75 research outputs found

    A Review On The Functional Response Of Chrysoperla Zastrowi Sillemi (Peterson-Esben) On Brevicorynae brassicae (Linnaeus)

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    Chrysoperla zastrowi sillemi, a common predator in agricultural ecosystems, exhibits significant potential for biological pest control. Study investigated the functional response of C. zastrowi sillemi to Brevicorynae brassicae, a destructive pest of cruciferous crops through laboratory experiments and field observations. Analysed the predatory behaviour of C. zastrowi sillemi in response to varying densities of B. brassicae. The functional response curves are constructed to elucidate the relationship between predator consumption rate and prey density. Factors influencing the predatory efficiency, including prey density, predator handling time, and environmental conditions, are comprehensively evaluated. The findings provided valuable insights into the potential of predator as a biological control agent against B. brassicae infestations, facilitating the development of sustainable pest management strategies in agriculture

    Role of an Alternatively Spliced KCNMA1 Variant in Glioma Growth

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    Gliomas develop genetic traits to rapidly form aggressive phenotypes. Hence, management of gliomas is complicated and difficult. Besides genetic aberrations such as oncogenic copy number variation and mutations, alternative mRNA splicing triggers prooncogenic episodes in many cancers. In gliomas, we found alternative splicing at the KCNMA transcription process. KCNMA1 encodes the pore forming α-subunit of large-conductance calcium-activated voltage-sensitive potassium (BKCa) channels. These channels play critical role in glioma invasion and proliferation. We identified a novel KCNMA1 mRNA splice variant with a deletion of 108 base pairs (KCNMA1v) mostly overexpressed in high grade gliomas. We found that KCNMA1 alternative pre-mRNA splicing enhanced glioma growth, progression and diffusion. The role of KCNMA1 and its splicing as a critical posttranscriptional regulator of BKCa channel expression is presented in this chapter. Our research implies that high grade gliomas express KCNMA1v and BKCa channel isoform to accelerate growth and transformation to glioblastoma multiforme (GBM). We demonstrated that tumors hardly develop in mice injected with KCNMA1v transfected cell line expressing short-hairpin RNA (shRNA) compared to mice injected with KCNMA1v transected glioma cells. We conclude that targeting the KCNMA1 variants may be a clinically beneficial strategy to prevent or at least slow down glioma transformation to GBM

    Evidence of BK<sub>Ca</sub> Channelopathy-Driven Breast Cancer Metastasis to Brain

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    KCNMA1 encodes the a-subunit of the large conductance, voltage and Ca2+-activated and Voltage-dependent potassium channel (BKCa) and was shown by others and us to be a potential drug target gene in several cancers, including breast cancer. In addition, we studied the role of alternative pre-mRNA splicing events of KCNMA1 in migration, invasion, proliferation and dispersal of breast cancer cells. It is conceivable that by targeting gene variants we can attenuate processes such as distant metastasis and angiogenesis. Here we reviewed literature on the alternative splicing events specific to breast cancer metastasis to brain, its microenvironment, the biological activity of most alternatively spliced isoforms. We conclude that based on our and others’ work KCNMA1 and other such gene variants contribute to breast cancer dispersion, invasion, growth, and progression in the tumor microenvironment. Thus KCNMA1/BKCa channels and their variants are opportunistic diagnostic, prognostic and treatment targets in breast cancer

    Role of KCNMA1 gene in breast cancer invasion and metastasis to brain

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    International audienceBACKGROUND: The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, large-conductance calcium- and voltage-activated potassium channel (BKCa) channels are significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene that encodes for the pore-forming alpha-subunit of BKCa channels in breast cancer metastasis and invasion. METHODS: We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer to brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of BKCa channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A), non-metastatic breast cancer (MCF-7), non-brain metastatic breast cancer cells (MDA-MB-231), and brain-specific metastatic breast cancer cells (MDA-MB-361) to study whether BKCa channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with Iberiotoxin (IBTX). RESULTS: The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BKCa channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1. CONCLUSION: Determining the relative abundance of BKCa channel expression in breast cancer metastatic to brain and the mechanism of its action in brain metastasis will provide a unique opportunity to identify and differentiate between low grade breast tumors that are at high risk for metastasis from those at low risk for metastasis. This distinction would in turn allow for the appropriate and efficient application of effective treatments while sparing patients with low risk for metastasis from the toxic side effects of chemotherapy

    Evidence of calcium-activated potassium channel subunit alpha-1 as a key promoter of glioma growth and tumorigenicity

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    Background and Aim: Mechanisms of glioma progression are poorly understood. Upregulation of calcium-activated potassium channel subunit alpha-1 (KCNMA1), which encodes the α-subunit of maxi-calcium-activated potassium (BKCa) channels, is shown to be a novel mechanism for the malignant phenotype of brain tumor cells. The aim of this study was to establish the functional role of KCNMA1 in glioma biology. Materials and Methods: U-87-MG (U-87) cells were transfected to increase BKCa channel expression and activity. Glioma cell proliferation, invasiveness, and transendothelial migration were then measured. BKCa channels were blocked with iberiotoxin or short hairpin RNA (shRNA), which significantly inhibited K+ currents and growth of U-87 cells. It was tested whether KCNMA1 overexpression enhanced tumorogenecity in glioma xenograft mouse models by injecting wild-type and KCNMA1- overexpressing U87-MG cells. In parallel experiment, it was studied whether shRNA KCNMA1-expressing U-87 cells show attenuated glioma growth in mice. The study protocol was approved by the Institutional Animal Care and Use Committee, Mercer University (A0706007_01), Atlanta, GA, USA on July 20, 2007. Results: The effect of KCNMA1 overexpression in glioma growth as well as on associated cell biology functions such as proliferation, invasion, and migration was presented in this study. Messenger RNA and protein analyses revealed that KCNMA1 was amplified in 90% of high-grade gliomas and in high-grade glioma cell line U-87. In contrast, KCNMA1 amplification was not found in normal brain tissues. These data indicate that KCNMA1 plays critical role in glioma biology by interacting with several cellular processes. The data demonstrate that KCNMA1 amplification drives glioma cell proliferation and growth, which can be attenuated by its downregulation. Conclusion: KCNMA1 is a regulator of glioma cell proliferation and growth and thus qualifies as a promising diagnostic and therapeutic target in the treatment of glioma

    Targeting Potassium Channels for Increasing Delivery of Imaging Agents and Therapeutics to Brain Tumors

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    Every year in the US, 20,000 new primary and nearly 200,000 metastatic brain tumor cases are reported. The cerebral microvessels/ capillaries that form the blood–brain barrier (BBB) not only protect the brain from toxic agents in the blood but also pose a significant hindrance to the delivery of small and large therapeutic molecules. Different strategies have been employed to circumvent the physiological barrier posed by blood-brain tumor barrier (BTB). Studies in our laboratory have identified significant differences in the expression levels of certain genes and proteins between normal and brain tumor capillary endothelial cells. In this study, we validated the non-invasive and clinically relevant Dynamic Contrast Enhancing-Magnetic Resonance Imaging (DCE-MRI) method with invasive, clinically irrelevant but highly accurate Quantitative Autoradiography (QAR) method using rat glioma model. We also showed that DCE-MRI metric of tissue vessel perfusion-permeability is sensitive to changes in blood vessel permeability following administration of calcium-activated potassium (BKCa) channel activator NS-1619. Our results show that human gliomas and brain tumor endothelial cells that overexpress BKCa channels can be targeted for increased BTB permeability for MRI enhancing agents to brain tumors. We conclude that monitoring the outcome of increased MRI enhancing agents’ delivery to microsatellites and leading tumor edges in glioma patients would lead to beneficial clinical outcome

    Eco-friendly and Targeted through Next-generation Approaches to Insect Pest Management

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    Insect pests pose significant challenges to agricultural productivity, human health, and ecosystem stability worldwide. Traditional pest management approaches, heavily reliant on broad-spectrum chemical insecticides, have led to the development of insecticide resistance, unintended effects on non-target organisms, and environmental contamination. In response to these challenges, next-generation approaches to insect pest management are emerging, focusing on eco-friendly and targeted strategies. This review article explores the latest advancements in sustainable pest management, including the use of biopesticides, semiochemicals, biotechnology-based approaches, and integrated pest management (IPM) strategies. Biopesticides, derived from natural sources such as plants, microorganisms, and insects, offer effective and environmentally benign alternatives to synthetic insecticides. Semiochemicals, including pheromones and allelochemicals, can be exploited for pest monitoring, mating disruption, and attract-and-kill strategies. Biotechnology-based approaches, such as RNA interference (RNAi), CRISPR/Cas9 gene editing, and transgenic crops, provide novel tools for targeting specific pest species and reducing reliance on chemical insecticides. IPM strategies, which combine multiple pest management tactics based on ecological principles, offer a holistic and sustainable approach to pest control. The adoption of these next-generation approaches faces challenges, including regulatory hurdles, public acceptance, and the need for further research and development. However, by embracing eco-friendly and targeted pest management strategies, we can reduce the environmental impact of insect pest control, promote biodiversity conservation, and ensure sustainable food production for a growing global population. Future research should focus on optimizing and integrating these approaches, understanding their long-term ecological impacts, and developing effective knowledge transfer mechanisms to promote their widespread adoption

    Targeted Brain Tumor Treatment-Current Perspectives

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    Brain tumor is associated with poor prognosis. The treatment option is severely limited for a patient with brain tumor, despite great advances in understanding the etiology and molecular biology of brain tumors that have lead to breakthroughs in developing pharmaceutical strategies, and ongoing NCI/Pharma-sponsored clinical trials. We reviewed the literature on molecular targeted agents in preclinical and clinical studies in brain tumor for the past decade, and observed that the molecular targeting in brain tumors is complex. This is because no single gene or protein can be affected by single molecular agent, requiring the use of combination molecular therapy with cytotoxic agents. In this review, we briefly discuss the potential molecular targets, and the challenges of targeted brain tumor treatment. For example, glial tumors are associated with over-expression of calcium-dependent potassium (K Ca ) channels, and high grade glioma express specific K Ca channel gene (gBK) splice variants, and mutant epidermal growth factor receptors (EGFRvIII). These specific genes are promising targets for molecular targeted treatment in brain tumors. In addition, drugs like Avastin and Gleevec target the molecular targets such as vascular endothelial cell growth factor receptor, platelet-derived growth factor receptors, and BRC-ABL/Akt. Recent discovery of non-coding RNA, specifically microRNAs could be used as potential targeted drugs. Finally, we discuss the role of anti-cancer drug delivery to brain tumors by breaching the blood-brain tumor barrier. This non-invasive strategy is particularly useful as novel molecules and humanized monoclonal antibodies that target receptor tyrosine kinase receptors are rapidly being developed
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