Short peptides based on the conserved regions of MIEN1 protein exhibit anticancer activity by targeting the MIEN1 signaling pathway.

Migration and invasion enhancer 1 (MIEN1) overexpression characterizes several cancers and facilitates cancer cell migration and invasion. Leveraging conserved immunoreceptor tyrosine-based activation motif and prenylation motifs within MIEN1, we identified potent anticancer peptides. Among them, bioactive peptides LA3IK and RP-7 induced pronounced transcriptomic and protein expression changes at sub-IC50 concentrations. The peptides effectively inhibited genes and proteins driving cancer cell migration, invasion, and epithelial-mesenchymal transition pathways, concurrently suppressing epidermal growth factor-induced nuclear factor kappa B nuclear translocation in metastatic breast cancer cells. Specifically, peptides targeted the same signal transduction pathway initiated by MIEN1. Molecular docking and CD spectra indicated the formation of MIEN1-peptide complexes. The third-positioned isoleucine in LA3IK and CVIL motif in RP-7 were crucial for inhibiting breast cancer cell migration. This is evident from the limited migration inhibition observed when MDA-MB-231 cells were treated with scrambled peptides LA3IK SCR and RP-7 SCR. Additionally, LA3IK and RP-7 effectively suppressed tumor growth in an orthotopic breast cancer model. Notably, mice tolerated high intraperitoneal (ip) peptide doses of 90 mg/Kg well, surpassing significantly lower doses of 5 mg/Kg intravenously (iv) and 30 mg/Kg intraperitoneally (ip) used in both in vivo pharmacokinetic studies and orthotopic mouse model assays. D-isomers of LA3IK and RP-7 showed enhanced anticancer activity compared to their L-isomers. D-LA3IK remained stable in mouse plasma for 24 h with 75% remaining, exhibiting superior pharmacokinetic properties over D/L-RP-7. In summary, our findings mark the first report of short peptides based on MIEN1 protein sequence capable of inhibiting cancer signaling pathways, effectively impeding cancer progression both in vitro and in vivo.

Cabazitaxel-Loaded Nanoparticles Reduce the Invasiveness in Metastatic Prostate Cancer Cells: Beyond the Classical Taxane Function.

Bone-metastatic prostate cancer symbolizes the beginning of the later stages of the disease. We designed a cabazitaxel-loaded, poly (lactic-co-glycolic acid) (PLGA) nanoparticle using an emulsion-diffusion-evaporation technique. Bis (sulfosuccinimidyl) suberate (BS3) was non-covalently inserted into the nanoparticle as a linker for the conjugation of a bone-targeting moiety to the outside of the nanoparticle. We hypothesized that the nanoparticles would have the ability to inhibit the epithelial-to-mesenchymal transition (EMT), invasion, and migration in prostate cancer cells. Targeted, cabazitaxel-loaded nanoparticles attenuated the EMT marker, Vimentin, and led to an increased E-cadherin expression. These changes impart epithelial characteristics and inhibit invasive properties in cancer progression. Consequently, progression to distant sites is also mitigated. We observed the reduction of phosphorylated Src at tyrosine 416, along with increased expression of phosphorylated cofilin at serine 3. These changes could affect migration and invasion pathways in cancer cells. Both increased p-120 catenin and inhibition in IL-8 expression were seen in targeted, cabazitaxel-loaded nanoparticles. Overall, our data show that the targeted, cabazitaxel-loaded nanoparticles can act as a promising treatment for metastatic prostate cancer by inhibiting EMT, invasion, and migration, in prostate cancer cells.

Higher Expression of Annexin A2 in Metastatic Bladder Urothelial Carcinoma Promotes Migration and Invasion.

In this study, we aim to evaluate the significance of AnxA2 in BLCA and establish its metastatic role in bladder cancer cells. Analysis of TCGA data showed that AnxA2 mRNA expression was significantly higher in BLCA tumors than in normal bladder tissues. High mRNA expression of AnxA2 in BLCA was significantly associated with high pathological grades and stages, non-papillary tumor histology, and poor overall survival (OS), progression-free survival (PFS), and diseases specific survival (DSS). Similarly, we found that AnxA2 expression was higher in bladder cancer cells derived from high-grade metastatic carcinoma than in cells derived from low-grade urothelial carcinoma. AnxA2 expression significantly mobilized to the surface of highly metastatic bladder cancer cells compared to cells derived from low-grade tumors and associated with high plasmin generation and AnxA2 secretion. In addition, the downregulation of AnxA2 cells significantly inhibited the proliferation, migration, and invasion in bladder cancer along with the reduction in proangiogenic factors and cytokines such as PDGF-BB, ANGPT1, ANGPT2, Tie-2, bFGF, GRO, IL-6, IL-8, and MMP-9. These findings suggest that AnxA2 could be a promising biomarker and therapeutic target for high-grade BLCA.

Nutraceuticals with Anti-inflammatory and Anti-oxidant Properties as an Intervention for Reducing the Health Effects of Fine Particulate Matter: Potential and Prospects.

Air pollution, especially particulate matter pollution, adversely affects human health. A growing pool of evidence has emerged which underscores the potential of individual-level nutritional interventions in attenuating the adverse health impact of exposure to PM2.5. Although controlling emission and reducing the overall levels of air pollution remains the ultimate objective globally, the sustainable achievement of such a target and thus consequent protection of human health will require a substantial amount of time and concerted efforts worldwide. In the meantime, smaller-scale individual-level interventions that can counter the inflammatory or oxidative stress effects triggered by exposure to particulate matter may be utilized to ameliorate the health effects of PM2.5 pollution. One such intervention is the incorporation of nutraceuticals in the diet. Here, we present a review of the evidence generated from various in vitro, in vivo and human studies regarding the effects of different anti-inflammatory and antioxidant nutraceuticals in ameliorating the health effects of particulate matter air pollution. The studies discussed in this review suggest that these nutraceuticals, when consumed as a part of the diet or as additional supplementation, can potentially negate the cellular level adverse effects of exposure to particulate pollution. The potential benefits of adopting a non-pharmacological diet-based approach to air pollution-induced disease management have also been discussed. We argue that before a nutraceuticals-based approach can be used for widespread public adoption, further research, especially human clinical trials, is essential to confirm the beneficial action of relevant nutraceuticals and to explore the safe limits of human supplementation and the risk of side effects. Future research should focus on systematically translating bench-based knowledge regarding nutraceuticals gained from in vitro and in vivo studies into clinically usable nutritional guidelines.

Combination of Small Extracellular Vesicle-Derived Annexin A2 Protein and mRNA as a Potential Predictive Biomarker for Chemotherapy Responsiveness in Aggressive Triple-Negative Breast Cancer.

Small extracellular vesicles (sEVs), mainly exosomes, are nanovesicles that shed from the membrane as intraluminal vesicles of the multivesicular bodies, serve as vehicles that carry cargo influential in modulating the tumor microenvironment for the multi-step process of cancer metastasis. Annexin A2 (AnxA2), a calcium(Ca2+)-dependent phospholipid-binding protein, is among sEV cargoes. sEV-derived AnxA2 (sEV-AnxA2) protein is involved in the process of metastasis in triple-negative breast cancer (TNBC). The objective of the current study is to determine whether sEV-AnxA2 protein and/or mRNA could be a useful biomarkers to predict the responsiveness of chemotherapy in TNBC. Removal of Immunoglobulin G (IgG) from the serum as well as using the System Bioscience's ExoQuick Ultra kit resulted in efficient sEV isolation and detection of sEV-AnxA2 protein and mRNA compared to the ultracentrifugation method. The standardized method was applied to the twenty TNBC patient sera for sEV isolation. High levels of sEV-AnxA2 protein and/or mRNA were associated with stage 3 and above in TNBC. Four patients who responded to neoadjuvant chemotherapy had high expression of AnxA2 protein and/or mRNA in sEVs, while other four who did not respond to chemotherapy had low levels of AnxA2 protein and mRNA in sEVs. Our data suggest that the sEV-AnxA2 protein and mRNA could be a combined predictive biomarker for responsiveness to chemotherapy in aggressive TNBC.

A surprisingly gentle approach to cavity containing spherocylindrical microparticles from ordinary polymer dispersions in flow.

Herein, we demonstrate a facile approach to fully transform spherical polymeric microparticles to elongated spherocylinders containing an internal cavity under ambient and mild stirring conditions. Critical to the process is to deform the amorphous and non-crosslinked particles under glassy conditions for an unusually long time; 120 hours for the poly(styrene-co-glycidyl methacrylate) microparticles discussed in greatest detail. Larger particles in the 5 micron and greater range were markedly more susceptible to the shear imposed by stirring the aqueous dispersion. The resulting morphology is robust and kinetically frozen yet reverts to the original spherical shape if annealed above the glass transition temperature with suitable temperature or plasticizer. The volume fraction of the internal void can be modulated by particle composition and process conditions and is irregular in shape we believe as a result of a cavitation event during plastic deformation.

Circulating microRNAs as biomarkers of environmental exposure to polycyclic aromatic hydrocarbons: potential and prospects.

Exposure to polycyclic aromatic hydrocarbons (PAHs) produced from various pyrogenic and petrogenic sources in the environment has been linked to a variety of toxic effects in the human body. Genome-wide analyses have shown that microRNAs (miRNAs) can function as novel and minimally invasive biomarkers of environmental exposure to PAHs. The objective of this study is to explore miRNA signatures associated with early health effects in response to chronic environmental exposure to PAHs. We systematically searched Scopus and PubMed databases for studies related to exposure of PAHs with changes in miRNA expression patterns that represent early health effects in the exposed population. Based on previous studies, we included 15 cell-based and 9 each of animal model and human population-based studies for assessment. A total of 11 differentially expressed PAH-responsive miRNAs were observed each in two or more cell-based studies (miR-181a and miR-30c-1), animal model studies (miR-291a and miR-292), and human population-based studies (miR-126, miR-142-5p, miR-150-5p, miR-24-3p, miR-27a-3p, miR-28-5p, and miR-320b). In addition, miRNAs belonging to family miR-122, miR-199, miR-203, miR-21, miR-26, miR-29, and miR-92 were found to be PAH-responsive in both animal model and cell-based studies; let-7, miR-126, miR-146, miR-30, and miR-320 in both cell-based and human population-based studies; and miR-142, miR-150, and miR-27 were found differentially expressed in both animal model and human population-based studies. The only miRNA whose expression was found to be altered in all the three groups of studies is miR-34c. Association of environmental exposure to PAHs with altered expression of specific miRNAs indicates that selective miRNAs can be used as early warning biomarkers in PAH-exposed population.

Crosslinking in Semi-Batch Seeded Emulsion Polymerization: Effect of Linear and Non-Linear Monomer Feeding Rate Profiles on Gel Formation.

Waterborne latex is often called a product-of-process. Here, the effect of semi-batch monomer feed rate on the kinetics and gel formation in seeded emulsion polymerization was investigated for the copolymerization of n-butyl methacrylate (n-BMA) and ethylene glycol dimethacrylate (EGDMA). Strikingly, the gel fraction was observed to be significantly influenced by monomer feed rate, even while most of the experiments were performed under so-called starve-fed conditions. More flooded conditions from faster monomer feed rates, including seeded batch reactions, counterintuitively resulted in significantly higher gel fraction. Chain transfer to polymer was intentionally suppressed here via monomer selection so as to focus mechanistic insights to relate only to the influence of a divinyl monomer, as opposed to being clouded by contributions to topology from long chain branching. Simulations revealed that the dominant influence on this phenomenon was the sensitivity of primary intramolecular cyclization to the instantaneous unreacted monomer concentration, which is directly impacted by monomer feed rate. The rate constant for cyclization for these conditions was determined to be first order and 4000 s-1, approximately 4 times that typically observed for backbiting in acrylates. This concept has been explored previously for bulk and solution polymerizations, but not for emulsified reaction environments and especially for the very low mole fraction divinyl monomer. In addition, while gel fraction could be dramatically manipulated by variations in linear monomer feed rates, it could be markedly enhanced by leveraging non-linear feed profiles built from combination sequences of flooded and starved conditions. For a 2 h total feed time, a fully linear profile resulted in 30% gel while a corresponding non-linear profile with an early fast-feed segment resulted in 80% gel.

Targeting Myeloid-Specific Integrin α9ß1 Improves Short- and Long-Term Stroke Outcomes in Murine Models With Preexisting Comorbidities by Limiting Thrombosis and Inflammation.

RATIONALE: Currently, there is no effective intervention available that can reduce brain damage following reperfusion. Clinical studies suggest a positive correlation between the increased influx of neutrophils and severity of brain injury following reperfusion. Integrin α9ß1 is highly expressed on activated neutrophils and contributes to stable adhesion, but its role in stroke outcome has not been demonstrated to date. OBJECTIVE: We sought to determine the mechanistic role of myeloid-specific α9ß1 in the progression of ischemic stroke in murine models with preexisting comorbidities. METHODS AND RESULTS: We generated novel myeloid-specific α9-deficient (α9-/-) wild type (α9fl/flLysMCre+/-), hyperlipidemic (α9fl/flLysMCre+/-Apoe-/-), and aged (bone marrow chimeric) mice to evaluate stroke outcome. Susceptibility to ischemia/reperfusion injury was evaluated at 1, 7, and 28 days following reperfusion in 2 models of experimental stroke: filament and embolic. We found that peripheral neutrophils displayed elevated α9 expression following stroke. Irrespective of sex, genetic deletion of α9 in myeloid cells improved short- and long-term stroke outcomes in the wild type, hyperlipidemic, and aged mice. Improved stroke outcome and enhanced survival in myeloid-specific α9-/- mice was because of marked decrease in cerebral thromboinflammatory response as evidenced by reduced fibrin, platelet thrombi, neutrophil, NETosis, and decreased phospho-NF-κB (nuclear factor-κB), TNF (tumor necrosis factor)-α, and IL (interleukin)-1ß levels. α9-/- mice were less susceptible to FeCl3 injury-induced carotid artery thrombosis that was concomitant with improved regional cerebral blood flow following stroke as revealed by laser speckle imaging. Mechanistically, fibronectin containing extra domain A, a ligand for integrin α9, partially contributed to α9-mediated stroke exacerbation. Infusion of a specific anti-integrin α9 inhibitor into hyperlipidemic mice following reperfusion significantly reduced infarct volume and improved short- and long-term functional outcomes up to 28 days. CONCLUSIONS: We provide genetic and pharmacological evidence for the first time that targeting myeloid-specific integrin α9ß1 improves short- and long-term functional outcomes in stroke models with preexisting comorbidities by limiting cerebral thrombosis and inflammation.

Manipulation of glyoxalase pathway confers tolerance to multiple stresses in rice.

Crop plants face a multitude of diverse abiotic and biotic stresses in the farmers' fields. Although there now exists a considerable knowledge of the underlying mechanisms of response to individual stresses, the crosstalk between response pathways to various abiotic and biotic stresses remains enigmatic. Here, we investigated if the cytotoxic metabolite methylglyoxal (MG), excess of which is generated as a common consequence of many abiotic and biotic stresses, may serve as a key molecule linking responses to diverse stresses. For this, we generated transgenic rice plants overexpressing the entire two-step glyoxalase pathway for MG detoxification. Through assessment of various morphological, physiological and agronomic parameters, we found that glyoxalase-overexpression imparts tolerance towards abiotic stresses like salinity, drought and heat and also provides resistance towards damage caused by the sheath blight fungus (Rhizoctonia solani) toxin phenylacetic acid. We show that the mechanism of observed tolerance of the glyoxalase-overexpressing plants towards these diverse abiotic and biotic stresses involves improved MG detoxification and reduced oxidative damage leading to better protection of chloroplast and mitochondrial ultrastructure and maintained photosynthetic efficiency under stress conditions. Together, our findings indicate that MG may serve as a key link between abiotic and biotic stress response in plants.

A nuclear-localized rice glyoxalase I enzyme, OsGLYI-8, functions in the detoxification of methylglyoxal in the nucleus.

The cellular levels of methylglyoxal (MG), a toxic byproduct of glycolysis, rise under various abiotic stresses in plants. Detoxification of MG is primarily through the glyoxalase pathway. The first enzyme of the pathway, glyoxalase I (GLYI), is a cytosolic metalloenzyme requiring either Ni2+ or Zn2+ for its activity. Plants possess multiple GLYI genes, of which only some have been partially characterized; hence, the precise molecular mechanism, subcellular localization and physiological relevance of these diverse isoforms remain enigmatic. Here, we report the biochemical properties and physiological role of a putative chloroplast-localized GLYI enzyme, OsGLYI-8, from rice, which is strikingly different from all hitherto studied GLYI enzymes in terms of its intracellular localization, metal dependency and kinetics. In contrast to its predicted localization, OsGLYI-8 was found to localize in the nucleus along with its substrate, MG. Further, OsGLYI-8 does not show a strict requirement for metal ions for its activity, is functional as a dimer and exhibits unusual biphasic steady-state kinetics with a low-affinity and a high-affinity substrate-binding component. Loss of AtGLYI-2, the closest Arabidopsis ortholog of OsGLYI-8, results in severe germination defects in the presence of MG and growth retardation under salinity stress conditions. These defects were rescued upon complementation with AtGLYI-2 or OsGLYI-8. Our findings thus provide evidence for the presence of a GLYI enzyme and MG detoxification in the nucleus.

TUNEL Assay to Assess Extent of DNA Fragmentation and Programmed Cell Death in Root Cells under Various Stress Conditions.

DNA damage is one of the common consequences of exposure to various stress conditions. Different methods have been developed to accurately assess DNA damage and fragmentation in cells and tissues exposed to different stress agents. However, owing to the presence of firm cellulosic cell wall and phenolics, plant cells and tissues are not easily amenable to be subjected to these assays. Here, we describe an optimized TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) assay-based protocol to determine the extent of DNA fragmentation and programmed cell death in plant root cells subjected to various stress conditions. The method described here has the advantages of simplicity, reliability and reproducibility.

A NAP-Family Histone Chaperone Functions in Abiotic Stress Response and Adaptation.

Modulation of gene expression is one of the most significant molecular mechanisms of abiotic stress response in plants. Via altering DNA accessibility, histone chaperones affect the transcriptional competence of genomic loci. However, in contrast to other factors affecting chromatin dynamics, the role of plant histone chaperones in abiotic stress response and adaptation remains elusive. Here, we studied the physiological function of a stress-responsive putative rice (Oryza sativa) histone chaperone of the NAP superfamily: OsNAPL6. We show that OsNAPL6 is a nuclear-localized H3/H4 histone chaperone capable of assembling a nucleosome-like structure. Utilizing overexpression and knockdown approaches, we found a positive correlation between OsNAPL6 expression levels and adaptation to multiple abiotic stresses. Results of comparative transcriptome profiling and promoter-recruitment studies indicate that OsNAPL6 functions during stress response via modulation of expression of various genes involved in diverse functions. For instance, we show that OsNAPL6 is recruited to OsRad51 promoter, activating its expression and leading to more efficient DNA repair and abrogation of programmed cell death under salinity and genotoxic stress conditions. These results suggest that the histone chaperone OsNAPL6 may serve a regulatory role in abiotic stress physiology possibly via modulating nucleosome dynamics at various stress-associated genomic loci. Taken together, our findings establish a hitherto unknown link between histone chaperones and abiotic stress response in plants.

Genome-wide investigation and expression analysis of Sodium/Calcium exchanger gene family in rice and Arabidopsis.

BACKGROUND: The Na(+)/Ca(2+) Exchanger (NCX) protein family is a member of the Cation/Ca(2+) exchanger superfamily and its members play important roles in cellular Ca(2+) homeostasis. While the functions of NCX family of proteins is well understood in humans, not much is known about the total complement of Na(+)/Ca(2+) exchangers in plants and their role in various physiological and developmental processes. In the present study, we have identified all the NCX proteins encoded in the genomes of rice and Arabidopsis and studied their phylogeny, domain architecture and expression profiles across different tissues, at various developmental stages and under stress conditions. RESULTS: Through whole genome investigation, we identified twenty-two NCX proteins encoded by fifteen genes in rice and sixteen NCX proteins encoded by thirteen genes in Arabidopsis. Based on phylogenetic reconstruction, these could be classified into five clades, members of most of which were found to possess distinct domain architecture. Expression profiling of the identified NCX genes using publicly available MPSS and microarray data showed differential expression patterns under abiotic stresses, and at various development stages. In rice, OsNCX1, OsNCX8, OsNCX9 and OsNCX15 were found to be highly expressed in all the plant parts and various developmental stages. qRT-PCR based expression analysis revealed that OsNCX3, OsNCX10 and OsNCX15 were highly induced by salt and dehydration stress. Besides, expression profiling showed differential regulation of rice NCX genes in response to calcium and EGTA. Interestingly, expression of none of the NCX genes was found to be co-regulated by NaCl and calcium. CONCLUSIONS: Together, our results present insights into the potential role of NCX family of proteins in abiotic stresses and development. Findings of the present investigation should serve as a starting point for future studies aiming functional characterization of plant NCX family proteins.

Histone chaperones in Arabidopsis and rice: genome-wide identification, phylogeny, architecture and transcriptional regulation.

BACKGROUND: Histone chaperones modulate chromatin architecture and hence play a pivotal role in epigenetic regulation of gene expression. In contrast to their animal and yeast counterparts, not much is known about plant histone chaperones. To gain insights into their functions in plants, we sought to identify histone chaperones from two model plant species and investigated their phylogeny, domain architecture and transcriptional profiles to establish correlation between their expression patterns and potential role in stress physiology and plant development. RESULTS: Through comprehensive whole genome analyses of Arabidopsis and rice, we identified twenty-two and twenty-five genes encoding histone chaperones in these plants, respectively. These could be classified into seven different families, namely NAP, CAF1, SPT6, ASF1, HIRA, NASP, and FACT. Phylogenetic analyses of histone chaperones from diverse organisms including representative species from each of the major plant groups, yeast and human indicated functional divergence in NAP and CAF1C in plants. For the largest histone chaperone family, NAP, phylogenetic reconstruction suggested the presence of two distinct groups in plants, possibly with differing histone preferences. Further, to comment upon their physiological roles in plants, we analyzed their expression at different developmental stages, across various plant tissues, and under biotic and abiotic stress conditions using pre-existing microarray and qRT-PCR. We found tight transcriptional regulation of some histone chaperone genes during development in both Arabidopsis and rice, suggesting that they may play a role in genetic reprogramming associated with the developmental process. Besides, we found significant differential expression of a few histone chaperones under various biotic and abiotic stresses pointing towards their potential function in stress response. CONCLUSIONS: Taken together, our findings shed light onto the possible evolutionary trajectory of plant histone chaperones and present novel prospects about their physiological roles. Considering that the developmental process and stress response require altered expression of a large array of genes, our results suggest that some plant histone chaperones may serve a regulatory role by controlling the expression of genes associated with these vital processes, possibly via modulating chromatin dynamics at the corresponding genetic loci.

Expression of a cyclophilin OsCyp2-P isolated from a salt-tolerant landrace of rice in tobacco alleviates stress via ion homeostasis and limiting ROS accumulation.

Cyclophilins are a set of ubiquitous proteins present in all subcellular compartments, involved in a wide variety of cellular processes. Comparative bioinformatics analysis of the rice and Arabidopsis genomes led us to identify novel putative cyclophilin gene family members in both the genomes not reported previously. We grouped cyclophilin members with similar molecular weight and subtypes together in the phylogenetic tree which indicated their co-evolution in rice and Arabidopsis. We also characterized a rice cyclophilin gene, OsCyp2-P (Os02g0121300), isolated from a salinity-tolerant landrace, Pokkali. Publicly available massively parallel signature sequencing (MPSS) and microarray data, besides our quantitative real time PCR (qRT-PCR) data suggest that transcript abundance of OsCyp2-P is regulated under different stress conditions in a developmental and organ specific manner. Ectopic expression of OsCyp2-P imparted multiple abiotic stress tolerance to transgenic tobacco plants as evidenced by higher root length, shoot length, chlorophyll content, and K(+)/Na(+) ratio under stress conditions. Transgenic plants also showed reduced lipid peroxidase content, electrolyte leakage, and superoxide content under stress conditions suggesting better ion homeostasis than WT plants. Localization studies confirmed that OsCyp2-P is localized in both cytosol and nucleus, indicating its possible interaction with several other proteins. The overall results suggest the explicit role of OsCyp2-P in bestowing multiple abiotic stress tolerance at the whole plant level. OsCyp2-P operates via reactive oxygen species (ROS) scavenging and ion homeostasis and thus is a promising candidate gene for enhancing multiple abiotic stress tolerance in crop plants.

MicroRNA: a new and promising potential biomarker for diagnosis and prognosis of ovarian cancer.

Epithelial ovarian cancer (EOC) is the leading cause of death among all gynecological malignancies. Despite the technological and medical advances over the past four decades, such as the development of several biological markers (mRNA and proteins biomarkers), the mortality rate of ovarian cancer remains a challenge because of its late diagnosis, which is specifically attributed to low specificities and sensitivities. Under this compulsive scenario, recent advances in expression biology have shifted in identifying and developing specific and sensitive biomarkers, such as microRNAs (miRNAs) for cancer diagnosis and prognosis. MiRNAs are a novel class of small non-coding RNAs that deregulate gene expression at the posttranscriptional level, either by translational repression or by mRNA degradation. These mechanisms may be involved in a complex cascade of cellular events associated with the pathophysiology of many types of cancer. MiRNAs are easily detectable in tissue and blood samples of cancer patients. Therefore, miRNAs hold good promise as potential biomarkers in ovarian cancer. In this review, we attempted to provide a comprehensive profile of key miRNAs involved in ovarian carcinoma to establish miRNAs as more reliable non-invasive clinical biomarkers for early detection of ovarian cancer compared with protein and DNA biomarkers.

A unique Ni2+ -dependent and methylglyoxal-inducible rice glyoxalase I possesses a single active site and functions in abiotic stress response.

The glyoxalase system constitutes the major pathway for the detoxification of metabolically produced cytotoxin methylglyoxal (MG) into a non-toxic metabolite D-lactate. Glyoxalase I (GLY I) is an evolutionarily conserved metalloenzyme requiring divalent metal ions for its activity: Zn(2+) in the case of eukaryotes or Ni(2+) for enzymes of prokaryotic origin. Plant GLY I proteins are part of a multimember family; however, not much is known about their physiological function, structure and metal dependency. In this study, we report a unique GLY I (OsGLYI-11.2) from Oryza sativa (rice) that requires Ni(2+) for its activity. Its biochemical, structural and functional characterization revealed it to be a monomeric enzyme, possessing a single Ni(2+) coordination site despite containing two GLY I domains. The requirement of Ni(2+) as a cofactor by an enzyme involved in cellular detoxification suggests an essential role for this otherwise toxic heavy metal in the stress response. Intriguingly, the expression of OsGLYI-11.2 was found to be highly substrate inducible, suggesting an important mode of regulation for its cellular levels. Heterologous expression of OsGLYI-11.2 in Escherichia coli and model plant Nicotiana tabacum (tobacco) resulted in improved adaptation to various abiotic stresses caused by increased scavenging of MG, lower Na(+) /K(+) ratio and maintenance of reduced glutathione levels. Together, our results suggest interesting links between MG cellular levels, its detoxification by GLY I, and Ni(2+) - the heavy metal cofactor of OsGLYI-11.2, in relation to stress response and adaptation in plants.

Narrowing down the targets for yield improvement in rice under normal and abiotic stress conditions via expression profiling of yield-related genes.

BACKGROUND: Crop improvement targeting high yield and tolerance to environmental stresses has become the need of the hour. Yield improvement via breeding or gene pyramiding aiming comprehensive incorporation of the agronomically favored traits requires an in-depth understanding of the molecular basis of these traits. The present study describes expression profiling of yield-related genes in rice with respect to different developmental stages and various abiotic stress conditions. RESULTS: Our analysis indicates developmental regulation of the yield-related genes pertaining to the genetic reprogramming involved at the corresponding developmental stage. The gene expression data can be utilized to specifically select particular genes which can potentially function synergistically for enhancing the yield while maintaining the source-sink balance. Furthermore, to gain some insights into the molecular basis of yield penalty during various abiotic stresses, the expression of selected yield-related genes has also been analyzed by qRT-PCR under such stress conditions. Our analysis clearly showed a tight transcriptional regulation of a few of these yield-related genes by abiotic stresses. The stress-responsive expression patterns of these genes could explain some of the most important stress-related physiological manifestations such as reduced tillering, smaller panicles and early completion of the life cycle owing to reduced duration of vegetative and reproductive phases. CONCLUSIONS: Development of high yielding rice varieties which maintain their yield even under stress conditions may be achieved by simultaneous genetic manipulation of certain combination of genes such as LRK1 and LOG, based on their function and expression profile obtained in the present study. Our study would aid in investigating in future, whether over-expressing or knocking down such yield-related genes can improve the grain yield potential in rice.

An improved protocol for efficient transformation and regeneration of diverse indica rice cultivars.

BACKGROUND: Rice genome sequencing projects have generated remarkable amount of information about genes and genome architecture having tremendous potential to be utilized in both basic and applied research. Success in transgenics is paving the way for preparing a road map of functional genomics which is expected to correlate action of a gene to a trait in cellular and organismal context. However, the lack of a simple and efficient method for transformation and regeneration is a major constraint for such studies in this important cereal crop. RESULTS: In the present study, we have developed an easy, rapid and highly efficient transformation and regeneration protocol using mature seeds as explants and found its successful applicability to a choice of elite indica rice genotypes. We have optimized various steps of transformation and standardized different components of the regeneration medium including growth hormones and the gelling agent. The modified regeneration medium triggers production of large number of shoots from smaller number of calli and promotes their faster growth, hence significantly advantageous over the existing protocols where the regeneration step requires maximum time. Using this protocol, significantly higher transformation efficiency (up to 46%) and regeneration frequency (up to 92% for the untransformed calli and 59% for the transformed calli) were achieved for the four tested cultivars. We have used this protocol to produce hundreds of independent transgenic lines of different indica rice genotypes. Upon maturity, these transgenic lines were fertile thereby indicating that faster regeneration during tissue culture did not affect their reproductive potential. CONCLUSIONS: This speedy, yet less labor-intensive, protocol overcomes major limitations associated with genetic manipulation in rice. Moreover, our protocol uses mature seeds as the explant, which can easily be obtained in quantity throughout the year and kept viable for a long time. Such an easy, efficient and generalized protocol has the potential to be a major tool for crop improvement and gene-function studies on the model monocot plant rice.