Prenatal exposure to environmental pro-oxidants induces mitochondria-mediated epigenetic changes: a cross-sectional pilot study.

Mitochondria play a central role in maintaining cellular and metabolic homeostasis during vital development cycles of foetal growth. Optimal mitochondrial functions are important not only to sustain adequate energy production but also for regulated epigenetic programming. However, these organelles are subtle targets of environmental exposures, and any perturbance in the defined mitochondrial machinery during the developmental stage can lead to the re-programming of the foetal epigenetic landscape. As these modifications can be transferred to subsequent generations, we herein performed a cross-sectional study to have an in-depth understanding of this intricate phenomenon. The study was conducted with two arms: whereas the first group consisted of in utero pro-oxidant exposed individuals and the second group included controls. Our results showed higher levels of oxidative mtDNA damage and associated integrated stress response among the exposed individuals. These disturbances were found to be closely related to the observed discrepancies in mitochondrial biogenesis. The exposed group showed mtDNA hypermethylation and changes in allied mitochondrial functioning. Altered expression of mitomiRs and their respective target genes in the exposed group indicated the possibilities of a disturbed mitochondrial-nuclear cross talk. This was further confirmed by the modified activity of the mitochondrial stress regulators and pro-inflammatory mediators among the exposed group. Importantly, the disturbed DNMT functioning, hypermethylation of nuclear DNA, and higher degree of post-translational histone modifications established the existence of aberrant epigenetic modifications in the exposed individuals. Overall, our results demonstrate the first molecular insights of in utero pro-oxidant exposure associated changes in the mitochondrial-epigenetic axis. Although, our study might not cement an exposure-response relationship for any particular environmental pro-oxidant, but suffice to establish a dogma of mito-epigenetic reprogramming at intrauterine milieu with chronic illness, a hitherto unreported interaction.

A photonic dual nano-hybrid assay for detection of cell-free circulating mitochondrial DNA.

Circulating cell free mitochondrial DNA (ccf-mtDNA) has emerged as a potential marker for diagnosis and prognosis of different chronic and age associated non-communicable diseases. Therefore, owing to its biomarker potential, we herein assessed a novel nano-photonic dual hybrid assay system for rapid and specific detection of ccf-mtDNA. The assay comprised of two systems, i.e. a capture and screen facet containing aminopyrene tethered carbon quantum dots for effective screening of circulating cell free nucleic acids (ccf-NAs) and a quantum dot conjugated probe for precise detection of ccf-mtDNA in the screened ccf-NAs. Our observations suggested that the developed dual-assay system possesses high feasibility and selectivity in screening of ccf-NAs and estimation of ccfmtDNA in a given sample. It also offers high versatility of measurement in different analytical platforms, indicating the translational potential of the method for possible disease risk assessment in control and field settings.

Immuno-cytometric detection of circulating cell free methylated DNA, post-translationally modified histones and micro RNAs using semi-conducting nanocrystals.

The diagnostic potential of cell free epigenomic signatures is largely driven by the fact that manifold quantities of methylated DNA, post-translationally modified histones and micro RNAs are released into systemic circulation in various non-communicable diseases. However, the time-consuming and specificity-related complications of conventional analytical procedures necessitate the development of a method which is rapid, selective and sensitive in nature. The present work illustrates a novel; prompt; "mix and measure" cytometric-based nano-biosensing system that offers direct quantification of cell-free circulating (ccf) epigenomic signatures (methylated ccf-DNA, tri-methylated histone H3 at lysine {4, 9, 27 & 36} and argonaute 2 protein-bound ccf-micro RNAs) using triple nano-assemblies in a single tube format. Each assembly with unique structural and spectral properties comprised of n-type semiconducting nanocrystals conjugated to a specific monoclonal antibody. Our results suggested that the developed combinatorial approach may offer simultaneous detection of three distinct yet biologically interrelated signatures with high selectivity and sensitivity using flow cytometry and fluorometry in the enriched and test samples. The proposed novel nano-assembly based detection system has a considerable potential of emerging as a minimal invasive easy-to-use method that could possibly permit real-time, rapid and reproducible monitoring of epigenomic markers in clinical and field settings.

Clostridium perfringens phospholipase C impairs innate immune response by inducing integrated stress response and mitochondrial-induced epigenetic modifications.

Clostridium perfringens, a rod-shaped, gram-positive, anaerobic, spore-forming bacterium is one of the most widely occurring bacterial pathogens, associated with a spectrum of diseases in humans. A major virulence factor during its infection is the enzyme phospholipase C encoded by the plc gene, known as Clostridium perfringens phospholipase C (CpPLC). The present study was designed to understand the role of CpPLC in inducing survival mechanisms and mitochondrial-induced epigenetic changes in a human lymphocyte cell culture model. Following exposure to CpPLC, a significant generation of mitochondrial reactive oxygen species was observed, which coincided with the changes in the expression of vital components of MAP/ERK/RTK signaling cascade that regulates the downstream cellular functions. These disturbances further led to alterations in the mitochondrial genome and functioning. This was supported by the observed upregulation in the expression of mitochondrial fission genes Drp1, Fis1, and Mff, and mitochondrial fusion genes MFN1, MFN2, and OPA1 following CpPLC exposure. CpPLC exposed cells showed upregulation of OMA1, DELE1, and HRI genes involved in the integrated stress response (ISR), which suggests that it may induce the ISR that provides a pro-survival mechanism to the host cell. CpPLC also initiated immune patho-physiologic mechanisms including mitochondrial-induced epigenetic modifications through a mitochondrial-ROS driven signaling pathway. Interestingly, epigenetic machinery not only play a pivotal role in lymphocyte homeostasis by contributing to cell-fate decisions but thought to be one of the mechanisms by which intracellular pathogens survive within the host cells. Importantly, the impairment of mtDNA repair among the CpPLC exposed cells, induced alterations within mtDNA methylation, and led to the deregulation of MT-CO1, MT-ND6, MT-ATPase 6, and MT-ATPase8 gene expression profiles that are important for mitochondrial bioenergetics and subsequent metabolic pathways. This was further confirmed by the changes in the activity of mitochondrial electron chain complexes (complex I, II, III, IV and V). The altered mtDNA methylation profile was also found to be closely associated with the varied expression of mitomiRs and their targets. CpPLC exposed cells showed up-regulation of miR24 expression and down-regulation of miR34a, miR150, and miR155, while the increased expression of mitomiR target genes i.e. of K-Ras, MYC, EGFR, and NF-kß was also observed in these cells. Altogether, our findings provide novel insights into the derailment of redox signaling machinery in CpPLC treated lymphocytes and its role in the induction of survival mechanisms and mitochondrial-induced epigenetic modifications.

Quantum dot nanoconjugates for immuno-detection of circulating cell-free miRNAs.

Argonaute protein (AGO2) bound circulating cell-free miRNAs (ccf-miRs), in the recent years, has attracted great attention due to their differential abundance in biological fluids. In the present work, a selective and technically uncomplicated quantum dot (QD) nanoconjugate has been fabricated combining the specific affinity of the antibody and fluorescent property of QDs for the precise immuno-detection of AGO2-bound ccf-miRs in plasma samples. The electrophoretic mobility assay confirmed the conjugation of antibody with QDs. The detection methodology involves a highly specific antigen-antibody reaction between the AGO2 proteins of miRNA-induced silencing complex and the anti-AGO2 antibody conjugated with QDs. The recognition efficiency of QD-Ab nanoconjugates was analysed using flow cytometry and fluorometry. The flow cytometry results demonstrated a significant change in the fluorescence intensity of the prepared nanoconjugates upon capture of ccf-miRs in the plasma samples with respect to the samples devoid of any miRNAs. Fluorometry measurements exhibited corroboration with the flow cytometry results indicating the selectivity and reproducibility of the developed method. Current research highlights the translational significance of the methodology as a novel flow cytometry based immunoassay for detection of differentially expressed AGO2-bound miRNAs in clinical and field settings.

Impairment of Mitochondrial-Nuclear Cross Talk in Lymphocytes Exposed to Landfill Leachate.

Landfill leachate, a complex mixture of different solid waste compounds, is widely known to possess toxic properties. However, the fundamental molecular mechanisms engaged with landfill leachate exposure inducing cellular and sub-cellular ramifications are not well explicated. Therefore, we aim to examine the potential of leachate to impair mitochondrial machinery and its associated mechanisms in human peripheral blood lymphocytes. On assessment, the significant increase in the dichlorofluorescein (DCF) fluorescence, accumulation of 8-Oxo-2'-deoxyguanosine (8-oxo-dG), and levels of nuclear factor erythroid 2-related factor 2 (Nrf-2) strongly indicated the ability of the leachate to induce a pro-oxidant state inside the cell. The decrease in the mitochondrial membrane potential and alterations in the mitochondrial genome observed in leachate-exposed cells further suggested the disturbances in mitochondrial machinery. Moreover, these mitochondrial-associated redox imbalances were accompanied by the increased level of NF-κß, pro-inflammatory cytokines, and DNA damage. In addition, the higher DNA fragmentation, release of nucleosomes, levels of polyadenosine diphosphate ADP-ribose polymerase (PARP), and activity of caspase-3 suggested the involvement of mitochondrial mediated apoptosis in leachate exposed cells. These observations were accompanied by the low proliferative index of the exposed cells. Conclusively, our results clearly indicate the ability of landfill leachate to disturb mitochondrial redox homeostasis, which might be a probable source for the immunotoxic consequences leading to plausible patho-physiological conditions in humans susceptible to such environmental exposures.

Exposure to ultrafine particulate matter induces NF-κß mediated epigenetic modifications.

Exposure to ultrafine particulate matter (PM0.1) is positively associated with the etiology of different acute and chronic disorders; however, the in-depth biological imprints that link these submicron particles with the disturbances in the epigenomic machinery are not well defined. Earlier, we showed that exposure to these particles causes significant disturbances in the mitochondrial machinery and triggers PI-3-kinase mediated DNA damage responses. In the present study, we aimed to further understand the epigenomic insights of the ultrafine PM exposure. The higher levels of intracellular reactive oxygen species and depleted Nrf-2 in ultrafine PM exposed cells reconfirmed its potential to induce oxidative stress. Importantly, the observed increase in the levels of NF-κß and associated cytokines among exposed cells suggested the activation of NF-κß mediated inflammatory loop which potentially serves as a platform for initiating epigenetic insinuations. This fact was strongly supported by the altered miRNA expression profile of the ultrafine PM exposed cells. These NF-κß induced miRNA alterations were also found to be associated with other epigenetic targets as the exposed cells showed higher expression levels of DNA methyltransferases which positively corresponded with the global changes in DNA methylation levels. Upon further analysis, significant alterations in histone code were also reported in ultrafine PM exposed cells. Conclusively our results suggested that NF-κß acts as an inflammatory switch that possesses the potential to induce genome-wide epigenetic modification upon ultrafine PM exposure.

Nano-engineered flavonoids for cancer protection.

Diet and environment are two critical regulators that influence an individual's epigenetic profile. Besides the anterograde signaling, mitochondria act as a key regulator of epigenetic alterations in cancer either by controlling the concentration of the cofactors, activity of vital enzymes or by affecting the transcription of NF-kappaB and associated signaling molecules. As epigenetic modifications are the major drivers of aberrant gene expression, designing novel nutri-epigenomic strategies to modulate reversible epigenetic modifications will be important for effective cancer protection. In this regard, nutraceuticals such as flavonoids holds significant promise to modulate the epigenome through a network of interconnected anti-redox mechanisms. However, low solubility, rapid metabolism and poor absorption of flavonoids in gastrointestinal tract hinder their use in clinical settings. Therefore, it is imperative to develop nano-engineered systems which could considerably improve the targeted delivery of these bioactive compounds with better efficacy and pharmacokinetic properties. Concerted efforts in nano-engineering of flavonoids using polymer, lipid and complexation based approaches could provide successful bench-to-bedside translation of flavonoids as broad spectrum anti-cancer agents.

Nanobiosensors: Point-of-care approaches for cancer diagnostics.

Early cancer diagnosis is of prime importance as it paves the way for effective treatment and possible patient survival. The recent advancements in the field of biosensorics have facilitated the development of functionalized nanobiosensors which have the potential to provide a cost-effective, reliable and rapid diagnostic strategy for cancers. These nanoscaled sensing systems utilize electrochemical, optical, mass and calorimetric sensing mechanisms to specifically identify the disease-specific biomarkers. Because of clinical translational utility, the present review aims to describe the recent developments and status of the nanobiosensors as a point-of-care approach for cancer diagnosis. The review also offers important insights into the design, preparation and characterization of these nano-frameworks. In particular, the state-of-art nanobiosensors based on carbon nanostructures, metal nanoparticles, magnetic nanoparticles, silica-based nanomaterials, conducting polymers based nanoparticles and quantum dots, which provide countless opportunities in the field of cancer biosensorics have been summarized. It also showcases the need to perform robust clinical validation of the emerging nanobiosensor strategies that would act as the ultimate point-of-care test for the personalized cancer therapeutics.

Air pollution associated epigenetic modifications: Transgenerational inheritance and underlying molecular mechanisms.

Air pollution is one of the leading causes of deaths in Southeast Asian countries including India. Exposure to air pollutants affects vital cellular mechanisms and is intimately linked with the etiology of a number of chronic diseases. Earlier work from our laboratory has shown that airborne particulate matter disturbs the mitochondrial machinery and causes significant damage to the epigenome. Mitochondrial reactive oxygen species possess the ability to trigger redox-sensitive signaling mechanisms and induce irreversible epigenomic changes. The electrophilic nature of reactive metabolites can directly result in deprotonation of cytosine at C-5 position or interfere with the DNA methyltransferases activity to cause alterations in DNA methylation. In addition, it also perturbs level of cellular metabolites critically involved in different epigenetic processes like acetylation and methylation of histone code and DNA hypo or hypermethylation. Interestingly, these modifications may persist through downstream generations and result in the transgenerational epigenomic inheritance. This phenomenon of subsequent transfer of epigenetic modifications is mainly associated with the germ cells and relies on the germline stability of the epigenetic states. Overall, the recent literature supports, and arguably strengthens, the contention that air pollution might contribute to transmission of epimutations from gametes to zygotes by involving mitochondrial DNA, parental allele imprinting, histone withholding and non-coding RNAs. However, larger prospective studies using innovative, integrated epigenome-wide metabolomic strategy are highly warranted to assess the air pollution induced transgenerational epigenetic inheritance and associated human health effects.

Pre-clinical Validation of Mito-targeted Nano-engineered Flavonoids Isolated From Selaginella bryopteris (Sanjeevani) As A Novel Cancer Prevention Strategy.

BACKGROUND: Novel bioactive plant secondary metabolites, including flavonoids, offer a spectrum of chemo-protective responses against a range of human tumor models. However, the clinical translation of these promising anti-cancer agents has been hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration. OBJECTIVE: To circumvent the challenges associated with herbal drug development and for effective integration into clinical setting, nano-engineering is one of the emerging pragmatic strategies which has promise to deliver therapeutic concentrations of bio-actives upon oral administration. METHOD: We assessed the nano-encapsulated flavonoid-rich fraction isolated from a traditional Indian herb Selaginella bryopteris (Sanjeevani) (NP.SB). Both in vitro and in vivo studies were performed to evidence the epigenetic protection mechanisms of NP.SB through a mitochondrial-targeted pre-clinical validation strategy. RESULTS: The mito-protective activity of NP.SB revealed a dose-dependent effect when tested in GC-1 spg (mouse spermatogonial epithelial) and B/CMBA.Ov (mouse ovarian epithelial) following exposure to Nsuccinimidyl N-methylcarbamate, a potential human carcinogen. Smaller size, rapid internalization, faster mobility and site specific delivery conferred significant cancer protection in cultured cells. Notably, this encapsulated flavonoid supplementation; prevented emergence of neoplastic daughter clones from senescent mother phenotypes in pro-oxidant treated GC-1 spg and B/CMBA.Ov cells by selective abrogation of mitochondrial oxidative stress-induced aberrant epigenetic modifications. In vivo studies using a diethylnitrosamine and 2- acetylaminofluorene mouse model demonstrated that NP.SB has a significant inhibitory effect on tumor growth which clearly substantiated our in vitro findings. CONCLUSION: Anti-carcinogenic property in conjunction with low toxicity of NP.SB, underscores the translational significance of dietary flavonoids as cancer-protective agents for preferential application in clinical settings.

Fetal nucleic acids in maternal plasma: from biology to clinical translation.

Exposure to environmental contaminants during the critical window of pregnancy results in deregulation of highly coordinated genetic and epigenetic mechanisms involved in prenatal growth. Such disturbances significantly alter the fetal programming, and lead to various developmental disorders immediately, over the lifetime, or transgenerationally. During the process of placental development, fetal nucleic acids enter maternal plasma as a result of necrotic, apoptotic, and inflammatory mechanisms. These nucleic acids reflect normal or abnormal ongoing cellular changes during prenatal fetal development. Here, we critically review the utility of maternally circulating cell free fetal nucleic acids towards developing reliable biomarkers for widespread screening of environmentally-associated fetal abnormalities. We further discuss the most recent developments in the fetal nucleic acid analysis, quantification methodologies, challenges involved in their accurate detection and their potential applications in fetomaternal medicine.

Epigenetic Biomarkers for Risk Assessment of Particulate Matter Associated Lung Cancer.

BACKGROUND: Particulate matter directly emitted into the air by sources such as combustion processes and windblown dust, or formed in the atmosphere by transformation of emitted gases are the major contributors to air pollution that triggers a diverse array of human pathologies including lung cancer. The mortality in lung cancer is usually high as the disease is not symptomatic at its early treatable stage. Moreover, available methods for screening are costly and mainly rely on imaging techniques which lack sufficient sensitivity and specificity. Despite progress in the identification of biomarkers, gene mutation based approaches still face formidable challenges as the disease evolves from a complex interplay between environment and host. Therefore, identification of an epigenomic signature might be useful for early diagnosis with the potential to reduce the environmental-associated disease burden. OBJECTIVE: The review discusses the utility of epigenomic signature in identification and management of the environmental-associated lung cancers. CONCLUSION: Non-invasive 'liquid biopsy' based epigenomic screening has recently emerged as a methodology which has potential to characterize tumor heterogeneity at initial stages. Epigenetic signatures (methylated DNA, miRNA, and post transcriptionally modified histones) known to reflect the vital cellular changes, circulate at higher levels in the individuals with lung cancer. These circulating biological entities are reported to be closely associated with the clinical outcome of lung cancer patients and thus strongly stand as the probable candidate to identify disease at an early stage and monitor treatment response, thereby, benefiting patients and improving their lives. However, for effective implementation of the strategy as "point-of-care" test for screening population-at-risk will require exhaustive clinical validation.

Cell-Free Circulating Epigenomic Signatures: Non-Invasive Biomarker for Cardiovascular and Other Age-Related Chronic Diseases.

The burden of cardio-vascular and other age-related non-communicable diseases are rapidly increasing worldwide. Majority of these chronic ailments are curable, if diagnosed at early stages. Candidate biomarkers of early detection are therefore essential for identification of high-risk individuals, prompt and accurate disease diagnosis, and to monitor therapeutic response. The functional significance of circulating nucleic acids that recapitulate specific disease profiles is now well established. But subtle changes in DNA sequence may not solely reflect the differentiation of gene expression patterns observed in diverse set of diseases as epigenetic phenomena play a larger role in aetiology and patho-physiology. Unlike genetic markers, knowledge about the diagnostic utility of circulating epigenetic signatures: methylated DNA; micro RNA and modified histones are deficient. Characterization of these novel entities through omics-based molecular technologies might prompt development of a range of laboratory-based strategies, thereby accelerating their broader translational purpose for early disease diagnosis, monitoring therapeutic response and drug resistance. However, largest opportunity for innovation lies in developing point-of-care tests with accurate diagnostic and higher prognostic score that is applicable for screening of high-risk populations.

Epigenetics: A key paradigm in reproductive health.

It is well established that there is a heritable element of susceptibility to chronic human ailments, yet there is compelling evidence that some components of such heritability are transmitted through non-genetic factors. Due to the complexity of reproductive processes, identifying the inheritance patterns of these factors is not easy. But little doubt exists that besides the genomic backbone, a range of epigenetic cues affect our genetic programme. The inter-generational transmission of epigenetic marks is believed to operate via four principal means that dramatically differ in their information content: DNA methylation, histone modifications, microRNAs and nucleosome positioning. These epigenetic signatures influence the cellular machinery through positive and negative feedback mechanisms either alone or interactively. Understanding how these mechanisms work to activate or deactivate parts of our genetic programme not only on a day-to-day basis but also over generations is an important area of reproductive health research.

Role of mitochondrial oxidative stress on lymphocyte homeostasis in patients diagnosed with extra-pulmonary tuberculosis.

Extra-pulmonary tuberculosis is often an underrated illness. Recent clinical studies have pointed out that lymphocyte homeostasis is dramatically disturbed as revealed through a series of signs and symptoms. Lymphocytes, the known effector cells of our immune system, play an important role in providing immunologic resistance against Mycobacterium infection. It is important to have quantitative insights into the lifespan of these cells; therefore, we aimed to study the precise effect of gastrointestinal tuberculosis infection on peripheral blood lymphocyte subpopulations and function. Our results indicated that gastrointestinal tuberculosis could increase mitochondrial oxidative stress, lower mitochondrial DNA copy number, promote nuclear DNA damage and repair response, decrease mitochondrial respiratory chain enzyme activities, and upregulate Bcl-2 and caspase-3 gene expression in lymphocytes. We further revealed that Mycobacterium infection induces autophagy for selective sequestration and subsequent degradation of the dysfunctional mitochondrion before activating cellular apoptosis in the peripheral lymphocyte pool. Together, these observations uncover a new role of mitochondrial-nuclear crosstalk that apparently contributes to lymphocyte homeostasis in gastrointestinal tuberculosis infection.

Mitochondrial anomalies: driver to age associated degenerative human ailments.

Mitochondria play a fundamental role in regulating a variety of complex metabolic processes to maintain adequate energy balance for cellular existence. To orchestrate these functions, an undisturbed mitochondrial dynamics is imperative through a set of tightly guided mechanisms. Interference in key signature processes by several genetic, epigenetic and age-linked factors triggers mitochondrial dysfunction through decrease in mitochondrial biogenesis, reduced mitochondrial content, aberrant mtDNA mutations, increased oxidative stress, deficient mitophagy, energy dysfunction, decrease in anti oxidant defense and impaired calcium homeostasis. Mitochondrial dysfunction is widely implicated in origin and development of various age associated degenerative human ailments including metabolic syndromes, cardiovascular diseases, cancer, diabetes and neurodegenerative disorders. The present review revisits the mitochondrial anomalies involved in aetiology of different human diseases and also highlights the translational significance of nano-vectors aimed for selective mitochondrial engineering which might pave way for development of novel therapeutics.

Molecular bio-dosimetry for carcinogenic risk assessment in survivors of Bhopal gas tragedy.

December 2014 marked the 30th year anniversary of Bhopal gas tragedy. This sudden and accidental leakage of deadly poisonous methyl isocyanate (MIC) gas instigated research efforts to understand the nature, severity of health damage and sufferings of 570 000 ailing survivors of this tragedy. In a decade-long period, our systematic laboratory investigations coupled with long-term molecular surveillance studies have comprehensively demonstrated that the risk of developing an environmental associated aberrant disease phenotype, including cancer, involves complex interplay of genomic and epigenetic reprogramming. These findings poised us to translate this knowledge into an investigative framework of "molecular biodosimetry" in a strictly selected cohort of MIC exposed individuals. A pragmatic cancer risk-assessment strategy pursued in concert with a large-scale epidemiological study might unfold molecular underpinnings of host-susceptibility and exposureresponse relationship. The challenges are enormous, but we postulate that the study will be necessary to establish a direct initiation-promotion paradigm of environmental carcinogenesis. Given that mitochondrial retrograde signaling-induced epigenetic reprogramming is apparently linked to neoplasticity, a cutting-edge tailored approach by an expert pool of biomedical researchers will be fundamental to drive these strategies from planning to execution. Validating the epigenomic signatures will hopefully result in the development of biomarkers to better protect human lives in an overburdened ecosystem, such as India, which is continuously challenged to meet population demands. Besides, delineating the mechanistic links between MIC exposure and cancer morbidity, our investigative strategy might help to formulate suitable regulatory policies and measures to reduce the overall burden of occupational and environmental carcinogenesis.

Epigenetic dimension of oxygen radical injury in spermatogonial epithelial cells.

The present work reports a direct role of mitochondrial oxidative stress induced aberrant chromatin regulation, as a central phenomenon, to perturbed genomic integrity in the testicular milieu. Oxygen-radical injury following N-succinimidyl N-methylcarbamate treatment in mouse spermatogonial epithelial (GC-1 spg) cells induced functional derailment of mitochondrial machinery. Mitophagy resulted in marked inhibition of mitochondrial respiration and reduced mtDNA copy number. Impaired cell cycle progression along with altered H3K9me1, H4K20me3, H3, AcH3 and uH2A histone modifications were observed in the treated cells. Dense heterochromatin foci and aberrant expression of HP1α in nuclei of treated cells implied onset of senescence associated secretory phenotype mediated through nuclear accumulation of NF-κB. Neoplastic nature of daughter clones, emerged from senescent mother phenotypes was confirmed by cytogenetic instability, aberrant let-7a and let-7b miRNA expression and anchorage independent growth. Together, our results provide the first insights of redox-dependent epigenomic imbalance in spermatogonia, a previously unknown molecular paradigm.

Nanoengineered strategies to optimize dendritic cells for gastrointestinal tumor immunotherapy: from biology to translational medicine.

Nanomedicine may play an important role in improving the clinical efficacy of dendritic cell-based immunotherapy against GI tract malignancies. Dendritic cell-based vaccines have proven their effectiveness against different established GI tract tumors, yet their success is mainly hindered by the strong tumor-induced suppressive microenvironment. The sustained and targeted release of tumor antigens to dendritic cells using different nanoengineered approaches would be an efficient strategy to overcome established immune tolerance. Encapsulation would result in low diffusivity, restricted movement, effective crosspresentation and enhanced T-cell responses. These nanotherapy-based approaches will certainly help with the designing of clinically translatable dendritic cell-based therapeutic vaccines and facilitate the selective removal of residual disease in gastrointestinal cancer patients following standard treatments.