Aug
12
Mon
2013
Invited Talk: Strategies for Diseases/Target Selection for Drug Discovery and a Multi-Targeted Approach to Metabolic Disorder @ Sathyam Hall
Aug 12 @ 11:45 am – 12:10 pm

PradipPradip K. Bhatnagar, Ph.D.
Former President & Head, Daiichi Sankyo Life Science Research Centre, India


Strategies for Diseases/Target Selection for Drug Discovery and a Multi-Targeted Approach to Metabolic Disorder

Drug discovery and development is a high risk and expensive undertaking.  Although, technologies, such as, bioinformatics, genomics, high throughput screening and computer-aided design have helped identify targets, biomarkers, lead candidates and reduced the time required for  advancing an idea from  bench to clinic, but it still takes 10-12 years and costs approximately one billion dollars to bring a drug to market globally. Therefore, it is imperative that the strategies to reduce the risk and increase efficiency are carefully selected. In this presentation I would discuss strategies for selecting potential diseases, targets and provide an example of multi-targeted approach to metabolic disorder.

 

Plenary Address: A novel strategy for targeting metalloproteinases in cancer @ Acharya Hall
Aug 12 @ 1:30 pm – 2:00 pm

gillianGillian Murphy, Ph.D.
Professor, Department of Oncology, University of Cambridge, UK


A novel strategy for targeting metalloproteinases in cancer

Epithelial tumours evolve in a multi-step manner, involving both inflammatory and mesenchymal cells. Although intrinsic factors drive malignant progression, the influence of the micro-environment of neoplastic cells is a major feature of tumorigenesis. Extracellular proteinases, notably the metalloproteinases, are key players in the regulation of this cellular environment, acting as major effectors of both cell-cell and cell-extracellular matrix (ECM) interactions. They are involved in modifying ECM integrity, growth factor availability and the function of cell surface signalling systems, with consequent effects on cellular differentiation, proliferation and apoptosis.This has made metalloproteinases important targets for therapeutic interventions in cancer and small molecule inhibitors focussed on chelation of the active site zinc and binding within the immediate active site pocket were developed.  These were not successful in early clinical trials due to the relative lack of specificity and precise knowledge of the target proteinase(s) in specific cancers. We can now appreciate that it is essential that we understand the relative roles of the different enzymes (of which there are over 60) in terms of their pro and anti tumour activity and their precise sites of expression The next generations of metalloproteinase inhibitors need the added specificity that might be gained from an understanding of the structure of individual active sites and the role of extra catalytic domains in substrate binding and other aspects of their biology. We have prepared scFv antibodies to the extra catalytic domains of two membrane metalloproteinases, MMP-14 and ADAM17, that play key roles in the tumour microenvironment. Our rationale and experiences with these agents will be presented in more detail.

Gillian

Aug
13
Tue
2013
Plenary Talk: Biosensor and Single Cell Manipulation using Nanopipettes @ Amriteshwari Hall
Aug 13 @ 10:06 am – 10:49 am

NaderNader Pourmand, Ph.D.
Director, UCSC Genome Technology Center,University of California, Santa Cruz


Biosensor and Single Cell Manipulation using Nanopipettes

Approaching sub-cellular biological problems from an engineering perspective begs for the incorporation of electronic readouts. With their high sensitivity and low invasiveness, nanotechnology-based tools hold great promise for biochemical sensing and single-cell manipulation. During my talk I will discuss the incorporation of electrical measurements into nanopipette technology and present results showing the rapid and reversible response of these subcellular sensors  to different analytes such as antigens, ions and carbohydrates. In addition, I will present the development of a single-cell manipulation platform that uses a nanopipette in a scanning ion-conductive microscopy technique. We use this newly developed technology to position the nanopipette with nanoscale precision, and to inject and/or aspirate a minute amount of material to and from individual cells or organelle without comprising cell viability. Furthermore, if time permits, I will show our strategy for a new, single-cell DNA/ RNA sequencing technology that will potentially use nanopipette technology to analyze the minute amount of aspirated cellular material.

Invited Talk: A cost-effective approach to Protein Structure-guided Drug Discovery: Aided by Bioinformatics, Chemoinformatics and computational chemistry @ Sathyam Hall
Aug 13 @ 11:15 am – 11:40 am

kalKal Ramnarayan, Ph.D.
Co-founder President & Chief Scientific Officer, Sapient Discovery, San Diego, CA, USA


A cost-effective approach to Protein Structure-guided Drug Discovery: Aided by Bioinformatics, Chemoinformatics and computational chemistry

With the mapping of the human genome completed almost a decade ago, efforts are still underway to understand the gene products (i.e., proteins) in the human biological and disease pathways.  Deciphering such information is very important for the discovery and development of small molecule drugs as well as protein therapeutics for various human diseases for which no cure exists.  As an example, with more than 500 members, the kinase family of protein targets continues to be an important and attractive class for drug discovery.  While how many of the members in this family are actually druggable is still to be established, there are several ongoing efforts on this class of proteins across a broad spectrum of disease categories.  Even though in general the protein structural topology might looks similar, there are issues with respect selectivity of identified small molecule inhibitors when, the lead molecule discovery is carried out at the ATP binding site.  As an added complexity, allosteric modulators are needed for some of the members, but the actual site for such modulation on the protein target can not resolved with uncertainty.  In this presentation we will describe a bioinformatics and computational based platform for small molecule discovery for protein targets that are involved in protein-protein interactions as well as targets like kinases and phosphatases.  We will describe a computational approach in which we have used an informatics based platform with several hundred kinases to sort through in silico and identify inhibitors that are likely to be highly selective in the lead generation phase.  We will discuss the implication of this approach on the drug discovery of the kinase and phosphatase classes in general and independent of the disease category.

 

Invited Talk: “Inside-out” NF-kappa B signaling in cancer and other pathologies @ Acharya Hall
Aug 13 @ 11:25 am – 11:40 am

ShigekiShigeki Miyamoto, Ph.D.
Professor, McArdle Laboratory for Cancer Research – UW Carbone Cancer Center
Department of Oncology, School of Medicine and Public Health
University of Wisconsin-Madison


“Inside-out” NF-κB signaling in cancer and other pathologies

The NF-κB/Rel family of transcription factors contributes to critical cellular processes, including immune, inflammatory and cell survival responses. As such, NF-κB is implicated in immunity-related diseases, as well as multiple types of human malignancies. Indeed, genetic alterations in the NF-κB signaling pathway are frequently observed in multiple human malignancies. NF-κB is normally kept inactive in the cytoplasm by inhibitor proteins. Extracellular ligands can induce the release of NF-κB from the inhibitors to allow its migration into the nucleus to regulate a variety of target genes.  NF-κB activation is also induced in response to multiple stress conditions, including those induced by DNA-damaging anticancer agents. Although precise mechanisms are still unclear, research from our group has revealed a unique nuclear-to-cytoplasmic signaling pathway. In collaboration with bioengineers, clinicians and pharmaceutical industry, our lab has developed new methods to analyze primary cancer patient samples and identified several compounds with different mechanisms that mitigate this cell survival pathway.  Further contributions from other labs have also revealed additional mechanisms and molecular players in this “inside-out” signaling pathway and expanded its role in other physiological and pathological processes, including B cell development, premature aging and therapy resistance of certain cancers. Our own new findings, along with these recent developments in the field, will be highlighted.

Shigeki

Invited Talk: Regulation of the MHC complex and HLA solubilisation by the Flavivirus, Japanese Encephalitis Virus @ Acharya Hall
Aug 13 @ 12:13 pm – 12:40 pm

ManjunathR. Manjunath, Ph.D.
Associate Professor, Dept of Biochemistry, Indian Institute of Science, Bengaluru, India


REGULATION OF THE MHC COMPLEX AND HLA SOLUBILISATION BY THE FLAVIVIRUS, JAPANESE ENCEPHALITIS VIRUS

Viral encephalitis caused by Japanese encephalitis virus (JEV) and West Nile Virus (WNV) is a mosquito-borne disease that is prevalent in different parts of India and other parts of South East Asia. JEV is a positive single stranded RNA virus that belongs to the Flavivirus genus of the family Flaviviridae. The genome of JEV is about 11 kb long and codes for a polyprotein which is cleaved by both host and viral encoded proteases to form 3 structural and 7 non-structural proteins. It is a neurotropic virus which infects the central nervous system (CNS) and causes death predominantly in newborn children and young adults. JEV follows a zoonotic life-cycle involving mosquitoes and vertebrate, chiefly pigs and ardeid birds, as amplifying hosts. Humans are infected when bitten by an infected mosquito and are dead end hosts. Its structural, pathological, immunological and epidemiological aspects have been well studied. After entry into the host following a mosquito bite, JEV infection leads to acute peripheral neutrophil leucocytosis in the brain and leads to elevated levels of type I interferon, macrophage-derived chemotactic factor, RANTES,TNF-α and IL-8 in the serum and cerebrospinal fluid.

Major Histocompatibility Complex (MHC) molecules play a very important role in adaptive immune responses. Along with various classical MHC class I molecules, other non-classical MHC class I molecules play an important role in modulating innate immune responses. Our lab has shown the activation of cytotoxic T-cells (CTLs) during JEV infection and CTLs recognize non-self peptides presented on MHC molecules and provide protection by eliminating infected cells. However, along with proinflammatory cytokines such as TNFα, they may also cause immunopathology within the JEV infected brain. Both JEV and WNV, another related flavivirus have been shown to increase MHC class I expression. Infection of human foreskin fibroblast cells (HFF) by WNV results in upregulation of HLA expression. Data from our lab has also shown that JEV infection upregulates classical as well as nonclassical (class Ib) MHC antigen expression on the surface of primary mouse brain astrocytes and mouse embryonic fibroblasts.

There are no reports that have discussed the expression of these molecules on other cells like endothelial and astrocyte that play an important role in viral invasion in humans. We have studied the expression of human classical class I molecules HLA-A, -B, -C and the non-classical HLA molecules, HLA-E as well as HLA-F in immortalized human brain microvascular endothelial cells (HBMEC), human endothelial cell line (ECV304), human glioblastoma cell line (U87MG) and human foreskin fibroblast cells (HFF). Nonclassical MHC molecules such as mouse Qa-1b and its human homologue, HLA-E have been shown to be the ligand for the inhibitory NK receptor, NKG2A/CD94 and may bridge innate and adaptive immune responses. We show that JEV infection of HBMEC and ECV 304 cells upregulates the expression of HLA-A, and –B antigens as well as HLA-E and HLA-F. Increased expression of total HLA-E upon JEV infection was also observed in other human cell lines as well like, human amniotic epithelial cells, AV-3, FL and WISH cells. Further, we show for the first time that soluble HLA-E (sHLA-E) was released from infected ECV and HBMECs. In contrast, HFF cells showed only upregulation of cell-surface HLA-E expression while U87MG, a human glioblastoma cell line neither showed any cell-surface induction nor its solubilization. This shedding of sHLA-E was found to be dependent on matrix metalloproteinase (MMP) and an important MMP, MMP-9 was upregulated during JEV infection. Treatment with IFNγ resulted in the shedding of sHLA-E from ECV as well as U87MG but not from HFF cells. Also, sHLA-E was shed upon treatment with IFNβ and both IFNβ and TNFα, when present together caused an additive increase in the shedding of sHLA-E. HLA-E is an inhibitory ligand for CD94/NKG2A receptor of Natural Killer cells. Thus, MMP mediated solubilization of HLA-E from infected endothelial cells may have important implications in JEV pathogenesis including its ability to compromise the blood brain barrier.

Manjunath (2)

Invited Talk: Probing Estrogen Receptor – Tumor Suppressor p53 Interaction in Cancer: From Basic Research to Clinical Trial @ Acharya Hall
Aug 13 @ 3:26 pm – 3:57 pm

gokuldasGokul Das, Ph.D.
Co-Director, Breast Disease Site Research Group, Roswell Park Cancer Institute, Buffalo, NY


Probing Estrogen Receptor−Tumor Suppressor p53 Interaction in Cancer: From Basic Research to Clinical Trial

Tumor suppressor p53 and estrogen receptor have opposite roles in the onset and progression of breast cancer. p53 responds to a variety of cellular of stresses by restricting the proliferation and survival of abnormal cells. Estrogen receptor plays an important role in normal mammary gland development and the preservation of adult mammary gland function; however, when deregulated it becomes abnormally pro-proliferative and greatly contributes to breast tumorigenesis. The biological actions of estrogens are mediated by two genetically distinct estrogen receptors (ERs): ER alpha and ER beta. In addition to its expression in several ER alpha-positive breast cancers and normal mammary cells, ER beta is usually present in ER alpha-negative cancers including triple-negative breast cancer. In spite of genetically being wild type, why p53 is functionally debilitated in breast cancer has remained unclear. Our recent finding that ER alpha binds directly to p53 and inhibits its function has provided a novel mechanism for inactivating genetically wild type p53 in human cancer. Using a combination of proliferation and apoptosis assays, RNAi technology, quantitative chromatin immunoprecipitation (qChIP), and quantitative real-time PCR (qRT-PCR), in situ proximity ligation assay (PLA), and protein expression analysis in patient tissue micro array (TMA), we have demonstrated binding of ER alpha to p53 and have delineated the domains on both the proteins necessary for the interaction. Importantly, ionizing radiation inhibits the ER-p53 interaction in vivo both in human cancer cells and human breast tumor xenografts in mice. In addition, antiestrogenstamoxifen and faslodex/fulvestrant (ICI 182780) disrupt the ER-p53 interaction and counteract the repressive effect of ER alpha on p53, whereas 17β-estradiol (E2) enhances the interaction. Intriguingly, E2 has diametrically opposite effects on corepressor recruitment to a p53-target gene promoter versus a prototypic ERE-containing promoter. Thus, we have uncovered a novel mechanism by which estrogen could be providing a strong proliferative advantage to cells by dual mechanisms: enhancing expression of ERE-containing pro-proliferative genes while at the same time inhibiting transcription of p53-dependent anti-proliferative genes. Consistently, ER alpha enhances cell cycle progression and inhibits apoptosis of breast cancer cells. Correlating with these observations, our retrospective clinical study shows that presence of wild type p53 in ER-positive breast tumors is associated with better response to tamoxifen therapy. These data suggest ER alpha-p53 interaction could be one of the mechanisms underlying resistance to tamoxifen therapy, a major clinical challenge encountered in breast cancer patients. We have launched a prospective clinical trial to analyze ER-p53 interaction in breast cancer patient tumors at Roswell Park Cancer Institute. Our more recent finding that ER beta has opposite functions depending on the mutational status of p53 in breast cancer cells is significant in understanding the hard-to-treat triple-negative breast cancer and in developing novel therapeutic strategies against it. Our integrated approach to analyze ER-p53 interaction at the basic, translational, and clinical research levels has major implications in the diagnosis, prognosis, and treatment of breast cancer.

 

Invited Talk: Cancer Stem Cells – Target Colon Cancer @ Acharya Hall
Aug 13 @ 4:25 pm – 5:04 pm

ShrikantShrikant Anant, Ph.D.
The Department of Molecular & Integrative Physiology, Kansas University Medical Center, USA


Cancer Stem Cells: Target Colon Cancers

Shrikant Anant, Deep Kwatra and Dharmalingam Subramaniam

Colon cancer is a leading cause of cancer related deaths in the US, and its rate is increasing at an alarming rate in lndia. Recent studies have suggested the drug resistance role for a mall number of cells within a tumor called cancer stem cells. We identified the colon cancer stem cell marker DCLK1, a member of the protein kinase superfamily and the doublecortin family. The protein encodes a Cterminal serinethreonine protein kinase domain, which shows substantial homology to Ca2calmodulindependent protein kinase. Our current studies have been to identify compounds that can either affect DCLK1 expression or inhibits its activity as a way to inhibit cancer stem cells. Honokiol is a biphenolic compound that has been used in the traditional Chinese Medicine for treating various ailments. In vitro kinase assays with recombinant DCLK1 demonstrated that honokiol inhibits its kinase activity in a dose dependent manner. We therefore determined the effect of honokiol on stem cells. One method to look at effects on stem cells is perform a spheroid assay, where spheroids formation is suggested to maintain stemlike characteristic of cancer cells. Honokiol significantly suppressed colonosphere formation of two colon cancer cell lines HCT116 and SW480. Flow cytometry studies confirmed that honokiol reduced the number of DCLK1cells. A critical signaling pathway known to modulate intestinal stem cell proliferation is the Hippo signaling pathway, and deregulation of the pathway leads to tumor development. DCLK1cells had high levels of YAP1, the nuclear target of Hippo signaling. We determined the effect of honokiol on components of the hipposignaling pathway. Honokiol reduced the phosphorylation of Mst1/2, Lats1/2 and YAP1. Furthermore, honokiol treatment resulted in downregulation of YAPTEAD complex protein TEAD-1. Ectopic expression of the TEAD-1 partially rescued the cells from honokiol mediated growth suppression. To determine the effect of honokiol on tumor growth in vivo, nude mice harboring HCT116 tumor xenografts in their flanks were administered the compound intraperitoneally every day for 21 days. Honokiol treatment significantly inhibited tumor xenograft growth. Western blot and immunohistochemistry analyses demonstrated significant inhibition in the expression of stem marker and Hippo signaling proteins in the honokioltreated xenograft tissues. Taken together, these data suggest that honokiol is a potent inhibitor of colon cancer that targets DCLK1 stem cells by inhibiting Hippo signaling pathway.

Delegate Talk: A Non-toxic Approach to Prevent Secondary Effects of Chemotherapies @ Acharya Hall
Aug 13 @ 6:26 pm – 6:38 pm
Delegate Talk: A Non-toxic Approach to Prevent Secondary Effects of Chemotherapies @ Acharya Hall | Vallikavu | Kerala | India

Tanu Sharma, Narendra Parihar, Someshwar Nath, Azad Singh, Savneet Kaur, Simendra Singh and Chandi Mandal.


In the recent years, there has been a surge in various forms of cancers especially in urban areas of India. Tumor recurrence and metastasis are the main causes of increased morbidity and mortality. In poor and developing countries like India chemotherapy is the choosen method of therapeutic intervention for different types of malignancies such as breast, prostate, pancreas, etc. Although general chemotherapy treatment is effective in controlling tumour growth but high doses of the treatment regimen often results in severe off-target toxicity to different organs including liver, kidney, heart, brain etc. (1) A large percentage of patients are unable to tolerate this toxicity and sometime it can also lead to life threatening complications. (2) Therefore, the primary objective of this study is to prevent this druginduced off-target toxicity. Omega 3 fatty acids (n-3FAs) such as DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) that are active components of fish oil play active role in preventing cancer growth and its metastasis. (3–5) We have recently identified that omega 3-fatty acids prevent breast cancer bone metastasis by targeting cancer stem cell marker CD44 and osteoclastogenic factor CSF-1(4, 5). With this background, the present study addresses the role of n-3FAs in preventing chemotherapeutic drug-induced off-target toxicity.

Methods
The cat fishes were divided into four groups (each group contains 4 fishes) for each set of experiments. Three different chemotherapeutic drugs etoposide, doxorubicin, cisplatin at higher dosages (4, 2, 2 mg/kg body wt respectively) and fish oil (60mg/kg body wt, DHA: EPA; 2:3) were administered to cat fish (Mangur) by gavage. After 6 days, cat fishes were sacrificed and different organs were isolated. SGPT and alkaline phosphatase (ALP) activity assays were performed to examine liver function and superoxide dismutase activity (SOD) assay was conducted to evaluate reactive oxygen species (ROS) level.

Results
Severe skin damages were observed both in doxorubicin and cisplatintreated cat fishes as compared to the control fishes, indicating side effects of chemotherapeutic drugs treatment. High level of SGPT as well as ALP activity was observed in liver samples of etoposide and doxorubicin – treated fishes, suggesting chemotherapeutic drug-induced liver toxicity. Mechanistically, we found that doxorubicin treatment showed significant decrease of SOD activity in liver samples in comparison to the control fishes, suggesting that chemotherapeutic drugs lead to organ toxicity presumably by increasing ROS levels (6). However, treatment of the fishes with n-3FAs of the fish oil led to a dramatic reduction of chemotherapeutic drug-induced skin damages. Also, low levels of SGPT and ALP activities were observed in the fishes given etoposide in combination with n-3FAs as compared to the fishes given etoposide alone. Similarly, fish oil also gave protection against doxorubicin-induced liver dysfunction. Our data further showed that n-3FAs treatment significantly increased etoposide and doxorubicin-inhibited SOD activity.

Conclusions
The study for the first time reports that the use of n-3FAs leads to a dramatic reduction of chemotherapeutic drug-induced skin damages and mitigates chemotherapeutic drug-driven liver dysfunction presumably by reducing ROS level. This study suggests that n-3FAs may possibly be used in combination with chemotherapeutic drugs to treat different cancers to reduce chemotherapeutic drugs-associated systemic toxicity and to increase anticancer activity. Ongoing research study will further address the role of n-3FAs on other off-target toxic effects of chemotherapeutic drugs.

Aug
14
Wed
2013
Invited Talk: Nature Nurtures New Drug Discovery @ Acharya Hall
Aug 14 @ 10:10 am – 10:40 am
Former Vice-President, SPIC Pharmaceuticals, Tamil Nadu, India

The global healthcare scene of which the pharmaceutical industry and its products are integral components is today at the cross roads. The high and unaffordable costs of drug research with estimates of over 1 billion dollars for every new drug discovered and developed, the very low success rates, the high degree of obsolescence due to undesirable adverse drug reactions, the decline in the development pipeline of new drugs, patent expiries leading to generic competition and the public’s disillusionment with use of chemicals for human consumption   as drugs have all significantly contributed to the problems of this lifeline industry. The strategy adopted by the large R&D based Corporations  to get bigger and bigger through mergers and acquisitions to improve cost-effectiveness and productivity  of R&D has so far not  worked effectively. Consequently, one of the recent trends in healthcare, articulated by many experts is to look for  alternate or even complementary approaches to reduce the impact of rising costs of drugs on  healthcare. Various new strategies for drug discovery such as the use of  Natural Products especially medicinal plants  are being actively pursued by healthcare planners and providers.   Side by side, traditional systems of medicine whether from the oriental countries or the western nations are also having a serious relook to understand their usefulness in healthcare. To achieve its legitimate position in the healthcare scenario,  it is essential  to scientifically validate their claimed utility through appropriate and systematic research efforts including pre-clinical and clinical studies. In addition to their own use as medicines, knowledge on the Indian Traditional Medicines can be used as a platform for new drug discovery. The huge potential for carrying out  systematic R&D programs for new Drug Discovery  based on  natural products  and possible strategies  to realise them in the coming decades will be explained in this presentation.

MDNair

Invited Talk: New Drug R&D in India: Challenges & Opportunities @ Acharya Hall
Aug 14 @ 10:45 am – 11:30 am

RamaniRamani A. Aiyer, Ph.D., MBA
Principal, Shasta BioVentures, San Jose, CA, USA


New Drug R&D in India: Challenges & Opportunities

New drug discovery and development has become a global endeavor, with Western big pharmaceutical companies farming out more and more chemistry and biology research to Asia, particularly India and China. During the last decade, several Indian pharmaceutical companies have embarked on ambitious R&D programs, with slow but steady progress in developing new chemical / molecular entities. The Indian government has also made a strong commitment to promote innovation and entrepreneurship in the biotechnology sector. The first part of the talk will focus on a case study showing the entire process of discovery and development of a new drug recently launched for Rheumatoid Arthritis. We will then address the challenges of conducting innovative R&D in India and actions necessary to overcome them. The second part of the talk will make the case for developing Ayurvedic drug formulations for the Western / Global markets, again using the example of Rheumatoid Arthritis (Aamavaata). Ayurveda takes a holistic approach to disease diagnosis and therapy based on interactions among body type (prakriti), tri-doshas (three body humors), sapta-dhatus (seven tissues) and malas (excretions). The drugs prescribed are usually herbo-mineral formulations comprising multiple medicinal plants and / or metals. The manufacturing processes date back to Ayurvedic texts several thousand years old, and are compiled in the Ayurvedic Pharmacopeia. Also, the treatment modalities and drug formulations are “personalized” to fit different patient types, based on the holistic diagnoses mentioned earlier. There is a tremendous need to establish a sound basis for Ayurvedic drug discovery R&D for the modern world. We must find a scientific and ethical way to leverage the vast body of anecdotal and possibly retrospective data on patients undergoing Ayurvedic treatment. Combined with in vitro and in vivo biological data on Ayurvedic herbo-mineral formulations, the adoption of stringent manufacturing practices, and designing sound clinical trials to establish the safety and efficacy, India has a golden opportunity to expand the reach of Ayurvedic drugs into Western / Global medical practice.

Ramani

Delegate Talk: Proteomic profiling of gallbladder cancer secretome – a source for circulatory biomarker discovery @ Amriteshwari Hall
Aug 14 @ 12:55 pm – 1:06 pm
Delegate Talk: Proteomic profiling of gallbladder cancer secretome – a source for circulatory biomarker discovery @ Amriteshwari Hall | Vallikavu | Kerala | India

Tejaswini Subbannayya, Nandini A. Sahasrabuddhe, Arivusudar Marimuthu, Santosh Renuse, Gajanan Sathe, Srinivas M. Srikanth, Mustafa A. Barbhuiya, Bipin Nair, Juan Carlos Roa, Rafael Guerrero-Preston, H. C. Harsha, David Sidransky, Akhilesh Pandey, T. S. Keshava Prasad and Aditi Chatterjee


Proteomic profiling of gallbladder cancer secretome – a source for circulatory biomarker discovery

Gallbladder cancer (GBC) is the fifth most common cancer of the gastrointestinal tract and one of the common malignancies that occur in the biliary tract (Misra et al. 2006; Lazcano-Ponce et al. 2001). It has a poor prognosis with survival of less than 5 years in 90% of the cases (Misra et al. 2003). The etiology is ill-defined. Several risk factors have been reported including cholelithiasis, obesity, female gender and exposure to carcinogens (Eslick 2010; Kumar et al. 2006). Poor prognosis in GBC is mainly due to late presentation of the disease and lack of reliable biomarkers for early diagnosis. This emphasizes the need to identify and characterize cancer biomarkers to aid in the diagnosis and prognosis of GBC. Secreted proteins are an important class of molecules which can be detected in body fluids and has been targeted for biomarker discovery. There are challenges faced in the proteomic interrogation of body fluids especially plasma such as low abundance of tumor secreted proteins, high complexity and high abundance of other proteins that are not released by the tumor cells (Tonack et al. 2009). Profiling of conditioned media from the cancer cell lines can be used as an alternate means to identify secreted proteins from tumor cells (Kashyap et al. 2010; Marimuthu et al. 2012). We analyzed the invasive property of 7 GBC cell lines (SNU-308, G-415, GB-d1, TGBC2TKB, TGBC24TKB, OCUG-1 and NOZ). Four cell lines were selected for analysis of the cancer secretome based on the invasive property of the cells. We employed isobaric tags for relative and absolute quantitation (iTRAQ) labeling technology coupled with high resolution mass spectrometry to identify and characterize secretome from the panel of 4GBC cancer cells mentioned above. In total, we have identified around 2,000 proteins of which 175 were secreted at differential abundance across all the four cell lines. This secretome analysis will act as a reservoir of candidate biomarkers. Currently, we are investigating and validating these candidate markers from GBC cell secretome. Through this study, we have shown mass spectrometry-based quantitative proteomic analysis as a robust approach to investigate secreted proteins in cancer cells.