Eva Martinez-Balibrea

Pharmacogenetic approach for capecitabine or 5-fluorouracil selection to be combined with oxaliplatin as first-line chemotherapy in advanced colorectal cancer

We studied the role of TS (5VNTR, 5SNP and 3UTR), XRCC1-399, XPD-751, ERCC1-118 and XRCC3-241 genetic polymorphisms in tailoring fluroropyrimidine/oxaliplatin treatment. For this purpose, 110 XELOX (capecitabine/oxaliplatin)- or FUOX (fluorouracil/oxaliplatin)-treated metastatic colorectal cancer patients were selected prospectively for genotyping. In the FUOX group, TS-3UTR +6bp/+6bp (hazards ratio, HR=2.62, p=0.007) and ERCC1-118C/T or C/C (HR=1.96, p=0.050) genotypes correlated with a shorter progression-free survival (PFS). When analysed jointly, the higher the number of favourable genotypes (FG) the longer the PFS (6.8m, 9.6m and 25.8m for 0, 1 or 2 FG; p=0.005). Disease-control rate was 100% in patients with 2 FG (87% and 38.5% for 1 or 0 FG; p=0.001). In the multivariate analysis, ERCC1-118 (HR=2.12, p=0.0037) and TS-3UTR (HR=2.68, p=0.006) were strong independent prognostic factors. According to this, patients harbouring TS-3UTR +6bp/+6bp and ERCC1-118C/T or C/C genotypes may better receive capecitabine instead of 5FU in an oxaliplatin-based first-line treatment.

Weekly regimen of irinotecan/docetaxel in previously treated non-small cell lung cancer patients and correlation with uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) polymorphism.

Purpose: Inherited variations in drug metabolizing enzymes may influence drug efficacy. This phase II study assesses the impact of second-line weekly irinotecan (CPT-11)/docetaxel in non-small cell lung cancer (NSCLC) patients, and gauges the uridine diphosphate glucuronosyl transferase (UGT1A1) polymorphism influence in toxicity and antitumor activity. Experimental Design: Fifty-one patients with NSCLC treated with at least one prior chemotherapy regimen were enrolled. Patients received irinotecan 70u2009mg/m2 followed by docetaxel 25u2009mg/m2. Both drugs were given on days 1, 8, and 15 every 28 days. UGT1A1 polymorphism were analyzed in blood samples of 47 patients. The UGT1A1 polymorphism are classified according to the number of TA repeats in the promoter region of this gene. Results: Three patients (6%) achieved a partial response and nineteen patients (37%) had stable disease. Median survival was 8 months (95% CI: 4.8–11.2) and 1-year survival 30%. Grade 3–4 hematologic toxicity was low (less than 10% of patients); 15% of patients had grade 3 asthenia and 25% of patients had grade 3/4 diarrhea. The frequency of UGT1A1 genotypes was as follows: 6/6 49%, 6/7 36%, and 7/7 15%. No differences in toxicity were observed according to UGT1A1 polymorphism. A nonsignificant improvement in time to progression (4 vs. 3 months) and median survival (11 vs. 8 months) was detected in patients with the variant alleles (6/7 and 7/7). Conclusions: This weekly irinotecan/docetaxel regimen has shown an acceptable toxicity profile while encouraging median and 1-year survival in heavily pretreated NSCLC patients. The tendency to better prognosis in patients carrying the variant genotypes 6/7 and 7/7 of UGT1A1 gene requires further validation.

Curcumin mediates oxaliplatin-acquired resistance reversion in colorectal cancer cell lines through modulation of CXC-Chemokine/NF-κB signalling pathway

Resistance to oxaliplatin (OXA) is a complex process affecting the outcomes of metastatic colorectal cancer (CRC) patients treated with this drug. De-regulation of the NF-κB signalling pathway has been proposed as an important mechanism involved in this phenomenon. Here, we show that NF-κB was hyperactivated in in vitro models of OXA-acquired resistance but was attenuated by the addition of Curcumin, a non-toxic NF-κB inhibitor. The concomitant combination of Curcuminu2009+u2009OXA was more effective and synergistic in cell lines with acquired resistance to OXA, leading to the reversion of their resistant phenotype, through the inhibition of the NF-κB signalling cascade. Transcriptomic profiling revealed the up-regulation of three NF-κB-regulated CXC-chemokines, CXCL8, CXCL1 and CXCL2, in the resistant cells that were more efficiently down-regulated after OXAu2009+u2009Curcumin treatment as compared to the sensitive cells. Moreover, CXCL8 and CXCL1 gene silencing made resistant cells more sensitive to OXA through the inhibition of the Akt/NF-κB pathway. High expression of CXCL1 in FFPE samples from explant cultures of CRC patients-derived liver metastases was associated with response to OXAu2009+u2009Curcumin. In conclusion, we suggest that combination of OXAu2009+u2009Curcumin could be an effective treatment, for which CXCL1 could be used as a predictive marker, in CRC patients.

Epigenetic Homogeneity Within Colorectal Tumors Predicts Shorter Relapse-Free and Overall Survival Times for Patients With Locoregional Cancer

BACKGROUND & AIMSnThere are few validated biomarkers that can be used to predict outcomes for patients with colorectal cancer. Part of the challenge is the genetic and molecular heterogeneity of colorectal tumors not only among patients, but also within tumors. We have explored intratumor heterogeneity at the epigenetic level, due to its dynamic nature. We analyzed DNA methylation profiles of the digestive tract surface and the central bulk and invasive front regions of colorectal tumors.nnnMETHODSnWe determined the DNA methylation profiles of >450,000 CpG sites in 3 macrodissected regions of 79 colorectal tumors and 23 associated liver metastases, obtained from 2 hospitals in Spain. We also analyzed samples for KRAS and BRAF mutations, 499,170 single nucleotide polymorphisms, and performed immunohistochemical analyses.nnnRESULTSnWe observed differences in DNA methylation among the 3 tumor sections; regions of tumor-host interface differed the most from the other tumor sections. Interestingly, tumor samples collected from areas closer to the gastrointestinal transit most frequently shared methylation events with metastases. When we calculated individual coefficients to quantify heterogeneity, we found that epigenetic homogeneity was significantly associated with short time of relapse-free survival (log-rank Pxa0= .037) and short time of overall survival (log-rank Pxa0= .026) in patients with locoregional colorectal cancer.nnnCONCLUSIONSnIn an analysis of 79 colorectal tumors, we found significant heterogeneity in patterns of DNA methylation within each tumor; the level of heterogeneity correlates with times of relapse-free and overall survival.

Antiproliferative effects of ZD0473 (AMD473) in combination with 5-Fluorouracil or SN38 in human colorectal cancer cell lines

Purpose: ZD0473 (AMD473) [cis-amminedichloro(2-methylpyridine) platinum(II)] is a novel platinum agent of proven activity in vitro against a variety of human tumor-derived cell lines even with intrinsic or acquired resistance to CDDP. The aim of this study is to provide the basis for a rational design of ZD0473-based combination in colon cancer. Experimental design: We evaluated the cytotoxic effect of ZD0473 administered alone or in combination with 5-Fluorouracil (5FU) or SN38 in a panel of sensitive and 5FU-resistant colorectal cell lines (HT29/HT29-5FUR and LoVo/LoVo-5FUR). We analyzed four sequential schedules of administration: ZD0473 → 5FU, 5FU → ZD0473, ZD0473 → SN38 and SN38 → ZD0473. MTT-assay and isobologram analyses were performed to determine the synergism/antagonism. Results: The pattern of response towards ZD0473, administered as single agent, was similar in all cases and independent of the 5FU-resistance phenotype (IC50 from 48.1 to 76.6 μM) and/or p53 status. No differences in sensitivity to ZD0473 alone or in combination were observed between DNA-mismatch repair-proficient (HT29/HT29-5FUR) and -deficient (LoVo/LoVo-5FUR) cells. ZD0473 administered prior to 5FU leads to synergistic/additive effect in all cell lines, while the 5FU → ZD047 schedule was only synergistic in HT29 cells. Exposure to ZD0473 prior to SN38 leads to a synergistic/additive schedule in LoVo/LoVo-5FUR cells, while SN38 → ZD0473 schedule was only synergistic in parental cell lines. Conclusions: The combinations of ZD0473 and 5FU or SN38 have shown to be active in sensitive and 5FU-resistant colorectal cell lines when a correct schedule of administration is applied. These results may be further exploited to promote new schedules of administration for advanced colorectal cancer treatment.

Nuclear IGF-1R predicts chemotherapy and targeted therapy resistance in metastatic colorectal cancer

Background:Although chemotherapy is the cornerstone treatment for patients with metastatic colorectal cancer (mCRC), acquired chemoresistance is common and constitutes the main reason for treatment failure. Monoclonal antibodies against insulin-like growth factor-1 receptor (IGF-1R) have been tested in pre-treated mCRC patients, but results have been largely deceiving.Methods:We analysed time to progression, overall survival, and the mutational status of RAS, BRAF and nuclear p-IGF-1R expression by immunohistochemistry, in 470 metastatic CRC patients. The effect of IGF-1R activation and distribution was also assessed using cellular models of CRC and RNAi for functional validation.Results:Nuclear IGF-1R increased in metastatic tumours compared to paired untreated primary tumours, and significantly correlated with poor overall survival in mCRC patients. In vitro, chemo-resistant cell lines presented significantly higher levels of IGF-1R expression within the nuclear compartment, and PIAS3, a protein implicated also in the sumoylation process of intranuclear proteins, contributed to IGF-1R nuclear sequestration, highlighting the essential role of PIAS3 in this process. Intriguingly, we observed that ganitumab, an IGF-1R blocking-antibody used in several clinical trials, and dasatinib, an SRC inhibitor, increased the nuclear localisation of IGF-1R.Conclusions:Our study demonstrates that IGF-1R nuclear location might lead to chemotherapy and targeted agent resistance.

Biología molecular del cáncer colorrectal

Resumen La biologia molecular del cancer colorrectal (CCR) abarca una amplisima variedad de aspectos que van desde la conocida teoria de las etapas multiples del desarrollo del tumor y los sindromes hereditarios hasta la aplicacion al tratamiento de determinantes moleculares de sensibilidad y resistencia a citostaticos. En el cancer hereditario cabe destacar las dos vias de la herencia, la via supresora mediada por el gen supresor APC de la poliposis multiple familiar y la via mutadora mediada por la mutacion en genes reparadores y conocida como sindrome de Lynch. No cabe duda del interes de los aspectos de la carcinogenesis y la herencia, pero donde mayor importancia alcanza la biologia molecular del CCR en el momento actual es en su aportacion al pronostico y tratamiento de los pacientes. Genes tan importantes como el oncogen k-ras nos proporcionaran informacion pronostica sobre la agresividad y capacidad de recaida y metastasis, informacion que podemos completar con el analisis de la inestabilidad alelica (chromosomyc imbalance) en determinados cromosomas como 8p y 18q, y tambien con la determinacion de los titulos de expresion de timidilato sintetasa. A nuestro entender, todavia es mas importante la aportacion que hace al tratamiento el analisis de la expresion de genes implicados en los mecanismos de reparacion del ADN, como ERCC1, y en los mecanismos de accion de citostaticos y el conocimiento de determinados polimorfismos geneticos tales como TS, UGT1A1, XRCC1, XPD, que van a modificar la sensibilidad o resistencia a determinados farmacos y que seran tratados ampliamente en esta revision.