Efficacy of Recombinant Methioninase on Late-stage Patient Cancer in the Histoculture Drug Response Assay (HDRA) as a Potential Functional Biomarker of Sensitivity to Methionine-restriction Therapy in the Clinic.

Background/Aim: The present study utilized the three-dimensional histoculture drug response assay (HDRA) to determine the efficacy of recombinant methioninase (rMETase) on tumor tissue resected from patients with late-stage cancer, as a functional biomarker of sensitivity to methionine restriction therapy. Patients and Methods: Resected peritoneal-metastatic cancer, including colorectal cancer, pancreatic cancer, ovarian cancer, and pseudomyxoma were placed on Gelform in RPMI 1640 medium for seven days and treated with rMETase from 2.5 U/ml to 20 U/ml. Cell viability was determined using the MTT assay. A total of 48 patients with late-stage cancer underwent testing for rMETase responsiveness using the HDRA. Results: Colorectal cancer and pseudomyxoma had the highest sensitivity to rMETase. Pancreatic and ovarian cancer also responded to rMETase, but to a lesser degree. Conclusion: Patients with tumors with at least 40% sensitivity to rMETase in the HDRA are being considered as candidates for methionine restriction therapy, which includes the use of rMETase in combination with a low-methionine diet.

CHFR-Promoter-Methylation Status Is Predictive of Response to Irinotecan-based Systemic Chemotherapy in Advanced Colorectal Cancer.

BACKGROUND/AIM: We investigated whether promoter methylation of the checkpoint-with-forkhead-and-ring-finger-domains (CHFR) gene is a predictor of the efficacy of irinotecan-based systemic chemotherapy for advanced colorectal cancer (CRC) patients. MATERIALS AND METHODS: CHFR-promoter methylation was measured by quantitative methylation-specific PCR (qMSP). The histoculture drug response assay (HDRA) was used in vitro to analyze the correlation between CHFR-promoter methylation and the efficacy of the irinotecan-active-metabolite SN38 in colorectal-cancer tissues from 44 CRC patients. CHFR promoter-methylation was also analyzed for its correlation with clinical response to irinotecan-based systemic chemotherapy of 49 CRC patients. RESULTS: CHFR-promoter methylation significantly-positively correlated with inhibition of colon cancer by SN38 in the HDRA (p=0.002). CHFR-promoter methylation also significantly-positively correlated with clinical response to irinotecan-based systemic chemotherapy (p=0.04 for disease control). CHFR-promoter methylation also significantly-positively correlated (p=0.01) with increased progression-free survival for patients treated with irinotecan-containing FLOFIRI in combination with bevacizumab, the most-frequent regimen in the cohort. CONCLUSION: Sensitivity of advanced CRC patients to irinotecan-based systemic chemotherapy can be predicted by the extent of CHFR-promoter methylation.

Can the Histoculture Drug Response Assay Predict the Clinical Results of Chemotherapy in Breast Cancer? / 한국유방암학회지

PURPOSE: The behavior of invasive carcinomas in human can be very varied with different individual responses to chemotherapy. Individualization is crucial to the optimization of chemotherapy. Therefore, the prediction of a tumor's sensitivity to anticancer agents has been the subject of intensive investigation. In order to investigate the pathobiology of breast cancer, it is necessary to maintain or recreate the characteristics of the three-dimensional architecture of the tissues in culture. In this study, we have evaluated the relationship between the Histoculture Drug Response Assay (HDRA) assessment and chemotherapy responses in breast cancer patients. METHODS: Tumor specimens from 30 patients with breast cancer were evaluated using the HDRA. Tumor tissues were cultured on gelfoam sponge gel in 24-well plates, followed by treatment with a variety of chemotherapeutic agents. All treatments were conducted in triplicate. The sensitivity of a chemotherapy regimen was defined as a tumor inhibition rate (IR) in excess of 30%. Neoadjuvant or palliative chemotherapy for patients, using anthracycline or taxane, was conducted on the basis of the established protocols. The responses to treatments were compared with the results of the HDRA. RESULTS: The mean IR for the combinations of doxorubicin and docetaxel and for FAC and AC were 48, 45, and 36%, respectively. The above partial rate of response to chemotherapy was 81.1%. The sensitivity and specificity of the HDRA assessment, with a 30% inhibition rate, were 81.5 and 66.7%, respectively. The positive and negative response prediction values were 91.7 and 44.4%, respectively. The responses to treatments and the results of the HDRA assessment were not correlated with the expressions of the hormonal receptor or c-erbB2. CONCLUSION: In cases in which the inhibition rate is in excess of 30%, the HDRA assessment yielded a high positive response prediction value. The sensitivity to chemotherapy, as determined by the HDRA, appears to be a good guide for selection in breast cancer patients. Thus the results presented herein should be integrated into future research on the subject.

Can the Histoculture Drug Response Assay Predict the Clinical Results of Chemotherapy in Breast Cancer? / 한국유방암학회지

PURPOSE: The behavior of invasive carcinomas in human can be very varied with different individual responses to chemotherapy. Individualization is crucial to the optimization of chemotherapy. Therefore, the prediction of a tumor's sensitivity to anticancer agents has been the subject of intensive investigation. In order to investigate the pathobiology of breast cancer, it is necessary to maintain or recreate the characteristics of the three-dimensional architecture of the tissues in culture. In this study, we have evaluated the relationship between the Histoculture Drug Response Assay (HDRA) assessment and chemotherapy responses in breast cancer patients. METHODS: Tumor specimens from 30 patients with breast cancer were evaluated using the HDRA. Tumor tissues were cultured on gelfoam sponge gel in 24-well plates, followed by treatment with a variety of chemotherapeutic agents. All treatments were conducted in triplicate. The sensitivity of a chemotherapy regimen was defined as a tumor inhibition rate (IR) in excess of 30%. Neoadjuvant or palliative chemotherapy for patients, using anthracycline or taxane, was conducted on the basis of the established protocols. The responses to treatments were compared with the results of the HDRA. RESULTS: The mean IR for the combinations of doxorubicin and docetaxel and for FAC and AC were 48, 45, and 36%, respectively. The above partial rate of response to chemotherapy was 81.1%. The sensitivity and specificity of the HDRA assessment, with a 30% inhibition rate, were 81.5 and 66.7%, respectively. The positive and negative response prediction values were 91.7 and 44.4%, respectively. The responses to treatments and the results of the HDRA assessment were not correlated with the expressions of the hormonal receptor or c-erbB2. CONCLUSION: In cases in which the inhibition rate is in excess of 30%, the HDRA assessment yielded a high positive response prediction value. The sensitivity to chemotherapy, as determined by the HDRA, appears to be a good guide for selection in breast cancer patients. Thus the results presented herein should be integrated into future research on the subject.

Histoculture Drug Response Assay in Colorectal Cancer Specimen

PURPOSE: For decades, systemic medical treatment for colorectal cancer has been limited almost entirely to 5- fluorouracil (5-FU). In cases of advanced colorectal cancer, the response rate to standard 5-FU regimen was lower than 20%. Recently, new drugs that have another action mechanism have been introduced-irinotecan, oxaliplatin, raltitrexed, capecitabine, etc. Clinicians have to choose the appropriate drug for advanced cases. Until recently, choice of chemotherapeutic agents was based on the experience of clinicians, or on retrospective or prospective clinical trial reports. In this study, we performed HDRA (histoculture drug response assay) to assess the effectiveness of chemotherapeutic agents in colorectal cancer. METHODS: Tumor specimens of 33 colorectal cancers were collected in 15 ml tubes containing PBS buffer. Tissues were minced using an autoclaved knife and histocultured on collagen sponge gel matrix, followed by treatment with 5-FU, 5-FU & leucovorin, oxaliplatin, oxaliplatin & 5-FU, irinotecan, or irinotecan & 5-FU. After 48 hours, cell viability was assessed by MTT assay. The inhibition rate of each drug was calculated for relative survival. Cases of drug responsibility below 30% were regarded as drug resistant cases. RESULTS: Thirty cases were tested. Three cases had synchronous lesion. Thirty-three tissues were evaluated using HDRA. Seventeen cases (53.3%) were rectal cancer. The initial 6 cases were tested using a single agent the other 27 cases were tested using combined agents. The regimen showing the best responses was oxaliplatin with 5-FU (8/26 cases, 30.8%). Seven cases were regarded as chemoresistant cases because they showed low IR below 30% for all agents. Synchronous lesions showed similar drug responses. CONCLUSION: HDRA is relatively simple and easily applicable to in vitro study to determine the appropriate chemotherapeutic agents. Further study is necessary to assess the effectiveness including tumor recurrence and survival.