Platinum-derived drugs such as cisplatin and carboplatin are among the most commonly used cancer chemotherapy drugs, but very few specific molecular and cellular markers predicting differential sensitivity to these agents in a given tumor type have been clearly identified. Epigenetic gene silencing is increasingly being recognized as a factor conferring distinct tumoral drug sensitivity, so we have used a comprehensive DNA methylation microarray platform to interrogate the widely characterized NCI60 panel of human cancer cell lines with respect to CpG methylation status and cisplatin/carboplatin sensitivity. Using this approach, we have found promoter CpG island hypermethylation-associated silencing of the putative DNA/RNA helicase Schlafen-11 (SLFN11) to be associated with increased resistance to platinum compounds. We have also experimentally validated these findings in vitro. In this setting, we also identified the BRCA1 interacting DHX9 RNA helicase (also known as RHA) as a protein partner for SLFN11, suggesting a mechanistic pathway for the observed chemoresistance effect. Most importantly, we have been able to extend these findings clinically, following the observation that those patients with ovarian and non-small cell lung cancer carrying SLFN11 hypermethylation had a poor response to both cisplatin and carboplatin treatments. Overall, these results identify SLFN11 epigenetic inactivation as a predictor of resistance to platinum drugs in human cancer.

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Background:Infusional fluorouracil/leucovorin (FU/LV) plus irinotecan (FOLFIRI) is one of the standard first-line options for patients with metastatic colorectal cancer (mCRC). Irinotecan is converted into 7-ethyl-10-hydroxycamptothecin (SN-38) by a carboxylsterase and metabolised through uridine diphosphate glucuronosyl transferase (UGT1A1). The UGT1A1*28 allele has been associated with the risk of developing severe toxicities. The present trial was designed to define the maximum tolerated dose according to UGT1A1 genotype. This report focuses on the results of tolerance to different escalated doses of FOLFIRI first-line of chemotherapy.Patients and methods:Patients undergoing first-line treatment for mCRC and eligible for treatment with FOLFIRI were classified according to UGT1A1 genotype. A total of 94 patients were eligible for dose escalation of irinotecan. The starting dose of biweekly irinotecan was 180 mg m−2 for the *1/*1, 110 mg m−2 for the *1/*28 and 90 mg m−2 for the *28/*28 genotypes.Results:The dose of irinotecan was escalated to 450 mg m−2 in patients with the *1/*1 genotype, to 390 mg m−2 in those with the *1/*28 genotype and to 150 mg m−2 in those with the *28/*28 genotype. Neutropenia and diarrhoea were the most common grade 3 or 4 toxicities.Conclusions:Our results demonstrated that the recommended dose of 180 mg m−2 for irinotecan in FOLFIRI is considerably lower than the dose that can be tolerated for patients with the UGT1A1 *1/*1 and *1/*28 genotypes. The maximum tolerable dose (MTD) in patients with a high-risk UGT1A1 *28/*28 genotype is 30% lower than the standard dose of 180 mg m−2.

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The Salvador-Warts-Hippo pathway controls cell fate and tissue growth. The main function of the Hippo pathway is to prevent YAP and TAZ translocation to the nucleus where they induce the transcription of genes involved in cell proliferation, survival, and stem cell maintenance. Hippo signaling is thus a complex tumor suppressor, and its deregulation is a key feature in many cancers. Recent mounting evidence suggests that the overexpression of Hippo components can be useful prognostic biomarkers. Moreover, Hippo signaling appears to be intimately linked to some of the most important signaling pathways involved in cancer development and progression. A better understanding of the Hippo pathway is thus essential to untangle tumor biology and to develop novel anticancer therapies. Here, we comment on the progress made in understanding Hippo signaling and its connections, and also on how new drugs modulating this pathway, such as Verteporfin and C19, are highly promising cancer therapeutics.

BackgroundPatients harbouring the UGT1A1*28/*28 genotype are at risk of severe toxicity with the standard irinotecan dose. However, this dose is considerably lower than the dose that can be tolerated by UGT1A1*1/*1 and *1/*28 patients. This randomised phase II trial evaluated the efficacy and safety of the FOLFIRI regimen with high-dose irinotecan (HD-FOLFIRI) in metastatic colorectal cancer patients.MethodsEighty-two patients with the UGT1A1*1/*1 or the *1/*28 genotype were randomised to receive HD-FOLFIRI versus FOLFIRI. Patients with the UGT1A1*28/*28 genotype were excluded. In the experimental group, the irinotecan dose was 300 mg/m2 for UGT1A1*1/*1 and 260 mg/m2 for *1/*28 patients. In the control group, the dose was 180 mg/m2. We analysed the overall response rate (ORR), toxicity, and survival.ResultsThe ORR was significantly higher in the HD-FOLFIRI group (67.5 versus 43.6%; p = 0.001 OR: 1.73 [95% CI:1.03–2.93]). Neutropenia (17.7%), diarrhoea (5.1%), and asthenia (5.1%) were the most common grade 3–4 toxicity. No differences were observed in severe toxicity (22.5% versus 20.5%), dose reduction (22.5% versus 28.2%), or prophylactic G-CSF (17.5% versus 12.8%). No difference in survival was found.ConclusionsPatients with the UGT1A1*1/*1 and *1/*28 genotypes can receive high doses of irinotecan to achieve a more favourable ORR without significant adverse events.

Background: Gastrointestinal stromal tumor (GIST) initiation and evolution is commonly framed by KIT/PDGFRA oncogenic activation, and in later stages by the polyclonal expansion of resistant subpopulations harboring KIT secondary mutations after the onset of imatinib resistance. Thus, circulating tumor (ct)DNA determination is expected to be an informative non-invasive dynamic biomarker in GIST patients. Methods: We performed amplicon-based next-generation sequencing (NGS) across 60 clinically relevant genes in 37 plasma samples from 18 GIST patients collected prospectively. ctDNA alterations were compared with NGS of matched tumor tissue samples (obtained either simultaneously or at the time of diagnosis) and cross-validated with droplet digital PCR (ddPCR). Results: We were able to identify cfDNA mutations in five out of 18 patients had detectable in at least one timepoint. Overall, NGS sensitivity for detection of cell-free (cf)DNA mutations in plasma was 28.6%, showing high concordance with ddPCR confirmation. We found that GIST had relatively low ctDNA shedding, and mutations were at low allele frequencies. ctDNA was detected only in GIST patients with advanced disease after imatinib failure, predicting tumor dynamics in serial monitoring. KIT secondary mutations were the only mechanism of resistance found across 10 imatinib-resistant GIST patients progressing to sunitinib or regorafenib. Conclusions: ctDNA evaluation with amplicon-based NGS detects KIT primary and secondary mutations in metastatic GIST patients, particularly after imatinib progression. GIST exhibits low ctDNA shedding, but ctDNA monitoring, when positive, reflects tumor dynamics.

Epidermal growth factor receptor (EGFR) activation by radiation leads to increased cell proliferation and acts as a radioresistance mechanism. Neoadjuvant chemoradiation is the standard of care for locally advanced rectal cancer, and to date, no biomarkers of response have been found. We analyzed polymorphisms in the EGFR and its ligands, DNA repair genes and the thymidylate synthase in 84 stages II and III rectal cancer patients treated with neoadjuvant capecitabine plus radiotherapy. The rs11942466 polymorphism in the amphiregulin (AREG) gene region was associated with a pathological complete response (ypCR) (odds ratio: 0.26; 95% confidence interval: 0.06-0.79; P=0.014). The rs11615 C>T polymorphism in the ERCC1 gene also correlated with the ypCR as no patients with a C/C genotype achieved ypCR; P=0.023. This is the first work to propose variants within the AREG and the ERCC1 genes as promising predictive biomarkers of ypCR in rectal cancer.