Regulation Of Normal Growth Research Articles

Screening Anthraquinones by Fluorescent Ubiquitination Cell Cycle Indicators

Cancer is one of the diseases with the highest mortality rate in the world, and its occurrence and development are mainly related to the uncontrolled cell cycle. The cell cycle is the completion of a cell division from the end of the n1ext division, the cell cycle is divided They are interphase and division phase. Specifically, there's a DNA synthesis phase (G1 phase), DNA synthesis phase (S phase), and DNA synthesis phase (G2 phase) Phase) and division phase (M phase). Tumor cells can proliferate indefinitely, mainly with the cell cycle getting out of control, making it not subject to normal Growth regulation. The current methods for detecting cell cycle mainly include: Acridine Orange (AO) method, 5-Bromo-2-deoxy Uridine (BrdU) labeling method, Western blot and flow cytometry, etc., but these methods have certain limitations, such as the inability to make real-time observations in living cells. Therefore, we constructed the Cell Cycle Ubiquitination-based Cell Cycle Indicator (FUCCI) tool in liver cancer cells, hoping to provide a new technical means for the screening of anti-tumor drugs.

The RNA-Binding Protein BoRHON1 Positively Regulates the Accumulation of Aliphatic Glucosinolates in Cabbage.

Aliphatic glucosinolates are an abundant group of plant secondary metabolites in Brassica vegetables, with some of their degradation products demonstrating significant anti-cancer effects. The transcription factors MYB28 and MYB29 play key roles in the transcriptional regulation of aliphatic glucosinolates biosynthesis, but little is known about whether BoMYB28 and BoMYB29 are also modulated by upstream regulators or how, nor their gene regulatory networks. In this study, we first explored the hierarchical transcriptional regulatory networks of MYB28 and MYB29 in a model plant, then systemically screened the regulators of the three BoMYB28 homologs in cabbage using a yeast one-hybrid. Furthermore, we selected a novel RNA binding protein, BoRHON1, to functionally validate its roles in modulating aliphatic glucosinolates biosynthesis. Importantly, BoRHON1 induced the accumulation of all detectable aliphatic and indolic glucosinolates, and the net photosynthetic rates of BoRHON1 overexpression lines were significantly increased. Interestingly, the growth and biomass of these overexpression lines of BoRHON1 remained the same as those of the control plants. BoRHON1 was shown to be a novel, potent, positive regulator of glucosinolates biosynthesis, as well as a novel regulator of normal plant growth and development, while significantly increasing plants' defense costs.

Abstract 2046: Targeting cellular models of glioblastoma versus non-target and off-target cell populations using U87-MG membrane lipid-modified nanoliposomes

Abstract Background: Glioblastoma Multiform (GBM) is an aggressive and malignant form of brain cancer known for its invasiveness and significant heterogenicity. The majority of GBM cases are linked to genetic mutations (ie. TP53, EGFR, and PTEN), which disrupt the normal regulation of cell growth and division, resulting in uncontrolled cell proliferation. The utilization of nanoparticles presents a promising approach for addressing the complexities associated with selective drug delivery to GMB and treatment. The purpose of this study was to investigate the effect of including U87-MG membrane lipid extracts in nanoliposomes using target, non-target, and normal healthy cellular populations in vitro. Methods: The nanoliposomes employed for the experiments included various ratios of U87-MG lipid extracts (lipids derived from U87-MG cells), DOPC, Cholesterol, and DPPE-Rhodamine for fluorescence studies. The particle size and zeta potential values were measured and monitored throughout for consistency. Fluorescence intensity values (arbitrary units) were used to assess extent of cell binding, and uptake at the various time points. In vitro studies were employed to evaluate the cellular uptake activity of U87-MG-modified nanoliposome preparations using mixed ratios and compositions of lipid materials. Cell lines employed were, LN-18 (human glioma), T98G (human glioma), U87-MG (human glioma), 4TI (murine breast), and HBEC-5i (normal healthy) cells. Results: The average size for the nanoliposomes (with and without lipid extract) fell within the range of 110 to 220 nm, while the zeta potential for the CLENs was negatively-charged. In vitro studies revealed that the inclusion of U87MG lipid extract in nanoliposomes increased cellular uptake in glioma cells when compared to control. Current investigations focus on different microenvironments, including non-target and off target cell populations. The findings from the cellular uptake analyses to date suggest that the in vitro cellular uptake of the CLENs varied in accordance with the total lipid extract content for all cell lines. Citation Format: Kaylee Janton, Duha Baamir, Aesha Patel, Sheren Boco, Robert Campbell. Targeting cellular models of glioblastoma versus non-target and off-target cell populations using U87-MG membrane lipid-modified nanoliposomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2046.

Crosstalk between Circadian Rhythm Dysregulation and Tumorigenesis, Tumor Metabolism and Tumor Immune Response.

Circadian rhythm is a self-regulating 24-hour system that synchronizes with the day and night cycle in organisms. The regulation of this system is controlled by clock genes, which function to harmoniously express molecular levels that facilitate the orderly coordination of various cellular processes, such as sleep, metabolism, endocrine function, cell proliferation and immunity. The root cause of tumorigenesis is that the body loses its normal regulation of cell growth at the genetic level. Long-term disruptions in circadian rhythms caused by factors such as shift work, jet lag, and unstable sleep patterns can impact cellular health, leading to various health problems, including cancer. Circadian rhythm controls most cellular functions related to cancer progression, which has a significant impact on the ability of immune cells to detect cancer cells and promote their clearance and has crucial implication for future tumor immunotherapy. This article aims to review the crosstalk between dysregulation of circadian rhythm and tumorigenesis, tumor metabolism, and immune response. Additionally, we discuss the role of circadian rhythm disruption in tumor therapy, highlighting its potential to optimize treatment timing and improve therapeutic outcomes.

Study on the Adaptive Regulation of Light on the Stress Response of Mandarin Fish (Siniperca chuatsi) with Re-Feeding after Starvation.

Light influences the stress response to environmental stimuli and feeding behaviors of Siniperca chuatsi and, thus, is an important regulator of normal growth and development. In this study, we first explored the important role of light on the digestive and stress capacity of S. chuatsi by studying the changes in physiological and biochemical indicators of S. chuatsi, taking the re-feeding after starvation as the constant environmental stimulus and the light intensity as the adjustable environmental stimulus. The activity of protease and lipase was generally higher in the stomach tissues than in the intestinal tissues, especially lipase, which was higher in stomach tissues under all light conditions, and the protease and lipase activity peaked in the stomach tissues of S. chuatsi at a light intensity of 18.44 ± 3.00 lx and in intestinal tissues at 11.15 ± 2.01 lx, respectively, indicating that greater light intensity increased the digestive capacity of stomach tissues, whereas lower light intensity facilitated the digestive capacity of intestinal tissues. The tissues of the gill, stomach, and intestine had relatively high activity of stress-related enzymes, whereas the tissues of the brain, kidney, liver, and plasma samples had relatively low activity of enzymes. Collectively, the results show that light intensity at 11.15 ± 2.01 lx promoted digestive capacity in the intestine and enhanced the anti-stress ability of S. chuatsi in response to stress induced by re-feeding after starvation. These findings should prove useful for artificial breeding of S. chuatsi.

The role of circadian rhythm in breast cancer, lung cancer, and colorectal cancer

Circadian rhythm is a biological rhythm system with a self-regulating function and a 24-hour cycle that is synchronized with the alternation of day and night and is driven by circadian clock genes and clock-control genes. The circadian clock governs and controls processes like immune, metabolism, endocrine, cell division and proliferation, apoptosis, and sleep, allowing cells, tissues, and organs to carry out different living activities in an organized and coordinated way. The root cause of tumors is gene mutations that cause the body to lose its normal regulation of cell growth. According to studies, cancer and problems of biological rhythm are tightly linked. Related epidemiological studies are related to the occurrence and inhibition of tumors by circadian rhythms the molecular mechanism of action has become a hot issue. In this paper, combined with relevant research at home and abroad, we focus on the specific association between circadian rhythm and the high occurrence of breast cancer, lung cancer, and colorectal cancer in three populations, as well as the part circadian clocks play at the molecular level in tumor development and progression, and discuss the timing of cancer. Therapeutics is a novel therapeutic field that has the potential to increase efficacy and minimize negative effects. A sounder theoretical foundation for the identification, management, and prognosis of clinical cancers will be made possible by the clarification of the circadian clock in cancer.

A multidisciplinary approach in the management of a patient with familial von Recklinghausen’s disease: A case report and review of literature

Abstract Neurofibromatosis type 1 (NF1), also known as von Recklinghausen’s disease (VRD), is an autosomal dominant genetic disorder caused by gene mutations located on chromosome 17. Of these, 90% are point mutations, and the rest have larger deletions, affecting nearly one in every 3500 births. The same gene is responsible for the synthesis of a protein known as neurofibromin, which helps in the regulation of normal cell growth. This disorder is characterized by the development of swellings all over the body along the distribution of nerves, skin changes, visual abnormalities, and bony deformities in some individuals. In addition to this, it is also a neoplastic predisposition syndrome that is associated with both benign and malignant tumors of the brain and spinal cord. In 20% of the cases with NF1, it is associated with gliomagenesis, which often affects the optic pathway and brain stem. In the early phases, it is associated with benign gliomas, whereas in the later stages, it is associated with malignant gliomas. But nevertheless, high-grade gliosarcomas (grade IV) of the brain are rare entities with reported higher risks in both children and adults. We report a case of familial NF1 (VRD) in a patient with an associated high-grade right parieto-temporo-occipital lobe glioma. Surgical excision via gross total resection is the mainstay of treatment. However, a multidisciplinary approach is also vital. This is described here, whereby timely intervention from neurology, ophthalmology, radiology, orthopedics, neurosurgery, and radiotherapy led to the successful management of the patient.

Determining the Potential Roles of Branched-Chain Amino Acids in the Regulation of Muscle Growth in Common Carp (Cyprinus carpio) Based on Transcriptome and MicroRNA Sequencing.

Branched-chain amino acids (BCAAs) can be critically involved in skeletal muscle growth and body energy homeostasis. Skeletal muscle growth is a complex process; some muscle-specific microRNAs (miRNAs) are involved in the regulation of muscle thickening and muscle mass. Additionally, the regulatory network between miRNA and messenger RNA (mRNA) in the modulation of the role of BCAAs on skeletal muscle growth in fish has not been studied. In this study, common carp was starved for 14 days, followed by a 14-day gavage therapy with BCAAs, to investigate some of the miRNAs and genes that contribute to the regulation of normal growth and maintenance of skeletal muscle in response to short-term BCAA starvation stress. Subsequently, the transcriptome and small RNAome sequencing of carp skeletal muscle were performed. A total of 43,414 known and 1,112 novel genes were identified, in addition to 142 known and 654 novel miRNAs targeting 22,008 and 33,824 targets, respectively. Based on their expression profiles, 2,146 differentially expressed genes (DEGs) and 84 differentially expressed miRNA (DEMs) were evaluated. Kyoto Encyclopedia of Genes and Genome pathways, including the proteasome, phagosome, autophagy in animals, proteasome activator complex, and ubiquitin-dependent protein catabolic process, were enriched for these DEGs and DEMs. Our findings revealed the role of atg5, map1lc3c, ctsl, cdc53, psma6, psme2, myl9, and mylk in skeletal muscle growth, protein synthesis, and catabolic metabolism. Furthermore, miR-135c, miR-192, miR-194, and miR-203a may play key roles in maintaining the normal activities of the organism by regulating genes related to muscle growth, protein synthesis, and catabolism. This study on transcriptome and miRNA reveals the potential molecular mechanisms underlying the regulation of muscle protein deposition and provides new insights into genetic engineering techniques to improve common carp muscle development.

Recombinant Insulin-Like Growth Factor 1 Dimers: Receptor Binding Affinities and Activation Abilities

Insulin-like growth factor 1 (IGF-1) and its IGF-1 receptor (IGF-1R) belong to an important biological system that is involved in the regulation of normal growth, but that has also been recognized as playing a role in cancer. IGF-1R antagonists could be interesting for the testing of their potential antiproliferative properties as an alternative to IGF-1R tyrosine-kinase inhibitors or anti-IGF-1R monoclonal antibodies. In this study, we were inspired by the successful development of insulin dimers capable of antagonizing insulin effects on the insulin receptor (IR) by simultaneous binding to two separated binding sites and by blocking structural rearrangement of the IR. We designed and produced in Escherichia coli three different IGF-1 dimers in which IGF-1 monomers are interlinked through their N- and C-termini, with linkers having 8, 15 or 25 amino acids. We found that the recombinant products were susceptible to the formation of misfolded or reduced variants, but that some of them were able to bind IGF-1R in low nanomolar affinities and all of them activate IGF-1R proportionally to their binding affinities. Overall, our work can be considered as a pilot study that, although it did not lead to the discovery of new IGF-1R antagonists, explored the possibility of recombinant production of IGF-1 dimers and led to the preparation of active compounds. This work could inspire further studies dealing, for example, with the preparation of IGF-1 conjugates with specific proteins for the study of the hormone and its receptor or for therapeutic applications.Graphical

Inhibition of the Mechanistic Targets of Rapamycin Beyond Transplant Immunosuppression: A Mini-Review

It has been about thirty years since identifying the target of rapamycin and using mTOR inhibitors in organ transplantation. There was a promise that they would replace calcineurin inhibitors with fewer nephrotoxic effects and better graft survival. Unfortunately, with time, the enthusiasm for using them in transplantation decreased due to the unpleasant profile of adverse events and limited evidence of tangible clinical benefit. With more understanding of physiology and judicious clinical application, new venues for mTOR inhibitors emerged. The mTOR pathway regulates primary cellular functions, including cell growth, metabolism, proliferation, and survival, and is critical for autophagy induction. Thus, as a master regulator, mTOR inhibitors emerged as anticancer therapies. In addition, such action proved beneficial for native or post-transplant malignancies. Signaling through components of the mTOR pathway is an essential regulator of normal cardiac growth and pathological hypertrophy. mTOR inhibitors are effective in reducing left ventricular thickness and mass. It could be an add-on benefit in kidney transplant recipients with high cardiovascular risk or attenuate cardiac allograft vasculopathy in heart transplant recipients. The mTOR inhibitors may help manage viral infections like cytomegalovirus, human herpesvirus 8-related Kaposi sarcoma, and possibly the BK virus. Furthermore, the mTOR pathway is modulated in many RNA viruses. Based on these facts, the idea of using mTOR inhibitors to treat COVID-19 infection has been evaluated. Accordingly, a new therapeutic role for mTOR inhibitors for treating COVID-19 infection t has emerged through reducing viral replication, and autophagocytosis, improving T cells function and preventing cytokine storm. This paper will review these applications of mTOR inhibitors beyond the horizon of transplant immunosuppression.

Function and Evolution of C1-2i Subclass of C2H2-Type Zinc Finger Transcription Factors in POPLAR.

C2H2 zinc finger (C2H2-ZF) transcription factors participate in various aspects of normal plant growth regulation and stress responses. C1-2i C2H2-ZFs are a special subclass of conserved proteins that contain two ZnF-C2H2 domains. Some C1-2i C2H2-ZFs in Arabidopsis (ZAT) are involved in stress resistance and other functions. However, there is limited information on C1-2i C2H2-ZFs in Populus trichocarpa (PtriZATs). To analyze the function and evolution of C1-2i C2H2-ZFs, eleven PtriZATs were identified in P. trichocarpa, which can be classified into two subgroups. The protein structure, conserved ZnF-C2H2 domains and QALGGH motifs, showed high conservation during the evolution of PtriZATs in P. trichocarpa. The spacing between two ZnF-C2H2 domains, chromosomal locations and cis-elements implied the original proteins and function of PtriZATs. Furthermore, the gene expression of different tissues and stress treatment showed the functional differentiation of PtriZATs subgroups and their stress response function. The analysis of C1-2i C2H2-ZFs in different Populus species and plants implied their evolution and differentiation, especially in terms of stress resistance. Cis-elements and expression pattern analysis of interaction proteins implied the function of PtriZATs through binding with stress-related genes, which are involved in gene regulation by via epigenetic modification through histone regulation, DNA methylation, ubiquitination, etc. Our results for the origin and evolution of PtriZATs will contribute to understanding the functional differentiation of C1-2i C2H2-ZFs in P. trichocarpa. The interaction and expression results will lay a foundation for the further functional investigation of their roles and biological processes in Populus.

Matrix metalloproteinase 2 is a target of the RAN-GTP pathway and mediates migration, invasion and metastasis in human breast cancer

RAS-related nuclear protein(RAN) is a nuclear shuttle and normally regulates events in the cell cycle. When overexpressed in cultured cells, it causes increases in cell migration/invasion in vitro and its overexpression is associated with early breast cancer patient deaths in vivo. However, the underlying mechanism is unknown. The effect of RAN overexpression on potential targets MMP2, ATF3, CXCR3 was investigated by Real-Time PCR/Western blots in the triple receptor negative breast cancer(TRNBC) cell line MDA-MB231 and consequent biological effects were measured by cell adhesion, cell migration and cell invasion assays. Results showed that knockdown of RAN lead to a reduction of MMP2 and its potential regulators ATF3 and CXCR3. Moreover, knockdown of ATF3 or CXCR3 downregulated MMP2 without affecting RAN, indicating that RAN regulates MMP2 through ATF3 and CXCR3. Knockdown of RAN and MMP2 reduced cell adhesion, cell migration and cell growth in agar, whilst overexpression of MMP2 reversed the knockdown of RAN. Furthermore, immunohistochemical staining for RAN and MMP2 are positively associated with each other in the same tumour and separately with patient survival times in breast cancer specimens, suggesting that a high level of RAN may be a pre-requisite for MMP2 overexpression and metastasis. Moreover, positive immunohistochemical staining for both RAN and MMP-2 reduces further patient survival times over that for either protein separately. Our results suggest that MMP2 expression can stratify progression of breast cancers with a high and low incidence of RAN, both RAN and MMP2 in combination can be used for a more accurate patient prognosis. Simple summaryRan is an important regulator of normal cell growth and behaviour. We have established in cell line models of breast cancer (BC) a molecular pathway between RAN and its protein-degrading effector MMP-2 and properties related to metastasis in culture. Using immunohistochemistry (IHC) staining of primary BCs, we have shown that RAN and MMP-2 are on their own significantly associated with patient demise from metastatic BC. Moreover, when staining for MMP-2 is added to that for RAN in the primary tumours, there is a significant decrease in patient survival time over that for either protein alone. Thus a combination of staining for RAN and MMP2 is an excellent marker for poor prognosis in breast cancer.

Transcript profiling of Polycomb gene family in Oryza sativa indicates their abiotic stress-specific response.

The precise regulation of gene expression is required for the determination of cell fate, differentiation, and developmental programs in eukaryotes. The Polycomb Group (PcG) genes are the key transcriptional regulators that constitute the repressive system, with two major protein complexes, Polycomb Repressive Complex 1 (PRC1) and Polycomb Repressive Complex 2 (PRC2). Previous studies have demonstrated the significance of these proteins in regulation of normal growth and development processes. However, the role of PcG in adaptation of crops to abiotic stress is still not well understood. The present study aimed to a comprehensive genome-wide identification of the PcG gene family in one of the economically important staple crops, Oryza sativa. Here, a total of 14 PcG genes have been identified, which were distributed over eight chromosomes. Protein structure analysis revealed that both the complexes have distinct domain and motifs that are conserved within the complexes. In silico promoter analysis showed that PcG gene promoters have abundance of abiotic stress-responsive elements. RNA-seq based expression analysis revealed that PcG genes are differentially expressed in different tissues and responded variably in different environmental stress. Validation of gene expression by qRT-PCR showed that most of the genes were upregulated at 1-h time point in shoot tissue and at 24-h time point in root tissue under the drought and salinity stress conditions. These findings provide important and extensive information on the PcG family of O. sativa, which will pave the path for understanding their role in stress signaling in plants.

Dicamba-Resistant Crops – Stumbling Over the Starting Block

The discovery phenoxy herbicides (i.e. 2,4-dichlorophenoxyacetic acid or 2,4-D) in the 1940s ushered in a new the era of weed management. Since then, the agrochemical industry has developed and commercialised a wide panoply of herbicides with at least 25 recognised mechanisms of action. Today, farmers rely heavily on the use of chemicals for controlling weeds. The process of discovering, developing and commercialising herbicides has been successful because of the mostly positive interactions between researchers from industry, academia and governmental institutions. This process has been self-correcting, where new compounds initially discovered by companies were made available to independent researchers outside industry to evaluate in their specific geographic location to identify potential weaknesses or problems that needed to be addressed before global commercialisation of a product. This system has worked well for industry, researchers, farmers and consumers, except for where dicamba use with dicamba-resistant crops is concerned. Dicamba (3,6-dichloro-2-methoxybenzoic acid) is a group 4 (auxin mimic or growth regulator) herbicide of the methoxybenzoic acid group. Group 4 herbicides mimic the action of auxin (indoleacetic acid). Their actual mechanism of action is fairly complicated, but in short, they bind to the receptor for auxin and disrupt normal hormonal regulation of cell growth, leading to abnormal growth and death of plants. Because auxin mimics tend to provide selective control of broadleaf weeds in grass crops, these herbicides were initially very popular for broadleaf weed management in corn and related cereals. Dicamba was first introduced in the US in the mid-1960s and was used for that purpose successfully for many years.

The Single-Cell Sequencing: A Dazzling Light Shining on the Dark Corner of Cancer.

Tumorigenesis refers to the process of clonal dysplasia that occurs due to the collapse of normal growth regulation in cells caused by the action of various carcinogenic factors. These “successful” tumor cells pass on the genetic templates to their generations in evolutionary terms, but they also constantly adapt to ever-changing host environments. A unique peculiarity known as intratumor heterogeneity (ITH) is extensively involved in tumor development, metastasis, chemoresistance, and immune escape. An understanding of ITH is urgently required to identify the diversity and complexity of the tumor microenvironment (TME), but achieving this understanding has been a challenge. Single-cell sequencing (SCS) is a powerful tool that can gauge the distribution of genomic sequences in a single cell and the genetic variability among tumor cells, which can improve the understanding of ITH. SCS provides fundamental ideas about existing diversity in specific TMEs, thus improving cancer diagnosis and prognosis prediction, as well as improving the monitoring of therapeutic response. Herein, we will discuss advances in SCS and review SCS application in tumors based on current evidence.

FSMP-12. A ROLE FOR PROLINE BIOSYNTHESIS IN HYPOXIC GLIOBLASTOMA

Hypoxia is a common feature of glioblastoma, and a known driver of therapy resistance in brain tumours. Understanding the metabolic adaptations to hypoxia is key to develop new effective treatments for patients. A recent screening study highlighted Pyrroline-5-carboxylate reductase-like (PYCRL) as one of the top three genes that allowed tumour survival in hypoxia. PYCRL is one of the three enzymes involved in proline biosynthesis along with the mitochondrial pyrroline-5-carboxylate reductase 1 and 2 (PYCR1/2). The latter use glutamine as the carbon source to fuel the pyrroline-5-carboxylate (P5C)-to-proline reaction, whereas the cytosolic PYCRL is known to use ornithine to produce proline. Our investigations have shown that PYCRL differs from PYCR1 and 2 in the impact on cellular redox, which is a critical factor in hypoxic survival. Our data suggest that PYCRL activity is required for normal regulation of glioblastoma cell growth and the ability to deal with cellular stress, and that this enzyme may therefore represent a novel target in the treatment of these devastating tumours. Importantly, our study also begins to provide much-needed clarity over the network surrounding proline metabolism and redox maintenance.

The Distinct Roles of Transcriptional Factor KLF11 in Normal Cell Growth Regulation and Cancer as a Mediator of TGF-β Signaling Pathway.

KLF11 (Krüppel-like factor 11) belongs to the family of Sp1/Krüppel-like zinc finger transcription factors that play important roles in a variety of cell types and tissues. KLF11 was initially described as a transforming growth factor-beta (TGF-β) inducible immediate early gene (TIEG). KLF11 promotes the effects of TGF-β on cell growth control by influencing the TGFβ–Smads signaling pathway and regulating the transcription of genes that induce either apoptosis or cell cycle arrest. In carcinogenesis, KLF11 can show diverse effects. Its function as a tumor suppressor gene can be suppressed by phosphorylation of its binding domains via oncogenic pathways. However, KLF 11 can itself also show tumor-promoting effects and seems to have a crucial role in the epithelial–mesenchymal transition process. Here, we review the current knowledge about the function of KLF11 in cell growth regulation. We focus on its transcriptional regulatory function and its influence on the TGF-β signaling pathway. We further discuss its possible role in mediating crosstalk between various signaling pathways in normal cell growth and in carcinogenesis.

IGF1R undergoes active and directed centripetal transport on filopodia upon receptor activation.

Filopodia are thin, actin-based membrane protrusions with roles in sensing external mechanical and chemical cues, such as growth factor gradients in tissues. It was proposed that the chemical sensing role of filopodia is achieved through clearance of activated signaling receptors from filopodia. Type I insulin-like growth factor receptor (IGF1R) is a key regulator of normal development and growth, as well as tumor development and progression. Its biological roles depend on its activation upon IGF1 binding at the cell membrane. IGF1R behavior at the cell membrane and in particular in filopodia, has not been established. We found that IGF1 activation led to a gradual reduction in IGF1R puncta in filopodia, and that this clearance depended on actin, non-muscle myosin II, and IGF1R kinase activity. Using single particle tracking of filopodial IGF1R, we established that ligand-free IGF1R undergoes non-directional unidimensional diffusion along the filopodium. Moreover, after initial diffusion, the ligand-bound IGF1R is actively transported along the filopodium towards the filopodium base, and consequently cleared from the filopodium. Our results show that IGF1R can move directionally on the plasma membrane protrusions, supporting a sensory role for filopodia in interpreting local IGF1 gradients.

Propagation of functional estrogen receptor positive normal human breast cells in 3D cultures.

Understanding how differentiation, microenvironment, and hormonal milieu influence human breast cell susceptibility to malignant transformation will require the use of physiologically relevant in vitro systems. We sought to develop a 3D culture model that enables the propagation of normal estrogen receptor alpha (ER) + cells. We tested soluble factors and protocols for the ability to maintain progenitor and ER + cells in cultures established from primary cells. Optimized conditions were then used to profile estrogen-induced gene expression changes in cultures from three pathology-free individuals. Long-term representation of ER + cells was optimal in medium that included three different TGFβ/activin receptor-like kinase inhibitors. We found that omitting the BMP signaling antagonist, Noggin, enhanced the responsiveness of the PGR gene to estradiol exposure without altering the proportions of ER + cells in the cultures. Profiling of estradiol-exposed cultures showed that while all the cultures showed immediate and robust induction of PGR, LRP2, and IGFB4, other responses varied qualitatively and quantitatively across specimens. We successfully identified conditions for the maintenance and propagation of functional ER + cells from normal human breast tissues. We propose that these 3D cultures will overcome limitations of conventional 2D cultures of partially or fully transformed cell lines by sustaining normal endocrine function and growth regulation of the cell populations that comprise intact breasts.

Proteomic analysis of Plasmodium falciparum histone deacetylase 1 complex proteins

Plasmodium falciparum histone deacetylases (PfHDACs) are an important class of epigenetic regulators that alter protein lysine acetylation, contributing to regulation of gene expression and normal parasite growth and development. PfHDACs are therefore under investigation as drug targets for malaria. Despite this, our understanding of the biological roles of these enzymes is only just beginning to emerge. In higher eukaryotes, HDACs function as part of multi-protein complexes and act on both histone and non-histone substrates. Here, we present a proteomics analysis of PfHDAC1 immunoprecipitates, identifying 26 putative P. falciparum complex proteins in trophozoite-stage asexual intraerythrocytic parasites. The co-migration of two of these (P. falciparum heat shock proteins 70-1 and 90) with PfHDAC1 was validated using Blue Native PAGE combined with Western blot. These data provide a snapshot of possible PfHDAC1 interactions and a starting point for future studies focused on elucidating the broader function of PfHDACs in Plasmodium parasites.