CBIO-23. ANTIAPOPTOTIC Bcl-xL RESTRICTS APOPTOSIS IN SHH MEDULLOBLASTOMA AND PROMOTES PROGRESSION

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi31-vi32
Author(s):  
Abigail Cleveland ◽  
Katherine Veleta ◽  
Timothy Gershon

Abstract Medulloblastomas in most patients are distinctively sensitive to radiation therapy, but the mechanisms that mediate this sensitivity are unclear. Current treatments still fail 20%-60% of patients with SHH medulloblastoma and can leave survivors with long-term neurocognitive and social deficits. Understanding the mechanisms driving the typical radiation-sensitivity may identify less-toxic therapeutic strategies and provide insight into treatment failure. We previously showed that radiation sensitivity depends on the intrinsic apoptotic pathway, mediated by pro-apoptotic BAX. In cerebellar granule neuron progenitors (CGNPs), the cell of origin for SHH medulloblastoma, BAX activity is directly inhibited by anti-apoptotic BCL-xL; Bcl-xL-deleted CGNPs undergo spontaneous apoptosis. To test the therapeutic potential of disrupting BCL-xL in medulloblastoma, we conditionally deleted Bcl-xL in mice genetically engineered to develop SHH medulloblastoma. Here, I show that Bcl-xL deletion slows SHH medulloblastoma growth and prolongs survival of medulloblastoma-bearing mice. Bcl-xL-deleted tumors initially showed increased rates of spontaneous apoptosis, but this effect waned over time, suggesting the emergence of BCL-xL-independent survival mechanisms. We also noted increased microglial infiltration in Bcl-xL-deleted medulloblastomas. We hypothesize that IGF1 produced by microglia in the tumor microenvironment may be contributing to tumor resistance by upregulating translation of MCL-1, an anti-apoptotic BCL-xL homolog. IGF1 is known to upregulate translation through the mTOR pathway, while anti-apoptotic MCL-1 protein abundance is dependent upon translation regulation. Our on-going studies are testing the efficacy of pharmacologically targeting BCL-xL in mice with medulloblastoma, in combination with targeting IGF1 signaling using mTORC1 inhibitors.

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi187-vi188
Author(s):  
Abigail Cleveland ◽  
Katherine Veleta ◽  
Timothy Gershon

Abstract Medulloblastomas, unlike other malignant brain tumors, are typically sensitive to radiation therapy (xRT). However, although xRT allows medulloblastoma patients to survive, it can also confer significant long term cognitive sequelae. Understanding the mechanisms of radiation sensitivity in medulloblastoma may identify ways to increase this sensitivity through targeted therapy. Cerebellar granule neuron progenitors (CGNPs), the cells of origin for SHH-subgroup medulloblastoma, are also sensitive to xRT. We have shown that SHH signaling, which induces CGN proliferation and in excess can cause medulloblastoma, induces the pro-apoptotic protein BIM, resulting in increased radiation sensitivity. SHH-stimulated CGNPs show robust BIM expression, which is blocked by the SMO inhibitor vismodegib. CGNPs in BIM null mice show normal SHH-driven proliferation, but are markedly less sensitive to radiation. Protein studies show that BIM binds to the anti-apoptotic proteins BCL-xL and MCL-1, suggesting a mechanism for increasing the sensitivity to radiation by lowering the apoptotic threshold. On-going studies will determine whether BIM is required for radiation sensitivity in SHH-driven medulloblastoma. If validated, the BIM interactions with BCL-xL and MCL-1 may be novel mechanisms to be targeted to improve medulloblastoma therapy.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii400-iii400
Author(s):  
Abigail Cleveland ◽  
Timothy Gershon

Abstract Medulloblastomas, unlike other malignant brain tumors, are typically sensitive to radiation therapy, but the mechanisms that mediate this sensitivity are unclear. Cerebellar granule neuron progenitors (CGNPs), the cell of origin for SHH-subgroup medulloblastoma, are also highly sensitive to radiation. In early life, CGNPs proliferate in response to Sonic Hedgehog (SHH) signaling, and hyperactivation of SHH signaling in CGNPs can lead to the development of SHH-subgroup medulloblastoma. We propose that SHH activation induces radiation sensitivity along with tumorigenesis. We have previously shown that the proapoptotic protein BAX is required for radiation sensitivity of both SHH-driven medulloblastomas and CGNPs in mice, and that BCL-xL supplies critical regulation of BAX, preventing spontaneous cell death. Here, we show that SHH signaling increases the radiation sensitivity of CGNPs by inducing the proapoptotic protein BIM. We found that BIM expression depends on SHH activity, and that genetic deletion of Bim decreases the radiation-sensitivity of CGNPs. Mechanistically, we show that BIM binds to anti-apoptotic proteins BCL-xL and MCL-1, where it may alter the balance of BAX and BCL-xL interactions. Consistent with our mechanistic model, human medulloblastoma patients with high BIM expression show a better prognosis. Based on these observations, we propose that SHH-induced BIM mediates the typical radiation sensitivity of SHH-driven medulloblastoma. Finding ways to enhance BIM activity may open new opportunities for targeted medulloblastoma therapy.


Author(s):  
Evi Zohar

Continuing the workshop I've given in the WPC Paris (2017), this article elaborates my discussion of the way I interlace Focusing with Differentiation Based Couples Therapy (Megged, 2017) under the systemic view, in order to facilitate processes of change and healing in working with intimate couples. This article presents the theory and rationale of integrating Differentiation (Bowen, 1978; Schnarch, 2009; Megged, 2017) and Focusing (Gendlin, 1981) approaches, and its therapeutic potential in couple's therapy. It is written from the point of view of a practicing professional in order to illustrate the experiential nature and dynamics of the suggested therapeutic path. Differentiation is a key to mutuality. It offers a solution to the central struggle of any long term intimate relationship: balancing two basic life forces - the drive for individuality and the drive for togetherness (Schnarch, 2009). Focusing is a body-oriented process of self-awareness and emotional healing, in which one learns to pay attention to the body and the ‘Felt Sense’, in order to unfold the implicit, keep it in motion at the precise pace it needs for carrying the next step forward (Gendlin, 1996). Combining Focusing and Differentiation perspectives can cultivate the kind of relationship where a conflict can be constructively and successfully held in the inner world of each partner, while taking into consideration the others' well-being. This creates the possibility for two people to build a mutual emotional field, open to changes, permeable and resilient.


2020 ◽  
Vol 06 ◽  
Author(s):  
Sayed Md Mumtaz ◽  
Madhu Gupta ◽  
Ramesh K. Goyal

Abstract:: The placenta that maintains and regulates the growth of fetus, consists of various biological treasures nutrients such as cytomedines, vitamins, trace elements, amino acids, peptides, growth factors and other biologically active constituents. Their therapeutic usefulness can well define in the terms of biochemical mechanisms of various components present in it. Biomedical waste derived extract is also a panacea for treatment of various diseases. Placental therapy has been reported specifically to have potent action on recovery of diseases and tissue regeneration. Placental bioactive components and their multi targeting identity prompted us to compile the précised information on placental extract products. However, some findings are needed to be explored by scientific community to prove their clinical potential with clinically significant statistical conclusions. In the light of available information and the usefulness of the placental extract, it is necessary for the development of various formulations for various unmet meet for the treatment as well as access their adverse effects as well as contradictions and precisely evaluated in the short and in the long-term periods.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi74-vi74
Author(s):  
Erin Smithberger ◽  
Abigail Shelton ◽  
Madison Butler ◽  
Alex Flores ◽  
Ryan Bash ◽  
...  

Abstract Glioblastoma (GBM) is an aggressive primary brain tumor with a poor survival rate. One of the most common molecular alterations seen in GBM is amplification and/or mutation of the Epidermal Growth Factor Receptor (EGFR), which has made it an attractive therapeutic target. However, several EGFR tyrosine kinase inhibitors have been tested clinically in GBM with minimal success. One reason for this lack of efficacy could be due to acute, adaptive resistance via alternative pathway activation. To investigate this mechanism of tumor resistance, we used RNA-seq and multiplex inhibitor bead/mass spectrometry (MIB-MS) to analyze the transcriptomes and kinomes of genetically engineered murine astrocytes with common GBM genotypes. We have previously shown that 38% of the expressed kinome varied among a panel of diverse nGEM astrocytes harboring Cdkn2a deletion (C) plus Pten deletion (CP), wild-type human EGFR (CE) or EGFRvIII (CEv3) overexpression or both EGFRvIII overexpression and Pten deletion (CEv3P). Although CE have a similar transcriptional profile to C cells at baseline, when treated with the EGFR inhibitor afatinib, CE respond more similarly to CEv3 cells. When cells containing endogenous murine EGFR (C and CP) are treated with afatinib, fewer than 0.5% of kinases showed differential expression. In cells with EGFR overexpression alone, more than 6% of kinases were differentially expressed upon afatinib treatment, including Ntrk3, Fgfr2 and 3, Lyn, Bmx, Epha2 and 5, Fn3k, a kinase involved in fructosamine processing, and Nrbp2, a kinase involved in regulation of apoptosis. This effect was blunted in cells lacking Pten in addition to having EGFRvIII (CEv3P), resulting in less than 2% of kinases being differentially expressed. The only kinase upregulated in all three EGFR-overexpressing cell types was Coq8a, which is involved in electron transport and response to DNA damage. Given this overlap in response, Coq8a could be a potential dual treatment target for GBM.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Rakesh E. Mutha ◽  
Anilkumar U. Tatiya ◽  
Sanjay J. Surana

Abstract Background Natural plants and plant-derived formulations have been used by mankind from the ancient period of time. For the past few years, many investigations elaborated the therapeutic potential of various secondary chemicals present in the plants. Literature revealed that the various secondary metabolites, viz. phenolics and flavonoids, are responsible for a variety of therapeutic action in humans. Main body In the present review, an attempt has been made to compile the exploration of natural phenolic compounds with major emphasis on flavonoids and their therapeutic potential too. Interestingly, long-term intake of many dietary foods (rich in phenolics) proved to be protective against the development and management of diabetes, cancer, osteoporosis, cardiovascular diseases and neurodegenerative diseases, etc. Conclusion This review presents an overview of flavonoid compounds to use them as a potential therapeutic alternative in various diseases and disorders. In addition, the present understanding of phenolics and flavonoids will serve as the basis for the next scientific studies.


Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 49
Author(s):  
Verena te Kamp ◽  
Virginia Friedrichs ◽  
Conrad M. Freuling ◽  
Ad Vos ◽  
Madlin Potratz ◽  
...  

The live genetically-engineered oral rabies virus (RABV) variant SPBN GASGAS induces long-lasting immunity in foxes and protection against challenge with an otherwise lethal dose of RABV field strains both after experimental oral and parenteral routes of administration. Induction of RABV-specific binding antibodies and immunoglobulin isotypes (IgM, total IgG, IgG1, IgG2) were comparable in orally and parenterally vaccinated foxes. Differences were only observed in the induction of virus-neutralizing (VNA) titers, which were significantly higher in the parenterally vaccinated group. The dynamics of rabies-specific antibodies pre- and post-challenge (365 days post vaccination) suggest the predominance of type-1 immunity protection of SPBN GASGAS. Independent of the route of administration, in the absence of IgG1 the immune response to SPBN GAGAS was mainly IgG2 driven. Interestingly, vaccination with SPBN GASGAS does not cause significant differences in inducible IFN-γ production in vaccinated animals, indicating a relatively weak cellular immune response during challenge. Notably, the parenteral application of SPBN GASGAS did not induce any adverse side effects in foxes, thus supporting safety studies of this oral rabies vaccine in various species.


2021 ◽  
Vol 22 (4) ◽  
pp. 1883
Author(s):  
Coralia Cotoraci ◽  
Alina Ciceu ◽  
Alciona Sasu ◽  
Anca Hermenean

Anemia, characterized by a decrease of the hemoglobin level in the blood and a reduction in carrying capacity of oxygen, is a major public health problem which affects people of all ages. The methods used to treat anemia are blood transfusion and oral administration of iron-based supplements, but these treatments are associated with a number of side effects, such as nausea, vomiting, constipation, and stomach pain, which limit its long-term use. In addition, oral iron supplements are poorly absorbed in the intestinal tract, due to overexpression of hepcidin, a peptide hormone that plays a central role in iron homeostasis. In this review, we conducted an analysis of the literature on biologically active compounds and plant extracts used in the treatment of various types of anemia. The purpose of this review is to provide up-to-date information on the use of these compounds and plant extracts, in order to explore their therapeutic potential. The advantage of using them is that they are available from natural resources and can be used as main, alternative, or adjuvant therapies in many diseases, such as various types of anemia.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1126
Author(s):  
Natasja Franceschini ◽  
Bas Verbruggen ◽  
Marianna A. Tryfonidou ◽  
Alwine B. Kruisselbrink ◽  
Hans Baelde ◽  
...  

Sarcomas are rare mesenchymal tumors with a broad histological spectrum, but they can be divided into two groups based on molecular pathology: sarcomas with simple or complex genomics. Tumors with complex genomics can have aneuploidy and copy number gains and losses, which hampers the detection of early, initiating events in tumorigenesis. Often, no benign precursors are known, which is why good models are essential. The mesenchymal stem cell (MSC) is the presumed cell of origin of sarcoma. In this study, MSCs of murine and canine origin are used as a model to identify driver events for sarcomas with complex genomic alterations as they transform spontaneously after long-term culture. All transformed murine but not canine MSCs formed sarcomas after subcutaneous injection in mice. Using whole genome sequencing, spontaneously transformed murine and canine MSCs displayed a complex karyotype with aneuploidy, point mutations, structural variants, inter-chromosomal translocations, and copy number gains and losses. Cross-species analysis revealed that point mutations in Tp53/Trp53 are common in transformed murine and canine MSCs. Murine MSCs with a cre-recombinase induced deletion of exon 2-10 of Trp53 transformed earlier compared to wild-type murine MSCs, confirming the contribution of loss of p53 to spontaneous transformation. Our comparative approach using transformed murine and canine MSCs points to a crucial role for p53 loss in the formation of sarcomas with complex genomics.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fei Xiao ◽  
Hongyu Li ◽  
Zhongxue Feng ◽  
Luping Huang ◽  
Lingmiao Kong ◽  
...  

AbstractAs one of the most malignant cancer types, hepatocellular carcinoma (HCC) is highly invasive and capable of metastasizing to distant organs. Intermedin (IMD), an endogenous peptide belonging to the calcitonin family, has been suggested playing important roles in cancer cell survival and invasion, including in HCC. However, how IMD affects the behavior of HCC cells and the underlying mechanisms have not been fully elucidated. Here, we show that IMD maintains an important homeostatic state by activating the ERK1/2-EGR1 (early growth response 1) signaling cascade, through which HCC cells acquire a highly invasive ability via significantly enhanced filopodia formation. The inhibition of IMD blocks the phosphorylation of ERK1/2, resulting in EGR1 downregulation and endoplasmic reticulum stress (ER) stress, which is evidenced by the upregulation of ER stress marker DDIT3 (DNA damage-inducible transcript 3). The high level of DDIT3 induces HCC cells into an ER-stress related apoptotic pathway. Along with our previous finding that IMD plays critical roles in the vascular remodeling process that improves tumor blood perfusion, IMD may facilitate the acquisition of increased invasive abilities and a survival benefit by HCC cells, and it is easier for HCC cells to obtain blood supply via the vascular remodeling activities of IMD. According to these results, blockade of IMD activity may have therapeutic potential in the treatment of HCC.


Sign in / Sign up

Export Citation Format

Share Document