title: Biomolecular characterization of exosomes released from cancer stem cells: Possible implications for biomarker and treatment of cancer.
abstract: Cancer recognized as one of the leading irrepressible health issues is contributing to increasing mortality-rate day-by-day. The tumor microenvironment is an important field of cancer to understand the detection, treatment and prevention of cancer. Recently, cancer stem cell (CSC) research has shown promising results aiming towards cancer diagnostics and treatment. Here, we found that prostate and breast cancer stem cells secreted vesicles of endosomal origin, called exosomes showed strong connection between autophagy and exosomes released from CSCs. Exosomes may serve as vesicles to communicate with neoplastic cells (autocrine and paracrine manner) and normal cells (paracrine and endocrine manner) and thereby suppress immune systems and regulate neoplastic growth, and metastasis. They can also be used as biomarkers for various cancers. We detected tetraspanin proteins (CD9, CD63, CD81), Alix and tumor susceptibility gene-101 (TSG101) of exosomal markers from rotenone treated CSCs. We have also detected the induction of autophagy genes, Atg7 and conversion of autophagy marker (LC3-I to LC3-II), and tetraspanin proteins (CD9, CD63, CD81) in rotenone treated CSCs by western blotting. The mRNA expression of CD9, CD63, CD81 and TSG101 analyzed by qRT-PCR showed that the rotenone induced the expression of CD9, CD63, CD81 and TSG101 in CSCs. Electron microscopy of rotenone treated CSCs showed the mitochondrial damage of CSCs as confirmed by the release of exosomes from CSCs. The constituents of exosomes may be useful to understand the mechanism of exosomes formation, release and function, and also serve as a useful biomarker and provide novel therapeutic strategies for the treatment and prevention of cancer.
authors: Department of Pharmacology, Toxicology & Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA.
authors: Dhruv
authors: D
authors: Kumar
authors: Center of Bioinformatics and Department of Biochemistry, University of Allahabad, Allahabad, India.
authors: Dwijendra
authors: D
authors: Gupta
authors: Kansas City VA Medical Center, Kansas City, MO, USA.
authors: Sharmila
authors: S
authors: Shankar
authors: Department of Pharmacology, Toxicology & Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA.
authors: Rakesh K
authors: RK
authors: Srivastava
mesh_terms: D019898:Autocrine Communication; D001343:Autophagy; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy / Q000648:ultrastructure; D055354:Exosomes / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000648:ultrastructure; D019899:Paracrine Communication; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured; D059016:Tumor Microenvironment
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger