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Leukemia Jun 2024Multiple myeloma (MM) cells effectively escape anti-tumoral immunity to survive in the tumor microenvironment (TME). Herein, we identify non-classical major...
Multiple myeloma (MM) cells effectively escape anti-tumoral immunity to survive in the tumor microenvironment (TME). Herein, we identify non-classical major histocompatibility complex (MHC) class I molecule HLA-E as a major contributing factor in immune escape. Clinically, HLA-E expression correlates with aggressive disease features such as t(4;14) and CD56 expression and is induced by IFN-gamma (IFN-γ) in the TME. We discovered that HLA-E is regulated by cAMP responsive element binding protein 1 (CREB1) transcription factor by direct promoter binding; genomic and pharmacological inhibition of CREB1 reduced HLA-E levels even in the presence of IFN-γ or IFN-γ activating agents, such as immunomodulatory drugs and panobinostat. HLA-E binds to natural killer group 2A (NKG2A), delivering an inhibitor signal to natural killer (NK) cells. Treatment with a CREB1 inhibitor was able to restore NK cell-mediated cytotoxicity against MM cell lines and patient samples. In conclusion, our results strongly demonstrate that CREB1 inhibition promotes anti-tumoral immunity in MM by limiting HLA-E expression and enhancing the activity of NK cells.
PubMed: 38902472
DOI: 10.1038/s41375-024-02303-w -
Biological & Pharmaceutical Bulletin 2024Microglia, resident immune cells in the central nervous system (CNS), play a critical role in maintaining CNS homeostasis. However, microglia activated in response to...
Microglia, resident immune cells in the central nervous system (CNS), play a critical role in maintaining CNS homeostasis. However, microglia activated in response to brain injury produce various inflammatory mediators, including nitric oxide (NO) and proinflammatory cytokines, leading to considerable neuronal damage. NO generated by inducible NO synthase (iNOS) rapidly reacts with superoxide to form a highly toxic product, peroxynitrite. Therefore, iNOS is considered to be a putative therapeutic target for cerebral ischemia. Here, we examined the effects of panobinostat (Pano), a histone deacetylase inhibitor, on lipopolysaccharide (LPS)-induced iNOS expression using rat immortalized microglia HAPI cells. Pano inhibited LPS-induced expression of iNOS mRNA and NO production in a dose-dependent manner; however, it had little effect on the LPS-induced activation of c-Jun N-terminal kinase (JNK) and p38 or nuclear translocation of nuclear factor-κB (NF-κB). The interferon-β (IFN-β)/signal transducer and activator of transcription (STAT) pathway is essential for LPS-induced iNOS expression in macrophages/microglia. We also examined the effects of Pano on LPS-induced IFN-β signaling. Pano markedly inhibited LPS-induced IFN-β expression and subsequent tyrosine phosphorylation of STAT1. However, the addition of IFN-β restored the decreased STAT1 phosphorylation but not the decreased iNOS expression. In addition, Pano inhibited the LPS-increased expression of octamer binding protein-2 and interferon regulatory factor 9 responsible for iNOS expression, but IFN-β addition also failed to restore the decreased expression of these factors. Thus, we conclude that the inhibitory effects of Pano are due not only to the inhibition of the IFN-β/STAT axis but also to the downregulation of other factors not involved in this axis.
Topics: Animals; Microglia; Lipopolysaccharides; Nitric Oxide Synthase Type II; Histone Deacetylase Inhibitors; Rats; Panobinostat; Nitric Oxide; NF-kappa B; Cell Line; Interferon-beta; STAT1 Transcription Factor; Signal Transduction
PubMed: 38897970
DOI: 10.1248/bpb.b24-00111 -
Biochemical and Biophysical Research... Jun 2024Type1 Non-specific Lipid Transfer Protein (CsLTP1) from Citrus sinensis is a small cationic protein possessing a long tunnel-like hydrophobic cavity. CsLTP1 performing...
Type1 Non-specific Lipid Transfer Protein (CsLTP1) from Citrus sinensis is a small cationic protein possessing a long tunnel-like hydrophobic cavity. CsLTP1 performing membrane trafficking of lipids is a promising candidate for developing a potent drug delivery system. The present work includes in-silico studies and the evaluation of drugs binding to CsLTP1 using biophysical techniques along with the investigation of CsLTP1's ability to enhance the efficacy of drugs employing cell-based bioassays. The in-silico investigations identified Panobinostat, Vorinostat, Cetylpyridinium Chloride, and Fulvestrant with higher affinities and stability of binding to the hydrophobic pocket of CsLTP1. SPR studies revealed strong binding affinities of anticancer drugs, Panobinostat (K = 1.40 μM) and Vorinostat (K = 2.17 μM) to CsLTP1 along with the binding and release kinetics. CD and fluorescent spectroscopy revealed drug-induced conformational changes in CsLTP1. CsLTP1-associated drug forms showed remarkably enhanced efficacy in MCF-7 cells, representing increased cell cytotoxicity, intracellular ROS, reduced mitochondrial membrane potential, and up-regulation of proapoptotic markers than the free drugs employing qRT-PCR and western blot analysis. The findings demonstrate that CsLTP1 binds strongly to hydrophobic drugs to facilitate their transport, hence improving their therapeutic efficacy revealed by the in-vitro investigations. This study establishes an excellent foundation for developing CsLTP1-based efficient drug delivery system.
PubMed: 38880080
DOI: 10.1016/j.bbrc.2024.150253 -
Biomedicine & Pharmacotherapy =... Jul 2024Soft tissue sarcomas (STS) are rare diseases typically arising from connective tissues in children and adults. However, chemotherapies involved in the treatment of STS...
BACKGROUND
Soft tissue sarcomas (STS) are rare diseases typically arising from connective tissues in children and adults. However, chemotherapies involved in the treatment of STS may cause toxic side effects and multi-drug chemoresistance, making the treatment even more challenging. Histone deacetylase inhibitors (HDACi) are epigenetic agents which have shown anti-tumor effects as single agent as well as combination use with other drugs. Our project intends to prove the same effects in STS.
METHODS
Panobinostat (LBH589) plus doxorubicin was selected for investigations based on our previous research. Tumor xenografts were tried in an epithelioid sarcoma model to validate good synergy effects in vivo and a leiomyosarcoma model was used as a negative comparison group. Gene profile changes were studied afterwards. The possible pathway changes caused by HDACi were explored and validated by several assays.
RESULTS
Synergy effect of LBH589 plus doxorubicin was successfully validated in STS cell lines and an epithelioid sarcoma mice model. We tried to reduce the dose of doxorubicin to a lower level and found the drug combination can still inhibit tumor size in mice. Furthermore, gene profile changes caused by LBH589 was studied by RNA-Sequencing analysis. Results showed LBH589 can exert effects on a group of target genes which can regulate potential biological functions especially in the cell cycle pathway.
Topics: Panobinostat; Doxorubicin; Animals; Sarcoma; Humans; Drug Synergism; Cell Line, Tumor; Histone Deacetylase Inhibitors; Mice; Xenograft Model Antitumor Assays; Antineoplastic Combined Chemotherapy Protocols; Mice, Nude; Gene Expression Regulation, Neoplastic
PubMed: 38876055
DOI: 10.1016/j.biopha.2024.116895 -
Journal of Colloid and Interface Science Jun 2024Breast cancers that overexpress human epidermal growth factor receptor 2 (HER2) have poor prognosis. Moreover, available chemotherapies cause numerous side effects due...
Breast cancers that overexpress human epidermal growth factor receptor 2 (HER2) have poor prognosis. Moreover, available chemotherapies cause numerous side effects due to poor selectivity. To advance more effective and safer therapies for HER2-positive breast cancer, we explored the fusion of drug delivery technology and immunotherapy. Our research led to the design of immunocubosomes loaded with panobinostat and functionalized with trastuzumab antibodies, enabling precise targeting of breast cancer cells that overexpress HER2. We characterised the nanostructure of cubosomes using small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). Moreover, we confirmed the integrity of the trastuzumab antibodies on the immunocubosomes by Fourier-transform infrared spectroscopy (FTIR) and sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, we found that panobinostat-loaded immunocubosomes were more cytotoxic, and in an uptake-dependant manner, towards a HER2-positive breast cancer cell line (SKBR3) compared to a cell line representing healthy cells (L929). These results support that the functionalization of cubosomes with antibodies enhances both the effectiveness of the loaded drug and its selectivity for targeting HER2-positive breast cancer cells.
PubMed: 38875795
DOI: 10.1016/j.jcis.2024.06.091 -
Oncotarget Jun 2024Histone deacetylase inhibitors (HDACi) can modulate the acetylation status of proteins, influencing the genomic instability exhibited by cancer cells. Poly (ADP ribose)...
Histone deacetylase inhibitors (HDACi) can modulate the acetylation status of proteins, influencing the genomic instability exhibited by cancer cells. Poly (ADP ribose) polymerase (PARP) inhibitors (PARPi) have a direct effect on protein poly (ADP-ribosyl)ation, which is important for DNA repair. Decitabine is a nucleoside cytidine analogue, which when phosphorylated gets incorporated into the growing DNA strand, inhibiting methylation and inducing DNA damage by inactivating and trapping DNA methyltransferase on the DNA, thereby activating transcriptionally silenced DNA loci. We explored various combinations of HDACi and PARPi +/- decitabine (hypomethylating agent) in pancreatic cancer cell lines BxPC-3 and PL45 (wild-type BRCA1 and BRCA2) and Capan-1 (mutated BRCA2). The combination of HDACi (panobinostat or vorinostat) with PARPi (talazoparib or olaparib) resulted in synergistic cytotoxicity in all cell lines tested. The addition of decitabine further increased the synergistic cytotoxicity noted with HDACi and PARPi, triggering apoptosis (evidenced by increased cleavage of caspase 3 and PARP1). The 3-drug combination treatments (vorinostat, talazoparib, and decitabine; vorinostat, olaparib, and decitabine; panobinostat, talazoparib, and decitabine; panobinostat, olaparib, and decitabine) induced more DNA damage (increased phosphorylation of histone 2AX) than the individual drugs and impaired the DNA repair pathways (decreased levels of ATM, BRCA1, and ATRX proteins). The 3-drug combinations also altered the epigenetic regulation of gene expression (NuRD complex subunits, reduced levels). This is the first study to demonstrate synergistic interactions between the aforementioned agents in pancreatic cancer cell lines and provides preclinical data to design individualized therapeutic approaches with the potential to improve pancreatic cancer treatment outcomes.
Topics: Humans; Decitabine; Pancreatic Neoplasms; Drug Synergism; Cell Line, Tumor; Histone Deacetylase Inhibitors; Poly(ADP-ribose) Polymerase Inhibitors; Azacitidine; Apoptosis; Antineoplastic Combined Chemotherapy Protocols
PubMed: 38829622
DOI: 10.18632/oncotarget.28588 -
Cell & Bioscience Jun 2024Mammalian or mechanistic target of rapamycin complex 1 (mTORC1) is an effective therapeutic target for diseases such as cancer, diabetes, aging, and neurodegeneration....
BACKGROUND
Mammalian or mechanistic target of rapamycin complex 1 (mTORC1) is an effective therapeutic target for diseases such as cancer, diabetes, aging, and neurodegeneration. However, an efficient tool for monitoring mTORC1 inhibition in living cells or tissues is lacking.
RESULTS
We developed a genetically encoded mTORC1 sensor called TORSEL. This sensor changes its fluorescence pattern from diffuse to punctate when 4EBP1 dephosphorylation occurs and interacts with eIF4E. TORSEL can specifically sense the physiological, pharmacological, and genetic inhibition of mTORC1 signaling in living cells and tissues. Importantly, TORSEL is a valuable tool for imaging-based visual screening of mTORC1 inhibitors. Using TORSEL, we identified histone deacetylase inhibitors that selectively block nutrient-sensing signaling to inhibit mTORC1.
CONCLUSIONS
TORSEL is a unique living cell sensor that efficiently detects the inhibition of mTORC1 activity, and histone deacetylase inhibitors such as panobinostat target mTORC1 signaling through amino acid sensing.
PubMed: 38824577
DOI: 10.1186/s13578-024-01250-4 -
In Silico Pharmacology 2024Chemotherapy is one of the most well-established and effective cancer treatments available. However, non-tumor-associated damage restrict the treatment's effectiveness...
UNLABELLED
Chemotherapy is one of the most well-established and effective cancer treatments available. However, non-tumor-associated damage restrict the treatment's effectiveness and safety. Our growing understanding of cancer epigenetics has resulted in new therapeutic options and the potential of better patient outcomes in recent decades. In cancer, epigenetic changes are widespread, particularly increased expression and activity of histone deacetylases (HDACs). Epi-drugs are chemical agents that modify the structure of DNA and chromatin facilitating disruption of transcriptional and post-transcriptional changes. First generation epi-drugs include HDAC inhibitors (HDACi) (approved to treat hematological malignancies) harbor various adverse effects demanding the discovery and development of potential natural HDACi that might benefit cancer treatment especially in hematological malignancies. Curcumin (diferuloylmethane), a polyphenolic, component of , is a well-known anti-inflammatory, anti-oxidative, and anti-lipidemic agent and has recently been shown to be a pan HDACi. Yet the potential of other curcuminoids in as pan HDACi remains unexplored. (i) To virtually screen curcumin and curcuminoids (Desmethoxycurcumin [DMC] & Bisdemethoxycurcumin [BDMC]) against human Histone deacetylase (HDAC) class I, II and IV enzymes in comparison to their pan HDAC inhibition activity with FDA approved human HDACis available in market and also (ii) to predict the drug likeness property and ADME/ toxicity of curcumin, curcuminoids and approved HDACis via computational approach. Homology modelling followed by docking was performed for human HDAC class I, II and IV enzymes with curcumin, Desmethoxycurcumin, Bisdemethoxycurcumin and with 5 reference HDACi compounds Vorinostat (SAHA), Trichostatin A (TSA), Chidamide, Romidepsin, and Panobinostat to understand the protein -ligand interactions and binding efficiencies. Further, the study ligands with low binding energy were predicted for pharmacokinetic properties and Lipinski's rule of 5. Our study revealed that BDMC followed by DMC and curcumin had high inhibitory effect by interacting at the active site of Zn HDACs similar to that of the standard HDACi (curcumin, DMC, BDMC, Belinostat, Chidamide, Romidepsin, Panobinostat, Trichostatin A and Vorinostat). Likewise, all of the chosen ligand molecules, with the exception of Romidepsin (refractive index > 130 mmol), adhered to Lipinski's rule of five and none of the natural compounds (curcumin, DMC, BDMC) did report any toxicity and mutagenic property also, the lethal doses (LD50) of all the natural compounds were higher when compared to chemical drugs. BDMC could be a potential pan HDACi than curcumin and DMC owing to high binding affinity among human Zn HDACs. The results of our present study can be useful for the design and development of novel compounds having better HDAC inhibitory activity against several types of cancers. Moreover, these findings could be validated with invitro investigations and by clinical trials to evaluate the survival outcomes in cancer patients when treated with the natural HDACi along with standard chemo regimen.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s40203-024-00221-4.
PubMed: 38817777
DOI: 10.1007/s40203-024-00221-4 -
Frontiers in Oncology 2024Cancer is a global health problem accounting for nearly one in six deaths worldwide. Conventional treatments together with new therapies have increased survival to this...
BACKGROUND
Cancer is a global health problem accounting for nearly one in six deaths worldwide. Conventional treatments together with new therapies have increased survival to this devastating disease. However, the persistent challenges of treatment resistance and the limited therapeutic arsenal available for specific cancer types still make research in new therapeutic strategies an urgent need.
METHODS
Chloroquine was tested in combination with different drugs (Panobinostat, KU-57788 and NU-7026) in 8 human-derived cancer cells lines (colorectal: HCT116 and HT29; breast: MDA-MB-231 and HCC1937; glioblastoma: A-172 and LN-18; head and neck: CAL-33 and 32816). Drug´s effect on proliferation was tested by MTT assays and cell death was assessed by Anexin V-PI apoptosis assays. The presence of DNA double-strand breaks was analyzed by phospho-H2AX fluorescent staining. To measure homologous recombination efficiency the HR-GFP reporter was used, which allows flow cytometry-based detection of HR stimulated by I-SceI endonuclease-induced DSBs.
RESULTS
The combination of chloroquine with any of the drugs employed displayed potent synergistic effects on apoptosis induction, with particularly pronounced efficacy observed in glioblastoma and head and neck cancer cell lines. We found that chloroquine produced DNA double strand breaks that depended on reactive oxygen species formation, whereas Panobinostat inhibited DNA double-strand breaks repair by homologous recombination. Cell death caused by chloroquine/Panobinostat combination were significantly reduced by N-Acetylcysteine, a reactive oxygen species scavenger, underscoring the pivotal role of DSB generation in CQ/LBH-induced lethality. Based on these data, we also explored the combination of CQ with KU-57788 and NU-7026, two inhibitors of the other main DSB repair pathway, nonhomologous end joining (NHEJ), and again synergistic effects on apoptosis induction were observed.
CONCLUSION
Our data provide a rationale for the clinical investigation of CQ in combination with DSB inhibitors for the treatment of different solid tumors.
PubMed: 38803536
DOI: 10.3389/fonc.2024.1390518 -
Proteome Science May 2024Patients with immunodeficiency virus-1 (HIV-1) infection are challenging to be cured completely due to the existence of HIV-1 latency reservoirs. However, the knowledge...
BACKGROUND
Patients with immunodeficiency virus-1 (HIV-1) infection are challenging to be cured completely due to the existence of HIV-1 latency reservoirs. However, the knowledge of the mechanisms and biomarkers associated with HIV-1 latency is limited. Therefore, identifying proteins related to HIV-1 latency could provide new insights into the underlying mechanisms of HIV-1 latency, and ultimately contribute to the eradication of HIV reservoirs.
METHODS
An Isobaric Tags for Relative and Absolute Quantification (iTRAQ)-labeled subcellular proteomic study was performed on an HIV-1 latently infected cell model (U1, a HIV-1-integrated U937 cell line) and its control (U937). Differentially expressed proteins (DEPs) were analyzed using STRING-DB. Selected DEPs were further evaluated by western blotting and multiple reaction monitoring technology in both cell model and patient-derived cluster of differentiation 4 (CD4) T cells. Finally, we investigated the relationship between a specific DEP lysosome-associated membrane glycoprotein 2 (LAMP2) and HIV-1 reactivation by panobinostat or lysosome regulation by a lysosomotropic agent hydroxychloroquine in U1 and U937 cells.
RESULTS
In total, 110 DEPs were identified in U1 cells comparing to U937 control cells. Bioinformatics analysis suggested associations of the altered proteins with the immune response and endosomal/lysosomal pathway. LAMP2, leukocyte surface antigen CD47, CD55, and ITGA6 were downregulated in HIV-1 latent cells. Downregulated LAMP2 was further confirmed in resting CD4 T cells from patients with latent HIV-1 infection. Furthermore, both HIV-1 reactivation by panobinostat and stimulation with hydroxychloroquine upregulated LAMP2 expression.
CONCLUSIONS
Our results indicated the involvement of the endosomal/lysosomal pathway in HIV-1 latency in macrophage cell model. The down-modulation of LAMP2 was associated with HIV latency, and the restoration of LAMP2 expression accompanied the transition of viral latency to active infection. This study provides new insights into the mechanism of HIV-1 latency and potential strategies for eradicating HIV-1 reservoirs by targeting LAMP2 expression.
PubMed: 38750478
DOI: 10.1186/s12953-024-00230-3