Recency Effects in the Inferior Parietal Lobe during Verbal Recognition Memory

The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such “recency effects” have shown that activation in the lateral inferior parietal cortex (LIPC) tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength) of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and “expectancy” hypotheses, respectively – of the parietal lobe recency effect

Radiopharmaceutical and Gene Therapy Program

The objective of our research program was to determine whether novel receptors can be induced in solid cancers as a target for therapy with radiolabeled unmodified peptides that bind to the receptors. The hypothesis was that induction of a high number of receptors on the surface of these cancer cells would result in an increased uptake of the radiolabeled monomeric peptides as compared to published results with radiolabeled antibodies or peptides to naturally expressed antigens or receptors, and therefore a better therapeutic outcome. The following is a summary of published results

Three-Dimensional Dose Model for the Comparison of 177Lu-HuCC49ΔCH2 and 177Lu-HuCC49 Radioimunotherapy in Mice Bearing Intraperitoneal Xenografts

Uptake and dose distributions in peritoneal LS174T colon tumor xenografts were compared for a humanized construct of the CC49 (HuCC49) high-affinity anti-TAG-72 monoclonal antibody and a construct with the CH2 region deleted (HuCC49ΔCH2), both labeled with 177Lu using a PA-DOTA bifunctional chelating agent and injected in the peritoneum. Tumors were resected and serially sectioned at 1 h, 4 h, 24 h, and 48 h postinjection. Between 5 and 24 (average 16) sections were retained per tumor for autoradiography. The typical section interval was 340 μm and thickness was 16 μm. Tumor sections were air dried and placed on film and/or phosphor screen. Section images were digitized at 100 μm resolution electronically (phosphor screen) or by laser densitometer (film). Section images were used to generate tumor surface descriptions and activity distributions by reconstructing the activity densities in three dimensions. Three-dimensional dose-rate calculations, performed using a point kernel for 177Lu, were used to prepare radial histograms describing the variation in dose rate as a function of distance from the tumor center to surface. At early times postinjection, the 177Lu-HuCC49ΔCH2 antibody displayed higher dose rates near the tumor surface compared to the 177Lu-HuCC49 antibody. At 24 h postinjection, dose rate distributions appeared similar for both antibodies and more uniform than at earlier times. The 177Lu-HuCC49ΔCH2 antibody indicated improved uniformity at 48 h postinjection. Cell survival calculations based on the three-dimensional dose rate distributions favored 177Lu-HuCC49ΔCH2 for equal injection activities. However the most significant effect was the greater injected dose tolerated for the 177Lu-HuCC49ΔCH2 antibody based on equivalent estimated bone marrow dose.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63413/1/108497803765036418.pd

Radioimmunotoxin Therapy of Experimental Colon and Ovarian Cancer

To pursue the development of radiolabeled immunotoxins (RIT) for colon cancer, it was first necessary to identify an immunotoxin (IT) that could selectively kill colon cancer cell lines. Recently, our collaborators in the Vallera laboratory have observed that potent recombinant IT can be synthesized using recombinant single chain antibodies (sFv) spliced to truncated diphtheria toxin (DT) consisting of the first 390 amino acids of native DT. DT was chosen as a toxin because it is a catalytic bacterial toxin that is easily manipulated in genetic engineering studies. Also, the Vallera lab has developed new procedures for preparing the sFv fusion toxins from bacterial inclusion bodies such as DT and another good genetic engineering toxin pseudomonas exotoxin (PE) based on detergent refolding. This allows for enhanced yields and higher purity that is essential for generating the protein that will be needed for preparation of larger amounts of RIT for therapy. Many potential sFvs were considered for targeting colon cancer. The best results have been obtained with an sFv recognizing EpCam. EpCam, also known as ESA or EGP40, is a 40 kDa epithelial transmembrane glycoprotein found on the basolateral surface of simple, pseudostratified, and transitional epithelia. It has been found overexpressed on 81% of adenocarcinomas of the colon (Went et al. Human pathology 35:122, 2004). EpCam sliced to DT (DTEpCam) was highly potent in studies in which we measured its ability to inhibit the proliferation of the HT-29 and COLO 205 colon cancer cell lines since we measured its IC50 at 1-2 x 10-2 nM. Potency is important, but is also critical that DTEpCam is selective in its cytotoxicity against EpCam-expressing target colon cancer cells. The activity of DTEpCam was highly selective since irrelevant control IT that did not recognize any markers on cancer cells, did not show any activity against the same colon cancer cell lines. Also, blocking studies were performed in which DTEpCam was mixed with the EpCam sFv that was synthesized without any toxin attached. The proliferation studies showed that EpCam sFv was able to block the killing of the EpCam expressing cells by DTEpCam. An irrelevant control protein, 1D10Fc was unable to block. Together, these studies indicated that EpCam was exquisitely selective. In order to produce an IT of even greater potency, we used a toxin containing the Golgi retention sequence KDEL. The same EpCam sFv was spliced to truncated PE containing the terminal KDEL sequence. The addition of KDEL enhanced the potency of the EpCam sFv IT at least 6 logs or 1000-fold with an IC50 of 2 to 7 x 10-8 nM. This conjugate was also shown to be highly selective. Taken together, all of these studies indicate that in vitro experiments have shown that we have a highly potent IT that selectively kills colon cancer cells. The next step was to show that the EpCam IT had the ability to inhibit the growth of flank tumors in vivo in nude mice. The same human colon tumor cells, HT29 used in the in vitro studies were injected into the flank of nude mice. Tumor cells were injected into groups of mice and when tumors reached the size of 0.5 cm3, we injected our best-performing EpCam IT called EpCamKDEL intratumorally. There was a significant drop in tumor size indicating that this agent was very effective against human colon cancer. Since the EpCamKDEL was injected intratumorally, it did not have to travel through the systemic circulation to find its target. Our next step will be to inject EpCamKDEL intravenously into mice with flank tumors to determine if EpCamKDEL has the ability to migrate to the tumor systemically. The next step was to radiolabel EpCamKDEL to see whether it could serve as an RIT. We radiolabeled EpCam with 111In as a surrogate for 90Y and then incubated it with HT29. The labeling efficiency was over 90% indicating that a high percentage of the protein molecules could be readily radiolabeled. However, the immunoreactivity was only 20% indicating that only 20% of those molecules were able to specifically bind antigen once they were radiolabeled. We are currently determining whether this labeling procedure is too harsh on the recombinant protein or whether some other labeling procedure might result in a higher level of immunoreactivity

Journey of Trail From Bench to Bedside and Its Potential Role in Immuno-Oncology

Induction of apoptosis in cancer cells has increasingly been the focus of many therapeutic approaches in oncology field. Since its identification as a TNF family member, TRAIL (TNF-related apoptosis-inducing ligand) paved a new path in apoptosis inducing cancer therapies. Its selective ability to activate extrinsic and intrinsic cell death pathways in cancer cells only, independently from p53 mutations responsible for conventional therapeutics resistance, spotted TRAIL as a potent cancer apoptotic agent. Many recombinant preparations of TRAIL and death receptor targeting monoclonal antibodies have been developed and being tested pre-clinically and clinically both as a single agent and in combinations. Of note, the monoclonal antibodies were not the only type of antibodies developed to target TRAIL receptors. Recent technology has brought forth several single chain variable domains (scFv) designs fused recombinantly to TRAIL as well. Also, it is becoming progressively more understandable that field of nanotechnology has revolutionized cancer diagnosis and therapy. The recent breakthroughs in materials science and protein engineering have helped considerably in strategically loading drugs into nanoparticles or conjugating drugs to their surface. In this review we aim to comprehensively highlight the molecular knowledge of TRAIL in the context of its pathway, receptors and resistance factors. We also aim to review the clinical trials that have been done using TRAIL based therapies and to review various scFv designs, the arsenal of nano-carriers and molecules available to selectively target tumor cells with TRAIL

Role of Nanotechnology and Gene Delivery Systems in TRAIL-Based Therapies

Since its identification as a member of the tumour necrosis factor (TNF) family, TRAIL (TNF-related apoptosis-inducing ligand) has emerged as a new avenue in apoptosis-inducing cancer therapies. Its ability to circumvent the chemoresistance of conventional therapeutics and to interact with cancer stem cells (CSCs) self-renewal pathways, amplified its potential as a cancer apoptotic agent. Many recombinant preparations of this death ligand and monoclonal antibodies targeting its death receptors have been tested in monotherapy and combinational clinical trials. Gene therapy is a new approach for cancer treatment which implies viral or non-viral functional transgene induction of apoptosis in cancer cells or repair of the underlying genetic abnormality on a molecular level. The role of this approach in overcoming the traditional barriers of radiation and chemotherapeutics systemic toxicity, risk of recurrence, and metastasis made it a promising platform for cancer treatment. The recent first Food Drug Administration (FDA) approved oncolytic herpes virus for melanoma treatment brings forth the potency of the cancer gene therapy approach in the future. Many gene delivery systems have been studied for intratumoural TRAIL gene delivery alone or in combination with chemotherapeutic agents to produce synergistic cancer cytotoxicity. However, there still remain many obstacles to be conquered for this different gene delivery systems. Nanomedicine on the other hand offers a new frontier for clinical trials and biomedical research. The FDA approved nanodrugs motivates horizon exploration for other nanoscale designed particles\u27 implications in gene delivery. In this review we aim to highlight the molecular role of TRAIL in apoptosis and interaction with cancer stem cells (CSCs) self-renewal pathways. Finally, we also aim to discuss the different roles of gene delivery systems, mesenchymal cells, and nanotechnology designs in TRAIL gene delivery

Measurement properties of tools used to assess depression in adults with and without Autism Spectrum Conditions: a systematic review

Depression is the most commonly experienced mental health condition in adults with Autism Spectrum Conditions (ASC). However, it is unclear what tools are currently being used to assess depression in ASC, or whether tools need to be adapted for this group. This systematic review therefore aimed to identify tools used to assess depression in adults with and without ASC, and then evaluate these tools for their appropriateness and measurement properties. Medline, PsychINFO and Web of Knowledge were searched for studies of depression in: a) adults with ASC, without co-morbid intellectual disability; and b) adults from the general population without co-morbid conditions. Articles examining the measurement properties of these tools were then searched for using a methodological filter in PubMed, and the quality of the evidence was evaluated using the COSMIN checklist. Twelve articles were identified which utilised three tools to assess depression in adults with ASC, but only one article which assessed the measurement properties of one of these tools was identified and thus evaluated. Sixty-five articles were identified which utilised five tools to assess depression in general population adults, and 14 articles had assessed the measurement properties of these tools. Overall, two tools were found to be robust in their measurement properties in the general population – the Beck Depression Inventory (BDI-II), and the Patient Health Questionnaire (PHQ-9). Crucially only one study was identified from the COSMIN search, which showed weak evidence in support of the measurement properties of the BDI-II in an ASC sample. Implications for effective measurement of depression in ASC are discussed

Cellular Model of Warburg Effect Identifies Tumor Promoting Function of UCP2 in Breast Cancer and Its Suppression by Genipin

The Warburg Effect is characterized by an irreversible injury to mitochondrial oxidative phosphorylation (OXPHOS) and an increased rate of aerobic glycolysis. In this study, we utilized a breast epithelial cell line lacking mitochondrial DNA (rho0) that exhibits the Warburg Effect associated with breast cancer. We developed a MitoExpress array for rapid analysis of all known nuclear genes encoding the mitochondrial proteome. The gene-expression pattern was compared among a normal breast epithelial cell line, its rho0 derivative, breast cancer cell lines and primary breast tumors. Among several genes, our study revealed that over-expression of mitochondrial uncoupling protein UCP2 in rho0 breast epithelial cells reflects gene expression changes in breast cancer cell lines and in primary breast tumors. Furthermore, over-expression of UCP2 was also found in leukemia, ovarian, bladder, esophagus, testicular, colorectal, kidney, pancreatic, lung and prostate tumors. Ectopic expression of UCP2 in MCF7 breast cancer cells led to a decreased mitochondrial membrane potential and increased tumorigenic properties as measured by cell migration, in vitro invasion and anchorage independent growth. Consistent with in vitro studies, we demonstrate that UCP2 over-expression leads to development of tumors in vivo in an orthotopic model of breast cancer. Genipin, a plant derived small molecule, suppressed the UCP2 led tumorigenic properties, which were mediated by decreased reactive oxygen species and down-regulation of UCP2. However, UCP1, 3, 4 and 5 gene expression was unaffected. UCP2 transcription was controlled by SMAD4. Together, these studies suggest a tumor-promoting function of UCP2 in breast cancer. In summary, our studies demonstrate that i) the Warburg Effect is mediated by UCP2; ii) UCP2 is over-expressed in breast and many other cancers; iii) UCP2 promotes tumorigenic properties in vitro and in vivo and iv) genipin suppresses the tumor promoting function of UCP2