Sanguinarine triggers intrinsic apoptosis to suppress colorectal cancer growth through disassociation between STRAP and MELK

Autor: Qinrui Han, Xianling Gong, Chunhui Chen, Zhihong Chen, Linlin Jing, Yawei Liu, Liang Zhao, Xueqing Yao, Xuegang Sun
Rok vydání: 2018
Předmět:
Male
0301 basic medicine
Mitochondrial ROS
Cancer Research
Apoptosis
Maternal embryonic leucine zipper kinase
Mice
chemistry.chemical_compound
0302 clinical medicine
Papaveraceae
Annexin
MELK
Phosphorylation
Mice
Inbred BALB C
Chemistry
RNA-Binding Proteins
Middle Aged
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Neoplasm Proteins
STRAP
Oncology
030220 oncology & carcinogenesis
Mitochondrial Membranes
Female
Colorectal Neoplasms
Protein Binding
Research Article
Mice
Nude
Protein Serine-Threonine Kinases
lcsh:RC254-282
Permeability
03 medical and health sciences
Biomarkers
Tumor
Genetics
Animals
Humans
Sanguinarine
Viability assay
Kinase activity
Benzophenanthridines
Intrinsic apoptosis
HCT116 Cells
Isoquinolines
Xenograft Model Antitumor Assays
Colorectal cancer
030104 developmental biology
Bax
Cancer research
Zdroj: BMC Cancer
BMC Cancer, Vol 18, Iss 1, Pp 1-15 (2018)
ISSN: 1471-2407
DOI: 10.1186/s12885-018-4463-x
Popis: Background Previous studies showed sanguinarine induced apoptosis in CRC cells but did not define the underlying mechanisms. The purpose of this work was to determine the in vivo and in vitro effects of sanguinarine on CRC tumors and to elucidate the mechanism in regulating the intrinsic apoptosis. Methods Cell viability of CRC cell lines treated with sanguinarine was measured by MTT assay. Apoptotic cells stained with Annexin V and 7-AAD were detected by flow cytometry. Mitochondrial membrane potential and reactive oxygen species (ROS) were analyzed by JC-1 and DCFH-DA staining, respectively. The in vitro kinase activity of MELK was analyzed by using HTRF® KinEASE™-STK kit. The expression of proteins were determined using Western blotting and immunohistochemistry. Co-immunoprecipitation and immunofluorecence were used to study the interaction between STRAP and MELK. The anti-neoplastic effect of sanguinarine was observed in vivo in an orthotopic CRC model. Results Sanguinarine decreased the tumor size in a dose-dependent manner in orthotopical colorectal carcinomas through intrinsic apoptosis pathway in BALB/c-nu mice. It significantly increased cleavage of caspase 3 and PARP in implanted colorectal tissues. Sanguinarine increased mitochondrial ROS and triggered mitochondrial outer membrane permeabilization in multiple colorectal cancer (CRC) cell lines. NAC pretreatment lowered ROS level and downregulated apoptosis induced by sanguinarine. The intrinsic apoptosis induced by sanguinarine was Bax-dependent. The elevated expression and association between serine-threonine kinase receptor-associated protein (STRAP) and maternal embryonic leucine zipper kinase (MELK) were observed in Bax positive cells but not in Bax negative cells. Sanguinarine dephosphorylated STRAP and MELK and disrupted the association between them in HCT116 and SW480 cells. The expression and association between STRAP and MELK were also attenuated by sanguinarine in the tumor tissues. Importantly, we found that STRAP and MELK were overexpressed and highly phosphorylated in colorectal adenocarcinomas and their expression were significantly correlated with tumor stages. Furthermore, the expression of MELK, but not STRAP, was associated with lymph node metastasis. Conclusions Sanguinarine dephosphorelates STRAP and MELK and disassociates the interaction between them to trigger intrinsic apoptosis. Overexpression of STRAP and MELK may be markers of CRC and their disassociation may be a determinant of therapeutic efficacy. Electronic supplementary material The online version of this article (10.1186/s12885-018-4463-x) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
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