Molecular Functional Imaging Lab (MFIL)
Research at MFIL
Characterization of mushroom luciferase reporter
Luciferase reporters are the backbone of optical imaging. In collaboration with IBCh, Moscow Academy of Sciences, Russia we are studying a novel Luciferase:luciferin pair isolated from a wild bioluminescence mushroom species. This luciferase is distinctively unique for its enzyme-substrate activity and therefore readily integrated with other common luciferase systems available, providing ability to perform multiplexed reporter assay. For cancer imaging application, we have engineered a humanized version of the fungal luciferase and used as an optical reporter for imaging of tumor growth in mice. A novel BRET pair for use in protein-protein interaction study was also developed, providing multiplexed BRET sensing option. Multiplexed BRET assay allows simultaneous monitoring of interacting proteins inside live cells.
Reporter sensor for cancer cell signaling
Cancer cell signaling is a vast area of research, where protein-protein interactions, protein activation and degradation kinetics play vital roles in cellular signaling. We have been rigorously developing and using bioluminescence resonance energy transfer (BRET) based assessment method to study cell signaling and protein-protein interactions. We are pursuing the design of various BRET reporter sensors for important cancer-targeting proteins intimately involved in oncogenic signaling. In recent years, our lab has designed multiple BRET sensors for determining protein activation in vivo. These sensors detect intracellular STAT3, AKT and ERK activation status directly from live cancer cells. Using phospho-STAT3 BRET sensor, we have identified few drug molecules with STAT3 inhibitory function [Experimental Cell Research 396 (2020) 112313; Experimental Cell Research 396 (2020) 112313]. Our work analyzing patient tumor tissue samples revealed the importance of phospho-serine post-translational modification as a measure of STAT3 activation in triple negative breast cancer (TNBC) subtype. Therefore, we further aim to develop spectrally separable multiplexed BRET-PTM sensor to study the underneath cancer biology in breast cancer cells, where downstram functional response is regulated by either canonical or non-canonical phosphoSTAT3 marks in different subtypes. For the AKT and the ERK sensors, work done in collaboration with Dr. Pritha Ray's laboratory at ACTREC, use of BRET based sensing was demonstrated for the first time in platinum drug resistant patient’s derived ovarian cancer cells [Translational Oncology 14 (2021) 101193] .
Human NIS mediated gene therapy
The aim of this project is to understand the basic biology of human sodium iodide symporter (hNIS) gene function in breast cancer (BC). The natural overexpression of hNIS protein in majority of BC samples has triggered global research initiatives to verify the possible targeted radioiodine therapy as an option in BC patients. We have published several novel findings in this area, with potential clinical application for treatment of metastatic breast cancer. A major challenge for translation of hNIS-based radio-iodine therapy in BC is due to its presence as a cytoplasmic protein inside the BC cells, thus limiting the scope of iodine accumulation for therapeutic use. Challenging this disparity in hNIS expression, we demonstrated specific improvements possible by tapping in the transcriptional and post-translational regulation of hNIS. We have shown benefits of using HDACi drug molecules for promoting NIS expression in BC cell types and later shown pretreatment of benzamide class of HDACi such as MS275 can benefit clinical trial initiatives [Scientific Reports (2016) 6:19341; Molecular Therapy: Oncolytics, 2020]. We have also identified the role of several glycosylation enzymes including mannosidase enzymes causing defective NIS protein transport due to which a major amount of NIS protein stay in the cytosol and lack iodine transport function in BC cells [Journal of Cell Science (2019) 132].
Receptor switching in HER2+ve breast cancer
The HER2 receptor is a tyrosine kinase that drives breast cancer commonly designated as HER2+ve subtype. In these patients, the HER2 receptor protein is either overexpressed and/or harbor mutations occurring in various segments of this receptor. We are specifically studying how the mutations occurring in the dimerization domain might alter the dynamics of signaling, thereby promoting resistance to the HER2 targeted therapies. Understanding the downstream signaling switches that occur in presence of specific acquired mutations would help develop effective precision treatment. As HER2 oncogenic overexpression is also well known in some other cancer types like gastric cancer, relevance of these findings are expected to impact clinical practices in those areas as well.
Cellular plasticity and clonal evolution in therapy resistant breast cancer
In 2022, cellular plasticity has been added as a new 'Hallmark of Cancer'. It can be defined as the ability of cancer cells to dynamically modulate biochemical and biomechanical properties in response to intracellular and extracellular stimuli. The plastic nature of the cells is known to be associated with altered heterogeneity, which has been linked with aggressive tumor phenotype contributing to metastasis and therapeutic resistance in different cancers. Recent findings from the lab have emphasized the role of EpCAM, a breast cancer stem cell marker, as a key modulator of cellular plasticity, contributing to radiotherapy resistance in ER/PR+ breast cancer. This motivated us to look at other aspects of plasticity and its role in different therapy resistance models. Currently, our lab is investigating the role of cellular plasticity with an emphasis on the role of EMT-MET hybrid status and metabolic plasticity in targeted therapy resistance in HER2+ve BC model.
Nanotherapeutics and photothermal therapy
Our group has long drawn interest in Cancer Nanomedicines which provide alternative treatment solutions for otherwise difficult to treat cancers. To develop various bio-functionalized, tumor-targeted nanomedicine materials for cancer therapy, we are actively engaged in multiple collaborative projects.
In one promising line of work done in collaboration with NanoBios Lab at IIT-B, we have tested multiple biocompatible gold-nanospheres (Au-NS) nanomaterial for photothermal therapy (PTT). This method shows exceptional therapy efficacy in vivo. This triggered, precisive treatment method of palpable solid tumors with accumulated nano-sized particles when briefly exposed to NIR laser irradiation confers excellent tumor tissue ablation, while keeping the surrounding tissue safe [ACS Nanoletters, 2015; Scientific Reports, 2018; Applied Materials Today, 2020; Nanomedicine: Nanotechnology, Biology, and Medicine 2021; Nanoscale 2022]. This mode of treatment is found to be fast, portable and could be a cost-effective procedure tested against human drug-resistant and radiation-resistant human cancers of multiple types using preclinical mouse models and non-invasive imaging [Biomaterials Advances, 2022].
Additionally, we have completed work validating two novel organic NIR dyes with exceptional photothermal effect and published in high impact international journals [ACS Appl. Mater. Interfaces, 2020; NPG Asia Materials, 2020]. We were granted with multiple patents on this line of work.
Working with Chemistry dept. NMIMS, Mumbai, very recently we have also reported synthesis of a multifunctional CuS–ZnS nanocomposites modified in situ for targeted cancer therapy and imaging. Here the CuS moiety enabled near-infrared light responsive photothermal therapy, whereas ZnS showed potential for
photoluminescence [Journal of Drug Delivery Science and Technology, 2022] .
Cancer nanomedicines
In the area of cancer nanomedicine, we have drawn long-standing collaborative projects with various groups in the neighboring institutes.
In a DBT funded collaborative project with Bombay college of Pharmacy, we developed sugar conjugated nano-formulation for intraocular carboplatin formulation in orthotopic retinoblastoma mouse model.
In another collaboration with Chemical Engineering dept. IIT-B, we have developed mesoporous silica nanoparticles (MSN) loaded Gemcitabine and/or curcumin for treatment of pancreatic cancer. Currently a modified biocompatible film based drug delivery system was developed and tested for in vivo Gemcitabine delivery in mouse orthotopic pancreatic cancer model. To circumvent the limitations of systemic drug administration, implantable drug formulations are gaining popularity for local drug delivery. We are developing a delivery system that can sustain controlled release of the drug molecule for use in pancreatic cancer clinic.
In collaboration with colleagues at Chemistry division, BARC, we have developed and tested zinc gallate (ZGO)-based persistent luminescence nanoparticles (NPs) coated with a synthetic peptide (pHLIP) as a targeting moiety. Initially, Cr3+-doped ZGO-NPs were prepared and functionalized to obtain ZGO-pHLIP NPs. Results showed that tumor specific homing of the ZGO-pHLIP was achieved within a short time of 6h. The ZGO-pHLIP formulation has the potential for detection and diagnosis of cancer using non-invasive methodology [ACS Appl. Bio Mater. 2021]. More recently, the zinc gallate (ZnGa2O4)-based nanoformulation was suitably modified for developing an innovative theranostic approach for boron neutron capture therapy (BNCT) modality of cancer treatment [ACS Appl. Bio Mater, 2022].
