Talks

Presenting Author

Anissa N. Sari

Academic/Professional Position (Other)

Doctoral Student

Presentation Type

Oral Presentation

Discipline Track

Biomedical Science

Abstract Type

Research/Clinical

Abstract

Background. The cessation of tumor cell growth through cell cycle arrest and apoptosis is determined by p53, a tumor suppressor protein. However, the interaction between mortalin-p53 within cytoplasm/nucleus leads to the inactivation of p53 transcriptional activation function. The disruption of mortalin-p53 complex has been suggested as an approach for developing a potential anticancer drug.

Methods. A screening of a high-content chemical library was performed to determine a molecule with mortalin-p53-interaction disrupting characteristics. After four-rounds of visual assays, we discovered a triazole derivative (4-[(1E)-2-(2-phenylindol-3-yl)-1-azavinyl]-1,2,4-triazole, named MortaparibPlus) with a potential ability of disrupting mortalin-p53-complex. In this study, we recruited two types of cells (different p53 status and point mutation), Colorectal Cancer Cells [HCT116 (p53WT) and DLD-1 (p53 (p53S241F)] and Luminal A Breast Cancer [MCF-7 (p53WT) and T47D (p53L194F)]. We further validated the activity of MortaparibPlus by bioinformatics/experimental analyses.

Results. Through bioinformatics analysis, we discovered that MortaparibPlus has potential to block the binding site of mortalin on p53, thus, preventing the formation of mortalin-p53 complex. Immunoprecipitation analyses showed that MortaparibPlus abrogated the mortalin-p53 complex formation and caused growth arrest/apoptosis (via activation of p21WAF1, BAX, and PUMA) in HCT116, DLD-1, and MCF-7 cells. Furthermore, MortaparibPlus posed a cytotoxic effect to cancer cells through various mechanisms (inhibition of PARP1, up-regulation of p73 proteins, downregulation of mortalin and CARF proteins). In contrast, we found that, despite the hyperactivation of PARP1 (PAR accumulation and loss of ATP) as an alternative tumor suppression mechanism, MortaparibPlus-treated T47D cells exhibited signs of neither complete apoptosis nor PAR-Thanatos. Such response was associated with the failure of MortaparibPlus to inhibit the formation of AIF-mortalin complexes.

Conclusions. MortaparibPlus is proposed as a potential multimodal small molecule for cancer treatment that requires further extensive laboratory and clinical studies.

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MortaparibPlus- A Novel Anticancer Small Molecule Abrogating Mortalin-p53 Interaction in Cancer Cells

Background. The cessation of tumor cell growth through cell cycle arrest and apoptosis is determined by p53, a tumor suppressor protein. However, the interaction between mortalin-p53 within cytoplasm/nucleus leads to the inactivation of p53 transcriptional activation function. The disruption of mortalin-p53 complex has been suggested as an approach for developing a potential anticancer drug.

Methods. A screening of a high-content chemical library was performed to determine a molecule with mortalin-p53-interaction disrupting characteristics. After four-rounds of visual assays, we discovered a triazole derivative (4-[(1E)-2-(2-phenylindol-3-yl)-1-azavinyl]-1,2,4-triazole, named MortaparibPlus) with a potential ability of disrupting mortalin-p53-complex. In this study, we recruited two types of cells (different p53 status and point mutation), Colorectal Cancer Cells [HCT116 (p53WT) and DLD-1 (p53 (p53S241F)] and Luminal A Breast Cancer [MCF-7 (p53WT) and T47D (p53L194F)]. We further validated the activity of MortaparibPlus by bioinformatics/experimental analyses.

Results. Through bioinformatics analysis, we discovered that MortaparibPlus has potential to block the binding site of mortalin on p53, thus, preventing the formation of mortalin-p53 complex. Immunoprecipitation analyses showed that MortaparibPlus abrogated the mortalin-p53 complex formation and caused growth arrest/apoptosis (via activation of p21WAF1, BAX, and PUMA) in HCT116, DLD-1, and MCF-7 cells. Furthermore, MortaparibPlus posed a cytotoxic effect to cancer cells through various mechanisms (inhibition of PARP1, up-regulation of p73 proteins, downregulation of mortalin and CARF proteins). In contrast, we found that, despite the hyperactivation of PARP1 (PAR accumulation and loss of ATP) as an alternative tumor suppression mechanism, MortaparibPlus-treated T47D cells exhibited signs of neither complete apoptosis nor PAR-Thanatos. Such response was associated with the failure of MortaparibPlus to inhibit the formation of AIF-mortalin complexes.

Conclusions. MortaparibPlus is proposed as a potential multimodal small molecule for cancer treatment that requires further extensive laboratory and clinical studies.

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