Biology subjects

Datta, D.

Publications and source records attributed to Datta, D..

At least 37 records · Page 2Linked to original sources

bioRxiv2023

p53 amyloid pathology with cancer grades and p53 mutations

p53 mutation and amyloid formation are implicated with cancer pathogenesis, but the direct demonstration of the link between p53 amyloid load and cancer progression is lacking. Using multi-disciplinary techniques and a cohort of 59 tumor tissues (53 from Indian cancer patients and six normal tissues) of oral and stomach cancer types, we showed that p53 amyloid load and cancer grades are highly correlated. Further, next-generation sequencing (NGS) data suggest that not only mutant p53 (e.g., SNVs, deletions, and insertions) but wild-type p53 also formed amyloids either in the nucleus (50%) and/or in the cytoplasm in most cancer tissues. Interestingly, in all these cancer tissues, p53 displays a loss of DNA binding and transcriptional activities, which is highly aggravated with the amyloid load and cancer grades. The p53 amyloids also sequester higher amounts of p63/p73 isoforms in higher-grade of tumor tissues. The data suggest p53 misfolding/aggregation and subsequent amyloid formation lead to loss and gain of p53 tumorigenic function, aggravation of which might determine the cancers grades.

cancer biology↗

bioRxiv2023

PERK arm of UPR selectively regulates ferroptosis in colon cancer cells by modulating the expression of SLC7A11 (System Xc-)

Ferroptosis, a genetically and biochemically distinct form of programmed cell death, is characterised by an iron-dependent accumulation of lipid peroxides. Therapy-resistant tumor cells display vulnerability toward ferroptosis. Endoplasmic Reticulum (ER) stress and Unfolded Protein Response (UPR) play a critical role in cancer cells to become therapy resistant. Tweaking the balance of UPR to make cancer cells susceptible to ferroptotic cell death could be an attractive therapeutic strategy. To decipher the emerging contribution of ER-stress in the ferroptotic process, we observe that ferroptosis inducer RSL3 promotes UPR (PERK, ATF6, and IRE1), along with overexpression of cystine-glutamate transporter SLC7A11 (System Xc-). Exploring the role of a particular UPR arm in modulating SLC7A11 expression and subsequent ferroptosis, we notice that PERK is selectively critical in inducing ferroptosis in colorectal carcinoma. PERK inhibition reduces ATF4 expression and recruitment to the promoter of SLC7A11 and results in its downregulation. Loss of PERK function not only primes cancer cells for increased lipid peroxidation but also limits in vivo colorectal tumor growth, demonstrating active signs of ferroptotic cell death in situ. Further, by performing TCGA data mining and using colorectal cancer patient samples, we demonstrate that the expression of PERK and SLC7A11 is positively correlated. Overall, our experimental data indicate that PERK is a negative regulator of ferroptosis and loss of PERK function sensitizes colorectal cancer cells to ferroptosis. Therefore, small molecule PERK inhibitors hold huge promise as novel therapeutics and their potential can be harnessed against the apoptosis-resistant condition.

cancer biology↗

bioRxiv2023

Interaction Between HCN and Slack Channels Regulates mPFC Pyramidal Cell Excitability and Working Memory

The ability of monkeys and rats to carry out spatial working memory tasks has been shown to depend on the persistent firing of pyramidal cells in the prefrontal cortex (PFC), arising from recurrent excitatory connections on dendritic spines. These spines express hyperpolarization-activated cyclic nucleotide-gated (HCN) channels whose open state is increased by cAMP signaling, and which markedly alter PFC network connectivity and neuronal firing. In traditional neural circuits, activation of these non-selective cation channels leads to neuronal depolarization and increased firing rate. Paradoxically, cAMP activation of HCN channels in PFC pyramidal cells reduces working memory-related neuronal firing. This suggests that activation of HCN channels may hyperpolarize rather than depolarize these neurons. The current study tested the hypothesis that Na+ influx through HCN channels activates Na+-activated K+ (KNa or Slack) channels to hyperpolarize the membrane. We have found that HCN and Slack KNa channels co-immunoprecipitate in cortical extracts and that, by immunoelectron microscopy, they colocalize at postsynaptic spines of PFC pyramidal neurons. A specific blocker of HCN channels, ZD7288, reduces KNa current in pyramidal cells that express both HCN and Slack channels, indicating that blockade of HCN channels reduced K+ current indirectly by lowering Na+ influx. In contrast, ZD7288 has no effect on KNa currents in an HEK cell line stably expressing this Slack channels but no HCN channels, demonstrating that ZD7288 does not block Slack channels directly. Activation of HCN channels by cAMP in a cell line expressing a Ca2+ reporter results in elevation of cytoplasmic Ca2+, but the effect of cAMP is completely reversed if the HCN channels are co-expressed with Slack channels. Finally, we have used a novel pharmacological blocker of Slack channels to show that inhibition of either Slack or HCN channels in rat PFC improves working memory performance, and that the actions of Slack and HCN channel blockers occlude each other in the memory task. Our results suggest that the regulation of working memory by HCN channels in PFC pyramidal neurons is mediated by an HCN-Slack channel complex that links activation HCN channels to suppression of neuronal excitability.

neuroscience↗

bioRxiv2023

Toxic metal uptake by oyster mushrooms grown in sugarcane bagasse

Fungiculture or Mushroom Cultivation is rapidly expanding throughout the world. It is further catalyzed by its high nutritional value and increased market demand. Additionally, the method of cultivation does not require much space and the per unit production is very high compared to other crops. Bagasse is the byproduct left after extracting the juice from sugarcane. It has been speculated that bagasse can be an excellent substrate due to its high carbohydrate and mineral content (Hoa et al., 2015). In the experiment spawns of Oyster Mushroom were inoculated in bagasse collected from industries. Remarkable growth of mushrooms in short period of time was observed. However, the metal toxicity being our primary concern in this experiment, AAS (Atomic Absorption Spectrometry) Test was used to detect the heavy metal ion concentrations in both the bagasse and the fruiting bodies of mushrooms. The concentrations of metals calculated are as follows, in bagasse (mg/kg): Cadmium - 0.015, Arsenic - 8.56, Copper-12.47, Chromium-9.17, Mercury - less than 0.01, and in mushroom (mg/kg): Cd - 0.022, As - 10.12, Cu - 14.29, Cr - 7.59, Hg - less than 0.01. These results indicated biomagnification of metal ion concentration in the mushrooms up taken from bagasse. These metals, in such high concentrations are lethal and causes many diseases in humans and other animals. Hence, from this experiment it can be deduced, that though bagasse is an excellent substrate for mushroom cultivation, the toxicity of metal ions present in it in such high concentrations overshadow the earlier benefits of bagasse as a good substrate. However, it has been proposed that if such metals are removed or their concentrations are lowered then the earlier mentioned benefits of bagasse are restored.

ecology↗

bioRxiv2023

Phenotypically Complex Living Materials Containing Engineered Cyanobacteria

A cyanobacterial photosynthetic biocomposite material was fabricated using 3D-printing and bioengineered to produce multiple functional outputs in response to an external chemical stimulus. Our investigations show the advantages of utilizing additive manufacturing techniques in controlling the design and shape of the fabricated materials, which proved to be important for the support and growth of obligate phototrophic microorganisms within the material. As an initial proof-of-concept, a synthetic theophylline-responsive riboswitch in Synechococcus elongatus PCC 7942 was used for regulating the expression of a yellow fluorescent protein (YFP) reporter. Upon induction with theophylline, the encapsulated cells produced YFP within the hydrogel matrix. Subsequently, a strain of S. elongatus was engineered to produce an oxidative enzyme that is useful for bioremediation, laccase, expressed either constitutively or under the control of the riboswitch. The responsive biomaterial can decolorize a common textile dye pollutant, indigo carmine, potentially serving as a useful tool in environmental bioremediation. Finally, cells were engineered to have the capacity for inducible cell death to eliminate their presence once their activity is no longer required, which is an important function for biocontainment and minimizing unintended environmental impact. By integrating genetically engineered stimuli-responsive cyanobacteria in patterned volumetric 3D-printed designs, we demonstrate the potential of programmable photosynthetic biocomposite materials capable of producing functional outputs including, but not limited to, bioremediation.

bioengineering↗

bioRxiv2022

Dentate gyrus morphogenesis is regulated by β-CATENIN function in hem-derived fimbrial glia.

The dentate gyrus, a gateway for input to the hippocampal formation, arises from progenitors in the medial telencephalic neuroepithelium adjacent to the cortical hem. Dentate progenitors navigate a complex migratory path guided by two cell populations that arise from the hem, the fimbrial glia, and Cajal-Retzius (CR) cells. Since the hem expresses multiple Wnt genes, we examined whether {beta}-CATENIN, which mediates canonical Wnt signaling and also participates in cell adhesion, is necessary for the development of hem-derived lineages. We report that the fimbrial glial scaffold is disorganized and CR cells are mispositioned upon hem-specific disruption of {beta}-CATENIN. Consequently, the dentate migratory stream is severely affected, and the dentate gyrus fails to form. Using selective Cre drivers, we further determined that {beta}-CATENIN function is required in the fimbrial glial scaffold, but not in the CR cells, for guiding the dentate migration. Our findings highlight a primary requirement for {beta}-CATENIN for the organization of the fimbrial scaffold and a secondary role for this factor in dentate gyrus morphogenesis.

neuroscience↗

bioRxiv2022

Targeting MALAT1 Augments Sensitivity to PARP Inhibition by Impairing Homologous Recombination in Prostate Cancer.

Poly(ADP-ribose) polymerase inhibitors (PARPi) have emerged as the most promising targeted therapeutic intervention for the treatment of metastatic castrate-resistant prostate cancer (mCRPC). However, the clinical utility of PARPi has been limited to a subset of patients who harbor aberrations in the homologous recombination (HR) pathway. Here, we report that targeting MALAT1, an oncogenic lncRNA, known to be elevated in advanced-stage prostate cancer (PCa) demonstrates contextual synthetic lethality with PARPi. We show that MALAT1 silencing reprograms the HR transcriptome, contriving BRCAness-like phenotype, thus enhancing sensitivity towards PARPi. Moreover, transcriptome profiles of mCRPC patients exhibit convergence between expression of MALAT1, HR pathway, and neuroendocrine markers. Mechanistically, we show that targeting MALAT1 leads to a decrease in EZH2, a member of polycomb repressor complex-2 (PRC2), which in turn upregulates the expression of RE1 Silencing Transcription Factor (REST), a key repressor of neuroendocrine differentiation. Overall, we showed that MALAT1 plays a pivotal role in maintaining genomic integrity, thereby promoting disease progression. Conclusively, our findings suggest that inhibiting MALAT1 confers PARPi sensitization in patients resistant to anti-androgens and conventional chemotherapeutics. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=195 SRC="FIGDIR/small/494272v1_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@80d842org.highwire.dtl.DTLVardef@f60793org.highwire.dtl.DTLVardef@6b81eforg.highwire.dtl.DTLVardef@1fa35d_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstract:C_FLOATNO The oncogenic lncRNA MALAT1 exhibits functional pleiotropy in PCa and promotes neuroendocrine differentiation. MALAT1 fosters PCa progression by modulating several hallmark oncogenic properties, such as malignant transformation, enhanced migratory capabilities, stemness, and ultimately contributes to drug resistance. MALAT1 enhances the transcriptional regulation of genes associated with homologous recombination thereby having a profound impact on the genome integrity in metastatic prostate cancer. Over the course of disease progression, it also promotes neuroendocrine trans-differentiation by depleting the levels of REST, the key repressor for NE transdifferentiation in prostate cancer. C_FIG

cancer biology↗

bioRxiv2022

The BRD4S-LOXL2-MED1 interaction at the forefront of cell cycle transcriptional control in triple-negative breast cancer

Triple-negative breast cancer often develops resistance to single-agent treatments, which can be circumvented with targeted combinatorial approaches. Here, we demonstrate that the simultaneous inhibition of LOXL2 and BRD4 cooperate to reduce triple-negative breast cancer proliferation in vitro and in vivo. Mechanistically, we reveal that LOXL2 interacts in the nucleus with the short isoform of BRD4 and MED1 to control cell cycle progression at the gene expression level via sustaining the formation of BRD4-MED1 nuclear transcriptional foci. Indeed, the pharmacological or transcriptional repression of LOXL2 provokes downregulation of cell cycle gene expression, G1-S cell cycle arrest, and loss of BRD4-MED1 foci. Our results indicate that the BRD4S-LOXL2-MED1 interaction is fundamental for the proliferation of triple-negative breast cancer. Therefore, targeting such interaction holds potential for the development of novel triple-negative breast cancer therapies.

cancer biology↗

bioRxiv2022

Liquid condensate is a common state of proteins and polypeptides at the regime of high intermolecular interactions

Liquid-liquid phase separation (LLPS) has emerged as a crucial biological mechanism for sequestering macromolecules (such as proteins and nucleic acids) into membraneless organelles in cells. Unstructured and intrinsically disordered domains are known to facilitate multivalent interactions driving protein LLPS. We hypothesized that LLPS could be an intrinsic property of proteins/polypeptides at their high intermolecular interaction regime. To examine this, we studied many (a total of 23) proteins/polypeptides with different structures and sequences for LLPS study using molecular crowder polyethylene glycol (PEG-8000). We showed that all proteins and even highly charged polypeptides (under study) can undergo liquid condensate formation, however with different phase space and conditions. Using a single component and combinations of protein multicomponent (co-LLPS) systems, we establish that a variety of intermolecular interactions can drive proteins/polypeptides LLPS.

biophysics↗

bioRxiv2021

Size-dependent secondary nucleation and amplification of α-synuclein amyloid fibrils

The size of the amyloid seeds is known to modulate their autocatalytic amplification and cellular toxicity. However, the seed size-dependent secondary nucleation mechanism, toxicity, and disease-associated biological processes mediated by -synuclein (-Syn) fibrils are largely unknown. Using the cellular model and in vitro reconstitution, we showed that the size of -Syn fibril seeds not only dictates its cellular internalization and associated cell death; but also the distinct mechanisms of fibril amplification pathways involved in the pathological conformational change of -Syn. Specifically, small-sized fibril seeds showed elongation possibly through monomer addition at the fibril termini; whereas longer fibrils template the fibril amplification by surface-mediated nucleation as demonstrated by super-resolution microscopy. The distinct mechanism of fibril amplification, and cellular uptake along with toxicity suggest that breakage of fibrils into different sizes of seeds determine the underlying pathological outcome of synucleinopathies.

neuroscience↗

bioRxiv2021

Possible Interference in Protein - Protein interaction as a new approach in microinhibition of respiratory pathogens on nasal- oral epithelium: An early on-screen study with reference toSARS-Cov-2-ACE2 binding interference

Upper and lower respiratory pathogens - both microbes and viruses -are responsible for very high morbidity, man-hour loss, residual long term clinical conditions and even mortality. In india only, high incidence of annual respiratory infections - both UT and LT - demands prophylactic intervention in addition to all therapeutic interventions available.The issue of respiratory infections is more pronounced now in the backdrop of nearly uncontrolled high incidences of SARS-Cov-2 affection resulting in death and damage of human lives to the extent of hundreds of millions spreading over entire world, with incidence variations from country to country. After the initial unanswered phase of spread of SARS-Cov-2 virus with attendant unseen mortalities, quickest invention of a series of unusual vaccines have stemmed the lethal progress to a very significant extent, although vaccinating each and every human subject - nearly 8 to 9 bn in supremely divided world -economically-- is an unthinkable proposition where economic disparity dictates vaccine availability and implementation.Moreover, being of highly unstable nucleic acid composition, the original virus, by now has a thick set of variants around the globe with variable clinical outcome. Given this complex background of scanty availability and inefficient implementation, there always is a need of a preventive approach which can possibly micro-fix the pathogens, including SARS-2 on nasal epithelium so as to interfere with viral [or any pathogen] entry through specified receptor gate[s] or any other ways. The present formulation is under study -- as a candidate of interference on nasal / oral mucosa for all respiratory pathogens. This brief report describes dry on-screen studies of protein - protein interaction as well as its possible interference by an amino acid Lysine. Phospholipid bilayerresponses in presence of added loads of the same essential amino acid -Lysine - showed unusual and unexplained behavior both in structural integrity as well in spatial orientation.

biochemistry↗

bioRxiv2021

Co-aggregation and secondary nucleation in the life cycle of human prolactin/galanin functional amyloids

Synergistic-aggregation and cross-seeding by two different amyloid proteins/peptides are well evident in various neurological disorders. However, this phenomenon is not well studied in functional amyloid aggregation. Here, we show Prolactin (PRL) is associated with lactation in mammals and neuropeptide galanin (GAL), which are co-stored in the lactotrophs facilitates the synergic aggregation in the absence of secretory granules helper molecules glycosaminoglycans (GAGS). Interestingly, although each partner possesses homotypic seeding ability, a unidirectional cross-seeding of GAL aggregation can be mediated by PRL seeds. The specificity of co-aggregation by PRL and GAL along with unidirectional cross-seeding suggests tight regulation of functional amyloid formation during co-storage of these hormones in secretory granule biogenesis of female rat lactotrophs. Further mixed fibrils release the constituent functional hormone much faster than the corresponding individual amyloid formed in presence of GAGs, suggesting that co-aggregation of functionally distant hormones might have evolved for efficient storage, synergistic and rapid release of both hormones upon stimulation. The co-aggregation and cross seeding by two different hormones of completely different structures and sequences (PRL and GAL) suggest a novel mechanism of heterologous amyloid formation both in disease and functional amyloids.

biophysics↗

bioRxiv2021

H3K27me3 mediated KRT14 upregulation promotes TNBC peritoneal metastasis

Triple Negative Breast Cancer (TNBC) is known to have poor prognosis and adverse clinical outcome among all breast cancer subtypes due to the absence of available targeted therapy for it. Emerging literature indicates that epigenetic reprogramming is now appreciated as a driving force for TNBC pathophysiology. High expression of epigenetic modulator EZH2 (Enhancer of zeste homolog 2) has been shown to correlate with TNBC poor prognosis but the contribution of EZH2 catalytic (H3K27me3) versus non-catalytic EZH2 (NC-EZH2) function in TNBC growth and progression remains elusive. In the process of dissecting the impact of H3K27me3 versus NC-EZH2 function in TNBC pathogenesis, we reveal that selective hyperactivation of H3K27me3 over NC-EZH2 not only promotes TNBC metastasis but also alters the metastatic landscape of TNBC. Using extensive in- vivo live animal imaging, we present conclusive evidence that peritoneal metastasis, particularly splenic metastasis of TNBC is governed by H3K27me3. Transcriptome analyses of hyperactive H3K27me3 cells lead us to discover Cytokeratin-14 (KRT14) as a new target of H3K27me3. Unlike classical H3K27me3 mediated suppression of gene expression, here; we observe that H3K27me3 enhances KRT14 transcription by attenuating the binding of transcriptional repressor Sp1 to its promoter. Further, loss of KRT14 significantly reduces TNBC migration, invasion and splenic metastasis. Finally, genetic ablation of EZH2 or pharmacological inhibition of EZH2 catalytic function by FDA approved drug tazemetostat (EPZ6438) robustly inhibits TNBC peritoneal metastasis. Altogether, our preclinical findings posit a rational insight for the clinical development of H3K27me3 inhibitor like tazemetostat as a targeted therapy against TNBC.

cancer biology↗

bioRxiv2021

Dynamic modulation of spleen germinal center reactions by gut bacteria during Plasmodium infection

Gut microbiota educate the local and distal immune system in early life to imprint long-term immunological outcomes while maintaining the capacity to dynamically modulate the local mucosal immune system throughout life. It is unknown if gut microbiota provide signals that dynamically regulate distal immune responses following an extra-gastrointestinal infection. Using the murine model of malaria, we show that existing spleen germinal center reactions are malleable to dynamic cues provided by gut bacteria that impact parasite burden. Gut bacteria composition was also shown to correlate with the severity of malaria in humans. Whereas antibiotic-induced changes in gut bacteria has been associated with immunopathology or impairment of immunity, our data demonstrate antibiotic-induced changes in gut bacteria can enhance humoral immunity to Plasmodium. This effect is not universal, but depends on baseline gut bacteria composition. These data demonstrate the dynamic communications that exist between gut bacteria and the systemic immune system as well as the plasticity of an ongoing humoral immune response. SummaryThe study by Mandal R, et al. provides new insight into the dynamic communications that exist between gut bacteria, the systemic immune system and the plasticity of spleen germinal center reactions during Plasmodium infection.

immunology↗

bioRxiv2021

Inhibition of Extracellular Vesicle-Associated MMP2 Abrogates Intercellular Transfer of Hepatic miR-122 to Tissue Macrophages and Curtails Liver Inflammation

microRNA-122 (miR-122), a liver specific regulatory RNA, plays an important role in controlling metabolic homeostasis in mammalian liver cells. Interestingly, miR-122 is also a proinflammatory microRNA and when exported to tissue resident macrophage induces expression of inflammatory cytokines there. We found intercellular transfer of miR-122 in lipid exposed liver plays a role in liver inflammation. Exploring the mechanism of intercellular miR-122 transfer from hepatic cells, we detected MMP2 on the membrane of extracellular vesicles derived from hepatic cells which proved to be essential for transfer of extracellular vesicles and their miRNA content from hepatic to non-hepatic cells. Matrix metalloprotease 2 or MMP2 is a metalloproteinase that plays a key role in shaping and remodelling the extracellular matrix of human tissue by targeting degradation of matrix proteins. MMP2 was found to increase the movement of the EVs along the extracellular matrix to enhance their uptake in recipient cells. Inhibition of MMP2 restricts functional transfer of hepatic miRNAs across the hepatic and non-hepatic cell boundaries. By targeting MMP2, we could reduce the innate immune response in mammalian liver by preventing intra-tissue miR-122 transfer. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=176 SRC="FIGDIR/small/425217v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@aec3b0org.highwire.dtl.DTLVardef@1b18e87org.highwire.dtl.DTLVardef@47e75org.highwire.dtl.DTLVardef@10a48e0_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIHuman hepatocytes on exposure to high lipid export out miRNAs including proinflammatory miR-122. C_LIO_LIExtracellular miR-122 is taken up by tissue macrophages to get them activated to produce inflammatory cytokines. C_LIO_LIMMP2 present on the surface of the EVs released by hepatocyte is essential for miRNA transfer to macrophage cells C_LIO_LIInhibition of MMP2 prevents miR-122 transfer to macrophage and stops activation of recipient macrophage. C_LI

cancer biology↗

bioRxiv2020

Amyloid fibril-based hydrogels for high-throughput tumor spheroid modeling

Biomaterials mimicking extracellular matrices (ECM) for three-dimensional (3D) cultures have gained immense interest in tumor modeling and in vitro organ development. Here, we introduce versatile, thixotropic amyloid hydrogels as a bio-mimetic ECM scaffold for 3D cell culture as well as high-throughput tumor spheroid formation using a drop cast method. The unique cross-{beta}-sheet structure, sticky surface, and thixotropicity of amyloid hydrogels allow robust cell adhesion, survival, proliferation, and migration, which are essential for 3D tumor modeling with various cancer cell types. The spheroids formed show overexpression of the signature cancer biomarkers and confer higher drug resistance compared to two-dimensional (2D) monolayer cultures. Using breast tumor tissue from mouse xenograft, we showed that these hydrogels support the formation of tumor spheroids with a well-defined necrotic core, cancer-associated gene expression, higher drug resistance, and tumor heterogeneity reminiscent of the original tumor. Altogether, we have developed a rapid and cost-effective platform for generating in vitro cancer models for the screening of anti-cancer therapeutics and developing personalized medicines.

bioengineering↗

bioRxiv2020

ProtTox: Toxin identification from Protein Sequences

Toxin classification of protein sequences is a challenging task with real world applications in healthcare and synthetic biology. Due to an ever expanding database of proteins and the inordinate cost of manual annotation, automated machine learning based approaches are crucial. Approaches need to overcome challenges of homology, multi-functionality, and structural diversity among proteins in this task. We propose a novel deep learning based method ProtTox, that aims to address some of the shortcomings of previous approaches in classifying proteins as toxins or not. Our method achieves a performance of 0.812 F1-score which is about 5% higher than the closest performing baseline.

bioinformatics↗

bioRxiv2020

Salinomycin inhibits epigenetic modulator EZH2 to enhance Death Receptors in Colon Cancer Stem Cells

Drug resistance is one of the trademark features of Cancer Stem Cells (CSCs). We and others have recently shown that paucity of functional death receptors (DR4/5) on the cell surface of tumor cells is one of the major reasons for drug resistance, but their involvement in the context of in CSCs is poorly understood. By harnessing CSC specific cytotoxic function of salinomycin, we discovered a critical role of epigenetic modulator EZH2 in regulating the expression of DRs in colon CSCs. Our unbiased proteome profiler array approach followed by ChIP analysis of salinomycin treated cells indicated that the expression of DRs, especially DR4 is epigenetically repressed in colon CSCs. Concurrently, EZH2 knockdown demonstrated increased expression of DR4/DR5, significant reduction of CSC phenotype such as spheroid formation in-vitro and tumorigenic potential in-vivo in colon cancer. TCGA data analysis of human colon cancer clinical samples shows strong inverse correlation between EZH2 and DR4. Taken together, this study provides an insight about epigenetic regulation of DR4 in colon CSCs and advocates that drug resistant colon cancer can be therapeutically targeted by combining TRAIL and small molecule EZH2 inhibitors.

cancer biology↗