Dingli, David

Abstract Oncolytic replication competent viruses are increasingly being tested in clinical trials. Their optimal use would be greatly facilitated by technologies that enable repeated and quantitative estimation of the location and population size of the virus as it propagates within the tumor. To address this, we have generated two replication competent measles viruses (MV) that express the thyroidal sodium iodide symporter (NIS) in injected cells. One virus, MV-NIS is in Phase 1 clinical trials and kills cells by formation of syncytia. The second virus, MV-I98A-NIS has a mutation in the MV hemagglutinin protein that prevents syncytium formation and kills cells by lysis. Cells infected with MV-I98A-NIS remain viable for longer compared to MV-NIS and are expected to express higher concentrations of NIS, facilitating in vivo imaging. BxPC-3 human pancreatic carcinoma cells were implanted in the flank of nude mice. Subsequently, the mice were injected with Opti-MEM (control), MV-NIS or MV-I98A-NIS (1x107 TCID50/ml) via the tail vein. On days 3, 5, 8, 10, 12, 15, 17 and 19 after virus injection, mice from the control, and virus injected groups were imaged with SPECT/CT (U-SPECT II) 1 hour after injection of 99mTc. Immediately afterwards, the mice were euthanized, the tumors excised, weighed and isotope activity measured. The tumors were divided into parts for histologic analysis and RNA extraction. NIS gene expression was determined by Q-RT-PCR and immunohistochemistry, while viral genome copy number was determined by Q-RT-PCR for the nucleoprotein (N). Image analysis using ROI was performed using AMIDE with background correction across all imaging planes. There was no correlation between tumor mass (volume) and isotope uptake (R2=0.0001 and 0.0051 for MV-NIS and MV-I98A-Nis respectively) suggesting that isotope uptake was strictly linked to virus infection. There was a strong, linear correlation between the levels of virus dependent NIS expression and isotope activity within the tumor (R2=0.79 and 0.93 for MV-NIS and MV-I98A-NIS respectively). Tumors infected with MV-I98A-NIS had a higher concentration of isotope compared with MV-NIS (p<0.004) and a higher correlation coefficient of NIS isotope uptake versus NIS expression (14.1 mCi/NIS copies/ng RNA versus 11.5, p=0.003), compatible with the observation that tumor cells infected with MV-I98A-NIS remain viable for longer compared to MV-NIS. Activity within tumors increased as a function of time, compatible with ongoing virus replication and spread within the tumors. Correlation of imaging studies with NIS expression and viral genome copy number is ongoing. Our preliminary studies suggest that in vivo imaging can be used to accurately determine the size of the oncolytic virus population within a tumor as a function of time. These observations will be used to understand the dynamics of virus spread within tumors and optimize therapy. Citation Format: Mi-Yeon Jung, Matthew K. Ennis, Chetan P. Offord, David Dingli. Quantitative in vivo imaging of oncolytic virus replication. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4947. doi:10.1158/1538-7445.AM2014-4947

The use of soluble cardiac biomarkers such as N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) and troponin has revolutionized prognostication for patients with AL amyloidosis. Soluble ST2 (sST2) and galectin‐3 have also been reported to have prognostic value in other cardiac patient populations. We identified 502 patients with AL amyloidosis, who provided a research sample and consent to review their medical records between 1/1/2006‐12/31/2010 within 90 days of their diagnosis. Samples were assayed for sST2 and galectin‐3. Within this AL amyloidosis population, overall survival (OS) was 25.5 months (95% CI 18, 35.7 months). Receiver operating curve analyses were done to detect the best cut‐points for sST2 and galectin‐3 to predict both 1‐ and 5‐year OS. The respective cut points for sST2 were 30 and 29.7 ng/mL, while the median sST2 for the entire population was 31 ng/mL (IQR 19.8, 53.6). The respective cut points for galectin‐3 were 11 and 10.4 ng/mL while the median for the entire population was 16.6 ng/mL (IQR 11.5, 24.0). Although on univariate analysis, both sST2 and galectin‐3 were prognostic, upon multivariate analysis, only sST2 was independent of troponin, NT‐proBNP, serum immunoglobulin free light chain, and blood pressure. Not only did sST2 add to previously reported prognostication systems, but a novel prognostication 5‐point system including sST2 was possible. The addition of sST2 – but not galectin‐3 – to existing prognostication systems for patients with AL amyloidosis strengthens the ability to predict for death. Am. J. Hematol. 90:524–528, 2015. © 2015 Wiley Periodicals, Inc.

AL amyloidosis (AL) is rare and frequently remains undiagnosed until organ function is compromised, even among patients with known pre‐existing untreated plasma cell dyscrasias (PCD). We identified 168 patients with AL amyloidosis who had a prior untreated PCD. The earliest symptom or sign (s/s) was defined as the first symptom reported by the patient that could be attributed to organ dysfunction caused by AL. The interval from the time of development of s/s to the establishment of diagnosis of AL (Interval‐SA) was calculated. PCD diagnosis preceded recorded onset of s/s in 75% (114/152) of patients, with a median interval‐SA for this group of 10 months. PCD was diagnosed after s/s in 25% (38/152) of patients, with a median interval‐SA of 20 months. Overall survival (OS) from diagnosis of AL was not different between the two groups. AL amyloidosis patients with an identified pre‐existing PCD had less advanced cardiac disease at AL diagnosis when compared to a control group of AL patients without preidentified PCD. Long‐term OS was not significantly superior among patients with a pre‐identified PCD. In patients with “asymptomatic” PCD, symptoms and signs of AL amyloidosis should be solicited, since timely diagnosis is important in AL amyloidosis. Am. J. Hematol. 89:1051–1054, 2014. © 2014 Wiley Periodicals, Inc.

Despite successful treatment of the clonal plasma cell implicated in its pathogenesis, patients with AL amyloidosis (AL) experience significant morbidity related to underlying amyloid mediated organ dysfunction. While normalization of the serum free light chain measurements [normal ratio of involved and uninvolved free light chains (nFLCr)] is the goal of therapy and centerpiece of hematologic response criteria, achieving (or not achieving) meaningful organ response (OR) is clinically significant for its implications on long‐term symptomatology as well as overall survival (OS), and remains the ultimate goal of treatment. Expectations for organ recovery following successful therapy leading to nFLCr in AL remain poorly described. We evaluated the timeframe and predictive factors for OR, and long‐term outcome, in 313 AL patients who achieved nFLCr following therapy initiation. OR was seen in 80% of surviving AL patients within 1‐year of nFLCr. Patients achieving early OR within 1 year of nFLCr had superior OS compared with those who despite obtaining nFLCr did not achieve early OR. We further evaluated factors predicting OR and OS among patients achieving nFLCr. Higher values of dFLC (involved–uninvolved) at diagnosis predict OR, and early OR predicts improved OS following successful hematologic therapy in AL. Am. J. Hematol. 90:181–186, 2015. © 2014 Wiley Periodicals, Inc.

Abstract RATIONALE: The inability to deliver viruses homogeneously throughout solid tumors is a universal obstacle encountered in oncolytic virotherapy. The initial intratumoral viral dispersion volume is a critical determinant of virotherapy efficacy, and depends not only on the number of infected cells, but also on the spatial distribution of the infected cells. In this study, we determined the feasibility and usefulness of monitoring the initial intratumoral delivery of oncolytic viruses to solid tumors using contrast-enhanced computed tomography (CT). EXPERIMENTAL PROCEDURES: Human BxPC-3 pancreatic tumor xenografts were established in nude mice. An engineered oncolytic measles virus expressing the sodium iodide symporter reporter (MV-NIS) was mixed with a 1:10 dilution of Omnipaque-300 contrast material and injected directly into mouse tumors. Mice were imaged with micro-CT immediately pre and post-injection of the virus + Omnipaque solution and on day 3 post-injection with 99mTcO4 micro-SPECT/CT. Tumors were harvested immediately after micro-SPECT/CT imaging for autoradiography and immunistochemistry analysis of radioactivity uptake and viral infection. Linear regression and Spearman correlation analyses were performed to determine the relationship between intratumoral contrast enhancement and subsequent intratumoral viral infection. RESULTS: This dilution of Omnipaque was found to have no effect on viral infectivity or cell viability in vitro, yet was more than adequate for CT imaging of the virus + Omnipaque injectate distribution following intratumoral injection. Ex vivo autoradiography and immunohistochemistry confirmed a strong correlation between intratumoral CT contrast enhancement, SPECT activity, viral infection, and sodium iodide symporter activity. CONCLUSIONS: This injection method is translatable to the clinic and should allow optimization of intratumoral injection in humans. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4145. doi:10.1158/1538-7445.AM2011-4145

Abstract Many tumors are believed to be maintained by a small number of cancer stem–like cells, where cure is thought to require eradication of this cell population. In this study, we investigated the dynamics of acute promyelocytic leukemia (APL) before and during therapy with regard to disease initiation, progression, and therapeutic response. This investigation used a mathematical model of hematopoiesis and a dataset derived from the North American Intergroup Study INT0129. The known phenotypic constraints of APL could be explained by a combination of differentiation blockade of PML–RARα–positive cells and suppression of normal hematopoiesis. All-trans retinoic acid (ATRA) neutralizes the differentiation block and decreases the proliferation rate of leukemic stem cells in vivo. Prolonged ATRA treatment after chemotherapy can cure patients with APL by eliminating the stem-like cell population over the course of approximately one year. To our knowledge, this study offers the first estimate of the average duration of therapy that is required to eliminate stem-like cancer cells from a human tumor, with the potential for the refinement of treatment strategies to better manage human malignancy. Cancer Res; 74(19); 5386–96. ©2014 AACR.

AbstractAn estimated 22 350 patients had multiple myeloma diagnosed in 2013, representing 1.3% of all new cancers; 10 710 deaths are projected, representing 1.8% of cancer deaths. Approximately 0.7% of US men and women will have a myeloma diagnosis in their lifetime, and with advances in therapy, 77 600 US patients are living with myeloma. The 5-year survival rate was 25.6% in 1989 and was 44.9% in 2005. The median age at diagnosis is 69 years, with 62.4% of patients aged 65 or older at diagnosis. Median age at death is 75 years. The rate of new myeloma cases has been rising 0.7% per year during the past decade. The most common indication for autologous stem cell transplantation in the United States is multiple myeloma, and this article is designed to provide the specifics of organizing a transplant program for multiple myeloma. We review the data justifying use of stem cell transplantation as initial management in myeloma patients. We provide selection criteria that minimize the risks of transplantation. Specific guidelines on mobilization and supportive care through the transplant course, as done at Mayo Clinic, are given. A review of the data on tandem vs sequential autologous transplants is provided.

Key Points Survival of patients with primary plasma cell leukemia has improved in recent years, but is still inferior to those patients with multiple myeloma. This survival benefit appears to be mainly in patients older than 65 years of age.

The accumulation of somatic mutations, to which the cellular genome is permanently exposed, often leads to cancer. Analysis of any tumour shows that, besides the malignant cells, one finds other ‘supporting’ cells such as fibroblasts, immune cells of various types and even blood vessels. Together, these cells generate the microenvironment that enables the malignant cell population to grow and ultimately lead to disease. Therefore, understanding the dynamics of tumour growth and response to therapy is incomplete unless the interactions between the malignant cells and normal cells are investigated in the environment in which they take place. The complex interactions between cells in such an ecosystem result from the exchange of information in the form of cytokines- and adhesion-dependent interactions. Such processes impose costs and benefits to the participating cells that may be conveniently recast in the form of a game pay-off matrix. As a result, tumour progression and dynamics can be described in terms of evolutionary game theory (EGT), which provides a convenient framework in which to capture the frequency-dependent nature of ecosystem dynamics. Here, we provide a tutorial review of the central aspects of EGT, establishing a relation with the problem of cancer. Along the way, we also digress on fitness and of ways to compute it. Subsequently, we show how EGT can be applied to the study of the various manifestations and dynamics of multiple myeloma bone disease and its preceding condition known as monoclonal gammopathy of undetermined significance. We translate the complex biochemical signals into costs and benefits of different cell types, thus defining a game pay-off matrix. Then we use the well-known properties of the EGT equations to reduce the number of core parameters that characterize disease evolution. Finally, we provide an interpretation of these core parameters in terms of what their function is in the ecosystem we are describing and generate predictions on the type and timing of interventions that can alter the natural history of these two conditions.