The analog of cGAMP, c-di-AMP, activates STING mediated cell death pathway in estrogen-receptor negative breast cancer cells

Immune adaptor protein like STING/MITA regulate innate immune response and plays a critical role in inflammation in the tumor microenvironment and regulation of metastasis including breast cancer. Chromosomal instability in highly metastatic cells releases fragmented chromosomal parts in the cytoplasm, hence the activation of STING via an increased level of cyclic dinucleotides (cDNs) synthesized by cGMP-AMP synthase (cGAS). Cyclic dinucleotides 2’ 3’-cGAMP and it's analog can potentially activate STING mediated pathways leading to nuclear translocation of p65 and IRF-3 and transcription of inflammatory genes. The differential modulation of STING pathway via 2’ 3’-cGAMP and its analog and its implication in breast tumorigenesis is still not well explored. In the current study, we demonstrated that c-di-AMP can activate type-1 IFN response in ER negative breast cancer cell lines which correlate with STING expression. c-di-AMP binds to STING and activates downstream IFN pathways in STING positive metastatic MDA-MB-231/MX-1 cells. Prolonged treatment of c-di-AMP induces cell death in STING positive metastatic MDA-MB-231/MX-1 cells mediated by IRF-3. c-di-AMP induces IRF-3 translocation to mitochondria and initiates Caspase-9 mediated cell death and inhibits clonogenicity of triple-negative breast cancer cells. This study suggests that c-di-AMP can activate and modulates STING pathway to induce mitochondrial mediated apoptosis in estrogen-receptor negative breast cancer cells

The spectrum of neurodevelopmental, neuromuscular and neurodegenerative disorders due to defective autophagy

Primary dysfunction of autophagy due to Mendelian defects affecting core components of the autophagy machinery or closely related proteins have recently emerged as an important cause of genetic disease. This novel group of human disorders may present throughout life and comprises severe early-onset neurodevelopmental and more common adult-onset neurodegenerative disorders. Early-onset (or congenital) disorders of autophagy often share a recognizable "clinical signature," including variable combinations of neurological, neuromuscular and multisystem manifestations. Structural CNS abnormalities, cerebellar involvement, spasticity and peripheral nerve pathology are prominent neurological features, indicating a specific vulnerability of certain neuronal populations to autophagic disturbance. A typically biphasic disease course of late-onset neurodegeneration occurring on the background of a neurodevelopmental disorder further supports a role of autophagy in both neuronal development and maintenance. Additionally, an associated myopathy has been characterized in several conditions. The differential diagnosis comprises a wide range of other multisystem disorders, including mitochondrial, glycogen and lysosomal storage disorders, as well as ciliopathies, glycosylation and vesicular trafficking defects. The clinical overlap between the congenital disorders of autophagy and these conditions reflects the multiple roles of the proteins and/or emerging molecular connections between the pathways implicated and suggests an exciting area for future research. Therapy development for congenital disorders of autophagy is still in its infancy but may result in the identification of molecules that target autophagy more specifically than currently available compounds. The close connection with adult-onset neurodegenerative disorders highlights the relevance of research into rare early-onset neurodevelopmental conditions for much more common, age-related human diseases.Peer reviewe

TNF-α differentially modulates subunit levels of respiratory electron transport complexes of ER/PR +ve/−ve breast cancer cells to regulate mitochondrial complex activity and tumorigenic potential

Background Tumor necrosis factor-α (TNF-α) is an immunostimulatory cytokine that is consistently high in the breast tumor microenvironment (TME); however, its differential role in mitochondrial functions and cell survival in ER/PR +ve and ER/PR −ve breast cancer cells is not well understood. Methods In the current study, we investigated TNF-α modulated mitochondrial proteome using high-resolution mass spectrometry and identified the differentially expressed proteins in two different breast cancer cell lines, ER/PR positive cell line; luminal, MCF-7 and ER/PR negative cell line; basal-like, MDA-MB-231 and explored its implication in regulating the tumorigenic potential of breast cancer cells. We also compared the activity of mitochondrial complexes, ATP, and ROS levels between MCF-7 and MDA-MB-231 in the presence of TNF-α. We used Tumor Immune Estimation Resource (TIMER) webserver to analyze the correlation between TNF-α and mitochondrial proteins in basal and luminal breast cancer patients. Kaplan-Meier method was used to analyze the correlation between mitochondrial protein expression and survival of breast cancer patients. Results The proteome analysis revealed that TNF-α differentially altered the level of critical proteins of mitochondrial respiratory chain complexes both in MCF-7 and MDA-MB-231, which correlated with differential assembly and activity of mitochondrial ETC complexes. The inhibition of the glycolytic pathway in the presence of TNF-α showed that glycolysis is indispensable for the proliferation and clonogenic ability of MDA-MB-231 cells (ER/PR −ve) as compared to MCF-7 cells (ER/PR +ve). The TIMER database showed a negative correlation between the expressions of TNF-α and key regulators of mitochondrial OXPHOS complexes in basal breast vs lobular carcinoma. Conversely, patient survival analysis showed an improved relapse-free survival with increased expression of identified proteins of ETC complexes and survival of the breast cancer patients. Conclusion The evidence presented in our study convincingly demonstrates that TNF-α regulates the survival and proliferation of aggressive tumor cells by modulating the levels of critical assembly factors and subunits involved in mitochondrial respiratory chain supercomplexes organization and function. This favors the rewiring of mitochondrial metabolism towards anaplerosis to support the survival and proliferation of breast cancer cells. Collectively, the results strongly suggest that TNF-α differentially regulates metabolic adaptation in ER/PR +ve (MCF-7) and ER/PR −ve (MDA-MB-231) cells by modulating the mitochondrial supercomplex assembly and activity.This work was supported by the Department of Science and Technology, Govt. of India, grant number INT/Korea/P-39 to Prof. Rajesh Singh. Global Infrastructure Program through the NRF funded by the Ministry of Science and ICT (NRF-2017K1A3A1A19071651 to ECY) and National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIP) (NRF-2016R1A5A1010764 and NRF-2015M3A9B6073835 to ECY) to Prof. Eugene C. Yi

The spectrum of neurodevelopmental, neuromuscular and neurodegenerative disorders due to defective autophagy

Primary dysfunction of autophagy due to Mendelian defects affecting core components of the autophagy machinery or closely related proteins have recently emerged as an important cause of genetic disease. This novel group of human disorders may present throughout life and comprises severe early-onset neurodevelopmental and more common adult-onset neurodegenerative disorders. Early-onset (or congenital) disorders of autophagy often share a recognizable "clinical signature," including variable combinations of neurological, neuromuscular and multisystem manifestations. Structural CNS abnormalities, cerebellar involvement, spasticity and peripheral nerve pathology are prominent neurological features, indicating a specific vulnerability of certain neuronal populations to autophagic disturbance. A typically biphasic disease course of late-onset neurodegeneration occurring on the background of a neurodevelopmental disorder further supports a role of autophagy in both neuronal development and maintenance. In addition, an associated myopathy has been characterized in several conditions. The differential diagnosis comprises a wide range of other multisystem disorders, including mitochondrial, glycogen and lysosomal storage disorders, as well as ciliopathies, glycosylation and vesicular trafficking defects. The clinical overlap between the congenital disorders of autophagy and these conditions reflects the multiple roles of the proteins and/or emerging molecular connections between the pathways implicated and suggests an exciting area for future research. Therapy development for congenital disorders of autophagy is still in its infancy but may result in the identification of molecules that target autophagy more specifically than currently available compounds. The close connection with adult-onset neurodegenerative disorders highlights the relevance of research into rare early-onset neurodevelopmental conditions for much more common, age-related human diseases

Analysis of Organization and Activity of Mitochondrial Respiratory Chain Complexes in Primary Fibroblasts Using Blue Native PAGE

Blue Native polyacrylamide gel electrophoresis (BN-PAGE) is a well-established technique for the isolation and separation of mitochondrial membrane protein complexes in a native conformation with high resolution. In combination with histochemical staining methods, BN-PAGE has been successfully used as clinical diagnostic tool for the detection of oxidative phosphorylation (OXPHOS) defects from small tissue biopsies from patients with primary mitochondrial disease. However, its application to patient-derived primary fibroblasts is difficult due to limited proliferation and high background staining. Here, we describe a rapid and convenient method to analyze the organization and activity of OXPHOS complexes from cultured skin fibroblasts

Animal models for preclinical drug research on ulcerative colitis: A review

Inflammatory bowel disease (IBD) represents a chronic, relapsing, remitting, and inflammatory condition categorized into two forms – ulcerative colitis (UC) and Crohn's disease. According to epidemiological data, the trend of IBD has been increasing in the world, including in India. The current management of UC does not aim at curing the patient from the illness but mainly at attenuating the symptoms and improving the daily life of the patient. Drugs such as sulfasalazine and corticosteroids are used to reduce inflammation, but they are associated with multiple side effects and the efficacy is also limited. Hence, there is an unmet need in exploring new drugs to manage UC in a more efficient and less harmful way. There are various animal models which have been used worldwide by researchers to assess new lead compounds before they can be tested in humans. Various types of models comprise of chemical models, bacterial models, immunity transfer models, and genetic models. In this review article, we try to give an overview of these animal models which can be used in drug research

Marine pharmacology: Potential, challenges, and future in India

More than 50% of the marketed drugs today are derived from natural sources. There are various cancers and diseases which cannot be managed well with the current available drugs. It is, therefore, important to identify new sources of drugs for the future. The biological diversity offered by the oceans shows promise in expressing some lead compounds for diseases which show a dearth of drug options for management. A handful of marine products have been approved by the United States – Food and Drug Administration (US-FDA) because of the involvement of academia and the pharmaceutical industry. However, there are many challenges involved which deter a better and faster process for drug development from marine sources. The current scenario in India is in a nascent phase, but steps are being taken in the right direction to develop a potential source of new drugs. In this review article, we try to give an overview over the history and impending potential of marine pharmacology, with an overlook on the current approved marine-sourced drugs by the US-FDA. We also take a brief look over the challenges involved in the field of marine pharmacology, its current progress in India and possible future scope

Data sharing: A viable resource for future

Clinical trials and research studies are being conducted worldwide at a rampant pace leading to generation of large amount of data. However, to reap the benefits of the data generated it is important that this data is shared with the general public without which it can be deemed useless. Despite its importance being known to us, data sharing does not come without its share of problems and it is not as easy to execute as it sounds on-paper. Over the past few years, multiple coveted organizations around the world involved in research activities have come up with their respective guidelines and initiatives to make sure the sharing of research data is smooth and ethical. Developing countries like India have made a few strides in the right direction with some initiatives in-place, but there still seems a long way to go before unanimous data sharing can be a reality. The stakeholders may have to face certain possible repercussions due to data sharing but there is no doubt that if done in the right way, it can lead to universal development

Is Coercion Involved in the Decision-Making of Medical Students Participating in Research?: A Cross-Sectional Study

10.1353/asb.2016.0002Asian Bioethics Review8120-3