Defining of preapoptotic nuclear condensation mediated by ROS in KRAS mutant cancer cells
Project goal: The main goal of this grant proposal is to define the mechanisms of a pre-apoptotic nuclear condensation by characterizing the induction of histone deacetylation and formation of heterochromatin.
Project description: The KRAS mutant cancers represent highly malignant oncologic disorders with a poor clinical outcome that are common in pancreatic, colorectal, and lung human cancers. There are no effective therapies have been developed to treat the KRAS mutant cancers, because it encodes a small GTPase that does not provide any distinctive “druggable” pocket for targeting. A specific and potent targeting of this highly malignant oncogenic pathway is one of the most challenging and demanding tasks in oncology. Hypothesis: Our main hypothesis is that glucose deprivation of KRAS mutant cancer cells causes a severe metabolic stress leading to generation of a mitochondrial ROS and priming the cancer cells for apoptotic event by inducing nuclear condensation and formation of heterochromatin. Scientific novelty: Study of the redox-dependent mechanism of preapoptotic nuclear condensation: the formation of heterochromatin on the periphery of the nucleus. As a model, we used KRAS mutant cancer cells that are sensitive to glucose deficiency. We determined that redox-dependent heterochromatin formation is mediated by functional activation of a chromatin repressive complex known as Nucleosome Remodeling Deacetylase (NuRD). Intense ROS generation caused by a lack of glucose in KRAS mutant cancer cells induces histone deacetylation via redox-dependent recruitment of the histone deacetylase complex (NuRD) to chromatin. As evidence, we demonstrate that oxidizing compounds mimic glucose-dependent histone deacetylation by inducing active recruitment of the histone deacetylase complex to chromatin. Targeting oncogenic KRAS oncology through the mechanism of redox-dependent nuclear condensation. Oncogenic KRAS is an "indestructible" target. Considering the sensitivity of KRAS mutant cancer cells to oxidative stress leading to pre-apoptotic nuclear condensation, we designed an oxidative combination that selectively acts on mutant cancer cells to induce cytotoxic oxidative stress. This discovery directs the redox-dependent activation of NuRD as a powerful tool for the process of pre-apoptotic chromatin/nucleus condensation and suppression of malignant KRAS mutant tumors.
Project facilitators: PI: Dinara Begimbetova. Dos Sarbassov, Bakhytgul Yermekbayeva, Assiya Kukanova, Zhansaya Kanketayeva
Realisation period: 2023-2025
Expected results: Types of oxidizing agents that mimic the action of reactive oxygen species and effectively cause the death of cancer cells due to nuclear condensation will be determined.
Nuclear condensation mediated by oxidants mimicking the action of reactive oxygen species will be determined.
The types of rigidity of the nuclei will be determined by AFM (atomic force microscopy).
Nuclear deacetylation will be determined by the action of oxidizing agents in imitation of glucose-dependent induction of pre-apoptotic nuclear condensation in cancer cells.
Areas of redox-dependent recruitment of the histone deacetylase complex (NuRD) to chromatin will be explored.
Histone deacetylation under the action of oxidizing agents that mimic the action of reactive oxygen species will be tested.
The role of inhibition of NURD activity in proapoptotic nuclear condensation will be determined.
Methodology: Microscopy (light, fluorescence atomic force microscopy, etc.), flow cytometry and spectrometry are analyzed to investigate the factors causing nuclear condensation and cancer cell death through the formation of reactive oxygen species (ROS) and to investigate histone deacetylation and activation of NuRD complex during pre-apoptotic nuclear condensation.
Co-financing: no
Contacts: dinara.begimbetova@nu.edu.kz
Project goal: The main goal of this grant proposal is to define the mechanisms of a pre-apoptotic nuclear condensation by characterizing the induction of histone deacetylation and formation of heterochromatin.
Project description: The KRAS mutant cancers represent highly malignant oncologic disorders with a poor clinical outcome that are common in pancreatic, colorectal, and lung human cancers. There are no effective therapies have been developed to treat the KRAS mutant cancers, because it encodes a small GTPase that does not provide any distinctive “druggable” pocket for targeting. A specific and potent targeting of this highly malignant oncogenic pathway is one of the most challenging and demanding tasks in oncology. Hypothesis: Our main hypothesis is that glucose deprivation of KRAS mutant cancer cells causes a severe metabolic stress leading to generation of a mitochondrial ROS and priming the cancer cells for apoptotic event by inducing nuclear condensation and formation of heterochromatin. Scientific novelty: Study of the redox-dependent mechanism of preapoptotic nuclear condensation: the formation of heterochromatin on the periphery of the nucleus. As a model, we used KRAS mutant cancer cells that are sensitive to glucose deficiency. We determined that redox-dependent heterochromatin formation is mediated by functional activation of a chromatin repressive complex known as Nucleosome Remodeling Deacetylase (NuRD). Intense ROS generation caused by a lack of glucose in KRAS mutant cancer cells induces histone deacetylation via redox-dependent recruitment of the histone deacetylase complex (NuRD) to chromatin. As evidence, we demonstrate that oxidizing compounds mimic glucose-dependent histone deacetylation by inducing active recruitment of the histone deacetylase complex to chromatin. Targeting oncogenic KRAS oncology through the mechanism of redox-dependent nuclear condensation. Oncogenic KRAS is an "indestructible" target. Considering the sensitivity of KRAS mutant cancer cells to oxidative stress leading to pre-apoptotic nuclear condensation, we designed an oxidative combination that selectively acts on mutant cancer cells to induce cytotoxic oxidative stress. This discovery directs the redox-dependent activation of NuRD as a powerful tool for the process of pre-apoptotic chromatin/nucleus condensation and suppression of malignant KRAS mutant tumors.
Project facilitators: PI: Dinara Begimbetova. Dos Sarbassov, Bakhytgul Yermekbayeva, Assiya Kukanova, Zhansaya Kanketayeva
Realisation period: 2023-2025
Expected results: Types of oxidizing agents that mimic the action of reactive oxygen species and effectively cause the death of cancer cells due to nuclear condensation will be determined.
Nuclear condensation mediated by oxidants mimicking the action of reactive oxygen species will be determined.
The types of rigidity of the nuclei will be determined by AFM (atomic force microscopy).
Nuclear deacetylation will be determined by the action of oxidizing agents in imitation of glucose-dependent induction of pre-apoptotic nuclear condensation in cancer cells.
Areas of redox-dependent recruitment of the histone deacetylase complex (NuRD) to chromatin will be explored.
Histone deacetylation under the action of oxidizing agents that mimic the action of reactive oxygen species will be tested.
The role of inhibition of NURD activity in proapoptotic nuclear condensation will be determined.
Methodology: Microscopy (light, fluorescence atomic force microscopy, etc.), flow cytometry and spectrometry are analyzed to investigate the factors causing nuclear condensation and cancer cell death through the formation of reactive oxygen species (ROS) and to investigate histone deacetylation and activation of NuRD complex during pre-apoptotic nuclear condensation.
Co-financing: no
Contacts: dinara.begimbetova@nu.edu.kz