Domain II of calmodulin is involved in activation of calcineurin

AbstractA family of mutant proteins related to calmodulin (CaM) has been produced using cDNA constructs in bacterial expression vectors. The new proteins contain amino acid substitutions in Ca2+-binding domains I, II, both I and II, or both II and IV. The calmodulin-like proteins have been characterized with respect to mobility on SDS-polyacrylamide gels, Ca2+-dependent enhancement of tyrosine fluorescence, and abilities to activate the CaM-dependent phosphatase calcineurin. These studies suggest that an intact Ca2+-binding domain II is minimally required for full activation of calcineurin

Establishment and Propagation of Human Retinoblastoma Tumors in Immune Deficient Mice

Culturing retinoblastoma tumor cells in defined stem cell media gives rise to primary tumorspheres that can be grown and maintained for only a limited time. These cultured tumorspheres may exhibit markedly different cellular phenotypes when compared to the original tumors. Demonstration that cultured cells have the capability of forming new tumors is important to ensure that cultured cells model the biology of the original tumor

Prospective randomized trial evaluating mandatory second look surgery with HIPEC and CRS vs. standard of care in patients at high risk of developing colorectal peritoneal metastases

<p>Abstract</p> <p>Background</p> <p>The standard of care for colorectal peritoneal carcinomatosis is evolving from chemotherapy to cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with disease limited to the peritoneum. Peritoneal carcinomatosis from colorectal cancer treated with chemotherapy alone results in median survival of 5 to 13 months, whereas CRS with HIPEC for early peritoneal carcinomatosis from colorectal cancer resulted in median survival of 48-63 months and 5 year survival of 51%.</p> <p>Completeness of cytoreduction and limited disease are associated with longer survival, yet early peritoneal carcinomatosis is undetectable by conventional imaging. Exploratory laparotomy can successfully identify early disease, but this approach can only be justified in patients with high risk of peritoneal carcinomatosis. Historical data indicates that patients presenting with synchronous peritoneal carcinomatosis, ovarian metastases, perforated primary tumor, and emergency presentation with bleeding or obstructing lesions are at high risk of peritoneal carcinomatosis. Approximately 55% of these patient populations will develop peritoneal carcinomatosis. We hypothesize that performing a mandatory second look laparotomy with CRS and HIPEC for patients who are at high risk for developing peritoneal carcinomatosis from colorectal cancer will lead to improved survival as compared to patients who receive standard of care with routine surveillance.</p> <p>Methods/Design</p> <p>This study is a prospective randomized trial designed to answer the question whether mandatory second look surgery with CRS and HIPEC will prolong overall survival compared to the standard of care in patients who are at high risk for developing peritoneal carcinomatosis from colorectal cancer (CRC). Patients with CRC at high risk for developing peritoneal carcinomatosis who underwent curative surgery and subsequently received standard of care adjuvant chemotherapy will be evaluated. The patients who remain without evidence of disease by imaging, physical examination, and tumor markers for 12 months after the primary operation will be randomized to mandatory second look surgery or standard-of-care surveillance. At laparotomy, CRS and HIPEC will be performed with intraperitoneal oxaliplatin with concurrent systemic 5-fluorouracil and leucovorin. Up to 100 patients will be enrolled to allow for 35 evaluable patients in each arm; accrual is expected to last 5 years.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov ID: NCT01095523</p

Tai Chi for osteopenic women: design and rationale of a pragmatic randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Post-menopausal osteopenic women are at increased risk for skeletal fractures. Current osteopenia treatment guidelines include exercise, however, optimal exercise regimens for attenuating bone mineral density (BMD) loss, or for addressing other fracture-related risk factors (e.g. poor balance, decreased muscle strength) are not well-defined. Tai Chi is an increasingly popular weight bearing mind-body exercise that has been reported to positively impact BMD dynamics and improve postural control, however, current evidence is inconclusive. This study will determine the effectiveness of Tai Chi in reducing rates of bone turnover in post-menopausal osteopenic women, compared with standard care, and will preliminarily explore biomechanical processes that might inform how Tai Chi impacts BMD and associated fracture risks.</p> <p>Methods/Design</p> <p>A total of 86 post-menopausal women, aged 45-70y, T-score of the hip and/or spine -1.0 and -2.5, have been recruited from primary care clinics of a large healthcare system based in Boston. They have been randomized to a group-based 9-month Tai Chi program plus standard care or to standard care only. A unique aspect of this trial is its pragmatic design, which allows participants randomized to Tai Chi to choose from a pre-screened list of community-based Tai Chi programs. Interviewers masked to participants' treatment group assess outcomes at baseline and 3 and 9 months after randomization. Primary outcomes are serum markers of bone resorption (C-terminal cross linking telopeptide of type I collagen), bone formation (osteocalcin), and BMD of the lumbar spine and proximal femur (dual-energy X-ray absorptiometry). Secondary outcomes include health-related quality-of-life, exercise behavior, and psychological well-being. In addition, kinetic and kinematic characterization of gait, standing, and rising from a chair are assessed in subset of participants (n = 16) to explore the feasibility of modeling skeletal mechanical loads and postural control as mediators of fracture risk.</p> <p>Discussion</p> <p>Results of this study will provide preliminary evidence regarding the value of Tai Chi as an intervention for decreasing fracture risk in osteopenic women. They will also inform the feasibility, value and potential limitations related to the use of pragmatic designs for the study of Tai Chi and related mind-body exercise. If the results are positive, this will help focus future, more in-depth, research on the most promising potential mechanisms of action identified by this study.</p> <p>Trial registration</p> <p>This trial is registered in Clinical Trials.gov, with the ID number of NCT01039012.</p

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Inhibitors of metalloprotease, γ-sectretase, protein kinase C and Rho kinase inhibit wild-type adenoviral replication.

Adenoviruses cause upper respiratory infections, conjunctivitis, keratitis, and gastrointestinal illness. These can be fatal in immunocompromised individuals. Adenoviruses have also been engineered into viral vectors to deliver therapeutic genes or induce immunity as vaccine carriers. The success of ocular gene therapy is driven partly by the immunologic and biochemical influences of the intraocular environment. We have shown that versican and hyaluronan modulate adenoviral vector transgene expression through CD44 signaling. Herein we explored the role of these pathways on virus replication and viral protein expression of wild type adenovirus. We report that the addition of vitreous humor (which contains both versican and hyaluronan) increases viral hexon protein levels. Vitreous humor also increased wild type adenovirus DNA replication in vitro. Metalloproteinase and γ-secretase inhibitors, which inhibit CD44 proteolytic activation, blocked adenoviral replication in vitro. Similarly, protein kinase C and RhoA kinase inhibitors, both proteins associated with CD44 mediated pathways, also inhibited wild type adenoviral replication in vitro. Application of metalloproteinase and γ-secretase inhibitors to human conjunctival explants sharply decreased adenoviral vector gene expression. Our results demonstrate that pharmacologic delivery of these inhibitors is easily achievable. The inhibition of these enzymes should be explored as potential therapies of wild type adenoviral infections

Tumorspheres but not adherent cells derived from retinoblastoma tumors are of malignant origin.

Verification that cell lines used for cancer research are derived from malignant cells in primary tumors is imperative to avoid invalidation of study results. Retinoblastoma is a childhood ocular tumor that develops from loss of functional retinoblastoma protein (pRb) as a result of genetic or epigenetic changes that affect both alleles of the RB1 gene. These patients contain unique identifiable genetic signatures specifically present in malignant cells. Primary cultures derived from retinoblastoma tumors can be established as non-adherent tumorspheres when grown in defined media or as attached monolayers when grown in serum-containing media. While the RB1 genotypes of tumorspheres match those of the primary tumor, adherent cultures have the germline RB1 genotype. Tumorspheres derived from pRb-negative tumors do not express pRb and express the neuroendocrine tumor markers synaptophysin and microtubule-associated protein 2 (MAP2). Adherent cells are synaptophysin-negative and express pRb, the epithelial cell marker cytokeratin that is expressed in the retinal pigmented epithelium and the vascular endothelial cell marker CD34. While tumorspheres are of malignant origin, our results cast doubt on the assumption that adherent tumor-derived cultures are always valid in vitro models of malignant cells and emphasize the need for validation of primary tumor cultures

Representative tumorsphere and attached phenotypes of cultures derived from primary retinoblastoma tumor cells.

<p>Biopsies from human Rb tumor cells were placed in culture medium. Cultures arose either as three-dimensional spherical aggregates of cells called tumorspheres or as an attached monolayer. Typically, tumorspheres arose when Rb cells were placed in neural stem cell-optimized medium without serum, and adherent cultures arose when Rb cells were placed in classical medium with FBS. However, in rare cases tumorspheres and attached cells both arose from Rb cells placed in classical medium with FBS. Scale bar = 100 µm.</p