Trop-2 induces ADAM10-mediated cleavage of E-cadherin and drives EMT-less metastasis in colon cancer.

We recently reported that activation of Trop-2 through its cleavage at R87-T88 by ADAM10 underlies Trop-2-driven progression of colon cancer. However, the mechanism of action and pathological impact of Trop-2 in metastatic diffusion remain unexplored. Through searches for molecular determinants of cancer metastasis, we identified TROP2 as unique in its up-regulation across independent colon cancer metastasis models. Overexpression of wild-type Trop-2 in KM12SM human colon cancer cells increased liver metastasis rates in vivo in immunosuppressed mice. Metastatic growth was further enhanced by a tail-less, activated ΔcytoTrop-2 mutant, indicating the Trop-2 tail as a pivotal inhibitory signaling element. In primary tumors and metastases, transcriptome analysis showed no down-regulation of CDH1 by transcription factors for epithelial-to-mesenchymal transition, thus suggesting that the pro-metastatic activity of Trop-2 is through alternative mechanisms. Trop-2 can tightly interact with ADAM10. Here, Trop-2 bound E-cadherin and stimulated ADAM10-mediated proteolytic cleavage of E-cadherin intracellular domain. This induced detachment of E-cadherin from ß-actin, and loss of cell-cell adhesion, acquisition of invasive capability, and membrane-driven activation of ß-catenin signaling, which were further enhanced by the ΔcytoTrop-2 mutant. This Trop-2/E-cadherin/ß-catenin program led to anti-apoptotic signaling, increased cell migration, and enhanced cancer-cell survival. In patients with colon cancer, activation of this Trop-2-centered program led to significantly reduced relapse-free and overall survival, indicating a major impact on progression to metastatic disease. Recently, the anti-Trop-2 mAb Sacituzumab govitecan-hziy was shown to be active against metastatic breast cancer. Our findings define the key relevance of Trop-2 as a target in metastatic colon cancer.

Treatment Intensification for Locally Advanced Rectal Cancer: Impact on Pathological Complete Response and Outcomes.

AIM: Pathological complete response (pCR) and clinical outcomes [overall survival (OS), disease-free survival (DFS), locoregional control (LC)] were evaluated in a single-institution experience of different schedules of neoadjuvant chemoradiotherapy (CRT) for patients with locally advanced rectal cancer (LARC). PATIENTS AND METHODS: Data for 322 patients with LARC were retrospectively analyzed. pCR was evaluated according to Mandard tumor regression grade (TRG). The Kaplan-Meier method was used to estimate OS, DFS and LC. RESULTS: Three hundred and three (94.1%) patients underwent surgery. pCR was observed in 81 patients (26.7%), with TRG1-2 rate of 41.8%. The 5- and 10-year OS, DFS and LC rates were 82.5%±2.5% and 65.5%±3.8%, 81.2%±2.4% and 79.3%±2.9%, 93.1%±1.7% and 90.5%±2.1%, respectively. CONCLUSION: Neoadjuvant CRT in LARC patients resulted in favorable long-term oncological outcomes, with a high pCR rate and acceptable toxicity.

5-Aza Exposure Improves Reprogramming Process Through Embryoid Body Formation in Human Gingival Stem Cells.

Embryoid bodies (EBs) are three-dimensional aggregates formed by pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells. They are used as an in vitro model to evaluate early extraembryonic tissue formation and differentiation process. In the adult organisms, cell differentiation is controlled and realized through the epigenetic regulation of gene expression, which consists of various mechanisms including DNA methylation. One demethylating agent is represented by 5-Azacytidine (5-Aza), considered able to induce epigenetic changes through gene derepression. Human gingival mesenchymal stem cells (hGMSCs), an easily accessible stem cells population, migrated from neural crest. They are particularly apt as an in vitro study model in regenerative medicine and in systemic diseases. The ability of 5-Aza treatment to induce hGMSCs toward a dedifferentiation stage and in particular versus EBs formation was investigated. For this purpose hGMSCs were treated for 48 h with 5-Aza (5 µM). After treatment, hGMSCs are organized as round 3D structures (EBs-hGMSCs). At light and transmission electron microscopy, the cells at the periphery of EBs-hGMSCs appear elongated, while ribbon-shaped cells and smaller cells with irregular shape surrounded by extracellular matrix were present in the center. By RT-PCR, EBs-hGMSCs expressed specific transcription markers related to the three germ layers as MAP-2, PAX-6 (ectoderm), MSX-1, Flk-1 (mesoderm), GATA-4, and GATA-6 (endoderm). Moreover, in EB-hGMSCs the overexpression of DNMT1 and ACH3 other than the down regulation of p21 was detectable. Immunofluorescence staining also showed a positivity for specific etodermal and mesodermal markers. In conclusion, 5-Aza was able to induce the direct conversion of adult hGMSCs into cells of three embryonic lineages: endoderm, ectoderm, and mesoderm, suggesting their possible application in autologous cell therapy for clinical organ repair.

Optical coherence tomography accurately identifies intermediate atherosclerotic lesions--an in vivo evaluation in the rabbit carotid artery.

OBJECTIVE: We tested the ability of optical coherence tomography (OCT) to identify very early stages of atherosclerosis in vivo. METHODS: Twelve New Zealand white male rabbits (weight 3.5-4.0 kg) underwent perivascular electrical injury of the common carotid arteries, and were then fed a cholesterol-rich diet. At 43+/-16 (range 27-63) days after injury, arteries were imaged by OCT, then rabbits were euthanized and vessels processed for histology. RESULTS: A total of 14 carotid arteries were imaged by OCT and histology; 22 atherosclerotic lesions were identified, 16 (73%) occurring at the site of the electrical injury. At histology, 4 lesions were defined as Stary type I (isolated macrophages), 8 as type II (intracellular lipid accumulations), and 10 as type III (small extracellular lipid pools). No advanced (> or =type IV) lesions were documented. OCT failed to detect any type I lesions, but correctly defined a minority (2/8, 25%) of type II lesions and the majority (8/10, 80%) of type III lesions. For type III lesions, sensitivity, specificity and diagnostic accuracy of OCT were 80%, 95%, and 95%, respectively. CONCLUSIONS: OCT can accurately detect intermediate (type-III) atherosclerotic lesions in vivo, but still fails to identify earlier stages of atherosclerosis.

Developing a decision-making model based on an interdisciplinary oncological care group for the management of colorectal cancer.

AIM: To report our experience on implementation and preliminary results of a decision-making model based on the recommendations of an Interdisciplinary Oncological Care Group developed for the management of colorectal cancer. PATIENTS AND METHODS: The multidisciplinary team identified a reference guideline using appraisal of guidelines for research and evaluation (AGREE) tool based on a sequential assessment of the guideline quality. Thereafter, internal guidelines with diagnostic and therapeutic management for early, locally advanced and metastatic colonic and rectal cancer were drafted; organizational aspects, responsibility matrices, protocol actions for each area of specialty involved and indicators for performing audits were also defined. RESULTS: The National Institute for Health and Care Excellence (NICE) UK guideline was the reference for drafting the internal guideline document; from February to November 2013, 125 patients with colorectal cancer were discussed by and taken under the care of the Interdisciplinary Oncological Care Group. The first audit performed in December 2013 revealed optimal adherence to the internal guideline, mainly in terms of uniformity and accuracy of perioperative staging, coordination and timing of multi-modal therapies. To date, all patients under observation are within the diagnostic and therapeutic course, no patient came out from the multidisciplinary "path" and only in 14% of cases have the first recommendations proposed been changed. The selected indicators appear effective and reliable, while at the moment, it is not yet possible to assess the impact of the multidisciplinary team on clinical outcome. CONCLUSION: Although having a short observation period, our model seems capable of determining optimal uniformity of diagnostic and therapeutic management, to a high degree of patient satisfaction. A longer observation period is necessary in order to confirm these observations and for assessing the impact on clinical outcome.