P = 0.014). qRT-PCR analysis of blood for circulating tumor cells correlated with overall survival (P = 0.040). Conclusion: Molecular assessment for micrometastasis in sentinel lymph node and blood specimens may help identify patients at high risk for recurrent colorectal cancer, who could benefit from adjuvant therapy.

mRNA Expression and BRAF Mutation in Circulating Melanoma Cells Isolated from Peripheral Blood with High Molecular Weight Melanoma-Associated Antigen–Specific Monoclonal Antibody Beads

BACKGROUND The detection of circulating tumor cells (CTCs) in the peripheral blood of melanoma patients by quantitative real-time reverse-transcription PCR (qRT-PCR) analysis correlates with a poor prognosis. The assessment of CTCs from blood has been difficult because of lack of a good monoclonal antibody (mAb) directed against surface cell antigens to capture melanoma cells. METHODS Blood was collected prospectively from 57 melanoma patients (43 test and 14 test-development cases) and 5 healthy donors. High molecular weight melanoma-associated antigen (HMW-MAA)-specific mAbs bound to immunomagnetic beads were used to isolate CTCs. mRNA and/or DNA were extracted from CTCs. Testing for the expression of a melanoma-associated gene panel (MLANA, MAGEA3, and MITF) with qRT-PCR and for the presence of BRAFmt (a BRAF gene variant encoding the V600E mutant protein) verified the beads-isolated CTCs to be melanoma cells. A peptide nucleic acid-clamping PCR assay was used for BRAFmt analysis. RESULTS Spiking of peripheral blood cells (PBCs) with melanoma cells showed that the beads-based detection assay can detect approximately 1 melanoma cell in 5 x 10(6) PBCs. qRT-PCR analysis detected MLANA, MAGEA3, and MITF expression in 19 (44%), 29 (67%), and 19 (44%) of the patients, respectively. At least one biomarker of the panel was positive in 40 (93%) of the 43 melanoma patients. BRAFmt was detected in 17 (81%) of the 21 assessed stage IV melanoma patients. CONCLUSION The assay of bead capture coupled with the PCR has utility for assessing CTCs in melanoma patients, which can then be characterized for both genomic and transcriptome expression.

Microphthalmia Transcription Factor as a Molecular Marker for Circulating Tumor Cell Detection in Blood of Melanoma Patients

PURPOSE: Microphthalmia transcription factor (Mitf), which is important in melanocyte development and melanoma growth, was assessed using real-time quantitative reverse transcription-PCR assay to investigate its expression as a marker for circulating melanoma cells in blood and determine the correlation with disease stage and survival in melanoma patients. EXPERIMENTAL DESIGN: In optimization studies for Mitf, we tested 15 melanoma cell lines, 41 peripheral blood lymphocytes from healthy volunteers, and 21 metastatic melanoma tissues. Blood specimens were procured from 90 patients with stage I (n = 20), stage II (n = 20), stage III (n = 28), and stage IV (n = 22) melanoma. Blood specimens were also obtained at four bleed intervals from 58 patients enrolled in a prospective multicenter trial of biochemotherapy before and after surgical treatment of American Joint Committee on Cancer stage III melanoma. RESULTS: Under the optimized conditions, Mitf was negative in healthy peripheral blood lymphocytes and positive in all melanoma cell lines and 18 (86%) melanoma tissues. In the 90 patients, the rate of Mitf detection was higher with increasing American Joint Committee on Cancer stage (P < 0.0001). In the 58 patients treated with biochemotherapy and surgery, Mitf detection decreased with treatment (P = 0.019). Mitf detection after treatment was associated with a significantly lower relapse-free (P < 0.0001) and overall (P = 0.001) survival and was a significant independent prognostic factor for relapse-free (risk ratio, 5.63; P = 0.0004) and overall (risk ratio, 5.36; P = 0.005) survival. CONCLUSIONS: Mitf detection in blood can indicate subclinical metastatic disease and predict treatment outcome in melanoma patients.

Serial Monitoring of Circulating Tumor Cells Predicts Outcome of Induction Biochemotherapy plus Maintenance Biotherapy for Metastatic Melanoma

Purpose: Molecular biomarkers in blood are promising for assessment of tumor progression and treatment response. We hypothesized that serial monitoring of circulating tumor cells (CTC) with the use of multimarker quantitative real-time reverse transcriptase-PCR assays could be a surrogate predictor of outcome for melanoma patients enrolled in a multicenter phase II clinical trial of biochemotherapy (BCT) combined with maintenance biotherapy (mBT). Experimental Design: Blood specimens were collected from 87 patients before and during induction BCT and mBT for stage IV melanoma. Expression of five melanoma-associated CTC biomarkers (MART-1, GalNAc-T, PAX-3, MAGE-A3, and Mitf) was assessed by quantitative real-time reverse transcriptase-PCR, and correlated with treatment response and disease outcome. Results: The number of positive CTC biomarkers decreased overall during induction BCT (P < 0.0001). CTC biomarker detection after two cycles of BCT was correlated with treatment response (P = 0.005) and overall survival (P = 0.001): an increase in the number of CTC biomarkers was associated with poor response (P = 0.006) and overall survival (P < 0.0001). Multivariate analyses with the use of a Cox proportional hazards model identified the change in CTC biomarkers after two cycles of BCT as an independent prognostic factor for disease progression (risk ratio, 12.6; 95% confidence interval, 4.78-33.4; P < 0.0001) and overall survival (risk ratio, 6.11; 95% confidence interval, 2.37-15.7; P = 0.0005). Conclusion: Serial monitoring of CTC during induction BCT may be useful for predicting therapeutic efficacy and disease outcome in patients receiving BCT and mBT for stage IV melanoma. Clin Cancer Res; 16(8); 2402–8. ©2010 AACR.