Following cytotoxic nanoconjugates from injection to halting the cell cycle machinery and its therapeutic implications in oral cancer

Abstract Background: The concept of personalized therapy has been proven to be a promising approach. A popular approach is to utilize gold nanoparticles (AuNPs) as drug delivery vectors for cytotoxic drugs and small molecule inhibitors to target and eradicate oral cancer cells in vitro and in vivo. While it is currently accepted that the cytotoxic drug’s mode of action remains the key regulator of the therapeutic outcome and toxicity beside nanocarrier design. None of the leading studies have compared multiple chemotherapeutics to their baseline free drugs nor used multiple nanocarriers to calculate drugs impact versus nanocarriers effect. We hypothesized that similarly constructed nanocarriers play a greater role than only acting as cargo-carriers. If proven, AuNPs may have a therapeutic role beyond bypassing cancer cell membrane and delivering their loaded drugs. We propose that similarly constructed AuNPs can flexibly leverage different conjugated drugs irrelevant to their mode of action enhancing the therapeutic outcome.Methods: We conjugated 5- fluorouracil (5Fu), camptothecin (CPT), and a fibroblast growth factor receptor1-inhibitor (FGFR1i) to gold nanospheres (AuNSs). We followed their trajectories in Syrian hamsters with chemically induced buccal carcinomas.Results: Flow cytometry and cell cycle data shows that 5Fu- and CPT- induced a similar ratio of S-phase cell cycle arrest as nanoconjugates and in their free forms. On the other hand, FGFR1i-AuNSs induced significant sub-G1 cell population compared with its free form. Despite cell cycle dynamics variability, there was no significant difference in tumor cells’ proliferation rate between CPT-, 5Fu- and FGFR1i- AuNSs treated groups. Clinically, FGFR1i-AuNSs induced the highest tumor reduction rates followed by 5Fu- AuNSs. CPT-AuNSs induced significantly lower tumor reduction rates compared with the 5Fu- and FGFR1i- AuNSs despite showing similar proliferative rates in tumor cells.Conclusions: Our data indicates that the cellular biological events do not predict the clinical outcome. Furthermore, our results suggest that AuNSs selectively enhances the therapeutic effect of small molecule inhibitors such as FGFR1i than potent anticancer drugs. Future studies are required to better understand the underlying mechanism.

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Following cytotoxic nanoconjugates from injection to halting the cell cycle machinery and its therapeutic implications in oral cancer

10.21203/rs.3.rs-52128/v2 ◽

2020 ◽

Author(s):

Hend Mohamed Abdel Hamid ◽

Zeinab El Sayed Darwish ◽

Sahar Mohamed Elsheikh ◽

Ghada Mourad ◽

Hanaa Donia ◽

...

Keyword(s):

Cell Cycle ◽

Oral Cancer ◽

Tumor Cells ◽

Small Molecule ◽

Mode Of Action ◽

Small Molecule Inhibitors ◽

Phase Cell ◽

Free Form ◽

Tumor Reduction

Abstract Background: The concept of personalized therapy has been proven to be a promising approach. A popular technique is to utilize gold nanoparticles (AuNPs) as drug delivery vectors for cytotoxic drugs and small molecule inhibitors to target and eradicate oral cancer cells in vitro and in vivo. Both drug and nanocarrier designs play important roles in the treatment efficacy. In our study, we standardized the nanosystem regarding NPs type, size, surface ligands and coverage percentage leaving only the drugs mode of action as the confounding variable. We propose that similarly constructed nanoparticles (NPs) can selectively leverage different conjugated drugs irrelevant to their original mode of action. If proven, AuNPs may have a secondary role beyond bypassing cancer cell membrane and delivering their loaded drugs.Methods: We conjugated 5- fluorouracil (5Fu), camptothecin (CPT), and a fibroblast growth factor receptor1-inhibitor (FGFR1i) to gold nanospheres (AuNSs). We followed their trajectories in Syrian hamsters with chemically induced buccal carcinomas.Results: Flow cytometry and cell cycle data shows that 5Fu- and CPT- induced a similar ratio of S-phase cell cycle arrest as nanoconjugates and in their free forms. On the other hand, FGFR1i-AuNSs induced significant sub-G1 cell population compared with its free form. Despite cell cycle dynamics variability, there was no significant difference in tumor cells’ proliferation rate between CPT-, 5Fu- and FGFR1i- AuNSs treated groups. In our in vivo model, FGFR1i-AuNSs induced the highest tumor reduction rates followed by 5Fu- AuNSs. CPT-AuNSs induced significantly lower tumor reduction rates compared with the 5Fu- and FGFR1i- AuNSs despite showing similar proliferative rates in tumor cells.Conclusions: Our data indicates that the cellular biological events do not predict the outcome seen in our in vivo model. Furthermore, our results suggest that AuNSs selectively enhance the therapeutic effect of small molecule inhibitors such as FGFR1i than potent anticancer drugs. Future studies are required to better understand the underlying mechanism.

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Following cytotoxic nanoconjugates from injection to halting the cell cycle machinery and its therapeutic implications in oral cancer

BMC Cancer ◽

10.1186/s12885-021-07849-x ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hend M. Abdel Hamid ◽

Zeinab E. Darwish ◽

Sahar M. Elsheikh ◽

Ghada M. Mourad ◽

Hanaa M. Donia ◽

...

Keyword(s):

Cell Cycle ◽

Oral Cancer ◽

Tumor Cells ◽

Small Molecule ◽

Mode Of Action ◽

Small Molecule Inhibitors ◽

Phase Cell ◽

In Vivo Model ◽

Tumor Reduction

Abstract Background The concept of personalized therapy has been proven to be a promising approach. A popular technique is to utilize gold nanoparticles (AuNPs) as drug delivery vectors for cytotoxic drugs and small molecule inhibitors to target and eradicate oral cancer cells in vitro and in vivo. Both drug and nanocarrier designs play important roles in the treatment efficacy. In our study, we standardized the nanosystem regarding NPs type, size, surface ligands and coverage percentage leaving only the drugs mode of action as the confounding variable. We propose that similarly constructed nanoparticles (NPs) can selectively leverage different conjugated drugs irrelevant to their original mode of action. If proven, AuNPs may have a secondary role beyond bypassing cancer cell membrane and delivering their loaded drugs. Methods We conjugated 5- fluorouracil (5Fu), camptothecin (CPT), and a fibroblast growth factor receptor1-inhibitor (FGFR1i) to gold nanospheres (AuNSs). We followed their trajectories in Syrian hamsters with chemically induced buccal carcinomas. Results Flow cytometry and cell cycle data shows that 5Fu- and CPT- induced a similar ratio of S-phase cell cycle arrest as nanoconjugates and in their free forms. On the other hand, FGFR1i-AuNSs induced significant sub-G1 cell population compared with its free form. Despite cell cycle dynamics variability, there was no significant difference in tumor cells’ proliferation rate between CPT-, 5Fu- and FGFR1i- AuNSs treated groups. In our in vivo model, FGFR1i-AuNSs induced the highest tumor reduction rates followed by 5Fu- AuNSs. CPT-AuNSs induced significantly lower tumor reduction rates compared with the 5Fu- and FGFR1i- AuNSs despite showing similar proliferative rates in tumor cells. Conclusions Our data indicates that the cellular biological events do not predict the outcome seen in our in vivo model. Furthermore, our results suggest that AuNSs selectively enhance the therapeutic effect of small molecule inhibitors such as FGFR1i than potent anticancer drugs. Future studies are required to better understand the underlying mechanism.

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Following cytotoxic nanoconjugates from injection to halting the cell cycle machinery and its therapeutic implications in oral cancer

10.21203/rs.3.rs-52128/v3 ◽

2020 ◽

Author(s):

Hend Mohamed Abdel Hamid ◽

Zeinab El Sayed Darwish ◽

Sahar Mohamed Elsheikh ◽

Ghada Mourad ◽

Hanaa Donia ◽

...

Keyword(s):

Cell Cycle ◽

Oral Cancer ◽

Tumor Cells ◽

Small Molecule ◽

Mode Of Action ◽

Small Molecule Inhibitors ◽

Phase Cell ◽

In Vivo Model ◽

Tumor Reduction

Abstract Background: The concept of personalized therapy has been proven to be a promising approach. A popular technique is to utilize gold nanoparticles (AuNPs) as drug delivery vectors for cytotoxic drugs and small molecule inhibitors to target and eradicate oral cancer cells in vitro and in vivo . Both drug and nanocarrier designs play important roles in the treatment efficacy. In our study, we standardized the nanosystem regarding NPs type, size, surface ligands and coverage percentage leaving only the drugs mode of action as the confounding variable. We propose that similarly constructed nanoparticles (NPs) can selectively leverage different conjugated drugs irrelevant to their original mode of action. If proven, AuNPs may have a secondary role beyond bypassing cancer cell membrane and delivering their loaded drugs. Methods: We conjugated 5- fluorouracil (5Fu), camptothecin (CPT), and a fibroblast growth factor receptor1-inhibitor (FGFR1i) to gold nanospheres (AuNSs). We followed their trajectories in Syrian hamsters with chemically induced buccal carcinomas. Results: Flow cytometry and cell cycle data shows that 5Fu- and CPT- induced a similar ratio of S-phase cell cycle arrest as nanoconjugates and in their free forms. On the other hand, FGFR1i-AuNSs induced significant sub-G1 cell population compared with its free form. Despite cell cycle dynamics variability, there was no significant difference in tumor cells’ proliferation rate between CPT-, 5Fu- and FGFR1i- AuNSs treated groups. In our in vivo model, FGFR1i-AuNSs induced the highest tumor reduction rates followed by 5Fu- AuNSs. CPT-AuNSs induced significantly lower tumor reduction rates compared with the 5Fu- and FGFR1i- AuNSs despite showing similar proliferative rates in tumor cells. Conclusions: Our data indicates that the cellular biological events do not predict the outcome seen in our in vivo model. Furthermore, our results suggest that AuNSs selectively enhance the therapeutic effect of small molecule inhibitors such as FGFR1i than potent anticancer drugs. Future studies are required to better understand the underlying mechanism.

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Attenuation of G 2 -Phase Cell Cycle Checkpoint Control Is Associated with Increased Frequencies of Unrejoined Chromosome Breaks in Human Tumor Cells

Radiation Research ◽

10.2307/3579585 ◽

1996 ◽

Vol 146 (2) ◽

pp. 139 ◽

Cited By ~ 7

Author(s):

Jeffrey L. Schwartz ◽

Janet Cowan ◽

David J. Grdina ◽

Ralph R. Weichselbaum

Keyword(s):

Cell Cycle ◽

Tumor Cells ◽

Human Tumor ◽

Cell Cycle Checkpoint ◽

Phase Cell ◽

Checkpoint Control ◽

Human Tumor Cells ◽

Chromosome Breaks ◽

Cycle Checkpoint

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207 Small molecule inhibitors of Sec61 cotranslational translocation regulate the phagocytosis checkpoint molecule CD47

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0207 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A223-A223

Author(s):

Jennifer Whang ◽

Andrea Fan ◽

Christopher Kirk ◽

Eric Lowe ◽

Dustin McMinn ◽

...

Keyword(s):

Tumor Cells ◽

Small Molecule ◽

Immune Checkpoint ◽

Small Molecule Inhibitors ◽

Protein Translocation ◽

Signal Sequence ◽

Checkpoint Proteins ◽

Cotranslational Translocation ◽

Macrophage Phagocytosis ◽

Immune Checkpoint Proteins

BackgroundMany tumor cells escape immune cell clearance by overexpressing CD47, a multi-pass transmembrane protein, which binds signal regulatory protein α (SIRPα) on macrophages leading to decreased phagocytic activity. Blockade of CD47/SIRPα interactions enhances macrophage phagocytosis and is being targeted with antibody-based drugs, some of which are used in combination therapies in clinical trials. A novel method to target CD47 is through the inhibition of cotranslational translocation of transmembrane proteins. Immediately after exiting the ribosome, signal sequences that are unique to each protein are directed through the Sec61 channel into the ER for extracellular expression.1 Several Sec61-targeting compounds have been identified to suppress translocation in a signal sequence-specific manner.2 We previously described Sec61 inhibitors capable of selectively targeting immune checkpoint proteins and enhancing T cell function.3 Here, we demonstrate the blockade of CD47 expression on tumor cells and enhancement of macrophage phagocytosis with small molecule inhibitors of Sec61.MethodsSec61-dependent expression of target proteins was assayed using HEK293 cells overexpressing constructs comprised of signal sequences fused to a luciferase reporter. Stimulated PBMCs or tumor cells were incubated with Sec61 inhibitors, and surface expression of checkpoint molecules were examined by flow cytometry. Necrotic and apoptotic cells were assessed by Annexin V and 7AAD labeling. Human CD14+ monocytes were differentiated to M1- or M2-type macrophages. Jurkat or SKBR3 cells were incubated with Sec61 inhibitors, labeled with a pH sensitive dye and co-cultured with macrophages to assess phagocytosis.ResultsWe identified Sec61 inhibitors that block select immune checkpoint proteins. Compounds demonstrated either selective or multi-target profiles in transient transfection screens, which was supported by decreased protein expression on activated T cells. KZR-9275 targeted multiple checkpoint molecules, including PD-1, LAG-3 and CD73, along with a potent inhibition of the CD47 signal sequence reporter. CD47 surface expression was decreased on Jurkat and SKBR3 cells following 72 hours of compound treatment. KZR-9275 treatment of SKBR3 cells induced a minor increase in apoptotic cells, which was not detected in Jurkat cells. Increased macrophage phagocytosis, especially with M2-type macrophages, was observed when Jurkat or SKBR3 cells were pre-treated with KZR-9275.ConclusionsOur findings demonstrate that Sec61 inhibitors can block the expression of CD47, a phagocytosis checkpoint protein, on tumor cells and subsequently modulate macrophage phagocytic activity. Small molecule inhibitors of Sec61 provide an opportunity to target multiple checkpoint proteins on various cell populations. Future in vivo tumor models will assess the efficacy of Sec61 inhibitors to provide combination-like therapy.ReferencesPark E, Rapoport TA. Mechanisms of Sec61/SecY-mediated protein translocation across membranes. Annu Rev Biophys 2012; 41:1–20.Van Puyenbroeck V, Vermeire K. Inhibitors of protein translocation across membranes of the secretory pathway: novel antimicrobial and anticancer agents. Cell Mol Life Sci 2018; 75:1541–1558.Whang J, Anderl J, Fan A, Kirk C, Lowe E, McMinn D, et al. Targeting multiple immune checkpoint proteins with novel small molecule inhibitors of Sec61-dependent cotranslational translocation. 34th Annual Meeting & Pre-Conference Programs of the Society for Immunotherapy of Cancer (SITC 2019): part 2. J Immunother Cancer 2019; 7: 283. Abstract 815.

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Identification of potential druggable targets of cell cycle with small-molecule inhibitors in oral squamous cell carcinoma

Pharmacogenetics and Genomics ◽

10.1097/fpc.0000000000000461 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Xiaoyi Zhou ◽

Wenke Jin ◽

Yanmei Chen ◽

Lingjuan Zhu ◽

Anchun Mo ◽

...

Keyword(s):

Cell Cycle ◽

Squamous Cell Carcinoma ◽

Oral Squamous Cell Carcinoma ◽

Cell Carcinoma ◽

Small Molecule ◽

Squamous Cell ◽

Small Molecule Inhibitors ◽

Druggable Targets

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Small-molecule degraders of cyclin-dependent kinase protein: a review

Future Medicinal Chemistry ◽

10.4155/fmc-2021-0154 ◽

2021 ◽

Author(s):

Bin Yu ◽

Zekun Du ◽

Yuming Zhang ◽

Zhiyu Li ◽

Jinlei Bian

Keyword(s):

Cell Cycle ◽

Drug Resistance ◽

Protein Degradation ◽

Small Molecule ◽

Small Molecule Inhibitors ◽

Structural Characteristics ◽

Protein A ◽

Cyclin Dependent Kinase ◽

Chemical Tools ◽

Potential Therapeutics

Proteolysis-targeting chimeras are a new modality of chemical tools and potential therapeutics involving the induction of protein degradation. Cyclin-dependent kinase (CDK) protein, which is involved in cycles and transcription cycles, participates in regulation of the cell cycle, transcription and splicing. Proteolysis-targeting chimeras targeting CDKs show several advantages over traditional CDK small-molecule inhibitors in potency, selectivity and drug resistance. In addition, the discovery of molecule glues promotes the development of CDK degraders. Herein, the authors describe the existing CDK degraders and focus on the discussion of the structural characteristics and design of these degraders.

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Histone Deacetylase Inhibitors Trigger a G2 Checkpoint in Normal Cells That Is Defective in Tumor Cells

Molecular Biology of the Cell ◽

10.1091/mbc.11.6.2069 ◽

2000 ◽

Vol 11 (6) ◽

pp. 2069-2083 ◽

Cited By ~ 178

Author(s):

Ling Qiu ◽

Andrew Burgess ◽

David P. Fairlie ◽

Helen Leonard ◽

Peter G. Parsons ◽

...

Keyword(s):

Cell Cycle ◽

Tumor Cells ◽

Histone Deacetylase ◽

Cell Cycle Progression ◽

Histone Deacetylase Inhibitors ◽

Cell Cycle Checkpoint ◽

Phase Cell ◽

Selective Toxicity ◽

Protective Mechanisms ◽

G2 Checkpoint

Important aspects of cell cycle regulation are the checkpoints, which respond to a variety of cellular stresses to inhibit cell cycle progression and act as protective mechanisms to ensure genomic integrity. An increasing number of tumor suppressors are being demonstrated to have roles in checkpoint mechanisms, implying that checkpoint dysfunction is likely to be a common feature of cancers. Here we report that histone deacetylase inhibitors, in particular azelaic bishydroxamic acid, triggers a G2 phase cell cycle checkpoint response in normal human cells, and this checkpoint is defective in a range of tumor cell lines. Loss of this G2 checkpoint results in the tumor cells undergoing an aberrant mitosis resulting in fractured multinuclei and micronuclei and eventually cell death. This histone deacetylase inhibitor-sensitive checkpoint appears to be distinct from G2/M checkpoints activated by genotoxins and microtubule poisons and may be the human homologue of a yeast G2 checkpoint, which responds to aberrant histone acetylation states. Azelaic bishydroxamic acid may represent a new class of anticancer drugs with selective toxicity based on its ability to target a dysfunctional checkpoint mechanism in tumor cells.

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