Line Schmidt Tarpgaard

Primary tumor location and bevacizumab effectiveness in patients with metastatic colorectal cancer

BACKGROUND There is an unmet need for predictive markers for the antiangiogenic agent bevacizumab in metastatic colorectal cancer (mCRC). We aimed to assess whether the location of the primary tumor is associated with bevacizumab effectiveness when combined with capecitabine and oxaliplatin (CAPEOX) in the first-line treatment of patients with mCRC. PATIENTS AND METHODS A cohort of 667 consecutive patients with mCRC from the general community treated from 2006 to 2011 with CAPEOX and bevacizumab as standard first-line therapy was compared with a cohort of 213 patients treated with CAPEOX from 2003 to 2006, before bevacizumab was approved. Main outcome measures were progression-free survival (PFS) and overall survival (OS). Differences in outcome were tested using Kaplan-Meier curves and log-rank tests, and multivariate analyses were carried out using Cox Proportional Hazards models. RESULTS Patients treated with CAPEOX and bevacizumab with primary tumors originating in the sigmoid colon and rectum had a significantly better outcome than patients with primary tumors originating from the cecum to the descending colon, both for PFS (median PFS 9.3 versus 7.2 months; hazard ratio (HR) 0.68, 95% confidence interval (CI) 0.56-0.82) and for OS (median OS 23.5 versus 13.0 months; HR 0.47, 95% CI 0.38-0.57). This difference was confirmed in multivariate analyses after adjustment for other potentially prognostic factors. For patients treated with CAPEOX, there was no association between primary tumor location and outcome, neither in unadjusted nor adjusted analyses. CONCLUSIONS The addition of bevacizumab to CAPEOX in first-line treatment of patients with mCRC may primarily benefit patients with primary tumors originating in the rectum and sigmoid colon. This hypothesis needs to be validated in data from completed randomized trials. CLINICALTRIALSGOV IDENTIFICATION NUMBER NCT00212615.

High expression of microRNA-625-3p is associated with poor response to first-line oxaliplatin based treatment of metastatic colorectal cancer

The backbone of current cytotoxic treatment of metastatic colorectal cancer (mCRC) consists of a fluoropyrimidine together with either oxaliplatin (XELOX/FOLFOX) or irinotecan (XELIRI/FOLFIRI). With an overall objective response rate of approximately 50% for either treatment combination, a major unsolved problem is that no predictors of response to these treatments are available. To address this issue, we profiled 742 microRNAs in laser‐capture microdissected cancer cells from responding and non‐responding patients receiving XELOX/FOLFOX as first‐line treatment for mCRC, and identified, among others, high expression of miR‐625‐3p, miR‐181b and miR‐27b to be associated with poor clinical response. In a validation cohort of 94 mCRC patients treated first‐line with XELOX, high expression of miR‐625‐3p was confirmed to be associated with poor response (OR = 6.25, 95%CI [1.8; 21.0]). Independent analyses showed that miR‐625‐3p was not dysregulated between normal and cancer samples, nor was its expression associated with recurrence of stage II or III disease, indicating that miR‐625‐3p solely is a response marker. Finally, we also found that these miRNAs were up‐regulated in oxaliplatin resistant HCT116/oxPt (miR‐625‐3p, miR‐181b and miR‐27b) and LoVo/oxPt (miR‐181b) colon cancer cell lines as compared with their isogenic parental cells. Altogether, our results suggest an association between miR‐625‐3p and response to first‐line oxaliplatin based chemotherapy of mCRC.

Tissue MicroRNAs as Predictors of Outcome in Patients with Metastatic Colorectal Cancer Treated with First Line Capecitabine and Oxaliplatin with or without Bevacizumab

Purpose We tested the hypothesis that expression of microRNAs (miRNAs) in cancer tissue can predict effectiveness of bevacizumab added to capecitabine and oxaliplatin (CAPEOX) in patients with metastatic colorectal cancer (mCRC). Experimental Design Patients with mCRC treated with first line CAPEOX and bevacizumab (CAPEOXBEV): screening (n = 212) and validation (n = 121) cohorts, or CAPEOX alone: control cohort (n = 127), were identified retrospectively and archival primary tumor samples were collected. Expression of 754 miRNAs was analyzed in the screening cohort using polymerase chain reaction (PCR) arrays and expression levels were related to time to disease progression (TTP) and overall survival (OS). Significant miRNAs from the screening study were analyzed in all three cohorts using custom PCR arrays. In situ hybridization (ISH) was done for selected miRNAs. Results In the screening study, 26 miRNAs were significantly correlated with outcome in multivariate analyses. Twenty-two miRNAs were selected for further study. Higher miR-664-3p expression and lower miR-455-5p expression were predictive of improved outcome in the CAPEOXBEV cohorts and showed a significant interaction with bevacizumab effectiveness. The effects were strongest for OS. Both miRNAs showed high expression in stromal cells. Higher expression of miR-196b-5p and miR-592 predicted improved outcome regardless of bevacizumab treatment, with similar effect estimates in all three cohorts. Conclusions We have identified potentially predictive miRNAs for bevacizumab effectiveness and additional miRNAs that could be related to chemotherapy effectiveness or prognosis in patients with mCRC. Our findings need further validation in large cohorts, preferably from completed randomized trials.

Establishment and characterization of models of chemotherapy resistance in colorectal cancer: Towards a predictive signature of chemoresistance

Current standard treatments for metastatic colorectal cancer (CRC) are based on combination regimens with one of the two chemotherapeutic drugs, irinotecan or oxaliplatin. However, drug resistance frequently limits the clinical efficacy of these therapies. In order to gain new insights into mechanisms associated with chemoresistance, and departing from three distinct CRC cell models, we generated a panel of human colorectal cancer cell lines with acquired resistance to either oxaliplatin or irinotecan. We characterized the resistant cell line variants with regards to their drug resistance profile and transcriptome, and matched our results with datasets generated from relevant clinical material to derive putative resistance biomarkers. We found that the chemoresistant cell line variants had distinctive irinotecan‐ or oxaliplatin‐specific resistance profiles, with non‐reciprocal cross‐resistance. Furthermore, we could identify several new, as well as some previously described, drug resistance‐associated genes for each resistant cell line variant. Each chemoresistant cell line variant acquired a unique set of changes that may represent distinct functional subtypes of chemotherapy resistance. In addition, and given the potential implications for selection of subsequent treatment, we also performed an exploratory analysis, in relevant patient cohorts, of the predictive value of each of the specific genes identified in our cellular models.

miR-625-3p regulates oxaliplatin resistance by targeting MAP2K6-p38 signalling in human colorectal adenocarcinoma cells

Oxaliplatin resistance in colorectal cancers (CRC) is a major medical problem, and predictive markers are urgently needed. Recently, miR-625-3p was reported as a promising predictive marker. Herein, we show that miR-625-3p functionally induces oxaliplatin resistance in CRC cells, and identify the signalling networks affected by miR-625-3p. We show that the p38 MAPK activator MAP2K6 is a direct target of miR-625-3p, and, accordingly, is downregulated in non-responder patients of oxaliplatin therapy. miR-625-3p-mediated resistance is reversed by anti-miR-625-3p treatment and ectopic expression of a miR-625-3p insensitive MAP2K6 variant. In addition, reduction of p38 signalling by using siRNAs, chemical inhibitors or expression of a dominant-negative MAP2K6 protein induces resistance to oxaliplatin. Transcriptome, proteome and phosphoproteome profiles confirm inactivation of MAP2K6-p38 signalling as one likely mechanism of oxaliplatin resistance. Our study shows that miR-625-3p induces oxaliplatin resistance by abrogating MAP2K6-p38-regulated apoptosis and cell cycle control networks, and corroborates the predictive power of miR-625-3p.

Plasma YKL-40 in Patients with Metastatic Colorectal Cancer Treated with First Line Oxaliplatin-Based Regimen with or without Cetuximab: RESULTS from the NORDIC VII Study

Background We aim to test the hypothesis that high plasma YKL-40 is associated with short progression-free survival (PFS) and overall survival (OS) in patients with metastatic colorectal cancer (mCRC) treated with first-line oxaliplatin and 5-flourouracil with or without cetuximab. Patients and Methods A total of 566 patients in the NORDIC VII Study were randomized 1∶1∶1 to arm A (Nordic FLOX), arm B (Nordic FLOX + cetuximab), or arm C (Nordic FLOX + cetuximab for 16 weeks followed by cetuximab alone as maintenance therapy). Pretreatment plasma samples were available from 510 patients. Plasma YKL-40 was determined by ELISA and dichotomized according to the age-corrected 95% YKL-40 level in 3130 healthy subjects. Results Pretreatment plasma YKL-40 was elevated in 204 patients (40%), and median YKL-40 was higher in patients with mCRC than in healthy subjects (age adjusted, P<0.001). Patients with elevated YKL-40 had shorter PFS than patients with normal YKL-40 (7.5 vs. 8.2 months; hazard ratio (HR)  = 1.27 95% confidence interval (CI) 1.05–1.53 P = 0.013) and shorter OS (16.8 vs. 23.9 months; HR = 1.33, 1.04–1.69, P = 0.024). Multivariate Cox analysis demonstrated that elevated pretreatment YKL-40 was an independent biomarker of short OS (HR = 1.12, 1.01–1.25, P = 0.033). The ratio of the updated plasma YKL-40 (i.e. level after 1, 2, 8 weeks of treatment, and at end of treatment compared to the baseline level) was associated with OS (HR = 1.27, 1.06–1.52, P = 0.011). Conclusions Plasma YKL-40 is an independent prognostic biomarker in patients with mCRC treated with first-line oxaliplatin-based therapy alone or combined with cetuximab.

The potential role of Alu Y in the development of resistance to SN38 (Irinotecan) or oxaliplatin in colorectal cancer.

BackgroundIrinotecan (SN38) and oxaliplatin are chemotherapeutic agents used in the treatment of colorectal cancer. However, the frequent development of resistance to these drugs represents a considerable challenge in the clinic. Alus as retrotransposons comprise 11% of the human genome. Genomic toxicity induced by carcinogens or drugs can reactivate Alus by altering DNA methylation. Whether or not reactivation of Alus occurs in SN38 and oxaliplatin resistance remains unknown.ResultsWe applied reduced representation bisulfite sequencing (RRBS) to investigate the DNA methylome in SN38 or oxaliplatin resistant colorectal cancer cell line models. Moreover, we extended the RRBS analysis to tumor tissue from 14 patients with colorectal cancer who either did or did not benefit from capecitabine + oxaliplatin treatment. For the clinical samples, we applied a concept of ‘DNA methylation entropy’ to estimate the diversity of DNA methylation states of the identified resistance phenotype-associated methylation loci observed in the cell line models. We identified different loci being characteristic for the different resistant cell lines. Interestingly, 53% of the identified loci were Alu sequences- especially the Alu Y subfamily. Furthermore, we identified an enrichment of Alu Y sequences that likely results from increased integration of new copies of Alu Y sequence in the drug-resistant cell lines. In the clinical samples, SOX1 and other SOX gene family members were shown to display variable DNA methylation states in their gene regions. The Alu Y sequences showed remarkable variation in DNA methylation states across the clinical samples.ConclusionOur findings imply a crucial role of Alu Y in colorectal cancer drug resistance. Our study underscores the complexity of colorectal cancer aggravated by mobility of Alu elements and stresses the importance of personalized strategies, using a systematic and dynamic view, for effective cancer therapy.

Intact and cleaved plasma soluble urokinase receptor in patients with metastatic colorectal cancer treated with oxaliplatin with or without cetuximab

Circulating forms of the urokinase plasminogen activator receptor (uPAR) are associated with prognosis in patients with colorectal cancer. Preclinical studies have shown that uPAR can influence the state of phosphorylation and signalling activity of the epidermal growth factor receptor (EGFR) in a ligand‐independent manner. The purpose of the study was to evaluate whether plasma soluble intact and cleaved uPAR(I‐III)+(II‐III) levels could identify a subpopulation of patients with metastatic colorectal cancer (mCRC) where treatment with cetuximab would have a beneficial effect. Plasma samples were available from 453 patients treated in the NORDIC VII study. Patients were randomized between FLOX and FLOX + cetuximab. The levels of uPAR(I‐III)+(II‐III) were determined by time‐resolved fluorescence immunoassay. We demonstrated that higher baseline plasma uPAR(I‐III)+(II‐III) levels were significantly associated with shorter progression‐free survival (PFS) (HR = 1.30, 1.14–1.48, p = 0.0001) and overall survival (OS) (HR = 1.75, 1.52–2.02, p < 0.0001). Multivariate Cox analysis showed that plasma uPAR(I‐III)+(II‐III) was an independent biomarker of short OS (HR = 1.45, 1.20–1.75, p = 0.0001). There were no significant interactions between plasma uPAR(I‐III)+(II‐III) levels, KRAS mutational status and treatment either PFS (p = 0.43) or OS (p = 0.095). However, further explorative analyses indicated that patients with low levels of circulating suPAR and a KRAS wild‐type tumor have improved effect from treatment with FLOX + cetuximab as compared to patients with KRAS wild‐type and high levels of suPAR. These results thus support the preclinical findings and should be further tested in an independent clinical data set.

TIMP-1 is under regulation of the EGF signaling axis and promotes an aggressive phenotype in KRAS -mutated colorectal cancer cells: a potential novel approach to the treatment of metastatic colorectal cancer

It is now widely accepted that therapeutic antibodies targeting epidermal growth factor receptor (EGFR) can have efficacy in KRAS wild-type advanced colorectal cancer (CRC) patients. What remains to be ascertained is whether a subgroup of KRAS-mutated CRC patients might not also derive benefit from EGFR inhibitors. Metalloproteinase inhibitor 1 (TIMP-1) is a pleiotropic factor predictive of survival outcome of CRC patients. Levels of TIMP-1 were measured in pre-treatment plasma samples (n = 426) of metastatic CRC patients randomized to Nordic FLOX (5-fluorouracil and oxaliplatin) +/− cetuximab (NORDIC VII study). Multivariate analysis demonstrated a significant interaction between plasma TIMP-1 protein levels, KRAS status and treatment with patients bearing KRAS mutated tumors and high TIMP-1 plasma level (> 3rd quartile) showing a significantly longer overall survival if treated with cetuximab (HR, 0.48; 95% CI, 0.25 to 0.93). To gain mechanistic insights into this association we analyzed a set of five different CRC cell lines. We show here that EGFR signaling induces TIMP-1 expression in CRC cells, and that TIMP-1 promotes a more aggressive behavior, specifically in KRAS mutated cells. The two sets of data, clinical and in vitro, are complementary and support each other, lending strength to our contention that TIMP- 1 plasma levels can identify a subset of patients with KRAS-mutated metastatic CRC that will have benefit from EGFR-inhibition therapy.

Abstract 1157: MicroRNA-625-3p is associated with response to first-line oxaliplatin-based treatment of metastatic colorectal cancer.

The backbone of current oncologic treatment of metastatic colorectal cancer (mCRC) consists of fluoropyrimidine together with either oxaliplatin (XELOX/FOLFOX) or irinotecan (XELIRI/FOLFIRI). With an overall objective response rate of approximately 50% for either treatment combination, a major unsolved problem is that no predictors of response to these treatments currently are available. To address this issue, we profiled 742 microRNAs in laser-capture microdissected cancer cells from responding and non-responding patients receiving XELOX/FOLFOX as first-line treatment for mCRC, and identified, among others, high expression of miR-625-3p, miR-181b and miR-27b to be associated with poor clinical response. In a validation cohort of 98 mCRC patients treated first-line with XELOX, high expression of miR-625-3p was confirmed to be associated with poor response (OR 6.25, 95%CI OR [1.8; 21.0]). Independent analyses showed that miR-625-3p was not dysregulated between normal and cancer samples, nor was its expression associated with recurrence of stage II or III disease, indicating that miR-625-3p solely is a response marker. Finally, we also found that these miRNAs are up-regulated in oxaliplatin resistant HCT116/oxPt (miR-625-3p, miR-181b and miR-27b) and LoVo/oxPt (miR-181b) CRC cell lines as compared with their isogenic parental cells. Altogether, our results suggest an association between miR-625-3p and response to first-line oxaliplatin based chemotherapy of mCRC. Citation Format: Mads H. Rasmussen, Niels F. Jensen, Line S. Tarpgaard, Camilla Qvortrup, Maria U. Romer, Jan Stenvang, Tine P. Hansen, Lise-Lotte Christensen, Jan Lindebjerg, Flemming Hansen, Benny V. Jensen, Torben F. Hansen, Anders M. Jakobsen, Per Pfeiffer, Nils Brunner, Torben F. Orntoft, Claus L. Andersen. MicroRNA-625-3p is associated with response to first-line oxaliplatin-based treatment of metastatic colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1157. doi:10.1158/1538-7445.AM2013-1157