CXCR4 knockdown inhibits the growth and invasion of nasopharyngeal cancer stem cells

Mechanisms on chemotherapy resistance of colorectal cancer stem cells and research progress of reverse transformation: A mini-review

Tumor recurrence and chemotherapy resistance are mainly responsible for poor prognosis in colorectal cancer (CRC) patients. Cancer stem cell (CSC) has been identified in many solid tumors, including CRC. Additionally, CSC cannot be completely killed during chemotherapy and develops resistance to chemotherapeutic drugs, which is the main reason for tumor recurrence. This study reviews the main mechanisms of CSC chemotherapy resistance in CRC, including activation of DNA damage checkpoints, epithelial-mesenchymal transition (EMT), inhibition of the overexpression of antiapoptotic regulatory factors, overexpression of ATP-binding cassette (ABC) transporters, maintenance of reactive oxygen species (ROS) levels, and the dormant state of CSC. Advances in research to reverse chemotherapy resistance are also discussed. Our study can provide the promising potential for eliminating CSC and preventing tumor progression for CRC treatment.

Bioinformatics Studies Provide Insight into Possible Target and Mechanisms of Action of Nobiletin against Cancer Stem Cells

OBJECTIVE

Nobiletin treatment on MDA-MB 231 cells reduces the expression of CXC chemokine receptor type 4 (CXCR4), which is highly expressed in cancer stem cell populations in tumor patients. However, the mechanisms of nobiletin in cancer stem cells (CSCs) remain elusive. This study was aimed to explore the potential target and mechanisms of nobiletin in cancer stem cells using bioinformatics approaches.

METHODS

Gene expression profiles by public COMPARE predicting the sensitivity of tumor cells to nobiletin. Functional annotations on gene lists are carried out with The Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.8, and WEB-based GEne SeT Analysis Toolkit (WebGestalt). The protein-protein interaction (PPI) network was analyzed by STRING-DB and visualized by Cytoscape.

RESULTS

Microarray analyses reveal many genes involved in protein binding, transcriptional and translational activity. Pathway enrichment analysis revealed breast cancer regulation of estrogen signaling and Wnt/ß-catenin by nobiletin. Moreover, three hub genes, i.e. ESR1, NCOA3, and RPS6KB1 and one significant module were filtered out and selected from the PPI network.

CONCLUSION

Nobiletin might serve as a lead compound for the development of CSCs-targeted drugs by targeting estrogen and Wnt/ß-catenin signaling. Further studies are needed to explore the full therapeutic potential of nobiletin in cancer stem cells.
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