Establishment of patient-derived tumor organoids to functionally inform treatment decisions in metastatic colorectal cancer.

BACKGROUND: Metastatic colorectal cancer (mCRC) patients tend to have modest benefits from molecularly driven therapeutics. Patient-derived tumor organoids (PDTOs) represent an unmatched model to elucidate tumor resistance to therapy, due to their high capacity to resemble tumor characteristics. MATERIALS AND METHODS: We used viable tumor tissue from two cohorts of patients with mCRC, naïve or refractory to treatment, respectively, for generating PDTOs. The derived models were subjected to a 6-day drug screening assay (DSA) with a comprehensive pipeline of chemotherapy and targeted drugs against almost all the actionable mCRC molecular drivers. For the second cohort DSA data were matched with those from PDTO genotyping. RESULTS: A total of 40 PDTOs included in the two cohorts were derived from mCRC primary tumors or metastases. The first cohort included 31 PDTOs derived from patients treated in front line. For this cohort, DSA results were matched with patient responses. Moreover, RAS/BRAF mutational status was matched with DSA cetuximab response. Ten out of 12 (83.3%) RAS wild-type PDTOs responded to cetuximab, while all the mutant PDTOs, 8 out of 8 (100%), were resistant. For the second cohort (chemorefractory patients), we used part of tumor tissue for genotyping. Four out of nine DSA/genotyping data resulted applicable in the clinic. Two RAS-mutant mCRC patients have been treated with FOLFOX-bevacizumab and mitomycin-capecitabine in third line, respectively, based on DSA results, obtaining disease control. One patient was treated with nivolumab-second mitochondrial-derived activator of caspases mimetic (phase I trial) due to high tumor mutational burden at genotyping, experiencing stable disease. In one case, the presence of BRCA2 mutation correlated with DSA sensitivity to olaparib; however, the patient could not receive the therapy. CONCLUSIONS: Using CRC as a model, we have designed and validated a clinically applicable methodology to potentially inform clinical decisions with functional data. Undoubtedly, further larger analyses are needed to improve methodology success rates and propose suitable treatment strategies for mCRC patients.

Induction of hemeoxygenase-1 expression after inhibition of hemeoxygenase activity promotes inflammation and worsens ischemic brain damage in mice.

Hemeoxygenase (HO) is an enzymatic system that degrades heme. HO-1 is an inducible isoform whereas HO-2 is constitutive. Stroke strongly induces HO-1 expression but the underlying mechanisms are not fully elucidated. Cytokines that are up-regulated after ischemia, like interleukin (IL)-10, can induce HO-1 gene expression, which is positively regulated by the transcriptional activator nuclear factor erythroid 2-related factor 2 (Nrf2) and negatively regulated by the transcriptional repressor breast cancer type 1 susceptibility protein (BRCA1) associated C-terminal helicase 1 (Bach-1). While Nrf2 is activated after ischemia and drugs promoting Nrf2 activation increase HO-1 and are beneficial, the involvement of Bach-1 is unknown. Here we investigated mechanisms involved in HO-1 induction and evaluated the effects of HO activity inhibition in mouse permanent middle cerebral artery occlusion (pMCAO). HO-1 was induced after ischemia in IL-10-deficient mice suggesting that post-ischemic HO-1 induction was IL-10-independent. Attenuation of Bach-1 gene repression after ischemia was associated to enhanced HO-1 induction. Administration of the HO activity inhibitor zinc proto-porphyrin IX (ZnPP) i.p. 24h before pMCAO exacerbated ischemia-induced tumor necrosis factor-α (TNF-α) and IL-1ß, nitro-oxidative stress, and the presence of neutrophils at 8h, and increased infarct volume at day 4. However, ZnPP did not worsen ischemic damage when given 30min before pMCAO. ZnPP induced HO-1 expression in the cerebral vasculature at 24h, when it was still detected by high-performance liquid chromatography (HPLC) in plasma. While ZnPP was not found in brain tissue extracts of controls, it could be detected after ischemia, supporting that a small fraction of the injected drug can reach the tissue following blood-brain barrier breakdown. The deleterious effect of inhibiting HO activity in ischemia became apparent in the presence of ZnPP-induced HO-1, which is known to exert effects independent of its enzymatic activity. In conclusion, HO-1 induction after ischemia was associated to down-regulation of transcriptional repressor Bach-1, and induction of HO-1 when HO enzymatic activity was inhibited was related to worst outcome after brain ischemia.

Colorectal liver metastases: Radiological diagnosis and staging.

The objective of this paper is to review imaging techniques useful for the diagnosis and staging of colorectal hepatic metastases. Semiological patterns will be reviewed as well as suggestions concerning performance of adequate preoperative staging. Radiological features suggesting non-resectability will be reviewed.

Activation of NF-kappaB by Akt upregulates Snail expression and induces epithelium mesenchyme transition.

Carcinoma progression is associated with the loss of epithelial features, and the acquisition of mesenchymal characteristics and invasive properties by tumour cells. The loss of cell-cell contacts may be the first step of the epithelium mesenchyme transition (EMT) and involves the functional inactivation of the cell-cell adhesion molecule E-cadherin. Repression of E-cadherin expression by the transcription factor Snail is a central event during the loss of epithelial phenotype. Akt kinase activation is frequent in human carcinomas, and Akt regulates various cellular mechanisms including EMT. Here, we show that Snail activation and consequent repression of E-cadherin may depend on AKT-mediated nuclear factor-kappaB (NF-kappaB) activation, and that NF-kappaB induces Snail expression. Expression of the NF-kappaB subunit p65 is sufficient for EMT induction, validating this signalling module during EMT. NF-kappaB pathway activation is associated with tumour progression and metastasis of several human tumour types; E-cadherin acts as a metastasis suppressor protein. Thus, this signalling and transcriptional network linking AKT, NF-kappaB, Snail and E-cadherin during EMT is a potential target for antimetastatic therapeutics.

Vitamin D(3) promotes the differentiation of colon carcinoma cells by the induction of E-cadherin and the inhibition of beta-catenin signaling.

The beta-catenin signaling pathway is deregulated in nearly all colon cancers. Nonhypercalcemic vitamin D3 (1alpha,25-dehydroxyvitamin D(3)) analogues are candidate drugs to treat this neoplasia. We show that these compounds promote the differentiation of human colon carcinoma SW480 cells expressing vitamin D receptors (VDRs) (SW480-ADH) but not that of a malignant subline (SW480-R) or metastasic derivative (SW620) cells lacking VDR. 1alpha,25(OH)2D(3) induced the expression of E-cadherin and other adhesion proteins (occludin, Zonula occludens [ZO]-1, ZO-2, vinculin) and promoted the translocation of beta-catenin, plakoglobin, and ZO-1 from the nucleus to the plasma membrane. Ligand-activated VDR competed with T cell transcription factor (TCF)-4 for beta-catenin binding. Accordingly, 1alpha,25(OH)2D(3) repressed beta-catenin-TCF-4 transcriptional activity. Moreover, VDR activity was enhanced by ectopic beta-catenin and reduced by TCF-4. Also, 1alpha,25(OH)2D(3) inhibited expression of beta-catenin-TCF-4-responsive genes, c-myc, peroxisome proliferator-activated receptor delta, Tcf-1, and CD44, whereas it induced expression of ZO-1. Our results show that 1alpha,25(OH)2D(3) induces E-cadherin and modulates beta-catenin-TCF-4 target genes in a manner opposite to that of beta-catenin, promoting the differentiation of colon carcinoma cells.

Intrahepatic peripheral cholangiocarcinoma: CT evaluation.

BACKGROUND: The purpose of our study was to evaluate the imaging features and patterns of contrast enhancement in peripheral cholangiocarcinomas with computed tomography (CT) and correlate these features with histologic findings when available. METHODS: We reviewed the CT scans of 24 patients with 25 peripheral cholangiocarcinomas proved by orthotopic liver transplantation (n = 1), liver resection (n = 7), percutaneous needle biopsy (n = 10), and fine needle aspiration biopsy (n = 6). Incremental dynamic nonhelical CT was performed in four cases and helical CT in 21 cases. Portal venous phase images were obtained in all 25 cases. Fourteen patients underwent helical CT during arterial and portal phases. Delayed images were obtained in 20 patients. RESULTS: The size of the tumors ranged from 1.2 to 17 cm. Bile duct dilatation was present in 13 patients (52%), and regional lymph node enlargement was observed in six patients (24%). Retraction of the liver capsule was present in nine patients (36%). In eight patients (32%), satellite nodules were also detected. All tumors were globally hypodense during the portal phase. In 14 patients (70%), delayed images disclosed hyperattenuating tumors. Rimlike contrast enhancement was the most frequent pattern observed in either arterial (57% of patients) or portal (60% of patients) phase imaging. Portal venous encasement was seen in 10 patients (40%). CONCLUSION: In the proper clinical setting, detection of a hypodense hepatic lesion with peripheral enhancement, biliary dilatation, and contrast enhancement on delayed images are highly suggestive of peripheral intrahepatic cholangiocarcinoma.

[Effectiveness of rectal metromidazole in acute infantile appendicitis]. / Eficacia del metronidazol rectal en la apendicitis aguda infantil.

Thirty two consecutive children who underwent surgery for suspected acute appendicitis, were treated with prophylactic metronidazole suppositories. A serum sample was taken at surgery to determine the serum concentration of the drug. After a preoperative dose of 15-20 mg/kg the minimal bactericidal concentration was achieved in almost all cases at the time of anesthetic induction. This drug showed an optimal biodisponibility when used rectally and no side-effects was noted. Neither a wound-infection, nor a wound-sepsis was reported and a satisfactory outcome was registered. We conclude that rectal dosing with metronidazole is effective for prophylactic wound infection in acute appendicitis.