Publications by authors named "Thillai Sekar"

Both innate and adaptive immunity are important components of the human defense system against various diseases including cancer. Human beta defensin-1 (hBD-1) is one such immunomodulatory peptide which is lost in malignant cancers, while high levels of expression are maintained in benign cells, making it a potential biomarker for the onset and metastasis of the disease. Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer for which no targeted therapy has been approved so far.

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  • Fibrosis is the abnormal buildup of connective tissue due to improper healing from injuries like lack of oxygen, infections, or trauma, affecting any organ and leading to dysfunction and failure.
  • It also plays a significant role in cancer development, making early diagnosis and monitoring vital for improving patient outcomes.
  • This paper specifically examines fibrosis in the genito-urinary system, highlighting current imaging technologies for detection and suggesting possible future research directions.
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  • Fibrosis is an abnormal buildup of connective tissue due to prolonged injuries like low oxygen, infections, or physical damage, which can lead to organ dysfunction and failure.
  • It is also linked to cancer development and progression, making early diagnosis and monitoring crucial for treatment and improving patient outcomes.
  • The text highlights the need for better understanding and application of advanced imaging techniques to detect fibrosis in abdominal organs, discussing both current technologies and future developments for early diagnosis.
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  • - Injury from factors like low oxygen, infections, or physical damage can disrupt normal tissue repair, leading to fibrosis, which affects organ function and can cause organ failure.
  • - Fibrosis plays a significant role in cancer development and progression, making early diagnosis and ongoing monitoring crucial for managing diseases and improving patients' quality of life.
  • - This work aims to review current imaging technologies used to detect fibrosis in thoracic organs and discuss future advancements in these imaging methods.
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In the rapidly advancing field of synthetic biology, there exists a critical need for technology to discover targeting moieties for therapeutic biologics. Here we present INSPIRE-seq, an approach that utilizes a nanobody library and next-generation sequencing to identify nanobodies selected for complex environments. INSPIRE-seq enables the parallel enrichment of immune cell-binding nanobodies that penetrate the tumor microenvironment.

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Both innate and adaptive immunity are the important components of the human defense system against various diseases including cancer. Human Beta Defensin (hBD-1) is one such immunomodulatory peptide which is lost at high frequencies in malignant cancers, while high levels of expression are maintained in benign regions making it a potential biomarker for the onset and metastasis of the disease. Loss of putative function of hBD-1 as a tumor suppressor gene combined with the defects in apoptosis pathways (CD95, ASK1) make tumor cells insensitive to chemotherapy and render it ineffective.

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Aim: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype. Since no targeted therapy is available, gene-directed enzyme prodrug therapy (GDEPT) could be an attractive strategy for treating TNBC.

Materials & Methods: Polyethylene glycol (PEG)ylated-poly(lactic-co-glycolic acid)/polyethyleneimine nanoparticles (PLGA/PEI NPs) were synthesized and complexed with TK-NTR fusion gene.

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Misfolding mutations in the DNA-binding domain of p53 alter its conformation, affecting the efficiency with which it binds to chromatin to regulate target gene expression and cell cycle checkpoint functions in many cancers, including glioblastoma. Small molecule drugs that recover misfolded p53 structure and function may improve chemotherapy by activating p53-mediated senescence. We constructed and optimized a split luciferase (RLUC) complementation molecular biosensor (NRLUC-p53-CRLUC) to determine small molecule-meditated folding changes in p53 protein.

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Temozolomide (TMZ) chemotherapy for glioblastoma (GBM) is generally well tolerated at standard doses but it can cause side effects. GBMs overexpress microRNA-21 and microRNA-10b, two known oncomiRs that promote cancer development, progression and resistance to drug treatment. We hypothesized that systemic injection of antisense microRNAs (antagomiR-21 and antagomiR-10b) encapsulated in cRGD-tagged PEG-PLGA nanoparticles would result in high cellular delivery of intact functional antagomiRs, with consequent efficient therapeutic response and increased sensitivity of GBM cells to lower doses of TMZ.

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Gaussia luciferase (GLUC) is a bioluminescent reporter protein of increasing importance. As a secretory protein, it has increased sensitivity in vitro and in vivo (∼20 000-fold, and ∼1000-fold, respectively) over its competitor, secreted alkaline phosphatase. Unfortunately, this same advantageous secretory nature of GLUC limits its usefulness for many other possible intracellular applications, e.

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Hepatocellular carcinoma (HCC) is highly prevalent, and the third most common cause of cancer-associated deaths worldwide. HCC tumors respond poorly to chemotherapeutic anticancer agents due to inherent and acquired drug resistance, and low drug permeability. Targeted drug delivery systems with significant improvement in therapeutic efficiency are needed for successful HCC therapy.

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Small molecule mediated stabilization of p53 tumor suppressor protein through sumoylation is a promising new strategy for improving cancer chemotherapy. A molecular tool that monitors p53 sumoylation status and expedites screening for drugs that enhance p53 sumoylation would be beneficial. We report a molecularly engineered reporter fragment complementation biosensor based on optical imaging of Firefly luciferase (FLuc), to quantitatively image p53 sumoylation and desumoylation in cells and living mice.

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Estrogen receptor-α (ERα) plays an important role in normal and abnormal physiology of the human reproductive system by interacting with the endogenous ligand estradiol (E2). However, other ligands, either analogous or dissimilar to E2, also bind to ERα. This may create unintentional activation of ER signaling in reproductive tissues that can lead to cancer development.

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Gene-directed enzyme prodrug therapy (GDEPT) is a promising therapeutic approach for treating cancers of various phenotypes. This strategy is independent of various other chemotherapeutic drugs used for treating cancers where the drugs are mainly designed to target endogenous cellular mechanisms, which are different in various cancer subtypes. In GDEPT an external enzyme, which is different from the cellular proteins, is expressed to convert the injected prodrug in to a toxic metabolite, that normally kill cancer cells express this protein.

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Histone modifications (methylation, acetylation, phosphorylation, sumoylation, etc.,) are at the heart of cellular regulatory mechanisms, which control expression of genes in an orderly fashion and control the entire cellular regulatory networks. Histone lysine methylation has been identified as one of the several posttranslational histone modifications that plays crucial role in regulating gene expressions in facultative heterochromatic DNA regions while maintaining structural integrity in constitutive heterochromatic DNA regions.

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Unlabelled: Aberrant protein folding represents the molecular basis of many important human diseases. Although the discovery of new anti-misfolding drugs is a major priority in molecular therapeutics, there is currently no generalizable protein folding assay for use in cell-based high throughput screening (HTS) of chemical libraries, or for in vivo imaging. We molecularly engineered a bioluminescence-based biosensor composed of rationally split Firefly luciferase reporter fragments flanking a test protein, and used this in a protein-fragment complementation assay to quantitatively measure folding of the test protein.

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Triple-negative breast cancer (TNBC) is a recalcitrant malignancy with no available targeted therapy. Off-target effects and poor bioavailability of the FDA-approved antiobesity drug orlistat hinder its clinical translation as a repurposed new drug against TNBC. Here, we demonstrate a newly engineered drug formulation for packaging orlistat tailored to TNBC treatment.

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Chemotherapy often fails due to cellular detoxifying mechanisms, including phase-II enzymes. Activation of Nrf2-Keap1 pathway induces phase-II enzymes expression through ARE-signaling and prevents cancer development. Nrf2-overexpression in cancer cells results in chemo- and/or radioresistance.

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Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulatory transcription factor that plays an important role in the antioxidant response pathway against anticancer drug-induced cytotoxic effects. RRx-001 is a new anticancer agent that generates reactive oxygen and nitrogen species, and leads to epigenetic alterations in cancer cells. Here we report the RRx-001 mediated nuclear translocation of Nrf2 and the activation of expression of its downstream enzymes HO-1 and NQO1 in tumor cells.

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Breast cancer is the second leading cause of cancer-related death in women. The majority of breast tumors are estrogen receptor-positive (ER+) and hormone-dependent. Neoadjuvant anti-estrogen therapy has been widely employed to reduce tumor mass prior to surgery.

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The current study shows the therapeutic outcome achieved in triple negative breast cancer (TNBC) by simultaneously antagonizing miR-21-induced antiapoptosis and miR-10b-induced metastasis, using antisense-miR-21-PS and antisense-miR-10b-PS delivered by polymer nanoparticles (NPs). We synthesized the antisense-miR-21 and antisense-miR-10b loaded PLGA-b-PEG polymer NPs and evaluated their cellular uptake, serum stability, release profile, and the subsequent synchronous blocking of endogenous miR-21 and miR-10b function in TNBC cells in culture, and tumor xenografts in living animals using molecular imaging. Results show that multitarget antagonization of endogenous miRNAs could be an efficient strategy for targeting metastasis and antiapoptosis in the treatment of metastatic cancer.

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Post-translational addition of methyl groups to the amino terminal tails of histone proteins regulates cellular gene expression at various stages of development and the pathogenesis of cellular diseases, including cancer. Several enzymes that modulate these post-translational modifications of histones are promising targets for development of small molecule drugs. However, there is no promising real-time histone methylation detection tool currently available to screen and validate potential small molecule histone methylation modulators in small animal models.

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Article Synopsis
  • - Lysine methylation of histone H3 and H4 is a key target for new treatments of cellular diseases, and a new assay can speed up drug development.
  • - Researchers developed a real-time molecular imaging biosensor that monitors the methylation of histone H3-K9 in live animals.
  • - The sensor proved effective in various tests, including its response to drugs in mice, showing promise for use in preclinical drug evaluations.
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Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors.

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Metastatic breast cancer is an obdurate cancer type that is not amenable to chemotherapy regimens currently used in clinic. There is a desperate need for alternative therapies to treat this resistant cancer type. Gene-Directed Enzyme Prodrug Therapy (GDEPT) is a superior gene therapy method when compared to chemotherapy and radiotherapy procedures, proven to be effective against many types of cancer in pre-clinical evaluations and clinical trials.

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