Rao Papineni

Chemoprevention in gastrointestinal physiology and disease. Natural products and microbiome.

The human intestinal tract harbors a complex ecosystem of commensal bacteria that play a fundamental role in the well-being of their host. There is a general consensus that diet rich in plant-based foods has many advantages in relation to the health and well-being of an individual. In adults, diets that have a high proportion of fruit and vegetables and a low consumption of meat are associated with a highly diverse microbiota and are defined by a greater abundance of Prevotella compared with Bacteroides, whereas the reverse is associated with a diet that contains a low proportion of plant-based foods. In a philosophical term, our consumption of processed foods, widespread use of antibiotics and disinfectants, and our modern lifestyle may have forever altered our ancient gut microbiome. We may never be able to identify or restore our microbiomes to their ancestral state, but dietary modulation to manipulate specific gut microbial species or groups of species may offer new therapeutic approaches to conditions that are prevalent in modern society, such as functional gastrointestinal disorders, obesity, and age-related nutritional deficiency. We believe that this will become an increasingly important area of health research.

Increased sensitivity in antigen detection with fluorescent latex nanosphere-IgG antibody conjugates.

IgG antibodies were conjugated to Kodak X-Sight nanospheres to develop fluorescent-labeled antibodies using two different synthetic routes: one involving the DTT reduction method, and the other involving Trauts Reagent modification method. These two methods result in different conjugation efficiencies and different performances in antigen detection. Western blotting shows that the nanosphere-IgG antibody conjugates synthesized using the DTT reduction method are more immunospecific than the conjugates synthesized using Trauts Reagent modification method. In addition, the conjugates synthesized using DTT reduction also show higher antigen detection sensitivity than other commercially available fluorescent-IgG antibody conjugates, including Alexa Fluor, Qdot, and CyDye conjugates.

Abstract 4921: X-ray irradiation induced bio luminescence: Ex vivo and endoscopic imaging of radiobioluminescence

Accurate dose delivery to malignant tissue in radiotherapy is essential for enhancing the treatment efficacy while minimizing morbidity of surrounding normal tissues. Advances in therapeutic strategies and diagnosis technologies along with our understanding of the biology of tumor response to radiation therapy have paved way to allow nearly 60% of current cancer patients to be treated with Radiation Therapy. The confluence of molecular imaging and nanotechnology fields are bridging physics and medicine and are quickly making strides in opening new avenues and therapeutic strategies that complement radiation therapy- with a distinct footprint in immunotherapy, adoptive cell therapy, and targeted chemotherapy. Incorporating optical imaging in radiation therapy in my laboratory, endogenous bioluminescence resulting from whole body irradiation in different organs, which is distinct from the cherenkov radiation, is described here. Mice were subjected to 5 - 10 Gy X-ray irradiation doses using commercially available X-RAD 320 irradiator (1Gy/min; F2 beam hardening filter 1.5mm Al, 0.25mm Cu, 0.75mm Sn; Precision X-ray inc, USA). The endogenous bioluminescence in response to irradiation, described here as radiobioluminescence, was captured using cooled CCD camera from live subjects, and from the excised organs/tissues. Significant increase (up to 100 fold) in the amounts of photons released as bioluminescence was detected during 5 -10 min capture from the mice subjected to irradiation compared to that of the control. The GI tract contributed significant portion of this radiobioluminescence and was confirmed both by ex-vivo and minimally invasive rectal endoscopic imaging. Other organs and tissues displaying such robust increase in radiobioluminescence include skin, and fat depots. The role, evaluation, and future assessment of nutrients, nutriceuticals, microbiome, and metabolites during the course of radiation therapy become highlighted with these findings. Thus such molecular imaging methodologies and modalities described will be useful tools in radiation treatment design and process. Citation Format: Rao V. Papineni. X-ray irradiation induced bio luminescence: Ex vivo and endoscopic imaging of radiobioluminescence. [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 4921. doi:10.1158/1538-7445.AM2014-4921

The tubercular badger and the uncertain curve:- The need for a multiple stressor approach in environmental radiation protection

&NA; This article presents the results of a workshop held in Stirling, Scotland in June 2018, called to examine critically the effects of low‐dose ionising radiation on the ecosphere. The meeting brought together participants from the fields of low‐ and high‐dose radiobiology and those working in radioecology to discuss the effects that low doses of radiation have on non‐human biota. In particular, the shape of the low‐dose response relationship and the extent to which the effects of low‐dose and chronic exposure may be predicted from high dose rate exposures were discussed. It was concluded that high dose effects were not predictive of low dose effects. It followed that the tools presently available were deemed insufficient to reliably predict risk of low dose exposures in ecosystems. The workshop participants agreed on three major recommendations for a path forward. First, as treating radiation as a single or unique stressor was considered insufficient, the development of a multidisciplinary approach is suggested to address key concerns about multiple stressors in the ecosphere. Second, agreed definitions are needed to deal with the multiplicity of factors determining outcome to low dose exposures as a term can have different meanings in different disciplines. Third, appropriate tools need to be developed to deal with the different time, space and organisation level scales. These recommendations permit a more accurate picture of prospective risks.

Abstract LB-012: Deoxyglucose and bisphosphonate shows common pathways in its drug repurposed anticancer and anti-infection actions

We earlier showed with Systems Biology approach that the genotoxic stress response evoked by cancer, infection, and radiation injury have similarities, particularly at the gastrointestinal tract. This was made possible using biophotonics, and show promise in drug screening opportunities using each of these pathologies as a surrogate model for one another. Using similar molecular Imaging methodology, we showed for the first time binding of osteoporosis drug bisphosphonate to prostate and ovarian cancer tumors and potential drug repurposing candidature. Recently, we presented similar drug re-tasking potential of 2-Deoxyglucose (2-DG) in anti-infection. Here, our data demonstrating mitigation of citrobacter rodentium infection by dietary treatment by 2-DG (0.4%), were analyzed with the bisphosphonate anti-infection response to enteric bacterial pathogens data reported elsewhere. Based on these results, a systems approach analysis is developed and presented demonstrating cross-talk and communication between different cells and integrated responses to pathogens and disease by 2-DG and bisphosphonate in anticancer and anti-infection actions. A role in EGFR signaling and modulation in the infiltration immune response cells by these two dissimilar compounds play a profound bridging event in anticancer and anti-infection activities. These system biology strategies will provide opportunities for drug repurposing in personalized cancer therapy and in anti-microbial management during cancer treatment. Also pave way for safer drugs in prevention and therapy of HER family-driven cancers. Citation Format: Rao V. Papineni, Shahid Umar, Alexey Goltsov, Ishfaq Ahmed. Deoxyglucose and bisphosphonate shows common pathways in its drug repurposed anticancer and anti-infection actions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-012. doi:10.1158/1538-7445.AM2017-LB-012

Abstract LB-317: Energy distruptor 2-deoxyglucose mitigates bacterial infection responsive hyperplasia and/or colitis

Transmissible murine crypt hyperplasia (TMCH) is a pathological outcome of Citrobacter rodentium (CR) infection, accompanied by intestinal inflammation during colitis though excessive induction of epithelial regeneration and repair mechanisms. The TMCH model, provides an excellent template to determine how alterations in intestinal stem cells promote trans-differentiation, crypt regeneration or colon carcinogenesis following bacterial infection. CR is a valuable infection model for the study of pathogenesis of the clinically significant human pathogens, enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC). During TMCH, there is a complex interplay between the Notch and Wnt/β-catenin pathways in colonic crypt hyperplasia. Blocking Notch signaling via chronic dibenzazepine (DBZ) administration inhibits both Notch and Wnt signaling, and disrupts the intestinal barrier during CR induced colitis. 2-deoxyglucose (2DG) is a glycolytic inhibitor has been used for cancer therapy exploiting the cancer cell9s high metabolic state. Added, the similarity of 2DG to mannose produces improper N-linked glycosylation resulting in an unfolded protein response (UPR) slowing growth of tumors. Here, using CR infection model, we show that dietary treatment of 2DG (0.4%) mitigates C. rodentium- and Notch signaling blocker dibenzazepine (DBZ)-induced colitis in NIH:Swiss mice. The survival curve shows no loss in mice administered with 2DG, compared to 40% loss in mice with vehicle alone during CR infection together with DBZ treatment. At tissue level, 2DG dietary intervention resulted in restoration of Hes-1, and β-catenin protein levels as observed from the western analyses of the C. rodentium-infected and DBZ-treated mice crypts. Histological staining show reduced dysbiosis upon 2DG intervention, as seen from reduced infiltration of inflammatory response cells during CR infection and the therapeutic effects are further substantiated with the Ki-67 staining. Thus, the energy distruptor 2-deoxyglucose (2DG) is described for the first time here to mitigate bacterial infection and its responsive hyperplasia/colitis. The current model in this novel mechanism of action will be presented. Citation Format: Ishfaq Ahmed, Shahid Umar, Rao V. Papineni. Energy distruptor 2-deoxyglucose mitigates bacterial infection responsive hyperplasia and/or colitis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-317.

Abstract 4901: Clostridium cluster XIVa species an early biomarker in radiation injury

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Radiation therapy is being used in the treatment of nearly 60% of the current cancer patients. In spite of the best efforts to provide special care in minimizing radiation exposure, significant radiation injury remains a common side-effect particularly to the gastro intestinal tract. Severe injury to GI tract may lead to multiple organ dysfunction syndrome. The status of fecal microbiota has been proposed as a rapid diagnostic platform in radiation injury. Gut microbes play a role in immunity, health, and disease. Imbalances in gut microbiota are related to numerous disorders, such as inflammatory bowel disease, colorectal cancer (CRC), and atopy. In patients with immune suppression due to high-dose chemotherapy or that undergoing radiation therapy, disruption of the microbiota through antibiotics and impairment of host immunity gives rise to perturbations favoring intestinal domination by pathogenic species, resulting in increased bacterial translocation and susceptibility to systemic infection. Here, using real-time PCR assays, we assessed the immediate changes and quantitative alterations to fecal microbiota in response to radiation injury. Swiss-albino Mice were subjected to 10 Gy X-ray whole body irradiation doses using commercially available X-RAD 320 irradiator (1Gy/min; F2 beam hardening filter 1.5mm Al, 0.25mm Cu, 0.75mm Sn; Precision X-ray inc, USA). Fecal samples collected immediately after the radiation exposure were analyzed. We show that Clostridium cluster XIVa that accounts for almost 60% of the mucin-adhered microbiota is significantly increased (11.71 +/- 0.29 fold n=6) in the fecal samples, compared to the total bacteria and other bacteria that tend to enrich in the luminal region. Along with the Bacteroidetes and Proteobacteria from the luminal region, minimal changes in the levels of Firmicutes that colonize the mucin layer were observed. Further, these changes varied considerably between the subjects and were inconsistent compared to the Clostridium cluster species. Clostridium cluster XIVa has been proposed to be the mucosal butyrate producers producing butyrate close to the epithelium. This enhances butyrate bioavailability required in treating diseases such as inflammatory bowel disease. These findings provide opportunities to evaluate the potential use of intestinal microbiota as biomarkers in radiation injury. Also, provides insights into the microbial changes tantamount to the radiation induced GI injury. Citation Format: Ishfaq Ahmed, William McLauglin, Shrikant Anant, Shahid Umar, Rao V. Papineni. Clostridium cluster XIVa species an early biomarker in radiation injury. [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 4901. doi:10.1158/1538-7445.AM2014-4901