TheraSphere Yttrium-90 Glass Microspheres Combined With Chemotherapy Versus Chemotherapy Alone in Second-Line Treatment of Patients With Metastatic Colorectal Carcinoma of the Liver: Protocol for the EPOCH Phase 3 Randomized Clinical Trial

BACKGROUND: Colorectal cancer is one of the most common cancers and causes of cancer-related death. Up to approximately 70% of patients with metastatic colorectal cancer (mCRC) have metastases to the liver at initial diagnosis. Second-line systemic treatment in mCRC can prolong survival after development of disease progression during or after first-line treatment and in those who are intolerant to first-line treatment. OBJECTIVE: The objective of this study is to evaluate the efficacy and safety of transarterial radioembolization (TARE) with TheraSphere yttrium-90 (⁹⁰Y)glass microspheres combined with second-line therapy in patients with mCRC of the liver who had disease progression during or after first-line chemotherapy. METHODS: EPOCH is an open-label, prospective, multicenter, randomized, phase 3 trial being conducted at up to 100 sites in the United States, Canada, Europe, and Asia. Eligible patients have mCRC of the liver and disease progression after first-line chemotherapy with either an oxaliplatin-based or irinotecan-based regimen and are eligible for second-line chemotherapy with the alternate regimen. Patients were randomized 1:1 to the TARE group (chemotherapy with TARE in place of the second chemotherapy infusion and subsequent resumption of chemotherapy) or the control group (chemotherapy alone). The addition of targeted agents is permitted. The primary end points are progression-free survival and hepatic progression-free survival. The study objective will be considered achieved if at least one primary end point is statistically significant. Secondary end points are overall survival, time to symptomatic progression defined as Eastern Cooperative Oncology Group Performance Status score of 2 or higher, objective response rate, disease control rate, quality-of-life assessment by the Functional Assessment of Cancer Therapy-Colorectal Cancer questionnaire, and adverse events. The study is an adaptive trial, comprising a group sequential design with 2 interim analyses with a planned maximum of 420 patients. The study is designed to detect a 2.5-month increase in median progression-free survival, from 6 months in the control group to 8.5 months in the TARE group (hazard ratio [HR] 0.71), and a 3.5-month increase in median hepatic progression-free survival time, from 6.5 months in the control group to 10 months in the TARE group (HR 0.65). On the basis of simulations, the power to detect the target difference in either progression-free survival or hepatic progression-free survival is >90%, and the power to detect the target difference in each end point alone is >80%. RESULTS: Patient enrollment ended in October 2018. The first interim analysis in June 2018 resulted in continuation of the study without any changes. CONCLUSIONS: The EPOCH study may contribute toward the establishment of the role of combination therapy with TARE and oxaliplatin- or irinotecan-based chemotherapy in the second-line treatment of mCRC of the liver. TRIAL REGISTRATION: ClinicalTrials.gov NCT01483027; https://clinicaltrials.gov/ct2/show/NCT01483027 (Archived by WebCite at http://www.webcitation.org/734A6PAYW)

Versican G3 Promotes Mouse Mammary Tumor Cell Growth, Migration, and Metastasis by Influencing EGF Receptor Signaling

Increased versican expression in breast tumors is predictive of relapse and has negative impact on survival rates. The C-terminal G3 domain of versican influences local and systemic tumor invasiveness in pre-clinical murine models. However, the mechanism(s) by which G3 influences breast tumor growth and metastasis is not well characterized. Here we evaluated the expression of versican in mouse mammary tumor cell lines observing that 4T1 cells expressed highest levels while 66c14 cells expressed low levels. We exogenously expressed a G3 construct in 66c14 cells and analyzed its effects on cell proliferation, migration, cell cycle progression, and EGFR signaling. Experiments in a syngeneic orthotopic animal model demonstrated that G3 promoted tumor growth and systemic metastasis in vivo. Activation of pERK correlated with high levels of G3 expression. In vitro, G3 enhanced breast cancer cell proliferation and migration by up-regulating EGFR signaling, and enhanced cell motility through chemotactic mechanisms to bone stromal cells, which was prevented by inhibitor AG 1478. G3 expressing cells demonstrated increased CDK2 and GSK-3β (S9P) expression, which were related to cell growth. The activity of G3 on mouse mammary tumor cell growth, migration and its effect on spontaneous metastasis to bone in an orthotopic model was modulated by up-regulating the EGFR-mediated signaling pathway. Taken together, EGFR-signaling appears to be an important pathway in versican G3-mediated breast cancer tumor invasiveness and metastasis

Heterogeneity in age-related white matter changes

White matter changes occur endemically in routine magnetic resonance imaging (MRI) scans of elderly persons. MRI appearance and histopathological correlates of white matter changes are heterogeneous. Smooth periventricular hyperintensities, including caps around the ventricular horns, periventricular lining and halos are likely to be of non-vascular origin. They relate to a disruption of the ependymal lining with subependymal widening of the extracellular space and have to be differentiated from subcortical and deep white matter abnormalities. For the latter a distinction needs to be made between punctate, early confluent and confluent types. Although punctate white matter lesions often represent widened perivascular spaces without substantial ischemic tissue damage, early confluent and confluent lesions correspond to incomplete ischemic destruction. Punctate abnormalities on MRI show a low tendency for progression, while early confluent and confluent changes progress rapidly. The causative and modifying pathways involved in the occurrence of sporadic age-related white matter changes are still incompletely understood, but recent microarray and genome-wide association approaches increased the notion of pathways that might be considered as targets for therapeutic intervention. The majority of differentially regulated transcripts in white matter lesions encode genes associated with immune function, cell cycle, proteolysis, and ion transport. Genome-wide association studies identified six SNPs mapping to a locus on chromosome 17q25 to be related to white matter lesion load in the general population. We also report first and preliminary data that demonstrate apolipoprotein E (ApoE) immunoreactivity in white matter lesions and support epidemiological findings indicating that ApoE is another factor possibly related to white matter lesion occurrence. Further insights come from modern MRI techniques, such as diffusion tensor and magnetization transfer imaging, as they provide tools for the characterization of normal-appearing brain tissue beyond what can be expected from standard MRI scans. There is a need for additional pre- and postmortem studies in humans, including these new imaging techniques

Association of MAD2 expression with mitotic checkpoint competence in hepatoma cells

Chromosomal instability (CIN) refers to high rates of chromosomal gains and losses and is a major cause of genomic instability of cells. It is thought that CIN caused by loss of mitotic checkpoint contributes to carcinogenesis. In this study, we evaluated the competence of mitotic checkpoint in hepatoma cells and investigated the cause of mitotic checkpoint defects. We found that 6 (54.5%) of the 11 hepatoma cell lines were defective in mitotic checkpoint control as monitored by mitotic indices and flow-cytometric analysis after treatment with microtubule toxins. Interestingly, all 6 hepatoma cell lines with defective mitotic checkpoint showed significant underexpression of mitotic arrest deficient 2 (MAD2), a key mitotic checkpoint protein. The level of MAD2 underexpression was significantly associated with defective mitotic checkpoint response (p < 0.001). In addition, no mutations were found in the coding sequences of MAD2 in all 11 hepatoma cell lines. Our findings suggest that MAD2 deficiency may cause a mitotic checkpoint defect in hepatoma cells. Copyright © 2004 National Science Council, ROC and S. Karger AG, Basel.link_to_subscribed_fulltex

Role of a novel splice variant of mitotic arrest deficient 1 (MAD1), MAD1β, in mitotic checkpoint control in liver cancer

Loss of mitotic checkpoint contributes to chromosomal instability, leading to carcinogenesis. In this study, we identified a novel splicing variant of mitotic arrest deficient 1 (MAD1), designated MAD1β, and investigated its role in mitotic checkpoint control in hepatocellular carcinoma (HCC). The expression levels of human MAD1β were examined in hepatoma cell lines and human HCC samples. The functional roles of MAD1β in relation to the mitotic checkpoint control, chromosomal instability, and binding with MAD2 were assessed in hepatoma cell lines. On sequencing, MAD1β was found to have deletion of exon 4. It was expressed at both mRNA and protein levels in the nine hepatoma cell lines tested and was overexpressed in 12 of 50 (24%) human HCCs. MAD1β localized in the cytoplasm, whereas MAD1α was found in the nucleus. This cytoplasmic localization of MAD1β was due to the absence of a nuclear localization signal in MAD1α. In addition, MAD1β was found to physically interact with MAD2 and sequester it in the cytoplasm. Furthermore, expression of MAD1β induced mitotic checkpoint impairment, chromosome bridge formation, and aberrant chromosome numbers via binding with MAD2. Our data suggest that the novel splicing variant MAD1β may have functions different from those of MAD1α and may play opposing roles to MAD1α in mitotic checkpoint control in hepatocarcinogenesis. ©2008 American Association for Cancer Research.link_to_OA_fulltex

Solution structures, dynamics, and lipid-binding of the sterile α-motif domain of the deleted in liver cancer 2

The deleted in liver cancer 2 (DLC2) is a tumor suppressor gene, frequently found to be underexpressed in hepatocellular carcinoma. DLC2 is a multidomain protein containing a sterile α-motif (SARI) domain, a GTPase-activating protein (GAP) domain, and a lipid-binding StAR-related lipid-transfer (START) domain. The SAM domain of DLC2, DLC2-SAM, exhibits a low level of sequence homology (15-30%) with other SAM domains, and appears to be the prototype of a new subfamily of SAM domains found in DLC2-related proteins. In the present study, we have determined the three-dimensional solution structure of DLC2-SAM using NMR methods together with molecular dynamics simulated annealing. In addition, we performed a backbone dynamics study. The DLC2-SAM packed as a unique four α-helical bundle stabilized by interhelix hydrophobic interactions. The arrangement of the four helices is distinct from all other known SAM domains. In contrast to some members of the SAM domain family which form either dinners or oligomers, both biochemical analyses and rotational correlation time (τc) measured by backbone 15N relaxation experiments indicated that DLC2-SAM exists as a monomer in solution. The interaction of DLC2-SAM domain with sodium dodecyl sulfate (SDS) micelles and 1,2-dimyristoyl-sn-glycerol-3-phosphatidylglycerol (DMPG) phospholipids was examined by CD and NMR spectroscopic techniques. The DLC2-SAM exhibits membrane binding properties accompanied by minor loss of the secondary structure of the protein. Deletion studies showed that the self-association of DLC2 in vivo does not require SARI domain, instead, a protein domain consisting of residues 120-672 mediates the self-association of DLC2. © 2007 Wiley-Liss, Inc.link_to_subscribed_fulltex